It is to unify map flags checking for lookup_elem, update_elem,
lookup_batch and update_batch APIs.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20251125145857.98134-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Implement the "jmp" mode for the bpf trampoline. For the ftrace_managed
case, we need only to set the FTRACE_OPS_FL_JMP on the tr->fops if "jmp"
is needed.
For the bpf poke case, we will check the origin poke type with the
"origin_flags", and current poke type with "tr->flags". The function
bpf_trampoline_update_fentry() is introduced to do the job.
The "jmp" mode will only be enabled with CONFIG_DYNAMIC_FTRACE_WITH_JMP
enabled and BPF_TRAMP_F_SHARE_IPMODIFY is not set. With
BPF_TRAMP_F_SHARE_IPMODIFY, we need to get the origin call ip from the
stack, so we can't use the "jmp" mode.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20251118123639.688444-7-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In the origin logic, the bpf_arch_text_poke() assume that the old and new
instructions have the same opcode. However, they can have different opcode
if we want to replace a "call" insn with a "jmp" insn.
Therefore, add the new function parameter "old_t" along with the "new_t",
which are used to indicate the old and new poke type. Meanwhile, adjust
the implement of bpf_arch_text_poke() for all the archs.
"BPF_MOD_NOP" is added to make the code more readable. In
bpf_arch_text_poke(), we still check if the new and old address is NULL to
determine if nop insn should be used, which I think is more safe.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20251118123639.688444-6-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In commit b4ce5923e7 ("bpf, x86: add new map type: instructions array")
env->used_map was copied to func[i]->aux->used_maps before jitting.
Clear these fields out after jitting such that pointer to freed memory
(env->used_maps is freed later) are not kept in a live data structure.
The reason why the copies were initially added is explained in
https://lore.kernel.org/bpf/20251105090410.1250500-1-a.s.protopopov@gmail.com
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Fixes: b4ce5923e7 ("bpf, x86: add new map type: instructions array")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20251124151515.2543403-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, nested rcu critical sections are rejected by the verifier and
rcu_lock state is managed by a boolean variable. Add support for nested
rcu critical sections by make active_rcu_locks a counter similar to
active_preempt_locks. bpf_rcu_read_lock() increments this counter and
bpf_rcu_read_unlock() decrements it, MEM_RCU -> PTR_UNTRUSTED transition
happens when active_rcu_locks drops to 0.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251117200411.25563-2-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This updates bpf_insn_successors() reflecting that control flow might
jump over the instructions between tail call and function exit, verifier
might assume that some writes to parent stack always happen, which is
not the case.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu>
Link: https://lore.kernel.org/r/20251119160355.1160932-4-martin.teichmann@xfel.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A successful ebpf tail call does not return to the caller, but to the
caller-of-the-caller, often just finishing the ebpf program altogether.
Any restrictions that the verifier needs to take into account - notably
the fact that the tail call might have modified packet pointers - are to
be checked on the caller-of-the-caller. Checking it on the caller made
the verifier refuse perfectly fine programs that would use the packet
pointers after a tail call, which is no problem as this code is only
executed if the tail call was unsuccessful, i.e. nothing happened.
This patch simulates the behavior of a tail call in the verifier. A
conditional jump to the code after the tail call is added for the case
of an unsucessful tail call, and a return to the caller is simulated for
a successful tail call.
For the successful case we assume that the tail call returns an int,
as tail calls are currently only allowed in functions that return and
int. We always assume that the tail call modified the packet pointers,
as we do not know what the tail call did.
For the unsuccessful case we know nothing happened, so we do not need to
add new constraints.
This approach also allows to check other problems that may occur with
tail calls, namely we are now able to check that precision is properly
propagated into subprograms using tail calls, as well as checking the
live slots in such a subprogram.
Fixes: 1a4607ffba ("bpf: consider that tail calls invalidate packet pointers")
Link: https://lore.kernel.org/bpf/20251029105828.1488347-1-martin.teichmann@xfel.eu/
Signed-off-by: Martin Teichmann <martin.teichmann@xfel.eu>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251119160355.1160932-2-martin.teichmann@xfel.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In [1] Dan Carpenter reported that the following code makes the
Smatch static analyser unhappy:
17904 value = map->ops->map_lookup_elem(map, &i);
17905 if (!value)
17906 return -EINVAL;
--> 17907 items[i - start] = value->xlated_off;
The analyser assumes that the `value` variable may contain an error
and thus it should be properly checked before the dereference.
On practice this will never happen as array maps do not return
error values in map_lookup_elem, but to make the Smatch and other
possible analysers happy this patch adds a formal check.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/bpf/aR2BN1Ix--8tmVrN@stanley.mountain/ [1]
Fixes: 493d9e0d60 ("bpf, x86: add support for indirect jumps")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20251119112517.1091793-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cross-merge networking fixes after downstream PR (net-6.18-rc7).
No conflicts, adjacent changes:
tools/testing/selftests/net/af_unix/Makefile
e1bb28bf13 ("selftest: af_unix: Add test for SO_PEEK_OFF.")
45a1cd8346 ("selftests: af_unix: Add tests for ECONNRESET and EOF semantics")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Replace bpf memory allocator with kmalloc_nolock() to reduce memory
wastage due to preallocation.
In bpf_selem_free(), an selem now needs to wait for a RCU grace period
before being freed when reuse_now == true. Therefore, rcu_barrier()
should be always be called in bpf_local_storage_map_free().
In bpf_local_storage_free(), since smap->storage_ma is no longer needed
to return the memory, the function is now independent from smap.
Remove the outdated comment in bpf_local_storage_alloc(). We already
free selem after an RCU grace period in bpf_local_storage_update() when
bpf_local_storage_alloc() failed the cmpxchg since commit c0d63f3091
("bpf: Add bpf_selem_free()").
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20251114201329.3275875-5-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Save the memory allocation method used for bpf_local_storage in the
struct explicitly so that we don't need to go through the hassle to
find out the info. When a later patch replaces BPF memory allocator
with kmalloc_noloc(), bpf_local_storage_free() will no longer need
smap->storage_ma to return the memory and completely remove the
dependency on smap in bpf_local_storage_free().
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20251114201329.3275875-4-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since selem already saves a pointer to smap, use it instead of an
additional argument in bpf_selem_free(). This requires moving the
SDATA(selem)->smap assignment from bpf_selem_link_map() to
bpf_selem_alloc() since bpf_selem_free() may be called without the
selem being linked to smap in bpf_local_storage_update().
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20251114201329.3275875-3-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since commit a96a44aba5 ("bpf: bpf_sk_storage: Fix invalid wait
context lockdep report"), {charge,uncharge}_mem are always true when
allocating a bpf_local_storage_elem or unlinking a bpf_local_storage_elem
from local storage, so drop these arguments. No functional change.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20251114201329.3275875-2-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Syzkaller triggers an invalid memory access issue following fault
injection in update_effective_progs. The issue can be described as
follows:
__cgroup_bpf_detach
update_effective_progs
compute_effective_progs
bpf_prog_array_alloc <-- fault inject
purge_effective_progs
/* change to dummy_bpf_prog */
array->items[index] = &dummy_bpf_prog.prog
---softirq start---
__do_softirq
...
__cgroup_bpf_run_filter_skb
__bpf_prog_run_save_cb
bpf_prog_run
stats = this_cpu_ptr(prog->stats)
/* invalid memory access */
flags = u64_stats_update_begin_irqsave(&stats->syncp)
---softirq end---
static_branch_dec(&cgroup_bpf_enabled_key[atype])
The reason is that fault injection caused update_effective_progs to fail
and then changed the original prog into dummy_bpf_prog.prog in
purge_effective_progs. Then a softirq came, and accessing the members of
dummy_bpf_prog.prog in the softirq triggers invalid mem access.
To fix it, skip updating stats when stats is NULL.
Fixes: 492ecee892 ("bpf: enable program stats")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/r/20251115102343.2200727-1-pulehui@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
mm_get_unmapped_area() is a wrapper around arch_get_unmapped_area() /
arch_get_unmapped_area_topdown(), both of which search current->mm for
some free space. Neither take an mm_struct - they implicitly operate on
current->mm.
But the wrapper takes an mm_struct and uses it to decide whether to search
bottom up or top down. All callers pass in current->mm for this, so
everything is working consistently. But it feels like an accident waiting
to happen; eventually someone will call that function with a different mm,
expecting to find free space in it, but what gets returned is free space
in the current mm.
So let's simplify by removing the parameter and have the wrapper use
current->mm to decide which end to start at. Now everything is consistent
and self-documenting.
Link: https://lkml.kernel.org/r/20251003155306.2147572-1-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
object creation goes through the normal VFS paths or approximation
thereof (user_path_create()/done_path_create() in case of bpf_obj_do_pin(),
open-coded simple_{start,done}_creating() in bpf_iter_link_pin_kernel()
at mount time), removals go entirely through the normal VFS paths (and
->unlink() is simple_unlink() there).
Enough to have bpf_dentry_finalize() use d_make_persistent() instead
of dget() and we are done.
Convert bpf_iter_link_pin_kernel() to simple_{start,done}_creating(),
while we are at it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If xlated_prog_insns should not be exposed, other information
(such as func_info) still can and should be filled in.
Therefore, instead of directly terminating in this case,
continue with the normal flow.
Signed-off-by: Max Altgelt <max.altgelt@nextron-systems.com>
Link: https://lore.kernel.org/r/efd00fcec5e3e247af551632726e2a90c105fbd8.camel@nextron-systems.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Metadata about a kfunc call is added to the kfunc_tab in
add_kfunc_call() but the call instruction itself could get removed by
opt_remove_dead_code() later if it is not reachable.
If the call instruction is removed, specialize_kfunc() is never called
for it and the desc->imm in the kfunc_tab is never initialized for this
kfunc call. In this case, sort_kfunc_descs_by_imm_off(env->prog); in
do_misc_fixups() doesn't sort the table correctly.
This is a problem for s390 as its JIT uses this table to find the
addresses for kfuncs, and if this table is not sorted properly, JIT may
fail to find addresses for valid kfunc calls.
This was exposed by:
commit d869d56ca8 ("bpf: verifier: refactor kfunc specialization")
as before this commit, desc->imm was initialised in add_kfunc_call()
which happens before dead code elimination.
Move desc->imm setup down to sort_kfunc_descs_by_imm_off(), this fixes
the problem and also saves us from having the same logic in
add_kfunc_call() and specialize_kfunc().
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251114154023.12801-1-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The error that returned by ftrace_set_filter_ip() in register_fentry() is
not handled properly. Just fix it.
Fixes: 00963a2e75 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20251110120705.1553694-1-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There are a few places where log level is not checked before calling
"verbose()". This forces programs working only at
BPF_LOG_LEVEL_STATS (e.g. veristat) to allocate unnecessarily large
log buffers. Add missing checks.
Reported-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251114200542.912386-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_try_get_buffers() returns one of multiple per-CPU buffers based on a
per-CPU nesting counter. This mechanism expects that buffers are not
endlessly acquired before being returned. migrate_disable() ensures that a
task remains on the same CPU, but it does not prevent the task from being
preempted by another task on that CPU.
Without disabled preemption, a task may be preempted while holding a
buffer, allowing another task to run on same CPU and acquire an
additional buffer. Several such preemptions can cause the per-CPU
nest counter to exceed MAX_BPRINTF_NEST_LEVEL and trigger the warning in
bpf_try_get_buffers(). Adding preempt_disable()/preempt_enable() around
buffer acquisition and release prevents this task preemption and
preserves the intended bounded nesting behavior.
Reported-by: syzbot+b0cff308140f79a9c4cb@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68f6a4c8.050a0220.1be48.0011.GAE@google.com/
Fixes: 4223bf833c ("bpf: Remove preempt_disable in bpf_try_get_buffers")
Suggested-by: Yonghong Song <yonghong.song@linux.dev>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sahil Chandna <chandna.sahil@gmail.com>
Link: https://lore.kernel.org/r/20251114064922.11650-1-chandna.sahil@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The usage pattern for widen_imprecise_scalars() looks as follows:
prev_st = find_prev_entry(env, ...);
queued_st = push_stack(...);
widen_imprecise_scalars(env, prev_st, queued_st);
Where prev_st is an ancestor of the queued_st in the explored states
tree. This ancestor is not guaranteed to have same allocated stack
depth as queued_st. E.g. in the following case:
def main():
for i in 1..2:
foo(i) // same callsite, differnt param
def foo(i):
if i == 1:
use 128 bytes of stack
iterator based loop
Here, for a second 'foo' call prev_st->allocated_stack is 128,
while queued_st->allocated_stack is much smaller.
widen_imprecise_scalars() needs to take this into account and avoid
accessing bpf_verifier_state->frame[*]->stack out of bounds.
Fixes: 2793a8b015 ("bpf: exact states comparison for iterator convergence checks")
Reported-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251114025730.772723-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As [lru_,]percpu_hash maps support BPF_KPTR_{REF,PERCPU}, missing
calls to 'bpf_obj_free_fields()' in 'pcpu_copy_value()' could cause the
memory referenced by BPF_KPTR_{REF,PERCPU} fields to be held until the
map gets freed.
Fix this by calling 'bpf_obj_free_fields()' after
'copy_map_value[,_long]()' in 'pcpu_copy_value()'.
Fixes: 65334e64a4 ("bpf: Support kptrs in percpu hashmap and percpu LRU hashmap")
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20251105151407.12723-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Return -ETIMEDOUT whenever non-head waiters are signalled by head, and fix
oversight in commit 7bd6e5ce5b ("rqspinlock: Disable queue destruction for
deadlocks"). We no longer signal on deadlocks.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Link: https://lore.kernel.org/r/20251111013827.1853484-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Exports three necessary symbols for implementing struct_ops with
tristate subsystem.
To hold or release refcnt of struct_ops refcnt by inline funcs
bpf_try_module_get and bpf_module_put which use bpf_struct_ops_get(put)
conditionally.
And to copy obj name from one to the other with effective checks by
bpf_obj_name_cpy.
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251107035632.115950-2-alibuda@linux.alibaba.com
Currently bpf_dynptr_from_skb_meta() marks the dynptr as read-only when
the skb is cloned, preventing writes to metadata.
Remove this restriction and unclone the skb head on bpf_dynptr_write() to
metadata, now that the metadata is preserved during uncloning. This makes
metadata dynptr consistent with skb dynptr, allowing writes regardless of
whether the skb is cloned.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251105-skb-meta-rx-path-v4-3-5ceb08a9b37b@cloudflare.com
The range tree uses bpf_mem_alloc() that is safe to be called from all
contexts and uses a pre-allocated pool of memory to serve these
allocations.
Replace bpf_mem_alloc() with kmalloc_nolock() as it can be called safely
from all contexts and is more scalable than bpf_mem_alloc().
Remove the migrate_disable/enable pairs as they were only needed for
bpf_mem_alloc() as it does per-cpu operations, kmalloc_nolock() doesn't
need this.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20251106170608.4800-1-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cross-merge networking fixes after downstream PR (net-6.18-rc5).
Conflicts:
drivers/net/wireless/ath/ath12k/mac.c
9222582ec5 ("Revert "wifi: ath12k: Fix missing station power save configuration"")
6917e268c4 ("wifi: ath12k: Defer vdev bring-up until CSA finalize to avoid stale beacon")
https://lore.kernel.org/11cece9f7e36c12efd732baa5718239b1bf8c950.camel@sipsolutions.net
Adjacent changes:
drivers/net/ethernet/intel/Kconfig
b1d16f7c00 ("libie: depend on DEBUG_FS when building LIBIE_FWLOG")
93f53db9f9 ("ice: switch to Page Pool")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support for a new instruction
BPF_JMP|BPF_X|BPF_JA, SRC=0, DST=Rx, off=0, imm=0
which does an indirect jump to a location stored in Rx. The register
Rx should have type PTR_TO_INSN. This new type assures that the Rx
register contains a value (or a range of values) loaded from a
correct jump table – map of type instruction array.
For example, for a C switch LLVM will generate the following code:
0: r3 = r1 # "switch (r3)"
1: if r3 > 0x13 goto +0x666 # check r3 boundaries
2: r3 <<= 0x3 # adjust to an index in array of addresses
3: r1 = 0xbeef ll # r1 is PTR_TO_MAP_VALUE, r1->map_ptr=M
5: r1 += r3 # r1 inherits boundaries from r3
6: r1 = *(u64 *)(r1 + 0x0) # r1 now has type INSN_TO_PTR
7: gotox r1 # jit will generate proper code
Here the gotox instruction corresponds to one particular map. This is
possible however to have a gotox instruction which can be loaded from
different maps, e.g.
0: r1 &= 0x1
1: r2 <<= 0x3
2: r3 = 0x0 ll # load from map M_1
4: r3 += r2
5: if r1 == 0x0 goto +0x4
6: r1 <<= 0x3
7: r3 = 0x0 ll # load from map M_2
9: r3 += r1
A: r1 = *(u64 *)(r3 + 0x0)
B: gotox r1 # jump to target loaded from M_1 or M_2
During check_cfg stage the verifier will collect all the maps which
point to inside the subprog being verified. When building the config,
the high 16 bytes of the insn_state are used, so this patch
(theoretically) supports jump tables of up to 2^16 slots.
During the later stage, in check_indirect_jump, it is checked that
the register Rx was loaded from a particular instruction array.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251105090410.1250500-9-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When bpf_jit_harden is enabled, all constants in the BPF code are
blinded to prevent JIT spraying attacks. This happens during JIT
phase. Adjust all the related instruction arrays accordingly.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251105090410.1250500-6-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
On bpf(BPF_PROG_LOAD) syscall user-supplied BPF programs are
translated by the verifier into "xlated" BPF programs. During this
process the original instructions offsets might be adjusted and/or
individual instructions might be replaced by new sets of instructions,
or deleted.
Add a new BPF map type which is aimed to keep track of how, for a
given program, the original instructions were relocated during the
verification. Also, besides keeping track of the original -> xlated
mapping, make x86 JIT to build the xlated -> jitted mapping for every
instruction listed in an instruction array. This is required for every
future application of instruction arrays: static keys, indirect jumps
and indirect calls.
A map of the BPF_MAP_TYPE_INSN_ARRAY type must be created with a u32
keys and value of size 8. The values have different semantics for
userspace and for BPF space. For userspace a value consists of two
u32 values – xlated and jitted offsets. For BPF side the value is
a real pointer to a jitted instruction.
On map creation/initialization, before loading the program, each
element of the map should be initialized to point to an instruction
offset within the program. Before the program load such maps should
be made frozen. After the program verification xlated and jitted
offsets can be read via the bpf(2) syscall.
If a tracked instruction is removed by the verifier, then the xlated
offset is set to (u32)-1 which is considered to be too big for a valid
BPF program offset.
One such a map can, obviously, be used to track one and only one BPF
program. If the verification process was unsuccessful, then the same
map can be re-used to verify the program with a different log level.
However, if the program was loaded fine, then such a map, being
frozen in any case, can't be reused by other programs even after the
program release.
Example. Consider the following original and xlated programs:
Original prog: Xlated prog:
0: r1 = 0x0 0: r1 = 0
1: *(u32 *)(r10 - 0x4) = r1 1: *(u32 *)(r10 -4) = r1
2: r2 = r10 2: r2 = r10
3: r2 += -0x4 3: r2 += -4
4: r1 = 0x0 ll 4: r1 = map[id:88]
6: call 0x1 6: r1 += 272
7: r0 = *(u32 *)(r2 +0)
8: if r0 >= 0x1 goto pc+3
9: r0 <<= 3
10: r0 += r1
11: goto pc+1
12: r0 = 0
7: r6 = r0 13: r6 = r0
8: if r6 == 0x0 goto +0x2 14: if r6 == 0x0 goto pc+4
9: call 0x76 15: r0 = 0xffffffff8d2079c0
17: r0 = *(u64 *)(r0 +0)
10: *(u64 *)(r6 + 0x0) = r0 18: *(u64 *)(r6 +0) = r0
11: r0 = 0x0 19: r0 = 0x0
12: exit 20: exit
An instruction array map, containing, e.g., instructions [0,4,7,12]
will be translated by the verifier to [0,4,13,20]. A map with
index 5 (the middle of 16-byte instruction) or indexes greater than 12
(outside the program boundaries) would be rejected.
The functionality provided by this patch will be extended in consequent
patches to implement BPF Static Keys, indirect jumps, and indirect calls.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251105090410.1250500-2-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Change struct bpf_sock_addr_kern to use sockaddr_unsized for the "uaddr"
field instead of sockaddr. This improves type safety in the BPF cgroup
socket address filtering code.
The casting in __cgroup_bpf_run_filter_sock_addr() is updated to match the
new type, removing an unnecessary cast in the initialization and updating
the conditional assignment to use the appropriate sockaddr_unsized cast.
Additionally rename the "unspec" variable to "storage" to better align
with its usage.
No binary changes expected.
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-7-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update BPF cgroup sockaddr filtering infrastructure to use sockaddr_unsized
consistently throughout the call chain, removing redundant explicit casts
from callers.
No binary changes expected.
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20251104002617.2752303-6-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Rename bpf_stream_vprintk() to bpf_stream_vprintk_impl().
This makes bpf_stream_vprintk() follow the already established "_impl"
suffix-based naming convention for kfuncs with the bpf_prog_aux
argument provided by the verifier implicitly. This convention will be
taken advantage of with the upcoming KF_IMPLICIT_ARGS feature to
preserve backwards compatibility to BPF programs.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20251104-implv2-v3-2-4772b9ae0e06@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Rename:
bpf_task_work_schedule_resume()->bpf_task_work_schedule_resume_impl()
bpf_task_work_schedule_signal()->bpf_task_work_schedule_signal_impl()
This aligns task work scheduling kfuncs with the established naming
scheme for kfuncs with the bpf_prog_aux argument provided by the
verifier implicitly. This convention will be taken advantage of with the
upcoming KF_IMPLICIT_ARGS feature to preserve backwards compatibility to
BPF programs.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20251104-implv2-v3-1-4772b9ae0e06@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
When conditional jumps are performed on the same scalar register
(e.g., r0 <= r0, r0 > r0, r0 < r0), the BPF verifier incorrectly
attempts to adjust the register's min/max bounds. This leads to
invalid range bounds and triggers a BUG warning.
The problematic BPF program:
0: call bpf_get_prandom_u32
1: w8 = 0x80000000
2: r0 &= r8
3: if r0 > r0 goto <exit>
The instruction 3 triggers kernel warning:
3: if r0 > r0 goto <exit>
true_reg1: range bounds violation u64=[0x1, 0x0] s64=[0x1, 0x0] u32=[0x1, 0x0] s32=[0x1, 0x0] var_off=(0x0, 0x0)
true_reg2: const tnum out of sync with range bounds u64=[0x0, 0xffffffffffffffff] s64=[0x8000000000000000, 0x7fffffffffffffff] var_off=(0x0, 0x0)
Comparing a register with itself should not change its bounds and
for most comparison operations, comparing a register with itself has
a known result (e.g., r0 == r0 is always true, r0 < r0 is always false).
Fix this by:
1. Enhance is_scalar_branch_taken() to properly handle branch direction
computation for same register comparisons across all BPF jump operations
2. Adds early return in reg_set_min_max() to avoid bounds adjustment
for unknown branch directions (e.g., BPF_JSET) on the same register
The fix ensures that unnecessary bounds adjustments are skipped, preventing
the verifier bug while maintaining correct branch direction analysis.
Reported-by: Kaiyan Mei <M202472210@hust.edu.cn>
Reported-by: Yinhao Hu <dddddd@hust.edu.cn>
Closes: https://lore.kernel.org/all/1881f0f5.300df.199f2576a01.Coremail.kaiyanm@hust.edu.cn/
Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251103063108.1111764-2-kafai.wan@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When livepatch is attached to the same function as bpf trampoline with
a fexit program, bpf trampoline code calls register_ftrace_direct()
twice. The first time will fail with -EAGAIN, and the second time it
will succeed. This requires register_ftrace_direct() to unregister
the address on the first attempt. Otherwise, the bpf trampoline cannot
attach. Here is an easy way to reproduce this issue:
insmod samples/livepatch/livepatch-sample.ko
bpftrace -e 'fexit:cmdline_proc_show {}'
ERROR: Unable to attach probe: fexit:vmlinux:cmdline_proc_show...
Fix this by cleaning up the hash when register_ftrace_function_nolock hits
errors.
Also, move the code that resets ops->func and ops->trampoline to the error
path of register_ftrace_direct(); and add a helper function reset_direct()
in register_ftrace_direct() and unregister_ftrace_direct().
Fixes: d05cb47066 ("ftrace: Fix modification of direct_function hash while in use")
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Andrey Grodzovsky <andrey.grodzovsky@crowdstrike.com>
Closes: https://lore.kernel.org/live-patching/c5058315a39d4615b333e485893345be@crowdstrike.com/
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-and-tested-by: Andrey Grodzovsky <andrey.grodzovsky@crowdstrike.com>
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20251027175023.1521602-2-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
BPF stream kfuncs need to be non-sleeping as they can be called from
programs running in any context, this requires a way to allocate memory
from any context. Currently, this is done by a custom per-CPU NMI-safe
bump allocation mechanism, backed by alloc_pages_nolock() and
free_pages_nolock() primitives.
As kmalloc_nolock() and kfree_nolock() primitives are available now, the
custom allocator can be removed in favor of these.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251023161448.4263-1-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Disable propagation and unwinding of the waiter queue in case the head
waiter detects a deadlock condition, but keep it enabled in case of the
timeout fallback.
Currently, when the head waiter experiences an AA deadlock, it will
signal all its successors in the queue to exit with an error. This is
not ideal for cases where the same lock is held in contexts which can
cause errors in an unrestricted fashion (e.g., BPF programs, or kernel
paths invoked through BPF programs), and core kernel logic which is
written in a correct fashion and does not expect deadlocks.
The same reasoning can be extended to ABBA situations. Depending on the
actual runtime schedule, one or both of the head waiters involved in an
ABBA situation can detect and exit directly without terminating their
waiter queue. If the ABBA situation manifests again, the waiters will
keep exiting until progress can be made, or a timeout is triggered in
case of more complicated locking dependencies.
We still preserve the queue destruction in case of timeouts, as either
the locking dependencies are too complex to be captured by AA and ABBA
heuristics, or the owner is perpetually stuck. As such, it would be
unwise to continue to apply the timeout for each new head waiter without
terminating the queue, since we may end up waiting for more than 250 ms
in aggregate with all participants in the locking transaction.
The patch itself is fairly simple; we can simply signal our successor to
become the next head waiter, and leave the queue without attempting to
acquire the lock.
With this change, the behavior for waiters in case of deadlocks
experienced by a predecessor changes. It is guaranteed that call sites
will no longer receive errors if the predecessors encounter deadlocks
and the successors do not participate in one. This should lower the
failure rate for waiters that are not doing improper locking opreations,
just because they were unlucky to queue behind a misbehaving waiter.
However, timeouts are still a possibility, hence they must be accounted
for, so users cannot rely upon errors not occuring at all.
Suggested-by: Amery Hung <ameryhung@gmail.com>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251029181828.231529-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for deferred userspace unwind to perf.
Where perf currently relies on in-place stack unwinding; from NMI
context and all that. This moves the userspace part of the unwind to
right before the return-to-userspace.
This has two distinct benefits, the biggest is that it moves the
unwind to a faultable context. It becomes possible to fault in debug
info (.eh_frame, SFrame etc.) that might not otherwise be readily
available. And secondly, it de-duplicates the user callchain where
multiple samples happen during the same kernel entry.
To facilitate this the perf interface is extended with a new record
type:
PERF_RECORD_CALLCHAIN_DEFERRED
and two new attribute flags:
perf_event_attr::defer_callchain - to request the user unwind be deferred
perf_event_attr::defer_output - to request PERF_RECORD_CALLCHAIN_DEFERRED records
The existing PERF_RECORD_SAMPLE callchain section gets a new
context type:
PERF_CONTEXT_USER_DEFERRED
After which will come a single entry, denoting the 'cookie' of the
deferred callchain that should be attached here, matching the 'cookie'
field of the above mentioned PERF_RECORD_CALLCHAIN_DEFERRED.
The 'defer_callchain' flag is expected on all events with
PERF_SAMPLE_CALLCHAIN. The 'defer_output' flag is expect on the event
responsible for collecting side-band events (like mmap, comm etc.).
Setting 'defer_output' on multiple events will get you duplicated
PERF_RECORD_CALLCHAIN_DEFERRED records.
Based on earlier patches by Josh and Steven.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251023150002.GR4067720@noisy.programming.kicks-ass.net
Extract the duplicated maximum allowed depth computation for stack
traces stored in BPF stacks from bpf_get_stackid() and __bpf_get_stack()
into a dedicated stack_map_calculate_max_depth() helper function.
This unifies the logic for:
- The max depth computation
- Enforcing the sysctl_perf_event_max_stack limit
No functional changes for existing code paths.
Signed-off-by: Arnaud Lecomte <contact@arnaud-lcm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20251025192858.31424-1-contact@arnaud-lcm.com
File dynptr reads may sleep when the requested folios are not in
the page cache. To avoid sleeping in non-sleepable contexts while still
supporting valid sleepable use, given that dynptrs are non-sleepable by
default, enable sleeping only when bpf_dynptr_from_file() is invoked
from a sleepable context.
This change:
* Introduces a sleepable constructor: bpf_dynptr_from_file_sleepable()
* Override non-sleepable constructor with sleepable if it's always
called in sleepable context
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-10-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Move kfunc specialization (function address substitution) to later stage
of verification to support a new use case, where we need to take into
consideration whether kfunc is called in sleepable context.
Minor refactoring in add_kfunc_call(), making sure that if function
fails, kfunc desc is not added to tab->descs (previously it could be
added or not, depending on what failed).
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-9-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for file dynptr.
Introduce struct bpf_dynptr_file_impl to hold internal state for file
dynptrs, with 64-bit size and offset support.
Introduce lifecycle management kfuncs:
- bpf_dynptr_from_file() for initialization
- bpf_dynptr_file_discard() for destruction
Extend existing helpers to support file dynptrs in:
- bpf_dynptr_read()
- bpf_dynptr_slice()
Write helpers (bpf_dynptr_write() and bpf_dynptr_data()) are not
modified, as file dynptr is read-only.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-8-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add the necessary verifier plumbing for the new file-backed dynptr type.
Introduce two kfuncs for its lifecycle management:
* bpf_dynptr_from_file() for initialization
* bpf_dynptr_file_discard() for destruction
Currently there is no mechanism for kfunc to release dynptr, this patch
add one:
* Dynptr release function sets meta->release_regno
* Call unmark_stack_slots_dynptr() if meta->release_regno is set and
dynptr ref_obj_id is set as well.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-7-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Move the const dynptr check into unmark_stack_slots_dynptr() so callers
don’t have to duplicate it. This puts the validation next to the code
that manipulates dynptr stack slots and allows upcoming changes to reuse
it directly.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-6-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Dynptr currently caps size and offset at 24 bits, which isn’t sufficient
for file-backed use cases; even 32 bits can be limiting. Refactor dynptr
helpers/kfuncs to use 64-bit size and offset, ensuring consistency
across the APIs.
This change does not affect internals of xdp, skb or other dynptrs,
which continue to behave as before. Also it does not break binary
compatibility.
The widening enables large-file access support via dynptr, implemented
in the next patches.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This old alias for in_hardirq() has been marked as deprecated since
2020; remove the stragglers.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251024180654.1691095-1-willy@infradead.org
The bpf_insn_successors() function is used to return successors
to a BPF instruction. So far, an instruction could have 0, 1 or 2
successors. Prepare the verifier code to introduction of instructions
with more than 2 successors (namely, indirect jumps).
To do this, introduce a new struct, struct bpf_iarray, containing
an array of bpf instruction indexes and make bpf_insn_successors
to return a pointer of that type. The storage for all instructions
is allocated in the env->succ, which holds an array of size 2,
to be used for all instructions.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251019202145.3944697-10-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The kernel/bpf/array.c file defines the array_map_get_next_key()
function which finds the next key for array maps. It actually doesn't
use any map fields besides the generic max_entries field. Generalize
it, and export as bpf_array_get_next_key() such that it can be
re-used by other array-like maps.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251019202145.3944697-4-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce a new subprog_start field in bpf_prog_aux. This field may
be used by JIT compilers wanting to know the real absolute xlated
offset of the function being jitted. The func_info[func_id] may have
served this purpose, but func_info may be NULL, so JIT compilers
can't rely on it.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251019202145.3944697-3-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In [1] Eduard mentioned that on push_stack failure verifier code
should return -ENOMEM instead of -EFAULT. After checking with the
other call sites I've found that code randomly returns either -ENOMEM
or -EFAULT. This patch unifies the return values for the push_stack
(and similar push_async_cb) functions such that error codes are
always assigned properly.
[1] https://lore.kernel.org/bpf/20250615085943.3871208-1-a.s.protopopov@gmail.com
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251019202145.3944697-2-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
propagate_to_outer_instance() calls get_outer_instance() and uses the
returned pointer to reset and commit stack write marks. Under normal
conditions, update_instance() guarantees that an outer instance exists,
so get_outer_instance() cannot return an ERR_PTR.
However, explicitly checking for IS_ERR(outer_instance) makes this code
more robust and self-documenting. It reduces cognitive load when reading
the control flow and silences potential false-positive reports from
static analysis or automated tooling.
No functional change intended.
Signed-off-by: Shardul Bankar <shardulsb08@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251021080849.860072-1-shardulsb08@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The vma->vm_mm might be NULL and it can be accessed outside of RCU. Thus,
we can mark it as trusted_or_null. With this change, BPF helpers can safely
access vma->vm_mm to retrieve the associated mm_struct from the VMA.
Then we can make policy decision from the VMA.
The "trusted" annotation enables direct access to vma->vm_mm within kfuncs
marked with KF_TRUSTED_ARGS or KF_RCU, such as bpf_task_get_cgroup1() and
bpf_task_under_cgroup(). Conversely, "null" enforcement requires all
callsites using vma->vm_mm to perform NULL checks.
The lsm selftest must be modified because it directly accesses vma->vm_mm
without a NULL pointer check; otherwise it will break due to this
change.
For the VMA based THP policy, the use case is as follows,
@mm = @vma->vm_mm; // vm_area_struct::vm_mm is trusted or null
if (!@mm)
return;
bpf_rcu_read_lock(); // rcu lock must be held to dereference the owner
@owner = @mm->owner; // mm_struct::owner is rcu trusted or null
if (!@owner)
goto out;
@cgroup1 = bpf_task_get_cgroup1(@owner, MEMCG_HIERARCHY_ID);
/* make the decision based on the @cgroup1 attribute */
bpf_cgroup_release(@cgroup1); // release the associated cgroup
out:
bpf_rcu_read_unlock();
PSI memory information can be obtained from the associated cgroup to inform
policy decisions. Since upstream PSI support is currently limited to cgroup
v2, the following example demonstrates cgroup v2 implementation:
@owner = @mm->owner;
if (@owner) {
// @ancestor_cgid is user-configured
@ancestor = bpf_cgroup_from_id(@ancestor_cgid);
if (bpf_task_under_cgroup(@owner, @ancestor)) {
@psi_group = @ancestor->psi;
/* Extract PSI metrics from @psi_group and
* implement policy logic based on the values
*/
}
}
The vma::vm_file can also be marked with __safe_trusted_or_null.
No additional selftests are required since vma->vm_file and vma->vm_mm are
already validated in the existing selftest suite.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Link: https://lore.kernel.org/r/20251016063929.13830-3-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When CONFIG_MEMCG is enabled, we can access mm->owner under RCU. The
owner can be NULL. With this change, BPF helpers can safely access
mm->owner to retrieve the associated task from the mm. We can then make
policy decision based on the task attribute.
The typical use case is as follows,
bpf_rcu_read_lock(); // rcu lock must be held for rcu trusted field
@owner = @mm->owner; // mm_struct::owner is rcu trusted or null
if (!@owner)
goto out;
/* Do something based on the task attribute */
out:
bpf_rcu_read_unlock();
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/r/20251016063929.13830-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When __lookup_instance() allocates a func_instance structure but fails
to allocate the must_write_set array, it returns an error without freeing
the previously allocated func_instance. This causes a memory leak of 192
bytes (sizeof(struct func_instance)) each time this error path is triggered.
Fix by freeing 'result' on must_write_set allocation failure.
Fixes: b3698c356a ("bpf: callchain sensitive stack liveness tracking using CFG")
Reported-by: BPF Runtime Fuzzer (BRF)
Signed-off-by: Shardul Bankar <shardulsb08@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20251016063330.4107547-1-shardulsb08@gmail.com
We have many places which open-code what's now is bpf_rcu_lock_held()
macro, so replace all those places with a clean and short macro invocation.
For that, move bpf_rcu_lock_held() macro into include/linux/bpf.h.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20251014201403.4104511-1-andrii@kernel.org
The following kmemleak splat:
[ 8.105530] kmemleak: Trying to color unknown object at 0xff11000100e918c0 as Black
[ 8.106521] Call Trace:
[ 8.106521] <TASK>
[ 8.106521] dump_stack_lvl+0x4b/0x70
[ 8.106521] kvfree_call_rcu+0xcb/0x3b0
[ 8.106521] ? hrtimer_cancel+0x21/0x40
[ 8.106521] bpf_obj_free_fields+0x193/0x200
[ 8.106521] htab_map_update_elem+0x29c/0x410
[ 8.106521] bpf_prog_cfc8cd0f42c04044_overwrite_cb+0x47/0x4b
[ 8.106521] bpf_prog_8c30cd7c4db2e963_overwrite_timer+0x65/0x86
[ 8.106521] bpf_prog_test_run_syscall+0xe1/0x2a0
happens due to the combination of features and fixes, but mainly due to
commit 6d78b4473c ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
It's using __GFP_HIGH, which instructs slub/kmemleak internals to skip
kmemleak_alloc_recursive() on allocation, so subsequent kfree_rcu()->
kvfree_call_rcu()->kmemleak_ignore() complains with the above splat.
To fix this imbalance, replace bpf_map_kmalloc_node() with
kmalloc_nolock() and kfree_rcu() with call_rcu() + kfree_nolock() to
make sure that the objects allocated with kmalloc_nolock() are freed
with kfree_nolock() rather than the implicit kfree() that kfree_rcu()
uses internally.
Note, the kmalloc_nolock() happens under bpf_spin_lock_irqsave(), so
it will always fail in PREEMPT_RT. This is not an issue at the moment,
since bpf_timers are disabled in PREEMPT_RT. In the future
bpf_spin_lock will be replaced with state machine similar to
bpf_task_work.
Fixes: 6d78b4473c ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/bpf/20251015000700.28988-1-alexei.starovoitov@gmail.com
The arraymap and hashtab duplicate the logic that checks for and frees
internal structs (timer, workqueue, task_work) based on
BTF record flags. Centralize this by introducing two helpers:
* bpf_map_has_internal_structs(map)
Returns true if the map value contains any of internal structs:
BPF_TIMER | BPF_WORKQUEUE | BPF_TASK_WORK.
* bpf_map_free_internal_structs(map, obj)
Frees the internal structs for a single value object.
Convert arraymap and both the prealloc/malloc hashtab paths to use the
new generic functions. This keeps the functionality for when/how to free
these special fields in one place and makes it easier to add support for
new internal structs in the future without touching every map
implementation.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251010164606.147298-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Fix handling maps with no BTF and non-constant offsets for the bpf_wq.
This de-duplicates logic with other internal structs (task_work, timer),
keeps error reporting consistent, and makes future changes to the layout
handling centralized.
Fixes: d940c9b94d ("bpf: add support for KF_ARG_PTR_TO_WORKQUEUE")
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251010164606.147298-1-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When unpinning a BPF hash table (htab or htab_lru) that contains internal
structures (timer, workqueue, or task_work) in its values, a BUG warning
is triggered:
BUG: sleeping function called from invalid context at kernel/bpf/hashtab.c:244
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 14, name: ksoftirqd/0
...
The issue arises from the interaction between BPF object unpinning and
RCU callback mechanisms:
1. BPF object unpinning uses ->free_inode() which schedules cleanup via
call_rcu(), deferring the actual freeing to an RCU callback that
executes within the RCU_SOFTIRQ context.
2. During cleanup of hash tables containing internal structures,
htab_map_free_internal_structs() is invoked, which includes
cond_resched() or cond_resched_rcu() calls to yield the CPU during
potentially long operations.
However, cond_resched() or cond_resched_rcu() cannot be safely called from
atomic RCU softirq context, leading to the BUG warning when attempting
to reschedule.
Fix this by changing from ->free_inode() to ->destroy_inode() and rename
bpf_free_inode() to bpf_destroy_inode() for BPF objects (prog, map, link).
This allows direct inode freeing without RCU callback scheduling,
avoiding the invalid context warning.
Reported-by: Le Chen <tom2cat@sjtu.edu.cn>
Closes: https://lore.kernel.org/all/1444123482.1827743.1750996347470.JavaMail.zimbra@sjtu.edu.cn/
Fixes: 68134668c1 ("bpf: Add map side support for bpf timers.")
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20251008102628.808045-2-kafai.wan@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_strcasestr() and bpf_strncasestr() functions perform same like
bpf_strstr() and bpf_strnstr() except ignoring the case of the
characters.
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Link: https://lore.kernel.org/r/tencent_B01165355D42A8B8BF5E8D0A21EE1A88090A@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Rename the storage_get_func_atomic flag to a more generic non_sleepable
flag that tracks whether a helper or kfunc may be called from a
non-sleepable context. This makes the flag more broadly applicable
beyond just storage_get helpers. See [0] for more context.
The flag is now set unconditionally for all helpers and kfuncs when:
- RCU critical section is active.
- Preemption is disabled.
- IRQs are disabled.
- In a non-sleepable context within a sleepable program (e.g., timer
callbacks), which is indicated by !in_sleepable().
Previously, the flag was only set for storage_get helpers in these
contexts. With this change, it can be used by any code that needs to
differentiate between sleepable and non-sleepable contexts at the
per-instruction level.
The existing usage in do_misc_fixups() for storage_get helpers is
preserved by checking is_storage_get_function() before using the flag.
[0]: https://lore.kernel.org/bpf/CAP01T76cbaNi4p-y8E0sjE2NXSra2S=Uja8G4hSQDu_SbXxREQ@mail.gmail.com
Cc: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com>
Link: https://lore.kernel.org/r/20251007220349.3852807-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Fix the BPF verifier to correctly determine the sleepable context of
async callbacks based on the async primitive type rather than the arming
program's context.
The bug is in in_sleepable() which uses OR logic to check if the current
execution context is sleepable. When a sleepable program arms a timer
callback, the callback's state correctly has in_sleepable=false, but
in_sleepable() would still return true due to env->prog->sleepable being
true. This incorrectly allows sleepable helpers like
bpf_copy_from_user() inside timer callbacks when armed from sleepable
programs, even though timer callbacks always execute in non-sleepable
context.
Fix in_sleepable() to rely solely on env->cur_state->in_sleepable, and
initialize state->in_sleepable to env->prog->sleepable in
do_check_common() for the main program entry. This ensures the sleepable
context is properly tracked per verification state rather than being
overridden by the program's sleepability.
The env->cur_state NULL check in in_sleepable() was only needed for
do_misc_fixups() which runs after verification when env->cur_state is
set to NULL. Update do_misc_fixups() to use env->prog->sleepable
directly for the storage_get_function check, and remove the redundant
NULL check from in_sleepable().
Introduce is_async_cb_sleepable() helper to explicitly determine async
callback sleepability based on the primitive type:
- bpf_timer callbacks are never sleepable
- bpf_wq and bpf_task_work callbacks are always sleepable
Add verifier_bug() check to catch unhandled async callback types,
ensuring future additions cannot be silently mishandled. Move the
is_task_work_add_kfunc() forward declaration to the top alongside other
callback-related helpers. We update push_async_cb() to adjust to the new
changes.
At the same time, while simplifying in_sleepable(), we notice a problem
in do_misc_fixups. Fix storage_get helpers to use GFP_ATOMIC when called
from non-sleepable contexts within sleepable programs, such as bpf_timer
callbacks.
Currently, the check in do_misc_fixups assumes that env->prog->sleepable,
previously in_sleepable(env) which only resolved to this check before
last commit, holds across the program's execution, but that is not true.
Instead, the func_atomic bit must be set whenever we see the function
being called in an atomic context. Previously, this is being done when
the helper is invoked in atomic contexts in sleepable programs, we can
simply just set the value to true without doing an in_sleepable() check.
We must also do a standalone in_sleepable() check to handle cases where
the async callback itself is armed from a sleepable program, but is
itself non-sleepable (e.g., timer callback) and invokes such a helper,
thus needing the func_atomic bit to be true for the said call.
Adjust do_misc_fixups() to drop any checks regarding sleepable nature of
the program, and just depend on the func_atomic bit to decide which GFP
flag to pass.
Fixes: 81f1d7a583 ("bpf: wq: add bpf_wq_set_callback_impl")
Fixes: b00fa38a9c ("bpf: Enable non-atomic allocations in local storage")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20251007220349.3852807-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Alexei Starovoitov:
- Fix selftests/bpf (typo, conflicts) and unbreak BPF CI (Jiri Olsa)
- Remove linux/unaligned.h dependency for libbpf_sha256 (Andrii
Nakryiko) and add a test (Eric Biggers)
- Reject negative offsets for ALU operations in the verifier (Yazhou
Tang) and add a test (Eduard Zingerman)
- Skip scalar adjustment for BPF_NEG operation if destination register
is a pointer (Brahmajit Das) and add a test (KaFai Wan)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
libbpf: Fix missing #pragma in libbpf_utils.c
selftests/bpf: Add tests for rejection of ALU ops with negative offsets
selftests/bpf: Add test for libbpf_sha256()
bpf: Reject negative offsets for ALU ops
libbpf: remove linux/unaligned.h dependency for libbpf_sha256()
libbpf: move libbpf_sha256() implementation into libbpf_utils.c
libbpf: move libbpf_errstr() into libbpf_utils.c
libbpf: remove unused libbpf_strerror_r and STRERR_BUFSIZE
libbpf: make libbpf_errno.c into more generic libbpf_utils.c
selftests/bpf: Add test for BPF_NEG alu on CONST_PTR_TO_MAP
bpf: Skip scalar adjustment for BPF_NEG if dst is a pointer
selftests/bpf: Fix realloc size in bpf_get_addrs
selftests/bpf: Fix typo in subtest_basic_usdt after merge conflict
selftests/bpf: Fix open-coded gettid syscall in uprobe syscall tests
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Merge tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
- A new layer for caching objects for allocation and free via percpu
arrays called sheaves.
The aim is to combine the good parts of SLAB (lower-overhead and
simpler percpu caching, compared to SLUB) without the past issues
with arrays for freeing remote NUMA node objects and their flushing.
It also allows more efficient kfree_rcu(), and cheaper object
preallocations for cases where the exact number of objects is
unknown, but an upper bound is.
Currently VMAs and maple nodes are using this new caching, with a
plan to enable it for all caches and remove the complex SLUB fastpath
based on cpu (partial) slabs and this_cpu_cmpxchg_double().
(Vlastimil Babka, with Liam Howlett and Pedro Falcato for the maple
tree changes)
- Re-entrant kmalloc_nolock(), which allows opportunistic allocations
from NMI and tracing/kprobe contexts.
Building on prior page allocator and memcg changes, it will result in
removing BPF-specific caches on top of slab (Alexei Starovoitov)
- Various fixes and cleanups. (Kuan-Wei Chiu, Matthew Wilcox, Suren
Baghdasaryan, Ye Liu)
* tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (40 commits)
slab: Introduce kmalloc_nolock() and kfree_nolock().
slab: Reuse first bit for OBJEXTS_ALLOC_FAIL
slab: Make slub local_(try)lock more precise for LOCKDEP
mm: Introduce alloc_frozen_pages_nolock()
mm: Allow GFP_ACCOUNT to be used in alloc_pages_nolock().
locking/local_lock: Introduce local_lock_is_locked().
maple_tree: Convert forking to use the sheaf interface
maple_tree: Add single node allocation support to maple state
maple_tree: Prefilled sheaf conversion and testing
tools/testing: Add support for prefilled slab sheafs
maple_tree: Replace mt_free_one() with kfree()
maple_tree: Use kfree_rcu in ma_free_rcu
testing/radix-tree/maple: Hack around kfree_rcu not existing
tools/testing: include maple-shim.c in maple.c
maple_tree: use percpu sheaves for maple_node_cache
mm, vma: use percpu sheaves for vm_area_struct cache
tools/testing: Add support for changes to slab for sheaves
slab: allow NUMA restricted allocations to use percpu sheaves
tools/testing/vma: Implement vm_refcnt reset
slab: skip percpu sheaves for remote object freeing
...
When verifying BPF programs, the check_alu_op() function validates
instructions with ALU operations. The 'offset' field in these
instructions is a signed 16-bit integer.
The existing check 'insn->off > 1' was intended to ensure the offset is
either 0, or 1 for BPF_MOD/BPF_DIV. However, because 'insn->off' is
signed, this check incorrectly accepts all negative values (e.g., -1).
This commit tightens the validation by changing the condition to
'(insn->off != 0 && insn->off != 1)'. This ensures that any value
other than the explicitly permitted 0 and 1 is rejected, hardening the
verifier against malformed BPF programs.
Co-developed-by: Shenghao Yuan <shenghaoyuan0928@163.com>
Signed-off-by: Shenghao Yuan <shenghaoyuan0928@163.com>
Co-developed-by: Tianci Cao <ziye@zju.edu.cn>
Signed-off-by: Tianci Cao <ziye@zju.edu.cn>
Signed-off-by: Yazhou Tang <tangyazhou518@outlook.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Fixes: ec0e2da95f ("bpf: Support new signed div/mod instructions.")
Link: https://lore.kernel.org/r/tencent_70D024BAE70A0A309A4781694C7B764B0608@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In check_alu_op(), the verifier currently calls check_reg_arg() and
adjust_scalar_min_max_vals() unconditionally for BPF_NEG operations.
However, if the destination register holds a pointer, these scalar
adjustments are unnecessary and potentially incorrect.
This patch adds a check to skip the adjustment logic when the destination
register contains a pointer.
Reported-by: syzbot+d36d5ae81e1b0a53ef58@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d36d5ae81e1b0a53ef58
Fixes: aced132599 ("bpf: Add range tracking for BPF_NEG")
Suggested-by: KaFai Wan <kafai.wan@linux.dev>
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Brahmajit Das <listout@listout.xyz>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251001191739.2323644-2-listout@listout.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Merge tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Support pulling non-linear xdp data with bpf_xdp_pull_data() kfunc
(Amery Hung)
Applied as a stable branch in bpf-next and net-next trees.
- Support reading skb metadata via bpf_dynptr (Jakub Sitnicki)
Also a stable branch in bpf-next and net-next trees.
- Enforce expected_attach_type for tailcall compatibility (Daniel
Borkmann)
- Replace path-sensitive with path-insensitive live stack analysis in
the verifier (Eduard Zingerman)
This is a significant change in the verification logic. More details,
motivation, long term plans are in the cover letter/merge commit.
- Support signed BPF programs (KP Singh)
This is another major feature that took years to materialize.
Algorithm details are in the cover letter/marge commit
- Add support for may_goto instruction to s390 JIT (Ilya Leoshkevich)
- Add support for may_goto instruction to arm64 JIT (Puranjay Mohan)
- Fix USDT SIB argument handling in libbpf (Jiawei Zhao)
- Allow uprobe-bpf program to change context registers (Jiri Olsa)
- Support signed loads from BPF arena (Kumar Kartikeya Dwivedi and
Puranjay Mohan)
- Allow access to union arguments in tracing programs (Leon Hwang)
- Optimize rcu_read_lock() + migrate_disable() combination where it's
used in BPF subsystem (Menglong Dong)
- Introduce bpf_task_work_schedule*() kfuncs to schedule deferred
execution of BPF callback in the context of a specific task using the
kernel’s task_work infrastructure (Mykyta Yatsenko)
- Enforce RCU protection for KF_RCU_PROTECTED kfuncs (Kumar Kartikeya
Dwivedi)
- Add stress test for rqspinlock in NMI (Kumar Kartikeya Dwivedi)
- Improve the precision of tnum multiplier verifier operation
(Nandakumar Edamana)
- Use tnums to improve is_branch_taken() logic (Paul Chaignon)
- Add support for atomic operations in arena in riscv JIT (Pu Lehui)
- Report arena faults to BPF error stream (Puranjay Mohan)
- Search for tracefs at /sys/kernel/tracing first in bpftool (Quentin
Monnet)
- Add bpf_strcasecmp() kfunc (Rong Tao)
- Support lookup_and_delete_elem command in BPF_MAP_STACK_TRACE (Tao
Chen)
* tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (197 commits)
libbpf: Replace AF_ALG with open coded SHA-256
selftests/bpf: Add stress test for rqspinlock in NMI
selftests/bpf: Add test case for different expected_attach_type
bpf: Enforce expected_attach_type for tailcall compatibility
bpftool: Remove duplicate string.h header
bpf: Remove duplicate crypto/sha2.h header
libbpf: Fix error when st-prefix_ops and ops from differ btf
selftests/bpf: Test changing packet data from kfunc
selftests/bpf: Add stacktrace map lookup_and_delete_elem test case
selftests/bpf: Refactor stacktrace_map case with skeleton
bpf: Add lookup_and_delete_elem for BPF_MAP_STACK_TRACE
selftests/bpf: Fix flaky bpf_cookie selftest
selftests/bpf: Test changing packet data from global functions with a kfunc
bpf: Emit struct bpf_xdp_sock type in vmlinux BTF
selftests/bpf: Task_work selftest cleanup fixes
MAINTAINERS: Delete inactive maintainers from AF_XDP
bpf: Mark kfuncs as __noclone
selftests/bpf: Add kprobe multi write ctx attach test
selftests/bpf: Add kprobe write ctx attach test
selftests/bpf: Add uprobe context ip register change test
...
Core perf code updates:
- Convert mmap() related reference counts to refcount_t. This
is in reaction to the recently fixed refcount bugs, which
could have been detected earlier and could have mitigated
the bug somewhat. (Thomas Gleixner, Peter Zijlstra)
- Clean up and simplify the callchain code, in preparation
for sframes. (Steven Rostedt, Josh Poimboeuf)
Uprobes updates:
- Add support to optimize usdt probes on x86-64, which
gives a substantial speedup. (Jiri Olsa)
- Cleanups and fixes on x86 (Peter Zijlstra)
PMU driver updates:
- Various optimizations and fixes to the Intel PMU driver
(Dapeng Mi)
Misc cleanups and fixes:
- Remove redundant __GFP_NOWARN (Qianfeng Rong)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
"Core perf code updates:
- Convert mmap() related reference counts to refcount_t. This is in
reaction to the recently fixed refcount bugs, which could have been
detected earlier and could have mitigated the bug somewhat (Thomas
Gleixner, Peter Zijlstra)
- Clean up and simplify the callchain code, in preparation for
sframes (Steven Rostedt, Josh Poimboeuf)
Uprobes updates:
- Add support to optimize usdt probes on x86-64, which gives a
substantial speedup (Jiri Olsa)
- Cleanups and fixes on x86 (Peter Zijlstra)
PMU driver updates:
- Various optimizations and fixes to the Intel PMU driver (Dapeng Mi)
Misc cleanups and fixes:
- Remove redundant __GFP_NOWARN (Qianfeng Rong)"
* tag 'perf-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value
uprobes/x86: Return error from uprobe syscall when not called from trampoline
perf: Skip user unwind if the task is a kernel thread
perf: Simplify get_perf_callchain() user logic
perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL
perf: Have get_perf_callchain() return NULL if crosstask and user are set
perf: Remove get_perf_callchain() init_nr argument
perf/x86: Print PMU counters bitmap in x86_pmu_show_pmu_cap()
perf/x86/intel: Add ICL_FIXED_0_ADAPTIVE bit into INTEL_FIXED_BITS_MASK
perf/x86/intel: Change macro GLOBAL_CTRL_EN_PERF_METRICS to BIT_ULL(48)
perf/x86: Add PERF_CAP_PEBS_TIMING_INFO flag
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
perf/x86/intel: Use early_initcall() to hook bts_init()
uprobes: Remove redundant __GFP_NOWARN
selftests/seccomp: validate uprobe syscall passes through seccomp
seccomp: passthrough uprobe systemcall without filtering
selftests/bpf: Fix uprobe syscall shadow stack test
selftests/bpf: Change test_uretprobe_regs_change for uprobe and uretprobe
selftests/bpf: Add uprobe_regs_equal test
selftests/bpf: Add optimized usdt variant for basic usdt test
...
Core scheduler changes:
- Make migrate_{en,dis}able() inline, to improve performance
(Menglong Dong)
- Move STDL_INIT() functions out-of-line (Peter Zijlstra)
- Unify the SCHED_{SMT,CLUSTER,MC} Kconfig (Peter Zijlstra)
Fair scheduling:
- Defer throttling when tasks exit to user-space, to reduce the
chance & impact of throttle-preemption with held locks and
other resources. (Aaron Lu, Valentin Schneider)
- Get rid of sched_domains_curr_level hack for tl->cpumask(),
as the warning was getting triggered on certain topologies.
(Peter Zijlstra)
Misc cleanups & fixes:
- Header cleanups (Menglong Dong)
- Fix race in push_dl_task() (Harshit Agarwal)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Core scheduler changes:
- Make migrate_{en,dis}able() inline, to improve performance
(Menglong Dong)
- Move STDL_INIT() functions out-of-line (Peter Zijlstra)
- Unify the SCHED_{SMT,CLUSTER,MC} Kconfig (Peter Zijlstra)
Fair scheduling:
- Defer throttling to when tasks exit to user-space, to reduce the
chance & impact of throttle-preemption with held locks and other
resources (Aaron Lu, Valentin Schneider)
- Get rid of sched_domains_curr_level hack for tl->cpumask(), as the
warning was getting triggered on certain topologies (Peter
Zijlstra)
Misc cleanups & fixes:
- Header cleanups (Menglong Dong)
- Fix race in push_dl_task() (Harshit Agarwal)"
* tag 'sched-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix some typos in include/linux/preempt.h
sched: Make migrate_{en,dis}able() inline
rcu: Replace preempt.h with sched.h in include/linux/rcupdate.h
arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c
sched/fair: Do not balance task to a throttled cfs_rq
sched/fair: Do not special case tasks in throttled hierarchy
sched/fair: update_cfs_group() for throttled cfs_rqs
sched/fair: Propagate load for throttled cfs_rq
sched/fair: Get rid of throttled_lb_pair()
sched/fair: Task based throttle time accounting
sched/fair: Switch to task based throttle model
sched/fair: Implement throttle task work and related helpers
sched/fair: Add related data structure for task based throttle
sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig
sched: Move STDL_INIT() functions out-of-line
sched/fair: Get rid of sched_domains_curr_level hack for tl->cpumask()
sched/deadline: Fix race in push_dl_task()
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Merge tag 'vfs-6.18-rc1.async' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs async directory updates from Christian Brauner:
"This contains further preparatory changes for the asynchronous directory
locking scheme:
- Add lookup_one_positive_killable() which allows overlayfs to
perform lookup that won't block on a fatal signal
- Unify the mount idmap handling in struct renamedata as a rename can
only happen within a single mount
- Introduce kern_path_parent() for audit which sets the path to the
parent and returns a dentry for the target without holding any
locks on return
- Rename kern_path_locked() as it is only used to prepare for the
removal of an object from the filesystem:
kern_path_locked() => start_removing_path()
kern_path_create() => start_creating_path()
user_path_create() => start_creating_user_path()
user_path_locked_at() => start_removing_user_path_at()
done_path_create() => end_creating_path()
NA => end_removing_path()"
* tag 'vfs-6.18-rc1.async' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
debugfs: rename start_creating() to debugfs_start_creating()
VFS: rename kern_path_locked() and related functions.
VFS/audit: introduce kern_path_parent() for audit
VFS: unify old_mnt_idmap and new_mnt_idmap in renamedata
VFS: discard err2 in filename_create()
VFS/ovl: add lookup_one_positive_killable()
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Merge tag 'vfs-6.18-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual selections of misc updates for this cycle.
Features:
- Add "initramfs_options" parameter to set initramfs mount options.
This allows to add specific mount options to the rootfs to e.g.,
limit the memory size
- Add RWF_NOSIGNAL flag for pwritev2()
Add RWF_NOSIGNAL flag for pwritev2. This flag prevents the SIGPIPE
signal from being raised when writing on disconnected pipes or
sockets. The flag is handled directly by the pipe filesystem and
converted to the existing MSG_NOSIGNAL flag for sockets
- Allow to pass pid namespace as procfs mount option
Ever since the introduction of pid namespaces, procfs has had very
implicit behaviour surrounding them (the pidns used by a procfs
mount is auto-selected based on the mounting process's active
pidns, and the pidns itself is basically hidden once the mount has
been constructed)
This implicit behaviour has historically meant that userspace was
required to do some special dances in order to configure the pidns
of a procfs mount as desired. Examples include:
* In order to bypass the mnt_too_revealing() check, Kubernetes
creates a procfs mount from an empty pidns so that user
namespaced containers can be nested (without this, the nested
containers would fail to mount procfs)
But this requires forking off a helper process because you cannot
just one-shot this using mount(2)
* Container runtimes in general need to fork into a container
before configuring its mounts, which can lead to security issues
in the case of shared-pidns containers (a privileged process in
the pidns can interact with your container runtime process)
While SUID_DUMP_DISABLE and user namespaces make this less of an
issue, the strict need for this due to a minor uAPI wart is kind
of unfortunate
Things would be much easier if there was a way for userspace to
just specify the pidns they want. So this pull request contains
changes to implement a new "pidns" argument which can be set
using fsconfig(2):
fsconfig(procfd, FSCONFIG_SET_FD, "pidns", NULL, nsfd);
fsconfig(procfd, FSCONFIG_SET_STRING, "pidns", "/proc/self/ns/pid", 0);
or classic mount(2) / mount(8):
// mount -t proc -o pidns=/proc/self/ns/pid proc /tmp/proc
mount("proc", "/tmp/proc", "proc", MS_..., "pidns=/proc/self/ns/pid");
Cleanups:
- Remove the last references to EXPORT_OP_ASYNC_LOCK
- Make file_remove_privs_flags() static
- Remove redundant __GFP_NOWARN when GFP_NOWAIT is used
- Use try_cmpxchg() in start_dir_add()
- Use try_cmpxchg() in sb_init_done_wq()
- Replace offsetof() with struct_size() in ioctl_file_dedupe_range()
- Remove vfs_ioctl() export
- Replace rwlock() with spinlock in epoll code as rwlock causes
priority inversion on preempt rt kernels
- Make ns_entries in fs/proc/namespaces const
- Use a switch() statement() in init_special_inode() just like we do
in may_open()
- Use struct_size() in dir_add() in the initramfs code
- Use str_plural() in rd_load_image()
- Replace strcpy() with strscpy() in find_link()
- Rename generic_delete_inode() to inode_just_drop() and
generic_drop_inode() to inode_generic_drop()
- Remove unused arguments from fcntl_{g,s}et_rw_hint()
Fixes:
- Document @name parameter for name_contains_dotdot() helper
- Fix spelling mistake
- Always return zero from replace_fd() instead of the file descriptor
number
- Limit the size for copy_file_range() in compat mode to prevent a
signed overflow
- Fix debugfs mount options not being applied
- Verify the inode mode when loading it from disk in minixfs
- Verify the inode mode when loading it from disk in cramfs
- Don't trigger automounts with RESOLVE_NO_XDEV
If openat2() was called with RESOLVE_NO_XDEV it didn't traverse
through automounts, but could still trigger them
- Add FL_RECLAIM flag to show_fl_flags() macro so it appears in
tracepoints
- Fix unused variable warning in rd_load_image() on s390
- Make INITRAMFS_PRESERVE_MTIME depend on BLK_DEV_INITRD
- Use ns_capable_noaudit() when determining net sysctl permissions
- Don't call path_put() under namespace semaphore in listmount() and
statmount()"
* tag 'vfs-6.18-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
fcntl: trim arguments
listmount: don't call path_put() under namespace semaphore
statmount: don't call path_put() under namespace semaphore
pid: use ns_capable_noaudit() when determining net sysctl permissions
fs: rename generic_delete_inode() and generic_drop_inode()
init: INITRAMFS_PRESERVE_MTIME should depend on BLK_DEV_INITRD
initramfs: Replace strcpy() with strscpy() in find_link()
initrd: Use str_plural() in rd_load_image()
initramfs: Use struct_size() helper to improve dir_add()
initrd: Fix unused variable warning in rd_load_image() on s390
fs: use the switch statement in init_special_inode()
fs/proc/namespaces: make ns_entries const
filelock: add FL_RECLAIM to show_fl_flags() macro
eventpoll: Replace rwlock with spinlock
selftests/proc: add tests for new pidns APIs
procfs: add "pidns" mount option
pidns: move is-ancestor logic to helper
openat2: don't trigger automounts with RESOLVE_NO_XDEV
namei: move cross-device check to __traverse_mounts
namei: remove LOOKUP_NO_XDEV check from handle_mounts
...
Change alloc_pages_nolock() to default to __GFP_COMP when allocating
pages, since upcoming reentrant alloc_slab_page() needs __GFP_COMP.
Also allow __GFP_ACCOUNT flag to be specified,
since most of BPF infra needs __GFP_ACCOUNT except BPF streams.
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Yinhao et al. recently reported:
Our fuzzer tool discovered an uninitialized pointer issue in the
bpf_prog_test_run_xdp() function within the Linux kernel's BPF subsystem.
This leads to a NULL pointer dereference when a BPF program attempts to
deference the txq member of struct xdp_buff object.
The test initializes two programs of BPF_PROG_TYPE_XDP: progA acts as the
entry point for bpf_prog_test_run_xdp() and its expected_attach_type can
neither be of be BPF_XDP_DEVMAP nor BPF_XDP_CPUMAP. progA calls into a slot
of a tailcall map it owns. progB's expected_attach_type must be BPF_XDP_DEVMAP
to pass xdp_is_valid_access() validation. The program returns struct xdp_md's
egress_ifindex, and the latter is only allowed to be accessed under mentioned
expected_attach_type. progB is then inserted into the tailcall which progA
calls.
The underlying issue goes beyond XDP though. Another example are programs
of type BPF_PROG_TYPE_CGROUP_SOCK_ADDR. sock_addr_is_valid_access() as well
as sock_addr_func_proto() have different logic depending on the programs'
expected_attach_type. Similarly, a program attached to BPF_CGROUP_INET4_GETPEERNAME
should not be allowed doing a tailcall into a program which calls bpf_bind()
out of BPF which is only enabled for BPF_CGROUP_INET4_CONNECT.
In short, specifying expected_attach_type allows to open up additional
functionality or restrictions beyond what the basic bpf_prog_type enables.
The use of tailcalls must not violate these constraints. Fix it by enforcing
expected_attach_type in __bpf_prog_map_compatible().
Note that we only enforce this for tailcall maps, but not for BPF devmaps or
cpumaps: There, the programs are invoked through dev_map_bpf_prog_run*() and
cpu_map_bpf_prog_run*() which set up a new environment / context and therefore
these situations are not prone to this issue.
Fixes: 5e43f899b0 ("bpf: Check attach type at prog load time")
Reported-by: Yinhao Hu <dddddd@hust.edu.cn>
Reported-by: Kaiyan Mei <M202472210@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250926171201.188490-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The stacktrace map can be easily full, which will lead to failure in
obtaining the stack. In addition to increasing the size of the map,
another solution is to delete the stack_id after looking it up from
the user, so extend the existing bpf_map_lookup_and_delete_elem()
functionality to stacktrace map types.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250925175030.1615837-1-chen.dylane@linux.dev
For now, migrate_enable and migrate_disable are global, which makes them
become hotspots in some case. Take BPF for example, the function calling
to migrate_enable and migrate_disable in BPF trampoline can introduce
significant overhead, and following is the 'perf top' of FENTRY's
benchmark (./tools/testing/selftests/bpf/bench trig-fentry):
54.63% bpf_prog_2dcccf652aac1793_bench_trigger_fentry [k]
bpf_prog_2dcccf652aac1793_bench_trigger_fentry
10.43% [kernel] [k] migrate_enable
10.07% bpf_trampoline_6442517037 [k] bpf_trampoline_6442517037
8.06% [kernel] [k] __bpf_prog_exit_recur
4.11% libc.so.6 [.] syscall
2.15% [kernel] [k] entry_SYSCALL_64
1.48% [kernel] [k] memchr_inv
1.32% [kernel] [k] fput
1.16% [kernel] [k] _copy_to_user
0.73% [kernel] [k] bpf_prog_test_run_raw_tp
So in this commit, we make migrate_enable/migrate_disable inline to obtain
better performance. The struct rq is defined internally in
kernel/sched/sched.h, and the field "nr_pinned" is accessed in
migrate_enable/migrate_disable, which makes it hard to make them inline.
Alexei Starovoitov suggests to generate the offset of "nr_pinned" in [1],
so we can define the migrate_enable/migrate_disable in
include/linux/sched.h and access "this_rq()->nr_pinned" with
"(void *)this_rq() + RQ_nr_pinned".
The offset of "nr_pinned" is generated in include/generated/rq-offsets.h
by kernel/sched/rq-offsets.c.
Generally speaking, we move the definition of migrate_enable and
migrate_disable to include/linux/sched.h from kernel/sched/core.c. The
calling to __set_cpus_allowed_ptr() is leaved in ___migrate_enable().
The "struct rq" is not available in include/linux/sched.h, so we can't
access the "runqueues" with this_cpu_ptr(), as the compilation will fail
in this_cpu_ptr() -> raw_cpu_ptr() -> __verify_pcpu_ptr():
typeof((ptr) + 0)
So we introduce the this_rq_raw() and access the runqueues with
arch_raw_cpu_ptr/PERCPU_PTR directly.
The variable "runqueues" is not visible in the kernel modules, and export
it is not a good idea. As Peter Zijlstra advised in [2], we define and
export migrate_enable/migrate_disable in kernel/sched/core.c too, and use
them for the modules.
Before this patch, the performance of BPF FENTRY is:
fentry : 113.030 ± 0.149M/s
fentry : 112.501 ± 0.187M/s
fentry : 112.828 ± 0.267M/s
fentry : 115.287 ± 0.241M/s
After this patch, the performance of BPF FENTRY increases to:
fentry : 143.644 ± 0.670M/s
fentry : 149.764 ± 0.362M/s
fentry : 149.642 ± 0.156M/s
fentry : 145.263 ± 0.221M/s
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/bpf/CAADnVQ+5sEDKHdsJY5ZsfGDO_1SEhhQWHrt2SMBG5SYyQ+jt7w@mail.gmail.com/ [1]
Link: https://lore.kernel.org/all/20250819123214.GH4067720@noisy.programming.kicks-ass.net/ [2]
bpf_xdp_pull_data() may change packet data and therefore packet pointers
need to be invalidated. Add bpf_xdp_pull_data() to the special kfunc
list instead of introducing a new KF_ flag until there are more kfuncs
changing packet data.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250922233356.3356453-5-ameryhung@gmail.com
Currently, functions with 'union' arguments cannot be traced with
fentry/fexit:
bpftrace -e 'fentry:release_pages { exit(); }' -v
The function release_pages arg0 type UNION is unsupported.
The type of the 'release_pages' arg0 is defined as:
typedef union {
struct page **pages;
struct folio **folios;
struct encoded_page **encoded_pages;
} release_pages_arg __attribute__ ((__transparent_union__));
This patch relaxes the restriction by allowing function arguments of type
'union' to be traced in verifier.
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20250919044110.23729-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, signed load instructions into arena memory are unsupported.
The compiler is free to generate these, and on GCC-14 we see a
corresponding error when it happens. The hurdle in supporting them is
deciding which unused opcode to use to mark them for the JIT's own
consumption. After much thinking, it appears 0xc0 / BPF_NOSPEC can be
combined with load instructions to identify signed arena loads. Use
this to recognize and JIT them appropriately, and remove the verifier
side limitation on the program if the JIT supports them.
Co-developed-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20250923110157.18326-2-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Implementation of the new bpf_task_work_schedule kfuncs, that let a BPF
program schedule task_work callbacks for a target task:
* bpf_task_work_schedule_signal() - schedules with TWA_SIGNAL
* bpf_task_work_schedule_resume() - schedules with TWA_RESUME
Each map value should embed a struct bpf_task_work, which the kernel
side pairs with struct bpf_task_work_kern, containing a pointer to
struct bpf_task_work_ctx, that maintains metadata relevant for the
concrete callback scheduling.
A small state machine and refcounting scheme ensures safe reuse and
teardown. State transitions:
_______________________________
| |
v |
[standby] ---> [pending] --> [scheduling] --> [scheduled]
^ |________________|_________
| |
| v
| [running]
|_______________________________________________________|
All states may transition into FREED state:
[pending] [scheduling] [scheduled] [running] [standby] -> [freed]
A FREED terminal state coordinates with map-value
deletion (bpf_task_work_cancel_and_free()).
Scheduling itself is deferred via irq_work to keep the kfunc callable
from NMI context.
Lifetime is guarded with refcount_t + RCU Tasks Trace.
Main components:
* struct bpf_task_work_context – Metadata and state management per task
work.
* enum bpf_task_work_state – A state machine to serialize work
scheduling and execution.
* bpf_task_work_schedule() – The central helper that initiates
scheduling.
* bpf_task_work_acquire_ctx() - Attempts to take ownership of the context,
pointed by passed struct bpf_task_work, allocates new context if none
exists yet.
* bpf_task_work_callback() – Invoked when the actual task_work runs.
* bpf_task_work_irq() – An intermediate step (runs in softirq context)
to enqueue task work.
* bpf_task_work_cancel_and_free() – Cleanup for deleted BPF map entries.
Flow of successful task work scheduling
1) bpf_task_work_schedule_* is called from BPF code.
2) Transition state from STANDBY to PENDING, mark context as owned by
this task work scheduler
3) irq_work_queue() schedules bpf_task_work_irq().
4) Transition state from PENDING to SCHEDULING (noop if transition
successful)
5) bpf_task_work_irq() attempts task_work_add(). If successful, state
transitions to SCHEDULED.
6) Task work calls bpf_task_work_callback(), which transition state to
RUNNING.
7) BPF callback is executed
8) Context is cleaned up, refcounts released, context state set back to
STANDBY.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250923112404.668720-8-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Calculation of the BPF map key, given the pointer to a value is
duplicated in a couple of places in helpers already, in the next patch
another use case is introduced as well.
This patch extracts that functionality into a separate function.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250923112404.668720-7-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds necessary plumbing in verifier, syscall and maps to
support handling new kfunc bpf_task_work_schedule and kernel structure
bpf_task_work. The idea is similar to how we already handle bpf_wq and
bpf_timer.
verifier changes validate calls to bpf_task_work_schedule to make sure
it is safe and expected invariants hold.
btf part is required to detect bpf_task_work structure inside map value
and store its offset, which will be used in the next patch to calculate
key and value addresses.
arraymap and hashtab changes are needed to handle freeing of the
bpf_task_work: run code needed to deinitialize it, for example cancel
task_work callback if possible.
The use of bpf_task_work and proper implementation for kfuncs are
introduced in the next patch.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250923112404.668720-6-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The verifier currently enforces a zero return value for all async
callbacks—a constraint originally introduced for bpf_timer. That
restriction is too narrow for other async use cases.
Relax the rule by allowing non-zero return codes from async callbacks in
general, while preserving the zero-return requirement for bpf_timer to
maintain its existing semantics.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250923112404.668720-5-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Extract the cleanup of known embedded structs into the dedicated helper.
Remove duplication and introduce a single source of truth for freeing
special embedded structs in hashtab.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250923112404.668720-4-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Refactor the verifier by pulling the common logic from
process_timer_func() into a dedicated helper. This allows reusing
process_async_func() helper for verifying bpf_task_work struct in the
next patch.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Tested-by: syzbot@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20250923112404.668720-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reduce code duplication in detection of the known special field types in
map values. This refactoring helps to avoid copying a chunk of code in
the next patch of the series.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250923112404.668720-2-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kern_path_locked() is now only used to prepare for removing an object
from the filesystem (and that is the only credible reason for wanting a
positive locked dentry). Thus it corresponds to kern_path_create() and
so should have a corresponding name.
Unfortunately the name "kern_path_create" is somewhat misleading as it
doesn't actually create anything. The recently added
simple_start_creating() provides a better pattern I believe. The
"start" can be matched with "end" to bracket the creating or removing.
So this patch changes names:
kern_path_locked -> start_removing_path
kern_path_create -> start_creating_path
user_path_create -> start_creating_user_path
user_path_locked_at -> start_removing_user_path_at
done_path_create -> end_creating_path
and also introduces end_removing_path() which is identical to
end_creating_path().
__start_removing_path (which was __kern_path_locked) is enhanced to
call mnt_want_write() for consistency with the start_creating_path().
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This patch extends the BPF_PROG_LOAD command by adding three new fields
to `union bpf_attr` in the user-space API:
- signature: A pointer to the signature blob.
- signature_size: The size of the signature blob.
- keyring_id: The serial number of a loaded kernel keyring (e.g.,
the user or session keyring) containing the trusted public keys.
When a BPF program is loaded with a signature, the kernel:
1. Retrieves the trusted keyring using the provided `keyring_id`.
2. Verifies the supplied signature against the BPF program's
instruction buffer.
3. If the signature is valid and was generated by a key in the trusted
keyring, the program load proceeds.
4. If no signature is provided, the load proceeds as before, allowing
for backward compatibility. LSMs can chose to restrict unsigned
programs and implement a security policy.
5. If signature verification fails for any reason,
the program is not loaded.
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250921160120.9711-2-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Converting bpf_insn_successors() to use lookup table makes it ~1.5
times faster.
Also remove unnecessary conditionals:
- `idx + 1 < prog->len` is unnecessary because after check_cfg() all
jump targets are guaranteed to be within a program;
- `i == 0 || succ[0] != dst` is unnecessary because any client of
bpf_insn_successors() can handle duplicate edges:
- compute_live_registers()
- compute_scc()
Moving bpf_insn_successors() to liveness.c allows its inlining in
liveness.c:__update_stack_liveness().
Such inlining speeds up __update_stack_liveness() by ~40%.
bpf_insn_successors() is used in both verifier.c and liveness.c.
perf shows such move does not negatively impact users in verifier.c,
as these are executed only once before main varification pass.
Unlike __update_stack_liveness() which can be triggered multiple
times.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-10-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Remove register chain based liveness tracking:
- struct bpf_reg_state->{parent,live} fields are no longer needed;
- REG_LIVE_WRITTEN marks are superseded by bpf_mark_stack_write()
calls;
- mark_reg_read() calls are superseded by bpf_mark_stack_read();
- log.c:print_liveness() is superseded by logging in liveness.c;
- propagate_liveness() is superseded by bpf_update_live_stack();
- no need to establish register chains in is_state_visited() anymore;
- fix a bunch of tests expecting "_w" suffixes in verifier log
messages.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-9-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Unlike the new algorithm, register chain based liveness tracking is
fully path sensitive, and thus should be strictly more accurate.
Validate the new algorithm by signaling an error whenever it considers
a stack slot dead while the old algorithm considers it alive.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-8-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allocate analysis instance:
- Add bpf_stack_liveness_{init,free}() calls to bpf_check().
Notify the instance about any stack reads and writes:
- Add bpf_mark_stack_write() call at every location where
REG_LIVE_WRITTEN is recorded for a stack slot.
- Add bpf_mark_stack_read() call at every location mark_reg_read() is
called.
- Both bpf_mark_stack_{read,write}() rely on
env->liveness->cur_instance callchain being in sync with
env->cur_state. It is possible to update env->liveness->cur_instance
every time a mark read/write is called, but that costs a hash table
lookup and is noticeable in the performance profile. Hence, manually
reset env->liveness->cur_instance whenever the verifier changes
env->cur_state call stack:
- call bpf_reset_live_stack_callchain() when the verifier enters a
subprogram;
- call bpf_update_live_stack() when the verifier exits a subprogram
(it implies the reset).
Make sure bpf_update_live_stack() is called for a callchain before
issuing liveness queries. And make sure that bpf_update_live_stack()
is called for any callee callchain first:
- Add bpf_update_live_stack() call at every location that processes
BPF_EXIT:
- exit from a subprogram;
- before pop_stack() call.
This makes sure that bpf_update_live_stack() is called for callee
callchains before caller callchains.
Make sure must_write marks are set to zero for instructions that
do not always access the stack:
- Wrap do_check_insn() with bpf_reset_stack_write_marks() /
bpf_commit_stack_write_marks() calls.
Any calls to bpf_mark_stack_write() are accumulated between this
pair of calls. If no bpf_mark_stack_write() calls were made
it means that the instruction does not access stack (at-least
on the current verification path) and it is important to record
this fact.
Finally, use bpf_live_stack_query_init() / bpf_stack_slot_alive()
to query stack liveness info.
The manual tracking of the correct order for callee/caller
bpf_update_live_stack() calls is a bit convoluted and may warrant some
automation in future revisions.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-7-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit adds a flow-sensitive, context-sensitive, path-insensitive
data flow analysis for live stack slots:
- flow-sensitive: uses program control flow graph to compute data flow
values;
- context-sensitive: collects data flow values for each possible call
chain in a program;
- path-insensitive: does not distinguish between separate control flow
graph paths reaching the same instruction.
Compared to the current path-sensitive analysis, this approach trades
some precision for not having to enumerate every path in the program.
This gives a theoretical capability to run the analysis before main
verification pass. See cover letter for motivation.
The basic idea is as follows:
- Data flow values indicate stack slots that might be read and stack
slots that are definitely written.
- Data flow values are collected for each
(call chain, instruction number) combination in the program.
- Within a subprogram, data flow values are propagated using control
flow graph.
- Data flow values are transferred from entry instructions of callee
subprograms to call sites in caller subprograms.
In other words, a tree of all possible call chains is constructed.
Each node of this tree represents a subprogram. Read and write marks
are collected for each instruction of each node. Live stack slots are
first computed for lower level nodes. Then, information about outer
stack slots that might be read or are definitely written by a
subprogram is propagated one level up, to the corresponding call
instructions of the upper nodes. Procedure repeats until root node is
processed.
In the absence of value range analysis, stack read/write marks are
collected during main verification pass, and data flow computation is
triggered each time verifier.c:states_equal() needs to query the
information.
Implementation details are documented in kernel/bpf/liveness.c.
Quantitative data about verification performance changes and memory
consumption is in the cover letter.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-6-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The next patch would require doing postorder traversal of individual
subprograms. Facilitate this by moving env->cfg.insn_postorder
computation from check_cfg() to a separate pass, as check_cfg()
descends into called subprograms (and it needs to, because of
merge_callee_effects() logic).
env->cfg.insn_postorder is used only by compute_live_registers(),
this function does not track cross subprogram dependencies,
thus the change does not affect it's operation.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-5-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
stacksafe() is called in exact == NOT_EXACT mode only for states that
had been porcessed by clean_verifier_states(). The latter replaces
dead stack spills with a series of STACK_INVALID masks. Such masks are
already handled by stacksafe().
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-3-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Prepare for bpf_reg_state->live field removal by leveraging
insn_aux_data->live_regs_before instead of bpf_reg_state->live in
compute_live_registers(). This is similar to logic in
func_states_equal(). No changes in verification performance for
selftests or sched_ext.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-2-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Prepare for bpf_reg_state->live field removal by introducing a
separate flag to track if clean_verifier_state() had been applied to
the state. No functional changes.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250918-callchain-sensitive-liveness-v3-1-c3cd27bacc60@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
No functional changes, except for the addition of the headers for the
kfuncs so that they can be used for signature verification.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-8-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently only array maps are supported, but the implementation can be
extended for other maps and objects. The hash is memoized only for
exclusive and frozen maps as their content is stable until the exclusive
program modifies the map.
This is required for BPF signing, enabling a trusted loader program to
verify a map's integrity. The loader retrieves
the map's runtime hash from the kernel and compares it against an
expected hash computed at build time.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-7-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Exclusive maps allow maps to only be accessed by program with a
program with a matching hash which is specified in the excl_prog_hash
attr.
For the signing use-case, this allows the trusted loader program
to load the map and verify the integrity
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-3-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Exclusive maps restrict map access to specific programs using a hash.
The current hash used for this is SHA1, which is prone to collisions.
This patch uses SHA256, which is more resilient against
collisions. This new hash is stored in bpf_prog and used by the verifier
to determine if a program can access a given exclusive map.
The original 64-bit tags are kept, as they are used by users as a short,
possibly colliding program identifier for non-security purposes.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-2-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, KF_RCU_PROTECTED only applies to iterator APIs and that too
in a convoluted fashion: the presence of this flag on the kfunc is used
to set MEM_RCU in iterator type, and the lack of RCU protection results
in an error only later, once next() or destroy() methods are invoked on
the iterator. While there is no bug, this is certainly a bit
unintuitive, and makes the enforcement of the flag iterator specific.
In the interest of making this flag useful for other upcoming kfuncs,
e.g. scx_bpf_cpu_curr() [0][1], add enforcement for invoking the kfunc
in an RCU critical section in general.
This would also mean that iterator APIs using KF_RCU_PROTECTED will
error out earlier, instead of throwing an error for lack of RCU CS
protection when next() or destroy() methods are invoked.
In addition to this, if the kfuncs tagged KF_RCU_PROTECTED return a
pointer value, ensure that this pointer value is only usable in an RCU
critical section. There might be edge cases where the return value is
special and doesn't need to imply MEM_RCU semantics, but in general, the
assumption should hold for the majority of kfuncs, and we can revisit
things if necessary later.
[0]: https://lore.kernel.org/all/20250903212311.369697-3-christian.loehle@arm.com
[1]: https://lore.kernel.org/all/20250909195709.92669-1-arighi@nvidia.com
Tested-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250917032755.4068726-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Syzbot generated a program that triggers a verifier_bug() call in
maybe_exit_scc(). maybe_exit_scc() assumes that, when called for a
state with insn_idx in some SCC, there should be an instance of struct
bpf_scc_visit allocated for that SCC. Turns out the assumption does
not hold for speculative execution paths. See example in the next
patch.
maybe_scc_exit() is called from update_branch_counts() for states that
reach branch count of zero, meaning that path exploration for a
particular path is finished. Path exploration can finish in one of
three ways:
a. Verification error is found. In this case, update_branch_counts()
is called only for non-speculative paths.
b. Top level BPF_EXIT is reached. Such instructions are never a part of
an SCC, so compute_scc_callchain() in maybe_scc_exit() will return
false, and maybe_scc_exit() will return early.
c. A checkpoint is reached and matched. Checkpoints are created by
is_state_visited(), which calls maybe_enter_scc(), which allocates
bpf_scc_visit instances for checkpoints within SCCs.
Hence, for non-speculative symbolic execution paths, the assumption
still holds: if maybe_scc_exit() is called for a state within an SCC,
bpf_scc_visit instance must exist.
This patch removes the verifier_bug() call for speculative paths.
Fixes: c9e31900b5 ("bpf: propagate read/precision marks over state graph backedges")
Reported-by: syzbot+3afc814e8df1af64b653@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/68c85acd.050a0220.2ff435.03a4.GAE@google.com/
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250916212251.3490455-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Function bpf_patch_insn_data() has the following structure:
static struct bpf_prog *bpf_patch_insn_data(... env ...)
{
struct bpf_prog *new_prog;
struct bpf_insn_aux_data *new_data = NULL;
if (len > 1) {
new_data = vrealloc(...); // <--------- (1)
if (!new_data)
return NULL;
env->insn_aux_data = new_data; // <---- (2)
}
new_prog = bpf_patch_insn_single(env->prog, off, patch, len);
if (IS_ERR(new_prog)) {
...
vfree(new_data); // <----------------- (3)
return NULL;
}
... happy path ...
}
In case if bpf_patch_insn_single() returns an error the `new_data`
allocated at (1) will be freed at (3). However, at (2) this pointer
is stored in `env->insn_aux_data`. Which is freed unconditionally
by verifier.c:bpf_check() on both happy and error paths.
Thus, leading to double-free.
Fix this by removing vfree() call at (3), ownership over `new_data` is
already passed to `env->insn_aux_data` at this point.
Fixes: 77620d1267 ("bpf: use realloc in bpf_patch_insn_data")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250912-patch-insn-data-double-free-v1-1-af05bd85a21a@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The bpf_cgroup_from_id kfunc relies on cgroup_get_from_id to obtain the
cgroup corresponding to a given cgroup ID. This helper can be called in
a lot of contexts where the current thread can be random. A recent
example was its use in sched_ext's ops.tick(), to obtain the root cgroup
pointer. Since the current task can be whatever random user space task
preempted by the timer tick, this makes the behavior of the helper
unreliable.
Refactor out __cgroup_get_from_id as the non-namespace aware version of
cgroup_get_from_id, and change bpf_cgroup_from_id to make use of it.
There is no compatibility breakage here, since changing the namespace
against which the lookup is being done to the root cgroup namespace only
permits a wider set of lookups to succeed now. The cgroup IDs across
namespaces are globally unique, and thus don't need to be retranslated.
Reported-by: Dan Schatzberg <dschatzberg@meta.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20250915032618.1551762-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
generic_delete_inode() is rather misleading for what the routine is
doing. inode_just_drop() should be much clearer.
The new naming is inconsistent with generic_drop_inode(), so rename that
one as well with inode_ as the suffix.
No functional changes.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Begin reporting arena page faults and the faulting address to BPF
program's stderr, this patch adds support in the arm64 and x86-64 JITs,
support for other archs can be added later.
The fault handlers receive the 32 bit address in the arena region so
the upper 32 bits of user_vm_start is added to it before printing the
address. This is what the user would expect to see as this is what is
printed by bpf_printk() is you pass it an address returned by
bpf_arena_alloc_pages();
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250911145808.58042-4-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BPF streams are only valid for the main programs, to make it easier to
access streams from subprogs, introduce main_prog_aux in struct
bpf_prog_aux.
prog->aux->main_prog_aux = prog->aux, for main programs and
prog->aux->main_prog_aux = main_prog->aux, for subprograms.
Make bpf_prog_find_from_stack() use the added main_prog_aux to return
the mainprog when a subprog is found on the stack.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250911145808.58042-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When enable CONFIG_PREEMPT_RT, the kernel will warn when run timer
selftests by './test_progs -t timer':
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
In order to avoid such warning, reject bpf_timer in verifier when
PREEMPT_RT is enabled.
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20250910125740.52172-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, calling bpf_map_kmalloc_node() from __bpf_async_init() can
cause various locking issues; see the following stack trace (edited for
style) as one example:
...
[10.011566] do_raw_spin_lock.cold
[10.011570] try_to_wake_up (5) double-acquiring the same
[10.011575] kick_pool rq_lock, causing a hardlockup
[10.011579] __queue_work
[10.011582] queue_work_on
[10.011585] kernfs_notify
[10.011589] cgroup_file_notify
[10.011593] try_charge_memcg (4) memcg accounting raises an
[10.011597] obj_cgroup_charge_pages MEMCG_MAX event
[10.011599] obj_cgroup_charge_account
[10.011600] __memcg_slab_post_alloc_hook
[10.011603] __kmalloc_node_noprof
...
[10.011611] bpf_map_kmalloc_node
[10.011612] __bpf_async_init
[10.011615] bpf_timer_init (3) BPF calls bpf_timer_init()
[10.011617] bpf_prog_xxxxxxxxxxxxxxxx_fcg_runnable
[10.011619] bpf__sched_ext_ops_runnable
[10.011620] enqueue_task_scx (2) BPF runs with rq_lock held
[10.011622] enqueue_task
[10.011626] ttwu_do_activate
[10.011629] sched_ttwu_pending (1) grabs rq_lock
...
The above was reproduced on bpf-next (b338cf849e) by modifying
./tools/sched_ext/scx_flatcg.bpf.c to call bpf_timer_init() during
ops.runnable(), and hacking the memcg accounting code a bit to make
a bpf_timer_init() call more likely to raise an MEMCG_MAX event.
We have also run into other similar variants (both internally and on
bpf-next), including double-acquiring cgroup_file_kn_lock, the same
worker_pool::lock, etc.
As suggested by Shakeel, fix this by using __GFP_HIGH instead of
GFP_ATOMIC in __bpf_async_init(), so that e.g. if try_charge_memcg()
raises an MEMCG_MAX event, we call __memcg_memory_event() with
@allow_spinning=false and avoid calling cgroup_file_notify() there.
Depends on mm patch
"memcg: skip cgroup_file_notify if spinning is not allowed":
https://lore.kernel.org/bpf/20250905201606.66198-1-shakeel.butt@linux.dev/
v0 approach s/bpf_map_kmalloc_node/bpf_mem_alloc/
https://lore.kernel.org/bpf/20250905061919.439648-1-yepeilin@google.com/
v1 approach:
https://lore.kernel.org/bpf/20250905234547.862249-1-yepeilin@google.com/
Fixes: b00628b1c7 ("bpf: Introduce bpf timers.")
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Peilin Ye <yepeilin@google.com>
Link: https://lore.kernel.org/r/20250909095222.2121438-1-yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
OpenWRT users reported regression on ARMv6 devices after updating to latest
HEAD, where tcpdump filter:
tcpdump "not ether host 3c37121a2b3c and not ether host 184ecbca2a3a \
and not ether host 14130b4d3f47 and not ether host f0f61cf440b7 \
and not ether host a84b4dedf471 and not ether host d022be17e1d7 \
and not ether host 5c497967208b and not ether host 706655784d5b"
fails with warning: "Kernel filter failed: No error information"
when using config:
# CONFIG_BPF_JIT_ALWAYS_ON is not set
CONFIG_BPF_JIT_DEFAULT_ON=y
The issue arises because commits:
1. "bpf: Fix array bounds error with may_goto" changed default runtime to
__bpf_prog_ret0_warn when jit_requested = 1
2. "bpf: Avoid __bpf_prog_ret0_warn when jit fails" returns error when
jit_requested = 1 but jit fails
This change restores interpreter fallback capability for BPF programs with
stack size <= 512 bytes when jit fails.
Reported-by: Felix Fietkau <nbd@nbd.name>
Closes: https://lore.kernel.org/bpf/2e267b4b-0540-45d8-9310-e127bf95fc63@nbd.name/
Fixes: 6ebc5030e0 ("bpf: Fix array bounds error with may_goto")
Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250909144614.2991253-1-kafai.wan@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, out of all 3 types of waiters in the rqspinlock slow path
(i.e., pending bit waiter, wait queue head waiter, and wait queue
non-head waiter), only the pending bit waiter and wait queue head
waiters apply deadlock checks and a timeout on their waiting loop. The
assumption here was that the wait queue head's forward progress would be
sufficient to identify cases where the lock owner or pending bit waiter
is stuck, and non-head waiters relying on the head waiter would prove to
be sufficient for their own forward progress.
However, the head waiter itself can be preempted by a non-head waiter
for the same lock (AA) or a different lock (ABBA) in a manner that
impedes its forward progress. In such a case, non-head waiters not
performing deadlock and timeout checks becomes insufficient, and the
system can enter a state of lockup.
This is typically not a concern with non-NMI lock acquisitions, as lock
holders which in run in different contexts (IRQ, non-IRQ) use "irqsave"
variants of the lock APIs, which naturally excludes such lock holders
from preempting one another on the same CPU.
It might seem likely that a similar case may occur for rqspinlock when
programs are attached to contention tracepoints (begin, end), however,
these tracepoints either precede the enqueue into the wait queue, or
succeed it, therefore cannot be used to preempt a head waiter's waiting
loop.
We must still be careful against nested kprobe and fentry programs that
may attach to the middle of the head's waiting loop to stall forward
progress and invoke another rqspinlock acquisition that proceeds as a
non-head waiter. To this end, drop CC_FLAGS_FTRACE from the rqspinlock.o
object file.
For now, this issue is resolved by falling back to a repeated trylock on
the lock word from NMI context, while performing the deadlock checks to
break out early in case forward progress is impossible, and use the
timeout as a final fallback.
A more involved fix to terminate the queue when such a condition occurs
will be made as a follow up. A selftest to stress this aspect of nested
NMI/non-NMI locking attempts will be added in a subsequent patch to the
bpf-next tree when this fix lands and trees are synchronized.
Reported-by: Josef Bacik <josef@toxicpanda.com>
Fixes: 164c246571 ("rqspinlock: Protect waiters in queue from stalls")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250909184959.3509085-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_strnstr() should not treat the ending '\0' of s2 as a matching character
if the parameter 'len' equal to s2 string length, for example:
1. bpf_strnstr("openat", "open", 4) = -ENOENT
2. bpf_strnstr("openat", "open", 5) = 0
This patch makes (1) return 0, fix just the `len == strlen(s2)` case.
And fix a more general case when s2 is a suffix of the first len
characters of s1.
Fixes: e91370550f ("bpf: Add kfuncs for read-only string operations")
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_17DC57B9D16BC443837021BEACE84B7C1507@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stanislav reported that in bpf_crypto_crypt() the destination dynptr's
size is not validated to be at least as large as the source dynptr's
size before calling into the crypto backend with 'len = src_len'. This
can result in an OOB write when the destination is smaller than the
source.
Concretely, in mentioned function, psrc and pdst are both linear
buffers fetched from each dynptr:
psrc = __bpf_dynptr_data(src, src_len);
[...]
pdst = __bpf_dynptr_data_rw(dst, dst_len);
[...]
err = decrypt ?
ctx->type->decrypt(ctx->tfm, psrc, pdst, src_len, piv) :
ctx->type->encrypt(ctx->tfm, psrc, pdst, src_len, piv);
The crypto backend expects pdst to be large enough with a src_len length
that can be written. Add an additional src_len > dst_len check and bail
out if it's the case. Note that these kfuncs are accessible under root
privileges only.
Fixes: 3e1c6f3540 ("bpf: make common crypto API for TC/XDP programs")
Reported-by: Stanislav Fort <disclosure@aisle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://lore.kernel.org/r/20250829143657.318524-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.
This patch adds a new WQ_PERCPU flag to explicitly request the use of
the per-CPU behavior. Both flags coexist for one release cycle to allow
callers to transition their calls.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.
With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.
All existing users have been updated accordingly.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/r/20250905085309.94596-4-marco.crivellari@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
Adding system_dfl_wq to encourage its use when unbound work should be used.
queue_work() / queue_delayed_work() / mod_delayed_work() will now use the
new unbound wq: whether the user still use the old wq a warn will be
printed along with a wq redirect to the new one.
The old system_unbound_wq will be kept for a few release cycles.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/r/20250905085309.94596-3-marco.crivellari@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_wq is a per-CPU worqueue, yet nothing in its name tells about that
CPU affinity constraint, which is very often not required by users. Make
it clear by adding a system_percpu_wq.
queue_work() / queue_delayed_work() mod_delayed_work() will now use the
new per-cpu wq: whether the user still stick on the old name a warn will
be printed along a wq redirect to the new one.
This patch add the new system_percpu_wq except for mm, fs and net
subsystem, whom are handled in separated patches.
The old wq will be kept for a few release cylces.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/r/20250905085309.94596-2-marco.crivellari@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_strcasecmp() function performs same like bpf_strcmp() except ignoring
the case of the characters.
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Viktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/r/tencent_292BD3682A628581AA904996D8E59F4ACD06@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Drop the value-mask decomposition technique and adopt straightforward
long-multiplication with a twist: when LSB(a) is uncertain, find the
two partial products (for LSB(a) = known 0 and LSB(a) = known 1) and
take a union.
Experiment shows that applying this technique in long multiplication
improves the precision in a significant number of cases (at the cost
of losing precision in a relatively lower number of cases).
Signed-off-by: Nandakumar Edamana <nandakumar@nandakumar.co.in>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Reviewed-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20250826034524.2159515-1-nandakumar@nandakumar.co.in
The 'init_nr' argument has double duty: it's used to initialize both the
number of contexts and the number of stack entries. That's confusing
and the callers always pass zero anyway. Hard code the zero.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <Namhyung@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20250820180428.259565081@kernel.org
Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
trampoline.c to obtain better performance when PREEMPT_RCU is not enabled.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250821090609.42508-8-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
bpf_prog_run_array_cg to obtain better performance when PREEMPT_RCU is
not enabled.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250821090609.42508-7-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
bpf_task_storage_free to obtain better performance when PREEMPT_RCU is
not enabled.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250821090609.42508-6-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
bpf_iter_run_prog to obtain better performance when PREEMPT_RCU is
not enabled.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250821090609.42508-5-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
bpf_inode_storage_free to obtain better performance when PREEMPT_RCU is
not enabled.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250821090609.42508-4-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
bpf_cgrp_storage_free to obtain better performance when PREEMPT_RCU is
not enabled.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250821090609.42508-3-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Now BPF program will run with migration disabled, so it is safe
to access this_cpu_inc_return(bpf_bprintf_nest_level).
Fixes: d9c9e4db18 ("bpf: Factorize bpf_trace_printk and bpf_seq_printf")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250819125638.2544715-1-chen.dylane@linux.dev
Now that there's a proper SHA-1 library API, just use that instead of
the low-level SHA-1 compression function. This eliminates the need for
bpf_prog_calc_tag() to implement the SHA-1 padding itself. No
functional change; the computed tags remain the same.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20250811201615.564461-1-ebiggers@kernel.org
In the following toy program (reg states minimized for readability), R0
and R1 always have different values at instruction 6. This is obvious
when reading the program but cannot be guessed from ranges alone as
they overlap (R0 in [0; 0xc0000000], R1 in [1024; 0xc0000400]).
0: call bpf_get_prandom_u32#7 ; R0_w=scalar()
1: w0 = w0 ; R0_w=scalar(var_off=(0x0; 0xffffffff))
2: r0 >>= 30 ; R0_w=scalar(var_off=(0x0; 0x3))
3: r0 <<= 30 ; R0_w=scalar(var_off=(0x0; 0xc0000000))
4: r1 = r0 ; R1_w=scalar(var_off=(0x0; 0xc0000000))
5: r1 += 1024 ; R1_w=scalar(var_off=(0x400; 0xc0000000))
6: if r1 != r0 goto pc+1
Looking at tnums however, we can deduce that R1 is always different from
R0 because their tnums don't agree on known bits. This patch uses this
logic to improve is_scalar_branch_taken in case of BPF_JEQ and BPF_JNE.
This change has a tiny impact on complexity, which was measured with
the Cilium complexity CI test. That test covers 72 programs with
various build and load time configurations for a total of 970 test
cases. For 80% of test cases, the patch has no impact. On the other
test cases, the patch decreases complexity by only 0.08% on average. In
the best case, the verifier needs to walk 3% less instructions and, in
the worst case, 1.5% more. Overall, the patch has a small positive
impact, especially for our largest programs.
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/be3ee70b6e489c49881cb1646114b1d861b5c334.1755694147.git.paul.chaignon@gmail.com
Now that we can create a dynptr to skb metadata, make reads to the metadata
area possible with bpf_dynptr_read() or through a bpf_dynptr_slice(), and
make writes to the metadata area possible with bpf_dynptr_write() or
through a bpf_dynptr_slice_rdwr().
Note that for cloned skbs which share data with the original, we limit the
skb metadata dynptr to be read-only since we don't unclone on a
bpf_dynptr_write to metadata.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250814-skb-metadata-thru-dynptr-v7-2-8a39e636e0fb@cloudflare.com
Add a dynptr type, similar to skb dynptr, but for the skb metadata access.
The dynptr provides an alternative to __sk_buff->data_meta for accessing
the custom metadata area allocated using the bpf_xdp_adjust_meta() helper.
More importantly, it abstracts away the fact where the storage for the
custom metadata lives, which opens up the way to persist the metadata by
relocating it as the skb travels through the network stack layers.
Writes to skb metadata invalidate any existing skb payload and metadata
slices. While this is more restrictive that needed at the moment, it leaves
the door open to reallocating the metadata on writes, and should be only a
minor inconvenience to the users.
Only the program types which can access __sk_buff->data_meta today are
allowed to create a dynptr for skb metadata at the moment. We need to
modify the network stack to persist the metadata across layers before
opening up access to other BPF hooks.
Once more BPF hooks gain access to skb_meta dynptr, we will also need to
add a read-only variant of the helper similar to
bpf_dynptr_from_skb_rdonly.
skb_meta dynptr ops are stubbed out and implemented by subsequent changes.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com>
Link: https://patch.msgid.link/20250814-skb-metadata-thru-dynptr-v7-1-8a39e636e0fb@cloudflare.com
When a BPF program which is being loaded reaches the map limit
(MAX_USED_MAPS) or the BTF limit (MAX_USED_BTFS) the -E2BIG is
returned. However, in the former case there is an accompanying
verifier verbose message, and in the latter case there is not.
Add a verbose message to make the behaviour symmetrical.
Reported-by: Kevin Sheldrake <kevin.sheldrake@isovalent.com>
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20250816151554.902995-1-a.s.protopopov@gmail.com
The get_next_cpu() function was only used in one place to find
the next possible CPU, which can be replaced by cpumask_next_wrap().
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20250818032344.23229-1-wangfushuai@baidu.com
When running an XDP bpf_prog on the remote CPU in cpumap code
then we must disable the direct return optimization that
xdp_return can perform for mem_type page_pool. This optimization
assumes code is still executing under RX-NAPI of the original
receiving CPU, which isn't true on this remote CPU.
The cpumap code already disabled this via helpers
xdp_set_return_frame_no_direct() and xdp_clear_return_frame_no_direct(),
but the scope didn't include xdp_do_flush().
When doing XDP_REDIRECT towards e.g devmap this causes the
function bq_xmit_all() to run with direct return optimization
enabled. This can lead to hard to find bugs. The issue
only happens when bq_xmit_all() cannot ndo_xdp_xmit all
frames and them frees them via xdp_return_frame_rx_napi().
Fix by expanding scope to include xdp_do_flush(). This was found
by Dragos Tatulea.
Fixes: 11941f8a85 ("bpf: cpumap: Implement generic cpumap")
Reported-by: Dragos Tatulea <dtatulea@nvidia.com>
Reported-by: Chris Arges <carges@cloudflare.com>
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Chris Arges <carges@cloudflare.com>
Link: https://patch.msgid.link/175519587755.3008742.1088294435150406835.stgit@firesoul
The 'backedge' pointer is allocated with kzalloc(), which returns
physically contiguous memory. Using kvfree() to deallocate such
memory is functionally safe but semantically incorrect.
Replace kvfree() with kfree() to avoid unnecessary is_vmalloc_addr()
check in kvfree().
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20250811123949.552885-1-rongqianfeng@vivo.com
Commit 16f5dfbc85 ("gfp: include __GFP_NOWARN in GFP_NOWAIT")
made GFP_NOWAIT implicitly include __GFP_NOWARN.
Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT
(e.g., `GFP_NOWAIT | __GFP_NOWARN`) is now redundant. Let's clean
up these redundant flags across subsystems.
No functional changes.
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250804122731.460158-1-rongqianfeng@vivo.com
Avoid excessive vzalloc/vfree calls when patching instructions in
do_misc_fixups(). bpf_patch_insn_data() uses vzalloc to allocate new
memory for env->insn_aux_data for each patch as follows:
struct bpf_prog *bpf_patch_insn_data(env, ...)
{
...
new_data = vzalloc(... O(program size) ...);
...
adjust_insn_aux_data(env, new_data, ...);
...
}
void adjust_insn_aux_data(env, new_data, ...)
{
...
memcpy(new_data, env->insn_aux_data);
vfree(env->insn_aux_data);
env->insn_aux_data = new_data;
...
}
The vzalloc/vfree pair is hot in perf report collected for e.g.
pyperf180 test case. It can be replaced with a call to vrealloc in
order to reduce the number of actual memory allocations.
This is a stop-gap solution, as bpf_patch_insn_data is still hot in
the profile. More comprehansive solutions had been discussed before
e.g. as in [1].
[1] https://lore.kernel.org/bpf/CAEf4BzY_E8MSL4mD0UPuuiDcbJhh9e2xQo2=5w+ppRWWiYSGvQ@mail.gmail.com/
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Tested-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20250807010205.3210608-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Parameter 'env' is not used by is_reg64() and insn_has_def32()
functions. Remove the parameter to make it clear that neither function
depends on 'env' state, e.g. env->insn_aux_data.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250807010205.3210608-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add bpf_struct_ops_id() to enable struct_ops implementors to use
struct_ops map id as the unique id of a struct_ops in their subsystem.
A subsystem that wishes to create a mapping between id and struct_ops
instance pointer can update the mapping accordingly during
bpf_struct_ops::reg(), unreg(), and update().
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250806162540.681679-2-ameryhung@gmail.com
env->scc_info array contains references to bpf_scc_info objects
allocated lazily in verifier.c:scc_visit_alloc().
env->scc_cnt was supposed to track env->scc_info array size
in order to free referenced objects in verifier.c:free_states().
Fix initialization of env->scc_cnt that was omitted in
verifier.c:compute_scc().
To reproduce the bug:
- build with CONFIG_DEBUG_KMEMLEAK
- boot and load bpf program with loops, e.g.:
./veristat -q pyperf180.bpf.o
- initiate memleak scan and check results:
echo scan > /sys/kernel/debug/kmemleak
cat /sys/kernel/debug/kmemleak
Fixes: c9e31900b5 ("bpf: propagate read/precision marks over state graph backedges")
Reported-by: Jens Axboe <axboe@kernel.dk>
Closes: https://lore.kernel.org/bpf/CAADnVQKXUWg9uRCPD5ebRXwN4dmBCRUFFM7kN=GxymYz3zU25A@mail.gmail.com/T/
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250801232330.1800436-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We've already had two "error during ctx access conversion" warnings
triggered by syzkaller. Let's improve the error message by dumping the
cnt variable so that we can more easily differentiate between the
different error cases.
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/cc94316c30dd76fae4a75a664b61a2dbfe68e205.1754039605.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Lonial reported that an out-of-bounds access in cgroup local storage
can be crafted via tail calls. Given two programs each utilizing a
cgroup local storage with a different value size, and one program
doing a tail call into the other. The verifier will validate each of
the indivial programs just fine. However, in the runtime context
the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the
BPF program as well as any cgroup local storage flavor the program
uses. Helpers such as bpf_get_local_storage() pick this up from the
runtime context:
ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
storage = ctx->prog_item->cgroup_storage[stype];
if (stype == BPF_CGROUP_STORAGE_SHARED)
ptr = &READ_ONCE(storage->buf)->data[0];
else
ptr = this_cpu_ptr(storage->percpu_buf);
For the second program which was called from the originally attached
one, this means bpf_get_local_storage() will pick up the former
program's map, not its own. With mismatching sizes, this can result
in an unintended out-of-bounds access.
To fix this issue, we need to extend bpf_map_owner with an array of
storage_cookie[] to match on i) the exact maps from the original
program if the second program was using bpf_get_local_storage(), or
ii) allow the tail call combination if the second program was not
using any of the cgroup local storage maps.
Fixes: 7d9c342789 ("bpf: Make cgroup storages shared between programs on the same cgroup")
Reported-by: Lonial Con <kongln9170@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250730234733.530041-4-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Given this is only relevant for BPF tail call maps, it is adding up space
and penalizing other map types. We also need to extend this with further
objects to track / compare to. Therefore, lets move this out into a separate
structure and dynamically allocate it only for BPF tail call maps.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250730234733.530041-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a cookie to BPF maps to uniquely identify BPF maps for the timespan
when the node is up. This is different to comparing a pointer or BPF map
id which could get rolled over and reused.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250730234733.530041-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Remove usermode driver (UMD) framework (Thomas Weißschuh)
- Introduce Strongly Connected Component (SCC) in the verifier to
detect loops and refine register liveness (Eduard Zingerman)
- Allow 'void *' cast using bpf_rdonly_cast() and corresponding
'__arg_untrusted' for global function parameters (Eduard Zingerman)
- Improve precision for BPF_ADD and BPF_SUB operations in the verifier
(Harishankar Vishwanathan)
- Teach the verifier that constant pointer to a map cannot be NULL
(Ihor Solodrai)
- Introduce BPF streams for error reporting of various conditions
detected by BPF runtime (Kumar Kartikeya Dwivedi)
- Teach the verifier to insert runtime speculation barrier (lfence on
x86) to mitigate speculative execution instead of rejecting the
programs (Luis Gerhorst)
- Various improvements for 'veristat' (Mykyta Yatsenko)
- For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
improve bug detection by syzbot (Paul Chaignon)
- Support BPF private stack on arm64 (Puranjay Mohan)
- Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
node (Song Liu)
- Introduce kfuncs for read-only string opreations (Viktor Malik)
- Implement show_fdinfo() for bpf_links (Tao Chen)
- Reduce verifier's stack consumption (Yonghong Song)
- Implement mprog API for cgroup-bpf programs (Yonghong Song)
* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
bpf: Add log for attaching tracing programs to functions in deny list
bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
bpf: Fix various typos in verifier.c comments
bpf: Add third round of bounds deduction
selftests/bpf: Test invariants on JSLT crossing sign
selftests/bpf: Test cross-sign 64bits range refinement
selftests/bpf: Update reg_bound range refinement logic
bpf: Improve bounds when s64 crosses sign boundary
bpf: Simplify bounds refinement from s32
selftests/bpf: Enable private stack tests for arm64
bpf, arm64: JIT support for private stack
bpf: Move bpf_jit_get_prog_name() to core.c
bpf, arm64: Fix fp initialization for exception boundary
umd: Remove usermode driver framework
bpf/preload: Don't select USERMODE_DRIVER
selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
selftests/bpf: Increase xdp data size for arm64 64K page size
...
Core & protocols
----------------
- Wrap datapath globals into net_aligned_data, to avoid false sharing.
- Preserve MSG_ZEROCOPY in forwarding (e.g. out of a container).
- Add SO_INQ and SCM_INQ support to AF_UNIX.
- Add SIOCINQ support to AF_VSOCK.
- Add TCP_MAXSEG sockopt to MPTCP.
- Add IPv6 force_forwarding sysctl to enable forwarding per interface.
- Make TCP validation of whether packet fully fits in the receive
window and the rcv_buf more strict. With increased use of HW
aggregation a single "packet" can be multiple 100s of kB.
- Add MSG_MORE flag to optimize large TCP transmissions via sockmap,
improves latency up to 33% for sockmap users.
- Convert TCP send queue handling from tasklet to BH workque.
- Improve BPF iteration over TCP sockets to see each socket exactly once.
- Remove obsolete and unused TCP RFC3517/RFC6675 loss recovery code.
- Support enabling kernel threads for NAPI processing on per-NAPI
instance basis rather than a whole device. Fully stop the kernel NAPI
thread when threaded NAPI gets disabled. Previously thread would stick
around until ifdown due to tricky synchronization.
- Allow multicast routing to take effect on locally-generated packets.
- Add output interface argument for End.X in segment routing.
- MCTP: add support for gateway routing, improve bind() handling.
- Don't require rtnl_lock when fetching an IPv6 neighbor over Netlink.
- Add a new neighbor flag ("extern_valid"), which cedes refresh
responsibilities to userspace. This is needed for EVPN multi-homing
where a neighbor entry for a multi-homed host needs to be synced
across all the VTEPs among which the host is multi-homed.
- Support NUD_PERMANENT for proxy neighbor entries.
- Add a new queuing discipline for IETF RFC9332 DualQ Coupled AQM.
- Add sequence numbers to netconsole messages. Unregister netconsole's
console when all net targets are removed. Code refactoring.
Add a number of selftests.
- Align IPSec inbound SA lookup to RFC 4301. Only SPI and protocol
should be used for an inbound SA lookup.
- Support inspecting ref_tracker state via DebugFS.
- Don't force bonding advertisement frames tx to ~333 ms boundaries.
Add broadcast_neighbor option to send ARP/ND on all bonded links.
- Allow providing upcall pid for the 'execute' command in openvswitch.
- Remove DCCP support from Netfilter's conntrack.
- Disallow multiple packet duplications in the queuing layer.
- Prevent use of deprecated iptables code on PREEMPT_RT.
Driver API
----------
- Support RSS and hashing configuration over ethtool Netlink.
- Add dedicated ethtool callbacks for getting and setting hashing fields.
- Add support for power budget evaluation strategy in PSE /
Power-over-Ethernet. Generate Netlink events for overcurrent etc.
- Support DPLL phase offset monitoring across all device inputs.
Support providing clock reference and SYNC over separate DPLL
inputs.
- Support traffic classes in devlink rate API for bandwidth management.
- Remove rtnl_lock dependency from UDP tunnel port configuration.
Device drivers
--------------
- Add a new Broadcom driver for 800G Ethernet (bnge).
- Add a standalone driver for Microchip ZL3073x DPLL.
- Remove IBM's NETIUCV device driver.
- Ethernet high-speed NICs:
- Broadcom (bnxt):
- support zero-copy Tx of DMABUF memory
- take page size into account for page pool recycling rings
- Intel (100G, ice, idpf):
- idpf: XDP and AF_XDP support preparations
- idpf: add flow steering
- add link_down_events statistic
- clean up the TSPLL code
- preparations for live VM migration
- nVidia/Mellanox:
- support zero-copy Rx/Tx interfaces (DMABUF and io_uring)
- optimize context memory usage for matchers
- expose serial numbers in devlink info
- support PCIe congestion metrics
- Meta (fbnic):
- add 25G, 50G, and 100G link modes to phylink
- support dumping FW logs
- Marvell/Cavium:
- support for CN20K generation of the Octeon chips
- Amazon:
- add HW clock (without timestamping, just hypervisor time access)
- Ethernet virtual:
- VirtIO net:
- support segmentation of UDP-tunnel-encapsulated packets
- Google (gve):
- support packet timestamping and clock synchronization
- Microsoft vNIC:
- add handler for device-originated servicing events
- allow dynamic MSI-X vector allocation
- support Tx bandwidth clamping
- Ethernet NICs consumer, and embedded:
- AMD:
- amd-xgbe: hardware timestamping and PTP clock support
- Broadcom integrated MACs (bcmgenet, bcmasp):
- use napi_complete_done() return value to support NAPI polling
- add support for re-starting auto-negotiation
- Broadcom switches (b53):
- support BCM5325 switches
- add bcm63xx EPHY power control
- Synopsys (stmmac):
- lots of code refactoring and cleanups
- TI:
- icssg-prueth: read firmware-names from device tree
- icssg: PRP offload support
- Microchip:
- lan78xx: convert to PHYLINK for improved PHY and MAC management
- ksz: add KSZ8463 switch support
- Intel:
- support similar queue priority scheme in multi-queue and
time-sensitive networking (taprio)
- support packet pre-emption in both
- RealTek (r8169):
- enable EEE at 5Gbps on RTL8126
- Airoha:
- add PPPoE offload support
- MDIO bus controller for Airoha AN7583
- Ethernet PHYs:
- support for the IPQ5018 internal GE PHY
- micrel KSZ9477 switch-integrated PHYs:
- add MDI/MDI-X control support
- add RX error counters
- add cable test support
- add Signal Quality Indicator (SQI) reporting
- dp83tg720: improve reset handling and reduce link recovery time
- support bcm54811 (and its MII-Lite interface type)
- air_en8811h: support resume/suspend
- support PHY counters for QCA807x and QCA808x
- support WoL for QCA807x
- CAN drivers:
- rcar_canfd: support for Transceiver Delay Compensation
- kvaser: report FW versions via devlink dev info
- WiFi:
- extended regulatory info support (6 GHz)
- add statistics and beacon monitor for Multi-Link Operation (MLO)
- support S1G aggregation, improve S1G support
- add Radio Measurement action fields
- support per-radio RTS threshold
- some work around how FIPS affects wifi, which was wrong (RC4 is used
by TKIP, not only WEP)
- improvements for unsolicited probe response handling
- WiFi drivers:
- RealTek (rtw88):
- IBSS mode for SDIO devices
- RealTek (rtw89):
- BT coexistence for MLO/WiFi7
- concurrent station + P2P support
- support for USB devices RTL8851BU/RTL8852BU
- Intel (iwlwifi):
- use embedded PNVM in (to be released) FW images to fix
compatibility issues
- many cleanups (unused FW APIs, PCIe code, WoWLAN)
- some FIPS interoperability
- MediaTek (mt76):
- firmware recovery improvements
- more MLO work
- Qualcomm/Atheros (ath12k):
- fix scan on multi-radio devices
- more EHT/Wi-Fi 7 features
- encapsulation/decapsulation offload
- Broadcom (brcm80211):
- support SDIO 43751 device
- Bluetooth:
- hci_event: add support for handling LE BIG Sync Lost event
- ISO: add socket option to report packet seqnum via CMSG
- ISO: support SCM_TIMESTAMPING for ISO TS
- Bluetooth drivers:
- intel_pcie: support Function Level Reset
- nxpuart: add support for 4M baudrate
- nxpuart: implement powerup sequence, reset, FW dump, and FW loading
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Wrap datapath globals into net_aligned_data, to avoid false sharing
- Preserve MSG_ZEROCOPY in forwarding (e.g. out of a container)
- Add SO_INQ and SCM_INQ support to AF_UNIX
- Add SIOCINQ support to AF_VSOCK
- Add TCP_MAXSEG sockopt to MPTCP
- Add IPv6 force_forwarding sysctl to enable forwarding per interface
- Make TCP validation of whether packet fully fits in the receive
window and the rcv_buf more strict. With increased use of HW
aggregation a single "packet" can be multiple 100s of kB
- Add MSG_MORE flag to optimize large TCP transmissions via sockmap,
improves latency up to 33% for sockmap users
- Convert TCP send queue handling from tasklet to BH workque
- Improve BPF iteration over TCP sockets to see each socket exactly
once
- Remove obsolete and unused TCP RFC3517/RFC6675 loss recovery code
- Support enabling kernel threads for NAPI processing on per-NAPI
instance basis rather than a whole device. Fully stop the kernel
NAPI thread when threaded NAPI gets disabled. Previously thread
would stick around until ifdown due to tricky synchronization
- Allow multicast routing to take effect on locally-generated packets
- Add output interface argument for End.X in segment routing
- MCTP: add support for gateway routing, improve bind() handling
- Don't require rtnl_lock when fetching an IPv6 neighbor over Netlink
- Add a new neighbor flag ("extern_valid"), which cedes refresh
responsibilities to userspace. This is needed for EVPN multi-homing
where a neighbor entry for a multi-homed host needs to be synced
across all the VTEPs among which the host is multi-homed
- Support NUD_PERMANENT for proxy neighbor entries
- Add a new queuing discipline for IETF RFC9332 DualQ Coupled AQM
- Add sequence numbers to netconsole messages. Unregister
netconsole's console when all net targets are removed. Code
refactoring. Add a number of selftests
- Align IPSec inbound SA lookup to RFC 4301. Only SPI and protocol
should be used for an inbound SA lookup
- Support inspecting ref_tracker state via DebugFS
- Don't force bonding advertisement frames tx to ~333 ms boundaries.
Add broadcast_neighbor option to send ARP/ND on all bonded links
- Allow providing upcall pid for the 'execute' command in openvswitch
- Remove DCCP support from Netfilter's conntrack
- Disallow multiple packet duplications in the queuing layer
- Prevent use of deprecated iptables code on PREEMPT_RT
Driver API:
- Support RSS and hashing configuration over ethtool Netlink
- Add dedicated ethtool callbacks for getting and setting hashing
fields
- Add support for power budget evaluation strategy in PSE /
Power-over-Ethernet. Generate Netlink events for overcurrent etc
- Support DPLL phase offset monitoring across all device inputs.
Support providing clock reference and SYNC over separate DPLL
inputs
- Support traffic classes in devlink rate API for bandwidth
management
- Remove rtnl_lock dependency from UDP tunnel port configuration
Device drivers:
- Add a new Broadcom driver for 800G Ethernet (bnge)
- Add a standalone driver for Microchip ZL3073x DPLL
- Remove IBM's NETIUCV device driver
- Ethernet high-speed NICs:
- Broadcom (bnxt):
- support zero-copy Tx of DMABUF memory
- take page size into account for page pool recycling rings
- Intel (100G, ice, idpf):
- idpf: XDP and AF_XDP support preparations
- idpf: add flow steering
- add link_down_events statistic
- clean up the TSPLL code
- preparations for live VM migration
- nVidia/Mellanox:
- support zero-copy Rx/Tx interfaces (DMABUF and io_uring)
- optimize context memory usage for matchers
- expose serial numbers in devlink info
- support PCIe congestion metrics
- Meta (fbnic):
- add 25G, 50G, and 100G link modes to phylink
- support dumping FW logs
- Marvell/Cavium:
- support for CN20K generation of the Octeon chips
- Amazon:
- add HW clock (without timestamping, just hypervisor time access)
- Ethernet virtual:
- VirtIO net:
- support segmentation of UDP-tunnel-encapsulated packets
- Google (gve):
- support packet timestamping and clock synchronization
- Microsoft vNIC:
- add handler for device-originated servicing events
- allow dynamic MSI-X vector allocation
- support Tx bandwidth clamping
- Ethernet NICs consumer, and embedded:
- AMD:
- amd-xgbe: hardware timestamping and PTP clock support
- Broadcom integrated MACs (bcmgenet, bcmasp):
- use napi_complete_done() return value to support NAPI polling
- add support for re-starting auto-negotiation
- Broadcom switches (b53):
- support BCM5325 switches
- add bcm63xx EPHY power control
- Synopsys (stmmac):
- lots of code refactoring and cleanups
- TI:
- icssg-prueth: read firmware-names from device tree
- icssg: PRP offload support
- Microchip:
- lan78xx: convert to PHYLINK for improved PHY and MAC management
- ksz: add KSZ8463 switch support
- Intel:
- support similar queue priority scheme in multi-queue and
time-sensitive networking (taprio)
- support packet pre-emption in both
- RealTek (r8169):
- enable EEE at 5Gbps on RTL8126
- Airoha:
- add PPPoE offload support
- MDIO bus controller for Airoha AN7583
- Ethernet PHYs:
- support for the IPQ5018 internal GE PHY
- micrel KSZ9477 switch-integrated PHYs:
- add MDI/MDI-X control support
- add RX error counters
- add cable test support
- add Signal Quality Indicator (SQI) reporting
- dp83tg720: improve reset handling and reduce link recovery time
- support bcm54811 (and its MII-Lite interface type)
- air_en8811h: support resume/suspend
- support PHY counters for QCA807x and QCA808x
- support WoL for QCA807x
- CAN drivers:
- rcar_canfd: support for Transceiver Delay Compensation
- kvaser: report FW versions via devlink dev info
- WiFi:
- extended regulatory info support (6 GHz)
- add statistics and beacon monitor for Multi-Link Operation (MLO)
- support S1G aggregation, improve S1G support
- add Radio Measurement action fields
- support per-radio RTS threshold
- some work around how FIPS affects wifi, which was wrong (RC4 is
used by TKIP, not only WEP)
- improvements for unsolicited probe response handling
- WiFi drivers:
- RealTek (rtw88):
- IBSS mode for SDIO devices
- RealTek (rtw89):
- BT coexistence for MLO/WiFi7
- concurrent station + P2P support
- support for USB devices RTL8851BU/RTL8852BU
- Intel (iwlwifi):
- use embedded PNVM in (to be released) FW images to fix
compatibility issues
- many cleanups (unused FW APIs, PCIe code, WoWLAN)
- some FIPS interoperability
- MediaTek (mt76):
- firmware recovery improvements
- more MLO work
- Qualcomm/Atheros (ath12k):
- fix scan on multi-radio devices
- more EHT/Wi-Fi 7 features
- encapsulation/decapsulation offload
- Broadcom (brcm80211):
- support SDIO 43751 device
- Bluetooth:
- hci_event: add support for handling LE BIG Sync Lost event
- ISO: add socket option to report packet seqnum via CMSG
- ISO: support SCM_TIMESTAMPING for ISO TS
- Bluetooth drivers:
- intel_pcie: support Function Level Reset
- nxpuart: add support for 4M baudrate
- nxpuart: implement powerup sequence, reset, FW dump, and FW loading"
* tag 'net-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1742 commits)
dpll: zl3073x: Fix build failure
selftests: bpf: fix legacy netfilter options
ipv6: annotate data-races around rt->fib6_nsiblings
ipv6: fix possible infinite loop in fib6_info_uses_dev()
ipv6: prevent infinite loop in rt6_nlmsg_size()
ipv6: add a retry logic in net6_rt_notify()
vrf: Drop existing dst reference in vrf_ip6_input_dst
net/sched: taprio: align entry index attr validation with mqprio
net: fsl_pq_mdio: use dev_err_probe
selftests: rtnetlink.sh: remove esp4_offload after test
vsock: remove unnecessary null check in vsock_getname()
igb: xsk: solve negative overflow of nb_pkts in zerocopy mode
stmmac: xsk: fix negative overflow of budget in zerocopy mode
dt-bindings: ieee802154: Convert at86rf230.txt yaml format
net: dsa: microchip: Disable PTP function of KSZ8463
net: dsa: microchip: Setup fiber ports for KSZ8463
net: dsa: microchip: Write switch MAC address differently for KSZ8463
net: dsa: microchip: Use different registers for KSZ8463
net: dsa: microchip: Add KSZ8463 switch support to KSZ DSA driver
dt-bindings: net: dsa: microchip: Add KSZ8463 switch support
...
- DEBUGFS
- Remove unneeded debugfs_file_{get,put}() instances
- Remove last remnants of debugfs_real_fops()
- Allow storing non-const void * in struct debugfs_inode_info::aux
- SYSFS
- Switch back to attribute_group::bin_attrs (treewide)
- Switch back to bin_attribute::read()/write() (treewide)
- Constify internal references to 'struct bin_attribute'
- Support cache-ids for device-tree systems
- Add arch hook arch_compact_of_hwid()
- Use arch_compact_of_hwid() to compact MPIDR values on arm64
- Rust
- Device
- Introduce CoreInternal device context (for bus internal methods)
- Provide generic drvdata accessors for bus devices
- Provide Driver::unbind() callbacks
- Use the infrastructure above for auxiliary, PCI and platform
- Implement Device::as_bound()
- Rename Device::as_ref() to Device::from_raw() (treewide)
- Implement fwnode and device property abstractions
- Implement example usage in the Rust platform sample driver
- Devres
- Remove the inner reference count (Arc) and use pin-init instead
- Replace Devres::new_foreign_owned() with devres::register()
- Require T to be Send in Devres<T>
- Initialize the data kept inside a Devres last
- Provide an accessor for the Devres associated Device
- Device ID
- Add support for ACPI device IDs and driver match tables
- Split up generic device ID infrastructure
- Use generic device ID infrastructure in net::phy
- DMA
- Implement the dma::Device trait
- Add DMA mask accessors to dma::Device
- Implement dma::Device for PCI and platform devices
- Use DMA masks from the DMA sample module
- I/O
- Implement abstraction for resource regions (struct resource)
- Implement resource-based ioremap() abstractions
- Provide platform device accessors for I/O (remap) requests
- Misc
- Support fallible PinInit types in Revocable
- Implement Wrapper<T> for Opaque<T>
- Merge pin-init blanket dependencies (for Devres)
- Misc
- Fix OF node leak in auxiliary_device_create()
- Use util macros in device property iterators
- Improve kobject sample code
- Add device_link_test() for testing device link flags
- Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
- Hint to prefer container_of_const() over container_of()
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Merge tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
"debugfs:
- Remove unneeded debugfs_file_{get,put}() instances
- Remove last remnants of debugfs_real_fops()
- Allow storing non-const void * in struct debugfs_inode_info::aux
sysfs:
- Switch back to attribute_group::bin_attrs (treewide)
- Switch back to bin_attribute::read()/write() (treewide)
- Constify internal references to 'struct bin_attribute'
Support cache-ids for device-tree systems:
- Add arch hook arch_compact_of_hwid()
- Use arch_compact_of_hwid() to compact MPIDR values on arm64
Rust:
- Device:
- Introduce CoreInternal device context (for bus internal methods)
- Provide generic drvdata accessors for bus devices
- Provide Driver::unbind() callbacks
- Use the infrastructure above for auxiliary, PCI and platform
- Implement Device::as_bound()
- Rename Device::as_ref() to Device::from_raw() (treewide)
- Implement fwnode and device property abstractions
- Implement example usage in the Rust platform sample driver
- Devres:
- Remove the inner reference count (Arc) and use pin-init instead
- Replace Devres::new_foreign_owned() with devres::register()
- Require T to be Send in Devres<T>
- Initialize the data kept inside a Devres last
- Provide an accessor for the Devres associated Device
- Device ID:
- Add support for ACPI device IDs and driver match tables
- Split up generic device ID infrastructure
- Use generic device ID infrastructure in net::phy
- DMA:
- Implement the dma::Device trait
- Add DMA mask accessors to dma::Device
- Implement dma::Device for PCI and platform devices
- Use DMA masks from the DMA sample module
- I/O:
- Implement abstraction for resource regions (struct resource)
- Implement resource-based ioremap() abstractions
- Provide platform device accessors for I/O (remap) requests
- Misc:
- Support fallible PinInit types in Revocable
- Implement Wrapper<T> for Opaque<T>
- Merge pin-init blanket dependencies (for Devres)
Misc:
- Fix OF node leak in auxiliary_device_create()
- Use util macros in device property iterators
- Improve kobject sample code
- Add device_link_test() for testing device link flags
- Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
- Hint to prefer container_of_const() over container_of()"
* tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (84 commits)
rust: io: fix broken intra-doc links to `platform::Device`
rust: io: fix broken intra-doc link to missing `flags` module
rust: io: mem: enable IoRequest doc-tests
rust: platform: add resource accessors
rust: io: mem: add a generic iomem abstraction
rust: io: add resource abstraction
rust: samples: dma: set DMA mask
rust: platform: implement the `dma::Device` trait
rust: pci: implement the `dma::Device` trait
rust: dma: add DMA addressing capabilities
rust: dma: implement `dma::Device` trait
rust: net::phy Change module_phy_driver macro to use module_device_table macro
rust: net::phy represent DeviceId as transparent wrapper over mdio_device_id
rust: device_id: split out index support into a separate trait
device: rust: rename Device::as_ref() to Device::from_raw()
arm64: cacheinfo: Provide helper to compress MPIDR value into u32
cacheinfo: Add arch hook to compress CPU h/w id into 32 bits for cache-id
cacheinfo: Set cache 'id' based on DT data
container_of: Document container_of() is not to be used in new code
driver core: auxiliary bus: fix OF node leak
...
Show the rejected function name when attaching tracing programs to
functions in deny list.
With this change, we know why tracing programs can't attach to functions
like __rcu_read_lock() from log.
$ ./fentry
libbpf: prog '__rcu_read_lock': BPF program load failed: -EINVAL
libbpf: prog '__rcu_read_lock': -- BEGIN PROG LOAD LOG --
Attaching tracing programs to function '__rcu_read_lock' is rejected.
Suggested-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250724151454.499040-3-kafai.wan@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
With this change, we know the precise rejected function name when
attaching fexit/fmod_ret to __noreturn functions from log.
$ ./fexit
libbpf: prog 'fexit': BPF program load failed: -EINVAL
libbpf: prog 'fexit': -- BEGIN PROG LOAD LOG --
Attaching fexit/fmod_ret to __noreturn function 'do_exit' is rejected.
Suggested-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250724151454.499040-2-kafai.wan@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This is the main crypto library pull request for 6.17. The main focus
this cycle is on reorganizing the SHA-1 and SHA-2 code, providing
high-quality library APIs for SHA-1 and SHA-2 including HMAC support,
and establishing conventions for lib/crypto/ going forward:
- Migrate the SHA-1 and SHA-512 code (and also SHA-384 which shares
most of the SHA-512 code) into lib/crypto/. This includes both the
generic and architecture-optimized code. Greatly simplify how the
architecture-optimized code is integrated. Add an easy-to-use
library API for each SHA variant, including HMAC support. Finally,
reimplement the crypto_shash support on top of the library API.
- Apply the same reorganization to the SHA-256 code (and also SHA-224
which shares most of the SHA-256 code). This is a somewhat smaller
change, due to my earlier work on SHA-256. But this brings in all
the same additional improvements that I made for SHA-1 and SHA-512.
There are also some smaller changes:
- Move the architecture-optimized ChaCha, Poly1305, and BLAKE2s code
from arch/$(SRCARCH)/lib/crypto/ to lib/crypto/$(SRCARCH)/. For
these algorithms it's just a move, not a full reorganization yet.
- Fix the MIPS chacha-core.S to build with the clang assembler.
- Fix the Poly1305 functions to work in all contexts.
- Fix a performance regression in the x86_64 Poly1305 code.
- Clean up the x86_64 SHA-NI optimized SHA-1 assembly code.
Note that since the new organization of the SHA code is much simpler,
the diffstat of this pull request is negative, despite the addition of
new fully-documented library APIs for multiple SHA and HMAC-SHA
variants. These APIs will allow further simplifications across the
kernel as users start using them instead of the old-school crypto API.
(I've already written a lot of such conversion patches, removing over
1000 more lines of code. But most of those will target 6.18 or later.)
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Merge tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux
Pull crypto library updates from Eric Biggers:
"This is the main crypto library pull request for 6.17. The main focus
this cycle is on reorganizing the SHA-1 and SHA-2 code, providing
high-quality library APIs for SHA-1 and SHA-2 including HMAC support,
and establishing conventions for lib/crypto/ going forward:
- Migrate the SHA-1 and SHA-512 code (and also SHA-384 which shares
most of the SHA-512 code) into lib/crypto/. This includes both the
generic and architecture-optimized code. Greatly simplify how the
architecture-optimized code is integrated. Add an easy-to-use
library API for each SHA variant, including HMAC support. Finally,
reimplement the crypto_shash support on top of the library API.
- Apply the same reorganization to the SHA-256 code (and also SHA-224
which shares most of the SHA-256 code). This is a somewhat smaller
change, due to my earlier work on SHA-256. But this brings in all
the same additional improvements that I made for SHA-1 and SHA-512.
There are also some smaller changes:
- Move the architecture-optimized ChaCha, Poly1305, and BLAKE2s code
from arch/$(SRCARCH)/lib/crypto/ to lib/crypto/$(SRCARCH)/. For
these algorithms it's just a move, not a full reorganization yet.
- Fix the MIPS chacha-core.S to build with the clang assembler.
- Fix the Poly1305 functions to work in all contexts.
- Fix a performance regression in the x86_64 Poly1305 code.
- Clean up the x86_64 SHA-NI optimized SHA-1 assembly code.
Note that since the new organization of the SHA code is much simpler,
the diffstat of this pull request is negative, despite the addition of
new fully-documented library APIs for multiple SHA and HMAC-SHA
variants.
These APIs will allow further simplifications across the kernel as
users start using them instead of the old-school crypto API. (I've
already written a lot of such conversion patches, removing over 1000
more lines of code. But most of those will target 6.18 or later)"
* tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (67 commits)
lib/crypto: arm64/sha512-ce: Drop compatibility macros for older binutils
lib/crypto: x86/sha1-ni: Convert to use rounds macros
lib/crypto: x86/sha1-ni: Minor optimizations and cleanup
crypto: sha1 - Remove sha1_base.h
lib/crypto: x86/sha1: Migrate optimized code into library
lib/crypto: sparc/sha1: Migrate optimized code into library
lib/crypto: s390/sha1: Migrate optimized code into library
lib/crypto: powerpc/sha1: Migrate optimized code into library
lib/crypto: mips/sha1: Migrate optimized code into library
lib/crypto: arm64/sha1: Migrate optimized code into library
lib/crypto: arm/sha1: Migrate optimized code into library
crypto: sha1 - Use same state format as legacy drivers
crypto: sha1 - Wrap library and add HMAC support
lib/crypto: sha1: Add HMAC support
lib/crypto: sha1: Add SHA-1 library functions
lib/crypto: sha1: Rename sha1_init() to sha1_init_raw()
crypto: x86/sha1 - Rename conflicting symbol
lib/crypto: sha2: Add hmac_sha*_init_usingrawkey()
lib/crypto: arm/poly1305: Remove unneeded empty weak function
lib/crypto: x86/poly1305: Fix performance regression on short messages
...
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Merge tag 'vfs-6.17-rc1.bpf' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs bpf updates from Christian Brauner:
"These changes allow bpf to read extended attributes from cgroupfs.
This is useful in redirecting AF_UNIX socket connections based on
cgroup membership of the socket. One use-case is the ability to
implement log namespaces in systemd so services and containers are
redirected to different journals"
* tag 'vfs-6.17-rc1.bpf' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
selftests/kernfs: test xattr retrieval
selftests/bpf: Add tests for bpf_cgroup_read_xattr
bpf: Mark cgroup_subsys_state->cgroup RCU safe
bpf: Introduce bpf_cgroup_read_xattr to read xattr of cgroup's node
kernfs: remove iattr_mutex
Commit d7f0087381 ("bpf: try harder to deduce register bounds from
different numeric domains") added a second call to __reg_deduce_bounds
in reg_bounds_sync because a single call wasn't enough to converge to a
fixed point in terms of register bounds.
With patch "bpf: Improve bounds when s64 crosses sign boundary" from
this series, Eduard noticed that calling __reg_deduce_bounds twice isn't
enough anymore to converge. The first selftest added in "selftests/bpf:
Test cross-sign 64bits range refinement" highlights the need for a third
call to __reg_deduce_bounds. After instruction 7, reg_bounds_sync
performs the following bounds deduction:
reg_bounds_sync entry: scalar(smin=-655,smax=0xeffffeee,smin32=-783,smax32=-146)
__update_reg_bounds: scalar(smin=-655,smax=0xeffffeee,smin32=-783,smax32=-146)
__reg_deduce_bounds:
__reg32_deduce_bounds: scalar(smin=-655,smax=0xeffffeee,smin32=-783,smax32=-146,umin32=0xfffffcf1,umax32=0xffffff6e)
__reg64_deduce_bounds: scalar(smin=-655,smax=0xeffffeee,smin32=-783,smax32=-146,umin32=0xfffffcf1,umax32=0xffffff6e)
__reg_deduce_mixed_bounds: scalar(smin=-655,smax=0xeffffeee,umin=umin32=0xfffffcf1,umax=0xffffffffffffff6e,smin32=-783,smax32=-146,umax32=0xffffff6e)
__reg_deduce_bounds:
__reg32_deduce_bounds: scalar(smin=-655,smax=0xeffffeee,umin=umin32=0xfffffcf1,umax=0xffffffffffffff6e,smin32=-783,smax32=-146,umax32=0xffffff6e)
__reg64_deduce_bounds: scalar(smin=-655,smax=smax32=-146,umin=0xfffffffffffffd71,umax=0xffffffffffffff6e,smin32=-783,umin32=0xfffffcf1,umax32=0xffffff6e)
__reg_deduce_mixed_bounds: scalar(smin=-655,smax=smax32=-146,umin=0xfffffffffffffd71,umax=0xffffffffffffff6e,smin32=-783,umin32=0xfffffcf1,umax32=0xffffff6e)
__reg_bound_offset: scalar(smin=-655,smax=smax32=-146,umin=0xfffffffffffffd71,umax=0xffffffffffffff6e,smin32=-783,umin32=0xfffffcf1,umax32=0xffffff6e,var_off=(0xfffffffffffffc00; 0x3ff))
__update_reg_bounds: scalar(smin=-655,smax=smax32=-146,umin=0xfffffffffffffd71,umax=0xffffffffffffff6e,smin32=-783,umin32=0xfffffcf1,umax32=0xffffff6e,var_off=(0xfffffffffffffc00; 0x3ff))
In particular, notice how:
1. In the first call to __reg_deduce_bounds, __reg32_deduce_bounds
learns new u32 bounds.
2. __reg64_deduce_bounds is unable to improve bounds at this point.
3. __reg_deduce_mixed_bounds derives new u64 bounds from the u32 bounds.
4. In the second call to __reg_deduce_bounds, __reg64_deduce_bounds
improves the smax and umin bounds thanks to patch "bpf: Improve
bounds when s64 crosses sign boundary" from this series.
5. Subsequent functions are unable to improve the ranges further (only
tnums). Yet, a better smin32 bound could be learned from the smin
bound.
__reg32_deduce_bounds is able to improve smin32 from smin, but for that
we need a third call to __reg_deduce_bounds.
As discussed in [1], there may be a better way to organize the deduction
rules to learn the same information with less calls to the same
functions. Such an optimization requires further analysis and is
orthogonal to the present patchset.
Link: https://lore.kernel.org/bpf/aIKtSK9LjQXB8FLY@mail.gmail.com/ [1]
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Co-developed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/79619d3b42e5525e0e174ed534b75879a5ba15de.1753695655.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
__reg64_deduce_bounds currently improves the s64 range using the u64
range and vice versa, but only if it doesn't cross the sign boundary.
This patch improves __reg64_deduce_bounds to cover the case where the
s64 range crosses the sign boundary but overlaps with the u64 range on
only one end. In that case, we can improve both ranges. Consider the
following example, with the s64 range crossing the sign boundary:
0 U64_MAX
| [xxxxxxxxxxxxxx u64 range xxxxxxxxxxxxxx] |
|----------------------------|----------------------------|
|xxxxx s64 range xxxxxxxxx] [xxxxxxx|
0 S64_MAX S64_MIN -1
The u64 range overlaps only with positive portion of the s64 range. We
can thus derive the following new s64 and u64 ranges.
0 U64_MAX
| [xxxxxx u64 range xxxxx] |
|----------------------------|----------------------------|
| [xxxxxx s64 range xxxxx] |
0 S64_MAX S64_MIN -1
The same logic can probably apply to the s32/u32 ranges, but this patch
doesn't implement that change.
In addition to the selftests, the __reg64_deduce_bounds change was
also tested with Agni, the formal verification tool for the range
analysis [1].
Link: https://github.com/bpfverif/agni [1]
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/933bd9ce1f36ded5559f92fdc09e5dbc823fa245.1753695655.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
During the bounds refinement, we improve the precision of various ranges
by looking at other ranges. Among others, we improve the following in
this order (other things happen between 1 and 2):
1. Improve u32 from s32 in __reg32_deduce_bounds.
2. Improve s/u64 from u32 in __reg_deduce_mixed_bounds.
3. Improve s/u64 from s32 in __reg_deduce_mixed_bounds.
In particular, if the s32 range forms a valid u32 range, we will use it
to improve the u32 range in __reg32_deduce_bounds. In
__reg_deduce_mixed_bounds, under the same condition, we will use the s32
range to improve the s/u64 ranges.
If at (1) we were able to learn from s32 to improve u32, we'll then be
able to use that in (2) to improve s/u64. Hence, as (3) happens under
the same precondition as (1), it won't improve s/u64 ranges further than
(1)+(2) did. Thus, we can get rid of (3).
In addition to the extensive suite of selftests for bounds refinement,
this patch was also tested with the Agni formal verification tool [1].
Additionally, Eduard mentioned:
The argument appears to be as follows:
Under precondition `(u32)reg->s32_min <= (u32)reg->s32_max`
__reg32_deduce_bounds produces:
reg->u32_min = max_t(u32, reg->s32_min, reg->u32_min);
reg->u32_max = min_t(u32, reg->s32_max, reg->u32_max);
And then first part of __reg_deduce_mixed_bounds assigns:
a. reg->umin umax= (reg->umin & ~0xffffffffULL) | max_t(u32, reg->s32_min, reg->u32_min);
b. reg->umax umin= (reg->umax & ~0xffffffffULL) | min_t(u32, reg->s32_max, reg->u32_max);
And then second part of __reg_deduce_mixed_bounds assigns:
c. reg->umin umax= (reg->umin & ~0xffffffffULL) | (u32)reg->s32_min;
d. reg->umax umin= (reg->umax & ~0xffffffffULL) | (u32)reg->s32_max;
But assignment (c) is a noop because:
max_t(u32, reg->s32_min, reg->u32_min) >= (u32)reg->s32_min
Hence RHS(a) >= RHS(c) and umin= does nothing.
Also assignment (d) is a noop because:
min_t(u32, reg->s32_max, reg->u32_max) <= (u32)reg->s32_max
Hence RHS(b) <= RHS(d) and umin= does nothing.
Plus the same reasoning for the part dealing with reg->s{min,max}_value:
e. reg->smin_value smax= (reg->smin_value & ~0xffffffffULL) | max_t(u32, reg->s32_min_value, reg->u32_min_value);
f. reg->smax_value smin= (reg->smax_value & ~0xffffffffULL) | min_t(u32, reg->s32_max_value, reg->u32_max_value);
vs
g. reg->smin_value smax= (reg->smin_value & ~0xffffffffULL) | (u32)reg->s32_min_value;
h. reg->smax_value smin= (reg->smax_value & ~0xffffffffULL) | (u32)reg->s32_max_value;
RHS(e) >= RHS(g) and RHS(f) <= RHS(h), hence smax=,smin= do nothing.
This appears to be correct.
Also, Shung-Hsi:
Beside going through the reasoning, I also played with CBMC a bit to
double check that as far as a single run of __reg_deduce_bounds() is
concerned (and that the register state matches certain handwavy
expectations), the change indeed still preserve the original behavior.
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://github.com/bpfverif/agni [1]
Link: https://lore.kernel.org/bpf/aIJwnFnFyUjNsCNa@mail.gmail.com
bpf_jit_get_prog_name() will be used by all JITs when enabling support
for private stack. This function is currently implemented in the x86
JIT.
Move the function to core.c so that other JITs can easily use it in
their implementation of private stack.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250724120257.7299-2-puranjay@kernel.org
The code is unused since 98e20e5e13 ("bpfilter: remove bpfilter"),
therefore remove it.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/bpf/20250721-remove-usermode-driver-v1-2-0d0083334382@linutronix.de
The usermode driver framework is not used anymore by the BPF
preload code.
Fixes: cb80ddc671 ("bpf: Convert bpf_preload.ko to use light skeleton.")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20250721-remove-usermode-driver-v1-1-0d0083334382@linutronix.de
Move multiple copies of same code snippet doing `gro_flush` and
`gro_normal_list` into separate helper function.
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250723013031.2911384-2-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Martin KaFai Lau says:
====================
pull-request: bpf-next 2025-07-24
We've added 3 non-merge commits during the last 3 day(s) which contain
a total of 4 files changed, 40 insertions(+), 15 deletions(-).
The main changes are:
1) Improved verifier error message for incorrect narrower load from
pointer field in ctx, from Paul Chaignon.
2) Disabled migration in nf_hook_run_bpf to address a syzbot report,
from Kuniyuki Iwashima.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
selftests/bpf: Test invalid narrower ctx load
bpf: Reject narrower access to pointer ctx fields
bpf: Disable migration in nf_hook_run_bpf().
====================
Link: https://patch.msgid.link/20250724173306.3578483-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The following BPF program, simplified from a syzkaller repro, causes a
kernel warning:
r0 = *(u8 *)(r1 + 169);
exit;
With pointer field sk being at offset 168 in __sk_buff. This access is
detected as a narrower read in bpf_skb_is_valid_access because it
doesn't match offsetof(struct __sk_buff, sk). It is therefore allowed
and later proceeds to bpf_convert_ctx_access. Note that for the
"is_narrower_load" case in the convert_ctx_accesses(), the insn->off
is aligned, so the cnt may not be 0 because it matches the
offsetof(struct __sk_buff, sk) in the bpf_convert_ctx_access. However,
the target_size stays 0 and the verifier errors with a kernel warning:
verifier bug: error during ctx access conversion(1)
This patch fixes that to return a proper "invalid bpf_context access
off=X size=Y" error on the load instruction.
The same issue affects multiple other fields in context structures that
allow narrow access. Some other non-affected fields (for sk_msg,
sk_lookup, and sockopt) were also changed to use bpf_ctx_range_ptr for
consistency.
Note this syzkaller crash was reported in the "Closes" link below, which
used to be about a different bug, fixed in
commit fce7bd8e38 ("bpf/verifier: Handle BPF_LOAD_ACQ instructions
in insn_def_regno()"). Because syzbot somehow confused the two bugs,
the new crash and repro didn't get reported to the mailing list.
Fixes: f96da09473 ("bpf: simplify narrower ctx access")
Fixes: 0df1a55afa ("bpf: Warn on internal verifier errors")
Reported-by: syzbot+0ef84a7bdf5301d4cbec@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0ef84a7bdf5301d4cbec
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/3b8dcee67ff4296903351a974ddd9c4dca768b64.1753194596.git.paul.chaignon@gmail.com
Intel linux test robot reported a warning that ERR_CAST can be used
for error pointer casting instead of more-complicated/rarely-used
ERR_PTR(PTR_ERR(...)) style.
There is no functionality change, but still let us replace two such
instances as it improves consistency and readability.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507201048.bceHy8zX-lkp@intel.com/
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20250720164754.3999140-1-yonghong.song@linux.dev
The 'commit 35f96de041 ("bpf: Introduce BPF token object")' added
BPF token as a new kind of BPF kernel object. And BPF_OBJ_GET_INFO_BY_FD
already used to get BPF object info, so we can also get token info with
this cmd.
One usage scenario, when program runs failed with token, because of
the permission failure, we can report what BPF token is allowing with
this API for debugging.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Link: https://lore.kernel.org/r/20250716134654.1162635-1-chen.dylane@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The last iterators update (commit 515ee52b22 ("bpf: make preloaded
map iterators to display map elements count")) missed the big-endian
skeleton. Update it by running "make big" with Debian clang version
21.0.0 (++20250706105601+01c97b4953e8-1~exp1~20250706225612.1558).
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20250710100907.45880-1-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Rename the existing sha1_init() to sha1_init_raw(), since it conflicts
with the upcoming library function. This will later be removed, but
this keeps the kernel building for the introduction of the library.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250712232329.818226-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Use attach_type in bpf_link, and remove it in bpf_netns_link.
And move netns_type field to the end to fill the byte hole.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20250710032038.888700-6-chen.dylane@linux.dev
Use attach_type in bpf_link to replace the location filed, and
remove location field in tcx_link.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20250710032038.888700-5-chen.dylane@linux.dev
Use attach_type in bpf_link, and remove it in bpf_cgroup_link.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250710032038.888700-3-chen.dylane@linux.dev
Attach_type will be set when a link is created by user. It is better to
record attach_type in bpf_link generically and have it available
universally for all link types. So add the attach_type field in bpf_link
and move the sleepable field to avoid unnecessary gap padding.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250710032038.888700-2-chen.dylane@linux.dev
Syzbot reported a kernel warning due to a range invariant violation on
the following BPF program.
0: call bpf_get_netns_cookie
1: if r0 == 0 goto <exit>
2: if r0 & Oxffffffff goto <exit>
The issue is on the path where we fall through both jumps.
That path is unreachable at runtime: after insn 1, we know r0 != 0, but
with the sign extension on the jset, we would only fallthrough insn 2
if r0 == 0. Unfortunately, is_branch_taken() isn't currently able to
figure this out, so the verifier walks all branches. The verifier then
refines the register bounds using the second condition and we end
up with inconsistent bounds on this unreachable path:
1: if r0 == 0 goto <exit>
r0: u64=[0x1, 0xffffffffffffffff] var_off=(0, 0xffffffffffffffff)
2: if r0 & 0xffffffff goto <exit>
r0 before reg_bounds_sync: u64=[0x1, 0xffffffffffffffff] var_off=(0, 0)
r0 after reg_bounds_sync: u64=[0x1, 0] var_off=(0, 0)
Improving the range refinement for JSET to cover all cases is tricky. We
also don't expect many users to rely on JSET given LLVM doesn't generate
those instructions. So instead of improving the range refinement for
JSETs, Eduard suggested we forget the ranges whenever we're narrowing
tnums after a JSET. This patch implements that approach.
Reported-by: syzbot+c711ce17dd78e5d4fdcf@syzkaller.appspotmail.com
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/9d4fd6432a095d281f815770608fdcd16028ce0b.1752171365.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a new BPF arena kfunc for reserving a range of arena virtual
addresses without backing them with pages. This prevents the range from
being populated using bpf_arena_alloc_pages().
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250709191312.29840-2-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We must terminate the speculative analysis if the just-analyzed insn had
nospec_result set. Using cur_aux() here is wrong because insn_idx might
have been incremented by do_check_insn(). Therefore, introduce and use
insn_aux variable.
Also change cur_aux(env)->nospec in case do_check_insn() ever manages to
increment insn_idx but still fail.
Change the warning to check the insn class (which prevents it from
triggering for ldimm64, for which nospec_result would not be
problematic) and use verifier_bug_if().
In line with Eduard's suggestion, do not introduce prev_aux() because
that requires one to understand that after do_check_insn() call what was
current became previous. This would at-least require a comment.
Fixes: d6f1c85f22 ("bpf: Fall back to nospec for Spectre v1")
Reported-by: Paul Chaignon <paul.chaignon@gmail.com>
Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Reported-by: syzbot+dc27c5fb8388e38d2d37@syzkaller.appspotmail.com
Link: https://lore.kernel.org/bpf/685b3c1b.050a0220.2303ee.0010.GAE@google.com/
Link: https://lore.kernel.org/bpf/4266fd5de04092aa4971cbef14f1b4b96961f432.camel@gmail.com/
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250705190908.1756862-2-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
On 32-bit platforms, we'll try to convert a u64 directly to a pointer
type which is 32-bit, which causes the compiler to complain about cast
from an integer of a different size to a pointer type. Cast to long
before casting to the pointer type to match the pointer width.
Reported-by: kernelci.org bot <bot@kernelci.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: d7c431cafc ("bpf: Add dump_stack() analogue to print to BPF stderr")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20250705053035.3020320-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We may overrun the bounds because linfo and jited_linfo are already
advanced to prog->aux->linfo_idx, hence we must only iterate the
remaining elements until we reach prog->aux->nr_linfo. Adjust the
nr_linfo calculation to fix this. Reported in [0].
[0]: https://lore.kernel.org/bpf/f3527af3b0620ce36e299e97e7532d2555018de2.camel@gmail.com
Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Fixes: 0e521efaf3 ("bpf: Add function to extract program source info")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250705053035.3020320-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow specifying __arg_untrusted for void */char */int */long *
parameters. Treat such parameters as
PTR_TO_MEM|MEM_RDONLY|PTR_UNTRUSTED of size zero.
Intended usage is as follows:
int memcmp(char *a __arg_untrusted, char *b __arg_untrusted, size_t n) {
bpf_for(i, 0, n) {
if (a[i] - b[i]) // load at any offset is allowed
return a[i] - b[i];
}
return 0;
}
Allocate register id for ARG_PTR_TO_MEM parameters only when
PTR_MAYBE_NULL is set. Register id for PTR_TO_MEM is used only to
propagate non-null status after conditionals.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250704230354.1323244-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for PTR_TO_BTF_ID | PTR_UNTRUSTED global function
parameters. Anything is allowed to pass to such parameters, as these
are read-only and probe read instructions would protect against
invalid memory access.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250704230354.1323244-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When processing a load from a PTR_TO_BTF_ID, the verifier calculates
the type of the loaded structure field based on the load offset.
For example, given the following types:
struct foo {
struct foo *a;
int *b;
} *p;
The verifier would calculate the type of `p->a` as a pointer to
`struct foo`. However, the type of `p->b` is currently calculated as a
SCALAR_VALUE.
This commit updates the logic for processing PTR_TO_BTF_ID to instead
calculate the type of p->b as PTR_TO_MEM|MEM_RDONLY|PTR_UNTRUSTED.
This change allows further dereferencing of such pointers (using probe
memory instructions).
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250704230354.1323244-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Non-functional change:
mark_btf_ld_reg() expects 'reg_type' parameter to be either
SCALAR_VALUE or PTR_TO_BTF_ID. Next commit expands this set, so update
this function to fail if unexpected type is passed. Also update
callers to propagate the error.
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250704230354.1323244-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a 'struct bpf_scc_callchain callchain_buf' field in bpf_verifier_env.
This way, the previous bpf_scc_callchain local variables can be
replaced by taking address of env->callchain_buf. This can reduce stack
usage and fix the following error:
kernel/bpf/verifier.c:19921:12: error: stack frame size (1368) exceeds limit (1280) in 'do_check'
[-Werror,-Wframe-larger-than]
Reported-by: Arnd Bergmann <arnd@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250703141117.1485108-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Arnd Bergmann reported an issue ([1]) where clang compiler (less than
llvm18) may trigger an error where the stack frame size exceeds the limit.
I can reproduce the error like below:
kernel/bpf/verifier.c:24491:5: error: stack frame size (2552) exceeds limit (1280) in 'bpf_check'
[-Werror,-Wframe-larger-than]
kernel/bpf/verifier.c:19921:12: error: stack frame size (1368) exceeds limit (1280) in 'do_check'
[-Werror,-Wframe-larger-than]
Use env->insn_buf for bpf insns instead of putting these insns on the
stack. This can resolve the above 'bpf_check' error. The 'do_check' error
will be resolved in the next patch.
[1] https://lore.kernel.org/bpf/20250620113846.3950478-1-arnd@kernel.org/
Reported-by: Arnd Bergmann <arnd@kernel.org>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250703141111.1484521-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In verifier.c, the following code patterns (in two places)
struct bpf_insn *patch = &insn_buf[0];
can be simplified to
struct bpf_insn *patch = insn_buf;
which is easier to understand.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250703141106.1483216-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Before handling the tail call in record_func_key(), we check that the
map is of the expected type and log a verifier error if it isn't. Such
an error however doesn't indicate anything wrong with the verifier. The
check for map<>func compatibility is done after record_func_key(), by
check_map_func_compatibility().
Therefore, this patch logs the error as a typical reject instead of a
verifier error.
Fixes: d2e4c1e6c2 ("bpf: Constant map key tracking for prog array pokes")
Fixes: 0df1a55afa ("bpf: Warn on internal verifier errors")
Reported-by: syzbot+efb099d5833bca355e51@syzkaller.appspotmail.com
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/1f395b74e73022e47e04a31735f258babf305420.1751578055.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce a kernel function which is the analogue of dump_stack()
printing some useful information and the stack trace. This is not
exposed to BPF programs yet, but can be made available in the future.
When we have a program counter for a BPF program in the stack trace,
also additionally output the filename and line number to make the trace
helpful. The rest of the trace can be passed into ./decode_stacktrace.sh
to obtain the line numbers for kernel symbols.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In preparation of figuring out the closest program that led to the
current point in the kernel, implement a function that scans through the
stack trace and finds out the closest BPF program when walking down the
stack trace.
Special care needs to be taken to skip over kernel and BPF subprog
frames. We basically scan until we find a BPF main prog frame. The
assumption is that if a program calls into us transitively, we'll
hit it along the way. If not, we end up returning NULL.
Contextually the function will be used in places where we know the
program may have called into us.
Due to reliance on arch_bpf_stack_walk(), this function only works on
x86 with CONFIG_UNWINDER_ORC, arm64, and s390. Remove the warning from
arch_bpf_stack_walk as well since we call it outside bpf_throw()
context.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a warning to ensure RCU lock is held around tree lookup, and then
fix one of the invocations in bpf_stack_walker. The program has an
active stack frame and won't disappear. Use the opportunity to remove
unneeded invocation of is_bpf_text_address.
Fixes: f18b03faba ("bpf: Implement BPF exceptions")
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Prepare a function for use in future patches that can extract the file
info, line info, and the source line number for a given BPF program
provided it's program counter.
Only the basename of the file path is provided, given it can be
excessively long in some cases.
This will be used in later patches to print source info to the BPF
stream.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for a stream API to the kernel and expose related kfuncs to
BPF programs. Two streams are exposed, BPF_STDOUT and BPF_STDERR. These
can be used for printing messages that can be consumed from user space,
thus it's similar in spirit to existing trace_pipe interface.
The kernel will use the BPF_STDERR stream to notify the program of any
errors encountered at runtime. BPF programs themselves may use both
streams for writing debug messages. BPF library-like code may use
BPF_STDERR to print warnings or errors on misuse at runtime.
The implementation of a stream is as follows. Everytime a message is
emitted from the kernel (directly, or through a BPF program), a record
is allocated by bump allocating from per-cpu region backed by a page
obtained using alloc_pages_nolock(). This ensures that we can allocate
memory from any context. The eventual plan is to discard this scheme in
favor of Alexei's kmalloc_nolock() [0].
This record is then locklessly inserted into a list (llist_add()) so
that the printing side doesn't require holding any locks, and works in
any context. Each stream has a maximum capacity of 4MB of text, and each
printed message is accounted against this limit.
Messages from a program are emitted using the bpf_stream_vprintk kfunc,
which takes a stream_id argument in addition to working otherwise
similar to bpf_trace_vprintk.
The bprintf buffer helpers are extracted out to be reused for printing
the string into them before copying it into the stream, so that we can
(with the defined max limit) format a string and know its true length
before performing allocations of the stream element.
For consuming elements from a stream, we expose a bpf(2) syscall command
named BPF_PROG_STREAM_READ_BY_FD, which allows reading data from the
stream of a given prog_fd into a user space buffer. The main logic is
implemented in bpf_stream_read(). The log messages are queued in
bpf_stream::log by the bpf_stream_vprintk kfunc, and then pulled and
ordered correctly in the stream backlog.
For this purpose, we hold a lock around bpf_stream_backlog_peek(), as
llist_del_first() (if we maintained a second lockless list for the
backlog) wouldn't be safe from multiple threads anyway. Then, if we
fail to find something in the backlog log, we splice out everything from
the lockless log, and place it in the backlog log, and then return the
head of the backlog. Once the full length of the element is consumed, we
will pop it and free it.
The lockless list bpf_stream::log is a LIFO stack. Elements obtained
using a llist_del_all() operation are in LIFO order, thus would break
the chronological ordering if printed directly. Hence, this batch of
messages is first reversed. Then, it is stashed into a separate list in
the stream, i.e. the backlog_log. The head of this list is the actual
message that should always be returned to the caller. All of this is
done in bpf_stream_backlog_fill().
From the kernel side, the writing into the stream will be a bit more
involved than the typical printk. First, the kernel typically may print
a collection of messages into the stream, and parallel writers into the
stream may suffer from interleaving of messages. To ensure each group of
messages is visible atomically, we can lift the advantage of using a
lockless list for pushing in messages.
To enable this, we add a bpf_stream_stage() macro, and require kernel
users to use bpf_stream_printk statements for the passed expression to
write into the stream. Underneath the macro, we have a message staging
API, where a bpf_stream_stage object on the stack accumulates the
messages being printed into a local llist_head, and then a commit
operation splices the whole batch into the stream's lockless log list.
This is especially pertinent for rqspinlock deadlock messages printed to
program streams. After this change, we see each deadlock invocation as a
non-interleaving contiguous message without any confusion on the
reader's part, improving their user experience in debugging the fault.
While programs cannot benefit from this staged stream writing API, they
could just as well hold an rqspinlock around their print statements to
serialize messages, hence this is kept kernel-internal for now.
Overall, this infrastructure provides NMI-safe any context printing of
messages to two dedicated streams.
Later patches will add support for printing splats in case of BPF arena
page faults, rqspinlock deadlocks, and cond_break timeouts, and
integration of this facility into bpftool for dumping messages to user
space.
[0]: https://lore.kernel.org/bpf/20250501032718.65476-1-alexei.starovoitov@gmail.com
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Refactor code to be able to get and put bprintf buffers and use
bpf_printf_prepare independently. This will be used in the next patch to
implement BPF streams support, particularly as a staging buffer for
strings that need to be formatted and then allocated and pushed into a
stream.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Alexei suggested, 'link_type' can be more precise and differentiate
for human in fdinfo. In fact BPF_LINK_TYPE_KPROBE_MULTI includes
kretprobe_multi type, the same as BPF_LINK_TYPE_UPROBE_MULTI, so we
can show it more concretely.
link_type: kprobe_multi
link_id: 1
prog_tag: d2b307e915f0dd37
...
link_type: kretprobe_multi
link_id: 2
prog_tag: ab9ea0545870781d
...
link_type: uprobe_multi
link_id: 9
prog_tag: e729f789e34a8eca
...
link_type: uretprobe_multi
link_id: 10
prog_tag: 7db356c03e61a4d4
Co-developed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Link: https://lore.kernel.org/r/20250702153958.639852-1-chen.dylane@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently there is no straightforward way to fill dynptr memory with a
value (most commonly zero). One can do it with bpf_dynptr_write(), but
a temporary buffer is necessary for that.
Implement bpf_dynptr_memset() - an analogue of memset() from libc.
Signed-off-by: Ihor Solodrai <isolodrai@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250702210309.3115903-2-isolodrai@meta.com
The description of full helper calls in syzkaller [1] and the addition of
kernel warnings in commit 0df1a55afa ("bpf: Warn on internal verifier
errors") allowed syzbot to reach a verifier state that was thought to
indicate a verifier bug [2]:
12: (85) call bpf_tcp_raw_gen_syncookie_ipv4#204
verifier bug: more than one arg with ref_obj_id R2 2 2
This error can be reproduced with the program from the previous commit:
0: (b7) r2 = 20
1: (b7) r3 = 0
2: (18) r1 = 0xffff92cee3cbc600
4: (85) call bpf_ringbuf_reserve#131
5: (55) if r0 == 0x0 goto pc+3
6: (bf) r1 = r0
7: (bf) r2 = r0
8: (85) call bpf_tcp_raw_gen_syncookie_ipv4#204
9: (95) exit
bpf_tcp_raw_gen_syncookie_ipv4 expects R1 and R2 to be
ARG_PTR_TO_FIXED_SIZE_MEM (with a size of at least sizeof(struct iphdr)
for R1). R0 is a ring buffer payload of 20B and therefore matches this
requirement.
The verifier reaches the check on ref_obj_id while verifying R2 and
rejects the program because the helper isn't supposed to take two
referenced arguments.
This case is a legitimate rejection and doesn't indicate a kernel bug,
so we shouldn't log it as such and shouldn't emit a kernel warning.
Link: https://github.com/google/syzkaller/pull/4313 [1]
Link: https://lore.kernel.org/all/686491d6.a70a0220.3b7e22.20ea.GAE@google.com/T/ [2]
Fixes: 457f44363a ("bpf: Implement BPF ring buffer and verifier support for it")
Fixes: 0df1a55afa ("bpf: Warn on internal verifier errors")
Reported-by: syzbot+69014a227f8edad4d8c6@syzkaller.appspotmail.com
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/cd09afbfd7bef10bbc432d72693f78ffdc1e8ee5.1751463262.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Commit f2362a57ae ("bpf: allow void* cast using bpf_rdonly_cast()")
added a notion of PTR_TO_MEM | MEM_RDONLY | PTR_UNTRUSTED type.
This simultaneously introduced a bug in jump prediction logic for
situations like below:
p = bpf_rdonly_cast(..., 0);
if (p) a(); else b();
Here verifier would wrongly predict that else branch cannot be taken.
This happens because:
- Function reg_not_null() assumes that PTR_TO_MEM w/o PTR_MAYBE_NULL
flag cannot be zero.
- The call to bpf_rdonly_cast() returns a rdonly_untrusted_mem value
w/o PTR_MAYBE_NULL flag.
Tracking of PTR_MAYBE_NULL flag for untrusted PTR_TO_MEM does not make
sense, as the main purpose of the flag is to catch null pointer access
errors. Such errors are not possible on load of PTR_UNTRUSTED values
and verifier makes sure that PTR_UNTRUSTED can't be passed to helpers
or kfuncs.
Hence, modify reg_not_null() to assume that nullness of untrusted
PTR_TO_MEM is not known.
Fixes: f2362a57ae ("bpf: allow void* cast using bpf_rdonly_cast()")
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250702073620.897517-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Mark struct cgroup_subsys_state->cgroup as safe under RCU read lock. This
will enable accessing css->cgroup from a bpf css iterator.
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/20250623063854.1896364-4-song@kernel.org
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
BPF programs, such as LSM and sched_ext, would benefit from tags on
cgroups. One common practice to apply such tags is to set xattrs on
cgroupfs folders.
Introduce kfunc bpf_cgroup_read_xattr, which allows reading cgroup's
xattr.
Note that, we already have bpf_get_[file|dentry]_xattr. However, these
two APIs are not ideal for reading cgroupfs xattrs, because:
1) These two APIs only works in sleepable contexts;
2) There is no kfunc that matches current cgroup to cgroupfs dentry.
bpf_cgroup_read_xattr is generic and can be useful for many program
types. It is also safe, because it requires trusted or rcu protected
argument (KF_RCU). Therefore, we make it available to all program types.
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/20250623063854.1896364-3-song@kernel.org
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
static const char fmt[] = "%p%";
bpf_trace_printk(fmt, sizeof(fmt));
The above BPF program isn't rejected and causes a kernel warning at
runtime:
Please remove unsupported %\x00 in format string
WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0
This happens because bpf_bprintf_prepare skips over the second %,
detected as punctuation, while processing %p. This patch fixes it by
not skipping over punctuation. %\x00 is then processed in the next
iteration and rejected.
Reported-by: syzbot+e2c932aec5c8a6e1d31c@syzkaller.appspotmail.com
Fixes: 48cac3f4a9 ("bpf: Implement formatted output helpers with bstr_printf")
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/a0e06cc479faec9e802ae51ba5d66420523251ee.1751395489.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch is a follow up to commit 1cb0f56d96 ("bpf: WARN_ONCE on
verifier bugs"). It generalizes the use of verifier_error throughout
the verifier, in particular for logs previously marked "verifier
internal error". As a consequence, all of those verifier bugs will now
come with a kernel warning (under CONFIG_DBEUG_KERNEL) detectable by
fuzzers.
While at it, some error messages that were too generic (ex., "bpf
verifier is misconfigured") have been reworded.
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/aGQqnzMyeagzgkCK@Tunnel
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Function bpf_cgroup_read_xattr is defined in fs/bpf_fs_kfuncs.c,
which is compiled only when CONFIG_BPF_LSM is set. Add CONFIG_BPF_LSM
check to bpf_cgroup_read_xattr spec in common_btf_ids in
kernel/bpf/helpers.c to avoid build failures for configs w/o
CONFIG_BPF_LSM.
Build failure example:
BTF .tmp_vmlinux1.btf.o
btf_encoder__tag_kfunc: failed to find kfunc 'bpf_cgroup_read_xattr' in BTF
...
WARN: resolve_btfids: unresolved symbol bpf_cgroup_read_xattr
make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux.unstripped] Error 255
Fixes: 535b070f4a ("bpf: Introduce bpf_cgroup_read_xattr to read xattr of cgroup's node")
Reported-by: Jake Hillion <jakehillion@meta.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250627175309.2710973-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cross-merge BPF, perf and other fixes after downstream PRs.
It restores BPF CI to green after critical fix
commit bc4394e5e7 ("perf: Fix the throttle error of some clock events")
No conflicts.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
String operations are commonly used so this exposes the most common ones
to BPF programs. For now, we limit ourselves to operations which do not
copy memory around.
Unfortunately, most in-kernel implementations assume that strings are
%NUL-terminated, which is not necessarily true, and therefore we cannot
use them directly in the BPF context. Instead, we open-code them using
__get_kernel_nofault instead of plain dereference to make them safe and
limit the strings length to XATTR_SIZE_MAX to make sure the functions
terminate. When __get_kernel_nofault fails, functions return -EFAULT.
Similarly, when the size bound is reached, the functions return -E2BIG.
In addition, we return -ERANGE when the passed strings are outside of
the kernel address space.
Note that thanks to these dynamic safety checks, no other constraints
are put on the kfunc args (they are marked with the "__ign" suffix to
skip any verifier checks for them).
All of the functions return integers, including functions which normally
(in kernel or libc) return pointers to the strings. The reason is that
since the strings are generally treated as unsafe, the pointers couldn't
be dereferenced anyways. So, instead, we return an index to the string
and let user decide what to do with it. This also nicely fits with
returning various error codes when necessary (see above).
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/r/4b008a6212852c1b056a413f86e3efddac73551c.1750917800.git.vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce support for `bpf_rdonly_cast(v, 0)`, which casts the value
`v` to an untyped, untrusted pointer, logically similar to a `void *`.
The memory pointed to by such a pointer is treated as read-only.
As with other untrusted pointers, memory access violations on loads
return zero instead of causing a fault.
Technically:
- The resulting pointer is represented as a register of type
`PTR_TO_MEM | MEM_RDONLY | PTR_UNTRUSTED` with size zero.
- Offsets within such pointers are not tracked.
- Same load instructions are allowed to have both
`PTR_TO_MEM | MEM_RDONLY | PTR_UNTRUSTED` and `PTR_TO_BTF_ID`
as the base pointer types.
In such cases, `bpf_insn_aux_data->ptr_type` is considered the
weaker of the two: `PTR_TO_MEM | MEM_RDONLY | PTR_UNTRUSTED`.
The following constraints apply to the new pointer type:
- can be used as a base for LDX instructions;
- can't be used as a base for ST/STX or atomic instructions;
- can't be used as parameter for kfuncs or helpers.
These constraints are enforced by existing handling of `MEM_RDONLY`
flag and `PTR_TO_MEM` of size zero.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250625182414.30659-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit adds a kernel side enum for use in conjucntion with BTF
CO-RE bpf_core_enum_value_exists. The goal of the enum is to assist
with available BPF features detection. Intended usage looks as
follows:
if (bpf_core_enum_value_exists(enum bpf_features, BPF_FEAT_<f>))
... use feature f ...
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250625182414.30659-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add range tracking for instruction BPF_NEG. Without this logic, a trivial
program like the following will fail
volatile bool found_value_b;
SEC("lsm.s/socket_connect")
int BPF_PROG(test_socket_connect)
{
if (!found_value_b)
return -1;
return 0;
}
with verifier log:
"At program exit the register R0 has smin=0 smax=4294967295 should have
been in [-4095, 0]".
This is because range information is lost in BPF_NEG:
0: R1=ctx() R10=fp0
; if (!found_value_b) @ xxxx.c:24
0: (18) r1 = 0xffa00000011e7048 ; R1_w=map_value(...)
2: (71) r0 = *(u8 *)(r1 +0) ; R0_w=scalar(smin32=0,smax=255)
3: (a4) w0 ^= 1 ; R0_w=scalar(smin32=0,smax=255)
4: (84) w0 = -w0 ; R0_w=scalar(range info lost)
Note that, the log above is manually modified to highlight relevant bits.
Fix this by maintaining proper range information with BPF_NEG, so that
the verifier will know:
4: (84) w0 = -w0 ; R0_w=scalar(smin32=-255,smax=0)
Also updated selftests based on the expected behavior.
Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250625164025.3310203-2-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch improves the precison of the scalar(32)_min_max_add and
scalar(32)_min_max_sub functions, which update the u(32)min/u(32)_max
ranges for the BPF_ADD and BPF_SUB instructions. We discovered this more
precise operator using a technique we are developing for automatically
synthesizing functions for updating tnums and ranges.
According to the BPF ISA [1], "Underflow and overflow are allowed during
arithmetic operations, meaning the 64-bit or 32-bit value will wrap".
Our patch leverages the wrap-around semantics of unsigned overflow and
underflow to improve precision.
Below is an example of our patch for scalar_min_max_add; the idea is
analogous for all four functions.
There are three cases to consider when adding two u64 ranges [dst_umin,
dst_umax] and [src_umin, src_umax]. Consider a value x in the range
[dst_umin, dst_umax] and another value y in the range [src_umin,
src_umax].
(a) No overflow: No addition x + y overflows. This occurs when even the
largest possible sum, i.e., dst_umax + src_umax <= U64_MAX.
(b) Partial overflow: Some additions x + y overflow. This occurs when
the largest possible sum overflows (dst_umax + src_umax > U64_MAX), but
the smallest possible sum does not overflow (dst_umin + src_umin <=
U64_MAX).
(c) Full overflow: All additions x + y overflow. This occurs when both
the smallest possible sum and the largest possible sum overflow, i.e.,
both (dst_umin + src_umin) and (dst_umax + src_umax) are > U64_MAX.
The current implementation conservatively sets the output bounds to
unbounded, i.e, [umin=0, umax=U64_MAX], whenever there is *any*
possibility of overflow, i.e, in cases (b) and (c). Otherwise it
computes tight bounds as [dst_umin + src_umin, dst_umax + src_umax]:
if (check_add_overflow(*dst_umin, src_reg->umin_value, dst_umin) ||
check_add_overflow(*dst_umax, src_reg->umax_value, dst_umax)) {
*dst_umin = 0;
*dst_umax = U64_MAX;
}
Our synthesis-based technique discovered a more precise operator.
Particularly, in case (c), all possible additions x + y overflow and
wrap around according to eBPF semantics, and the computation of the
output range as [dst_umin + src_umin, dst_umax + src_umax] continues to
work. Only in case (b), do we need to set the output bounds to
unbounded, i.e., [0, U64_MAX].
Case (b) can be checked by seeing if the minimum possible sum does *not*
overflow and the maximum possible sum *does* overflow, and when that
happens, we set the output to unbounded:
min_overflow = check_add_overflow(*dst_umin, src_reg->umin_value, dst_umin);
max_overflow = check_add_overflow(*dst_umax, src_reg->umax_value, dst_umax);
if (!min_overflow && max_overflow) {
*dst_umin = 0;
*dst_umax = U64_MAX;
}
Below is an example eBPF program and the corresponding log from the
verifier.
The current implementation of scalar_min_max_add() sets r3's bounds to
[0, U64_MAX] at instruction 5: (0f) r3 += r3, due to conservative
overflow handling.
0: R1=ctx() R10=fp0
0: (b7) r4 = 0 ; R4_w=0
1: (87) r4 = -r4 ; R4_w=scalar()
2: (18) r3 = 0xa000000000000000 ; R3_w=0xa000000000000000
4: (4f) r3 |= r4 ; R3_w=scalar(smin=0xa000000000000000,smax=-1,umin=0xa000000000000000,var_off=(0xa000000000000000; 0x5fffffffffffffff)) R4_w=scalar()
5: (0f) r3 += r3 ; R3_w=scalar()
6: (b7) r0 = 1 ; R0_w=1
7: (95) exit
With our patch, r3's bounds after instruction 5 are set to a much more
precise [0x4000000000000000,0xfffffffffffffffe].
...
5: (0f) r3 += r3 ; R3_w=scalar(umin=0x4000000000000000,umax=0xfffffffffffffffe)
6: (b7) r0 = 1 ; R0_w=1
7: (95) exit
The logic for scalar32_min_max_add is analogous. For the
scalar(32)_min_max_sub functions, the reasoning is similar but applied
to detecting underflow instead of overflow.
We verified the correctness of the new implementations using Agni [3,4].
We since also discovered that a similar technique has been used to
calculate output ranges for unsigned interval addition and subtraction
in Hacker's Delight [2].
[1] https://docs.kernel.org/bpf/standardization/instruction-set.html
[2] Hacker's Delight Ch.4-2, Propagating Bounds through Add’s and Subtract’s
[3] https://github.com/bpfverif/agni
[4] https://people.cs.rutgers.edu/~sn349/papers/sas24-preprint.pdf
Co-developed-by: Matan Shachnai <m.shachnai@rutgers.edu>
Signed-off-by: Matan Shachnai <m.shachnai@rutgers.edu>
Co-developed-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Signed-off-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Co-developed-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250623040359.343235-2-harishankar.vishwanathan@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The second argument of bpf_sysctl_get_name() helper is a pointer to a
buffer that is being written to. However that isn't specify in the
prototype.
Until commit 37cce22dbd ("bpf: verifier: Refactor helper access
type tracking"), all helper accesses were considered as a possible
write access by the verifier, so no big harm was done. However, since
then, the verifier might make wrong asssumption about the content of
that address which might lead it to make faulty optimizations (such as
removing code that was wrongly labeled dead). This is what happens in
test_sysctl selftest to the tests related to sysctl_get_name.
Add MEM_WRITE flag the second argument of bpf_sysctl_get_name().
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250619140603.148942-2-jmarchan@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The function update_prog_stats() will be called in the bpf trampoline.
In most cases, it will be optimized by the compiler by making it inline.
However, we can't rely on the compiler all the time, and just make it
__always_inline to reduce the possible overhead.
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250621045501.101187-1-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Mark struct cgroup_subsys_state->cgroup as safe under RCU read lock. This
will enable accessing css->cgroup from a bpf css iterator.
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/20250623063854.1896364-4-song@kernel.org
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
BPF programs, such as LSM and sched_ext, would benefit from tags on
cgroups. One common practice to apply such tags is to set xattrs on
cgroupfs folders.
Introduce kfunc bpf_cgroup_read_xattr, which allows reading cgroup's
xattr.
Note that, we already have bpf_get_[file|dentry]_xattr. However, these
two APIs are not ideal for reading cgroupfs xattrs, because:
1) These two APIs only works in sleepable contexts;
2) There is no kfunc that matches current cgroup to cgroupfs dentry.
bpf_cgroup_read_xattr is generic and can be useful for many program
types. It is also safe, because it requires trusted or rcu protected
argument (KF_RCU). Therefore, we make it available to all program types.
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/20250623063854.1896364-3-song@kernel.org
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
BPF_MAP_TYPE_LRU_HASH can recycle most recent elements well before the
map is full, due to percpu reservations and force shrink before
neighbor stealing. Once a CPU is unable to borrow from the global map,
it will once steal one elem from a neighbor and after that each time
flush this one element to the global list and immediately recycle it.
Batch value LOCAL_FREE_TARGET (128) will exhaust a 10K element map
with 79 CPUs. CPU 79 will observe this behavior even while its
neighbors hold 78 * 127 + 1 * 15 == 9921 free elements (99%).
CPUs need not be active concurrently. The issue can appear with
affinity migration, e.g., irqbalance. Each CPU can reserve and then
hold onto its 128 elements indefinitely.
Avoid global list exhaustion by limiting aggregate percpu caches to
half of map size, by adjusting LOCAL_FREE_TARGET based on cpu count.
This change has no effect on sufficiently large tables.
Similar to LOCAL_NR_SCANS and lru->nr_scans, introduce a map variable
lru->free_target. The extra field fits in a hole in struct bpf_lru.
The cacheline is already warm where read in the hot path. The field is
only accessed with the lru lock held.
Tested-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://lore.kernel.org/r/20250618215803.3587312-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Remove 3rd argument in prepare_seq_file() to clean up the code a bit.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250615004719.GE3011112@ZenIV
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
LSM hooks such as security_path_mknod() and security_inode_rename() have
access to newly allocated negative dentry, which has NULL d_inode.
Therefore, it is necessary to do the NULL pointer check for d_inode.
Also add selftests that checks the verifier enforces the NULL pointer
check.
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Matt Bobrowski <mattbobrowski@google.com>
Link: https://lore.kernel.org/r/20250613052857.1992233-1-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch removes duplicated code.
Eduard points out [1]:
Same cleanup cycles are done in push_stack() and push_async_cb(),
both functions are only reachable from do_check_common() via
do_check() -> do_check_insn().
Hence, I think that cur state should not be freed in push_*()
functions and pop_stack() loop there is not needed.
This would also fix the 'symptom' for [2], but the issue also has a
simpler fix which was sent separately. This fix also makes sure the
push_*() callers always return an error for which
error_recoverable_with_nospec(err) is false. This is required because
otherwise we try to recover and access the stale `state`.
Moving free_verifier_state() and pop_stack(..., pop_log=false) to happen
after the bpf_vlog_reset() call in do_check_common() is fine because the
pop_stack() call that is moved does not call bpf_vlog_reset() with the
pop_log=false parameter.
[1] https://lore.kernel.org/all/b6931bd0dd72327c55287862f821ca6c4c3eb69a.camel@gmail.com/
[2] https://lore.kernel.org/all/68497853.050a0220.33aa0e.036a.GAE@google.com/
Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/all/b6931bd0dd72327c55287862f821ca6c4c3eb69a.camel@gmail.com/
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Link: https://lore.kernel.org/r/20250613090157.568349-2-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BPF_JSET is a conditional jump and currently verifier.c:can_jump()
does not know about that. This can lead to incorrect live registers
and SCC computation.
E.g. in the following example:
1: r0 = 1;
2: r2 = 2;
3: if r1 & 0x7 goto +1;
4: exit;
5: r0 = r2;
6: exit;
W/o this fix insn_successors(3) will return only (4), a jump to (5)
would be missed and r2 won't be marked as alive at (3).
Fixes: 14c8552db6 ("bpf: simple DFA-based live registers analysis")
Reported-by: syzbot+a36aac327960ff474804@syzkaller.appspotmail.com
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250613175331.3238739-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit adds __GFP_ACCOUNT flag to verifier induced memory
allocations. The intent is to account for all allocations reachable
from BPF_PROG_LOAD command, which is needed to track verifier memory
consumption in veristat. This includes allocations done in verifier.c,
and some allocations in btf.c, functions in log.c do not allocate.
There is also a utility function bpf_memcg_flags() which selectively
adds GFP_ACCOUNT flag depending on the `cgroup.memory=nobpf` option.
As far as I understand [1], the idea is to remove bpf_prog instances
and maps from memcg accounting as these objects do not strictly belong
to cgroup, hence it should not apply here.
(btf_parse_fields() is reachable from both program load and map
creation, but allocated record is not persistent as is freed as soon
as map_check_btf() exits).
[1] https://lore.kernel.org/all/20230210154734.4416-1-laoar.shao@gmail.com/
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250613072147.3938139-2-eddyz87@gmail.com
With input changed == NULL, a local variable is used for "changed".
Initialize tmp properly, so that it can be used in the following:
*changed |= err > 0;
Otherwise, UBSAN will complain:
UBSAN: invalid-load in kernel/bpf/verifier.c:18924:4
load of value <some random value> is not a valid value for type '_Bool'
Fixes: dfb2d4c64b ("bpf: set 'changed' status if propagate_liveness() did any updates")
Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250612221100.2153401-1-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Without this, `state->speculative` is used after the cleanup cycles in
push_stack() or push_async_cb() freed `env->cur_state` (i.e., `state`).
Avoid this by relying on the short-circuit logic to only access `state`
if the error is recoverable (and make sure it never is after push_*()
failed).
push_*() callers must always return an error for which
error_recoverable_with_nospec(err) is false if push_*() returns NULL,
otherwise we try to recover and access the stale `state`. This is only
violated by sanitize_ptr_alu(), thus also fix this case to return
-ENOMEM.
state->speculative does not make sense if the error path of push_*()
ran. In that case, `state->speculative &&
error_recoverable_with_nospec(err)` as a whole should already never
evaluate to true (because all cases where push_stack() fails must return
-ENOMEM/-EFAULT). As mentioned, this is only violated by the
push_stack() call in sanitize_speculative_path() which returns -EACCES
without [1] (through REASON_STACK in sanitize_err() after
sanitize_ptr_alu()). To fix this, return -ENOMEM for REASON_STACK (which
is also the behavior we will have after [1]).
Checked that it fixes the syzbot reproducer as expected.
[1] https://lore.kernel.org/all/20250603213232.339242-1-luis.gerhorst@fau.de/
Fixes: d6f1c85f22 ("bpf: Fall back to nospec for Spectre v1")
Reported-by: syzbot+b5eb72a560b8149a1885@syzkaller.appspotmail.com
Reported-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/all/38862a832b91382cddb083dddd92643bed0723b8.camel@gmail.com/
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611210728.266563-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The previous patch switched read and precision tracking for
iterator-based loops from state-graph-based loop tracking to
control-flow-graph-based loop tracking.
This patch removes the now-unused `update_loop_entry()` and
`get_loop_entry()` functions, which were part of the state-graph-based
logic.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-9-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Current loop_entry-based exact states comparison logic does not handle
the following case:
.-> A --. Assume the states are visited in the order A, B, C.
| | | Assume that state B reaches a state equivalent to state A.
| v v At this point, state C is not processed yet, so state A
'-- B C has not received any read or precision marks from C.
As a result, these marks won't be propagated to B.
If B has incomplete marks, it is unsafe to use it in states_equal()
checks.
This commit replaces the existing logic with the following:
- Strongly connected components (SCCs) are computed over the program's
control flow graph (intraprocedurally).
- When a verifier state enters an SCC, that state is recorded as the
SCC entry point.
- When a verifier state is found equivalent to another (e.g., B to A
in the example), it is recorded as a states graph backedge.
Backedges are accumulated per SCC.
- When an SCC entry state reaches `branches == 0`, read and precision
marks are propagated through the backedges (e.g., from A to B, from
C to A, and then again from A to B).
To support nested subprogram calls, the entry state and backedge list
are associated not with the SCC itself but with an object called
`bpf_scc_callchain`. A callchain is a tuple `(callsite*, scc_id)`,
where `callsite` is the index of a call instruction for each frame
except the last.
See the comments added in `is_state_visited()` and
`compute_scc_callchain()` for more details.
Fixes: 2a0992829e ("bpf: correct loop detection for iterators convergence")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The next patch would add some relatively heavy-weight operation to
clean_live_states(), this operation can be skipped if REG_LIVE_DONE
is set. Move the check from clean_verifier_state() to
clean_verifier_state() as a small refactoring commit.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add an out parameter to `propagate_liveness()` to record whether any
new liveness bits were set during its execution.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add an out parameter to `propagate_precision()` to record whether any
new precision bits were set during its execution.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-5-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow `mark_chain_precision()` to run from an arbitrary starting state
by replacing direct references to `env->cur_state` with a parameter.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A function to return IP for a given frame in a call stack of a state.
Will be used by a next patch.
The `state->insn_idx = env->insn_idx;` assignment in the do_check()
allows to use frame_insn_idx with env->cur_state.
At the moment bpf_verifier_state->insn_idx is set when new cached
state is added in is_state_visited() and accessed only in the contexts
when the state is already in the cache. Hence this assignment does not
change verifier behaviour.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This reverts commit 96a30e469c.
Next patches in the series modify propagate_precision() to allow
arbitrary starting state. Precision propagation requires access to
jump history, and arbitrary states represent history not belonging to
`env->cur_state`.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250611200836.4135542-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This implements the core of the series and causes the verifier to fall
back to mitigating Spectre v1 using speculation barriers. The approach
was presented at LPC'24 [1] and RAID'24 [2].
If we find any forbidden behavior on a speculative path, we insert a
nospec (e.g., lfence speculation barrier on x86) before the instruction
and stop verifying the path. While verifying a speculative path, we can
furthermore stop verification of that path whenever we encounter a
nospec instruction.
A minimal example program would look as follows:
A = true
B = true
if A goto e
f()
if B goto e
unsafe()
e: exit
There are the following speculative and non-speculative paths
(`cur->speculative` and `speculative` referring to the value of the
push_stack() parameters):
- A = true
- B = true
- if A goto e
- A && !cur->speculative && !speculative
- exit
- !A && !cur->speculative && speculative
- f()
- if B goto e
- B && cur->speculative && !speculative
- exit
- !B && cur->speculative && speculative
- unsafe()
If f() contains any unsafe behavior under Spectre v1 and the unsafe
behavior matches `state->speculative &&
error_recoverable_with_nospec(err)`, do_check() will now add a nospec
before f() instead of rejecting the program:
A = true
B = true
if A goto e
nospec
f()
if B goto e
unsafe()
e: exit
Alternatively, the algorithm also takes advantage of nospec instructions
inserted for other reasons (e.g., Spectre v4). Taking the program above
as an example, speculative path exploration can stop before f() if a
nospec was inserted there because of Spectre v4 sanitization.
In this example, all instructions after the nospec are dead code (and
with the nospec they are also dead code speculatively).
For this, it relies on the fact that speculation barriers generally
prevent all later instructions from executing if the speculation was not
correct:
* On Intel x86_64, lfence acts as full speculation barrier, not only as
a load fence [3]:
An LFENCE instruction or a serializing instruction will ensure that
no later instructions execute, even speculatively, until all prior
instructions complete locally. [...] Inserting an LFENCE instruction
after a bounds check prevents later operations from executing before
the bound check completes.
This was experimentally confirmed in [4].
* On AMD x86_64, lfence is dispatch-serializing [5] (requires MSR
C001_1029[1] to be set if the MSR is supported, this happens in
init_amd()). AMD further specifies "A dispatch serializing instruction
forces the processor to retire the serializing instruction and all
previous instructions before the next instruction is executed" [8]. As
dispatch is not specific to memory loads or branches, lfence therefore
also affects all instructions there. Also, if retiring a branch means
it's PC change becomes architectural (should be), this means any
"wrong" speculation is aborted as required for this series.
* ARM's SB speculation barrier instruction also affects "any instruction
that appears later in the program order than the barrier" [6].
* PowerPC's barrier also affects all subsequent instructions [7]:
[...] executing an ori R31,R31,0 instruction ensures that all
instructions preceding the ori R31,R31,0 instruction have completed
before the ori R31,R31,0 instruction completes, and that no
subsequent instructions are initiated, even out-of-order, until
after the ori R31,R31,0 instruction completes. The ori R31,R31,0
instruction may complete before storage accesses associated with
instructions preceding the ori R31,R31,0 instruction have been
performed
Regarding the example, this implies that `if B goto e` will not execute
before `if A goto e` completes. Once `if A goto e` completes, the CPU
should find that the speculation was wrong and continue with `exit`.
If there is any other path that leads to `if B goto e` (and therefore
`unsafe()`) without going through `if A goto e`, then a nospec will
still be needed there. However, this patch assumes this other path will
be explored separately and therefore be discovered by the verifier even
if the exploration discussed here stops at the nospec.
This patch furthermore has the unfortunate consequence that Spectre v1
mitigations now only support architectures which implement BPF_NOSPEC.
Before this commit, Spectre v1 mitigations prevented exploits by
rejecting the programs on all architectures. Because some JITs do not
implement BPF_NOSPEC, this patch therefore may regress unpriv BPF's
security to a limited extent:
* The regression is limited to systems vulnerable to Spectre v1, have
unprivileged BPF enabled, and do NOT emit insns for BPF_NOSPEC. The
latter is not the case for x86 64- and 32-bit, arm64, and powerpc
64-bit and they are therefore not affected by the regression.
According to commit a6f6a95f25 ("LoongArch, bpf: Fix jit to skip
speculation barrier opcode"), LoongArch is not vulnerable to Spectre
v1 and therefore also not affected by the regression.
* To the best of my knowledge this regression may therefore only affect
MIPS. This is deemed acceptable because unpriv BPF is still disabled
there by default. As stated in a previous commit, BPF_NOSPEC could be
implemented for MIPS based on GCC's speculation_barrier
implementation.
* It is unclear which other architectures (besides x86 64- and 32-bit,
ARM64, PowerPC 64-bit, LoongArch, and MIPS) supported by the kernel
are vulnerable to Spectre v1. Also, it is not clear if barriers are
available on these architectures. Implementing BPF_NOSPEC on these
architectures therefore is non-trivial. Searching GCC and the kernel
for speculation barrier implementations for these architectures
yielded no result.
* If any of those regressed systems is also vulnerable to Spectre v4,
the system was already vulnerable to Spectre v4 attacks based on
unpriv BPF before this patch and the impact is therefore further
limited.
As an alternative to regressing security, one could still reject
programs if the architecture does not emit BPF_NOSPEC (e.g., by removing
the empty BPF_NOSPEC-case from all JITs except for LoongArch where it
appears justified). However, this will cause rejections on these archs
that are likely unfounded in the vast majority of cases.
In the tests, some are now successful where we previously had a
false-positive (i.e., rejection). Change them to reflect where the
nospec should be inserted (using __xlated_unpriv) and modify the error
message if the nospec is able to mitigate a problem that previously
shadowed another problem (in that case __xlated_unpriv does not work,
therefore just add a comment).
Define SPEC_V1 to avoid duplicating this ifdef whenever we check for
nospec insns using __xlated_unpriv, define it here once. This also
improves readability. PowerPC can probably also be added here. However,
omit it for now because the BPF CI currently does not include a test.
Limit it to EPERM, EACCES, and EINVAL (and not everything except for
EFAULT and ENOMEM) as it already has the desired effect for most
real-world programs. Briefly went through all the occurrences of EPERM,
EINVAL, and EACCESS in verifier.c to validate that catching them like
this makes sense.
Thanks to Dustin for their help in checking the vendor documentation.
[1] https://lpc.events/event/18/contributions/1954/ ("Mitigating
Spectre-PHT using Speculation Barriers in Linux eBPF")
[2] https://arxiv.org/pdf/2405.00078 ("VeriFence: Lightweight and
Precise Spectre Defenses for Untrusted Linux Kernel Extensions")
[3] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/runtime-speculative-side-channel-mitigations.html
("Managed Runtime Speculative Execution Side Channel Mitigations")
[4] https://dl.acm.org/doi/pdf/10.1145/3359789.3359837 ("Speculator: a
tool to analyze speculative execution attacks and mitigations" -
Section 4.6 "Stopping Speculative Execution")
[5] https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/software-techniques-for-managing-speculation.pdf
("White Paper - SOFTWARE TECHNIQUES FOR MANAGING SPECULATION ON AMD
PROCESSORS - REVISION 5.09.23")
[6] https://developer.arm.com/documentation/ddi0597/2020-12/Base-Instructions/SB--Speculation-Barrier-
("SB - Speculation Barrier - Arm Armv8-A A32/T32 Instruction Set
Architecture (2020-12)")
[7] https://wiki.raptorcs.com/w/images/5/5f/OPF_PowerISA_v3.1C.pdf
("Power ISA™ - Version 3.1C - May 26, 2024 - Section 9.2.1 of Book
III")
[8] https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/40332.pdf
("AMD64 Architecture Programmer’s Manual Volumes 1–5 - Revision 4.08
- April 2024 - 7.6.4 Serializing Instructions")
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Dustin Nguyen <nguyen@cs.fau.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603212428.338473-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This is made to clarify that this flag will cause a nospec to be added
after this insn and can therefore be relied upon to reduce speculative
path analysis.
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603212024.338154-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This changes the semantics of BPF_NOSPEC (previously a v4-only barrier)
to always emit a speculation barrier that works against both Spectre v1
AND v4. If mitigation is not needed on an architecture, the backend
should set bpf_jit_bypass_spec_v4/v1().
As of now, this commit only has the user-visible implication that unpriv
BPF's performance on PowerPC is reduced. This is the case because we
have to emit additional v1 barrier instructions for BPF_NOSPEC now.
This commit is required for a future commit to allow us to rely on
BPF_NOSPEC for Spectre v1 mitigation. As of this commit, the feature
that nospec acts as a v1 barrier is unused.
Commit f5e81d1117 ("bpf: Introduce BPF nospec instruction for
mitigating Spectre v4") noted that mitigation instructions for v1 and v4
might be different on some archs. While this would potentially offer
improved performance on PowerPC, it was dismissed after the following
considerations:
* Only having one barrier simplifies the verifier and allows us to
easily rely on v4-induced barriers for reducing the complexity of
v1-induced speculative path verification.
* For the architectures that implemented BPF_NOSPEC, only PowerPC has
distinct instructions for v1 and v4. Even there, some insns may be
shared between the barriers for v1 and v4 (e.g., 'ori 31,31,0' and
'sync'). If this is still found to impact performance in an
unacceptable way, BPF_NOSPEC can be split into BPF_NOSPEC_V1 and
BPF_NOSPEC_V4 later. As an optimization, we can already skip v1/v4
insns from being emitted for PowerPC with this setup if
bypass_spec_v1/v4 is set.
Vulnerability-status for BPF_NOSPEC-based Spectre mitigations (v4 as of
this commit, v1 in the future) is therefore:
* x86 (32-bit and 64-bit), ARM64, and PowerPC (64-bit): Mitigated - This
patch implements BPF_NOSPEC for these architectures. The previous
v4-only version was supported since commit f5e81d1117 ("bpf:
Introduce BPF nospec instruction for mitigating Spectre v4") and
commit b7540d6250 ("powerpc/bpf: Emit stf barrier instruction
sequences for BPF_NOSPEC").
* LoongArch: Not Vulnerable - Commit a6f6a95f25 ("LoongArch, bpf: Fix
jit to skip speculation barrier opcode") is the only other past commit
related to BPF_NOSPEC and indicates that the insn is not required
there.
* MIPS: Vulnerable (if unprivileged BPF is enabled) -
Commit a6f6a95f2580 ("LoongArch, bpf: Fix jit to skip speculation
barrier opcode") indicates that it is not vulnerable, but this
contradicts the kernel and Debian documentation. Therefore, I assume
that there exist vulnerable MIPS CPUs (but maybe not from Loongson?).
In the future, BPF_NOSPEC could be implemented for MIPS based on the
GCC speculation_barrier [1]. For now, we rely on unprivileged BPF
being disabled by default.
* Other: Unknown - To the best of my knowledge there is no definitive
information available that indicates that any other arch is
vulnerable. They are therefore left untouched (BPF_NOSPEC is not
implemented, but bypass_spec_v1/v4 is also not set).
I did the following testing to ensure the insn encoding is correct:
* ARM64:
* 'dsb nsh; isb' was successfully tested with the BPF CI in [2]
* 'sb' locally using QEMU v7.2.15 -cpu max (emitted sb insn is
executed for example with './test_progs -t verifier_array_access')
* PowerPC: The following configs were tested locally with ppc64le QEMU
v8.2 '-machine pseries -cpu POWER9':
* STF_BARRIER_EIEIO + CONFIG_PPC_BOOK32_64
* STF_BARRIER_SYNC_ORI (forced on) + CONFIG_PPC_BOOK32_64
* STF_BARRIER_FALLBACK (forced on) + CONFIG_PPC_BOOK32_64
* CONFIG_PPC_E500 (forced on) + STF_BARRIER_EIEIO
* CONFIG_PPC_E500 (forced on) + STF_BARRIER_SYNC_ORI (forced on)
* CONFIG_PPC_E500 (forced on) + STF_BARRIER_FALLBACK (forced on)
* CONFIG_PPC_E500 (forced on) + STF_BARRIER_NONE (forced on)
Most of those cobinations should not occur in practice, but I was not
able to get an PPC e6500 rootfs (for testing PPC_E500 without forcing
it on). In any case, this should ensure that there are no unexpected
conflicts between the insns when combined like this. Individual v1/v4
barriers were already emitted elsewhere.
Hari's ack is for the PowerPC changes only.
[1] https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=29b74545531f6afbee9fc38c267524326dbfbedf
("MIPS: Add speculation_barrier support")
[2] https://github.com/kernel-patches/bpf/pull/8576
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Cc: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603211703.337860-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
JITs can set bpf_jit_bypass_spec_v1/v4() if they want the verifier to
skip analysis/patching for the respective vulnerability. For v4, this
will reduce the number of barriers the verifier inserts. For v1, it
allows more programs to be accepted.
The primary motivation for this is to not regress unpriv BPF's
performance on ARM64 in a future commit where BPF_NOSPEC is also used
against Spectre v1.
This has the user-visible change that v1-induced rejections on
non-vulnerable PowerPC CPUs are avoided.
For now, this does not change the semantics of BPF_NOSPEC. It is still a
v4-only barrier and must not be implemented if bypass_spec_v4 is always
true for the arch. Changing it to a v1 AND v4-barrier is done in a
future commit.
As an alternative to bypass_spec_v1/v4, one could introduce NOSPEC_V1
AND NOSPEC_V4 instructions and allow backends to skip their lowering as
suggested by commit f5e81d1117 ("bpf: Introduce BPF nospec instruction
for mitigating Spectre v4"). Adding bpf_jit_bypass_spec_v1/v4() was
found to be preferable for the following reason:
* bypass_spec_v1/v4 benefits non-vulnerable CPUs: Always performing the
same analysis (not taking into account whether the current CPU is
vulnerable), needlessly restricts users of CPUs that are not
vulnerable. The only use case for this would be portability-testing,
but this can later be added easily when needed by allowing users to
force bypass_spec_v1/v4 to false.
* Portability is still acceptable: Directly disabling the analysis
instead of skipping the lowering of BPF_NOSPEC(_V1/V4) might allow
programs on non-vulnerable CPUs to be accepted while the program will
be rejected on vulnerable CPUs. With the fallback to speculation
barriers for Spectre v1 implemented in a future commit, this will only
affect programs that do variable stack-accesses or are very complex.
For PowerPC, the SEC_FTR checking in bpf_jit_bypass_spec_v4() is based
on the check that was previously located in the BPF_NOSPEC case.
For LoongArch, it would likely be safe to set both
bpf_jit_bypass_spec_v1() and _v4() according to
commit a6f6a95f2580 ("LoongArch, bpf: Fix jit to skip speculation
barrier opcode"). This is omitted here as I am unable to do any testing
for LoongArch.
Hari's ack concerns the PowerPC part only.
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Cc: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603211318.337474-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This prevents us from trying to recover from these on speculative paths
in the future.
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603205800.334980-4-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Mark these cases as non-recoverable to later prevent them from being
caught when they occur during speculative path verification.
Eduard writes [1]:
The only pace I'm aware of that might act upon specific error code
from verifier syscall is libbpf. Looking through libbpf code, it seems
that this change does not interfere with libbpf.
[1] https://lore.kernel.org/all/785b4531ce3b44a84059a4feb4ba458c68fce719.camel@gmail.com/
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603205800.334980-3-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This is required to catch the errors later and fall back to a nospec if
on a speculative path.
Eliminate the regs variable as it is only used once and insn_idx is not
modified in-between the definition and usage.
Do not pass insn but compute it in the function itself. As Eduard points
out [1], insn is assumed to correspond to env->insn_idx in many places
(e.g, __check_reg_arg()).
Move code into do_check_insn(), replace
* "continue" with "return 0" after modifying insn_idx
* "goto process_bpf_exit" with "return PROCESS_BPF_EXIT"
* "goto process_bpf_exit_full" with "return process_bpf_exit_full()"
* "do_print_state = " with "*do_print_state = "
[1] https://lore.kernel.org/all/293dbe3950a782b8eb3b87b71d7a967e120191fd.camel@gmail.com/
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603205800.334980-2-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When reg->type is CONST_PTR_TO_MAP, it can not be null. However the
verifier explores the branches under rX == 0 in check_cond_jmp_op()
even if reg->type is CONST_PTR_TO_MAP, because it was not checked for
in reg_not_null().
Fix this by adding CONST_PTR_TO_MAP to the set of types that are
considered non nullable in reg_not_null().
An old "unpriv: cmp map pointer with zero" selftest fails with this
change, because now early out correctly triggers in
check_cond_jmp_op(), making the verification to pass.
In practice verifier may allow pointer to null comparison in unpriv,
since in many cases the relevant branch and comparison op are removed
as dead code. So change the expected test result to __success_unpriv.
Signed-off-by: Ihor Solodrai <isolodrai@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250609183024.359974-2-isolodrai@meta.com
Current cgroup prog ordering is appending at attachment time. This is not
ideal. In some cases, users want specific ordering at a particular cgroup
level. To address this, the existing mprog API seems an ideal solution with
supporting BPF_F_BEFORE and BPF_F_AFTER flags.
But there are a few obstacles to directly use kernel mprog interface.
Currently cgroup bpf progs already support prog attach/detach/replace
and link-based attach/detach/replace. For example, in struct
bpf_prog_array_item, the cgroup_storage field needs to be together
with bpf prog. But the mprog API struct bpf_mprog_fp only has bpf_prog
as the member, which makes it difficult to use kernel mprog interface.
In another case, the current cgroup prog detach tries to use the
same flag as in attach. This is different from mprog kernel interface
which uses flags passed from user space.
So to avoid modifying existing behavior, I made the following changes to
support mprog API for cgroup progs:
- The support is for prog list at cgroup level. Cross-level prog list
(a.k.a. effective prog list) is not supported.
- Previously, BPF_F_PREORDER is supported only for prog attach, now
BPF_F_PREORDER is also supported by link-based attach.
- For attach, BPF_F_BEFORE/BPF_F_AFTER/BPF_F_ID/BPF_F_LINK is supported
similar to kernel mprog but with different implementation.
- For detach and replace, use the existing implementation.
- For attach, detach and replace, the revision for a particular prog
list, associated with a particular attach type, will be updated
by increasing count by 1.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250606163141.2428937-1-yonghong.song@linux.dev
As is, it appears as if pointer arithmetic is allowed for everything
except PTR_TO_{STACK,MAP_VALUE} if one only looks at
sanitize_check_bounds(). However, this is misleading as the function
only works together with retrieve_ptr_limit() and the two must be kept
in sync. This patch documents the interdependency and adds a check to
ensure they stay in sync.
adjust_ptr_min_max_vals(): Because the preceding switch returns -EACCES
for every opcode except for ADD/SUB, the sanitize_needed() following the
sanitize_check_bounds() call is always true if reached. This means,
unless sanitize_check_bounds() detected that the pointer goes OOB
because of the ADD/SUB and returns -EACCES, sanitize_ptr_alu() always
executes after sanitize_check_bounds().
The following shows that this also implies that retrieve_ptr_limit()
runs in all relevant cases.
Note that there are two calls to sanitize_ptr_alu(), these are simply
needed to easily calculate the correct alu_limit as explained in
commit 7fedb63a8307 ("bpf: Tighten speculative pointer arithmetic
mask"). The truncation-simulation is already performed on the first
call.
In the second sanitize_ptr_alu(commit_window = true), we always run
retrieve_ptr_limit(), unless:
* can_skip_alu_sanititation() is true, notably `BPF_SRC(insn->code) ==
BPF_K`. BPF_K is fine because it means that there is no scalar
register (which could be subject to speculative scalar confusion due
to Spectre v4) that goes into the ALU operation. The pointer register
can not be subject to v4-based value confusion due to the nospec
added. Thus, in this case it would have been fine to also skip
sanitize_check_bounds().
* If we are on a speculative path (`vstate->speculative`) and in the
second "commit" phase, sanitize_ptr_alu() always just returns 0. This
makes sense because there are no ALU sanitization limits to be learned
from speculative paths. Furthermore, because the sanitization will
ensure that pointer arithmetic stays in (architectural) bounds, the
sanitize_check_bounds() on the speculative path could also be skipped.
The second case needs more attention: Assume we have some ALU operation
that is used with scalars architecturally, but with a
non-PTR_TO_{STACK,MAP_VALUE} pointer (e.g., PTR_TO_PACKET)
speculatively. It might appear as if this would allow an unsanitized
pointer ALU operations, but this can not happen because one of the
following two always holds:
* The type mismatch stems from Spectre v4, then it is prevented by a
nospec after the possibly-bypassed store involving the pointer. There
is no speculative path simulated for this case thus it never happens.
* The type mismatch stems from a Spectre v1 gadget like the following:
r1 = slow(0)
r4 = fast(0)
r3 = SCALAR // Spectre v4 scalar confusion
if (r1) {
r2 = PTR_TO_PACKET
} else {
r2 = 42
}
if (r4) {
r2 += r3
*r2
}
If `r2 = PTR_TO_PACKET` is indeed dead code, it will be sanitized to
`goto -1` (as is the case for the r4-if block). If it is not (e.g., if
`r1 = r4 = 1` is possible), it will also be explored on an
architectural path and retrieve_ptr_limit() will reject it.
To summarize, the exception for `vstate->speculative` is safe.
Back to retrieve_ptr_limit(): It only allows the ALU operation if the
involved pointer register (can be either source or destination for ADD)
is PTR_TO_STACK or PTR_TO_MAP_VALUE. Otherwise, it returns -EOPNOTSUPP.
Therefore, sanitize_check_bounds() returning 0 for
non-PTR_TO_{STACK,MAP_VALUE} is fine because retrieve_ptr_limit() also
runs for all relevant cases and prevents unsafe operations.
To summarize, we allow unsanitized pointer arithmetic with 64-bit
ADD/SUB for the following instructions if the requirements from
retrieve_ptr_limit() AND sanitize_check_bounds() hold:
* ptr -=/+= imm32 (i.e. `BPF_SRC(insn->code) == BPF_K`)
* PTR_TO_{STACK,MAP_VALUE} -= scalar
* PTR_TO_{STACK,MAP_VALUE} += scalar
* scalar += PTR_TO_{STACK,MAP_VALUE}
To document the interdependency between sanitize_check_bounds() and
retrieve_ptr_limit(), add a verifier_bug_if() to make sure they stay in
sync.
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/CAP01T76HZ+s5h+_REqRFkRjjoKwnZZn9YswpSVinGicah1pGJw@mail.gmail.com/
Link: https://lore.kernel.org/bpf/CAP01T75oU0zfZCiymEcH3r-GQ5A6GOc6GmYzJEnMa3=53XuUQQ@mail.gmail.com/
Link: https://lore.kernel.org/r/20250603204557.332447-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
After commit 68ca5d4eeb ("bpf: support BPF cookie in raw tracepoint
(raw_tp, tp_btf) programs"), we can show the cookie in bpf_link_info
like kprobe etc.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250603154309.3063644-1-chen.dylane@linux.dev
simplifies the act of creating a pte which addresses the first page in a
folio and reduces the amount of plumbing which architecture must
implement to provide this.
- The 8 patch series "Misc folio patches for 6.16" from Matthew Wilcox
is a shower of largely unrelated folio infrastructure changes which
clean things up and better prepare us for future work.
- The 3 patch series "memory,x86,acpi: hotplug memory alignment
advisement" from Gregory Price adds early-init code to prevent x86 from
leaving physical memory unused when physical address regions are not
aligned to memory block size.
- The 2 patch series "mm/compaction: allow more aggressive proactive
compaction" from Michal Clapinski provides some tuning of the (sadly,
hard-coded (more sadly, not auto-tuned)) thresholds for our invokation
of proactive compaction. In a simple test case, the reduction of a guest
VM's memory consumption was dramatic.
- The 8 patch series "Minor cleanups and improvements to swap freeing
code" from Kemeng Shi provides some code cleaups and a small efficiency
improvement to this part of our swap handling code.
- The 6 patch series "ptrace: introduce PTRACE_SET_SYSCALL_INFO API"
from Dmitry Levin adds the ability for a ptracer to modify syscalls
arguments. At this time we can alter only "system call information that
are used by strace system call tampering, namely, syscall number,
syscall arguments, and syscall return value.
This series should have been incorporated into mm.git's "non-MM"
branch, but I goofed.
- The 3 patch series "fs/proc: extend the PAGEMAP_SCAN ioctl to report
guard regions" from Andrei Vagin extends the info returned by the
PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more
efficiently get at the info about guard regions.
- The 2 patch series "Fix parameter passed to page_mapcount_is_type()"
from Gavin Shan implements that fix. No runtime effect is expected
because validate_page_before_insert() happens to fix up this error.
- The 3 patch series "kernel/events/uprobes: uprobe_write_opcode()
rewrite" from David Hildenbrand basically brings uprobe text poking into
the current decade. Remove a bunch of hand-rolled implementation in
favor of using more current facilities.
- The 3 patch series "mm/ptdump: Drop assumption that pxd_val() is u64"
from Anshuman Khandual provides enhancements and generalizations to the
pte dumping code. This might be needed when 128-bit Page Table
Descriptors are enabled for ARM.
- The 12 patch series "Always call constructor for kernel page tables"
from Kevin Brodsky "ensures that the ctor/dtor is always called for
kernel pgtables, as it already is for user pgtables". This permits the
addition of more functionality such as "insert hooks to protect page
tables". This change does result in various architectures performing
unnecesary work, but this is fixed up where it is anticipated to occur.
- The 9 patch series "Rust support for mm_struct, vm_area_struct, and
mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM
structures.
- The 3 patch series "fix incorrectly disallowed anonymous VMA merges"
from Lorenzo Stoakes takes advantage of some VMA merging opportunities
which we've been missing for 15 years.
- The 4 patch series "mm/madvise: batch tlb flushes for MADV_DONTNEED
and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB
flushing. Instead of flushing each address range in the provided iovec,
we batch the flushing across all the iovec entries. The syscall's cost
was approximately halved with a microbenchmark which was designed to
load this particular operation.
- The 6 patch series "Track node vacancy to reduce worst case allocation
counts" from Sidhartha Kumar makes the maple tree smarter about its node
preallocation. stress-ng mmap performance increased by single-digit
percentages and the amount of unnecessarily preallocated memory was
dramaticelly reduced.
- The 3 patch series "mm/gup: Minor fix, cleanup and improvements" from
Baoquan He removes a few unnecessary things which Baoquan noted when
reading the code.
- The 3 patch series ""Enhance sysfs handling for memory hotplug in
weighted interleave" from Rakie Kim "enhances the weighted interleave
policy in the memory management subsystem by improving sysfs handling,
fixing memory leaks, and introducing dynamic sysfs updates for memory
hotplug support". Fixes things on error paths which we are unlikely to
hit.
- The 7 patch series "mm/damon: auto-tune DAMOS for NUMA setups
including tiered memory" from SeongJae Park introduces new DAMOS quota
goal metrics which eliminate the manual tuning which is required when
utilizing DAMON for memory tiering.
- The 5 patch series "mm/vmalloc.c: code cleanup and improvements" from
Baoquan He provides cleanups and small efficiency improvements which
Baoquan found via code inspection.
- The 2 patch series "vmscan: enforce mems_effective during demotion"
from Gregory Price "changes reclaim to respect cpuset.mems_effective
during demotion when possible". because "presently, reclaim explicitly
ignores cpuset.mems_effective when demoting, which may cause the cpuset
settings to violated." "This is useful for isolating workloads on a
multi-tenant system from certain classes of memory more consistently."
- The 2 patch series ""Clean up split_huge_pmd_locked() and remove
unnecessary folio pointers" from Gavin Guo provides minor cleanups and
efficiency gains in in the huge page splitting and migrating code.
- The 3 patch series "Use kmem_cache for memcg alloc" from Huan Yang
creates a slab cache for `struct mem_cgroup', yielding improved memory
utilization.
- The 4 patch series "add max arg to swappiness in memory.reclaim and
lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness="
argument for memory.reclaim MGLRU's lru_gen. This directs proactive
reclaim to reclaim from only anon folios rather than file-backed folios.
- The 17 patch series "kexec: introduce Kexec HandOver (KHO)" from Mike
Rapoport is the first step on the path to permitting the kernel to
maintain existing VMs while replacing the host kernel via file-based
kexec. At this time only memblock's reserve_mem is preserved.
- The 7 patch series "mm: Introduce for_each_valid_pfn()" from David
Woodhouse provides and uses a smarter way of looping over a pfn range.
By skipping ranges of invalid pfns.
- The 2 patch series "sched/numa: Skip VMA scanning on memory pinned to
one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless
VMA scanning when a task is pinned a single NUMA mode. Dramatic
performance benefits were seen in some real world cases.
- The 2 patch series "JFS: Implement migrate_folio for
jfs_metapage_aops" from Shivank Garg addresses a warning which occurs
during memory compaction when using JFS.
- The 4 patch series "move all VMA allocation, freeing and duplication
logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c
into the more appropriate mm/vma.c.
- The 6 patch series "mm, swap: clean up swap cache mapping helper" from
Kairui Song provides code consolidation and cleanups related to the
folio_index() function.
- The 2 patch series "mm/gup: Cleanup memfd_pin_folios()" from Vishal
Moola does that.
- The 8 patch series "memcg: Fix test_memcg_min/low test failures" from
Waiman Long addresses some bogus failures which are being reported by
the test_memcontrol selftest.
- The 3 patch series "eliminate mmap() retry merge, add .mmap_prepare
hook" from Lorenzo Stoakes commences the deprecation of
file_operations.mmap() in favor of the new
file_operations.mmap_prepare(). The latter is more restrictive and
prevents drivers from messing with things in ways which, amongst other
problems, may defeat VMA merging.
- The 4 patch series "memcg: decouple memcg and objcg stocks"" from
Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's
one. This is a step along the way to making memcg and objcg charging
NMI-safe, which is a BPF requirement.
- The 6 patch series "mm/damon: minor fixups and improvements for code,
tests, and documents" from SeongJae Park is "yet another batch of
miscellaneous DAMON changes. Fix and improve minor problems in code,
tests and documents."
- The 7 patch series "memcg: make memcg stats irq safe" from Shakeel
Butt converts memcg stats to be irq safe. Another step along the way to
making memcg charging and stats updates NMI-safe, a BPF requirement.
- The 4 patch series "Let unmap_hugepage_range() and several related
functions take folio instead of page" from Fan Ni provides folio
conversions in the hugetlb code.
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Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
creating a pte which addresses the first page in a folio and reduces
the amount of plumbing which architecture must implement to provide
this.
- "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
largely unrelated folio infrastructure changes which clean things up
and better prepare us for future work.
- "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
Price adds early-init code to prevent x86 from leaving physical
memory unused when physical address regions are not aligned to memory
block size.
- "mm/compaction: allow more aggressive proactive compaction" from
Michal Clapinski provides some tuning of the (sadly, hard-coded (more
sadly, not auto-tuned)) thresholds for our invokation of proactive
compaction. In a simple test case, the reduction of a guest VM's
memory consumption was dramatic.
- "Minor cleanups and improvements to swap freeing code" from Kemeng
Shi provides some code cleaups and a small efficiency improvement to
this part of our swap handling code.
- "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
adds the ability for a ptracer to modify syscalls arguments. At this
time we can alter only "system call information that are used by
strace system call tampering, namely, syscall number, syscall
arguments, and syscall return value.
This series should have been incorporated into mm.git's "non-MM"
branch, but I goofed.
- "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
against /proc/pid/pagemap. This permits CRIU to more efficiently get
at the info about guard regions.
- "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
implements that fix. No runtime effect is expected because
validate_page_before_insert() happens to fix up this error.
- "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
Hildenbrand basically brings uprobe text poking into the current
decade. Remove a bunch of hand-rolled implementation in favor of
using more current facilities.
- "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
Khandual provides enhancements and generalizations to the pte dumping
code. This might be needed when 128-bit Page Table Descriptors are
enabled for ARM.
- "Always call constructor for kernel page tables" from Kevin Brodsky
ensures that the ctor/dtor is always called for kernel pgtables, as
it already is for user pgtables.
This permits the addition of more functionality such as "insert hooks
to protect page tables". This change does result in various
architectures performing unnecesary work, but this is fixed up where
it is anticipated to occur.
- "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
Ryhl adds plumbing to permit Rust access to core MM structures.
- "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
Stoakes takes advantage of some VMA merging opportunities which we've
been missing for 15 years.
- "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
SeongJae Park optimizes process_madvise()'s TLB flushing.
Instead of flushing each address range in the provided iovec, we
batch the flushing across all the iovec entries. The syscall's cost
was approximately halved with a microbenchmark which was designed to
load this particular operation.
- "Track node vacancy to reduce worst case allocation counts" from
Sidhartha Kumar makes the maple tree smarter about its node
preallocation.
stress-ng mmap performance increased by single-digit percentages and
the amount of unnecessarily preallocated memory was dramaticelly
reduced.
- "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
a few unnecessary things which Baoquan noted when reading the code.
- ""Enhance sysfs handling for memory hotplug in weighted interleave"
from Rakie Kim "enhances the weighted interleave policy in the memory
management subsystem by improving sysfs handling, fixing memory
leaks, and introducing dynamic sysfs updates for memory hotplug
support". Fixes things on error paths which we are unlikely to hit.
- "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
from SeongJae Park introduces new DAMOS quota goal metrics which
eliminate the manual tuning which is required when utilizing DAMON
for memory tiering.
- "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
provides cleanups and small efficiency improvements which Baoquan
found via code inspection.
- "vmscan: enforce mems_effective during demotion" from Gregory Price
changes reclaim to respect cpuset.mems_effective during demotion when
possible. because presently, reclaim explicitly ignores
cpuset.mems_effective when demoting, which may cause the cpuset
settings to violated.
This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently.
- "Clean up split_huge_pmd_locked() and remove unnecessary folio
pointers" from Gavin Guo provides minor cleanups and efficiency gains
in in the huge page splitting and migrating code.
- "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
for `struct mem_cgroup', yielding improved memory utilization.
- "add max arg to swappiness in memory.reclaim and lru_gen" from
Zhongkun He adds a new "max" argument to the "swappiness=" argument
for memory.reclaim MGLRU's lru_gen.
This directs proactive reclaim to reclaim from only anon folios
rather than file-backed folios.
- "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
first step on the path to permitting the kernel to maintain existing
VMs while replacing the host kernel via file-based kexec. At this
time only memblock's reserve_mem is preserved.
- "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
and uses a smarter way of looping over a pfn range. By skipping
ranges of invalid pfns.
- "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
when a task is pinned a single NUMA mode.
Dramatic performance benefits were seen in some real world cases.
- "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
Garg addresses a warning which occurs during memory compaction when
using JFS.
- "move all VMA allocation, freeing and duplication logic to mm" from
Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
appropriate mm/vma.c.
- "mm, swap: clean up swap cache mapping helper" from Kairui Song
provides code consolidation and cleanups related to the folio_index()
function.
- "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.
- "memcg: Fix test_memcg_min/low test failures" from Waiman Long
addresses some bogus failures which are being reported by the
test_memcontrol selftest.
- "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
Stoakes commences the deprecation of file_operations.mmap() in favor
of the new file_operations.mmap_prepare().
The latter is more restrictive and prevents drivers from messing with
things in ways which, amongst other problems, may defeat VMA merging.
- "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
the per-cpu memcg charge cache from the objcg's one.
This is a step along the way to making memcg and objcg charging
NMI-safe, which is a BPF requirement.
- "mm/damon: minor fixups and improvements for code, tests, and
documents" from SeongJae Park is yet another batch of miscellaneous
DAMON changes. Fix and improve minor problems in code, tests and
documents.
- "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
stats to be irq safe. Another step along the way to making memcg
charging and stats updates NMI-safe, a BPF requirement.
- "Let unmap_hugepage_range() and several related functions take folio
instead of page" from Fan Ni provides folio conversions in the
hugetlb code.
* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
mm: pcp: increase pcp->free_count threshold to trigger free_high
mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
mm/hugetlb: pass folio instead of page to unmap_ref_private()
memcg: objcg stock trylock without irq disabling
memcg: no stock lock for cpu hot-unplug
memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
memcg: make count_memcg_events re-entrant safe against irqs
memcg: make mod_memcg_state re-entrant safe against irqs
memcg: move preempt disable to callers of memcg_rstat_updated
memcg: memcg_rstat_updated re-entrant safe against irqs
mm: khugepaged: decouple SHMEM and file folios' collapse
selftests/eventfd: correct test name and improve messages
alloc_tag: check mem_profiling_support in alloc_tag_init
Docs/damon: update titles and brief introductions to explain DAMOS
selftests/damon/_damon_sysfs: read tried regions directories in order
mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
...
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Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Fix and improve BTF deduplication of identical BTF types (Alan
Maguire and Andrii Nakryiko)
- Support up to 12 arguments in BPF trampoline on arm64 (Xu Kuohai and
Alexis Lothoré)
- Support load-acquire and store-release instructions in BPF JIT on
riscv64 (Andrea Parri)
- Fix uninitialized values in BPF_{CORE,PROBE}_READ macros (Anton
Protopopov)
- Streamline allowed helpers across program types (Feng Yang)
- Support atomic update for hashtab of BPF maps (Hou Tao)
- Implement json output for BPF helpers (Ihor Solodrai)
- Several s390 JIT fixes (Ilya Leoshkevich)
- Various sockmap fixes (Jiayuan Chen)
- Support mmap of vmlinux BTF data (Lorenz Bauer)
- Support BPF rbtree traversal and list peeking (Martin KaFai Lau)
- Tests for sockmap/sockhash redirection (Michal Luczaj)
- Introduce kfuncs for memory reads into dynptrs (Mykyta Yatsenko)
- Add support for dma-buf iterators in BPF (T.J. Mercier)
- The verifier support for __bpf_trap() (Yonghong Song)
* tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (135 commits)
bpf, arm64: Remove unused-but-set function and variable.
selftests/bpf: Add tests with stack ptr register in conditional jmp
bpf: Do not include stack ptr register in precision backtracking bookkeeping
selftests/bpf: enable many-args tests for arm64
bpf, arm64: Support up to 12 function arguments
bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()
bpf: Avoid __bpf_prog_ret0_warn when jit fails
bpftool: Add support for custom BTF path in prog load/loadall
selftests/bpf: Add unit tests with __bpf_trap() kfunc
bpf: Warn with __bpf_trap() kfunc maybe due to uninitialized variable
bpf: Remove special_kfunc_set from verifier
selftests/bpf: Add test for open coded dmabuf_iter
selftests/bpf: Add test for dmabuf_iter
bpf: Add open coded dmabuf iterator
bpf: Add dmabuf iterator
dma-buf: Rename debugfs symbols
bpf: Fix error return value in bpf_copy_from_user_dynptr
libbpf: Use mmap to parse vmlinux BTF from sysfs
selftests: bpf: Add a test for mmapable vmlinux BTF
btf: Allow mmap of vmlinux btf
...
Core
----
- Implement the Device Memory TCP transmit path, allowing zero-copy
data transmission on top of TCP from e.g. GPU memory to the wire.
- Move all the IPv6 routing tables management outside the RTNL scope,
under its own lock and RCU. The route control path is now 3x times
faster.
- Convert queue related netlink ops to instance lock, reducing
again the scope of the RTNL lock. This improves the control plane
scalability.
- Refactor the software crc32c implementation, removing unneeded
abstraction layers and improving significantly the related
micro-benchmarks.
- Optimize the GRO engine for UDP-tunneled traffic, for a 10%
performance improvement in related stream tests.
- Cover more per-CPU storage with local nested BH locking; this is a
prep work to remove the current per-CPU lock in local_bh_disable()
on PREMPT_RT.
- Introduce and use nlmsg_payload helper, combining buffer bounds
verification with accessing payload carried by netlink messages.
Netfilter
---------
- Rewrite the procfs conntrack table implementation, improving
considerably the dump performance. A lot of user-space tools
still use this interface.
- Implement support for wildcard netdevice in netdev basechain
and flowtables.
- Integrate conntrack information into nft trace infrastructure.
- Export set count and backend name to userspace, for better
introspection.
BPF
---
- BPF qdisc support: BPF-qdisc can be implemented with BPF struct_ops
programs and can be controlled in similar way to traditional qdiscs
using the "tc qdisc" command.
- Refactor the UDP socket iterator, addressing long standing issues
WRT duplicate hits or missed sockets.
Protocols
---------
- Improve TCP receive buffer auto-tuning and increase the default
upper bound for the receive buffer; overall this improves the single
flow maximum thoughput on 200Gbs link by over 60%.
- Add AFS GSSAPI security class to AF_RXRPC; it provides transport
security for connections to the AFS fileserver and VL server.
- Improve TCP multipath routing, so that the sources address always
matches the nexthop device.
- Introduce SO_PASSRIGHTS for AF_UNIX, to allow disabling SCM_RIGHTS,
and thus preventing DoS caused by passing around problematic FDs.
- Retire DCCP socket. DCCP only receives updates for bugs, and major
distros disable it by default. Its removal allows for better
organisation of TCP fields to reduce the number of cache lines hit
in the fast path.
- Extend TCP drop-reason support to cover PAWS checks.
Driver API
----------
- Reorganize PTP ioctl flag support to require an explicit opt-in for
the drivers, avoiding the problem of drivers not rejecting new
unsupported flags.
- Converted several device drivers to timestamping APIs.
- Introduce per-PHY ethtool dump helpers, improving the support for
dump operations targeting PHYs.
Tests and tooling
-----------------
- Add support for classic netlink in user space C codegen, so that
ynl-c can now read, create and modify links, routes addresses and
qdisc layer configuration.
- Add ynl sub-types for binary attributes, allowing ynl-c to output
known struct instead of raw binary data, clarifying the classic
netlink output.
- Extend MPTCP selftests to improve the code-coverage.
- Add tests for XDP tail adjustment in AF_XDP.
New hardware / drivers
----------------------
- OpenVPN virtual driver: offload OpenVPN data channels processing
to the kernel-space, increasing the data transfer throughput WRT
the user-space implementation.
- Renesas glue driver for the gigabit ethernet RZ/V2H(P) SoC.
- Broadcom asp-v3.0 ethernet driver.
- AMD Renoir ethernet device.
- ReakTek MT9888 2.5G ethernet PHY driver.
- Aeonsemi 10G C45 PHYs driver.
Drivers
-------
- Ethernet high-speed NICs:
- nVidia/Mellanox (mlx5):
- refactor the stearing table handling to reduce significantly
the amount of memory used
- add support for complex matches in H/W flow steering
- improve flow streeing error handling
- convert to netdev instance locking
- Intel (100G, ice, igb, ixgbe, idpf):
- ice: add switchdev support for LLDP traffic over VF
- ixgbe: add firmware manipulation and regions devlink support
- igb: introduce support for frame transmission premption
- igb: adds persistent NAPI configuration
- idpf: introduce RDMA support
- idpf: add initial PTP support
- Meta (fbnic):
- extend hardware stats coverage
- add devlink dev flash support
- Broadcom (bnxt):
- add support for RX-side device memory TCP
- Wangxun (txgbe):
- implement support for udp tunnel offload
- complete PTP and SRIOV support for AML 25G/10G devices
- Ethernet NICs embedded and virtual:
- Google (gve):
- add device memory TCP TX support
- Amazon (ena):
- support persistent per-NAPI config
- Airoha:
- add H/W support for L2 traffic offload
- add per flow stats for flow offloading
- RealTek (rtl8211): add support for WoL magic packet
- Synopsys (stmmac):
- dwmac-socfpga 1000BaseX support
- add Loongson-2K3000 support
- introduce support for hardware-accelerated VLAN stripping
- Broadcom (bcmgenet):
- expose more H/W stats
- Freescale (enetc, dpaa2-eth):
- enetc: add MAC filter, VLAN filter RSS and loopback support
- dpaa2-eth: convert to H/W timestamping APIs
- vxlan: convert FDB table to rhashtable, for better scalabilty
- veth: apply qdisc backpressure on full ring to reduce TX drops
- Ethernet switches:
- Microchip (kzZ88x3): add ETS scheduler support
- Ethernet PHYs:
- RealTek (rtl8211):
- add support for WoL magic packet
- add support for PHY LEDs
- CAN:
- Adds RZ/G3E CANFD support to the rcar_canfd driver.
- Preparatory work for CAN-XL support.
- Add self-tests framework with support for CAN physical interfaces.
- WiFi:
- mac80211:
- scan improvements with multi-link operation (MLO)
- Qualcomm (ath12k):
- enable AHB support for IPQ5332
- add monitor interface support to QCN9274
- add multi-link operation support to WCN7850
- add 802.11d scan offload support to WCN7850
- monitor mode for WCN7850, better 6 GHz regulatory
- Qualcomm (ath11k):
- restore hibernation support
- MediaTek (mt76):
- WiFi-7 improvements
- implement support for mt7990
- Intel (iwlwifi):
- enhanced multi-link single-radio (EMLSR) support on 5 GHz links
- rework device configuration
- RealTek (rtw88):
- improve throughput for RTL8814AU
- RealTek (rtw89):
- add multi-link operation support
- STA/P2P concurrency improvements
- support different SAR configs by antenna
- Bluetooth:
- introduce HCI Driver protocol
- btintel_pcie: do not generate coredump for diagnostic events
- btusb: add HCI Drv commands for configuring altsetting
- btusb: add RTL8851BE device 0x0bda:0xb850
- btusb: add new VID/PID 13d3/3584 for MT7922
- btusb: add new VID/PID 13d3/3630 and 13d3/3613 for MT7925
- btnxpuart: implement host-wakeup feature
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Paolo Abeni:
"Core:
- Implement the Device Memory TCP transmit path, allowing zero-copy
data transmission on top of TCP from e.g. GPU memory to the wire.
- Move all the IPv6 routing tables management outside the RTNL scope,
under its own lock and RCU. The route control path is now 3x times
faster.
- Convert queue related netlink ops to instance lock, reducing again
the scope of the RTNL lock. This improves the control plane
scalability.
- Refactor the software crc32c implementation, removing unneeded
abstraction layers and improving significantly the related
micro-benchmarks.
- Optimize the GRO engine for UDP-tunneled traffic, for a 10%
performance improvement in related stream tests.
- Cover more per-CPU storage with local nested BH locking; this is a
prep work to remove the current per-CPU lock in local_bh_disable()
on PREMPT_RT.
- Introduce and use nlmsg_payload helper, combining buffer bounds
verification with accessing payload carried by netlink messages.
Netfilter:
- Rewrite the procfs conntrack table implementation, improving
considerably the dump performance. A lot of user-space tools still
use this interface.
- Implement support for wildcard netdevice in netdev basechain and
flowtables.
- Integrate conntrack information into nft trace infrastructure.
- Export set count and backend name to userspace, for better
introspection.
BPF:
- BPF qdisc support: BPF-qdisc can be implemented with BPF struct_ops
programs and can be controlled in similar way to traditional qdiscs
using the "tc qdisc" command.
- Refactor the UDP socket iterator, addressing long standing issues
WRT duplicate hits or missed sockets.
Protocols:
- Improve TCP receive buffer auto-tuning and increase the default
upper bound for the receive buffer; overall this improves the
single flow maximum thoughput on 200Gbs link by over 60%.
- Add AFS GSSAPI security class to AF_RXRPC; it provides transport
security for connections to the AFS fileserver and VL server.
- Improve TCP multipath routing, so that the sources address always
matches the nexthop device.
- Introduce SO_PASSRIGHTS for AF_UNIX, to allow disabling SCM_RIGHTS,
and thus preventing DoS caused by passing around problematic FDs.
- Retire DCCP socket. DCCP only receives updates for bugs, and major
distros disable it by default. Its removal allows for better
organisation of TCP fields to reduce the number of cache lines hit
in the fast path.
- Extend TCP drop-reason support to cover PAWS checks.
Driver API:
- Reorganize PTP ioctl flag support to require an explicit opt-in for
the drivers, avoiding the problem of drivers not rejecting new
unsupported flags.
- Converted several device drivers to timestamping APIs.
- Introduce per-PHY ethtool dump helpers, improving the support for
dump operations targeting PHYs.
Tests and tooling:
- Add support for classic netlink in user space C codegen, so that
ynl-c can now read, create and modify links, routes addresses and
qdisc layer configuration.
- Add ynl sub-types for binary attributes, allowing ynl-c to output
known struct instead of raw binary data, clarifying the classic
netlink output.
- Extend MPTCP selftests to improve the code-coverage.
- Add tests for XDP tail adjustment in AF_XDP.
New hardware / drivers:
- OpenVPN virtual driver: offload OpenVPN data channels processing to
the kernel-space, increasing the data transfer throughput WRT the
user-space implementation.
- Renesas glue driver for the gigabit ethernet RZ/V2H(P) SoC.
- Broadcom asp-v3.0 ethernet driver.
- AMD Renoir ethernet device.
- ReakTek MT9888 2.5G ethernet PHY driver.
- Aeonsemi 10G C45 PHYs driver.
Drivers:
- Ethernet high-speed NICs:
- nVidia/Mellanox (mlx5):
- refactor the steering table handling to significantly
reduce the amount of memory used
- add support for complex matches in H/W flow steering
- improve flow streeing error handling
- convert to netdev instance locking
- Intel (100G, ice, igb, ixgbe, idpf):
- ice: add switchdev support for LLDP traffic over VF
- ixgbe: add firmware manipulation and regions devlink support
- igb: introduce support for frame transmission premption
- igb: adds persistent NAPI configuration
- idpf: introduce RDMA support
- idpf: add initial PTP support
- Meta (fbnic):
- extend hardware stats coverage
- add devlink dev flash support
- Broadcom (bnxt):
- add support for RX-side device memory TCP
- Wangxun (txgbe):
- implement support for udp tunnel offload
- complete PTP and SRIOV support for AML 25G/10G devices
- Ethernet NICs embedded and virtual:
- Google (gve):
- add device memory TCP TX support
- Amazon (ena):
- support persistent per-NAPI config
- Airoha:
- add H/W support for L2 traffic offload
- add per flow stats for flow offloading
- RealTek (rtl8211): add support for WoL magic packet
- Synopsys (stmmac):
- dwmac-socfpga 1000BaseX support
- add Loongson-2K3000 support
- introduce support for hardware-accelerated VLAN stripping
- Broadcom (bcmgenet):
- expose more H/W stats
- Freescale (enetc, dpaa2-eth):
- enetc: add MAC filter, VLAN filter RSS and loopback support
- dpaa2-eth: convert to H/W timestamping APIs
- vxlan: convert FDB table to rhashtable, for better scalabilty
- veth: apply qdisc backpressure on full ring to reduce TX drops
- Ethernet switches:
- Microchip (kzZ88x3): add ETS scheduler support
- Ethernet PHYs:
- RealTek (rtl8211):
- add support for WoL magic packet
- add support for PHY LEDs
- CAN:
- Adds RZ/G3E CANFD support to the rcar_canfd driver.
- Preparatory work for CAN-XL support.
- Add self-tests framework with support for CAN physical interfaces.
- WiFi:
- mac80211:
- scan improvements with multi-link operation (MLO)
- Qualcomm (ath12k):
- enable AHB support for IPQ5332
- add monitor interface support to QCN9274
- add multi-link operation support to WCN7850
- add 802.11d scan offload support to WCN7850
- monitor mode for WCN7850, better 6 GHz regulatory
- Qualcomm (ath11k):
- restore hibernation support
- MediaTek (mt76):
- WiFi-7 improvements
- implement support for mt7990
- Intel (iwlwifi):
- enhanced multi-link single-radio (EMLSR) support on 5 GHz links
- rework device configuration
- RealTek (rtw88):
- improve throughput for RTL8814AU
- RealTek (rtw89):
- add multi-link operation support
- STA/P2P concurrency improvements
- support different SAR configs by antenna
- Bluetooth:
- introduce HCI Driver protocol
- btintel_pcie: do not generate coredump for diagnostic events
- btusb: add HCI Drv commands for configuring altsetting
- btusb: add RTL8851BE device 0x0bda:0xb850
- btusb: add new VID/PID 13d3/3584 for MT7922
- btusb: add new VID/PID 13d3/3630 and 13d3/3613 for MT7925
- btnxpuart: implement host-wakeup feature"
* tag 'net-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1611 commits)
selftests/bpf: Fix bpf selftest build warning
selftests: netfilter: Fix skip of wildcard interface test
net: phy: mscc: Stop clearing the the UDPv4 checksum for L2 frames
net: openvswitch: Fix the dead loop of MPLS parse
calipso: Don't call calipso functions for AF_INET sk.
selftests/tc-testing: Add a test for HFSC eltree double add with reentrant enqueue behaviour on netem
net_sched: hfsc: Address reentrant enqueue adding class to eltree twice
octeontx2-pf: QOS: Refactor TC_HTB_LEAF_DEL_LAST callback
octeontx2-pf: QOS: Perform cache sync on send queue teardown
net: mana: Add support for Multi Vports on Bare metal
net: devmem: ncdevmem: remove unused variable
net: devmem: ksft: upgrade rx test to send 1K data
net: devmem: ksft: add 5 tuple FS support
net: devmem: ksft: add exit_wait to make rx test pass
net: devmem: ksft: add ipv4 support
net: devmem: preserve sockc_err
page_pool: fix ugly page_pool formatting
net: devmem: move list_add to net_devmem_bind_dmabuf.
selftests: netfilter: nft_queue.sh: include file transfer duration in log message
net: phy: mscc: Fix memory leak when using one step timestamping
...
- cgroup rstat shared the tracking tree across all controlers with the
rationale being that a cgroup which is using one resource is likely to be
using other resources at the same time (ie. if something is allocating
memory, it's probably consuming CPU cycles). However, this turned out to
not scale very well especially with memcg using rstat for internal
operations which made memcg stat read and flush patterns substantially
different from other controllers. JP Kobryn split the rstat tree per
controller.
- cgroup BPF support was hooking into cgroup init/exit paths directly.
Convert them to use a notifier chain instead so that other usages can be
added easily. The two of the patches which implement this are mislabeled
as belonging to sched_ext instead of cgroup. Sorry.
- Relatively minor cpuset updates.
- Documentation updates.
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Merge tag 'cgroup-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cgroup rstat shared the tracking tree across all controllers with the
rationale being that a cgroup which is using one resource is likely
to be using other resources at the same time (ie. if something is
allocating memory, it's probably consuming CPU cycles).
However, this turned out to not scale very well especially with memcg
using rstat for internal operations which made memcg stat read and
flush patterns substantially different from other controllers. JP
Kobryn split the rstat tree per controller.
- cgroup BPF support was hooking into cgroup init/exit paths directly.
Convert them to use a notifier chain instead so that other usages can
be added easily. The two of the patches which implement this are
mislabeled as belonging to sched_ext instead of cgroup. Sorry.
- Relatively minor cpuset updates
- Documentation updates
* tag 'cgroup-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (23 commits)
sched_ext: Convert cgroup BPF support to use cgroup_lifetime_notifier
sched_ext: Introduce cgroup_lifetime_notifier
cgroup: Minor reorganization of cgroup_create()
cgroup, docs: cpu controller's interaction with various scheduling policies
cgroup, docs: convert space indentation to tab indentation
cgroup: avoid per-cpu allocation of size zero rstat cpu locks
cgroup, docs: be specific about bandwidth control of rt processes
cgroup: document the rstat per-cpu initialization
cgroup: helper for checking rstat participation of css
cgroup: use subsystem-specific rstat locks to avoid contention
cgroup: use separate rstat trees for each subsystem
cgroup: compare css to cgroup::self in helper for distingushing css
cgroup: warn on rstat usage by early init subsystems
cgroup/cpuset: drop useless cpumask_empty() in compute_effective_exclusive_cpumask()
cgroup/rstat: Improve cgroup_rstat_push_children() documentation
cgroup: fix goto ordering in cgroup_init()
cgroup: fix pointer check in css_rstat_init()
cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs
cgroup/cpuset: Fix obsolete comment in cpuset_css_offline()
cgroup/cpuset: Always use cpu_active_mask
...
Add two tests:
- one test has 'rX <op> r10' where rX is not r10, and
- another test has 'rX <op> rY' where rX and rY are not r10
but there is an early insn 'rX = r10'.
Without previous verifier change, both tests will fail.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250524041340.4046304-1-yonghong.song@linux.dev
syzkaller reported an issue:
WARNING: CPU: 3 PID: 217 at kernel/bpf/core.c:2357 __bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357
Modules linked in:
CPU: 3 UID: 0 PID: 217 Comm: kworker/u32:6 Not tainted 6.15.0-rc4-syzkaller-00040-g8bac8898fe39
RIP: 0010:__bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357
Call Trace:
<TASK>
bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
__bpf_prog_run include/linux/filter.h:718 [inline]
bpf_prog_run include/linux/filter.h:725 [inline]
cls_bpf_classify+0x74a/0x1110 net/sched/cls_bpf.c:105
...
When creating bpf program, 'fp->jit_requested' depends on bpf_jit_enable.
This issue is triggered because of CONFIG_BPF_JIT_ALWAYS_ON is not set
and bpf_jit_enable is set to 1, causing the arch to attempt JIT the prog,
but jit failed due to FAULT_INJECTION. As a result, incorrectly
treats the program as valid, when the program runs it calls
`__bpf_prog_ret0_warn` and triggers the WARN_ON_ONCE(1).
Reported-by: syzbot+0903f6d7f285e41cdf10@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/6816e34e.a70a0220.254cdc.002c.GAE@google.com
Fixes: fa9dd599b4 ("bpf: get rid of pure_initcall dependency to enable jits")
Signed-off-by: KaFai Wan <mannkafai@gmail.com>
Link: https://lore.kernel.org/r/20250526133358.2594176-1-mannkafai@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Marc Suñé (Isovalent, part of Cisco) reported an issue where an
uninitialized variable caused generating bpf prog binary code not
working as expected. The reproducer is in [1] where the flags
“-Wall -Werror” are enabled, but there is no warning as the compiler
takes advantage of uninitialized variable to do aggressive optimization.
The optimized code looks like below:
; {
0: bf 16 00 00 00 00 00 00 r6 = r1
; bpf_printk("Start");
1: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0x0 ll
0000000000000008: R_BPF_64_64 .rodata
3: b4 02 00 00 06 00 00 00 w2 = 0x6
4: 85 00 00 00 06 00 00 00 call 0x6
; DEFINE_FUNC_CTX_POINTER(data)
5: 61 61 4c 00 00 00 00 00 w1 = *(u32 *)(r6 + 0x4c)
; bpf_printk("pre ipv6_hdrlen_offset");
6: 18 01 00 00 06 00 00 00 00 00 00 00 00 00 00 00 r1 = 0x6 ll
0000000000000030: R_BPF_64_64 .rodata
8: b4 02 00 00 17 00 00 00 w2 = 0x17
9: 85 00 00 00 06 00 00 00 call 0x6
<END>
The verifier will report the following failure:
9: (85) call bpf_trace_printk#6
last insn is not an exit or jmp
The above verifier log does not give a clear hint about how to fix
the problem and user may take quite some time to figure out that
the issue is due to compiler taking advantage of uninitialized variable.
In llvm internals, uninitialized variable usage may generate
'unreachable' IR insn and these 'unreachable' IR insns may indicate
uninitialized variable impact on code optimization. So far, llvm
BPF backend ignores 'unreachable' IR hence the above code is generated.
With clang21 patch [2], those 'unreachable' IR insn are converted
to func __bpf_trap(). In order to maintain proper control flow
graph for bpf progs, [2] also adds an 'exit' insn after bpf_trap()
if __bpf_trap() is the last insn in the function. The new code looks like:
; {
0: bf 16 00 00 00 00 00 00 r6 = r1
; bpf_printk("Start");
1: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0x0 ll
0000000000000008: R_BPF_64_64 .rodata
3: b4 02 00 00 06 00 00 00 w2 = 0x6
4: 85 00 00 00 06 00 00 00 call 0x6
; DEFINE_FUNC_CTX_POINTER(data)
5: 61 61 4c 00 00 00 00 00 w1 = *(u32 *)(r6 + 0x4c)
; bpf_printk("pre ipv6_hdrlen_offset");
6: 18 01 00 00 06 00 00 00 00 00 00 00 00 00 00 00 r1 = 0x6 ll
0000000000000030: R_BPF_64_64 .rodata
8: b4 02 00 00 17 00 00 00 w2 = 0x17
9: 85 00 00 00 06 00 00 00 call 0x6
10: 85 10 00 00 ff ff ff ff call -0x1
0000000000000050: R_BPF_64_32 __bpf_trap
11: 95 00 00 00 00 00 00 00 exit
<END>
In kernel, a new kfunc __bpf_trap() is added. During insn
verification, any hit with __bpf_trap() will result in
verification failure. The kernel is able to provide better
log message for debugging.
With llvm patch [2] and without this patch (no __bpf_trap()
kfunc for existing kernel), e.g., for old kernels, the verifier
outputs
10: <invalid kfunc call>
kfunc '__bpf_trap' is referenced but wasn't resolved
Basically, kernel does not support __bpf_trap() kfunc.
This still didn't give clear signals about possible reason.
With llvm patch [2] and with this patch, the verifier outputs
10: (85) call __bpf_trap#74479
unexpected __bpf_trap() due to uninitialized variable?
It gives much better hints for verification failure.
[1] https://github.com/msune/clang_bpf/blob/main/Makefile#L3
[2] https://github.com/llvm/llvm-project/pull/131731
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250523205326.1291640-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, the verifier has both special_kfunc_set and special_kfunc_list.
When adding a new kfunc usage to the verifier, it is often confusing
about whether special_kfunc_set or special_kfunc_list or both should
add that kfunc. For example, some kfuncs, e.g., bpf_dynptr_from_skb,
bpf_dynptr_clone, bpf_wq_set_callback_impl, does not need to be
in special_kfunc_set.
To avoid potential future confusion, special_kfunc_set is deleted
and btf_id_set_contains(&special_kfunc_set, ...) is removed.
The code is refactored with a new func check_special_kfunc(),
which contains all codes covered by original branch
meta.btf == btf_vmlinux && btf_id_set_contains(&special_kfunc_set, meta.func_id)
There is no functionality change.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250523205321.1291431-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This open coded iterator allows for more flexibility when creating BPF
programs. It can support output in formats other than text. With an open
coded iterator, a single BPF program can traverse multiple kernel data
structures (now including dmabufs), allowing for more efficient analysis
of kernel data compared to multiple reads from procfs, sysfs, or
multiple traditional BPF iterator invocations.
Signed-off-by: T.J. Mercier <tjmercier@google.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250522230429.941193-4-tjmercier@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The dmabuf iterator traverses the list of all DMA buffers.
DMA buffers are refcounted through their associated struct file. A
reference is taken on each buffer as the list is iterated to ensure each
buffer persists for the duration of the bpf program execution without
holding the list mutex.
Signed-off-by: T.J. Mercier <tjmercier@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250522230429.941193-3-tjmercier@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Merge tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs directory lookup updates from Christian Brauner:
"This contains cleanups for the lookup_one*() family of helpers.
We expose a set of functions with names containing "lookup_one_len"
and others without the "_len". This difference has nothing to do with
"len". It's rater a historical accident that can be confusing.
The functions without "_len" take a "mnt_idmap" pointer. This is found
in the "vfsmount" and that is an important question when choosing
which to use: do you have a vfsmount, or are you "inside" the
filesystem. A related question is "is permission checking relevant
here?".
nfsd and cachefiles *do* have a vfsmount but *don't* use the non-_len
functions. They pass nop_mnt_idmap and refuse to work on filesystems
which have any other idmap.
This work changes nfsd and cachefile to use the lookup_one family of
functions and to explictily pass &nop_mnt_idmap which is consistent
with all other vfs interfaces used where &nop_mnt_idmap is explicitly
passed.
The remaining uses of the "_one" functions do not require permission
checks so these are renamed to be "_noperm" and the permission
checking is removed.
This series also changes these lookup function to take a qstr instead
of separate name and len. In many cases this simplifies the call"
* tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
VFS: change lookup_one_common and lookup_noperm_common to take a qstr
Use try_lookup_noperm() instead of d_hash_and_lookup() outside of VFS
VFS: rename lookup_one_len family to lookup_noperm and remove permission check
cachefiles: Use lookup_one() rather than lookup_one_len()
nfsd: Use lookup_one() rather than lookup_one_len()
VFS: improve interface for lookup_one functions
User space needs access to kernel BTF for many modern features of BPF.
Right now each process needs to read the BTF blob either in pieces or
as a whole. Allow mmaping the sysfs file so that processes can directly
access the memory allocated for it in the kernel.
remap_pfn_range is used instead of vm_insert_page due to aarch64
compatibility issues.
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://lore.kernel.org/bpf/20250520-vmlinux-mmap-v5-1-e8c941acc414@isovalent.com
The "try_" prefix is confusing, since it made people believe that
try_alloc_pages() is analogous to spin_trylock() and NULL return means
EAGAIN. This is not the case. If it returns NULL there is no reason to
call it again. It will most likely return NULL again. Hence rename it to
alloc_pages_nolock() to make it symmetrical to free_pages_nolock() and
document that NULL means ENOMEM.
Link: https://lkml.kernel.org/r/20250517003446.60260-1-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Throughout the verifier's logic, there are multiple checks for
inconsistent states that should never happen and would indicate a
verifier bug. These bugs are typically logged in the verifier logs and
sometimes preceded by a WARN_ONCE.
This patch reworks these checks to consistently emit a verifier log AND
a warning when CONFIG_DEBUG_KERNEL is enabled. The consistent use of
WARN_ONCE should help fuzzers (ex. syzkaller) expose any situation
where they are actually able to reach one of those buggy verifier
states.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/aCs1nYvNNMq8dAWP@mail.gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There is currently some confusion in the s390x JIT regarding whether
orig_call can be NULL and what that means. Originally the NULL value
was used to distinguish the struct_ops case, but this was superseded by
BPF_TRAMP_F_INDIRECT (see commit 0c970ed2f8 ("s390/bpf: Fix indirect
trampoline generation").
The remaining reason to have this check is that NULL can actually be
passed to the arch_bpf_trampoline_size() call - but not to the
respective arch_prepare_bpf_trampoline()! call - by
bpf_struct_ops_prepare_trampoline().
Remove this asymmetry by passing stub_func to both functions, so that
JITs may rely on orig_call never being NULL.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250512221911.61314-2-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Instead of hardcoding the list of kfuncs that need prog->aux passed to
them with a combination of fixup_kfunc_call adjustment + __ign suffix,
combine both in __prog suffix, which ignores the argument passed in, and
fixes it up to the prog->aux. This allows kfuncs to have the prog->aux
passed into them without having to touch the verifier.
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250513142812.1021591-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch introduces a new set of kfuncs for working with dynptrs in
BPF programs, enabling reading variable-length user or kernel data
into dynptr directly. To enable memory-safety, verifier allows only
constant-sized reads via existing bpf_probe_read_{user|kernel} etc.
kfuncs, dynptr-based kfuncs allow dynamically-sized reads without memory
safety shortcomings.
The following kfuncs are introduced:
* `bpf_probe_read_kernel_dynptr()`: probes kernel-space data into a dynptr
* `bpf_probe_read_user_dynptr()`: probes user-space data into a dynptr
* `bpf_probe_read_kernel_str_dynptr()`: probes kernel-space string into
a dynptr
* `bpf_probe_read_user_str_dynptr()`: probes user-space string into a
dynptr
* `bpf_copy_from_user_dynptr()`: sleepable, copies user-space data into
a dynptr for the current task
* `bpf_copy_from_user_str_dynptr()`: sleepable, copies user-space string
into a dynptr for the current task
* `bpf_copy_from_user_task_dynptr()`: sleepable, copies user-space data
of the task into a dynptr
* `bpf_copy_from_user_task_str_dynptr()`: sleepable, copies user-space
string of the task into a dynptr
The implementation is built on two generic functions:
* __bpf_dynptr_copy
* __bpf_dynptr_copy_str
These functions take function pointers as arguments, enabling the
copying of data from various sources, including both kernel and user
space.
Use __always_inline for generic functions and callbacks to make sure the
compiler doesn't generate indirect calls into callbacks, which is more
expensive, especially on some kernel configurations. Inlining allows
compiler to put direct calls into all the specific callback implementations
(copy_user_data_sleepable, copy_user_data_nofault, and so on).
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20250512205348.191079-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Make bpf_dynptr_slice_rdwr, bpf_dynptr_check_off_len and
__bpf_dynptr_write available outside of the helpers.c by
adding their prototypes into linux/include/bpf.h.
bpf_dynptr_check_off_len() implementation is moved to header and made
inline explicitly, as small function should typically be inlined.
These functions are going to be used from bpf_trace.c in the next
patch of this series.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20250512205348.191079-2-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding support to retrieve ref_ctr_offset for uprobe perf link,
which got somehow omitted from the initial uprobe link info changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/bpf/20250509153539.779599-2-jolsa@kernel.org
In preparation for supporting BPF load-acquire and store-release
instructions for architectures where bpf_jit_needs_zext() returns true
(e.g. riscv64), make insn_def_regno() handle load-acquires properly.
Acked-by: Björn Töpel <bjorn@kernel.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com> # QEMU/RVA23
Signed-off-by: Peilin Ye <yepeilin@google.com>
Reviewed-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/r/09cb2aec979aaed9d16db41f0f5b364de39377c0.1746588351.git.yepeilin@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In the kernel fq qdisc implementation, it only needs to look at
the fields of the first node in a list but does not always
need to remove it from the list. It is more convenient to have
a peek kfunc for the list. It works similar to the bpf_rbtree_first().
This patch adds bpf_list_{front,back} kfunc. The verifier is changed
such that the kfunc returning "struct bpf_list_node *" will be
marked as non-owning. The exception is the KF_ACQUIRE kfunc. The
net effect is only the new bpf_list_{front,back} kfuncs will
have its return pointer marked as non-owning.
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-8-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The next patch will add bpf_list_{front,back} kfuncs to peek the head
and tail of a list. Both of them will return a 'struct bpf_list_node *'.
Follow the earlier change for rbtree, this patch checks the
return btf type is a 'struct bpf_list_node' pointer instead
of checking each kfuncs individually to decide if
mark_reg_graph_node should be called. This will make
the bpf_list_{front,back} kfunc addition easier in
the later patch.
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-7-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The bpf_rbtree_{remove,left,right} requires the root's lock to be held.
They also check the node_internal->owner is still owned by that root
before proceeding, so it is safe to allow refcounted bpf_rb_node
pointer to be used in these kfuncs.
In a bpf fq implementation which is much closer to the kernel fq,
https://lore.kernel.org/bpf/20250418224652.105998-13-martin.lau@linux.dev/,
a networking flow (allocated by bpf_obj_new) can be added to two different
rbtrees. There are cases that the flow is searched from one rbtree,
held the refcount of the flow, and then removed from another rbtree:
struct fq_flow {
struct bpf_rb_node fq_node;
struct bpf_rb_node rate_node;
struct bpf_refcount refcount;
unsigned long sk_long;
};
int bpf_fq_enqueue(...)
{
/* ... */
bpf_spin_lock(&root->lock);
while (can_loop) {
/* ... */
if (!p)
break;
gc_f = bpf_rb_entry(p, struct fq_flow, fq_node);
if (gc_f->sk_long == sk_long) {
f = bpf_refcount_acquire(gc_f);
break;
}
/* ... */
}
bpf_spin_unlock(&root->lock);
if (f) {
bpf_spin_lock(&q->lock);
bpf_rbtree_remove(&q->delayed, &f->rate_node);
bpf_spin_unlock(&q->lock);
}
}
bpf_rbtree_{left,right} do not need this change but are relaxed together
with bpf_rbtree_remove instead of adding extra verifier logic
to exclude these kfuncs.
To avoid bi-sect failure, this patch also changes the selftests together.
The "rbtree_api_remove_unadded_node" is not expecting verifier's error.
The test now expects bpf_rbtree_remove(&groot, &m->node) to return NULL.
The test uses __retval(0) to ensure this NULL return value.
Some of the "only take non-owning..." failure messages are changed also.
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-5-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In a bpf fq implementation that is much closer to the kernel fq,
it will need to traverse the rbtree:
https://lore.kernel.org/bpf/20250418224652.105998-13-martin.lau@linux.dev/
The much simplified logic that uses the bpf_rbtree_{root,left,right}
to traverse the rbtree is like:
struct fq_flow {
struct bpf_rb_node fq_node;
struct bpf_rb_node rate_node;
struct bpf_refcount refcount;
unsigned long sk_long;
};
struct fq_flow_root {
struct bpf_spin_lock lock;
struct bpf_rb_root root __contains(fq_flow, fq_node);
};
struct fq_flow *fq_classify(...)
{
struct bpf_rb_node *tofree[FQ_GC_MAX];
struct fq_flow_root *root;
struct fq_flow *gc_f, *f;
struct bpf_rb_node *p;
int i, fcnt = 0;
/* ... */
f = NULL;
bpf_spin_lock(&root->lock);
p = bpf_rbtree_root(&root->root);
while (can_loop) {
if (!p)
break;
gc_f = bpf_rb_entry(p, struct fq_flow, fq_node);
if (gc_f->sk_long == sk_long) {
f = bpf_refcount_acquire(gc_f);
break;
}
/* To be removed from the rbtree */
if (fcnt < FQ_GC_MAX && fq_gc_candidate(gc_f, jiffies_now))
tofree[fcnt++] = p;
if (gc_f->sk_long > sk_long)
p = bpf_rbtree_left(&root->root, p);
else
p = bpf_rbtree_right(&root->root, p);
}
/* remove from the rbtree */
for (i = 0; i < fcnt; i++) {
p = tofree[i];
tofree[i] = bpf_rbtree_remove(&root->root, p);
}
bpf_spin_unlock(&root->lock);
/* bpf_obj_drop the fq_flow(s) that have just been removed
* from the rbtree.
*/
for (i = 0; i < fcnt; i++) {
p = tofree[i];
if (p) {
gc_f = bpf_rb_entry(p, struct fq_flow, fq_node);
bpf_obj_drop(gc_f);
}
}
return f;
}
The above simplified code needs to traverse the rbtree for two purposes,
1) find the flow with the desired sk_long value
2) while searching for the sk_long, collect flows that are
the fq_gc_candidate. They will be removed from the rbtree.
This patch adds the bpf_rbtree_{root,left,right} kfunc to enable
the rbtree traversal. The returned bpf_rb_node pointer will be a
non-owning reference which is the same as the returned pointer
of the exisiting bpf_rbtree_first kfunc.
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-4-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The current rbtree kfunc, bpf_rbtree_{first, remove}, returns the
bpf_rb_node pointer. The check_kfunc_call currently checks the
kfunc btf_id instead of its return pointer type to decide
if it needs to do mark_reg_graph_node(reg0) and ref_set_non_owning(reg0).
The later patch will add bpf_rbtree_{root,left,right} that will also
return a bpf_rb_node pointer. Instead of adding more kfunc btf_id
checks to the "if" case, this patch changes the test to check the
kfunc's return type. is_rbtree_node_type() function is added to
test if a pointer type is a bpf_rb_node. The callers have already
skipped the modifiers of the pointer type.
A note on the ref_set_non_owning(), although bpf_rbtree_remove()
also returns a bpf_rb_node pointer, the bpf_rbtree_remove()
has the KF_ACQUIRE flag. Thus, its reg0 will not become non-owning.
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-3-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In a later patch, two new kfuncs will take the bpf_rb_node pointer arg.
struct bpf_rb_node *bpf_rbtree_left(struct bpf_rb_root *root,
struct bpf_rb_node *node);
struct bpf_rb_node *bpf_rbtree_right(struct bpf_rb_root *root,
struct bpf_rb_node *node);
In the check_kfunc_call, there is a "case KF_ARG_PTR_TO_RB_NODE"
to check if the reg->type should be an allocated pointer or should be
a non_owning_ref.
The later patch will need to ensure that the bpf_rb_node pointer passing
to the new bpf_rbtree_{left,right} must be a non_owning_ref. This
should be the same requirement as the existing bpf_rbtree_remove.
This patch swaps the current "if else" statement. Instead of checking
the bpf_rbtree_remove, it checks the bpf_rbtree_add. Then the new
bpf_rbtree_{left,right} will fall into the "else" case to make
the later patch simpler. bpf_rbtree_add should be the only
one that needs an allocated pointer.
This should be a no-op change considering there are only two kfunc(s)
taking bpf_rb_node pointer arg, rbtree_add and rbtree_remove.
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-2-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In the current implementation if the program is dev-bound to a specific
device, it will not be possible to perform XDP_REDIRECT into a DEVMAP
or CPUMAP even if the program is running in the driver NAPI context and
it is not attached to any map entry. This seems in contrast with the
explanation available in bpf_prog_map_compatible routine.
Fix the issue introducing __bpf_prog_map_compatible utility routine in
order to avoid bpf_prog_is_dev_bound() check running bpf_check_tail_call()
at program load time (bpf_prog_select_runtime()).
Continue forbidding to attach a dev-bound program to XDP maps
(BPF_MAP_TYPE_PROG_ARRAY, BPF_MAP_TYPE_DEVMAP and BPF_MAP_TYPE_CPUMAP).
Fixes: 3d76a4d3d4 ("bpf: XDP metadata RX kfuncs")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Add namespace to BPF internal symbols used by light skeleton
to prevent abuse and document with the code their allowed usage.
Fixes: b1d18a7574 ("bpf: Extend sys_bpf commands for bpf_syscall programs.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20250425014542.62385-1-alexei.starovoitov@gmail.com
The _safe variant used here gets the next element before running the callback,
avoiding the endless loop condition.
Signed-off-by: Brandon Kammerdiener <brandon.kammerdiener@intel.com>
Link: https://lore.kernel.org/r/20250424153246.141677-2-brandon.kammerdiener@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>
Adding support to access arguments with const void pointer arguments
in tracing programs.
Currently we allow tracing programs to access void pointers. If we try to
access argument which is pointer to const void like 2nd argument in kfree,
verifier will fail to load the program with;
0: R1=ctx() R10=fp0
; asm volatile ("r2 = *(u64 *)(r1 + 8); ");
0: (79) r2 = *(u64 *)(r1 +8)
func 'kfree' arg1 type UNKNOWN is not a struct
Changing the is_int_ptr to void and generic integer check and renaming
it to is_void_or_int_ptr.
Signed-off-by: KaFai Wan <mannkafai@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250423121329.3163461-2-mannkafai@gmail.com
The calculation of the index used to access the mask field in 'struct
bpf_raw_tp_null_args' is done with 'int' type, which could overflow when
the tracepoint being attached has more than 8 arguments.
While none of the tracepoints mentioned in raw_tp_null_args[] currently
have more than 8 arguments, there do exist tracepoints that had more
than 8 arguments (e.g. iocost_iocg_forgive_debt), so use the correct
type for calculation and avoid Smatch static checker warning.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20250418074946.35569-1-shung-hsi.yu@suse.com
Closes: https://lore.kernel.org/r/843a3b94-d53d-42db-93d4-be10a4090146@stanley.mountain/
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Martin KaFai Lau says:
====================
pull-request: bpf-next 2025-04-17
We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 18 files changed, 1748 insertions(+), 19 deletions(-).
The main changes are:
1) bpf qdisc support, from Amery Hung.
A qdisc can be implemented in bpf struct_ops programs and
can be used the same as other existing qdiscs in the
"tc qdisc" command.
2) Add xsk tail adjustment tests, from Tushar Vyavahare.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
selftests/bpf: Test attaching bpf qdisc to mq and non root
selftests/bpf: Add a bpf fq qdisc to selftest
selftests/bpf: Add a basic fifo qdisc test
libbpf: Support creating and destroying qdisc
bpf: net_sched: Disable attaching bpf qdisc to non root
bpf: net_sched: Support updating bstats
bpf: net_sched: Add a qdisc watchdog timer
bpf: net_sched: Add basic bpf qdisc kfuncs
bpf: net_sched: Support implementation of Qdisc_ops in bpf
bpf: Prepare to reuse get_ctx_arg_idx
selftests/xsk: Add tail adjustment tests and support check
selftests/xsk: Add packet stream replacement function
====================
Link: https://patch.msgid.link/20250417184338.3152168-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Rename get_ctx_arg_idx to bpf_ctx_arg_idx, and allow others to call it.
No functional change.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250409214606.2000194-2-ameryhung@gmail.com
Add a tracepoint to monitor TCP send operations, enabling detailed
visibility into TCP message transmission.
Create a new tracepoint within the tcp_sendmsg_locked function,
capturing traditional fields along with size_goal, which indicates the
optimal data size for a single TCP segment. Additionally, a reference to
the struct sock sk is passed, allowing direct access for BPF programs.
The implementation is largely based on David's patch[1] and suggestions.
Link: https://lore.kernel.org/all/70168c8f-bf52-4279-b4c4-be64527aa1ac@kernel.org/ [1]
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250408-tcpsendmsg-v3-2-208b87064c28@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The update of element in fd htab is in-place now, therefore, there is no
need to allocate per-cpu extra_elems, just remove it.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250401062250.543403-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As reported by Cody Haas [1], when there is concurrent map lookup and
map update operation in an existing element for htab of maps, the map
lookup procedure may return -ENOENT unexpectedly.
The root cause is twofold:
1) the update of existing element involves two separated list operation
In htab_map_update_elem(), it first inserts the new element at the head
of list, then it deletes the old element. Therefore, it is possible a
lookup operation has already iterated to the middle of the list when a
concurrent update operation begins, and the lookup operation will fail
to find the target element.
2) the immediate reuse of htab element.
It is more subtle. Even through the lookup operation finds the old
element, it is possible that the target element has been removed by a
concurrent update operation, and the element has been reused immediately
by other update operation which runs on the same CPU as the previous
update operation, and the element is inserted into the same bucket list.
After these steps above, when the lookup operation tries to compare the
key in the old element with the expected key, the match will fail
because the key in the old element have been overwritten by other update
operation.
The two-step update process is relatively straightforward to address.
The more challenging aspect is the immediate reuse. As Alexei pointed
out:
So since 2022 both prealloc and no_prealloc reuse elements.
We can consider a new flag for the hash map like F_REUSE_AFTER_RCU_GP
that will use _rcu() flavor of freeing into bpf_ma,
but it has to have a strong reason.
Given that htab of maps doesn't support special field in value and
directly stores the inner map pointer in htab_element, just do in-place
update for htab of maps instead of attempting to address the immediate
reuse issue.
[1]: https://lore.kernel.org/xdp-newbies/CAH7f-ULFTwKdoH_t2SFc5rWCVYLEg-14d1fBYWH2eekudsnTRg@mail.gmail.com/
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250401062250.543403-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Rename __htab_percpu_map_update_elem to htab_map_update_elem_in_place,
and add a new percpu argument for the helper to support in-place update
for both per-cpu htab and htab of maps.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250401062250.543403-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
All hash maps store map key and map value together. The relative offset
of the map value compared to the map key is round_up(key_size, 8).
Therefore, factor out a common helper htab_elem_value() to calculate the
address of the map value instead of duplicating the logic.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250401062250.543403-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The lookup_one_len family of functions is (now) only used internally by
a filesystem on itself either
- in a context where permission checking is irrelevant such as by a
virtual filesystem populating itself, or xfs accessing its ORPHANAGE
or dquota accessing the quota file; or
- in a context where a permission check (MAY_EXEC on the parent) has just
been performed such as a network filesystem finding in "silly-rename"
file in the same directory. This is also the context after the
_parentat() functions where currently lookup_one_qstr_excl() is used.
So the permission check is pointless.
The name "one_len" is unhelpful in understanding the purpose of these
functions and should be changed. Most of the callers pass the len as
"strlen()" so using a qstr and QSTR() can simplify the code.
This patch renames these functions (include lookup_positive_unlocked()
which is part of the family despite the name) to have a name based on
"lookup_noperm". They are changed to receive a 'struct qstr' instead
of separate name and len. In a few cases the use of QSTR() results in a
new call to strlen().
try_lookup_noperm() takes a pointer to a qstr instead of the whole
qstr. This is consistent with d_hash_and_lookup() (which is nearly
identical) and useful for lookup_noperm_unlocked().
The new lookup_noperm_common() doesn't take a qstr yet. That will be
tidied up in a subsequent patch.
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/r/20250319031545.2999807-5-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Merge tag 'bpf_try_alloc_pages' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf try_alloc_pages() support from Alexei Starovoitov:
"The pull includes work from Sebastian, Vlastimil and myself with a lot
of help from Michal and Shakeel.
This is a first step towards making kmalloc reentrant to get rid of
slab wrappers: bpf_mem_alloc, kretprobe's objpool, etc. These patches
make page allocator safe from any context.
Vlastimil kicked off this effort at LSFMM 2024:
https://lwn.net/Articles/974138/
and we continued at LSFMM 2025:
https://lore.kernel.org/all/CAADnVQKfkGxudNUkcPJgwe3nTZ=xohnRshx9kLZBTmR_E1DFEg@mail.gmail.com/
Why:
SLAB wrappers bind memory to a particular subsystem making it
unavailable to the rest of the kernel. Some BPF maps in production
consume Gbytes of preallocated memory. Top 5 in Meta: 1.5G, 1.2G,
1.1G, 300M, 200M. Once we have kmalloc that works in any context BPF
map preallocation won't be necessary.
How:
Synchronous kmalloc/page alloc stack has multiple stages going from
fast to slow: cmpxchg16 -> slab_alloc -> new_slab -> alloc_pages ->
rmqueue_pcplist -> __rmqueue, where rmqueue_pcplist was already
relying on trylock.
This set changes rmqueue_bulk/rmqueue_buddy to attempt a trylock and
return ENOMEM if alloc_flags & ALLOC_TRYLOCK. It then wraps this
functionality into try_alloc_pages() helper. We make sure that the
logic is sane in PREEMPT_RT.
End result: try_alloc_pages()/free_pages_nolock() are safe to call
from any context.
try_kmalloc() for any context with similar trylock approach will
follow. It will use try_alloc_pages() when slab needs a new page.
Though such try_kmalloc/page_alloc() is an opportunistic allocator,
this design ensures that the probability of successful allocation of
small objects (up to one page in size) is high.
Even before we have try_kmalloc(), we already use try_alloc_pages() in
BPF arena implementation and it's going to be used more extensively in
BPF"
* tag 'bpf_try_alloc_pages' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
mm: Fix the flipped condition in gfpflags_allow_spinning()
bpf: Use try_alloc_pages() to allocate pages for bpf needs.
mm, bpf: Use memcg in try_alloc_pages().
memcg: Use trylock to access memcg stock_lock.
mm, bpf: Introduce free_pages_nolock()
mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation
locking/local_lock: Introduce localtry_lock_t
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Merge tag 'bpf_res_spin_lock' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf relisient spinlock support from Alexei Starovoitov:
"This patch set introduces Resilient Queued Spin Lock (or rqspinlock
with res_spin_lock() and res_spin_unlock() APIs).
This is a qspinlock variant which recovers the kernel from a stalled
state when the lock acquisition path cannot make forward progress.
This can occur when a lock acquisition attempt enters a deadlock
situation (e.g. AA, or ABBA), or more generally, when the owner of the
lock (which we’re trying to acquire) isn’t making forward progress.
Deadlock detection is the main mechanism used to provide instant
recovery, with the timeout mechanism acting as a final line of
defense. Detection is triggered immediately when beginning the waiting
loop of a lock slow path.
Additionally, BPF programs attached to different parts of the kernel
can introduce new control flow into the kernel, which increases the
likelihood of deadlocks in code not written to handle reentrancy.
There have been multiple syzbot reports surfacing deadlocks in
internal kernel code due to the diverse ways in which BPF programs can
be attached to different parts of the kernel. By switching the BPF
subsystem’s lock usage to rqspinlock, all of these issues are
mitigated at runtime.
This spin lock implementation allows BPF maps to become safer and
remove mechanisms that have fallen short in assuring safety when
nesting programs in arbitrary ways in the same context or across
different contexts.
We run benchmarks that stress locking scalability and perform
comparison against the baseline (qspinlock). For the rqspinlock case,
we replace the default qspinlock with it in the kernel, such that all
spin locks in the kernel use the rqspinlock slow path. As such,
benchmarks that stress kernel spin locks end up exercising rqspinlock.
More details in the cover letter in commit 6ffb9017e9 ("Merge branch
'resilient-queued-spin-lock'")"
* tag 'bpf_res_spin_lock' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (24 commits)
selftests/bpf: Add tests for rqspinlock
bpf: Maintain FIFO property for rqspinlock unlock
bpf: Implement verifier support for rqspinlock
bpf: Introduce rqspinlock kfuncs
bpf: Convert lpm_trie.c to rqspinlock
bpf: Convert percpu_freelist.c to rqspinlock
bpf: Convert hashtab.c to rqspinlock
rqspinlock: Add locktorture support
rqspinlock: Add entry to Makefile, MAINTAINERS
rqspinlock: Add macros for rqspinlock usage
rqspinlock: Add basic support for CONFIG_PARAVIRT
rqspinlock: Add a test-and-set fallback
rqspinlock: Add deadlock detection and recovery
rqspinlock: Protect waiters in trylock fallback from stalls
rqspinlock: Protect waiters in queue from stalls
rqspinlock: Protect pending bit owners from stalls
rqspinlock: Hardcode cond_acquire loops for arm64
rqspinlock: Add support for timeouts
rqspinlock: Drop PV and virtualization support
rqspinlock: Add rqspinlock.h header
...
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Merge tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
"For this merge window we're splitting BPF pull request into three for
higher visibility: main changes, res_spin_lock, try_alloc_pages.
These are the main BPF changes:
- Add DFA-based live registers analysis to improve verification of
programs with loops (Eduard Zingerman)
- Introduce load_acquire and store_release BPF instructions and add
x86, arm64 JIT support (Peilin Ye)
- Fix loop detection logic in the verifier (Eduard Zingerman)
- Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet)
- Add kfunc for populating cpumask bits (Emil Tsalapatis)
- Convert various shell based tests to selftests/bpf/test_progs
format (Bastien Curutchet)
- Allow passing referenced kptrs into struct_ops callbacks (Amery
Hung)
- Add a flag to LSM bpf hook to facilitate bpf program signing
(Blaise Boscaccy)
- Track arena arguments in kfuncs (Ihor Solodrai)
- Add copy_remote_vm_str() helper for reading strings from remote VM
and bpf_copy_from_user_task_str() kfunc (Jordan Rome)
- Add support for timed may_goto instruction (Kumar Kartikeya
Dwivedi)
- Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy)
- Reduce bpf_cgrp_storage_busy false positives when accessing cgroup
local storage (Martin KaFai Lau)
- Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko)
- Allow retrieving BTF data with BTF token (Mykyta Yatsenko)
- Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix
(Song Liu)
- Reject attaching programs to noreturn functions (Yafang Shao)
- Introduce pre-order traversal of cgroup bpf programs (Yonghong
Song)"
* tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits)
selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
bpf: Fix out-of-bounds read in check_atomic_load/store()
libbpf: Add namespace for errstr making it libbpf_errstr
bpf: Add struct_ops context information to struct bpf_prog_aux
selftests/bpf: Sanitize pointer prior fclose()
selftests/bpf: Migrate test_xdp_vlan.sh into test_progs
selftests/bpf: test_xdp_vlan: Rename BPF sections
bpf: clarify a misleading verifier error message
selftests/bpf: Add selftest for attaching fexit to __noreturn functions
bpf: Reject attaching fexit/fmod_ret to __noreturn functions
bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage
bpf: Make perf_event_read_output accessible in all program types.
bpftool: Using the right format specifiers
bpftool: Add -Wformat-signedness flag to detect format errors
selftests/bpf: Test freplace from user namespace
libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
bpf: Return prog btf_id without capable check
bpf: BPF token support for BPF_BTF_GET_FD_BY_ID
bpf, x86: Fix objtool warning for timed may_goto
bpf: Check map->record at the beginning of check_and_free_fields()
...
Core & protocols
----------------
- Continue Netlink conversions to per-namespace RTNL lock
(IPv4 routing, routing rules, routing next hops, ARP ioctls).
- Continue extending the use of netdev instance locks. As a driver
opt-in protect queue operations and (in due course) ethtool
operations with the instance lock and not RTNL lock.
- Support collecting TCP timestamps (data submitted, sent, acked)
in BPF, allowing for transparent (to the application) and lower
overhead tracking of TCP RPC performance.
- Tweak existing networking Rx zero-copy infra to support zero-copy
Rx via io_uring.
- Optimize MPTCP performance in single subflow mode by 29%.
- Enable GRO on packets which went thru XDP CPU redirect (were queued
for processing on a different CPU). Improving TCP stream performance
up to 2x.
- Improve performance of contended connect() by 200% by searching
for an available 4-tuple under RCU rather than a spin lock.
Bring an additional 229% improvement by tweaking hash distribution.
- Avoid unconditionally touching sk_tsflags on RX, improving
performance under UDP flood by as much as 10%.
- Avoid skb_clone() dance in ping_rcv() to improve performance under
ping flood.
- Avoid FIB lookup in netfilter if socket is available, 20% perf win.
- Rework network device creation (in-kernel) API to more clearly
identify network namespaces and their roles.
There are up to 4 namespace roles but we used to have just 2 netns
pointer arguments, interpreted differently based on context.
- Use sysfs_break_active_protection() instead of trylock to avoid
deadlocks between unregistering objects and sysfs access.
- Add a new sysctl and sockopt for capping max retransmit timeout
in TCP.
- Support masking port and DSCP in routing rule matches.
- Support dumping IPv4 multicast addresses with RTM_GETMULTICAST.
- Support specifying at what time packet should be sent on AF_XDP
sockets.
- Expose TCP ULP diagnostic info (for TLS and MPTCP) to non-admin users.
- Add Netlink YAML spec for WiFi (nl80211) and conntrack.
- Introduce EXPORT_IPV6_MOD() and EXPORT_IPV6_MOD_GPL() for symbols
which only need to be exported when IPv6 support is built as a module.
- Age FDB entries based on Rx not Tx traffic in VxLAN, similar
to normal bridging.
- Allow users to specify source port range for GENEVE tunnels.
- netconsole: allow attaching kernel release, CPU ID and task name
to messages as metadata
Driver API
----------
- Continue rework / fixing of Energy Efficient Ethernet (EEE) across
the SW layers. Delegate the responsibilities to phylink where possible.
Improve its handling in phylib.
- Support symmetric OR-XOR RSS hashing algorithm.
- Support tracking and preserving IRQ affinity by NAPI itself.
- Support loopback mode speed selection for interface selftests.
Device drivers
--------------
- Remove the IBM LCS driver for s390.
- Remove the sb1000 cable modem driver.
- Add support for SFP module access over SMBus.
- Add MCTP transport driver for MCTP-over-USB.
- Enable XDP metadata support in multiple drivers.
- Ethernet high-speed NICs:
- Broadcom (bnxt):
- add PCIe TLP Processing Hints (TPH) support for new AMD platforms
- support dumping RoCE queue state for debug
- opt into instance locking
- Intel (100G, ice, idpf):
- ice: rework MSI-X IRQ management and distribution
- ice: support for E830 devices
- iavf: add support for Rx timestamping
- iavf: opt into instance locking
- nVidia/Mellanox:
- mlx4: use page pool memory allocator for Rx
- mlx5: support for one PTP device per hardware clock
- mlx5: support for 200Gbps per-lane link modes
- mlx5: move IPSec policy check after decryption
- AMD/Solarflare:
- support FW flashing via devlink
- Cisco (enic):
- use page pool memory allocator for Rx
- enable 32, 64 byte CQEs
- get max rx/tx ring size from the device
- Meta (fbnic):
- support flow steering and RSS configuration
- report queue stats
- support TCP segmentation
- support IRQ coalescing
- support ring size configuration
- Marvell/Cavium:
- support AF_XDP
- Wangxun:
- support for PTP clock and timestamping
- Huawei (hibmcge):
- checksum offload
- add more statistics
- Ethernet virtual:
- VirtIO net:
- aggressively suppress Tx completions, improve perf by 96% with
1 CPU and 55% with 2 CPUs
- expose NAPI to IRQ mapping and persist NAPI settings
- Google (gve):
- support XDP in DQO RDA Queue Format
- opt into instance locking
- Microsoft vNIC:
- support BIG TCP
- Ethernet NICs consumer, and embedded:
- Synopsys (stmmac):
- cleanup Tx and Tx clock setting and other link-focused cleanups
- enable SGMII and 2500BASEX mode switching for Intel platforms
- support Sophgo SG2044
- Broadcom switches (b53):
- support for BCM53101
- TI:
- iep: add perout configuration support
- icssg: support XDP
- Cadence (macb):
- implement BQL
- Xilinx (axinet):
- support dynamic IRQ moderation and changing coalescing at runtime
- implement BQL
- report standard stats
- MediaTek:
- support phylink managed EEE
- Intel:
- igc: don't restart the interface on every XDP program change
- RealTek (r8169):
- support reading registers of internal PHYs directly
- increase max jumbo packet size on RTL8125/RTL8126
- Airoha:
- support for RISC-V NPU packet processing unit
- enable scatter-gather and support MTU up to 9kB
- Tehuti (tn40xx):
- support cards with TN4010 MAC and an Aquantia AQR105 PHY
- Ethernet PHYs:
- support for TJA1102S, TJA1121
- dp83tg720: add randomized polling intervals for link detection
- dp83822: support changing the transmit amplitude voltage
- support for LEDs on 88q2xxx
- CAN:
- canxl: support Remote Request Substitution bit access
- flexcan: add S32G2/S32G3 SoC
- WiFi:
- remove cooked monitor support
- strict mode for better AP testing
- basic EPCS support
- OMI RX bandwidth reduction support
- batman-adv: add support for jumbo frames
- WiFi drivers:
- RealTek (rtw88):
- support RTL8814AE and RTL8814AU
- RealTek (rtw89):
- switch using wiphy_lock and wiphy_work
- add BB context to manipulate two PHY as preparation of MLO
- improve BT-coexistence mechanism to play A2DP smoothly
- Intel (iwlwifi):
- add new iwlmld sub-driver for latest HW/FW combinations
- MediaTek (mt76):
- preparation for mt7996 Multi-Link Operation (MLO) support
- Qualcomm/Atheros (ath12k):
- continued work on MLO
- Silabs (wfx):
- Wake-on-WLAN support
- Bluetooth:
- add support for skb TX SND/COMPLETION timestamping
- hci_core: enable buffer flow control for SCO/eSCO
- coredump: log devcd dumps into the monitor
- Bluetooth drivers:
- intel: add support to configure TX power
- nxp: handle bootloader error during cmd5 and cmd7
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Continue Netlink conversions to per-namespace RTNL lock
(IPv4 routing, routing rules, routing next hops, ARP ioctls)
- Continue extending the use of netdev instance locks. As a driver
opt-in protect queue operations and (in due course) ethtool
operations with the instance lock and not RTNL lock.
- Support collecting TCP timestamps (data submitted, sent, acked) in
BPF, allowing for transparent (to the application) and lower
overhead tracking of TCP RPC performance.
- Tweak existing networking Rx zero-copy infra to support zero-copy
Rx via io_uring.
- Optimize MPTCP performance in single subflow mode by 29%.
- Enable GRO on packets which went thru XDP CPU redirect (were queued
for processing on a different CPU). Improving TCP stream
performance up to 2x.
- Improve performance of contended connect() by 200% by searching for
an available 4-tuple under RCU rather than a spin lock. Bring an
additional 229% improvement by tweaking hash distribution.
- Avoid unconditionally touching sk_tsflags on RX, improving
performance under UDP flood by as much as 10%.
- Avoid skb_clone() dance in ping_rcv() to improve performance under
ping flood.
- Avoid FIB lookup in netfilter if socket is available, 20% perf win.
- Rework network device creation (in-kernel) API to more clearly
identify network namespaces and their roles. There are up to 4
namespace roles but we used to have just 2 netns pointer arguments,
interpreted differently based on context.
- Use sysfs_break_active_protection() instead of trylock to avoid
deadlocks between unregistering objects and sysfs access.
- Add a new sysctl and sockopt for capping max retransmit timeout in
TCP.
- Support masking port and DSCP in routing rule matches.
- Support dumping IPv4 multicast addresses with RTM_GETMULTICAST.
- Support specifying at what time packet should be sent on AF_XDP
sockets.
- Expose TCP ULP diagnostic info (for TLS and MPTCP) to non-admin
users.
- Add Netlink YAML spec for WiFi (nl80211) and conntrack.
- Introduce EXPORT_IPV6_MOD() and EXPORT_IPV6_MOD_GPL() for symbols
which only need to be exported when IPv6 support is built as a
module.
- Age FDB entries based on Rx not Tx traffic in VxLAN, similar to
normal bridging.
- Allow users to specify source port range for GENEVE tunnels.
- netconsole: allow attaching kernel release, CPU ID and task name to
messages as metadata
Driver API:
- Continue rework / fixing of Energy Efficient Ethernet (EEE) across
the SW layers. Delegate the responsibilities to phylink where
possible. Improve its handling in phylib.
- Support symmetric OR-XOR RSS hashing algorithm.
- Support tracking and preserving IRQ affinity by NAPI itself.
- Support loopback mode speed selection for interface selftests.
Device drivers:
- Remove the IBM LCS driver for s390
- Remove the sb1000 cable modem driver
- Add support for SFP module access over SMBus
- Add MCTP transport driver for MCTP-over-USB
- Enable XDP metadata support in multiple drivers
- Ethernet high-speed NICs:
- Broadcom (bnxt):
- add PCIe TLP Processing Hints (TPH) support for new AMD
platforms
- support dumping RoCE queue state for debug
- opt into instance locking
- Intel (100G, ice, idpf):
- ice: rework MSI-X IRQ management and distribution
- ice: support for E830 devices
- iavf: add support for Rx timestamping
- iavf: opt into instance locking
- nVidia/Mellanox:
- mlx4: use page pool memory allocator for Rx
- mlx5: support for one PTP device per hardware clock
- mlx5: support for 200Gbps per-lane link modes
- mlx5: move IPSec policy check after decryption
- AMD/Solarflare:
- support FW flashing via devlink
- Cisco (enic):
- use page pool memory allocator for Rx
- enable 32, 64 byte CQEs
- get max rx/tx ring size from the device
- Meta (fbnic):
- support flow steering and RSS configuration
- report queue stats
- support TCP segmentation
- support IRQ coalescing
- support ring size configuration
- Marvell/Cavium:
- support AF_XDP
- Wangxun:
- support for PTP clock and timestamping
- Huawei (hibmcge):
- checksum offload
- add more statistics
- Ethernet virtual:
- VirtIO net:
- aggressively suppress Tx completions, improve perf by 96%
with 1 CPU and 55% with 2 CPUs
- expose NAPI to IRQ mapping and persist NAPI settings
- Google (gve):
- support XDP in DQO RDA Queue Format
- opt into instance locking
- Microsoft vNIC:
- support BIG TCP
- Ethernet NICs consumer, and embedded:
- Synopsys (stmmac):
- cleanup Tx and Tx clock setting and other link-focused
cleanups
- enable SGMII and 2500BASEX mode switching for Intel platforms
- support Sophgo SG2044
- Broadcom switches (b53):
- support for BCM53101
- TI:
- iep: add perout configuration support
- icssg: support XDP
- Cadence (macb):
- implement BQL
- Xilinx (axinet):
- support dynamic IRQ moderation and changing coalescing at
runtime
- implement BQL
- report standard stats
- MediaTek:
- support phylink managed EEE
- Intel:
- igc: don't restart the interface on every XDP program change
- RealTek (r8169):
- support reading registers of internal PHYs directly
- increase max jumbo packet size on RTL8125/RTL8126
- Airoha:
- support for RISC-V NPU packet processing unit
- enable scatter-gather and support MTU up to 9kB
- Tehuti (tn40xx):
- support cards with TN4010 MAC and an Aquantia AQR105 PHY
- Ethernet PHYs:
- support for TJA1102S, TJA1121
- dp83tg720: add randomized polling intervals for link detection
- dp83822: support changing the transmit amplitude voltage
- support for LEDs on 88q2xxx
- CAN:
- canxl: support Remote Request Substitution bit access
- flexcan: add S32G2/S32G3 SoC
- WiFi:
- remove cooked monitor support
- strict mode for better AP testing
- basic EPCS support
- OMI RX bandwidth reduction support
- batman-adv: add support for jumbo frames
- WiFi drivers:
- RealTek (rtw88):
- support RTL8814AE and RTL8814AU
- RealTek (rtw89):
- switch using wiphy_lock and wiphy_work
- add BB context to manipulate two PHY as preparation of MLO
- improve BT-coexistence mechanism to play A2DP smoothly
- Intel (iwlwifi):
- add new iwlmld sub-driver for latest HW/FW combinations
- MediaTek (mt76):
- preparation for mt7996 Multi-Link Operation (MLO) support
- Qualcomm/Atheros (ath12k):
- continued work on MLO
- Silabs (wfx):
- Wake-on-WLAN support
- Bluetooth:
- add support for skb TX SND/COMPLETION timestamping
- hci_core: enable buffer flow control for SCO/eSCO
- coredump: log devcd dumps into the monitor
- Bluetooth drivers:
- intel: add support to configure TX power
- nxp: handle bootloader error during cmd5 and cmd7"
* tag 'net-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1681 commits)
unix: fix up for "apparmor: add fine grained af_unix mediation"
mctp: Fix incorrect tx flow invalidation condition in mctp-i2c
net: usb: asix: ax88772: Increase phy_name size
net: phy: Introduce PHY_ID_SIZE — minimum size for PHY ID string
net: libwx: fix Tx L4 checksum
net: libwx: fix Tx descriptor content for some tunnel packets
atm: Fix NULL pointer dereference
net: tn40xx: add pci-id of the aqr105-based Tehuti TN4010 cards
net: tn40xx: prepare tn40xx driver to find phy of the TN9510 card
net: tn40xx: create swnode for mdio and aqr105 phy and add to mdiobus
net: phy: aquantia: add essential functions to aqr105 driver
net: phy: aquantia: search for firmware-name in fwnode
net: phy: aquantia: add probe function to aqr105 for firmware loading
net: phy: Add swnode support to mdiobus_scan
gve: add XDP DROP and PASS support for DQ
gve: update XDP allocation path support RX buffer posting
gve: merge packet buffer size fields
gve: update GQ RX to use buf_size
gve: introduce config-based allocation for XDP
gve: remove xdp_xsk_done and xdp_xsk_wakeup statistics
...
hrtimers are initialized with hrtimer_init() and a subsequent store to
the callback pointer. This turned out to be suboptimal for the upcoming
Rust integration and is obviously a silly implementation to begin with.
This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
with hrtimer_setup(T, cb);
The conversion was done with Coccinelle and a few manual fixups.
Once the conversion has completely landed in mainline, hrtimer_init()
will be removed and the hrtimer::function becomes a private member.
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Merge tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer cleanups from Thomas Gleixner:
"A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to
the callback pointer. This turned out to be suboptimal for the
upcoming Rust integration and is obviously a silly implementation to
begin with.
This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
with hrtimer_setup(T, cb);
The conversion was done with Coccinelle and a few manual fixups.
Once the conversion has completely landed in mainline, hrtimer_init()
will be removed and the hrtimer::function becomes a private member"
* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
wifi: rt2x00: Switch to use hrtimer_update_function()
io_uring: Use helper function hrtimer_update_function()
serial: xilinx_uartps: Use helper function hrtimer_update_function()
ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
RDMA: Switch to use hrtimer_setup()
virtio: mem: Switch to use hrtimer_setup()
drm/vmwgfx: Switch to use hrtimer_setup()
drm/xe/oa: Switch to use hrtimer_setup()
drm/vkms: Switch to use hrtimer_setup()
drm/msm: Switch to use hrtimer_setup()
drm/i915/request: Switch to use hrtimer_setup()
drm/i915/uncore: Switch to use hrtimer_setup()
drm/i915/pmu: Switch to use hrtimer_setup()
drm/i915/perf: Switch to use hrtimer_setup()
drm/i915/gvt: Switch to use hrtimer_setup()
drm/i915/huc: Switch to use hrtimer_setup()
drm/amdgpu: Switch to use hrtimer_setup()
stm class: heartbeat: Switch to use hrtimer_setup()
i2c: Switch to use hrtimer_setup()
iio: Switch to use hrtimer_setup()
...
two locking commits in the locking tree,
part of the locking-core-2025-03-22 pull request. ]
x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid='
(Brendan Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and
related cleanups (Brian Gerst)
- Convert the stackprotector canary to a regular percpu
variable (Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB instruction
(Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation
(Kirill A. Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems,
to support PCI BAR space beyond the 10TiB region
(CONFIG_PCI_P2PDMA=y) (Balbir Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Bootup:
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0
(Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI headers
(Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
(Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking instructions
(Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus()
(Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel,
Artem Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst,
Dan Carpenter, Dr. David Alan Gilbert, H. Peter Anvin,
Ingo Molnar, Josh Poimboeuf, Kevin Brodsky, Mike Rapoport,
Lukas Bulwahn, Maciej Wieczor-Retman, Max Grobecker,
Patryk Wlazlyn, Pawan Gupta, Peter Zijlstra,
Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak,
Vitaly Kuznetsov, Xin Li, liuye.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Ingo Molnar:
"x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan
Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and related cleanups
(Brian Gerst)
- Convert the stackprotector canary to a regular percpu variable
(Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB
instruction (Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation (Kirill A.
Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI
BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir
Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan
Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan
Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI
headers (Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh
Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from
<asm/asm.h> (Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking
instructions (Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in
nmi_shootdown_cpus() (Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem
Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan
Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar,
Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej
Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter
Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly
Kuznetsov, Xin Li, liuye"
* tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits)
zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault
x86/asm: Make asm export of __ref_stack_chk_guard unconditional
x86/mm: Only do broadcast flush from reclaim if pages were unmapped
perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones
perf/x86/intel, x86/cpu: Simplify Intel PMU initialization
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers
x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions
x86/asm: Use asm_inline() instead of asm() in clwb()
x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h>
x86/hweight: Use asm_inline() instead of asm()
x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()
x86/hweight: Use named operands in inline asm()
x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP
x86/head/64: Avoid Clang < 17 stack protector in startup code
x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro
x86/cpu/intel: Limit the non-architectural constant_tsc model checks
x86/mm/pat: Replace Intel x86_model checks with VFM ones
x86/cpu/intel: Fix fast string initialization for extended Families
...
syzbot reported the following splat [0].
In check_atomic_load/store(), register validity is not checked before
atomic_ptr_type_ok(). This causes the out-of-bounds read in is_ctx_reg()
called from atomic_ptr_type_ok() when the register number is MAX_BPF_REG
or greater.
Call check_load_mem()/check_store_reg() before atomic_ptr_type_ok()
to avoid the OOB read.
However, some tests introduced by commit ff3afe5da9 ("selftests/bpf: Add
selftests for load-acquire and store-release instructions") assume
calling atomic_ptr_type_ok() before checking register validity.
Therefore the swapping of order unintentionally changes verifier messages
of these tests.
For example in the test load_acquire_from_pkt_pointer(), expected message
is 'BPF_ATOMIC loads from R2 pkt is not allowed' although actual messages
are different.
validate_msgs:FAIL:754 expect_msg
VERIFIER LOG:
=============
Global function load_acquire_from_pkt_pointer() doesn't return scalar. Only those are supported.
0: R1=ctx() R10=fp0
; asm volatile ( @ verifier_load_acquire.c:140
0: (61) r2 = *(u32 *)(r1 +0) ; R1=ctx() R2_w=pkt(r=0)
1: (d3) r0 = load_acquire((u8 *)(r2 +0))
invalid access to packet, off=0 size=1, R2(id=0,off=0,r=0)
R2 offset is outside of the packet
processed 2 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
=============
EXPECTED SUBSTR: 'BPF_ATOMIC loads from R2 pkt is not allowed'
#505/19 verifier_load_acquire/load-acquire from pkt pointer:FAIL
This is because instructions in the test don't pass check_load_mem() and
therefore don't enter the atomic_ptr_type_ok() path.
In this case, we have to modify instructions so that they pass the
check_load_mem() and trigger atomic_ptr_type_ok().
Similarly for store-release tests, we need to modify instructions so that
they pass check_store_reg().
Like load_acquire_from_pkt_pointer(), modify instructions in:
load_acquire_from_sock_pointer()
store_release_to_ctx_pointer()
store_release_to_pkt_pointer()
Also in store_release_to_sock_pointer(), check_store_reg() returns error
early and atomic_ptr_type_ok() is not triggered, since write to sock
pointer is not possible in general.
We might be able to remove the test, but for now let's leave it and just
change the expected message.
[0]
BUG: KASAN: slab-out-of-bounds in is_ctx_reg kernel/bpf/verifier.c:6185 [inline]
BUG: KASAN: slab-out-of-bounds in atomic_ptr_type_ok+0x3d7/0x550 kernel/bpf/verifier.c:6223
Read of size 4 at addr ffff888141b0d690 by task syz-executor143/5842
CPU: 1 UID: 0 PID: 5842 Comm: syz-executor143 Not tainted 6.14.0-rc3-syzkaller-gf28214603dc6 #0
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0x16e/0x5b0 mm/kasan/report.c:521
kasan_report+0x143/0x180 mm/kasan/report.c:634
is_ctx_reg kernel/bpf/verifier.c:6185 [inline]
atomic_ptr_type_ok+0x3d7/0x550 kernel/bpf/verifier.c:6223
check_atomic_store kernel/bpf/verifier.c:7804 [inline]
check_atomic kernel/bpf/verifier.c:7841 [inline]
do_check+0x89dd/0xedd0 kernel/bpf/verifier.c:19334
do_check_common+0x1678/0x2080 kernel/bpf/verifier.c:22600
do_check_main kernel/bpf/verifier.c:22691 [inline]
bpf_check+0x165c8/0x1cca0 kernel/bpf/verifier.c:23821
Reported-by: syzbot+a5964227adc0f904549c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a5964227adc0f904549c
Tested-by: syzbot+a5964227adc0f904549c@syzkaller.appspotmail.com
Fixes: e24bbad29a8d ("bpf: Introduce load-acquire and store-release instructions")
Fixes: ff3afe5da9 ("selftests/bpf: Add selftests for load-acquire and store-release instructions")
Signed-off-by: Kohei Enju <enjuk@amazon.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250322045340.18010-5-enjuk@amazon.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds struct_ops context information to struct bpf_prog_aux.
This context information will be used in the kfunc filter.
Currently the added context information includes struct_ops member
offset and a pointer to struct bpf_struct_ops.
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20250319215358.2287371-2-ameryhung@gmail.com
Since out-of-order unlocks are unsupported for rqspinlock, and irqsave
variants enforce strict FIFO ordering anyway, make the same change for
normal non-irqsave variants, such that FIFO ordering is enforced.
Two new verifier state fields (active_lock_id, active_lock_ptr) are used
to denote the top of the stack, and prev_id and prev_ptr are ascertained
whenever popping the topmost entry through an unlock.
Take special care to make these fields part of the state comparison in
refsafe.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-25-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce verifier-side support for rqspinlock kfuncs. The first step is
allowing bpf_res_spin_lock type to be defined in map values and
allocated objects, so BTF-side is updated with a new BPF_RES_SPIN_LOCK
field to recognize and validate.
Any object cannot have both bpf_spin_lock and bpf_res_spin_lock, only
one of them (and at most one of them per-object, like before) must be
present. The bpf_res_spin_lock can also be used to protect objects that
require lock protection for their kfuncs, like BPF rbtree and linked
list.
The verifier plumbing to simulate success and failure cases when calling
the kfuncs is done by pushing a new verifier state to the verifier state
stack which will verify the failure case upon calling the kfunc. The
path where success is indicated creates all lock reference state and IRQ
state (if necessary for irqsave variants). In the case of failure, the
state clears the registers r0-r5, sets the return value, and skips kfunc
processing, proceeding to the next instruction.
When marking the return value for success case, the value is marked as
0, and for the failure case as [-MAX_ERRNO, -1]. Then, in the program,
whenever user checks the return value as 'if (ret)' or 'if (ret < 0)'
the verifier never traverses such branches for success cases, and would
be aware that the lock is not held in such cases.
We push the kfunc state in check_kfunc_call whenever rqspinlock kfuncs
are invoked. We introduce a kfunc_class state to avoid mixing lock
irqrestore kfuncs with IRQ state created by bpf_local_irq_save.
With all this infrastructure, these kfuncs become usable in programs
while satisfying all safety properties required by the kernel.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-24-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce four new kfuncs, bpf_res_spin_lock, and bpf_res_spin_unlock,
and their irqsave/irqrestore variants, which wrap the rqspinlock APIs.
bpf_res_spin_lock returns a conditional result, depending on whether the
lock was acquired (NULL is returned when lock acquisition succeeds,
non-NULL upon failure). The memory pointed to by the returned pointer
upon failure can be dereferenced after the NULL check to obtain the
error code.
Instead of using the old bpf_spin_lock type, introduce a new type with
the same layout, and the same alignment, but a different name to avoid
type confusion.
Preemption is disabled upon successful lock acquisition, however IRQs
are not. Special kfuncs can be introduced later to allow disabling IRQs
when taking a spin lock. Resilient locks are safe against AA deadlocks,
hence not disabling IRQs currently does not allow violation of kernel
safety.
__irq_flag annotation is used to accept IRQ flags for the IRQ-variants,
with the same semantics as existing bpf_local_irq_{save, restore}.
These kfuncs will require additional verifier-side support in subsequent
commits, to allow programs to hold multiple locks at the same time.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-23-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Convert all LPM trie usage of raw_spinlock to rqspinlock.
Note that rcu_dereference_protected in trie_delete_elem is switched over
to plain rcu_dereference, the RCU read lock should be held from BPF
program side or eBPF syscall path, and the trie->lock is just acquired
before the dereference. It is not clear the reason the protected variant
was used from the commit history, but the above reasoning makes sense so
switch over.
Closes: https://lore.kernel.org/lkml/000000000000adb08b061413919e@google.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-22-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Ensure that the rqspinlock code is only built when the BPF subsystem is
compiled in. Depending on queued spinlock support, we may or may not end
up building the queued spinlock slowpath, and instead fallback to the
test-and-set implementation. Also add entries to MAINTAINERS file.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-18-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We ripped out PV and virtualization related bits from rqspinlock in an
earlier commit, however, a fair lock performs poorly within a virtual
machine when the lock holder is preempted. As such, retain the
virt_spin_lock fallback to test and set lock, but with timeout and
deadlock detection. We can do this by simply depending on the
resilient_tas_spin_lock implementation from the previous patch.
We don't integrate support for CONFIG_PARAVIRT_SPINLOCKS yet, as that
requires more involved algorithmic changes and introduces more
complexity. It can be done when the need arises in the future.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-15-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Include a test-and-set fallback when queued spinlock support is not
available. Introduce a rqspinlock type to act as a fallback when
qspinlock support is absent.
Include ifdef guards to ensure the slow path in this file is only
compiled when CONFIG_QUEUED_SPINLOCKS=y. Subsequent patches will add
further logic to ensure fallback to the test-and-set implementation
when queued spinlock support is unavailable on an architecture.
Unlike other waiting loops in rqspinlock code, the one for test-and-set
has no theoretical upper bound under contention, therefore we need a
longer timeout than usual. Bump it up to a second in this case.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-14-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
While the timeout logic provides guarantees for the waiter's forward
progress, the time until a stalling waiter unblocks can still be long.
The default timeout of 1/4 sec can be excessively long for some use
cases. Additionally, custom timeouts may exacerbate recovery time.
Introduce logic to detect common cases of deadlocks and perform quicker
recovery. This is done by dividing the time from entry into the locking
slow path until the timeout into intervals of 1 ms. Then, after each
interval elapses, deadlock detection is performed, while also polling
the lock word to ensure we can quickly break out of the detection logic
and proceed with lock acquisition.
A 'held_locks' table is maintained per-CPU where the entry at the bottom
denotes a lock being waited for or already taken. Entries coming before
it denote locks that are already held. The current CPU's table can thus
be looked at to detect AA deadlocks. The tables from other CPUs can be
looked at to discover ABBA situations. Finally, when a matching entry
for the lock being taken on the current CPU is found on some other CPU,
a deadlock situation is detected. This function can take a long time,
therefore the lock word is constantly polled in each loop iteration to
ensure we can preempt detection and proceed with lock acquisition, using
the is_lock_released check.
We set 'spin' member of rqspinlock_timeout struct to 0 to trigger
deadlock checks immediately to perform faster recovery.
Note: Extending lock word size by 4 bytes to record owner CPU can allow
faster detection for ABBA. It is typically the owner which participates
in a ABBA situation. However, to keep compatibility with existing lock
words in the kernel (struct qspinlock), and given deadlocks are a rare
event triggered by bugs, we choose to favor compatibility over faster
detection.
The release_held_lock_entry function requires an smp_wmb, while the
release store on unlock will provide the necessary ordering for us. Add
comments to document the subtleties of why this is correct. It is
possible for stores to be reordered still, but in the context of the
deadlock detection algorithm, a release barrier is sufficient and
needn't be stronger for unlock's case.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-13-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When we run out of maximum rqnodes, the original queued spin lock slow
path falls back to a try lock. In such a case, we are again susceptible
to stalls in case the lock owner fails to make progress. We use the
timeout as a fallback to break out of this loop and return to the
caller. This is a fallback for an extreme edge case, when on the same
CPU we run out of all 4 qnodes. When could this happen? We are in slow
path in task context, we get interrupted by an IRQ, which while in the
slow path gets interrupted by an NMI, whcih in the slow path gets
another nested NMI, which enters the slow path. All of the interruptions
happen after node->count++.
We use RES_DEF_TIMEOUT as our spinning duration, but in the case of this
fallback, no fairness is guaranteed, so the duration may be too small
for contended cases, as the waiting time is not bounded. Since this is
an extreme corner case, let's just prefer timing out instead of
attempting to spin for longer.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-12-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Implement the wait queue cleanup algorithm for rqspinlock. There are
three forms of waiters in the original queued spin lock algorithm. The
first is the waiter which acquires the pending bit and spins on the lock
word without forming a wait queue. The second is the head waiter that is
the first waiter heading the wait queue. The third form is of all the
non-head waiters queued behind the head, waiting to be signalled through
their MCS node to overtake the responsibility of the head.
In this commit, we are concerned with the second and third kind. First,
we augment the waiting loop of the head of the wait queue with a
timeout. When this timeout happens, all waiters part of the wait queue
will abort their lock acquisition attempts. This happens in three steps.
First, the head breaks out of its loop waiting for pending and locked
bits to turn to 0, and non-head waiters break out of their MCS node spin
(more on that later). Next, every waiter (head or non-head) attempts to
check whether they are also the tail waiter, in such a case they attempt
to zero out the tail word and allow a new queue to be built up for this
lock. If they succeed, they have no one to signal next in the queue to
stop spinning. Otherwise, they signal the MCS node of the next waiter to
break out of its spin and try resetting the tail word back to 0. This
goes on until the tail waiter is found. In case of races, the new tail
will be responsible for performing the same task, as the old tail will
then fail to reset the tail word and wait for its next pointer to be
updated before it signals the new tail to do the same.
We terminate the whole wait queue because of two main reasons. Firstly,
we eschew per-waiter timeouts with one applied at the head of the wait
queue. This allows everyone to break out faster once we've seen the
owner / pending waiter not responding for the timeout duration from the
head. Secondly, it avoids complicated synchronization, because when not
leaving in FIFO order, prev's next pointer needs to be fixed up etc.
Lastly, all of these waiters release the rqnode and return to the
caller. This patch underscores the point that rqspinlock's timeout does
not apply to each waiter individually, and cannot be relied upon as an
upper bound. It is possible for the rqspinlock waiters to return early
from a failed lock acquisition attempt as soon as stalls are detected.
The head waiter cannot directly WRITE_ONCE the tail to zero, as it may
race with a concurrent xchg and a non-head waiter linking its MCS node
to the head's MCS node through 'prev->next' assignment.
One notable thing is that we must use RES_DEF_TIMEOUT * 2 as our maximum
duration for the waiting loop (for the wait queue head), since we may
have both the owner and pending bit waiter ahead of us, and in the worst
case, need to span their maximum permitted critical section lengths.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-11-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The pending bit is used to avoid queueing in case the lock is
uncontended, and has demonstrated benefits for the 2 contender scenario,
esp. on x86. In case the pending bit is acquired and we wait for the
locked bit to disappear, we may get stuck due to the lock owner not
making progress. Hence, this waiting loop must be protected with a
timeout check.
To perform a graceful recovery once we decide to abort our lock
acquisition attempt in this case, we must unset the pending bit since we
own it. All waiters undoing their changes and exiting gracefully allows
the lock word to be restored to the unlocked state once all participants
(owner, waiters) have been recovered, and the lock remains usable.
Hence, set the pending bit back to zero before returning to the caller.
Introduce a lockevent (rqspinlock_lock_timeout) to capture timeout
event statistics.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-10-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, for rqspinlock usage, the implementation of
smp_cond_load_acquire (and thus, atomic_cond_read_acquire) are
susceptible to stalls on arm64, because they do not guarantee that the
conditional expression will be repeatedly invoked if the address being
loaded from is not written to by other CPUs. When support for
event-streams is absent (which unblocks stuck WFE-based loops every
~100us), we may end up being stuck forever.
This causes a problem for us, as we need to repeatedly invoke the
RES_CHECK_TIMEOUT in the spin loop to break out when the timeout
expires.
Let us import the smp_cond_load_acquire_timewait implementation Ankur is
proposing in [0], and then fallback to it once it is merged.
While we rely on the implementation to amortize the cost of sampling
check_timeout for us, it will not happen when event stream support is
unavailable. This is not the common case, and it would be difficult to
fit our logic in the time_expr_ns >= time_limit_ns comparison, hence
just let it be.
[0]: https://lore.kernel.org/lkml/20250203214911.898276-1-ankur.a.arora@oracle.com
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-9-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce policy macro RES_CHECK_TIMEOUT which can be used to detect
when the timeout has expired for the slow path to return an error. It
depends on being passed two variables initialized to 0: ts, ret. The
'ts' parameter is of type rqspinlock_timeout.
This macro resolves to the (ret) expression so that it can be used in
statements like smp_cond_load_acquire to break the waiting loop
condition.
The 'spin' member is used to amortize the cost of checking time by
dispatching to the implementation every 64k iterations. The
'timeout_end' member is used to keep track of the timestamp that denotes
the end of the waiting period. The 'ret' parameter denotes the status of
the timeout, and can be checked in the slow path to detect timeouts
after waiting loops.
The 'duration' member is used to store the timeout duration for each
waiting loop. The default timeout value defined in the header
(RES_DEF_TIMEOUT) is 0.25 seconds.
This macro will be used as a condition for waiting loops in the slow
path. Since each waiting loop applies a fresh timeout using the same
rqspinlock_timeout, we add a new RES_RESET_TIMEOUT as well to ensure the
values can be easily reinitialized to the default state.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Changes to rqspinlock in subsequent commits will be algorithmic
modifications, which won't remain in agreement with the implementations
of paravirt spin lock and virt_spin_lock support. These future changes
include measures for terminating waiting loops in slow path after a
certain point. While using a fair lock like qspinlock directly inside
virtual machines leads to suboptimal performance under certain
conditions, we cannot use the existing virtualization support before we
make it resilient as well. Therefore, drop it for now.
Note that we need to drop qspinlock_stat.h, as it's only relevant in
case of CONFIG_PARAVIRT_SPINLOCKS=y, but we need to keep lock_events.h
in the includes, which was indirectly pulled in before.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This header contains the public declarations usable in the rest of the
kernel for rqspinlock.
Let's also type alias qspinlock to rqspinlock_t to ensure consistent use
of the new lock type. We want to remove dependence on the qspinlock type
in later patches as we need to provide a test-and-set fallback, hence
begin abstracting away from now onwards.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In preparation for introducing a new lock implementation, Resilient
Queued Spin Lock, or rqspinlock, we first begin our modifications by
using the existing qspinlock.c code as the base. Simply copy the code to
a new file and rename functions and variables from 'queued' to
'resilient_queued'.
Since we place the file in kernel/bpf, include needs to be relative.
This helps each subsequent commit in clearly showing how and where the
code is being changed. The only change after a literal copy in this
commit is renaming the functions where necessary, and rename qnodes to
rqnodes. Let's also use EXPORT_SYMBOL_GPL for rqspinlock slowpath.
Reviewed-by: Barret Rhoden <brho@google.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The current verifier error message states that tail_calls are not
allowed in non-JITed programs with BPF-to-BPF calls. While this is
accurate, it is not the only scenario where this restriction applies.
Some architectures do not support this feature combination even when
programs are JITed. This update improves the error message to better
reflect these limitations.
Suggested-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrea Terzolo <andreaterzolo3@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20250318083551.8192-1-andreaterzolo3@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If we attach fexit/fmod_ret to __noreturn functions, it will cause an
issue that the bpf trampoline image will be left over even if the bpf
link has been destroyed. Take attaching do_exit() with fexit for example.
The fexit works as follows,
bpf_trampoline
+ __bpf_tramp_enter
+ percpu_ref_get(&tr->pcref);
+ call do_exit()
+ __bpf_tramp_exit
+ percpu_ref_put(&tr->pcref);
Since do_exit() never returns, the refcnt of the trampoline image is
never decremented, preventing it from being freed. That can be verified
with as follows,
$ bpftool link show <<<< nothing output
$ grep "bpf_trampoline_[0-9]" /proc/kallsyms
ffffffffc04cb000 t bpf_trampoline_6442526459 [bpf] <<<< leftover
In this patch, all functions annotated with __noreturn are rejected, except
for the following cases:
- Functions that result in a system reboot, such as panic,
machine_real_restart and rust_begin_unwind
- Functions that are never executed by tasks, such as rest_init and
cpu_startup_entry
- Functions implemented in assembly, such as rewind_stack_and_make_dead and
xen_cpu_bringup_again, lack an associated BTF ID.
With this change, attaching fexit probes to functions like do_exit() will
be rejected.
$ ./fexit
libbpf: prog 'fexit': BPF program load failed: -EINVAL
libbpf: prog 'fexit': -- BEGIN PROG LOAD LOG --
Attaching fexit/fmod_ret to __noreturn functions is rejected.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20250318114447.75484-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
