This comment was thoughtlessly copied from the x86 version and doesn't
apply to arm64. Remove it.
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20260614210209.2371030-1-tj@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BPF_MAP_TYPE_ARENA supports direct-value pseudo loads, but unlike array
maps its map value_size is zero and the valid direct-value range is the
arena mmap size, max_entries * PAGE_SIZE.
Commit 3ac1a467e3 ("bpf: Fix off-by-one boundary validation in arena
direct-value access") fixed arena_map_direct_value_addr() to reject an
offset exactly at the end of the arena mapping. Add a regression test
that loads a BPF_PSEUDO_MAP_VALUE with off == arena_size and verifies
that the verifier rejects it with the expected offset in the log.
This is intentionally kept as a userspace raw-instruction test. I tried
expressing the same BPF_PSEUDO_MAP_VALUE + off == arena_size case in
verifier_arena.c with inline assembly. The only form that produces the
desired instruction bytes uses __imm_addr(arena), but that emits
R_BPF_64_NODYLD32, which the libbpf/bpftool link step rejects. Other
register, immediate, and memory constraints either fail in the BPF
backend or lower to a normal R_BPF_64_64 load followed by an ALU add,
which does not exercise arena_map_direct_value_addr() with the boundary
offset in the second ldimm64 slot.
A legacy test_verifier fixture can express the raw instruction directly,
but it needs arena map creation, mmap, and fixup plumbing in the legacy
runner. That is more intrusive than the small prog_tests raw-instruction
test.
Use the userspace raw-instruction test, following the existing selftests
pattern used for direct map-value pseudo loads, so insns[1].imm can be
set to arena_size precisely.
Assisted-by: ChatGPT:gpt-5.5
Signed-off-by: Woojin Ji <random6.xyz@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Cc: Emil Tsalapatis <emil@etsalapatis.com>
Cc: Junyoung Jang <graypanda.inzag@gmail.com>
Link: https://lore.kernel.org/r/20260612-arena-direct-value-v1-v4-1-b81b642f5277@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
raw_res_spin_unlock_irqrestore() calls raw_res_spin_unlock() and then
restores interrupts, this means preemption is enabled when interrupts
are still disabled (as part of raw_res_spin_unlock()) so this cannot
trigger an actual preemption.
This is inconsistent with other spinlock implementations
(raw_spin_unlock_irqrestore() and bpf_res_spin_unlock_irqrestore()
itself).
Adjust the macro to ensure interrupts are enabled before enabling
preemption, allowing to schedule at that point. Make the same
modification in the error path of raw_res_spin_lock_irqsave().
Fixes: 101acd2e78 ("rqspinlock: Add macros for rqspinlock usage")
Cc: stable@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de> # asm-generic
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20260610090431.32427-1-gmonaco@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Xu Kuohai says:
====================
bpf: Fix setting retval to -EPERM for cgroup hooks not returning errno
This series fixes the issue reported by sashiko in [1]. The issue is that,
when a cgroup BPF program exits with 0, bpf_prog_run_array_cg() sets
the hook return value to -EPERM if it is not a valid errno. This is
correct for errno-based hooks, which return 0 on success and negative
errno on failure, but wrong for void and boolean LSM hooks. Boolean
LSM hooks should only return true or false, and void LSM hooks have
no return value at all.
Fix it by skipping setting -EPERM for hooks not returning errno.
[1] https://lore.kernel.org/bpf/20260605144232.95A141F00893@smtp.kernel.org/
====================
Link: https://patch.msgid.link/20260610201724.733943-1-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add test to check the return value when a BPF program exits with 0 for
a boolean and an errno LSM hook.
For each hook, two BPF programs are attached. The first program returns
0 without calling bpf_set_retval() to exercise the return value translation
logic, while the second program reads the retval via bpf_get_retval().
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20260610201724.733943-3-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When a cgroup BPF program exits with 0, bpf_prog_run_array_cg() sets
the hook return value to -EPERM if it is not a valid errno. This is
correct for errno-based hooks, which return 0 on success and negative
errno on failure, but wrong for boolean and void LSM hooks. Boolean
LSM hooks should only return true or false, and void LSM hooks have
no return value at all.
Fix it by skipping setting -EPERM for hooks not returning errno.
Fixes: 69fd337a97 ("bpf: per-cgroup lsm flavor")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20260610201724.733943-2-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Sun Jian says:
====================
bpf: Fix generic devmap egress skb sharing
Generic XDP devmap multi redirect can leave cloned skbs sharing packet
data. When a devmap egress program mutates packet data, another
destination sharing the same data may observe that mutation.
Fix this by making cloned skbs private before running the generic devmap
egress program. The private copy is made in dev_map_generic_redirect()
so dev_map_bpf_prog_run_skb() can keep returning the XDP action directly.
Add selftest coverage for the last-destination case, where the final
destination runs on the original skb while earlier destinations use
cloned skbs. The test records the source MAC observed by an earlier
destination and checks that it is neither the sentinel value left in the
result map nor the MAC written by the final destination.
---
v5:
- Move the skb_copy() check back to dev_map_generic_redirect() to keep
dev_map_bpf_prog_run_skb() returning only the XDP action.
- Preserve mac_len after skb_copy().
- Use __be64 temporary values when updating mac_map from userspace.
- Initialize rx_mac with a sentinel in the last-destination test instead
of relying on -ENOENT for ARRAY map lookups.
- Adjust the last-destination test topology so the checked earlier
destination is not the ingress/source veth.
- Split the last-destination check into two assertions: one for store_mac_1
updating rx_mac and one for detecting last-destination rewrite leakage.
v4: https://lore.kernel.org/bpf/20260611080850.536996-1-sun.jian.kdev@gmail.com/T/#mf830f03d362f33e0941d1b0e425169698fce76e5
- Preserve mac_len after skb_copy().
- Separate errno return from XDP action output in
dev_map_bpf_prog_run_skb().
- Zero-initialize net_config in the new selftest.
v3: https://lore.kernel.org/bpf/20260611043317.512843-1-sun.jian.kdev@gmail.com/
- Split the kernel fix and selftest into separate patches.
- Move the private-copy logic into dev_map_bpf_prog_run_skb().
- Use deterministic DEVMAP_HASH keys in the last-destination selftest.
- Fix the Fixes tag.
v2: https://lore.kernel.org/bpf/08c35c70-a59e-4e0e-91db-22b5ec30b611@linux.dev/
- Move the private-copy step into dev_map_generic_redirect() so the
last-destination path is covered as well.
- Use skb_copy() instead of skb_unshare() to keep caller ownership
unchanged on allocation failure.
- Add a generic XDP last-destination selftest case.
v1: https://lore.kernel.org/bpf/CABFUUZFimdrZdq=NWi+N-0sJZWvMwY=f4iF6-3TVMS8=m07Zmw@mail.gmail.com/
====================
Link: https://patch.msgid.link/20260612114032.244616-1-sun.jian.kdev@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Strengthen xdp_veth_egress to check that each destination observes the
MAC selected for its own egress ifindex, instead of only checking that
the observed MAC differs from a single magic value.
Add a generic XDP last-destination test where an earlier destination does
not have a devmap egress program while the final destination does. This
covers the case where the final destination runs on the original skb and
could otherwise rewrite packet data still shared with an earlier cloned
skb.
Use deterministic DEVMAP_HASH keys for the egress map so the intended
last destination is stable. Initialize the result map with a sentinel
value and check that store_mac_1 overwrites it before checking that the
earlier destination did not observe the MAC written by the final
destination.
Suggested-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/r/20260612114032.244616-3-sun.jian.kdev@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Generic XDP devmap multi redirect uses skb_clone() for intermediate
destinations and sends the last destination with the original skb. This
can leave multiple destinations sharing the same packet data.
This becomes visible after generic devmap egress-program support was
added: a devmap egress program may mutate packet data, and another
destination sharing the same data can observe that mutation.
Native XDP broadcast redirect does not have this issue because
xdpf_clone() copies the frame data for each destination. Generic XDP
should provide the same per-destination isolation before running a
devmap egress program.
Fix this by making cloned skbs private before running the generic devmap
egress program. Use skb_copy() instead of skb_unshare() so allocation
failure does not consume the skb and the existing caller error paths keep
their ownership semantics.
Fixes: 2ea5eabaf0 ("bpf: devmap: Implement devmap prog execution for generic XDP")
Suggested-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/r/20260612114032.244616-2-sun.jian.kdev@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add tail-call selftests for prog-array ownership when cgroup storage
is in use. Verify that loading succeeds when callers and callees reuse
the owner's cgroup storage map, and that loading fails for a different
storage map and for the A(storage) -> B(no storage) -> C(storage)
bridge case addressed in the previous commit.
Also verify that a storage-less leaf program which cannot perform tail
calls itself is still allowed to join a storage-owned prog array, while
a storage-less tail-caller is rejected also at map update time.
# LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t tailcalls
[...]
#475/25 tailcalls/tailcall_freplace:OK
#475/26 tailcalls/tailcall_bpf2bpf_freplace:OK
#475/27 tailcalls/tailcall_failure:OK
#475/28 tailcalls/reject_tail_call_spin_lock:OK
#475/29 tailcalls/reject_tail_call_rcu_lock:OK
#475/30 tailcalls/reject_tail_call_preempt_lock:OK
#475/31 tailcalls/reject_tail_call_ref:OK
#475/32 tailcalls/tailcall_sleepable:OK
#475/33 tailcalls/tailcall_cgrp_storage:OK
#475/34 tailcalls/tailcall_cgrp_storage_diff_storage:OK
#475/35 tailcalls/tailcall_cgrp_storage_no_storage:OK
#475/36 tailcalls/tailcall_cgrp_storage_no_storage_leaf:OK
#475/37 tailcalls/tailcall_cgrp_storage_no_storage_bridge:OK
#475 tailcalls:OK
Summary: 1/37 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Lin Ma <malin89@huawei.com>
Signed-off-by: Rongzhen Cui <cuirongzhen@huawei.com>
Signed-off-by: Jingguo Tan <tanjingguo@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260610105539.705887-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The fix in commit abad3d0bad ("bpf: Fix oob access in cgroup local
storage") is still incomplete. The prog-array compatibility check
treats a program with no cgroup storage as compatible with any stored
storage cookie. This allows a storage-less program to bridge a tail
call chain between an entry program and a storage-using callee even
though cgroup local storage at runtime still follows the caller's
context, that is, A -> B(no storage) -> C(storage) path.
Requiring exact cookie equality would break the legitimate case of a
storage-less leaf program being tail called from a storage-using one.
Instead, only accept a zero storage cookie if the program cannot
perform tail calls itself. This keeps A -> B(no storage) working
while rejecting the A -> B(no storage) -> C(storage) bridge.
Fixes: abad3d0bad ("bpf: Fix oob access in cgroup local storage")
Reported-by: Lin Ma <malin89@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260610105539.705887-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
For selftest bpf_iter/task_vma, I got a failure like below on my qemu run:
test_task_vma_common:FAIL:compare_output unexpected compare_output:
actual
'561593546000-561593585000r--p0000000000:241256579534/root/devshare/bpf-next/tools/testing/selftests/bpf/test_progs'
!= expected
'561593546000-561593585000r--p0000000000:245551546830/root/devshare/bpf-next/tools/testing/selftests/bpf/test_progs'
Further debugging found out file->f_inode->i_ino value may exceed 32bit,
e.g., i_ino = 0x14c2eae35, but the format string is '%u'. This caused
inode mismatch between bpf iter and proc result.
Fix the issue by using format string '%llu' to accommodate 64bit i_ino.
Fixes: e8168840e1 ("selftests/bpf: Add test for bpf_iter_task_vma")
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260610051831.1346659-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add focused map_kptr coverage for BPF-side map updates that touch values
containing referenced kptrs.
The new syscall programs stash the testmod refcounted object in an array
map, a preallocated hash map, and a no-prealloc hash map, then update the
same map from BPF. The refcount must remain elevated after the update,
while the userspace runner destroys the skeleton and reuses the existing
refcount wait to confirm map teardown releases the kptr.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260609202548.3571690-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add task_kfunc failure cases for bpf_obj_drop() on local objects with
referenced kptr fields from tracing and NMI tracing programs. These programs
must be rejected because dropping the object would run full special-field
destruction synchronously in an unsafe context.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260609202548.3571690-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Map update and delete paths currently call bpf_obj_free_fields() when a
value is being replaced or recycled. That makes field destruction depend
on the context of the update/delete operation. For tracing programs this
can include NMI context, where referenced kptr destructors, uptr
unpinning, and graph root destruction are not generally safe.
Introduce bpf_obj_cancel_fields() for the reusable-value path. It only
performs NMI-safe cleanup for timer, workqueue, and task_work fields.
Fields that need full destruction are left attached to the recycled value
and are destroyed by the final cleanup path instead.
Switch array and hashtab update/delete/recycle paths to this cancel
helper. Keep bpf_obj_free_fields() for final map destruction and for
bpf_mem_alloc destructors. Preallocated hashtabs do not have allocator
destructors, so teardown continues to walk the normal and extra elements
and fully destroy their fields.
This deliberately relaxes the eager-free semantics of map update/delete
for special fields. Programs that relied on a recycled map slot becoming
empty immediately after update/delete were relying on behavior that
cannot be implemented safely from every BPF execution context without
offloading arbitrary destructors.
There is a chance this change breaks programs making assumptions
regarding the eager freeing of fields. If so, we can relax semantics to
cancellation only when irqs_disabled() is true in the future. However,
theoretically, map values that get reused eagerly already have weaker
guarantees as parallel users can recreate freed fields before the new
element becomes visible again.
Fixes: 14a324f6a6 ("bpf: Wire up freeing of referenced kptr")
Signed-off-by: Justin Suess <utilityemal77@gmail.com>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260609202548.3571690-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_obj_drop() runs bpf_obj_free_fields() synchronously for
program-allocated objects. When such an object contains NMI unsafe
fields, tracing programs that can run from arbitrary instrumented
context can reach that destruction from unsafe contexts, including NMI.
NMI is likely one instance of this problem, and other instances would
include possible unsafe reentrancy. Deferring bpf_obj_drop() is not
appealing either: it would add delayed-free machinery to a release
operation that otherwise has straightforward synchronous ownership
semantics.
Reject bpf_obj_drop() and bpf_percpu_obj_drop() from tracing programs
that may run from unsafe contexts unless every field in the object's BTF
record is explicitly NMI safe. Do not reject sleepable
BPF_PROG_TYPE_TRACING programs, since they are not the arbitrary/NMI
contexts that motivate the restriction.
Note that while bpf_rb_root and bpf_list_head would be NMI safe on their
own to free, the objects recursively held by them may not be; be
conservative and just mark them as not NMI safe for now.
Use a whitelist for the NMI-safe field set instead of listing only known
NMI unsafe fields. Locks, async fields, unreferenced kptrs, and
refcounts are known to be NMI safe because their destruction is either a
no-op, simple state reset, or async cancellation. Referenced kptrs,
percpu referenced kptrs, uptrs, graph roots, graph nodes, and any future
field type are rejected until audited for arbitrary tracing and NMI
contexts. This is less susceptible to future changes in fields that were
previously safe by exclusion, and to new fields being added without
updating this check.
Convert the existing recursive local-object drop success case to a
syscall program in the same commit, since this verifier change makes the
old tracing program form invalid. The test still exercises
bpf_obj_drop() releasing a referenced task kptr from a safe program
type.
Fixes: ac9f06050a ("bpf: Introduce bpf_obj_drop")
Signed-off-by: Justin Suess <utilityemal77@gmail.com>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260609202548.3571690-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yonghong Song says:
====================
selftests/bpf: Fix tests for llvm23 true signature
LLVM23 ([1]) records the 'true' function signature in BTF, i.e. the
signature inferred after optimization rather than the one written in C.
This caused two kinds of selftest failures (see below).
Case 1: keep int return type for tailcall subprogs
The verifier requires any subprog that issues a bpf_tail_call to return
an 'int' (see check_btf_func() in kernel/bpf/check_btf.c, which rejects
it with "tail_call is only allowed in functions that return 'int'").
Several tailcall subprogs do 'return 0' (or another constant) whose
result no caller uses. With llvm23 the compiler folds the constant and,
since the return value is dead, optimizes the subprog to effectively
return 'void' and records 'void' in BTF, so the program fails to load.
Use barrier_var() and __sink() to prevent returned value from being
optimized.
Case 2: adjust tracing prog ctx layout for the true signature
test_pkt_access_subprog2() has an unused argument that llvm optimizes
away. Before llvm23 the BTF signature did not match the optimized
assembly, so the verifier fell back to MAX_BPF_FUNC_REG_ARGS (5) u64
arguments and the fexit return value sat after args[5]. With llvm23 the
true signature has a single argument, so the return value moves to the
slot after args[1]. Select the matching ctx struct based on __clang_major__
so the test works with both old and new llvm.
[1] https://github.com/llvm/llvm-project/pull/198426
Changelogs:
v1 -> v2:
- v1: https://lore.kernel.org/bpf/20260609163947.1717694-1-yonghong.song@linux.dev/
- Do not use bpf array map or bpf global var. Use __sink() instead.
====================
Link: https://patch.msgid.link/20260609233402.2711071-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
test_pkt_access_subprog2() is defined in C as
int test_pkt_access_subprog2(int val, volatile struct __sk_buff *skb)
but llvm optimizes away the unused 'int val' argument. Before llvm23 the
BTF signature did not match the optimized assembly, so the verifier set
attach_func_proto to NULL and fell back to MAX_BPF_FUNC_REG_ARGS (5) u64
arguments (see btf_ctx_access()). The fexit ctx struct therefore placed
the return value after args[5].
With llvm23 the 'true' signature
int test_pkt_access_subprog2(volatile struct __sk_buff *skb)
is recorded in BTF, so nr_args becomes 1 and the return value moves to
the slot right after args[1]. Select the matching args_subprog2 layout
based on __clang_major__ so the test works with both old and new llvm.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260609233412.2712178-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
LLVM23 ([1]) supports 'true' function signature in BTF. The return type
of the caller of a tailcall must be an 'int'. Otherwise, verification will
fail (see check_btf_func() in check_btf.c). So with llvm23, it is possible
that the compiler may change the caller's return type from 'int' to 'void'.
To prevent this, barrier_var() and __sink() are used to avoid returning
a constant prone to be optimized.
[1] https://github.com/llvm/llvm-project/pull/198426
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260609233407.2711577-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Vlad Poenaru says:
====================
bpf, lpm_trie: Allow sleepable BPF programs to use LPM tries
trie_lookup_elem() annotates its rcu_dereference_check() walks with only
rcu_read_lock_bh_held(), so a sleepable BPF program that touches an LPM
trie (e.g. a sleepable LSM hook calling bpf_map_lookup_elem()) trips a
"suspicious RCU usage" lockdep splat on debug kernels: it holds only
rcu_read_lock_trace(), which that annotation does not accept.
Patch 1 relaxes the rcu_dereference annotations in the trie walks so they
no longer trip lockdep from the Tasks Trace context, including the
trie_update_elem()/trie_delete_elem() writer walks (protected by
trie->lock). Patch 2 adds BPF_MAP_TYPE_LPM_TRIE to the verifier's
sleepable map whitelist so sleepable programs can reference an LPM trie
directly, not just as the inner map of a map-of-maps. LPM trie nodes are
reclaimed via bpf_mem_cache_free_rcu(), which chains a regular RCU grace
period into a Tasks Trace grace period before freeing -- the same
discipline BPF_MAP_TYPE_HASH relies on for sleepable access.
Changes since v1:
- Split into a 2-patch series.
- Patch 1 now also converts the trie_update_elem()/trie_delete_elem()
walks from rcu_dereference() to rcu_dereference_protected(*p, 1),
addressing review feedback that v1 only fixed the lookup path and left
the same splat on the writer paths.
- New patch 2 adds the verifier whitelist entry so the fix is actually
reachable for directly-referenced LPM tries.
- Retitled v1 ("Allow lookups from sleepable BPF programs").
v1: https://lore.kernel.org/all/20260529174233.2954240-1-vlad.wing@gmail.com/
====================
Link: https://patch.msgid.link/20260609135558.193287-1-vlad.wing@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The previous change relaxed the rcu_dereference annotations in
lpm_trie.c so the trie walks no longer trip lockdep when reached from a
sleepable BPF program holding only rcu_read_lock_trace(). By itself
that only helps tries reached as the inner map of a map-of-maps, or
from the classic-RCU syscall path: a sleepable program that references
an LPM trie directly is still rejected at load time by
check_map_prog_compatibility(), whose sleepable whitelist omits
BPF_MAP_TYPE_LPM_TRIE:
Sleepable programs can only use array, hash, ringbuf and local storage maps
LPM trie nodes are allocated from a bpf_mem_alloc (trie->ma) and freed
with bpf_mem_cache_free_rcu(), which chains a regular RCU grace period
into a Tasks Trace grace period before the node -- and the value
embedded in it that trie_lookup_elem() returns to the program -- is
released. That is the same reclaim discipline BPF_MAP_TYPE_HASH relies
on for sleepable access, so a value handed to a sleepable reader cannot
be freed while the program is still running under rcu_read_lock_trace().
The writer paths take trie->lock across the walk and never relied on the
RCU read-side lock to keep nodes alive.
Add BPF_MAP_TYPE_LPM_TRIE to the sleepable map whitelist so these
programs can use LPM tries directly.
Signed-off-by: Vlad Poenaru <vlad.wing@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260609135558.193287-3-vlad.wing@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
trie_lookup_elem() annotates its rcu_dereference_check() walks with
only rcu_read_lock_bh_held(). Because rcu_dereference_check(p, c)
resolves to "c || rcu_read_lock_held()", this passes for XDP/NAPI and
classic RCU readers but fails for sleepable BPF programs, which enter
via __bpf_prog_enter_sleepable() and hold only rcu_read_lock_trace().
trie_update_elem() and trie_delete_elem() have the same problem in a
different form: they walk the trie with plain rcu_dereference(), which
asserts rcu_read_lock_held() unconditionally. Both are reachable from
sleepable BPF programs via the bpf_map_update_elem / bpf_map_delete_elem
helpers, and from the syscall path under classic rcu_read_lock(). In
the writer paths the trie is actually protected by trie->lock (an
rqspinlock taken across the walk); we never relied on the RCU read-side
lock to keep nodes alive there.
A sleepable LSM hook that ends up touching an LPM trie therefore
triggers lockdep on debug kernels:
=============================
WARNING: suspicious RCU usage
7.1.0-... Tainted: G E
-----------------------------
kernel/bpf/lpm_trie.c:249 suspicious rcu_dereference_check() usage!
1 lock held by net_tests/540:
#0: (rcu_tasks_trace_srcu_struct){....}-{0:0},
at: __bpf_prog_enter_sleepable+0x26/0x280
Call Trace:
dump_stack_lvl
lockdep_rcu_suspicious
trie_lookup_elem
bpf_prog_..._enforce_security_socket_connect
bpf_trampoline_...
security_socket_connect
__sys_connect
do_syscall_64
This is lockdep-only -- no UAF, since Tasks Trace RCU does serialize
against the trie's reclaim path -- but it spams the console once per
distinct callsite on every debug kernel running a sleepable BPF LSM
that touches an LPM trie, which is increasingly common.
For the lookup path, switch the rcu_dereference_check() annotation
from rcu_read_lock_bh_held() to bpf_rcu_lock_held(), which accepts all
three contexts (classic, BH, Tasks Trace). Other map types already
follow this convention.
For trie_update_elem() and trie_delete_elem(), annotate the walks as
rcu_dereference_protected(*p, 1) -- matching trie_free() in the same
file -- since trie->lock is held across the walk. rqspinlock has no
lockdep_map, so the predicate degenerates to '1' rather than
lockdep_is_held(&trie->lock); the protection is real but not
machine-verifiable. trie_get_next_key() also uses bare
rcu_dereference() but is reachable only from the BPF syscall, which
holds classic rcu_read_lock() before dispatching, so it is left
untouched.
Fixes: 694cea395f ("bpf: Allow RCU-protected lookups to happen from bh context")
Cc: stable@vger.kernel.org
Signed-off-by: Vlad Poenaru <vlad.wing@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260609135558.193287-2-vlad.wing@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The libarena parallel spmc selftest is nondeterministic by design.
As a result it depends up to a point on the relative timing between the
producer and consumer threads. This introduces the possibility for two
kinds of spurious failures that this patch addresses.
1) Spurious timeouts. The test proceeds in phases, and threads use a
common counter as a barrier to avoid proceeding to the next phase
until all threads are ready to do so. If a thread takes too long to
reach the barrier, the already waiting threads may time out.
Increase the current timeout. The timeout's value is a balance
between the maximum amount of time spent on the test and the
possibility of spurious failures. Right now the timeout is too short.
Err on the side of caution and significantly increase it to avoid
spurious failures.
2) Spurious resize failures. Some selftests require the spmc queue to
resize itself. This in turn requires for the producer side to be
materially faster than the consumer side so that the queue gets full
enough for a resize. However, in the benchmark the spmc queue's producer
is outnumbered 3:1. To offset it we add busy waits for consume
queues. However, we still see occasional failures due to the queue
never resizing.
Minimize the possibility for this in two ways: First, remove one of
the consumers. The 2 consumers still exercise the "race between
consumers" scenario. Second, increase the busy wait duration to
decrease the rate by which the consumers act on the queue.
While at it, also replace a stray invalid error value "153" with EINVAL.
Fixes: 42998f8192 ("selftests/bpf: libarena: parallel test harness and spmc parallel selftest")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260609063630.10245-1-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Nuoqi Gui says:
====================
bpf: Enforce BTF pointer write checks for global args
check_mem_reg() verifies both read and write access when a caller passes
memory into a global subprogram. For PTR_TO_BTF_ID callers,
check_helper_mem_access() currently always checks the access as BPF_READ.
That lets a tracing program pass a task_struct field pointer to a global
subprogram argument typed as writable memory. The direct field store is rejected
with "only read is supported", but the callee is validated with a generic
writable PTR_TO_MEM argument and can store through it.
Forward the requested access type into the PTR_TO_BTF_ID helper-access path and
add verifier coverage for the global-subprogram argument case.
Validation (tested on bpf-next 8496d9020f):
Without this series:
direct BTF field store rejected with "only read is supported";
global-subprogram candidate loaded, attached, and runtime-confirmed.
With this series applied:
direct BTF field store rejected with "only read is supported";
global-subprogram candidate rejected with "only read is supported".
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
---
====================
Link: https://patch.msgid.link/20260609-f01-04-btf-writable-arg-v1-0-f449cd970669@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Add a verifier test for passing a BTF-backed task_struct field pointer to a
global subprogram argument typed as writable memory.
The direct field store is already rejected.
The global subprogram path should be rejected too.
The callee must not lose the BTF pointer's read-only provenance.
It must not validate the argument as ordinary writable memory.
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Link: https://lore.kernel.org/bpf/20260609-f01-04-btf-writable-arg-v1-2-f449cd970669@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
check_mem_reg() verifies both read and write access for global subprogram
memory arguments. When the caller register is PTR_TO_BTF_ID,
check_helper_mem_access() currently forwards the access to
check_ptr_to_btf_access() as BPF_READ regardless of the requested access
type.
This lets a BTF-backed kernel object field pointer pass the caller-side
writable memory check for a global subprogram argument. The callee is then
validated with a generic writable PTR_TO_MEM argument and can store through
it, even though an equivalent direct BTF field store is rejected with "only
read is supported".
Forward the requested access type to check_ptr_to_btf_access().
This enforces existing BTF write restrictions for global subprogram memory
arguments as well.
Fixes: 3e30be4288 ("bpf: Allow helpers access trusted PTR_TO_BTF_ID.")
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Link: https://lore.kernel.org/bpf/20260609-f01-04-btf-writable-arg-v1-1-f449cd970669@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
btf_parse_struct_metas() walks user-supplied BTF during BPF_BTF_LOAD,
and btf_repeat_fields() expands repeatable fields from array elements
into the fixed BTF_FIELDS_MAX scratch array used by btf_parse_fields().
The remaining-capacity check performs the expanded field count calculation
in u32. A malformed BTF can wrap that calculation, causing the check to
pass even when the expanded field count exceeds the scratch array
capacity. The following memcpy() can then write past the end of the
array.
Use checked addition and multiplication before copying repeated fields
and reject impossible counts.
Fixes: 797d73ee23 ("bpf: Check the remaining info_cnt before repeating btf fields")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moses <p@1g4.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260605234301.1109063-1-p@1g4.org
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
bpf_task_from_vpid() looks up a task in the pid namespace of the
current task, via find_task_by_vpid():
find_task_by_vpid(vpid)
find_task_by_pid_ns(vpid, task_active_pid_ns(current))
find_pid_ns(nr, ns) -> idr_find(&ns->idr, nr)
cgroup_skb programs run in softirq, which may interrupt a task that is
itself in do_exit(). Once that task has passed
exit_notify() -> release_task() -> __unhash_process(), its thread_pid is
cleared, so task_active_pid_ns(current) returns NULL and find_pid_ns()
dereferences &NULL->idr:
BUG: kernel NULL pointer dereference, address: 0000000000000050
RIP: 0010:idr_find+0x11/0x30 lib/idr.c:176
Call Trace:
<IRQ>
find_pid_ns kernel/pid.c:370 [inline]
find_task_by_pid_ns+0x3b/0xe0 kernel/pid.c:485
bpf_task_from_vpid+0x5b/0x200 kernel/bpf/helpers.c:2916
bpf_prog_run_array_cg+0x17e/0x530 kernel/bpf/cgroup.c:81
__cgroup_bpf_run_filter_skb+0x12b/0x250 kernel/bpf/cgroup.c:1612
sk_filter_trim_cap+0x1dc/0x4c0 net/core/filter.c:148
tcp_v4_rcv+0x18d1/0x2200 net/ipv4/tcp_ipv4.c:2223
</IRQ>
<TASK>
do_exit+0xa63/0x1270 kernel/exit.c:1010
get_signal+0x141c/0x1530 kernel/signal.c:3037
Bail out when current has no pid namespace.
Fixes: 675c3596ff ("bpf: Add bpf_task_from_vpid() kfunc")
Signed-off-by: Sechang Lim <rhkrqnwk98@gmail.com>
Acked-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/bpf/20260608050001.2545245-1-rhkrqnwk98@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Nuoqi Gui says:
====================
Keep dynamic inner array lookups nullable
An ARRAY_OF_MAPS can use an array created with BPF_F_INNER_MAP as its
inner map template. The flag allows a concrete inner array with a
different max_entries value to replace the template.
The verifier currently uses the template's max_entries to elide
nullness for a constant-key lookup through the inner map pointer. At
runtime, the lookup uses the concrete inner array's max_entries instead.
The verifier can therefore accept an unchecked dereference even though
the runtime helper returns NULL.
Patch 1 keeps lookups through BPF_F_INNER_MAP array templates nullable.
Patch 2 adds a verifier regression test for the unchecked dereference.
Before the fix, the regression program is accepted and the runtime
reproducer triggers a NULL dereference. With the fix, both programs are
rejected with an invalid map_value_or_null access.
Tested by compiling kernel/bpf/verifier.o and
verifier_map_in_map.bpf.o, and by running the regression program and
runtime reproducer in QEMU before and after the fix.
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Acked-by: Jiri Olsa <jolsa@kernel.org>
---
v1->v2:
- Update the can_elide_value_nullness() comment to match the changed
parameter (const struct bpf_map *map).
v1: https://patch.msgid.link/20260604151153.2488051-1-gnq25@mails.tsinghua.edu.cn
To: Alexei Starovoitov <ast@kernel.org>
To: Daniel Borkmann <daniel@iogearbox.net>
To: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Xu <dxu@dxuuu.xyz>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Song Liu <song@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ihor Solodrai <isolodrai@meta.com>
Cc: bpf@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
---
====================
Link: https://patch.msgid.link/20260607-f01-v2-v2-0-da48453146e8@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Add a verifier regression test that looks up a constant key through a
dynamic inner array template and dereferences the result without a NULL
check.
The verifier must reject the program because BPF_F_INNER_MAP allows the
concrete runtime array to have fewer entries than the template.
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20260607-f01-v2-v2-2-da48453146e8@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
An ARRAY_OF_MAPS can use an array created with BPF_F_INNER_MAP as its
inner map template. A concrete inner array with a different max_entries
value can then replace the template.
After a successful outer map lookup, the verifier represents the
resulting map pointer using the inner map template. Const-key lookup
nullness elision consequently uses the template max_entries even though
the runtime helper uses the concrete inner map max_entries.
Do not elide lookup result nullness for maps marked with BPF_F_INNER_MAP,
because the template max_entries does not prove that the key is in bounds
for the concrete runtime map.
Fixes: d2102f2f5d ("bpf: verifier: Support eliding map lookup nullness")
Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20260607-f01-v2-v2-1-da48453146e8@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
ptep_try_set() installs a kernel PTE with try_cmpxchg() but, unlike
__set_pte(), skips the barriers that arm64 requires after writing a valid
kernel PTE. Without them a subsequent access can fault instead of seeing
the new mapping.
Issue them with emit_pte_barriers() rather than __set_pte_complete().
ptep_try_set() must finish the store before it returns, but
__set_pte_complete() would defer the barriers when the calling context is in
lazy MMU mode.
v2: Emit the barriers directly instead of __set_pte_complete(). (Catalin)
Fixes: 258df8fce4 ("mm: Add ptep_try_set() for lockless empty-slot installs")
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/all/aiRFcz78QTZdIHHB@arm.com/
Link: https://lore.kernel.org/bpf/7f5f7c94601312c1a401fb18998291cc@kernel.org
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Mykyta Yatsenko says:
====================
bpf: Fix LRU NMI/tracepoint re-entry deadlock
This series fixes AA-deadlocks where NMI and tracepoint BPF programs
re-enter the per-CPU or global LRU lock already held on the same CPU
(syzbot c69a0a2c816716f1e0d5, 18b26edb69b2e19f3b33).
Patch 1 converts every LRU lock site to rqspinlock_t
and adds explicit recovery for some failures so no node leaks.
Patch 2 refreshes Documentation/bpf/map_lru_hash_update.dot to show
the new rqspinlock failure exits and recovery routes.
Patch 3 introduces a stress test.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
---
Changes in v3:
- Removed RFC tag
- Link to v2: https://patch.msgid.link/20260603-lru_map_spin-v2-0-7060cfb6cdac@meta.com
Changes in v2:
- Patch 1: __bpf_lru_node_move_in() now clears pending_free only when
moving to the FREE list.
- Patch 3: address sashiko's feedback.
- Link to v1: https://patch.msgid.link/20260528-lru_map_spin-v1-0-4f52223170cf@meta.com
====================
Link: https://patch.msgid.link/20260607-lru_map_spin-v3-0-bcd9332e911b@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduces stress test for bpf_lru_list that exercises
lock-failures and orphan-recovery, added by the LRU rqspinlock
conversion.
Runs three subtests: common LRU, per-CPU LRU lists (BPF_F_NO_COMMON_LRU),
and per-CPU LRU map. Each pins one userspace hammer per CPU and attaches
the perf_event NMI BPF prog (update+delete mix) on every online CPU.
Pre-fix, lockdep fires the "INITIAL USE -> IN-NMI" splat during stress.
After stress test, drain_then_verify_capacity() drains every key
and refills the lru map.
A stranded node on any CPU's pool would have forced eviction of
a just-inserted key on that CPU, surfacing here as a missing lookup.
Marked serial_ because per-CPU pinning and high-rate HW perf events
would perturb parallel tests.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260607-lru_map_spin-v3-3-bcd9332e911b@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reflect the rqspinlock conversion and orphan-recovery paths added in
the previous commit:
- All LRU locks are rqspinlock_t; any acquire can fail (AA or
timeout). A shared "rqspinlock acquire failed" terminal collapses
to the existing -ENOMEM exit. Dashed arrows from each acquire site
mark the failure paths.
- The per-CPU local freelist is now lockless (free_llist).
- Post-steal: re-acquiring loc_l->lock to insert the stolen node
into the local pending list can fail; on failure the node is
published to free_llist instead of being orphaned, and the call
returns -ENOMEM.
- Steal-loop victim lock failure is silent: skip the victim and try
the next CPU.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260607-lru_map_spin-v3-2-bcd9332e911b@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
rhashtable.o builds with warnings as rhashtable_next_key() kdoc
from lib/rhashtable.c does not have the arguments descriptions.
Move rhashtable_next_key() kdoc from header to c file, matching
other functions.
Move rhashtable_next_key() next to the other forward declarations
in the header file.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202606061925.WI4bYI8k-lkp@intel.com/
Fixes: 8f4fa9f89b ("rhashtable: Add rhashtable_next_key() API")
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260606-rhash_fixes_1-v1-1-932ab036e6bc@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Jiri Olsa says:
====================
bpf: tracing_multi link
Add tracing_multi link support that allows fast attachment
of tracing program to many functions.
RFC: https://lore.kernel.org/bpf/20260203093819.2105105-1-jolsa@kernel.org/
v1: https://lore.kernel.org/bpf/20260220100649.628307-1-jolsa@kernel.org/
v2: https://lore.kernel.org/bpf/20260304222141.497203-1-jolsa@kernel.org/
v3: https://lore.kernel.org/bpf/20260316075138.465430-1-jolsa@kernel.org/
v4: https://lore.kernel.org/bpf/20260324081846.2334094-1-jolsa@kernel.org/
v5: https://lore.kernel.org/bpf/20260417192502.194548-1-jolsa@kernel.org/
v6: https://lore.kernel.org/bpf/20260527113951.46265-1-jolsa@kernel.org/
v7: https://lore.kernel.org/bpf/20260603110554.29590-1-jolsa@kernel.org/
v8 changes:
- add back the btf_is_union check to btf_get_type_size [sashiko]
v7 changes:
- added ftrace_hash_count stub for !CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS cade [sashiko]
- selftests fixes [sashiko]
- use hash_ptr in select_trampoline_lock [sashiko]
- changed the check duplicate logic in check_dup_ids [sashiko]
- use sort_r_nonatomic in check_dup_ids [sashiko]
- added BPF_TRACE_FSESSION_MULTI to can_be_sleepable,
plus added testcase for sleepable fsession
- make bpf_tracing_multi_opts pointer fields as const
- add ___migrate_enable to trace_blacklist
v6 changes:
- move ftrace_hash_count declaration under CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS [sashiko]
- fix ftrace_hash_remove check/deref [sashiko]
- disable context access for multi programs by using stub function with no arguments
for verification [sashiko]
- add __used for bpf_multi_func, and removed arguments, we do not allow direct access [sashiko]
- rebased on latest loongarch changes, fix ppc build
- guard update_ftrace_direct_del with ftrace_hash_count on rollback [sashiko]
- fix noreturn attachment condition in bpf_check_attach_btf_id_multi [sashiko]
- fail early on multiple same IDs provided by user [sashiko]
- fix selftests error paths [sashiko]
- add MAX_RESOLVE_DEPTH check to btf_get_type_size [sashiko]
- use btf__pointer_size [sashiko]
- fixed compilation on powerpc [sashiko]
- added verifier fails selftest
- after discussing with Song, it was determined that cleaning up FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER
is not strictly necessary — keeping the trampoline in the ipmodify_enabled state is acceptable.
The race condition this introduces remains unlikely, so the concern raised in [1] will not be
addressed at this time.
[1] https://lore.kernel.org/bpf/aec7bAbGlnEo3R1g@krava/
v5 changes:
- add dedicated hashes used for detach, so there's no need to allocate
them on detach [sashiko]
- safely release old trampoline images [sashiko]
- add cond_resched() to couple of loops [sashiko]
- validate attr->link_create.target_fd [sashiko]
- allow only bpf_get_func_ret() for return value retrieval [sashiko]
- do not allow attachment of fexit/fsession_multi for noreturn functions [sashiko]
- fixed double free/close in libbpf btf cleanup, in separate patch [sashiko]
- make btf_type_is_traceable_func closer to btf_distill_func_proto [sashiko]
- add prog->attach_btf_obj_fd check to collect_func_ids_by_glob,
to check we don't load module programs for kernel [sashiko]
- make sure program is loaded in bpf_program__attach_tracing_multi [sashiko]
- several selftests fixes [sashiko]
- add attach_type to fdinfo output [Leon Hwang]
- selftests cleanup fixes [Leon Hwang]
v4 changes:
- unlink rollback fix (added ftrace_hash_count) [bot]
- use const for some bpf_link_create_opts tracing_multi members [bot]
- adding missing comment for lockdep keys [bot]
- selftest error path fixes (leaks) and other assorted test fixes [Leon Hwang]
- several compile fixes wrt CONFIG_BPF_SYSCALL and CONFIG_BPF_JIT [kernel test robot]
- make ftrace_hash_clear global, because it's needed in rollback
v3 changes:
- fix module parsing [Leon Hwang]
- use function traceable check from libbpf [Leon Hwang]
- use ptr_to_u64 and fix/updated few comments [ci]
- display cookies as decimal numbers [ci]
- added link_create.flags check [ci]
- fix error path in bpf_trampoline_multi_detach [ci]
- make fentry/fexit.multi not extendable [ci]
- add missing OPTS_VALID to bpf_program__attach_tracing_multi [ci]
v2 changes:
- allocate data.unreg in bpf_trampoline_multi_attach for rollback path [ci]
and fixed link count setup in rollback path [ci]
- several small assorted fixes [ci]
- added loongarch and powerpc changes for struct bpf_tramp_node change
- added support to attach functions from modules
- added tests for sleepable programs
- added rollback tests
v1 changes:
- added ftrace_hash_count as wrapper for hash_count [Steven]
- added trampoline mutex pool [Andrii]
- reworked 'struct bpf_tramp_node' separatoin [Andrii]
- the 'struct bpf_tramp_node' now holds pointer to bpf_link,
which is similar to what we do for uprobe_multi;
I understand it's not a fundamental change compared to previous
version which used bpf_prog pointer instead, but I don't see better
way of doing this.. I'm happy to discuss this further if there's
better idea
- reworked 'struct bpf_fsession_link' based on bpf_tramp_node
- made btf__find_by_glob_kind function internal helper [Andrii]
- many small assorted fixes [Andrii,CI]
- added session support [Leon Hwang]
- added cookies support
- added more tests
Note I plan to send linkinfo support separately, the patchset is big enough.
thanks,
jirka
====================
Link: https://patch.msgid.link/20260606123955.345967-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding tests for the rollback code when the tracing_multi
link won't get attached, covering 2 reasons:
- wrong btf id passed by user, where all previously allocated
trampolines will be released
- trampoline for requested function is fully attached (has already
maximum programs attached) and the link fails, the rollback code
needs to release all previously link-ed trampolines and release
them
We need the bpf_fentry_test* unattached for the tests to pass,
so the rollback tests are serial.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-30-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding benchmark test that attaches to (almost) all allowed tracing
functions and display attach/detach times.
# ./test_progs -t tracing_multi_bench_attach -v
bpf_testmod.ko is already unloaded.
Loading bpf_testmod.ko...
Successfully loaded bpf_testmod.ko.
serial_test_tracing_multi_bench_attach:PASS:btf__load_vmlinux_btf 0 nsec
serial_test_tracing_multi_bench_attach:PASS:tracing_multi_bench__open_and_load 0 nsec
serial_test_tracing_multi_bench_attach:PASS:get_syms 0 nsec
serial_test_tracing_multi_bench_attach:PASS:bpf_program__attach_tracing_multi 0 nsec
serial_test_tracing_multi_bench_attach: found 51186 functions
serial_test_tracing_multi_bench_attach: attached in 1.295s
serial_test_tracing_multi_bench_attach: detached in 0.243s
#507 tracing_multi_bench_attach:OK
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
Successfully unloaded bpf_testmod.ko.
Exporting skip_entry as is_unsafe_function and using it in the test.
Also updating trace_blacklist with ___migrate_enable to be in sync
with kernel functions deny list.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-29-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding tracing multi tests for intersecting attached functions.
Using bits from (from 1 to 16 values) to specify (up to 4) attached
programs, and randomly choosing bpf_fentry_test* functions they are
attached to.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-24-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding tests for tracing_multi link attachment via all possible
libbpf apis - skeleton, function pattern and btf ids on top of
bpf_testmod kernel module.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-23-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding tests for tracing_multi link attachment via all possible
libbpf apis - skeleton, function pattern and btf ids.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-22-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
