perf c2c:
- Add 'function view' in perf c2c report TUI (switched by pressing 'TAB'
in the cacheline view) to organize samples around functions rather than
cachelines in 3-level hierarchy:
Level 1: Read-side function (sorted by estimated Cycles %)
Level 2: Contending writer functions (sorted by Store count)
Level 3: Shared cacheline addresses
Users can navigate the entries and fold/unfold using 'e' key. An example
output would look like below:
Shared Data Functions Table (19 entries, sorted on Cycles %)
Cycles Store
% count Function / Contending function / Cacheline
----------------------------------------------------------------------
+ 35.67% 876 + [k] cpupri_set
+ 24.31% 424 + [k] pull_rt_task
- 16.53% 555 - [k] dequeue_pushable_task
145 - [k] pull_rt_task
145 0xff2d0082809da080
139 - [k] enqueue_pushable_task
70 0xff2d00a2071f9640
69 0xff2d0082809da000
python module support:
- Extend "perf" python module so that it can be fully functional. The goal
is to run scripts directly, not by 'perf script' command. This would give
better performance as well as more control to build standalone programs
with UI.
- Add LiveSession helper (perf_live.py) to enable live event collection
directly from Python using perf.evlist and perf.parse_events.
perf stat:
- Add --hide-zero-events option to suppress zero-count events.
- Reject conflicting --field-separator and --json-output options.
- Fix duplicate event output with --for-each-cgroup.
perf sched latency:
- Add -H/--histogram and --hist-mode (log|linear) options to show scheduler
wait latency histograms.
- Add --time option to filter analysis by time span in 'perf sched latency'.
ARM CoreSight:
- Synthesize callchains for instruction samples from CoreSight trace
using thread stack ('--itrace=g...').
- Support call indentation ('perf script -F +callindent') to display call
depth hierarchy on branch samples.
- Decode ETE (Embedded Trace Extension) exception packets.
Build system:
- Add 'make install-build-deps' target to install required packages.
- Parallelize JSON and metric pre-computation in jevents.py for faster builds.
Vendor event/metric updates:
- Add Intel Nova Lake events and update tables for existing models.
- Update AMD Zen 5 and Zen 6 core events.
- Update Arm64 Tegra410 metrics and PowerPC hcalls.
Internal changes and fixes:
- Harden trace-event and synthetic event parsing against corrupted data.
- Fix unwinding of multi-threaded processes in libdw unwinder.
- Fix memory leaks in various commands and python bindings.
- Speed up 'perf test' shell tests.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v7.3-2026-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools
Pull perf tools updates from Namhyung Kim:
"perf c2c:
- Add 'function view' in perf c2c report TUI (switched by pressing
'TAB' in the cacheline view) to organize samples around functions
rather than cachelines in 3-level hierarchy:
Level 1: Read-side function (sorted by estimated Cycles %)
Level 2: Contending writer functions (sorted by Store count)
Level 3: Shared cacheline addresses
Users can navigate the entries and fold/unfold using 'e' key. An
example output would look like below:
Shared Data Functions Table (19 entries, sorted on Cycles %)
Cycles Store
% count Function / Contending function / Cacheline
----------------------------------------------------------------------
+ 35.67% 876 + [k] cpupri_set
+ 24.31% 424 + [k] pull_rt_task
- 16.53% 555 - [k] dequeue_pushable_task
145 - [k] pull_rt_task
145 0xff2d0082809da080
139 - [k] enqueue_pushable_task
70 0xff2d00a2071f9640
69 0xff2d0082809da000
python module support:
- Extend "perf" python module so that it can be fully functional. The
goal is to run scripts directly, not by 'perf script' command. This
would give better performance as well as more control to build
standalone programs with UI.
- Add LiveSession helper (perf_live.py) to enable live event
collection directly from Python using perf.evlist and
perf.parse_events.
perf stat:
- Add --hide-zero-events option to suppress zero-count events
- Reject conflicting --field-separator and --json-output options
- Fix duplicate event output with --for-each-cgroup
perf sched latency:
- Add -H/--histogram and --hist-mode (log|linear) options to show
scheduler wait latency histograms
- Add --time option to filter analysis by time span in 'perf sched
latency'
ARM CoreSight:
- Synthesize callchains for instruction samples from CoreSight trace
using thread stack ('--itrace=g...')
- Support call indentation ('perf script -F +callindent') to display
call depth hierarchy on branch samples
- Decode ETE (Embedded Trace Extension) exception packets
Build system:
- Add 'make install-build-deps' target to install required packages
- Parallelize JSON and metric pre-computation in jevents.py for
faster builds
Vendor event/metric updates:
- Add Intel Nova Lake events and update tables for existing models
- Update AMD Zen 5 and Zen 6 core events
- Update Arm64 Tegra410 metrics and PowerPC hcalls
Internal changes and fixes:
- Harden trace-event and synthetic event parsing against corrupted
data
- Fix unwinding of multi-threaded processes in libdw unwinder
- Fix memory leaks in various commands and python bindings
- Speed up 'perf test' shell tests"
* tag 'perf-tools-for-v7.3-2026-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (232 commits)
perf vendor events arm64: Fix Tegra410 Olympus event 0x0197
perf vendor events arm64: fix swapped MetricGroup for Tegra410 L1 prefetcher metrics
perf evlist: Warn when 'sleep' workload is used without system-wide (-a) option
perf c2c: document function view in perf-c2c man page
perf c2c: add function view browser UI and cacheline detail
perf c2c: build and finalize the function view hierarchy
perf c2c: add function view hierarchy entry creation
perf c2c: add function view stats merge and memory management
perf c2c: add HPP list parsing for function view columns
perf c2c: add column rendering for function view
perf c2c: add function view model skeleton
perf c2c: extract shared data structures into util/c2c.h
perf test sample-parsing: Validate PERF_FORMAT_GROUP values without LOST
perf dso: Replace assert with runtime check in dso__read_symbol()
perf dso: Guard against cache underflow on short reads in dso_cache__memcpy()
perf dso: Use stored fd error instead of stale errno in file_read() and file_size()
perf dso: Guard close() against invalid fd in dso__decompress_kmodule_path()
perf dso: Guard against errno==0 when dso__get_filename() returns NULL
perf build: install-build-deps: add RHEL family devel package mapping
perf build: Remove leftover feature tests for removed cxx and clang support
...
- Redesign the verifier error reporting: failures now carry source and
instruction annotations along with the causal event history that led
to them, making program rejections far easier to debug and repair
(Kumar Kartikeya Dwivedi)
- Add arena argument support to kfuncs and struct_ops through the new
__arena and __arena__nullable suffixes (Tejun Heo, Puranjay Mohan,
Kumar Kartikeya Dwivedi, Ihor Solodrai)
- Signed BPF program loader rework to accommodate both BPF and security
community needs where the kernel runs the signature verification at
BPF_PROG_LOAD time before the LSM admission hook (Daniel Borkmann)
- Add a set of ksock kfuncs which let BPF LSM and syscall programs
create, connect and send on UDP sockets in order to emit telemetry
data (Mahe Tardy)
- Unify helper and kfunc call argument verification and classify kfunc
arguments purely from BTF into a generated bpf_func_proto which is
computed once at add-call time (Amery Hung)
Other features and fixes:
- Enable EXECMEM_ROX_CACHE for BPF allocations on x86 (Mike Rapoport)
- Add bidirectional VLAN support to bpf_fib_lookup() through the new
BPF_FIB_LOOKUP_VLAN and BPF_FIB_LOOKUP_VLAN_INPUT flags
(Avinash Duduskar)
- Infer zext_dst from static register liveness analysis to fix 32-bit
zero-extension semantics, and remove the artificial limitations on
pointer types eligible for spilling (Eduard Zingerman)
- Inline the numeric open-coded iterator kfuncs so that bpf_for() loops
no longer pay a kfunc call on every iteration (Puranjay Mohan)
- Add an arena-based bitmap data structure to libarena along with
serial and parallel selftests (Emil Tsalapatis)
- Teach resolve_btfids to discover kfuncs from the kernel's BTF ID sets
and to emit kfunc BTF decl tags, reducing the kernel build's
dependency on pahole features (Ihor Solodrai)
- Add BPF_F_ADJ_ROOM_DECAP_* flags to bpf_skb_adjust_room() so that
tunnel decapsulation can update the GSO and encapsulation state of
the skb (Nick Hudson)
- Fix the ring buffer pending_pos walk and the available-data
accounting on 32-bit position wrap (Israel Téllez García)
- Add memory usage accounting for arena maps and fix an mmap_lock
deadlock on arena lock failure (Jiayuan Chen)
- Add tracing_multi link info support to the kernel UAPI and bpftool,
and refactor the stack map code to run with preemption disabled
(Jiri Olsa)
- Support BPF_F_EGRESS in bpf_redirect_peer() to emit the skb in the
egress direction of the target's peer device (Jordan Rife)
- Add a KF_SPINLOCK_SAFE kfunc flag so that providers, in particular
modules, can declare kfuncs safe to call under bpf_spin_lock instead
of relying on the verifier's hard-coded allowlist (Kaitao Cheng)
- Introduce global percpu data for BPF programs with libbpf probing
and bpftool skeleton support, and stop exposing uninitialized kernel
heap memory when copying per-CPU map values (Leon Hwang)
- Add s390 JIT support for load-acquire and store-release instructions
(Maxim Khmelevskii)
- Fix a CFI mismatch in the task work callback and an arm64 KASAN
false positive after bpf_throw() (Mykyta Yatsenko)
- Reject writes through untrusted BTF pointers and bound the
rdonly/rdwr_buf_size kfunc arguments (Nicholas Dudar)
- Invalidate RCU pointers only after the final spin unlock and account
for preempt and IRQ disabled regions as overlapping RCU protection
(Ning Ding)
- Support mixing bpf2bpf calls and tail calls on RV64, add signed
operations and 32-bit atomics to the RV32 JIT, and add timed may_goto
support (Pu Lehui, Kuan-Wei Chiu, Feng Jiang)
- Fix a use-after-free on mm_struct in bpf_find_vma() for foreign tasks
and an mmap_lock leak in the irq_work path (Sanghyun Park)
- Populate mmap-able BPF array map memory lazily which makes mmap() O(1)
instead of proportional to the map size (Song Liu)
- Introduce a jit_required flag and reject programs with inlined
helpers when no JIT is available, where the interpreter would
otherwise jump into an invalid address (Tiezhu Yang)
- Fix the x86 JIT per-CPU address resolution into an extended register
where the REX prefix dropped the high destination register bit
(Vineet Gupta)
- Reject MEM_ALLOC BTF accesses past object bounds, arena frees below
the arena base, and mixed arena and ordinary atomic paths
(Yiyang Chen)
- Fix the trampoline handling of 128-bit arguments and of return values
larger than 8 bytes (Yonghong Song)
- Ensure that any fault prone load is rewritten with exception table
handling, and fix the arena load-acquire and atomic fetch handling
in the x86, arm64, riscv and s390 JITs (Daniel Borkmann)
- Many more fixes and cleanups across the verifier, arena, trampolines,
sockmap, cgroup, ring buffer, x86/arm64/riscv/s390 JITs, libbpf,
bpftool, resolve_btfids and selftests.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Merge tag 'bpf-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Daniel Borkmann:
"Major changes:
- Redesign the verifier error reporting: failures now carry source
and instruction annotations along with the causal event history
that led to them, making program rejections far easier to debug and
repair (Kumar Kartikeya Dwivedi)
- Add arena argument support to kfuncs and struct_ops through the new
__arena and __arena__nullable suffixes (Tejun Heo, Puranjay Mohan,
Kumar Kartikeya Dwivedi, Ihor Solodrai)
- Signed BPF program loader rework to accommodate both BPF and
security community needs where the kernel runs the signature
verification at BPF_PROG_LOAD time before the LSM admission hook
(Daniel Borkmann)
- Add a set of ksock kfuncs which let BPF LSM and syscall programs
create, connect and send on UDP sockets in order to emit telemetry
data (Mahe Tardy)
- Unify helper and kfunc call argument verification and classify
kfunc arguments purely from BTF into a generated bpf_func_proto
which is computed once at add-call time (Amery Hung)
Other features and fixes:
- Enable EXECMEM_ROX_CACHE for BPF allocations on x86 (Mike Rapoport)
- Add bidirectional VLAN support to bpf_fib_lookup() through the new
BPF_FIB_LOOKUP_VLAN and BPF_FIB_LOOKUP_VLAN_INPUT flags (Avinash
Duduskar)
- Infer zext_dst from static register liveness analysis to fix 32-bit
zero-extension semantics, and remove the artificial limitations on
pointer types eligible for spilling (Eduard Zingerman)
- Inline the numeric open-coded iterator kfuncs so that bpf_for()
loops no longer pay a kfunc call on every iteration (Puranjay
Mohan)
- Add an arena-based bitmap data structure to libarena along with
serial and parallel selftests (Emil Tsalapatis)
- Teach resolve_btfids to discover kfuncs from the kernel's BTF ID
sets and to emit kfunc BTF decl tags, reducing the kernel build's
dependency on pahole features (Ihor Solodrai)
- Add BPF_F_ADJ_ROOM_DECAP_* flags to bpf_skb_adjust_room() so that
tunnel decapsulation can update the GSO and encapsulation state of
the skb (Nick Hudson)
- Fix the ring buffer pending_pos walk and the available-data
accounting on 32-bit position wrap (Israel Téllez García)
- Add memory usage accounting for arena maps and fix an mmap_lock
deadlock on arena lock failure (Jiayuan Chen)
- Add tracing_multi link info support to the kernel UAPI and bpftool,
and refactor the stack map code to run with preemption disabled
(Jiri Olsa)
- Support BPF_F_EGRESS in bpf_redirect_peer() to emit the skb in the
egress direction of the target's peer device (Jordan Rife)
- Add a KF_SPINLOCK_SAFE kfunc flag so that providers, in particular
modules, can declare kfuncs safe to call under bpf_spin_lock
instead of relying on the verifier's hard-coded allowlist (Kaitao
Cheng)
- Introduce global percpu data for BPF programs with libbpf probing
and bpftool skeleton support, and stop exposing uninitialized
kernel heap memory when copying per-CPU map values (Leon Hwang)
- Add s390 JIT support for load-acquire and store-release
instructions (Maxim Khmelevskii)
- Fix a CFI mismatch in the task work callback and an arm64 KASAN
false positive after bpf_throw() (Mykyta Yatsenko)
- Reject writes through untrusted BTF pointers and bound the
rdonly/rdwr_buf_size kfunc arguments (Nicholas Dudar)
- Invalidate RCU pointers only after the final spin unlock and
account for preempt and IRQ disabled regions as overlapping RCU
protection (Ning Ding)
- Support mixing bpf2bpf calls and tail calls on RV64, add signed
operations and 32-bit atomics to the RV32 JIT, and add timed
may_goto support (Pu Lehui, Kuan-Wei Chiu, Feng Jiang)
- Fix a use-after-free on mm_struct in bpf_find_vma() for foreign
tasks and an mmap_lock leak in the irq_work path (Sanghyun Park)
- Populate mmap-able BPF array map memory lazily which makes mmap()
O(1) instead of proportional to the map size (Song Liu)
- Introduce a jit_required flag and reject programs with inlined
helpers when no JIT is available, where the interpreter would
otherwise jump into an invalid address (Tiezhu Yang)
- Fix the x86 JIT per-CPU address resolution into an extended
register where the REX prefix dropped the high destination register
bit (Vineet Gupta)
- Reject MEM_ALLOC BTF accesses past object bounds, arena frees below
the arena base, and mixed arena and ordinary atomic paths (Yiyang
Chen)
- Fix the trampoline handling of 128-bit arguments and of return
values larger than 8 bytes (Yonghong Song)
- Ensure that any fault prone load is rewritten with exception table
handling, and fix the arena load-acquire and atomic fetch handling
in the x86, arm64, riscv and s390 JITs (Daniel Borkmann)
- Many more fixes and cleanups across the verifier, arena,
trampolines, sockmap, cgroup, ring buffer, x86/arm64/riscv/s390
JITs, libbpf, bpftool, resolve_btfids and selftests"
* tag 'bpf-next-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (373 commits)
selftests/bpf: Add tests for a store on a fault prone qdisc pointer
selftests/bpf: Add tests for fault prone loads out of RCU pointers
selftests/bpf: Add tests for pointer type merge at a shared load
selftests/bpf: Remove duplicate copies of the arena spinlock qnodes
selftests/bpf: Retry stat generation in cgroup_iter_memcg
selftests/bpf: Test pseudo-function policy diagnostics
bpf: Distinguish function references in policy diagnostics
bpf: Preserve source attribution without source text
selftests/bpf: Test kfunc argument diagnostics
bpf: Correct kfunc argument diagnostics
bpf: Use canonical stack argument names in diagnostics
bpf: Preserve R0 lineage across helper calls
selftests/bpf: Exercise negative optlen in cgroup getsockopt hook
bpf: Reject negative optlen in cgroup getsockopt hook
selftests/bpf: tc_tunnel - validate decap GSO and encapsulation state
bpf: Clear decap state on skb_adjust_room shrink path
bpf: Allow new DECAP flags and add guard rails
bpf: Add BPF_F_ADJ_ROOM_DECAP_* flags for tunnel decapsulation
bpf: Refactor masks for ADJ_ROOM flags and encap validation
bpf: Name the enum for BPF_FUNC_skb_adjust_room flags
...
ringbuf_process_ring() walks the records between the consumer and the
producer with an ordering comparison:
while (cons_pos < prod_pos) {
cons_pos and prod_pos mirror the kernel's ring positions and are
unsigned long here too, so on 32-bit they wrap at 2^32 bytes of traffic.
When producer_pos has wrapped and consumer_pos has not, prod_pos is the
smaller of the two, the loop body never runs and no record is consumed.
Since consumer_pos only advances inside that loop, it never wraps either
and the consumer stops delivering samples for good, with no error
returned to the caller: ring_buffer__poll() keeps reporting zero
records while the kernel side fills up and starts dropping.
Compare the distance instead. The consumer never runs ahead of the
producer, so prod_pos - cons_pos is the amount of unconsumed data and
stays correct across the wrap.
64-bit hosts are unaffected in practice: the counters would need 16 EiB
to wrap. This is the userspace counterpart of the kernel-side walk fixed
in "bpf: Fix pending_pos walk on 32-bit ring position wrap"; a 32-bit
consumer hits whichever of the two comes first.
Signed-off-by: Israel Téllez García <i.tellez@btesa.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260814124843.22041-5-i.tellez@btesa.com
Use array_map_mmap_sz() for PERCPU_ARRAY like ARRAY in bpf_map_mmap_sz().
This lets bpf_map__set_value_size() skip mmap(), memcpy(), and munmap()
when the old and new value sizes occupy the same number of pages.
Fix some typos btw:
* mmapble -> mmapable
* satisified -> satisfied
* relocatin -> relocation
* atach_btf_obj_fd -> attach_btf_obj_fd
* len_secnd -> len_second
* precendence -> precedence
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260814173206.93082-3-leon.hwang@linux.dev
Enhance bpftool to generate skeletons that properly handle global percpu
variables. The generated skeleton now includes a dedicated structure for
percpu data, allowing users to initialize and access percpu variables more
efficiently.
For global percpu variables, the skeleton now includes a nested
structure, e.g.:
struct test_global_percpu_data {
struct bpf_object_skeleton *skeleton;
struct bpf_object *obj;
struct {
struct bpf_map *percpu;
} maps;
// ...
struct test_global_percpu_data__percpu {
int data;
char run;
struct {
char set;
int i;
int nums[7];
} struct_data;
int nums[7];
} *percpu;
// ...
};
* The "struct test_global_percpu_data__percpu *percpu" points to
initialized data, which is actually "maps.percpu->mmaped".
* Before loading the skeleton, updating the
"struct test_global_percpu_data__percpu *percpu" modifies the initial
value of the corresponding global percpu variables.
* After loading the skeleton, "maps.percpu->mmaped" has been marked as
read-only in libbpf. If users want to update the global percpu
variables, they have to update the "maps.percpu" map instead.
* For lightweight skeleton, "lskel->percpu" will be protected by
"mprotect(p, sz, PROT_READ)".
* For subskeleton, those variables of global percpu data will be
skipped.
Assisted-by: Codex:gpt-5.5-xhigh
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/bpf/20260813152324.97937-7-leon.hwang@linux.dev
Add support for global percpu data in libbpf by adding a new ".percpu"
section, similar to ".data". It enables efficient handling of percpu
global variables in bpf programs.
When generating loader for lightweight skeleton, update the percpu_array
map used for global percpu data using BPF_F_ALL_CPUS, in order to update
values across all CPUs using one value slot.
Unlike global data, the mmaped data for global percpu data will be marked
as read-only after populating the percpu_array map. Thereafter, users can
read those initialized percpu data after loading prog. If they want to
update the percpu data after loading prog, they have to update the
percpu_array map using key=0 instead.
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260813152324.97937-6-leon.hwang@linux.dev
libbpf needs a reliable way to distinguish kernels that can support
global percpu data from those that cannot.
Add a dedicated feature probe, so libbpf can make capability decisions
early and fail predictably when global percpu data is unavailable.
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260813152324.97937-5-leon.hwang@linux.dev
btf__find_by_name_kind() searches the base BTF before the split BTF,
so in case of a name collision between base and split it always
returns a base type. Tools that process split BTF may need to restrict
a lookup to the split's own types.
The internal helper btf__find_by_name_kind_own() already does exactly
that. Make it a public API.
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260722233518.778854-5-ihor.solodrai@linux.dev
Documentation/kbuild/llvm.rst mentions that readelf is included in the
LLVM toolchain, but it's not currently included in this block.
Add it so that LLVM=... options also apply to readelf. Users in tools/
were Perf which was hardcoding it, and another was the BPF makefile.
Both already include Makefile.include so convert them to use the new
variables.
Where readelf wasn't doing anything arch specific, use HOSTREADELF
because it's more likely to be installed.
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
attach_probe/uprobe-lib and uprobe_autoattach selftests fail with "failed
to resolve full path for libc.so.6" on older non-usrmerged distros, where
libc.so.6 lives under a top-level /lib64 or /lib rather than /usr/lib64 or
/usr/lib. Add /lib64:/lib to the search paths, alongside the existing
/usr/lib64:/usr/lib and Debian multiarch entries.
Fixes: 1ce3a60e3c ("libbpf: auto-resolve programs/libraries when necessary for uprobes")
Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/bpf/20260720-selftests-bpf_fixes-v2-3-b450eda93dfe@suse.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
When btf_parse_elf() is called without a caller-supplied base_btf (i.e.
via the public btf__parse_elf()) and the object file carries a .BTF.base
(distilled base) section, a dist_base_btf object is created and used as
the base of the split BTF built from the .BTF section. Because base_btf
is NULL, the relocation block that would otherwise free and clear
dist_base_btf is skipped, and ownership of dist_base_btf is instead
transferred to the split btf by setting btf->owns_base = true.
That ownership transfer was performed before the fallible btf_ext__new()
call that parses the .BTF.ext section. If .BTF.ext is malformed,
btf_ext__new() fails and the function jumps to the error path, which
frees dist_base_btf directly and then frees btf. Since owns_base is
already set, btf__free(btf) also frees btf->base_btf, which is the same
dist_base_btf object. The result is a use-after-free read followed by a
double free of the base BTF, driven entirely by a crafted object file
(a .BTF + .BTF.base + malformed .BTF.ext combination) passed to
btf__parse_elf(), as used by bpftool, pahole and similar tools.
Transfer ownership only after .BTF.ext has been parsed successfully, so
that any earlier failure leaves dist_base_btf owned solely by the local
cleanup path and it is freed exactly once.
Signed-off-by: Naveed Khan <naveed@digiscrypt.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/178345549172.94179.7948304165383170781@digiscrypt.com
The signed gen_loader used to police its own metadata map from within
BPF: emit_signature_match() read the kernel-cached map->sha[] back
through hardcoded struct bpf_map offsets and compared it against a hash
that compute_sha_update_offsets() baked into the signed instructions,
after a BPF_OBJ_GET_INFO_BY_FD round-trip to populate map->sha[].
The kernel now verifies the metadata at BPF_PROG_LOAD time by folding
the frozen contents of the loader's exclusive fd_array maps into the
signature, so the loader no longer checks anything itself. Generated
loaders thus carry no verification logic of their own anymore: Nothing
in the signing chain depends on emitted loader bytecode doing the right
thing.
On the loading side, skel_internal.h now sets fd_array_cnt for a signed
load so the kernel scans fd_array for the exclusive metadata map -
still frozen, as the kernel requires - and the BPF_OBJ_GET_INFO_BY_FD
round-trip to populate map->sha[] is gone. The struct bpf_map layout
BUILD_BUG_ON()s on the kernel side are removed as well: they only
pinned the ABI for the in-BPF read of map->sha[] that is no longer
needed. Same for the map->excl member. Note: gen_hash is retained; it
still marks a loader as signed so an untrusted host cannot re-dimension
maps or override initial values now covered by the signature.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708075343.358712-4-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
In the previous optimized uprobe fix we changed the syscall
error used for its detection from ENXIO to EPROTO.
Changing related probe_uprobe_syscall detection check.
Fixes: 05738da0ef ("libbpf: Add uprobe syscall feature detection")
Fixes: 554ba38456 ("uprobes/x86: Move optimized uprobe from nop5 to nop10")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://patch.msgid.link/20260703114917.238144-8-jolsa@kernel.org
We now expect nop combo with 10 bytes nop instead of 5 bytes nop,
fixing has_nop_combo to reflect that.
Fixes: 41a5c7df44 ("libbpf: Add support to detect nop,nop5 instructions combo for usdt probe")
Fixes: 554ba38456 ("uprobes/x86: Move optimized uprobe from nop5 to nop10")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://patch.msgid.link/20260703114917.238144-7-jolsa@kernel.org
bpf_object__probe_loading() tries to load trivial SOCKET_FILTER and
TRACEPOINT programs to verify the BPF environment works. When a
BPF token is in use with restricted program type permissions, these
probe loads may fail because the token does not allow the specific
program types, even though BPF loading is perfectly functional.
Fix by skipping the probe when a token FD is present: BPF token
creation itself proves the kernel has a working BPF subsystem.
Real BPF issues will be caught during actual program and map loading.
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260610145059.113412-2-chenyuan_fl@163.com
Building libbpf with -Wall (as happens via bpftool's bootstrap build)
surfaces ~120 -Wformat warnings where pr_warn/pr_debug format specifiers
don't match their argument types: %d for __u32/Elf64_Word, %u for signed
ints, %zd for size_t, %ld for unsigned long, and %x/%lx/%llx applied to
signed values.
Match each specifier to its argument's type where a correctly-signed
specifier exists (%d<->%u, %ld->%lu, %zd->%zu). For hex conversions,
which have no signed form, cast the argument instead (%x->(unsigned),
%lx->(unsigned long), %llx->(unsigned long long)). No functional change.
Note, the fdinfo map_flags sscanf used %i into a __u32 *, which warns.
The kernel prints map_flags as hex ("map_flags:\t%#x\n" in
bpf_map_show_fdinfo(), unchanged since the field was added to fdinfo), so
switch the conversion to %x: it parses the 0x-prefixed value and expects
unsigned int *, matching the destination, so the warning is gone with no
cast.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20260624204946.2901178-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tools/scripts/Makefile.include may expand EXTRA_CFLAGS in a future
change. This could alter the initialization of CFLAGS, as the default
options "-g -O2" would never be set once EXTRA_CFLAGS is expanded.
Prepare for this by moving the CFLAGS initialization before including
tools/scripts/Makefile.include, so it is not affected by the extended
EXTRA_CFLAGS.
Append EXTRA_CFLAGS to CFLAGS only after including Makefile.include and
place it last so that the extra flags propagate properly and can
override the default options.
tools/scripts/Makefile.include already appends $(CLANG_CROSS_FLAGS) to
CFLAGS, the Makefile appends $(CLANG_CROSS_FLAGS) again, remove the
redundant append.
Signed-off-by: Leo Yan <leo.yan@arm.com>
Acked-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/r/20260602-tools_build_fix_zero_init_bpf_only-v2-4-c76e5250ea1c@arm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding the path_fd field to struct bpf_link_create_opts and passing it
through kernel attr interface.
Assisted-by: Codex:GPT-5.4
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260611114230.950379-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding bpf_program__attach_tracing_multi function for attaching
tracing program to multiple functions.
struct bpf_link *
bpf_program__attach_tracing_multi(const struct bpf_program *prog,
const char *pattern,
const struct bpf_tracing_multi_opts *opts);
User can specify functions to attach with 'pattern' argument that
allows wildcards (*?' supported) or provide BTF ids of functions
in array directly via opts argument. These options are mutually
exclusive.
When using BTF ids, user can also provide cookie value for each
provided id/function, that can be retrieved later in bpf program
with bpf_get_attach_cookie helper. Each cookie value is paired with
provided BTF id with the same array index.
Adding support to auto attach programs with following sections:
fsession.multi/<pattern>
fsession.multi.s/<pattern>
fentry.multi/<pattern>
fexit.multi/<pattern>
fentry.multi.s/<pattern>
fexit.multi.s/<pattern>
The provided <pattern> is used as 'pattern' argument in
bpf_program__attach_kprobe_multi_opts function.
The <pattern> allows to specify optional kernel module name with
following syntax:
<module>:<function_pattern>
In order to attach tracing_multi link to a module functions:
- program must be loaded with 'module' btf fd
(in attr::attach_btf_obj_fd)
- bpf_program__attach_tracing_multi must either have
pattern with module spec or BTF ids from the module
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-21-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding btf_type_is_traceable_func function to perform same checks
as the kernel's btf_distill_func_proto function to prevent attachment
on some of the functions.
Exporting the function via libbpf_internal.h because it will be used
by benchmark test in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-20-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding bpf_link_create support for tracing_multi link with
new tracing_multi record in struct bpf_link_create_opts.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-19-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding bpf_object_cleanup_btf function to cleanup btf objects.
It will be used in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-18-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding support to use session attachment with tracing_multi link.
Adding new BPF_TRACE_FSESSION_MULTI program attach type, that follows
the BPF_TRACE_FSESSION behaviour but on the tracing_multi link.
Such program is called on entry and exit of the attached function
and allows to pass cookie value from entry to exit execution.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-16-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding new link to allow to attach program to multiple function
BTF IDs. The link is represented by struct bpf_tracing_multi_link.
To configure the link, new fields are added to bpf_attr::link_create
to pass array of BTF IDs;
struct {
__aligned_u64 ids;
__u32 cnt;
} tracing_multi;
Each BTF ID represents function (BTF_KIND_FUNC) that the link will
attach bpf program to.
We use previously added bpf_trampoline_multi_attach/detach functions
to attach/detach the link.
The linkinfo/fdinfo callbacks will be implemented in following changes.
Note this is supported only for archs (x86_64) with ftrace direct and
have single ops support.
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS &&
CONFIG_HAVE_SINGLE_FTRACE_DIRECT_OPS
Note using sort_r (instead of plain sort) in check_dup_ids, because we
will use the swap callback in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-14-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding new program attach types multi tracing attachment:
BPF_TRACE_FENTRY_MULTI
BPF_TRACE_FEXIT_MULTI
and their base support in verifier code.
Programs with such attach type will use specific link attachment
interface coming in following changes.
This was suggested by Andrii some (long) time ago and turned out
to be easier than having special program flag for that.
Bpf programs with such types have 'bpf_multi_func' function set as
their attach_btf_id and keep module reference when it's specified
by attach_prog_fd.
They are also accepted as sleepable programs during verification,
and the real validation for specific BTF_IDs/functions will happen
during the multi link attachment in following changes.
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260606123955.345967-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add BPF_MAP_TYPE_RHASH to libbpf's map type name table and feature
probing so that libbpf-based tools can create and identify resizable
hash maps.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260605-rhash-v7-8-5b8e05f8630d@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
add_data() computes size8 = roundup(size, 8) and then hands size8 to
realloc_data_buf() before doing memcpy(gen->data_cur, data, size) with
the original size. A wrapped size8 passes through the realloc_data_buf()
INT32_MAX check. Harden this against overflow, though not realistic to
happen in practice.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260602133052.423725-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_gen__map_create() lets the host-supplied loader ctx override a
map's max_entries at runtime (map_desc[idx].max_entries, when non-zero).
This is how the light skeleton sizes maps to the target machine, but
it happens after emit_signature_match() and is covered by neither the
signed loader instructions nor the hashed blob.
For a signed loader this means an untrusted host can re-dimension the
program's maps, outside what the signature attests to. Gate the override
on gen_hash so signed loaders use the signer-provided max_entries baked
into the blob.
Fixes: ea923080c1 ("libbpf: Embed and verify the metadata hash in the loader")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260601150248.394863-6-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_gen__map_update_elem() emits code that, when the host-supplied
loader ctx provides a non-NULL map_desc[idx].initial_value, overwrites
the blob value with bytes read from the host (bpf_copy_from_user /
bpf_probe_read_kernel) before the BPF_MAP_UPDATE_ELEM that populates
the program's .data/.rodata/.bss maps.
This override runs after emit_signature_match() has validated map->sha[],
and initial_value is part of neither the signed loader instructions nor
the hashed data blob. For a signed loader this lets an untrusted host
substitute global-variable contents into a program whose code carries
a valid signature, thus weakening what the signature attests to.
The blob already contains the signer-provided value (added via add_data()
and covered by the embedded, signed hash), so simply skip emitting the
override for signed loaders (gen_hash). Runtime initialization stays
available for the unsigned light-skeleton path as before. The jump
offsets within the override block are internal to it, so guarding the
whole block leaves them unchanged.
Fixes: ea923080c1 ("libbpf: Embed and verify the metadata hash in the loader")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260601150248.394863-5-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The loader verifies map->sha against the metadata hash in its
instructions. map->sha is calculated when BPF_OBJ_GET_INFO_BY_FD is
called on the frozen map.
While the map is frozen, the /signed loader/ must also ensure the map
is exclusive, as, without exclusivity (which a hostile host could just
omit when loading the loader), another BPF program with map access can
mutate the contents afterwards, so the check passes on stale data.
With the extra check as part of the signed loader, it now refuses to
move on with map->sha validation if the host set it up wrongly.
Fixes: fb2b0e2901 ("libbpf: Update light skeleton for signing")
Signed-off-by: KP Singh <kpsingh@kernel.org>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260601150248.394863-4-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_gen__prog_load() byte-swaps the program insns and the {func,line}_info
and CO-RE relo blobs in place for cross-endian targets. The blob offsets
come from add_data(), which returns 0 on failure: realloc_data_buf() either
frees and NULLs gen->data_start (realloc OOM) or returns early on an
already-latched gen->error, leaving a stale, possibly too-small buffer.
Neither bswap site checked for this. With gen->swapped_endian set and a
failed generation, "gen->data_start + off" becomes NULL + 0. Guard the
same way via !gen->error so they are skipped once generation has failed.
Fixes: 8ca3323dce ("libbpf: Support creating light skeleton of either endianness")
Reported-by: sashiko <sashiko@sashiko.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260529162829.315921-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
realloc_insn_buf() as well as realloc_data_buf() free and NULL
gen->insn_start / gen->data_start on -ENOMEM but leave gen->insn_cur /
gen->data_cur pointing into the old, freed buffer. Just reset the
cursors to NULL alongside the base pointers so the freed state is
coherent.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260529094119.307264-3-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_gen__finish() calls compute_sha_update_offsets() gated only on
the gen_hash option, without first consulting gen->error. On a failed
generation this is buggy: a failed realloc_data_buf() sets gen->data_start
to NULL (leaving gen->data_cur dangling), so compute_sha_update_offsets()
runs libbpf_sha256() over a NULL buffer with a bogus length; a failed
realloc_insn_buf() likewise sets gen->insn_start to NULL and the hash
immediates get patched through that NULL base.
The computed program is discarded in either case, since the following
"if (!gen->error)" block does not publish opts->insns once an error is
set. Thus, skip the hash pass when generation has already failed.
Fixes: ea923080c1 ("libbpf: Embed and verify the metadata hash in the loader")
Reported-by: sashiko <sashiko@sashiko.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260529094119.307264-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When the cleanup-label jump offset does not fit in s16, emit_check_err()
sets gen->error = -ERANGE and then emits a BPF_JMP_IMM(BPF_JA, 0, 0, -1)
self-loop.
The latter emit() is dead: gen->error is assigned on the preceding line,
and emit() then bails out early in realloc_insn_buf() the moment gen->error
is set, so the jump is never written into the instruction stream.
gen->error alone already marks the generation as failed. This is a follow-up
to 7dd62566e0 ("libbpf: fix off-by-one in emit_signature_match jump offset")
which removed the jump in emit_signature_match() but not in other locations.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260529094119.307264-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
LoongArch uses the generic syscall table, where __NR_bpf is defined
as 280 in include/uapi/asm-generic/unistd.h.
To align with other architectures, add the __NR_bpf definition for
LoongArch to avoid a potential compilation failure: "error __NR_bpf
not defined. libbpf does not support your arch."
This is a follow up patch of:
commit b0c47807d3 ("bpf: Add sparc support to tools and samples.")
commit bad1926dd2 ("bpf, s390: fix build for libbpf and selftest suite")
commit ca31ca8247 ("tools/bpf: fix perf build error with uClibc (seen on ARC)")
commit e32cb12ff5 ("bpf, mips: Fix build errors about __NR_bpf undeclared")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260526063936.16769-1-yangtiezhu@loongson.cn
strset_add_str_mem() might reallocate the strset data buffer in order to
accommodate the provided string 's'. However, if 's' points to a string
already present in the buffer, it becomes dangling after the realloc.
This leads to a use-after-free when attempting to memcpy() the string
into the new buffer.
One scenario that triggers this problematic path is when resolve_btfids
attempts to patch kfunc prototypes using existing BTF parameter names:
| resolve_btfids: function bpf_list_push_back_impl already exists in BTF
| Segmentation fault (core dumped)
Compiling resolve_btfids with fsanitize=address generates a detailed
report of the UAF:
| =================================================================
| ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4
| ==1507892==ERROR: AddressSanitizer: heap-use-after-free on address 0x7f4c4a500bd4 at pc 0x55d25155a2a8 bp 0x7ffcef879060 sp 0x7ffcef878818
| READ of size 5 at 0x7f4c4a500bd4 thread T0
| #0 0x55d25155a2a7 in memcpy (tools/bpf/resolve_btfids/resolve_btfids+0xcf2a7)
| #1 0x55d2515d708e in strset__add_str tools/lib/bpf/strset.c:162:2
| #2 0x55d2515c730b in btf__add_str tools/lib/bpf/btf.c:2109:8
| #3 0x55d2515c9020 in btf__add_func_param tools/lib/bpf/btf.c:3108:14
| #4 0x55d25159f0b5 in process_kfunc_with_implicit_args tools/bpf/resolve_btfids/main.c:1196:9
| #5 0x55d25159e004 in btf2btf tools/bpf/resolve_btfids/main.c:1229:9
| #6 0x55d25159cee7 in main tools/bpf/resolve_btfids/main.c:1535:6
| #7 0x7f4c78e29f76 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
| #8 0x7f4c78e2a026 in __libc_start_main csu/../csu/libc-start.c:360:3
| #9 0x55d2514bb860 in _start (tools/bpf/resolve_btfids/resolve_btfids+0x30860)
|
| 0x7f4c4a500bd4 is located 13268 bytes inside of 2829000-byte region [0x7f4c4a4fd800,0x7f4c4a7b02c8)
| freed by thread T0 here:
| #0 0x55d25155b700 in realloc (tools/bpf/resolve_btfids/resolve_btfids+0xd0700)
| #1 0x55d2515c426c in libbpf_reallocarray tools/lib/bpf/./libbpf_internal.h:220:9
| #2 0x55d2515c426c in libbpf_add_mem tools/lib/bpf/btf.c:224:13
|
| previously allocated by thread T0 here:
| #0 0x55d25155b2e3 in malloc (tools/bpf/resolve_btfids/resolve_btfids+0xd02e3)
| #1 0x55d2515d6e7d in strset__new tools/lib/bpf/strset.c:58:20
While resolve_btfids could be refactored to avoid this call path, let's
instead fix this issue at the source in strset__add_str() and avoid
similar scenarios.
Let's check if set->strs_data was reallocated and whether 's' points to
an internal string within the old strset buffer. In such case, 's' is
reconstructed to point to the new buffer.
While already here, also fix strset__find_str() which suffers from the
same problem by factoring out the common operations into a new helper
function strset_str_append().
Fixes: 90d76d3ece ("libbpf: Extract internal set-of-strings datastructure APIs")
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Suggested-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260523162722.2718940-1-cmllamas@google.com
parse_vma_segs() in tools/lib/bpf/usdt.c parses /proc/<pid>/maps
with two widthless scansets, "%s" into mode[16] and "%[^\n]"
into line[4096]. A VMA name in maps is not limited to that local
buffer; a deeply nested backing path can produce a maps record long
enough to overflow the stack buffer.
Bound both scansets to the declared buffer sizes ("%15s" for mode[16]
and "%4095[^\n]" for line[4096]) and drain any residue past line[4094]
with "%*[^\n]" before the trailing "\n". Without the drain, the residue
of an over-long record would stay in the stream and break the next
"%zx-%zx" parse, so the loop would exit early and silently skip later
maps records.
Also stop using sscanf(..., "%s") to peel the /proc/<pid>/root prefix
from lib_path. Parse the pid and prefix length with "%n", check for the
following slash, and copy the remainder with libbpf_strlcpy(). That
removes a second unbounded stack write and preserves paths containing
spaces.
Fixes: 74cc6311ce ("libbpf: Add USDT notes parsing and resolution logic")
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/bpf/20260522201353.1454653-1-michael.bommarito@gmail.com
The offset for the cleanup-label jump is computed before the MOV R7
instruction is emitted, but the JMP lands after it. Account for the
extra insn in the offset calculation (-2 instead of -1). Drop the
redundant self-loop in the else branch; gen->error = -ERANGE already
marks the generation as failed.
Fixes: fb2b0e2901 ("libbpf: Update light skeleton for signing")
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20260522215337.662271-2-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There should be an OPTS_VALID() check for log_opts before extracting its
fields.
If no such OPTS_VALID() check and an application compiled against a future
libbpf header passes a log_opts with new, non-zero fields to libbpf.so,
those fields will be ignored silently.
Fixes: 702259006f ("libbpf: Add syscall common attributes support for map_create")
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260518145446.6794-4-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux has deprecated[1] strncpy(), and the use in skel_map_create()
is best replaced with strscpy(). Since we still need to build this
file in userspace, leave the strncpy() in place in that case. This
is the last use of strncpy() in the kernel.
Link: https://github.com/KSPP/linux/issues/90 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20260513050806.do.620-kees@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
With the previous commit adding common attribute support for
BPF_MAP_CREATE, users can now retrieve detailed error messages when map
creation fails via the log_buf field.
Introduce struct bpf_log_opts with the following fields:
log_buf, log_size, log_level, and log_true_size.
Extend bpf_map_create_opts with a new field log_opts, allowing users to
capture and inspect log messages on map creation failures.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260512153157.28382-8-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
To support the extended BPF syscall introduced in the previous commit,
introduce the following internal APIs:
* 'sys_bpf_ext()'
* 'sys_bpf_ext_fd()'
They wrap the raw 'syscall()' interface to support passing extended
attributes.
* 'probe_sys_bpf_ext()'
Check whether current kernel supports the BPF syscall common attributes.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260512153157.28382-3-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When deduplicating definitions for a module, typedef defined in the base
are not removed. This is because the hash used for base types differs
from the one used in the deduplication logic in btf_dedup_struct_type.
This was introduced by the referenced commit when moving the typedef
deduplication logic handling from btf_dedup_ref_type to
btf_dedup_struct_type, as this also changed the hash logic
(btf_hash_common to btf_hash_typedef).
This also impacts other types referencing those typedef (e.g. const). In
my test, the BTF section size of the openvswitch module went from 31KB
to 45KB.
Fixes: 3781413465 ("libbpf: Fix BTF dedup to support recursive typedef definitions").
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20260417083319.32716-1-atenart@kernel.org
Now that vlen is 24 bits, btf_vlen() must return a __u32.
Adjust use cases in libbpf accordingly. Also add error
handling to avoid vlen overflow in btf_type_inc_vlen().
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260417143023.1551481-3-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In attach_kprobe(), the parsing logic uses sscanf() to extract the
target function name and offset from the section definition. Currently,
if a user specifies a negative offset (e.g., SEC("kprobe/func+-100")),
the input is not explicitly caught and reported as an error.
This commit updates the logic to explicitly notify the user when a
negative integer is provided. To facilitate this check, the offset
variable is changed from unsigned long to long so that sscanf()
can accurately capture a negative input for evaluation.
If a negative offset is detected, the loader will now print an
informative warning stating that the offset must be non-negative,
and return -EINVAL.
Additionally, free(func) is called in this new error path to prevent
a memory leak, as the function name string is dynamically allocated
by sscanf().
Fixes: e3f9bc35ea ("libbpf: Allow decimal offset for kprobes")
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/bpf/20260419030944.1423642-1-atomlin@atomlin.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Sashiko found possible double close of btf object fd [1],
which happens when strdup in load_module_btfs fails at which
point the obj->btf_module_cnt is already incremented.
The error path close btf fd and so does later cleanup code in
bpf_object_post_load_cleanup function.
Also libbpf_ensure_mem failure leaves btf object not assigned
and it's leaked.
Replacing the err_out label with break to make the error path
less confusing as suggested by Alan.
Incrementing obj->btf_module_cnt only if there's no failure
and releasing btf object in error path.
Fixes: 91abb4a6d7 ("libbpf: Support attachment of BPF tracing programs to kernel modules")
[1] https://sashiko.dev/#/patchset/20260324081846.2334094-1-jolsa%40kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20260416100034.1610852-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow bpf object feat_cache assignment in BPF selftests
to simulate missing features via inclusion of libbpf_internal.h
and use of bpf_object_set_feat_cache() and bpf_object__sanitize_btf() to
test BTF sanitization for cases where missing features are simulated.
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/r/20260408165735.843763-2-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
CO-RE accessor strings are colon-separated indices that describe a path
from a root BTF type to a target field, e.g. "0:1:2" walks through
nested struct members. bpf_core_parse_spec() parses each component with
sscanf("%d"), so negative values like -1 are silently accepted. The
subsequent bounds checks (access_idx >= btf_vlen(t)) only guard the
upper bound and always pass for negative values because C integer
promotion converts the __u16 btf_vlen result to int, making the
comparison (int)(-1) >= (int)(N) false for any positive N.
When -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,
producing an out-of-bounds read far past the members array. A crafted
BPF program with a negative CO-RE accessor on any struct that exists in
vmlinux BTF (e.g. task_struct) crashes the kernel deterministically
during BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y
(default on major distributions). The bug is reachable with CAP_BPF:
BUG: unable to handle page fault for address: ffffed11818b6626
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)
RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)
RAX: 00000000ffffffff
Call Trace:
<TASK>
bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)
bpf_core_apply (kernel/bpf/btf.c:9507)
check_core_relo (kernel/bpf/verifier.c:19475)
bpf_check (kernel/bpf/verifier.c:26031)
bpf_prog_load (kernel/bpf/syscall.c:3089)
__sys_bpf (kernel/bpf/syscall.c:6228)
</TASK>
CO-RE accessor indices are inherently non-negative (struct member index,
array element index, or enumerator index), so reject them immediately
after parsing.
Fixes: ddc7c30426 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260404161221.961828-2-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
