Gh0st
/
linux
mirror of https://github.com/torvalds/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
1,397,016 Commits 1 Branch 911 Tags 8.3 GiB
Commit Graph

4 Commits

Author SHA1 Message Date
Ian Rogers 01be43f2a0 perf bpf-utils: Harden get_bpf_prog_info_linear 
In get_bpf_prog_info_linear two calls to bpf_obj_get_info_by_fd are
made, the first to compute memory requirements for a struct perf_bpil
and the second to fill it in. Previously the code would warn when the
second call didn't match the first. Such races can be common place in
things like perf test, whose perf trace tests will frequently load BPF
programs. Rather than a debug message, return actual errors for this
case. Out of paranoia also validate the read bpf_prog_info array
value. Change the type of ptr to avoid mismatched pointer type
compiler warnings. Add some additional debug print outs and sanity
asserts.

Closes: https://lore.kernel.org/lkml/CAP-5=fWJQcmUOP7MuCA2ihKnDAHUCOBLkQFEkQES-1ZZTrgf8Q@mail.gmail.com/
Fixes: 6ac22d036f ("perf bpf: Pull in bpf_program__get_prog_info_linear()")
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250902181713.309797-4-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
 2025-09-02 14:55:32 -07:00
Ian Rogers 1654a0e4d5 perf bpf-utils: Constify bpil_array_desc 
The array's contents is a compile time constant. Constify to make the
code more intention revealing and avoid unintended errors.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250902181713.309797-3-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
 2025-09-02 14:55:20 -07:00
Ian Rogers 579d6c6d77 perf bpf: 8 byte align bpil data 
bpil data is accessed assuming 64-bit alignment resulting in undefined
behavior as the data is just byte aligned. With an -fsanitize=undefined
build the following errors are observed:

  $ sudo perf record -a sleep 1
  util/bpf-event.c:310:22: runtime error: load of misaligned address 0x55f61084520f for type '__u64', which requires 8 byte alignment
  0x55f61084520f: note: pointer points here
   a8 fe ff ff 3c  51 d3 c0 ff ff ff ff 04  84 d3 c0 ff ff ff ff d8  aa d3 c0 ff ff ff ff a4  c0 d3 c0
               ^
  util/bpf-event.c:311:20: runtime error: load of misaligned address 0x55f61084522f for type '__u32', which requires 4 byte alignment
  0x55f61084522f: note: pointer points here
   ff ff ff ff c7  17 00 00 f1 02 00 00 1f  04 00 00 58 04 00 00 00  00 00 00 0f 00 00 00 63  02 00 00
               ^
  util/bpf-event.c:198:33: runtime error: member access within misaligned address 0x55f61084523f for type 'const struct bpf_func_info', which requires 4 byte alignment
  0x55f61084523f: note: pointer points here
   58 04 00 00 00  00 00 00 0f 00 00 00 63  02 00 00 3b 00 00 00 ab  02 00 00 44 00 00 00 14  03 00 00

Correct this by rouding up the data sizes and aligning the pointers.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Dave Marchevsky <davemarchevsky@fb.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20220614014714.1407239-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2022-06-28 12:05:25 -03:00
Dave Marchevsky 6ac22d036f perf bpf: Pull in bpf_program__get_prog_info_linear() 
To prepare for impending deprecation of libbpf's bpf_program__get_prog_info_linear(),
pull in the function and associated helpers into the perf codebase and migrate
existing uses to the perf copy.

Since libbpf's deprecated definitions will still be visible to perf, it is necessary
to rename perf's definitions.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211011082031.4148337-4-davemarchevsky@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 2021-11-01 18:16:40 -03:00