Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH -tip] bpf: Check flags for branch stack in bpf_read_branch_records helper | Date | Tue, 27 Sep 2022 22:32:59 +0200 |
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Recent commit [1] changed branch stack data indication from br_stack pointer to sample_flags in perf_sample_data struct.
We need to check sample_flags for PERF_SAMPLE_BRANCH_STACK bit for valid branch stack data.
[1] a9a931e26668 ("perf: Use sample_flags for branch stack")
Cc: Kan Liang <kan.liang@linux.intel.com> Fixes: a9a931e26668 ("perf: Use sample_flags for branch stack") Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- NOTE sending on top of tip/master because [1] is not merged in bpf-next/master yet
kernel/trace/bpf_trace.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 68e5cdd24cef..1fcd1234607e 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1507,6 +1507,9 @@ BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx, if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE)) return -EINVAL; + if (unlikely(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK))) + return -ENOENT; + if (unlikely(!br_stack)) return -ENOENT; -- 2.37.3
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