From cce6a2d7e0e494c453ad73e1e78bd50684f20cca Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Tue, 27 Sep 2022 22:32:59 +0200 Subject: [PATCH] bpf: Check flags for branch stack in bpf_read_branch_records helper 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") Fixes: a9a931e26668 ("perf: Use sample_flags for branch stack") Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kan Liang Link: https://lore.kernel.org/r/20220927203259.590950-1-jolsa@kernel.org --- 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 68e5cdd..1fcd123 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; -- 2.7.4