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| author | Namhyung Kim <namhyung@kernel.org> | 2022-09-09 00:41:03 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-09-13 16:03:22 +0300 |
| commit | 16817ad7e8b31728b44ff9f17d8d894ed8a450d0 (patch) | |
| tree | 5d73d416cb0e2fe4b2f8f4c1a283ef3fff01a90b /kernel/events | |
| parent | 3749d33e510c3dc695b3a5886b706310890d7ebd (diff) | |
| download | linux-16817ad7e8b31728b44ff9f17d8d894ed8a450d0.tar.xz | |
perf/bpf: Always use perf callchains if exist
If the perf_event has PERF_SAMPLE_CALLCHAIN, BPF can use it for stack trace.
The problematic cases like PEBS and IBS already handled in the PMU driver and
they filled the callchain info in the sample data. For others, we can call
perf_callchain() before the BPF handler.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220908214104.3851807-2-namhyung@kernel.org
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index c98ecf3e09ba..7da5515082f9 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10000,8 +10000,16 @@ static void bpf_overflow_handler(struct perf_event *event, goto out; rcu_read_lock(); prog = READ_ONCE(event->prog); - if (prog) + if (prog) { + if (prog->call_get_stack && + (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) && + !(data->sample_flags & PERF_SAMPLE_CALLCHAIN)) { + data->callchain = perf_callchain(event, regs); + data->sample_flags |= PERF_SAMPLE_CALLCHAIN; + } + ret = bpf_prog_run(prog, &ctx); + } rcu_read_unlock(); out: __this_cpu_dec(bpf_prog_active); @@ -10027,7 +10035,7 @@ static int perf_event_set_bpf_handler(struct perf_event *event, if (event->attr.precise_ip && prog->call_get_stack && - (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY) || + (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) || event->attr.exclude_callchain_kernel || event->attr.exclude_callchain_user)) { /* |