diff options
Diffstat (limited to 'kernel/events/core.c')
| -rw-r--r-- | kernel/events/core.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 78e69e10482a..d1f0a7e5b182 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9644,6 +9644,24 @@ static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd) if (IS_ERR(prog)) return PTR_ERR(prog); + if (event->attr.precise_ip && + prog->call_get_stack && + (!(event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY) || + event->attr.exclude_callchain_kernel || + event->attr.exclude_callchain_user)) { + /* + * On perf_event with precise_ip, calling bpf_get_stack() + * may trigger unwinder warnings and occasional crashes. + * bpf_get_[stack|stackid] works around this issue by using + * callchain attached to perf_sample_data. If the + * perf_event does not full (kernel and user) callchain + * attached to perf_sample_data, do not allow attaching BPF + * program that calls bpf_get_[stack|stackid]. + */ + bpf_prog_put(prog); + return -EPROTO; + } + event->prog = prog; event->orig_overflow_handler = READ_ONCE(event->overflow_handler); WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); |