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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-05-21 12:31:09 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-05-31 08:46:09 +0200 |
| commit | 3771f0771154675d4a0ca780be2411f3cc357208 (patch) | |
| tree | 106512f307e2aa0a89f92c01598d5fa75903af47 /kernel/trace/trace_event_perf.c | |
| parent | 8a49542c0554af7d0073aac0ee73ee65b807ef34 (diff) | |
| download | linux-3771f0771154675d4a0ca780be2411f3cc357208.tar.gz linux-3771f0771154675d4a0ca780be2411f3cc357208.tar.xz | |
perf_events, trace: Fix probe unregister race
tracepoint_probe_unregister() does not synchronize against the probe
callbacks, so do that explicitly. This properly serializes the callbacks
and the free of the data used therein.
Also, use this_cpu_ptr() where possible.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1274438476.1674.1702.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace_event_perf.c')
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index cb6f365016e4..49c7abf2ba5c 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -116,7 +116,7 @@ int perf_trace_enable(struct perf_event *p_event) if (WARN_ON_ONCE(!list)) return -EINVAL; - list = per_cpu_ptr(list, smp_processor_id()); + list = this_cpu_ptr(list); hlist_add_head_rcu(&p_event->hlist_entry, list); return 0; @@ -142,6 +142,12 @@ void perf_trace_destroy(struct perf_event *p_event) tp_event->class->perf_probe, tp_event); + /* + * Ensure our callback won't be called anymore. See + * tracepoint_probe_unregister() and __DO_TRACE(). + */ + synchronize_sched(); + free_percpu(tp_event->perf_events); tp_event->perf_events = NULL; @@ -169,7 +175,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, if (*rctxp < 0) return NULL; - raw_data = per_cpu_ptr(perf_trace_buf[*rctxp], smp_processor_id()); + raw_data = this_cpu_ptr(perf_trace_buf[*rctxp]); /* zero the dead bytes from align to not leak stack to user */ memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64)); |