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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-16 10:14:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-16 10:14:22 -0700 |
| commit | 4ede125902386c6fa946852da81709fcf490ae4a (patch) | |
| tree | 2f6048de2bc6cbec4c585dc4cde3efc0bed498fa | |
| parent | keys: Fix proc_keys_next to increase position index (diff) | |
| parent | tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation (diff) | |
| download | wireguard-linux-4ede125902386c6fa946852da81709fcf490ae4a.tar.xz wireguard-linux-4ede125902386c6fa946852da81709fcf490ae4a.zip | |
Merge tag 'trace-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"This fixes a small race between allocating a snapshot buffer and
setting the snapshot trigger.
On a slow machine, the trigger can occur before the snapshot is
allocated causing a warning to be displayed in the ring buffer, and no
snapshot triggering. Reversing the allocation and the enabling of the
trigger fixes the problem"
* tag 'trace-v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation
| -rw-r--r-- | kernel/trace/trace_events_trigger.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index dd34a1b46a86..3a74736da363 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1088,14 +1088,10 @@ register_snapshot_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) { - int ret = register_trigger(glob, ops, data, file); - - if (ret > 0 && tracing_alloc_snapshot_instance(file->tr) != 0) { - unregister_trigger(glob, ops, data, file); - ret = 0; - } + if (tracing_alloc_snapshot_instance(file->tr) != 0) + return 0; - return ret; + return register_trigger(glob, ops, data, file); } static int |