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tracing: Do not synchronize freeing of trigger filter on boot up

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If a trigger filter on the kernel command line fails to apply (due to
syntax error), it will be freed. The freeing will call
tracepoint_synchronize_unregister(), but this is not needed during early
boot up, and will even trigger a lockdep splat.

Avoid calling the synchronization function when system_state is
SYSTEM_BOOTING.

Link: https://lore.kernel.org/linux-trace-kernel/20221213172429.7774f4ba@gandalf.local.home

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Google)
2022-12-13 17:24:29 -05:00
parent fab89a09c8
commit fb9f5ee9bf
1 changed files with 8 additions and 2 deletions
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10
kernel/trace/trace_events_trigger.c
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@@ -1085,8 +1085,14 @@ int set_trigger_filter(char *filter_str,
rcu_assign_pointer(data->filter, filter); rcu_assign_pointer(data->filter, filter);
if (tmp) { if (tmp) {
/* Make sure the call is done with the filter */ /*
tracepoint_synchronize_unregister(); * Make sure the call is done with the filter.
* It is possible that a filter could fail at boot up,
* and then this path will be called. Avoid the synchronization
* in that case.
*/
if (system_state != SYSTEM_BOOTING)
tracepoint_synchronize_unregister();
free_event_filter(tmp); free_event_filter(tmp);
} }