tracing: Ensure module defining synth event cannot be unloaded while tracing

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commit 21581dd4e7 upstream.

Currently, using synth_event_delete() will fail if the event is being
used (tracing in progress), but that is normally done in the module exit
function. At that stage, failing is problematic as returning a non-zero
status means the module will become locked (impossible to unload or
reload again).

Instead, ensure the module exit function does not get called in the
first place by increasing the module refcnt when the event is enabled.

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 35ca5207c2 ("tracing: Add synthetic event command generation functions")
Link: https://lore.kernel.org/20250318180906.226841-1-douglas.raillard@arm.com
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Douglas Raillard 2025-03-18 18:09:05 +00:00 • committed by Greg Kroah-Hartman

parent a2cce54c17

commit bb9616ba5b

1 changed files with 29 additions and 1 deletions

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kernel/trace/trace_events_synth.c

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