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tracing: Clear all trace buffers when unloaded module event was used

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Currently we do not know what buffer a module event was enabled in.
On unload, it is safest to clear all buffer instances, not just the
top level buffer.

Todo: Clear only the buffer that the event was used in. The
infrastructure is there to do this, but it makes the code a bit
more complex. Lets get the current code vetted before we add that.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Red Hat)
2013-03-04 23:26:06 -05:00
committed by Steven Rostedt
parent 575380da8b
commit 873c642f59
3 changed files with 16 additions and 6 deletions
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10
kernel/trace/trace_events.c
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@@ -1649,14 +1649,18 @@ static void trace_module_remove_events(struct module *mod)
list_del(&file_ops->list);
kfree(file_ops);
}
up_write(&trace_event_mutex);
/*
* It is safest to reset the ring buffer if the module being unloaded
* registered any events that were used.
* registered any events that were used. The only worry is if
* a new module gets loaded, and takes on the same id as the events
* of this module. When printing out the buffer, traced events left
* over from this module may be passed to the new module events and
* unexpected results may occur.
*/
if (clear_trace)
tracing_reset_current_online_cpus();
up_write(&trace_event_mutex);
tracing_reset_all_online_cpus();
}
static int trace_module_notify(struct notifier_block *self,