From: Tom Zanussi <tzanussi@gmail.com>
Date: Fri, 17 Apr 2009 05:27:08 +0000 (-0500)
Subject: tracing/filters: add filter_mutex to protect filter predicates
X-Git-Tag: v2.6.31-rc1~401^2~143
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac1adc55fc71c7515caa2eb0e63e49b3d1c6a47c;p=pandora-kernel.git

tracing/filters: add filter_mutex to protect filter predicates

This patch adds a filter_mutex to prevent the filter predicates from
being accessed concurrently by various external functions.

It's based on a previous patch by Li Zefan:
        "[PATCH 7/7] tracing/filters: make filter preds RCU safe"

v2 changes:

- fixed wrong value returned in a add_subsystem_pred() failure case
  noticed by Li Zefan.

[ Impact: fix trace filter corruption/crashes on parallel access ]

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1239946028.6639.13.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

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