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| author | Li Zefan <lizf@cn.fujitsu.com> | 2010-08-23 16:50:12 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-09-20 13:36:33 -0700 |
| commit | b8536db269735d35d2b9a6480d40de212fed1b3c (patch) | |
| tree | 12dbd74f71599e82bed62fd097b6f038f6baaab7 /Documentation/cpu-freq | |
| parent | 803ac2f1bd3eea08152c253dbc5f7c9865010331 (diff) | |
tracing: Fix a race in function profile
commit 3aaba20f26f58843e8f20611e5c0b1c06954310f upstream.
While we are reading trace_stat/functionX and someone just
disabled function_profile at that time, we can trigger this:
divide error: 0000 [#1] PREEMPT SMP
...
EIP is at function_stat_show+0x90/0x230
...
This fix just takes the ftrace_profile_lock and checks if
rec->counter is 0. If it's 0, we know the profile buffer
has been reset.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4C723644.4040708@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/cpu-freq')
0 files changed, 0 insertions, 0 deletions