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| author | Carsten Emde <Carsten.Emde@osadl.org> | 2009-03-18 09:00:41 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-18 10:10:18 +0100 |
| commit | a635cf0497342978d417cae19d4a4823932977ff (patch) | |
| tree | afacf84eb85388801a04996ed62e000cdfad3bc2 | |
| parent | 50d88758a3f9787cbdbdbc030560b815721eab4b (diff) | |
| download | op-kernel-dev-a635cf0497342978d417cae19d4a4823932977ff.zip op-kernel-dev-a635cf0497342978d417cae19d4a4823932977ff.tar.gz | |
tracing: fix command line to pid reverse map
Impact: fix command line to pid mapping
map_cmdline_to_pid[] is checked in trace_save_cmdline(), but never
updated. This results in stale pid to command line mappings and the
tracer output will associate the wrong comm string.
Signed-off-by: Carsten Emde <Carsten.Emde@osadl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/trace/trace.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 06c69a2..305c562 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -738,8 +738,7 @@ void trace_stop_cmdline_recording(void); static void trace_save_cmdline(struct task_struct *tsk) { - unsigned map; - unsigned idx; + unsigned pid, idx; if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) return; @@ -757,10 +756,17 @@ static void trace_save_cmdline(struct task_struct *tsk) if (idx == NO_CMDLINE_MAP) { idx = (cmdline_idx + 1) % SAVED_CMDLINES; - map = map_cmdline_to_pid[idx]; - if (map != NO_CMDLINE_MAP) - map_pid_to_cmdline[map] = NO_CMDLINE_MAP; + /* + * Check whether the cmdline buffer at idx has a pid + * mapped. We are going to overwrite that entry so we + * need to clear the map_pid_to_cmdline. Otherwise we + * would read the new comm for the old pid. + */ + pid = map_cmdline_to_pid[idx]; + if (pid != NO_CMDLINE_MAP) + map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; + map_cmdline_to_pid[idx] = tsk->pid; map_pid_to_cmdline[tsk->pid] = idx; cmdline_idx = idx; |
