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| author | Jaswinder Singh Rajput <jaswinder@kernel.org> | 2009-03-18 22:18:56 +0530 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-18 18:54:39 +0100 |
| commit | 09933a108e6730a464a1ab676c9decc11aee0edc (patch) | |
| tree | 1233d15bd2e1e0e4fbfa4144a878f553a3b04a35 /kernel/tracepoint.c | |
| parent | 490362003457f8d387f6f6e73e3a7efbf56c3314 (diff) | |
| download | lwn-09933a108e6730a464a1ab676c9decc11aee0edc.tar.gz lwn-09933a108e6730a464a1ab676c9decc11aee0edc.zip | |
tracing: fix oops in tracepoint_update_probe_range()
Change this crash:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8107d4de>] tracepoint_update_probe_range+0x1f/0x9b
PGD 13d5fb067 PUD 13d688067 PMD 0
Oops: 0000 [#1] SMP
To a more debuggable WARN_ONCE().
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1237394936.3132.1.camel@localhost.localdomain>
[ moved the check outside the lock and added a WARN_ON(). ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/tracepoint.c')
| -rw-r--r-- | kernel/tracepoint.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 79602740bbb5..adf28734fe2d 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -272,12 +272,17 @@ static void disable_tracepoint(struct tracepoint *elem) * * Updates the probe callback corresponding to a range of tracepoints. */ -void tracepoint_update_probe_range(struct tracepoint *begin, - struct tracepoint *end) +void +tracepoint_update_probe_range(struct tracepoint *begin, struct tracepoint *end) { struct tracepoint *iter; struct tracepoint_entry *mark_entry; + if (!begin) { + WARN_ON_ONCE(1); + return; + } + mutex_lock(&tracepoints_mutex); for (iter = begin; iter < end; iter++) { mark_entry = get_tracepoint(iter->name); |