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>
This commit is contained in:
Jaswinder Singh Rajput 2009-03-18 22:18:56 +05:30 коммит произвёл Ingo Molnar
Родитель 4903620034
Коммит 09933a108e
1 изменённых файлов: 7 добавлений и 2 удалений

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@ -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);