From 09933a108e6730a464a1ab676c9decc11aee0edc Mon Sep 17 00:00:00 2001 From: Jaswinder Singh Rajput Date: Wed, 18 Mar 2009 22:18:56 +0530 Subject: tracing: fix oops in tracepoint_update_probe_range() Change this crash: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] 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 Cc: Frederic Weisbecker Cc: Steven Rostedt LKML-Reference: <1237394936.3132.1.camel@localhost.localdomain> [ moved the check outside the lock and added a WARN_ON(). ] Signed-off-by: Ingo Molnar --- kernel/tracepoint.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'kernel/tracepoint.c') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 79602740bbb..adf28734fe2 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); -- cgit v1.2.3 From ec625cb29e66824f7ce41082617aeb93fa4e42e2 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 18 Mar 2009 19:54:04 +0100 Subject: tracepoints: dont update zero-sized tracepoint sections Zero-sized tracepoint sections can occur if tracing is enabled but no tracepoint is defined. Do not emit a warning in that case. Cc: Frederic Weisbecker Cc: Steven Rostedt Cc: Jaswinder Singh Rajput LKML-Reference: <1237394936.3132.1.camel@localhost.localdomain> Signed-off-by: Ingo Molnar --- kernel/tracepoint.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'kernel/tracepoint.c') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index adf28734fe2..1ef5d3a601c 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -278,10 +278,8 @@ tracepoint_update_probe_range(struct tracepoint *begin, struct tracepoint *end) struct tracepoint *iter; struct tracepoint_entry *mark_entry; - if (!begin) { - WARN_ON_ONCE(1); + if (!begin) return; - } mutex_lock(&tracepoints_mutex); for (iter = begin; iter < end; iter++) { -- cgit v1.2.3