From 05cbaa2853cdfc255fdd04e65a82bfe9208c4e52 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 30 Dec 2009 16:00:35 +0100 Subject: perf: Fix NULL deref in inheritance code Liming found a NULL deref when a task has a perf context but no counters when it forks. This can occur in two cases, a race during construction where the fork hits after installing the context but before the first counter gets inserted, or more reproducably, a fork after the last counter is closed (which leaves the context around). Reported-by: Wang Liming Signed-off-by: Peter Zijlstra Cc: Frederic Weisbecker Cc: Paul Mackerras CC: LKML-Reference: <1262185684.7135.222.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel/perf_event.c') diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 03cc061398d..58ed1dae587 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -5148,7 +5148,7 @@ int perf_event_init_task(struct task_struct *child) GFP_KERNEL); if (!child_ctx) { ret = -ENOMEM; - goto exit; + break; } __perf_event_init_context(child_ctx, child); @@ -5164,7 +5164,7 @@ int perf_event_init_task(struct task_struct *child) } } - if (inherited_all) { + if (child_ctx && inherited_all) { /* * Mark the child context as a clone of the parent * context, or of whatever the parent is a clone of. @@ -5184,7 +5184,6 @@ int perf_event_init_task(struct task_struct *child) get_ctx(child_ctx->parent_ctx); } -exit: mutex_unlock(&parent_ctx->mutex); perf_unpin_context(parent_ctx); -- cgit v1.2.3-70-g09d2 From 22e190851f8709c48baf00ed9ce6144cdc54d025 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 18 Jan 2010 09:12:32 +0100 Subject: perf: Honour event state for aux stream data Anton reported that perf record kept receiving events even after calling ioctl(PERF_EVENT_IOC_DISABLE). It turns out that FORK,COMM and MMAP events didn't respect the disabled state and kept flowing in. Reported-by: Anton Blanchard Signed-off-by: Peter Zijlstra Tested-by: Anton Blanchard LKML-Reference: <1263459187.4244.265.camel@laptop> CC: stable@kernel.org Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel/perf_event.c') diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 603c0d8b5df..d27746bd3a0 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -3268,6 +3268,9 @@ static void perf_event_task_output(struct perf_event *event, static int perf_event_task_match(struct perf_event *event) { + if (event->state != PERF_EVENT_STATE_ACTIVE) + return 0; + if (event->cpu != -1 && event->cpu != smp_processor_id()) return 0; @@ -3377,6 +3380,9 @@ static void perf_event_comm_output(struct perf_event *event, static int perf_event_comm_match(struct perf_event *event) { + if (event->state != PERF_EVENT_STATE_ACTIVE) + return 0; + if (event->cpu != -1 && event->cpu != smp_processor_id()) return 0; @@ -3494,6 +3500,9 @@ static void perf_event_mmap_output(struct perf_event *event, static int perf_event_mmap_match(struct perf_event *event, struct perf_mmap_event *mmap_event) { + if (event->state != PERF_EVENT_STATE_ACTIVE) + return 0; + if (event->cpu != -1 && event->cpu != smp_processor_id()) return 0; -- cgit v1.2.3-70-g09d2