perf_events: Fix FORK events

Commit 22e19085 ("Honour event state for aux stream data")
introduced a bug where we would drop FORK events.

The thing is that we deliver FORK events to the child process'
event, which at that time will be PERF_EVENT_STATE_INACTIVE
because the child won't be scheduled in (we're in the middle of
fork).

Solve this twice, change the event state filter to exclude only
disabled (STATE_OFF) or worse, and deliver FORK events to the
current (parent).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
LKML-Reference: <1266142324.5273.411.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 6 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 2b19297742c..2ae7409bf38 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -3259,8 +3259,6 @@ static void perf_event_task_output(struct perf_event *event,
         task_event->event_id.tid = perf_event_tid(event, task);
         task_event->event_id.ptid = perf_event_tid(event, current);
 
-        task_event->event_id.time = perf_clock();
-
         perf_output_put(&handle, task_event->event_id);
 
         perf_output_end(&handle);
@@ -3268,7 +3266,7 @@ 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)
+        if (event->state < PERF_EVENT_STATE_INACTIVE)
                 return 0;
 
         if (event->cpu != -1 && event->cpu != smp_processor_id())
@@ -3300,7 +3298,7 @@ static void perf_event_task_event(struct perf_task_event *task_event)
         cpuctx = &get_cpu_var(perf_cpu_context);
         perf_event_task_ctx(&cpuctx->ctx, task_event);
         if (!ctx)
-                ctx = rcu_dereference(task_event->task->perf_event_ctxp);
+                ctx = rcu_dereference(current->perf_event_ctxp);
         if (ctx)
                 perf_event_task_ctx(ctx, task_event);
         put_cpu_var(perf_cpu_context);
@@ -3331,6 +3329,7 @@ static void perf_event_task(struct task_struct *task,
                         /* .ppid */
                         /* .tid  */
                         /* .ptid */
+                        .time = perf_clock(),
                 },
         };
 
@@ -3380,7 +3379,7 @@ 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)
+        if (event->state < PERF_EVENT_STATE_INACTIVE)
                 return 0;
 
         if (event->cpu != -1 && event->cpu != smp_processor_id())
@@ -3500,7 +3499,7 @@ 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)
+        if (event->state < PERF_EVENT_STATE_INACTIVE)
                 return 0;
 
         if (event->cpu != -1 && event->cpu != smp_processor_id())