perf: fix the missing event initialization when pmu is found in idr

perf: fix the missing event initialization when pmu is found in idr

[Lin Ming]

Currently, the event is not initialized if pmu is found in idr.
This never causes bug just because now no pmu is associated with the idr
id.
This patch fixes the potential bug.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
---
 kernel/perf_event.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 64a018e..821ce82 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -6098,17 +6098,22 @@ struct pmu *perf_init_event(struct perf_event *event)
 {
 	struct pmu *pmu = NULL;
 	int idx;
+	int ret;
 
 	idx = srcu_read_lock(&pmus_srcu);
 
 	rcu_read_lock();
 	pmu = idr_find(&pmu_idr, event->attr.type);
 	rcu_read_unlock();
-	if (pmu)
+	if (pmu) {
+		ret = pmu->event_init(event);
+		if (ret)
+			pmu = ERR_PTR(ret);
 		goto unlock;
+	}
 
 	list_for_each_entry_rcu(pmu, &pmus, entry) {
-		int ret = pmu->event_init(event);
+		ret = pmu->event_init(event);
 		if (!ret)
 			goto unlock;
 

Re: perf: fix the missing event initialization when pmu is found in idr

[Peter Zijlstra]

On Sun, 2011-02-27 at 21:13 +0800, Lin Ming wrote:
> Currently, the event is not initialized if pmu is found in idr.
> This never causes bug just because now no pmu is associated with the
> idr id. 

Yeah, d'0h, thanks!

[tip:perf/core] perf: Fix the missing event initialization when pmu is found in idr

[tip-bot for Lin Ming]

Commit-ID:  940c5b2971de443df22eed0441bc74fb0116e9f5
Gitweb:     http://git.kernel.org/tip/940c5b2971de443df22eed0441bc74fb0116e9f5
Author:     Lin Ming <ming.m.lin@intel.com>
AuthorDate: Sun, 27 Feb 2011 21:13:31 +0800
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 4 Mar 2011 11:32:50 +0100

perf: Fix the missing event initialization when pmu is found in idr

Currently, the event is not initialized if pmu is found in idr. This
never causes bug just because now no pmu is associated with the idr
id.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1298812411.2699.9.camel@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/perf_event.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 64a018e..821ce82 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -6098,17 +6098,22 @@ struct pmu *perf_init_event(struct perf_event *event)
 {
 	struct pmu *pmu = NULL;
 	int idx;
+	int ret;
 
 	idx = srcu_read_lock(&pmus_srcu);
 
 	rcu_read_lock();
 	pmu = idr_find(&pmu_idr, event->attr.type);
 	rcu_read_unlock();
-	if (pmu)
+	if (pmu) {
+		ret = pmu->event_init(event);
+		if (ret)
+			pmu = ERR_PTR(ret);
 		goto unlock;
+	}
 
 	list_for_each_entry_rcu(pmu, &pmus, entry) {
-		int ret = pmu->event_init(event);
+		ret = pmu->event_init(event);
 		if (!ret)
 			goto unlock;