2017-06-29 19:11:45

by Liang, Kan

Subject: [PATCH] perf/x86/intel/uncore: fix wrong box pointer check

From: Kan Liang <[email protected]>

Should not init a NULL box. It will cause system crash.
The issue looks like caused by a typo. It is introduced from:

commit fff4b87e594a ("perf/x86/intel/uncore: Make package handling
more robust")

This was not noticed because there is no NULL box. Also, for most
boxes, they are enabled by default. The init code is not critical.

Signed-off-by: Kan Liang <[email protected]>
---
arch/x86/events/intel/uncore.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 758c1aa5009d..44ec523287f6 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1170,7 +1170,7 @@ static int uncore_event_cpu_online(unsigned int cpu)
pmu = type->pmus;
for (i = 0; i < type->num_boxes; i++, pmu++) {
box = pmu->boxes[pkg];
- if (!box && atomic_inc_return(&box->refcnt) == 1)
+ if (box && atomic_inc_return(&box->refcnt) == 1)
uncore_box_init(box);
}
}
--
2.11.0

2017-06-29 19:36:29

by tip-bot for Vasyl Gomonovych

Subject: [tip:x86/urgent] perf/x86/intel/uncore: Fix wrong box pointer check

Commit-ID: 80c65fdb4c6920e332a9781a3de5877594b07522
Gitweb: http://git.kernel.org/tip/80c65fdb4c6920e332a9781a3de5877594b07522
Author: Kan Liang <[email protected]>
AuthorDate: Thu, 29 Jun 2017 12:09:26 -0700
Committer: Thomas Gleixner <[email protected]>
CommitDate: Thu, 29 Jun 2017 21:28:13 +0200

perf/x86/intel/uncore: Fix wrong box pointer check

Should not init a NULL box. It will cause system crash.
The issue looks like caused by a typo.

This was not noticed because there is no NULL box. Also, for most
boxes, they are enabled by default. The init code is not critical.

Fixes: fff4b87e594a ("perf/x86/intel/uncore: Make package handling more robust")
Signed-off-by: Kan Liang <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]

---
arch/x86/events/intel/uncore.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 758c1aa..44ec523 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1170,7 +1170,7 @@ static int uncore_event_cpu_online(unsigned int cpu)
pmu = type->pmus;
for (i = 0; i < type->num_boxes; i++, pmu++) {
box = pmu->boxes[pkg];
- if (!box && atomic_inc_return(&box->refcnt) == 1)
+ if (box && atomic_inc_return(&box->refcnt) == 1)
uncore_box_init(box);
}
}