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

[tip-bot for Kan Liang]

Commit-ID:  80c65fdb4c6920e332a9781a3de5877594b07522
Gitweb:     http://git.kernel.org/tip/80c65fdb4c6920e332a9781a3de5877594b07522
Author:     Kan Liang <kan.liang@xxxxxxxxx>
AuthorDate: Thu, 29 Jun 2017 12:09:26 -0700
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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 <kan.liang@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20170629190926.2456-1-kan.liang@xxxxxxxxx

---
 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);
 		}
 	}