Merge branch 'for-4.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

298a2d87 · Linus Torvalds <[email protected]> · 2017-01-31 13:10:59 -08:00

Pull percpu fix from Tejun Heo:
 "Douglas found and fixed a ref leak bug in percpu_ref_tryget[_live]().

  The bug is caused by storing the return value of atomic_long_inc_not_zero()
  into an int temp variable before returning it as a bool. The interim
  cast to int loses the upper bits and can lead to false negatives. As
  percpu_ref uses a high bit to mark a draining counter, this can happen
  relatively easily.

  Fixed by using bool for the temp variable"

* 'for-4.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu-refcount: fix reference leak during percpu-atomic transition

Commit: 298a2d87518ec01bb36070fafe31da7746556db0
Parents: 52e02f27 · 966d2b04

Merge commit. Changes below are compared with the first parent: 52e02f27.

Changes

1 files changed · +2 −2

File	Status	Add	Del	Content
include/linux/percpu-refcount.h	modified	+2	−2	View file

include/linux/percpu-refcount.h

View file

diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 1c7eec0..3a481a4 100644
--- a/include/linux/percpu-refcount.h
+++ b/include/linux/percpu-refcount.h
@@ -204,7 +204,7 @@ static inline void percpu_ref_get(struct percpu_ref *ref)
 static inline bool percpu_ref_tryget(struct percpu_ref *ref)
 {
 	unsigned long __percpu *percpu_count;
-	int ret;
+	bool ret;
 
 	rcu_read_lock_sched();
 
@@ -238,7 +238,7 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref)
 static inline bool percpu_ref_tryget_live(struct percpu_ref *ref)
 {
 	unsigned long __percpu *percpu_count;
-	int ret = false;
+	bool ret = false;
 
 	rcu_read_lock_sched();
 