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authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-31 22:10:59 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-31 22:10:59 +0100
commit298a2d87518ec01bb36070fafe31da7746556db0 (patch)
tree7598b4a8b90fa7f0d5e319f29bd7d5c13fbcc282
parentMerge branch 'for-4.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/gi... (diff)
parentpercpu-refcount: fix reference leak during percpu-atomic transition (diff)
downloadlinux-298a2d87518ec01bb36070fafe31da7746556db0.tar.xz
linux-298a2d87518ec01bb36070fafe31da7746556db0.zip
Merge branch 'for-4.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
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
-rw-r--r--include/linux/percpu-refcount.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
index 1c7eec09e5eb..3a481a49546e 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();