refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: David Windsor <dwindsor@xxxxxxxxx>
Reviewed-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Elena Reshetova <elena.reshetova@xxxxxxxxx>
---
kernel/sched/fair.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c95880e..5f7f997 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1130,7 +1130,7 @@ static void account_numa_dequeue(struct rq *rq, struct task_struct *p)
}
struct numa_group {
- atomic_t refcount;
+ refcount_t refcount;
spinlock_t lock; /* nr_tasks, tasks */
int nr_tasks;
@@ -2177,12 +2177,12 @@ static void task_numa_placement(struct task_struct *p)
static inline int get_numa_group(struct numa_group *grp)
{
- return atomic_inc_not_zero(&grp->refcount);
+ return refcount_inc_not_zero(&grp->refcount);
}
static inline void put_numa_group(struct numa_group *grp)
{
- if (atomic_dec_and_test(&grp->refcount))
+ if (refcount_dec_and_test(&grp->refcount))
kfree_rcu(grp, rcu);
}
@@ -2203,7 +2203,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags,
if (!grp)
return;
- atomic_set(&grp->refcount, 1);
+ refcount_set(&grp->refcount, 1);
grp->active_nodes = 1;
grp->max_faults_cpu = 0;
spin_lock_init(&grp->lock);
--
2.7.4
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