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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-07-24 12:25:30 +0200
committerIngo Molnar <mingo@elte.hu>2009-08-02 14:26:14 +0200
commit8f48894fcc89ddec62e1762f73a0825793e59e91 (patch)
tree63b071af185d7049c854cbf4d000949968236bac /kernel/sched_fair.c
parent00aec93d10a051ea64f83eff75d4065a19508ea6 (diff)
downloadlwn-8f48894fcc89ddec62e1762f73a0825793e59e91.tar.gz
lwn-8f48894fcc89ddec62e1762f73a0825793e59e91.zip
sched: Add debug check to task_of()
A frequent mistake appears to be to call task_of() on a scheduler entity that is not actually a task, which can result in a wild pointer. Add a check to catch these mistakes. Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 493472984879..342000b31ad6 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -79,11 +79,6 @@ static const struct sched_class fair_sched_class;
* CFS operations on generic schedulable entities:
*/
-static inline struct task_struct *task_of(struct sched_entity *se)
-{
- return container_of(se, struct task_struct, se);
-}
-
#ifdef CONFIG_FAIR_GROUP_SCHED
/* cpu runqueue to which this cfs_rq is attached */
@@ -95,6 +90,14 @@ static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
/* An entity is a task if it doesn't "own" a runqueue */
#define entity_is_task(se) (!se->my_q)
+static inline struct task_struct *task_of(struct sched_entity *se)
+{
+#ifdef CONFIG_SCHED_DEBUG
+ WARN_ON_ONCE(!entity_is_task(se));
+#endif
+ return container_of(se, struct task_struct, se);
+}
+
/* Walk up scheduling entities hierarchy */
#define for_each_sched_entity(se) \
for (; se; se = se->parent)
@@ -186,7 +189,12 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse)
}
}
-#else /* CONFIG_FAIR_GROUP_SCHED */
+#else /* !CONFIG_FAIR_GROUP_SCHED */
+
+static inline struct task_struct *task_of(struct sched_entity *se)
+{
+ return container_of(se, struct task_struct, se);
+}
static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
{