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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-07-24 06:25:30 -0400
committerIngo Molnar <mingo@elte.hu>2009-08-02 08:26:14 -0400
commit8f48894fcc89ddec62e1762f73a0825793e59e91 (patch)
tree63b071af185d7049c854cbf4d000949968236bac
parent00aec93d10a051ea64f83eff75d4065a19508ea6 (diff)
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>
-rw-r--r--kernel/sched_fair.c20
-rw-r--r--kernel/sched_rt.c16
2 files changed, 26 insertions, 10 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;
79 * CFS operations on generic schedulable entities: 79 * CFS operations on generic schedulable entities:
80 */ 80 */
81 81
82static inline struct task_struct *task_of(struct sched_entity *se)
83{
84 return container_of(se, struct task_struct, se);
85}
86
87#ifdef CONFIG_FAIR_GROUP_SCHED 82#ifdef CONFIG_FAIR_GROUP_SCHED
88 83
89/* cpu runqueue to which this cfs_rq is attached */ 84/* cpu runqueue to which this cfs_rq is attached */
@@ -95,6 +90,14 @@ static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
95/* An entity is a task if it doesn't "own" a runqueue */ 90/* An entity is a task if it doesn't "own" a runqueue */
96#define entity_is_task(se) (!se->my_q) 91#define entity_is_task(se) (!se->my_q)
97 92
93static inline struct task_struct *task_of(struct sched_entity *se)
94{
95#ifdef CONFIG_SCHED_DEBUG
96 WARN_ON_ONCE(!entity_is_task(se));
97#endif
98 return container_of(se, struct task_struct, se);
99}
100
98/* Walk up scheduling entities hierarchy */ 101/* Walk up scheduling entities hierarchy */
99#define for_each_sched_entity(se) \ 102#define for_each_sched_entity(se) \
100 for (; se; se = se->parent) 103 for (; se; se = se->parent)
@@ -186,7 +189,12 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse)
186 } 189 }
187} 190}
188 191
189#else /* CONFIG_FAIR_GROUP_SCHED */ 192#else /* !CONFIG_FAIR_GROUP_SCHED */
193
194static inline struct task_struct *task_of(struct sched_entity *se)
195{
196 return container_of(se, struct task_struct, se);
197}
190 198
191static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 199static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
192{ 200{
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 13f728ef5b38..f365e66b3d49 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -3,15 +3,18 @@
3 * policies) 3 * policies)
4 */ 4 */
5 5
6#ifdef CONFIG_RT_GROUP_SCHED
7
8#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
9
6static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) 10static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
7{ 11{
12#ifdef CONFIG_SCHED_DEBUG
13 WARN_ON_ONCE(!rt_entity_is_task(rt_se));
14#endif
8 return container_of(rt_se, struct task_struct, rt); 15 return container_of(rt_se, struct task_struct, rt);
9} 16}
10 17
11#ifdef CONFIG_RT_GROUP_SCHED
12
13#define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
14
15static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) 18static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
16{ 19{
17 return rt_rq->rq; 20 return rt_rq->rq;
@@ -26,6 +29,11 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
26 29
27#define rt_entity_is_task(rt_se) (1) 30#define rt_entity_is_task(rt_se) (1)
28 31
32static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
33{
34 return container_of(rt_se, struct task_struct, rt);
35}
36
29static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) 37static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
30{ 38{
31 return container_of(rt_rq, struct rq, rt); 39 return container_of(rt_rq, struct rq, rt);