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memcontrol: rcu_read_lock() to protect mm_match_cgroup()

PATCH In review Lai Jiangshan 3 participants 3 messages Nov 21, 2008 1 message not in the archive memcg

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Lai Jiangshan

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#0 lore raw

PATCH 1/1 memcontrol: rcu_read_lock() to protect mm_match_cgroup()

mm_match_cgroup() calls cgroup_subsys_state().

we must use rcu_read_lock() to protect cgroup_subsys_state().

Signed-off-by Lai Jiangshan <[email protected]>

---

include/linux/memcontrol.h +9 -2
index 1fbe14d..ce89ff0 100644
@@ -47,8 +47,15 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);
 
 extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 
-#define mm_match_cgroup(mm, cgroup)	\
-	((cgroup) == mem_cgroup_from_task((mm)->owner))
+static inline
+int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
+{
+	struct mem_cgroup *mem;
+	rcu_read_lock();
+	mem = mem_cgroup_from_task((mm)->owner);
+	rcu_read_unlock();
+	return cgroup == mem;
+}
 
 extern int
 mem_cgroup_prepare_migration(struct page *page, struct page *newpage);

A message that is not in the archive (sent off-list or not yet received): [email protected]

Reviewed-by
#2 lore raw
Quoted 5 lines · On Fri, 21 Nov 2008 16:49:43 +0800 Lai Jiangshan…

mm_match_cgroup() calls cgroup_subsys_state().

we must use rcu_read_lock() to protect cgroup_subsys_state().

Thanks,

Reviewed-by KAMEZAWA Hiroyuki <[email protected]>
Quoted 26 lines
Signed-off-by Lai Jiangshan <[email protected]>

---

include/linux/memcontrol.h +9 -2
index 1fbe14d..ce89ff0 100644
@@ -47,8 +47,15 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);
 
 extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 
-#define mm_match_cgroup(mm, cgroup)	\
-	((cgroup) == mem_cgroup_from_task((mm)->owner))
+static inline
+int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
+{
+	struct mem_cgroup *mem;
+	rcu_read_lock();
+	mem = mem_cgroup_from_task((mm)->owner);
+	rcu_read_unlock();
+	return cgroup == mem;
+}
 
 extern int
 mem_cgroup_prepare_migration(struct page *page, struct page *newpage);
Reviewed-by on v1 1/1
#3 lore raw
In reply to Lai Jiangshan
Quoted 5 lines · On Fri, 21 Nov 2008 16:49:43 +0800 Lai Jiangshan <[email protected]> wrote:

mm_match_cgroup() calls cgroup_subsys_state().

we must use rcu_read_lock() to protect cgroup_subsys_state().

Thanks,

Reviewed-by KAMEZAWA Hiroyuki <[email protected]>
Quoted 26 lines
Signed-off-by Lai Jiangshan <[email protected]>

---

include/linux/memcontrol.h +9 -2
index 1fbe14d..ce89ff0 100644
@@ -47,8 +47,15 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);
 
 extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
 
-#define mm_match_cgroup(mm, cgroup)	\
-	((cgroup) == mem_cgroup_from_task((mm)->owner))
+static inline
+int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
+{
+	struct mem_cgroup *mem;
+	rcu_read_lock();
+	mem = mem_cgroup_from_task((mm)->owner);
+	rcu_read_unlock();
+	return cgroup == mem;
+}
 
 extern int
 mem_cgroup_prepare_migration(struct page *page, struct page *newpage);