| From | KOSAKI Motohiro <> | Subject | Re: [patch 4/9] oom: Add missing rcu protection of __task_cred() in dump_tasks | Date | Thu, 10 Dec 2009 10:57:49 +0900 (JST) |
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> dump_tasks accesses __task_cred() without being in a RCU read side > critical section. tasklist_lock is not protecting that when > CONFIG_TREE_PREEMPT_RCU=y. > > Add a rcu_read_lock/unlock() section around the code which accesses > __task_cred(). > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: linux-mm@kvack.org > --- > mm/oom_kill.c | 3 +++ > 1 file changed, 3 insertions(+) > > Index: linux-2.6-tip/mm/oom_kill.c > =================================================================== > --- linux-2.6-tip.orig/mm/oom_kill.c > +++ linux-2.6-tip/mm/oom_kill.c > @@ -329,10 +329,13 @@ static void dump_tasks(const struct mem_ > task_unlock(p); > continue; > } > + /* Protect __task_cred() access */ > + rcu_read_lock(); > printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n", > p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm, > get_mm_rss(mm), (int)task_cpu(p), p->signal->oom_adj, > p->comm); > + rcu_read_unlock(); > task_unlock(p); > } while_each_thread(g, p); > }
Looks straight forward and correct to me.
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
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