oom: fix possible oom_dump_tasks NULL pointer
When /proc/sys/vm/oom_dump_tasks is enabled, it is possible to get a NULL pointer for tasks that have detached mm's since task_lock() is not held during the tasklist scan. Add the task_lock(). Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
681a1b4032
commit
6d2661ede5
|
@ -284,22 +284,28 @@ static void dump_tasks(const struct mem_cgroup *mem)
|
|||
printk(KERN_INFO "[ pid ] uid tgid total_vm rss cpu oom_adj "
|
||||
"name\n");
|
||||
do_each_thread(g, p) {
|
||||
/*
|
||||
* total_vm and rss sizes do not exist for tasks with a
|
||||
* detached mm so there's no need to report them.
|
||||
*/
|
||||
if (!p->mm)
|
||||
continue;
|
||||
struct mm_struct *mm;
|
||||
|
||||
if (mem && !task_in_mem_cgroup(p, mem))
|
||||
continue;
|
||||
if (!thread_group_leader(p))
|
||||
continue;
|
||||
|
||||
task_lock(p);
|
||||
mm = p->mm;
|
||||
if (!mm) {
|
||||
/*
|
||||
* total_vm and rss sizes do not exist for tasks with no
|
||||
* mm so there's no need to report them; they can't be
|
||||
* oom killed anyway.
|
||||
*/
|
||||
task_unlock(p);
|
||||
continue;
|
||||
}
|
||||
printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n",
|
||||
p->pid, __task_cred(p)->uid, p->tgid,
|
||||
p->mm->total_vm, get_mm_rss(p->mm), (int)task_cpu(p),
|
||||
p->oomkilladj, p->comm);
|
||||
p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm,
|
||||
get_mm_rss(mm), (int)task_cpu(p), p->oomkilladj,
|
||||
p->comm);
|
||||
task_unlock(p);
|
||||
} while_each_thread(g, p);
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue