Commit 55cfaa3cbdd29c4919ecb5fb8965c310f357e48c
Committed by
Linus Torvalds
Linus Torvalds
1 parent
1f64d69c7a
Exists in
master
and in
20 other branches
mm/mempolicy.c: add rcu read lock to protect pid structure
find_task_by_vpid() should be protected by rcu_read_lock(), to prevent free_pid() reclaiming pid. Signed-off-by: Zeng Zhaoming <zengzm.kernel@gmail.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 3 additions and 0 deletions Side-by-side Diff
mm/mempolicy.c
| ... | ... | @@ -1307,15 +1307,18 @@ |
| 1307 | 1307 | goto out; |
| 1308 | 1308 | |
| 1309 | 1309 | /* Find the mm_struct */ |
| 1310 | + rcu_read_lock(); | |
| 1310 | 1311 | read_lock(&tasklist_lock); |
| 1311 | 1312 | task = pid ? find_task_by_vpid(pid) : current; |
| 1312 | 1313 | if (!task) { |
| 1313 | 1314 | read_unlock(&tasklist_lock); |
| 1315 | + rcu_read_unlock(); | |
| 1314 | 1316 | err = -ESRCH; |
| 1315 | 1317 | goto out; |
| 1316 | 1318 | } |
| 1317 | 1319 | mm = get_task_mm(task); |
| 1318 | 1320 | read_unlock(&tasklist_lock); |
| 1321 | + rcu_read_unlock(); | |
| 1319 | 1322 | |
| 1320 | 1323 | err = -EINVAL; |
| 1321 | 1324 | if (!mm) |