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| author | Zeng Zhaoming <zengzm.kernel@gmail.com> | 2010-12-02 14:31:13 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-12-02 14:51:14 -0800 |
| commit | 55cfaa3cbdd29c4919ecb5fb8965c310f357e48c (patch) | |
| tree | 914fad20ce59c42bd3781820c8fb73286581a5ae /mm/mempolicy.c | |
| parent | 1f64d69c7ad2e48e697493e45590679f7a69b7b2 (diff) | |
| download | lwn-55cfaa3cbdd29c4919ecb5fb8965c310f357e48c.tar.gz lwn-55cfaa3cbdd29c4919ecb5fb8965c310f357e48c.zip | |
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>
Diffstat (limited to 'mm/mempolicy.c')
| -rw-r--r-- | mm/mempolicy.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4a57f135b76e..11ff260fb282 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1307,15 +1307,18 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, goto out; /* Find the mm_struct */ + rcu_read_lock(); read_lock(&tasklist_lock); task = pid ? find_task_by_vpid(pid) : current; if (!task) { read_unlock(&tasklist_lock); + rcu_read_unlock(); err = -ESRCH; goto out; } mm = get_task_mm(task); read_unlock(&tasklist_lock); + rcu_read_unlock(); err = -EINVAL; if (!mm) |