The patch titled
mm/mempolicy.c: add rcu read lock to protect pid structure
has been added to the -mm tree. Its filename is
mm-mempolicyc-add-rcu-read-lock-to-protect-pid-structure.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm/mempolicy.c: add rcu read lock to protect pid structure
From: Zeng Zhaoming <zengzm.kernel@xxxxxxxxx>
find_task_by_vpid() should be protected by rcu_read_lock(), to prevent
free_pid() reclaiming pid.
Signed-off-by: Zeng Zhaoming <zengzm.kernel@xxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempolicy.c | 3 +++
1 file changed, 3 insertions(+)
diff -puN mm/mempolicy.c~mm-mempolicyc-add-rcu-read-lock-to-protect-pid-structure mm/mempolicy.c
--- a/mm/mempolicy.c~mm-mempolicyc-add-rcu-read-lock-to-protect-pid-structure
+++ a/mm/mempolicy.c
@@ -1307,15 +1307,18 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pi
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)
_
Patches currently in -mm which might be from zengzm.kernel@xxxxxxxxx are
mm-mempolicyc-add-rcu-read-lock-to-protect-pid-structure.patch
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