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authorOleg Nesterov <oleg@tv-sign.ru>2008-04-30 00:52:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 08:29:33 -0700
commit1406f2d321bae5ac5ff729dcb773336d9c05ec74 (patch)
tree178f7e2d800cee7be211225952f397458707587a
parentbfc4b0890af566940de6e7aeb4b5faf46d3c3513 (diff)
lock_task_sighand: add rcu lock/unlock
Most of the callers of lock_task_sighand() doesn't actually need rcu_lock(). lock_task_sighand() needs it only to safely play with tsk->sighand, it can take the lock itself. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/signal.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 29aca40be33..4a45bac2c63 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -971,13 +971,11 @@ int __fatal_signal_pending(struct task_struct *tsk)
}
EXPORT_SYMBOL(__fatal_signal_pending);
-/*
- * Must be called under rcu_read_lock() or with tasklist_lock read-held.
- */
struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags)
{
struct sighand_struct *sighand;
+ rcu_read_lock();
for (;;) {
sighand = rcu_dereference(tsk->sighand);
if (unlikely(sighand == NULL))
@@ -988,6 +986,7 @@ struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long
break;
spin_unlock_irqrestore(&sighand->siglock, *flags);
}
+ rcu_read_unlock();
return sighand;
}