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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-04-30 00:52:37 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 08:29:33 -0700 |
| commit | 1406f2d321bae5ac5ff729dcb773336d9c05ec74 (patch) | |
| tree | 178f7e2d800cee7be211225952f397458707587a /kernel/signal.c | |
| parent | bfc4b0890af566940de6e7aeb4b5faf46d3c3513 (diff) | |
| download | lwn-1406f2d321bae5ac5ff729dcb773336d9c05ec74.tar.gz lwn-1406f2d321bae5ac5ff729dcb773336d9c05ec74.zip | |
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>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 29aca40be33f..4a45bac2c632 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; } |