diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-20 15:56:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-20 15:56:25 -0700 |
| commit | cf6ace16a3cd8b728fb0afa68368fd40bbeae19f (patch) | |
| tree | 489c64380668e8c5a29d3f36f37554e4b081a647 /kernel/signal.c | |
| parent | acc11eab70591744369722280c9ce162a6193494 (diff) | |
| parent | d1e9ae47a0285d3f1699e8219ce50f656243b93f (diff) | |
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
signal: align __lock_task_sighand() irq disabling and RCU
softirq,rcu: Inform RCU of irq_exit() activity
sched: Add irq_{enter,exit}() to scheduler_ipi()
rcu: protect __rcu_read_unlock() against scheduler-using irq handlers
rcu: Streamline code produced by __rcu_read_unlock()
rcu: Fix RCU_BOOST race handling current->rcu_read_unlock_special
rcu: decrease rcu_report_exp_rnp coupling with scheduler
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index ff7678603328..415d85d6f6c6 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1178,18 +1178,25 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, { struct sighand_struct *sighand; - rcu_read_lock(); for (;;) { + local_irq_save(*flags); + rcu_read_lock(); sighand = rcu_dereference(tsk->sighand); - if (unlikely(sighand == NULL)) + if (unlikely(sighand == NULL)) { + rcu_read_unlock(); + local_irq_restore(*flags); break; + } - spin_lock_irqsave(&sighand->siglock, *flags); - if (likely(sighand == tsk->sighand)) + spin_lock(&sighand->siglock); + if (likely(sighand == tsk->sighand)) { + rcu_read_unlock(); break; - spin_unlock_irqrestore(&sighand->siglock, *flags); + } + spin_unlock(&sighand->siglock); + rcu_read_unlock(); + local_irq_restore(*flags); } - rcu_read_unlock(); return sighand; } |