Attachment 311625 Details for Bug 453507 – lock sighand->siglock in release_task()

[patch] lock sighand->siglock in release_task()

123.patch (text/plain), 2.07 KB, created by Vitaly Mayatskikh on 2008-07-11 23:03:31 UTC

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Creator: Vitaly Mayatskikh

Created: 2008-07-11 23:03:31 UTC

Size: 2.07 KB

patch

obsolete

>diff --git a/kernel/exit.c b/kernel/exit.c
>index ff47022..906f8fa 100644
>--- a/kernel/exit.c
>+++ b/kernel/exit.c
>@@ -64,6 +64,7 @@ repeat:
> 	spin_lock(&p->proc_lock);
> 	proc_dentry = proc_pid_unhash(p);
> 	write_lock_irq(&tasklist_lock);
>+	spin_lock(&p->sighand->siglock);
> 	if (unlikely(p->ptrace))
> 		__ptrace_unlink(p);
> 	BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
>@@ -93,6 +94,8 @@ repeat:
> 	}
> 
> 	sched_exit(p);
>+	if (p->sighand)		/* __exit_sighand() can free it */
>+		spin_unlock(&p->sighand->siglock);
> 	write_unlock_irq(&tasklist_lock);
> 	spin_unlock(&p->proc_lock);
> 	proc_pid_flush(proc_dentry);
>diff --git a/kernel/signal.c b/kernel/signal.c
>index a30cf6f..93e2d5a 100644
>--- a/kernel/signal.c
>+++ b/kernel/signal.c
>@@ -353,9 +353,10 @@ void __exit_sighand(struct task_struct *tsk)
> 	struct sighand_struct * sighand = tsk->sighand;
> 
> 	/* Ok, we're done with the signal handlers */
>-	tsk->sighand = NULL;
>-	if (atomic_dec_and_test(&sighand->count))
>+	if (atomic_dec_and_test(&sighand->count)) {
>+		tsk->sighand = NULL;
> 		kmem_cache_free(sighand_cachep, sighand);
>+	}
> }
> 
> void exit_sighand(struct task_struct *tsk)
>@@ -377,12 +378,10 @@ void __exit_signal(struct task_struct *tsk)
> 		BUG();
> 	if (!atomic_read(&sig->count))
> 		BUG();
>-	spin_lock(&sighand->siglock);
> 	if (atomic_dec_and_test(&sig->count)) {
> 		if (tsk == sig->curr_target)
> 			sig->curr_target = next_thread(tsk);
> 		tsk->signal = NULL;
>-		spin_unlock(&sighand->siglock);
> 		flush_sigqueue(&sig->shared_pending);
> 	} else {
> 		/*
>@@ -414,7 +413,6 @@ void __exit_signal(struct task_struct *tsk)
> 		sig->nivcsw += tsk->nivcsw;
> 		sig->inblock += task_io_get_inblock(tsk);
> 		sig->oublock += task_io_get_oublock(tsk);
>-		spin_unlock(&sighand->siglock);
> 		sig = NULL;	/* Marker for below.  */
> 	}
> 	clear_tsk_thread_flag(tsk,TIF_SIGPENDING);
>@@ -445,7 +443,9 @@ void exit_signal(struct task_struct *tsk)
> 	atomic_dec(&tsk->signal->live);	
> 
> 	write_lock_irq(&tasklist_lock);
>+	spin_lock(&tsk->sighand->siglock);
> 	__exit_signal(tsk);
>+	spin_unlock(&tsk->sighand->siglock);
> 	write_unlock_irq(&tasklist_lock);
> }
>

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Attachments on bug 453507: 310639 | 311326 | 311625 | 311626 | 311684