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To: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>, Linus Torvalds <torvalds@osdl.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] notify_parent and ptrace cleanup
References: <200408210109.i7L19Kjf006151@magilla.sf.frob.com>
From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Date: Sat, 21 Aug 2004 20:47:55 +0900
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Roland McGrath <roland@redhat.com> writes:

> +	spin_unlock_irq(&current->sighand->siglock);

This unlock is odd. lock is missing?

> +	read_lock(&tasklist_lock);
> +	do_notify_parent_cldstop(current, current->parent);
> +	read_unlock(&tasklist_lock);
> +	schedule();
> +
> +	/* We are back.  */
> +	current->last_siginfo = NULL;
> +}

->last_siginfo is racy. Please, really please don't extend it until
the race condition is fixed.

SIGCONT restart the stopped task. Any lock doesn't prevent it.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>