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Date: Sun, 26 Sep 2010 19:51:50 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Namhyung Kim <namhyung@gmail.com>
Cc: Roland McGrath <roland@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] ptrace: annotate siglock acquisition
Message-ID: <20100926175150.GA26579@redhat.com>
References: <1285415621-28548-1-git-send-email-namhyung@gmail.com>
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On 09/25, Namhyung Kim wrote:
>
> --- a/kernel/ptrace.c
> +++ b/kernel/ptrace.c
> @@ -435,7 +435,8 @@ static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
>  	unsigned long flags;
>  	int error = -ESRCH;
>
> -	if (lock_task_sighand(child, &flags)) {
> +	if (__cond_lock(&child->sighand->siglock,
> +			lock_task_sighand(child, &flags))) {

Well, this looks fine, but if we are going to make sparse happy
then we have more callers to fix.

Perhaps we should just renam lock_task_sighand to __lock_task_sighand
and add

	#define lock_task_sighand(tsk, flagsp)	\
		__cond_lock((tsk)->sighand->siglock, __lock_task_sighand((tsk), (flagsp)))

?

Oleg.