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Date:   Wed, 6 Jul 2022 13:13:46 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Oleg Nesterov <oleg@redhat.com>
Cc:     Sven Schnelle <svens@linux.ibm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ptrace: fix clearing of JOBCTL_TRACED in
 ptrace_unfreeze_traced()
Message-ID: <YsVuak0/upU2Rvm6@worktop.programming.kicks-ass.net>
References: <20220706101625.2100298-1-svens@linux.ibm.com>
 <20220706110438.GB9868@redhat.com>
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On Wed, Jul 06, 2022 at 01:04:38PM +0200, Oleg Nesterov wrote:
> On 07/06, Sven Schnelle wrote:
> >
> > --- a/kernel/ptrace.c
> > +++ b/kernel/ptrace.c
> > @@ -222,7 +222,7 @@ static void ptrace_unfreeze_traced(struct task_struct *task)
> >  	if (lock_task_sighand(task, &flags)) {
> >  		task->jobctl &= ~JOBCTL_PTRACE_FROZEN;
> >  		if (__fatal_signal_pending(task)) {
> > -			task->jobctl &= ~TASK_TRACED;
> > +			task->jobctl &= ~JOBCTL_TRACED;
> 
> Heh. I have read this code many times, but I'm afraid I could read it
> 1000 times more and didn't notice the problem ;)

Heh, same here, I've read it today and didn't spot the problem. Brains
are weird.