From: Thomas Gleixner <tglx@linutronix.de>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Oleg Nesterov <oleg@redhat.com>, Ingo Molnar <mingo@kernel.org>,
Kees Cook <keescook@chromium.org>
Subject: Re: [patch 6/6] posix-cpu-timers: Make PID=0 and PID=self handling consistent
Date: Mon, 23 Sep 2019 16:17:14 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1909231615200.2003@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20190923141324.GB10778@lenoir>
On Mon, 23 Sep 2019, Frederic Weisbecker wrote:
> On Thu, Sep 05, 2019 at 02:03:45PM +0200, Thomas Gleixner wrote:
> > If the PID encoded into the clock id is 0 then the target is either the
> > calling thread itself or the process to which it belongs.
> >
> > If the current thread encodes its own PID on a process wide clock then
> > there is no reason not to treat it in the same way as the PID=0 case.
> >
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > ---
> > kernel/time/posix-cpu-timers.c | 9 ++++++++-
> > 1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > --- a/kernel/time/posix-cpu-timers.c
> > +++ b/kernel/time/posix-cpu-timers.c
> > @@ -90,7 +90,14 @@ static struct task_struct *lookup_task(c
> >
> > } else {
> > /*
> > - * For processes require that p is group leader.
> > + * Timer is going to be attached to a process. If p is
> > + * current then treat it like the PID=0 case above.
> > + */
> > + if (p == current)
> > + return current->group_leader;
> > +
> > + /*
> > + * For foreign processes require that p is group leader.
> > */
> > if (!has_group_leader_pid(p))
> > return NULL;
>
> So, right after you should have that:
>
> if (same_thread_group(p, current))
> return p;
>
> Which I suggested to convert as:
>
> if (p == current)
> return p;
Indeed :)
next prev parent reply other threads:[~2019-09-23 14:17 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-05 12:03 [patch 0/6] posix-cpu-timers: Fallout fixes and permission tightening Thomas Gleixner
2019-09-05 12:03 ` [patch 1/6] posix-cpu-timers: Always clear head pointer on dequeue Thomas Gleixner
2019-09-05 15:49 ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 2/6] posix-cpu-timers: Fix permission check regression Thomas Gleixner
2019-09-05 17:31 ` Frederic Weisbecker
2019-09-05 18:55 ` Thomas Gleixner
2019-09-05 21:15 ` [patch V2 " Thomas Gleixner
2019-09-09 15:13 ` Frederic Weisbecker
2019-09-10 11:18 ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2019-09-05 12:03 ` [patch 3/6] posix-cpu-timers: Restrict timer_create() permissions Thomas Gleixner
2019-09-21 0:44 ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 4/6] posix-cpu-timers: Restrict clock_gettime() permissions Thomas Gleixner
2019-09-23 13:39 ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 5/6] posix-cpu-timers: Sanitize thread clock permissions Thomas Gleixner
2019-09-05 12:21 ` Peter Zijlstra
2019-09-05 14:11 ` Thomas Gleixner
2019-09-23 14:03 ` Frederic Weisbecker
2019-09-05 12:03 ` [patch 6/6] posix-cpu-timers: Make PID=0 and PID=self handling consistent Thomas Gleixner
2019-09-23 14:13 ` Frederic Weisbecker
2019-09-23 14:17 ` Thomas Gleixner [this message]
2019-09-05 14:48 ` [patch 0/6] posix-cpu-timers: Fallout fixes and permission tightening Frederic Weisbecker
2019-09-05 14:57 ` Thomas Gleixner
2019-09-05 15:21 ` Frederic Weisbecker
2019-09-05 20:32 ` Kees Cook
2019-09-05 21:13 ` Thomas Gleixner
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