From: Steven Rostedt <rostedt@goodmis.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
tglx@linutronix.de, mingo@kernel.org, juri.lelli@arm.com,
xlpang@redhat.com, linux-kernel@vger.kernel.org,
mathieu.desnoyers@efficios.com, jdesfossez@efficios.com,
bristot@redhat.com, dvhart@infradead.org
Subject: Re: [PATCH] futex: move debug_rt_mutex_free_waiter() further down
Date: Wed, 8 Mar 2017 11:20:59 -0500 [thread overview]
Message-ID: <20170308112059.64e06683@gandalf.local.home> (raw)
In-Reply-To: <20170308152901.kumylhi7l3hescxd@linutronix.de>
On Wed, 8 Mar 2017 16:29:02 +0100
Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
> Without this, futex_requeue_pi_signal_restart will trigger
>
> |kernel BUG at locking/rtmutex_common.h:55!
> |Call Trace:
> | rt_mutex_cleanup_proxy_lock+0x54/0x90
> | futex_wait_requeue_pi.constprop.21+0x387/0x4d0
> | do_futex+0x289/0xbf0
> |RIP: remove_waiter+0x157/0x170 RSP: ffffc90000e0fbe0
>
> with BUG 2222222222222222 != pointer once this patch is applied.
This sentence makes no sense. It's a no-sensetence ;-)
-- Steve
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
> kernel/futex.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/futex.c b/kernel/futex.c
> index 00ec4a01d3f5..73abfe0da4d0 100644
> --- a/kernel/futex.c
> +++ b/kernel/futex.c
> @@ -3046,11 +3046,11 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
> WARN_ON(!q.pi_state);
> pi_mutex = &q.pi_state->pi_mutex;
> ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter);
> - debug_rt_mutex_free_waiter(&rt_waiter);
>
> spin_lock(q.lock_ptr);
> if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter))
> ret = 0;
> + debug_rt_mutex_free_waiter(&rt_waiter);
>
> /*
> * Fixup the pi_state owner and possibly acquire the lock if we
next prev parent reply other threads:[~2017-03-08 16:21 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-04 9:27 [PATCH -v5 00/14] the saga of FUTEX_UNLOCK_PI wobbles continues Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 01/14] futex: Fix potential use-after-free in FUTEX_REQUEUE_PI Peter Zijlstra
2017-03-14 20:48 ` [tip:locking/urgent] " tip-bot for Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 02/14] futex: Add missing error handling to FUTEX_REQUEUE_PI Peter Zijlstra
2017-03-14 20:49 ` [tip:locking/urgent] " tip-bot for Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 03/14] futex: Cleanup variable names for futex_top_waiter() Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 04/14] futex: Use smp_store_release() in mark_wake_futex() Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 05/14] futex: Remove rt_mutex_deadlock_account_*() Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 06/14] futex,rt_mutex: Provide futex specific rt_mutex API Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 07/14] futex: Change locking rules Peter Zijlstra
2017-03-07 13:22 ` Thomas Gleixner
2017-03-07 16:47 ` Sebastian Andrzej Siewior
2017-03-07 18:01 ` Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 08/14] futex: Cleanup refcounting Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 09/14] futex: Rework inconsistent rt_mutex/futex_q state Peter Zijlstra
2017-03-07 13:26 ` Thomas Gleixner
2017-03-04 9:27 ` [PATCH -v5 10/14] futex: Pull rt_mutex_futex_unlock() out from under hb->lock Peter Zijlstra
2017-03-07 14:08 ` Thomas Gleixner
2017-03-07 18:01 ` Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 11/14] futex,rt_mutex: Introduce rt_mutex_init_waiter() Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 12/14] futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock() Peter Zijlstra
2017-03-07 14:18 ` Thomas Gleixner
2017-03-07 17:57 ` Peter Zijlstra
2017-03-07 17:59 ` Thomas Gleixner
2017-03-08 15:29 ` [PATCH] futex: move debug_rt_mutex_free_waiter() further down Sebastian Andrzej Siewior
2017-03-08 15:37 ` Sebastian Andrzej Siewior
2017-03-08 16:21 ` Steven Rostedt
2017-03-08 16:20 ` Steven Rostedt [this message]
2017-03-13 9:16 ` Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 13/14] futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock() Peter Zijlstra
2017-03-04 9:27 ` [PATCH -v5 14/14] futex: futex_unlock_pi() determinism Peter Zijlstra
2017-03-07 14:31 ` Thomas Gleixner
2017-03-07 17:59 ` Peter Zijlstra
2017-03-13 9:25 ` Peter Zijlstra
2017-03-13 14:25 ` Thomas Gleixner
2017-03-13 15:11 ` Peter Zijlstra
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