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From: Andrew Morton <akpm@linux-foundation.org>
To: Andrea Righi <righi.andrea@gmail.com>
Cc: Pavel Roskin <proski@gnu.org>,
	"Antonino A. Daplas" <adaplas@gmail.com>,
	Andrey Borzenkov <arvidjaar@gmail.com>,
	Harvey@smtp1.linux-foundation.org,
	Johannes Weiner <hannes@cmpxchg.org>,
	Krzysztof Helt <krzysztof.h1@poczta.fm>,
	LKML <linux-kernel@vger.kernel.org>,
	Stefan Richter <stefanr@s5r6.in-berlin.de>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	linux-fbdev-devel@lists.sourceforge.net,
	linux-pm@lists.linux-foundation.org,
	Harrison <harvey.harrison@gmail.com>
Subject: Re: [REGRESSION] commit 66c1ca0: {fbmem: fix fb_info->lock and mm->mmap_sem ...} causes Xfbdev not working
Date: Sat, 11 Apr 2009 11:21:31 -0700	[thread overview]
Message-ID: <20090411112131.cc38dcf0.akpm@linux-foundation.org> (raw)
In-Reply-To: <20090411150359.GA8265@linux>

On Sat, 11 Apr 2009 17:04:00 +0200 Andrea Righi <righi.andrea@gmail.com> wrote:

> fbdev: fix info->lock deadlock in fbcon_event_notify()
> 
> fb_notifier_call_chain() is called with info->lock held, i.e. in
> do_fb_ioctl() => FBIOPUT_VSCREENINFO => fb_set_var() and the some
> notifier callbacks, like fbcon_event_notify(), try to re-acquire
> info->lock again.
> 
> Remove the lock/unlock_fb_info() in all the framebuffer notifier
> callbacks' and be sure to always call fb_notifier_call_chain() with
> info->lock held.

Thanks.  So do you think we should proceed with this patch instead of
reverting 66c1ca0?

WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org>
To: Andrea Righi <righi.andrea@gmail.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>,
	Krzysztof Helt <krzysztof.h1@poczta.fm>,
	Eric Miao <eric.y.miao@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	"Rafael J. Wysocki" <rjw@sisk.pl>,
	Andrey Borzenkov <arvidjaar@gmail.com>,
	"Antonino A. Daplas" <adaplas@gmail.com>,
	linux-fbdev-devel@lists.sourceforge.net,
	linux-pm@lists.linux-foundation.org,
	Dave Jones <davej@redhat.com>,
	Harvey Harrison <harvey.harrison@gmail.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Pavel Roskin <proski@gnu.org>
Subject: Re: [REGRESSION] commit 66c1ca0: {fbmem: fix fb_info->lock and mm->mmap_sem ...} causes Xfbdev not working
Date: Sat, 11 Apr 2009 11:21:31 -0700	[thread overview]
Message-ID: <20090411112131.cc38dcf0.akpm@linux-foundation.org> (raw)
In-Reply-To: <20090411150359.GA8265@linux>

On Sat, 11 Apr 2009 17:04:00 +0200 Andrea Righi <righi.andrea@gmail.com> wrote:

> fbdev: fix info->lock deadlock in fbcon_event_notify()
> 
> fb_notifier_call_chain() is called with info->lock held, i.e. in
> do_fb_ioctl() => FBIOPUT_VSCREENINFO => fb_set_var() and the some
> notifier callbacks, like fbcon_event_notify(), try to re-acquire
> info->lock again.
> 
> Remove the lock/unlock_fb_info() in all the framebuffer notifier
> callbacks' and be sure to always call fb_notifier_call_chain() with
> info->lock held.

Thanks.  So do you think we should proceed with this patch instead of
reverting 66c1ca0?

  reply	other threads:[~2009-04-11 18:21 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-09 11:36 [REGRESSION] commit 66c1ca0: {fbmem: fix fb_info->lock and mm->mmap_sem ...} causes Xfbdev not working Eric Miao
2009-04-09 12:58 ` Andrea Righi
2009-04-09 12:58 ` Andrea Righi
2009-04-10 20:21   ` Krzysztof Helt
2009-04-10 21:16     ` Andrew Morton
2009-04-10 21:16       ` Andrew Morton
2009-04-10 22:05     ` Andrea Righi
2009-04-11  6:04       ` Krzysztof Helt
2009-04-11  9:00         ` Stefan Richter
2009-04-11  9:00         ` Stefan Richter
2009-04-11 11:08           ` Andrea Righi
2009-04-11 11:08           ` Andrea Righi
2009-04-11 15:04             ` Andrea Righi
2009-04-11 15:04             ` Andrea Righi
2009-04-11 18:21               ` Andrew Morton [this message]
2009-04-11 18:21                 ` Andrew Morton
2009-04-11 19:32                 ` Andrea Righi
2009-04-11 19:32                 ` Andrea Righi
2009-04-13 23:34               ` Andreas Schwab
2009-04-13 23:34               ` Andreas Schwab
2009-04-17 16:25               ` Krzysztof Helt
     [not found]               ` <20090417182507.0bd85ccc.krzysztof.h1@poczta.fm>
2009-04-17 22:51                 ` Andrea Righi
2009-04-17 22:51                 ` Andrea Righi
2009-04-11 15:04             ` Andrea Righi
2009-04-11  6:04       ` Krzysztof Helt
2009-04-10 22:05     ` Andrea Righi
2009-04-10 20:21   ` Krzysztof Helt
2009-04-10 17:40 ` Krzysztof Helt

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