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From: "Liu, Chuansheng" <chuansheng.liu@intel.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] Fix the race between the fget() and close()
Date: Tue, 27 Aug 2013 00:53:37 +0000	[thread overview]
Message-ID: <27240C0AC20F114CBF8149A2696CBE4A01AEEE9C@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <20130827004247.GG27005@ZenIV.linux.org.uk>

Thanks Al.

> -----Original Message-----
> From: Al Viro [mailto:viro@ftp.linux.org.uk] On Behalf Of Al Viro
> Sent: Tuesday, August 27, 2013 8:43 AM
> To: Liu, Chuansheng
> Cc: Eric Dumazet; linux-fsdevel@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] Fix the race between the fget() and close()
> 
> On Mon, Aug 26, 2013 at 11:56:43PM +0000, Liu, Chuansheng wrote:
> 
> 
> Hell, might be buggered refcounting on descriptor table - binder is playing
I also suspected binder do some strange thing there, but in the panic log, there is another
process causes this case during vfs_read(), maybe it is not related with binder totally.
<1>[  392.669816] BUG: unable to handle kernel NULL pointer dereference at 00000020
<1>[  392.678055] IP: [<c131c8a7>] vfs_read+0x97/0x160

> interesting games there.  Try to reproduce that with
> CONFIG_DEBUG_KMEMLEAK
> and slab debugging turned on, see if you hit anything from those; if it's
> more or less readily reproducible, I would start with that - too many
> scenarios involve broken refcounting of one sort or another.
It is not easy to hit, will try with CONFIG_DEBUG_KMEMLEAK and SLAB DEBUGGING on.

  parent reply	other threads:[~2013-08-27  0:53 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-26 16:12 [PATCH] Fix the race between the fget() and close() Chuansheng Liu
2013-08-26 11:29 ` Al Viro
2013-08-26 23:56   ` Liu, Chuansheng
2013-08-27  0:42     ` Al Viro
2013-08-27  0:48       ` Al Viro
2013-08-31  5:53         ` Liu, Chuansheng
2013-08-31  6:48           ` Al Viro
2013-08-31  7:01             ` Liu, Chuansheng
2013-08-31  7:35               ` Al Viro
2013-08-31  7:44                 ` Liu, Chuansheng
2013-08-27  0:53       ` Liu, Chuansheng [this message]
2013-08-26 15:14 ` Eric Dumazet

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