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Date: Wed, 2 Aug 2006 18:23:21 -0400
From: Dave Jones <davej@redhat.com>
To: David Miller <davem@davemloft.net>
Cc: linux-kernel@vger.kernel.org, jbaron@redhat.com
Subject: Re: frequent slab corruption (since a long time)
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On Tue, Aug 01, 2006 at 10:31:10PM -0700, David Miller wrote:
 > From: David Miller <davem@davemloft.net>
 > Date: Tue, 01 Aug 2006 22:05:38 -0700 (PDT)
 > 
 > > The corruption is always a 32-bit 0xffffffff followed by
 > > a 32-bit 0x00000000, 12 bytes into the object.
 > 
 > This analysis is wrong, it's "0xb0 + 12" bytes into the object
 > which is 188 bytes.  For x86, this lands us at the "count"
 > member of the tty_struct, and it shows that the tty count
 > has decremented to -1 (0xffffffff) which is a serious bug.

<stabbing in the dark here>

None of the code manipulating tty->count seems to be under
the tty_mutex.  Should it be ?
Or is this protected through some other means?

Jason, ISTR you've done some digging around this area wrt races,
any insight ?

		Dave

-- 
http://www.codemonkey.org.uk
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