Subject: Re: frequent slab corruption (since a long time)
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Dave Jones <davej@redhat.com>
Cc: David Miller <davem@davemloft.net>, linux-kernel@vger.kernel.org,
       jbaron@redhat.com
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Date: Thu, 03 Aug 2006 00:14:21 +0100
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Ar Mer, 2006-08-02 am 18:23 -0400, ysgrifennodd Dave Jones:
> 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?

Its old lock_kernel() code so its a prime suspect for most offences.

Given the age of the reports it appears that the tty buffering changes
are too new. The ldisc locking changes are a candidate but shouldn't be
doing anything that breaks the kernel lock stuff. Will look tomorrow see
if anything strikes me about that lot.

The tty_mutex primarily protected current->signal.tty (except if you are
using SELinux which has some extremely dubious looking code for tty
handling). Someone ought to review flush_unauthorized_files() although
it doesn't fit this problem.

Alan

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