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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Cc: Scott Wood <scottwood@freescale.com>,
	"linuxppc-dev@ozlabs.org" <linuxppc-dev@ozlabs.org>,
	Rex Feany <RFeany@mrv.com>
Subject: Re: [PATCH 0/6] PowerPc 8xx TLB/MMU fixes
Date: Tue, 06 Oct 2009 09:37:28 +1100	[thread overview]
Message-ID: <1254782248.7122.49.camel@pasglop> (raw)
In-Reply-To: <OF9AD6CA21.DCD59A1B-ONC1257646.007AE622-C1257646.007BB767@transmode.se>

On Tue, 2009-10-06 at 00:31 +0200, Joakim Tjernlund wrote:
> 
> regs or regs->nip is NULL? Either one does not make sense
> In any case it might be a secondary problem as DAR is NULL already
> when you
> enter the page fault.
> >
> >                 insn = *((unsigned long *)regs->nip);
> > c000e110:       80 a9 00 00     lwz     r5,0(r9)
> >
> > fails.
> 
> hmm, I wonder if you managed to invalidate the a kernel TLB?
> Are you using pinned kernel TLBs? 

You should not dereference a user address like that. Use get_user !

Obviously you got 0 in SRR0 for some reason (somebody tried to jump
to 0, either intentionally or as a result of some other problem) and
the above will crash the kernel when it happens.

Cheers,
Ben.

  reply	other threads:[~2009-10-05 22:37 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-05 12:16 [PATCH 0/6] PowerPc 8xx TLB/MMU fixes Joakim Tjernlund
2009-10-05 12:16 ` [PATCH 1/6] 8xx: DTLB Error must check for more errors Joakim Tjernlund
2009-10-05 12:16   ` [PATCH 2/6] 8xx, fault: Add some debug code to do_page_fault() Joakim Tjernlund
2009-10-05 12:16     ` [PATCH 3/6] 8xx: get rid of _PAGE_HWWRITE dependency in MMU Joakim Tjernlund
2009-10-05 12:16       ` [PATCH 4/6] 8xx: Tag DAR with 0x00f0 to catch buggy instructions Joakim Tjernlund
2009-10-05 12:16         ` [PATCH 5/6] 8xx: Fixup DAR from buggy dcbX instructions Joakim Tjernlund
2009-10-05 12:16           ` [PATCH 6/6] 8xx: start using dcbX instructions in various copy routines Joakim Tjernlund
2009-10-05 20:17       ` [PATCH 3/6] 8xx: get rid of _PAGE_HWWRITE dependency in MMU Benjamin Herrenschmidt
2009-10-05 21:25         ` Joakim Tjernlund
2009-10-05 21:37           ` Benjamin Herrenschmidt
2009-10-05 22:00             ` Joakim Tjernlund
2009-10-05 22:09               ` Benjamin Herrenschmidt
2009-10-05 22:55                 ` Joakim Tjernlund
2009-10-05 23:15                   ` Benjamin Herrenschmidt
2009-10-05 23:35                     ` Joakim Tjernlund
2009-10-06  0:34                       ` Benjamin Herrenschmidt
2009-10-06  6:15                         ` Joakim Tjernlund
2009-10-06  6:45                           ` Benjamin Herrenschmidt
2009-10-06  7:54                             ` Joakim Tjernlund
2009-10-06 15:40                             ` Joakim Tjernlund
2009-10-06 17:28                               ` Joakim Tjernlund
2009-10-06 22:05                         ` Joakim Tjernlund
2009-10-06 23:25                           ` Benjamin Herrenschmidt
2009-10-07  1:07                           ` Benjamin Herrenschmidt
2009-10-07  7:47                             ` Joakim Tjernlund
2009-10-05 18:12 ` [PATCH 0/6] PowerPc 8xx TLB/MMU fixes Scott Wood
2009-10-05 18:27   ` Joakim Tjernlund
2009-10-05 20:09     ` Scott Wood
2009-10-05 21:04       ` Joakim Tjernlund
2009-10-05 21:31         ` Benjamin Herrenschmidt
2009-10-05 21:41           ` Joakim Tjernlund
2009-10-05 21:46             ` Scott Wood
2009-10-05 21:31         ` Scott Wood
2009-10-05 22:04 ` Rex Feany
2009-10-05 22:31   ` Joakim Tjernlund
2009-10-05 22:37     ` Benjamin Herrenschmidt [this message]
2009-10-05 22:58       ` Joakim Tjernlund
2009-10-05 23:49       ` Joakim Tjernlund
2009-10-06  1:52         ` Benjamin Herrenschmidt
2009-10-06  8:06           ` Joakim Tjernlund
2009-10-06  8:32             ` Benjamin Herrenschmidt
2009-10-06 10:58               ` Joakim Tjernlund
2009-10-06 11:06                 ` Benjamin Herrenschmidt
2009-10-06 11:39                   ` Joakim Tjernlund
2009-10-06 13:18                   ` Joakim Tjernlund
2009-10-05 22:42     ` Rex Feany
2009-10-05 23:00       ` Joakim Tjernlund
2009-10-06  6:25       ` Joakim Tjernlund
2009-10-06  6:44         ` Benjamin Herrenschmidt

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