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From: Ingo Molnar <mingo@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
	Fengguang Wu <fengguang.wu@intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [x86] BUG: unable to handle kernel paging request at 00740060
Date: Wed, 9 Oct 2013 16:32:26 +0200	[thread overview]
Message-ID: <20131009143226.GA24911@gmail.com> (raw)
In-Reply-To: <20131009140734.GH3081@twins.programming.kicks-ass.net>


* Peter Zijlstra <peterz@infradead.org> wrote:

> > This is what we are going to return. But note that -20(%ebp) was not
> > initialized if TIF_NOTIFY_RESUME was already set, "jc .L2" skips .L5
> > above. IOW, in this case we seem to return a random value from stack.
> 
> I think you're quite right, and I can confirm I can reproduce this with
> gcc-4.8.1 and Wu's .config:
>
> [...]
>
> Once I force a x86_64 build using the 'same' config it goes away and 
> generates 'sensible' code again [...]

So this at least opens up the possibility that we can create a not too 
painful quirk and only use the 'asm goto' optimization tricks on 64-bit 
kernels?

Thanks,

	Ingo

  parent reply	other threads:[~2013-10-09 14:32 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-05 23:44 [x86] BUG: unable to handle kernel paging request at 00740060 Fengguang Wu
2013-10-05 23:47 ` [x86] BUG: unable to handle kernel paging request at 08000060 Fengguang Wu
2013-10-06  7:27   ` Mike Galbraith
2013-10-06  7:36     ` Fengguang Wu
2013-10-07  8:49   ` Peter Zijlstra
2013-10-07  9:17     ` Fengguang Wu
2013-10-07  9:36       ` Peter Zijlstra
2013-10-07  9:46         ` Fengguang Wu
2013-10-07  8:55 ` [x86] BUG: unable to handle kernel paging request at 00740060 Peter Zijlstra
2013-10-07  9:08   ` Peter Zijlstra
2013-10-07 11:32     ` Fengguang Wu
2013-10-07  9:27   ` Fengguang Wu
2013-10-07 18:47 ` Linus Torvalds
2013-10-08  7:51   ` Fengguang Wu
2013-10-08 16:21     ` Linus Torvalds
2013-10-08 17:15       ` [x86] BUG: unable to handle kernel NULL pointer dereference at (null) Fengguang Wu
2013-10-08 17:31         ` Linus Torvalds
2013-10-09  1:09           ` Fengguang Wu
2013-10-09  1:33             ` Linus Torvalds
2013-10-08 18:51       ` [x86] BUG: unable to handle kernel paging request at 00740060 Oleg Nesterov
2013-10-08 19:05         ` Jakub Jelinek
2013-10-08 19:20           ` Linus Torvalds
2013-10-08 19:34             ` Linus Torvalds
2013-10-08 19:35           ` Oleg Nesterov
2013-10-08 19:49             ` Linus Torvalds
2013-10-09  1:43           ` Mike Galbraith
2013-10-08 19:05         ` Linus Torvalds
2013-10-08 16:46     ` Oleg Nesterov
2013-10-08 14:34   ` Oleg Nesterov
2013-10-09  8:04     ` Fengguang Wu
2013-10-09 12:19       ` Fengguang Wu
2013-10-09 12:21         ` Fengguang Wu
2013-10-09 12:27         ` Peter Zijlstra
2013-10-09 12:52           ` Ingo Molnar
2013-10-09 17:18             ` Ingo Molnar
2013-10-10  2:15               ` Mike Galbraith
2013-10-09 12:56           ` Fengguang Wu
2013-10-09 12:43       ` Oleg Nesterov
2013-10-09 14:07         ` Peter Zijlstra
2013-10-09 14:17           ` Oleg Nesterov
2013-10-09 14:32           ` Ingo Molnar [this message]
2013-10-09 14:33           ` Peter Zijlstra
2013-10-09 14:46             ` Peter Zijlstra
2013-10-09 18:16               ` Jakub Jelinek
2013-10-09 18:54                 ` Linus Torvalds
2013-10-09 19:02                 ` Peter Zijlstra
2013-10-09 19:08                   ` Jakub Jelinek
2013-10-10  6:22                     ` Ingo Molnar
2013-10-10  6:51                       ` Jakub Jelinek
2013-10-10  8:04                         ` Jakub Jelinek
2013-10-10  8:24                           ` [PATCH] gcc4: Add 'asm goto' miscompilation quirk Ingo Molnar
2013-10-10  8:31                             ` Jakub Jelinek
2013-10-10  8:45                               ` Ingo Molnar
2013-10-10  8:55                                 ` [PATCH, -v2] compiler/gcc4: Add quirk for 'asm goto' miscompilation bug Ingo Molnar
2013-10-10 11:56                                   ` Peter Zijlstra
2013-10-10 12:32                                     ` Jakub Jelinek
2013-10-10 13:10                                       ` Peter Zijlstra
2013-10-10 15:04                                         ` Ingo Molnar
2013-10-10 14:04                               ` [PATCH] gcc4: Add 'asm goto' miscompilation quirk Richard Henderson
2013-10-10 14:27                                 ` Jakub Jelinek
2013-10-10 15:12                                   ` [PATCH, -v3] compiler/gcc4: Add quirk for 'asm goto' miscompilation bug Ingo Molnar
2013-10-10 16:15                                     ` Richard Henderson
2013-10-10 16:49                                       ` Ingo Molnar
2013-10-11  4:35                                     ` Fengguang Wu
2013-10-11  5:46                                       ` Ingo Molnar
2013-10-11  6:51                                         ` Fengguang Wu
2013-10-11  9:30                                           ` Fengguang Wu
2013-10-12 17:03                                             ` Ingo Molnar
2013-10-10  8:34                             ` [PATCH] gcc4: Add 'asm goto' miscompilation quirk Ingo Molnar

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