linux-kernel - Re: v2.6.27-rc7: x86: #GP on panic?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 25 Sep 2008 10:04:17 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Vegard Nossum <vegard.nossum@...il.com>
Cc:	x86@...nel.org, linux-kernel@...r.kernel.org,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: v2.6.27-rc7: x86: #GP on panic?


* Vegard Nossum <vegard.nossum@...il.com> wrote:

> Hi,
> 
> With 2.6.27-rc7 on qemu-x86_64, it seems that panic will trigger a 
> General Protection Fault. I haven't seen it before.

> [    4.523641] Code: eb fd 55 48 89 e5 53 51 83 3d 25 e8 78 00 00 75
> 1a 31 d2 31 f6 48 c7 c7 e1 9c 01 81 e8 f7 a4 03 00 9c 5b fa e8 94 09
> 00 00 53 9d <5a> 5b c9 c3 55 31 c0 48 89 e5 89 04 25 b0 c0 5f ff 65 83
> 04 25

hm, 0x5a is a simple pop %rdx. A #GP there means the stack segment is 
bust?

hm:

> ffffffff8101a6b9 <disable_local_APIC>
> ffffffff81019d25:       53                      push   %rbx
> ffffffff81019d26:       9d                      popfq
> ffffffff81019d27:       5a                      pop    %rdx

so it's preceded by a popfq and on the next instruction we #GP.

but the stack and flags state looks good:

  [    4.523641] RSP: 0018:ffff880007867d70  EFLAGS: 00000286

weird.

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/