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From: "H. Peter Anvin" <hpa@zytor.com>
To: "Klaus S. Madsen" <ksm@hjernemadsen.org>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
	Pavel Machek <pavel@ucw.cz>, "Rafael J. Wysocki" <rjw@sisk.pl>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: Regression in 2.6.25-rc3: s2ram segfaults before suspending
Date: Fri, 29 Feb 2008 13:05:46 -0800	[thread overview]
Message-ID: <47C873AA.6040305@zytor.com> (raw)
In-Reply-To: <20080229070028.GK17932@hjernemadsen.org>

Klaus S. Madsen wrote:
> open("/dev/mem", O_RDWR)                = 5
> mmap2(NULL, 1282, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED|MAP_FIXED, 5, 0) = 0
> mmap2(0xa0000, 393216, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 5, 0xa0) = 0xa0000
                          ^^^^^^^^^^^^^^^^^^^^
> close(5)                                = 0
> ioperm(0, 0x400, 0x1)                   = 0
> iopl(0x3)                               = 0
> access("/sys/bus/pci", R_OK)            = 0
> write(1, "Calling get_mode\n", 17)      = 17
> vm86(0x1, 0xb7f14ccc, 0xb7f14830, 0xc000, 0x18b6 <unfinished ...>
> --- SIGSEGV (Segmentation fault) @ 0 (0) ---
> +++ killed by SIGSEGV (core dumped) +++

This is the VGA BIOS being mapped, it's mapped PROT_READ|PROT_WRITE, but 
  no PROT_EXEC; if the kernel is NX-capable it *should* segfault trying 
to execute out of this area, which is exactly what will happen when vm86 
executes INT 10h.

If we can find that mmap() in the s2ram source code and add PROT_EXEC to 
it, it would be interesting.

	-hpa

  reply	other threads:[~2008-02-29 21:06 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-27 22:10 Regression in 2.6.25-rc3: s2ram segfaults before suspending Klaus S. Madsen
2008-02-27 22:19 ` Rafael J. Wysocki
2008-02-27 22:40   ` Pavel Machek
2008-02-28  6:47   ` Klaus S. Madsen
2008-02-28  7:03     ` Pavel Machek
2008-02-28  7:08 ` Klaus S. Madsen
2008-02-28  9:16 ` Ingo Molnar
2008-02-28  9:28   ` Klaus S. Madsen
2008-02-28  9:40     ` Ingo Molnar
2008-02-28 15:04       ` Klaus S. Madsen
2008-02-28 17:52         ` H. Peter Anvin
2008-02-28 19:24           ` Klaus S. Madsen
2008-02-28 19:31             ` H. Peter Anvin
2008-02-28 19:49               ` Klaus S. Madsen
2008-02-28 22:45                 ` H. Peter Anvin
2008-02-29  7:00                   ` Klaus S. Madsen
2008-02-29 21:05                     ` H. Peter Anvin [this message]
2008-02-29 21:26                       ` Ingo Molnar
2008-03-01  9:45                         ` Klaus S. Madsen
2008-03-01 19:53                           ` H. Peter Anvin
2008-03-03 12:17                           ` Pavel Machek
2008-03-03 15:11                             ` Klaus S. Madsen
2008-03-03 17:48                               ` Ingo Molnar
2008-03-03 17:53                                 ` H. Peter Anvin
2008-03-03 20:52                                 ` Klaus S. Madsen
2008-03-03 20:58                                   ` H. Peter Anvin
2008-03-03 21:05                                   ` Pavel Machek
2008-03-03 21:06                                     ` Matthew Garrett
2008-03-03 21:06                                     ` Pavel Machek
2008-03-03 21:21                                       ` Klaus S. Madsen
2008-03-04 12:36                                   ` Ingo Molnar
2008-03-04 21:58                                     ` Klaus S. Madsen
2008-03-04 22:08                                       ` H. Peter Anvin
2008-03-04 23:00                                     ` Jeremy Fitzhardinge
2008-03-04 23:11                                       ` H. Peter Anvin
2008-03-04 23:21                                         ` Jeremy Fitzhardinge
2008-03-04 23:30                                         ` Matthew Garrett
2008-03-04 12:42                                   ` Ingo Molnar
2008-03-03 15:40                             ` Rafael J. Wysocki
2008-03-03 17:10                             ` H. Peter Anvin
2008-03-03 17:47                               ` Pavel Machek
2008-03-03 17:50                                 ` H. Peter Anvin
2008-03-03 17:53                               ` Ingo Molnar
2008-03-03 17:58                                 ` H. Peter Anvin
2008-03-01  1:18                       ` Rafael J. Wysocki

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