lkml.org 
[lkml]   [2011]   [Jul]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: add missing verify_cpu to 32bit wakeup
On 07/01/2011 02:19 PM, Kees Cook wrote:
> Some BIOSes will reset the Intel XD_DISABLE MSR bit when resuming from S3,
> which can interact poorly with ebba638ae723d8a8fc2f7abce5ec18b688b791d7.
> In 32bit PAE mode, this can lead to a fault when EFER is restored by
> the kernel wakeup routines, due to it setting the NX bit for a CPU
> that (thanks to the BIOS reset) now incorrectly thinks it lacks the NX
> feature. 64bit wakeup already handled this through its common call path
> that would hit verify_cpu(). 32bit has a separate path for restoring
> CPU state on S3 wakeup, and needed to call verify_cpu() to handle this
> situation.

For S3, we should save/restore MISC_ENABLE instead... in fact, we
already save it, we just restore it too late.

-hpa


\
 
 \ /
  Last update: 2011-07-01 23:35    [W:1.056 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site