Messages in this thread | | | Date | Sun, 3 Jul 2011 23:34:07 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH] x86: add missing verify_cpu to 32bit wakeup |
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On Sun 2011-07-03 12:15:22, Kees Cook wrote: > Hi Pavel, > > On Sun, Jul 03, 2011 at 02:15:49PM +0200, Pavel Machek 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. > > > > > > Signed-off-by: Kees Cook <kees.cook@canonical.com> > > > Cc: stable@kernel.org > > > > Looks ok to me, but I'm not sure it is stable material. > > Well, I figured anything that shipped with > ebba638ae723d8a8fc2f7abce5ec18b688b791d7 should get it, since it is > a regression in the 32bit PAE with BIOS-disabled NX corner-case.
Aha, if it is an regression it makes sense for stable..
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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