Re: [boot crash] Re: [tip:x86/mce3] x86, mce: use 64bit machinecheck code on 32bit

From: Ingo Molnar
Date: Mon Aug 17 2009 - 05:21:40 EST



* Hidetoshi Seto <seto.hidetoshi@xxxxxxxxxxxxxx> wrote:

> One possibility is: if the BIOS doesn't clear status in banks, new
> mce codes will try to log such junks. If the junk is totally junk
> but can be decoded as a valid log with MISCV or ADDRV bit, and if
> the cpu try to access register which is not implemented (e.g.
> IA32_MCi_MISC/ADDR), then such access might cause a general
> protection exception. (ref. ASDM 3A 15.3.2.3)

btw., that reminds me: mce_rdmsrl() needs to be fixed to use
rdmsrl_safe() and it should emit a WARN_ONCE() if it ever hits an
error while trying to access registers.

Ingo
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