Re: As of kernel 4.4-rc1 segmentation fault if msr module not loaded. [REGRESSION][BISECTED]

From: Borislav Petkov
Date: Thu Nov 26 2015 - 13:09:47 EST


On Thu, Nov 26, 2015 at 08:25:43AM -0800, Doug Smythies wrote:
> Hi,
>
> This might be considered a minor issue, but I submit my
> findings anyhow.
>
> In some distros, the msr module is not loaded by default.
> (I guess not built in by default, would be more correct.)
> I often forget to load it before using "rdmsr" or "wrmsr".
> It was never an issue before, but as of Kernel 4.4-rc1
> it causes a segmentation fault crash. Example:
>
> # rdmsr -a 0x19a
> Segmentation fault (core dumped)

You can either cherrypick

http://git.kernel.org/tip/2d5be37d686c4dae8e60d20283d6f44ac2c44f65

or wait until it trickles upwards to Linus, most likely -rc3.

Thanks for the report. Good to know what else broke.

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.
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