Re: [PATCH] x86/fpu: Allow PKRU to be (once again) written by ptrace. #forregzbot

[Thorsten Leemhuis <regressions@leemhuis.info>]

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On 09.11.22 11:23, Thorsten Leemhuis wrote:

> On 31.07.22 07:03, Kyle Huey wrote:
>> From: Kyle Huey <me@kylehuey.com>
>>
>> When management of the PKRU register was moved away from XSTATE, emulation
>> of PKRU's existence in XSTATE was added for APIs that read XSTATE, but not
>> for APIs that write XSTATE. This can be seen by running gdb and executing
>> `p $pkru`, `set $pkru = 42`, and `p $pkru`. On affected kernels (5.14+) the
>> write to the PKRU register (which gdb performs through ptrace) is ignored.
> 
> Seem I missed this one, but apparently it needs tracking.
> 
> #regzbot ^introduced e84ba47e313dbc
> #regzbot title x86/fpu: emulation of PKRU's existence in XSTATE missing
> for APIs that write XSTATE
> #regzbot ignore-activity
> #regzbot monitor
> https://lore.kernel.org/all/20221107063807.81774-1-khuey@kylehuey.com/

#regzbot fixed-by: 4a804c4f83