Re: [patch V3 53/66] x86/fpu: Hook up PKRU into ptrace()

[Borislav Petkov]

On Fri, Jun 18, 2021 at 04:19:16PM +0200, Thomas Gleixner wrote:
> From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> 
> One nice thing about having PKRU be XSAVE-managed is that it gets naturally
> exposed into the XSAVE-using ABIs.  Now that XSAVE will not be used to
> manage PKRU, these ABIs need to be manually enabled to deal with PKRU.
> 
> ptrace() uses copy_uabi_xstate_to_kernel() to collect the tracee's
> XSTATE. As PKRU is not in the task's XSTATE buffer, use task->thread.pkru
> for filling in up the ptrace buffer.
> 
> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
>  arch/x86/include/asm/fpu/xstate.h |    2 +-
>  arch/x86/kernel/fpu/regset.c      |   10 ++++------
>  arch/x86/kernel/fpu/xstate.c      |   25 ++++++++++++++++++-------
>  3 files changed, 23 insertions(+), 14 deletions(-)

Reviewed-by: Borislav Petkov <bp@xxxxxxx>

-- 
Regards/Gruss,
    Boris.

SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG Nürnberg