linux-kernel - Re: [patch V3 21/66] x86/fpu/regset: Move fpu__read

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Date:   Mon, 21 Jun 2021 15:26:45 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Yu-cheng Yu <yu-cheng.yu@...el.com>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Kan Liang <kan.liang@...ux.intel.com>
Subject: Re: [patch V3 21/66] x86/fpu/regset: Move fpu__read_begin() into
 regset

On Fri, Jun 18, 2021 at 04:18:44PM +0200, Thomas Gleixner wrote:
> The function can only be used from the regset get() callbacks safely. So
> there is no reason to have it globaly exposed.

"globally"

> 
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> ---
>  arch/x86/include/asm/fpu/internal.h |    1 -
>  arch/x86/kernel/fpu/core.c          |   20 --------------------
>  arch/x86/kernel/fpu/regset.c        |   22 +++++++++++++++++++---
>  3 files changed, 19 insertions(+), 24 deletions(-)

...

> --- a/arch/x86/kernel/fpu/regset.c
> +++ b/arch/x86/kernel/fpu/regset.c
> @@ -28,6 +28,22 @@ int regset_xregset_fpregs_active(struct
>  		return 0;
>  }
>  
> +/*
> + * The regset get() functions are invoked from:
> + *
> + *   - coredump to dump the current task's fpstate. If the current task
> + *     owns the FPU then the memory state has to be synchronized and the
> + *     FPU register state preserved. Otherwise fpstate is already in sync.
> + *
> + *   - ptrace to dump fpstate of a stopped task, in which case the register
									^

"registers"

With that:

Reviewed-by: Borislav Petkov <bp@...e.de>

-- 
Regards/Gruss,
    Boris.

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