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SubjectRe: [PATCH 2/6] x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig()
On Fri, Aug 24, 2012 at 02:12:58PM -0700, Suresh Siddha wrote:
> Few lines below we do drop_fpu() which is more safer. Remove the
> unnecessary user_fpu_end() in save_xstate_sig(), which allows
> the drop_fpu() to ignore any pending exceptions from the user-space
> and drop the current fpu.
>
> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
> ---
> arch/x86/include/asm/fpu-internal.h | 17 +++--------------
> arch/x86/kernel/xsave.c | 1 -
> 2 files changed, 3 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
> index fe95ad0..fac39e9 100644
> --- a/arch/x86/include/asm/fpu-internal.h
> +++ b/arch/x86/include/asm/fpu-internal.h
> @@ -412,22 +412,11 @@ static inline void __drop_fpu(struct task_struct *tsk)
> }
>
> /*
> - * The actual user_fpu_begin/end() functions
> - * need to be preemption-safe.
> + * Need to be preemption-safe.
> *
> - * NOTE! user_fpu_end() must be used only after you
> - * have saved the FP state, and user_fpu_begin() must
> - * be used only immediately before restoring it.
> - * These functions do not do any save/restore on
> - * their own.
> + * NOTE! user_fpu_begin() must be used only immediately before restoring
> + * it. This function does not do any save/restore on their own.
> */
> -static inline void user_fpu_end(void)
> -{
> - preempt_disable();
> - __thread_fpu_end(current);
> - preempt_enable();
> -}

Now that user_fpu_begin has lost its counterpart user_fpu_end, maybe
rename it to user_fpu_init() or something similar which doesn't suggest
there's a _begin and an _end thingy?

Thanks.

--
Regards/Gruss,
Boris.

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