Re: [RFC PATCH v4 03/27] x86/fpu/xstate: Enable XSAVES system states

[Peter Zijlstra]

On Fri, Sep 21, 2018 at 08:03:27AM -0700, Yu-cheng Yu wrote:
> diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
> index 4bd56079048f..9f51b0e1da25 100644
> --- a/arch/x86/kernel/fpu/core.c
> +++ b/arch/x86/kernel/fpu/core.c
> @@ -365,8 +365,13 @@ void fpu__drop(struct fpu *fpu)
>   */
>  static inline void copy_init_user_fpstate_to_fpregs(void)
>  {
> +	/*
> +	 * Only XSAVES user states are copied.
> +	 * System states are preserved.
> +	 */
>  	if (use_xsave())
> -		copy_kernel_to_xregs(&init_fpstate.xsave, -1);
> +		copy_kernel_to_xregs(&init_fpstate.xsave,
> +				     xfeatures_mask_user);

By my counting, that doesn't qualify for a line-break, it hits 80.

If you were to do this line-break, coding style would have you liberally
sprinkle {} around.

>  	else if (static_cpu_has(X86_FEATURE_FXSR))
>  		copy_kernel_to_fxregs(&init_fpstate.fxsave);
>  	else