On Tue, 2018-09-25 at 19:03 +0200, Peter Zijlstra wrote:

On Fri, Sep 21, 2018 at 08:03:27AM -0700, Yu-cheng Yu wrote:

quoted

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.

Ok, will fix it.