x86/fpu: Use 'struct fpu' in fpu__save()

Migrate this function to pure 'struct fpu' usage.

Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/i387.h

@@ -100,7 +100,7 @@ static inline int user_has_fpu(void)
 	return current->thread.fpu.has_fpu;
 }
 
-extern void fpu__save(struct task_struct *tsk);
+extern void fpu__save(struct fpu *fpu);
 
 #endif /* __ASSEMBLY__ */
 

arch/x86/kernel/fpu/core.c

@@ -142,11 +142,9 @@ static void __save_fpu(struct fpu *fpu)
  *
  * This only ever gets called for the current task.
  */
-void fpu__save(struct task_struct *tsk)
+void fpu__save(struct fpu *fpu)
 {
-	struct fpu *fpu = &tsk->thread.fpu;
-
-	WARN_ON(tsk != current);
+	WARN_ON(fpu != &current->thread.fpu);
 
 	preempt_disable();
 	if (fpu->has_fpu) {
@@ -240,7 +238,7 @@ static void fpu_copy(struct task_struct *dst, struct task_struct *src)
 		memset(&dst->thread.fpu.state->xsave, 0, xstate_size);
 		__save_fpu(dst_fpu);
 	} else {
-		fpu__save(src);
+		fpu__save(src_fpu);
 		memcpy(dst_fpu->state, src_fpu->state, xstate_size);
 	}
 }

arch/x86/kernel/traps.c

@@ -730,7 +730,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)
 	/*
 	 * Save the info for the exception handler and clear the error.
 	 */
-	fpu__save(task);
+	fpu__save(&task->thread.fpu);
 	task->thread.trap_nr = trapnr;
 	task->thread.error_code = error_code;
 	info.si_signo = SIGFPE;