x86/fpu: Simplify fpu__unlazy_stopped()

Open code the PF_USED_MATH logic, to make the logic more obvious.

(We'll slowly convert the other users of *_used_math() methods as well.)

Reviewed-by: Borislav Petkov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 76006a701dbbab1c50d39f931fcbdf655034fe26..5e4dae70ffa5705f950a89c5b833ec8cd3f4f18c 100644 (file)
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -290,7 +290,7 @@ static int fpu__unlazy_stopped(struct task_struct *child)
        if (WARN_ON_ONCE(child == current))
                return -EINVAL;
 
-       if (tsk_used_math(child)) {
+       if (child->flags & PF_USED_MATH) {
                task_disable_lazy_fpu_restore(child);
                return 0;
        }
@@ -304,7 +304,9 @@ static int fpu__unlazy_stopped(struct task_struct *child)
 
        fpu_finit(&child->thread.fpu);
 
-       set_stopped_child_used_math(child);
+       /* Safe to do for stopped child tasks: */
+       child->flags |= PF_USED_MATH;
+
        return 0;
 }