x86/fpu: Add comments to fpu__save() and restrict its export

Add an explanation to fpu__save() and also don't export it to
random modules - we don't want them to futz around with deep kernel
internals.

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 ec1a744eb853ff858d1776c7670174a12c646960..ac47278cde719201f846f62c4b9406493b2aa4d4 100644 (file)
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -117,6 +117,9 @@ void __kernel_fpu_end(void)
 }
 EXPORT_SYMBOL(__kernel_fpu_end);
 
+/*
+ * Save the FPU state (initialize it if necessary):
+ */
 void fpu__save(struct task_struct *tsk)
 {
        preempt_disable();
@@ -130,7 +133,7 @@ void fpu__save(struct task_struct *tsk)
        }
        preempt_enable();
 }
-EXPORT_SYMBOL(fpu__save);
+EXPORT_SYMBOL_GPL(fpu__save);
 
 unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
 unsigned int xstate_size;