x86/fpu: Don't export __kernel_fpu_{begin,end}()

There is one user of __kernel_fpu_begin() and before invoking it,
it invokes preempt_disable(). So it could invoke kernel_fpu_begin()
right away. The 32bit version of arch_efi_call_virt_setup() and
arch_efi_call_virt_teardown() does this already.

The comment above *kernel_fpu*() claims that before invoking
__kernel_fpu_begin() preemption should be disabled and that KVM is a
good example of doing it. Well, KVM doesn't do that since commit

  f775b13eedee2 ("x86,kvm: move qemu/guest FPU switching out to vcpu_run")

so it is not an example anymore.

With EFI gone as the last user of __kernel_fpu_{begin|end}(), both can
be made static and not exported anymore.

Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: "Jason A. Donenfeld" <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Nicolai Stange <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: kvm ML <[email protected]>
Cc: linux-efi <[email protected]>
Cc: x86-ml <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

1 files changed, 2 insertions, 4 deletions

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 2ea85b32421a..2e5003fef51a 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -93,7 +93,7 @@ bool irq_fpu_usable(void)
 }
 EXPORT_SYMBOL(irq_fpu_usable);
 
-void __kernel_fpu_begin(void)
+static void __kernel_fpu_begin(void)
 {
 	struct fpu *fpu = &current->thread.fpu;
 
@@ -111,9 +111,8 @@ void __kernel_fpu_begin(void)
 		__cpu_invalidate_fpregs_state();
 	}
 }
-EXPORT_SYMBOL(__kernel_fpu_begin);
 
-void __kernel_fpu_end(void)
+static void __kernel_fpu_end(void)
 {
 	struct fpu *fpu = &current->thread.fpu;
 
@@ -122,7 +121,6 @@ void __kernel_fpu_end(void)
 
 	kernel_fpu_enable();
 }
-EXPORT_SYMBOL(__kernel_fpu_end);
 
 void kernel_fpu_begin(void)
 {