From: Thomas Gleixner <t...@linutronix.de>
GAS cannot optimize out the test and conditional jump when context tracking
is disabled and CALL_enter_from_user_mode is an empty macro.
Wrap it in #ifdeffery. Will go away once all this is moved to C.
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.char...@oracle.com>
Acked-by: Frederic Weisbecker <frede...@kernel.org>
Acked-by: Andy Lutomirski <l...@kernel.org>
---
arch/x86/entry/entry_64.S | 2 ++
1 file changed, 2 insertions(+)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -888,12 +888,14 @@ apicinterrupt IRQ_WORK_VECTOR irq_work
TRACE_IRQS_OFF
.endif
+#ifdef CONFIG_CONTEXT_TRACKING
.if \paranoid == 0
testb $3, CS(%rsp)
jz .Lfrom_kernel_no_context_tracking_\@
CALL_enter_from_user_mode
.Lfrom_kernel_no_context_tracking_\@:
.endif
+#endif
movq %rsp, %rdi /* pt_regs pointer */
