[PATCH 4.14 039/159] x86/entry/64: Shrink paranoid_exit_restore and make labels local

Greg Kroah-Hartman
2017-12-22T09:54:50Z

From: Andy Lutomirski <luto@kernel.org>

commit e53178328c9b96fbdbc719e78c93b5687ee007c3 upstream.

paranoid_exit_restore was a copy of restore_regs_and_return_to_kernel.
Merge them and make the paranoid_exit internal labels local.

Keeping .Lparanoid_exit makes the code a bit shorter because it
allows a 2-byte jnz instead of a 5-byte jnz.

Saves 96 bytes of text.

( This is still a bit suboptimal in a non-CONFIG_TRACE_IRQFLAGS
kernel, but fixing that would make the code rather messy. )

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/510d66a1895cda9473c84b1086f0bb974f22de6a.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/entry/entry_64.S | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1124,17 +1124,14 @@ ENTRY(paranoid_exit)
DISABLE_INTERRUPTS(CLBR_ANY)
TRACE_IRQS_OFF_DEBUG
testl %ebx, %ebx /* swapgs needed? */
- jnz paranoid_exit_no_swapgs
+ jnz .Lparanoid_exit_no_swapgs
TRACE_IRQS_IRETQ
SWAPGS_UNSAFE_STACK
- jmp paranoid_exit_restore
-paranoid_exit_no_swapgs:
+ jmp .Lparanoid_exit_restore
+.Lparanoid_exit_no_swapgs:
TRACE_IRQS_IRETQ_DEBUG
-paranoid_exit_restore:
- RESTORE_EXTRA_REGS
- RESTORE_C_REGS
- REMOVE_PT_GPREGS_FROM_STACK 8
- INTERRUPT_RETURN
+.Lparanoid_exit_restore:
+ jmp restore_regs_and_return_to_kernel
END(paranoid_exit)

/*