x86/entry/64: Shorten TEST instructions

Convert TESTL to TESTB and save 3 bytes per callsite.

No functionality change.

Signed-off-by: Borislav Petkov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 40e9933a2d33f015745822f58366cd96acf2f0db..84263c79a1199be6f32f33e3a416a120327e8ce0 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -620,7 +620,7 @@ GLOBAL(retint_user)
 GLOBAL(swapgs_restore_regs_and_return_to_usermode)
 #ifdef CONFIG_DEBUG_ENTRY
        /* Assert that pt_regs indicates user mode. */
-       testl   $3, CS(%rsp)
+       testb   $3, CS(%rsp)
        jnz     1f
        ud2
 1:
@@ -653,7 +653,7 @@ retint_kernel:
 GLOBAL(restore_regs_and_return_to_kernel)
 #ifdef CONFIG_DEBUG_ENTRY
        /* Assert that pt_regs indicates kernel mode. */
-       testl   $3, CS(%rsp)
+       testb   $3, CS(%rsp)
        jz      1f
        ud2
 1: