[PATCH 4.14 028/159] x86/asm: Dont use the confusing .ifeq directive

From: Greg Kroah-Hartman
Date: Fri Dec 22 2017 - 04:58:17 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

commit 82c62fa0c49aa305104013cee4468772799bb391 upstream.

I find the '.ifeq <expression>' directive to be confusing. Reading it
quickly seems to suggest its opposite meaning, or that it's missing an
argument.

Improve readability by replacing all of its x86 uses with
'.if <expression> == 0'.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Andrei Vagin <avagin@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/757da028e802c7e98d23fbab8d234b1063e161cf.1508516398.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/entry/entry_64.S | 2 +-
arch/x86/kernel/head_32.S | 2 +-
arch/x86/kernel/head_64.S | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -818,7 +818,7 @@ ENTRY(\sym)

ASM_CLAC

- .ifeq \has_error_code
+ .if \has_error_code == 0
pushq $-1 /* ORIG_RAX: no syscall to restart */
.endif

--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -402,7 +402,7 @@ ENTRY(early_idt_handler_array)
# 24(%rsp) error code
i = 0
.rept NUM_EXCEPTION_VECTORS
- .ifeq (EXCEPTION_ERRCODE_MASK >> i) & 1
+ .if ((EXCEPTION_ERRCODE_MASK >> i) & 1) == 0
pushl $0 # Dummy error code, to make stack frame uniform
.endif
pushl $i # 20(%esp) Vector number
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -275,7 +275,7 @@ ENDPROC(start_cpu0)
ENTRY(early_idt_handler_array)
i = 0
.rept NUM_EXCEPTION_VECTORS
- .ifeq (EXCEPTION_ERRCODE_MASK >> i) & 1
+ .if ((EXCEPTION_ERRCODE_MASK >> i) & 1) == 0
UNWIND_HINT_IRET_REGS
pushq $0 # Dummy error code, to make stack frame uniform
.else