[PATCH] x86/asm/entry/32: tidy up JNZ insns after TESTs

[PATCH] x86/asm/entry/32: tidy up JNZ insns after TESTs

[Denys Vlasenko]

After TESTs, use logically correct JNZ mnemonic instead of JNE
This doesn't change code.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
 arch/x86/kernel/entry_32.S | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 02bec0f..1c30976 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -435,7 +435,7 @@ sysenter_after_call:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $_TIF_ALLWORK_MASK, %ecx
-	jne sysexit_audit
+	jnz sysexit_audit
 sysenter_exit:
 /* if something modifies registers it must also disable sysexit */
 	movl PT_EIP(%esp), %edx
@@ -463,7 +463,7 @@ sysenter_audit:
 
 sysexit_audit:
 	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
-	jne syscall_exit_work
+	jnz syscall_exit_work
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_ANY)
 	movl %eax,%edx		/* second arg, syscall return value */
@@ -475,7 +475,7 @@ sysexit_audit:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
-	jne syscall_exit_work
+	jnz syscall_exit_work
 	movl PT_EAX(%esp),%eax	/* reload syscall return value */
 	jmp sysenter_exit
 #endif
@@ -513,7 +513,7 @@ syscall_exit:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $_TIF_ALLWORK_MASK, %ecx	# current->work
-	jne syscall_exit_work
+	jnz syscall_exit_work
 
 restore_all:
 	TRACE_IRQS_IRET
@@ -615,7 +615,7 @@ work_notifysig:				# deal with pending signals and
 #ifdef CONFIG_VM86
 	testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
 	movl %esp, %eax
-	jne work_notifysig_v86		# returning to kernel-space or
+	jnz work_notifysig_v86		# returning to kernel-space or
 					# vm86-space
 1:
 #else
-- 
1.8.1.4

Re: [PATCH] x86/asm/entry/32: tidy up JNZ insns after TESTs

[Andy Lutomirski]

On Fri, Apr 10, 2015 at 11:13 AM, Denys Vlasenko <dvlasenk@redhat.com> wrote:
> After TESTs, use logically correct JNZ mnemonic instead of JNE
> This doesn't change code.

Acked-by: Andy Lutomirski <luto@kernel.org>

[tip:x86/asm] x86/asm/entry/32: Tidy up JNZ instructions after TESTs

[tip-bot for Denys Vlasenko]

Commit-ID:  54cfa458b492fcf76d653698d362743bcb329055
Gitweb:     http://git.kernel.org/tip/54cfa458b492fcf76d653698d362743bcb329055
Author:     Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Fri, 10 Apr 2015 20:13:40 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 11 Apr 2015 10:40:02 +0200

x86/asm/entry/32: Tidy up JNZ instructions after TESTs

After TESTs, use logically correct JNZ mnemonic instead of JNE.

This doesn't change code:

  md5:
   c3005b39a11fe582b7df7908561ad4ee  entry_32.o.before.asm
   c3005b39a11fe582b7df7908561ad4ee  entry_32.o.after.asm

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428689620-21881-1-git-send-email-dvlasenk@redhat.com
[ Added object file comparison. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/entry_32.S | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 02bec0f..1c30976 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -435,7 +435,7 @@ sysenter_after_call:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $_TIF_ALLWORK_MASK, %ecx
-	jne sysexit_audit
+	jnz sysexit_audit
 sysenter_exit:
 /* if something modifies registers it must also disable sysexit */
 	movl PT_EIP(%esp), %edx
@@ -463,7 +463,7 @@ sysenter_audit:
 
 sysexit_audit:
 	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
-	jne syscall_exit_work
+	jnz syscall_exit_work
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_ANY)
 	movl %eax,%edx		/* second arg, syscall return value */
@@ -475,7 +475,7 @@ sysexit_audit:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
-	jne syscall_exit_work
+	jnz syscall_exit_work
 	movl PT_EAX(%esp),%eax	/* reload syscall return value */
 	jmp sysenter_exit
 #endif
@@ -513,7 +513,7 @@ syscall_exit:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $_TIF_ALLWORK_MASK, %ecx	# current->work
-	jne syscall_exit_work
+	jnz syscall_exit_work
 
 restore_all:
 	TRACE_IRQS_IRET
@@ -615,7 +615,7 @@ work_notifysig:				# deal with pending signals and
 #ifdef CONFIG_VM86
 	testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
 	movl %esp, %eax
-	jne work_notifysig_v86		# returning to kernel-space or
+	jnz work_notifysig_v86		# returning to kernel-space or
 					# vm86-space
 1:
 #else