From: Denys Vlasenko <dvlasenk@redhat.com>
Date: Wed, 25 Mar 2015 17:18:15 +0000 (+0100)
Subject: x86/asm/entry/64: Use smaller instructions
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=47eb582e702880c302036d17341c7ea1a7dc2a53;p=linux-beck.git

x86/asm/entry/64: Use smaller instructions

The $AUDIT_ARCH_X86_64 parameter to syscall_trace_enter_phase1/2
is a 32-bit constant, loading it with 32-bit MOV produces 5-byte
insn instead of 10-byte MOVABS one.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
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/1427303896-24023-3-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 9988c4b2de33..f85d2ccec6d2 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -305,7 +305,7 @@ system_call_fastpath:
 	/* Do syscall entry tracing */
 tracesys:
 	movq %rsp, %rdi
-	movq $AUDIT_ARCH_X86_64, %rsi
+	movl $AUDIT_ARCH_X86_64, %esi
 	call syscall_trace_enter_phase1
 	test %rax, %rax
 	jnz tracesys_phase2		/* if needed, run the slow path */
@@ -316,7 +316,7 @@ tracesys:
 tracesys_phase2:
 	SAVE_EXTRA_REGS
 	movq %rsp, %rdi
-	movq $AUDIT_ARCH_X86_64, %rsi
+	movl $AUDIT_ARCH_X86_64, %esi
 	movq %rax,%rdx
 	call syscall_trace_enter_phase2