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 9988c4b2de330c13a93f3ff7581e31dbf8b1a9e1..f85d2ccec6d26982425f0ad19aa8021843187a7f 100644 (file)
--- 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