Эх сурвалжийг харах

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>
Denys Vlasenko 10 жил өмнө
parent
commit
47eb582e70

+ 2 - 2
arch/x86/kernel/entry_64.S

@@ -305,7 +305,7 @@ system_call_fastpath:
 	/* Do syscall entry tracing */
 	/* Do syscall entry tracing */
 tracesys:
 tracesys:
 	movq %rsp, %rdi
 	movq %rsp, %rdi
-	movq $AUDIT_ARCH_X86_64, %rsi
+	movl $AUDIT_ARCH_X86_64, %esi
 	call syscall_trace_enter_phase1
 	call syscall_trace_enter_phase1
 	test %rax, %rax
 	test %rax, %rax
 	jnz tracesys_phase2		/* if needed, run the slow path */
 	jnz tracesys_phase2		/* if needed, run the slow path */
@@ -316,7 +316,7 @@ tracesys:
 tracesys_phase2:
 tracesys_phase2:
 	SAVE_EXTRA_REGS
 	SAVE_EXTRA_REGS
 	movq %rsp, %rdi
 	movq %rsp, %rdi
-	movq $AUDIT_ARCH_X86_64, %rsi
+	movl $AUDIT_ARCH_X86_64, %esi
 	movq %rax,%rdx
 	movq %rax,%rdx
 	call syscall_trace_enter_phase2
 	call syscall_trace_enter_phase2