From 16d1a8e6e3701a8ed2e9b16f7c9b8e70a7b1fc8d Mon Sep 17 00:00:00 2001
From: Keith Randall <khr@golang.org>
Date: Mon, 30 Apr 2018 19:55:41 -0700
Subject: [PATCH] runtime: move open/close/read/write from syscall to libc on
 Darwin

Update #17490

Change-Id: Ia0bb0ba10dc0bbb299290a60b8228275d55125d7
Reviewed-on: https://go-review.googlesource.com/110438
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
---
 src/runtime/sys_darwin.go      |  5 +++
 src/runtime/sys_darwin_386.s   | 72 ++++++++++++++++++++++++----------
 src/runtime/sys_darwin_amd64.s | 48 +++++++++++++----------
 3 files changed, 85 insertions(+), 40 deletions(-)

diff --git a/src/runtime/sys_darwin.go b/src/runtime/sys_darwin.go
index e2789207677..6af52cbab32 100644
--- a/src/runtime/sys_darwin.go
+++ b/src/runtime/sys_darwin.go
@@ -86,6 +86,11 @@ func pthread_self_trampoline() pthread
 //go:cgo_import_dynamic libc_pthread_kill pthread_kill "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_pthread_self pthread_self "/usr/lib/libSystem.B.dylib"
 
+//go:cgo_import_dynamic libc_open open "/usr/lib/libSystem.B.dylib"
+//go:cgo_import_dynamic libc_close close "/usr/lib/libSystem.B.dylib"
+//go:cgo_import_dynamic libc_read read "/usr/lib/libSystem.B.dylib"
+//go:cgo_import_dynamic libc_write write "/usr/lib/libSystem.B.dylib"
+
 //go:cgo_import_dynamic libc_mmap mmap "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_munmap munmap "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_madvise madvise "/usr/lib/libSystem.B.dylib"
diff --git a/src/runtime/sys_darwin_386.s b/src/runtime/sys_darwin_386.s
index 8dc4efc631b..ea6116eb0aa 100644
--- a/src/runtime/sys_darwin_386.s
+++ b/src/runtime/sys_darwin_386.s
@@ -29,35 +29,67 @@ TEXT runtime·exitThread(SB),NOSPLIT,$0-4
 	MOVL	$0xf1, 0xf1  // crash
 	RET
 
-TEXT runtime·open(SB),NOSPLIT,$0
-	MOVL	$5, AX
-	INT	$0x80
-	JAE	2(PC)
-	MOVL	$-1, AX
+TEXT runtime·open(SB),NOSPLIT,$0-16
+	MOVL	name+0(FP), AX		// arg 1 name
+	MOVL	mode+4(FP), CX		// arg 2 mode
+	MOVL	perm+8(FP), DX		// arg 3 perm
+	PUSHL	BP
+	MOVL	SP, BP
+	SUBL	$12, SP
+	ANDL	$~15, SP
+	MOVL	AX, 0(SP)
+	MOVL	CX, 4(SP)
+	MOVL	DX, 8(SP)
+	CALL	libc_open(SB)
+	MOVL	BP, SP
+	POPL	BP
 	MOVL	AX, ret+12(FP)
 	RET
 
-TEXT runtime·closefd(SB),NOSPLIT,$0
-	MOVL	$6, AX
-	INT	$0x80
-	JAE	2(PC)
-	MOVL	$-1, AX
+TEXT runtime·closefd(SB),NOSPLIT,$0-8
+	MOVL	fd+0(FP), AX		// arg 1 fd
+	PUSHL	BP
+	MOVL	SP, BP
+	SUBL	$4, SP
+	ANDL	$~15, SP
+	MOVL	AX, 0(SP)
+	CALL	libc_close(SB)
+	MOVL	BP, SP
+	POPL	BP
 	MOVL	AX, ret+4(FP)
 	RET
 
-TEXT runtime·read(SB),NOSPLIT,$0
-	MOVL	$3, AX
-	INT	$0x80
-	JAE	2(PC)
-	MOVL	$-1, AX
+TEXT runtime·read(SB),NOSPLIT,$0-16
+	MOVL	fd+0(FP), AX		// arg 1 fd
+	MOVL	p+4(FP), CX		// arg 2 buf
+	MOVL	n+8(FP), DX		// arg 3 count
+	PUSHL	BP
+	MOVL	SP, BP
+	SUBL	$12, SP
+	ANDL	$~15, SP
+	MOVL	AX, 0(SP)
+	MOVL	CX, 4(SP)
+	MOVL	DX, 8(SP)
+	CALL	libc_read(SB)
+	MOVL	BP, SP
+	POPL	BP
 	MOVL	AX, ret+12(FP)
 	RET
 
-TEXT runtime·write(SB),NOSPLIT,$0
-	MOVL	$4, AX
-	INT	$0x80
-	JAE	2(PC)
-	MOVL	$-1, AX
+TEXT runtime·write(SB),NOSPLIT,$0-16
+	MOVL	fd+0(FP), AX		// arg 1 fd
+	MOVL	p+4(FP), CX		// arg 2 buf
+	MOVL	n+8(FP), DX		// arg 3 count
+	PUSHL	BP
+	MOVL	SP, BP
+	SUBL	$12, SP
+	ANDL	$~15, SP
+	MOVL	AX, 0(SP)
+	MOVL	CX, 4(SP)
+	MOVL	DX, 8(SP)
+	CALL	libc_write(SB)
+	MOVL	BP, SP
+	POPL	BP
 	MOVL	AX, ret+12(FP)
 	RET
 
diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index 1fbc5c52d60..bf5a34a15e3 100644
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -32,45 +32,53 @@ TEXT runtime·exitThread(SB),NOSPLIT,$0-8
 	MOVL	$0xf1, 0xf1  // crash
 	RET
 
-TEXT runtime·open(SB),NOSPLIT,$0
+TEXT runtime·open(SB),NOSPLIT,$0-20
 	MOVQ	name+0(FP), DI		// arg 1 pathname
 	MOVL	mode+8(FP), SI		// arg 2 flags
 	MOVL	perm+12(FP), DX		// arg 3 mode
-	MOVL	$(0x2000000+5), AX	// syscall entry
-	SYSCALL
-	JCC	2(PC)
-	MOVL	$-1, AX
+	PUSHQ	BP
+	MOVQ	SP, BP
+	ANDQ	$~15, SP // align stack
+	CALL	libc_open(SB)
+	MOVQ	BP, SP
+	POPQ	BP
 	MOVL	AX, ret+16(FP)
 	RET
 
-TEXT runtime·closefd(SB),NOSPLIT,$0
+TEXT runtime·closefd(SB),NOSPLIT,$0-12
 	MOVL	fd+0(FP), DI		// arg 1 fd
-	MOVL	$(0x2000000+6), AX	// syscall entry
-	SYSCALL
-	JCC	2(PC)
-	MOVL	$-1, AX
+	PUSHQ	BP
+	MOVQ	SP, BP
+	ANDQ	$~15, SP // align stack
+	CALL	libc_close(SB)
+	MOVQ	BP, SP
+	POPQ	BP
 	MOVL	AX, ret+8(FP)
 	RET
 
-TEXT runtime·read(SB),NOSPLIT,$0
+TEXT runtime·read(SB),NOSPLIT,$0-28
 	MOVL	fd+0(FP), DI		// arg 1 fd
 	MOVQ	p+8(FP), SI		// arg 2 buf
 	MOVL	n+16(FP), DX		// arg 3 count
-	MOVL	$(0x2000000+3), AX	// syscall entry
-	SYSCALL
-	JCC	2(PC)
-	MOVL	$-1, AX
+	PUSHQ	BP
+	MOVQ	SP, BP
+	ANDQ	$~15, SP // align stack
+	CALL	libc_read(SB)
+	MOVQ	BP, SP
+	POPQ	BP
 	MOVL	AX, ret+24(FP)
 	RET
 
-TEXT runtime·write(SB),NOSPLIT,$0
+TEXT runtime·write(SB),NOSPLIT,$0-28
 	MOVQ	fd+0(FP), DI		// arg 1 fd
 	MOVQ	p+8(FP), SI		// arg 2 buf
 	MOVL	n+16(FP), DX		// arg 3 count
-	MOVL	$(0x2000000+4), AX	// syscall entry
-	SYSCALL
-	JCC	2(PC)
-	MOVL	$-1, AX
+	PUSHQ	BP
+	MOVQ	SP, BP
+	ANDQ	$~15, SP // align stack
+	CALL	libc_write(SB)
+	MOVQ	BP, SP
+	POPQ	BP
 	MOVL	AX, ret+24(FP)
 	RET