From 315f4c70f123cfbf061d097543af555547acd9c7 Mon Sep 17 00:00:00 2001
From: Shenghou Ma <minux@golang.org>
Date: Thu, 18 Feb 2016 16:29:39 -0500
Subject: [PATCH] runtime: use correct psABI SP alignment before calling libc
mmap
Fixes #14384.
Change-Id: Ib025cf2d20754b4c2db52f0a8a4717fd303371d6
Reviewed-on: https://go-review.googlesource.com/19660
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
---
src/runtime/sys_linux_amd64.s | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/src/runtime/sys_linux_amd64.s b/src/runtime/sys_linux_amd64.s
index aed85cb..f407078 100644
--- a/src/runtime/sys_linux_amd64.s
+++ b/src/runtime/sys_linux_amd64.s
@@ -258,7 +258,7 @@ TEXT runtime·sysMmap(SB),NOSPLIT,$0
// Call the function stored in _cgo_mmap using the GCC calling convention.
// This must be called on the system stack.
-TEXT runtime·callCgoMmap(SB),NOSPLIT,$0
+TEXT runtime·callCgoMmap(SB),NOSPLIT,$16
MOVQ addr+0(FP), DI
MOVQ n+8(FP), SI
MOVL prot+16(FP), DX
@@ -266,7 +266,11 @@ TEXT runtime·callCgoMmap(SB),NOSPLIT,$0
MOVL fd+24(FP), R8
MOVL off+28(FP), R9
MOVQ _cgo_mmap(SB), AX
+ MOVQ SP, BX
+ ANDQ $~15, SP // alignment as per amd64 psABI
+ MOVQ BX, 0(SP)
CALL AX
+ MOVQ 0(SP), SP
MOVQ AX, ret+32(FP)
RET