Files
sys/windows/svc/sys_amd64.s
Alex Brainman 4b90ce9b60 windows/svc: align stack in servicemain before calling syscall
I noticed that we call syscall in servicemain without aligning stack.
That is against Windows rules, so align the stack as required.

I tried running this code with specifically non-aligned stack (I aligned
stack, and then subtracted 1 from SP) on my Windows 10 to test this
change. But it makes no difference on my Windows 10 PC - I built and run
golang.org/x/sys/windows/svc/example, and it runs successfully
regardless of stack alignment. But alignment might make difference on
other computers.

Maybe fixes golang/go#40160

Change-Id: I351f7f730fba4aa6dc409a79de4ad737b4a0a7d4
Reviewed-on: https://go-review.googlesource.com/c/sys/+/246317
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2020-08-02 09:19:54 +00:00

49 lines
1.2 KiB
ArmAsm

// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build windows
// func servicemain(argc uint32, argv **uint16)
TEXT ·servicemain(SB),7,$0
MOVQ SP, AX
ANDQ $~15, SP // alignment as per Windows requirement
SUBQ $48, SP // room for SP and 4 args as per Windows requirement
// plus one extra word to keep stack 16 bytes aligned
MOVQ AX, 32(SP)
MOVL CX, ·sArgc(SB)
MOVQ DX, ·sArgv(SB)
MOVQ ·sName(SB), CX
MOVQ $·servicectlhandler(SB), DX
// BUG(pastarmovj): Figure out a way to pass in context in R8.
// Set context to 123456 to test issue #25660.
MOVQ $123456, R8
MOVQ ·cRegisterServiceCtrlHandlerExW(SB), AX
CALL AX
CMPQ AX, $0
JE exit
MOVQ AX, ·ssHandle(SB)
MOVQ ·goWaitsH(SB), CX
MOVQ ·cSetEvent(SB), AX
CALL AX
MOVQ ·cWaitsH(SB), CX
MOVQ $4294967295, DX
MOVQ ·cWaitForSingleObject(SB), AX
CALL AX
exit:
MOVQ 32(SP), SP
RET
// I do not know why, but this seems to be the only way to call
// ctlHandlerProc on Windows 7.
// func ·servicectlhandler(ctl uint32, evtype uint32, evdata uintptr, context uintptr) uintptr {
TEXT ·servicectlhandler(SB),7,$0
MOVQ ·ctlHandlerExProc(SB), AX
JMP AX