1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
// Copyright 2014 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 !gccgo
#include "textflag.h"
TEXT ·RewindAndSetgid(SB),NOSPLIT,$-8-0
// Save link register
MOVD R30, R9
// Rewind stack pointer so anything that happens on the stack
// will clobber the test pattern created by the caller
ADD $(1024 * 8), RSP
// Ask signaller to setgid
MOVD $·Baton(SB), R0
MOVD $1, R1
storeloop:
LDAXRW (R0), R2
STLXRW R1, (R0), R3
CBNZ R3, storeloop
// Wait for setgid completion
MOVW $0, R1
MOVW $0, R2
loop:
LDAXRW (R0), R3
CMPW R1, R3
BNE loop
STLXRW R2, (R0), R3
CBNZ R3, loop
// Restore stack
SUB $(1024 * 8), RSP
MOVD R9, R30
RET
|
