aboutsummaryrefslogtreecommitdiff
path: root/src/syscall/asm_linux_386.s
blob: e86a859f4e294857375c51827203f5ef76753184 (plain)
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
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
// Copyright 2009 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.

#include "textflag.h"
#include "funcdata.h"

//
// System calls for 386, Linux
//

// See ../runtime/sys_linux_386.s for the reason why we always use int 0x80
// instead of the glibc-specific "CALL 0x10(GS)".
#define INVOKE_SYSCALL	INT	$0x80

// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-16
	MOVL	trap+0(FP), AX	// syscall entry
	MOVL	a1+4(FP), BX
	MOVL	$0, CX
	MOVL	$0, DX
	POPL	SI // preserve return address
	INVOKE_SYSCALL
	PUSHL	SI
	CMPL	AX, $0xfffff001
	JLS	ok
	MOVL	$-1, r1+8(FP)
	NEGL	AX
	MOVL	AX, err+12(FP)
	RET
ok:
	MOVL	AX, r1+8(FP)
	MOVL	$0, err+12(FP)
	RET

// func rawSyscallNoError(trap uintptr, a1, a2, a3 uintptr) (r1, r2 uintptr);
TEXT ·rawSyscallNoError(SB),NOSPLIT,$0-24
	MOVL	trap+0(FP), AX	// syscall entry
	MOVL	a1+4(FP), BX
	MOVL	a2+8(FP), CX
	MOVL	a3+12(FP), DX
	MOVL	$0, SI
	MOVL	$0, DI
	INVOKE_SYSCALL
	MOVL	AX, r1+16(FP)
	MOVL	DX, r2+20(FP)
	RET

#define SYS_SOCKETCALL 102	/* from zsysnum_linux_386.go */

// func socketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (n int, err int)
// Kernel interface gets call sub-number and pointer to a0.
TEXT ·socketcall(SB),NOSPLIT,$0-36
	CALL	runtime·entersyscall(SB)
	MOVL	$SYS_SOCKETCALL, AX	// syscall entry
	MOVL	call+0(FP), BX	// socket call number
	LEAL	a0+4(FP), CX	// pointer to call arguments
	MOVL	$0, DX
	MOVL	$0, SI
	MOVL	$0, DI
	INVOKE_SYSCALL
	CMPL	AX, $0xfffff001
	JLS	oksock
	MOVL	$-1, n+28(FP)
	NEGL	AX
	MOVL	AX, err+32(FP)
	CALL	runtime·exitsyscall(SB)
	RET
oksock:
	MOVL	AX, n+28(FP)
	MOVL	$0, err+32(FP)
	CALL	runtime·exitsyscall(SB)
	RET

// func rawsocketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (n int, err int)
// Kernel interface gets call sub-number and pointer to a0.
TEXT ·rawsocketcall(SB),NOSPLIT,$0-36
	MOVL	$SYS_SOCKETCALL, AX	// syscall entry
	MOVL	call+0(FP), BX	// socket call number
	LEAL		a0+4(FP), CX	// pointer to call arguments
	MOVL	$0, DX
	MOVL	$0, SI
	MOVL	$0, DI
	INVOKE_SYSCALL
	CMPL	AX, $0xfffff001
	JLS	oksock1
	MOVL	$-1, n+28(FP)
	NEGL	AX
	MOVL	AX, err+32(FP)
	RET
oksock1:
	MOVL	AX, n+28(FP)
	MOVL	$0, err+32(FP)
	RET

#define SYS__LLSEEK 140	/* from zsysnum_linux_386.go */
// func Seek(fd int, offset int64, whence int) (newoffset int64, err int)
// Implemented in assembly to avoid allocation when
// taking the address of the return value newoffset.
// Underlying system call is
//	llseek(int fd, int offhi, int offlo, int64 *result, int whence)
TEXT ·seek(SB),NOSPLIT,$0-28
	CALL	runtime·entersyscall(SB)
	MOVL	$SYS__LLSEEK, AX	// syscall entry
	MOVL	fd+0(FP), BX
	MOVL	offset_hi+8(FP), CX
	MOVL	offset_lo+4(FP), DX
	LEAL	newoffset_lo+16(FP), SI	// result pointer
	MOVL	whence+12(FP), DI
	INVOKE_SYSCALL
	CMPL	AX, $0xfffff001
	JLS	okseek
	MOVL	$-1, newoffset_lo+16(FP)
	MOVL	$-1, newoffset_hi+20(FP)
	NEGL	AX
	MOVL	AX, err+24(FP)
	CALL	runtime·exitsyscall(SB)
	RET
okseek:
	// system call filled in newoffset already
	MOVL	$0, err+24(FP)
	CALL	runtime·exitsyscall(SB)
	RET