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asm_linux_386.s
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// 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, a2, a3 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-24
MOVL trap+0(FP), AX // syscall entry
MOVL a1+4(FP), BX
MOVL a2+8(FP), CX
MOVL a3+12(FP), DX
POPL SI // preserve return address
INVOKE_SYSCALL
PUSHL SI
CMPL AX, $0xfffff001
JLS ok
MOVL $-1, r1+16(FP)
NEGL AX
MOVL AX, err+20(FP)
RET
ok:
MOVL AX, r1+16(FP)
MOVL $0, err+20(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