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go/src/syscall/asm_linux_386.s
Tobias Klauser 36951a9f63 syscall: support syscalls without error return on Linux
Add the rawSyscallNoError wrapper function which is used for Linux
syscalls that don't return an error and convert all applicable
occurences of RawSyscall to use it instead.

Fixes #22924

Change-Id: Iff1eddb54573d459faa01471f10398b3d38528dd
Reviewed-on: https://go-review.googlesource.com/84485
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-02-13 15:57:31 +00:00

201 lines
4.7 KiB
ArmAsm

// 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 Syscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
// Trap # in AX, args in BX CX DX SI DI, return in AX
TEXT ·Syscall(SB),NOSPLIT,$0-28
CALL runtime·entersyscall(SB)
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
CMPL AX, $0xfffff001
JLS ok
MOVL $-1, r1+16(FP)
MOVL $0, r2+20(FP)
NEGL AX
MOVL AX, err+24(FP)
CALL runtime·exitsyscall(SB)
RET
ok:
MOVL AX, r1+16(FP)
MOVL DX, r2+20(FP)
MOVL $0, err+24(FP)
CALL runtime·exitsyscall(SB)
RET
// func Syscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
TEXT ·Syscall6(SB),NOSPLIT,$0-40
CALL runtime·entersyscall(SB)
MOVL trap+0(FP), AX // syscall entry
MOVL a1+4(FP), BX
MOVL a2+8(FP), CX
MOVL a3+12(FP), DX
MOVL a4+16(FP), SI
MOVL a5+20(FP), DI
MOVL a6+24(FP), BP
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS ok6
MOVL $-1, r1+28(FP)
MOVL $0, r2+32(FP)
NEGL AX
MOVL AX, err+36(FP)
CALL runtime·exitsyscall(SB)
RET
ok6:
MOVL AX, r1+28(FP)
MOVL DX, r2+32(FP)
MOVL $0, err+36(FP)
CALL runtime·exitsyscall(SB)
RET
// func RawSyscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
TEXT ·RawSyscall(SB),NOSPLIT,$0-28
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
CMPL AX, $0xfffff001
JLS ok1
MOVL $-1, r1+16(FP)
MOVL $0, r2+20(FP)
NEGL AX
MOVL AX, err+24(FP)
RET
ok1:
MOVL AX, r1+16(FP)
MOVL DX, r2+20(FP)
MOVL $0, err+24(FP)
RET
// func RawSyscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
TEXT ·RawSyscall6(SB),NOSPLIT,$0-40
MOVL trap+0(FP), AX // syscall entry
MOVL a1+4(FP), BX
MOVL a2+8(FP), CX
MOVL a3+12(FP), DX
MOVL a4+16(FP), SI
MOVL a5+20(FP), DI
MOVL a6+24(FP), BP
INVOKE_SYSCALL
CMPL AX, $0xfffff001
JLS ok2
MOVL $-1, r1+28(FP)
MOVL $0, r2+32(FP)
NEGL AX
MOVL AX, err+36(FP)
RET
ok2:
MOVL AX, r1+28(FP)
MOVL DX, r2+32(FP)
MOVL $0, err+36(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