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go/src/syscall/asm_plan9_amd64.s
Matthew Dempsky 9828b7c468 runtime, syscall: use FP instead of SP for parameters
Consistently access function parameters using the FP pseudo-register
instead of SP (e.g., x+0(FP) instead of x+4(SP) or x+8(SP), depending
on register size). Two reasons: 1) doc/asm says the SP pseudo-register
should use negative offsets in the range [-framesize, 0), and 2)
cmd/vet only validates parameter offsets when indexed from the FP
pseudo-register.

No binary changes to the compiled object files for any of the affected
package/OS/arch combinations.

Change-Id: I0efc6079bc7519fcea588c114ec6a39b245d68b0
Reviewed-on: https://go-review.googlesource.com/30085
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-30 05:40:43 +00:00

165 lines
2.9 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.
// TODO(rsc): Rewrite all nn(SP) references into name+(nn-8)(FP)
// so that go vet can check that they are correct.
#include "textflag.h"
#include "funcdata.h"
//
// System call support for Plan 9
//
//func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err string)
//func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err string)
//func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr)
//func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr)
TEXT ·Syscall(SB),NOSPLIT,$0-64
CALL runtime·entersyscall(SB)
MOVQ trap+0(FP), BP // syscall entry
// slide args down on top of system call number
LEAQ 16(SP), SI
LEAQ 8(SP), DI
CLD
MOVSQ
MOVSQ
MOVSQ
SYSCALL
MOVQ AX, r1+32(FP)
MOVQ $0, r2+40(FP)
CMPL AX, $-1
JNE ok3
SUBQ $16, SP
CALL runtime·errstr(SB)
MOVQ SP, SI
ADDQ $16, SP
JMP copyresult3
ok3:
LEAQ runtime·emptystring(SB), SI
copyresult3:
LEAQ err+48(FP), DI
CLD
MOVSQ
MOVSQ
CALL runtime·exitsyscall(SB)
RET
TEXT ·Syscall6(SB),NOSPLIT,$0-88
CALL runtime·entersyscall(SB)
MOVQ trap+0(FP), BP // syscall entry
// slide args down on top of system call number
LEAQ 16(SP), SI
LEAQ 8(SP), DI
CLD
MOVSQ
MOVSQ
MOVSQ
MOVSQ
MOVSQ
MOVSQ
SYSCALL
MOVQ AX, r1+56(FP)
MOVQ $0, r2+64(FP)
CMPL AX, $-1
JNE ok4
SUBQ $16, SP
CALL runtime·errstr(SB)
MOVQ SP, SI
ADDQ $16, SP
JMP copyresult4
ok4:
LEAQ runtime·emptystring(SB), SI
copyresult4:
LEAQ err+72(FP), DI
CLD
MOVSQ
MOVSQ
CALL runtime·exitsyscall(SB)
RET
TEXT ·RawSyscall(SB),NOSPLIT,$0-56
MOVQ trap+0(FP), BP // syscall entry
// slide args down on top of system call number
LEAQ 16(SP), SI
LEAQ 8(SP), DI
CLD
MOVSQ
MOVSQ
MOVSQ
SYSCALL
MOVQ AX, r1+32(FP)
MOVQ AX, r2+40(FP)
MOVQ AX, err+48(FP)
RET
TEXT ·RawSyscall6(SB),NOSPLIT,$0-80
MOVQ trap+0(FP), BP // syscall entry
// slide args down on top of system call number
LEAQ 16(SP), SI
LEAQ 8(SP), DI
CLD
MOVSQ
MOVSQ
MOVSQ
MOVSQ
MOVSQ
MOVSQ
SYSCALL
MOVQ AX, r1+56(FP)
MOVQ AX, r2+64(FP)
MOVQ AX, err+72(FP)
RET
#define SYS_SEEK 39 /* from zsysnum_plan9_amd64.go */
//func seek(placeholder uintptr, fd int, offset int64, whence int) (newoffset int64, err string)
TEXT ·seek(SB),NOSPLIT,$0-56
LEAQ newoffset+32(FP), AX
MOVQ AX, placeholder+0(FP)
MOVQ $SYS_SEEK, BP // syscall entry
SYSCALL
CMPL AX, $-1
JNE ok6
MOVQ $-1, newoffset+32(FP)
SUBQ $16, SP
CALL syscall·errstr(SB)
MOVQ SP, SI
ADDQ $16, SP
JMP copyresult6
ok6:
LEAQ runtime·emptystring(SB), SI
copyresult6:
LEAQ err+40(FP), DI
CLD
MOVSQ
MOVSQ
RET
//func exit(code int)
// Import runtime·exit for cleanly exiting.
TEXT ·exit(SB),NOSPLIT,$8-8
NO_LOCAL_POINTERS
MOVQ code+0(FP), AX
MOVQ AX, 0(SP)
CALL runtime·exit(SB)
RET