go.sys/unix: just jump to syscall.Syscall etc.
Don't re-implement these functions.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/124390043
diff --git a/unix/asm_linux_386.s b/unix/asm_linux_386.s
index 05cf89a..5d3ad9a 100644
--- a/unix/asm_linux_386.s
+++ b/unix/asm_linux_386.s
@@ -2,185 +2,32 @@
// 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"
//
// System calls for 386, Linux
//
-// 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
+// Just jump to package syscall's implementation for all these functions.
+// The runtime may know about them.
TEXT ·Syscall(SB),NOSPLIT,$0-28
- CALL runtime·entersyscall(SB)
- MOVL 4(SP), AX // syscall entry
- MOVL 8(SP), BX
- MOVL 12(SP), CX
- MOVL 16(SP), DX
- MOVL $0, SI
- MOVL $0, DI
- CALL *runtime·_vdso(SB)
- CMPL AX, $0xfffff001
- JLS ok
- MOVL $-1, 20(SP) // r1
- MOVL $0, 24(SP) // r2
- NEGL AX
- MOVL AX, 28(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
-ok:
- MOVL AX, 20(SP) // r1
- MOVL DX, 24(SP) // r2
- MOVL $0, 28(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
+ JMP syscall·Syscall(SB)
-// 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 4(SP), AX // syscall entry
- MOVL 8(SP), BX
- MOVL 12(SP), CX
- MOVL 16(SP), DX
- MOVL 20(SP), SI
- MOVL 24(SP), DI
- MOVL 28(SP), BP
- CALL *runtime·_vdso(SB)
- CMPL AX, $0xfffff001
- JLS ok6
- MOVL $-1, 32(SP) // r1
- MOVL $0, 36(SP) // r2
- NEGL AX
- MOVL AX, 40(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
-ok6:
- MOVL AX, 32(SP) // r1
- MOVL DX, 36(SP) // r2
- MOVL $0, 40(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
+ JMP syscall·Syscall6(SB)
-// func RawSyscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
TEXT ·RawSyscall(SB),NOSPLIT,$0-28
- MOVL 4(SP), AX // syscall entry
- MOVL 8(SP), BX
- MOVL 12(SP), CX
- MOVL 16(SP), DX
- MOVL $0, SI
- MOVL $0, DI
- CALL *runtime·_vdso(SB)
- CMPL AX, $0xfffff001
- JLS ok1
- MOVL $-1, 20(SP) // r1
- MOVL $0, 24(SP) // r2
- NEGL AX
- MOVL AX, 28(SP) // errno
- RET
-ok1:
- MOVL AX, 20(SP) // r1
- MOVL DX, 24(SP) // r2
- MOVL $0, 28(SP) // errno
- RET
+ JMP syscall·RawSyscall(SB)
-// func RawSyscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
TEXT ·RawSyscall6(SB),NOSPLIT,$0-40
- MOVL 4(SP), AX // syscall entry
- MOVL 8(SP), BX
- MOVL 12(SP), CX
- MOVL 16(SP), DX
- MOVL 20(SP), SI
- MOVL 24(SP), DI
- MOVL 28(SP), BP
- CALL *runtime·_vdso(SB)
- CMPL AX, $0xfffff001
- JLS ok2
- MOVL $-1, 32(SP) // r1
- MOVL $0, 36(SP) // r2
- NEGL AX
- MOVL AX, 40(SP) // errno
- RET
-ok2:
- MOVL AX, 32(SP) // r1
- MOVL DX, 36(SP) // r2
- MOVL $0, 40(SP) // errno
- RET
+ JMP syscall·RawSyscall6(SB)
-#define SYS_SOCKETCALL 102 /* from zsysnum_linux_386.go */
-
-// func socketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (n int, errno 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 4(SP), BX // socket call number
- LEAL 8(SP), CX // pointer to call arguments
- MOVL $0, DX
- MOVL $0, SI
- MOVL $0, DI
- CALL *runtime·_vdso(SB)
- CMPL AX, $0xfffff001
- JLS oksock
- MOVL $-1, 32(SP) // n
- NEGL AX
- MOVL AX, 36(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
-oksock:
- MOVL AX, 32(SP) // n
- MOVL $0, 36(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
+ JMP syscall·socketcall(SB)
-// func rawsocketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (n int, errno int)
-// Kernel interface gets call sub-number and pointer to a0.
TEXT ·rawsocketcall(SB),NOSPLIT,$0-36
- MOVL $SYS_SOCKETCALL, AX // syscall entry
- MOVL 4(SP), BX // socket call number
- LEAL 8(SP), CX // pointer to call arguments
- MOVL $0, DX
- MOVL $0, SI
- MOVL $0, DI
- CALL *runtime·_vdso(SB)
- CMPL AX, $0xfffff001
- JLS oksock1
- MOVL $-1, 32(SP) // n
- NEGL AX
- MOVL AX, 36(SP) // errno
- RET
-oksock1:
- MOVL AX, 32(SP) // n
- MOVL $0, 36(SP) // errno
- RET
+ JMP syscall·rawsocketcall(SB)
-#define SYS__LLSEEK 140 /* from zsysnum_linux_386.go */
-// func Seek(fd int, offset int64, whence int) (newoffset int64, errno 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 4(SP), BX // fd
- MOVL 12(SP), CX // offset-high
- MOVL 8(SP), DX // offset-low
- LEAL 20(SP), SI // result pointer
- MOVL 16(SP), DI // whence
- CALL *runtime·_vdso(SB)
- CMPL AX, $0xfffff001
- JLS okseek
- MOVL $-1, 20(SP) // newoffset low
- MOVL $-1, 24(SP) // newoffset high
- NEGL AX
- MOVL AX, 28(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
-okseek:
- // system call filled in newoffset already
- MOVL $0, 28(SP) // errno
- CALL runtime·exitsyscall(SB)
- RET
+ JMP syscall·seek(SB)
