syscall: define Syscall in terms of RawSyscall on linux
For #51087
Change-Id: I9de7e85ccf137ae73662759382334bcbe7208150
Reviewed-on: https://go-review.googlesource.com/c/go/+/388477
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index 4535f62..b281d9f 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -3658,7 +3658,7 @@
// Standard syscall entry used by the go syscall library and normal cgo calls.
//
-// This is exported via linkname to assembly in the syscall package.
+// This is exported via linkname to assembly in the syscall package and x/sys.
//
//go:nosplit
//go:linkname entersyscall
diff --git a/src/syscall/asm_linux_386.s b/src/syscall/asm_linux_386.s
index 546d279..ae0047b 100644
--- a/src/syscall/asm_linux_386.s
+++ b/src/syscall/asm_linux_386.s
@@ -13,32 +13,6 @@
// 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)
diff --git a/src/syscall/asm_linux_amd64.s b/src/syscall/asm_linux_amd64.s
index bd50b5e..ea939b3 100644
--- a/src/syscall/asm_linux_amd64.s
+++ b/src/syscall/asm_linux_amd64.s
@@ -11,33 +11,6 @@
#define SYS_gettimeofday 96
-// func Syscall(trap int64, a1, a2, a3 uintptr) (r1, r2, err uintptr);
-// Trap # in AX, args in DI SI DX R10 R8 R9, return in AX DX
-// Note that this differs from "standard" ABI convention, which
-// would pass 4th arg in CX, not R10.
-
-TEXT ·Syscall(SB),NOSPLIT,$0-56
- CALL runtime·entersyscall<ABIInternal>(SB)
- MOVQ a1+8(FP), DI
- MOVQ a2+16(FP), SI
- MOVQ a3+24(FP), DX
- MOVQ trap+0(FP), AX // syscall entry
- SYSCALL
- CMPQ AX, $0xfffffffffffff001
- JLS ok
- MOVQ $-1, r1+32(FP)
- MOVQ $0, r2+40(FP)
- NEGQ AX
- MOVQ AX, err+48(FP)
- CALL runtime·exitsyscall<ABIInternal>(SB)
- RET
-ok:
- MOVQ AX, r1+32(FP)
- MOVQ DX, r2+40(FP)
- MOVQ $0, err+48(FP)
- CALL runtime·exitsyscall<ABIInternal>(SB)
- RET
-
// func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr)
TEXT ·Syscall6(SB),NOSPLIT,$0-80
CALL runtime·entersyscall<ABIInternal>(SB)
diff --git a/src/syscall/asm_linux_arm.s b/src/syscall/asm_linux_arm.s
index 12986f8..6f9a612 100644
--- a/src/syscall/asm_linux_arm.s
+++ b/src/syscall/asm_linux_arm.s
@@ -9,36 +9,6 @@
// System calls for arm, Linux
//
-// func Syscall(syscall uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
-TEXT ·Syscall(SB),NOSPLIT,$0-28
- BL runtime·entersyscall(SB)
- MOVW trap+0(FP), R7
- MOVW a1+4(FP), R0
- MOVW a2+8(FP), R1
- MOVW a3+12(FP), R2
- MOVW $0, R3
- MOVW $0, R4
- MOVW $0, R5
- SWI $0
- MOVW $0xfffff001, R1
- CMP R1, R0
- BLS ok
- MOVW $-1, R1
- MOVW R1, r1+16(FP)
- MOVW $0, R2
- MOVW R2, r2+20(FP)
- RSB $0, R0, R0
- MOVW R0, err+24(FP)
- BL runtime·exitsyscall(SB)
- RET
-ok:
- MOVW R0, r1+16(FP)
- MOVW $0, R0
- MOVW R0, r2+20(FP)
- MOVW R0, err+24(FP)
- BL runtime·exitsyscall(SB)
- RET
-
// func Syscall6(trap uintptr, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
// Actually Syscall5 but the rest of the code expects it to be named Syscall6.
TEXT ·Syscall6(SB),NOSPLIT,$0-40
diff --git a/src/syscall/asm_linux_arm64.s b/src/syscall/asm_linux_arm64.s
index fc1466c..c9d28d3 100644
--- a/src/syscall/asm_linux_arm64.s
+++ b/src/syscall/asm_linux_arm64.s
@@ -4,33 +4,6 @@
#include "textflag.h"
-// func Syscall(trap int64, a1, a2, a3 int64) (r1, r2, err int64);
-TEXT ·Syscall(SB),NOSPLIT,$0-56
- BL runtime·entersyscall<ABIInternal>(SB)
- MOVD a1+8(FP), R0
- MOVD a2+16(FP), R1
- MOVD a3+24(FP), R2
- MOVD $0, R3
- MOVD $0, R4
- MOVD $0, R5
- MOVD trap+0(FP), R8 // syscall entry
- SVC
- CMN $4095, R0
- BCC ok
- MOVD $-1, R4
- MOVD R4, r1+32(FP) // r1
- MOVD ZR, r2+40(FP) // r2
- NEG R0, R0
- MOVD R0, err+48(FP) // errno
- BL runtime·exitsyscall<ABIInternal>(SB)
- RET
-ok:
- MOVD R0, r1+32(FP) // r1
- MOVD R1, r2+40(FP) // r2
- MOVD ZR, err+48(FP) // errno
- BL runtime·exitsyscall<ABIInternal>(SB)
- RET
-
TEXT ·Syscall6(SB),NOSPLIT,$0-80
BL runtime·entersyscall<ABIInternal>(SB)
MOVD a1+8(FP), R0
diff --git a/src/syscall/asm_linux_mips64x.s b/src/syscall/asm_linux_mips64x.s
index b6f2934..994d777 100644
--- a/src/syscall/asm_linux_mips64x.s
+++ b/src/syscall/asm_linux_mips64x.s
@@ -10,31 +10,6 @@
// System calls for mips64, Linux
//
-// func Syscall(trap int64, a1, a2, a3 int64) (r1, r2, err int64);
-TEXT ·Syscall(SB),NOSPLIT,$0-56
- JAL runtime·entersyscall(SB)
- MOVV a1+8(FP), R4
- MOVV a2+16(FP), R5
- MOVV a3+24(FP), R6
- MOVV R0, R7
- MOVV R0, R8
- MOVV R0, R9
- MOVV trap+0(FP), R2 // syscall entry
- SYSCALL
- BEQ R7, ok
- MOVV $-1, R1
- MOVV R1, r1+32(FP) // r1
- MOVV R0, r2+40(FP) // r2
- MOVV R2, err+48(FP) // errno
- JAL runtime·exitsyscall(SB)
- RET
-ok:
- MOVV R2, r1+32(FP) // r1
- MOVV R3, r2+40(FP) // r2
- MOVV R0, err+48(FP) // errno
- JAL runtime·exitsyscall(SB)
- RET
-
TEXT ·Syscall6(SB),NOSPLIT,$0-80
JAL runtime·entersyscall(SB)
MOVV a1+8(FP), R4
diff --git a/src/syscall/asm_linux_mipsx.s b/src/syscall/asm_linux_mipsx.s
index 041c353..8c45861 100644
--- a/src/syscall/asm_linux_mipsx.s
+++ b/src/syscall/asm_linux_mipsx.s
@@ -11,29 +11,6 @@
// System calls for mips, Linux
//
-// func Syscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
-TEXT ·Syscall(SB),NOSPLIT,$0-28
- JAL runtime·entersyscall(SB)
- MOVW a1+4(FP), R4
- MOVW a2+8(FP), R5
- MOVW a3+12(FP), R6
- MOVW R0, R7
- MOVW trap+0(FP), R2 // syscall entry
- SYSCALL
- BEQ R7, ok
- MOVW $-1, R1
- MOVW R1, r1+16(FP) // r1
- MOVW R0, r2+20(FP) // r2
- MOVW R2, err+24(FP) // errno
- JAL runtime·exitsyscall(SB)
- RET
-ok:
- MOVW R2, r1+16(FP) // r1
- MOVW R3, r2+20(FP) // r2
- MOVW R0, err+24(FP) // errno
- JAL runtime·exitsyscall(SB)
- RET
-
// func Syscall6(trap trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr);
// 5th and 6th arg go at sp+16, sp+20.
// Note that frame size of 20 means that 24 bytes gets reserved on stack.
diff --git a/src/syscall/asm_linux_ppc64x.s b/src/syscall/asm_linux_ppc64x.s
index b03d859..d60e472 100644
--- a/src/syscall/asm_linux_ppc64x.s
+++ b/src/syscall/asm_linux_ppc64x.s
@@ -10,31 +10,6 @@
// System calls for ppc64, Linux
//
-// func Syscall(trap int64, a1, a2, a3 int64) (r1, r2, err int64);
-TEXT ·Syscall(SB),NOSPLIT,$0-56
- BL runtime·entersyscall<ABIInternal>(SB)
- MOVD a1+8(FP), R3
- MOVD a2+16(FP), R4
- MOVD a3+24(FP), R5
- MOVD R0, R6
- MOVD R0, R7
- MOVD R0, R8
- MOVD trap+0(FP), R9 // syscall entry
- SYSCALL R9
- BVC ok
- MOVD $-1, R4
- MOVD R4, r1+32(FP) // r1
- MOVD R0, r2+40(FP) // r2
- MOVD R3, err+48(FP) // errno
- BL runtime·exitsyscall<ABIInternal>(SB)
- RET
-ok:
- MOVD R3, r1+32(FP) // r1
- MOVD R0, r2+40(FP) // r2
- MOVD R0, err+48(FP) // errno
- BL runtime·exitsyscall<ABIInternal>(SB)
- RET
-
TEXT ·Syscall6(SB),NOSPLIT,$0-80
BL runtime·entersyscall<ABIInternal>(SB)
MOVD a1+8(FP), R3
diff --git a/src/syscall/asm_linux_riscv64.s b/src/syscall/asm_linux_riscv64.s
index f6b7d11..60b5cdb 100644
--- a/src/syscall/asm_linux_riscv64.s
+++ b/src/syscall/asm_linux_riscv64.s
@@ -8,30 +8,6 @@
// System calls for riscv64, Linux
//
-// func Syscall(trap int64, a1, a2, a3 int64) (r1, r2, err int64)
-TEXT ·Syscall(SB),NOSPLIT,$0-56
- CALL runtime·entersyscall(SB)
- MOV a1+8(FP), A0
- MOV a2+16(FP), A1
- MOV a3+24(FP), A2
- MOV trap+0(FP), A7 // syscall entry
- ECALL
- MOV $-4096, T0
- BLTU T0, A0, err
- MOV A0, r1+32(FP) // r1
- MOV A1, r2+40(FP) // r2
- MOV ZERO, err+48(FP) // errno
- CALL runtime·exitsyscall(SB)
- RET
-err:
- MOV $-1, T0
- MOV T0, r1+32(FP) // r1
- MOV ZERO, r2+40(FP) // r2
- SUB A0, ZERO, A0
- MOV A0, err+48(FP) // errno
- CALL runtime·exitsyscall(SB)
- RET
-
// func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr)
TEXT ·Syscall6(SB),NOSPLIT,$0-80
CALL runtime·entersyscall(SB)
diff --git a/src/syscall/asm_linux_s390x.s b/src/syscall/asm_linux_s390x.s
index 0a49137..14dabd8 100644
--- a/src/syscall/asm_linux_s390x.s
+++ b/src/syscall/asm_linux_s390x.s
@@ -8,32 +8,6 @@
// System calls for s390x, Linux
//
-// func Syscall(trap int64, a1, a2, a3 int64) (r1, r2, err int64)
-TEXT ·Syscall(SB),NOSPLIT,$0-56
- BL runtime·entersyscall(SB)
- MOVD a1+8(FP), R2
- MOVD a2+16(FP), R3
- MOVD a3+24(FP), R4
- MOVD $0, R5
- MOVD $0, R6
- MOVD $0, R7
- MOVD trap+0(FP), R1 // syscall entry
- SYSCALL
- MOVD $0xfffffffffffff001, R8
- CMPUBLT R2, R8, ok
- MOVD $-1, r1+32(FP)
- MOVD $0, r2+40(FP)
- NEG R2, R2
- MOVD R2, err+48(FP) // errno
- BL runtime·exitsyscall(SB)
- RET
-ok:
- MOVD R2, r1+32(FP)
- MOVD R3, r2+40(FP)
- MOVD $0, err+48(FP) // errno
- BL runtime·exitsyscall(SB)
- RET
-
// func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, err uintptr)
TEXT ·Syscall6(SB),NOSPLIT,$0-80
BL runtime·entersyscall(SB)
diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go
index a9a8ecb..57e4769 100644
--- a/src/syscall/syscall_linux.go
+++ b/src/syscall/syscall_linux.go
@@ -16,7 +16,6 @@
"unsafe"
)
-func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
func Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
// N.B. RawSyscall6 is provided via linkname by runtime/internal/syscall.
@@ -26,6 +25,18 @@
func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
+// Pull in entersyscall/exitsyscall for Syscall/Syscall6.
+//
+// Note that this can't be a push linkname because the runtime already has a
+// nameless linkname to export to assembly here and in x/sys. Additionally,
+// entersyscall fetches the caller PC and SP and thus can't have a wrapper
+// inbetween.
+
+//go:linkname runtime_entersyscall runtime.entersyscall
+func runtime_entersyscall()
+//go:linkname runtime_exitsyscall runtime.exitsyscall
+func runtime_exitsyscall()
+
// N.B. For the Syscall functions below:
//
// //go:uintptrkeepalive because the uintptr argument may be converted pointers
@@ -47,6 +58,16 @@
return RawSyscall6(trap, a1, a2, a3, 0, 0, 0)
}
+//go:uintptrkeepalive
+//go:nosplit
+//go:linkname Syscall
+func Syscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) {
+ runtime_entersyscall()
+ r1, r2, err = RawSyscall(trap, a1, a2, a3)
+ runtime_exitsyscall()
+ return
+}
+
func rawSyscallNoError(trap, a1, a2, a3 uintptr) (r1, r2 uintptr)
/*
