syscall: define RawSyscall in terms of RawSyscall6 on linux
For #51087
Change-Id: I63e07638507328efe33dbf7dd5f8a8b78890e037
Reviewed-on: https://go-review.googlesource.com/c/go/+/388476
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/syscall/asm_linux_386.s b/src/syscall/asm_linux_386.s
index a2b5efb..546d279 100644
--- a/src/syscall/asm_linux_386.s
+++ b/src/syscall/asm_linux_386.s
@@ -65,28 +65,6 @@
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 rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-16
MOVL trap+0(FP), AX // syscall entry
diff --git a/src/syscall/asm_linux_amd64.s b/src/syscall/asm_linux_amd64.s
index a981259..bd50b5e 100644
--- a/src/syscall/asm_linux_amd64.s
+++ b/src/syscall/asm_linux_amd64.s
@@ -64,26 +64,6 @@
CALL runtime·exitsyscall<ABIInternal>(SB)
RET
-// func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr)
-TEXT ·RawSyscall(SB),NOSPLIT,$0-56
- 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 ok1
- MOVQ $-1, r1+32(FP)
- MOVQ $0, r2+40(FP)
- NEGQ AX
- MOVQ AX, err+48(FP)
- RET
-ok1:
- MOVQ AX, r1+32(FP)
- MOVQ DX, r2+40(FP)
- MOVQ $0, err+48(FP)
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-32
MOVQ a1+8(FP), DI
diff --git a/src/syscall/asm_linux_arm.s b/src/syscall/asm_linux_arm.s
index 5010317..12986f8 100644
--- a/src/syscall/asm_linux_arm.s
+++ b/src/syscall/asm_linux_arm.s
@@ -102,30 +102,6 @@
BL runtime·exitsyscall(SB)
RET
-// func RawSyscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr);
-TEXT ·RawSyscall(SB),NOSPLIT,$0-28
- MOVW trap+0(FP), R7 // syscall entry
- MOVW a1+4(FP), R0
- MOVW a2+8(FP), R1
- MOVW a3+12(FP), R2
- SWI $0
- MOVW $0xfffff001, R1
- CMP R1, R0
- BLS ok1
- 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)
- RET
-ok1:
- MOVW R0, r1+16(FP)
- MOVW $0, R0
- MOVW R0, r2+20(FP)
- MOVW R0, err+24(FP)
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-16
MOVW trap+0(FP), R7 // syscall entry
diff --git a/src/syscall/asm_linux_arm64.s b/src/syscall/asm_linux_arm64.s
index c9c6bfa..fc1466c 100644
--- a/src/syscall/asm_linux_arm64.s
+++ b/src/syscall/asm_linux_arm64.s
@@ -57,29 +57,6 @@
BL runtime·exitsyscall<ABIInternal>(SB)
RET
-TEXT ·RawSyscall(SB),NOSPLIT,$0-56
- 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
- RET
-ok:
- MOVD R0, r1+32(FP) // r1
- MOVD R1, r2+40(FP) // r2
- MOVD ZR, err+48(FP) // errno
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT,$0-32
MOVD a1+8(FP), R0
diff --git a/src/syscall/asm_linux_mips64x.s b/src/syscall/asm_linux_mips64x.s
index bc2f72c..b6f2934 100644
--- a/src/syscall/asm_linux_mips64x.s
+++ b/src/syscall/asm_linux_mips64x.s
@@ -59,27 +59,6 @@
JAL runtime·exitsyscall(SB)
RET
-TEXT ·RawSyscall(SB),NOSPLIT,$0-56
- 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, ok1
- MOVV $-1, R1
- MOVV R1, r1+32(FP) // r1
- MOVV R0, r2+40(FP) // r2
- MOVV R2, err+48(FP) // errno
- RET
-ok1:
- MOVV R2, r1+32(FP) // r1
- MOVV R3, r2+40(FP) // r2
- MOVV R0, err+48(FP) // errno
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-32
MOVV a1+8(FP), R4
diff --git a/src/syscall/asm_linux_mipsx.s b/src/syscall/asm_linux_mipsx.s
index 04fad40..041c353 100644
--- a/src/syscall/asm_linux_mipsx.s
+++ b/src/syscall/asm_linux_mipsx.s
@@ -97,24 +97,6 @@
JAL runtime·exitsyscall(SB)
RET
-TEXT ·RawSyscall(SB),NOSPLIT,$24-28
- MOVW a1+4(FP), R4
- MOVW a2+8(FP), R5
- MOVW a3+12(FP), R6
- MOVW trap+0(FP), R2 // syscall entry
- SYSCALL
- BEQ R7, ok1
- MOVW $-1, R1
- MOVW R1, r1+16(FP) // r1
- MOVW R0, r2+20(FP) // r2
- MOVW R2, err+24(FP) // errno
- RET
-ok1:
- MOVW R2, r1+16(FP) // r1
- MOVW R3, r2+20(FP) // r2
- MOVW R0, err+24(FP) // errno
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-16
MOVW a1+4(FP), R4
diff --git a/src/syscall/asm_linux_ppc64x.s b/src/syscall/asm_linux_ppc64x.s
index 4c9c383..b03d859 100644
--- a/src/syscall/asm_linux_ppc64x.s
+++ b/src/syscall/asm_linux_ppc64x.s
@@ -59,27 +59,6 @@
BL runtime·exitsyscall<ABIInternal>(SB)
RET
-TEXT ·RawSyscall(SB),NOSPLIT,$0-56
- 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 ok1
- MOVD $-1, R4
- MOVD R4, r1+32(FP) // r1
- MOVD R0, r2+40(FP) // r2
- MOVD R3, err+48(FP) // errno
- RET
-ok1:
- MOVD R3, r1+32(FP) // r1
- MOVD R0, r2+40(FP) // r2
- MOVD R0, err+48(FP) // errno
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-32
MOVD a1+8(FP), R3
diff --git a/src/syscall/asm_linux_riscv64.s b/src/syscall/asm_linux_riscv64.s
index c7e1003..f6b7d11 100644
--- a/src/syscall/asm_linux_riscv64.s
+++ b/src/syscall/asm_linux_riscv64.s
@@ -59,27 +59,6 @@
CALL runtime·exitsyscall(SB)
RET
-// func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr)
-TEXT ·RawSyscall(SB),NOSPLIT,$0-56
- 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
- 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
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-32
MOV a1+8(FP), A0
diff --git a/src/syscall/asm_linux_s390x.s b/src/syscall/asm_linux_s390x.s
index 3fbda38..0a49137 100644
--- a/src/syscall/asm_linux_s390x.s
+++ b/src/syscall/asm_linux_s390x.s
@@ -60,29 +60,6 @@
BL runtime·exitsyscall(SB)
RET
-// func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2, err uintptr)
-TEXT ·RawSyscall(SB),NOSPLIT,$0-56
- 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, ok1
- MOVD $-1, r1+32(FP)
- MOVD $0, r2+40(FP)
- NEG R2, R2
- MOVD R2, err+48(FP) // errno
- RET
-ok1:
- MOVD R2, r1+32(FP)
- MOVD R3, r2+40(FP)
- MOVD $0, err+48(FP) // errno
- RET
-
// func rawVforkSyscall(trap, a1 uintptr) (r1, err uintptr)
TEXT ·rawVforkSyscall(SB),NOSPLIT|NOFRAME,$0-32
MOVD $0, R2
diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go
index b0e2cdb..a9a8ecb 100644
--- a/src/syscall/syscall_linux.go
+++ b/src/syscall/syscall_linux.go
@@ -18,7 +18,6 @@
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)
-func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno)
// N.B. RawSyscall6 is provided via linkname by runtime/internal/syscall.
//
@@ -27,6 +26,27 @@
func RawSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno)
+// N.B. For the Syscall functions below:
+//
+// //go:uintptrkeepalive because the uintptr argument may be converted pointers
+// that need to be kept alive in the caller (this is implied for RawSyscall6
+// since it has no body).
+//
+// //go:nosplit because stack copying does not account for uintptrkeepalive, so
+// the stack must not grow. Stack copying cannot blindly assume that all
+// uintptr arguments are pointers, because some values may look like pointers,
+// but not really be pointers, and adjusting their value would break the call.
+//
+// //go:linkname to ensure ABI wrappers are generated for external callers
+// (notably x/sys/unix assembly).
+
+//go:uintptrkeepalive
+//go:nosplit
+//go:linkname RawSyscall
+func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) {
+ return RawSyscall6(trap, a1, a2, a3, 0, 0, 0)
+}
+
func rawSyscallNoError(trap, a1, a2, a3 uintptr) (r1, r2 uintptr)
/*
