From 64e69d3925e2d1f3fb903a2b4f422cf1cbc49ec1 Mon Sep 17 00:00:00 2001 From: Michael Pratt Date: Thu, 24 Feb 2022 16:54:13 -0500 Subject: [PATCH] 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 Reviewed-by: Cherry Mui TryBot-Result: Gopher Robot --- src/runtime/proc.go | 2 +- src/syscall/asm_linux_386.s | 26 -------------------------- src/syscall/asm_linux_amd64.s | 27 --------------------------- src/syscall/asm_linux_arm.s | 30 ------------------------------ src/syscall/asm_linux_arm64.s | 27 --------------------------- src/syscall/asm_linux_mips64x.s | 25 ------------------------- src/syscall/asm_linux_mipsx.s | 23 ----------------------- src/syscall/asm_linux_ppc64x.s | 25 ------------------------- src/syscall/asm_linux_riscv64.s | 24 ------------------------ src/syscall/asm_linux_s390x.s | 26 -------------------------- src/syscall/syscall_linux.go | 23 ++++++++++++++++++++++- 11 files changed, 23 insertions(+), 235 deletions(-) diff --git a/src/runtime/proc.go b/src/runtime/proc.go index 4535f62053..b281d9f3b8 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -3658,7 +3658,7 @@ func reentersyscall(pc, sp uintptr) { // 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 546d27932d..ae0047b6fb 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 bd50b5ebfe..ea939b39f0 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(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(SB) - RET -ok: - MOVQ AX, r1+32(FP) - MOVQ DX, r2+40(FP) - MOVQ $0, err+48(FP) - 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_arm.s b/src/syscall/asm_linux_arm.s index 12986f801e..6f9a612fa1 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 fc1466cc80..c9d28d301a 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(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(SB) - RET -ok: - MOVD R0, r1+32(FP) // r1 - MOVD R1, r2+40(FP) // r2 - MOVD ZR, err+48(FP) // errno - BL runtime·exitsyscall(SB) - RET - TEXT ·Syscall6(SB),NOSPLIT,$0-80 BL runtime·entersyscall(SB) MOVD a1+8(FP), R0 diff --git a/src/syscall/asm_linux_mips64x.s b/src/syscall/asm_linux_mips64x.s index b6f293471d..994d7779fb 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 041c353e79..8c45861d64 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 b03d859ca2..d60e472226 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(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(SB) - RET -ok: - MOVD R3, r1+32(FP) // r1 - MOVD R0, r2+40(FP) // r2 - MOVD R0, err+48(FP) // errno - BL runtime·exitsyscall(SB) - RET - TEXT ·Syscall6(SB),NOSPLIT,$0-80 BL runtime·entersyscall(SB) MOVD a1+8(FP), R3 diff --git a/src/syscall/asm_linux_riscv64.s b/src/syscall/asm_linux_riscv64.s index f6b7d11c08..60b5cdbc1c 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 0a4913779a..14dabd85c2 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 a9a8ecbefd..57e4769731 100644 --- a/src/syscall/syscall_linux.go +++ b/src/syscall/syscall_linux.go @@ -16,7 +16,6 @@ import ( "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 Syscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) 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 @@ func RawSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) { 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) /* -- 2.48.1