diff --git a/src/runtime/cgo/gcc_mmap.c b/src/runtime/cgo/gcc_mmap.c
index eb710a039d4e05..47f326140509c7 100644
--- a/src/runtime/cgo/gcc_mmap.c
+++ b/src/runtime/cgo/gcc_mmap.c
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && (amd64 || arm64 || loong64 || ppc64le)) || (freebsd && amd64)
+//go:build (linux && (amd64 || arm64 || loong64 || ppc64le || riscv64)) || (freebsd && amd64)
 
 #include <errno.h>
 #include <stdint.h>
diff --git a/src/runtime/cgo/gcc_sigaction.c b/src/runtime/cgo/gcc_sigaction.c
index f7a10df0f72449..300fdffd6a7cc0 100644
--- a/src/runtime/cgo/gcc_sigaction.c
+++ b/src/runtime/cgo/gcc_sigaction.c
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && (386 || amd64 || arm64 || loong64 || ppc64 || ppc64le)
+//go:build linux && (386 || amd64 || arm64 || loong64 || ppc64 || ppc64le || riscv64)
 
 #include <errno.h>
 #include <stddef.h>
@@ -18,7 +18,7 @@
 typedef struct {
 	uintptr_t handler;
 	unsigned long flags;
-#ifdef __loongarch__
+#if defined(__loongarch__) || defined(__riscv)
 	uint64_t mask;
 	uintptr_t restorer;
 #else
diff --git a/src/runtime/cgo/mmap.go b/src/runtime/cgo/mmap.go
index 144af2b2caf826..a9973b41dc2d99 100644
--- a/src/runtime/cgo/mmap.go
+++ b/src/runtime/cgo/mmap.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && (amd64 || arm64 || loong64)) || (freebsd && amd64)
+//go:build (linux && (amd64 || arm64 || loong64 || riscv64)) || (freebsd && amd64)
 
 package cgo
 
diff --git a/src/runtime/cgo/sigaction.go b/src/runtime/cgo/sigaction.go
index 62b144dbd45110..11345f1e37e09f 100644
--- a/src/runtime/cgo/sigaction.go
+++ b/src/runtime/cgo/sigaction.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && (386 || amd64 || arm64 || loong64 || ppc64 || ppc64le)) || (freebsd && amd64)
+//go:build (linux && (386 || amd64 || arm64 || loong64 || ppc64 || ppc64le || riscv64)) || (freebsd && amd64)
 
 package cgo
 
diff --git a/src/runtime/cgo_mmap.go b/src/runtime/cgo_mmap.go
index 36d776e628143e..6ad4e6abbe577c 100644
--- a/src/runtime/cgo_mmap.go
+++ b/src/runtime/cgo_mmap.go
@@ -4,7 +4,7 @@
 
 // Support for memory sanitizer. See runtime/cgo/mmap.go.
 
-//go:build (linux && (amd64 || arm64 || loong64)) || (freebsd && amd64)
+//go:build (linux && (amd64 || arm64 || loong64 || riscv64)) || (freebsd && amd64)
 
 package runtime
 
diff --git a/src/runtime/cgo_sigaction.go b/src/runtime/cgo_sigaction.go
index b78a336a214755..d697f05bc99b08 100644
--- a/src/runtime/cgo_sigaction.go
+++ b/src/runtime/cgo_sigaction.go
@@ -6,7 +6,7 @@
 // Also used on linux/386 to clear the SA_RESTORER flag
 // when using cgo; see issue #75253.
 
-//go:build (linux && (386 || amd64 || arm64 || loong64 || ppc64 || ppc64le)) || (freebsd && amd64)
+//go:build (linux && (386 || amd64 || arm64 || loong64 || ppc64 || ppc64le || riscv64)) || (freebsd && amd64)
 
 package runtime
 
diff --git a/src/runtime/mmap.go b/src/runtime/mmap.go
index 9a7b2985623d68..61568529e81c28 100644
--- a/src/runtime/mmap.go
+++ b/src/runtime/mmap.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !aix && !darwin && !js && !((linux && (amd64 || arm64 || loong64)) || (freebsd && amd64)) && !openbsd && !plan9 && !solaris && !windows
+//go:build !aix && !darwin && !js && !((linux && (amd64 || arm64 || loong64 || riscv64)) || (freebsd && amd64)) && !openbsd && !plan9 && !solaris && !windows
 
 package runtime
 
diff --git a/src/runtime/sigaction.go b/src/runtime/sigaction.go
index 79497763546639..898be53dbf8a44 100644
--- a/src/runtime/sigaction.go
+++ b/src/runtime/sigaction.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && !386 && !amd64 && !arm64 && !loong64 && !ppc64 && !ppc64le) || (freebsd && !amd64)
+//go:build (linux && !386 && !amd64 && !arm64 && !loong64 && !ppc64 && !ppc64le && !riscv64) || (freebsd && !amd64)
 
 package runtime
 
diff --git a/src/runtime/sys_linux_riscv64.s b/src/runtime/sys_linux_riscv64.s
index 72534f4128689c..313952b23d0cd8 100644
--- a/src/runtime/sys_linux_riscv64.s
+++ b/src/runtime/sys_linux_riscv64.s
@@ -396,31 +396,28 @@ TEXT runtime·cgoSigtramp(SB),NOSPLIT,$0
 	MOV	$runtime·sigtramp(SB), T1
 	JALR	ZERO, T1
 
+// func callCgoSigaction(sig uintptr, new, old *sigactiont) int32
+TEXT runtime·callCgoSigaction<ABIInternal>(SB),NOSPLIT,$0
+	MOV	_cgo_sigaction(SB), A7
+	JALR	X1, A7
+	MOV	X10, X10 // return value from C, NOP OP
+	RET
+
 // func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) (p unsafe.Pointer, err int)
-TEXT runtime·mmap(SB),NOSPLIT|NOFRAME,$0
-	MOV	addr+0(FP), A0
-	MOV	n+8(FP), A1
-	MOVW	prot+16(FP), A2
-	MOVW	flags+20(FP), A3
-	MOVW	fd+24(FP), A4
-	MOVW	off+28(FP), A5
+TEXT runtime·sysMmap<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
 	MOV	$SYS_mmap, A7
 	ECALL
 	MOV	$-4096, T0
-	BGEU	T0, A0, 5(PC)
-	SUB	A0, ZERO, A0
-	MOV	ZERO, p+32(FP)
-	MOV	A0, err+40(FP)
+	BGEU	T0, A0, ok
+	SUB	A0, ZERO, A1
+	MOV	ZERO, A0
 	RET
 ok:
-	MOV	A0, p+32(FP)
-	MOV	ZERO, err+40(FP)
+	MOV	ZERO, A1
 	RET
 
 // func munmap(addr unsafe.Pointer, n uintptr)
-TEXT runtime·munmap(SB),NOSPLIT|NOFRAME,$0
-	MOV	addr+0(FP), A0
-	MOV	n+8(FP), A1
+TEXT runtime·sysMunmap<ABIInternal>(SB),NOSPLIT|NOFRAME,$0
 	MOV	$SYS_munmap, A7
 	ECALL
 	MOV	$-4096, T0
@@ -428,6 +425,19 @@ TEXT runtime·munmap(SB),NOSPLIT|NOFRAME,$0
 	WORD	$0	// crash
 	RET
 
+// func callCgoMmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) uintptr
+TEXT runtime·callCgoMmap<ABIInternal>(SB),NOSPLIT,$0
+	MOV	_cgo_mmap(SB), A7
+	JALR	X1, A7
+	MOV	X10, X10 // return value from C, NOP OP
+	RET
+
+// func callCgoMunmap(addr unsafe.Pointer, n uintptr)
+TEXT runtime·callCgoMunmap<ABIInternal>(SB),NOSPLIT,$0
+	MOV	_cgo_munmap(SB), A7
+	JALR	X1, A7
+	RET
+
 // func madvise(addr unsafe.Pointer, n uintptr, flags int32)
 TEXT runtime·madvise<ABIInternal>(SB),NOSPLIT,$0
 	MOV	$SYS_madvise, A7