diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index a8ae8a5..6a2c5cd 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go
@@ -13,7 +13,6 @@
 
 import (
 	"encoding/binary"
-	"runtime"
 	"syscall"
 	"unsafe"
 )
@@ -1820,11 +1819,7 @@
 //sys	Dup(oldfd int) (fd int, err error)
 
 func Dup2(oldfd, newfd int) error {
-	// Android O and newer blocks dup2; riscv and arm64 don't implement dup2.
-	if runtime.GOOS == "android" || runtime.GOARCH == "riscv64" || runtime.GOARCH == "arm64" {
-		return Dup3(oldfd, newfd, 0)
-	}
-	return dup2(oldfd, newfd)
+	return Dup3(oldfd, newfd, 0)
 }
 
 //sys	Dup3(oldfd int, newfd int, flags int) (err error)
diff --git a/unix/syscall_linux_386.go b/unix/syscall_linux_386.go
index 9ce9221..08b3f6a 100644
--- a/unix/syscall_linux_386.go
+++ b/unix/syscall_linux_386.go
@@ -21,7 +21,6 @@
 
 // 64-bit file system and 32-bit uid calls
 // (386 default is 32-bit file system and 16-bit uid).
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64_64
 //sys	Fchown(fd int, uid int, gid int) (err error) = SYS_FCHOWN32
diff --git a/unix/syscall_linux_amd64.go b/unix/syscall_linux_amd64.go
index f18b63a..dc31a15 100644
--- a/unix/syscall_linux_amd64.go
+++ b/unix/syscall_linux_amd64.go
@@ -7,7 +7,6 @@
 
 package unix
 
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
diff --git a/unix/syscall_linux_arm.go b/unix/syscall_linux_arm.go
index 7d1dbd3..1d136ba 100644
--- a/unix/syscall_linux_arm.go
+++ b/unix/syscall_linux_arm.go
@@ -46,7 +46,6 @@
 
 // 64-bit file system and 32-bit uid calls
 // (16-bit uid calls are not always supported in newer kernels)
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fchown(fd int, uid int, gid int) (err error) = SYS_FCHOWN32
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
diff --git a/unix/syscall_linux_arm64.go b/unix/syscall_linux_arm64.go
index 75b40a9..9c715dc 100644
--- a/unix/syscall_linux_arm64.go
+++ b/unix/syscall_linux_arm64.go
@@ -180,10 +180,6 @@
 	rsa.Service_name_len = uint64(length)
 }
 
-// dup2 exists because func Dup3 in syscall_linux.go references
-// it in an unreachable path. dup2 isn't available on arm64.
-func dup2(oldfd int, newfd int) error
-
 func Pause() error {
 	_, err := ppoll(nil, 0, nil, nil)
 	return err
diff --git a/unix/syscall_linux_mips64x.go b/unix/syscall_linux_mips64x.go
index 36b2752..d47ceaf 100644
--- a/unix/syscall_linux_mips64x.go
+++ b/unix/syscall_linux_mips64x.go
@@ -8,7 +8,6 @@
 
 package unix
 
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
diff --git a/unix/syscall_linux_mipsx.go b/unix/syscall_linux_mipsx.go
index d0b8b23..27ee4db 100644
--- a/unix/syscall_linux_mipsx.go
+++ b/unix/syscall_linux_mipsx.go
@@ -15,7 +15,6 @@
 
 func Syscall9(trap, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno)
 
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
diff --git a/unix/syscall_linux_ppc.go b/unix/syscall_linux_ppc.go
index c28fa34..299ba9d 100644
--- a/unix/syscall_linux_ppc.go
+++ b/unix/syscall_linux_ppc.go
@@ -12,7 +12,6 @@
 	"unsafe"
 )
 
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error) = SYS_FSTAT64
diff --git a/unix/syscall_linux_ppc64x.go b/unix/syscall_linux_ppc64x.go
index 2ba4aa7..0873b07 100644
--- a/unix/syscall_linux_ppc64x.go
+++ b/unix/syscall_linux_ppc64x.go
@@ -8,7 +8,6 @@
 
 package unix
 
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
diff --git a/unix/syscall_linux_riscv64.go b/unix/syscall_linux_riscv64.go
index 97468c5..e2c5b32 100644
--- a/unix/syscall_linux_riscv64.go
+++ b/unix/syscall_linux_riscv64.go
@@ -194,7 +194,3 @@
 	}
 	return kexecFileLoad(kernelFd, initrdFd, cmdlineLen, cmdline, flags)
 }
-
-// dup2 exists because func Dup3 in syscall_linux.go references
-// it in an unreachable path. dup2 isn't available on arm64.
-func dup2(oldfd int, newfd int) error
diff --git a/unix/syscall_linux_s390x.go b/unix/syscall_linux_s390x.go
index 3236fee..dfa204d 100644
--- a/unix/syscall_linux_s390x.go
+++ b/unix/syscall_linux_s390x.go
@@ -11,7 +11,6 @@
 	"unsafe"
 )
 
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
 //sys	Fchown(fd int, uid int, gid int) (err error)
diff --git a/unix/syscall_linux_sparc64.go b/unix/syscall_linux_sparc64.go
index 0544d96..4c54e09 100644
--- a/unix/syscall_linux_sparc64.go
+++ b/unix/syscall_linux_sparc64.go
@@ -9,7 +9,6 @@
 
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
-//sys	dup2(oldfd int, newfd int) (err error)
 //sys	Fchown(fd int, uid int, gid int) (err error)
 //sys	Fstat(fd int, stat *Stat_t) (err error)
 //sys	Fstatat(dirfd int, path string, stat *Stat_t, flags int) (err error) = SYS_FSTATAT64
diff --git a/unix/zsyscall_linux_386.go b/unix/zsyscall_linux_386.go
index f32cec9..7f3eccf 100644
--- a/unix/zsyscall_linux_386.go
+++ b/unix/zsyscall_linux_386.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_amd64.go b/unix/zsyscall_linux_amd64.go
index c9bf2fe..c1c9ac4 100644
--- a/unix/zsyscall_linux_amd64.go
+++ b/unix/zsyscall_linux_amd64.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_arm.go b/unix/zsyscall_linux_arm.go
index 39cca71..d89b8be 100644
--- a/unix/zsyscall_linux_arm.go
+++ b/unix/zsyscall_linux_arm.go
@@ -225,16 +225,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_mips.go b/unix/zsyscall_linux_mips.go
index 1bf9898..9e609dd 100644
--- a/unix/zsyscall_linux_mips.go
+++ b/unix/zsyscall_linux_mips.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_mips64.go b/unix/zsyscall_linux_mips64.go
index f7d253f..46b1d82 100644
--- a/unix/zsyscall_linux_mips64.go
+++ b/unix/zsyscall_linux_mips64.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_mips64le.go b/unix/zsyscall_linux_mips64le.go
index f5799bf..ab2f9db 100644
--- a/unix/zsyscall_linux_mips64le.go
+++ b/unix/zsyscall_linux_mips64le.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_mipsle.go b/unix/zsyscall_linux_mipsle.go
index 199e4ef..0d4a48b 100644
--- a/unix/zsyscall_linux_mipsle.go
+++ b/unix/zsyscall_linux_mipsle.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_ppc.go b/unix/zsyscall_linux_ppc.go
index daff312..078f1cc 100644
--- a/unix/zsyscall_linux_ppc.go
+++ b/unix/zsyscall_linux_ppc.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_ppc64.go b/unix/zsyscall_linux_ppc64.go
index aa164b2..791efbb 100644
--- a/unix/zsyscall_linux_ppc64.go
+++ b/unix/zsyscall_linux_ppc64.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_ppc64le.go b/unix/zsyscall_linux_ppc64le.go
index f289eac..dbc7621 100644
--- a/unix/zsyscall_linux_ppc64le.go
+++ b/unix/zsyscall_linux_ppc64le.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_s390x.go b/unix/zsyscall_linux_s390x.go
index d7bf4b1..8f65b2e 100644
--- a/unix/zsyscall_linux_s390x.go
+++ b/unix/zsyscall_linux_s390x.go
@@ -46,16 +46,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {
diff --git a/unix/zsyscall_linux_sparc64.go b/unix/zsyscall_linux_sparc64.go
index 8329e91..227f0f8 100644
--- a/unix/zsyscall_linux_sparc64.go
+++ b/unix/zsyscall_linux_sparc64.go
@@ -73,16 +73,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func dup2(oldfd int, newfd int) (err error) {
-	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fchown(fd int, uid int, gid int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHOWN, uintptr(fd), uintptr(uid), uintptr(gid))
 	if e1 != 0 {