libgo: update to Go1.18beta2

gotools/
	* Makefile.am (go_cmd_cgo_files): Add ast_go118.go
	(check-go-tool): Copy golang.org/x/tools directories.
	* Makefile.in: Regenerate.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/384695

51 files changed, 728 insertions, 336 deletions

diff --git a/libgo/go/syscall/asan0.go b/libgo/go/syscall/asan0.go
new file mode 100644
index 0000000..08bc44d
--- /dev/null
+++ b/libgo/go/syscall/asan0.go
@@ -0,0 +1,19 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !asan
+
+package syscall
+
+import (
+	"unsafe"
+)
+
+const asanenabled = false
+
+func asanRead(addr unsafe.Pointer, len int) {
+}
+
+func asanWrite(addr unsafe.Pointer, len int) {
+}
diff --git a/libgo/go/syscall/bpf_bsd.go b/libgo/go/syscall/bpf_bsd.go
index 452d4cf..735c078 100644
--- a/libgo/go/syscall/bpf_bsd.go
+++ b/libgo/go/syscall/bpf_bsd.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build dragonfly || freebsd || netbsd || openbsd
-// +build dragonfly freebsd netbsd openbsd
 
 // Berkeley packet filter for BSD variants
 
diff --git a/libgo/go/syscall/creds_test.go b/libgo/go/syscall/creds_test.go
index c1a8b51..1ee56fc 100644
--- a/libgo/go/syscall/creds_test.go
+++ b/libgo/go/syscall/creds_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build linux
-// +build linux
 
 package syscall_test
 
diff --git a/libgo/go/syscall/dirent.go b/libgo/go/syscall/dirent.go
index 1e95946..504b9fb 100644
--- a/libgo/go/syscall/dirent.go
+++ b/libgo/go/syscall/dirent.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || (js && wasm) || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd hurd js,wasm linux netbsd openbsd solaris
 
 package syscall
 
diff --git a/libgo/go/syscall/dirent_test.go b/libgo/go/syscall/dirent_test.go
index 71b445b..aeb40e5 100644
--- a/libgo/go/syscall/dirent_test.go
+++ b/libgo/go/syscall/dirent_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
 
 package syscall_test
 
@@ -23,7 +22,7 @@ import (
 
 func TestDirent(t *testing.T) {
 	const (
-		direntBufSize   = 2048
+		direntBufSize   = 2048 // arbitrary? See https://go.dev/issue/37323.
 		filenameMinSize = 11
 	)
 
@@ -38,23 +37,38 @@ func TestDirent(t *testing.T) {
 		}
 	}
 
-	buf := bytes.Repeat([]byte("DEADBEAF"), direntBufSize/8)
+	names := make([]string, 0, 10)
+
 	fd, err := syscall.Open(d, syscall.O_RDONLY, 0)
 	if err != nil {
 		t.Fatalf("syscall.open: %v", err)
 	}
 	defer syscall.Close(fd)
-	n, err := syscall.ReadDirent(fd, buf)
-	if err != nil {
-		t.Fatalf("syscall.readdir: %v", err)
-	}
-	buf = buf[:n]
 
-	names := make([]string, 0, 10)
-	for len(buf) > 0 {
-		var bc int
-		bc, _, names = syscall.ParseDirent(buf, -1, names)
-		buf = buf[bc:]
+	buf := bytes.Repeat([]byte{0xCD}, direntBufSize)
+	for {
+		n, err := syscall.ReadDirent(fd, buf)
+		if err == syscall.EINVAL {
+			// On linux, 'man getdents64' says that EINVAL indicates “result buffer is too small”.
+			// Try a bigger buffer.
+			t.Logf("ReadDirent: %v; retrying with larger buffer", err)
+			buf = bytes.Repeat([]byte{0xCD}, len(buf)*2)
+			continue
+		}
+		if err != nil {
+			t.Fatalf("syscall.readdir: %v", err)
+		}
+		t.Logf("ReadDirent: read %d bytes", n)
+		if n == 0 {
+			break
+		}
+
+		var consumed, count int
+		consumed, count, names = syscall.ParseDirent(buf[:n], -1, names)
+		t.Logf("ParseDirent: %d new name(s)", count)
+		if consumed != n {
+			t.Fatalf("ParseDirent: consumed %d bytes; expected %d", consumed, n)
+		}
 	}
 
 	sort.Strings(names)
diff --git a/libgo/go/syscall/endian_big.go b/libgo/go/syscall/endian_big.go
index a38e9c6..e6b1163 100644
--- a/libgo/go/syscall/endian_big.go
+++ b/libgo/go/syscall/endian_big.go
@@ -1,9 +1,8 @@
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
-//
+
 //go:build ppc64 || s390x || mips || mips64 || armbe || arm64be || m68k || ppc || mips64p32 || s390 || shbe || sparc || sparc64
-// +build ppc64 s390x mips mips64 armbe arm64be m68k ppc mips64p32 s390 shbe sparc sparc64
 
 package syscall
 
diff --git a/libgo/go/syscall/endian_little.go b/libgo/go/syscall/endian_little.go
index 2332fa3..63e46d8 100644
--- a/libgo/go/syscall/endian_little.go
+++ b/libgo/go/syscall/endian_little.go
@@ -1,9 +1,8 @@
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
-//
+
 //go:build 386 || alpha || amd64 || amd64p32 || arm || arm64 || ia64 || ppc64le || mips64le || mipsle || mips64p32le || nios2 || riscv || riscv64 || sh || wasm
-// +build 386 alpha amd64 amd64p32 arm arm64 ia64 ppc64le mips64le mipsle mips64p32le nios2 riscv riscv64 sh wasm
 
 package syscall
 
diff --git a/libgo/go/syscall/env_unix.go b/libgo/go/syscall/env_unix.go
index 0d95c55..8d82d58 100644
--- a/libgo/go/syscall/env_unix.go
+++ b/libgo/go/syscall/env_unix.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || (js && wasm) || linux || netbsd || openbsd || solaris || plan9
-// +build aix darwin dragonfly freebsd hurd js,wasm linux netbsd openbsd solaris plan9
 
 // Unix environment variables.
 
diff --git a/libgo/go/syscall/exec_bsd.go b/libgo/go/syscall/exec_bsd.go
index ad65f63..c05ae13 100644
--- a/libgo/go/syscall/exec_bsd.go
+++ b/libgo/go/syscall/exec_bsd.go
@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build aix || darwin || dragonfly || freebsd || hurd || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd hurd netbsd openbsd solaris
+//go:build aix || darwin || dragonfly || hurd || netbsd || openbsd || solaris
 
 package syscall
 
 import (
+	"runtime"
 	"unsafe"
 )
 
@@ -152,12 +152,7 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr
 			groups = &gids[0]
 		}
 		if !cred.NoSetGroups {
-			err2 := setgroups(ngroups, groups)
-			if err2 == nil {
-				err1 = 0
-			} else {
-				err1 = err2.(Errno)
-			}
+			err1 = raw_setgroups(ngroups, groups)
 			if err1 != 0 {
 				goto childerror
 			}
@@ -185,11 +180,19 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr
 	// Pass 1: look for fd[i] < i and move those up above len(fd)
 	// so that pass 2 won't stomp on an fd it needs later.
 	if pipe < nextfd {
-		err1 = raw_dup2(pipe, nextfd)
-		if err1 != 0 {
-			goto childerror
+		switch runtime.GOOS {
+		case "netbsd":
+			err1 = raw_dup3(pipe, nextfd, O_CLOEXEC)
+			if err1 != 0 {
+				goto childerror
+			}
+		default:
+			err1 = raw_dup2(pipe, nextfd)
+			if err1 != 0 {
+				goto childerror
+			}
+			raw_fcntl(nextfd, F_SETFD, FD_CLOEXEC)
 		}
-		raw_fcntl(nextfd, F_SETFD, FD_CLOEXEC)
 		pipe = nextfd
 		nextfd++
 	}
@@ -198,11 +201,19 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr
 			if nextfd == pipe { // don't stomp on pipe
 				nextfd++
 			}
-			err1 = raw_dup2(fd[i], nextfd)
-			if err1 != 0 {
-				goto childerror
+			switch runtime.GOOS {
+			case "netbsd":
+				err1 = raw_dup3(fd[i], nextfd, O_CLOEXEC)
+				if err1 != 0 {
+					goto childerror
+				}
+			default:
+				err1 = raw_dup2(fd[i], nextfd)
+				if err1 != 0 {
+					goto childerror
+				}
+				raw_fcntl(nextfd, F_SETFD, FD_CLOEXEC)
 			}
-			raw_fcntl(nextfd, F_SETFD, FD_CLOEXEC)
 			fd[i] = nextfd
 			nextfd++
 		}
diff --git a/libgo/go/syscall/exec_freebsd.go b/libgo/go/syscall/exec_freebsd.go
new file mode 100644
index 0000000..f02f89d
--- /dev/null
+++ b/libgo/go/syscall/exec_freebsd.go
@@ -0,0 +1,294 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package syscall
+
+import (
+	"runtime"
+	"unsafe"
+)
+
+//sysnb	raw_procctl(idtype int, id int64, cmd int, data unsafe.Pointer) (ret int, err Errno)
+//procctl(idtype _C_int, id int64, cmd int, data unsafe.Pointer) _C_int
+
+type SysProcAttr struct {
+	Chroot     string      // Chroot.
+	Credential *Credential // Credential.
+	Ptrace     bool        // Enable tracing.
+	Setsid     bool        // Create session.
+	// Setpgid sets the process group ID of the child to Pgid,
+	// or, if Pgid == 0, to the new child's process ID.
+	Setpgid bool
+	// Setctty sets the controlling terminal of the child to
+	// file descriptor Ctty. Ctty must be a descriptor number
+	// in the child process: an index into ProcAttr.Files.
+	// This is only meaningful if Setsid is true.
+	Setctty bool
+	Noctty  bool // Detach fd 0 from controlling terminal
+	Ctty    int  // Controlling TTY fd
+	// Foreground places the child process group in the foreground.
+	// This implies Setpgid. The Ctty field must be set to
+	// the descriptor of the controlling TTY.
+	// Unlike Setctty, in this case Ctty must be a descriptor
+	// number in the parent process.
+	Foreground bool
+	Pgid       int    // Child's process group ID if Setpgid.
+	Pdeathsig  Signal // Signal that the process will get when its parent dies (Linux and FreeBSD only)
+}
+
+const (
+	_P_PID = 0
+
+	_PROC_PDEATHSIG_CTL = 11
+)
+
+// Implemented in runtime package.
+func runtime_BeforeFork()
+func runtime_AfterFork()
+func runtime_AfterForkInChild()
+
+// Fork, dup fd onto 0..len(fd), and exec(argv0, argvv, envv) in child.
+// If a dup or exec fails, write the errno error to pipe.
+// (Pipe is close-on-exec so if exec succeeds, it will be closed.)
+// In the child, this function must not acquire any locks, because
+// they might have been locked at the time of the fork. This means
+// no rescheduling, no malloc calls, and no new stack segments.
+// For the same reason compiler does not race instrument it.
+// The calls to RawSyscall are okay because they are assembly
+// functions that do not grow the stack.
+//go:norace
+func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr *ProcAttr, sys *SysProcAttr, pipe int) (pid int, err Errno) {
+	// Declare all variables at top in case any
+	// declarations require heap allocation (e.g., err1).
+	var (
+		r1     Pid_t
+		err1   Errno
+		nextfd int
+		i      int
+	)
+
+	// Record parent PID so child can test if it has died.
+	ppid := raw_getpid()
+
+	// guard against side effects of shuffling fds below.
+	// Make sure that nextfd is beyond any currently open files so
+	// that we can't run the risk of overwriting any of them.
+	fd := make([]int, len(attr.Files))
+	nextfd = len(attr.Files)
+	for i, ufd := range attr.Files {
+		if nextfd < int(ufd) {
+			nextfd = int(ufd)
+		}
+		fd[i] = int(ufd)
+	}
+	nextfd++
+
+	// About to call fork.
+	// No more allocation or calls of non-assembly functions.
+	runtime_BeforeFork()
+	r1, err1 = raw_fork()
+	if err1 != 0 {
+		runtime_AfterFork()
+		return 0, err1
+	}
+
+	if r1 != 0 {
+		// parent; return PID
+		runtime_AfterFork()
+		return int(r1), 0
+	}
+
+	// Fork succeeded, now in child.
+
+	// Enable tracing if requested.
+	if sys.Ptrace {
+		err1 = raw_ptrace(_PTRACE_TRACEME, 0, 0, 0)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// Session ID
+	if sys.Setsid {
+		err1 = raw_setsid()
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// Set process group
+	if sys.Setpgid || sys.Foreground {
+		// Place child in process group.
+		err1 = raw_setpgid(0, sys.Pgid)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	if sys.Foreground {
+		pgrp := Pid_t(sys.Pgid)
+		if pgrp == 0 {
+			pgrp = raw_getpid()
+		}
+
+		// Place process group in foreground.
+		err1 = raw_ioctl(sys.Ctty, TIOCSPGRP, unsafe.Pointner(&pgrp))
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// Restore the signal mask. We do this after TIOCSPGRP to avoid
+	// having the kernel send a SIGTTOU signal to the process group.
+	runtime_AfterForkInChild()
+
+	// Chroot
+	if chroot != nil {
+		err1 = raw_chroot(chroot)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// User and groups
+	if cred := sys.Credential; cred != nil {
+		ngroups := len(cred.Groups)
+		var groups *Gid_t
+		if ngroups > 0 {
+			gids := make([]Gid_t, ngroups)
+			for i, v := range cred.Groups {
+				gids[i] = Gid_t(v)
+			}
+			groups = &gids[0]
+		}
+
+		if !cred.NoSetGroups {
+			err1 = raw_setgroups(ngroups, groups)
+			if err1 != 0 {
+				goto childerror
+			}
+		}
+		err2 := Setgid(int(cred.Gid))
+		if err2 != nil {
+			err1 = err2.(Errno)
+			goto childerror
+		}
+		err2 = Setuid(int(cred.Uid))
+		if err2 != nil {
+			err1 = err2.(Errno)
+			goto childerror
+		}
+
+	}
+
+	// Chdir
+	if dir != nil {
+		err1 = raw_chdir(dir)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// Parent death signal
+	if sys.Pdeathsig != 0 {
+		_, err1 = raw_procctl(_P_PID, 0, _PROC_PDEATHSIG_CTL, unsafe.Pointer(&sys.Pdeathsig))
+
+		if err1 != 0 {
+			goto childerror
+		}
+
+		// Signal self if parent is already dead. This might cause a
+		// duplicate signal in rare cases, but it won't matter when
+		// using SIGKILL.
+		r1 = raw_getppid()
+		if r1 != ppid {
+			pid := raw_getpid()
+			err1 = raw_kill(pid, sys.Pdeathsig)
+			if err1 != 0 {
+				goto childerror
+			}
+		}
+	}
+
+	// Pass 1: look for fd[i] < i and move those up above len(fd)
+	// so that pass 2 won't stomp on an fd it needs later.
+	if pipe < nextfd {
+		_, err1 = raw_fcntl(pipe, _F_DUP2FD_CLOEXEC, nextfd)
+		if err1 != 0 {
+			goto childerror
+		}
+		pipe = nextfd
+		nextfd++
+	}
+	for i = 0; i < len(fd); i++ {
+		if fd[i] >= 0 && fd[i] < int(i) {
+			if nextfd == pipe { // don't stomp on pipe
+				nextfd++
+			}
+			err1 = raw_fcntl(fd[i], _F_DUP2FD_CLOEXEC, nextfd)
+			if err1 != 0 {
+				goto childerror
+			}
+			fd[i] = nextfd
+			nextfd++
+		}
+	}
+
+	// Pass 2: dup fd[i] down onto i.
+	for i = 0; i < len(fd); i++ {
+		if fd[i] == -1 {
+			raw_close(i)
+			continue
+		}
+		if fd[i] == int(i) {
+			// dup2(i, i) won't clear close-on-exec flag on Linux,
+			// probably not elsewhere either.
+			_, err1 = raw_fcntl(fd[i], _F_SETFD, 0)
+			if err1 != 0 {
+				goto childerror
+			}
+			continue
+		}
+		// The new fd is created NOT close-on-exec,
+		// which is exactly what we want.
+		err1 = raw_dup2(fd[i], i)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// By convention, we don't close-on-exec the fds we are
+	// started with, so if len(fd) < 3, close 0, 1, 2 as needed.
+	// Programs that know they inherit fds >= 3 will need
+	// to set them close-on-exec.
+	for i = len(fd); i < 3; i++ {
+		raw_close(i)
+	}
+
+	// Detach fd 0 from tty
+	if sys.Noctty {
+		_, err = raw_ioctl(0, TIOCNOTTY, 0)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// Set the controlling TTY to Ctty
+	if sys.Setctty {
+		_, err1 = raw_ioctl(sys.Cty, TIOCSCTTY, 0)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// Time to exec.
+	err1 = raw_execve(argv0, &argv[0], &envv[0])
+
+childerror:
+	// send error code on pipe
+	raw_write(pipe, (*byte)(unsafe.Pointer(&err1)), int(unsafe.Sizeof(err1)))
+	for {
+		raw_exit(253)
+	}
+}
diff --git a/libgo/go/syscall/exec_linux.go b/libgo/go/syscall/exec_linux.go
index c9be86b..86fb8e8 100644
--- a/libgo/go/syscall/exec_linux.go
+++ b/libgo/go/syscall/exec_linux.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build linux
-// +build linux
 
 package syscall
 
@@ -57,7 +56,7 @@ type SysProcAttr struct {
 	// number in the parent process.
 	Foreground   bool
 	Pgid         int            // Child's process group ID if Setpgid.
-	Pdeathsig    Signal         // Signal that the process will get when its parent dies (Linux only)
+	Pdeathsig    Signal         // Signal that the process will get when its parent dies (Linux and FreeBSD only)
 	Cloneflags   uintptr        // Flags for clone calls (Linux only)
 	Unshareflags uintptr        // Flags for unshare calls (Linux only)
 	UidMappings  []SysProcIDMap // User ID mappings for user namespaces.
@@ -459,13 +458,7 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att
 	// so that pass 2 won't stomp on an fd it needs later.
 	if pipe < nextfd {
 		err1 = raw_dup3(pipe, nextfd, O_CLOEXEC)
-		if err1 == ENOSYS {
-			err1 = raw_dup2(pipe, nextfd)
-			if err1 != 0 {
-				goto childerror
-			}
-			raw_fcntl(nextfd, F_SETFD, FD_CLOEXEC)
-		} else if err1 != 0 {
+		if err1 != 0 {
 			goto childerror
 		}
 		pipe = nextfd
@@ -477,13 +470,7 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att
 				nextfd++
 			}
 			err1 = raw_dup3(fd[i], nextfd, O_CLOEXEC)
-			if err1 == ENOSYS {
-				err1 = raw_dup2(fd[i], nextfd)
-				if err1 != 0 {
-					goto childerror
-				}
-				raw_fcntl(nextfd, F_SETFD, FD_CLOEXEC)
-			} else if err1 != 0 {
+			if err1 != 0 {
 				goto childerror
 			}
 			fd[i] = nextfd
@@ -508,7 +495,7 @@ func forkAndExecInChild1(argv0 *byte, argv, envv []*byte, chroot, dir *byte, att
 		}
 		// The new fd is created NOT close-on-exec,
 		// which is exactly what we want.
-		err1 = raw_dup2(fd[i], i)
+		err1 = raw_dup3(fd[i], i, 0)
 		if err1 != 0 {
 			goto childerror
 		}
@@ -561,19 +548,7 @@ childerror:
 
 // Try to open a pipe with O_CLOEXEC set on both file descriptors.
 func forkExecPipe(p []int) (err error) {
-	err = Pipe2(p, O_CLOEXEC)
-	// pipe2 was added in 2.6.27 and our minimum requirement is 2.6.23, so it
-	// might not be implemented.
-	if err == ENOSYS {
-		if err = Pipe(p); err != nil {
-			return
-		}
-		if _, err = fcntl(p[0], F_SETFD, FD_CLOEXEC); err != nil {
-			return
-		}
-		_, err = fcntl(p[1], F_SETFD, FD_CLOEXEC)
-	}
-	return
+	return Pipe2(p, O_CLOEXEC)
 }
 
 func formatIDMappings(idMap []SysProcIDMap) []byte {
diff --git a/libgo/go/syscall/exec_linux_test.go b/libgo/go/syscall/exec_linux_test.go
index ec0a4c0..abe6fdb 100644
--- a/libgo/go/syscall/exec_linux_test.go
+++ b/libgo/go/syscall/exec_linux_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build linux
-// +build linux
 
 package syscall_test
 
@@ -111,14 +110,6 @@ func checkUserNS(t *testing.T) {
 			t.Skip("kernel doesn't support user namespaces")
 		}
 	}
-
-	// When running under the Go continuous build, skip tests for
-	// now when under Kubernetes. (where things are root but not quite)
-	// Both of these are our own environment variables.
-	// See Issue 12815.
-	if os.Getenv("GO_BUILDER_NAME") != "" && os.Getenv("IN_KUBERNETES") == "1" {
-		t.Skip("skipping test on Kubernetes-based builders; see Issue 12815")
-	}
 }
 
 func whoamiCmd(t *testing.T, uid, gid int, setgroups bool) *exec.Cmd {
@@ -201,14 +192,6 @@ func TestUnshare(t *testing.T) {
 		t.Skip("kernel prohibits unshare in unprivileged process, unless using user namespace")
 	}
 
-	// When running under the Go continuous build, skip tests for
-	// now when under Kubernetes. (where things are root but not quite)
-	// Both of these are our own environment variables.
-	// See Issue 12815.
-	if os.Getenv("GO_BUILDER_NAME") != "" && os.Getenv("IN_KUBERNETES") == "1" {
-		t.Skip("skipping test on Kubernetes-based builders; see Issue 12815")
-	}
-
 	path := "/proc/net/dev"
 	if _, err := os.Stat(path); err != nil {
 		if os.IsNotExist(err) {
@@ -526,9 +509,7 @@ func mustSupportAmbientCaps(t *testing.T) {
 		buf[i] = byte(b)
 	}
 	ver := string(buf[:])
-	if i := strings.Index(ver, "\x00"); i != -1 {
-		ver = ver[:i]
-	}
+	ver, _, _ = strings.Cut(ver, "\x00")
 	if strings.HasPrefix(ver, "2.") ||
 		strings.HasPrefix(ver, "3.") ||
 		strings.HasPrefix(ver, "4.1.") ||
diff --git a/libgo/go/syscall/exec_pdeathsig_test.go b/libgo/go/syscall/exec_pdeathsig_test.go
new file mode 100644
index 0000000..96ae27b
--- /dev/null
+++ b/libgo/go/syscall/exec_pdeathsig_test.go
@@ -0,0 +1,134 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build freebsd || linux
+
+package syscall_test
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path/filepath"
+	"syscall"
+	"testing"
+	"time"
+)
+
+func TestDeathSignal(t *testing.T) {
+	if os.Getuid() != 0 {
+		t.Skip("skipping root only test")
+	}
+
+	// Copy the test binary to a location that a non-root user can read/execute
+	// after we drop privileges
+	tempDir, err := os.MkdirTemp("", "TestDeathSignal")
+	if err != nil {
+		t.Fatalf("cannot create temporary directory: %v", err)
+	}
+	defer os.RemoveAll(tempDir)
+	os.Chmod(tempDir, 0755)
+
+	tmpBinary := filepath.Join(tempDir, filepath.Base(os.Args[0]))
+
+	src, err := os.Open(os.Args[0])
+	if err != nil {
+		t.Fatalf("cannot open binary %q, %v", os.Args[0], err)
+	}
+	defer src.Close()
+
+	dst, err := os.OpenFile(tmpBinary, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
+	if err != nil {
+		t.Fatalf("cannot create temporary binary %q, %v", tmpBinary, err)
+	}
+	if _, err := io.Copy(dst, src); err != nil {
+		t.Fatalf("failed to copy test binary to %q, %v", tmpBinary, err)
+	}
+	err = dst.Close()
+	if err != nil {
+		t.Fatalf("failed to close test binary %q, %v", tmpBinary, err)
+	}
+
+	cmd := exec.Command(tmpBinary)
+	cmd.Env = append(os.Environ(), "GO_DEATHSIG_PARENT=1")
+	chldStdin, err := cmd.StdinPipe()
+	if err != nil {
+		t.Fatalf("failed to create new stdin pipe: %v", err)
+	}
+	chldStdout, err := cmd.StdoutPipe()
+	if err != nil {
+		t.Fatalf("failed to create new stdout pipe: %v", err)
+	}
+	cmd.Stderr = os.Stderr
+
+	err = cmd.Start()
+	defer cmd.Wait()
+	if err != nil {
+		t.Fatalf("failed to start first child process: %v", err)
+	}
+
+	chldPipe := bufio.NewReader(chldStdout)
+
+	if got, err := chldPipe.ReadString('\n'); got == "start\n" {
+		syscall.Kill(cmd.Process.Pid, syscall.SIGTERM)
+
+		go func() {
+			time.Sleep(5 * time.Second)
+			chldStdin.Close()
+		}()
+
+		want := "ok\n"
+		if got, err = chldPipe.ReadString('\n'); got != want {
+			t.Fatalf("expected %q, received %q, %v", want, got, err)
+		}
+	} else {
+		t.Fatalf("did not receive start from child, received %q, %v", got, err)
+	}
+}
+
+func deathSignalParent() {
+	cmd := exec.Command(os.Args[0])
+	cmd.Env = append(os.Environ(),
+		"GO_DEATHSIG_PARENT=",
+		"GO_DEATHSIG_CHILD=1",
+	)
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	attrs := syscall.SysProcAttr{
+		Pdeathsig: syscall.SIGUSR1,
+		// UID/GID 99 is the user/group "nobody" on RHEL/Fedora and is
+		// unused on Ubuntu
+		Credential: &syscall.Credential{Uid: 99, Gid: 99},
+	}
+	cmd.SysProcAttr = &attrs
+
+	err := cmd.Start()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "death signal parent error: %v\n", err)
+		os.Exit(1)
+	}
+	cmd.Wait()
+	os.Exit(0)
+}
+
+func deathSignalChild() {
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, syscall.SIGUSR1)
+	go func() {
+		<-c
+		fmt.Println("ok")
+		os.Exit(0)
+	}()
+	fmt.Println("start")
+
+	buf := make([]byte, 32)
+	os.Stdin.Read(buf)
+
+	// We expected to be signaled before stdin closed
+	fmt.Println("not ok")
+	os.Exit(1)
+}
diff --git a/libgo/go/syscall/exec_unix.go b/libgo/go/syscall/exec_unix.go
index 7e01648..c99171b 100644
--- a/libgo/go/syscall/exec_unix.go
+++ b/libgo/go/syscall/exec_unix.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
 
 // Fork, exec, wait, etc.
 
@@ -210,9 +209,6 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 		sys = &zeroSysProcAttr
 	}
 
-	p[0] = -1
-	p[1] = -1
-
 	// Convert args to C form.
 	argv0p, err := BytePtrFromString(argv0)
 	if err != nil {
@@ -262,14 +258,17 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 
 	// Allocate child status pipe close on exec.
 	if err = forkExecPipe(p[:]); err != nil {
-		goto error
+		ForkLock.Unlock()
+		return 0, err
 	}
 
 	// Kick off child.
 	pid, err1 = forkAndExecInChild(argv0p, argvp, envvp, chroot, dir, attr, sys, p[1])
 	if err1 != 0 {
-		err = Errno(err1)
-		goto error
+		Close(p[0])
+		Close(p[1])
+		ForkLock.Unlock()
+		return 0, Errno(err1)
 	}
 	ForkLock.Unlock()
 
@@ -301,14 +300,6 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 
 	// Read got EOF, so pipe closed on exec, so exec succeeded.
 	return pid, nil
-
-error:
-	if p[0] >= 0 {
-		Close(p[0])
-		Close(p[1])
-	}
-	ForkLock.Unlock()
-	return 0, err
 }
 
 // Combination of fork and exec, careful to be thread safe.
diff --git a/libgo/go/syscall/exec_unix_test.go b/libgo/go/syscall/exec_unix_test.go
index 3b78d20..29fd760 100644
--- a/libgo/go/syscall/exec_unix_test.go
+++ b/libgo/go/syscall/exec_unix_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
 
 package syscall_test
 
@@ -329,7 +328,6 @@ func TestExecHelper(t *testing.T) {
 	// We don't have to worry about restoring these values.
 	// We are in a child process that only runs this test,
 	// and we are going to call syscall.Exec anyhow.
-	runtime.GOMAXPROCS(50)
 	os.Setenv("GO_WANT_HELPER_PROCESS", "3")
 
 	stop := time.Now().Add(time.Second)
diff --git a/libgo/go/syscall/exec_windows.go b/libgo/go/syscall/exec_windows.go
index 18d1502..9d10d6a 100644
--- a/libgo/go/syscall/exec_windows.go
+++ b/libgo/go/syscall/exec_windows.go
@@ -390,8 +390,10 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 	}
 	fd = fd[:j]
 
+	willInheritHandles := len(fd) > 0 && !sys.NoInheritHandles
+
 	// Do not accidentally inherit more than these handles.
-	if len(fd) > 0 {
+	if willInheritHandles {
 		err = updateProcThreadAttribute(si.ProcThreadAttributeList, 0, _PROC_THREAD_ATTRIBUTE_HANDLE_LIST, unsafe.Pointer(&fd[0]), uintptr(len(fd))*unsafe.Sizeof(fd[0]), nil, nil)
 		if err != nil {
 			return 0, 0, err
@@ -401,9 +403,9 @@ func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle
 	pi := new(ProcessInformation)
 	flags := sys.CreationFlags | CREATE_UNICODE_ENVIRONMENT | _EXTENDED_STARTUPINFO_PRESENT
 	if sys.Token != 0 {
-		err = CreateProcessAsUser(sys.Token, argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, len(fd) > 0 && !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
+		err = CreateProcessAsUser(sys.Token, argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, willInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
 	} else {
-		err = CreateProcess(argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, len(fd) > 0 && !sys.NoInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
+		err = CreateProcess(argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, willInheritHandles, flags, createEnvBlock(attr.Env), dirp, &si.StartupInfo, pi)
 	}
 	if err != nil {
 		return 0, 0, err
diff --git a/libgo/go/syscall/export_unix_test.go b/libgo/go/syscall/export_unix_test.go
index f32118b5..184eb84 100644
--- a/libgo/go/syscall/export_unix_test.go
+++ b/libgo/go/syscall/export_unix_test.go
@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
-// +build dragonfly freebsd hurd linux netbsd openbsd solaris
+//go:build dragonfly || freebsd || hurd || linux || netbsd || openbsd
 
 package syscall
 
diff --git a/libgo/go/syscall/forkpipe.go b/libgo/go/syscall/forkpipe.go
index 79cbdf4..6f7d29c 100644
--- a/libgo/go/syscall/forkpipe.go
+++ b/libgo/go/syscall/forkpipe.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || solaris
-// +build aix darwin solaris
 
 package syscall
 
diff --git a/libgo/go/syscall/forkpipe2.go b/libgo/go/syscall/forkpipe2.go
index bdffdcd..01c8048 100644
--- a/libgo/go/syscall/forkpipe2.go
+++ b/libgo/go/syscall/forkpipe2.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build dragonfly || freebsd || hurd || netbsd || openbsd
-// +build dragonfly freebsd hurd netbsd openbsd
 
 package syscall
 
diff --git a/libgo/go/syscall/fs_js.go b/libgo/go/syscall/fs_js.go
index 0170516..3541446 100644
--- a/libgo/go/syscall/fs_js.go
+++ b/libgo/go/syscall/fs_js.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build js && wasm
-// +build js,wasm
 
 package syscall
 
@@ -492,14 +491,14 @@ func Pipe(fd []int) error {
 	return ENOSYS
 }
 
-func fsCall(name string, args ...interface{}) (js.Value, error) {
+func fsCall(name string, args ...any) (js.Value, error) {
 	type callResult struct {
 		val js.Value
 		err error
 	}
 
 	c := make(chan callResult, 1)
-	f := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	f := js.FuncOf(func(this js.Value, args []js.Value) any {
 		var res callResult
 
 		if len(args) >= 1 { // on Node.js 8, fs.utimes calls the callback without any arguments
diff --git a/libgo/go/syscall/getdirentries_test.go b/libgo/go/syscall/getdirentries_test.go
index 814e656..ddd8208 100644
--- a/libgo/go/syscall/getdirentries_test.go
+++ b/libgo/go/syscall/getdirentries_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build darwin || freebsd || netbsd || openbsd
-// +build darwin freebsd netbsd openbsd
 
 package syscall_test
 
diff --git a/libgo/go/syscall/js/export_test.go b/libgo/go/syscall/js/export_test.go
index 1b5ed3c..fb61dae 100644
--- a/libgo/go/syscall/js/export_test.go
+++ b/libgo/go/syscall/js/export_test.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.
 
-// +build js,wasm
+//go:build js && wasm
 
 package js
 
diff --git a/libgo/go/syscall/js/func.go b/libgo/go/syscall/js/func.go
index da4cf68..cc94972 100644
--- a/libgo/go/syscall/js/func.go
+++ b/libgo/go/syscall/js/func.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.
 
-// +build js,wasm
+//go:build js && wasm
 
 package js
 
@@ -10,12 +10,10 @@ import "sync"
 
 var (
 	funcsMu    sync.Mutex
-	funcs             = make(map[uint32]func(Value, []Value) interface{})
+	funcs             = make(map[uint32]func(Value, []Value) any)
 	nextFuncID uint32 = 1
 )
 
-var _ Wrapper = Func{} // Func must implement Wrapper
-
 // Func is a wrapped Go function to be called by JavaScript.
 type Func struct {
 	Value // the JavaScript function that invokes the Go function
@@ -40,7 +38,7 @@ type Func struct {
 // new goroutine.
 //
 // Func.Release must be called to free up resources when the function will not be invoked any more.
-func FuncOf(fn func(this Value, args []Value) interface{}) Func {
+func FuncOf(fn func(this Value, args []Value) any) Func {
 	funcsMu.Lock()
 	id := nextFuncID
 	nextFuncID++
diff --git a/libgo/go/syscall/js/js.go b/libgo/go/syscall/js/js.go
index a48bbd4..a5210fa 100644
--- a/libgo/go/syscall/js/js.go
+++ b/libgo/go/syscall/js/js.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.
 
-// +build js,wasm
+//go:build js && wasm
 
 // Package js gives access to the WebAssembly host environment when using the js/wasm architecture.
 // Its API is based on JavaScript semantics.
@@ -27,12 +27,6 @@ type ref uint64
 // nanHead are the upper 32 bits of a ref which are set if the value is not encoded as an IEEE 754 number (see above).
 const nanHead = 0x7FF80000
 
-// Wrapper is implemented by types that are backed by a JavaScript value.
-type Wrapper interface {
-	// JSValue returns a JavaScript value associated with an object.
-	JSValue() Value
-}
-
 // Value represents a JavaScript value. The zero value is the JavaScript value "undefined".
 // Values can be checked for equality with the Equal method.
 type Value struct {
@@ -50,11 +44,6 @@ const (
 	typeFlagFunction
 )
 
-// JSValue implements Wrapper interface.
-func (v Value) JSValue() Value {
-	return v
-}
-
 func makeValue(r ref) Value {
 	var gcPtr *ref
 	typeFlag := (r >> 32) & 7
@@ -159,12 +148,12 @@ func Global() Value {
 //  | map[string]interface{} | new object             |
 //
 // Panics if x is not one of the expected types.
-func ValueOf(x interface{}) Value {
+func ValueOf(x any) Value {
 	switch x := x.(type) {
-	case Value: // should precede Wrapper to avoid a loop
+	case Value:
 		return x
-	case Wrapper:
-		return x.JSValue()
+	case Func:
+		return x.Value
 	case nil:
 		return valueNull
 	case bool:
@@ -203,13 +192,13 @@ func ValueOf(x interface{}) Value {
 		return floatValue(x)
 	case string:
 		return makeValue(stringVal(x))
-	case []interface{}:
+	case []any:
 		a := arrayConstructor.New(len(x))
 		for i, s := range x {
 			a.SetIndex(i, s)
 		}
 		return a
-	case map[string]interface{}:
+	case map[string]any:
 		o := objectConstructor.New()
 		for k, v := range x {
 			o.Set(k, v)
@@ -307,7 +296,7 @@ func valueGet(v ref, p string) ref
 
 // Set sets the JavaScript property p of value v to ValueOf(x).
 // It panics if v is not a JavaScript object.
-func (v Value) Set(p string, x interface{}) {
+func (v Value) Set(p string, x any) {
 	if vType := v.Type(); !vType.isObject() {
 		panic(&ValueError{"Value.Set", vType})
 	}
@@ -346,7 +335,7 @@ func valueIndex(v ref, i int) ref
 
 // SetIndex sets the JavaScript index i of value v to ValueOf(x).
 // It panics if v is not a JavaScript object.
-func (v Value) SetIndex(i int, x interface{}) {
+func (v Value) SetIndex(i int, x any) {
 	if vType := v.Type(); !vType.isObject() {
 		panic(&ValueError{"Value.SetIndex", vType})
 	}
@@ -358,7 +347,7 @@ func (v Value) SetIndex(i int, x interface{}) {
 
 func valueSetIndex(v ref, i int, x ref)
 
-func makeArgs(args []interface{}) ([]Value, []ref) {
+func makeArgs(args []any) ([]Value, []ref) {
 	argVals := make([]Value, len(args))
 	argRefs := make([]ref, len(args))
 	for i, arg := range args {
@@ -385,7 +374,7 @@ func valueLength(v ref) int
 // Call does a JavaScript call to the method m of value v with the given arguments.
 // It panics if v has no method m.
 // The arguments get mapped to JavaScript values according to the ValueOf function.
-func (v Value) Call(m string, args ...interface{}) Value {
+func (v Value) Call(m string, args ...any) Value {
 	argVals, argRefs := makeArgs(args)
 	res, ok := valueCall(v.ref, m, argRefs)
 	runtime.KeepAlive(v)
@@ -407,7 +396,7 @@ func valueCall(v ref, m string, args []ref) (ref, bool)
 // Invoke does a JavaScript call of the value v with the given arguments.
 // It panics if v is not a JavaScript function.
 // The arguments get mapped to JavaScript values according to the ValueOf function.
-func (v Value) Invoke(args ...interface{}) Value {
+func (v Value) Invoke(args ...any) Value {
 	argVals, argRefs := makeArgs(args)
 	res, ok := valueInvoke(v.ref, argRefs)
 	runtime.KeepAlive(v)
@@ -426,7 +415,7 @@ func valueInvoke(v ref, args []ref) (ref, bool)
 // New uses JavaScript's "new" operator with value v as constructor and the given arguments.
 // It panics if v is not a JavaScript function.
 // The arguments get mapped to JavaScript values according to the ValueOf function.
-func (v Value) New(args ...interface{}) Value {
+func (v Value) New(args ...any) Value {
 	argVals, argRefs := makeArgs(args)
 	res, ok := valueNew(v.ref, argRefs)
 	runtime.KeepAlive(v)
diff --git a/libgo/go/syscall/js/js_test.go b/libgo/go/syscall/js/js_test.go
index 5fc9107..f860a5b 100644
--- a/libgo/go/syscall/js/js_test.go
+++ b/libgo/go/syscall/js/js_test.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.
 
-// +build js,wasm
+//go:build js && wasm
 
 // To run these tests:
 //
@@ -364,8 +364,8 @@ func TestType(t *testing.T) {
 	}
 }
 
-type object = map[string]interface{}
-type array = []interface{}
+type object = map[string]any
+type array = []any
 
 func TestValueOf(t *testing.T) {
 	a := js.ValueOf(array{0, array{0, 42, 0}, 0})
@@ -388,7 +388,7 @@ func TestZeroValue(t *testing.T) {
 
 func TestFuncOf(t *testing.T) {
 	c := make(chan struct{})
-	cb := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	cb := js.FuncOf(func(this js.Value, args []js.Value) any {
 		if got := args[0].Int(); got != 42 {
 			t.Errorf("got %#v, want %#v", got, 42)
 		}
@@ -402,8 +402,8 @@ func TestFuncOf(t *testing.T) {
 
 func TestInvokeFunction(t *testing.T) {
 	called := false
-	cb := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
-		cb2 := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	cb := js.FuncOf(func(this js.Value, args []js.Value) any {
+		cb2 := js.FuncOf(func(this js.Value, args []js.Value) any {
 			called = true
 			return 42
 		})
@@ -423,7 +423,7 @@ func TestInterleavedFunctions(t *testing.T) {
 	c1 := make(chan struct{})
 	c2 := make(chan struct{})
 
-	js.Global().Get("setTimeout").Invoke(js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	js.Global().Get("setTimeout").Invoke(js.FuncOf(func(this js.Value, args []js.Value) any {
 		c1 <- struct{}{}
 		<-c2
 		return nil
@@ -432,7 +432,7 @@ func TestInterleavedFunctions(t *testing.T) {
 	<-c1
 	c2 <- struct{}{}
 	// this goroutine is running, but the callback of setTimeout did not return yet, invoke another function now
-	f := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	f := js.FuncOf(func(this js.Value, args []js.Value) any {
 		return nil
 	})
 	f.Invoke()
@@ -440,7 +440,7 @@ func TestInterleavedFunctions(t *testing.T) {
 
 func ExampleFuncOf() {
 	var cb js.Func
-	cb = js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	cb = js.FuncOf(func(this js.Value, args []js.Value) any {
 		fmt.Println("button clicked")
 		cb.Release() // release the function if the button will not be clicked again
 		return nil
@@ -593,7 +593,7 @@ func BenchmarkDOM(b *testing.B) {
 }
 
 func TestGlobal(t *testing.T) {
-	ident := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+	ident := js.FuncOf(func(this js.Value, args []js.Value) any {
 		return args[0]
 	})
 	defer ident.Release()
diff --git a/libgo/go/syscall/mkasm.go b/libgo/go/syscall/mkasm.go
index e0ec466..dce61f3 100644
--- a/libgo/go/syscall/mkasm.go
+++ b/libgo/go/syscall/mkasm.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 // mkasm.go generates assembly trampolines to call library routines from Go.
 // This program must be run after mksyscall.pl.
diff --git a/libgo/go/syscall/mmap_unix_test.go b/libgo/go/syscall/mmap_unix_test.go
index f4eb54d..e5f8ffc 100644
--- a/libgo/go/syscall/mmap_unix_test.go
+++ b/libgo/go/syscall/mmap_unix_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd
-// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd
 
 package syscall_test
 
diff --git a/libgo/go/syscall/msan0.go b/libgo/go/syscall/msan0.go
index 8509702..fba8a5f 100644
--- a/libgo/go/syscall/msan0.go
+++ b/libgo/go/syscall/msan0.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !msan
-// +build !msan
 
 package syscall
 
diff --git a/libgo/go/syscall/net_js.go b/libgo/go/syscall/net_js.go
index ed46202..2ed4e19 100644
--- a/libgo/go/syscall/net_js.go
+++ b/libgo/go/syscall/net_js.go
@@ -6,7 +6,6 @@
 // This file only exists to make the compiler happy.
 
 //go:build js && wasm
-// +build js,wasm
 
 package syscall
 
@@ -46,8 +45,7 @@ const (
 	SYS_FCNTL = 500 // unsupported
 )
 
-type Sockaddr interface {
-}
+type Sockaddr any
 
 type SockaddrInet4 struct {
 	Port int
diff --git a/libgo/go/syscall/netlink_linux.go b/libgo/go/syscall/netlink_linux.go
index 0937ff7..2d81070 100644
--- a/libgo/go/syscall/netlink_linux.go
+++ b/libgo/go/syscall/netlink_linux.go
@@ -55,14 +55,22 @@ func NetlinkRIB(proto, family int) ([]byte, error) {
 		return nil, err
 	}
 	defer Close(s)
-	lsa := &SockaddrNetlink{Family: AF_NETLINK}
-	if err := Bind(s, lsa); err != nil {
+	sa := &SockaddrNetlink{Family: AF_NETLINK}
+	if err := Bind(s, sa); err != nil {
 		return nil, err
 	}
 	wb := newNetlinkRouteRequest(proto, 1, family)
-	if err := Sendto(s, wb, 0, lsa); err != nil {
+	if err := Sendto(s, wb, 0, sa); err != nil {
 		return nil, err
 	}
+	lsa, err := Getsockname(s)
+	if err != nil {
+		return nil, err
+	}
+	lsanl, ok := lsa.(*SockaddrNetlink)
+	if !ok {
+		return nil, EINVAL
+	}
 	var tab []byte
 	rbNew := make([]byte, Getpagesize())
 done:
@@ -82,16 +90,7 @@ done:
 			return nil, err
 		}
 		for _, m := range msgs {
-			lsa, err := Getsockname(s)
-			if err != nil {
-				return nil, err
-			}
-			switch v := lsa.(type) {
-			case *SockaddrNetlink:
-				if m.Header.Seq != 1 || m.Header.Pid != v.Pid {
-					return nil, EINVAL
-				}
-			default:
+			if m.Header.Seq != 1 || m.Header.Pid != lsanl.Pid {
 				return nil, EINVAL
 			}
 			if m.Header.Type == NLMSG_DONE {
diff --git a/libgo/go/syscall/route_bsd.go b/libgo/go/syscall/route_bsd.go
index 0dc5fc0..b9d19c5 100644
--- a/libgo/go/syscall/route_bsd.go
+++ b/libgo/go/syscall/route_bsd.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build darwin || dragonfly || freebsd || netbsd || openbsd
-// +build darwin dragonfly freebsd netbsd openbsd
 
 package syscall
 
diff --git a/libgo/go/syscall/route_freebsd_32bit.go b/libgo/go/syscall/route_freebsd_32bit.go
index 412833a..c70f0bb 100644
--- a/libgo/go/syscall/route_freebsd_32bit.go
+++ b/libgo/go/syscall/route_freebsd_32bit.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build (freebsd && 386) || (freebsd && arm)
-// +build freebsd,386 freebsd,arm
 
 package syscall
 
diff --git a/libgo/go/syscall/route_freebsd_64bit.go b/libgo/go/syscall/route_freebsd_64bit.go
index 5300bed..9febdfa 100644
--- a/libgo/go/syscall/route_freebsd_64bit.go
+++ b/libgo/go/syscall/route_freebsd_64bit.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build (freebsd && amd64) || (freebsd && arm64)
-// +build freebsd,amd64 freebsd,arm64
 
 package syscall
 
diff --git a/libgo/go/syscall/setuidgid_32_linux.go b/libgo/go/syscall/setuidgid_32_linux.go
index 4e657c8..cb73fde 100644
--- a/libgo/go/syscall/setuidgid_32_linux.go
+++ b/libgo/go/syscall/setuidgid_32_linux.go
@@ -3,8 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build linux && (386 || arm)
-// +build linux
-// +build 386 arm
 
 package syscall
 
diff --git a/libgo/go/syscall/setuidgid_linux.go b/libgo/go/syscall/setuidgid_linux.go
index c15090f..4e1804e 100644
--- a/libgo/go/syscall/setuidgid_linux.go
+++ b/libgo/go/syscall/setuidgid_linux.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build linux && !386 && !arm
-// +build linux,!386,!arm
 
 package syscall
 
diff --git a/libgo/go/syscall/sockcmsg_unix.go b/libgo/go/syscall/sockcmsg_unix.go
index aaeecdb..44ef9b8 100644
--- a/libgo/go/syscall/sockcmsg_unix.go
+++ b/libgo/go/syscall/sockcmsg_unix.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
 
 // Socket control messages
 
diff --git a/libgo/go/syscall/sockcmsg_unix_other.go b/libgo/go/syscall/sockcmsg_unix_other.go
index 0b75b18..6503dbd 100644
--- a/libgo/go/syscall/sockcmsg_unix_other.go
+++ b/libgo/go/syscall/sockcmsg_unix_other.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || freebsd || hurd || linux || netbsd || openbsd || solaris
-// +build aix darwin freebsd hurd linux netbsd openbsd solaris
 
 package syscall
 
diff --git a/libgo/go/syscall/socket.go b/libgo/go/syscall/socket.go
index f42679d..54a4a99 100644
--- a/libgo/go/syscall/socket.go
+++ b/libgo/go/syscall/socket.go
@@ -12,6 +12,18 @@ package syscall
 
 import "unsafe"
 
+// These functions are called from the internal/syscall/unix package.
+// Use go:linkname to export them.
+//
+//go:linkname recvfromInet4
+//go:linkname recvfromInet6
+//go:linkname sendtoInet4
+//go:linkname sendtoInet6
+//go:linkname sendmsgNInet4
+//go:linkname sendmsgNInet6
+//go:linkname recvmsgInet4
+//go:linkname recvmsgInet6
+
 // For testing: clients can set this flag to force
 // creation of IPv6 sockets to return EAFNOSUPPORT.
 var SocketDisableIPv6 bool
@@ -332,6 +344,119 @@ func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
 	return
 }
 
+func recvfromInet4(fd int, p []byte, flags int, from *SockaddrInet4) (n int, err error) {
+	var rsa RawSockaddrAny
+	var socklen Socklen_t = SizeofSockaddrAny
+	if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
+		return
+	}
+	pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
+	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
+	from.Port = int(port[0])<<8 + int(port[1])
+	from.Addr = pp.Addr
+	return
+}
+
+func recvfromInet6(fd int, p []byte, flags int, from *SockaddrInet6) (n int, err error) {
+	var rsa RawSockaddrAny
+	var socklen Socklen_t = SizeofSockaddrAny
+	if n, err = recvfrom(fd, p, flags, &rsa, &socklen); err != nil {
+		return
+	}
+	pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
+	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
+	from.Port = int(port[0])<<8 + int(port[1])
+	from.ZoneId = pp.Scope_id
+	from.Addr = pp.Addr
+	return
+}
+
+func recvmsgInet4(fd int, p, oob []byte, flags int, from *SockaddrInet4) (n, oobn int, recvflags int, err error) {
+	var rsa RawSockaddrAny
+	n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
+	if err != nil {
+		return
+	}
+	pp := (*RawSockaddrInet4)(unsafe.Pointer(&rsa))
+	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
+	from.Port = int(port[0])<<8 + int(port[1])
+	from.Addr = pp.Addr
+	return
+}
+
+func recvmsgInet6(fd int, p, oob []byte, flags int, from *SockaddrInet6) (n, oobn int, recvflags int, err error) {
+	var rsa RawSockaddrAny
+	n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
+	if err != nil {
+		return
+	}
+	pp := (*RawSockaddrInet6)(unsafe.Pointer(&rsa))
+	port := (*[2]byte)(unsafe.Pointer(&pp.Port))
+	from.Port = int(port[0])<<8 + int(port[1])
+	from.ZoneId = pp.Scope_id
+	from.Addr = pp.Addr
+	return
+}
+
+func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
+	var rsa RawSockaddrAny
+	n, oobn, recvflags, err = recvmsgRaw(fd, p, oob, flags, &rsa)
+	// source address is only specified if the socket is unconnected
+	if rsa.Addr.Family != AF_UNSPEC {
+		from, err = anyToSockaddr(&rsa)
+	}
+	return
+}
+
+func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
+	_, err = SendmsgN(fd, p, oob, to, flags)
+	return
+}
+
+func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
+	var ptr *RawSockaddrAny
+	var salen Socklen_t
+	if to != nil {
+		ptr, salen, err = to.sockaddr()
+		if err != nil {
+			return 0, err
+		}
+	}
+	return sendmsgN(fd, p, oob, ptr, salen, flags)
+}
+
+func sendmsgNInet4(fd int, p, oob []byte, to *SockaddrInet4, flags int) (n int, err error) {
+	ptr, salen, err := to.sockaddr()
+	if err != nil {
+		return 0, err
+	}
+	return sendmsgN(fd, p, oob, ptr, salen, flags)
+}
+
+func sendmsgNInet6(fd int, p, oob []byte, to *SockaddrInet6, flags int) (n int, err error) {
+	ptr, salen, err := to.sockaddr()
+	if err != nil {
+		return 0, err
+	}
+	return sendmsgN(fd, p, oob, ptr, salen, flags)
+}
+
+func sendtoInet4(fd int, p []byte, flags int, to *SockaddrInet4) (err error) {
+	ptr, n, err := to.sockaddr()
+	if err != nil {
+		return err
+	}
+	return sendto(fd, p, flags, ptr, n)
+}
+
+func sendtoInet6(fd int, p []byte, flags int, to *SockaddrInet6) (err error) {
+	ptr, n, err := to.sockaddr()
+	if err != nil {
+		return err
+	}
+	return sendto(fd, p, flags, ptr, n)
+}
+
 func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
 	ptr, n, err := to.sockaddr()
 	if err != nil {
@@ -340,9 +465,8 @@ func Sendto(fd int, p []byte, flags int, to Sockaddr) (err error) {
 	return sendto(fd, p, flags, ptr, n)
 }
 
-func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
+func recvmsgRaw(fd int, p, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
 	var msg Msghdr
-	var rsa RawSockaddrAny
 	msg.Name = (*byte)(unsafe.Pointer(&rsa))
 	msg.Namelen = uint32(SizeofSockaddrAny)
 	var iov Iovec
@@ -372,30 +496,12 @@ func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from
 	}
 	oobn = int(msg.Controllen)
 	recvflags = int(msg.Flags)
-	// source address is only specified if the socket is unconnected
-	if rsa.Addr.Family != AF_UNSPEC {
-		from, err = anyToSockaddr(&rsa)
-	}
-	return
-}
-
-func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
-	_, err = SendmsgN(fd, p, oob, to, flags)
 	return
 }
 
-func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
-	var ptr *RawSockaddrAny
-	var salen Socklen_t
-	if to != nil {
-		var err error
-		ptr, salen, err = to.sockaddr()
-		if err != nil {
-			return 0, err
-		}
-	}
+func sendmsgN(fd int, p, oob []byte, to *RawSockaddrAny, salen Socklen_t, flags int) (n int, err error) {
 	var msg Msghdr
-	msg.Name = (*byte)(unsafe.Pointer(ptr))
+	msg.Name = (*byte)(unsafe.Pointer(to))
 	msg.Namelen = uint32(salen)
 	var iov Iovec
 	if len(p) > 0 {
diff --git a/libgo/go/syscall/syscall_dragonfly.go b/libgo/go/syscall/syscall_dragonfly.go
index 930bb46..4b4ed77 100644
--- a/libgo/go/syscall/syscall_dragonfly.go
+++ b/libgo/go/syscall/syscall_dragonfly.go
@@ -9,6 +9,8 @@ import (
 	"unsafe"
 )
 
+const _SYS_DUP3 = 0
+
 // See version list in https://github.com/DragonFlyBSD/DragonFlyBSD/blob/master/sys/sys/param.h
 var (
 	osreldateOnce sync.Once
diff --git a/libgo/go/syscall/syscall_freebsd_test.go b/libgo/go/syscall/syscall_freebsd_test.go
index 89c7959..f04b12b 100644
--- a/libgo/go/syscall/syscall_freebsd_test.go
+++ b/libgo/go/syscall/syscall_freebsd_test.go
@@ -3,12 +3,12 @@
 // license that can be found in the LICENSE file.
 
 //go:build freebsd
-// +build freebsd
 
 package syscall_test
 
 import (
 	"fmt"
+	"os"
 	"syscall"
 	"testing"
 	"unsafe"
@@ -53,3 +53,13 @@ func TestConvertFromDirent11(t *testing.T) {
 		}
 	}
 }
+
+func TestMain(m *testing.M) {
+	if os.Getenv("GO_DEATHSIG_PARENT") == "1" {
+		deathSignalParent()
+	} else if os.Getenv("GO_DEATHSIG_CHILD") == "1" {
+		deathSignalChild()
+	}
+
+	os.Exit(m.Run())
+}
diff --git a/libgo/go/syscall/syscall_js.go b/libgo/go/syscall/syscall_js.go
index ed70d62..cd95499 100644
--- a/libgo/go/syscall/syscall_js.go
+++ b/libgo/go/syscall/syscall_js.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build js && wasm
-// +build js,wasm
 
 package syscall
 
diff --git a/libgo/go/syscall/syscall_linux_mipsx.go b/libgo/go/syscall/syscall_linux_mipsx.go
index 1df7a5f..809775f 100644
--- a/libgo/go/syscall/syscall_linux_mipsx.go
+++ b/libgo/go/syscall/syscall_linux_mipsx.go
@@ -3,8 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build linux && (mips || mipsle || mips64 || mips64le || mips64p32 || mips64p32le)
-// +build linux
-// +build mips mipsle mips64 mips64le mips64p32 mips64p32le
 
 package syscall
 
diff --git a/libgo/go/syscall/syscall_linux_test.go b/libgo/go/syscall/syscall_linux_test.go
index fd826e9..6be48e2 100644
--- a/libgo/go/syscall/syscall_linux_test.go
+++ b/libgo/go/syscall/syscall_linux_test.go
@@ -5,13 +5,11 @@
 package syscall_test
 
 import (
-	"bufio"
 	"fmt"
 	"io"
 	"io/fs"
 	"os"
 	"os/exec"
-	"os/signal"
 	"path/filepath"
 	"runtime"
 	"sort"
@@ -19,7 +17,6 @@ import (
 	"strings"
 	"syscall"
 	"testing"
-	"time"
 	"unsafe"
 )
 
@@ -153,120 +150,6 @@ func TestMain(m *testing.M) {
 	os.Exit(m.Run())
 }
 
-func TestLinuxDeathSignal(t *testing.T) {
-	if os.Getuid() != 0 {
-		t.Skip("skipping root only test")
-	}
-
-	// Copy the test binary to a location that a non-root user can read/execute
-	// after we drop privileges
-	tempDir, err := os.MkdirTemp("", "TestDeathSignal")
-	if err != nil {
-		t.Fatalf("cannot create temporary directory: %v", err)
-	}
-	defer os.RemoveAll(tempDir)
-	os.Chmod(tempDir, 0755)
-
-	tmpBinary := filepath.Join(tempDir, filepath.Base(os.Args[0]))
-
-	src, err := os.Open(os.Args[0])
-	if err != nil {
-		t.Fatalf("cannot open binary %q, %v", os.Args[0], err)
-	}
-	defer src.Close()
-
-	dst, err := os.OpenFile(tmpBinary, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
-	if err != nil {
-		t.Fatalf("cannot create temporary binary %q, %v", tmpBinary, err)
-	}
-	if _, err := io.Copy(dst, src); err != nil {
-		t.Fatalf("failed to copy test binary to %q, %v", tmpBinary, err)
-	}
-	err = dst.Close()
-	if err != nil {
-		t.Fatalf("failed to close test binary %q, %v", tmpBinary, err)
-	}
-
-	cmd := exec.Command(tmpBinary)
-	cmd.Env = append(os.Environ(), "GO_DEATHSIG_PARENT=1")
-	chldStdin, err := cmd.StdinPipe()
-	if err != nil {
-		t.Fatalf("failed to create new stdin pipe: %v", err)
-	}
-	chldStdout, err := cmd.StdoutPipe()
-	if err != nil {
-		t.Fatalf("failed to create new stdout pipe: %v", err)
-	}
-	cmd.Stderr = os.Stderr
-
-	err = cmd.Start()
-	defer cmd.Wait()
-	if err != nil {
-		t.Fatalf("failed to start first child process: %v", err)
-	}
-
-	chldPipe := bufio.NewReader(chldStdout)
-
-	if got, err := chldPipe.ReadString('\n'); got == "start\n" {
-		syscall.Kill(cmd.Process.Pid, syscall.SIGTERM)
-
-		go func() {
-			time.Sleep(5 * time.Second)
-			chldStdin.Close()
-		}()
-
-		want := "ok\n"
-		if got, err = chldPipe.ReadString('\n'); got != want {
-			t.Fatalf("expected %q, received %q, %v", want, got, err)
-		}
-	} else {
-		t.Fatalf("did not receive start from child, received %q, %v", got, err)
-	}
-}
-
-func deathSignalParent() {
-	cmd := exec.Command(os.Args[0])
-	cmd.Env = append(os.Environ(),
-		"GO_DEATHSIG_PARENT=",
-		"GO_DEATHSIG_CHILD=1",
-	)
-	cmd.Stdin = os.Stdin
-	cmd.Stdout = os.Stdout
-	attrs := syscall.SysProcAttr{
-		Pdeathsig: syscall.SIGUSR1,
-		// UID/GID 99 is the user/group "nobody" on RHEL/Fedora and is
-		// unused on Ubuntu
-		Credential: &syscall.Credential{Uid: 99, Gid: 99},
-	}
-	cmd.SysProcAttr = &attrs
-
-	err := cmd.Start()
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "death signal parent error: %v\n", err)
-		os.Exit(1)
-	}
-	cmd.Wait()
-	os.Exit(0)
-}
-
-func deathSignalChild() {
-	c := make(chan os.Signal, 1)
-	signal.Notify(c, syscall.SIGUSR1)
-	go func() {
-		<-c
-		fmt.Println("ok")
-		os.Exit(0)
-	}()
-	fmt.Println("start")
-
-	buf := make([]byte, 32)
-	os.Stdin.Read(buf)
-
-	// We expected to be signaled before stdin closed
-	fmt.Println("not ok")
-	os.Exit(1)
-}
-
 func TestParseNetlinkMessage(t *testing.T) {
 	for i, b := range [][]byte{
 		{103, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 11, 0, 1, 0, 0, 0, 0, 5, 8, 0, 3,
diff --git a/libgo/go/syscall/syscall_ptrace_test.go b/libgo/go/syscall/syscall_ptrace_test.go
index 45729d9..5b128de 100644
--- a/libgo/go/syscall/syscall_ptrace_test.go
+++ b/libgo/go/syscall/syscall_ptrace_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd
-// +build darwin dragonfly freebsd linux netbsd openbsd
 
 package syscall_test
 
diff --git a/libgo/go/syscall/syscall_solaris.go b/libgo/go/syscall/syscall_solaris.go
index 673ba82..13c60a4 100644
--- a/libgo/go/syscall/syscall_solaris.go
+++ b/libgo/go/syscall/syscall_solaris.go
@@ -6,6 +6,8 @@ package syscall
 
 import "unsafe"
 
+const _F_DUP2FD_CLOEXEC = F_DUP2FD_CLOEXEC
+
 func (ts *Timestruc) Unix() (sec int64, nsec int64) {
 	return int64(ts.Sec), int64(ts.Nsec)
 }
diff --git a/libgo/go/syscall/syscall_unix.go b/libgo/go/syscall/syscall_unix.go
index 730cbfa..bd9b79c 100644
--- a/libgo/go/syscall/syscall_unix.go
+++ b/libgo/go/syscall/syscall_unix.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
 
 package syscall
 
@@ -157,6 +156,9 @@ func Read(fd int, p []byte) (n int, err error) {
 	if msanenabled && n > 0 {
 		msanWrite(unsafe.Pointer(&p[0]), n)
 	}
+	if asanenabled && n > 0 {
+		asanWrite(unsafe.Pointer(&p[0]), n)
+	}
 	return
 }
 
@@ -178,6 +180,9 @@ func Write(fd int, p []byte) (n int, err error) {
 	if msanenabled && n > 0 {
 		msanRead(unsafe.Pointer(&p[0]), n)
 	}
+	if asanenabled && n > 0 {
+		asanRead(unsafe.Pointer(&p[0]), n)
+	}
 	return
 }
 
diff --git a/libgo/go/syscall/syscall_unix_test.go b/libgo/go/syscall/syscall_unix_test.go
index d3d4673..205c600 100644
--- a/libgo/go/syscall/syscall_unix_test.go
+++ b/libgo/go/syscall/syscall_unix_test.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
 
 package syscall_test
 
@@ -87,16 +86,24 @@ func TestFcntlFlock(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Open failed: %v", err)
 		}
-		defer syscall.Close(fd)
-		if err := syscall.Ftruncate(fd, 1<<20); err != nil {
+		// f takes ownership of fd, and will close it.
+		//
+		// N.B. This defer is also necessary to keep f alive
+		// while we use its fd, preventing its finalizer from
+		// executing.
+		f := os.NewFile(uintptr(fd), name)
+		defer f.Close()
+
+		if err := syscall.Ftruncate(int(f.Fd()), 1<<20); err != nil {
 			t.Fatalf("Ftruncate(1<<20) failed: %v", err)
 		}
-		if err := syscall.FcntlFlock(uintptr(fd), syscall.F_SETLK, &flock); err != nil {
+		if err := syscall.FcntlFlock(f.Fd(), syscall.F_SETLK, &flock); err != nil {
 			t.Fatalf("FcntlFlock(F_SETLK) failed: %v", err)
 		}
+
 		cmd := exec.Command(os.Args[0], "-test.run=^TestFcntlFlock$")
 		cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
-		cmd.ExtraFiles = []*os.File{os.NewFile(uintptr(fd), name)}
+		cmd.ExtraFiles = []*os.File{f}
 		out, err := cmd.CombinedOutput()
 		if len(out) > 0 || err != nil {
 			t.Fatalf("child process: %q, %v", out, err)
@@ -254,6 +261,10 @@ func passFDChild() {
 		fmt.Printf("TempFile: %v", err)
 		return
 	}
+	// N.B. This defer is also necessary to keep f alive
+	// while we use its fd, preventing its finalizer from
+	// executing.
+	defer f.Close()
 
 	f.Write([]byte("Hello from child process!\n"))
 	f.Seek(0, io.SeekStart)
diff --git a/libgo/go/syscall/tables_js.go b/libgo/go/syscall/tables_js.go
index 64d9584..78a1e71 100644
--- a/libgo/go/syscall/tables_js.go
+++ b/libgo/go/syscall/tables_js.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build js && wasm
-// +build js,wasm
 
 package syscall
 
diff --git a/libgo/go/syscall/time_fake.go b/libgo/go/syscall/time_fake.go
index cf88aeb..b60fe60 100644
--- a/libgo/go/syscall/time_fake.go
+++ b/libgo/go/syscall/time_fake.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build faketime
-// +build faketime
 
 package syscall
 
diff --git a/libgo/go/syscall/time_nofake.go b/libgo/go/syscall/time_nofake.go
index 5eaa2da..231875d 100644
--- a/libgo/go/syscall/time_nofake.go
+++ b/libgo/go/syscall/time_nofake.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !faketime
-// +build !faketime
 
 package syscall
 
diff --git a/libgo/go/syscall/timestruct.go b/libgo/go/syscall/timestruct.go
index f22c282..3a98985 100644
--- a/libgo/go/syscall/timestruct.go
+++ b/libgo/go/syscall/timestruct.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || hurd || (js && wasm) || linux || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd hurd js,wasm linux netbsd openbsd solaris
 
 package syscall