libgo: update Hurd support

Patches from Svante Signell for PR go/104290.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/386797

8 files changed, 297 insertions, 9 deletions

diff --git a/libgo/go/internal/testenv/testenv_unix.go b/libgo/go/internal/testenv/testenv_unix.go
index 3dc5daf45e7..19112076a3c 100644
--- a/libgo/go/internal/testenv/testenv_unix.go
+++ b/libgo/go/internal/testenv/testenv_unix.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 || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+//go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
 
 package testenv
 
diff --git a/libgo/go/os/exec/internal/fdtest/exists_unix.go b/libgo/go/os/exec/internal/fdtest/exists_unix.go
index 49f264cebda..fca328fc65b 100644
--- a/libgo/go/os/exec/internal/fdtest/exists_unix.go
+++ b/libgo/go/os/exec/internal/fdtest/exists_unix.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 || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+//go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
 
 // Package fdtest provides test helpers for working with file descriptors across exec.
 package fdtest
diff --git a/libgo/go/os/user/cgo_listgroups_unix.go b/libgo/go/os/user/cgo_listgroups_unix.go
index 5621c1a63aa..09ec1cc5d2a 100644
--- a/libgo/go/os/user/cgo_listgroups_unix.go
+++ b/libgo/go/os/user/cgo_listgroups_unix.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 (dragonfly || darwin || freebsd || (!android && linux) || netbsd || openbsd || (solaris && !illumos)) && cgo && !osusergo
+//go:build (dragonfly || darwin || freebsd || hurd || (!android && linux) || netbsd || openbsd || (solaris && !illumos)) && cgo && !osusergo
 
 package user
 
diff --git a/libgo/go/os/user/getgrouplist_unix.go b/libgo/go/os/user/getgrouplist_unix.go
index 527d941308e..e97e0bc64f6 100644
--- a/libgo/go/os/user/getgrouplist_unix.go
+++ b/libgo/go/os/user/getgrouplist_unix.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 (dragonfly || freebsd || (!android && linux) || netbsd || openbsd || (solaris && !illumos)) && cgo && !osusergo
+//go:build (dragonfly || freebsd || hurd || (!android && linux) || netbsd || openbsd || (solaris && !illumos)) && cgo && !osusergo
 
 package user
 
diff --git a/libgo/go/runtime/netpoll_hurd.go b/libgo/go/runtime/netpoll_hurd.go
index 3d3fa4b76d3..96b013845fa 100644
--- a/libgo/go/runtime/netpoll_hurd.go
+++ b/libgo/go/runtime/netpoll_hurd.go
@@ -238,10 +238,7 @@ retry:
 			pfd.events &= ^_POLLOUT
 		}
 		if mode != 0 {
-			pds[i].everr = false
-			if pfd.revents == _POLLERR {
-				pds[i].everr = true
-			}
+			pds[i].setEventErr(pfd.revents == _POLLERR)
 			netpollready(&toRun, pds[i], mode)
 			n--
 		}
diff --git a/libgo/go/runtime/os_hurd.go b/libgo/go/runtime/os_hurd.go
index 8bde23edb81..9750a4822cf 100644
--- a/libgo/go/runtime/os_hurd.go
+++ b/libgo/go/runtime/os_hurd.go
@@ -129,3 +129,16 @@ func osinit() {
 		physPageSize = uintptr(getPageSize())
 	}
 }
+
+func setProcessCPUProfiler(hz int32) {
+	setProcessCPUProfilerTimer(hz)
+}
+
+func setThreadCPUProfiler(hz int32) {
+	setThreadCPUProfilerHz(hz)
+}
+
+//go:nosplit
+func validSIGPROF(mp *m, c *sigctxt) bool {
+	return true
+}
diff --git a/libgo/go/syscall/exec_bsd.go b/libgo/go/syscall/exec_bsd.go
index ff88bc45366..86e513efdea 100644
--- a/libgo/go/syscall/exec_bsd.go
+++ b/libgo/go/syscall/exec_bsd.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 || dragonfly || hurd || netbsd || openbsd || solaris
+//go:build aix || darwin || dragonfly || netbsd || openbsd || solaris
 
 package syscall
 
diff --git a/libgo/go/syscall/exec_hurd.go b/libgo/go/syscall/exec_hurd.go
new file mode 100644
index 00000000000..06df513c55c
--- /dev/null
+++ b/libgo/go/syscall/exec_hurd.go
@@ -0,0 +1,278 @@
+// Copyright 2022 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 hurd
+
+package syscall
+
+import (
+	"runtime"
+	"unsafe"
+)
+
+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.
+}
+
+// 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
+	)
+
+	// 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_ptr(sys.Ctty, TIOCSPGRP, unsafe.Pointer(&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 unsafe.Pointer
+		if ngroups > 0 {
+			groups = unsafe.Pointer(&cred.Groups[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
+		}
+	}
+
+	// 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 {
+		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)
+		}
+		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++
+			}
+			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)
+			}
+			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 {
+		_, err1 = raw_ioctl(0, TIOCNOTTY, 0)
+		if err1 != 0 {
+			goto childerror
+		}
+	}
+
+	// Set the controlling TTY to Ctty
+	if sys.Setctty {
+		if TIOCSCTTY == 0 {
+			err1 = ENOSYS
+			goto childerror
+		}
+		_, err1 = raw_ioctl(sys.Ctty, 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)
+	}
+}