syscall: add Hurd support

Loosely based on a patch by Svante Signell.

Change-Id: I7e7efa1cc295c800d03ed5a5eaf1b2e94b5cf3bf
Reviewed-on: https://go-review.googlesource.com/c/161518
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/libgo/go/syscall/errstr_linux.go b/libgo/go/syscall/errstr_glibc.go
similarity index 89%
rename from libgo/go/syscall/errstr_linux.go
rename to libgo/go/syscall/errstr_glibc.go
index 7156b79..5b19e6f 100644
--- a/libgo/go/syscall/errstr_linux.go
+++ b/libgo/go/syscall/errstr_glibc.go
@@ -1,4 +1,4 @@
-// errstr_linux.go -- GNU/Linux specific error strings.
+// errstr_glibc.go -- GNU/Linux and GNU/Hurd specific error strings.
 
 // Copyright 2010 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -7,6 +7,8 @@
 // We use this rather than errstr.go because on GNU/Linux sterror_r
 // returns a pointer to the error message, and may not use buf at all.
 
+// +build hurd linux
+
 package syscall
 
 import "unsafe"
diff --git a/libgo/go/syscall/exec_unix.go b/libgo/go/syscall/exec_unix.go
index 54e322c..bad2ce4 100644
--- a/libgo/go/syscall/exec_unix.go
+++ b/libgo/go/syscall/exec_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.
 
-// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
 
 // Fork, exec, wait, etc.
 
@@ -319,7 +319,7 @@
 	runtime_BeforeExec()
 
 	var err1 error
-	if runtime.GOOS == "solaris" || runtime.GOOS == "aix" {
+	if runtime.GOOS == "solaris" || runtime.GOOS == "aix" || runtime.GOOS == "hurd" {
 		// RawSyscall should never be used on Solaris or AIX.
 		err1 = execveLibc(
 			uintptr(unsafe.Pointer(argv0p)),
diff --git a/libgo/go/syscall/libcall_glibc.go b/libgo/go/syscall/libcall_glibc.go
new file mode 100644
index 0000000..a90fc9b
--- /dev/null
+++ b/libgo/go/syscall/libcall_glibc.go
@@ -0,0 +1,135 @@
+// Copyright 2009 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.
+
+// +build hurd linux
+
+// glibc library calls.
+
+package syscall
+
+import (
+	"internal/race"
+	"unsafe"
+)
+
+//sys	Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
+//__go_openat(dirfd _C_int, path *byte, flags _C_int, mode Mode_t) _C_int
+
+//sys	futimesat(dirfd int, path *byte, times *[2]Timeval) (err error)
+//futimesat(dirfd _C_int, path *byte, times *[2]Timeval) _C_int
+func Futimesat(dirfd int, path string, tv []Timeval) (err error) {
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	return futimesat(dirfd, StringBytePtr(path), (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
+func Futimes(fd int, tv []Timeval) (err error) {
+	// Believe it or not, this is the best we can do on GNU/Linux
+	// (and is what glibc does).
+	return Utimes("/proc/self/fd/"+itoa(fd), tv)
+}
+
+//sys	ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
+//ptrace(request _C_int, pid Pid_t, addr *byte, data *byte) _C_long
+
+//sys	accept4(fd int, sa *RawSockaddrAny, len *Socklen_t, flags int) (nfd int, err error)
+//accept4(fd _C_int, sa *RawSockaddrAny, len *Socklen_t, flags _C_int) _C_int
+
+func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {
+	var rsa RawSockaddrAny
+	var len Socklen_t = SizeofSockaddrAny
+	nfd, err = accept4(fd, &rsa, &len, flags)
+	if err != nil {
+		return -1, nil, err
+	}
+	sa, err = anyToSockaddr(&rsa)
+	if err != nil {
+		Close(nfd)
+		return -1, nil, err
+	}
+	return nfd, sa, nil
+}
+
+//sysnb	Dup3(oldfd int, newfd int, flags int) (err error)
+//dup3(oldfd _C_int, newfd _C_int, flags _C_int) _C_int
+
+//sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
+//faccessat(dirfd _C_int, pathname *byte, mode _C_int, flags _C_int) _C_int
+
+//sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
+//fallocate(fd _C_int, mode _C_int, offset Offset_t, len Offset_t) _C_int
+
+//sys	Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
+//fchmodat(dirfd _C_int, pathname *byte, mode Mode_t, flags _C_int) _C_int
+
+//sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
+//fchownat(dirfd _C_int, path *byte, owner Uid_t, group Gid_t, flags _C_int) _C_int
+
+//sys	Flock(fd int, how int) (err error)
+//flock(fd _C_int, how _C_int) _C_int
+
+func Getdents(fd int, buf []byte) (n int, err error) {
+	var p *byte
+	if len(buf) > 0 {
+		p = &buf[0]
+	} else {
+		p = (*byte)(unsafe.Pointer(&_zero))
+	}
+	s := SYS_GETDENTS64
+	if s == 0 {
+		s = SYS_GETDENTS
+	}
+	r1, _, errno := Syscall(uintptr(s), uintptr(fd), uintptr(unsafe.Pointer(p)), uintptr(len(buf)))
+	n = int(r1)
+	if n < 0 {
+		err = errno
+	}
+	return
+}
+
+func ReadDirent(fd int, buf []byte) (n int, err error) {
+	return Getdents(fd, buf)
+}
+
+//sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
+//mkdirat(dirfd _C_int, path *byte, mode Mode_t) _C_int
+
+//sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
+//mknodat(dirfd _C_int, path *byte, mode Mode_t, dev _dev_t) _C_int
+
+//sysnb	pipe2(p *[2]_C_int, flags int) (err error)
+//pipe2(p *[2]_C_int, flags _C_int) _C_int
+func Pipe2(p []int, flags int) (err error) {
+	if len(p) != 2 {
+		return EINVAL
+	}
+	var pp [2]_C_int
+	err = pipe2(&pp, flags)
+	p[0] = int(pp[0])
+	p[1] = int(pp[1])
+	return
+}
+
+//sys	sendfile(outfd int, infd int, offset *Offset_t, count int) (written int, err error)
+//sendfile64(outfd _C_int, infd _C_int, offset *Offset_t, count Size_t) Ssize_t
+func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
+	if race.Enabled {
+		race.ReleaseMerge(unsafe.Pointer(&ioSync))
+	}
+	var soff Offset_t
+	var psoff *Offset_t
+	if offset != nil {
+		soff = Offset_t(*offset)
+		psoff = &soff
+	}
+	written, err = sendfile(outfd, infd, psoff, count)
+	if offset != nil {
+		*offset = int64(soff)
+	}
+	return
+}
+
+//sys	SyncFileRange(fd int, off int64, n int64, flags int) (err error)
+//sync_file_range(fd _C_int, off Offset_t, n Offset_t, flags _C_uint) _C_int
diff --git a/libgo/go/syscall/libcall_hurd.go b/libgo/go/syscall/libcall_hurd.go
new file mode 100644
index 0000000..f0e038c
--- /dev/null
+++ b/libgo/go/syscall/libcall_hurd.go
@@ -0,0 +1,18 @@
+// Copyright 2014 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.
+
+// GNU/Hurd library calls.
+
+package syscall
+
+// Dummy function
+func raw_ptrace(request int, pid int, addr *byte, data *byte) Errno {
+	return ENOSYS
+}
+
+//sys   Fstatfs(fd int, buf *Statfs_t) (err error)
+//fstatfs(fd _C_int, buf *Statfs_t) _C_int
+
+// For exec_unix.go.
+const SYS_EXECVE = 0
diff --git a/libgo/go/syscall/libcall_hurd_386.go b/libgo/go/syscall/libcall_hurd_386.go
new file mode 100644
index 0000000..783429c
--- /dev/null
+++ b/libgo/go/syscall/libcall_hurd_386.go
@@ -0,0 +1,11 @@
+// Copyright 2012 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.
+
+// GNU/Hurd library calls 386 specific derived from libcall_linux_386.go.
+// Remove Iopl, iopl.
+
+package syscall
+
+//sys	Ioperm(from int, num int, on int) (err error)
+//ioperm(from _C_long, num _C_long, on _C_int) _C_int
diff --git a/libgo/go/syscall/libcall_linux.go b/libgo/go/syscall/libcall_linux.go
index 7903328..88286c0 100644
--- a/libgo/go/syscall/libcall_linux.go
+++ b/libgo/go/syscall/libcall_linux.go
@@ -7,31 +7,9 @@
 package syscall
 
 import (
-	"internal/race"
 	"unsafe"
 )
 
-//sys	Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
-//__go_openat(dirfd _C_int, path *byte, flags _C_int, mode Mode_t) _C_int
-
-//sys	futimesat(dirfd int, path *byte, times *[2]Timeval) (err error)
-//futimesat(dirfd _C_int, path *byte, times *[2]Timeval) _C_int
-func Futimesat(dirfd int, path string, tv []Timeval) (err error) {
-	if len(tv) != 2 {
-		return EINVAL
-	}
-	return futimesat(dirfd, StringBytePtr(path), (*[2]Timeval)(unsafe.Pointer(&tv[0])))
-}
-
-func Futimes(fd int, tv []Timeval) (err error) {
-	// Believe it or not, this is the best we can do on GNU/Linux
-	// (and is what glibc does).
-	return Utimes("/proc/self/fd/"+itoa(fd), tv)
-}
-
-//sys	ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
-//ptrace(request _C_int, pid Pid_t, addr *byte, data *byte) _C_long
-
 //sysnb raw_ptrace(request int, pid int, addr *byte, data *byte) (err Errno)
 //ptrace(request _C_int, pid Pid_t, addr *byte, data *byte) _C_long
 
@@ -169,48 +147,12 @@
 	return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "")
 }
 
-//sys	accept4(fd int, sa *RawSockaddrAny, len *Socklen_t, flags int) (nfd int, err error)
-//accept4(fd _C_int, sa *RawSockaddrAny, len *Socklen_t, flags _C_int) _C_int
-
-func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {
-	var rsa RawSockaddrAny
-	var len Socklen_t = SizeofSockaddrAny
-	nfd, err = accept4(fd, &rsa, &len, flags)
-	if err != nil {
-		return -1, nil, err
-	}
-	sa, err = anyToSockaddr(&rsa)
-	if err != nil {
-		Close(nfd)
-		return -1, nil, err
-	}
-	return nfd, sa, nil
-}
-
 //sys	Acct(path string) (err error)
 //acct(path *byte) _C_int
 
 //sys	Adjtimex(buf *Timex) (state int, err error)
 //adjtimex(buf *Timex) _C_int
 
-//sysnb	Dup3(oldfd int, newfd int, flags int) (err error)
-//dup3(oldfd _C_int, newfd _C_int, flags _C_int) _C_int
-
-//sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
-//faccessat(dirfd _C_int, pathname *byte, mode _C_int, flags _C_int) _C_int
-
-//sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
-//fallocate(fd _C_int, mode _C_int, offset Offset_t, len Offset_t) _C_int
-
-//sys	Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
-//fchmodat(dirfd _C_int, pathname *byte, mode Mode_t, flags _C_int) _C_int
-
-//sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
-//fchownat(dirfd _C_int, path *byte, owner Uid_t, group Gid_t, flags _C_int) _C_int
-
-//sys	Flock(fd int, how int) (err error)
-//flock(fd _C_int, how _C_int) _C_int
-
 //sys	Fstatfs(fd int, buf *Statfs_t) (err error)
 //fstatfs64(fd _C_int, buf *Statfs_t) _C_int
 
@@ -219,29 +161,6 @@
 	return int(r1)
 }
 
-func Getdents(fd int, buf []byte) (n int, err error) {
-	var p *byte
-	if len(buf) > 0 {
-		p = &buf[0]
-	} else {
-		p = (*byte)(unsafe.Pointer(&_zero))
-	}
-	s := SYS_GETDENTS64
-	if s == 0 {
-		s = SYS_GETDENTS
-	}
-	r1, _, errno := Syscall(uintptr(s), uintptr(fd), uintptr(unsafe.Pointer(p)), uintptr(len(buf)))
-	n = int(r1)
-	if n < 0 {
-		err = errno
-	}
-	return
-}
-
-func ReadDirent(fd int, buf []byte) (n int, err error) {
-	return Getdents(fd, buf)
-}
-
 //sys	Getxattr(path string, attr string, dest []byte) (sz int, err error)
 //getxattr(path *byte, attr *byte, buf *byte, count Size_t) Ssize_t
 
@@ -263,25 +182,6 @@
 //sys	Listxattr(path string, dest []byte) (sz int, err error)
 //listxattr(path *byte, list *byte, size Size_t) Ssize_t
 
-//sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
-//mkdirat(dirfd _C_int, path *byte, mode Mode_t) _C_int
-
-//sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
-//mknodat(dirfd _C_int, path *byte, mode Mode_t, dev _dev_t) _C_int
-
-//sysnb	pipe2(p *[2]_C_int, flags int) (err error)
-//pipe2(p *[2]_C_int, flags _C_int) _C_int
-func Pipe2(p []int, flags int) (err error) {
-	if len(p) != 2 {
-		return EINVAL
-	}
-	var pp [2]_C_int
-	err = pipe2(&pp, flags)
-	p[0] = int(pp[0])
-	p[1] = int(pp[1])
-	return
-}
-
 //sys	PivotRoot(newroot string, putold string) (err error)
 //pivot_root(newroot *byte, putold *byte) _C_int
 
@@ -291,25 +191,6 @@
 //sys	Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error)
 //renameat(olddirfd _C_int, oldpath *byte, newdirfd _C_int, newpath *byte) _C_int
 
-//sys	sendfile(outfd int, infd int, offset *Offset_t, count int) (written int, err error)
-//sendfile64(outfd _C_int, infd _C_int, offset *Offset_t, count Size_t) Ssize_t
-func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
-	if race.Enabled {
-		race.ReleaseMerge(unsafe.Pointer(&ioSync))
-	}
-	var soff Offset_t
-	var psoff *Offset_t
-	if offset != nil {
-		soff = Offset_t(*offset)
-		psoff = &soff
-	}
-	written, err = sendfile(outfd, infd, psoff, count)
-	if offset != nil {
-		*offset = int64(soff)
-	}
-	return
-}
-
 //sys	Setfsgid(gid int) (err error)
 //setfsgid(gid Gid_t) _C_int
 
@@ -353,9 +234,6 @@
 //sys	Statfs(path string, buf *Statfs_t) (err error)
 //statfs64(path *byte, buf *Statfs_t) _C_int
 
-//sys	SyncFileRange(fd int, off int64, n int64, flags int) (err error)
-//sync_file_range(fd _C_int, off Offset_t, n Offset_t, flags _C_uint) _C_int
-
 //sysnb	Sysinfo(info *Sysinfo_t) (err error)
 //sysinfo(info *Sysinfo_t) _C_int
 
diff --git a/libgo/go/syscall/libcall_posix.go b/libgo/go/syscall/libcall_posix.go
index f572763..d2fa0d9 100644
--- a/libgo/go/syscall/libcall_posix.go
+++ b/libgo/go/syscall/libcall_posix.go
@@ -9,8 +9,6 @@
 // Note that sometimes we use a lowercase //sys name and
 // wrap it in our own nicer implementation.
 
-// +build !hurd
-
 package syscall
 
 import "unsafe"
@@ -267,9 +265,6 @@
 //sys	Mknod(path string, mode uint32, dev int) (err error)
 //mknod(path *byte, mode Mode_t, dev _dev_t) _C_int
 
-//sys	Mount(source string, target string, fstype string, flags uintptr, data string) (err error)
-//mount(source *byte, target *byte, fstype *byte, flags _C_long, data *byte) _C_int
-
 //sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
 //nanosleep(time *Timespec, leftover *Timespec) _C_int
 
@@ -355,9 +350,6 @@
 //sys	munmap(addr uintptr, length uintptr) (err error)
 //munmap(addr *byte, length Size_t) _C_int
 
-//sys Madvise(b []byte, advice int) (err error)
-//madvise(addr *byte, len Size_t, advice _C_int) _C_int
-
 //sys	Mprotect(b []byte, prot int) (err error)
 //mprotect(addr *byte, len Size_t, prot _C_int) _C_int
 
diff --git a/libgo/go/syscall/libcall_posix_nonhurd.go b/libgo/go/syscall/libcall_posix_nonhurd.go
new file mode 100644
index 0000000..afdca3f
--- /dev/null
+++ b/libgo/go/syscall/libcall_posix_nonhurd.go
@@ -0,0 +1,17 @@
+// Copyright 2019 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.
+
+// +build !hurd
+
+package syscall
+
+// Removed the mount call for GNU/Hurd, it exists but use translators.
+// Functionality is not the same as descibed in Linux <sys/mount.h>.
+// Removed the madvise call for GNU/Hurd, not yet implemented.
+
+//sys	Mount(source string, target string, fstype string, flags uintptr, data string) (err error)
+//mount(source *byte, target *byte, fstype *byte, flags _C_long, data *byte) _C_int
+
+//sys Madvise(b []byte, advice int) (err error)
+//madvise(addr *byte, len Size_t, advice _C_int) _C_int
diff --git a/libgo/go/syscall/syscall_linux.go b/libgo/go/syscall/syscall_glibc.go
similarity index 96%
rename from libgo/go/syscall/syscall_linux.go
rename to libgo/go/syscall/syscall_glibc.go
index d2d49c3..b40f297 100644
--- a/libgo/go/syscall/syscall_linux.go
+++ b/libgo/go/syscall/syscall_glibc.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build hurd linux
+
 package syscall
 
 import "unsafe"