syscall: make pwd process-wide on Plan 9

On Plan 9, the pwd is apparently per-thread not per process. That
means different goroutines saw different current directories, even
changing within a goroutine as they were scheduled.

Instead, track the the process-wide pwd protected by a mutex in the
syscall package and set the current goroutine thread's pwd to the
correct once at critical points.

Fixes #9428

Change-Id: I928e90886355be4a95c2be834f5883e2b50fc0cf
Reviewed-on: https://go-review.googlesource.com/6350
Reviewed-by: David du Colombier <0intro@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

6 files changed, 304 insertions, 193 deletions

diff --git a/src/syscall/env_plan9.go b/src/syscall/env_plan9.go
index 9ea36c886a..cbf7f41092 100644
--- a/src/syscall/env_plan9.go
+++ b/src/syscall/env_plan9.go
@@ -16,7 +16,7 @@ var (
 )
 
 func readenv(key string) (string, error) {
-	fd, err := Open("/env/"+key, O_RDONLY)
+	fd, err := open("/env/"+key, O_RDONLY)
 	if err != nil {
 		return "", err
 	}
@@ -35,7 +35,7 @@ func readenv(key string) (string, error) {
 }
 
 func writeenv(key, value string) error {
-	fd, err := Create("/env/"+key, O_RDWR, 0666)
+	fd, err := create("/env/"+key, O_RDWR, 0666)
 	if err != nil {
 		return err
 	}
@@ -86,7 +86,7 @@ func Unsetenv(key string) error {
 }
 
 func Environ() []string {
-	fd, err := Open("/env", O_RDONLY)
+	fd, err := open("/env", O_RDONLY)
 	if err != nil {
 		return nil
 	}
diff --git a/src/syscall/exec_plan9.go b/src/syscall/exec_plan9.go
index 45ee542bb0..ed358385b9 100644
--- a/src/syscall/exec_plan9.go
+++ b/src/syscall/exec_plan9.go
@@ -396,9 +396,15 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 		return 0, err
 	}
 
+	destDir := attr.Dir
+	if destDir == "" {
+		wdmu.Lock()
+		destDir = wdStr
+		wdmu.Unlock()
+	}
 	var dir *byte
-	if attr.Dir != "" {
-		dir, err = BytePtrFromString(attr.Dir)
+	if destDir != "" {
+		dir, err = BytePtrFromString(destDir)
 		if err != nil {
 			return 0, err
 		}
diff --git a/src/syscall/pwd_plan9.go b/src/syscall/pwd_plan9.go
new file mode 100644
index 0000000000..f8cafad92e
--- /dev/null
+++ b/src/syscall/pwd_plan9.go
@@ -0,0 +1,85 @@
+// 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.
+
+// The working directory in Plan 9 is effectively per P, so different
+// goroutines and even the same goroutine as it's rescheduled on
+// different Ps can see different working directories.
+//
+// Instead, track a Go process-wide intent of the current working directory,
+// and switch to it at important points.
+
+package syscall
+
+import "sync"
+
+var (
+	wdmu  sync.Mutex // guards following
+	wdSet bool
+	wdStr string
+)
+
+func Fixwd() {
+	wdmu.Lock()
+	defer wdmu.Unlock()
+	fixwdLocked()
+}
+
+func fixwdLocked() {
+	if !wdSet {
+		return
+	}
+	wd, err := getwd()
+	if err != nil {
+		return
+	}
+	if wd == wdStr {
+		return
+	}
+	if err := chdir(wdStr); err != nil {
+		return
+	}
+}
+
+// goroutine-specific getwd
+func getwd() (wd string, err error) {
+	fd, err := open(".", O_RDONLY)
+	if err != nil {
+		return "", err
+	}
+	defer Close(fd)
+	return Fd2path(fd)
+}
+
+func Getwd() (wd string, err error) {
+	wdmu.Lock()
+	defer wdmu.Unlock()
+
+	if wdSet {
+		return wdStr, nil
+	}
+	wd, err = getwd()
+	if err != nil {
+		return
+	}
+	wdSet = true
+	wdStr = wd
+	return wd, nil
+}
+
+func Chdir(path string) error {
+	wdmu.Lock()
+	defer wdmu.Unlock()
+
+	if err := chdir(path); err != nil {
+		return err
+	}
+
+	wd, err := getwd()
+	if err != nil {
+		return err
+	}
+	wdSet = true
+	wdStr = wd
+	return nil
+}
diff --git a/src/syscall/syscall_plan9.go b/src/syscall/syscall_plan9.go
index 618e02cecf..79857ccbd6 100644
--- a/src/syscall/syscall_plan9.go
+++ b/src/syscall/syscall_plan9.go
@@ -129,17 +129,6 @@ func Write(fd int, p []byte) (n int, err error) {
 
 var ioSync int64
 
-func Getwd() (wd string, err error) {
-	fd, e := Open(".", O_RDONLY)
-
-	if e != nil {
-		return "", e
-	}
-	defer Close(fd)
-
-	return Fd2path(fd)
-}
-
 //sys	fd2path(fd int, buf []byte) (err error)
 func Fd2path(fd int) (path string, err error) {
 	var buf [512]byte
@@ -242,6 +231,7 @@ func Await(w *Waitmsg) (err error) {
 }
 
 func Unmount(name, old string) (err error) {
+	Fixwd()
 	oldp, err := BytePtrFromString(old)
 	if err != nil {
 		return err
@@ -325,17 +315,47 @@ func Getgroups() (gids []int, err error) {
 	return make([]int, 0), nil
 }
 
+//sys	open(path string, mode int) (fd int, err error)
+func Open(path string, mode int) (fd int, err error) {
+	Fixwd()
+	return open(path, mode)
+}
+
+//sys	create(path string, mode int, perm uint32) (fd int, err error)
+func Create(path string, mode int, perm uint32) (fd int, err error) {
+	Fixwd()
+	return create(path, mode, perm)
+}
+
+//sys	remove(path string) (err error)
+func Remove(path string) error {
+	Fixwd()
+	return remove(path)
+}
+
+//sys	stat(path string, edir []byte) (n int, err error)
+func Stat(path string, edir []byte) (n int, err error) {
+	Fixwd()
+	return stat(path, edir)
+}
+
+//sys	bind(name string, old string, flag int) (err error)
+func Bind(name string, old string, flag int) (err error) {
+	Fixwd()
+	return bind(name, old, flag)
+}
+
+//sys	wstat(path string, edir []byte) (err error)
+func Wstat(path string, edir []byte) (err error) {
+	Fixwd()
+	return wstat(path, edir)
+}
+
+//sys	chdir(path string) (err error)
 //sys	Dup(oldfd int, newfd int) (fd int, err error)
-//sys	Open(path string, mode int) (fd int, err error)
-//sys	Create(path string, mode int, perm uint32) (fd int, err error)
-//sys	Remove(path string) (err error)
 //sys	Pread(fd int, p []byte, offset int64) (n int, err error)
 //sys	Pwrite(fd int, p []byte, offset int64) (n int, err error)
 //sys	Close(fd int) (err error)
-//sys	Chdir(path string) (err error)
-//sys	Bind(name string, old string, flag int) (err error)
 //sys	Mount(fd int, afd int, old string, flag int, aname string) (err error)
-//sys	Stat(path string, edir []byte) (n int, err error)
 //sys	Fstat(fd int, edir []byte) (n int, err error)
-//sys	Wstat(path string, edir []byte) (err error)
 //sys	Fwstat(fd int, edir []byte) (err error)
diff --git a/src/syscall/zsyscall_plan9_386.go b/src/syscall/zsyscall_plan9_386.go
index 44b74d71c1..aa9f588edc 100644
--- a/src/syscall/zsyscall_plan9_386.go
+++ b/src/syscall/zsyscall_plan9_386.go
@@ -50,18 +50,7 @@ func await(s []byte) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Dup(oldfd int, newfd int) (fd int, err error) {
-	r0, _, e1 := Syscall(SYS_DUP, uintptr(oldfd), uintptr(newfd), 0)
-	fd = int(r0)
-	if int32(r0) == -1 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Open(path string, mode int) (fd int, err error) {
+func open(path string, mode int) (fd int, err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
@@ -78,7 +67,7 @@ func Open(path string, mode int) (fd int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Create(path string, mode int, perm uint32) (fd int, err error) {
+func create(path string, mode int, perm uint32) (fd int, err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
@@ -95,7 +84,7 @@ func Create(path string, mode int, perm uint32) (fd int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Remove(path string) (err error) {
+func remove(path string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
@@ -111,14 +100,20 @@ func Remove(path string) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pread(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
+func stat(path string, edir []byte) (n int, err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	var _p1 unsafe.Pointer
+	if len(edir) > 0 {
+		_p1 = unsafe.Pointer(&edir[0])
 	} else {
-		_p0 = unsafe.Pointer(&_zero)
+		_p1 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall6(SYS_PREAD, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
+	r0, _, e1 := Syscall(SYS_STAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
+	use(unsafe.Pointer(_p0))
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -128,25 +123,20 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
+func bind(name string, old string, flag int) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(name)
+	if err != nil {
+		return
 	}
-	r0, _, e1 := Syscall6(SYS_PWRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
-	n = int(r0)
-	if int32(r0) == -1 {
-		err = e1
+	var _p1 *byte
+	_p1, err = BytePtrFromString(old)
+	if err != nil {
+		return
 	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Close(fd int) (err error) {
-	r0, _, e1 := Syscall(SYS_CLOSE, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_BIND, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flag))
+	use(unsafe.Pointer(_p0))
+	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -155,13 +145,19 @@ func Close(fd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Chdir(path string) (err error) {
+func wstat(path string, edir []byte) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
 		return
 	}
-	r0, _, e1 := Syscall(SYS_CHDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	var _p1 unsafe.Pointer
+	if len(edir) > 0 {
+		_p1 = unsafe.Pointer(&edir[0])
+	} else {
+		_p1 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS_WSTAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
 	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
@@ -171,20 +167,14 @@ func Chdir(path string) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Bind(name string, old string, flag int) (err error) {
+func chdir(path string) (err error) {
 	var _p0 *byte
-	_p0, err = BytePtrFromString(name)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(old)
+	_p0, err = BytePtrFromString(path)
 	if err != nil {
 		return
 	}
-	r0, _, e1 := Syscall(SYS_BIND, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flag))
+	r0, _, e1 := Syscall(SYS_CHDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -193,20 +183,9 @@ func Bind(name string, old string, flag int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Mount(fd int, afd int, old string, flag int, aname string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(old)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(aname)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := Syscall6(SYS_MOUNT, uintptr(fd), uintptr(afd), uintptr(unsafe.Pointer(_p0)), uintptr(flag), uintptr(unsafe.Pointer(_p1)), 0)
-	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
+func Dup(oldfd int, newfd int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(oldfd), uintptr(newfd), 0)
+	fd = int(r0)
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -215,20 +194,14 @@ func Mount(fd int, afd int, old string, flag int, aname string) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Stat(path string, edir []byte) (n int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 unsafe.Pointer
-	if len(edir) > 0 {
-		_p1 = unsafe.Pointer(&edir[0])
+func Pread(fd int, p []byte, offset int64) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(p) > 0 {
+		_p0 = unsafe.Pointer(&p[0])
 	} else {
-		_p1 = unsafe.Pointer(&_zero)
+		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_STAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
+	r0, _, e1 := Syscall6(SYS_PREAD, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -238,14 +211,14 @@ func Stat(path string, edir []byte) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Fstat(fd int, edir []byte) (n int, err error) {
+func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
-	if len(edir) > 0 {
-		_p0 = unsafe.Pointer(&edir[0])
+	if len(p) > 0 {
+		_p0 = unsafe.Pointer(&p[0])
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_FSTAT, uintptr(fd), uintptr(_p0), uintptr(len(edir)))
+	r0, _, e1 := Syscall6(SYS_PWRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -255,20 +228,47 @@ func Fstat(fd int, edir []byte) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Wstat(path string, edir []byte) (err error) {
+func Close(fd int) (err error) {
+	r0, _, e1 := Syscall(SYS_CLOSE, uintptr(fd), 0, 0)
+	if int32(r0) == -1 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Mount(fd int, afd int, old string, flag int, aname string) (err error) {
 	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
+	_p0, err = BytePtrFromString(old)
 	if err != nil {
 		return
 	}
-	var _p1 unsafe.Pointer
+	var _p1 *byte
+	_p1, err = BytePtrFromString(aname)
+	if err != nil {
+		return
+	}
+	r0, _, e1 := Syscall6(SYS_MOUNT, uintptr(fd), uintptr(afd), uintptr(unsafe.Pointer(_p0)), uintptr(flag), uintptr(unsafe.Pointer(_p1)), 0)
+	use(unsafe.Pointer(_p0))
+	use(unsafe.Pointer(_p1))
+	if int32(r0) == -1 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Fstat(fd int, edir []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
 	if len(edir) > 0 {
-		_p1 = unsafe.Pointer(&edir[0])
+		_p0 = unsafe.Pointer(&edir[0])
 	} else {
-		_p1 = unsafe.Pointer(&_zero)
+		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_WSTAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
+	r0, _, e1 := Syscall(SYS_FSTAT, uintptr(fd), uintptr(_p0), uintptr(len(edir)))
+	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
 	}
diff --git a/src/syscall/zsyscall_plan9_amd64.go b/src/syscall/zsyscall_plan9_amd64.go
index 44b74d71c1..aa9f588edc 100644
--- a/src/syscall/zsyscall_plan9_amd64.go
+++ b/src/syscall/zsyscall_plan9_amd64.go
@@ -50,18 +50,7 @@ func await(s []byte) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Dup(oldfd int, newfd int) (fd int, err error) {
-	r0, _, e1 := Syscall(SYS_DUP, uintptr(oldfd), uintptr(newfd), 0)
-	fd = int(r0)
-	if int32(r0) == -1 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Open(path string, mode int) (fd int, err error) {
+func open(path string, mode int) (fd int, err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
@@ -78,7 +67,7 @@ func Open(path string, mode int) (fd int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Create(path string, mode int, perm uint32) (fd int, err error) {
+func create(path string, mode int, perm uint32) (fd int, err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
@@ -95,7 +84,7 @@ func Create(path string, mode int, perm uint32) (fd int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Remove(path string) (err error) {
+func remove(path string) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
@@ -111,14 +100,20 @@ func Remove(path string) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pread(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
+func stat(path string, edir []byte) (n int, err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	var _p1 unsafe.Pointer
+	if len(edir) > 0 {
+		_p1 = unsafe.Pointer(&edir[0])
 	} else {
-		_p0 = unsafe.Pointer(&_zero)
+		_p1 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall6(SYS_PREAD, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
+	r0, _, e1 := Syscall(SYS_STAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
+	use(unsafe.Pointer(_p0))
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -128,25 +123,20 @@ func Pread(fd int, p []byte, offset int64) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
-	var _p0 unsafe.Pointer
-	if len(p) > 0 {
-		_p0 = unsafe.Pointer(&p[0])
-	} else {
-		_p0 = unsafe.Pointer(&_zero)
+func bind(name string, old string, flag int) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(name)
+	if err != nil {
+		return
 	}
-	r0, _, e1 := Syscall6(SYS_PWRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
-	n = int(r0)
-	if int32(r0) == -1 {
-		err = e1
+	var _p1 *byte
+	_p1, err = BytePtrFromString(old)
+	if err != nil {
+		return
 	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Close(fd int) (err error) {
-	r0, _, e1 := Syscall(SYS_CLOSE, uintptr(fd), 0, 0)
+	r0, _, e1 := Syscall(SYS_BIND, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flag))
+	use(unsafe.Pointer(_p0))
+	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -155,13 +145,19 @@ func Close(fd int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Chdir(path string) (err error) {
+func wstat(path string, edir []byte) (err error) {
 	var _p0 *byte
 	_p0, err = BytePtrFromString(path)
 	if err != nil {
 		return
 	}
-	r0, _, e1 := Syscall(SYS_CHDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
+	var _p1 unsafe.Pointer
+	if len(edir) > 0 {
+		_p1 = unsafe.Pointer(&edir[0])
+	} else {
+		_p1 = unsafe.Pointer(&_zero)
+	}
+	r0, _, e1 := Syscall(SYS_WSTAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
 	use(unsafe.Pointer(_p0))
 	if int32(r0) == -1 {
 		err = e1
@@ -171,20 +167,14 @@ func Chdir(path string) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Bind(name string, old string, flag int) (err error) {
+func chdir(path string) (err error) {
 	var _p0 *byte
-	_p0, err = BytePtrFromString(name)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(old)
+	_p0, err = BytePtrFromString(path)
 	if err != nil {
 		return
 	}
-	r0, _, e1 := Syscall(SYS_BIND, uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(_p1)), uintptr(flag))
+	r0, _, e1 := Syscall(SYS_CHDIR, uintptr(unsafe.Pointer(_p0)), 0, 0)
 	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -193,20 +183,9 @@ func Bind(name string, old string, flag int) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Mount(fd int, afd int, old string, flag int, aname string) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(old)
-	if err != nil {
-		return
-	}
-	var _p1 *byte
-	_p1, err = BytePtrFromString(aname)
-	if err != nil {
-		return
-	}
-	r0, _, e1 := Syscall6(SYS_MOUNT, uintptr(fd), uintptr(afd), uintptr(unsafe.Pointer(_p0)), uintptr(flag), uintptr(unsafe.Pointer(_p1)), 0)
-	use(unsafe.Pointer(_p0))
-	use(unsafe.Pointer(_p1))
+func Dup(oldfd int, newfd int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_DUP, uintptr(oldfd), uintptr(newfd), 0)
+	fd = int(r0)
 	if int32(r0) == -1 {
 		err = e1
 	}
@@ -215,20 +194,14 @@ func Mount(fd int, afd int, old string, flag int, aname string) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Stat(path string, edir []byte) (n int, err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	var _p1 unsafe.Pointer
-	if len(edir) > 0 {
-		_p1 = unsafe.Pointer(&edir[0])
+func Pread(fd int, p []byte, offset int64) (n int, err error) {
+	var _p0 unsafe.Pointer
+	if len(p) > 0 {
+		_p0 = unsafe.Pointer(&p[0])
 	} else {
-		_p1 = unsafe.Pointer(&_zero)
+		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_STAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
+	r0, _, e1 := Syscall6(SYS_PREAD, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -238,14 +211,14 @@ func Stat(path string, edir []byte) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Fstat(fd int, edir []byte) (n int, err error) {
+func Pwrite(fd int, p []byte, offset int64) (n int, err error) {
 	var _p0 unsafe.Pointer
-	if len(edir) > 0 {
-		_p0 = unsafe.Pointer(&edir[0])
+	if len(p) > 0 {
+		_p0 = unsafe.Pointer(&p[0])
 	} else {
 		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_FSTAT, uintptr(fd), uintptr(_p0), uintptr(len(edir)))
+	r0, _, e1 := Syscall6(SYS_PWRITE, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
 	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
@@ -255,20 +228,47 @@ func Fstat(fd int, edir []byte) (n int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Wstat(path string, edir []byte) (err error) {
+func Close(fd int) (err error) {
+	r0, _, e1 := Syscall(SYS_CLOSE, uintptr(fd), 0, 0)
+	if int32(r0) == -1 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Mount(fd int, afd int, old string, flag int, aname string) (err error) {
 	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
+	_p0, err = BytePtrFromString(old)
 	if err != nil {
 		return
 	}
-	var _p1 unsafe.Pointer
+	var _p1 *byte
+	_p1, err = BytePtrFromString(aname)
+	if err != nil {
+		return
+	}
+	r0, _, e1 := Syscall6(SYS_MOUNT, uintptr(fd), uintptr(afd), uintptr(unsafe.Pointer(_p0)), uintptr(flag), uintptr(unsafe.Pointer(_p1)), 0)
+	use(unsafe.Pointer(_p0))
+	use(unsafe.Pointer(_p1))
+	if int32(r0) == -1 {
+		err = e1
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Fstat(fd int, edir []byte) (n int, err error) {
+	var _p0 unsafe.Pointer
 	if len(edir) > 0 {
-		_p1 = unsafe.Pointer(&edir[0])
+		_p0 = unsafe.Pointer(&edir[0])
 	} else {
-		_p1 = unsafe.Pointer(&_zero)
+		_p0 = unsafe.Pointer(&_zero)
 	}
-	r0, _, e1 := Syscall(SYS_WSTAT, uintptr(unsafe.Pointer(_p0)), uintptr(_p1), uintptr(len(edir)))
-	use(unsafe.Pointer(_p0))
+	r0, _, e1 := Syscall(SYS_FSTAT, uintptr(fd), uintptr(_p0), uintptr(len(edir)))
+	n = int(r0)
 	if int32(r0) == -1 {
 		err = e1
 	}