unix: check faccessat flags parameter on Linux

Currently Linux faccessat(2) syscall implementation doesn't support the
flags parameter. As per discuss in golang/go#25845, permit the same flags
as glibc [1].

[1] https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/faccessat.c;h=ea42b2303ff4b2d2d6548ea04376fb265f773436;hb=HEAD

Fixes golang/go#25845

Change-Id: I390ba14b2816283399472f3572967b19d0a36042
Reviewed-on: https://go-review.googlesource.com/119495
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

unix/linux/types.go

@@ -142,6 +142,10 @@ struct stat {
 # define AT_STATX_DONT_SYNC	0x4000	// - Don't sync attributes with the server
 #endif
 
+#ifndef AT_EACCESS
+# define AT_EACCESS		0x200	// Test access permitted for effective IDs, not real IDs.
+#endif
+
 #ifdef TCSETS2
 // On systems that have "struct termios2" use this as type Termios.
 typedef struct termios2 termios_t;
@@ -650,6 +654,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = C.AT_SYMLINK_FOLLOW
 	AT_SYMLINK_NOFOLLOW = C.AT_SYMLINK_NOFOLLOW
+
+	AT_EACCESS = C.AT_EACCESS
 )
 
 type PollFd C.struct_pollfd

unix/syscall_linux.go

@@ -1217,7 +1217,6 @@ func Mount(source string, target string, fstype string, flags uintptr, data stri
 //sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
 //sys	Eventfd(initval uint, flags int) (fd int, err error) = SYS_EVENTFD2
 //sys	Exit(code int) = SYS_EXIT_GROUP
-//sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
 //sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
 //sys	Fchdir(fd int) (err error)
 //sys	Fchmod(fd int, mode uint32) (err error)
@@ -1346,6 +1345,17 @@ func Vmsplice(fd int, iovs []Iovec, flags int) (int, error) {
 	return int(n), nil
 }
 
+//sys	faccessat(dirfd int, path string, mode uint32) (err error)
+
+func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
+	if flags & ^(AT_SYMLINK_NOFOLLOW|AT_EACCESS) != 0 {
+		return EINVAL
+	} else if flags&(AT_SYMLINK_NOFOLLOW|AT_EACCESS) != 0 {
+		return EOPNOTSUPP
+	}
+	return faccessat(dirfd, path, mode)
+}
+
 /*
  * Unimplemented
  */

unix/syscall_linux_test.go

@@ -384,3 +384,33 @@ func stringsFromByteSlice(buf []byte) []string {
 	}
 	return result
 }
+
+func TestFaccessat(t *testing.T) {
+	defer chtmpdir(t)()
+	touch(t, "file1")
+
+	err := unix.Faccessat(unix.AT_FDCWD, "file1", unix.O_RDONLY, 0)
+	if err != nil {
+		t.Errorf("Faccessat: unexpected error: %v", err)
+	}
+
+	err = unix.Faccessat(unix.AT_FDCWD, "file1", unix.O_RDONLY, 2)
+	if err != unix.EINVAL {
+		t.Errorf("Faccessat: unexpected error: %v, want EINVAL", err)
+	}
+
+	err = unix.Faccessat(unix.AT_FDCWD, "file1", unix.O_RDONLY, unix.AT_EACCESS)
+	if err != unix.EOPNOTSUPP {
+		t.Errorf("Faccessat: unexpected error: %v, want EOPNOTSUPP", err)
+	}
+
+	err = os.Symlink("file1", "symlink1")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = unix.Faccessat(unix.AT_FDCWD, "symlink1", unix.O_RDONLY, unix.AT_SYMLINK_NOFOLLOW)
+	if err != unix.EOPNOTSUPP {
+		t.Errorf("Faccessat: unexpected error: %v, want EOPNOTSUPP", err)
+	}
+}

unix/zsyscall_linux_386.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(off>>32), uintptr(len), uintptr(len>>32))
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func pipe(p *[2]_C_int) (err error) {
 	_, _, e1 := RawSyscall(SYS_PIPE, uintptr(unsafe.Pointer(p)), 0, 0)
 	if e1 != 0 {

unix/zsyscall_linux_amd64.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Dup2(oldfd int, newfd int) (err error) {
 	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {

unix/zsyscall_linux_arm.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(off>>32), uintptr(len), uintptr(len>>32))
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func pipe2(p *[2]_C_int, flags int) (err error) {
 	_, _, e1 := RawSyscall(SYS_PIPE2, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
 	if e1 != 0 {

unix/zsyscall_linux_arm64.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_mips.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off>>32), uintptr(off), uintptr(len>>32), uintptr(len))
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Dup2(oldfd int, newfd int) (err error) {
 	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {

unix/zsyscall_linux_mips64.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Dup2(oldfd int, newfd int) (err error) {
 	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {

unix/zsyscall_linux_mips64le.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Dup2(oldfd int, newfd int) (err error) {
 	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {

unix/zsyscall_linux_mipsle.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(off>>32), uintptr(len), uintptr(len>>32))
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Dup2(oldfd int, newfd int) (err error) {
 	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {

unix/zsyscall_linux_ppc64.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {
@@ -1510,6 +1495,21 @@ func EpollCreate(size int) (fd int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_ppc64le.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {
@@ -1510,6 +1495,21 @@ func EpollCreate(size int) (fd int, err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(events) > 0 {

unix/zsyscall_linux_s390x.go

@@ -508,21 +508,6 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
-	var _p0 *byte
-	_p0, err = BytePtrFromString(path)
-	if err != nil {
-		return
-	}
-	_, _, e1 := Syscall6(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode), uintptr(flags), 0, 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Fallocate(fd int, mode uint32, off int64, len int64) (err error) {
 	_, _, e1 := Syscall6(SYS_FALLOCATE, uintptr(fd), uintptr(mode), uintptr(off), uintptr(len), 0, 0)
 	if e1 != 0 {
@@ -1489,6 +1474,21 @@ func Munlockall() (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func faccessat(dirfd int, path string, mode uint32) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall(SYS_FACCESSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(mode))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Dup2(oldfd int, newfd int) (err error) {
 	_, _, e1 := Syscall(SYS_DUP2, uintptr(oldfd), uintptr(newfd), 0)
 	if e1 != 0 {

unix/ztypes_linux_386.go

@@ -705,6 +705,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_amd64.go

@@ -723,6 +723,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_arm.go

@@ -693,6 +693,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_arm64.go

@@ -702,6 +702,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_mips.go

@@ -697,6 +697,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_mips64.go

@@ -704,6 +704,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_mips64le.go

@@ -704,6 +704,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_mipsle.go

@@ -697,6 +697,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_ppc64.go

@@ -712,6 +712,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_ppc64le.go

@@ -712,6 +712,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {

unix/ztypes_linux_s390x.go

@@ -728,6 +728,8 @@ const (
 
 	AT_SYMLINK_FOLLOW   = 0x400
 	AT_SYMLINK_NOFOLLOW = 0x100
+
+	AT_EACCESS = 0x200
 )
 
 type PollFd struct {