Commit c23410a8 authored by Tobias Klauser's avatar Tobias Klauser Committed by Ian Lance Taylor

unix: check Fchmodat flags parameter on Linux

Currently Linux' fchmodat(2) syscall implementation doesn't support the
flags parameter (though it might in future versions [1]). Fchmodat in
x/sys/unix takes the parameter and (wrongly) passes it on to the syscall
which will ignore it.

According to the POSIX.1-2008 manual page [2], AT_SYMLINK_NOFOLLOW is
the only valid value for the flags parameter and EOPNOTSUPP should be
returned in case changing the mode of a symbolic link is not supported
by the underlying system.  EINVAL should be returned for any other value
of the flags parameter.

  [1] https://patchwork.kernel.org/patch/9596301/
  [2] http://pubs.opengroup.org/onlinepubs/9699919799/functions/chmod.html

Change the Fchmodat implementation accordingly and also add the
corresponding test.

Fixes golang/go#20130

Change-Id: I62e677e6674d3702eaf388af0ac3d7e623a35c24
Reviewed-on: https://go-review.googlesource.com/46474Reviewed-by: 's avatarIan Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
parent fb4cac33
......@@ -36,6 +36,20 @@ func Creat(path string, mode uint32) (fd int, err error) {
return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode)
}
//sys fchmodat(dirfd int, path string, mode uint32) (err error)
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
// Linux fchmodat doesn't support the flags parameter. Mimick glibc's behavior
// and check the flags. Otherwise the mode would be applied to the symlink
// destination which is not what the user expects.
if flags&^AT_SYMLINK_NOFOLLOW != 0 {
return EINVAL
} else if flags&AT_SYMLINK_NOFOLLOW != 0 {
return EOPNOTSUPP
}
return fchmodat(dirfd, path, mode)
}
//sys ioctl(fd int, req uint, arg uintptr) (err error)
// ioctl itself should not be exposed directly, but additional get/set
......@@ -1177,7 +1191,6 @@ func Mount(source string, target string, fstype string, flags uintptr, data stri
//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)
//sys Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
//sys Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
//sys fcntl(fd int, cmd int, arg int) (val int, err error)
//sys Fdatasync(fd int) (err error)
......
......@@ -15,6 +15,32 @@ import (
"golang.org/x/sys/unix"
)
func TestFchmodat(t *testing.T) {
defer chtmpdir(t)()
touch(t, "file1")
os.Symlink("file1", "symlink1")
err := unix.Fchmodat(unix.AT_FDCWD, "symlink1", 0444, 0)
if err != nil {
t.Fatalf("Fchmodat: unexpected error: %v", err)
}
fi, err := os.Stat("file1")
if err != nil {
t.Fatal(err)
}
if fi.Mode() != 0444 {
t.Errorf("Fchmodat: failed to change mode: expected %v, got %v", 0444, fi.Mode())
}
err = unix.Fchmodat(unix.AT_FDCWD, "symlink1", 0444, unix.AT_SYMLINK_NOFOLLOW)
if err != unix.EOPNOTSUPP {
t.Fatalf("Fchmodat: unexpected error: %v, expected EOPNOTSUPP", err)
}
}
func TestIoctlGetInt(t *testing.T) {
f, err := os.Open("/dev/random")
if err != nil {
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
......@@ -14,6 +14,21 @@ var _ syscall.Errno
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func fchmodat(dirfd int, path string, mode uint32) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall(SYS_FCHMODAT, 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 ioctl(fd int, req uint, arg uintptr) (err error) {
_, _, e1 := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), uintptr(arg))
if e1 != 0 {
......@@ -574,21 +589,6 @@ func Fchmod(fd int, mode uint32) (err error) {
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
if err != nil {
return
}
_, _, e1 := Syscall6(SYS_FCHMODAT, 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 Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error) {
var _p0 *byte
_p0, err = BytePtrFromString(path)
......
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