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/46474
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/unix/zsyscall_linux_mips64.go b/unix/zsyscall_linux_mips64.go
index 1ee4a5e..f77f1d0 100644
--- a/unix/zsyscall_linux_mips64.go
+++ b/unix/zsyscall_linux_mips64.go
@@ -14,6 +14,21 @@
// 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 @@
// 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)
