On Tue, Jul 16, 2019 at 06:27:17PM -0700, Palmer Dabbelt wrote:
-int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
+int do_fchmodat4(int dfd, const char __user *filename, umode_t mode, int flags)
{
struct path path;
int error;
- unsigned int lookup_flags = LOOKUP_FOLLOW;
+ unsigned int lookup_flags;
+
+ if (unlikely(flags & ~AT_SYMLINK_NOFOLLOW))
+ return -EINVAL;
+
+ lookup_flags = flags & AT_SYMLINK_NOFOLLOW ? 0 : LOOKUP_FOLLOW;
+
Why not do that in sys_fchmodat4() itself, passing lookup_flags to
do_fchmodat() and updating old callers to pass it 0 as extra argument?
