Re: [PATCH v2 2/4] Add fchmodat4(), a new syscall
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2019-07-17 01:48:30
Also in:
linux-alpha, linux-api, linux-arch, linux-fsdevel, linux-mips, linux-s390, linux-sh, lkml, sparclinux
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?