Here again we are copying form one buffer to another, while jumping through
hoops to make kernel memory look like userspace memory.
For no good reason, since vfs_get_link() provides exactly what is needed.
As a bonus, now the security hook for readlink is also called on the
underlying inode.
Note: this can be called from link-following context. But this is okay:
- not in RCU mode
- commit e54ad7f1ee ("proc: prevent stacking filesystems on top")
- ecryptfs is *reading* the underlying symlink not following it, so the
right security hook is being called
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>