commit dd254f5a382cc7879db7a07ed266b12d38fe3ab6
author Al Viro <viro@zeniv.linux.org.uk> Mon May 09 11:54:48 2016 -0400
committer Al Viro <viro@zeniv.linux.org.uk> Mon May 09 14:04:29 2016 -0400
tree bd644bbc841c64c265d72c74d9c82d9df61d4064
parent 7367ab9157d6829351dd4aa404352402f064686c

fold checks into iterate_and_advance()

they are open-coded in all users except iov_iter_advance(), and there
they wouldn't be a bad idea either - as it is, iov_iter_advance(i, 0)
ends up dereferencing potentially past the end of iovec array.  It
doesn't do anything with the value it reads, and very unlikely to
trigger an oops on dereference, but it is not impossible.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>