[PATCH] Bug fixes and cleanup for the BSD Secure Levels LSM

[PATCH] Bug fixes and cleanup for the BSD Secure Levels LSM

This patch address several issues in the current BSD Secure Levels code:

o plaintext_to_sha1: Missing check for a NULL return from __get_free_page

o passwd_write_file: A page is leaked if the password is wrong.

o fix securityfs registration order

o seclvl_init is a mess and can't properly tolerate failures, failure
  path is upside down (deldif and delf should be switched)

Cleanups:

o plaintext_to_sha1: Use buffers passed in
o passwd_write_file: Use kmalloc() instead of get_zeroed_page()
o passwd_write_file: hashedPassword comparison is just memcmp
o s/ENOSYS/EINVAL/
o misc

(akpm: after some discussion it appears that the BSD secure levels feature
should be scheduled for removal.  But for now, let's fix these problems up).

Signed-off-by: Davi Arnaut <davi.arnaut@gmail.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Cc: James Morris <jmorris@namei.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>