s390: do not clobber personality flags in sys_32_personality()
authorJiri Kosina <jkosina@suse.cz>
Thu, 2 Aug 2012 07:11:23 +0000 (09:11 +0200)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>
Wed, 8 Aug 2012 14:32:56 +0000 (07:32 -0700)
commit5ab37e1b226b7b40a44eea7d8d1fe19e67ff65a9
tree0f267a0f5bdbc07797895369f5e04024ba2fb987
parentc63cb468f373f479ff52b4a1b75f8ecdeaaf4f16
s390: do not clobber personality flags in sys_32_personality()

There are multiple errors in how sys_32_personality() handles personality
flags stored in top three bytes.

- directly comparing current->personality against PER_LINUX32 doesn't work
  in cases when any of the personality flags stored in the top three bytes
  are used.
- directly forcefully setting personality to PER_LINUX32 or PER_LINUX
  discards any flags stored in the top three bytes

Fix the first one by properly using personality() macro to compare only
PER_MASK bytes.
Fix the second one by setting only the bits that should be set, instead of
overwriting the whole value.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/kernel/sys_s390.c