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Commit 5ab37e1b authored by Jiri Kosina's avatar Jiri Kosina Committed by Martin Schwidefsky
Browse files

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: default avatarJiri Kosina <jkosina@suse.cz>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent c63cb468

arch/s390/kernel/sys_s390.c

+5 −4
Original line number Diff line number Diff line
@@ -81,11 +81,12 @@ SYSCALL_DEFINE1(s390_personality, unsigned int, personality) 
{

	unsigned int ret;



	if (current->personality == PER_LINUX32 && personality == PER_LINUX)

		personality = PER_LINUX32;

	if (personality(current->personality) == PER_LINUX32 &&

	    personality(personality) == PER_LINUX)

		personality |= PER_LINUX32;

	ret = sys_personality(personality);

	if (ret == PER_LINUX32)

		ret = PER_LINUX;

	if (personality(ret) == PER_LINUX32)

		ret &= ~PER_LINUX32;



	return ret;

}