Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

s390/kasan: fix early pgm check handler execution

Browse source 
[ Upstream commit 998f5bbe3dbdab81c1cfb1aef7c3892f5d24f6c7 ]

Currently if early_pgm_check_handler is called it ends up in pgm check
loop. The problem is that early_pgm_check_handler is instrumented by
KASAN but executed without DAT flag enabled which leads to addressing
exception when KASAN checks try to access shadow memory.

Fix that by executing early handlers with DAT flag on under KASAN as
expected.

Reported-and-tested-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Vasily Gorbik 2020-06-17 15:05:49 +02:00 committed by Greg Kroah-Hartman
parent 14a7ef71fb
commit 7e7f71be56
1 changed files with 2 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/s390/kernel/early.c
View file

@ -155,6 +155,8 @@ static noinline __init void setup_lowcore_early(void)
psw_t psw;
psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
if (IS_ENABLED(CONFIG_KASAN))
psw.mask |= PSW_MASK_DAT;
psw.addr = (unsigned long) s390_base_ext_handler;
S390_lowcore.external_new_psw = psw;
psw.addr = (unsigned long) s390_base_pgm_handler;