From 998f5bbe3dbdab81c1cfb1aef7c3892f5d24f6c7 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik <gor@linux.ibm.com> Date: Wed, 17 Jun 2020 15:05:49 +0200 Subject: [PATCH] s390/kasan: fix early pgm check handler execution 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> --- arch/s390/kernel/early.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c index cd241ee66eff4..0782772318580 100644 --- a/arch/s390/kernel/early.c +++ b/arch/s390/kernel/early.c @@ -170,6 +170,8 @@ 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; -- GitLab