From: Alexander Gordeev Date: Wed, 20 Jul 2022 05:24:03 +0000 (+0200) Subject: s390/smp: enforce lowcore protection on CPU restart X-Git-Tag: v5.15.73~1161 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9536d5451cf476fc0a90b6e71bd9c8c7d53826ca;p=platform%2Fkernel%2Flinux-rpi.git s390/smp: enforce lowcore protection on CPU restart [ Upstream commit 6f5c672d17f583b081e283927f5040f726c54598 ] As result of commit 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") the low-address protection bit gets mistakenly unset in control register 0 save area of the absolute zero memory. That area is used when manual PSW restart happened to hit an offline CPU. In this case the low-address protection for that CPU will be dropped. Reviewed-by: Heiko Carstens Fixes: 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") Signed-off-by: Alexander Gordeev Signed-off-by: Sasha Levin --- diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 6b1a869..c8e7b3d 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -507,8 +507,8 @@ static void __init setup_lowcore_dat_on(void) S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT; S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT; S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT; - __ctl_store(S390_lowcore.cregs_save_area, 0, 15); __ctl_set_bit(0, 28); + __ctl_store(S390_lowcore.cregs_save_area, 0, 15); put_abs_lowcore(restart_flags, RESTART_FLAG_CTLREGS); put_abs_lowcore(program_new_psw, lc->program_new_psw); for (cr = 0; cr < ARRAY_SIZE(lc->cregs_save_area); cr++)