Commit 8d96bba7 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Vasily Gorbik
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s390/smp: enforce lowcore protection on CPU restart 



As result of commit 915fea04 ("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: default avatarHeiko Carstens <hca@linux.ibm.com>
Fixes: 915fea04 ("s390/smp: enable DAT before CPU restart callback is called")
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 12dd19c1

arch/s390/kernel/setup.c

+1 −1
Original line number Diff line number Diff line
@@ -508,8 +508,8 @@ 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++)