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Commit 8f100bb1 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/cpumf: add missing lpp magic initialization 



Add the missing lpp magic initialization for cpu 0. Without this all
samples on cpu 0 do not have the most significant bit set in the
program parameter field, which we use to distinguish between guest and
host samples if the pid is also 0.

We did initialize the lpp magic in the absolute zero lowcore but
forgot that when switching to the allocated lowcore on cpu 0 only.

Reported-by: default avatarShu Juan Zhang <zhshuj@cn.ibm.com>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: e22cf8ca ("s390/cpumf: rework program parameter setting to detect guest samples")
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 7eb792bf

arch/s390/kernel/setup.c

+1 −0
Original line number Diff line number Diff line
@@ -327,6 +327,7 @@ static void __init setup_lowcore(void) 
		+ PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);

	lc->current_task = (unsigned long) init_thread_union.thread_info.task;

	lc->thread_info = (unsigned long) &init_thread_union;

	lc->lpp = LPP_MAGIC;

	lc->machine_flags = S390_lowcore.machine_flags;

	lc->stfl_fac_list = S390_lowcore.stfl_fac_list;

	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,