From 8f100bb1ff27873dd71f636da670e503b9ade3c6 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 10 Mar 2016 10:32:21 +0100 Subject: [PATCH] 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: Shu Juan Zhang Acked-by: Christian Borntraeger Cc: stable@vger.kernel.org # v4.4+ Fixes: e22cf8ca6f75 ("s390/cpumf: rework program parameter setting to detect guest samples") Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/setup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index b1fbcc0..cc46767 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -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, -- 2.7.4