Patch "s390/cpumf: add missing lpp magic initialization" has been added to the 4.4-stable tree

Patch "s390/cpumf: add missing lpp magic initialization" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    s390/cpumf: add missing lpp magic initialization

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     s390-cpumf-add-missing-lpp-magic-initialization.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 8f100bb1ff27873dd71f636da670e503b9ade3c6 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Thu, 10 Mar 2016 10:32:21 +0100
Subject: s390/cpumf: add missing lpp magic initialization

From: Heiko Carstens <heiko.carstens@de.ibm.com>

commit 8f100bb1ff27873dd71f636da670e503b9ade3c6 upstream.

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 <zhshuj@cn.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: e22cf8ca6f75 ("s390/cpumf: rework program parameter setting to detect guest samples")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/s390/kernel/setup.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -329,6 +329,7 @@ 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,


Patches currently in stable-queue which might be from heiko.carstens@de.ibm.com are

queue-4.4/s390-cpumf-add-missing-lpp-magic-initialization.patch