[PATCH 2/2] s390/cpumf: Fix lpp detection

[tim.gardner at canonical.com]

From: Christian Borntraeger <borntraeger at de.ibm.com>

BugLink: http://bugs.launchpad.net/bugs/1555344

we have to check bit 40 of the facility list before issuing LPP
and not bit 48. Otherwise a guest running on a system with
"The decimal-floating-point zoned-conversion facility" and without
the "The set-program-parameters facility" might crash on an lpp
instruction.

Signed-off-by: Christian Borntraeger <borntraeger at de.ibm.com>
Cc: stable at vger.kernel.org # v4.4+
Fixes: e22cf8ca6f75 ("s390/cpumf: rework program parameter setting to detect guest samples")
Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com>
(cherry picked from commit 7a76aa95f6f6682db5629449d763251d1c9f8c4e)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 arch/s390/kernel/head64.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index c5febe8..03c2b46 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -16,7 +16,7 @@
 
 __HEAD
 ENTRY(startup_continue)
-	tm	__LC_STFLE_FAC_LIST+6,0x80	# LPP available ?
+	tm	__LC_STFLE_FAC_LIST+5,0x80	# LPP available ?
 	jz	0f
 	xc	__LC_LPP+1(7,0),__LC_LPP+1	# clear lpp and current_pid
 	mvi	__LC_LPP,0x80			#   and set LPP_MAGIC
-- 
2.7.4