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Commit 7a76aa95 authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Martin Schwidefsky
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s390/cpumf: Fix lpp detection 



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: 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 avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent ce0c12b6

arch/s390/kernel/head64.S

+1 −1
Original line number Diff line number Diff line
@@ -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