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[5.12,133/178] s390/mcck: fix invalid KVM guest condition check

Message ID 20210621154927.309454936@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH June 21, 2021, 4:15 p.m. UTC 
From: Alexander Gordeev <agordeev@linux.ibm.com>

commit 1874cb13d5d7cafa61ce93a760093ebc5485b6ab upstream.

Wrong condition check is used to decide if a machine check hit
while in KVM guest. As result of this check the instruction
following the SIE critical section might be considered as still
in KVM guest and _CIF_MCCK_GUEST CPU flag mistakenly set as
result.

Fixes: c929500d7a5a ("s390/nmi: s390: New low level handling for machine check happening in guest")
Cc: <stable@vger.kernel.org>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/s390/kernel/entry.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -653,7 +653,7 @@  ENDPROC(stack_overflow)
 	slgr	%r9,%r13
 	larl	%r13,.Lsie_skip
 	clgr	%r9,%r13
-	jh	.Lcleanup_sie_int
+	jhe	.Lcleanup_sie_int
 	oi	__LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
 .Lcleanup_sie_int:
 	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)