[PATCH 1/2] KVM: s390: sthyi: fix sthyi inline assembly

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

The sthyi inline assembly misses register r3 within the clobber
list. The sthyi instruction will always write a return code to
register "R2+1", which in this case would be r3. Due to that we may
have register corruption and see host crashes or data corruption
depending on how gcc decided to allocate and use registers during
compile time.

Fixes: 95ca2cb57985 ("KVM: s390: Add sthyi emulation")
Cc: <stable@xxxxxxxxxxxxxxx> # 4.8+
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
 arch/s390/kvm/sthyi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kvm/sthyi.c b/arch/s390/kvm/sthyi.c
index 926b524..2773a2f 100644
--- a/arch/s390/kvm/sthyi.c
+++ b/arch/s390/kvm/sthyi.c
@@ -394,7 +394,7 @@ static int sthyi(u64 vaddr)
 		"srl     %[cc],28\n"
 		: [cc] "=d" (cc)
 		: [code] "d" (code), [addr] "a" (addr)
-		: "memory", "cc");
+		: "3", "memory", "cc");
 	return cc;
 }
 
-- 
2.7.4




[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux