[3.16.y-ckt stable] Patch "MIPS: KVM: Do not sign extend on unsigned MMIO load" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    MIPS: KVM: Do not sign extend on unsigned MMIO load

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt14.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 4c4ae634491a443d4ec81217de248b194be8ad7a Mon Sep 17 00:00:00 2001
From: Nicholas Mc Guire <hofrat at osadl.org>
Date: Thu, 7 May 2015 14:47:50 +0200
Subject: MIPS: KVM: Do not sign extend on unsigned MMIO load

commit ed9244e6c534612d2b5ae47feab2f55a0d4b4ced upstream.

Fix possible unintended sign extension in unsigned MMIO loads by casting
to uint16_t in the case of mmio_needed != 2.

Signed-off-by: Nicholas Mc Guire <hofrat at osadl.org>
Reviewed-by: James Hogan <james.hogan at imgtec.com>
Tested-by: James Hogan <james.hogan at imgtec.com>
Cc: Gleb Natapov <gleb at kernel.org>
Cc: Paolo Bonzini <pbonzini at redhat.com>
Cc: kvm at vger.kernel.org
Cc: linux-mips at linux-mips.org
Cc: linux-kernel at vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9985/
Signed-off-by: Ralf Baechle <ralf at linux-mips.org>
[ luis: backported to 3.16:
  - file rename: emulate.c -> kvm_mips_emul.c ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/mips/kvm/kvm_mips_emul.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c
index 2071472bc3c4..18b4e2fdae33 100644
--- a/arch/mips/kvm/kvm_mips_emul.c
+++ b/arch/mips/kvm/kvm_mips_emul.c
@@ -2130,7 +2130,7 @@ kvm_mips_complete_mmio_load(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		if (vcpu->mmio_needed == 2)
 			*gpr = *(int16_t *) run->mmio.data;
 		else
-			*gpr = *(int16_t *) run->mmio.data;
+			*gpr = *(uint16_t *)run->mmio.data;

 		break;
 	case 1: