[3.16.y-ckt stable] Patch "KVM: ARM/arm64: avoid returning negative error code as bool" has been added to staging queue

[Luis Henriques]

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

    KVM: ARM/arm64: avoid returning negative error code as bool

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-ckt12.

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 5f606e57aa91f13923fdfd5cee06c6d0a1341d71 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon at arm.com>
Date: Tue, 26 Aug 2014 15:13:22 +0100
Subject: KVM: ARM/arm64: avoid returning negative error code as bool

commit 18d457661fb9fa69352822ab98d39331c3d0e571 upstream.

is_valid_cache returns true if the specified cache is valid.
Unfortunately, if the parameter passed it out of range, we return
-ENOENT, which ends up as true leading to potential hilarity.

This patch returns false on the failure path instead.

Cc: Christoffer Dall <christoffer.dall at linaro.org>
Cc: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Will Deacon <will.deacon at arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/arm/kvm/coproc.c     | 2 +-
 arch/arm64/kvm/sys_regs.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index c58a35116f63..7c732908f1df 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -742,7 +742,7 @@ static bool is_valid_cache(u32 val)
 	u32 level, ctype;

 	if (val >= CSSELR_MAX)
-		return -ENOENT;
+		return false;

 	/* Bottom bit is Instruction or Data bit.  Next 3 bits are level. */
         level = (val >> 1);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 34f25a590bd7..444e8edd71b2 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -836,7 +836,7 @@ static bool is_valid_cache(u32 val)
 	u32 level, ctype;

 	if (val >= CSSELR_MAX)
-		return -ENOENT;
+		return false;

 	/* Bottom bit is Instruction or Data bit.  Next 3 bits are level. */
 	level = (val >> 1);