diff mbox

kvm: arm64: Disable compiler instrumentation for hypervisor code

Message ID 1458558017-6414-1-git-send-email-catalin.marinas@arm.com
State Accepted
Commit a6cdf1c08cbfe0818a3d8042844d75bf74fd82bd
Headers show

Commit Message

Catalin Marinas March 21, 2016, 11 a.m. UTC
With the recent rewrite of the arm64 KVM hypervisor code in C, enabling
certain options like KASAN would allow the compiler to generate memory
accesses or function calls to addresses not mapped at EL2. This patch
disables the compiler instrumentation on the arm64 hypervisor code for
gcov-based profiling (GCOV_KERNEL), undefined behaviour sanity checker
(UBSAN) and kernel address sanitizer (KASAN).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: <stable@vger.kernel.org> # 4.5+
---

A better fix, at least for KASAN, would be nice but that's a lot more
intrusive as we need to map the KASAN shadow into the EL2 space. In the
meantime, especially since it needs backporting to 4.5, this patch would
solve KASAN getting stuck with KVM (similar to what we do for EFI_STUB).

 arch/arm64/kvm/hyp/Makefile | 4 ++++
 1 file changed, 4 insertions(+)


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Comments

Christoffer Dall March 21, 2016, 1:01 p.m. UTC | #1
On Mon, Mar 21, 2016 at 11:00:17AM +0000, Catalin Marinas wrote:
> With the recent rewrite of the arm64 KVM hypervisor code in C, enabling

> certain options like KASAN would allow the compiler to generate memory

> accesses or function calls to addresses not mapped at EL2. This patch

> disables the compiler instrumentation on the arm64 hypervisor code for

> gcov-based profiling (GCOV_KERNEL), undefined behaviour sanity checker

> (UBSAN) and kernel address sanitizer (KASAN).

> 

> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

> Cc: Christoffer Dall <christoffer.dall@linaro.org>

> Cc: Marc Zyngier <marc.zyngier@arm.com>

> Cc: Paolo Bonzini <pbonzini@redhat.com>

> Cc: <stable@vger.kernel.org> # 4.5+


Acked-by: Christoffer Dall <christoffer.dall@linaro.org>


Applied, thanks.
-Christoffer

> ---

> 

> A better fix, at least for KASAN, would be nice but that's a lot more

> intrusive as we need to map the KASAN shadow into the EL2 space. In the

> meantime, especially since it needs backporting to 4.5, this patch would

> solve KASAN getting stuck with KVM (similar to what we do for EFI_STUB).

> 

>  arch/arm64/kvm/hyp/Makefile | 4 ++++

>  1 file changed, 4 insertions(+)

> 

> diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile

> index 826032bc3945..acde4782621a 100644

> --- a/arch/arm64/kvm/hyp/Makefile

> +++ b/arch/arm64/kvm/hyp/Makefile

> @@ -12,3 +12,7 @@ obj-$(CONFIG_KVM_ARM_HOST) += switch.o

>  obj-$(CONFIG_KVM_ARM_HOST) += fpsimd.o

>  obj-$(CONFIG_KVM_ARM_HOST) += tlb.o

>  obj-$(CONFIG_KVM_ARM_HOST) += hyp-entry.o

> +

> +GCOV_PROFILE	:= n

> +KASAN_SANITIZE	:= n

> +UBSAN_SANITIZE	:= n


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diff mbox

Patch

diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index 826032bc3945..acde4782621a 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -12,3 +12,7 @@  obj-$(CONFIG_KVM_ARM_HOST) += switch.o
 obj-$(CONFIG_KVM_ARM_HOST) += fpsimd.o
 obj-$(CONFIG_KVM_ARM_HOST) += tlb.o
 obj-$(CONFIG_KVM_ARM_HOST) += hyp-entry.o
+
+GCOV_PROFILE	:= n
+KASAN_SANITIZE	:= n
+UBSAN_SANITIZE	:= n