Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f42798c6 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

ARM: KVM: Fix length of mmio access 



Instead of hardcoding the maximum MMIO access to be 4 bytes,
compare it to sizeof(unsigned long), which will do the
right thing on both 32 and 64bit systems.

Same thing for sign extention.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <cdall@cs.columbia.edu>
parent 000d3996

arch/arm/kvm/mmio.c

+4 −3
Original line number Diff line number Diff line
@@ -39,10 +39,10 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) 


	if (!run->mmio.is_write) {

		dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt);

		memset(dest, 0, sizeof(int));

		*dest = 0;



		len = run->mmio.len;

		if (len > 4)

		if (len > sizeof(unsigned long))

			return -EINVAL;



		memcpy(dest, run->mmio.data, len);
@@ -50,7 +50,8 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run) 
		trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,

				*((u64 *)run->mmio.data));



		if (vcpu->arch.mmio_decode.sign_extend && len < 4) {

		if (vcpu->arch.mmio_decode.sign_extend &&

		    len < sizeof(unsigned long)) {

			mask = 1U << ((len * 8) - 1);

			*dest = (*dest ^ mask) - mask;

		}