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Commit ed840ee9 authored by Scott Wood's avatar Scott Wood Committed by Alexander Graf
Browse files

kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write 



These functions do an srcu_dereference without acquiring the srcu lock
themselves.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
parent 1d6f6b73

arch/powerpc/kvm/powerpc.c

+19 −4
Original line number Diff line number Diff line
@@ -622,6 +622,8 @@ static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu, 
int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,

                       unsigned int rt, unsigned int bytes, int is_bigendian)

{

	int idx, ret;



	if (bytes > sizeof(run->mmio.data)) {

		printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,

		       run->mmio.len);
@@ -637,8 +639,14 @@ int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu, 
	vcpu->mmio_is_write = 0;

	vcpu->arch.mmio_sign_extend = 0;



	if (!kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,

			     bytes, &run->mmio.data)) {

	idx = srcu_read_lock(&vcpu->kvm->srcu);



	ret = kvm_io_bus_read(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,

			      bytes, &run->mmio.data);



	srcu_read_unlock(&vcpu->kvm->srcu, idx);



	if (!ret) {

		kvmppc_complete_mmio_load(vcpu, run);

		vcpu->mmio_needed = 0;

		return EMULATE_DONE;
@@ -663,6 +671,7 @@ int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu, 
                        u64 val, unsigned int bytes, int is_bigendian)

{

	void *data = run->mmio.data;

	int idx, ret;



	if (bytes > sizeof(run->mmio.data)) {

		printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
@@ -692,8 +701,14 @@ int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu, 
		}

	}



	if (!kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,

			      bytes, &run->mmio.data)) {

	idx = srcu_read_lock(&vcpu->kvm->srcu);



	ret = kvm_io_bus_write(vcpu->kvm, KVM_MMIO_BUS, run->mmio.phys_addr,

			       bytes, &run->mmio.data);



	srcu_read_unlock(&vcpu->kvm->srcu, idx);



	if (!ret) {

		vcpu->mmio_needed = 0;

		return EMULATE_DONE;

	}