On 2011-04-17 11:16, Avi Kivity wrote:
> On 04/13/2011 02:32 AM, Jan Kiszka wrote:
>> From: Jan Kiszka<jan.kiszka@xxxxxxxxxxx>
>>
>> If kvm_arch_vcpu_setup failed, we leaked the allocated VCPU structure so
>> far.
>
>> @@ -1609,18 +1609,18 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm
>> *kvm, u32 id)
>>
>> r = kvm_arch_vcpu_setup(vcpu);
>> if (r)
>> - return r;
>> + goto vcpu_destroy;
>>
>
> kvm_arch_vcpu_setup() (at least x86's) does a vcpu->free() on failure.
> I think the current code is correct (if confusing).
Right. How about cleaning this inconsistency up? It looks like there is
no problem calling kvm_arch_vcpu_destroy even if kvm_arch_vcpu_setup
bailed out early.
Jan
------8<------
From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
So far kvm_arch_vcpu_setup is responsible for freeing the vcpu struct if
it fails. Move this confusing resonsibility back into the hands of
kvm_vm_ioctl_create_vcpu. Only kvm_arch_vcpu_setup of x86 is affected,
all other archs cannot fail.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
arch/x86/kvm/x86.c | 5 -----
virt/kvm/kvm_main.c | 11 ++++++-----
2 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1d5a7f4..9826d5d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6002,12 +6002,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
if (r == 0)
r = kvm_mmu_setup(vcpu);
vcpu_put(vcpu);
- if (r < 0)
- goto free_vcpu;
- return 0;
-free_vcpu:
- kvm_x86_ops->vcpu_free(vcpu);
return r;
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5814645..57b173c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1609,18 +1609,18 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
r = kvm_arch_vcpu_setup(vcpu);
if (r)
- return r;
+ goto vcpu_destroy;
mutex_lock(&kvm->lock);
if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
r = -EINVAL;
- goto vcpu_destroy;
+ goto unlock_vcpu_destroy;
}
kvm_for_each_vcpu(r, v, kvm)
if (v->vcpu_id == id) {
r = -EEXIST;
- goto vcpu_destroy;
+ goto unlock_vcpu_destroy;
}
BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
@@ -1630,7 +1630,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
r = create_vcpu_fd(vcpu);
if (r < 0) {
kvm_put_kvm(kvm);
- goto vcpu_destroy;
+ goto unlock_vcpu_destroy;
}
kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
@@ -1644,8 +1644,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
mutex_unlock(&kvm->lock);
return r;
-vcpu_destroy:
+unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
+vcpu_destroy:
kvm_arch_vcpu_destroy(vcpu);
return r;
}
--
1.7.1
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