diff options
| -rw-r--r-- | include/linux/kvm_host.h | 2 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 15 |
2 files changed, 12 insertions, 5 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 0b50e7b35ed4..bcd37b855c66 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -234,7 +234,7 @@ struct kvm_vcpu { int guest_fpu_loaded, guest_xcr0_loaded; struct swait_queue_head wq; - struct pid *pid; + struct pid __rcu *pid; int sigset_active; sigset_t sigset; struct kvm_vcpu_stat stat; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 19f0ecb9b93e..fc2d58312fd5 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -293,7 +293,12 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_init); void kvm_vcpu_uninit(struct kvm_vcpu *vcpu) { - put_pid(vcpu->pid); + /* + * no need for rcu_read_lock as VCPU_RUN is the only place that + * will change the vcpu->pid pointer and on uninit all file + * descriptors are already gone. + */ + put_pid(rcu_dereference_protected(vcpu->pid, 1)); kvm_arch_vcpu_uninit(vcpu); free_page((unsigned long)vcpu->run); } @@ -2551,13 +2556,14 @@ static long kvm_vcpu_ioctl(struct file *filp, if (r) return r; switch (ioctl) { - case KVM_RUN: + case KVM_RUN: { + struct pid *oldpid; r = -EINVAL; if (arg) goto out; - if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) { + oldpid = rcu_access_pointer(vcpu->pid); + if (unlikely(oldpid != current->pids[PIDTYPE_PID].pid)) { /* The thread running this VCPU changed. */ - struct pid *oldpid = vcpu->pid; struct pid *newpid = get_task_pid(current, PIDTYPE_PID); rcu_assign_pointer(vcpu->pid, newpid); @@ -2568,6 +2574,7 @@ static long kvm_vcpu_ioctl(struct file *filp, r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run); trace_kvm_userspace_exit(vcpu->run->exit_reason, r); break; + } case KVM_GET_REGS: { struct kvm_regs *kvm_regs; |