diff options
| author | Radim Krčmář <rkrcmar@redhat.com> | 2017-07-10 20:53:28 +0200 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2017-07-12 22:38:26 +0200 |
| commit | fb5307298e49ec1668c3a9ec888c1b9da4347395 (patch) | |
| tree | e5bebb368b41803c9910806cc21cf2a2c17c1ea0 | |
| parent | 949c033694864082db9b3f5304723a6d7407f8e2 (diff) | |
| download | linux-exynos-fb5307298e49ec1668c3a9ec888c1b9da4347395.tar.gz linux-exynos-fb5307298e49ec1668c3a9ec888c1b9da4347395.tar.bz2 linux-exynos-fb5307298e49ec1668c3a9ec888c1b9da4347395.zip | |
KVM: x86: take slots_lock in kvm_free_pit
kvm_vm_release() did not have slots_lock when calling
kvm_io_bus_unregister_dev() and this went unnoticed until 4a12f9517728
("KVM: mark kvm->busses as rcu protected") added dynamic checks.
Luckily, there should be no race at that point:
=============================
WARNING: suspicious RCU usage
4.12.0.kvm+ #0 Not tainted
-----------------------------
./include/linux/kvm_host.h:479 suspicious rcu_dereference_check() usage!
lockdep_rcu_suspicious+0xc5/0x100
kvm_io_bus_unregister_dev+0x173/0x190 [kvm]
kvm_free_pit+0x28/0x80 [kvm]
kvm_arch_sync_events+0x2d/0x30 [kvm]
kvm_put_kvm+0xa7/0x2a0 [kvm]
kvm_vm_release+0x21/0x30 [kvm]
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| -rw-r--r-- | arch/x86/kvm/i8254.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index a78b445ce411..af192895b1fc 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -724,8 +724,10 @@ void kvm_free_pit(struct kvm *kvm) struct kvm_pit *pit = kvm->arch.vpit; if (pit) { + mutex_lock(&kvm->slots_lock); kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev); kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->speaker_dev); + mutex_unlock(&kvm->slots_lock); kvm_pit_set_reinject(pit, false); hrtimer_cancel(&pit->pit_state.timer); kthread_destroy_worker(pit->worker); |