Memo:
- kvm_io_bus_register_dev() was protected as far as I checked.
- kvm_create_pit() was commented like "Caller must hold slots_lock"
but kvm_free_pit() was not. So I don't know if I should protect
the whole kvm_free_pit().
What is the best fix? -- or I misread something?
Thanks,
Takuya
===
From: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>
The comment for kvm_io_bus_unregister_dev() says "Caller must hold
slots_lock" but some callers don't do so.
Though this patch fixes these, more consistent locking manner may be
needed in the future.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>
---
arch/x86/kvm/i8254.c | 2 ++
arch/x86/kvm/i8259.c | 2 ++
arch/x86/kvm/x86.c | 2 ++
virt/kvm/ioapic.c | 2 ++
4 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index efad723..f64393c 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -744,9 +744,11 @@ void kvm_free_pit(struct kvm *kvm)
struct hrtimer *timer;
if (kvm->arch.vpit) {
+ mutex_lock(&kvm->slots_lock);
kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev);
kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS,
&kvm->arch.vpit->speaker_dev);
+ mutex_unlock(&kvm->slots_lock);
kvm_unregister_irq_mask_notifier(kvm, 0,
&kvm->arch.vpit->mask_notifier);
kvm_unregister_irq_ack_notifier(kvm,
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index f628234..d9fe35d 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -596,7 +596,9 @@ void kvm_destroy_pic(struct kvm *kvm)
struct kvm_pic *vpic = kvm->arch.vpic;
if (vpic) {
+ mutex_lock(&kvm->slots_lock);
kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &vpic->dev);
+ mutex_unlock(&kvm->slots_lock);
kvm->arch.vpic = NULL;
kfree(vpic);
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ed373ba..48e59d1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3313,8 +3313,10 @@ long kvm_arch_vm_ioctl(struct file *filp,
if (vpic) {
r = kvm_ioapic_init(kvm);
if (r) {
+ mutex_lock(&kvm->slots_lock);
kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS,
&vpic->dev);
+ mutex_unlock(&kvm->slots_lock);
kfree(vpic);
goto create_irqchip_unlock;
}
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 0b9df83..fa76380 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -409,7 +409,9 @@ void kvm_ioapic_destroy(struct kvm *kvm)
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
if (ioapic) {
+ mutex_lock(&kvm->slots_lock);
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
+ mutex_unlock(&kvm->slots_lock);
kvm->arch.vioapic = NULL;
kfree(ioapic);
}
--
1.7.1
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