diff options
| -rw-r--r-- | arch/x86/kvm/x86.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7fa89c39c64f..1b270fd60634 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2797,7 +2797,6 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot; unsigned long n; unsigned long is_dirty = 0; - unsigned long *dirty_bitmap = NULL; mutex_lock(&kvm->slots_lock); @@ -2812,27 +2811,30 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, n = kvm_dirty_bitmap_bytes(memslot); - r = -ENOMEM; - dirty_bitmap = vmalloc(n); - if (!dirty_bitmap) - goto out; - memset(dirty_bitmap, 0, n); - for (i = 0; !is_dirty && i < n/sizeof(long); i++) is_dirty = memslot->dirty_bitmap[i]; /* If nothing is dirty, don't bother messing with page tables. */ if (is_dirty) { struct kvm_memslots *slots, *old_slots; + unsigned long *dirty_bitmap; spin_lock(&kvm->mmu_lock); kvm_mmu_slot_remove_write_access(kvm, log->slot); spin_unlock(&kvm->mmu_lock); - slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); - if (!slots) - goto out_free; + r = -ENOMEM; + dirty_bitmap = vmalloc(n); + if (!dirty_bitmap) + goto out; + memset(dirty_bitmap, 0, n); + r = -ENOMEM; + slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); + if (!slots) { + vfree(dirty_bitmap); + goto out; + } memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots)); slots->memslots[log->slot].dirty_bitmap = dirty_bitmap; @@ -2841,13 +2843,20 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, synchronize_srcu_expedited(&kvm->srcu); dirty_bitmap = old_slots->memslots[log->slot].dirty_bitmap; kfree(old_slots); + + r = -EFAULT; + if (copy_to_user(log->dirty_bitmap, dirty_bitmap, n)) { + vfree(dirty_bitmap); + goto out; + } + vfree(dirty_bitmap); + } else { + r = -EFAULT; + if (clear_user(log->dirty_bitmap, n)) + goto out; } r = 0; - if (copy_to_user(log->dirty_bitmap, dirty_bitmap, n)) - r = -EFAULT; -out_free: - vfree(dirty_bitmap); out: mutex_unlock(&kvm->slots_lock); return r; |