KVM: fix the handling of dirty bitmaps to avoid overflows

Int is not long enough to store the size of a dirty bitmap.

This patch fixes this problem with the introduction of a wrapper
function to calculate the sizes of dirty bitmaps.

Note: in mark_page_dirty(), we have to consider the fact that
  __set_bit() takes the offset as int, not long.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Takuya Yoshikawa
2010-04-12 19:35:35 +09:00
committed by Avi Kivity
parent 77662e0028
commit 87bf6e7de1
5 changed files with 24 additions and 13 deletions

View File

@@ -1004,7 +1004,8 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
struct kvm_vcpu *vcpu;
ulong ga, ga_end;
int is_dirty = 0;
int r, n;
int r;
unsigned long n;
mutex_lock(&kvm->slots_lock);
@@ -1022,7 +1023,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
kvm_for_each_vcpu(n, vcpu, kvm)
kvmppc_mmu_pte_pflush(vcpu, ga, ga_end);
n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
n = kvm_dirty_bitmap_bytes(memslot);
memset(memslot->dirty_bitmap, 0, n);
}