path: root/virt
diff options
authorHuang Ying <ying.huang@intel.com>2010-06-22 14:23:11 +0800
committerAvi Kivity <avi@redhat.com>2010-08-01 10:47:11 +0300
commitbbeb34062fbad287c949a945a516a0c15b179993 (patch)
treecf29b50e076ba1ddc07d5b1292f243653a2f67a9 /virt
parent6c3f6041172b78d5532c6bf3680d304e92ec2e66 (diff)
KVM: Fix a race condition for usage of is_hwpoison_address()
is_hwpoison_address accesses the page table, so the caller must hold current->mm->mmap_sem in read mode. So fix its usage in hva_to_pfn of kvm accordingly. Comment is_hwpoison_address to remind other users. Reported-by: Avi Kivity <avi@redhat.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt')
1 files changed, 2 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 74f731920945..ec2e3c6ac7ed 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -947,12 +947,13 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr)
if (unlikely(npages != 1)) {
struct vm_area_struct *vma;
+ down_read(&current->mm->mmap_sem);
if (is_hwpoison_address(addr)) {
+ up_read(&current->mm->mmap_sem);
return page_to_pfn(hwpoison_page);
- down_read(&current->mm->mmap_sem);
vma = find_vma(current->mm, addr);
if (vma == NULL || addr < vma->vm_start ||

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