Commit acaa3e72 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'vfio-v6.15-rc6' of https://github.com/awilliam/linux-vfio 

Pull vfio fix from Alex Williamson:

 - Fix an issue in vfio-pci huge_fault handling by aligning faults to
   the order, resulting in deterministic use of huge pages.  This
   avoids a race where simultaneous aligned and unaligned faults to
   the same PMD can result in a VM_FAULT_OOM and subsequent VM crash.
   (Alex Williamson)

* tag 'vfio-v6.15-rc6' of https://github.com/awilliam/linux-vfio:
  vfio/pci: Align huge faults to order
parents 2c89c1b6 c1d9dac0

drivers/vfio/pci/vfio_pci_core.c

+6 −6
Original line number Diff line number Diff line
@@ -1646,14 +1646,14 @@ static vm_fault_t vfio_pci_mmap_huge_fault(struct vm_fault *vmf, 
{

	struct vm_area_struct *vma = vmf->vma;

	struct vfio_pci_core_device *vdev = vma->vm_private_data;

	unsigned long pfn, pgoff = vmf->pgoff - vma->vm_pgoff;

	unsigned long addr = vmf->address & ~((PAGE_SIZE << order) - 1);

	unsigned long pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;

	unsigned long pfn = vma_to_pfn(vma) + pgoff;

	vm_fault_t ret = VM_FAULT_SIGBUS;



	pfn = vma_to_pfn(vma) + pgoff;



	if (order && (pfn & ((1 << order) - 1) ||

		      vmf->address & ((PAGE_SIZE << order) - 1) ||

		      vmf->address + (PAGE_SIZE << order) > vma->vm_end)) {

	if (order && (addr < vma->vm_start ||

		      addr + (PAGE_SIZE << order) > vma->vm_end ||

		      pfn & ((1 << order) - 1))) {

		ret = VM_FAULT_FALLBACK;

		goto out;

	}