| Message ID | 161351571186.15573.5602248562129684350.stgit@gimli.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] vfio/type1: Use follow_pte() | expand |
On Tue, Feb 16, 2021 at 03:49:34PM -0700, Alex Williamson wrote: > follow_pfn() doesn't make sure that we're using the correct page > protections, get the pte with follow_pte() so that we can test > protections and get the pfn from the pte. > > Fixes: 5cbf3264bc71 ("vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()") > Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> > Reviewed-by: Cornelia Huck <cohuck@redhat.com> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>
On Tue, 16 Feb 2021 15:49:34 -0700 Alex Williamson <alex.williamson@redhat.com> wrote: > follow_pfn() doesn't make sure that we're using the correct page > protections, get the pte with follow_pte() so that we can test > protections and get the pfn from the pte. > > Fixes: 5cbf3264bc71 ("vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()") > Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> > Reviewed-by: Cornelia Huck <cohuck@redhat.com> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > --- > > v2: Update to current follow_pte() API, add Reviews > > drivers/vfio/vfio_iommu_type1.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index ec9fd95a138b..ae4fd2295c95 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -463,9 +463,11 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, > unsigned long vaddr, unsigned long *pfn, > bool write_fault) > { > + pte_t *ptep; > + spinlock_t *ptl; > int ret; > > - ret = follow_pfn(vma, vaddr, pfn); > + ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); > if (ret) { > bool unlocked = false; > > @@ -479,9 +481,17 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, > if (ret) > return ret; > > - ret = follow_pfn(vma, vaddr, pfn); > + ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); > + if (ret) > + return ret; > } > > + if (write_fault && !pte_write(*ptep)) > + ret = -EFAULT; > + else > + *pfn = pte_pfn(*ptep); > + > + pte_unmap_unlock(ptep, ptl); > return ret; > } > > Adding the following to resolve 32-bit build: diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 8a777250764a..ed03f3fcb07e 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -24,6 +24,7 @@ #include <linux/compat.h> #include <linux/device.h> #include <linux/fs.h> +#include <linux/highmem.h> #include <linux/iommu.h> #include <linux/module.h> #include <linux/mm.h>
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index ec9fd95a138b..ae4fd2295c95 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -463,9 +463,11 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, unsigned long vaddr, unsigned long *pfn, bool write_fault) { + pte_t *ptep; + spinlock_t *ptl; int ret; - ret = follow_pfn(vma, vaddr, pfn); + ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); if (ret) { bool unlocked = false; @@ -479,9 +481,17 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, if (ret) return ret; - ret = follow_pfn(vma, vaddr, pfn); + ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl); + if (ret) + return ret; } + if (write_fault && !pte_write(*ptep)) + ret = -EFAULT; + else + *pfn = pte_pfn(*ptep); + + pte_unmap_unlock(ptep, ptl); return ret; }
follow_pfn() doesn't make sure that we're using the correct page protections, get the pte with follow_pte() so that we can test protections and get the pfn from the pte. Fixes: 5cbf3264bc71 ("vfio/type1: Fix VA->PA translation for PFNMAP VMAs in vaddr_get_pfn()") Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> --- v2: Update to current follow_pte() API, add Reviews drivers/vfio/vfio_iommu_type1.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)