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authorAlex Williamson <alex.williamson@redhat.com>2021-02-16 15:49:34 -0700
committerAlex Williamson <alex.williamson@redhat.com>2021-02-22 10:17:13 -0700
commit07956b6269d3ed05d854233d5bb776dca91751dd (patch)
tree17738c3164a557a03f357d3f483ee6fe347b1454 /drivers/vfio
parent72d6e4871f0457dc9e498f8437ea344ee6b78075 (diff)
vfio/type1: Use follow_pte()
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> Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/vfio_iommu_type1.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index b3df383d7028..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>
@@ -462,9 +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;
@@ -478,9 +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;
}