Switch from follow_pfn to follow_pte so that we can get rid of
follow_pfn. Note that this doesn't fix any of the pre-existing
raciness and lack of permission checking in the code.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/virt/acrn/mm.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/virt/acrn/mm.c b/drivers/virt/acrn/mm.c
index fa5d9ca6be5706..69c3f619f88196 100644
--- a/drivers/virt/acrn/mm.c
+++ b/drivers/virt/acrn/mm.c
@@ -171,18 +171,24 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap)
mmap_read_lock(current->mm);
vma = vma_lookup(current->mm, memmap->vma_base);
if (vma && ((vma->vm_flags & VM_PFNMAP) != 0)) {
+ spinlock_t *ptl;
+ pte_t *ptep;
+
if ((memmap->vma_base + memmap->len) > vma->vm_end) {
mmap_read_unlock(current->mm);
return -EINVAL;
}
- ret = follow_pfn(vma, memmap->vma_base, &pfn);
- mmap_read_unlock(current->mm);
+ ret = follow_pte(vma->vm_mm, memmap->vma_base, &ptep, &ptl);
if (ret < 0) {
+ mmap_read_unlock(current->mm);
dev_dbg(acrn_dev.this_device,
"Failed to lookup PFN at VMA:%pK.\n", (void *)memmap->vma_base);
return ret;
}
+ pfn = pte_pfn(ptep_get(ptep));
+ pte_unmap_unlock(ptep, ptl);
+ mmap_read_unlock(current->mm);
return acrn_mm_region_add(vm, memmap->user_vm_pa,
PFN_PHYS(pfn), memmap->len,
--
2.39.2
