1 files changed, 48 insertions, 22 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 164951c47305..f01b7eed6e16 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -669,6 +669,16 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
         if (is_vm_hugetlb_page(vma))
                 return copy_hugetlb_page_range(dst_mm, src_mm, vma);
 
+        if (unlikely(is_pfn_mapping(vma))) {
+                /*
+                 * We do not free on error cases below as remove_vma
+                 * gets called on error from higher level routine
+                 */
+                ret = track_pfn_vma_copy(vma);
+                if (ret)
+                        return ret;
+        }
+
         /*
          * We need to invalidate the secondary MMU mappings only when
          * there could be a permission downgrade on the ptes of the
@@ -915,6 +925,9 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
                 if (vma->vm_flags & VM_ACCOUNT)
                         *nr_accounted += (end - start) >> PAGE_SHIFT;
 
+                if (unlikely(is_pfn_mapping(vma)))
+                        untrack_pfn_vma(vma, 0, 0);
+
                 while (start != end) {
                         if (!tlb_start_valid) {
                                 tlb_start = start;
@@ -1430,6 +1443,7 @@ out:
 int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
                         unsigned long pfn)
 {
+        int ret;
         /*
          * Technically, architectures with pte_special can avoid all these
          * restrictions (same for remap_pfn_range).  However we would like
@@ -1444,7 +1458,15 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
 
         if (addr < vma->vm_start || addr >= vma->vm_end)
                 return -EFAULT;
-        return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+        if (track_pfn_vma_new(vma, vma->vm_page_prot, pfn, PAGE_SIZE))
+                return -EINVAL;
+
+        ret = insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+
+        if (ret)
+                untrack_pfn_vma(vma, pfn, PAGE_SIZE);
+
+        return ret;
 }
 EXPORT_SYMBOL(vm_insert_pfn);
 
@@ -1575,14 +1597,17 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
          * behaviour that some programs depend on. We mark the "original"
          * un-COW'ed pages by matching them up with "vma->vm_pgoff".
          */
-        if (is_cow_mapping(vma->vm_flags)) {
-                if (addr != vma->vm_start || end != vma->vm_end)
-                        return -EINVAL;
+        if (addr == vma->vm_start && end == vma->vm_end)
                 vma->vm_pgoff = pfn;
-        }
+        else if (is_cow_mapping(vma->vm_flags))
+                return -EINVAL;
 
         vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
 
+        err = track_pfn_vma_new(vma, prot, pfn, PAGE_ALIGN(size));
+        if (err)
+                return -EINVAL;
+
         BUG_ON(addr >= end);
         pfn -= addr >> PAGE_SHIFT;
         pgd = pgd_offset(mm, addr);
@@ -1594,6 +1619,10 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
                 if (err)
                         break;
         } while (pgd++, addr = next, addr != end);
+
+        if (err)
+                untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size));
+
         return err;
 }
 EXPORT_SYMBOL(remap_pfn_range);
@@ -2865,9 +2894,9 @@ int in_gate_area_no_task(unsigned long addr)
 #endif  /* __HAVE_ARCH_GATE_AREA */
 
 #ifdef CONFIG_HAVE_IOREMAP_PROT
-static resource_size_t follow_phys(struct vm_area_struct *vma,
-                        unsigned long address, unsigned int flags,
-                        unsigned long *prot)
+int follow_phys(struct vm_area_struct *vma,
+                unsigned long address, unsigned int flags,
+                unsigned long *prot, resource_size_t *phys)
 {
         pgd_t *pgd;
         pud_t *pud;
@@ -2876,24 +2905,26 @@ static resource_size_t follow_phys(struct vm_area_struct *vma,
         spinlock_t *ptl;
         resource_size_t phys_addr = 0;
         struct mm_struct *mm = vma->vm_mm;
+        int ret = -EINVAL;
 
-        VM_BUG_ON(!(vma->vm_flags & (VM_IO | VM_PFNMAP)));
+        if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
+                goto out;
 
         pgd = pgd_offset(mm, address);
         if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
-                goto no_page_table;
+                goto out;
 
         pud = pud_offset(pgd, address);
         if (pud_none(*pud) || unlikely(pud_bad(*pud)))
-                goto no_page_table;
+                goto out;
 
         pmd = pmd_offset(pud, address);
         if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
-                goto no_page_table;
+                goto out;
 
         /* We cannot handle huge page PFN maps. Luckily they don't exist. */
         if (pmd_huge(*pmd))
-                goto no_page_table;
+                goto out;
 
         ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
         if (!ptep)
@@ -2908,13 +2939,13 @@ static resource_size_t follow_phys(struct vm_area_struct *vma,
         phys_addr <<= PAGE_SHIFT; /* Shift here to avoid overflow on PAE */
 
         *prot = pgprot_val(pte_pgprot(pte));
+        *phys = phys_addr;
+        ret = 0;
 
 unlock:
         pte_unmap_unlock(ptep, ptl);
 out:
-        return phys_addr;
-no_page_table:
-        return 0;
+        return ret;
 }
 
 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
@@ -2925,12 +2956,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
         void *maddr;
         int offset = addr & (PAGE_SIZE-1);
 
-        if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
-                return -EINVAL;
-
-        phys_addr = follow_phys(vma, addr, write, &prot);
-
-        if (!phys_addr)
+        if (follow_phys(vma, addr, write, &prot, &phys_addr))
                 return -EINVAL;
 
         maddr = ioremap_prot(phys_addr, PAGE_SIZE, prot);