1 files changed, 95 insertions, 3 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 9ab206b829a..990e7dc666f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -988,7 +988,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 				return i ? : -EFAULT;
 			}
 			if (pages) {
-				struct page *page = vm_normal_page(vma, start, *pte);
+				struct page *page = vm_normal_page(gate_vma, start, *pte);
 				pages[i] = page;
 				if (page)
 					get_page(page);
@@ -1147,6 +1147,95 @@ int zeromap_page_range(struct vm_area_struct *vma,
 }
 
 /*
+ * This is the old fallback for page remapping.
+ *
+ * For historical reasons, it only allows reserved pages. Only
+ * old drivers should use this, and they needed to mark their
+ * pages reserved for the old functions anyway.
+ */
+static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)
+{
+	int retval;
+	pgd_t * pgd;
+	pud_t * pud;
+	pmd_t * pmd;  
+	pte_t * pte;
+	spinlock_t *ptl;  
+
+	retval = -EINVAL;
+	if (PageAnon(page) || !PageReserved(page))
+		goto out;
+	retval = -ENOMEM;
+	flush_dcache_page(page);
+	pgd = pgd_offset(mm, addr);
+	pud = pud_alloc(mm, pgd, addr);
+	if (!pud)
+		goto out;
+	pmd = pmd_alloc(mm, pud, addr);
+	if (!pmd)
+		goto out;
+	pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
+	if (!pte)
+		goto out;
+	retval = -EBUSY;
+	if (!pte_none(*pte))
+		goto out_unlock;
+
+	/* Ok, finally just insert the thing.. */
+	get_page(page);
+	inc_mm_counter(mm, file_rss);
+	page_add_file_rmap(page);
+	set_pte_at(mm, addr, pte, mk_pte(page, prot));
+
+	retval = 0;
+out_unlock:
+	pte_unmap_unlock(pte, ptl);
+out:
+	return retval;
+}
+
+/*
+ * Somebody does a pfn remapping that doesn't actually work as a vma.
+ *
+ * Do it as individual pages instead, and warn about it. It's bad form,
+ * and very inefficient.
+ */
+static int incomplete_pfn_remap(struct vm_area_struct *vma,
+		unsigned long start, unsigned long end,
+		unsigned long pfn, pgprot_t prot)
+{
+	static int warn = 10;
+	struct page *page;
+	int retval;
+
+	if (!(vma->vm_flags & VM_INCOMPLETE)) {
+		if (warn) {
+			warn--;
+			printk("%s does an incomplete pfn remapping", current->comm);
+			dump_stack();
+		}
+	}
+	vma->vm_flags |= VM_INCOMPLETE | VM_IO | VM_RESERVED;
+
+	if (start < vma->vm_start || end > vma->vm_end)
+		return -EINVAL;
+
+	if (!pfn_valid(pfn))
+		return -EINVAL;
+
+	retval = 0;
+	page = pfn_to_page(pfn);
+	while (start < end) {
+		retval = insert_page(vma->vm_mm, start, page, prot);
+		if (retval < 0)
+			break;
+		start += PAGE_SIZE;
+		page++;
+	}
+	return retval;
+}
+
+/*
  * maps a range of physical memory into the requested pages. the old
  * mappings are removed. any references to nonexistent pages results
  * in null mappings (currently treated as "copy-on-access")
@@ -1220,6 +1309,9 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
 	struct mm_struct *mm = vma->vm_mm;
 	int err;
 
+	if (addr != vma->vm_start || end != vma->vm_end)
+		return incomplete_pfn_remap(vma, addr, end, pfn, prot);
+
 	/*
 	 * Physically remapped pages are special. Tell the
 	 * rest of the world about it:
@@ -1345,7 +1437,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		int reuse = can_share_swap_page(old_page);
 		unlock_page(old_page);
 		if (reuse) {
-			flush_cache_page(vma, address, pfn);
+			flush_cache_page(vma, address, pte_pfn(orig_pte));
 			entry = pte_mkyoung(orig_pte);
 			entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 			ptep_set_access_flags(vma, address, page_table, entry, 1);
@@ -1389,7 +1481,7 @@ gotten:
 			}
 		} else
 			inc_mm_counter(mm, anon_rss);
-		flush_cache_page(vma, address, pfn);
+		flush_cache_page(vma, address, pte_pfn(orig_pte));
 		entry = mk_pte(new_page, vma->vm_page_prot);
 		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 		ptep_establish(vma, address, page_table, entry);