Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / mm / internal.h

diff --git a/mm/internal.h b/mm/internal.h
index 2f11829..e8fdb53 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -384,27 +384,52 @@ static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
 
 /*
- * At what user virtual address is page expected in @vma?
+ * At what user virtual address is page expected in vma?
+ * Returns -EFAULT if all of the page is outside the range of vma.
+ * If page is a compound head, the entire compound page is considered.
  */
 static inline unsigned long
-__vma_address(struct page *page, struct vm_area_struct *vma)
+vma_address(struct page *page, struct vm_area_struct *vma)
 {
-       pgoff_t pgoff = page_to_pgoff(page);
-       return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+       pgoff_t pgoff;
+       unsigned long address;
+
+       VM_BUG_ON_PAGE(PageKsm(page), page);    /* KSM page->index unusable */
+       pgoff = page_to_pgoff(page);
+       if (pgoff >= vma->vm_pgoff) {
+               address = vma->vm_start +
+                       ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+               /* Check for address beyond vma (or wrapped through 0?) */
+               if (address < vma->vm_start || address >= vma->vm_end)
+                       address = -EFAULT;
+       } else if (PageHead(page) &&
+                  pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
+               /* Test above avoids possibility of wrap to 0 on 32-bit */
+               address = vma->vm_start;
+       } else {
+               address = -EFAULT;
+       }
+       return address;
 }
 
+/*
+ * Then at what user virtual address will none of the page be found in vma?
+ * Assumes that vma_address() already returned a good starting address.
+ * If page is a compound head, the entire compound page is considered.
+ */
 static inline unsigned long
-vma_address(struct page *page, struct vm_area_struct *vma)
+vma_address_end(struct page *page, struct vm_area_struct *vma)
 {
-       unsigned long start, end;
-
-       start = __vma_address(page, vma);
-       end = start + thp_size(page) - PAGE_SIZE;
-
-       /* page should be within @vma mapping range */
-       VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma);
-
-       return max(start, vma->vm_start);
+       pgoff_t pgoff;
+       unsigned long address;
+
+       VM_BUG_ON_PAGE(PageKsm(page), page);    /* KSM page->index unusable */
+       pgoff = page_to_pgoff(page) + compound_nr(page);
+       address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+       /* Check for address beyond vma (or wrapped through 0?) */
+       if (address < vma->vm_start || address > vma->vm_end)
+               address = vma->vm_end;
+       return address;
 }
 
 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,