[PATCH] Pass vma argument to copy_user_highpage().

To allow a more effective copy_user_highpage() on certain architectures,
a vma argument is added to the function and cow_user_page() allowing
the implementation of these functions to check for the VM_EXEC bit.

The main part of this patch was originally written by Ralf Baechle;
Atushi Nemoto did the the debugging.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 10 insertions, 9 deletions

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index ea5780b518ef..ca9a602cffd7 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -98,7 +98,8 @@ static inline void memclear_highpage_flush(struct page *page, unsigned int offse
 
 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
 
-static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr)
+static inline void copy_user_highpage(struct page *to, struct page *from,
+        unsigned long vaddr, struct vm_area_struct *vma)
 {
         char *vfrom, *vto;
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 089092d152ab..cb362f761f17 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -44,14 +44,14 @@ static void clear_huge_page(struct page *page, unsigned long addr)
 }
 
 static void copy_huge_page(struct page *dst, struct page *src,
-                           unsigned long addr)
+                           unsigned long addr, struct vm_area_struct *vma)
 {
         int i;
 
         might_sleep();
         for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) {
                 cond_resched();
-                copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE);
+                copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
         }
 }
 
@@ -442,7 +442,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
         }
 
         spin_unlock(&mm->page_table_lock);
-        copy_huge_page(new_page, old_page, address);
+        copy_huge_page(new_page, old_page, address, vma);
         spin_lock(&mm->page_table_lock);
 
         ptep = huge_pte_offset(mm, address & HPAGE_MASK);
diff --git a/mm/memory.c b/mm/memory.c
index bf6100236e62..c00bac66ce9f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1441,7 +1441,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
         return pte;
 }
 
-static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va)
+static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)
 {
         /*
          * If the source page was a PFN mapping, we don't have
@@ -1464,9 +1464,9 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
                 kunmap_atomic(kaddr, KM_USER0);
                 flush_dcache_page(dst);
                 return;
-                
+
         }
-        copy_user_highpage(dst, src, va);
+        copy_user_highpage(dst, src, va, vma);
 }
 
 /*
@@ -1577,7 +1577,7 @@ gotten:
                 new_page = alloc_page_vma(GFP_HIGHUSER, vma, address);
                 if (!new_page)
                         goto oom;
-                cow_user_page(new_page, old_page, address);
+                cow_user_page(new_page, old_page, address, vma);
         }
 
         /*
@@ -2200,7 +2200,7 @@ retry:
                         page = alloc_page_vma(GFP_HIGHUSER, vma, address);
                         if (!page)
                                 goto oom;
-                        copy_user_highpage(page, new_page, address);
+                        copy_user_highpage(page, new_page, address, vma);
                         page_cache_release(new_page);
                         new_page = page;
                         anon = 1;