7 files changed, 30 insertions, 47 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 7c89b4549049..7e5e7ec2e36d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -203,13 +203,14 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                                 struct mem_size_stats *mss)
 {
         pte_t *pte, ptent;
+        spinlock_t *ptl;
         unsigned long pfn;
         struct page *page;
 
-        pte = pte_offset_map(pmd, addr);
+        pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
         do {
                 ptent = *pte;
-                if (pte_none(ptent) || !pte_present(ptent))
+                if (!pte_present(ptent))
                         continue;
 
                 mss->resident += PAGE_SIZE;
@@ -230,8 +231,8 @@ static void smaps_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                                 mss->private_clean += PAGE_SIZE;
                 }
         } while (pte++, addr += PAGE_SIZE, addr != end);
-        pte_unmap(pte - 1);
-        cond_resched_lock(&vma->vm_mm->page_table_lock);
+        pte_unmap_unlock(pte - 1, ptl);
+        cond_resched();
 }
 
 static inline void smaps_pmd_range(struct vm_area_struct *vma, pud_t *pud,
@@ -285,17 +286,11 @@ static inline void smaps_pgd_range(struct vm_area_struct *vma,
 static int show_smap(struct seq_file *m, void *v)
 {
         struct vm_area_struct *vma = v;
-        struct mm_struct *mm = vma->vm_mm;
         struct mem_size_stats mss;
 
         memset(&mss, 0, sizeof mss);
-
-        if (mm) {
-                spin_lock(&mm->page_table_lock);
+        if (vma->vm_mm)
                 smaps_pgd_range(vma, vma->vm_start, vma->vm_end, &mss);
-                spin_unlock(&mm->page_table_lock);
-        }
-
         return show_map_internal(m, v, &mss);
 }
 
diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h
index d101ac414f07..0e3ec809352d 100644
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -203,7 +203,8 @@ extern unsigned long pg0[];
 #define pte_present(x)  ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE))
 #define pte_clear(mm,addr,xp)   do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
 
-#define pmd_none(x)     (!pmd_val(x))
+/* To avoid harmful races, pmd_none(x) should check only the lower when PAE */
+#define pmd_none(x)     (!(unsigned long)pmd_val(x))
 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 #define pmd_clear(xp)   do { set_pmd(xp, __pmd(0)); } while (0)
 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
diff --git a/include/asm-um/pgtable.h b/include/asm-um/pgtable.h
index 616d02b57ea9..ac64eb955868 100644
--- a/include/asm-um/pgtable.h
+++ b/include/asm-um/pgtable.h
@@ -138,7 +138,7 @@ extern unsigned long pg0[1024];
 
 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
 
-#define pmd_none(x)     (!(pmd_val(x) & ~_PAGE_NEWPAGE))
+#define pmd_none(x)     (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 11d824f282f1..902d4c9eccdc 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -228,9 +228,9 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 {
         pte_t *orig_pte;
         pte_t *pte;
+        spinlock_t *ptl;
 
-        spin_lock(&vma->vm_mm->page_table_lock);
-        orig_pte = pte = pte_offset_map(pmd, addr);
+        orig_pte = pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
         do {
                 unsigned long pfn;
                 unsigned int nid;
@@ -246,8 +246,7 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                 if (!node_isset(nid, *nodes))
                         break;
         } while (pte++, addr += PAGE_SIZE, addr != end);
-        pte_unmap(orig_pte);
-        spin_unlock(&vma->vm_mm->page_table_lock);
+        pte_unmap_unlock(orig_pte, ptl);
         return addr != end;
 }
 
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 672a76fddd5e..17a2b52b753b 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -29,8 +29,9 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
                 unsigned long addr, unsigned long end, pgprot_t newprot)
 {
         pte_t *pte;
+        spinlock_t *ptl;
 
-        pte = pte_offset_map(pmd, addr);
+        pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
         do {
                 if (pte_present(*pte)) {
                         pte_t ptent;
@@ -44,7 +45,7 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
                         lazy_mmu_prot_update(ptent);
                 }
         } while (pte++, addr += PAGE_SIZE, addr != end);
-        pte_unmap(pte - 1);
+        pte_unmap_unlock(pte - 1, ptl);
 }
 
 static inline void change_pmd_range(struct mm_struct *mm, pud_t *pud,
@@ -88,7 +89,6 @@ static void change_protection(struct vm_area_struct *vma,
         BUG_ON(addr >= end);
         pgd = pgd_offset(mm, addr);
         flush_cache_range(vma, addr, end);
-        spin_lock(&mm->page_table_lock);
         do {
                 next = pgd_addr_end(addr, end);
                 if (pgd_none_or_clear_bad(pgd))
@@ -96,7 +96,6 @@ static void change_protection(struct vm_area_struct *vma,
                 change_pud_range(mm, pgd, addr, next, newprot);
         } while (pgd++, addr = next, addr != end);
         flush_tlb_range(vma, start, end);
-        spin_unlock(&mm->page_table_lock);
 }
 
 static int
diff --git a/mm/msync.c b/mm/msync.c
index 860395486060..0e040e9c39d8 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -17,28 +17,22 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 
-/*
- * Called with mm->page_table_lock held to protect against other
- * threads/the swapper from ripping pte's out from under us.
- */
-
 static void msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                                 unsigned long addr, unsigned long end)
 {
-        struct mm_struct *mm = vma->vm_mm;
         pte_t *pte;
+        spinlock_t *ptl;
         int progress = 0;
 
 again:
-        pte = pte_offset_map(pmd, addr);
+        pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
         do {
                 unsigned long pfn;
                 struct page *page;
 
                 if (progress >= 64) {
                         progress = 0;
-                        if (need_resched() ||
-                            need_lockbreak(&mm->page_table_lock))
+                        if (need_resched() || need_lockbreak(ptl))
                                 break;
                 }
                 progress++;
@@ -58,8 +52,8 @@ again:
                         set_page_dirty(page);
                 progress += 3;
         } while (pte++, addr += PAGE_SIZE, addr != end);
-        pte_unmap(pte - 1);
-        cond_resched_lock(&mm->page_table_lock);
+        pte_unmap_unlock(pte - 1, ptl);
+        cond_resched();
         if (addr != end)
                 goto again;
 }
@@ -97,7 +91,6 @@ static inline void msync_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
 static void msync_page_range(struct vm_area_struct *vma,
                                 unsigned long addr, unsigned long end)
 {
-        struct mm_struct *mm = vma->vm_mm;
         pgd_t *pgd;
         unsigned long next;
 
@@ -110,16 +103,14 @@ static void msync_page_range(struct vm_area_struct *vma,
                 return;
 
         BUG_ON(addr >= end);
-        pgd = pgd_offset(mm, addr);
+        pgd = pgd_offset(vma->vm_mm, addr);
         flush_cache_range(vma, addr, end);
-        spin_lock(&mm->page_table_lock);
         do {
                 next = pgd_addr_end(addr, end);
                 if (pgd_none_or_clear_bad(pgd))
                         continue;
                 msync_pud_range(vma, pgd, addr, next);
         } while (pgd++, addr = next, addr != end);
-        spin_unlock(&mm->page_table_lock);
 }
 
 /*
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 296e0bbf7836..510f0039b000 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -401,8 +401,6 @@ void free_swap_and_cache(swp_entry_t entry)
  * No need to decide whether this PTE shares the swap entry with others,
  * just let do_wp_page work it out if a write is requested later - to
  * force COW, vm_page_prot omits write permission from any private vma.
- *
- * vma->vm_mm->page_table_lock is held.
  */
 static void unuse_pte(struct vm_area_struct *vma, pte_t *pte,
                 unsigned long addr, swp_entry_t entry, struct page *page)
@@ -424,23 +422,25 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                                 unsigned long addr, unsigned long end,
                                 swp_entry_t entry, struct page *page)
 {
-        pte_t *pte;
         pte_t swp_pte = swp_entry_to_pte(entry);
+        pte_t *pte;
+        spinlock_t *ptl;
+        int found = 0;
 
-        pte = pte_offset_map(pmd, addr);
+        pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
         do {
                 /*
                  * swapoff spends a _lot_ of time in this loop!
                  * Test inline before going to call unuse_pte.
                  */
                 if (unlikely(pte_same(*pte, swp_pte))) {
-                        unuse_pte(vma, pte, addr, entry, page);
-                        pte_unmap(pte);
-                        return 1;
+                        unuse_pte(vma, pte++, addr, entry, page);
+                        found = 1;
+                        break;
                 }
         } while (pte++, addr += PAGE_SIZE, addr != end);
-        pte_unmap(pte - 1);
-        return 0;
+        pte_unmap_unlock(pte - 1, ptl);
+        return found;
 }
 
 static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
@@ -522,12 +522,10 @@ static int unuse_mm(struct mm_struct *mm,
                 down_read(&mm->mmap_sem);
                 lock_page(page);
         }
-        spin_lock(&mm->page_table_lock);
         for (vma = mm->mmap; vma; vma = vma->vm_next) {
                 if (vma->anon_vma && unuse_vma(vma, entry, page))
                         break;
         }
-        spin_unlock(&mm->page_table_lock);
         up_read(&mm->mmap_sem);
         /*
          * Currently unuse_mm cannot fail, but leave error handling