dm: table use uninitialized_var

[safe/jmp/linux-2.6] / mm / mprotect.c

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 14f93e6..4de5468 100644 (file)
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -27,12 +27,14 @@
 #include <asm/tlbflush.h>
 
 static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
-               unsigned long addr, unsigned long end, pgprot_t newprot)
+               unsigned long addr, unsigned long end, pgprot_t newprot,
+               int dirty_accountable)
 {
        pte_t *pte, oldpte;
        spinlock_t *ptl;
 
        pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+       arch_enter_lazy_mmu_mode();
        do {
                oldpte = *pte;
                if (pte_present(oldpte)) {
@@ -42,9 +44,15 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
                         * bits by wiping the pte and then setting the new pte
                         * into place.
                         */
-                       ptent = pte_modify(ptep_get_and_clear(mm, addr, pte), newprot);
+                       ptent = ptep_get_and_clear(mm, addr, pte);
+                       ptent = pte_modify(ptent, newprot);
+                       /*
+                        * Avoid taking write faults for pages we know to be
+                        * dirty.
+                        */
+                       if (dirty_accountable && pte_dirty(ptent))
+                               ptent = pte_mkwrite(ptent);
                        set_pte_at(mm, addr, pte, ptent);
-                       lazy_mmu_prot_update(ptent);
 #ifdef CONFIG_MIGRATION
                } else if (!pte_file(oldpte)) {
                        swp_entry_t entry = pte_to_swp_entry(oldpte);
@@ -62,11 +70,13 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
                }
 
        } while (pte++, addr += PAGE_SIZE, addr != end);
+       arch_leave_lazy_mmu_mode();
        pte_unmap_unlock(pte - 1, ptl);
 }
 
 static inline void change_pmd_range(struct mm_struct *mm, pud_t *pud,
-               unsigned long addr, unsigned long end, pgprot_t newprot)
+               unsigned long addr, unsigned long end, pgprot_t newprot,
+               int dirty_accountable)
 {
        pmd_t *pmd;
        unsigned long next;
@@ -76,12 +86,13 @@ static inline void change_pmd_range(struct mm_struct *mm, pud_t *pud,
                next = pmd_addr_end(addr, end);
                if (pmd_none_or_clear_bad(pmd))
                        continue;
-               change_pte_range(mm, pmd, addr, next, newprot);
+               change_pte_range(mm, pmd, addr, next, newprot, dirty_accountable);
        } while (pmd++, addr = next, addr != end);
 }
 
 static inline void change_pud_range(struct mm_struct *mm, pgd_t *pgd,
-               unsigned long addr, unsigned long end, pgprot_t newprot)
+               unsigned long addr, unsigned long end, pgprot_t newprot,
+               int dirty_accountable)
 {
        pud_t *pud;
        unsigned long next;
@@ -91,12 +102,13 @@ static inline void change_pud_range(struct mm_struct *mm, pgd_t *pgd,
                next = pud_addr_end(addr, end);
                if (pud_none_or_clear_bad(pud))
                        continue;
-               change_pmd_range(mm, pud, addr, next, newprot);
+               change_pmd_range(mm, pud, addr, next, newprot, dirty_accountable);
        } while (pud++, addr = next, addr != end);
 }
 
 static void change_protection(struct vm_area_struct *vma,
-               unsigned long addr, unsigned long end, pgprot_t newprot)
+               unsigned long addr, unsigned long end, pgprot_t newprot,
+               int dirty_accountable)
 {
        struct mm_struct *mm = vma->vm_mm;
        pgd_t *pgd;
@@ -110,12 +122,12 @@ static void change_protection(struct vm_area_struct *vma,
                next = pgd_addr_end(addr, end);
                if (pgd_none_or_clear_bad(pgd))
                        continue;
-               change_pud_range(mm, pgd, addr, next, newprot);
+               change_pud_range(mm, pgd, addr, next, newprot, dirty_accountable);
        } while (pgd++, addr = next, addr != end);
        flush_tlb_range(vma, start, end);
 }
 
-static int
+int
 mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
        unsigned long start, unsigned long end, unsigned long newflags)
 {
@@ -123,9 +135,9 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
        unsigned long oldflags = vma->vm_flags;
        long nrpages = (end - start) >> PAGE_SHIFT;
        unsigned long charged = 0;
-       pgprot_t newprot;
        pgoff_t pgoff;
        int error;
+       int dirty_accountable = 0;
 
        if (newflags == oldflags) {
                *pprev = vma;
@@ -149,8 +161,6 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
                }
        }
 
-       newprot = protection_map[newflags & 0xf];
-
        /*
         * First try to merge with previous and/or next vma.
         */
@@ -182,11 +192,16 @@ success:
         * held in write mode.
         */
        vma->vm_flags = newflags;
-       vma->vm_page_prot = newprot;
+       vma->vm_page_prot = vm_get_page_prot(newflags);
+       if (vma_wants_writenotify(vma)) {
+               vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED);
+               dirty_accountable = 1;
+       }
+
        if (is_vm_hugetlb_page(vma))
-               hugetlb_change_protection(vma, start, end, newprot);
+               hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
        else
-               change_protection(vma, start, end, newprot);
+               change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable);
        vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
        vm_stat_account(mm, newflags, vma->vm_file, nrpages);
        return 0;