vserver 1.9.5.x5

[linux-2.6.git] / mm / mprotect.c

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 67d02dc..0427711 100644 (file)
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -18,6 +18,7 @@
 #include <linux/security.h>
 #include <linux/mempolicy.h>
 #include <linux/personality.h>
+#include <linux/syscalls.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
@@ -61,12 +62,38 @@ change_pte_range(pmd_t *pmd, unsigned long address,
 }
 
 static inline void
-change_pmd_range(pgd_t *pgd, unsigned long address,
+change_pmd_range(pud_t *pud, unsigned long address,
                unsigned long size, pgprot_t newprot)
 {
        pmd_t * pmd;
        unsigned long end;
 
+       if (pud_none(*pud))
+               return;
+       if (pud_bad(*pud)) {
+               pud_ERROR(*pud);
+               pud_clear(pud);
+               return;
+       }
+       pmd = pmd_offset(pud, address);
+       address &= ~PUD_MASK;
+       end = address + size;
+       if (end > PUD_SIZE)
+               end = PUD_SIZE;
+       do {
+               change_pte_range(pmd, address, end - address, newprot);
+               address = (address + PMD_SIZE) & PMD_MASK;
+               pmd++;
+       } while (address && (address < end));
+}
+
+static inline void
+change_pud_range(pgd_t *pgd, unsigned long address,
+               unsigned long size, pgprot_t newprot)
+{
+       pud_t * pud;
+       unsigned long end;
+
        if (pgd_none(*pgd))
                return;
        if (pgd_bad(*pgd)) {
@@ -74,15 +101,15 @@ change_pmd_range(pgd_t *pgd, unsigned long address,
                pgd_clear(pgd);
                return;
        }
-       pmd = pmd_offset(pgd, address);
+       pud = pud_offset(pgd, address);
        address &= ~PGDIR_MASK;
        end = address + size;
        if (end > PGDIR_SIZE)
                end = PGDIR_SIZE;
        do {
-               change_pte_range(pmd, address, end - address, newprot);
-               address = (address + PMD_SIZE) & PMD_MASK;
-               pmd++;
+               change_pmd_range(pud, address, end - address, newprot);
+               address = (address + PUD_SIZE) & PUD_MASK;
+               pud++;
        } while (address && (address < end));
 }
 
@@ -90,35 +117,40 @@ static void
 change_protection(struct vm_area_struct *vma, unsigned long start,
                unsigned long end, pgprot_t newprot)
 {
-       pgd_t *dir;
-       unsigned long beg = start;
+       struct mm_struct *mm = current->mm;
+       pgd_t *pgd;
+       unsigned long beg = start, next;
+       int i;
 
-       dir = pgd_offset(current->mm, start);
+       pgd = pgd_offset(mm, start);
        flush_cache_range(vma, beg, end);
-       if (start >= end)
-               BUG();
-       spin_lock(&current->mm->page_table_lock);
-       do {
-               change_pmd_range(dir, start, end - start, newprot);
-               start = (start + PGDIR_SIZE) & PGDIR_MASK;
-               dir++;
-       } while (start && (start < end));
+       BUG_ON(start >= end);
+       spin_lock(&mm->page_table_lock);
+       for (i = pgd_index(start); i <= pgd_index(end-1); i++) {
+               next = (start + PGDIR_SIZE) & PGDIR_MASK;
+               if (next <= start || next > end)
+                       next = end;
+               change_pud_range(pgd, start, next - start, newprot);
+               start = next;
+               pgd++;
+       }
        flush_tlb_range(vma, beg, end);
-       spin_unlock(&current->mm->page_table_lock);
-       return;
+       spin_unlock(&mm->page_table_lock);
 }
 
 static int
 mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
-       unsigned long start, unsigned long end, unsigned int newflags)
+       unsigned long start, unsigned long end, unsigned long newflags)
 {
        struct mm_struct * mm = vma->vm_mm;
+       unsigned long oldflags = vma->vm_flags;
+       long nrpages = (end - start) >> PAGE_SHIFT;
        unsigned long charged = 0;
        pgprot_t newprot;
        pgoff_t pgoff;
        int error;
 
-       if (newflags == vma->vm_flags) {
+       if (newflags == oldflags) {
                *pprev = vma;
                return 0;
        }
@@ -132,8 +164,8 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
         * a MAP_NORESERVE private mapping to writable will now reserve.
         */
        if (newflags & VM_WRITE) {
-               if (!(vma->vm_flags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
-                       charged = (end - start) >> PAGE_SHIFT;
+               if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
+                       charged = nrpages;
                        if (security_vm_enough_memory(charged))
                                return -ENOMEM;
                        newflags |= VM_ACCOUNT;
@@ -175,11 +207,11 @@ success:
         * vm_flags and vm_page_prot are protected by the mmap_sem
         * held in write mode.
         */
-       vm_stat_unaccount(vma);
        vma->vm_flags = newflags;
        vma->vm_page_prot = newprot;
        change_protection(vma, start, end, newprot);
-       vm_stat_account(vma);
+       __vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
+       __vm_stat_account(mm, newflags, vma->vm_file, nrpages);
        return 0;
 
 fail:
@@ -245,7 +277,7 @@ sys_mprotect(unsigned long start, size_t len, unsigned long prot)
                prev = vma;
 
        for (nstart = start ; ; ) {
-               unsigned int newflags;
+               unsigned long newflags;
 
                /* Here we know that  vma->vm_start <= nstart < vma->vm_end. */