mm/mempolicy.c: refix mbind_range() vma issue

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

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b1f70d6eec35af18b96bf5b3b85f98c9ce4fdeba..2775fd04924c7e5dd533e1519f57bacc578ff38b 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -636,6 +636,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
        struct vm_area_struct *prev;
        struct vm_area_struct *vma;
        int err = 0;
+       pgoff_t pgoff;
        unsigned long vmstart;
        unsigned long vmend;
 
@@ -643,13 +644,21 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
        if (!vma || vma->vm_start > start)
                return -EFAULT;
 
+       if (start > vma->vm_start)
+               prev = vma;
+
        for (; vma && vma->vm_start < end; prev = vma, vma = next) {
                next = vma->vm_next;
                vmstart = max(start, vma->vm_start);
                vmend   = min(end, vma->vm_end);
 
+               if (mpol_equal(vma_policy(vma), new_pol))
+                       continue;
+
+               pgoff = vma->vm_pgoff +
+                       ((vmstart - vma->vm_start) >> PAGE_SHIFT);
                prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
-                                 vma->anon_vma, vma->vm_file, vma->vm_pgoff,
+                                 vma->anon_vma, vma->vm_file, pgoff,
                                  new_pol);
                if (prev) {
                        vma = prev;
@@ -1411,7 +1420,9 @@ asmlinkage long compat_sys_get_mempolicy(int __user *policy,
        err = sys_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
 
        if (!err && nmask) {
-               err = copy_from_user(bm, nm, alloc_size);
+               unsigned long copy_size;
+               copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
+               err = copy_from_user(bm, nm, copy_size);
                /* ensure entire bitmap is zeroed */
                err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
                err |= compat_put_bitmap(nmask, bm, nr_bits);