mempolicy rcu fix

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b9ad22a963f899f76daafd1f4e5d9742ba0260f6..b38e2db832232a7ca977afad2b4e59ab7a2d979d 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -407,8 +407,10 @@ void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
        MA_STATE(mas, &mm->mm_mt, 0, 0);
 
        mmap_write_lock(mm);
+       mas_lock(&mas);
        mas_for_each(&mas, vma, ULONG_MAX)
                mpol_rebind_policy(vma->vm_policy, new);
+       mas_unlock(&mas);
        mmap_write_unlock(mm);
 }
 
@@ -812,6 +814,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
        unsigned long vmend;
        MA_STATE(mas, &mm->mm_mt, start, start);
 
+       rcu_read_lock();
        vma = mas_find(&mas, ULONG_MAX);
        VM_BUG_ON(!vma);
 
@@ -858,6 +861,7 @@ next:
        }
 
 out:
+       rcu_read_unlock();
        return err;
 }
 
@@ -1222,11 +1226,13 @@ static struct page *new_page(struct page *page, unsigned long start)
        unsigned long address;
        MA_STATE(mas, &current->mm->mm_mt, start, start);
 
+       rcu_read_lock();
        mas_for_each(&mas, vma, ULONG_MAX) {
                address = page_address_in_vma(page, vma);
                if (address != -EFAULT)
                        break;
        }
+       rcu_read_unlock();
 
        if (PageHuge(page)) {
                return alloc_huge_page_vma(page_hstate(compound_head(page)),