[IPV4]: UDP header annotations

[pandora-kernel.git] / mm / mremap.c

diff --git a/mm/mremap.c b/mm/mremap.c
index 8de77b6..7c15cf3 100644 (file)
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -13,6 +13,7 @@
 #include <linux/shm.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
+#include <linux/capability.h>
 #include <linux/fs.h>
 #include <linux/highmem.h>
 #include <linux/security.h>
@@ -72,7 +73,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
        struct address_space *mapping = NULL;
        struct mm_struct *mm = vma->vm_mm;
        pte_t *old_pte, *new_pte, pte;
-       spinlock_t *old_ptl;
+       spinlock_t *old_ptl, *new_ptl;
 
        if (vma->vm_file) {
                /*
@@ -88,8 +89,15 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
                        new_vma->vm_truncate_count = 0;
        }
 
+       /*
+        * We don't have to worry about the ordering of src and dst
+        * pte locks because exclusive mmap_sem prevents deadlock.
+        */
        old_pte = pte_offset_map_lock(mm, old_pmd, old_addr, &old_ptl);
        new_pte = pte_offset_map_nested(new_pmd, new_addr);
+       new_ptl = pte_lockptr(mm, new_pmd);
+       if (new_ptl != old_ptl)
+               spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
 
        for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
                                   new_pte++, new_addr += PAGE_SIZE) {
@@ -101,6 +109,8 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
                set_pte_at(mm, new_addr, new_pte, pte);
        }
 
+       if (new_ptl != old_ptl)
+               spin_unlock(new_ptl);
        pte_unmap_nested(new_pte - 1);
        pte_unmap_unlock(old_pte - 1, old_ptl);
        if (mapping)
@@ -314,7 +324,7 @@ unsigned long do_mremap(unsigned long addr,
        /* We can't remap across vm area boundaries */
        if (old_len > vma->vm_end - addr)
                goto out;
-       if (vma->vm_flags & VM_DONTEXPAND) {
+       if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP)) {
                if (new_len > old_len)
                        goto out;
        }