mm: avoid livelock on !__GFP_FS allocations
[linux-2.6.git] / mm / fremap.c
index 46f5dac..b8e0e2d 100644 (file)
@@ -125,7 +125,6 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 {
        struct mm_struct *mm = current->mm;
        struct address_space *mapping;
-       unsigned long end = start + size;
        struct vm_area_struct *vma;
        int err = -EINVAL;
        int has_write_lock = 0;
@@ -142,6 +141,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
        if (start + size <= start)
                return err;
 
+       /* Does pgoff wrap? */
+       if (pgoff + (size >> PAGE_SHIFT) < pgoff)
+               return err;
+
        /* Can we represent this offset inside this architecture's pte's? */
 #if PTE_FILE_MAX_BITS < BITS_PER_LONG
        if (pgoff + (size >> PAGE_SHIFT) >= (1UL << PTE_FILE_MAX_BITS))
@@ -168,7 +171,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
        if (!(vma->vm_flags & VM_CAN_NONLINEAR))
                goto out;
 
-       if (end <= start || start < vma->vm_start || end > vma->vm_end)
+       if (start < vma->vm_start || start + size > vma->vm_end)
                goto out;
 
        /* Must set VM_NONLINEAR before any pages are populated. */
@@ -208,20 +211,20 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
                        }
                        goto out;
                }
-               spin_lock(&mapping->i_mmap_lock);
+               mutex_lock(&mapping->i_mmap_mutex);
                flush_dcache_mmap_lock(mapping);
                vma->vm_flags |= VM_NONLINEAR;
                vma_prio_tree_remove(vma, &mapping->i_mmap);
                vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear);
                flush_dcache_mmap_unlock(mapping);
-               spin_unlock(&mapping->i_mmap_lock);
+               mutex_unlock(&mapping->i_mmap_mutex);
        }
 
        if (vma->vm_flags & VM_LOCKED) {
                /*
                 * drop PG_Mlocked flag for over-mapped range
                 */
-               unsigned int saved_flags = vma->vm_flags;
+               vm_flags_t saved_flags = vma->vm_flags;
                munlock_vma_pages_range(vma, start, start + size);
                vma->vm_flags = saved_flags;
        }