Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux-2.6-microblaze.git] / mm / vmalloc.c

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 3d7b94e..b482d24 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -512,6 +512,10 @@ static struct vmap_area *__find_vmap_area(unsigned long addr)
 /*
  * This function returns back addresses of parent node
  * and its left or right link for further processing.
+ *
+ * Otherwise NULL is returned. In that case all further
+ * steps regarding inserting of conflicting overlap range
+ * have to be declined and actually considered as a bug.
  */
 static __always_inline struct rb_node **
 find_va_links(struct vmap_area *va,
@@ -550,8 +554,12 @@ find_va_links(struct vmap_area *va,
                else if (va->va_end > tmp_va->va_start &&
                                va->va_start >= tmp_va->va_end)
                        link = &(*link)->rb_right;
-               else
-                       BUG();
+               else {
+                       WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
+                               va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
+
+                       return NULL;
+               }
        } while (*link);
 
        *parent = &tmp_va->rb_node;
@@ -697,7 +705,8 @@ insert_vmap_area(struct vmap_area *va,
        struct rb_node *parent;
 
        link = find_va_links(va, root, NULL, &parent);
-       link_va(va, root, parent, link, head);
+       if (link)
+               link_va(va, root, parent, link, head);
 }
 
 static void
@@ -713,8 +722,10 @@ insert_vmap_area_augment(struct vmap_area *va,
        else
                link = find_va_links(va, root, NULL, &parent);
 
-       link_va(va, root, parent, link, head);
-       augment_tree_propagate_from(va);
+       if (link) {
+               link_va(va, root, parent, link, head);
+               augment_tree_propagate_from(va);
+       }
 }
 
 /*
@@ -722,6 +733,11 @@ insert_vmap_area_augment(struct vmap_area *va,
  * and next free blocks. If coalesce is not done a new
  * free area is inserted. If VA has been merged, it is
  * freed.
+ *
+ * Please note, it can return NULL in case of overlap
+ * ranges, followed by WARN() report. Despite it is a
+ * buggy behaviour, a system can be alive and keep
+ * ongoing.
  */
 static __always_inline struct vmap_area *
 merge_or_add_vmap_area(struct vmap_area *va,
@@ -738,6 +754,8 @@ merge_or_add_vmap_area(struct vmap_area *va,
         * inserted, unless it is merged with its sibling/siblings.
         */
        link = find_va_links(va, root, NULL, &parent);
+       if (!link)
+               return NULL;
 
        /*
         * Get next node of VA to check if merging can be done.
@@ -1346,6 +1364,9 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
                va = merge_or_add_vmap_area(va, &free_vmap_area_root,
                                            &free_vmap_area_list);
 
+               if (!va)
+                       continue;
+
                if (is_vmalloc_or_module_addr((void *)orig_start))
                        kasan_release_vmalloc(orig_start, orig_end,
                                              va->va_start, va->va_end);
@@ -3330,8 +3351,9 @@ recovery:
                orig_end = vas[area]->va_end;
                va = merge_or_add_vmap_area(vas[area], &free_vmap_area_root,
                                            &free_vmap_area_list);
-               kasan_release_vmalloc(orig_start, orig_end,
-                                     va->va_start, va->va_end);
+               if (va)
+                       kasan_release_vmalloc(orig_start, orig_end,
+                               va->va_start, va->va_end);
                vas[area] = NULL;
        }
 
@@ -3379,8 +3401,9 @@ err_free_shadow:
                orig_end = vas[area]->va_end;
                va = merge_or_add_vmap_area(vas[area], &free_vmap_area_root,
                                            &free_vmap_area_list);
-               kasan_release_vmalloc(orig_start, orig_end,
-                                     va->va_start, va->va_end);
+               if (va)
+                       kasan_release_vmalloc(orig_start, orig_end,
+                               va->va_start, va->va_end);
                vas[area] = NULL;
                kfree(vms[area]);
        }