flex_array: poison free elements

[~andy/linux] / lib / flex_array.c

diff --git a/lib/flex_array.c b/lib/flex_array.c
index b68f99be4080283ab6c0b1e0c5d630330640cbb4..e22d0e9776aa604e8742dbb4314816e62e7d8d4b 100644 (file)
--- a/lib/flex_array.c
+++ b/lib/flex_array.c
@@ -113,6 +113,8 @@ struct flex_array *flex_array_alloc(int element_size, unsigned int total,
                return NULL;
        ret->element_size = element_size;
        ret->total_nr_elements = total;
+       if (elements_fit_in_base(ret) && !(flags & __GFP_ZERO))
+               memset(ret->parts[0], FLEX_ARRAY_FREE, bytes_left_in_base());
        return ret;
 }
 
@@ -159,15 +161,12 @@ __fa_get_part(struct flex_array *fa, int part_nr, gfp_t flags)
 {
        struct flex_array_part *part = fa->parts[part_nr];
        if (!part) {
-               /*
-                * This leaves the part pages uninitialized
-                * and with potentially random data, just
-                * as if the user had kmalloc()'d the whole.
-                * __GFP_ZERO can be used to zero it.
-                */
-               part = kmalloc(FLEX_ARRAY_PART_SIZE, flags);
+               part = kmalloc(sizeof(struct flex_array_part), flags);
                if (!part)
                        return NULL;
+               if (!(flags & __GFP_ZERO))
+                       memset(part, FLEX_ARRAY_FREE,
+                               sizeof(struct flex_array_part));
                fa->parts[part_nr] = part;
        }
        return part;
@@ -228,7 +227,7 @@ int flex_array_clear(struct flex_array *fa, unsigned int element_nr)
                        return -EINVAL;
        }
        dst = &part->elements[index_inside_part(fa, element_nr)];
-       memset(dst, 0, fa->element_size);
+       memset(dst, FLEX_ARRAY_FREE, fa->element_size);
        return 0;
 }