lib/bloom: Fix bloom hashing on 32-bit architectures

There was an implicit cast from guint64 to gsize (which is 32-bit on armhf, for example) before the modulus arithmetic which safely narrows the index. Fix that by using a guint64 intermediate variable and making the cast explicit. Signed-off-by: Philip Withnall <[email protected]>
ostreedev · Sep 30, 2017 · fddad99 · fddad99
1 parent 4262a4b
commit fddad99
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/src/libostree/ostree-bloom.c b/src/libostree/ostree-bloom.c
@@ -273,11 +273,11 @@ ostree_bloom_maybe_contains (OstreeBloom   *bloom,
 
   for (i = 0; i < bloom->k; i++)
     {
-      gsize idx;
+      guint64 idx;
 
       idx = bloom->hash_func (element, i);
 
-      if (!ostree_bloom_get_bit (bloom, idx % (bloom->n_bytes * 8)))
+      if (!ostree_bloom_get_bit (bloom, (gsize) (idx % (bloom->n_bytes * 8))))
         return FALSE;  /* definitely not in the set */
     }
 
@@ -337,8 +337,8 @@ ostree_bloom_add_element (OstreeBloom   *bloom,
 
   for (i = 0; i < bloom->k; i++)
     {
-      gsize idx = bloom->hash_func (element, i);
-      ostree_bloom_set_bit (bloom, idx % (bloom->n_bytes * 8));
+      guint64 idx = bloom->hash_func (element, i);
+      ostree_bloom_set_bit (bloom, (gsize) (idx % (bloom->n_bytes * 8)));
     }
 }