Do not try to mmap empty cache.

diff --git a/src/symbols_cache.c b/src/symbols_cache.c
index 5940bb4c21187810659587d5a5c127334daba999..49934b6d2e530226e4c6f425de9bccc636c0e29c 100644 (file)
--- a/src/symbols_cache.c
+++ b/src/symbols_cache.c
@@ -151,33 +151,35 @@ mmap_cache_file (struct symbols_cache *cache, gint fd, memory_pool_t *pool)
        GList                          *cur;
        struct cache_item              *item;
 
-       map = mmap (NULL, cache->used_items * sizeof (struct saved_cache_item), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-       if (map == MAP_FAILED) {
-               msg_err ("cannot mmap cache file: %d, %s", errno, strerror (errno));
+       if (cache->used_items > 0) {
+               map = mmap (NULL, cache->used_items * sizeof (struct saved_cache_item), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+               if (map == MAP_FAILED) {
+                       msg_err ("cannot mmap cache file: %d, %s", errno, strerror (errno));
+                       close (fd);
+                       return FALSE;
+               }
+               /* Close descriptor as it would never be used */
                close (fd);
-               return FALSE;
-       }
-       /* Close descriptor as it would never be used */
-       close (fd);
-       cache->map = map;
-       /* Now free old values for saved cache items and fill them with mmapped ones */
-       i = 0;
-       cur = g_list_first (cache->negative_items);
-       while (cur) {
-               item = cur->data;
-               item->s = (struct saved_cache_item *)(map + i * sizeof (struct saved_cache_item));
-               cur = g_list_next (cur);
-               i ++;
-       }
-       cur = g_list_first (cache->static_items);
-       while (cur) {
-               item = cur->data;
-               item->s = (struct saved_cache_item *)(map + i * sizeof (struct saved_cache_item));
-               cur = g_list_next (cur);
-               i ++;
-       }
+               cache->map = map;
+               /* Now free old values for saved cache items and fill them with mmapped ones */
+               i = 0;
+               cur = g_list_first (cache->negative_items);
+               while (cur) {
+                       item = cur->data;
+                       item->s = (struct saved_cache_item *)(map + i * sizeof (struct saved_cache_item));
+                       cur = g_list_next (cur);
+                       i ++;
+               }
+               cur = g_list_first (cache->static_items);
+               while (cur) {
+                       item = cur->data;
+                       item->s = (struct saved_cache_item *)(map + i * sizeof (struct saved_cache_item));
+                       cur = g_list_next (cur);
+                       i ++;
+               }
 
-       post_cache_init (cache);
+               post_cache_init (cache);
+       }
 
        return TRUE;
 }