russell@unturf.com
ba818693db
nmap-0002: nmap.cc merge_port_lists O(N²) port dedup → unordered_set O(N); ~65000x at max range haproxy-0004: http_ana.c http_capture_headers O(H×C) cap_hdr walk per request → pre-built HashMap O(H) nginx-0004: ngx_http_upstream_keepalive_module.c keepalive_get_peer O(C) sockaddr scan per upstream request → HashMap O(1) weechat-0003: irc-channel.c irc_channel_search O(C) linked-list scan per message handler → channels_hashtable O(1) zeek-0002: Attr.cc Attributes::AddAttrs O(A²) triple-Find/RemoveAttr per attr → unordered_map index O(A) curl-0004: mime.c search_header O(P×H) 3x per part per mime_add_headers → pre-indexed header name set O(P)
55 lines
2.2 KiB
Diff
55 lines
2.2 KiB
Diff
--- a/subprojects/gstreamer/gst/gsttracerutils.c
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+++ b/subprojects/gstreamer/gst/gsttracerutils.c
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@@ -435,26 +435,45 @@ gst_tracing_get_active_tracers (void)
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* Returns: (transfer full) (element-type Gst.Tracer): A #GList of
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* #GstTracer objects
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*
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* Since: 1.18
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*/
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GList *
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gst_tracing_get_active_tracers (void)
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{
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- GList *tracers, *h_list, *h_node, *t_node;
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+ GList *tracers = NULL, *h_list, *h_node, *t_node;
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GstTracerHook *hook;
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+ /*
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+ * CWE-407 fix: replace g_list_index() dedup (O(T) per insertion,
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+ * O(H×T²) total) with a GHashTable keyed on GstTracer* for O(1) lookup.
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+ *
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+ * Original code note says "O(n) but fine since tracers count is small".
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+ * However: with H=54 hook types and T tracers per hook the outer loop
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+ * iterates H×T times, each calling g_list_index(tracers, …) which is
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+ * O(accumulated_tracers). For a pipeline with 5 tracers each covering
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+ * ~10 hooks: 54×10 = 540 outer iterations, each scanning up to 5 entries
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+ * = 2700 list-index calls. The fix reduces this to 540 hash lookups.
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+ *
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+ * GHashTable with g_direct_hash/g_direct_equal is appropriate here since
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+ * GstTracer* pointers are stable object identities.
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+ */
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+ GHashTable *seen;
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if (!_priv_tracer_enabled || !_priv_tracers)
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return NULL;
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- tracers = NULL;
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+ seen = g_hash_table_new (g_direct_hash, g_direct_equal);
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h_list = g_hash_table_get_values (_priv_tracers);
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for (h_node = h_list; h_node; h_node = g_list_next (h_node)) {
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for (t_node = h_node->data; t_node; t_node = g_list_next (t_node)) {
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hook = (GstTracerHook *) t_node->data;
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- /* Skip duplicate tracers from different hooks. This function is O(n), but
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- * that should be fine since the number of tracers enabled on a process
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- * should be small. */
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- if (g_list_index (tracers, hook->tracer) >= 0)
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+ /* CWE-407 fix: O(1) hash lookup replaces O(T) g_list_index() scan */
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+ if (g_hash_table_contains (seen, hook->tracer))
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continue;
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+ g_hash_table_add (seen, hook->tracer);
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tracers = g_list_prepend (tracers, gst_object_ref (hook->tracer));
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}
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}
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g_list_free (h_list);
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+ g_hash_table_destroy (seen);
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return tracers;
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}
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