Fix iterator: various fixes
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fri, 22 Jun 2012 14:35:54 +0000 (10:35 -0400)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fri, 22 Jun 2012 14:35:54 +0000 (10:35 -0400)
- various return values were untested
- seek_file_stream_by_timestamp off-by-one
- multi-trace logic issue
- not testing the return value of g_ptr_array_index() for NULL (possible
  NULL pointer dereference)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
lib/iterator.c

index e3ae0689d80ce429da64748f0d7866536900f01b..52ec064904d066ce7812c6787f607099ebea7554 100644 (file)
@@ -100,8 +100,8 @@ void bt_iter_free_pos(struct bt_iter_pos *iter_pos)
  * are looking for (either the exact timestamp or the event just after the
  * timestamp).
  *
- * Return 0 if the seek succeded and EOF if we didn't find any packet
- * containing the timestamp.
+ * Return 0 if the seek succeded, EOF if we didn't find any packet
+ * containing the timestamp, or a positive integer for error.
  */
 static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
                uint64_t timestamp)
@@ -114,16 +114,21 @@ static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
        for (i = 0; i < stream_pos->packet_index->len; i++) {
                index = &g_array_index(stream_pos->packet_index,
                                struct packet_index, i);
-               if (index->timestamp_end <= timestamp)
+               if (index->timestamp_end < timestamp)
                        continue;
 
                stream_pos->packet_seek(&stream_pos->parent, i, SEEK_SET);
                do {
                        ret = stream_read_event(cfs);
-               } while (cfs->parent.timestamp < timestamp && ret >= 0);
+               } while (cfs->parent.timestamp < timestamp && ret == 0);
 
-               return 0;
+               /* Can return either EOF, 0, or error (> 0). */
+               return ret;
        }
+       /*
+        * Cannot find the timestamp within the stream packets, return
+        * EOF.
+        */
        return EOF;
 }
 
@@ -133,42 +138,52 @@ static int seek_file_stream_by_timestamp(struct ctf_file_stream *cfs,
  *
  * Return 0 on success.
  * If the timestamp is not part of any file stream, return EOF to inform the
- * user the timestamp is out of the scope
+ * user the timestamp is out of the scope.
+ * On other errors, return positive value.
  */
 static int seek_ctf_trace_by_timestamp(struct ctf_trace *tin,
                uint64_t timestamp, struct ptr_heap *stream_heap)
 {
        int i, j, ret;
-       int found = EOF;
+       int found = 0;
 
        /* for each stream_class */
        for (i = 0; i < tin->streams->len; i++) {
                struct ctf_stream_declaration *stream_class;
 
                stream_class = g_ptr_array_index(tin->streams, i);
+               if (!stream_class)
+                       continue;
                /* for each file_stream */
                for (j = 0; j < stream_class->streams->len; j++) {
                        struct ctf_stream_definition *stream;
                        struct ctf_file_stream *cfs;
 
                        stream = g_ptr_array_index(stream_class->streams, j);
+                       if (!stream)
+                               continue;
                        cfs = container_of(stream, struct ctf_file_stream,
                                        parent);
                        ret = seek_file_stream_by_timestamp(cfs, timestamp);
                        if (ret == 0) {
                                /* Add to heap */
                                ret = heap_insert(stream_heap, cfs);
-                               if (ret)
-                                       goto error;
-                               found = 0;
+                               if (ret) {
+                                       /* Return positive error. */
+                                       return -ret;
+                               }
+                               found = 1;
+                       } else if (ret > 0) {
+                               /*
+                                * Error in seek (not EOF), failure.
+                                */
+                               return ret;
                        }
+                       /* on EOF just do not put stream into heap. */
                }
        }
 
-       return found;
-
-error:
-       return -2;
+       return found ? 0 : EOF;
 }
 
 int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
@@ -241,12 +256,21 @@ int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
                        struct trace_descriptor *td_read;
 
                        td_read = g_ptr_array_index(tc->array, i);
+                       if (!td_read)
+                               continue;
                        tin = container_of(td_read, struct ctf_trace, parent);
 
                        ret = seek_ctf_trace_by_timestamp(tin,
                                        iter_pos->u.seek_time,
                                        iter->stream_heap);
-                       if (ret < 0)
+                       /*
+                        * Positive errors are failure. Negative value
+                        * is EOF (for which we continue with other
+                        * traces). 0 is success. Note: on EOF, it just
+                        * means that no stream has been added to the
+                        * iterator for that trace, which is fine.
+                        */
+                       if (ret != 0 && ret != EOF)
                                goto error;
                }
                return 0;
@@ -258,6 +282,8 @@ int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
                        int stream_id;
 
                        td_read = g_ptr_array_index(tc->array, i);
+                       if (!td_read)
+                               continue;
                        tin = container_of(td_read, struct ctf_trace, parent);
 
                        /* Populate heap with each stream */
@@ -276,9 +302,14 @@ int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *iter_pos)
                                        file_stream = g_ptr_array_index(
                                                        stream->streams,
                                                        filenr);
+                                       if (!file_stream)
+                                               continue;
                                        ret = babeltrace_filestream_seek(
                                                        file_stream, iter_pos,
                                                        stream_id);
+                                       if (ret != 0 && ret != EOF) {
+                                               goto error;
+                                       }
                                }
                        }
                }
@@ -320,6 +351,8 @@ struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
                struct trace_descriptor *td_read;
 
                td_read = g_ptr_array_index(tc->array, i);
+               if (!td_read)
+                       continue;
                tin = container_of(td_read, struct ctf_trace, parent);
 
                for (stream_class_id = 0; stream_class_id < tin->streams->len;
@@ -328,6 +361,8 @@ struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
 
                        stream_class = g_ptr_array_index(tin->streams,
                                        stream_class_id);
+                       if (!stream_class)
+                               continue;
                        for (stream_id = 0;
                                        stream_id < stream_class->streams->len;
                                        stream_id++) {
@@ -338,6 +373,8 @@ struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter)
                                stream = g_ptr_array_index(
                                                stream_class->streams,
                                                stream_id);
+                               if (!stream)
+                                       continue;
                                cfs = container_of(stream,
                                                struct ctf_file_stream,
                                                parent);
@@ -438,6 +475,8 @@ int bt_iter_seek(struct bt_iter *iter,
                struct trace_descriptor *td_read;
 
                td_read = g_ptr_array_index(tc->array, i);
+               if (!td_read)
+                       continue;
                tin = container_of(td_read, struct ctf_trace, parent);
 
                /* Populate heap with each stream */
@@ -447,12 +486,16 @@ int bt_iter_seek(struct bt_iter *iter,
                        int filenr;
 
                        stream = g_ptr_array_index(tin->streams, stream_id);
+                       if (!stream)
+                               continue;
                        for (filenr = 0; filenr < stream->streams->len;
                                        filenr++) {
                                struct ctf_file_stream *file_stream;
 
                                file_stream = g_ptr_array_index(stream->streams,
                                                filenr);
+                               if (!file_stream)
+                                       continue;
                                ret = babeltrace_filestream_seek(file_stream, begin_pos,
                                                stream_id);
                                if (ret < 0)
@@ -491,6 +534,8 @@ int bt_iter_init(struct bt_iter *iter,
                struct trace_descriptor *td_read;
 
                td_read = g_ptr_array_index(ctx->tc->array, i);
+               if (!td_read)
+                       continue;
                tin = container_of(td_read, struct ctf_trace, parent);
 
                /* Populate heap with each stream */
@@ -508,7 +553,8 @@ int bt_iter_init(struct bt_iter *iter,
 
                                file_stream = g_ptr_array_index(stream->streams,
                                                filenr);
-
+                               if (!file_stream)
+                                       continue;
                                if (begin_pos) {
                                        ret = babeltrace_filestream_seek(
                                                        file_stream,
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