Fix ust app tracepoint list realloc

- memcpy data _after_ reallocation (corruption fix),
- fix off-by-one in size check (corruption fix),
- multiply size by 2 each time size increase is needed (optimisation).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/lttng-sessiond/ust-app.c b/lttng-sessiond/ust-app.c
index 69164126beafbe15e276a7f694bc5dc2045cd7b9..3847004d4349abe70e17a517cfeb8b07b8da3f23 100644 (file)
--- a/lttng-sessiond/ust-app.c
+++ b/lttng-sessiond/ust-app.c
@@ -1383,12 +1383,11 @@ int ust_app_list_events(struct lttng_event **events)
 
                while ((ret = ustctl_tracepoint_list_get(app->key.sock, handle,
                                                &iter)) != -ENOENT) {
-                       memcpy(tmp[count].name, iter.name, LTTNG_UST_SYM_NAME_LEN);
                        /* TODO : get loglevel too */
-                       if (count > nbmem) {
-                               DBG2("Reallocating event list from %zu to %zu bytes", nbmem,
-                                               nbmem + UST_APP_EVENT_LIST_SIZE);
-                               nbmem += UST_APP_EVENT_LIST_SIZE;
+                       if (count >= nbmem) {
+                               DBG2("Reallocating event list from %zu to %zu entries", nbmem,
+                                               2 * nbmem);
+                               nbmem *= 2;
                                tmp = realloc(tmp, nbmem * sizeof(struct lttng_event));
                                if (tmp == NULL) {
                                        PERROR("realloc ust app events");
@@ -1396,7 +1395,7 @@ int ust_app_list_events(struct lttng_event **events)
                                        goto rcu_error;
                                }
                        }
-
+                       memcpy(tmp[count].name, iter.name, LTTNG_UST_SYM_NAME_LEN);
                        tmp[count].type = LTTNG_UST_TRACEPOINT;
                        tmp[count].pid = app->key.pid;
                        tmp[count].enabled = -1;