Fix: memory leak in lttng_enable_event_with_exclusions

[lttng-tools.git] / src / lib / lttng-ctl / lttng-ctl.c

diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c
index 921db6f598fb30195398750f9a906e355e36707e..29f8a10d4d65f7d2295a289793789e520f79ed08 100644 (file)
--- a/src/lib/lttng-ctl/lttng-ctl.c
+++ b/src/lib/lttng-ctl/lttng-ctl.c
@@ -753,14 +753,21 @@ end:
  */
 int lttng_enable_event_with_exclusions(struct lttng_handle *handle,
                struct lttng_event *ev, const char *channel_name,
-               const char *filter_expression,
+               const char *original_filter_expression,
                int exclusion_count, char **exclusion_list)
 {
        struct lttcomm_session_msg lsm;
-       char *varlen_data, *jul_filter = NULL;
+       char *varlen_data;
        int ret = 0;
        struct filter_parser_ctx *ctx = NULL;
        FILE *fmem = NULL;
+       /*
+        * Cast as non-const since we may replace the filter expression
+        * by a dynamically allocated string. Otherwise, the original
+        * string is not modified.
+        */
+       char *filter_expression = (char *) original_filter_expression;
+       int free_filter_expression = 0;
 
        if (handle == NULL || ev == NULL) {
                return -LTTNG_ERR_INVALID;
@@ -817,10 +824,20 @@ int lttng_enable_event_with_exclusions(struct lttng_handle *handle,
        /* Parse filter expression */
        if (filter_expression != NULL || handle->domain.type == LTTNG_DOMAIN_JUL) {
                if (handle->domain.type == LTTNG_DOMAIN_JUL) {
+                       char *jul_filter;
+
                        /* Setup JUL filter if needed. */
-                       filter_expression = set_jul_filter(filter_expression, ev);
-                       if (!filter_expression) {
+                       jul_filter = set_jul_filter(filter_expression, ev);
+                       if (!jul_filter && !filter_expression) {
+                               /* No JUL and no filter, just skip everything below. */
                                goto ask_sessiond;
+                       } else {
+                               /*
+                                * With a JUL filter, the original filter has been added to it
+                                * thus replace the filter expression.
+                                */
+                               filter_expression = jul_filter;
+                               free_filter_expression = 1;
                        }
                }
 
@@ -832,7 +849,6 @@ int lttng_enable_event_with_exclusions(struct lttng_handle *handle,
                                strlen(filter_expression), "r");
                if (!fmem) {
                        fprintf(stderr, "Error opening memory as stream\n");
-                       free(jul_filter);
                        return -LTTNG_ERR_FILTER_NOMEM;
                }
                ctx = filter_parser_ctx_alloc(fmem);
@@ -942,8 +958,15 @@ varlen_alloc_error:
                if (fclose(fmem) != 0) {
                        perror("fclose");
                }
+               if (free_filter_expression) {
+                       /*
+                        * The filter expression has been replaced and must be
+                        * freed as it is not the original filter expression
+                        * received as a parameter.
+                        */
+                       free(filter_expression);
+               }
        }
-       free(jul_filter);
        return ret;
 
 parse_error:
@@ -954,7 +977,6 @@ filter_alloc_error:
        if (fclose(fmem) != 0) {
                perror("fclose");
        }
-       free(jul_filter);
        return ret;
 
 ask_sessiond: