Fix: use non block waitpid to lookup child state

[lttng-tools.git] / src / bin / lttng-sessiond / main.c

diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index bedc61c110654744223f25de55f1713c97be8abd..67ecc5228a194c7b6edda49431f0f20dcfa3ea16 100644 (file)
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -2937,9 +2937,74 @@ skip_domain:
        }
        case LTTNG_ENABLE_EVENT:
        {
+               struct lttng_event_exclusion *exclusion = NULL;
+               struct lttng_filter_bytecode *bytecode = NULL;
+
+               /* Handle exclusion events and receive it from the client. */
+               if (cmd_ctx->lsm->u.enable.exclusion_count > 0) {
+                       size_t count = cmd_ctx->lsm->u.enable.exclusion_count;
+
+                       exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
+                                       (count * LTTNG_SYMBOL_NAME_LEN));
+                       if (!exclusion) {
+                               ret = LTTNG_ERR_EXCLUSION_NOMEM;
+                               goto error;
+                       }
+
+                       DBG("Receiving var len exclusion event list from client ...");
+                       exclusion->count = count;
+                       ret = lttcomm_recv_unix_sock(sock, exclusion->names,
+                                       count * LTTNG_SYMBOL_NAME_LEN);
+                       if (ret <= 0) {
+                               DBG("Nothing recv() from client var len data... continuing");
+                               *sock_error = 1;
+                               free(exclusion);
+                               ret = LTTNG_ERR_EXCLUSION_INVAL;
+                               goto error;
+                       }
+               }
+
+               /* Handle filter and get bytecode from client. */
+               if (cmd_ctx->lsm->u.enable.bytecode_len > 0) {
+                       size_t bytecode_len = cmd_ctx->lsm->u.enable.bytecode_len;
+
+                       if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
+                               ret = LTTNG_ERR_FILTER_INVAL;
+                               free(exclusion);
+                               goto error;
+                       }
+
+                       bytecode = zmalloc(bytecode_len);
+                       if (!bytecode) {
+                               free(exclusion);
+                               ret = LTTNG_ERR_FILTER_NOMEM;
+                               goto error;
+                       }
+
+                       /* Receive var. len. data */
+                       DBG("Receiving var len filter's bytecode from client ...");
+                       ret = lttcomm_recv_unix_sock(sock, bytecode, bytecode_len);
+                       if (ret <= 0) {
+                               DBG("Nothing recv() from client car len data... continuing");
+                               *sock_error = 1;
+                               free(bytecode);
+                               free(exclusion);
+                               ret = LTTNG_ERR_FILTER_INVAL;
+                               goto error;
+                       }
+
+                       if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
+                               free(bytecode);
+                               free(exclusion);
+                               ret = LTTNG_ERR_FILTER_INVAL;
+                               goto error;
+                       }
+               }
+
                ret = cmd_enable_event(cmd_ctx->session, &cmd_ctx->lsm->domain,
                                cmd_ctx->lsm->u.enable.channel_name,
-                               &cmd_ctx->lsm->u.enable.event, NULL, kernel_poll_pipe[1]);
+                               &cmd_ctx->lsm->u.enable.event, bytecode, exclusion,
+                               kernel_poll_pipe[1]);
                break;
        }
        case LTTNG_ENABLE_ALL_EVENT:
@@ -3263,46 +3328,6 @@ skip_domain:
                                cmd_ctx->lsm->u.reg.path, cdata);
                break;
        }
-       case LTTNG_ENABLE_EVENT_WITH_FILTER:
-       {
-               struct lttng_filter_bytecode *bytecode;
-
-               if (cmd_ctx->lsm->u.enable.bytecode_len > LTTNG_FILTER_MAX_LEN) {
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-               if (cmd_ctx->lsm->u.enable.bytecode_len == 0) {
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-               bytecode = zmalloc(cmd_ctx->lsm->u.enable.bytecode_len);
-               if (!bytecode) {
-                       ret = LTTNG_ERR_FILTER_NOMEM;
-                       goto error;
-               }
-               /* Receive var. len. data */
-               DBG("Receiving var len data from client ...");
-               ret = lttcomm_recv_unix_sock(sock, bytecode,
-                               cmd_ctx->lsm->u.enable.bytecode_len);
-               if (ret <= 0) {
-                       DBG("Nothing recv() from client var len data... continuing");
-                       *sock_error = 1;
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-
-               if (bytecode->len + sizeof(*bytecode)
-                               != cmd_ctx->lsm->u.enable.bytecode_len) {
-                       free(bytecode);
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-
-               ret = cmd_enable_event(cmd_ctx->session, &cmd_ctx->lsm->domain,
-                               cmd_ctx->lsm->u.enable.channel_name,
-                               &cmd_ctx->lsm->u.enable.event, bytecode, kernel_poll_pipe[1]);
-               break;
-       }
        case LTTNG_DATA_PENDING:
        {
                ret = cmd_data_pending(cmd_ctx->session);
@@ -4555,6 +4580,18 @@ static int daemonize(void)
                 * user.
                 */
                while (!CMM_LOAD_SHARED(recv_child_signal)) {
+                       int status;
+                       pid_t ret;
+
+                       /*
+                        * Check if child exists without blocking. If so, we have to stop
+                        * this parent process and return an error.
+                        */
+                       ret = waitpid(pid, &status, WNOHANG);
+                       if (ret < 0 || (ret != 0 && WIFEXITED(status))) {
+                               /* The child exited somehow or was not valid. */
+                               goto error;
+                       }
                        sleep(1);
                }