+ pid_t pid;
+ int i, ret = 0;
+ ssize_t readlen;
+ struct run_as_ret recvret;
+ struct run_as_worker *worker;
+
+ assert(!global_worker);
+ if (!use_clone()) {
+ /*
+ * Don't initialize a worker, all run_as tasks will be performed
+ * in the current process.
+ */
+ ret = 0;
+ goto end;
+ }
+ worker = zmalloc(sizeof(*worker));
+ if (!worker) {
+ ret = -ENOMEM;
+ goto end;
+ }
+ worker->procname = strdup(procname);
+ if (!worker->procname) {
+ ret = -ENOMEM;
+ goto error_procname_alloc;
+ }
+ /* Create unix socket. */
+ if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) {
+ ret = -1;
+ goto error_sock;
+ }
+
+ /* Fork worker. */
+ pid = fork();
+ if (pid < 0) {
+ PERROR("fork");
+ ret = -1;
+ goto error_fork;
+ } else if (pid == 0) {
+ /* Child */
+
+ reset_sighandler();
+
+ set_worker_sighandlers();
+ if (clean_up_func) {
+ if (clean_up_func(clean_up_user_data) < 0) {
+ ERR("Run-as post-fork clean-up failed, exiting.");
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ /* Just close, no shutdown. */
+ if (close(worker->sockpair[0])) {
+ PERROR("close");
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1]
+ * Sockpair[1] is used as a control channel with the master
+ */
+ for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
+ if (i != worker->sockpair[1]) {
+ (void) close(i);
+ }
+ }
+
+ worker->sockpair[0] = -1;
+ ret = run_as_worker(worker);
+ if (lttcomm_close_unix_sock(worker->sockpair[1])) {
+ PERROR("close");
+ ret = -1;
+ }
+ worker->sockpair[1] = -1;
+ free(worker->procname);
+ free(worker);
+ LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret);
+ exit(ret ? EXIT_FAILURE : EXIT_SUCCESS);
+ } else {
+ /* Parent */
+
+ /* Just close, no shutdown. */
+ if (close(worker->sockpair[1])) {
+ PERROR("close");
+ ret = -1;
+ goto error_fork;
+ }
+ worker->sockpair[1] = -1;
+ worker->pid = pid;
+ /* Wait for worker to become ready. */
+ readlen = lttcomm_recv_unix_sock(worker->sockpair[0],
+ &recvret, sizeof(recvret));
+ if (readlen < sizeof(recvret)) {
+ ERR("readlen: %zd", readlen);
+ PERROR("Error reading response from run_as at creation");
+ ret = -1;
+ goto error_fork;
+ }
+ global_worker = worker;
+ }
+end:
+ return ret;
+
+ /* Error handling. */
+error_fork:
+ for (i = 0; i < 2; i++) {
+ if (worker->sockpair[i] < 0) {
+ continue;
+ }
+ if (lttcomm_close_unix_sock(worker->sockpair[i])) {
+ PERROR("close");
+ }
+ worker->sockpair[i] = -1;
+ }
+error_sock:
+ free(worker->procname);
+error_procname_alloc:
+ free(worker);
+ return ret;
+}
+
+static
+void run_as_destroy_worker_no_lock(void)
+{
+ struct run_as_worker *worker = global_worker;
+
+ DBG("Destroying run_as worker");
+ if (!worker) {
+ return;
+ }
+ /* Close unix socket */
+ DBG("Closing run_as worker socket");
+ if (lttcomm_close_unix_sock(worker->sockpair[0])) {
+ PERROR("close");
+ }
+ worker->sockpair[0] = -1;
+ /* Wait for worker. */
+ for (;;) {
+ int status;
+ pid_t wait_ret;
+
+ wait_ret = waitpid(worker->pid, &status, 0);
+ if (wait_ret < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+ PERROR("waitpid");
+ break;
+ }
+
+ if (WIFEXITED(status)) {
+ LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR,
+ DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d",
+ WEXITSTATUS(status));
+ break;
+ } else if (WIFSIGNALED(status)) {
+ ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d",
+ WTERMSIG(status));
+ break;
+ }
+ }
+ free(worker->procname);
+ free(worker);
+ global_worker = NULL;
+}
+
+static
+int run_as_restart_worker(struct run_as_worker *worker)
+{
+ int ret = 0;
+ char *procname = NULL;
+
+ procname = worker->procname;
+
+ /* Close socket to run_as worker process and clean up the zombie process */
+ run_as_destroy_worker_no_lock();
+
+ /* Create a new run_as worker process*/
+ ret = run_as_create_worker_no_lock(procname, NULL, NULL);
+ if (ret < 0 ) {
+ ERR("Restarting the worker process failed");
+ ret = -1;
+ goto err;
+ }
+err:
+ return ret;
+}
+
+static
+int run_as(enum run_as_cmd cmd, struct run_as_data *data,
+ struct run_as_ret *ret_value, uid_t uid, gid_t gid)
+{
+ int ret, saved_errno;
+
+ pthread_mutex_lock(&worker_lock);