+ path, (int) uid, (int) gid);
+ strncpy(data.u.unlink.path, path, PATH_MAX - 1);
+ data.u.unlink.path[PATH_MAX - 1] = '\0';
+ return run_as(RUN_AS_UNLINK, &data, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid)
+{
+ struct run_as_data data;
+
+ DBG3("rmdir_recursive() %s with for uid %d and gid %d",
+ path, (int) uid, (int) gid);
+ strncpy(data.u.rmdir_recursive.path, path, PATH_MAX - 1);
+ data.u.rmdir_recursive.path[PATH_MAX - 1] = '\0';
+ return run_as(RUN_AS_RMDIR_RECURSIVE, &data, uid, gid);
+}
+
+static
+int reset_sighandler(void)
+{
+ int sig;
+
+ DBG("Resetting run_as worker signal handlers to default");
+ for (sig = 1; sig <= 31; sig++) {
+ (void) signal(sig, SIG_DFL);
+ }
+ return 0;
+}
+
+static
+void worker_sighandler(int sig)
+{
+ const char *signame;
+
+ /*
+ * The worker will inherit its parent's signals since they are part of
+ * the same process group. However, in the case of SIGINT and SIGTERM,
+ * we want to give the worker a chance to teardown gracefully when its
+ * parent closes the command socket.
+ */
+ switch (sig) {
+ case SIGINT:
+ signame = "SIGINT";
+ break;
+ case SIGTERM:
+ signame = "SIGTERM";
+ break;
+ default:
+ signame = NULL;
+ }
+
+ if (signame) {
+ DBG("run_as worker received signal %s", signame);
+ } else {
+ DBG("run_as_worker received signal %d", sig);
+ }
+}
+
+static
+int set_worker_sighandlers(void)
+{
+ int ret = 0;
+ sigset_t sigset;
+ struct sigaction sa;
+
+ if ((ret = sigemptyset(&sigset)) < 0) {
+ PERROR("sigemptyset");
+ goto end;
+ }
+
+ sa.sa_handler = worker_sighandler;
+ sa.sa_mask = sigset;
+ sa.sa_flags = 0;
+ if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
+ PERROR("sigaction SIGINT");
+ goto end;
+ }
+
+ if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
+ PERROR("sigaction SIGTERM");
+ goto end;
+ }
+
+ DBG("run_as signal handler set for SIGTERM and SIGINT");
+end:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_create_worker(char *procname)
+{
+ pid_t pid;
+ int i, ret = 0;
+ ssize_t readlen;
+ struct run_as_ret recvret;
+ struct run_as_worker *worker;
+
+ pthread_mutex_lock(&worker_lock);
+ 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 = procname;
+ /* 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();
+
+ /* The child has no use for this lock. */
+ pthread_mutex_unlock(&worker_lock);
+ /* Just close, no shutdown. */
+ if (close(worker->sockpair[0])) {
+ PERROR("close");
+ exit(EXIT_FAILURE);
+ }
+ 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;
+ 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:
+ pthread_mutex_unlock(&worker_lock);
+ 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);
+ pthread_mutex_unlock(&worker_lock);
+ return ret;