X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;ds=sidebyside;f=src%2Fcommon%2Frunas.c;h=57f7382bd2b6b6f8dd5f07adf4a7dfe90584f58a;hb=de3fb857f034c208c135a10a3cdec2dfe43fbda6;hp=3a1de0a3acdd2b3613d715d48f404c3a60eb9eeb;hpb=9f21bc2c96ab5615e7410539b114484382d46b83;p=lttng-tools.git

diff --git a/src/common/runas.c b/src/common/runas.c
index 3a1de0a3a..57f7382bd 100644
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -31,6 +31,7 @@
 #include <sched.h>
 #include <sys/signal.h>
 #include <assert.h>
+#include <sys/prctl.h>
 
 #include <common/common.h>
 #include <common/utils.h>
@@ -322,12 +323,11 @@ int run_as_worker(struct run_as_worker *worker)
 	memset(worker->procname, 0, proc_orig_len);
 	strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len);
 
-	ret = pthread_setname_np(pthread_self(), DEFAULT_RUN_AS_WORKER_NAME);
+	ret = prctl(PR_SET_NAME, DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0);
 	if (ret) {
-		errno = ret;
-		ret = -1;
-		PERROR("pthread_setname_np");
-		return EXIT_FAILURE;
+		/* Don't fail as this is not essential. */
+		PERROR("prctl PR_SET_NAME");
+		ret = 0;
 	}
 
 	sendret.ret = 0;
@@ -527,6 +527,81 @@ int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid)
 	return run_as(RUN_AS_RMDIR_RECURSIVE, &data, uid, gid);
 }
 
+static
+int reset_sighandler(void)
+{
+	int sig, ret = 0;
+
+	for (sig = SIGHUP; sig <= SIGUNUSED; sig++) {
+		/* Skip unblockable signals. */
+		if (sig == SIGKILL || sig == SIGSTOP) {
+			continue;
+		}
+		if (signal(sig, SIG_DFL) == SIG_ERR) {
+			PERROR("reset signal %d", sig);
+			ret = -1;
+			goto end;
+		}
+	}
+end:
+	return ret;
+}
+
+static
+void worker_sighandler(int sig)
+{
+	const char *signame;
+
+	/*
+	 * The worker will 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 = "Unknown";
+	}
+
+	DBG("run_as worker received signal %s", signame);
+}
+
+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)
 {
@@ -566,6 +641,10 @@ int run_as_create_worker(char *procname)
 	} 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. */
@@ -628,8 +707,6 @@ LTTNG_HIDDEN
 void run_as_destroy_worker(void)
 {
 	struct run_as_worker *worker = global_worker;
-	int status;
-	pid_t pid;
 
 	pthread_mutex_lock(&worker_lock);
 	if (!worker) {
@@ -641,9 +718,29 @@ void run_as_destroy_worker(void)
 	}
 	worker->sockpair[0] = -1;
 	/* Wait for worker. */
-	pid = waitpid(worker->pid, &status, 0);
-	if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
-		PERROR("wait");
+	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);
 	global_worker = NULL;