X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Frunas.c;h=1105f207fb83d3b4ef1734159fbd7a7e0e0a3f04;hp=3a1de0a3acdd2b3613d715d48f404c3a60eb9eeb;hb=5b5bb8c82d70cf65707d5561e0640bf2ae8c2e6e;hpb=749b7a0c92f961c87318691bf44efc250d29ce2a

diff --git a/src/common/runas.c b/src/common/runas.c
index 3a1de0a3a..1105f207f 100644
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -31,10 +31,12 @@
 #include <sched.h>
 #include <sys/signal.h>
 #include <assert.h>
+#include <signal.h>
 
 #include <common/common.h>
 #include <common/utils.h>
 #include <common/compat/getenv.h>
+#include <common/compat/prctl.h>
 #include <common/sessiond-comm/unix.h>
 
 #include "runas.h"
@@ -322,12 +324,12 @@ 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);
-	if (ret) {
-		errno = ret;
-		ret = -1;
-		PERROR("pthread_setname_np");
-		return EXIT_FAILURE;
+	ret = lttng_prctl(PR_SET_NAME,
+			(unsigned long) DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0);
+	if (ret && ret != -ENOSYS) {
+		/* Don't fail as this is not essential. */
+		PERROR("prctl PR_SET_NAME");
+		ret = 0;
 	}
 
 	sendret.ret = 0;
@@ -527,6 +529,73 @@ 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;
+
+	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 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 +635,10 @@ 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. */
@@ -580,6 +653,7 @@ int run_as_create_worker(char *procname)
 			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 */
@@ -628,22 +702,42 @@ LTTNG_HIDDEN
 void run_as_destroy_worker(void)
 {
 	struct run_as_worker *worker = global_worker;
-	int status;
-	pid_t pid;
 
+	DBG("Destroying run_as worker");
 	pthread_mutex_lock(&worker_lock);
 	if (!worker) {
 		goto end;
 	}
 	/* 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. */
-	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;