* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
#define _LGPL_SOURCE
#include <errno.h>
#include <limits.h>
#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"
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;
}
static
-void reset_sighandler(void)
+int reset_sighandler(void)
{
int sig;
- 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);
- }
+ 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
reset_sighandler();
+ set_worker_sighandlers();
+
/* The child has no use for this lock. */
pthread_mutex_unlock(&worker_lock);
/* Just close, no shutdown. */
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 */
{
struct run_as_worker *worker = global_worker;
+ 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");
}