Fix: Handle EINTR of waipid in run-as worker

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/runas.c b/src/common/runas.c
index 3a1de0a3acdd2b3613d715d48f404c3a60eb9eeb..08979fb79c15bee3bfd9f60bd3d084a141e79d08 100644 (file)
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -527,6 +527,22 @@ 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
+void 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);
+               }
+       }
+}
+
 LTTNG_HIDDEN
 int run_as_create_worker(char *procname)
 {
@@ -566,6 +582,8 @@ int run_as_create_worker(char *procname)
        } else if (pid == 0) {
                /* Child */
 
+               reset_sighandler();
+
                /* The child has no use for this lock. */
                pthread_mutex_unlock(&worker_lock);
                /* Just close, no shutdown. */
@@ -628,8 +646,6 @@ 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 +657,29 @@ 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;