cleanup runsvc: merge codepaths for execution, remove cleanup code

Simply execute the last entry in the list directly instead of forking and
remove the cleanup code.

If the list is empty, we return success.

If the list only has one entry, we directly execute that. No need to make a
distinction between single entry vs list anymore.

If the list is an actual list, we run it as before but execute the last one
directly. Typically, the last one is something like a daemon preceeded by
setup code. The daemon ends up directly underneath init, without a dummy
waiting runsvc stuck in the process list.

If we always do an exec, there is no point in doing cleanup. All our mapped
memory is evicted anyway. Same if we exit appruptly because of an error.

Signed-off-by: David Oberhollenzer <goliath@infraroot.at>

1 files changed, 12 insertions, 20 deletions

diff --git a/cmd/runsvc/runsvc.c b/cmd/runsvc/runsvc.c
index fdece64..794aa29 100644
--- a/cmd/runsvc/runsvc.c
+++ b/cmd/runsvc/runsvc.c
@@ -1,12 +1,15 @@
 /* SPDX-License-Identifier: ISC */
 #include "runsvc.h"
 
-static int runlst_wait(exec_t *list)
+static int run_sequentially(exec_t *list)
 {
 	pid_t ret, pid;
 	int status;
 
 	for (; list != NULL; list = list->next) {
+		if (list->next == NULL)
+			argv_exec(list);
+
 		pid = fork();
 
 		if (pid == 0)
@@ -35,46 +38,35 @@ static int runlst_wait(exec_t *list)
 
 int main(int argc, char **argv)
 {
-	int dirfd, ret = EXIT_FAILURE;
 	service_t *svc = NULL;
+	int dirfd;
 
 	if (argc != 3) {
 		fputs("usage: runsvc <directory> <filename>\n", stderr);
-		goto out;
+		return EXIT_FAILURE;
 	}
 
 	if (getppid() != 1) {
 		fputs("must be run by init!\n", stderr);
-		goto out;
+		return EXIT_FAILURE;
 	}
 
 	dirfd = open(argv[1], O_RDONLY | O_DIRECTORY);
 	if (dirfd < 0) {
 		perror(argv[1]);
-		goto out;
+		return EXIT_FAILURE;
 	}
 
 	svc = rdsvc(dirfd, argv[2], RDSVC_NO_FNAME | RDSVC_NO_DEPS);
 	close(dirfd);
 	if (svc == NULL)
-		goto out;
-
-	if (svc->exec == NULL) {
-		ret = EXIT_SUCCESS;
-		goto out;
-	}
+		return EXIT_FAILURE;
 
 	if (initenv())
-		goto out;
+		return EXIT_FAILURE;
 
 	if (setup_tty(svc->ctty, (svc->flags & SVC_FLAG_TRUNCATE_OUT) != 0))
-		goto out;
-
-	if (svc->exec->next == NULL)
-		argv_exec(svc->exec);
+		return EXIT_FAILURE;
 
-	ret = runlst_wait(svc->exec);
-out:
-	delsvc(svc);
-	return ret;
+	return run_sequentially(svc->exec);
 }