properly handle return codes

Signed-off-by: John Crispin <blogic@openwrt.org>

initd/early.c

@@ -77,7 +77,8 @@ early_mounts(void)
 	mkdir("/tmp/run", 0777);
 	mkdir("/tmp/lock", 0777);
 	mkdir("/tmp/state", 0777);
-	symlink("/tmp", "/var");
+	if (symlink("/tmp", "/var"))
+		ERROR("failed to symlink /tmp -> /var\n");
 }
 
 static void

initd/mkdev.c

@@ -121,7 +121,5 @@ int mkdev(const char *name, int _mode)
 	n_patterns = 1;
 	find_devs(true);
 	find_devs(false);
-	chdir("/");
-
-	return 0;
+	return chdir("/");
 }

initd/preinit.c

@@ -38,7 +38,8 @@ check_dbglvl(void)
 
 	if (!fp)
 		return;
-	fscanf(fp, "%d", &lvl);
+	if (fscanf(fp, "%d", &lvl) == EOF)
+		ERROR("failed to read debug level\n");
 	fclose(fp);
 	unlink("/tmp/debug_level");
 

inittab.c

@@ -70,9 +70,11 @@ static int dev_open(const char *dev)
 	int fd = -1;
 
 	if (dev) {
-		chdir("/dev");
-		fd = open( dev, O_RDWR);
-		chdir("/");
+		if (chdir("/dev"))
+			ERROR("failed to change dir to /dev\n");
+		fd = open(dev, O_RDWR);
+		if (chdir("/"))
+			ERROR("failed to change dir to /\n");
 	}
 
 	return fd;
@@ -83,9 +85,8 @@ static int dev_exist(const char *dev)
 	int res;
 
 	res = dev_open(dev);
-	if (res != -1) {
+	if (res != -1)
 		close(res);
-	}
 
 	return (res != -1);
 }

jail/jail.c

@@ -313,12 +313,16 @@ static int spawn_child(void *arg)
 			sysfs = 1;
 			break;
 		case 'n':
-			sethostname(optarg, strlen(optarg));
+			if (sethostname(optarg, strlen(optarg)))
+				ERROR("failed to sethostname: %s\n", strerror(errno));
 			break;
 		}
 	}
 
-	asprintf(&mpoint, "%s/old", path);
+	if (asprintf(&mpoint, "%s/old", path) < 0) {
+		ERROR("failed to alloc pivot path: %s\n", strerror(errno));
+		return -1;
+	}
 	mkdir_p(mpoint, 0755);
 	if (pivot_root(path, mpoint) == -1) {
 		ERROR("pivot_root failed:%s\n", strerror(errno));
@@ -370,13 +374,17 @@ static void spawn_namespace(const char *path, int argc, char **argv)
 	char *dir = get_current_dir_name();
 
 	uloop_init();
-	chdir(path);
+	if (chdir(path)) {
+		ERROR("failed to chdir() into the jail\n");
+		return;
+	}
 	namespace_process.pid = clone(spawn_child,
 			child_stack + STACK_SIZE,
 			CLONE_NEWUTS | CLONE_NEWPID | CLONE_NEWNS | SIGCHLD, argv);
 
 	if (namespace_process.pid != -1) {
-		chdir(dir);
+		if (chdir(dir))
+			ERROR("failed to chdir() out of the jail\n");
 		free(dir);
 		uloop_process_add(&namespace_process);
 		uloop_run();

plug/hotplug.c

@@ -198,7 +198,10 @@ static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
 		ERROR("Failed to open %s\n", loadpath);
 		exit(-1);
 	}
-	write(load, "1", 1);
+	if (write(load, "1", 1) == -1) {
+		ERROR("Failed to write to %s\n", loadpath);
+		exit(-1);
+	}
 	close(load);
 
 	snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
@@ -214,15 +217,19 @@ static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
 		if (len <= 0)
 			break;
 
-		write(fw, buf, len);
+		if (write(fw, buf, len) == -1) {
+			ERROR("failed to write firmware file %s/%s to %s\n", dir, file, dev);
+			break;
+		}
 	}
 
 	if (src >= 0)
 		close(src);
 	close(fw);
 
 	load = open(loadpath, O_WRONLY);
-	write(load, "0", 1);
+	if (write(load, "0", 1) == -1)
+		ERROR("failed to write to %s\n", loadpath);
 	close(load);
 
 	DEBUG(2, "Done loading %s\n", path);

service/instance.c

@@ -283,8 +283,10 @@ instance_run(struct service_instance *in, int _stdout, int _stderr)
 	}
 
 	if (in->uid || in->gid) {
-		setuid(in->uid);
-		setgid(in->gid);
+		if (setuid(in->uid) || setgid(in->gid)) {
+			ERROR("failed to set uid:%d, gid:%d\n", in->uid, in->gid);
+			exit(127);
+		}
 	}
 	execvp(argv[0], argv);
 	exit(127);

state.c

@@ -43,12 +43,14 @@ static int reboot_event;
 
 static void set_stdio(const char* tty)
 {
-	chdir("/dev");
-	freopen(tty, "r", stdin);
-	freopen(tty, "w", stdout);
-	freopen(tty, "w", stderr);
-	chdir("/");
-	fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK);
+	if (chdir("/dev") ||
+	    !freopen(tty, "r", stdin) ||
+	    !freopen(tty, "w", stdout) ||
+	    !freopen(tty, "w", stderr) ||
+	    chdir("/"))
+		ERROR("failed to set stdio\n");
+	else
+		fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK);
 }
 
 static void set_console(void)
@@ -70,7 +72,10 @@ static void set_console(void)
 		i++;
 	}
 
-	chdir("/dev");
+	if (chdir("/dev")) {
+		ERROR("failed to change dir to /dev\n");
+		return;
+	}
 	while (tty!=NULL) {
 		f = open(tty, O_RDONLY);
 		if (f >= 0) {
@@ -81,7 +86,8 @@ static void set_console(void)
 		tty=try[i];
 		i++;
 	}
-	chdir("/");
+	if (chdir("/"))
+		ERROR("failed to change dir to /\n");
 
 	if (tty != NULL)
 		set_stdio(tty);

trace/trace.c

@@ -214,7 +214,8 @@ int main(int argc, char **argv, char **envp)
 	uloop_done();
 
 	if (!json)
-		asprintf(&json, "/tmp/%s.%u.json", basename(*argv), child);
+		if (asprintf(&json, "/tmp/%s.%u.json", basename(*argv), child) < 0)
+			ERROR("failed to allocate output path: %s\n", strerror(errno));
 
 	print_syscalls(policy, json);
 

upgraded/upgraded.c

@@ -18,6 +18,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include <libubox/uloop.h>
 
@@ -55,12 +56,14 @@ int main(int argc, char **argv)
 {
 	pid_t p = getpid();
 
-	chdir("/tmp");
-
 	if (p != 1) {
 		fprintf(stderr, "this tool needs to run as pid 1\n");
 		return -1;
 	}
+	if (chdir("/tmp") == -1) {
+		fprintf(stderr, "failed to chdir to /tmp: %s\n", strerror(errno));
+		return -1;
+	}
 	if (argc != 2) {
 		fprintf(stderr, "sysupgrade stage 2 failed, no folder specified\n");
 		return -1;