hush: use NOFORK applets as appropriate. Net reduction of code size.

applets/applets.c

@@ -514,14 +514,14 @@ static void install_links(const char *busybox, int use_symbolic_links)
 
 
 /* If we were called as "busybox..." */
-static int busybox_main(int argc, char **argv)
+static int busybox_main(char **argv)
 {
-	if (ENABLE_FEATURE_INSTALLER && argc > 1 && !strcmp(argv[1], "--install")) {
+	if (ENABLE_FEATURE_INSTALLER && argv[1] && !strcmp(argv[1], "--install")) {
 		int use_symbolic_links = 0;
 		char *busybox;
 
 		/* to use symlinks, or not to use symlinks... */
-		if (argc > 2)
+		if (argv[2])
 			if (strcmp(argv[2], "-s") == 0)
 				use_symbolic_links = 1;
 
@@ -537,11 +537,12 @@ static int busybox_main(int argc, char **argv)
 
 	/* Deal with --help. Also print help when called with no arguments */
 
-	if (argc == 1 || !strcmp(argv[1], "--help") ) {
+	if (!argv[1] || !strcmp(argv[1], "--help") ) {
-		if (argc > 2) {
+		if (argv[2]) {
 			/* set name for proper "<name>: applet not found" */
 			applet_name = argv[2];
-			run_applet_and_exit(applet_name, 2, argv);
+			argv[2] = NULL;
+			run_applet_and_exit(applet_name, argv);
 		} else {
 			const struct bb_applet *a;
 			int col, output_width;
@@ -582,14 +583,19 @@ static int busybox_main(int argc, char **argv)
 	} else {
 		/* we want "<argv[1]>: applet not found", not "busybox: ..." */
 		applet_name = argv[1];
-		run_applet_and_exit(argv[1], argc - 1, argv + 1);
+		run_applet_and_exit(argv[1], argv + 1);
 	}
 
 	bb_error_msg_and_die("applet not found");
 }
 
-void run_current_applet_and_exit(int argc, char **argv)
+void run_current_applet_and_exit(char **argv)
 {
+	int argc = 1;
+
+	while (argv[argc])
+		argc++;
+
 	/* Reinit some shared global data */
 	optind = 1;
 	xfunc_error_retval = EXIT_FAILURE;
@@ -602,13 +608,13 @@ void run_current_applet_and_exit(int argc, char **argv)
 	exit(current_applet->main(argc, argv));
 }
 
-void run_applet_and_exit(const char *name, int argc, char **argv)
+void run_applet_and_exit(const char *name, char **argv)
 {
 	current_applet = find_applet_by_name(name);
 	if (current_applet)
-		run_current_applet_and_exit(argc, argv);
+		run_current_applet_and_exit(argv);
 	if (!strncmp(name, "busybox", 7))
-		exit(busybox_main(argc, argv));
+		exit(busybox_main(argv));
 }
 
 
@@ -637,6 +643,6 @@ int main(int argc, char **argv)
 	if (ENABLE_LOCALE_SUPPORT && getpid() != 1)
 		setlocale(LC_ALL, "");
 
-	run_applet_and_exit(applet_name, argc, argv);
+	run_applet_and_exit(applet_name, argv);
 	bb_error_msg_and_die("applet not found");
 }

findutils/xargs.c

@@ -176,7 +176,7 @@ set:
 			}
 			if (!eof_str_detected) {
 				size_t length = (p - buf);
-
+// TODO: smarter llist_t
 				cur = xzalloc(sizeof(xlist_t) + length);
 				cur->data = memcpy(cur + 1, s, length);
 				cur->length = length;
@@ -247,6 +247,7 @@ static xlist_t *process_stdin(xlist_t *list_arg,
 				size_t length = (p - buf);
 
 				cur = xzalloc(sizeof(xlist_t) + length);
+// TODO: smarter llist_t
 				cur->data = memcpy(cur + 1, s, length);
 				cur->length = length;
 				/*cur->link = NULL;*/
@@ -329,6 +330,7 @@ static xlist_t *process0_stdin(xlist_t *list_arg,
 			size_t length = (p - buf);
 
 			cur = xzalloc(sizeof(xlist_t) + length);
+// TODO: smarter llist_t
 			cur->data = memcpy(cur + 1, s, length);
 			cur->length = length;
 			/*cur->link = NULL;*/

include/libbb.h

@@ -123,35 +123,6 @@
 /* scary. better ideas? (but do *test* them first!) */
 #define OFF_T_MAX  ((off_t)~((off_t)1 << (sizeof(off_t)*8-1)))
 
-/* This structure defines protocol families and their handlers. */
-struct aftype {
-	const char *name;
-	const char *title;
-	int af;
-	int alen;
-	char *(*print) (unsigned char *);
-	const char *(*sprint) (struct sockaddr *, int numeric);
-	int (*input) (/*int type,*/ const char *bufp, struct sockaddr *);
-	void (*herror) (char *text);
-	int (*rprint) (int options);
-	int (*rinput) (int typ, int ext, char **argv);
-
-	/* may modify src */
-	int (*getmask) (char *src, struct sockaddr * mask, char *name);
-};
-
-/* This structure defines hardware protocols and their handlers. */
-struct hwtype {
-	const char *name;
-	const char *title;
-	int type;
-	int alen;
-	char *(*print) (unsigned char *);
-	int (*input) (const char *, struct sockaddr *);
-	int (*activate) (int fd);
-	int suppress_null_addr;
-};
-
 /* Some useful definitions */
 #undef FALSE
 #define FALSE   ((int) 0)
@@ -504,6 +475,7 @@ void clear_username_cache(void);
 enum { USERNAME_MAX_SIZE = 16 - sizeof(int) };
 
 
+struct bb_applet;
 int execable_file(const char *name);
 char *find_execable(const char *filename);
 int exists_execable(const char *filename);
@@ -537,6 +509,8 @@ int wait_nohang(int *wstat);
 #define wait_exitcode(w) ((w) >> 8)
 #define wait_stopsig(w) ((w) >> 8)
 #define wait_stopped(w) (((w) & 127) == 127)
+/* Does NOT check that applet is NOFORK, just blindly runs it */
+int run_nofork_applet(const struct bb_applet *a, char **argv);
 /* wait4pid(spawn(argv)) + NOFORK/NOEXEC (if configured) */
 int spawn_and_wait(char **argv);
 
@@ -669,6 +643,33 @@ int bbunpack(char **argv,
 int create_icmp_socket(void);
 int create_icmp6_socket(void);
 /* interface.c */
+/* This structure defines protocol families and their handlers. */
+struct aftype {
+	const char *name;
+	const char *title;
+	int af;
+	int alen;
+	char *(*print) (unsigned char *);
+	const char *(*sprint) (struct sockaddr *, int numeric);
+	int (*input) (/*int type,*/ const char *bufp, struct sockaddr *);
+	void (*herror) (char *text);
+	int (*rprint) (int options);
+	int (*rinput) (int typ, int ext, char **argv);
+
+	/* may modify src */
+	int (*getmask) (char *src, struct sockaddr * mask, char *name);
+};
+/* This structure defines hardware protocols and their handlers. */
+struct hwtype {
+	const char *name;
+	const char *title;
+	int type;
+	int alen;
+	char *(*print) (unsigned char *);
+	int (*input) (const char *, struct sockaddr *);
+	int (*activate) (int fd);
+	int suppress_null_addr;
+};
 extern int interface_opt_a;
 int display_interfaces(char *ifname);
 const struct aftype *get_aftype(const char *name);
@@ -677,11 +678,10 @@ const struct hwtype *get_hwntype(int type);
 
 
 #ifndef BUILD_INDIVIDUAL
-struct bb_applet;
 extern const struct bb_applet *find_applet_by_name(const char *name);
 /* Returns only if applet is not found. */
-extern void run_applet_and_exit(const char *name, int argc, char **argv);
+extern void run_applet_and_exit(const char *name, char **argv);
-extern void run_current_applet_and_exit(int argc, char **argv) ATTRIBUTE_NORETURN;
+extern void run_current_applet_and_exit(char **argv) ATTRIBUTE_NORETURN;
 #endif
 
 extern int match_fstype(const struct mntent *mt, const char *fstypes);

libbb/vfork_daemon_rexec.c

@@ -100,25 +100,10 @@ int wait_pid(int *wstat, int pid)
 	return r;
 }
 
-int spawn_and_wait(char **argv)
+int run_nofork_applet(const struct bb_applet *a, char **argv)
 {
-	int rc;
+	int rc, argc;
-#if ENABLE_FEATURE_PREFER_APPLETS
-	const struct bb_applet *a = find_applet_by_name(argv[0]);
 
-	if (a && (a->nofork
-#if BB_MMU
-		 || a->noexec /* NOEXEC trick needs fork() */
-#endif
-	)) {
-		int argc = 1;
-		char **pp = argv;
-		while (*++pp)
-			argc++;
-#if BB_MMU
-		if (a->nofork)
-#endif
-		{
 	/* Save some shared globals */
 	const struct bb_applet *old_a = current_applet;
 	int old_x = xfunc_error_retval;
@@ -134,6 +119,10 @@ int spawn_and_wait(char **argv)
 	 * die_sleep and longjmp here instead. */
 	die_sleep = -1;
 
+	argc = 1;
+	while (argv[argc])
+		argc++;
+
 	rc = setjmp(die_jmp);
 	if (!rc) {
 		/* Some callers (xargs)
@@ -155,6 +144,24 @@ int spawn_and_wait(char **argv)
 	option_mask32 = old_m;
 	die_sleep = old_sleep;
 	return rc;
+}
+
+int spawn_and_wait(char **argv)
+{
+	int rc;
+#if ENABLE_FEATURE_PREFER_APPLETS
+	const struct bb_applet *a = find_applet_by_name(argv[0]);
+
+	if (a && (a->nofork
+#if BB_MMU
+		 || a->noexec /* NOEXEC trick needs fork() */
+#endif
+	)) {
+#if BB_MMU
+		if (a->nofork)
+#endif
+		{
+			return run_nofork_applet(a, argv);
 		}
 #if BB_MMU
 		/* MMU only */
@@ -165,7 +172,7 @@ int spawn_and_wait(char **argv)
 		/* child */
 		xfunc_error_retval = EXIT_FAILURE;
 		current_applet = a;
-		run_current_applet_and_exit(argc, argv);
+		run_current_applet_and_exit(argv);
 #endif
 	}
 #endif /* FEATURE_PREFER_APPLETS */

shell/ash.c

@@ -6539,10 +6539,8 @@ tryexec(char *cmd, char **argv, char **envp)
 		a = find_applet_by_name(cmd);
 		if (a) {
 			if (a->noexec) {
-				char **c = argv;
-				while (*c) c++;
 				current_applet = a;
-				run_current_applet_and_exit(c - argv, argv);
+				run_current_applet_and_exit(argv);
 			}
 			/* re-exec ourselves with the new arguments */
 			execve(CONFIG_BUSYBOX_EXEC_PATH, argv, envp);

shell/hush.c

@@ -765,7 +765,7 @@ static int b_check_space(o_string *o, int len)
 	 * in here, such as setting a maximum string length */
 	if (o->length + len > o->maxlen) {
 		char *old_data = o->data;
-		/* assert (data == NULL || o->maxlen != 0); */
+		/* assert(data == NULL || o->maxlen != 0); */
 		o->maxlen += max(2*len, B_CHUNK);
 		o->data = realloc(o->data, 1 + o->maxlen);
 		if (o->data == NULL) {
@@ -1113,17 +1113,10 @@ static void pseudo_exec(struct child_prog *child)
 		 * from global_argv[0], but if we are in a chroot, we may not be able
 		 * to find ourself... */
 #if ENABLE_FEATURE_SH_STANDALONE
-		{
+		debug_printf("running applet %s\n", child->argv[0]);
-			int argc_l;
+		run_applet_and_exit(child->argv[0], child->argv);
-			char** argv_l = child->argv;
+// is it ok that run_applet_and_exit() does exit(), not _exit()?
-			char *name = child->argv[0];
+// NB: IIRC on NOMMU we are after _vfork_, not fork!
-
-			/* Count argc for use in a second... */
-			for (argc_l = 0; *argv_l; argv_l++, argc_l++)
-				continue;
-			debug_printf("running applet %s\n", name);
-			run_applet_and_exit(name, argc_l, child->argv);
-		}
 #endif
 		debug_printf("exec of %s\n", child->argv[0]);
 		execvp(child->argv[0], child->argv);
@@ -1304,6 +1297,9 @@ static int run_pipe_real(struct pipe *pi)
 	struct child_prog *child;
 	const struct built_in_command *x;
 	char *p;
+	/* it is not always needed, but we aim to smaller code */
+	int squirrel[] = { -1, -1, -1 };
+	int rcode;
 
 	nextin = 0;
 	pi->pgrp = -1;
@@ -1314,8 +1310,6 @@ static int run_pipe_real(struct pipe *pi)
 	 */
 	child = &(pi->progs[0]);
 	if (pi->num_progs == 1 && child->group && child->subshell == 0) {
-		int squirrel[] = { -1, -1, -1 };
-		int rcode;
 		debug_printf("non-subshell grouping\n");
 		setup_redirects(child, squirrel);
 		/* XXX could we merge code with following builtin case,
@@ -1366,15 +1360,13 @@ static int run_pipe_real(struct pipe *pi)
 		if (child->sp) {
 			char *str;
 
-			str = make_string((child->argv + i));
+			str = make_string(child->argv + i);
 			parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
 			free(str);
 			return last_return_code;
 		}
 		for (x = bltins; x->cmd; x++) {
 			if (strcmp(child->argv[i], x->cmd) == 0) {
-				int squirrel[] = { -1, -1, -1 };
-				int rcode;
 				if (x->function == builtin_exec && child->argv[i+1] == NULL) {
 					debug_printf("magic exec\n");
 					setup_redirects(child, NULL);
@@ -1393,6 +1385,17 @@ static int run_pipe_real(struct pipe *pi)
 				return rcode;
 			}
 		}
+#if ENABLE_FEATURE_SH_STANDALONE
+		{
+			const struct bb_applet *a = find_applet_by_name(child->argv[i]);
+			if (a && a->nofork) {
+				setup_redirects(child, squirrel);
+				rcode = run_nofork_applet(a, child->argv + i);
+				restore_redirects(squirrel);
+				return rcode;
+			}
+		}
+#endif
 	}
 
 	for (i = 0; i < pi->num_progs; i++) {
@@ -2587,8 +2590,8 @@ int parse_stream(o_string *dest, struct p_context *ctx,
 
 static void mapset(const char *set, int code)
 {
-	while (*s)
+	while (*set)
-		map[(unsigned char)*s++] = code;
+		map[(unsigned char)*set++] = code;
 }
 
 static void update_ifs_map(void)

shell/lash.c

@@ -1158,12 +1158,7 @@ static int pseudo_exec(struct child_prog *child)
 	 * /bin/foo is a symlink to busybox.
 	 */
 	if (ENABLE_FEATURE_SH_STANDALONE) {
-		char **argv_l = child->argv;
+		run_applet_and_exit(child->argv[0], child->argv);
-		int argc_l;
-
-		for (argc_l = 0; *argv_l; argv_l++, argc_l++)
-			continue;
-		run_applet_and_exit(child->argv[0], argc_l, child->argv);
 	}
 
 	execvp(child->argv[0], child->argv);