modutils/*: rewrite by Timo Teras <timo.teras AT iki.fi>

- a lot faster (linear algorithmic complexity, smaller memory foot print)
- a lot smaller (the old code was overly complicated)
- loading of aliases is now module-init-tools compliant
- blacklisting is done correctly (-b option added)
- module argument quoting done right
- depmod now correctly generates modules.symbols and modules.alias

add/remove: 16/21 grow/shrink: 4/6 up/down: 6930/-9316 Total: -2386 bytes
   text    data     bss     dec     hex filename
 806039     592    6680  813311   c68ff busybox_old
 803498     592    6676  810766   c5f0e busybox_unstripped

1 files changed, 152 insertions, 226 deletions

diff --git a/modutils/depmod.c b/modutils/depmod.c
index b6a914e..35df4a8 100644
--- a/modutils/depmod.c
+++ b/modutils/depmod.c
@@ -2,6 +2,8 @@
 /*
  * depmod - generate modules.dep
  * Copyright (c) 2008 Bernhard Fischer
+ * Copyrihgt (c) 2008 Timo Teras <timo.teras@iki.fi>
+ * Copyright (c) 2008 Vladimir Dronnikov
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
@@ -10,6 +12,8 @@
 #define _GNU_SOURCE
 #include <libbb.h>
 #include <sys/utsname.h> /* uname() */
+#include "modutils.h"
+
 /*
  * Theory of operation:
  * - iterate over all modules and record their full path
@@ -17,272 +21,194 @@
  *   for each depends, look through our list of full paths and emit if found
  */
 
-typedef struct dep_lst_t {
-	char *name;
+typedef struct module_info {
+	struct module_info *next;
+	char *name, *modname;
 	llist_t *dependencies;
 	llist_t *aliases;
-	struct dep_lst_t *next;
-} dep_lst_t;
-
-struct globals {
-	dep_lst_t *lst; /* modules without their corresponding extension */
+	llist_t *symbols;
+	struct module_info *dnext, *dprev;
+} module_info;
+
+enum {
+	ARG_a = (1<<0), /* All modules, ignore mods in argv */
+	ARG_A = (1<<1), /* Only emit .ko that are newer than modules.dep file */
+	ARG_b = (1<<2), /* not /lib/modules/$(uname -r)/ but this base-dir */
+	ARG_e = (1<<3), /* with -F, print unresolved symbols */
+	ARG_F = (1<<4), /* System.map that contains the symbols */
+	ARG_n = (1<<5)  /* dry-run, print to stdout only */
 };
-#define G (*(struct globals*)&bb_common_bufsiz1)
-/* We have to zero it out because of NOEXEC */
-#define INIT_G() memset(&G, 0, sizeof(G))
 
-static char* find_keyword(void *the_module, size_t len, const char * const word)
+static int FAST_FUNC parse_module(const char *fname, struct stat *sb,
+				  void *data, int UNUSED_PARAM depth)
 {
-	char *ptr = the_module;
-	do {
-		/* search for the first char in word */
-		ptr = memchr(ptr, *word, len - (ptr - (char*)the_module));
-		if (ptr == NULL) /* no occurance left, done */
-			return NULL;
-		if (!strncmp(ptr, word, strlen(word))) {
-			ptr += strlen(word);
-			break;
+	module_info **first = (module_info **) data;
+	char *image, *ptr;
+	module_info *info;
+	size_t len = sb->st_size;
+
+	if (strrstr(fname, ".ko") == NULL)
+		return TRUE;
+
+	image = (char *) xmalloc_open_zipped_read_close(fname, &len);
+	info = xzalloc(sizeof(module_info));
+
+	info->next = *first;
+	*first = info;
+
+	info->dnext = info->dprev = info;
+	info->name = xstrdup(fname);
+	info->modname = filename2modname(fname, NULL);
+	for (ptr = image; ptr < image + len - 10; ptr++) {
+		if (strncmp(ptr, "depends=", 8) == 0) {
+			char *u;
+
+			ptr += 8;
+			for (u = ptr; *u; u++)
+				if (*u == '-')
+					*u = '_';
+			ptr += string_to_llist(ptr, &info->dependencies, ",");
+		} else if (ENABLE_FEATURE_MODUTILS_ALIAS &&
+			   strncmp(ptr, "alias=", 6) == 0) {
+			llist_add_to(&info->aliases, xstrdup(ptr + 6));
+			ptr += strlen(ptr);
+		} else if (ENABLE_FEATURE_MODUTILS_SYMBOLS &&
+			   strncmp(ptr, "__ksymtab_", 10) == 0) {
+			ptr += 10;
+			if (strncmp(ptr, "gpl", 3) == 0 ||
+			    strcmp(ptr, "strings") == 0)
+				continue;
+			llist_add_to(&info->symbols, xstrdup(ptr));
+			ptr += strlen(ptr);
 		}
-		++ptr;
-	} while (1);
-	return ptr;
+	}
+	free(image);
+
+	return TRUE;
 }
-static int FAST_FUNC fileAction(const char *fname, struct stat *sb,
-					void UNUSED_PARAM *data, int UNUSED_PARAM depth)
-{
-	size_t len = sb->st_size;
-	void *the_module;
-	char *ptr;
-	int fd;
-	char *depends, *deps;
-	dep_lst_t *this;
 
-	if (strrstr(fname, ".ko") == NULL) /* not a module */
-		goto skip;
+static module_info *find_module(module_info *modules, const char *modname)
+{
+	module_info *m;
 
-/*XXX: FIXME: does not handle compressed modules!
- * There should be a function that looks at the extension and sets up
- * open_transformer for us.
- */
-	fd = xopen(fname, O_RDONLY);
-	the_module = mmap(NULL, len, PROT_READ, MAP_SHARED
-#if defined MAP_POPULATE
-						|MAP_POPULATE
-#endif
-						, fd, 0);
-	close(fd);
-	if (the_module == MAP_FAILED)
-		bb_perror_msg_and_die("mmap");
+	for (m = modules; m != NULL; m = m->next)
+		if (strcmp(m->modname, modname) == 0)
+			return m;
+	return NULL;
+}
 
-	this = xzalloc(sizeof(dep_lst_t));
-	this->name = xstrdup(fname);
-	this->next = G.lst;
-	G.lst = this;
-//bb_info_msg("fname='%s'", fname);
-	ptr = find_keyword(the_module, len, "depends=");
-	if (!*ptr)
-		goto d_none;
-	deps = depends = xstrdup(ptr);
-//bb_info_msg(" depends='%s'", depends);
-	while (deps) {
-		ptr = strsep(&deps, ",");
-//bb_info_msg("[%s] -> '%s'", fname, (char*)ptr);
-		llist_add_to_end(&this->dependencies, xstrdup(ptr));
-	}
-	free(depends);
- d_none:
-	if (ENABLE_FEATURE_DEPMOD_ALIAS)
-	{
-		size_t pos = 0;
-		do {
-			ptr = find_keyword(the_module + pos, len - pos, "alias=");
-			if (ptr) {
-//bb_info_msg("[%s] alias '%s'", fname, (char*)ptr);
-					llist_add_to_end(&this->aliases, xstrdup(ptr));
-			} else
-				break;
-			pos = (ptr - (char*)the_module);
-		} while (1);
+static void order_dep_list(module_info *modules, module_info *start,
+			   llist_t *add)
+{
+	module_info *m;
+	llist_t *n;
+
+	for (n = add; n != NULL; n = n->link) {
+		m = find_module(modules, n->data);
+		if (m == NULL)
+			continue;
+
+		/* unlink current entry */
+		m->dnext->dprev = m->dprev;
+		m->dprev->dnext = m->dnext;
+
+		/* and add it to tail */
+		m->dnext = start;
+		m->dprev = start->dprev;
+		start->dprev->dnext = m;
+		start->dprev = m;
+
+		/* recurse */
+		order_dep_list(modules, start, m->dependencies);
 	}
-	munmap(the_module, sb->st_size);
- skip:
-	return TRUE;
 }
 
 int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int depmod_main(int argc UNUSED_PARAM, char **argv)
 {
-	int ret;
-	size_t moddir_base_len = 0; /* length of the "-b basedir" */
-	char *moddir_base = NULL, *moddir, *system_map, *chp;
-	FILE *filedes = stdout;
-	enum {
-		ARG_a = (1<<0), /* All modules, ignore mods in argv */
-		ARG_A = (1<<1), /* Only emit .ko that are newer than modules.dep file */
-		ARG_b = (1<<2), /* not /lib/modules/$(uname -r)/ but this base-dir */
-		ARG_e = (1<<3), /* with -F, print unresolved symbols */
-		ARG_F = (1<<4), /* System.map that contains the symbols */
-		ARG_n = (1<<5)  /* dry-run, print to stdout only */
-	};
-	INIT_G();
+	module_info *modules = NULL, *m, *dep;
+	char *moddir_base = (char *)CONFIG_DEFAULT_MODULES_DIR;
+	int tmp;
 
-	getopt32(argv, "aAb:eF:n", &moddir_base, &system_map);
+	getopt32(argv, "aAb:eF:n", &moddir_base, NULL);
 	argv += optind;
 
-	/* If a version is provided, then that kernel version’s module directory
+	/* goto modules location */
+
+	/* If a version is provided, then that kernel version's module directory
 	 * is used, rather than the current kernel version (as returned by
 	 * "uname -r").  */
-	if (*argv && (sscanf(*argv, "%d.%d.%d", &ret, &ret, &ret) == 3)) {
-		moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, *argv++);
+	xchdir(moddir_base);
+	if (*argv && (sscanf(*argv, "%d.%d.%d", &tmp, &tmp, &tmp) == 3)) {
+		xchdir(*argv++);
 	} else {
 		struct utsname uts;
-		if (uname(&uts) < 0)
-			bb_simple_perror_msg_and_die("uname");
-		moddir = concat_path_file(CONFIG_DEFAULT_MODULES_DIR, uts.release);
+		uname(&uts);
+		xchdir(uts.release);
 	}
 	/* If no modules are given on the command-line, -a is on per default.  */
 	option_mask32 |= *argv == NULL;
 
-	if (option_mask32 & ARG_b) {
-		moddir_base_len = strlen(moddir_base) + 1;
-		xchdir(moddir_base);
-	}
-
-	if (!(option_mask32 & ARG_n)) { /* --dry-run */
-		chp = concat_path_file(moddir, CONFIG_DEFAULT_DEPMOD_FILE);
-		filedes = xfopen_for_write(chp);
-		if (ENABLE_FEATURE_CLEAN_UP)
-			free(chp);
-	}
-	ret = EXIT_SUCCESS;
+	/* Scan modules */
+	moddir_base = xrealloc_getcwd_or_warn(NULL);
 	do {
-		chp = option_mask32 & ARG_a ? moddir : (*argv + moddir_base_len);
-
-		if (!recursive_action(chp,
-				ACTION_RECURSE, /* flags */
-				fileAction, /* file action */
-				NULL, /* dir action */
-				NULL, /* user data */
-				0)) { /* depth */
-			ret = EXIT_FAILURE;
+		recursive_action((option_mask32 & ARG_a) ? moddir_base : *argv,
+				ACTION_RECURSE, parse_module, NULL,  &modules, 0);
+	} while (!(option_mask32 & ARG_a) && *(++argv));
+	if (ENABLE_FEATURE_CLEAN_UP)
+		free(moddir_base);
+
+	/* Generate dependency and alias files */
+	if (!(option_mask32 & ARG_n))
+		freopen(CONFIG_DEFAULT_DEPMOD_FILE, "w", stdout);
+	for (m = modules; m != NULL; m = m->next) {
+		printf("%s:", m->name);
+
+		order_dep_list(modules, m, m->dependencies);
+		while (m->dnext != m) {
+			dep = m->dnext;
+			printf(" %s", dep->name);
+
+			/* unlink current entry */
+			dep->dnext->dprev = dep->dprev;
+			dep->dprev->dnext = dep->dnext;
+			dep->dnext = dep->dprev = dep;
 		}
-	} while (!(option_mask32 & ARG_a) && *++argv);
-
-	{
-	dep_lst_t *mods = G.lst;
-
-	/* Fixup the module names in the depends list */
-	while (mods) {
-		llist_t *deps = NULL, *old_deps = mods->dependencies;
-
-		while (old_deps) {
-			dep_lst_t *all = G.lst;
-			char *longname = NULL;
-			char *shortname = llist_pop(&old_deps);
-
-			while (all) {
-				char *nam =
-					xstrdup(bb_get_last_path_component_nostrip(all->name));
-				char *tmp = strrstr(nam, ".ko");
-
-				*tmp = '\0';
-				if (!strcmp(nam, shortname)) {
-					if (ENABLE_FEATURE_CLEAN_UP)
-						free(nam);
-					longname = all->name;
-					break;
-				}
-				free(nam);
-				all = all->next;
-			}
-			llist_add_to_end(&deps, longname);
-		}
-		mods->dependencies = deps;
-		mods = mods->next;
+		puts("");
 	}
 
-#if ENABLE_FEATURE_DEPMOD_PRUNE_FANCY
-	/* modprobe allegedly wants dependencies without duplicates, i.e.
-	 * mod1: mod2 mod3
-	 * mod2: mod3
-	 * mod3:
-	 * implies that mod1 directly depends on mod2 and _not_ mod3 as mod3 is
-	 * already implicitely pulled in via mod2. This leaves us with:
-	 * mod1: mod2
-	 * mod2: mod3
-	 * mod3:
-	 */
-	mods = G.lst;
-	while (mods) {
-		llist_t *deps = mods->dependencies;
-		while (deps) {
-			dep_lst_t *all = G.lst;
-			while (all) {
-				if (!strcmp(all->name, deps->data)) {
-					llist_t *implied = all->dependencies;
-					while (implied) {
-						/* XXX:FIXME: erm, it would be nicer to just
-						 * llist_unlink(&mods->dependencies, implied)  */
-						llist_t *prune = mods->dependencies;
-						while (prune) {
-							if (!strcmp(implied->data, prune->data))
-								break;
-							prune = prune->link;
-						}
-//if (prune) bb_info_msg("[%s] '%s' implies '%s', removing", mods->name, all->name, implied->data);
-						llist_unlink(&mods->dependencies, prune);
-						implied = implied->link;
-					}
-				}
-				all = all->next;
-			}
-			deps = deps->link;
+#if ENABLE_FEATURE_MODUTILS_ALIAS
+	if (!(option_mask32 & ARG_n))
+		freopen("modules.alias", "w", stdout);
+	for (m = modules; m != NULL; m = m->next) {
+		while (m->aliases) {
+			printf("alias %s %s\n",
+				(char*)llist_pop(&m->aliases),
+				m->modname);
 		}
-		mods = mods->next;
 	}
 #endif
-
-	mods = G.lst;
-	/* Finally print them.  */
-	while (mods) {
-		fprintf(filedes, "%s:", mods->name);
-		/* If we did not resolve all modules, then it's likely that we just did
-		 * not see the names of all prerequisites (which will be NULL in this
-		 * case).  */
-		while (mods->dependencies) {
-			char *the_dep = llist_pop(&mods->dependencies);
-			if (the_dep)
-				fprintf(filedes, " %s", the_dep);
-		}
-		fprintf(filedes, "\n");
-		if (ENABLE_FEATURE_DEPMOD_ALIAS)
-		{
-			char *shortname =
-				xstrdup(bb_get_last_path_component_nostrip(mods->name));
-			char *tmp = strrstr(shortname, ".ko");
-
-			*tmp = '\0';
-
-			while (mods->aliases) {
-				fprintf(filedes, "alias %s %s\n",
-					(char*)llist_pop(&mods->aliases),
-					shortname);
-			}
-			free(shortname);
+#if ENABLE_FEATURE_MODUTILS_SYMBOLS
+	if (!(option_mask32 & ARG_n))
+		freopen("modules.symbols", "w", stdout);
+	for (m = modules; m != NULL; m = m->next) {
+		while (m->symbols) {
+			printf("alias symbol:%s %s\n",
+				(char*)llist_pop(&m->symbols),
+				m->modname);
 		}
-		mods = mods->next;
-	}
 	}
+#endif
 
 	if (ENABLE_FEATURE_CLEAN_UP) {
-		fclose_if_not_stdin(filedes);
-		free(moddir);
-		while (G.lst) {
-			dep_lst_t *old = G.lst;
-			G.lst = G.lst->next;
+		while (modules) {
+			module_info *old = modules;
+			modules = modules->next;
 			free(old->name);
+			free(old->modname);
 			free(old);
 		}
 	}
-	return ret;
+
+	return EXIT_SUCCESS;
 }