summaryrefslogtreecommitdiff
path: root/modutils/depmod.c
blob: 35df4a8e2ade14c2d963366cd5183f555353c465 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/* vi: set sw=4 ts=4: */
/*
 * 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.
 */

#undef _GNU_SOURCE
#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
 * - iterate over all modules looking for "depends=" entries
 *   for each depends, look through our list of full paths and emit if found
 */

typedef struct module_info {
	struct module_info *next;
	char *name, *modname;
	llist_t *dependencies;
	llist_t *aliases;
	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 */
};

static int FAST_FUNC parse_module(const char *fname, struct stat *sb,
				  void *data, int UNUSED_PARAM depth)
{
	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);
		}
	}
	free(image);

	return TRUE;
}

static module_info *find_module(module_info *modules, const char *modname)
{
	module_info *m;

	for (m = modules; m != NULL; m = m->next)
		if (strcmp(m->modname, modname) == 0)
			return m;
	return NULL;
}

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);
	}
}

int depmod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int depmod_main(int argc UNUSED_PARAM, char **argv)
{
	module_info *modules = NULL, *m, *dep;
	char *moddir_base = (char *)CONFIG_DEFAULT_MODULES_DIR;
	int tmp;

	getopt32(argv, "aAb:eF:n", &moddir_base, NULL);
	argv += optind;

	/* 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").  */
	xchdir(moddir_base);
	if (*argv && (sscanf(*argv, "%d.%d.%d", &tmp, &tmp, &tmp) == 3)) {
		xchdir(*argv++);
	} else {
		struct utsname uts;
		uname(&uts);
		xchdir(uts.release);
	}
	/* If no modules are given on the command-line, -a is on per default.  */
	option_mask32 |= *argv == NULL;

	/* Scan modules */
	moddir_base = xrealloc_getcwd_or_warn(NULL);
	do {
		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;
		}
		puts("");
	}

#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);
		}
	}
#endif
#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);
		}
	}
#endif

	if (ENABLE_FEATURE_CLEAN_UP) {
		while (modules) {
			module_info *old = modules;
			modules = modules->next;
			free(old->name);
			free(old->modname);
			free(old);
		}
	}

	return EXIT_SUCCESS;
}