xref: /openbmc/linux/scripts/mod/modpost.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 /* Postprocess module symbol versions
2  *
3  * Copyright 2003       Kai Germaschewski
4  * Copyright 2002-2004  Rusty Russell, IBM Corporation
5  *
6  * Based in part on module-init-tools/depmod.c,file2alias
7  *
8  * This software may be used and distributed according to the terms
9  * of the GNU General Public License, incorporated herein by reference.
10  *
11  * Usage: modpost vmlinux module1.o module2.o ...
12  */
13 
14 #include <ctype.h>
15 #include "modpost.h"
16 
17 /* Are we using CONFIG_MODVERSIONS? */
18 int modversions = 0;
19 /* Warn about undefined symbols? (do so if we have vmlinux) */
20 int have_vmlinux = 0;
21 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
22 static int all_versions = 0;
23 
24 void
25 fatal(const char *fmt, ...)
26 {
27 	va_list arglist;
28 
29 	fprintf(stderr, "FATAL: ");
30 
31 	va_start(arglist, fmt);
32 	vfprintf(stderr, fmt, arglist);
33 	va_end(arglist);
34 
35 	exit(1);
36 }
37 
38 void
39 warn(const char *fmt, ...)
40 {
41 	va_list arglist;
42 
43 	fprintf(stderr, "WARNING: ");
44 
45 	va_start(arglist, fmt);
46 	vfprintf(stderr, fmt, arglist);
47 	va_end(arglist);
48 }
49 
50 void *do_nofail(void *ptr, const char *expr)
51 {
52 	if (!ptr) {
53 		fatal("modpost: Memory allocation failure: %s.\n", expr);
54 	}
55 	return ptr;
56 }
57 
58 /* A list of all modules we processed */
59 
60 static struct module *modules;
61 
62 struct module *
63 find_module(char *modname)
64 {
65 	struct module *mod;
66 
67 	for (mod = modules; mod; mod = mod->next)
68 		if (strcmp(mod->name, modname) == 0)
69 			break;
70 	return mod;
71 }
72 
73 struct module *
74 new_module(char *modname)
75 {
76 	struct module *mod;
77 	char *p, *s;
78 
79 	mod = NOFAIL(malloc(sizeof(*mod)));
80 	memset(mod, 0, sizeof(*mod));
81 	p = NOFAIL(strdup(modname));
82 
83 	/* strip trailing .o */
84 	if ((s = strrchr(p, '.')) != NULL)
85 		if (strcmp(s, ".o") == 0)
86 			*s = '\0';
87 
88 	/* add to list */
89 	mod->name = p;
90 	mod->next = modules;
91 	modules = mod;
92 
93 	return mod;
94 }
95 
96 /* A hash of all exported symbols,
97  * struct symbol is also used for lists of unresolved symbols */
98 
99 #define SYMBOL_HASH_SIZE 1024
100 
101 struct symbol {
102 	struct symbol *next;
103 	struct module *module;
104 	unsigned int crc;
105 	int crc_valid;
106 	unsigned int weak:1;
107 	char name[0];
108 };
109 
110 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
111 
112 /* This is based on the hash agorithm from gdbm, via tdb */
113 static inline unsigned int tdb_hash(const char *name)
114 {
115 	unsigned value;	/* Used to compute the hash value.  */
116 	unsigned   i;	/* Used to cycle through random values. */
117 
118 	/* Set the initial value from the key size. */
119 	for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
120 		value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
121 
122 	return (1103515243 * value + 12345);
123 }
124 
125 /* Allocate a new symbols for use in the hash of exported symbols or
126  * the list of unresolved symbols per module */
127 
128 struct symbol *
129 alloc_symbol(const char *name, unsigned int weak, struct symbol *next)
130 {
131 	struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
132 
133 	memset(s, 0, sizeof(*s));
134 	strcpy(s->name, name);
135 	s->weak = weak;
136 	s->next = next;
137 	return s;
138 }
139 
140 /* For the hash of exported symbols */
141 
142 void
143 new_symbol(const char *name, struct module *module, unsigned int *crc)
144 {
145 	unsigned int hash;
146 	struct symbol *new;
147 
148 	hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
149 	new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
150 	new->module = module;
151 	if (crc) {
152 		new->crc = *crc;
153 		new->crc_valid = 1;
154 	}
155 }
156 
157 struct symbol *
158 find_symbol(const char *name)
159 {
160 	struct symbol *s;
161 
162 	/* For our purposes, .foo matches foo.  PPC64 needs this. */
163 	if (name[0] == '.')
164 		name++;
165 
166 	for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) {
167 		if (strcmp(s->name, name) == 0)
168 			return s;
169 	}
170 	return NULL;
171 }
172 
173 /* Add an exported symbol - it may have already been added without a
174  * CRC, in this case just update the CRC */
175 void
176 add_exported_symbol(const char *name, struct module *module, unsigned int *crc)
177 {
178 	struct symbol *s = find_symbol(name);
179 
180 	if (!s) {
181 		new_symbol(name, module, crc);
182 		return;
183 	}
184 	if (crc) {
185 		s->crc = *crc;
186 		s->crc_valid = 1;
187 	}
188 }
189 
190 void *
191 grab_file(const char *filename, unsigned long *size)
192 {
193 	struct stat st;
194 	void *map;
195 	int fd;
196 
197 	fd = open(filename, O_RDONLY);
198 	if (fd < 0 || fstat(fd, &st) != 0)
199 		return NULL;
200 
201 	*size = st.st_size;
202 	map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
203 	close(fd);
204 
205 	if (map == MAP_FAILED)
206 		return NULL;
207 	return map;
208 }
209 
210 /*
211    Return a copy of the next line in a mmap'ed file.
212    spaces in the beginning of the line is trimmed away.
213    Return a pointer to a static buffer.
214 */
215 char*
216 get_next_line(unsigned long *pos, void *file, unsigned long size)
217 {
218 	static char line[4096];
219 	int skip = 1;
220 	size_t len = 0;
221 	signed char *p = (signed char *)file + *pos;
222 	char *s = line;
223 
224 	for (; *pos < size ; (*pos)++)
225 	{
226 		if (skip && isspace(*p)) {
227 			p++;
228 			continue;
229 		}
230 		skip = 0;
231 		if (*p != '\n' && (*pos < size)) {
232 			len++;
233 			*s++ = *p++;
234 			if (len > 4095)
235 				break; /* Too long, stop */
236 		} else {
237 			/* End of string */
238 			*s = '\0';
239 			return line;
240 		}
241 	}
242 	/* End of buffer */
243 	return NULL;
244 }
245 
246 void
247 release_file(void *file, unsigned long size)
248 {
249 	munmap(file, size);
250 }
251 
252 void
253 parse_elf(struct elf_info *info, const char *filename)
254 {
255 	unsigned int i;
256 	Elf_Ehdr *hdr = info->hdr;
257 	Elf_Shdr *sechdrs;
258 	Elf_Sym  *sym;
259 
260 	hdr = grab_file(filename, &info->size);
261 	if (!hdr) {
262 		perror(filename);
263 		abort();
264 	}
265 	info->hdr = hdr;
266 	if (info->size < sizeof(*hdr))
267 		goto truncated;
268 
269 	/* Fix endianness in ELF header */
270 	hdr->e_shoff    = TO_NATIVE(hdr->e_shoff);
271 	hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
272 	hdr->e_shnum    = TO_NATIVE(hdr->e_shnum);
273 	hdr->e_machine  = TO_NATIVE(hdr->e_machine);
274 	sechdrs = (void *)hdr + hdr->e_shoff;
275 	info->sechdrs = sechdrs;
276 
277 	/* Fix endianness in section headers */
278 	for (i = 0; i < hdr->e_shnum; i++) {
279 		sechdrs[i].sh_type   = TO_NATIVE(sechdrs[i].sh_type);
280 		sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
281 		sechdrs[i].sh_size   = TO_NATIVE(sechdrs[i].sh_size);
282 		sechdrs[i].sh_link   = TO_NATIVE(sechdrs[i].sh_link);
283 		sechdrs[i].sh_name   = TO_NATIVE(sechdrs[i].sh_name);
284 	}
285 	/* Find symbol table. */
286 	for (i = 1; i < hdr->e_shnum; i++) {
287 		const char *secstrings
288 			= (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
289 
290 		if (sechdrs[i].sh_offset > info->size)
291 			goto truncated;
292 		if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) {
293 			info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
294 			info->modinfo_len = sechdrs[i].sh_size;
295 		}
296 		if (sechdrs[i].sh_type != SHT_SYMTAB)
297 			continue;
298 
299 		info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
300 		info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset
301 			                         + sechdrs[i].sh_size;
302 		info->strtab       = (void *)hdr +
303 			             sechdrs[sechdrs[i].sh_link].sh_offset;
304 	}
305 	if (!info->symtab_start) {
306 		fprintf(stderr, "modpost: %s no symtab?\n", filename);
307 		abort();
308 	}
309 	/* Fix endianness in symbols */
310 	for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
311 		sym->st_shndx = TO_NATIVE(sym->st_shndx);
312 		sym->st_name  = TO_NATIVE(sym->st_name);
313 		sym->st_value = TO_NATIVE(sym->st_value);
314 		sym->st_size  = TO_NATIVE(sym->st_size);
315 	}
316 	return;
317 
318  truncated:
319 	fprintf(stderr, "modpost: %s is truncated.\n", filename);
320 	abort();
321 }
322 
323 void
324 parse_elf_finish(struct elf_info *info)
325 {
326 	release_file(info->hdr, info->size);
327 }
328 
329 #define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
330 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
331 
332 void
333 handle_modversions(struct module *mod, struct elf_info *info,
334 		   Elf_Sym *sym, const char *symname)
335 {
336 	unsigned int crc;
337 
338 	switch (sym->st_shndx) {
339 	case SHN_COMMON:
340 		fprintf(stderr, "*** Warning: \"%s\" [%s] is COMMON symbol\n",
341 			symname, mod->name);
342 		break;
343 	case SHN_ABS:
344 		/* CRC'd symbol */
345 		if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
346 			crc = (unsigned int) sym->st_value;
347 			add_exported_symbol(symname + strlen(CRC_PFX),
348 					    mod, &crc);
349 		}
350 		break;
351 	case SHN_UNDEF:
352 		/* undefined symbol */
353 		if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
354 		    ELF_ST_BIND(sym->st_info) != STB_WEAK)
355 			break;
356 		/* ignore global offset table */
357 		if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
358 			break;
359 		/* ignore __this_module, it will be resolved shortly */
360 		if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
361 			break;
362 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
363 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
364 /* add compatibility with older glibc */
365 #ifndef STT_SPARC_REGISTER
366 #define STT_SPARC_REGISTER STT_REGISTER
367 #endif
368 		if (info->hdr->e_machine == EM_SPARC ||
369 		    info->hdr->e_machine == EM_SPARCV9) {
370 			/* Ignore register directives. */
371 			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
372 				break;
373  			if (symname[0] == '.') {
374  				char *munged = strdup(symname);
375  				munged[0] = '_';
376  				munged[1] = toupper(munged[1]);
377  				symname = munged;
378  			}
379 		}
380 #endif
381 
382 		if (memcmp(symname, MODULE_SYMBOL_PREFIX,
383 			   strlen(MODULE_SYMBOL_PREFIX)) == 0)
384 			mod->unres = alloc_symbol(symname +
385 						  strlen(MODULE_SYMBOL_PREFIX),
386 						  ELF_ST_BIND(sym->st_info) == STB_WEAK,
387 						  mod->unres);
388 		break;
389 	default:
390 		/* All exported symbols */
391 		if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
392 			add_exported_symbol(symname + strlen(KSYMTAB_PFX),
393 					    mod, NULL);
394 		}
395 		if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
396 			mod->has_init = 1;
397 		if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
398 			mod->has_cleanup = 1;
399 		break;
400 	}
401 }
402 
403 int
404 is_vmlinux(const char *modname)
405 {
406 	const char *myname;
407 
408 	if ((myname = strrchr(modname, '/')))
409 		myname++;
410 	else
411 		myname = modname;
412 
413 	return strcmp(myname, "vmlinux") == 0;
414 }
415 
416 /* Parse tag=value strings from .modinfo section */
417 static char *next_string(char *string, unsigned long *secsize)
418 {
419 	/* Skip non-zero chars */
420 	while (string[0]) {
421 		string++;
422 		if ((*secsize)-- <= 1)
423 			return NULL;
424 	}
425 
426 	/* Skip any zero padding. */
427 	while (!string[0]) {
428 		string++;
429 		if ((*secsize)-- <= 1)
430 			return NULL;
431 	}
432 	return string;
433 }
434 
435 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
436 			 const char *tag)
437 {
438 	char *p;
439 	unsigned int taglen = strlen(tag);
440 	unsigned long size = modinfo_len;
441 
442 	for (p = modinfo; p; p = next_string(p, &size)) {
443 		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
444 			return p + taglen + 1;
445 	}
446 	return NULL;
447 }
448 
449 void
450 read_symbols(char *modname)
451 {
452 	const char *symname;
453 	char *version;
454 	struct module *mod;
455 	struct elf_info info = { };
456 	Elf_Sym *sym;
457 
458 	parse_elf(&info, modname);
459 
460 	mod = new_module(modname);
461 
462 	/* When there's no vmlinux, don't print warnings about
463 	 * unresolved symbols (since there'll be too many ;) */
464 	if (is_vmlinux(modname)) {
465 		unsigned int fake_crc = 0;
466 		have_vmlinux = 1;
467 		add_exported_symbol("struct_module", mod, &fake_crc);
468 		mod->skip = 1;
469 	}
470 
471 	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
472 		symname = info.strtab + sym->st_name;
473 
474 		handle_modversions(mod, &info, sym, symname);
475 		handle_moddevtable(mod, &info, sym, symname);
476 	}
477 
478 	version = get_modinfo(info.modinfo, info.modinfo_len, "version");
479 	if (version)
480 		maybe_frob_rcs_version(modname, version, info.modinfo,
481 				       version - (char *)info.hdr);
482 	if (version || (all_versions && !is_vmlinux(modname)))
483 		get_src_version(modname, mod->srcversion,
484 				sizeof(mod->srcversion)-1);
485 
486 	parse_elf_finish(&info);
487 
488 	/* Our trick to get versioning for struct_module - it's
489 	 * never passed as an argument to an exported function, so
490 	 * the automatic versioning doesn't pick it up, but it's really
491 	 * important anyhow */
492 	if (modversions)
493 		mod->unres = alloc_symbol("struct_module", 0, mod->unres);
494 }
495 
496 #define SZ 500
497 
498 /* We first write the generated file into memory using the
499  * following helper, then compare to the file on disk and
500  * only update the later if anything changed */
501 
502 void __attribute__((format(printf, 2, 3)))
503 buf_printf(struct buffer *buf, const char *fmt, ...)
504 {
505 	char tmp[SZ];
506 	int len;
507 	va_list ap;
508 
509 	va_start(ap, fmt);
510 	len = vsnprintf(tmp, SZ, fmt, ap);
511 	if (buf->size - buf->pos < len + 1) {
512 		buf->size += 128;
513 		buf->p = realloc(buf->p, buf->size);
514 	}
515 	strncpy(buf->p + buf->pos, tmp, len + 1);
516 	buf->pos += len;
517 	va_end(ap);
518 }
519 
520 void
521 buf_write(struct buffer *buf, const char *s, int len)
522 {
523 	if (buf->size - buf->pos < len) {
524 		buf->size += len;
525 		buf->p = realloc(buf->p, buf->size);
526 	}
527 	strncpy(buf->p + buf->pos, s, len);
528 	buf->pos += len;
529 }
530 
531 /* Header for the generated file */
532 
533 void
534 add_header(struct buffer *b, struct module *mod)
535 {
536 	buf_printf(b, "#include <linux/module.h>\n");
537 	buf_printf(b, "#include <linux/vermagic.h>\n");
538 	buf_printf(b, "#include <linux/compiler.h>\n");
539 	buf_printf(b, "\n");
540 	buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
541 	buf_printf(b, "\n");
542 	buf_printf(b, "#undef unix\n"); /* We have a module called "unix" */
543 	buf_printf(b, "struct module __this_module\n");
544 	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
545 	buf_printf(b, " .name = __stringify(KBUILD_MODNAME),\n");
546 	if (mod->has_init)
547 		buf_printf(b, " .init = init_module,\n");
548 	if (mod->has_cleanup)
549 		buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
550 			      " .exit = cleanup_module,\n"
551 			      "#endif\n");
552 	buf_printf(b, "};\n");
553 }
554 
555 /* Record CRCs for unresolved symbols */
556 
557 void
558 add_versions(struct buffer *b, struct module *mod)
559 {
560 	struct symbol *s, *exp;
561 
562 	for (s = mod->unres; s; s = s->next) {
563 		exp = find_symbol(s->name);
564 		if (!exp || exp->module == mod) {
565 			if (have_vmlinux && !s->weak)
566 				fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
567 				"undefined!\n",	s->name, mod->name);
568 			continue;
569 		}
570 		s->module = exp->module;
571 		s->crc_valid = exp->crc_valid;
572 		s->crc = exp->crc;
573 	}
574 
575 	if (!modversions)
576 		return;
577 
578 	buf_printf(b, "\n");
579 	buf_printf(b, "static const struct modversion_info ____versions[]\n");
580 	buf_printf(b, "__attribute_used__\n");
581 	buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
582 
583 	for (s = mod->unres; s; s = s->next) {
584 		if (!s->module) {
585 			continue;
586 		}
587 		if (!s->crc_valid) {
588 			fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
589 				"has no CRC!\n",
590 				s->name, mod->name);
591 			continue;
592 		}
593 		buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
594 	}
595 
596 	buf_printf(b, "};\n");
597 }
598 
599 void
600 add_depends(struct buffer *b, struct module *mod, struct module *modules)
601 {
602 	struct symbol *s;
603 	struct module *m;
604 	int first = 1;
605 
606 	for (m = modules; m; m = m->next) {
607 		m->seen = is_vmlinux(m->name);
608 	}
609 
610 	buf_printf(b, "\n");
611 	buf_printf(b, "static const char __module_depends[]\n");
612 	buf_printf(b, "__attribute_used__\n");
613 	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
614 	buf_printf(b, "\"depends=");
615 	for (s = mod->unres; s; s = s->next) {
616 		if (!s->module)
617 			continue;
618 
619 		if (s->module->seen)
620 			continue;
621 
622 		s->module->seen = 1;
623 		buf_printf(b, "%s%s", first ? "" : ",",
624 			   strrchr(s->module->name, '/') + 1);
625 		first = 0;
626 	}
627 	buf_printf(b, "\";\n");
628 }
629 
630 void
631 add_srcversion(struct buffer *b, struct module *mod)
632 {
633 	if (mod->srcversion[0]) {
634 		buf_printf(b, "\n");
635 		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
636 			   mod->srcversion);
637 	}
638 }
639 
640 void
641 write_if_changed(struct buffer *b, const char *fname)
642 {
643 	char *tmp;
644 	FILE *file;
645 	struct stat st;
646 
647 	file = fopen(fname, "r");
648 	if (!file)
649 		goto write;
650 
651 	if (fstat(fileno(file), &st) < 0)
652 		goto close_write;
653 
654 	if (st.st_size != b->pos)
655 		goto close_write;
656 
657 	tmp = NOFAIL(malloc(b->pos));
658 	if (fread(tmp, 1, b->pos, file) != b->pos)
659 		goto free_write;
660 
661 	if (memcmp(tmp, b->p, b->pos) != 0)
662 		goto free_write;
663 
664 	free(tmp);
665 	fclose(file);
666 	return;
667 
668  free_write:
669 	free(tmp);
670  close_write:
671 	fclose(file);
672  write:
673 	file = fopen(fname, "w");
674 	if (!file) {
675 		perror(fname);
676 		exit(1);
677 	}
678 	if (fwrite(b->p, 1, b->pos, file) != b->pos) {
679 		perror(fname);
680 		exit(1);
681 	}
682 	fclose(file);
683 }
684 
685 void
686 read_dump(const char *fname)
687 {
688 	unsigned long size, pos = 0;
689 	void *file = grab_file(fname, &size);
690 	char *line;
691 
692         if (!file)
693 		/* No symbol versions, silently ignore */
694 		return;
695 
696 	while ((line = get_next_line(&pos, file, size))) {
697 		char *symname, *modname, *d;
698 		unsigned int crc;
699 		struct module *mod;
700 
701 		if (!(symname = strchr(line, '\t')))
702 			goto fail;
703 		*symname++ = '\0';
704 		if (!(modname = strchr(symname, '\t')))
705 			goto fail;
706 		*modname++ = '\0';
707 		if (strchr(modname, '\t'))
708 			goto fail;
709 		crc = strtoul(line, &d, 16);
710 		if (*symname == '\0' || *modname == '\0' || *d != '\0')
711 			goto fail;
712 
713 		if (!(mod = find_module(modname))) {
714 			if (is_vmlinux(modname)) {
715 				have_vmlinux = 1;
716 			}
717 			mod = new_module(NOFAIL(strdup(modname)));
718 			mod->skip = 1;
719 		}
720 		add_exported_symbol(symname, mod, &crc);
721 	}
722 	return;
723 fail:
724 	fatal("parse error in symbol dump file\n");
725 }
726 
727 void
728 write_dump(const char *fname)
729 {
730 	struct buffer buf = { };
731 	struct symbol *symbol;
732 	int n;
733 
734 	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
735 		symbol = symbolhash[n];
736 		while (symbol) {
737 			symbol = symbol->next;
738 		}
739 	}
740 
741 	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
742 		symbol = symbolhash[n];
743 		while (symbol) {
744 			buf_printf(&buf, "0x%08x\t%s\t%s\n", symbol->crc,
745 				symbol->name, symbol->module->name);
746 			symbol = symbol->next;
747 		}
748 	}
749 	write_if_changed(&buf, fname);
750 }
751 
752 int
753 main(int argc, char **argv)
754 {
755 	struct module *mod;
756 	struct buffer buf = { };
757 	char fname[SZ];
758 	char *dump_read = NULL, *dump_write = NULL;
759 	int opt;
760 
761 	while ((opt = getopt(argc, argv, "i:mo:a")) != -1) {
762 		switch(opt) {
763 			case 'i':
764 				dump_read = optarg;
765 				break;
766 			case 'm':
767 				modversions = 1;
768 				break;
769 			case 'o':
770 				dump_write = optarg;
771 				break;
772 			case 'a':
773 				all_versions = 1;
774 				break;
775 			default:
776 				exit(1);
777 		}
778 	}
779 
780 	if (dump_read)
781 		read_dump(dump_read);
782 
783 	while (optind < argc) {
784 		read_symbols(argv[optind++]);
785 	}
786 
787 	for (mod = modules; mod; mod = mod->next) {
788 		if (mod->skip)
789 			continue;
790 
791 		buf.pos = 0;
792 
793 		add_header(&buf, mod);
794 		add_versions(&buf, mod);
795 		add_depends(&buf, mod, modules);
796 		add_moddevtable(&buf, mod);
797 		add_srcversion(&buf, mod);
798 
799 		sprintf(fname, "%s.mod.c", mod->name);
800 		write_if_changed(&buf, fname);
801 	}
802 
803 	if (dump_write)
804 		write_dump(dump_write);
805 
806 	return 0;
807 }
808 
809