1/* Postprocess module symbol versions
2 *
3 * Copyright 2003       Kai Germaschewski
4 * Copyright 2002-2004  Rusty Russell, IBM Corporation
5 * Copyright 2006-2008  Sam Ravnborg
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#define _GNU_SOURCE
15#include <stdio.h>
16#include <ctype.h>
17#include <string.h>
18#include "modpost.h"
19#include "../../include/generated/autoconf.h"
20#include "../../include/linux/license.h"
21
22/* Some toolchains use a `_' prefix for all user symbols. */
23#ifdef CONFIG_SYMBOL_PREFIX
24#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
25#else
26#define MODULE_SYMBOL_PREFIX ""
27#endif
28
29
30/* Are we using CONFIG_MODVERSIONS? */
31int modversions = 0;
32/* Warn about undefined symbols? (do so if we have vmlinux) */
33int have_vmlinux = 0;
34/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35static int all_versions = 0;
36/* If we are modposting external module set to 1 */
37static int external_module = 0;
38/* Warn about section mismatch in vmlinux if set to 1 */
39static int vmlinux_section_warnings = 1;
40/* Only warn about unresolved symbols */
41static int warn_unresolved = 0;
42/* How a symbol is exported */
43static int sec_mismatch_count = 0;
44static int sec_mismatch_verbose = 1;
45
46enum export {
47	export_plain,      export_unused,     export_gpl,
48	export_unused_gpl, export_gpl_future, export_unknown
49};
50
51#define PRINTF __attribute__ ((format (printf, 1, 2)))
52
53PRINTF void fatal(const char *fmt, ...)
54{
55	va_list arglist;
56
57	fprintf(stderr, "FATAL: ");
58
59	va_start(arglist, fmt);
60	vfprintf(stderr, fmt, arglist);
61	va_end(arglist);
62
63	exit(1);
64}
65
66PRINTF void warn(const char *fmt, ...)
67{
68	va_list arglist;
69
70	fprintf(stderr, "WARNING: ");
71
72	va_start(arglist, fmt);
73	vfprintf(stderr, fmt, arglist);
74	va_end(arglist);
75}
76
77PRINTF void merror(const char *fmt, ...)
78{
79	va_list arglist;
80
81	fprintf(stderr, "ERROR: ");
82
83	va_start(arglist, fmt);
84	vfprintf(stderr, fmt, arglist);
85	va_end(arglist);
86}
87
88static int is_vmlinux(const char *modname)
89{
90	const char *myname;
91
92	myname = strrchr(modname, '/');
93	if (myname)
94		myname++;
95	else
96		myname = modname;
97
98	return (strcmp(myname, "vmlinux") == 0) ||
99	       (strcmp(myname, "vmlinux.o") == 0);
100}
101
102void *do_nofail(void *ptr, const char *expr)
103{
104	if (!ptr)
105		fatal("modpost: Memory allocation failure: %s.\n", expr);
106
107	return ptr;
108}
109
110/* A list of all modules we processed */
111static struct module *modules;
112
113static struct module *find_module(char *modname)
114{
115	struct module *mod;
116
117	for (mod = modules; mod; mod = mod->next)
118		if (strcmp(mod->name, modname) == 0)
119			break;
120	return mod;
121}
122
123static struct module *new_module(char *modname)
124{
125	struct module *mod;
126	char *p, *s;
127
128	mod = NOFAIL(malloc(sizeof(*mod)));
129	memset(mod, 0, sizeof(*mod));
130	p = NOFAIL(strdup(modname));
131
132	/* strip trailing .o */
133	s = strrchr(p, '.');
134	if (s != NULL)
135		if (strcmp(s, ".o") == 0) {
136			*s = '\0';
137			mod->is_dot_o = 1;
138		}
139
140	/* add to list */
141	mod->name = p;
142	mod->gpl_compatible = -1;
143	mod->next = modules;
144	modules = mod;
145
146	return mod;
147}
148
149/* A hash of all exported symbols,
150 * struct symbol is also used for lists of unresolved symbols */
151
152#define SYMBOL_HASH_SIZE 1024
153
154struct symbol {
155	struct symbol *next;
156	struct module *module;
157	unsigned int crc;
158	int crc_valid;
159	unsigned int weak:1;
160	unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
161	unsigned int kernel:1;     /* 1 if symbol is from kernel
162				    *  (only for external modules) **/
163	unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
164	enum export  export;       /* Type of export */
165	char name[0];
166};
167
168static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
169
170/* This is based on the hash agorithm from gdbm, via tdb */
171static inline unsigned int tdb_hash(const char *name)
172{
173	unsigned value;	/* Used to compute the hash value.  */
174	unsigned   i;	/* Used to cycle through random values. */
175
176	/* Set the initial value from the key size. */
177	for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
178		value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
179
180	return (1103515243 * value + 12345);
181}
182
183/**
184 * Allocate a new symbols for use in the hash of exported symbols or
185 * the list of unresolved symbols per module
186 **/
187static struct symbol *alloc_symbol(const char *name, unsigned int weak,
188				   struct symbol *next)
189{
190	struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
191
192	memset(s, 0, sizeof(*s));
193	strcpy(s->name, name);
194	s->weak = weak;
195	s->next = next;
196	return s;
197}
198
199/* For the hash of exported symbols */
200static struct symbol *new_symbol(const char *name, struct module *module,
201				 enum export export)
202{
203	unsigned int hash;
204	struct symbol *new;
205
206	hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
207	new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
208	new->module = module;
209	new->export = export;
210	return new;
211}
212
213static struct symbol *find_symbol(const char *name)
214{
215	struct symbol *s;
216
217	/* For our purposes, .foo matches foo.  PPC64 needs this. */
218	if (name[0] == '.')
219		name++;
220
221	for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
222		if (strcmp(s->name, name) == 0)
223			return s;
224	}
225	return NULL;
226}
227
228static struct {
229	const char *str;
230	enum export export;
231} export_list[] = {
232	{ .str = "EXPORT_SYMBOL",            .export = export_plain },
233	{ .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
234	{ .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
235	{ .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
236	{ .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
237	{ .str = "(unknown)",                .export = export_unknown },
238};
239
240
241static const char *export_str(enum export ex)
242{
243	return export_list[ex].str;
244}
245
246static enum export export_no(const char *s)
247{
248	int i;
249
250	if (!s)
251		return export_unknown;
252	for (i = 0; export_list[i].export != export_unknown; i++) {
253		if (strcmp(export_list[i].str, s) == 0)
254			return export_list[i].export;
255	}
256	return export_unknown;
257}
258
259static const char *sec_name(struct elf_info *elf, int secindex);
260
261#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
262
263static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
264{
265	const char *secname = sec_name(elf, sec);
266
267	if (strstarts(secname, "___ksymtab+"))
268		return export_plain;
269	else if (strstarts(secname, "___ksymtab_unused+"))
270		return export_unused;
271	else if (strstarts(secname, "___ksymtab_gpl+"))
272		return export_gpl;
273	else if (strstarts(secname, "___ksymtab_unused_gpl+"))
274		return export_unused_gpl;
275	else if (strstarts(secname, "___ksymtab_gpl_future+"))
276		return export_gpl_future;
277	else
278		return export_unknown;
279}
280
281static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
282{
283	if (sec == elf->export_sec)
284		return export_plain;
285	else if (sec == elf->export_unused_sec)
286		return export_unused;
287	else if (sec == elf->export_gpl_sec)
288		return export_gpl;
289	else if (sec == elf->export_unused_gpl_sec)
290		return export_unused_gpl;
291	else if (sec == elf->export_gpl_future_sec)
292		return export_gpl_future;
293	else
294		return export_unknown;
295}
296
297/**
298 * Add an exported symbol - it may have already been added without a
299 * CRC, in this case just update the CRC
300 **/
301static struct symbol *sym_add_exported(const char *name, struct module *mod,
302				       enum export export)
303{
304	struct symbol *s = find_symbol(name);
305
306	if (!s) {
307		s = new_symbol(name, mod, export);
308	} else {
309		if (!s->preloaded) {
310			warn("%s: '%s' exported twice. Previous export "
311			     "was in %s%s\n", mod->name, name,
312			     s->module->name,
313			     is_vmlinux(s->module->name) ?"":".ko");
314		} else {
315			/* In case Modules.symvers was out of date */
316			s->module = mod;
317		}
318	}
319	s->preloaded = 0;
320	s->vmlinux   = is_vmlinux(mod->name);
321	s->kernel    = 0;
322	s->export    = export;
323	return s;
324}
325
326static void sym_update_crc(const char *name, struct module *mod,
327			   unsigned int crc, enum export export)
328{
329	struct symbol *s = find_symbol(name);
330
331	if (!s)
332		s = new_symbol(name, mod, export);
333	s->crc = crc;
334	s->crc_valid = 1;
335}
336
337void *grab_file(const char *filename, unsigned long *size)
338{
339	struct stat st;
340	void *map;
341	int fd;
342
343	fd = open(filename, O_RDONLY);
344	if (fd < 0 || fstat(fd, &st) != 0)
345		return NULL;
346
347	*size = st.st_size;
348	map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
349	close(fd);
350
351	if (map == MAP_FAILED)
352		return NULL;
353	return map;
354}
355
356/**
357  * Return a copy of the next line in a mmap'ed file.
358  * spaces in the beginning of the line is trimmed away.
359  * Return a pointer to a static buffer.
360  **/
361char *get_next_line(unsigned long *pos, void *file, unsigned long size)
362{
363	static char line[4096];
364	int skip = 1;
365	size_t len = 0;
366	signed char *p = (signed char *)file + *pos;
367	char *s = line;
368
369	for (; *pos < size ; (*pos)++) {
370		if (skip && isspace(*p)) {
371			p++;
372			continue;
373		}
374		skip = 0;
375		if (*p != '\n' && (*pos < size)) {
376			len++;
377			*s++ = *p++;
378			if (len > 4095)
379				break; /* Too long, stop */
380		} else {
381			/* End of string */
382			*s = '\0';
383			return line;
384		}
385	}
386	/* End of buffer */
387	return NULL;
388}
389
390void release_file(void *file, unsigned long size)
391{
392	munmap(file, size);
393}
394
395static int parse_elf(struct elf_info *info, const char *filename)
396{
397	unsigned int i;
398	Elf_Ehdr *hdr;
399	Elf_Shdr *sechdrs;
400	Elf_Sym  *sym;
401	const char *secstrings;
402	unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
403
404	hdr = grab_file(filename, &info->size);
405	if (!hdr) {
406		perror(filename);
407		exit(1);
408	}
409	info->hdr = hdr;
410	if (info->size < sizeof(*hdr)) {
411		/* file too small, assume this is an empty .o file */
412		return 0;
413	}
414	/* Is this a valid ELF file? */
415	if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
416	    (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
417	    (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
418	    (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
419		/* Not an ELF file - silently ignore it */
420		return 0;
421	}
422	/* Fix endianness in ELF header */
423	hdr->e_type      = TO_NATIVE(hdr->e_type);
424	hdr->e_machine   = TO_NATIVE(hdr->e_machine);
425	hdr->e_version   = TO_NATIVE(hdr->e_version);
426	hdr->e_entry     = TO_NATIVE(hdr->e_entry);
427	hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
428	hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
429	hdr->e_flags     = TO_NATIVE(hdr->e_flags);
430	hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
431	hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
432	hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
433	hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
434	hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
435	hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
436	sechdrs = (void *)hdr + hdr->e_shoff;
437	info->sechdrs = sechdrs;
438
439	/* Check if file offset is correct */
440	if (hdr->e_shoff > info->size) {
441		fatal("section header offset=%lu in file '%s' is bigger than "
442		      "filesize=%lu\n", (unsigned long)hdr->e_shoff,
443		      filename, info->size);
444		return 0;
445	}
446
447	if (hdr->e_shnum == SHN_UNDEF) {
448		/*
449		 * There are more than 64k sections,
450		 * read count from .sh_size.
451		 */
452		info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
453	}
454	else {
455		info->num_sections = hdr->e_shnum;
456	}
457	if (hdr->e_shstrndx == SHN_XINDEX) {
458		info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
459	}
460	else {
461		info->secindex_strings = hdr->e_shstrndx;
462	}
463
464	/* Fix endianness in section headers */
465	for (i = 0; i < info->num_sections; i++) {
466		sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
467		sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
468		sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
469		sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
470		sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
471		sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
472		sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
473		sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
474		sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
475		sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
476	}
477	/* Find symbol table. */
478	secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
479	for (i = 1; i < info->num_sections; i++) {
480		const char *secname;
481		int nobits = sechdrs[i].sh_type == SHT_NOBITS;
482
483		if (!nobits && sechdrs[i].sh_offset > info->size) {
484			fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
485			      "sizeof(*hrd)=%zu\n", filename,
486			      (unsigned long)sechdrs[i].sh_offset,
487			      sizeof(*hdr));
488			return 0;
489		}
490		secname = secstrings + sechdrs[i].sh_name;
491		if (strcmp(secname, ".modinfo") == 0) {
492			if (nobits)
493				fatal("%s has NOBITS .modinfo\n", filename);
494			info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
495			info->modinfo_len = sechdrs[i].sh_size;
496		} else if (strcmp(secname, "__ksymtab") == 0)
497			info->export_sec = i;
498		else if (strcmp(secname, "__ksymtab_unused") == 0)
499			info->export_unused_sec = i;
500		else if (strcmp(secname, "__ksymtab_gpl") == 0)
501			info->export_gpl_sec = i;
502		else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
503			info->export_unused_gpl_sec = i;
504		else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
505			info->export_gpl_future_sec = i;
506
507		if (sechdrs[i].sh_type == SHT_SYMTAB) {
508			unsigned int sh_link_idx;
509			symtab_idx = i;
510			info->symtab_start = (void *)hdr +
511			    sechdrs[i].sh_offset;
512			info->symtab_stop  = (void *)hdr +
513			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
514			sh_link_idx = sechdrs[i].sh_link;
515			info->strtab       = (void *)hdr +
516			    sechdrs[sh_link_idx].sh_offset;
517		}
518
519		/* 32bit section no. table? ("more than 64k sections") */
520		if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
521			symtab_shndx_idx = i;
522			info->symtab_shndx_start = (void *)hdr +
523			    sechdrs[i].sh_offset;
524			info->symtab_shndx_stop  = (void *)hdr +
525			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
526		}
527	}
528	if (!info->symtab_start)
529		fatal("%s has no symtab?\n", filename);
530
531	/* Fix endianness in symbols */
532	for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
533		sym->st_shndx = TO_NATIVE(sym->st_shndx);
534		sym->st_name  = TO_NATIVE(sym->st_name);
535		sym->st_value = TO_NATIVE(sym->st_value);
536		sym->st_size  = TO_NATIVE(sym->st_size);
537	}
538
539	if (symtab_shndx_idx != ~0U) {
540		Elf32_Word *p;
541		if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
542			fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
543			      filename, sechdrs[symtab_shndx_idx].sh_link,
544			      symtab_idx);
545		/* Fix endianness */
546		for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
547		     p++)
548			*p = TO_NATIVE(*p);
549	}
550
551	return 1;
552}
553
554static void parse_elf_finish(struct elf_info *info)
555{
556	release_file(info->hdr, info->size);
557}
558
559static int ignore_undef_symbol(struct elf_info *info, const char *symname)
560{
561	/* ignore __this_module, it will be resolved shortly */
562	if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
563		return 1;
564	/* ignore global offset table */
565	if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
566		return 1;
567	if (info->hdr->e_machine == EM_PPC)
568		/* Special register function linked on all modules during final link of .ko */
569		if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
570		    strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
571		    strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
572		    strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
573			return 1;
574	if (info->hdr->e_machine == EM_PPC64)
575		/* Special register function linked on all modules during final link of .ko */
576		if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
577		    strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
578			return 1;
579	/* Do not ignore this symbol */
580	return 0;
581}
582
583#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
584#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
585
586static void handle_modversions(struct module *mod, struct elf_info *info,
587			       Elf_Sym *sym, const char *symname)
588{
589	unsigned int crc;
590	enum export export;
591
592	if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
593	    strncmp(symname, "__ksymtab", 9) == 0)
594		export = export_from_secname(info, get_secindex(info, sym));
595	else
596		export = export_from_sec(info, get_secindex(info, sym));
597
598	switch (sym->st_shndx) {
599	case SHN_COMMON:
600		warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
601		break;
602	case SHN_ABS:
603		/* CRC'd symbol */
604		if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
605			crc = (unsigned int) sym->st_value;
606			sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
607					export);
608		}
609		break;
610	case SHN_UNDEF:
611		/* undefined symbol */
612		if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
613		    ELF_ST_BIND(sym->st_info) != STB_WEAK)
614			break;
615		if (ignore_undef_symbol(info, symname))
616			break;
617/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
618#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
619/* add compatibility with older glibc */
620#ifndef STT_SPARC_REGISTER
621#define STT_SPARC_REGISTER STT_REGISTER
622#endif
623		if (info->hdr->e_machine == EM_SPARC ||
624		    info->hdr->e_machine == EM_SPARCV9) {
625			/* Ignore register directives. */
626			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
627				break;
628			if (symname[0] == '.') {
629				char *munged = strdup(symname);
630				munged[0] = '_';
631				munged[1] = toupper(munged[1]);
632				symname = munged;
633			}
634		}
635#endif
636
637		if (memcmp(symname, MODULE_SYMBOL_PREFIX,
638			   strlen(MODULE_SYMBOL_PREFIX)) == 0) {
639			mod->unres =
640			  alloc_symbol(symname +
641			               strlen(MODULE_SYMBOL_PREFIX),
642			               ELF_ST_BIND(sym->st_info) == STB_WEAK,
643			               mod->unres);
644		}
645		break;
646	default:
647		/* All exported symbols */
648		if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
649			sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
650					export);
651		}
652		if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
653			mod->has_init = 1;
654		if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
655			mod->has_cleanup = 1;
656		break;
657	}
658}
659
660/**
661 * Parse tag=value strings from .modinfo section
662 **/
663static char *next_string(char *string, unsigned long *secsize)
664{
665	/* Skip non-zero chars */
666	while (string[0]) {
667		string++;
668		if ((*secsize)-- <= 1)
669			return NULL;
670	}
671
672	/* Skip any zero padding. */
673	while (!string[0]) {
674		string++;
675		if ((*secsize)-- <= 1)
676			return NULL;
677	}
678	return string;
679}
680
681static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
682			      const char *tag, char *info)
683{
684	char *p;
685	unsigned int taglen = strlen(tag);
686	unsigned long size = modinfo_len;
687
688	if (info) {
689		size -= info - (char *)modinfo;
690		modinfo = next_string(info, &size);
691	}
692
693	for (p = modinfo; p; p = next_string(p, &size)) {
694		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
695			return p + taglen + 1;
696	}
697	return NULL;
698}
699
700static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
701			 const char *tag)
702
703{
704	return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
705}
706
707/**
708 * Test if string s ends in string sub
709 * return 0 if match
710 **/
711static int strrcmp(const char *s, const char *sub)
712{
713	int slen, sublen;
714
715	if (!s || !sub)
716		return 1;
717
718	slen = strlen(s);
719	sublen = strlen(sub);
720
721	if ((slen == 0) || (sublen == 0))
722		return 1;
723
724	if (sublen > slen)
725		return 1;
726
727	return memcmp(s + slen - sublen, sub, sublen);
728}
729
730static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
731{
732	if (sym)
733		return elf->strtab + sym->st_name;
734	else
735		return "(unknown)";
736}
737
738static const char *sec_name(struct elf_info *elf, int secindex)
739{
740	Elf_Shdr *sechdrs = elf->sechdrs;
741	return (void *)elf->hdr +
742		elf->sechdrs[elf->secindex_strings].sh_offset +
743		sechdrs[secindex].sh_name;
744}
745
746static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
747{
748	return (void *)elf->hdr +
749		elf->sechdrs[elf->secindex_strings].sh_offset +
750		sechdr->sh_name;
751}
752
753/* if sym is empty or point to a string
754 * like ".[0-9]+" then return 1.
755 * This is the optional prefix added by ld to some sections
756 */
757static int number_prefix(const char *sym)
758{
759	if (*sym++ == '\0')
760		return 1;
761	if (*sym != '.')
762		return 0;
763	do {
764		char c = *sym++;
765		if (c < '0' || c > '9')
766			return 0;
767	} while (*sym);
768	return 1;
769}
770
771/* The pattern is an array of simple patterns.
772 * "foo" will match an exact string equal to "foo"
773 * "*foo" will match a string that ends with "foo"
774 * "foo*" will match a string that begins with "foo"
775 * "foo$" will match a string equal to "foo" or "foo.1"
776 *   where the '1' can be any number including several digits.
777 *   The $ syntax is for sections where ld append a dot number
778 *   to make section name unique.
779 */
780static int match(const char *sym, const char * const pat[])
781{
782	const char *p;
783	while (*pat) {
784		p = *pat++;
785		const char *endp = p + strlen(p) - 1;
786
787		/* "*foo" */
788		if (*p == '*') {
789			if (strrcmp(sym, p + 1) == 0)
790				return 1;
791		}
792		/* "foo*" */
793		else if (*endp == '*') {
794			if (strncmp(sym, p, strlen(p) - 1) == 0)
795				return 1;
796		}
797		/* "foo$" */
798		else if (*endp == '$') {
799			if (strncmp(sym, p, strlen(p) - 1) == 0) {
800				if (number_prefix(sym + strlen(p) - 1))
801					return 1;
802			}
803		}
804		/* no wildcards */
805		else {
806			if (strcmp(p, sym) == 0)
807				return 1;
808		}
809	}
810	/* no match */
811	return 0;
812}
813
814/* sections that we do not want to do full section mismatch check on */
815static const char *section_white_list[] =
816{
817	".comment*",
818	".debug*",
819	".zdebug*",		/* Compressed debug sections. */
820	".GCC-command-line",	/* mn10300 */
821	".mdebug*",        /* alpha, score, mips etc. */
822	".pdr",            /* alpha, score, mips etc. */
823	".stab*",
824	".note*",
825	".got*",
826	".toc*",
827	NULL
828};
829
830/*
831 * This is used to find sections missing the SHF_ALLOC flag.
832 * The cause of this is often a section specified in assembler
833 * without "ax" / "aw".
834 */
835static void check_section(const char *modname, struct elf_info *elf,
836                          Elf_Shdr *sechdr)
837{
838	const char *sec = sech_name(elf, sechdr);
839
840	if (sechdr->sh_type == SHT_PROGBITS &&
841	    !(sechdr->sh_flags & SHF_ALLOC) &&
842	    !match(sec, section_white_list)) {
843		warn("%s (%s): unexpected non-allocatable section.\n"
844		     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
845		     "Note that for example <linux/init.h> contains\n"
846		     "section definitions for use in .S files.\n\n",
847		     modname, sec);
848	}
849}
850
851
852
853#define ALL_INIT_DATA_SECTIONS \
854	".init.setup$", ".init.rodata$", \
855	".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$", \
856	".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
857#define ALL_EXIT_DATA_SECTIONS \
858	".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
859
860#define ALL_INIT_TEXT_SECTIONS \
861	".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
862#define ALL_EXIT_TEXT_SECTIONS \
863	".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
864
865#define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
866	MEM_INIT_SECTIONS
867#define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
868	MEM_EXIT_SECTIONS
869
870#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
871#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
872
873#define DATA_SECTIONS ".data$", ".data.rel$"
874#define TEXT_SECTIONS ".text$"
875
876#define INIT_SECTIONS      ".init.*"
877#define DEV_INIT_SECTIONS  ".devinit.*"
878#define CPU_INIT_SECTIONS  ".cpuinit.*"
879#define MEM_INIT_SECTIONS  ".meminit.*"
880
881#define EXIT_SECTIONS      ".exit.*"
882#define DEV_EXIT_SECTIONS  ".devexit.*"
883#define CPU_EXIT_SECTIONS  ".cpuexit.*"
884#define MEM_EXIT_SECTIONS  ".memexit.*"
885
886/* init data sections */
887static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
888
889/* all init sections */
890static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
891
892/* All init and exit sections (code + data) */
893static const char *init_exit_sections[] =
894	{ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
895
896/* data section */
897static const char *data_sections[] = { DATA_SECTIONS, NULL };
898
899
900/* symbols in .data that may refer to init/exit sections */
901#define DEFAULT_SYMBOL_WHITE_LIST					\
902	"*driver",							\
903	"*_template", /* scsi uses *_template a lot */			\
904	"*_timer",    /* arm uses ops structures named _timer a lot */	\
905	"*_sht",      /* scsi also used *_sht to some extent */		\
906	"*_ops",							\
907	"*_probe",							\
908	"*_probe_one",							\
909	"*_console"
910
911static const char *head_sections[] = { ".head.text*", NULL };
912static const char *linker_symbols[] =
913	{ "__init_begin", "_sinittext", "_einittext", NULL };
914
915enum mismatch {
916	TEXT_TO_ANY_INIT,
917	DATA_TO_ANY_INIT,
918	TEXT_TO_ANY_EXIT,
919	DATA_TO_ANY_EXIT,
920	XXXINIT_TO_SOME_INIT,
921	XXXEXIT_TO_SOME_EXIT,
922	ANY_INIT_TO_ANY_EXIT,
923	ANY_EXIT_TO_ANY_INIT,
924	EXPORT_TO_INIT_EXIT,
925};
926
927struct sectioncheck {
928	const char *fromsec[20];
929	const char *tosec[20];
930	enum mismatch mismatch;
931	const char *symbol_white_list[20];
932};
933
934const struct sectioncheck sectioncheck[] = {
935/* Do not reference init/exit code/data from
936 * normal code and data
937 */
938{
939	.fromsec = { TEXT_SECTIONS, NULL },
940	.tosec   = { ALL_INIT_SECTIONS, NULL },
941	.mismatch = TEXT_TO_ANY_INIT,
942	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
943},
944{
945	.fromsec = { DATA_SECTIONS, NULL },
946	.tosec   = { ALL_XXXINIT_SECTIONS, NULL },
947	.mismatch = DATA_TO_ANY_INIT,
948	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
949},
950{
951	.fromsec = { DATA_SECTIONS, NULL },
952	.tosec   = { INIT_SECTIONS, NULL },
953	.mismatch = DATA_TO_ANY_INIT,
954	.symbol_white_list = {
955		"*_template", "*_timer", "*_sht", "*_ops",
956		"*_probe", "*_probe_one", "*_console", NULL
957	},
958},
959{
960	.fromsec = { TEXT_SECTIONS, NULL },
961	.tosec   = { ALL_EXIT_SECTIONS, NULL },
962	.mismatch = TEXT_TO_ANY_EXIT,
963	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
964},
965{
966	.fromsec = { DATA_SECTIONS, NULL },
967	.tosec   = { ALL_EXIT_SECTIONS, NULL },
968	.mismatch = DATA_TO_ANY_EXIT,
969	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
970},
971/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
972{
973	.fromsec = { ALL_XXXINIT_SECTIONS, NULL },
974	.tosec   = { INIT_SECTIONS, NULL },
975	.mismatch = XXXINIT_TO_SOME_INIT,
976	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
977},
978/* Do not reference cpuinit code/data from meminit code/data */
979{
980	.fromsec = { MEM_INIT_SECTIONS, NULL },
981	.tosec   = { CPU_INIT_SECTIONS, NULL },
982	.mismatch = XXXINIT_TO_SOME_INIT,
983	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
984},
985/* Do not reference meminit code/data from cpuinit code/data */
986{
987	.fromsec = { CPU_INIT_SECTIONS, NULL },
988	.tosec   = { MEM_INIT_SECTIONS, NULL },
989	.mismatch = XXXINIT_TO_SOME_INIT,
990	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
991},
992/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
993{
994	.fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
995	.tosec   = { EXIT_SECTIONS, NULL },
996	.mismatch = XXXEXIT_TO_SOME_EXIT,
997	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
998},
999/* Do not reference cpuexit code/data from memexit code/data */
1000{
1001	.fromsec = { MEM_EXIT_SECTIONS, NULL },
1002	.tosec   = { CPU_EXIT_SECTIONS, NULL },
1003	.mismatch = XXXEXIT_TO_SOME_EXIT,
1004	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1005},
1006/* Do not reference memexit code/data from cpuexit code/data */
1007{
1008	.fromsec = { CPU_EXIT_SECTIONS, NULL },
1009	.tosec   = { MEM_EXIT_SECTIONS, NULL },
1010	.mismatch = XXXEXIT_TO_SOME_EXIT,
1011	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1012},
1013/* Do not use exit code/data from init code */
1014{
1015	.fromsec = { ALL_INIT_SECTIONS, NULL },
1016	.tosec   = { ALL_EXIT_SECTIONS, NULL },
1017	.mismatch = ANY_INIT_TO_ANY_EXIT,
1018	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1019},
1020/* Do not use init code/data from exit code */
1021{
1022	.fromsec = { ALL_EXIT_SECTIONS, NULL },
1023	.tosec   = { ALL_INIT_SECTIONS, NULL },
1024	.mismatch = ANY_EXIT_TO_ANY_INIT,
1025	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1026},
1027/* Do not export init/exit functions or data */
1028{
1029	.fromsec = { "__ksymtab*", NULL },
1030	.tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1031	.mismatch = EXPORT_TO_INIT_EXIT,
1032	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1033}
1034};
1035
1036static const struct sectioncheck *section_mismatch(
1037		const char *fromsec, const char *tosec)
1038{
1039	int i;
1040	int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1041	const struct sectioncheck *check = &sectioncheck[0];
1042
1043	for (i = 0; i < elems; i++) {
1044		if (match(fromsec, check->fromsec) &&
1045		    match(tosec, check->tosec))
1046			return check;
1047		check++;
1048	}
1049	return NULL;
1050}
1051
1052/**
1053 * Whitelist to allow certain references to pass with no warning.
1054 *
1055 * Pattern 1:
1056 *   If a module parameter is declared __initdata and permissions=0
1057 *   then this is legal despite the warning generated.
1058 *   We cannot see value of permissions here, so just ignore
1059 *   this pattern.
1060 *   The pattern is identified by:
1061 *   tosec   = .init.data
1062 *   fromsec = .data*
1063 *   atsym   =__param*
1064 *
1065 * Pattern 1a:
1066 *   module_param_call() ops can refer to __init set function if permissions=0
1067 *   The pattern is identified by:
1068 *   tosec   = .init.text
1069 *   fromsec = .data*
1070 *   atsym   = __param_ops_*
1071 *
1072 * Pattern 2:
1073 *   Many drivers utilise a *driver container with references to
1074 *   add, remove, probe functions etc.
1075 *   These functions may often be marked __devinit and we do not want to
1076 *   warn here.
1077 *   the pattern is identified by:
1078 *   tosec   = init or exit section
1079 *   fromsec = data section
1080 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
1081 *           *probe_one, *_console, *_timer
1082 *
1083 * Pattern 3:
1084 *   Whitelist all references from .head.text to any init section
1085 *
1086 * Pattern 4:
1087 *   Some symbols belong to init section but still it is ok to reference
1088 *   these from non-init sections as these symbols don't have any memory
1089 *   allocated for them and symbol address and value are same. So even
1090 *   if init section is freed, its ok to reference those symbols.
1091 *   For ex. symbols marking the init section boundaries.
1092 *   This pattern is identified by
1093 *   refsymname = __init_begin, _sinittext, _einittext
1094 *
1095 **/
1096static int secref_whitelist(const struct sectioncheck *mismatch,
1097			    const char *fromsec, const char *fromsym,
1098			    const char *tosec, const char *tosym)
1099{
1100	/* Check for pattern 1 */
1101	if (match(tosec, init_data_sections) &&
1102	    match(fromsec, data_sections) &&
1103	    (strncmp(fromsym, "__param", strlen("__param")) == 0))
1104		return 0;
1105
1106	/* Check for pattern 1a */
1107	if (strcmp(tosec, ".init.text") == 0 &&
1108	    match(fromsec, data_sections) &&
1109	    (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1110		return 0;
1111
1112	/* Check for pattern 2 */
1113	if (match(tosec, init_exit_sections) &&
1114	    match(fromsec, data_sections) &&
1115	    match(fromsym, mismatch->symbol_white_list))
1116		return 0;
1117
1118	/* Check for pattern 3 */
1119	if (match(fromsec, head_sections) &&
1120	    match(tosec, init_sections))
1121		return 0;
1122
1123	/* Check for pattern 4 */
1124	if (match(tosym, linker_symbols))
1125		return 0;
1126
1127	return 1;
1128}
1129
1130/**
1131 * Find symbol based on relocation record info.
1132 * In some cases the symbol supplied is a valid symbol so
1133 * return refsym. If st_name != 0 we assume this is a valid symbol.
1134 * In other cases the symbol needs to be looked up in the symbol table
1135 * based on section and address.
1136 *  **/
1137static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1138				Elf_Sym *relsym)
1139{
1140	Elf_Sym *sym;
1141	Elf_Sym *near = NULL;
1142	Elf64_Sword distance = 20;
1143	Elf64_Sword d;
1144	unsigned int relsym_secindex;
1145
1146	if (relsym->st_name != 0)
1147		return relsym;
1148
1149	relsym_secindex = get_secindex(elf, relsym);
1150	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1151		if (get_secindex(elf, sym) != relsym_secindex)
1152			continue;
1153		if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1154			continue;
1155		if (sym->st_value == addr)
1156			return sym;
1157		/* Find a symbol nearby - addr are maybe negative */
1158		d = sym->st_value - addr;
1159		if (d < 0)
1160			d = addr - sym->st_value;
1161		if (d < distance) {
1162			distance = d;
1163			near = sym;
1164		}
1165	}
1166	/* We need a close match */
1167	if (distance < 20)
1168		return near;
1169	else
1170		return NULL;
1171}
1172
1173static inline int is_arm_mapping_symbol(const char *str)
1174{
1175	return str[0] == '$' && strchr("atd", str[1])
1176	       && (str[2] == '\0' || str[2] == '.');
1177}
1178
1179/*
1180 * If there's no name there, ignore it; likewise, ignore it if it's
1181 * one of the magic symbols emitted used by current ARM tools.
1182 *
1183 * Otherwise if find_symbols_between() returns those symbols, they'll
1184 * fail the whitelist tests and cause lots of false alarms ... fixable
1185 * only by merging __exit and __init sections into __text, bloating
1186 * the kernel (which is especially evil on embedded platforms).
1187 */
1188static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1189{
1190	const char *name = elf->strtab + sym->st_name;
1191
1192	if (!name || !strlen(name))
1193		return 0;
1194	return !is_arm_mapping_symbol(name);
1195}
1196
1197/*
1198 * Find symbols before or equal addr and after addr - in the section sec.
1199 * If we find two symbols with equal offset prefer one with a valid name.
1200 * The ELF format may have a better way to detect what type of symbol
1201 * it is, but this works for now.
1202 **/
1203static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1204				 const char *sec)
1205{
1206	Elf_Sym *sym;
1207	Elf_Sym *near = NULL;
1208	Elf_Addr distance = ~0;
1209
1210	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1211		const char *symsec;
1212
1213		if (is_shndx_special(sym->st_shndx))
1214			continue;
1215		symsec = sec_name(elf, get_secindex(elf, sym));
1216		if (strcmp(symsec, sec) != 0)
1217			continue;
1218		if (!is_valid_name(elf, sym))
1219			continue;
1220		if (sym->st_value <= addr) {
1221			if ((addr - sym->st_value) < distance) {
1222				distance = addr - sym->st_value;
1223				near = sym;
1224			} else if ((addr - sym->st_value) == distance) {
1225				near = sym;
1226			}
1227		}
1228	}
1229	return near;
1230}
1231
1232/*
1233 * Convert a section name to the function/data attribute
1234 * .init.text => __init
1235 * .cpuinit.data => __cpudata
1236 * .memexitconst => __memconst
1237 * etc.
1238 *
1239 * The memory of returned value has been allocated on a heap. The user of this
1240 * method should free it after usage.
1241*/
1242static char *sec2annotation(const char *s)
1243{
1244	if (match(s, init_exit_sections)) {
1245		char *p = malloc(20);
1246		char *r = p;
1247
1248		*p++ = '_';
1249		*p++ = '_';
1250		if (*s == '.')
1251			s++;
1252		while (*s && *s != '.')
1253			*p++ = *s++;
1254		*p = '\0';
1255		if (*s == '.')
1256			s++;
1257		if (strstr(s, "rodata") != NULL)
1258			strcat(p, "const ");
1259		else if (strstr(s, "data") != NULL)
1260			strcat(p, "data ");
1261		else
1262			strcat(p, " ");
1263		return r;
1264	} else {
1265		return strdup("");
1266	}
1267}
1268
1269static int is_function(Elf_Sym *sym)
1270{
1271	if (sym)
1272		return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1273	else
1274		return -1;
1275}
1276
1277static void print_section_list(const char * const list[20])
1278{
1279	const char *const *s = list;
1280
1281	while (*s) {
1282		fprintf(stderr, "%s", *s);
1283		s++;
1284		if (*s)
1285			fprintf(stderr, ", ");
1286	}
1287	fprintf(stderr, "\n");
1288}
1289
1290/*
1291 * Print a warning about a section mismatch.
1292 * Try to find symbols near it so user can find it.
1293 * Check whitelist before warning - it may be a false positive.
1294 */
1295static void report_sec_mismatch(const char *modname,
1296				const struct sectioncheck *mismatch,
1297                                const char *fromsec,
1298                                unsigned long long fromaddr,
1299                                const char *fromsym,
1300                                int from_is_func,
1301                                const char *tosec, const char *tosym,
1302                                int to_is_func)
1303{
1304	const char *from, *from_p;
1305	const char *to, *to_p;
1306	char *prl_from;
1307	char *prl_to;
1308
1309	switch (from_is_func) {
1310	case 0: from = "variable"; from_p = "";   break;
1311	case 1: from = "function"; from_p = "()"; break;
1312	default: from = "(unknown reference)"; from_p = ""; break;
1313	}
1314	switch (to_is_func) {
1315	case 0: to = "variable"; to_p = "";   break;
1316	case 1: to = "function"; to_p = "()"; break;
1317	default: to = "(unknown reference)"; to_p = ""; break;
1318	}
1319
1320	sec_mismatch_count++;
1321	if (!sec_mismatch_verbose)
1322		return;
1323
1324	warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1325	     "to the %s %s:%s%s\n",
1326	     modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1327	     tosym, to_p);
1328
1329	switch (mismatch->mismatch) {
1330	case TEXT_TO_ANY_INIT:
1331		prl_from = sec2annotation(fromsec);
1332		prl_to = sec2annotation(tosec);
1333		fprintf(stderr,
1334		"The function %s%s() references\n"
1335		"the %s %s%s%s.\n"
1336		"This is often because %s lacks a %s\n"
1337		"annotation or the annotation of %s is wrong.\n",
1338		prl_from, fromsym,
1339		to, prl_to, tosym, to_p,
1340		fromsym, prl_to, tosym);
1341		free(prl_from);
1342		free(prl_to);
1343		break;
1344	case DATA_TO_ANY_INIT: {
1345		prl_to = sec2annotation(tosec);
1346		fprintf(stderr,
1347		"The variable %s references\n"
1348		"the %s %s%s%s\n"
1349		"If the reference is valid then annotate the\n"
1350		"variable with __init* or __refdata (see linux/init.h) "
1351		"or name the variable:\n",
1352		fromsym, to, prl_to, tosym, to_p);
1353		print_section_list(mismatch->symbol_white_list);
1354		free(prl_to);
1355		break;
1356	}
1357	case TEXT_TO_ANY_EXIT:
1358		prl_to = sec2annotation(tosec);
1359		fprintf(stderr,
1360		"The function %s() references a %s in an exit section.\n"
1361		"Often the %s %s%s has valid usage outside the exit section\n"
1362		"and the fix is to remove the %sannotation of %s.\n",
1363		fromsym, to, to, tosym, to_p, prl_to, tosym);
1364		free(prl_to);
1365		break;
1366	case DATA_TO_ANY_EXIT: {
1367		prl_to = sec2annotation(tosec);
1368		fprintf(stderr,
1369		"The variable %s references\n"
1370		"the %s %s%s%s\n"
1371		"If the reference is valid then annotate the\n"
1372		"variable with __exit* (see linux/init.h) or "
1373		"name the variable:\n",
1374		fromsym, to, prl_to, tosym, to_p);
1375		print_section_list(mismatch->symbol_white_list);
1376		free(prl_to);
1377		break;
1378	}
1379	case XXXINIT_TO_SOME_INIT:
1380	case XXXEXIT_TO_SOME_EXIT:
1381		prl_from = sec2annotation(fromsec);
1382		prl_to = sec2annotation(tosec);
1383		fprintf(stderr,
1384		"The %s %s%s%s references\n"
1385		"a %s %s%s%s.\n"
1386		"If %s is only used by %s then\n"
1387		"annotate %s with a matching annotation.\n",
1388		from, prl_from, fromsym, from_p,
1389		to, prl_to, tosym, to_p,
1390		tosym, fromsym, tosym);
1391		free(prl_from);
1392		free(prl_to);
1393		break;
1394	case ANY_INIT_TO_ANY_EXIT:
1395		prl_from = sec2annotation(fromsec);
1396		prl_to = sec2annotation(tosec);
1397		fprintf(stderr,
1398		"The %s %s%s%s references\n"
1399		"a %s %s%s%s.\n"
1400		"This is often seen when error handling "
1401		"in the init function\n"
1402		"uses functionality in the exit path.\n"
1403		"The fix is often to remove the %sannotation of\n"
1404		"%s%s so it may be used outside an exit section.\n",
1405		from, prl_from, fromsym, from_p,
1406		to, prl_to, tosym, to_p,
1407		prl_to, tosym, to_p);
1408		free(prl_from);
1409		free(prl_to);
1410		break;
1411	case ANY_EXIT_TO_ANY_INIT:
1412		prl_from = sec2annotation(fromsec);
1413		prl_to = sec2annotation(tosec);
1414		fprintf(stderr,
1415		"The %s %s%s%s references\n"
1416		"a %s %s%s%s.\n"
1417		"This is often seen when error handling "
1418		"in the exit function\n"
1419		"uses functionality in the init path.\n"
1420		"The fix is often to remove the %sannotation of\n"
1421		"%s%s so it may be used outside an init section.\n",
1422		from, prl_from, fromsym, from_p,
1423		to, prl_to, tosym, to_p,
1424		prl_to, tosym, to_p);
1425		free(prl_from);
1426		free(prl_to);
1427		break;
1428	case EXPORT_TO_INIT_EXIT:
1429		prl_to = sec2annotation(tosec);
1430		fprintf(stderr,
1431		"The symbol %s is exported and annotated %s\n"
1432		"Fix this by removing the %sannotation of %s "
1433		"or drop the export.\n",
1434		tosym, prl_to, prl_to, tosym);
1435		free(prl_to);
1436		break;
1437	}
1438	fprintf(stderr, "\n");
1439}
1440
1441static void check_section_mismatch(const char *modname, struct elf_info *elf,
1442                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1443{
1444	const char *tosec;
1445	const struct sectioncheck *mismatch;
1446
1447	tosec = sec_name(elf, get_secindex(elf, sym));
1448	mismatch = section_mismatch(fromsec, tosec);
1449	if (mismatch) {
1450		Elf_Sym *to;
1451		Elf_Sym *from;
1452		const char *tosym;
1453		const char *fromsym;
1454
1455		from = find_elf_symbol2(elf, r->r_offset, fromsec);
1456		fromsym = sym_name(elf, from);
1457		to = find_elf_symbol(elf, r->r_addend, sym);
1458		tosym = sym_name(elf, to);
1459
1460		/* check whitelist - we may ignore it */
1461		if (secref_whitelist(mismatch,
1462					fromsec, fromsym, tosec, tosym)) {
1463			report_sec_mismatch(modname, mismatch,
1464			   fromsec, r->r_offset, fromsym,
1465			   is_function(from), tosec, tosym,
1466			   is_function(to));
1467		}
1468	}
1469}
1470
1471static unsigned int *reloc_location(struct elf_info *elf,
1472				    Elf_Shdr *sechdr, Elf_Rela *r)
1473{
1474	Elf_Shdr *sechdrs = elf->sechdrs;
1475	int section = sechdr->sh_info;
1476
1477	return (void *)elf->hdr + sechdrs[section].sh_offset +
1478		r->r_offset;
1479}
1480
1481static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1482{
1483	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1484	unsigned int *location = reloc_location(elf, sechdr, r);
1485
1486	switch (r_typ) {
1487	case R_386_32:
1488		r->r_addend = TO_NATIVE(*location);
1489		break;
1490	case R_386_PC32:
1491		r->r_addend = TO_NATIVE(*location) + 4;
1492		/* For CONFIG_RELOCATABLE=y */
1493		if (elf->hdr->e_type == ET_EXEC)
1494			r->r_addend += r->r_offset;
1495		break;
1496	}
1497	return 0;
1498}
1499
1500static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1501{
1502	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1503
1504	switch (r_typ) {
1505	case R_ARM_ABS32:
1506		/* From ARM ABI: (S + A) | T */
1507		r->r_addend = (int)(long)
1508		              (elf->symtab_start + ELF_R_SYM(r->r_info));
1509		break;
1510	case R_ARM_PC24:
1511		/* From ARM ABI: ((S + A) | T) - P */
1512		r->r_addend = (int)(long)(elf->hdr +
1513		              sechdr->sh_offset +
1514		              (r->r_offset - sechdr->sh_addr));
1515		break;
1516	default:
1517		return 1;
1518	}
1519	return 0;
1520}
1521
1522static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1523{
1524	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1525	unsigned int *location = reloc_location(elf, sechdr, r);
1526	unsigned int inst;
1527
1528	if (r_typ == R_MIPS_HI16)
1529		return 1;	/* skip this */
1530	inst = TO_NATIVE(*location);
1531	switch (r_typ) {
1532	case R_MIPS_LO16:
1533		r->r_addend = inst & 0xffff;
1534		break;
1535	case R_MIPS_26:
1536		r->r_addend = (inst & 0x03ffffff) << 2;
1537		break;
1538	case R_MIPS_32:
1539		r->r_addend = inst;
1540		break;
1541	}
1542	return 0;
1543}
1544
1545static void section_rela(const char *modname, struct elf_info *elf,
1546                         Elf_Shdr *sechdr)
1547{
1548	Elf_Sym  *sym;
1549	Elf_Rela *rela;
1550	Elf_Rela r;
1551	unsigned int r_sym;
1552	const char *fromsec;
1553
1554	Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1555	Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1556
1557	fromsec = sech_name(elf, sechdr);
1558	fromsec += strlen(".rela");
1559	/* if from section (name) is know good then skip it */
1560	if (match(fromsec, section_white_list))
1561		return;
1562
1563	for (rela = start; rela < stop; rela++) {
1564		r.r_offset = TO_NATIVE(rela->r_offset);
1565#if KERNEL_ELFCLASS == ELFCLASS64
1566		if (elf->hdr->e_machine == EM_MIPS) {
1567			unsigned int r_typ;
1568			r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1569			r_sym = TO_NATIVE(r_sym);
1570			r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1571			r.r_info = ELF64_R_INFO(r_sym, r_typ);
1572		} else {
1573			r.r_info = TO_NATIVE(rela->r_info);
1574			r_sym = ELF_R_SYM(r.r_info);
1575		}
1576#else
1577		r.r_info = TO_NATIVE(rela->r_info);
1578		r_sym = ELF_R_SYM(r.r_info);
1579#endif
1580		r.r_addend = TO_NATIVE(rela->r_addend);
1581		sym = elf->symtab_start + r_sym;
1582		/* Skip special sections */
1583		if (is_shndx_special(sym->st_shndx))
1584			continue;
1585		check_section_mismatch(modname, elf, &r, sym, fromsec);
1586	}
1587}
1588
1589static void section_rel(const char *modname, struct elf_info *elf,
1590                        Elf_Shdr *sechdr)
1591{
1592	Elf_Sym *sym;
1593	Elf_Rel *rel;
1594	Elf_Rela r;
1595	unsigned int r_sym;
1596	const char *fromsec;
1597
1598	Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1599	Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1600
1601	fromsec = sech_name(elf, sechdr);
1602	fromsec += strlen(".rel");
1603	/* if from section (name) is know good then skip it */
1604	if (match(fromsec, section_white_list))
1605		return;
1606
1607	for (rel = start; rel < stop; rel++) {
1608		r.r_offset = TO_NATIVE(rel->r_offset);
1609#if KERNEL_ELFCLASS == ELFCLASS64
1610		if (elf->hdr->e_machine == EM_MIPS) {
1611			unsigned int r_typ;
1612			r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1613			r_sym = TO_NATIVE(r_sym);
1614			r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1615			r.r_info = ELF64_R_INFO(r_sym, r_typ);
1616		} else {
1617			r.r_info = TO_NATIVE(rel->r_info);
1618			r_sym = ELF_R_SYM(r.r_info);
1619		}
1620#else
1621		r.r_info = TO_NATIVE(rel->r_info);
1622		r_sym = ELF_R_SYM(r.r_info);
1623#endif
1624		r.r_addend = 0;
1625		switch (elf->hdr->e_machine) {
1626		case EM_386:
1627			if (addend_386_rel(elf, sechdr, &r))
1628				continue;
1629			break;
1630		case EM_ARM:
1631			if (addend_arm_rel(elf, sechdr, &r))
1632				continue;
1633			break;
1634		case EM_MIPS:
1635			if (addend_mips_rel(elf, sechdr, &r))
1636				continue;
1637			break;
1638		}
1639		sym = elf->symtab_start + r_sym;
1640		/* Skip special sections */
1641		if (is_shndx_special(sym->st_shndx))
1642			continue;
1643		check_section_mismatch(modname, elf, &r, sym, fromsec);
1644	}
1645}
1646
1647/**
1648 * A module includes a number of sections that are discarded
1649 * either when loaded or when used as built-in.
1650 * For loaded modules all functions marked __init and all data
1651 * marked __initdata will be discarded when the module has been initialized.
1652 * Likewise for modules used built-in the sections marked __exit
1653 * are discarded because __exit marked function are supposed to be called
1654 * only when a module is unloaded which never happens for built-in modules.
1655 * The check_sec_ref() function traverses all relocation records
1656 * to find all references to a section that reference a section that will
1657 * be discarded and warns about it.
1658 **/
1659static void check_sec_ref(struct module *mod, const char *modname,
1660                          struct elf_info *elf)
1661{
1662	int i;
1663	Elf_Shdr *sechdrs = elf->sechdrs;
1664
1665	/* Walk through all sections */
1666	for (i = 0; i < elf->num_sections; i++) {
1667		check_section(modname, elf, &elf->sechdrs[i]);
1668		/* We want to process only relocation sections and not .init */
1669		if (sechdrs[i].sh_type == SHT_RELA)
1670			section_rela(modname, elf, &elf->sechdrs[i]);
1671		else if (sechdrs[i].sh_type == SHT_REL)
1672			section_rel(modname, elf, &elf->sechdrs[i]);
1673	}
1674}
1675
1676static void read_symbols(char *modname)
1677{
1678	const char *symname;
1679	char *version;
1680	char *license;
1681	struct module *mod;
1682	struct elf_info info = { };
1683	Elf_Sym *sym;
1684
1685	if (!parse_elf(&info, modname))
1686		return;
1687
1688	mod = new_module(modname);
1689
1690	/* When there's no vmlinux, don't print warnings about
1691	 * unresolved symbols (since there'll be too many ;) */
1692	if (is_vmlinux(modname)) {
1693		have_vmlinux = 1;
1694		mod->skip = 1;
1695	}
1696
1697	license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1698	if (info.modinfo && !license && !is_vmlinux(modname))
1699		warn("modpost: missing MODULE_LICENSE() in %s\n"
1700		     "see include/linux/module.h for "
1701		     "more information\n", modname);
1702	while (license) {
1703		if (license_is_gpl_compatible(license))
1704			mod->gpl_compatible = 1;
1705		else {
1706			mod->gpl_compatible = 0;
1707			break;
1708		}
1709		license = get_next_modinfo(info.modinfo, info.modinfo_len,
1710					   "license", license);
1711	}
1712
1713	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1714		symname = info.strtab + sym->st_name;
1715
1716		handle_modversions(mod, &info, sym, symname);
1717		handle_moddevtable(mod, &info, sym, symname);
1718	}
1719	if (!is_vmlinux(modname) ||
1720	     (is_vmlinux(modname) && vmlinux_section_warnings))
1721		check_sec_ref(mod, modname, &info);
1722
1723	version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1724	if (version)
1725		maybe_frob_rcs_version(modname, version, info.modinfo,
1726				       version - (char *)info.hdr);
1727	if (version || (all_versions && !is_vmlinux(modname)))
1728		get_src_version(modname, mod->srcversion,
1729				sizeof(mod->srcversion)-1);
1730
1731	parse_elf_finish(&info);
1732
1733	/* Our trick to get versioning for module struct etc. - it's
1734	 * never passed as an argument to an exported function, so
1735	 * the automatic versioning doesn't pick it up, but it's really
1736	 * important anyhow */
1737	if (modversions)
1738		mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1739}
1740
1741#define SZ 500
1742
1743/* We first write the generated file into memory using the
1744 * following helper, then compare to the file on disk and
1745 * only update the later if anything changed */
1746
1747void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1748						      const char *fmt, ...)
1749{
1750	char tmp[SZ];
1751	int len;
1752	va_list ap;
1753
1754	va_start(ap, fmt);
1755	len = vsnprintf(tmp, SZ, fmt, ap);
1756	buf_write(buf, tmp, len);
1757	va_end(ap);
1758}
1759
1760void buf_write(struct buffer *buf, const char *s, int len)
1761{
1762	if (buf->size - buf->pos < len) {
1763		buf->size += len + SZ;
1764		buf->p = realloc(buf->p, buf->size);
1765	}
1766	strncpy(buf->p + buf->pos, s, len);
1767	buf->pos += len;
1768}
1769
1770static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1771{
1772	const char *e = is_vmlinux(m) ?"":".ko";
1773
1774	switch (exp) {
1775	case export_gpl:
1776		fatal("modpost: GPL-incompatible module %s%s "
1777		      "uses GPL-only symbol '%s'\n", m, e, s);
1778		break;
1779	case export_unused_gpl:
1780		fatal("modpost: GPL-incompatible module %s%s "
1781		      "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1782		break;
1783	case export_gpl_future:
1784		warn("modpost: GPL-incompatible module %s%s "
1785		      "uses future GPL-only symbol '%s'\n", m, e, s);
1786		break;
1787	case export_plain:
1788	case export_unused:
1789	case export_unknown:
1790		/* ignore */
1791		break;
1792	}
1793}
1794
1795static void check_for_unused(enum export exp, const char *m, const char *s)
1796{
1797	const char *e = is_vmlinux(m) ?"":".ko";
1798
1799	switch (exp) {
1800	case export_unused:
1801	case export_unused_gpl:
1802		warn("modpost: module %s%s "
1803		      "uses symbol '%s' marked UNUSED\n", m, e, s);
1804		break;
1805	default:
1806		/* ignore */
1807		break;
1808	}
1809}
1810
1811static void check_exports(struct module *mod)
1812{
1813	struct symbol *s, *exp;
1814
1815	for (s = mod->unres; s; s = s->next) {
1816		const char *basename;
1817		exp = find_symbol(s->name);
1818		if (!exp || exp->module == mod)
1819			continue;
1820		basename = strrchr(mod->name, '/');
1821		if (basename)
1822			basename++;
1823		else
1824			basename = mod->name;
1825		if (!mod->gpl_compatible)
1826			check_for_gpl_usage(exp->export, basename, exp->name);
1827		check_for_unused(exp->export, basename, exp->name);
1828	}
1829}
1830
1831/**
1832 * Header for the generated file
1833 **/
1834static void add_header(struct buffer *b, struct module *mod)
1835{
1836	buf_printf(b, "#include <linux/module.h>\n");
1837	buf_printf(b, "#include <linux/vermagic.h>\n");
1838	buf_printf(b, "#include <linux/compiler.h>\n");
1839	buf_printf(b, "\n");
1840	buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1841	buf_printf(b, "\n");
1842	buf_printf(b, "struct module __this_module\n");
1843	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1844	buf_printf(b, " .name = KBUILD_MODNAME,\n");
1845	if (mod->has_init)
1846		buf_printf(b, " .init = init_module,\n");
1847	if (mod->has_cleanup)
1848		buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1849			      " .exit = cleanup_module,\n"
1850			      "#endif\n");
1851	buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1852	buf_printf(b, "};\n");
1853}
1854
1855static void add_staging_flag(struct buffer *b, const char *name)
1856{
1857	static const char *staging_dir = "drivers/staging";
1858
1859	if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1860		buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1861}
1862
1863/**
1864 * Record CRCs for unresolved symbols
1865 **/
1866static int add_versions(struct buffer *b, struct module *mod)
1867{
1868	struct symbol *s, *exp;
1869	int err = 0;
1870
1871	for (s = mod->unres; s; s = s->next) {
1872		exp = find_symbol(s->name);
1873		if (!exp || exp->module == mod) {
1874			if (have_vmlinux && !s->weak) {
1875				if (warn_unresolved) {
1876					warn("\"%s\" [%s.ko] undefined!\n",
1877					     s->name, mod->name);
1878				} else {
1879					merror("\"%s\" [%s.ko] undefined!\n",
1880					          s->name, mod->name);
1881					err = 1;
1882				}
1883			}
1884			continue;
1885		}
1886		s->module = exp->module;
1887		s->crc_valid = exp->crc_valid;
1888		s->crc = exp->crc;
1889	}
1890
1891	if (!modversions)
1892		return err;
1893
1894	buf_printf(b, "\n");
1895	buf_printf(b, "static const struct modversion_info ____versions[]\n");
1896	buf_printf(b, "__used\n");
1897	buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1898
1899	for (s = mod->unres; s; s = s->next) {
1900		if (!s->module)
1901			continue;
1902		if (!s->crc_valid) {
1903			warn("\"%s\" [%s.ko] has no CRC!\n",
1904				s->name, mod->name);
1905			continue;
1906		}
1907		buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1908	}
1909
1910	buf_printf(b, "};\n");
1911
1912	return err;
1913}
1914
1915static void add_depends(struct buffer *b, struct module *mod,
1916			struct module *modules)
1917{
1918	struct symbol *s;
1919	struct module *m;
1920	int first = 1;
1921
1922	for (m = modules; m; m = m->next)
1923		m->seen = is_vmlinux(m->name);
1924
1925	buf_printf(b, "\n");
1926	buf_printf(b, "static const char __module_depends[]\n");
1927	buf_printf(b, "__used\n");
1928	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1929	buf_printf(b, "\"depends=");
1930	for (s = mod->unres; s; s = s->next) {
1931		const char *p;
1932		if (!s->module)
1933			continue;
1934
1935		if (s->module->seen)
1936			continue;
1937
1938		s->module->seen = 1;
1939		p = strrchr(s->module->name, '/');
1940		if (p)
1941			p++;
1942		else
1943			p = s->module->name;
1944		buf_printf(b, "%s%s", first ? "" : ",", p);
1945		first = 0;
1946	}
1947	buf_printf(b, "\";\n");
1948}
1949
1950static void add_srcversion(struct buffer *b, struct module *mod)
1951{
1952	if (mod->srcversion[0]) {
1953		buf_printf(b, "\n");
1954		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1955			   mod->srcversion);
1956	}
1957}
1958
1959static void write_if_changed(struct buffer *b, const char *fname)
1960{
1961	char *tmp;
1962	FILE *file;
1963	struct stat st;
1964
1965	file = fopen(fname, "r");
1966	if (!file)
1967		goto write;
1968
1969	if (fstat(fileno(file), &st) < 0)
1970		goto close_write;
1971
1972	if (st.st_size != b->pos)
1973		goto close_write;
1974
1975	tmp = NOFAIL(malloc(b->pos));
1976	if (fread(tmp, 1, b->pos, file) != b->pos)
1977		goto free_write;
1978
1979	if (memcmp(tmp, b->p, b->pos) != 0)
1980		goto free_write;
1981
1982	free(tmp);
1983	fclose(file);
1984	return;
1985
1986 free_write:
1987	free(tmp);
1988 close_write:
1989	fclose(file);
1990 write:
1991	file = fopen(fname, "w");
1992	if (!file) {
1993		perror(fname);
1994		exit(1);
1995	}
1996	if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1997		perror(fname);
1998		exit(1);
1999	}
2000	fclose(file);
2001}
2002
2003/* parse Module.symvers file. line format:
2004 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2005 **/
2006static void read_dump(const char *fname, unsigned int kernel)
2007{
2008	unsigned long size, pos = 0;
2009	void *file = grab_file(fname, &size);
2010	char *line;
2011
2012	if (!file)
2013		/* No symbol versions, silently ignore */
2014		return;
2015
2016	while ((line = get_next_line(&pos, file, size))) {
2017		char *symname, *modname, *d, *export, *end;
2018		unsigned int crc;
2019		struct module *mod;
2020		struct symbol *s;
2021
2022		if (!(symname = strchr(line, '\t')))
2023			goto fail;
2024		*symname++ = '\0';
2025		if (!(modname = strchr(symname, '\t')))
2026			goto fail;
2027		*modname++ = '\0';
2028		if ((export = strchr(modname, '\t')) != NULL)
2029			*export++ = '\0';
2030		if (export && ((end = strchr(export, '\t')) != NULL))
2031			*end = '\0';
2032		crc = strtoul(line, &d, 16);
2033		if (*symname == '\0' || *modname == '\0' || *d != '\0')
2034			goto fail;
2035		mod = find_module(modname);
2036		if (!mod) {
2037			if (is_vmlinux(modname))
2038				have_vmlinux = 1;
2039			mod = new_module(modname);
2040			mod->skip = 1;
2041		}
2042		s = sym_add_exported(symname, mod, export_no(export));
2043		s->kernel    = kernel;
2044		s->preloaded = 1;
2045		sym_update_crc(symname, mod, crc, export_no(export));
2046	}
2047	return;
2048fail:
2049	fatal("parse error in symbol dump file\n");
2050}
2051
2052/* For normal builds always dump all symbols.
2053 * For external modules only dump symbols
2054 * that are not read from kernel Module.symvers.
2055 **/
2056static int dump_sym(struct symbol *sym)
2057{
2058	if (!external_module)
2059		return 1;
2060	if (sym->vmlinux || sym->kernel)
2061		return 0;
2062	return 1;
2063}
2064
2065static void write_dump(const char *fname)
2066{
2067	struct buffer buf = { };
2068	struct symbol *symbol;
2069	int n;
2070
2071	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2072		symbol = symbolhash[n];
2073		while (symbol) {
2074			if (dump_sym(symbol))
2075				buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2076					symbol->crc, symbol->name,
2077					symbol->module->name,
2078					export_str(symbol->export));
2079			symbol = symbol->next;
2080		}
2081	}
2082	write_if_changed(&buf, fname);
2083}
2084
2085struct ext_sym_list {
2086	struct ext_sym_list *next;
2087	const char *file;
2088};
2089
2090int main(int argc, char **argv)
2091{
2092	struct module *mod;
2093	struct buffer buf = { };
2094	char *kernel_read = NULL, *module_read = NULL;
2095	char *dump_write = NULL;
2096	int opt;
2097	int err;
2098	struct ext_sym_list *extsym_iter;
2099	struct ext_sym_list *extsym_start = NULL;
2100
2101	while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2102		switch (opt) {
2103		case 'i':
2104			kernel_read = optarg;
2105			break;
2106		case 'I':
2107			module_read = optarg;
2108			external_module = 1;
2109			break;
2110		case 'c':
2111			cross_build = 1;
2112			break;
2113		case 'e':
2114			external_module = 1;
2115			extsym_iter =
2116			   NOFAIL(malloc(sizeof(*extsym_iter)));
2117			extsym_iter->next = extsym_start;
2118			extsym_iter->file = optarg;
2119			extsym_start = extsym_iter;
2120			break;
2121		case 'm':
2122			modversions = 1;
2123			break;
2124		case 'o':
2125			dump_write = optarg;
2126			break;
2127		case 'a':
2128			all_versions = 1;
2129			break;
2130		case 's':
2131			vmlinux_section_warnings = 0;
2132			break;
2133		case 'S':
2134			sec_mismatch_verbose = 0;
2135			break;
2136		case 'w':
2137			warn_unresolved = 1;
2138			break;
2139		default:
2140			exit(1);
2141		}
2142	}
2143
2144	if (kernel_read)
2145		read_dump(kernel_read, 1);
2146	if (module_read)
2147		read_dump(module_read, 0);
2148	while (extsym_start) {
2149		read_dump(extsym_start->file, 0);
2150		extsym_iter = extsym_start->next;
2151		free(extsym_start);
2152		extsym_start = extsym_iter;
2153	}
2154
2155	while (optind < argc)
2156		read_symbols(argv[optind++]);
2157
2158	for (mod = modules; mod; mod = mod->next) {
2159		if (mod->skip)
2160			continue;
2161		check_exports(mod);
2162	}
2163
2164	err = 0;
2165
2166	for (mod = modules; mod; mod = mod->next) {
2167		char fname[strlen(mod->name) + 10];
2168
2169		if (mod->skip)
2170			continue;
2171
2172		buf.pos = 0;
2173
2174		add_header(&buf, mod);
2175		add_staging_flag(&buf, mod->name);
2176		err |= add_versions(&buf, mod);
2177		add_depends(&buf, mod, modules);
2178		add_moddevtable(&buf, mod);
2179		add_srcversion(&buf, mod);
2180
2181		sprintf(fname, "%s.mod.c", mod->name);
2182		write_if_changed(&buf, fname);
2183	}
2184
2185	if (dump_write)
2186		write_dump(dump_write);
2187	if (sec_mismatch_count && !sec_mismatch_verbose)
2188		warn("modpost: Found %d section mismatch(es).\n"
2189		     "To see full details build your kernel with:\n"
2190		     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2191		     sec_mismatch_count);
2192
2193	return err;
2194}
2195