projects/linux·blob v2.6.26 · refs

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