Merge branch 'for-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj...
[linux-2.6.git] / scripts / mod / modpost.c
blob8247979e8f64dd2eef5671544d3b39e8ed3487fc
1 /* Postprocess module symbol versions
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
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
11 * Usage: modpost vmlinux module1.o module2.o ...
14 #define _GNU_SOURCE
15 #include <stdio.h>
16 #include <ctype.h>
17 #include <string.h>
18 #include <limits.h>
19 #include <stdbool.h>
20 #include "modpost.h"
21 #include "../../include/generated/autoconf.h"
22 #include "../../include/linux/license.h"
23 #include "../../include/linux/export.h"
25 /* Are we using CONFIG_MODVERSIONS? */
26 int modversions = 0;
27 /* Warn about undefined symbols? (do so if we have vmlinux) */
28 int have_vmlinux = 0;
29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
30 static int all_versions = 0;
31 /* If we are modposting external module set to 1 */
32 static int external_module = 0;
33 /* Warn about section mismatch in vmlinux if set to 1 */
34 static int vmlinux_section_warnings = 1;
35 /* Only warn about unresolved symbols */
36 static int warn_unresolved = 0;
37 /* How a symbol is exported */
38 static int sec_mismatch_count = 0;
39 static int sec_mismatch_verbose = 1;
41 enum export {
42 export_plain, export_unused, export_gpl,
43 export_unused_gpl, export_gpl_future, export_unknown
46 #define PRINTF __attribute__ ((format (printf, 1, 2)))
48 PRINTF void fatal(const char *fmt, ...)
50 va_list arglist;
52 fprintf(stderr, "FATAL: ");
54 va_start(arglist, fmt);
55 vfprintf(stderr, fmt, arglist);
56 va_end(arglist);
58 exit(1);
61 PRINTF void warn(const char *fmt, ...)
63 va_list arglist;
65 fprintf(stderr, "WARNING: ");
67 va_start(arglist, fmt);
68 vfprintf(stderr, fmt, arglist);
69 va_end(arglist);
72 PRINTF void merror(const char *fmt, ...)
74 va_list arglist;
76 fprintf(stderr, "ERROR: ");
78 va_start(arglist, fmt);
79 vfprintf(stderr, fmt, arglist);
80 va_end(arglist);
83 static inline bool strends(const char *str, const char *postfix)
85 if (strlen(str) < strlen(postfix))
86 return false;
88 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
91 static int is_vmlinux(const char *modname)
93 const char *myname;
95 myname = strrchr(modname, '/');
96 if (myname)
97 myname++;
98 else
99 myname = modname;
101 return (strcmp(myname, "vmlinux") == 0) ||
102 (strcmp(myname, "vmlinux.o") == 0);
105 void *do_nofail(void *ptr, const char *expr)
107 if (!ptr)
108 fatal("modpost: Memory allocation failure: %s.\n", expr);
110 return ptr;
113 /* A list of all modules we processed */
114 static struct module *modules;
116 static struct module *find_module(char *modname)
118 struct module *mod;
120 for (mod = modules; mod; mod = mod->next)
121 if (strcmp(mod->name, modname) == 0)
122 break;
123 return mod;
126 static struct module *new_module(const char *modname)
128 struct module *mod;
129 char *p;
131 mod = NOFAIL(malloc(sizeof(*mod)));
132 memset(mod, 0, sizeof(*mod));
133 p = NOFAIL(strdup(modname));
135 /* strip trailing .o */
136 if (strends(p, ".o")) {
137 p[strlen(p) - 2] = '\0';
138 mod->is_dot_o = 1;
141 /* add to list */
142 mod->name = p;
143 mod->gpl_compatible = -1;
144 mod->next = modules;
145 modules = mod;
147 return mod;
150 /* A hash of all exported symbols,
151 * struct symbol is also used for lists of unresolved symbols */
153 #define SYMBOL_HASH_SIZE 1024
155 struct symbol {
156 struct symbol *next;
157 struct module *module;
158 unsigned int crc;
159 int crc_valid;
160 unsigned int weak:1;
161 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
162 unsigned int kernel:1; /* 1 if symbol is from kernel
163 * (only for external modules) **/
164 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
165 enum export export; /* Type of export */
166 char name[0];
169 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
171 /* This is based on the hash agorithm from gdbm, via tdb */
172 static inline unsigned int tdb_hash(const char *name)
174 unsigned value; /* Used to compute the hash value. */
175 unsigned i; /* Used to cycle through random values. */
177 /* Set the initial value from the key size. */
178 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
179 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
181 return (1103515243 * value + 12345);
185 * Allocate a new symbols for use in the hash of exported symbols or
186 * the list of unresolved symbols per module
188 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
189 struct symbol *next)
191 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
193 memset(s, 0, sizeof(*s));
194 strcpy(s->name, name);
195 s->weak = weak;
196 s->next = next;
197 return s;
200 /* For the hash of exported symbols */
201 static struct symbol *new_symbol(const char *name, struct module *module,
202 enum export export)
204 unsigned int hash;
205 struct symbol *new;
207 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
208 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
209 new->module = module;
210 new->export = export;
211 return new;
214 static struct symbol *find_symbol(const char *name)
216 struct symbol *s;
218 /* For our purposes, .foo matches foo. PPC64 needs this. */
219 if (name[0] == '.')
220 name++;
222 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
223 if (strcmp(s->name, name) == 0)
224 return s;
226 return NULL;
229 static struct {
230 const char *str;
231 enum export export;
232 } export_list[] = {
233 { .str = "EXPORT_SYMBOL", .export = export_plain },
234 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
235 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
236 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
237 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
238 { .str = "(unknown)", .export = export_unknown },
242 static const char *export_str(enum export ex)
244 return export_list[ex].str;
247 static enum export export_no(const char *s)
249 int i;
251 if (!s)
252 return export_unknown;
253 for (i = 0; export_list[i].export != export_unknown; i++) {
254 if (strcmp(export_list[i].str, s) == 0)
255 return export_list[i].export;
257 return export_unknown;
260 static const char *sec_name(struct elf_info *elf, int secindex);
262 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
264 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
266 const char *secname = sec_name(elf, sec);
268 if (strstarts(secname, "___ksymtab+"))
269 return export_plain;
270 else if (strstarts(secname, "___ksymtab_unused+"))
271 return export_unused;
272 else if (strstarts(secname, "___ksymtab_gpl+"))
273 return export_gpl;
274 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
275 return export_unused_gpl;
276 else if (strstarts(secname, "___ksymtab_gpl_future+"))
277 return export_gpl_future;
278 else
279 return export_unknown;
282 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
284 if (sec == elf->export_sec)
285 return export_plain;
286 else if (sec == elf->export_unused_sec)
287 return export_unused;
288 else if (sec == elf->export_gpl_sec)
289 return export_gpl;
290 else if (sec == elf->export_unused_gpl_sec)
291 return export_unused_gpl;
292 else if (sec == elf->export_gpl_future_sec)
293 return export_gpl_future;
294 else
295 return export_unknown;
299 * Add an exported symbol - it may have already been added without a
300 * CRC, in this case just update the CRC
302 static struct symbol *sym_add_exported(const char *name, struct module *mod,
303 enum export export)
305 struct symbol *s = find_symbol(name);
307 if (!s) {
308 s = new_symbol(name, mod, export);
309 } else {
310 if (!s->preloaded) {
311 warn("%s: '%s' exported twice. Previous export "
312 "was in %s%s\n", mod->name, name,
313 s->module->name,
314 is_vmlinux(s->module->name) ?"":".ko");
315 } else {
316 /* In case Modules.symvers was out of date */
317 s->module = mod;
320 s->preloaded = 0;
321 s->vmlinux = is_vmlinux(mod->name);
322 s->kernel = 0;
323 s->export = export;
324 return s;
327 static void sym_update_crc(const char *name, struct module *mod,
328 unsigned int crc, enum export export)
330 struct symbol *s = find_symbol(name);
332 if (!s)
333 s = new_symbol(name, mod, export);
334 s->crc = crc;
335 s->crc_valid = 1;
338 void *grab_file(const char *filename, unsigned long *size)
340 struct stat st;
341 void *map = MAP_FAILED;
342 int fd;
344 fd = open(filename, O_RDONLY);
345 if (fd < 0)
346 return NULL;
347 if (fstat(fd, &st))
348 goto failed;
350 *size = st.st_size;
351 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
353 failed:
354 close(fd);
355 if (map == MAP_FAILED)
356 return NULL;
357 return map;
361 * Return a copy of the next line in a mmap'ed file.
362 * spaces in the beginning of the line is trimmed away.
363 * Return a pointer to a static buffer.
365 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
367 static char line[4096];
368 int skip = 1;
369 size_t len = 0;
370 signed char *p = (signed char *)file + *pos;
371 char *s = line;
373 for (; *pos < size ; (*pos)++) {
374 if (skip && isspace(*p)) {
375 p++;
376 continue;
378 skip = 0;
379 if (*p != '\n' && (*pos < size)) {
380 len++;
381 *s++ = *p++;
382 if (len > 4095)
383 break; /* Too long, stop */
384 } else {
385 /* End of string */
386 *s = '\0';
387 return line;
390 /* End of buffer */
391 return NULL;
394 void release_file(void *file, unsigned long size)
396 munmap(file, size);
399 static int parse_elf(struct elf_info *info, const char *filename)
401 unsigned int i;
402 Elf_Ehdr *hdr;
403 Elf_Shdr *sechdrs;
404 Elf_Sym *sym;
405 const char *secstrings;
406 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
408 hdr = grab_file(filename, &info->size);
409 if (!hdr) {
410 perror(filename);
411 exit(1);
413 info->hdr = hdr;
414 if (info->size < sizeof(*hdr)) {
415 /* file too small, assume this is an empty .o file */
416 return 0;
418 /* Is this a valid ELF file? */
419 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
420 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
421 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
422 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
423 /* Not an ELF file - silently ignore it */
424 return 0;
426 /* Fix endianness in ELF header */
427 hdr->e_type = TO_NATIVE(hdr->e_type);
428 hdr->e_machine = TO_NATIVE(hdr->e_machine);
429 hdr->e_version = TO_NATIVE(hdr->e_version);
430 hdr->e_entry = TO_NATIVE(hdr->e_entry);
431 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
432 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
433 hdr->e_flags = TO_NATIVE(hdr->e_flags);
434 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
435 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
436 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
437 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
438 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
439 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
440 sechdrs = (void *)hdr + hdr->e_shoff;
441 info->sechdrs = sechdrs;
443 /* Check if file offset is correct */
444 if (hdr->e_shoff > info->size) {
445 fatal("section header offset=%lu in file '%s' is bigger than "
446 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
447 filename, info->size);
448 return 0;
451 if (hdr->e_shnum == SHN_UNDEF) {
453 * There are more than 64k sections,
454 * read count from .sh_size.
456 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
458 else {
459 info->num_sections = hdr->e_shnum;
461 if (hdr->e_shstrndx == SHN_XINDEX) {
462 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
464 else {
465 info->secindex_strings = hdr->e_shstrndx;
468 /* Fix endianness in section headers */
469 for (i = 0; i < info->num_sections; i++) {
470 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
471 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
472 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
473 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
474 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
475 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
476 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
477 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
478 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
479 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
481 /* Find symbol table. */
482 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
483 for (i = 1; i < info->num_sections; i++) {
484 const char *secname;
485 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
487 if (!nobits && sechdrs[i].sh_offset > info->size) {
488 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
489 "sizeof(*hrd)=%zu\n", filename,
490 (unsigned long)sechdrs[i].sh_offset,
491 sizeof(*hdr));
492 return 0;
494 secname = secstrings + sechdrs[i].sh_name;
495 if (strcmp(secname, ".modinfo") == 0) {
496 if (nobits)
497 fatal("%s has NOBITS .modinfo\n", filename);
498 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
499 info->modinfo_len = sechdrs[i].sh_size;
500 } else if (strcmp(secname, "__ksymtab") == 0)
501 info->export_sec = i;
502 else if (strcmp(secname, "__ksymtab_unused") == 0)
503 info->export_unused_sec = i;
504 else if (strcmp(secname, "__ksymtab_gpl") == 0)
505 info->export_gpl_sec = i;
506 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
507 info->export_unused_gpl_sec = i;
508 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
509 info->export_gpl_future_sec = i;
511 if (sechdrs[i].sh_type == SHT_SYMTAB) {
512 unsigned int sh_link_idx;
513 symtab_idx = i;
514 info->symtab_start = (void *)hdr +
515 sechdrs[i].sh_offset;
516 info->symtab_stop = (void *)hdr +
517 sechdrs[i].sh_offset + sechdrs[i].sh_size;
518 sh_link_idx = sechdrs[i].sh_link;
519 info->strtab = (void *)hdr +
520 sechdrs[sh_link_idx].sh_offset;
523 /* 32bit section no. table? ("more than 64k sections") */
524 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
525 symtab_shndx_idx = i;
526 info->symtab_shndx_start = (void *)hdr +
527 sechdrs[i].sh_offset;
528 info->symtab_shndx_stop = (void *)hdr +
529 sechdrs[i].sh_offset + sechdrs[i].sh_size;
532 if (!info->symtab_start)
533 fatal("%s has no symtab?\n", filename);
535 /* Fix endianness in symbols */
536 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
537 sym->st_shndx = TO_NATIVE(sym->st_shndx);
538 sym->st_name = TO_NATIVE(sym->st_name);
539 sym->st_value = TO_NATIVE(sym->st_value);
540 sym->st_size = TO_NATIVE(sym->st_size);
543 if (symtab_shndx_idx != ~0U) {
544 Elf32_Word *p;
545 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
546 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
547 filename, sechdrs[symtab_shndx_idx].sh_link,
548 symtab_idx);
549 /* Fix endianness */
550 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
551 p++)
552 *p = TO_NATIVE(*p);
555 return 1;
558 static void parse_elf_finish(struct elf_info *info)
560 release_file(info->hdr, info->size);
563 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
565 /* ignore __this_module, it will be resolved shortly */
566 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
567 return 1;
568 /* ignore global offset table */
569 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
570 return 1;
571 if (info->hdr->e_machine == EM_PPC)
572 /* Special register function linked on all modules during final link of .ko */
573 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
574 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
575 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
576 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
577 return 1;
578 if (info->hdr->e_machine == EM_PPC64)
579 /* Special register function linked on all modules during final link of .ko */
580 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
581 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
582 return 1;
583 /* Do not ignore this symbol */
584 return 0;
587 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
588 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
590 static void handle_modversions(struct module *mod, struct elf_info *info,
591 Elf_Sym *sym, const char *symname)
593 unsigned int crc;
594 enum export export;
596 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
597 strncmp(symname, "__ksymtab", 9) == 0)
598 export = export_from_secname(info, get_secindex(info, sym));
599 else
600 export = export_from_sec(info, get_secindex(info, sym));
602 switch (sym->st_shndx) {
603 case SHN_COMMON:
604 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
605 break;
606 case SHN_ABS:
607 /* CRC'd symbol */
608 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
609 crc = (unsigned int) sym->st_value;
610 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
611 export);
613 break;
614 case SHN_UNDEF:
615 /* undefined symbol */
616 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
617 ELF_ST_BIND(sym->st_info) != STB_WEAK)
618 break;
619 if (ignore_undef_symbol(info, symname))
620 break;
621 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
622 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
623 /* add compatibility with older glibc */
624 #ifndef STT_SPARC_REGISTER
625 #define STT_SPARC_REGISTER STT_REGISTER
626 #endif
627 if (info->hdr->e_machine == EM_SPARC ||
628 info->hdr->e_machine == EM_SPARCV9) {
629 /* Ignore register directives. */
630 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
631 break;
632 if (symname[0] == '.') {
633 char *munged = strdup(symname);
634 munged[0] = '_';
635 munged[1] = toupper(munged[1]);
636 symname = munged;
639 #endif
641 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
642 if (symname[0] != '_')
643 break;
644 else
645 symname++;
646 #endif
647 mod->unres = alloc_symbol(symname,
648 ELF_ST_BIND(sym->st_info) == STB_WEAK,
649 mod->unres);
650 break;
651 default:
652 /* All exported symbols */
653 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
654 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
655 export);
657 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
658 mod->has_init = 1;
659 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
660 mod->has_cleanup = 1;
661 break;
666 * Parse tag=value strings from .modinfo section
668 static char *next_string(char *string, unsigned long *secsize)
670 /* Skip non-zero chars */
671 while (string[0]) {
672 string++;
673 if ((*secsize)-- <= 1)
674 return NULL;
677 /* Skip any zero padding. */
678 while (!string[0]) {
679 string++;
680 if ((*secsize)-- <= 1)
681 return NULL;
683 return string;
686 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
687 const char *tag, char *info)
689 char *p;
690 unsigned int taglen = strlen(tag);
691 unsigned long size = modinfo_len;
693 if (info) {
694 size -= info - (char *)modinfo;
695 modinfo = next_string(info, &size);
698 for (p = modinfo; p; p = next_string(p, &size)) {
699 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
700 return p + taglen + 1;
702 return NULL;
705 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
706 const char *tag)
709 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
713 * Test if string s ends in string sub
714 * return 0 if match
716 static int strrcmp(const char *s, const char *sub)
718 int slen, sublen;
720 if (!s || !sub)
721 return 1;
723 slen = strlen(s);
724 sublen = strlen(sub);
726 if ((slen == 0) || (sublen == 0))
727 return 1;
729 if (sublen > slen)
730 return 1;
732 return memcmp(s + slen - sublen, sub, sublen);
735 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
737 if (sym)
738 return elf->strtab + sym->st_name;
739 else
740 return "(unknown)";
743 static const char *sec_name(struct elf_info *elf, int secindex)
745 Elf_Shdr *sechdrs = elf->sechdrs;
746 return (void *)elf->hdr +
747 elf->sechdrs[elf->secindex_strings].sh_offset +
748 sechdrs[secindex].sh_name;
751 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
753 return (void *)elf->hdr +
754 elf->sechdrs[elf->secindex_strings].sh_offset +
755 sechdr->sh_name;
758 /* if sym is empty or point to a string
759 * like ".[0-9]+" then return 1.
760 * This is the optional prefix added by ld to some sections
762 static int number_prefix(const char *sym)
764 if (*sym++ == '\0')
765 return 1;
766 if (*sym != '.')
767 return 0;
768 do {
769 char c = *sym++;
770 if (c < '0' || c > '9')
771 return 0;
772 } while (*sym);
773 return 1;
776 /* The pattern is an array of simple patterns.
777 * "foo" will match an exact string equal to "foo"
778 * "*foo" will match a string that ends with "foo"
779 * "foo*" will match a string that begins with "foo"
780 * "foo$" will match a string equal to "foo" or "foo.1"
781 * where the '1' can be any number including several digits.
782 * The $ syntax is for sections where ld append a dot number
783 * to make section name unique.
785 static int match(const char *sym, const char * const pat[])
787 const char *p;
788 while (*pat) {
789 p = *pat++;
790 const char *endp = p + strlen(p) - 1;
792 /* "*foo" */
793 if (*p == '*') {
794 if (strrcmp(sym, p + 1) == 0)
795 return 1;
797 /* "foo*" */
798 else if (*endp == '*') {
799 if (strncmp(sym, p, strlen(p) - 1) == 0)
800 return 1;
802 /* "foo$" */
803 else if (*endp == '$') {
804 if (strncmp(sym, p, strlen(p) - 1) == 0) {
805 if (number_prefix(sym + strlen(p) - 1))
806 return 1;
809 /* no wildcards */
810 else {
811 if (strcmp(p, sym) == 0)
812 return 1;
815 /* no match */
816 return 0;
819 /* sections that we do not want to do full section mismatch check on */
820 static const char *section_white_list[] =
822 ".comment*",
823 ".debug*",
824 ".cranges", /* sh64 */
825 ".zdebug*", /* Compressed debug sections. */
826 ".GCC-command-line", /* mn10300 */
827 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
828 ".mdebug*", /* alpha, score, mips etc. */
829 ".pdr", /* alpha, score, mips etc. */
830 ".stab*",
831 ".note*",
832 ".got*",
833 ".toc*",
834 ".xt.prop", /* xtensa */
835 ".xt.lit", /* xtensa */
836 ".arcextmap*", /* arc */
837 ".gnu.linkonce.arcext*", /* arc : modules */
838 NULL
842 * This is used to find sections missing the SHF_ALLOC flag.
843 * The cause of this is often a section specified in assembler
844 * without "ax" / "aw".
846 static void check_section(const char *modname, struct elf_info *elf,
847 Elf_Shdr *sechdr)
849 const char *sec = sech_name(elf, sechdr);
851 if (sechdr->sh_type == SHT_PROGBITS &&
852 !(sechdr->sh_flags & SHF_ALLOC) &&
853 !match(sec, section_white_list)) {
854 warn("%s (%s): unexpected non-allocatable section.\n"
855 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
856 "Note that for example <linux/init.h> contains\n"
857 "section definitions for use in .S files.\n\n",
858 modname, sec);
864 #define ALL_INIT_DATA_SECTIONS \
865 ".init.setup$", ".init.rodata$", ".meminit.rodata$", \
866 ".init.data$", ".meminit.data$"
867 #define ALL_EXIT_DATA_SECTIONS \
868 ".exit.data$", ".memexit.data$"
870 #define ALL_INIT_TEXT_SECTIONS \
871 ".init.text$", ".meminit.text$"
872 #define ALL_EXIT_TEXT_SECTIONS \
873 ".exit.text$", ".memexit.text$"
875 #define ALL_PCI_INIT_SECTIONS \
876 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
877 ".pci_fixup_enable$", ".pci_fixup_resume$", \
878 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
880 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
881 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
883 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
884 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
886 #define DATA_SECTIONS ".data$", ".data.rel$"
887 #define TEXT_SECTIONS ".text$", ".text.unlikely$"
889 #define INIT_SECTIONS ".init.*"
890 #define MEM_INIT_SECTIONS ".meminit.*"
892 #define EXIT_SECTIONS ".exit.*"
893 #define MEM_EXIT_SECTIONS ".memexit.*"
895 /* init data sections */
896 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
898 /* all init sections */
899 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
901 /* All init and exit sections (code + data) */
902 static const char *init_exit_sections[] =
903 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
905 /* data section */
906 static const char *data_sections[] = { DATA_SECTIONS, NULL };
909 /* symbols in .data that may refer to init/exit sections */
910 #define DEFAULT_SYMBOL_WHITE_LIST \
911 "*driver", \
912 "*_template", /* scsi uses *_template a lot */ \
913 "*_timer", /* arm uses ops structures named _timer a lot */ \
914 "*_sht", /* scsi also used *_sht to some extent */ \
915 "*_ops", \
916 "*_probe", \
917 "*_probe_one", \
918 "*_console"
920 static const char *head_sections[] = { ".head.text*", NULL };
921 static const char *linker_symbols[] =
922 { "__init_begin", "_sinittext", "_einittext", NULL };
924 enum mismatch {
925 TEXT_TO_ANY_INIT,
926 DATA_TO_ANY_INIT,
927 TEXT_TO_ANY_EXIT,
928 DATA_TO_ANY_EXIT,
929 XXXINIT_TO_SOME_INIT,
930 XXXEXIT_TO_SOME_EXIT,
931 ANY_INIT_TO_ANY_EXIT,
932 ANY_EXIT_TO_ANY_INIT,
933 EXPORT_TO_INIT_EXIT,
936 struct sectioncheck {
937 const char *fromsec[20];
938 const char *tosec[20];
939 enum mismatch mismatch;
940 const char *symbol_white_list[20];
943 const struct sectioncheck sectioncheck[] = {
944 /* Do not reference init/exit code/data from
945 * normal code and data
948 .fromsec = { TEXT_SECTIONS, NULL },
949 .tosec = { ALL_INIT_SECTIONS, NULL },
950 .mismatch = TEXT_TO_ANY_INIT,
951 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
954 .fromsec = { DATA_SECTIONS, NULL },
955 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
956 .mismatch = DATA_TO_ANY_INIT,
957 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
960 .fromsec = { DATA_SECTIONS, NULL },
961 .tosec = { INIT_SECTIONS, NULL },
962 .mismatch = DATA_TO_ANY_INIT,
963 .symbol_white_list = {
964 "*_template", "*_timer", "*_sht", "*_ops",
965 "*_probe", "*_probe_one", "*_console", NULL
969 .fromsec = { TEXT_SECTIONS, NULL },
970 .tosec = { ALL_EXIT_SECTIONS, NULL },
971 .mismatch = TEXT_TO_ANY_EXIT,
972 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
975 .fromsec = { DATA_SECTIONS, NULL },
976 .tosec = { ALL_EXIT_SECTIONS, NULL },
977 .mismatch = DATA_TO_ANY_EXIT,
978 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
980 /* Do not reference init code/data from meminit code/data */
982 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
983 .tosec = { INIT_SECTIONS, NULL },
984 .mismatch = XXXINIT_TO_SOME_INIT,
985 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
987 /* Do not reference exit code/data from memexit code/data */
989 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
990 .tosec = { EXIT_SECTIONS, NULL },
991 .mismatch = XXXEXIT_TO_SOME_EXIT,
992 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
994 /* Do not use exit code/data from init code */
996 .fromsec = { ALL_INIT_SECTIONS, NULL },
997 .tosec = { ALL_EXIT_SECTIONS, NULL },
998 .mismatch = ANY_INIT_TO_ANY_EXIT,
999 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1001 /* Do not use init code/data from exit code */
1003 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1004 .tosec = { ALL_INIT_SECTIONS, NULL },
1005 .mismatch = ANY_EXIT_TO_ANY_INIT,
1006 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1009 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1010 .tosec = { INIT_SECTIONS, NULL },
1011 .mismatch = ANY_INIT_TO_ANY_EXIT,
1012 .symbol_white_list = { NULL },
1014 /* Do not export init/exit functions or data */
1016 .fromsec = { "__ksymtab*", NULL },
1017 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1018 .mismatch = EXPORT_TO_INIT_EXIT,
1019 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1023 static const struct sectioncheck *section_mismatch(
1024 const char *fromsec, const char *tosec)
1026 int i;
1027 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1028 const struct sectioncheck *check = &sectioncheck[0];
1030 for (i = 0; i < elems; i++) {
1031 if (match(fromsec, check->fromsec) &&
1032 match(tosec, check->tosec))
1033 return check;
1034 check++;
1036 return NULL;
1040 * Whitelist to allow certain references to pass with no warning.
1042 * Pattern 1:
1043 * If a module parameter is declared __initdata and permissions=0
1044 * then this is legal despite the warning generated.
1045 * We cannot see value of permissions here, so just ignore
1046 * this pattern.
1047 * The pattern is identified by:
1048 * tosec = .init.data
1049 * fromsec = .data*
1050 * atsym =__param*
1052 * Pattern 1a:
1053 * module_param_call() ops can refer to __init set function if permissions=0
1054 * The pattern is identified by:
1055 * tosec = .init.text
1056 * fromsec = .data*
1057 * atsym = __param_ops_*
1059 * Pattern 2:
1060 * Many drivers utilise a *driver container with references to
1061 * add, remove, probe functions etc.
1062 * the pattern is identified by:
1063 * tosec = init or exit section
1064 * fromsec = data section
1065 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1066 * *probe_one, *_console, *_timer
1068 * Pattern 3:
1069 * Whitelist all references from .head.text to any init section
1071 * Pattern 4:
1072 * Some symbols belong to init section but still it is ok to reference
1073 * these from non-init sections as these symbols don't have any memory
1074 * allocated for them and symbol address and value are same. So even
1075 * if init section is freed, its ok to reference those symbols.
1076 * For ex. symbols marking the init section boundaries.
1077 * This pattern is identified by
1078 * refsymname = __init_begin, _sinittext, _einittext
1081 static int secref_whitelist(const struct sectioncheck *mismatch,
1082 const char *fromsec, const char *fromsym,
1083 const char *tosec, const char *tosym)
1085 /* Check for pattern 1 */
1086 if (match(tosec, init_data_sections) &&
1087 match(fromsec, data_sections) &&
1088 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1089 return 0;
1091 /* Check for pattern 1a */
1092 if (strcmp(tosec, ".init.text") == 0 &&
1093 match(fromsec, data_sections) &&
1094 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1095 return 0;
1097 /* Check for pattern 2 */
1098 if (match(tosec, init_exit_sections) &&
1099 match(fromsec, data_sections) &&
1100 match(fromsym, mismatch->symbol_white_list))
1101 return 0;
1103 /* Check for pattern 3 */
1104 if (match(fromsec, head_sections) &&
1105 match(tosec, init_sections))
1106 return 0;
1108 /* Check for pattern 4 */
1109 if (match(tosym, linker_symbols))
1110 return 0;
1112 return 1;
1116 * Find symbol based on relocation record info.
1117 * In some cases the symbol supplied is a valid symbol so
1118 * return refsym. If st_name != 0 we assume this is a valid symbol.
1119 * In other cases the symbol needs to be looked up in the symbol table
1120 * based on section and address.
1121 * **/
1122 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1123 Elf_Sym *relsym)
1125 Elf_Sym *sym;
1126 Elf_Sym *near = NULL;
1127 Elf64_Sword distance = 20;
1128 Elf64_Sword d;
1129 unsigned int relsym_secindex;
1131 if (relsym->st_name != 0)
1132 return relsym;
1134 relsym_secindex = get_secindex(elf, relsym);
1135 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1136 if (get_secindex(elf, sym) != relsym_secindex)
1137 continue;
1138 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1139 continue;
1140 if (sym->st_value == addr)
1141 return sym;
1142 /* Find a symbol nearby - addr are maybe negative */
1143 d = sym->st_value - addr;
1144 if (d < 0)
1145 d = addr - sym->st_value;
1146 if (d < distance) {
1147 distance = d;
1148 near = sym;
1151 /* We need a close match */
1152 if (distance < 20)
1153 return near;
1154 else
1155 return NULL;
1158 static inline int is_arm_mapping_symbol(const char *str)
1160 return str[0] == '$' && strchr("atd", str[1])
1161 && (str[2] == '\0' || str[2] == '.');
1165 * If there's no name there, ignore it; likewise, ignore it if it's
1166 * one of the magic symbols emitted used by current ARM tools.
1168 * Otherwise if find_symbols_between() returns those symbols, they'll
1169 * fail the whitelist tests and cause lots of false alarms ... fixable
1170 * only by merging __exit and __init sections into __text, bloating
1171 * the kernel (which is especially evil on embedded platforms).
1173 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1175 const char *name = elf->strtab + sym->st_name;
1177 if (!name || !strlen(name))
1178 return 0;
1179 return !is_arm_mapping_symbol(name);
1183 * Find symbols before or equal addr and after addr - in the section sec.
1184 * If we find two symbols with equal offset prefer one with a valid name.
1185 * The ELF format may have a better way to detect what type of symbol
1186 * it is, but this works for now.
1188 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1189 const char *sec)
1191 Elf_Sym *sym;
1192 Elf_Sym *near = NULL;
1193 Elf_Addr distance = ~0;
1195 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1196 const char *symsec;
1198 if (is_shndx_special(sym->st_shndx))
1199 continue;
1200 symsec = sec_name(elf, get_secindex(elf, sym));
1201 if (strcmp(symsec, sec) != 0)
1202 continue;
1203 if (!is_valid_name(elf, sym))
1204 continue;
1205 if (sym->st_value <= addr) {
1206 if ((addr - sym->st_value) < distance) {
1207 distance = addr - sym->st_value;
1208 near = sym;
1209 } else if ((addr - sym->st_value) == distance) {
1210 near = sym;
1214 return near;
1218 * Convert a section name to the function/data attribute
1219 * .init.text => __init
1220 * .memexitconst => __memconst
1221 * etc.
1223 * The memory of returned value has been allocated on a heap. The user of this
1224 * method should free it after usage.
1226 static char *sec2annotation(const char *s)
1228 if (match(s, init_exit_sections)) {
1229 char *p = malloc(20);
1230 char *r = p;
1232 *p++ = '_';
1233 *p++ = '_';
1234 if (*s == '.')
1235 s++;
1236 while (*s && *s != '.')
1237 *p++ = *s++;
1238 *p = '\0';
1239 if (*s == '.')
1240 s++;
1241 if (strstr(s, "rodata") != NULL)
1242 strcat(p, "const ");
1243 else if (strstr(s, "data") != NULL)
1244 strcat(p, "data ");
1245 else
1246 strcat(p, " ");
1247 return r;
1248 } else {
1249 return strdup("");
1253 static int is_function(Elf_Sym *sym)
1255 if (sym)
1256 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1257 else
1258 return -1;
1261 static void print_section_list(const char * const list[20])
1263 const char *const *s = list;
1265 while (*s) {
1266 fprintf(stderr, "%s", *s);
1267 s++;
1268 if (*s)
1269 fprintf(stderr, ", ");
1271 fprintf(stderr, "\n");
1275 * Print a warning about a section mismatch.
1276 * Try to find symbols near it so user can find it.
1277 * Check whitelist before warning - it may be a false positive.
1279 static void report_sec_mismatch(const char *modname,
1280 const struct sectioncheck *mismatch,
1281 const char *fromsec,
1282 unsigned long long fromaddr,
1283 const char *fromsym,
1284 int from_is_func,
1285 const char *tosec, const char *tosym,
1286 int to_is_func)
1288 const char *from, *from_p;
1289 const char *to, *to_p;
1290 char *prl_from;
1291 char *prl_to;
1293 switch (from_is_func) {
1294 case 0: from = "variable"; from_p = ""; break;
1295 case 1: from = "function"; from_p = "()"; break;
1296 default: from = "(unknown reference)"; from_p = ""; break;
1298 switch (to_is_func) {
1299 case 0: to = "variable"; to_p = ""; break;
1300 case 1: to = "function"; to_p = "()"; break;
1301 default: to = "(unknown reference)"; to_p = ""; break;
1304 sec_mismatch_count++;
1305 if (!sec_mismatch_verbose)
1306 return;
1308 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1309 "to the %s %s:%s%s\n",
1310 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1311 tosym, to_p);
1313 switch (mismatch->mismatch) {
1314 case TEXT_TO_ANY_INIT:
1315 prl_from = sec2annotation(fromsec);
1316 prl_to = sec2annotation(tosec);
1317 fprintf(stderr,
1318 "The function %s%s() references\n"
1319 "the %s %s%s%s.\n"
1320 "This is often because %s lacks a %s\n"
1321 "annotation or the annotation of %s is wrong.\n",
1322 prl_from, fromsym,
1323 to, prl_to, tosym, to_p,
1324 fromsym, prl_to, tosym);
1325 free(prl_from);
1326 free(prl_to);
1327 break;
1328 case DATA_TO_ANY_INIT: {
1329 prl_to = sec2annotation(tosec);
1330 fprintf(stderr,
1331 "The variable %s references\n"
1332 "the %s %s%s%s\n"
1333 "If the reference is valid then annotate the\n"
1334 "variable with __init* or __refdata (see linux/init.h) "
1335 "or name the variable:\n",
1336 fromsym, to, prl_to, tosym, to_p);
1337 print_section_list(mismatch->symbol_white_list);
1338 free(prl_to);
1339 break;
1341 case TEXT_TO_ANY_EXIT:
1342 prl_to = sec2annotation(tosec);
1343 fprintf(stderr,
1344 "The function %s() references a %s in an exit section.\n"
1345 "Often the %s %s%s has valid usage outside the exit section\n"
1346 "and the fix is to remove the %sannotation of %s.\n",
1347 fromsym, to, to, tosym, to_p, prl_to, tosym);
1348 free(prl_to);
1349 break;
1350 case DATA_TO_ANY_EXIT: {
1351 prl_to = sec2annotation(tosec);
1352 fprintf(stderr,
1353 "The variable %s references\n"
1354 "the %s %s%s%s\n"
1355 "If the reference is valid then annotate the\n"
1356 "variable with __exit* (see linux/init.h) or "
1357 "name the variable:\n",
1358 fromsym, to, prl_to, tosym, to_p);
1359 print_section_list(mismatch->symbol_white_list);
1360 free(prl_to);
1361 break;
1363 case XXXINIT_TO_SOME_INIT:
1364 case XXXEXIT_TO_SOME_EXIT:
1365 prl_from = sec2annotation(fromsec);
1366 prl_to = sec2annotation(tosec);
1367 fprintf(stderr,
1368 "The %s %s%s%s references\n"
1369 "a %s %s%s%s.\n"
1370 "If %s is only used by %s then\n"
1371 "annotate %s with a matching annotation.\n",
1372 from, prl_from, fromsym, from_p,
1373 to, prl_to, tosym, to_p,
1374 tosym, fromsym, tosym);
1375 free(prl_from);
1376 free(prl_to);
1377 break;
1378 case ANY_INIT_TO_ANY_EXIT:
1379 prl_from = sec2annotation(fromsec);
1380 prl_to = sec2annotation(tosec);
1381 fprintf(stderr,
1382 "The %s %s%s%s references\n"
1383 "a %s %s%s%s.\n"
1384 "This is often seen when error handling "
1385 "in the init function\n"
1386 "uses functionality in the exit path.\n"
1387 "The fix is often to remove the %sannotation of\n"
1388 "%s%s so it may be used outside an exit section.\n",
1389 from, prl_from, fromsym, from_p,
1390 to, prl_to, tosym, to_p,
1391 prl_to, tosym, to_p);
1392 free(prl_from);
1393 free(prl_to);
1394 break;
1395 case ANY_EXIT_TO_ANY_INIT:
1396 prl_from = sec2annotation(fromsec);
1397 prl_to = sec2annotation(tosec);
1398 fprintf(stderr,
1399 "The %s %s%s%s references\n"
1400 "a %s %s%s%s.\n"
1401 "This is often seen when error handling "
1402 "in the exit function\n"
1403 "uses functionality in the init path.\n"
1404 "The fix is often to remove the %sannotation of\n"
1405 "%s%s so it may be used outside an init section.\n",
1406 from, prl_from, fromsym, from_p,
1407 to, prl_to, tosym, to_p,
1408 prl_to, tosym, to_p);
1409 free(prl_from);
1410 free(prl_to);
1411 break;
1412 case EXPORT_TO_INIT_EXIT:
1413 prl_to = sec2annotation(tosec);
1414 fprintf(stderr,
1415 "The symbol %s is exported and annotated %s\n"
1416 "Fix this by removing the %sannotation of %s "
1417 "or drop the export.\n",
1418 tosym, prl_to, prl_to, tosym);
1419 free(prl_to);
1420 break;
1422 fprintf(stderr, "\n");
1425 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1426 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1428 const char *tosec;
1429 const struct sectioncheck *mismatch;
1431 tosec = sec_name(elf, get_secindex(elf, sym));
1432 mismatch = section_mismatch(fromsec, tosec);
1433 if (mismatch) {
1434 Elf_Sym *to;
1435 Elf_Sym *from;
1436 const char *tosym;
1437 const char *fromsym;
1439 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1440 fromsym = sym_name(elf, from);
1441 to = find_elf_symbol(elf, r->r_addend, sym);
1442 tosym = sym_name(elf, to);
1444 /* check whitelist - we may ignore it */
1445 if (secref_whitelist(mismatch,
1446 fromsec, fromsym, tosec, tosym)) {
1447 report_sec_mismatch(modname, mismatch,
1448 fromsec, r->r_offset, fromsym,
1449 is_function(from), tosec, tosym,
1450 is_function(to));
1455 static unsigned int *reloc_location(struct elf_info *elf,
1456 Elf_Shdr *sechdr, Elf_Rela *r)
1458 Elf_Shdr *sechdrs = elf->sechdrs;
1459 int section = sechdr->sh_info;
1461 return (void *)elf->hdr + sechdrs[section].sh_offset +
1462 r->r_offset;
1465 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1467 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1468 unsigned int *location = reloc_location(elf, sechdr, r);
1470 switch (r_typ) {
1471 case R_386_32:
1472 r->r_addend = TO_NATIVE(*location);
1473 break;
1474 case R_386_PC32:
1475 r->r_addend = TO_NATIVE(*location) + 4;
1476 /* For CONFIG_RELOCATABLE=y */
1477 if (elf->hdr->e_type == ET_EXEC)
1478 r->r_addend += r->r_offset;
1479 break;
1481 return 0;
1484 #ifndef R_ARM_CALL
1485 #define R_ARM_CALL 28
1486 #endif
1487 #ifndef R_ARM_JUMP24
1488 #define R_ARM_JUMP24 29
1489 #endif
1491 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1493 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1495 switch (r_typ) {
1496 case R_ARM_ABS32:
1497 /* From ARM ABI: (S + A) | T */
1498 r->r_addend = (int)(long)
1499 (elf->symtab_start + ELF_R_SYM(r->r_info));
1500 break;
1501 case R_ARM_PC24:
1502 case R_ARM_CALL:
1503 case R_ARM_JUMP24:
1504 /* From ARM ABI: ((S + A) | T) - P */
1505 r->r_addend = (int)(long)(elf->hdr +
1506 sechdr->sh_offset +
1507 (r->r_offset - sechdr->sh_addr));
1508 break;
1509 default:
1510 return 1;
1512 return 0;
1515 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1517 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1518 unsigned int *location = reloc_location(elf, sechdr, r);
1519 unsigned int inst;
1521 if (r_typ == R_MIPS_HI16)
1522 return 1; /* skip this */
1523 inst = TO_NATIVE(*location);
1524 switch (r_typ) {
1525 case R_MIPS_LO16:
1526 r->r_addend = inst & 0xffff;
1527 break;
1528 case R_MIPS_26:
1529 r->r_addend = (inst & 0x03ffffff) << 2;
1530 break;
1531 case R_MIPS_32:
1532 r->r_addend = inst;
1533 break;
1535 return 0;
1538 static void section_rela(const char *modname, struct elf_info *elf,
1539 Elf_Shdr *sechdr)
1541 Elf_Sym *sym;
1542 Elf_Rela *rela;
1543 Elf_Rela r;
1544 unsigned int r_sym;
1545 const char *fromsec;
1547 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1548 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1550 fromsec = sech_name(elf, sechdr);
1551 fromsec += strlen(".rela");
1552 /* if from section (name) is know good then skip it */
1553 if (match(fromsec, section_white_list))
1554 return;
1556 for (rela = start; rela < stop; rela++) {
1557 r.r_offset = TO_NATIVE(rela->r_offset);
1558 #if KERNEL_ELFCLASS == ELFCLASS64
1559 if (elf->hdr->e_machine == EM_MIPS) {
1560 unsigned int r_typ;
1561 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1562 r_sym = TO_NATIVE(r_sym);
1563 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1564 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1565 } else {
1566 r.r_info = TO_NATIVE(rela->r_info);
1567 r_sym = ELF_R_SYM(r.r_info);
1569 #else
1570 r.r_info = TO_NATIVE(rela->r_info);
1571 r_sym = ELF_R_SYM(r.r_info);
1572 #endif
1573 r.r_addend = TO_NATIVE(rela->r_addend);
1574 sym = elf->symtab_start + r_sym;
1575 /* Skip special sections */
1576 if (is_shndx_special(sym->st_shndx))
1577 continue;
1578 check_section_mismatch(modname, elf, &r, sym, fromsec);
1582 static void section_rel(const char *modname, struct elf_info *elf,
1583 Elf_Shdr *sechdr)
1585 Elf_Sym *sym;
1586 Elf_Rel *rel;
1587 Elf_Rela r;
1588 unsigned int r_sym;
1589 const char *fromsec;
1591 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1592 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1594 fromsec = sech_name(elf, sechdr);
1595 fromsec += strlen(".rel");
1596 /* if from section (name) is know good then skip it */
1597 if (match(fromsec, section_white_list))
1598 return;
1600 for (rel = start; rel < stop; rel++) {
1601 r.r_offset = TO_NATIVE(rel->r_offset);
1602 #if KERNEL_ELFCLASS == ELFCLASS64
1603 if (elf->hdr->e_machine == EM_MIPS) {
1604 unsigned int r_typ;
1605 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1606 r_sym = TO_NATIVE(r_sym);
1607 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1608 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1609 } else {
1610 r.r_info = TO_NATIVE(rel->r_info);
1611 r_sym = ELF_R_SYM(r.r_info);
1613 #else
1614 r.r_info = TO_NATIVE(rel->r_info);
1615 r_sym = ELF_R_SYM(r.r_info);
1616 #endif
1617 r.r_addend = 0;
1618 switch (elf->hdr->e_machine) {
1619 case EM_386:
1620 if (addend_386_rel(elf, sechdr, &r))
1621 continue;
1622 break;
1623 case EM_ARM:
1624 if (addend_arm_rel(elf, sechdr, &r))
1625 continue;
1626 break;
1627 case EM_MIPS:
1628 if (addend_mips_rel(elf, sechdr, &r))
1629 continue;
1630 break;
1632 sym = elf->symtab_start + r_sym;
1633 /* Skip special sections */
1634 if (is_shndx_special(sym->st_shndx))
1635 continue;
1636 check_section_mismatch(modname, elf, &r, sym, fromsec);
1641 * A module includes a number of sections that are discarded
1642 * either when loaded or when used as built-in.
1643 * For loaded modules all functions marked __init and all data
1644 * marked __initdata will be discarded when the module has been initialized.
1645 * Likewise for modules used built-in the sections marked __exit
1646 * are discarded because __exit marked function are supposed to be called
1647 * only when a module is unloaded which never happens for built-in modules.
1648 * The check_sec_ref() function traverses all relocation records
1649 * to find all references to a section that reference a section that will
1650 * be discarded and warns about it.
1652 static void check_sec_ref(struct module *mod, const char *modname,
1653 struct elf_info *elf)
1655 int i;
1656 Elf_Shdr *sechdrs = elf->sechdrs;
1658 /* Walk through all sections */
1659 for (i = 0; i < elf->num_sections; i++) {
1660 check_section(modname, elf, &elf->sechdrs[i]);
1661 /* We want to process only relocation sections and not .init */
1662 if (sechdrs[i].sh_type == SHT_RELA)
1663 section_rela(modname, elf, &elf->sechdrs[i]);
1664 else if (sechdrs[i].sh_type == SHT_REL)
1665 section_rel(modname, elf, &elf->sechdrs[i]);
1669 static void read_symbols(char *modname)
1671 const char *symname;
1672 char *version;
1673 char *license;
1674 struct module *mod;
1675 struct elf_info info = { };
1676 Elf_Sym *sym;
1678 if (!parse_elf(&info, modname))
1679 return;
1681 mod = new_module(modname);
1683 /* When there's no vmlinux, don't print warnings about
1684 * unresolved symbols (since there'll be too many ;) */
1685 if (is_vmlinux(modname)) {
1686 have_vmlinux = 1;
1687 mod->skip = 1;
1690 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1691 if (info.modinfo && !license && !is_vmlinux(modname))
1692 warn("modpost: missing MODULE_LICENSE() in %s\n"
1693 "see include/linux/module.h for "
1694 "more information\n", modname);
1695 while (license) {
1696 if (license_is_gpl_compatible(license))
1697 mod->gpl_compatible = 1;
1698 else {
1699 mod->gpl_compatible = 0;
1700 break;
1702 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1703 "license", license);
1706 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1707 symname = info.strtab + sym->st_name;
1709 handle_modversions(mod, &info, sym, symname);
1710 handle_moddevtable(mod, &info, sym, symname);
1712 if (!is_vmlinux(modname) ||
1713 (is_vmlinux(modname) && vmlinux_section_warnings))
1714 check_sec_ref(mod, modname, &info);
1716 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1717 if (version)
1718 maybe_frob_rcs_version(modname, version, info.modinfo,
1719 version - (char *)info.hdr);
1720 if (version || (all_versions && !is_vmlinux(modname)))
1721 get_src_version(modname, mod->srcversion,
1722 sizeof(mod->srcversion)-1);
1724 parse_elf_finish(&info);
1726 /* Our trick to get versioning for module struct etc. - it's
1727 * never passed as an argument to an exported function, so
1728 * the automatic versioning doesn't pick it up, but it's really
1729 * important anyhow */
1730 if (modversions)
1731 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1734 static void read_symbols_from_files(const char *filename)
1736 FILE *in = stdin;
1737 char fname[PATH_MAX];
1739 if (strcmp(filename, "-") != 0) {
1740 in = fopen(filename, "r");
1741 if (!in)
1742 fatal("Can't open filenames file %s: %m", filename);
1745 while (fgets(fname, PATH_MAX, in) != NULL) {
1746 if (strends(fname, "\n"))
1747 fname[strlen(fname)-1] = '\0';
1748 read_symbols(fname);
1751 if (in != stdin)
1752 fclose(in);
1755 #define SZ 500
1757 /* We first write the generated file into memory using the
1758 * following helper, then compare to the file on disk and
1759 * only update the later if anything changed */
1761 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1762 const char *fmt, ...)
1764 char tmp[SZ];
1765 int len;
1766 va_list ap;
1768 va_start(ap, fmt);
1769 len = vsnprintf(tmp, SZ, fmt, ap);
1770 buf_write(buf, tmp, len);
1771 va_end(ap);
1774 void buf_write(struct buffer *buf, const char *s, int len)
1776 if (buf->size - buf->pos < len) {
1777 buf->size += len + SZ;
1778 buf->p = realloc(buf->p, buf->size);
1780 strncpy(buf->p + buf->pos, s, len);
1781 buf->pos += len;
1784 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1786 const char *e = is_vmlinux(m) ?"":".ko";
1788 switch (exp) {
1789 case export_gpl:
1790 fatal("modpost: GPL-incompatible module %s%s "
1791 "uses GPL-only symbol '%s'\n", m, e, s);
1792 break;
1793 case export_unused_gpl:
1794 fatal("modpost: GPL-incompatible module %s%s "
1795 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1796 break;
1797 case export_gpl_future:
1798 warn("modpost: GPL-incompatible module %s%s "
1799 "uses future GPL-only symbol '%s'\n", m, e, s);
1800 break;
1801 case export_plain:
1802 case export_unused:
1803 case export_unknown:
1804 /* ignore */
1805 break;
1809 static void check_for_unused(enum export exp, const char *m, const char *s)
1811 const char *e = is_vmlinux(m) ?"":".ko";
1813 switch (exp) {
1814 case export_unused:
1815 case export_unused_gpl:
1816 warn("modpost: module %s%s "
1817 "uses symbol '%s' marked UNUSED\n", m, e, s);
1818 break;
1819 default:
1820 /* ignore */
1821 break;
1825 static void check_exports(struct module *mod)
1827 struct symbol *s, *exp;
1829 for (s = mod->unres; s; s = s->next) {
1830 const char *basename;
1831 exp = find_symbol(s->name);
1832 if (!exp || exp->module == mod)
1833 continue;
1834 basename = strrchr(mod->name, '/');
1835 if (basename)
1836 basename++;
1837 else
1838 basename = mod->name;
1839 if (!mod->gpl_compatible)
1840 check_for_gpl_usage(exp->export, basename, exp->name);
1841 check_for_unused(exp->export, basename, exp->name);
1846 * Header for the generated file
1848 static void add_header(struct buffer *b, struct module *mod)
1850 buf_printf(b, "#include <linux/module.h>\n");
1851 buf_printf(b, "#include <linux/vermagic.h>\n");
1852 buf_printf(b, "#include <linux/compiler.h>\n");
1853 buf_printf(b, "\n");
1854 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1855 buf_printf(b, "\n");
1856 buf_printf(b, "struct module __this_module\n");
1857 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1858 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1859 if (mod->has_init)
1860 buf_printf(b, "\t.init = init_module,\n");
1861 if (mod->has_cleanup)
1862 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1863 "\t.exit = cleanup_module,\n"
1864 "#endif\n");
1865 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1866 buf_printf(b, "};\n");
1869 static void add_intree_flag(struct buffer *b, int is_intree)
1871 if (is_intree)
1872 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1875 static void add_staging_flag(struct buffer *b, const char *name)
1877 static const char *staging_dir = "drivers/staging";
1879 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1880 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1884 * Record CRCs for unresolved symbols
1886 static int add_versions(struct buffer *b, struct module *mod)
1888 struct symbol *s, *exp;
1889 int err = 0;
1891 for (s = mod->unres; s; s = s->next) {
1892 exp = find_symbol(s->name);
1893 if (!exp || exp->module == mod) {
1894 if (have_vmlinux && !s->weak) {
1895 if (warn_unresolved) {
1896 warn("\"%s\" [%s.ko] undefined!\n",
1897 s->name, mod->name);
1898 } else {
1899 merror("\"%s\" [%s.ko] undefined!\n",
1900 s->name, mod->name);
1901 err = 1;
1904 continue;
1906 s->module = exp->module;
1907 s->crc_valid = exp->crc_valid;
1908 s->crc = exp->crc;
1911 if (!modversions)
1912 return err;
1914 buf_printf(b, "\n");
1915 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1916 buf_printf(b, "__used\n");
1917 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1919 for (s = mod->unres; s; s = s->next) {
1920 if (!s->module)
1921 continue;
1922 if (!s->crc_valid) {
1923 warn("\"%s\" [%s.ko] has no CRC!\n",
1924 s->name, mod->name);
1925 continue;
1927 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1928 s->crc, s->name);
1931 buf_printf(b, "};\n");
1933 return err;
1936 static void add_depends(struct buffer *b, struct module *mod,
1937 struct module *modules)
1939 struct symbol *s;
1940 struct module *m;
1941 int first = 1;
1943 for (m = modules; m; m = m->next)
1944 m->seen = is_vmlinux(m->name);
1946 buf_printf(b, "\n");
1947 buf_printf(b, "static const char __module_depends[]\n");
1948 buf_printf(b, "__used\n");
1949 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1950 buf_printf(b, "\"depends=");
1951 for (s = mod->unres; s; s = s->next) {
1952 const char *p;
1953 if (!s->module)
1954 continue;
1956 if (s->module->seen)
1957 continue;
1959 s->module->seen = 1;
1960 p = strrchr(s->module->name, '/');
1961 if (p)
1962 p++;
1963 else
1964 p = s->module->name;
1965 buf_printf(b, "%s%s", first ? "" : ",", p);
1966 first = 0;
1968 buf_printf(b, "\";\n");
1971 static void add_srcversion(struct buffer *b, struct module *mod)
1973 if (mod->srcversion[0]) {
1974 buf_printf(b, "\n");
1975 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1976 mod->srcversion);
1980 static void write_if_changed(struct buffer *b, const char *fname)
1982 char *tmp;
1983 FILE *file;
1984 struct stat st;
1986 file = fopen(fname, "r");
1987 if (!file)
1988 goto write;
1990 if (fstat(fileno(file), &st) < 0)
1991 goto close_write;
1993 if (st.st_size != b->pos)
1994 goto close_write;
1996 tmp = NOFAIL(malloc(b->pos));
1997 if (fread(tmp, 1, b->pos, file) != b->pos)
1998 goto free_write;
2000 if (memcmp(tmp, b->p, b->pos) != 0)
2001 goto free_write;
2003 free(tmp);
2004 fclose(file);
2005 return;
2007 free_write:
2008 free(tmp);
2009 close_write:
2010 fclose(file);
2011 write:
2012 file = fopen(fname, "w");
2013 if (!file) {
2014 perror(fname);
2015 exit(1);
2017 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2018 perror(fname);
2019 exit(1);
2021 fclose(file);
2024 /* parse Module.symvers file. line format:
2025 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2027 static void read_dump(const char *fname, unsigned int kernel)
2029 unsigned long size, pos = 0;
2030 void *file = grab_file(fname, &size);
2031 char *line;
2033 if (!file)
2034 /* No symbol versions, silently ignore */
2035 return;
2037 while ((line = get_next_line(&pos, file, size))) {
2038 char *symname, *modname, *d, *export, *end;
2039 unsigned int crc;
2040 struct module *mod;
2041 struct symbol *s;
2043 if (!(symname = strchr(line, '\t')))
2044 goto fail;
2045 *symname++ = '\0';
2046 if (!(modname = strchr(symname, '\t')))
2047 goto fail;
2048 *modname++ = '\0';
2049 if ((export = strchr(modname, '\t')) != NULL)
2050 *export++ = '\0';
2051 if (export && ((end = strchr(export, '\t')) != NULL))
2052 *end = '\0';
2053 crc = strtoul(line, &d, 16);
2054 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2055 goto fail;
2056 mod = find_module(modname);
2057 if (!mod) {
2058 if (is_vmlinux(modname))
2059 have_vmlinux = 1;
2060 mod = new_module(modname);
2061 mod->skip = 1;
2063 s = sym_add_exported(symname, mod, export_no(export));
2064 s->kernel = kernel;
2065 s->preloaded = 1;
2066 sym_update_crc(symname, mod, crc, export_no(export));
2068 return;
2069 fail:
2070 fatal("parse error in symbol dump file\n");
2073 /* For normal builds always dump all symbols.
2074 * For external modules only dump symbols
2075 * that are not read from kernel Module.symvers.
2077 static int dump_sym(struct symbol *sym)
2079 if (!external_module)
2080 return 1;
2081 if (sym->vmlinux || sym->kernel)
2082 return 0;
2083 return 1;
2086 static void write_dump(const char *fname)
2088 struct buffer buf = { };
2089 struct symbol *symbol;
2090 int n;
2092 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2093 symbol = symbolhash[n];
2094 while (symbol) {
2095 if (dump_sym(symbol))
2096 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2097 symbol->crc, symbol->name,
2098 symbol->module->name,
2099 export_str(symbol->export));
2100 symbol = symbol->next;
2103 write_if_changed(&buf, fname);
2106 struct ext_sym_list {
2107 struct ext_sym_list *next;
2108 const char *file;
2111 int main(int argc, char **argv)
2113 struct module *mod;
2114 struct buffer buf = { };
2115 char *kernel_read = NULL, *module_read = NULL;
2116 char *dump_write = NULL, *files_source = NULL;
2117 int opt;
2118 int err;
2119 struct ext_sym_list *extsym_iter;
2120 struct ext_sym_list *extsym_start = NULL;
2122 while ((opt = getopt(argc, argv, "i:I:e:msST:o:awM:K:")) != -1) {
2123 switch (opt) {
2124 case 'i':
2125 kernel_read = optarg;
2126 break;
2127 case 'I':
2128 module_read = optarg;
2129 external_module = 1;
2130 break;
2131 case 'e':
2132 external_module = 1;
2133 extsym_iter =
2134 NOFAIL(malloc(sizeof(*extsym_iter)));
2135 extsym_iter->next = extsym_start;
2136 extsym_iter->file = optarg;
2137 extsym_start = extsym_iter;
2138 break;
2139 case 'm':
2140 modversions = 1;
2141 break;
2142 case 'o':
2143 dump_write = optarg;
2144 break;
2145 case 'a':
2146 all_versions = 1;
2147 break;
2148 case 's':
2149 vmlinux_section_warnings = 0;
2150 break;
2151 case 'S':
2152 sec_mismatch_verbose = 0;
2153 break;
2154 case 'T':
2155 files_source = optarg;
2156 break;
2157 case 'w':
2158 warn_unresolved = 1;
2159 break;
2160 default:
2161 exit(1);
2165 if (kernel_read)
2166 read_dump(kernel_read, 1);
2167 if (module_read)
2168 read_dump(module_read, 0);
2169 while (extsym_start) {
2170 read_dump(extsym_start->file, 0);
2171 extsym_iter = extsym_start->next;
2172 free(extsym_start);
2173 extsym_start = extsym_iter;
2176 while (optind < argc)
2177 read_symbols(argv[optind++]);
2179 if (files_source)
2180 read_symbols_from_files(files_source);
2182 for (mod = modules; mod; mod = mod->next) {
2183 if (mod->skip)
2184 continue;
2185 check_exports(mod);
2188 err = 0;
2190 for (mod = modules; mod; mod = mod->next) {
2191 char fname[strlen(mod->name) + 10];
2193 if (mod->skip)
2194 continue;
2196 buf.pos = 0;
2198 add_header(&buf, mod);
2199 add_intree_flag(&buf, !external_module);
2200 add_staging_flag(&buf, mod->name);
2201 err |= add_versions(&buf, mod);
2202 add_depends(&buf, mod, modules);
2203 add_moddevtable(&buf, mod);
2204 add_srcversion(&buf, mod);
2206 sprintf(fname, "%s.mod.c", mod->name);
2207 write_if_changed(&buf, fname);
2210 if (dump_write)
2211 write_dump(dump_write);
2212 if (sec_mismatch_count && !sec_mismatch_verbose)
2213 warn("modpost: Found %d section mismatch(es).\n"
2214 "To see full details build your kernel with:\n"
2215 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2216 sec_mismatch_count);
2218 return err;