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 ...
22 #include "../../include/generated/autoconf.h"
23 #include "../../include/linux/license.h"
24 #include "../../include/linux/export.h"
26 /* Are we using CONFIG_MODVERSIONS? */
27 static int modversions = 0;
28 /* Warn about undefined symbols? (do so if we have vmlinux) */
29 static int have_vmlinux = 0;
30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
31 static int all_versions = 0;
32 /* If we are modposting external module set to 1 */
33 static int external_module = 0;
34 /* Warn about section mismatch in vmlinux if set to 1 */
35 static int vmlinux_section_warnings = 1;
36 /* Only warn about unresolved symbols */
37 static int warn_unresolved = 0;
38 /* How a symbol is exported */
39 static int sec_mismatch_count = 0;
40 static int sec_mismatch_verbose = 1;
41 static int sec_mismatch_fatal = 0;
42 /* ignore missing files */
43 static int ignore_missing_files;
46 export_plain, export_unused, export_gpl,
47 export_unused_gpl, export_gpl_future, export_unknown
50 /* In kernel, this size is defined in linux/module.h;
51 * here we use Elf_Addr instead of long for covering cross-compile
54 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
56 #define PRINTF __attribute__ ((format (printf, 1, 2)))
58 PRINTF void fatal(const char *fmt, ...)
62 fprintf(stderr, "FATAL: ");
64 va_start(arglist, fmt);
65 vfprintf(stderr, fmt, arglist);
71 PRINTF void warn(const char *fmt, ...)
75 fprintf(stderr, "WARNING: ");
77 va_start(arglist, fmt);
78 vfprintf(stderr, fmt, arglist);
82 PRINTF void merror(const char *fmt, ...)
86 fprintf(stderr, "ERROR: ");
88 va_start(arglist, fmt);
89 vfprintf(stderr, fmt, arglist);
93 static inline bool strends(const char *str, const char *postfix)
95 if (strlen(str) < strlen(postfix))
98 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
101 static int is_vmlinux(const char *modname)
105 myname = strrchr(modname, '/');
111 return (strcmp(myname, "vmlinux") == 0) ||
112 (strcmp(myname, "vmlinux.o") == 0);
115 void *do_nofail(void *ptr, const char *expr)
118 fatal("modpost: Memory allocation failure: %s.\n", expr);
123 /* A list of all modules we processed */
124 static struct module *modules;
126 static struct module *find_module(char *modname)
130 for (mod = modules; mod; mod = mod->next)
131 if (strcmp(mod->name, modname) == 0)
136 static struct module *new_module(const char *modname)
141 mod = NOFAIL(malloc(sizeof(*mod)));
142 memset(mod, 0, sizeof(*mod));
143 p = NOFAIL(strdup(modname));
145 /* strip trailing .o */
146 if (strends(p, ".o")) {
147 p[strlen(p) - 2] = '\0';
153 mod->gpl_compatible = -1;
160 /* A hash of all exported symbols,
161 * struct symbol is also used for lists of unresolved symbols */
163 #define SYMBOL_HASH_SIZE 1024
167 struct module *module;
171 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
172 unsigned int kernel:1; /* 1 if symbol is from kernel
173 * (only for external modules) **/
174 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
175 enum export export; /* Type of export */
179 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
181 /* This is based on the hash agorithm from gdbm, via tdb */
182 static inline unsigned int tdb_hash(const char *name)
184 unsigned value; /* Used to compute the hash value. */
185 unsigned i; /* Used to cycle through random values. */
187 /* Set the initial value from the key size. */
188 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
189 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
191 return (1103515243 * value + 12345);
195 * Allocate a new symbols for use in the hash of exported symbols or
196 * the list of unresolved symbols per module
198 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
201 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
203 memset(s, 0, sizeof(*s));
204 strcpy(s->name, name);
210 /* For the hash of exported symbols */
211 static struct symbol *new_symbol(const char *name, struct module *module,
217 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
218 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
219 new->module = module;
220 new->export = export;
224 static struct symbol *find_symbol(const char *name)
228 /* For our purposes, .foo matches foo. PPC64 needs this. */
232 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
233 if (strcmp(s->name, name) == 0)
239 static const struct {
243 { .str = "EXPORT_SYMBOL", .export = export_plain },
244 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
245 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
246 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
247 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
248 { .str = "(unknown)", .export = export_unknown },
252 static const char *export_str(enum export ex)
254 return export_list[ex].str;
257 static enum export export_no(const char *s)
262 return export_unknown;
263 for (i = 0; export_list[i].export != export_unknown; i++) {
264 if (strcmp(export_list[i].str, s) == 0)
265 return export_list[i].export;
267 return export_unknown;
270 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
272 return (void *)elf->hdr +
273 elf->sechdrs[elf->secindex_strings].sh_offset +
277 static const char *sec_name(struct elf_info *elf, int secindex)
279 return sech_name(elf, &elf->sechdrs[secindex]);
282 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
284 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
286 const char *secname = sec_name(elf, sec);
288 if (strstarts(secname, "___ksymtab+"))
290 else if (strstarts(secname, "___ksymtab_unused+"))
291 return export_unused;
292 else if (strstarts(secname, "___ksymtab_gpl+"))
294 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
295 return export_unused_gpl;
296 else if (strstarts(secname, "___ksymtab_gpl_future+"))
297 return export_gpl_future;
299 return export_unknown;
302 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
304 if (sec == elf->export_sec)
306 else if (sec == elf->export_unused_sec)
307 return export_unused;
308 else if (sec == elf->export_gpl_sec)
310 else if (sec == elf->export_unused_gpl_sec)
311 return export_unused_gpl;
312 else if (sec == elf->export_gpl_future_sec)
313 return export_gpl_future;
315 return export_unknown;
319 * Add an exported symbol - it may have already been added without a
320 * CRC, in this case just update the CRC
322 static struct symbol *sym_add_exported(const char *name, struct module *mod,
325 struct symbol *s = find_symbol(name);
328 s = new_symbol(name, mod, export);
331 warn("%s: '%s' exported twice. Previous export "
332 "was in %s%s\n", mod->name, name,
334 is_vmlinux(s->module->name) ?"":".ko");
336 /* In case Module.symvers was out of date */
341 s->vmlinux = is_vmlinux(mod->name);
347 static void sym_update_crc(const char *name, struct module *mod,
348 unsigned int crc, enum export export)
350 struct symbol *s = find_symbol(name);
353 s = new_symbol(name, mod, export);
354 /* Don't complain when we find it later. */
361 void *grab_file(const char *filename, unsigned long *size)
364 void *map = MAP_FAILED;
367 fd = open(filename, O_RDONLY);
374 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
378 if (map == MAP_FAILED)
384 * Return a copy of the next line in a mmap'ed file.
385 * spaces in the beginning of the line is trimmed away.
386 * Return a pointer to a static buffer.
388 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
390 static char line[4096];
393 signed char *p = (signed char *)file + *pos;
396 for (; *pos < size ; (*pos)++) {
397 if (skip && isspace(*p)) {
402 if (*p != '\n' && (*pos < size)) {
406 break; /* Too long, stop */
417 void release_file(void *file, unsigned long size)
422 static int parse_elf(struct elf_info *info, const char *filename)
428 const char *secstrings;
429 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
431 hdr = grab_file(filename, &info->size);
433 if (ignore_missing_files) {
434 fprintf(stderr, "%s: %s (ignored)\n", filename,
442 if (info->size < sizeof(*hdr)) {
443 /* file too small, assume this is an empty .o file */
446 /* Is this a valid ELF file? */
447 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
448 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
449 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
450 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
451 /* Not an ELF file - silently ignore it */
454 /* Fix endianness in ELF header */
455 hdr->e_type = TO_NATIVE(hdr->e_type);
456 hdr->e_machine = TO_NATIVE(hdr->e_machine);
457 hdr->e_version = TO_NATIVE(hdr->e_version);
458 hdr->e_entry = TO_NATIVE(hdr->e_entry);
459 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
460 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
461 hdr->e_flags = TO_NATIVE(hdr->e_flags);
462 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
463 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
464 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
465 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
466 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
467 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
468 sechdrs = (void *)hdr + hdr->e_shoff;
469 info->sechdrs = sechdrs;
471 /* Check if file offset is correct */
472 if (hdr->e_shoff > info->size) {
473 fatal("section header offset=%lu in file '%s' is bigger than "
474 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
475 filename, info->size);
479 if (hdr->e_shnum == SHN_UNDEF) {
481 * There are more than 64k sections,
482 * read count from .sh_size.
484 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
487 info->num_sections = hdr->e_shnum;
489 if (hdr->e_shstrndx == SHN_XINDEX) {
490 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
493 info->secindex_strings = hdr->e_shstrndx;
496 /* Fix endianness in section headers */
497 for (i = 0; i < info->num_sections; i++) {
498 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
499 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
500 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
501 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
502 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
503 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
504 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
505 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
506 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
507 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
509 /* Find symbol table. */
510 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
511 for (i = 1; i < info->num_sections; i++) {
513 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
515 if (!nobits && sechdrs[i].sh_offset > info->size) {
516 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
517 "sizeof(*hrd)=%zu\n", filename,
518 (unsigned long)sechdrs[i].sh_offset,
522 secname = secstrings + sechdrs[i].sh_name;
523 if (strcmp(secname, ".modinfo") == 0) {
525 fatal("%s has NOBITS .modinfo\n", filename);
526 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
527 info->modinfo_len = sechdrs[i].sh_size;
528 } else if (strcmp(secname, "__ksymtab") == 0)
529 info->export_sec = i;
530 else if (strcmp(secname, "__ksymtab_unused") == 0)
531 info->export_unused_sec = i;
532 else if (strcmp(secname, "__ksymtab_gpl") == 0)
533 info->export_gpl_sec = i;
534 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
535 info->export_unused_gpl_sec = i;
536 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
537 info->export_gpl_future_sec = i;
539 if (sechdrs[i].sh_type == SHT_SYMTAB) {
540 unsigned int sh_link_idx;
542 info->symtab_start = (void *)hdr +
543 sechdrs[i].sh_offset;
544 info->symtab_stop = (void *)hdr +
545 sechdrs[i].sh_offset + sechdrs[i].sh_size;
546 sh_link_idx = sechdrs[i].sh_link;
547 info->strtab = (void *)hdr +
548 sechdrs[sh_link_idx].sh_offset;
551 /* 32bit section no. table? ("more than 64k sections") */
552 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
553 symtab_shndx_idx = i;
554 info->symtab_shndx_start = (void *)hdr +
555 sechdrs[i].sh_offset;
556 info->symtab_shndx_stop = (void *)hdr +
557 sechdrs[i].sh_offset + sechdrs[i].sh_size;
560 if (!info->symtab_start)
561 fatal("%s has no symtab?\n", filename);
563 /* Fix endianness in symbols */
564 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
565 sym->st_shndx = TO_NATIVE(sym->st_shndx);
566 sym->st_name = TO_NATIVE(sym->st_name);
567 sym->st_value = TO_NATIVE(sym->st_value);
568 sym->st_size = TO_NATIVE(sym->st_size);
571 if (symtab_shndx_idx != ~0U) {
573 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
574 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
575 filename, sechdrs[symtab_shndx_idx].sh_link,
578 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
586 static void parse_elf_finish(struct elf_info *info)
588 release_file(info->hdr, info->size);
591 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
593 /* ignore __this_module, it will be resolved shortly */
594 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
596 /* ignore global offset table */
597 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
599 if (info->hdr->e_machine == EM_PPC)
600 /* Special register function linked on all modules during final link of .ko */
601 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
602 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
603 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
604 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
605 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
606 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
608 if (info->hdr->e_machine == EM_PPC64)
609 /* Special register function linked on all modules during final link of .ko */
610 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
611 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
612 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
613 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0 ||
614 strcmp(symname, ".TOC.") == 0)
616 /* Do not ignore this symbol */
620 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
621 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
623 static void handle_modversions(struct module *mod, struct elf_info *info,
624 Elf_Sym *sym, const char *symname)
630 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
631 strncmp(symname, "__ksymtab", 9) == 0)
632 export = export_from_secname(info, get_secindex(info, sym));
634 export = export_from_sec(info, get_secindex(info, sym));
637 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
639 crc = (unsigned int) sym->st_value;
640 if (sym->st_shndx != SHN_UNDEF && sym->st_shndx != SHN_ABS) {
643 /* symbol points to the CRC in the ELF object */
644 crcp = (void *)info->hdr + sym->st_value +
645 info->sechdrs[sym->st_shndx].sh_offset -
646 (info->hdr->e_type != ET_REL ?
647 info->sechdrs[sym->st_shndx].sh_addr : 0);
648 crc = TO_NATIVE(*crcp);
650 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
654 switch (sym->st_shndx) {
656 if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
657 /* Should warn here, but modpost runs before the linker */
659 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
662 /* undefined symbol */
663 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
664 ELF_ST_BIND(sym->st_info) != STB_WEAK)
666 if (ignore_undef_symbol(info, symname))
668 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
669 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
670 /* add compatibility with older glibc */
671 #ifndef STT_SPARC_REGISTER
672 #define STT_SPARC_REGISTER STT_REGISTER
674 if (info->hdr->e_machine == EM_SPARC ||
675 info->hdr->e_machine == EM_SPARCV9) {
676 /* Ignore register directives. */
677 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
679 if (symname[0] == '.') {
680 char *munged = NOFAIL(strdup(symname));
682 munged[1] = toupper(munged[1]);
688 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
689 if (symname[0] != '_')
695 const char *e = is_vmlinux(mod->name) ?"":".ko";
696 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", symname + strlen(CRC_PFX), mod->name, e);
698 mod->unres = alloc_symbol(symname,
699 ELF_ST_BIND(sym->st_info) == STB_WEAK,
703 /* All exported symbols */
704 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
705 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
708 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
710 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
711 mod->has_cleanup = 1;
717 * Parse tag=value strings from .modinfo section
719 static char *next_string(char *string, unsigned long *secsize)
721 /* Skip non-zero chars */
724 if ((*secsize)-- <= 1)
728 /* Skip any zero padding. */
731 if ((*secsize)-- <= 1)
737 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
738 const char *tag, char *info)
741 unsigned int taglen = strlen(tag);
742 unsigned long size = modinfo_len;
745 size -= info - (char *)modinfo;
746 modinfo = next_string(info, &size);
749 for (p = modinfo; p; p = next_string(p, &size)) {
750 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
751 return p + taglen + 1;
756 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
760 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
764 * Test if string s ends in string sub
767 static int strrcmp(const char *s, const char *sub)
775 sublen = strlen(sub);
777 if ((slen == 0) || (sublen == 0))
783 return memcmp(s + slen - sublen, sub, sublen);
786 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
789 return elf->strtab + sym->st_name;
794 /* The pattern is an array of simple patterns.
795 * "foo" will match an exact string equal to "foo"
796 * "*foo" will match a string that ends with "foo"
797 * "foo*" will match a string that begins with "foo"
798 * "*foo*" will match a string that contains "foo"
800 static int match(const char *sym, const char * const pat[])
805 const char *endp = p + strlen(p) - 1;
808 if (*p == '*' && *endp == '*') {
809 char *here, *bare = strndup(p + 1, strlen(p) - 2);
811 here = strstr(sym, bare);
817 else if (*p == '*') {
818 if (strrcmp(sym, p + 1) == 0)
822 else if (*endp == '*') {
823 if (strncmp(sym, p, strlen(p) - 1) == 0)
828 if (strcmp(p, sym) == 0)
836 /* sections that we do not want to do full section mismatch check on */
837 static const char *const section_white_list[] =
841 ".cranges", /* sh64 */
842 ".zdebug*", /* Compressed debug sections. */
843 ".GCC-command-line", /* mn10300 */
844 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
845 ".mdebug*", /* alpha, score, mips etc. */
846 ".pdr", /* alpha, score, mips etc. */
851 ".xt.prop", /* xtensa */
852 ".xt.lit", /* xtensa */
853 ".arcextmap*", /* arc */
854 ".gnu.linkonce.arcext*", /* arc : modules */
855 ".cmem*", /* EZchip */
856 ".fmt_slot*", /* EZchip */
863 * This is used to find sections missing the SHF_ALLOC flag.
864 * The cause of this is often a section specified in assembler
865 * without "ax" / "aw".
867 static void check_section(const char *modname, struct elf_info *elf,
870 const char *sec = sech_name(elf, sechdr);
872 if (sechdr->sh_type == SHT_PROGBITS &&
873 !(sechdr->sh_flags & SHF_ALLOC) &&
874 !match(sec, section_white_list)) {
875 warn("%s (%s): unexpected non-allocatable section.\n"
876 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
877 "Note that for example <linux/init.h> contains\n"
878 "section definitions for use in .S files.\n\n",
885 #define ALL_INIT_DATA_SECTIONS \
886 ".init.setup", ".init.rodata", ".meminit.rodata", \
887 ".init.data", ".meminit.data"
888 #define ALL_EXIT_DATA_SECTIONS \
889 ".exit.data", ".memexit.data"
891 #define ALL_INIT_TEXT_SECTIONS \
892 ".init.text", ".meminit.text"
893 #define ALL_EXIT_TEXT_SECTIONS \
894 ".exit.text", ".memexit.text"
896 #define ALL_PCI_INIT_SECTIONS \
897 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
898 ".pci_fixup_enable", ".pci_fixup_resume", \
899 ".pci_fixup_resume_early", ".pci_fixup_suspend"
901 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
902 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
904 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
905 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
907 #define DATA_SECTIONS ".data", ".data.rel"
908 #define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
909 ".kprobes.text", ".cpuidle.text"
910 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
911 ".fixup", ".entry.text", ".exception.text", ".text.*", \
914 #define INIT_SECTIONS ".init.*"
915 #define MEM_INIT_SECTIONS ".meminit.*"
917 #define EXIT_SECTIONS ".exit.*"
918 #define MEM_EXIT_SECTIONS ".memexit.*"
920 #define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
921 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
923 /* init data sections */
924 static const char *const init_data_sections[] =
925 { ALL_INIT_DATA_SECTIONS, NULL };
927 /* all init sections */
928 static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
930 /* All init and exit sections (code + data) */
931 static const char *const init_exit_sections[] =
932 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
934 /* all text sections */
935 static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
938 static const char *const data_sections[] = { DATA_SECTIONS, NULL };
941 /* symbols in .data that may refer to init/exit sections */
942 #define DEFAULT_SYMBOL_WHITE_LIST \
944 "*_template", /* scsi uses *_template a lot */ \
945 "*_timer", /* arm uses ops structures named _timer a lot */ \
946 "*_sht", /* scsi also used *_sht to some extent */ \
952 static const char *const head_sections[] = { ".head.text*", NULL };
953 static const char *const linker_symbols[] =
954 { "__init_begin", "_sinittext", "_einittext", NULL };
955 static const char *const optim_symbols[] = { "*.constprop.*", NULL };
962 XXXINIT_TO_SOME_INIT,
963 XXXEXIT_TO_SOME_EXIT,
964 ANY_INIT_TO_ANY_EXIT,
965 ANY_EXIT_TO_ANY_INIT,
971 * Describe how to match sections on different criterias:
973 * @fromsec: Array of sections to be matched.
975 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
976 * this array is forbidden (black-list). Can be empty.
978 * @good_tosec: Relocations applied to a section in @fromsec must be
979 * targetting sections in this array (white-list). Can be empty.
981 * @mismatch: Type of mismatch.
983 * @symbol_white_list: Do not match a relocation to a symbol in this list
984 * even if it is targetting a section in @bad_to_sec.
986 * @handler: Specific handler to call when a match is found. If NULL,
987 * default_mismatch_handler() will be called.
990 struct sectioncheck {
991 const char *fromsec[20];
992 const char *bad_tosec[20];
993 const char *good_tosec[20];
994 enum mismatch mismatch;
995 const char *symbol_white_list[20];
996 void (*handler)(const char *modname, struct elf_info *elf,
997 const struct sectioncheck* const mismatch,
998 Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
1002 static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
1003 const struct sectioncheck* const mismatch,
1004 Elf_Rela *r, Elf_Sym *sym,
1005 const char *fromsec);
1007 static const struct sectioncheck sectioncheck[] = {
1008 /* Do not reference init/exit code/data from
1009 * normal code and data
1012 .fromsec = { TEXT_SECTIONS, NULL },
1013 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1014 .mismatch = TEXT_TO_ANY_INIT,
1015 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1018 .fromsec = { DATA_SECTIONS, NULL },
1019 .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
1020 .mismatch = DATA_TO_ANY_INIT,
1021 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1024 .fromsec = { DATA_SECTIONS, NULL },
1025 .bad_tosec = { INIT_SECTIONS, NULL },
1026 .mismatch = DATA_TO_ANY_INIT,
1027 .symbol_white_list = {
1028 "*_template", "*_timer", "*_sht", "*_ops",
1029 "*_probe", "*_probe_one", "*_console", NULL
1033 .fromsec = { TEXT_SECTIONS, NULL },
1034 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1035 .mismatch = TEXT_TO_ANY_EXIT,
1036 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1039 .fromsec = { DATA_SECTIONS, NULL },
1040 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1041 .mismatch = DATA_TO_ANY_EXIT,
1042 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1044 /* Do not reference init code/data from meminit code/data */
1046 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1047 .bad_tosec = { INIT_SECTIONS, NULL },
1048 .mismatch = XXXINIT_TO_SOME_INIT,
1049 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1051 /* Do not reference exit code/data from memexit code/data */
1053 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1054 .bad_tosec = { EXIT_SECTIONS, NULL },
1055 .mismatch = XXXEXIT_TO_SOME_EXIT,
1056 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1058 /* Do not use exit code/data from init code */
1060 .fromsec = { ALL_INIT_SECTIONS, NULL },
1061 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1062 .mismatch = ANY_INIT_TO_ANY_EXIT,
1063 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1065 /* Do not use init code/data from exit code */
1067 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1068 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1069 .mismatch = ANY_EXIT_TO_ANY_INIT,
1070 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1073 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1074 .bad_tosec = { INIT_SECTIONS, NULL },
1075 .mismatch = ANY_INIT_TO_ANY_EXIT,
1076 .symbol_white_list = { NULL },
1078 /* Do not export init/exit functions or data */
1080 .fromsec = { "___ksymtab*", NULL },
1081 .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1082 .mismatch = EXPORT_TO_INIT_EXIT,
1083 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1086 .fromsec = { "__ex_table", NULL },
1087 /* If you're adding any new black-listed sections in here, consider
1088 * adding a special 'printer' for them in scripts/check_extable.
1090 .bad_tosec = { ".altinstr_replacement", NULL },
1091 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
1092 .mismatch = EXTABLE_TO_NON_TEXT,
1093 .handler = extable_mismatch_handler,
1097 static const struct sectioncheck *section_mismatch(
1098 const char *fromsec, const char *tosec)
1101 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1102 const struct sectioncheck *check = §ioncheck[0];
1105 * The target section could be the SHT_NUL section when we're
1106 * handling relocations to un-resolved symbols, trying to match it
1107 * doesn't make much sense and causes build failures on parisc and
1108 * mn10300 architectures.
1113 for (i = 0; i < elems; i++) {
1114 if (match(fromsec, check->fromsec)) {
1115 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
1117 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
1126 * Whitelist to allow certain references to pass with no warning.
1129 * If a module parameter is declared __initdata and permissions=0
1130 * then this is legal despite the warning generated.
1131 * We cannot see value of permissions here, so just ignore
1133 * The pattern is identified by:
1134 * tosec = .init.data
1139 * module_param_call() ops can refer to __init set function if permissions=0
1140 * The pattern is identified by:
1141 * tosec = .init.text
1143 * atsym = __param_ops_*
1146 * Many drivers utilise a *driver container with references to
1147 * add, remove, probe functions etc.
1148 * the pattern is identified by:
1149 * tosec = init or exit section
1150 * fromsec = data section
1151 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1152 * *probe_one, *_console, *_timer
1155 * Whitelist all references from .head.text to any init section
1158 * Some symbols belong to init section but still it is ok to reference
1159 * these from non-init sections as these symbols don't have any memory
1160 * allocated for them and symbol address and value are same. So even
1161 * if init section is freed, its ok to reference those symbols.
1162 * For ex. symbols marking the init section boundaries.
1163 * This pattern is identified by
1164 * refsymname = __init_begin, _sinittext, _einittext
1167 * GCC may optimize static inlines when fed constant arg(s) resulting
1168 * in functions like cpumask_empty() -- generating an associated symbol
1169 * cpumask_empty.constprop.3 that appears in the audit. If the const that
1170 * is passed in comes from __init, like say nmi_ipi_mask, we get a
1171 * meaningless section warning. May need to add isra symbols too...
1172 * This pattern is identified by
1173 * tosec = init section
1174 * fromsec = text section
1175 * refsymname = *.constprop.*
1178 * Hide section mismatch warnings for ELF local symbols. The goal
1179 * is to eliminate false positive modpost warnings caused by
1180 * compiler-generated ELF local symbol names such as ".LANCHOR1".
1181 * Autogenerated symbol names bypass modpost's "Pattern 2"
1182 * whitelisting, which relies on pattern-matching against symbol
1183 * names to work. (One situation where gcc can autogenerate ELF
1184 * local symbols is when "-fsection-anchors" is used.)
1186 static int secref_whitelist(const struct sectioncheck *mismatch,
1187 const char *fromsec, const char *fromsym,
1188 const char *tosec, const char *tosym)
1190 /* Check for pattern 1 */
1191 if (match(tosec, init_data_sections) &&
1192 match(fromsec, data_sections) &&
1193 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1196 /* Check for pattern 1a */
1197 if (strcmp(tosec, ".init.text") == 0 &&
1198 match(fromsec, data_sections) &&
1199 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1202 /* Check for pattern 2 */
1203 if (match(tosec, init_exit_sections) &&
1204 match(fromsec, data_sections) &&
1205 match(fromsym, mismatch->symbol_white_list))
1208 /* Check for pattern 3 */
1209 if (match(fromsec, head_sections) &&
1210 match(tosec, init_sections))
1213 /* Check for pattern 4 */
1214 if (match(tosym, linker_symbols))
1217 /* Check for pattern 5 */
1218 if (match(fromsec, text_sections) &&
1219 match(tosec, init_sections) &&
1220 match(fromsym, optim_symbols))
1223 /* Check for pattern 6 */
1224 if (strstarts(fromsym, ".L"))
1230 static inline int is_arm_mapping_symbol(const char *str)
1232 return str[0] == '$' &&
1233 (str[1] == 'a' || str[1] == 'd' || str[1] == 't' || str[1] == 'x')
1234 && (str[2] == '\0' || str[2] == '.');
1238 * If there's no name there, ignore it; likewise, ignore it if it's
1239 * one of the magic symbols emitted used by current ARM tools.
1241 * Otherwise if find_symbols_between() returns those symbols, they'll
1242 * fail the whitelist tests and cause lots of false alarms ... fixable
1243 * only by merging __exit and __init sections into __text, bloating
1244 * the kernel (which is especially evil on embedded platforms).
1246 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1248 const char *name = elf->strtab + sym->st_name;
1250 if (!name || !strlen(name))
1252 return !is_arm_mapping_symbol(name);
1256 * Find symbol based on relocation record info.
1257 * In some cases the symbol supplied is a valid symbol so
1258 * return refsym. If st_name != 0 we assume this is a valid symbol.
1259 * In other cases the symbol needs to be looked up in the symbol table
1260 * based on section and address.
1262 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1266 Elf_Sym *near = NULL;
1267 Elf64_Sword distance = 20;
1269 unsigned int relsym_secindex;
1271 if (relsym->st_name != 0)
1274 relsym_secindex = get_secindex(elf, relsym);
1275 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1276 if (get_secindex(elf, sym) != relsym_secindex)
1278 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1280 if (!is_valid_name(elf, sym))
1282 if (sym->st_value == addr)
1284 /* Find a symbol nearby - addr are maybe negative */
1285 d = sym->st_value - addr;
1287 d = addr - sym->st_value;
1293 /* We need a close match */
1301 * Find symbols before or equal addr and after addr - in the section sec.
1302 * If we find two symbols with equal offset prefer one with a valid name.
1303 * The ELF format may have a better way to detect what type of symbol
1304 * it is, but this works for now.
1306 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1310 Elf_Sym *near = NULL;
1311 Elf_Addr distance = ~0;
1313 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1316 if (is_shndx_special(sym->st_shndx))
1318 symsec = sec_name(elf, get_secindex(elf, sym));
1319 if (strcmp(symsec, sec) != 0)
1321 if (!is_valid_name(elf, sym))
1323 if (sym->st_value <= addr) {
1324 if ((addr - sym->st_value) < distance) {
1325 distance = addr - sym->st_value;
1327 } else if ((addr - sym->st_value) == distance) {
1336 * Convert a section name to the function/data attribute
1337 * .init.text => __init
1338 * .memexitconst => __memconst
1341 * The memory of returned value has been allocated on a heap. The user of this
1342 * method should free it after usage.
1344 static char *sec2annotation(const char *s)
1346 if (match(s, init_exit_sections)) {
1347 char *p = NOFAIL(malloc(20));
1354 while (*s && *s != '.')
1359 if (strstr(s, "rodata") != NULL)
1360 strcat(p, "const ");
1361 else if (strstr(s, "data") != NULL)
1367 return NOFAIL(strdup(""));
1371 static int is_function(Elf_Sym *sym)
1374 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1379 static void print_section_list(const char * const list[20])
1381 const char *const *s = list;
1384 fprintf(stderr, "%s", *s);
1387 fprintf(stderr, ", ");
1389 fprintf(stderr, "\n");
1392 static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1395 case 0: *name = "variable"; *name_p = ""; break;
1396 case 1: *name = "function"; *name_p = "()"; break;
1397 default: *name = "(unknown reference)"; *name_p = ""; break;
1402 * Print a warning about a section mismatch.
1403 * Try to find symbols near it so user can find it.
1404 * Check whitelist before warning - it may be a false positive.
1406 static void report_sec_mismatch(const char *modname,
1407 const struct sectioncheck *mismatch,
1408 const char *fromsec,
1409 unsigned long long fromaddr,
1410 const char *fromsym,
1412 const char *tosec, const char *tosym,
1415 const char *from, *from_p;
1416 const char *to, *to_p;
1420 sec_mismatch_count++;
1421 if (!sec_mismatch_verbose)
1424 get_pretty_name(from_is_func, &from, &from_p);
1425 get_pretty_name(to_is_func, &to, &to_p);
1427 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1428 "to the %s %s:%s%s\n",
1429 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1432 switch (mismatch->mismatch) {
1433 case TEXT_TO_ANY_INIT:
1434 prl_from = sec2annotation(fromsec);
1435 prl_to = sec2annotation(tosec);
1437 "The function %s%s() references\n"
1439 "This is often because %s lacks a %s\n"
1440 "annotation or the annotation of %s is wrong.\n",
1442 to, prl_to, tosym, to_p,
1443 fromsym, prl_to, tosym);
1447 case DATA_TO_ANY_INIT: {
1448 prl_to = sec2annotation(tosec);
1450 "The variable %s references\n"
1452 "If the reference is valid then annotate the\n"
1453 "variable with __init* or __refdata (see linux/init.h) "
1454 "or name the variable:\n",
1455 fromsym, to, prl_to, tosym, to_p);
1456 print_section_list(mismatch->symbol_white_list);
1460 case TEXT_TO_ANY_EXIT:
1461 prl_to = sec2annotation(tosec);
1463 "The function %s() references a %s in an exit section.\n"
1464 "Often the %s %s%s has valid usage outside the exit section\n"
1465 "and the fix is to remove the %sannotation of %s.\n",
1466 fromsym, to, to, tosym, to_p, prl_to, tosym);
1469 case DATA_TO_ANY_EXIT: {
1470 prl_to = sec2annotation(tosec);
1472 "The variable %s references\n"
1474 "If the reference is valid then annotate the\n"
1475 "variable with __exit* (see linux/init.h) or "
1476 "name the variable:\n",
1477 fromsym, to, prl_to, tosym, to_p);
1478 print_section_list(mismatch->symbol_white_list);
1482 case XXXINIT_TO_SOME_INIT:
1483 case XXXEXIT_TO_SOME_EXIT:
1484 prl_from = sec2annotation(fromsec);
1485 prl_to = sec2annotation(tosec);
1487 "The %s %s%s%s references\n"
1489 "If %s is only used by %s then\n"
1490 "annotate %s with a matching annotation.\n",
1491 from, prl_from, fromsym, from_p,
1492 to, prl_to, tosym, to_p,
1493 tosym, fromsym, tosym);
1497 case ANY_INIT_TO_ANY_EXIT:
1498 prl_from = sec2annotation(fromsec);
1499 prl_to = sec2annotation(tosec);
1501 "The %s %s%s%s references\n"
1503 "This is often seen when error handling "
1504 "in the init function\n"
1505 "uses functionality in the exit path.\n"
1506 "The fix is often to remove the %sannotation of\n"
1507 "%s%s so it may be used outside an exit section.\n",
1508 from, prl_from, fromsym, from_p,
1509 to, prl_to, tosym, to_p,
1510 prl_to, tosym, to_p);
1514 case ANY_EXIT_TO_ANY_INIT:
1515 prl_from = sec2annotation(fromsec);
1516 prl_to = sec2annotation(tosec);
1518 "The %s %s%s%s references\n"
1520 "This is often seen when error handling "
1521 "in the exit function\n"
1522 "uses functionality in the init path.\n"
1523 "The fix is often to remove the %sannotation of\n"
1524 "%s%s so it may be used outside an init section.\n",
1525 from, prl_from, fromsym, from_p,
1526 to, prl_to, tosym, to_p,
1527 prl_to, tosym, to_p);
1531 case EXPORT_TO_INIT_EXIT:
1532 prl_to = sec2annotation(tosec);
1534 "The symbol %s is exported and annotated %s\n"
1535 "Fix this by removing the %sannotation of %s "
1536 "or drop the export.\n",
1537 tosym, prl_to, prl_to, tosym);
1540 case EXTABLE_TO_NON_TEXT:
1541 fatal("There's a special handler for this mismatch type, "
1542 "we should never get here.");
1545 fprintf(stderr, "\n");
1548 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1549 const struct sectioncheck* const mismatch,
1550 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1556 const char *fromsym;
1558 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1559 fromsym = sym_name(elf, from);
1561 if (!strncmp(fromsym, "reference___initcall",
1562 sizeof("reference___initcall")-1))
1565 tosec = sec_name(elf, get_secindex(elf, sym));
1566 to = find_elf_symbol(elf, r->r_addend, sym);
1567 tosym = sym_name(elf, to);
1569 /* check whitelist - we may ignore it */
1570 if (secref_whitelist(mismatch,
1571 fromsec, fromsym, tosec, tosym)) {
1572 report_sec_mismatch(modname, mismatch,
1573 fromsec, r->r_offset, fromsym,
1574 is_function(from), tosec, tosym,
1579 static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1581 if (section_index > elf->num_sections)
1582 fatal("section_index is outside elf->num_sections!\n");
1584 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1588 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1589 * to know the sizeof(struct exception_table_entry) for the target architecture.
1591 static unsigned int extable_entry_size = 0;
1592 static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1595 * If we're currently checking the second relocation within __ex_table,
1596 * that relocation offset tells us the offsetof(struct
1597 * exception_table_entry, fixup) which is equal to sizeof(struct
1598 * exception_table_entry) divided by two. We use that to our advantage
1599 * since there's no portable way to get that size as every architecture
1600 * seems to go with different sized types. Not pretty but better than
1601 * hard-coding the size for every architecture..
1603 if (!extable_entry_size)
1604 extable_entry_size = r->r_offset * 2;
1607 static inline bool is_extable_fault_address(Elf_Rela *r)
1610 * extable_entry_size is only discovered after we've handled the
1611 * _second_ relocation in __ex_table, so only abort when we're not
1612 * handling the first reloc and extable_entry_size is zero.
1614 if (r->r_offset && extable_entry_size == 0)
1615 fatal("extable_entry size hasn't been discovered!\n");
1617 return ((r->r_offset == 0) ||
1618 (r->r_offset % extable_entry_size == 0));
1621 #define is_second_extable_reloc(Start, Cur, Sec) \
1622 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1624 static void report_extable_warnings(const char* modname, struct elf_info* elf,
1625 const struct sectioncheck* const mismatch,
1626 Elf_Rela* r, Elf_Sym* sym,
1627 const char* fromsec, const char* tosec)
1629 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1630 const char* fromsym_name = sym_name(elf, fromsym);
1631 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1632 const char* tosym_name = sym_name(elf, tosym);
1633 const char* from_pretty_name;
1634 const char* from_pretty_name_p;
1635 const char* to_pretty_name;
1636 const char* to_pretty_name_p;
1638 get_pretty_name(is_function(fromsym),
1639 &from_pretty_name, &from_pretty_name_p);
1640 get_pretty_name(is_function(tosym),
1641 &to_pretty_name, &to_pretty_name_p);
1643 warn("%s(%s+0x%lx): Section mismatch in reference"
1644 " from the %s %s%s to the %s %s:%s%s\n",
1645 modname, fromsec, (long)r->r_offset, from_pretty_name,
1646 fromsym_name, from_pretty_name_p,
1647 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1649 if (!match(tosec, mismatch->bad_tosec) &&
1650 is_executable_section(elf, get_secindex(elf, sym)))
1652 "The relocation at %s+0x%lx references\n"
1653 "section \"%s\" which is not in the list of\n"
1654 "authorized sections. If you're adding a new section\n"
1655 "and/or if this reference is valid, add \"%s\" to the\n"
1656 "list of authorized sections to jump to on fault.\n"
1657 "This can be achieved by adding \"%s\" to \n"
1658 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1659 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1662 static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1663 const struct sectioncheck* const mismatch,
1664 Elf_Rela* r, Elf_Sym* sym,
1665 const char *fromsec)
1667 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1669 sec_mismatch_count++;
1671 if (sec_mismatch_verbose)
1672 report_extable_warnings(modname, elf, mismatch, r, sym,
1675 if (match(tosec, mismatch->bad_tosec))
1676 fatal("The relocation at %s+0x%lx references\n"
1677 "section \"%s\" which is black-listed.\n"
1678 "Something is seriously wrong and should be fixed.\n"
1679 "You might get more information about where this is\n"
1680 "coming from by using scripts/check_extable.sh %s\n",
1681 fromsec, (long)r->r_offset, tosec, modname);
1682 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1683 if (is_extable_fault_address(r))
1684 fatal("The relocation at %s+0x%lx references\n"
1685 "section \"%s\" which is not executable, IOW\n"
1686 "it is not possible for the kernel to fault\n"
1687 "at that address. Something is seriously wrong\n"
1688 "and should be fixed.\n",
1689 fromsec, (long)r->r_offset, tosec);
1691 fatal("The relocation at %s+0x%lx references\n"
1692 "section \"%s\" which is not executable, IOW\n"
1693 "the kernel will fault if it ever tries to\n"
1694 "jump to it. Something is seriously wrong\n"
1695 "and should be fixed.\n",
1696 fromsec, (long)r->r_offset, tosec);
1700 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1701 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1703 const char *tosec = sec_name(elf, get_secindex(elf, sym));;
1704 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1707 if (mismatch->handler)
1708 mismatch->handler(modname, elf, mismatch,
1711 default_mismatch_handler(modname, elf, mismatch,
1716 static unsigned int *reloc_location(struct elf_info *elf,
1717 Elf_Shdr *sechdr, Elf_Rela *r)
1719 Elf_Shdr *sechdrs = elf->sechdrs;
1720 int section = sechdr->sh_info;
1722 return (void *)elf->hdr + sechdrs[section].sh_offset +
1726 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1728 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1729 unsigned int *location = reloc_location(elf, sechdr, r);
1733 r->r_addend = TO_NATIVE(*location);
1736 r->r_addend = TO_NATIVE(*location) + 4;
1737 /* For CONFIG_RELOCATABLE=y */
1738 if (elf->hdr->e_type == ET_EXEC)
1739 r->r_addend += r->r_offset;
1746 #define R_ARM_CALL 28
1748 #ifndef R_ARM_JUMP24
1749 #define R_ARM_JUMP24 29
1752 #ifndef R_ARM_THM_CALL
1753 #define R_ARM_THM_CALL 10
1755 #ifndef R_ARM_THM_JUMP24
1756 #define R_ARM_THM_JUMP24 30
1758 #ifndef R_ARM_THM_JUMP19
1759 #define R_ARM_THM_JUMP19 51
1762 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1764 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1768 /* From ARM ABI: (S + A) | T */
1769 r->r_addend = (int)(long)
1770 (elf->symtab_start + ELF_R_SYM(r->r_info));
1775 case R_ARM_THM_CALL:
1776 case R_ARM_THM_JUMP24:
1777 case R_ARM_THM_JUMP19:
1778 /* From ARM ABI: ((S + A) | T) - P */
1779 r->r_addend = (int)(long)(elf->hdr +
1781 (r->r_offset - sechdr->sh_addr));
1789 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1791 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1792 unsigned int *location = reloc_location(elf, sechdr, r);
1795 if (r_typ == R_MIPS_HI16)
1796 return 1; /* skip this */
1797 inst = TO_NATIVE(*location);
1800 r->r_addend = inst & 0xffff;
1803 r->r_addend = (inst & 0x03ffffff) << 2;
1812 static void section_rela(const char *modname, struct elf_info *elf,
1819 const char *fromsec;
1821 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1822 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1824 fromsec = sech_name(elf, sechdr);
1825 fromsec += strlen(".rela");
1826 /* if from section (name) is know good then skip it */
1827 if (match(fromsec, section_white_list))
1830 for (rela = start; rela < stop; rela++) {
1831 r.r_offset = TO_NATIVE(rela->r_offset);
1832 #if KERNEL_ELFCLASS == ELFCLASS64
1833 if (elf->hdr->e_machine == EM_MIPS) {
1835 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1836 r_sym = TO_NATIVE(r_sym);
1837 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1838 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1840 r.r_info = TO_NATIVE(rela->r_info);
1841 r_sym = ELF_R_SYM(r.r_info);
1844 r.r_info = TO_NATIVE(rela->r_info);
1845 r_sym = ELF_R_SYM(r.r_info);
1847 r.r_addend = TO_NATIVE(rela->r_addend);
1848 sym = elf->symtab_start + r_sym;
1849 /* Skip special sections */
1850 if (is_shndx_special(sym->st_shndx))
1852 if (is_second_extable_reloc(start, rela, fromsec))
1853 find_extable_entry_size(fromsec, &r);
1854 check_section_mismatch(modname, elf, &r, sym, fromsec);
1858 static void section_rel(const char *modname, struct elf_info *elf,
1865 const char *fromsec;
1867 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1868 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1870 fromsec = sech_name(elf, sechdr);
1871 fromsec += strlen(".rel");
1872 /* if from section (name) is know good then skip it */
1873 if (match(fromsec, section_white_list))
1876 for (rel = start; rel < stop; rel++) {
1877 r.r_offset = TO_NATIVE(rel->r_offset);
1878 #if KERNEL_ELFCLASS == ELFCLASS64
1879 if (elf->hdr->e_machine == EM_MIPS) {
1881 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1882 r_sym = TO_NATIVE(r_sym);
1883 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1884 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1886 r.r_info = TO_NATIVE(rel->r_info);
1887 r_sym = ELF_R_SYM(r.r_info);
1890 r.r_info = TO_NATIVE(rel->r_info);
1891 r_sym = ELF_R_SYM(r.r_info);
1894 switch (elf->hdr->e_machine) {
1896 if (addend_386_rel(elf, sechdr, &r))
1900 if (addend_arm_rel(elf, sechdr, &r))
1904 if (addend_mips_rel(elf, sechdr, &r))
1908 sym = elf->symtab_start + r_sym;
1909 /* Skip special sections */
1910 if (is_shndx_special(sym->st_shndx))
1912 if (is_second_extable_reloc(start, rel, fromsec))
1913 find_extable_entry_size(fromsec, &r);
1914 check_section_mismatch(modname, elf, &r, sym, fromsec);
1919 * A module includes a number of sections that are discarded
1920 * either when loaded or when used as built-in.
1921 * For loaded modules all functions marked __init and all data
1922 * marked __initdata will be discarded when the module has been initialized.
1923 * Likewise for modules used built-in the sections marked __exit
1924 * are discarded because __exit marked function are supposed to be called
1925 * only when a module is unloaded which never happens for built-in modules.
1926 * The check_sec_ref() function traverses all relocation records
1927 * to find all references to a section that reference a section that will
1928 * be discarded and warns about it.
1930 static void check_sec_ref(struct module *mod, const char *modname,
1931 struct elf_info *elf)
1934 Elf_Shdr *sechdrs = elf->sechdrs;
1936 /* Walk through all sections */
1937 for (i = 0; i < elf->num_sections; i++) {
1938 check_section(modname, elf, &elf->sechdrs[i]);
1939 /* We want to process only relocation sections and not .init */
1940 if (sechdrs[i].sh_type == SHT_RELA)
1941 section_rela(modname, elf, &elf->sechdrs[i]);
1942 else if (sechdrs[i].sh_type == SHT_REL)
1943 section_rel(modname, elf, &elf->sechdrs[i]);
1947 static char *remove_dot(char *s)
1949 size_t n = strcspn(s, ".");
1952 size_t m = strspn(s + n + 1, "0123456789");
1953 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1959 static void read_symbols(char *modname)
1961 const char *symname;
1965 struct elf_info info = { };
1968 if (!parse_elf(&info, modname))
1971 mod = new_module(modname);
1973 /* When there's no vmlinux, don't print warnings about
1974 * unresolved symbols (since there'll be too many ;) */
1975 if (is_vmlinux(modname)) {
1980 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1981 if (info.modinfo && !license && !is_vmlinux(modname))
1982 warn("modpost: missing MODULE_LICENSE() in %s\n"
1983 "see include/linux/module.h for "
1984 "more information\n", modname);
1986 if (license_is_gpl_compatible(license))
1987 mod->gpl_compatible = 1;
1989 mod->gpl_compatible = 0;
1992 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1993 "license", license);
1996 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1997 symname = remove_dot(info.strtab + sym->st_name);
1999 handle_modversions(mod, &info, sym, symname);
2000 handle_moddevtable(mod, &info, sym, symname);
2002 if (!is_vmlinux(modname) ||
2003 (is_vmlinux(modname) && vmlinux_section_warnings))
2004 check_sec_ref(mod, modname, &info);
2006 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
2008 maybe_frob_rcs_version(modname, version, info.modinfo,
2009 version - (char *)info.hdr);
2010 if (version || (all_versions && !is_vmlinux(modname)))
2011 get_src_version(modname, mod->srcversion,
2012 sizeof(mod->srcversion)-1);
2014 parse_elf_finish(&info);
2016 /* Our trick to get versioning for module struct etc. - it's
2017 * never passed as an argument to an exported function, so
2018 * the automatic versioning doesn't pick it up, but it's really
2019 * important anyhow */
2021 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
2024 static void read_symbols_from_files(const char *filename)
2027 char fname[PATH_MAX];
2029 if (strcmp(filename, "-") != 0) {
2030 in = fopen(filename, "r");
2032 fatal("Can't open filenames file %s: %m", filename);
2035 while (fgets(fname, PATH_MAX, in) != NULL) {
2036 if (strends(fname, "\n"))
2037 fname[strlen(fname)-1] = '\0';
2038 read_symbols(fname);
2047 /* We first write the generated file into memory using the
2048 * following helper, then compare to the file on disk and
2049 * only update the later if anything changed */
2051 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2052 const char *fmt, ...)
2059 len = vsnprintf(tmp, SZ, fmt, ap);
2060 buf_write(buf, tmp, len);
2064 void buf_write(struct buffer *buf, const char *s, int len)
2066 if (buf->size - buf->pos < len) {
2067 buf->size += len + SZ;
2068 buf->p = NOFAIL(realloc(buf->p, buf->size));
2070 strncpy(buf->p + buf->pos, s, len);
2074 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2076 const char *e = is_vmlinux(m) ?"":".ko";
2080 fatal("modpost: GPL-incompatible module %s%s "
2081 "uses GPL-only symbol '%s'\n", m, e, s);
2083 case export_unused_gpl:
2084 fatal("modpost: GPL-incompatible module %s%s "
2085 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
2087 case export_gpl_future:
2088 warn("modpost: GPL-incompatible module %s%s "
2089 "uses future GPL-only symbol '%s'\n", m, e, s);
2093 case export_unknown:
2099 static void check_for_unused(enum export exp, const char *m, const char *s)
2101 const char *e = is_vmlinux(m) ?"":".ko";
2105 case export_unused_gpl:
2106 warn("modpost: module %s%s "
2107 "uses symbol '%s' marked UNUSED\n", m, e, s);
2115 static void check_exports(struct module *mod)
2117 struct symbol *s, *exp;
2119 for (s = mod->unres; s; s = s->next) {
2120 const char *basename;
2121 exp = find_symbol(s->name);
2122 if (!exp || exp->module == mod)
2124 basename = strrchr(mod->name, '/');
2128 basename = mod->name;
2129 if (!mod->gpl_compatible)
2130 check_for_gpl_usage(exp->export, basename, exp->name);
2131 check_for_unused(exp->export, basename, exp->name);
2135 static int check_modname_len(struct module *mod)
2137 const char *mod_name;
2139 mod_name = strrchr(mod->name, '/');
2140 if (mod_name == NULL)
2141 mod_name = mod->name;
2144 if (strlen(mod_name) >= MODULE_NAME_LEN) {
2145 merror("module name is too long [%s.ko]\n", mod->name);
2153 * Header for the generated file
2155 static void add_header(struct buffer *b, struct module *mod)
2157 buf_printf(b, "#include <linux/module.h>\n");
2158 buf_printf(b, "#include <linux/vermagic.h>\n");
2159 buf_printf(b, "#include <linux/compiler.h>\n");
2160 buf_printf(b, "\n");
2161 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2162 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
2163 buf_printf(b, "\n");
2164 buf_printf(b, "__visible struct module __this_module\n");
2165 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
2166 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2168 buf_printf(b, "\t.init = init_module,\n");
2169 if (mod->has_cleanup)
2170 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2171 "\t.exit = cleanup_module,\n"
2173 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2174 buf_printf(b, "};\n");
2177 static void add_intree_flag(struct buffer *b, int is_intree)
2180 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2183 /* Cannot check for assembler */
2184 static void add_retpoline(struct buffer *b)
2186 buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n");
2187 buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
2188 buf_printf(b, "#endif\n");
2191 static void add_staging_flag(struct buffer *b, const char *name)
2193 static const char *staging_dir = "drivers/staging";
2195 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
2196 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2200 * Record CRCs for unresolved symbols
2202 static int add_versions(struct buffer *b, struct module *mod)
2204 struct symbol *s, *exp;
2207 for (s = mod->unres; s; s = s->next) {
2208 exp = find_symbol(s->name);
2209 if (!exp || exp->module == mod) {
2210 if (have_vmlinux && !s->weak) {
2211 if (warn_unresolved) {
2212 warn("\"%s\" [%s.ko] undefined!\n",
2213 s->name, mod->name);
2215 merror("\"%s\" [%s.ko] undefined!\n",
2216 s->name, mod->name);
2222 s->module = exp->module;
2223 s->crc_valid = exp->crc_valid;
2230 buf_printf(b, "\n");
2231 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2232 buf_printf(b, "__used\n");
2233 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
2235 for (s = mod->unres; s; s = s->next) {
2238 if (!s->crc_valid) {
2239 warn("\"%s\" [%s.ko] has no CRC!\n",
2240 s->name, mod->name);
2243 if (strlen(s->name) >= MODULE_NAME_LEN) {
2244 merror("too long symbol \"%s\" [%s.ko]\n",
2245 s->name, mod->name);
2249 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
2253 buf_printf(b, "};\n");
2258 static void add_depends(struct buffer *b, struct module *mod,
2259 struct module *modules)
2265 for (m = modules; m; m = m->next)
2266 m->seen = is_vmlinux(m->name);
2268 buf_printf(b, "\n");
2269 buf_printf(b, "static const char __module_depends[]\n");
2270 buf_printf(b, "__used\n");
2271 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
2272 buf_printf(b, "\"depends=");
2273 for (s = mod->unres; s; s = s->next) {
2278 if (s->module->seen)
2281 s->module->seen = 1;
2282 p = strrchr(s->module->name, '/');
2286 p = s->module->name;
2287 buf_printf(b, "%s%s", first ? "" : ",", p);
2290 buf_printf(b, "\";\n");
2293 static void add_srcversion(struct buffer *b, struct module *mod)
2295 if (mod->srcversion[0]) {
2296 buf_printf(b, "\n");
2297 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2302 static void write_if_changed(struct buffer *b, const char *fname)
2308 file = fopen(fname, "r");
2312 if (fstat(fileno(file), &st) < 0)
2315 if (st.st_size != b->pos)
2318 tmp = NOFAIL(malloc(b->pos));
2319 if (fread(tmp, 1, b->pos, file) != b->pos)
2322 if (memcmp(tmp, b->p, b->pos) != 0)
2334 file = fopen(fname, "w");
2339 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2346 /* parse Module.symvers file. line format:
2347 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2349 static void read_dump(const char *fname, unsigned int kernel)
2351 unsigned long size, pos = 0;
2352 void *file = grab_file(fname, &size);
2356 /* No symbol versions, silently ignore */
2359 while ((line = get_next_line(&pos, file, size))) {
2360 char *symname, *modname, *d, *export, *end;
2365 if (!(symname = strchr(line, '\t')))
2368 if (!(modname = strchr(symname, '\t')))
2371 if ((export = strchr(modname, '\t')) != NULL)
2373 if (export && ((end = strchr(export, '\t')) != NULL))
2375 crc = strtoul(line, &d, 16);
2376 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2378 mod = find_module(modname);
2380 if (is_vmlinux(modname))
2382 mod = new_module(modname);
2385 s = sym_add_exported(symname, mod, export_no(export));
2388 sym_update_crc(symname, mod, crc, export_no(export));
2390 release_file(file, size);
2393 release_file(file, size);
2394 fatal("parse error in symbol dump file\n");
2397 /* For normal builds always dump all symbols.
2398 * For external modules only dump symbols
2399 * that are not read from kernel Module.symvers.
2401 static int dump_sym(struct symbol *sym)
2403 if (!external_module)
2405 if (sym->vmlinux || sym->kernel)
2410 static void write_dump(const char *fname)
2412 struct buffer buf = { };
2413 struct symbol *symbol;
2416 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2417 symbol = symbolhash[n];
2419 if (dump_sym(symbol))
2420 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2421 symbol->crc, symbol->name,
2422 symbol->module->name,
2423 export_str(symbol->export));
2424 symbol = symbol->next;
2427 write_if_changed(&buf, fname);
2431 struct ext_sym_list {
2432 struct ext_sym_list *next;
2436 int main(int argc, char **argv)
2439 struct buffer buf = { };
2440 char *kernel_read = NULL, *module_read = NULL;
2441 char *dump_write = NULL, *files_source = NULL;
2444 struct ext_sym_list *extsym_iter;
2445 struct ext_sym_list *extsym_start = NULL;
2447 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:E")) != -1) {
2450 kernel_read = optarg;
2453 module_read = optarg;
2454 external_module = 1;
2457 external_module = 1;
2459 NOFAIL(malloc(sizeof(*extsym_iter)));
2460 extsym_iter->next = extsym_start;
2461 extsym_iter->file = optarg;
2462 extsym_start = extsym_iter;
2468 ignore_missing_files = 1;
2471 dump_write = optarg;
2477 vmlinux_section_warnings = 0;
2480 sec_mismatch_verbose = 0;
2483 files_source = optarg;
2486 warn_unresolved = 1;
2489 sec_mismatch_fatal = 1;
2497 read_dump(kernel_read, 1);
2499 read_dump(module_read, 0);
2500 while (extsym_start) {
2501 read_dump(extsym_start->file, 0);
2502 extsym_iter = extsym_start->next;
2504 extsym_start = extsym_iter;
2507 while (optind < argc)
2508 read_symbols(argv[optind++]);
2511 read_symbols_from_files(files_source);
2513 for (mod = modules; mod; mod = mod->next) {
2521 for (mod = modules; mod; mod = mod->next) {
2522 char fname[PATH_MAX];
2529 err |= check_modname_len(mod);
2530 add_header(&buf, mod);
2531 add_intree_flag(&buf, !external_module);
2532 add_retpoline(&buf);
2533 add_staging_flag(&buf, mod->name);
2534 err |= add_versions(&buf, mod);
2535 add_depends(&buf, mod, modules);
2536 add_moddevtable(&buf, mod);
2537 add_srcversion(&buf, mod);
2539 sprintf(fname, "%s.mod.c", mod->name);
2540 write_if_changed(&buf, fname);
2543 write_dump(dump_write);
2544 if (sec_mismatch_count) {
2545 if (!sec_mismatch_verbose) {
2546 warn("modpost: Found %d section mismatch(es).\n"
2547 "To see full details build your kernel with:\n"
2548 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2549 sec_mismatch_count);
2551 if (sec_mismatch_fatal) {
2552 fatal("modpost: Section mismatches detected.\n"
2553 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");