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] == '$' && strchr("axtd", str[1])
1233 && (str[2] == '\0' || str[2] == '.');
1237 * If there's no name there, ignore it; likewise, ignore it if it's
1238 * one of the magic symbols emitted used by current ARM tools.
1240 * Otherwise if find_symbols_between() returns those symbols, they'll
1241 * fail the whitelist tests and cause lots of false alarms ... fixable
1242 * only by merging __exit and __init sections into __text, bloating
1243 * the kernel (which is especially evil on embedded platforms).
1245 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1247 const char *name = elf->strtab + sym->st_name;
1249 if (!name || !strlen(name))
1251 return !is_arm_mapping_symbol(name);
1255 * Find symbol based on relocation record info.
1256 * In some cases the symbol supplied is a valid symbol so
1257 * return refsym. If st_name != 0 we assume this is a valid symbol.
1258 * In other cases the symbol needs to be looked up in the symbol table
1259 * based on section and address.
1261 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1265 Elf_Sym *near = NULL;
1266 Elf64_Sword distance = 20;
1268 unsigned int relsym_secindex;
1270 if (relsym->st_name != 0)
1273 relsym_secindex = get_secindex(elf, relsym);
1274 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1275 if (get_secindex(elf, sym) != relsym_secindex)
1277 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1279 if (!is_valid_name(elf, sym))
1281 if (sym->st_value == addr)
1283 /* Find a symbol nearby - addr are maybe negative */
1284 d = sym->st_value - addr;
1286 d = addr - sym->st_value;
1292 /* We need a close match */
1300 * Find symbols before or equal addr and after addr - in the section sec.
1301 * If we find two symbols with equal offset prefer one with a valid name.
1302 * The ELF format may have a better way to detect what type of symbol
1303 * it is, but this works for now.
1305 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1309 Elf_Sym *near = NULL;
1310 Elf_Addr distance = ~0;
1312 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1315 if (is_shndx_special(sym->st_shndx))
1317 symsec = sec_name(elf, get_secindex(elf, sym));
1318 if (strcmp(symsec, sec) != 0)
1320 if (!is_valid_name(elf, sym))
1322 if (sym->st_value <= addr) {
1323 if ((addr - sym->st_value) < distance) {
1324 distance = addr - sym->st_value;
1326 } else if ((addr - sym->st_value) == distance) {
1335 * Convert a section name to the function/data attribute
1336 * .init.text => __init
1337 * .memexitconst => __memconst
1340 * The memory of returned value has been allocated on a heap. The user of this
1341 * method should free it after usage.
1343 static char *sec2annotation(const char *s)
1345 if (match(s, init_exit_sections)) {
1346 char *p = NOFAIL(malloc(20));
1353 while (*s && *s != '.')
1358 if (strstr(s, "rodata") != NULL)
1359 strcat(p, "const ");
1360 else if (strstr(s, "data") != NULL)
1366 return NOFAIL(strdup(""));
1370 static int is_function(Elf_Sym *sym)
1373 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1378 static void print_section_list(const char * const list[20])
1380 const char *const *s = list;
1383 fprintf(stderr, "%s", *s);
1386 fprintf(stderr, ", ");
1388 fprintf(stderr, "\n");
1391 static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1394 case 0: *name = "variable"; *name_p = ""; break;
1395 case 1: *name = "function"; *name_p = "()"; break;
1396 default: *name = "(unknown reference)"; *name_p = ""; break;
1401 * Print a warning about a section mismatch.
1402 * Try to find symbols near it so user can find it.
1403 * Check whitelist before warning - it may be a false positive.
1405 static void report_sec_mismatch(const char *modname,
1406 const struct sectioncheck *mismatch,
1407 const char *fromsec,
1408 unsigned long long fromaddr,
1409 const char *fromsym,
1411 const char *tosec, const char *tosym,
1414 const char *from, *from_p;
1415 const char *to, *to_p;
1419 sec_mismatch_count++;
1420 if (!sec_mismatch_verbose)
1423 get_pretty_name(from_is_func, &from, &from_p);
1424 get_pretty_name(to_is_func, &to, &to_p);
1426 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1427 "to the %s %s:%s%s\n",
1428 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1431 switch (mismatch->mismatch) {
1432 case TEXT_TO_ANY_INIT:
1433 prl_from = sec2annotation(fromsec);
1434 prl_to = sec2annotation(tosec);
1436 "The function %s%s() references\n"
1438 "This is often because %s lacks a %s\n"
1439 "annotation or the annotation of %s is wrong.\n",
1441 to, prl_to, tosym, to_p,
1442 fromsym, prl_to, tosym);
1446 case DATA_TO_ANY_INIT: {
1447 prl_to = sec2annotation(tosec);
1449 "The variable %s references\n"
1451 "If the reference is valid then annotate the\n"
1452 "variable with __init* or __refdata (see linux/init.h) "
1453 "or name the variable:\n",
1454 fromsym, to, prl_to, tosym, to_p);
1455 print_section_list(mismatch->symbol_white_list);
1459 case TEXT_TO_ANY_EXIT:
1460 prl_to = sec2annotation(tosec);
1462 "The function %s() references a %s in an exit section.\n"
1463 "Often the %s %s%s has valid usage outside the exit section\n"
1464 "and the fix is to remove the %sannotation of %s.\n",
1465 fromsym, to, to, tosym, to_p, prl_to, tosym);
1468 case DATA_TO_ANY_EXIT: {
1469 prl_to = sec2annotation(tosec);
1471 "The variable %s references\n"
1473 "If the reference is valid then annotate the\n"
1474 "variable with __exit* (see linux/init.h) or "
1475 "name the variable:\n",
1476 fromsym, to, prl_to, tosym, to_p);
1477 print_section_list(mismatch->symbol_white_list);
1481 case XXXINIT_TO_SOME_INIT:
1482 case XXXEXIT_TO_SOME_EXIT:
1483 prl_from = sec2annotation(fromsec);
1484 prl_to = sec2annotation(tosec);
1486 "The %s %s%s%s references\n"
1488 "If %s is only used by %s then\n"
1489 "annotate %s with a matching annotation.\n",
1490 from, prl_from, fromsym, from_p,
1491 to, prl_to, tosym, to_p,
1492 tosym, fromsym, tosym);
1496 case ANY_INIT_TO_ANY_EXIT:
1497 prl_from = sec2annotation(fromsec);
1498 prl_to = sec2annotation(tosec);
1500 "The %s %s%s%s references\n"
1502 "This is often seen when error handling "
1503 "in the init function\n"
1504 "uses functionality in the exit path.\n"
1505 "The fix is often to remove the %sannotation of\n"
1506 "%s%s so it may be used outside an exit section.\n",
1507 from, prl_from, fromsym, from_p,
1508 to, prl_to, tosym, to_p,
1509 prl_to, tosym, to_p);
1513 case ANY_EXIT_TO_ANY_INIT:
1514 prl_from = sec2annotation(fromsec);
1515 prl_to = sec2annotation(tosec);
1517 "The %s %s%s%s references\n"
1519 "This is often seen when error handling "
1520 "in the exit function\n"
1521 "uses functionality in the init path.\n"
1522 "The fix is often to remove the %sannotation of\n"
1523 "%s%s so it may be used outside an init section.\n",
1524 from, prl_from, fromsym, from_p,
1525 to, prl_to, tosym, to_p,
1526 prl_to, tosym, to_p);
1530 case EXPORT_TO_INIT_EXIT:
1531 prl_to = sec2annotation(tosec);
1533 "The symbol %s is exported and annotated %s\n"
1534 "Fix this by removing the %sannotation of %s "
1535 "or drop the export.\n",
1536 tosym, prl_to, prl_to, tosym);
1539 case EXTABLE_TO_NON_TEXT:
1540 fatal("There's a special handler for this mismatch type, "
1541 "we should never get here.");
1544 fprintf(stderr, "\n");
1547 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1548 const struct sectioncheck* const mismatch,
1549 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1555 const char *fromsym;
1557 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1558 fromsym = sym_name(elf, from);
1560 if (!strncmp(fromsym, "reference___initcall",
1561 sizeof("reference___initcall")-1))
1564 tosec = sec_name(elf, get_secindex(elf, sym));
1565 to = find_elf_symbol(elf, r->r_addend, sym);
1566 tosym = sym_name(elf, to);
1568 /* check whitelist - we may ignore it */
1569 if (secref_whitelist(mismatch,
1570 fromsec, fromsym, tosec, tosym)) {
1571 report_sec_mismatch(modname, mismatch,
1572 fromsec, r->r_offset, fromsym,
1573 is_function(from), tosec, tosym,
1578 static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1580 if (section_index > elf->num_sections)
1581 fatal("section_index is outside elf->num_sections!\n");
1583 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1587 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1588 * to know the sizeof(struct exception_table_entry) for the target architecture.
1590 static unsigned int extable_entry_size = 0;
1591 static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1594 * If we're currently checking the second relocation within __ex_table,
1595 * that relocation offset tells us the offsetof(struct
1596 * exception_table_entry, fixup) which is equal to sizeof(struct
1597 * exception_table_entry) divided by two. We use that to our advantage
1598 * since there's no portable way to get that size as every architecture
1599 * seems to go with different sized types. Not pretty but better than
1600 * hard-coding the size for every architecture..
1602 if (!extable_entry_size)
1603 extable_entry_size = r->r_offset * 2;
1606 static inline bool is_extable_fault_address(Elf_Rela *r)
1609 * extable_entry_size is only discovered after we've handled the
1610 * _second_ relocation in __ex_table, so only abort when we're not
1611 * handling the first reloc and extable_entry_size is zero.
1613 if (r->r_offset && extable_entry_size == 0)
1614 fatal("extable_entry size hasn't been discovered!\n");
1616 return ((r->r_offset == 0) ||
1617 (r->r_offset % extable_entry_size == 0));
1620 #define is_second_extable_reloc(Start, Cur, Sec) \
1621 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1623 static void report_extable_warnings(const char* modname, struct elf_info* elf,
1624 const struct sectioncheck* const mismatch,
1625 Elf_Rela* r, Elf_Sym* sym,
1626 const char* fromsec, const char* tosec)
1628 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1629 const char* fromsym_name = sym_name(elf, fromsym);
1630 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1631 const char* tosym_name = sym_name(elf, tosym);
1632 const char* from_pretty_name;
1633 const char* from_pretty_name_p;
1634 const char* to_pretty_name;
1635 const char* to_pretty_name_p;
1637 get_pretty_name(is_function(fromsym),
1638 &from_pretty_name, &from_pretty_name_p);
1639 get_pretty_name(is_function(tosym),
1640 &to_pretty_name, &to_pretty_name_p);
1642 warn("%s(%s+0x%lx): Section mismatch in reference"
1643 " from the %s %s%s to the %s %s:%s%s\n",
1644 modname, fromsec, (long)r->r_offset, from_pretty_name,
1645 fromsym_name, from_pretty_name_p,
1646 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1648 if (!match(tosec, mismatch->bad_tosec) &&
1649 is_executable_section(elf, get_secindex(elf, sym)))
1651 "The relocation at %s+0x%lx references\n"
1652 "section \"%s\" which is not in the list of\n"
1653 "authorized sections. If you're adding a new section\n"
1654 "and/or if this reference is valid, add \"%s\" to the\n"
1655 "list of authorized sections to jump to on fault.\n"
1656 "This can be achieved by adding \"%s\" to \n"
1657 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1658 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1661 static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1662 const struct sectioncheck* const mismatch,
1663 Elf_Rela* r, Elf_Sym* sym,
1664 const char *fromsec)
1666 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1668 sec_mismatch_count++;
1670 if (sec_mismatch_verbose)
1671 report_extable_warnings(modname, elf, mismatch, r, sym,
1674 if (match(tosec, mismatch->bad_tosec))
1675 fatal("The relocation at %s+0x%lx references\n"
1676 "section \"%s\" which is black-listed.\n"
1677 "Something is seriously wrong and should be fixed.\n"
1678 "You might get more information about where this is\n"
1679 "coming from by using scripts/check_extable.sh %s\n",
1680 fromsec, (long)r->r_offset, tosec, modname);
1681 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1682 if (is_extable_fault_address(r))
1683 fatal("The relocation at %s+0x%lx references\n"
1684 "section \"%s\" which is not executable, IOW\n"
1685 "it is not possible for the kernel to fault\n"
1686 "at that address. Something is seriously wrong\n"
1687 "and should be fixed.\n",
1688 fromsec, (long)r->r_offset, tosec);
1690 fatal("The relocation at %s+0x%lx references\n"
1691 "section \"%s\" which is not executable, IOW\n"
1692 "the kernel will fault if it ever tries to\n"
1693 "jump to it. Something is seriously wrong\n"
1694 "and should be fixed.\n",
1695 fromsec, (long)r->r_offset, tosec);
1699 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1700 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1702 const char *tosec = sec_name(elf, get_secindex(elf, sym));;
1703 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1706 if (mismatch->handler)
1707 mismatch->handler(modname, elf, mismatch,
1710 default_mismatch_handler(modname, elf, mismatch,
1715 static unsigned int *reloc_location(struct elf_info *elf,
1716 Elf_Shdr *sechdr, Elf_Rela *r)
1718 Elf_Shdr *sechdrs = elf->sechdrs;
1719 int section = sechdr->sh_info;
1721 return (void *)elf->hdr + sechdrs[section].sh_offset +
1725 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1727 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1728 unsigned int *location = reloc_location(elf, sechdr, r);
1732 r->r_addend = TO_NATIVE(*location);
1735 r->r_addend = TO_NATIVE(*location) + 4;
1736 /* For CONFIG_RELOCATABLE=y */
1737 if (elf->hdr->e_type == ET_EXEC)
1738 r->r_addend += r->r_offset;
1745 #define R_ARM_CALL 28
1747 #ifndef R_ARM_JUMP24
1748 #define R_ARM_JUMP24 29
1751 #ifndef R_ARM_THM_CALL
1752 #define R_ARM_THM_CALL 10
1754 #ifndef R_ARM_THM_JUMP24
1755 #define R_ARM_THM_JUMP24 30
1757 #ifndef R_ARM_THM_JUMP19
1758 #define R_ARM_THM_JUMP19 51
1761 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1763 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1767 /* From ARM ABI: (S + A) | T */
1768 r->r_addend = (int)(long)
1769 (elf->symtab_start + ELF_R_SYM(r->r_info));
1774 case R_ARM_THM_CALL:
1775 case R_ARM_THM_JUMP24:
1776 case R_ARM_THM_JUMP19:
1777 /* From ARM ABI: ((S + A) | T) - P */
1778 r->r_addend = (int)(long)(elf->hdr +
1780 (r->r_offset - sechdr->sh_addr));
1788 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1790 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1791 unsigned int *location = reloc_location(elf, sechdr, r);
1794 if (r_typ == R_MIPS_HI16)
1795 return 1; /* skip this */
1796 inst = TO_NATIVE(*location);
1799 r->r_addend = inst & 0xffff;
1802 r->r_addend = (inst & 0x03ffffff) << 2;
1811 static void section_rela(const char *modname, struct elf_info *elf,
1818 const char *fromsec;
1820 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1821 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1823 fromsec = sech_name(elf, sechdr);
1824 fromsec += strlen(".rela");
1825 /* if from section (name) is know good then skip it */
1826 if (match(fromsec, section_white_list))
1829 for (rela = start; rela < stop; rela++) {
1830 r.r_offset = TO_NATIVE(rela->r_offset);
1831 #if KERNEL_ELFCLASS == ELFCLASS64
1832 if (elf->hdr->e_machine == EM_MIPS) {
1834 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1835 r_sym = TO_NATIVE(r_sym);
1836 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1837 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1839 r.r_info = TO_NATIVE(rela->r_info);
1840 r_sym = ELF_R_SYM(r.r_info);
1843 r.r_info = TO_NATIVE(rela->r_info);
1844 r_sym = ELF_R_SYM(r.r_info);
1846 r.r_addend = TO_NATIVE(rela->r_addend);
1847 sym = elf->symtab_start + r_sym;
1848 /* Skip special sections */
1849 if (is_shndx_special(sym->st_shndx))
1851 if (is_second_extable_reloc(start, rela, fromsec))
1852 find_extable_entry_size(fromsec, &r);
1853 check_section_mismatch(modname, elf, &r, sym, fromsec);
1857 static void section_rel(const char *modname, struct elf_info *elf,
1864 const char *fromsec;
1866 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1867 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1869 fromsec = sech_name(elf, sechdr);
1870 fromsec += strlen(".rel");
1871 /* if from section (name) is know good then skip it */
1872 if (match(fromsec, section_white_list))
1875 for (rel = start; rel < stop; rel++) {
1876 r.r_offset = TO_NATIVE(rel->r_offset);
1877 #if KERNEL_ELFCLASS == ELFCLASS64
1878 if (elf->hdr->e_machine == EM_MIPS) {
1880 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1881 r_sym = TO_NATIVE(r_sym);
1882 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1883 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1885 r.r_info = TO_NATIVE(rel->r_info);
1886 r_sym = ELF_R_SYM(r.r_info);
1889 r.r_info = TO_NATIVE(rel->r_info);
1890 r_sym = ELF_R_SYM(r.r_info);
1893 switch (elf->hdr->e_machine) {
1895 if (addend_386_rel(elf, sechdr, &r))
1899 if (addend_arm_rel(elf, sechdr, &r))
1903 if (addend_mips_rel(elf, sechdr, &r))
1907 sym = elf->symtab_start + r_sym;
1908 /* Skip special sections */
1909 if (is_shndx_special(sym->st_shndx))
1911 if (is_second_extable_reloc(start, rel, fromsec))
1912 find_extable_entry_size(fromsec, &r);
1913 check_section_mismatch(modname, elf, &r, sym, fromsec);
1918 * A module includes a number of sections that are discarded
1919 * either when loaded or when used as built-in.
1920 * For loaded modules all functions marked __init and all data
1921 * marked __initdata will be discarded when the module has been initialized.
1922 * Likewise for modules used built-in the sections marked __exit
1923 * are discarded because __exit marked function are supposed to be called
1924 * only when a module is unloaded which never happens for built-in modules.
1925 * The check_sec_ref() function traverses all relocation records
1926 * to find all references to a section that reference a section that will
1927 * be discarded and warns about it.
1929 static void check_sec_ref(struct module *mod, const char *modname,
1930 struct elf_info *elf)
1933 Elf_Shdr *sechdrs = elf->sechdrs;
1935 /* Walk through all sections */
1936 for (i = 0; i < elf->num_sections; i++) {
1937 check_section(modname, elf, &elf->sechdrs[i]);
1938 /* We want to process only relocation sections and not .init */
1939 if (sechdrs[i].sh_type == SHT_RELA)
1940 section_rela(modname, elf, &elf->sechdrs[i]);
1941 else if (sechdrs[i].sh_type == SHT_REL)
1942 section_rel(modname, elf, &elf->sechdrs[i]);
1946 static char *remove_dot(char *s)
1948 size_t n = strcspn(s, ".");
1951 size_t m = strspn(s + n + 1, "0123456789");
1952 if (m && (s[n + m] == '.' || s[n + m] == 0))
1958 static void read_symbols(char *modname)
1960 const char *symname;
1964 struct elf_info info = { };
1967 if (!parse_elf(&info, modname))
1970 mod = new_module(modname);
1972 /* When there's no vmlinux, don't print warnings about
1973 * unresolved symbols (since there'll be too many ;) */
1974 if (is_vmlinux(modname)) {
1979 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1980 if (info.modinfo && !license && !is_vmlinux(modname))
1981 warn("modpost: missing MODULE_LICENSE() in %s\n"
1982 "see include/linux/module.h for "
1983 "more information\n", modname);
1985 if (license_is_gpl_compatible(license))
1986 mod->gpl_compatible = 1;
1988 mod->gpl_compatible = 0;
1991 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1992 "license", license);
1995 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1996 symname = remove_dot(info.strtab + sym->st_name);
1998 handle_modversions(mod, &info, sym, symname);
1999 handle_moddevtable(mod, &info, sym, symname);
2001 if (!is_vmlinux(modname) ||
2002 (is_vmlinux(modname) && vmlinux_section_warnings))
2003 check_sec_ref(mod, modname, &info);
2005 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
2007 maybe_frob_rcs_version(modname, version, info.modinfo,
2008 version - (char *)info.hdr);
2009 if (version || (all_versions && !is_vmlinux(modname)))
2010 get_src_version(modname, mod->srcversion,
2011 sizeof(mod->srcversion)-1);
2013 parse_elf_finish(&info);
2015 /* Our trick to get versioning for module struct etc. - it's
2016 * never passed as an argument to an exported function, so
2017 * the automatic versioning doesn't pick it up, but it's really
2018 * important anyhow */
2020 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
2023 static void read_symbols_from_files(const char *filename)
2026 char fname[PATH_MAX];
2028 if (strcmp(filename, "-") != 0) {
2029 in = fopen(filename, "r");
2031 fatal("Can't open filenames file %s: %m", filename);
2034 while (fgets(fname, PATH_MAX, in) != NULL) {
2035 if (strends(fname, "\n"))
2036 fname[strlen(fname)-1] = '\0';
2037 read_symbols(fname);
2046 /* We first write the generated file into memory using the
2047 * following helper, then compare to the file on disk and
2048 * only update the later if anything changed */
2050 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2051 const char *fmt, ...)
2058 len = vsnprintf(tmp, SZ, fmt, ap);
2059 buf_write(buf, tmp, len);
2063 void buf_write(struct buffer *buf, const char *s, int len)
2065 if (buf->size - buf->pos < len) {
2066 buf->size += len + SZ;
2067 buf->p = NOFAIL(realloc(buf->p, buf->size));
2069 strncpy(buf->p + buf->pos, s, len);
2073 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2075 const char *e = is_vmlinux(m) ?"":".ko";
2079 fatal("modpost: GPL-incompatible module %s%s "
2080 "uses GPL-only symbol '%s'\n", m, e, s);
2082 case export_unused_gpl:
2083 fatal("modpost: GPL-incompatible module %s%s "
2084 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
2086 case export_gpl_future:
2087 warn("modpost: GPL-incompatible module %s%s "
2088 "uses future GPL-only symbol '%s'\n", m, e, s);
2092 case export_unknown:
2098 static void check_for_unused(enum export exp, const char *m, const char *s)
2100 const char *e = is_vmlinux(m) ?"":".ko";
2104 case export_unused_gpl:
2105 warn("modpost: module %s%s "
2106 "uses symbol '%s' marked UNUSED\n", m, e, s);
2114 static void check_exports(struct module *mod)
2116 struct symbol *s, *exp;
2118 for (s = mod->unres; s; s = s->next) {
2119 const char *basename;
2120 exp = find_symbol(s->name);
2121 if (!exp || exp->module == mod)
2123 basename = strrchr(mod->name, '/');
2127 basename = mod->name;
2128 if (!mod->gpl_compatible)
2129 check_for_gpl_usage(exp->export, basename, exp->name);
2130 check_for_unused(exp->export, basename, exp->name);
2134 static int check_modname_len(struct module *mod)
2136 const char *mod_name;
2138 mod_name = strrchr(mod->name, '/');
2139 if (mod_name == NULL)
2140 mod_name = mod->name;
2143 if (strlen(mod_name) >= MODULE_NAME_LEN) {
2144 merror("module name is too long [%s.ko]\n", mod->name);
2152 * Header for the generated file
2154 static void add_header(struct buffer *b, struct module *mod)
2156 buf_printf(b, "#include <linux/module.h>\n");
2157 buf_printf(b, "#include <linux/vermagic.h>\n");
2158 buf_printf(b, "#include <linux/compiler.h>\n");
2159 buf_printf(b, "\n");
2160 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2161 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
2162 buf_printf(b, "\n");
2163 buf_printf(b, "__visible struct module __this_module\n");
2164 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
2165 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2167 buf_printf(b, "\t.init = init_module,\n");
2168 if (mod->has_cleanup)
2169 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2170 "\t.exit = cleanup_module,\n"
2172 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2173 buf_printf(b, "};\n");
2176 static void add_intree_flag(struct buffer *b, int is_intree)
2179 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2182 /* Cannot check for assembler */
2183 static void add_retpoline(struct buffer *b)
2185 buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n");
2186 buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
2187 buf_printf(b, "#endif\n");
2190 static void add_staging_flag(struct buffer *b, const char *name)
2192 static const char *staging_dir = "drivers/staging";
2194 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
2195 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2199 * Record CRCs for unresolved symbols
2201 static int add_versions(struct buffer *b, struct module *mod)
2203 struct symbol *s, *exp;
2206 for (s = mod->unres; s; s = s->next) {
2207 exp = find_symbol(s->name);
2208 if (!exp || exp->module == mod) {
2209 if (have_vmlinux && !s->weak) {
2210 if (warn_unresolved) {
2211 warn("\"%s\" [%s.ko] undefined!\n",
2212 s->name, mod->name);
2214 merror("\"%s\" [%s.ko] undefined!\n",
2215 s->name, mod->name);
2221 s->module = exp->module;
2222 s->crc_valid = exp->crc_valid;
2229 buf_printf(b, "\n");
2230 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2231 buf_printf(b, "__used\n");
2232 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
2234 for (s = mod->unres; s; s = s->next) {
2237 if (!s->crc_valid) {
2238 warn("\"%s\" [%s.ko] has no CRC!\n",
2239 s->name, mod->name);
2242 if (strlen(s->name) >= MODULE_NAME_LEN) {
2243 merror("too long symbol \"%s\" [%s.ko]\n",
2244 s->name, mod->name);
2248 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
2252 buf_printf(b, "};\n");
2257 static void add_depends(struct buffer *b, struct module *mod,
2258 struct module *modules)
2264 for (m = modules; m; m = m->next)
2265 m->seen = is_vmlinux(m->name);
2267 buf_printf(b, "\n");
2268 buf_printf(b, "static const char __module_depends[]\n");
2269 buf_printf(b, "__used\n");
2270 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
2271 buf_printf(b, "\"depends=");
2272 for (s = mod->unres; s; s = s->next) {
2277 if (s->module->seen)
2280 s->module->seen = 1;
2281 p = strrchr(s->module->name, '/');
2285 p = s->module->name;
2286 buf_printf(b, "%s%s", first ? "" : ",", p);
2289 buf_printf(b, "\";\n");
2292 static void add_srcversion(struct buffer *b, struct module *mod)
2294 if (mod->srcversion[0]) {
2295 buf_printf(b, "\n");
2296 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2301 static void write_if_changed(struct buffer *b, const char *fname)
2307 file = fopen(fname, "r");
2311 if (fstat(fileno(file), &st) < 0)
2314 if (st.st_size != b->pos)
2317 tmp = NOFAIL(malloc(b->pos));
2318 if (fread(tmp, 1, b->pos, file) != b->pos)
2321 if (memcmp(tmp, b->p, b->pos) != 0)
2333 file = fopen(fname, "w");
2338 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2345 /* parse Module.symvers file. line format:
2346 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2348 static void read_dump(const char *fname, unsigned int kernel)
2350 unsigned long size, pos = 0;
2351 void *file = grab_file(fname, &size);
2355 /* No symbol versions, silently ignore */
2358 while ((line = get_next_line(&pos, file, size))) {
2359 char *symname, *modname, *d, *export, *end;
2364 if (!(symname = strchr(line, '\t')))
2367 if (!(modname = strchr(symname, '\t')))
2370 if ((export = strchr(modname, '\t')) != NULL)
2372 if (export && ((end = strchr(export, '\t')) != NULL))
2374 crc = strtoul(line, &d, 16);
2375 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2377 mod = find_module(modname);
2379 if (is_vmlinux(modname))
2381 mod = new_module(modname);
2384 s = sym_add_exported(symname, mod, export_no(export));
2387 sym_update_crc(symname, mod, crc, export_no(export));
2389 release_file(file, size);
2392 release_file(file, size);
2393 fatal("parse error in symbol dump file\n");
2396 /* For normal builds always dump all symbols.
2397 * For external modules only dump symbols
2398 * that are not read from kernel Module.symvers.
2400 static int dump_sym(struct symbol *sym)
2402 if (!external_module)
2404 if (sym->vmlinux || sym->kernel)
2409 static void write_dump(const char *fname)
2411 struct buffer buf = { };
2412 struct symbol *symbol;
2415 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2416 symbol = symbolhash[n];
2418 if (dump_sym(symbol))
2419 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2420 symbol->crc, symbol->name,
2421 symbol->module->name,
2422 export_str(symbol->export));
2423 symbol = symbol->next;
2426 write_if_changed(&buf, fname);
2430 struct ext_sym_list {
2431 struct ext_sym_list *next;
2435 int main(int argc, char **argv)
2438 struct buffer buf = { };
2439 char *kernel_read = NULL, *module_read = NULL;
2440 char *dump_write = NULL, *files_source = NULL;
2443 struct ext_sym_list *extsym_iter;
2444 struct ext_sym_list *extsym_start = NULL;
2446 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:E")) != -1) {
2449 kernel_read = optarg;
2452 module_read = optarg;
2453 external_module = 1;
2456 external_module = 1;
2458 NOFAIL(malloc(sizeof(*extsym_iter)));
2459 extsym_iter->next = extsym_start;
2460 extsym_iter->file = optarg;
2461 extsym_start = extsym_iter;
2467 ignore_missing_files = 1;
2470 dump_write = optarg;
2476 vmlinux_section_warnings = 0;
2479 sec_mismatch_verbose = 0;
2482 files_source = optarg;
2485 warn_unresolved = 1;
2488 sec_mismatch_fatal = 1;
2496 read_dump(kernel_read, 1);
2498 read_dump(module_read, 0);
2499 while (extsym_start) {
2500 read_dump(extsym_start->file, 0);
2501 extsym_iter = extsym_start->next;
2503 extsym_start = extsym_iter;
2506 while (optind < argc)
2507 read_symbols(argv[optind++]);
2510 read_symbols_from_files(files_source);
2512 for (mod = modules; mod; mod = mod->next) {
2520 for (mod = modules; mod; mod = mod->next) {
2521 char fname[PATH_MAX];
2528 err |= check_modname_len(mod);
2529 add_header(&buf, mod);
2530 add_intree_flag(&buf, !external_module);
2531 add_retpoline(&buf);
2532 add_staging_flag(&buf, mod->name);
2533 err |= add_versions(&buf, mod);
2534 add_depends(&buf, mod, modules);
2535 add_moddevtable(&buf, mod);
2536 add_srcversion(&buf, mod);
2538 sprintf(fname, "%s.mod.c", mod->name);
2539 write_if_changed(&buf, fname);
2542 write_dump(dump_write);
2543 if (sec_mismatch_count) {
2544 if (!sec_mismatch_verbose) {
2545 warn("modpost: Found %d section mismatch(es).\n"
2546 "To see full details build your kernel with:\n"
2547 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2548 sec_mismatch_count);
2550 if (sec_mismatch_fatal) {
2551 fatal("modpost: Section mismatches detected.\n"
2552 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");