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 ...
24 #include "../../include/linux/license.h"
26 static bool module_enabled;
27 /* Are we using CONFIG_MODVERSIONS? */
28 static bool modversions;
29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
30 static bool all_versions;
31 /* If we are modposting external module set to 1 */
32 static bool external_module;
33 /* Only warn about unresolved symbols */
34 static bool warn_unresolved;
36 static int sec_mismatch_count;
37 static bool sec_mismatch_warn_only = true;
38 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
39 static bool trim_unused_exports;
41 /* ignore missing files */
42 static bool ignore_missing_files;
43 /* If set to 1, only warn (instead of error) about missing ns imports */
44 static bool allow_missing_ns_imports;
46 static bool error_occurred;
48 static bool extra_warn;
51 * Cut off the warnings when there are too many. This typically occurs when
52 * vmlinux is missing. ('make modules' without building vmlinux.)
54 #define MAX_UNRESOLVED_REPORTS 10
55 static unsigned int nr_unresolved;
57 /* In kernel, this size is defined in linux/module.h;
58 * here we use Elf_Addr instead of long for covering cross-compile
61 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
63 void modpost_log(enum loglevel loglevel, const char *fmt, ...)
69 fprintf(stderr, "WARNING: ");
72 fprintf(stderr, "ERROR: ");
73 error_occurred = true;
75 default: /* invalid loglevel, ignore */
79 fprintf(stderr, "modpost: ");
81 va_start(arglist, fmt);
82 vfprintf(stderr, fmt, arglist);
86 static inline bool strends(const char *str, const char *postfix)
88 if (strlen(str) < strlen(postfix))
91 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
94 void *do_nofail(void *ptr, const char *expr)
97 fatal("Memory allocation failure: %s.\n", expr);
102 char *read_text_file(const char *filename)
109 fd = open(filename, O_RDONLY);
115 if (fstat(fd, &st) < 0) {
120 buf = NOFAIL(malloc(st.st_size + 1));
127 bytes_read = read(fd, buf, nbytes);
128 if (bytes_read < 0) {
133 nbytes -= bytes_read;
135 buf[st.st_size] = '\0';
142 char *get_line(char **stringp)
144 char *orig = *stringp, *next;
146 /* do not return the unwanted extra line at EOF */
147 if (!orig || *orig == '\0')
150 /* don't use strsep here, it is not available everywhere */
151 next = strchr(orig, '\n');
160 /* A list of all modules we processed */
163 static struct module *find_module(const char *modname)
167 list_for_each_entry(mod, &modules, list) {
168 if (strcmp(mod->name, modname) == 0)
174 static struct module *new_module(const char *name, size_t namelen)
178 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
179 memset(mod, 0, sizeof(*mod));
181 INIT_LIST_HEAD(&mod->exported_symbols);
182 INIT_LIST_HEAD(&mod->unresolved_symbols);
183 INIT_LIST_HEAD(&mod->missing_namespaces);
184 INIT_LIST_HEAD(&mod->imported_namespaces);
186 memcpy(mod->name, name, namelen);
187 mod->name[namelen] = '\0';
188 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
191 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
192 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
193 * modpost will exit wiht error anyway.
195 mod->is_gpl_compatible = true;
197 list_add_tail(&mod->list, &modules);
202 /* A hash of all exported symbols,
203 * struct symbol is also used for lists of unresolved symbols */
205 #define SYMBOL_HASH_SIZE 1024
209 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
210 struct module *module;
216 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
217 bool used; /* there exists a user of this symbol */
221 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
223 /* This is based on the hash algorithm from gdbm, via tdb */
224 static inline unsigned int tdb_hash(const char *name)
226 unsigned value; /* Used to compute the hash value. */
227 unsigned i; /* Used to cycle through random values. */
229 /* Set the initial value from the key size. */
230 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
231 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
233 return (1103515243 * value + 12345);
237 * Allocate a new symbols for use in the hash of exported symbols or
238 * the list of unresolved symbols per module
240 static struct symbol *alloc_symbol(const char *name)
242 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
244 memset(s, 0, sizeof(*s));
245 strcpy(s->name, name);
250 /* For the hash of exported symbols */
251 static void hash_add_symbol(struct symbol *sym)
255 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
256 sym->next = symbolhash[hash];
257 symbolhash[hash] = sym;
260 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
264 sym = alloc_symbol(name);
267 list_add_tail(&sym->list, &mod->unresolved_symbols);
270 static struct symbol *sym_find_with_module(const char *name, struct module *mod)
274 /* For our purposes, .foo matches foo. PPC64 needs this. */
278 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
279 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
285 static struct symbol *find_symbol(const char *name)
287 return sym_find_with_module(name, NULL);
290 struct namespace_list {
291 struct list_head list;
295 static bool contains_namespace(struct list_head *head, const char *namespace)
297 struct namespace_list *list;
300 * The default namespace is null string "", which is always implicitly
306 list_for_each_entry(list, head, list) {
307 if (!strcmp(list->namespace, namespace))
314 static void add_namespace(struct list_head *head, const char *namespace)
316 struct namespace_list *ns_entry;
318 if (!contains_namespace(head, namespace)) {
319 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
320 strlen(namespace) + 1));
321 strcpy(ns_entry->namespace, namespace);
322 list_add_tail(&ns_entry->list, head);
326 static void *sym_get_data_by_offset(const struct elf_info *info,
327 unsigned int secindex, unsigned long offset)
329 Elf_Shdr *sechdr = &info->sechdrs[secindex];
331 return (void *)info->hdr + sechdr->sh_offset + offset;
334 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
336 return sym_get_data_by_offset(info, get_secindex(info, sym),
340 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
342 return sym_get_data_by_offset(info, info->secindex_strings,
346 static const char *sec_name(const struct elf_info *info, unsigned int secindex)
349 * If sym->st_shndx is a special section index, there is no
350 * corresponding section header.
351 * Return "" if the index is out of range of info->sechdrs[] array.
353 if (secindex >= info->num_sections)
356 return sech_name(info, &info->sechdrs[secindex]);
359 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
361 static struct symbol *sym_add_exported(const char *name, struct module *mod,
362 bool gpl_only, const char *namespace)
364 struct symbol *s = find_symbol(name);
366 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
367 error("%s: '%s' exported twice. Previous export was in %s%s\n",
368 mod->name, name, s->module->name,
369 s->module->is_vmlinux ? "" : ".ko");
372 s = alloc_symbol(name);
374 s->is_gpl_only = gpl_only;
375 s->namespace = NOFAIL(strdup(namespace));
376 list_add_tail(&s->list, &mod->exported_symbols);
382 static void sym_set_crc(struct symbol *sym, unsigned int crc)
385 sym->crc_valid = true;
388 static void *grab_file(const char *filename, size_t *size)
391 void *map = MAP_FAILED;
394 fd = open(filename, O_RDONLY);
401 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
405 if (map == MAP_FAILED)
410 static void release_file(void *file, size_t size)
415 static int parse_elf(struct elf_info *info, const char *filename)
421 const char *secstrings;
422 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
424 hdr = grab_file(filename, &info->size);
426 if (ignore_missing_files) {
427 fprintf(stderr, "%s: %s (ignored)\n", filename,
435 if (info->size < sizeof(*hdr)) {
436 /* file too small, assume this is an empty .o file */
439 /* Is this a valid ELF file? */
440 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
441 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
442 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
443 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
444 /* Not an ELF file - silently ignore it */
447 /* Fix endianness in ELF header */
448 hdr->e_type = TO_NATIVE(hdr->e_type);
449 hdr->e_machine = TO_NATIVE(hdr->e_machine);
450 hdr->e_version = TO_NATIVE(hdr->e_version);
451 hdr->e_entry = TO_NATIVE(hdr->e_entry);
452 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
453 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
454 hdr->e_flags = TO_NATIVE(hdr->e_flags);
455 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
456 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
457 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
458 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
459 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
460 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
461 sechdrs = (void *)hdr + hdr->e_shoff;
462 info->sechdrs = sechdrs;
464 /* modpost only works for relocatable objects */
465 if (hdr->e_type != ET_REL)
466 fatal("%s: not relocatable object.", filename);
468 /* Check if file offset is correct */
469 if (hdr->e_shoff > info->size)
470 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
471 (unsigned long)hdr->e_shoff, filename, info->size);
473 if (hdr->e_shnum == SHN_UNDEF) {
475 * There are more than 64k sections,
476 * read count from .sh_size.
478 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
481 info->num_sections = hdr->e_shnum;
483 if (hdr->e_shstrndx == SHN_XINDEX) {
484 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
487 info->secindex_strings = hdr->e_shstrndx;
490 /* Fix endianness in section headers */
491 for (i = 0; i < info->num_sections; i++) {
492 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
493 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
494 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
495 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
496 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
497 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
498 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
499 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
500 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
501 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
503 /* Find symbol table. */
504 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
505 for (i = 1; i < info->num_sections; i++) {
507 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
509 if (!nobits && sechdrs[i].sh_offset > info->size)
510 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
511 filename, (unsigned long)sechdrs[i].sh_offset,
514 secname = secstrings + sechdrs[i].sh_name;
515 if (strcmp(secname, ".modinfo") == 0) {
517 fatal("%s has NOBITS .modinfo\n", filename);
518 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
519 info->modinfo_len = sechdrs[i].sh_size;
520 } else if (!strcmp(secname, ".export_symbol")) {
521 info->export_symbol_secndx = i;
524 if (sechdrs[i].sh_type == SHT_SYMTAB) {
525 unsigned int sh_link_idx;
527 info->symtab_start = (void *)hdr +
528 sechdrs[i].sh_offset;
529 info->symtab_stop = (void *)hdr +
530 sechdrs[i].sh_offset + sechdrs[i].sh_size;
531 sh_link_idx = sechdrs[i].sh_link;
532 info->strtab = (void *)hdr +
533 sechdrs[sh_link_idx].sh_offset;
536 /* 32bit section no. table? ("more than 64k sections") */
537 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
538 symtab_shndx_idx = i;
539 info->symtab_shndx_start = (void *)hdr +
540 sechdrs[i].sh_offset;
541 info->symtab_shndx_stop = (void *)hdr +
542 sechdrs[i].sh_offset + sechdrs[i].sh_size;
545 if (!info->symtab_start)
546 fatal("%s has no symtab?\n", filename);
548 /* Fix endianness in symbols */
549 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
550 sym->st_shndx = TO_NATIVE(sym->st_shndx);
551 sym->st_name = TO_NATIVE(sym->st_name);
552 sym->st_value = TO_NATIVE(sym->st_value);
553 sym->st_size = TO_NATIVE(sym->st_size);
556 if (symtab_shndx_idx != ~0U) {
558 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
559 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
560 filename, sechdrs[symtab_shndx_idx].sh_link,
563 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
568 symsearch_init(info);
573 static void parse_elf_finish(struct elf_info *info)
575 symsearch_finish(info);
576 release_file(info->hdr, info->size);
579 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
581 /* ignore __this_module, it will be resolved shortly */
582 if (strcmp(symname, "__this_module") == 0)
584 /* ignore global offset table */
585 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
587 if (info->hdr->e_machine == EM_PPC)
588 /* Special register function linked on all modules during final link of .ko */
589 if (strstarts(symname, "_restgpr_") ||
590 strstarts(symname, "_savegpr_") ||
591 strstarts(symname, "_rest32gpr_") ||
592 strstarts(symname, "_save32gpr_") ||
593 strstarts(symname, "_restvr_") ||
594 strstarts(symname, "_savevr_"))
596 if (info->hdr->e_machine == EM_PPC64)
597 /* Special register function linked on all modules during final link of .ko */
598 if (strstarts(symname, "_restgpr0_") ||
599 strstarts(symname, "_savegpr0_") ||
600 strstarts(symname, "_restvr_") ||
601 strstarts(symname, "_savevr_") ||
602 strcmp(symname, ".TOC.") == 0)
605 if (info->hdr->e_machine == EM_S390)
606 /* Expoline thunks are linked on all kernel modules during final link of .ko */
607 if (strstarts(symname, "__s390_indirect_jump_r"))
609 /* Do not ignore this symbol */
613 static void handle_symbol(struct module *mod, struct elf_info *info,
614 const Elf_Sym *sym, const char *symname)
616 switch (sym->st_shndx) {
618 if (strstarts(symname, "__gnu_lto_")) {
619 /* Should warn here, but modpost runs before the linker */
621 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
624 /* undefined symbol */
625 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
626 ELF_ST_BIND(sym->st_info) != STB_WEAK)
628 if (ignore_undef_symbol(info, symname))
630 if (info->hdr->e_machine == EM_SPARC ||
631 info->hdr->e_machine == EM_SPARCV9) {
632 /* Ignore register directives. */
633 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
635 if (symname[0] == '.') {
636 char *munged = NOFAIL(strdup(symname));
638 munged[1] = toupper(munged[1]);
643 sym_add_unresolved(symname, mod,
644 ELF_ST_BIND(sym->st_info) == STB_WEAK);
647 if (strcmp(symname, "init_module") == 0)
648 mod->has_init = true;
649 if (strcmp(symname, "cleanup_module") == 0)
650 mod->has_cleanup = true;
656 * Parse tag=value strings from .modinfo section
658 static char *next_string(char *string, unsigned long *secsize)
660 /* Skip non-zero chars */
663 if ((*secsize)-- <= 1)
667 /* Skip any zero padding. */
670 if ((*secsize)-- <= 1)
676 static char *get_next_modinfo(struct elf_info *info, const char *tag,
680 unsigned int taglen = strlen(tag);
681 char *modinfo = info->modinfo;
682 unsigned long size = info->modinfo_len;
685 size -= prev - modinfo;
686 modinfo = next_string(prev, &size);
689 for (p = modinfo; p; p = next_string(p, &size)) {
690 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
691 return p + taglen + 1;
696 static char *get_modinfo(struct elf_info *info, const char *tag)
699 return get_next_modinfo(info, tag, NULL);
702 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
705 return elf->strtab + sym->st_name;
711 * Check whether the 'string' argument matches one of the 'patterns',
712 * an array of shell wildcard patterns (glob).
714 * Return true is there is a match.
716 static bool match(const char *string, const char *const patterns[])
720 while ((pattern = *patterns++)) {
721 if (!fnmatch(pattern, string, 0))
728 /* useful to pass patterns to match() directly */
729 #define PATTERNS(...) \
731 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
735 /* sections that we do not want to do full section mismatch check on */
736 static const char *const section_white_list[] =
740 ".zdebug*", /* Compressed debug sections. */
741 ".GCC.command.line", /* record-gcc-switches */
742 ".mdebug*", /* alpha, score, mips etc. */
743 ".pdr", /* alpha, score, mips etc. */
748 ".xt.prop", /* xtensa */
749 ".xt.lit", /* xtensa */
750 ".arcextmap*", /* arc */
751 ".gnu.linkonce.arcext*", /* arc : modules */
752 ".cmem*", /* EZchip */
753 ".fmt_slot*", /* EZchip */
756 ".llvm.call-graph-profile", /* call graph */
761 * This is used to find sections missing the SHF_ALLOC flag.
762 * The cause of this is often a section specified in assembler
763 * without "ax" / "aw".
765 static void check_section(const char *modname, struct elf_info *elf,
768 const char *sec = sech_name(elf, sechdr);
770 if (sechdr->sh_type == SHT_PROGBITS &&
771 !(sechdr->sh_flags & SHF_ALLOC) &&
772 !match(sec, section_white_list)) {
773 warn("%s (%s): unexpected non-allocatable section.\n"
774 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
775 "Note that for example <linux/init.h> contains\n"
776 "section definitions for use in .S files.\n\n",
783 #define ALL_INIT_DATA_SECTIONS \
784 ".init.setup", ".init.rodata", ".meminit.rodata", \
785 ".init.data", ".meminit.data"
787 #define ALL_PCI_INIT_SECTIONS \
788 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
789 ".pci_fixup_enable", ".pci_fixup_resume", \
790 ".pci_fixup_resume_early", ".pci_fixup_suspend"
792 #define ALL_XXXINIT_SECTIONS ".meminit.*"
794 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
795 #define ALL_EXIT_SECTIONS ".exit.*"
797 #define DATA_SECTIONS ".data", ".data.rel"
798 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
799 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
801 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
802 ".fixup", ".entry.text", ".exception.text", \
803 ".coldtext", ".softirqentry.text"
805 #define INIT_SECTIONS ".init.*"
807 #define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \
808 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
811 TEXTDATA_TO_ANY_INIT_EXIT,
812 XXXINIT_TO_SOME_INIT,
813 ANY_INIT_TO_ANY_EXIT,
814 ANY_EXIT_TO_ANY_INIT,
819 * Describe how to match sections on different criteria:
821 * @fromsec: Array of sections to be matched.
823 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
824 * this array is forbidden (black-list). Can be empty.
826 * @good_tosec: Relocations applied to a section in @fromsec must be
827 * targeting sections in this array (white-list). Can be empty.
829 * @mismatch: Type of mismatch.
831 struct sectioncheck {
832 const char *fromsec[20];
833 const char *bad_tosec[20];
834 const char *good_tosec[20];
835 enum mismatch mismatch;
838 static const struct sectioncheck sectioncheck[] = {
839 /* Do not reference init/exit code/data from
840 * normal code and data
843 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
844 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
845 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
847 /* Do not reference init code/data from meminit code/data */
849 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
850 .bad_tosec = { INIT_SECTIONS, NULL },
851 .mismatch = XXXINIT_TO_SOME_INIT,
853 /* Do not use exit code/data from init code */
855 .fromsec = { ALL_INIT_SECTIONS, NULL },
856 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
857 .mismatch = ANY_INIT_TO_ANY_EXIT,
859 /* Do not use init code/data from exit code */
861 .fromsec = { ALL_EXIT_SECTIONS, NULL },
862 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
863 .mismatch = ANY_EXIT_TO_ANY_INIT,
866 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
867 .bad_tosec = { INIT_SECTIONS, NULL },
868 .mismatch = ANY_INIT_TO_ANY_EXIT,
871 .fromsec = { "__ex_table", NULL },
872 /* If you're adding any new black-listed sections in here, consider
873 * adding a special 'printer' for them in scripts/check_extable.
875 .bad_tosec = { ".altinstr_replacement", NULL },
876 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
877 .mismatch = EXTABLE_TO_NON_TEXT,
881 static const struct sectioncheck *section_mismatch(
882 const char *fromsec, const char *tosec)
887 * The target section could be the SHT_NUL section when we're
888 * handling relocations to un-resolved symbols, trying to match it
889 * doesn't make much sense and causes build failures on parisc
895 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
896 const struct sectioncheck *check = §ioncheck[i];
898 if (match(fromsec, check->fromsec)) {
899 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
901 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
909 * Whitelist to allow certain references to pass with no warning.
912 * If a module parameter is declared __initdata and permissions=0
913 * then this is legal despite the warning generated.
914 * We cannot see value of permissions here, so just ignore
916 * The pattern is identified by:
922 * module_param_call() ops can refer to __init set function if permissions=0
923 * The pattern is identified by:
926 * atsym = __param_ops_*
929 * Whitelist all references from .head.text to any init section
932 * Some symbols belong to init section but still it is ok to reference
933 * these from non-init sections as these symbols don't have any memory
934 * allocated for them and symbol address and value are same. So even
935 * if init section is freed, its ok to reference those symbols.
936 * For ex. symbols marking the init section boundaries.
937 * This pattern is identified by
938 * refsymname = __init_begin, _sinittext, _einittext
941 * GCC may optimize static inlines when fed constant arg(s) resulting
942 * in functions like cpumask_empty() -- generating an associated symbol
943 * cpumask_empty.constprop.3 that appears in the audit. If the const that
944 * is passed in comes from __init, like say nmi_ipi_mask, we get a
945 * meaningless section warning. May need to add isra symbols too...
946 * This pattern is identified by
947 * tosec = init section
948 * fromsec = text section
949 * refsymname = *.constprop.*
952 static int secref_whitelist(const char *fromsec, const char *fromsym,
953 const char *tosec, const char *tosym)
955 /* Check for pattern 1 */
956 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
957 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
958 strstarts(fromsym, "__param"))
961 /* Check for pattern 1a */
962 if (strcmp(tosec, ".init.text") == 0 &&
963 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
964 strstarts(fromsym, "__param_ops_"))
967 /* symbols in data sections that may refer to any init/exit sections */
968 if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
969 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
970 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
974 * symbols in data sections must not refer to .exit.*, but there are
975 * quite a few offenders, so hide these unless for W=1 builds until
979 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
980 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) &&
981 match(fromsym, PATTERNS("*driver")))
984 /* Check for pattern 3 */
985 if (strstarts(fromsec, ".head.text") &&
986 match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
989 /* Check for pattern 4 */
990 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
993 /* Check for pattern 5 */
994 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
995 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
996 match(fromsym, PATTERNS("*.constprop.*")))
1002 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
1003 unsigned int secndx)
1005 return symsearch_find_nearest(elf, addr, secndx, false, ~0);
1008 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1010 /* If the supplied symbol has a valid name, return it */
1011 if (is_valid_name(elf, sym))
1015 * Strive to find a better symbol name, but the resulting name may not
1016 * match the symbol referenced in the original code.
1018 return symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
1022 static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1024 if (secndx >= elf->num_sections)
1027 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1030 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1031 const struct sectioncheck* const mismatch,
1033 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1034 const char *tosec, Elf_Addr taddr)
1038 const char *fromsym;
1040 from = find_fromsym(elf, faddr, fsecndx);
1041 fromsym = sym_name(elf, from);
1043 tsym = find_tosym(elf, taddr, tsym);
1044 tosym = sym_name(elf, tsym);
1046 /* check whitelist - we may ignore it */
1047 if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1050 sec_mismatch_count++;
1052 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1054 (unsigned int)(faddr - (from ? from->st_value : 0)),
1055 fromsec, tosym, tosec);
1057 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1058 if (match(tosec, mismatch->bad_tosec))
1059 fatal("The relocation at %s+0x%lx references\n"
1060 "section \"%s\" which is black-listed.\n"
1061 "Something is seriously wrong and should be fixed.\n"
1062 "You might get more information about where this is\n"
1063 "coming from by using scripts/check_extable.sh %s\n",
1064 fromsec, (long)faddr, tosec, modname);
1065 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1066 warn("The relocation at %s+0x%lx references\n"
1067 "section \"%s\" which is not in the list of\n"
1068 "authorized sections. If you're adding a new section\n"
1069 "and/or if this reference is valid, add \"%s\" to the\n"
1070 "list of authorized sections to jump to on fault.\n"
1071 "This can be achieved by adding \"%s\" to\n"
1072 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1073 fromsec, (long)faddr, tosec, tosec, tosec);
1075 error("%s+0x%lx references non-executable section '%s'\n",
1076 fromsec, (long)faddr, tosec);
1080 static void check_export_symbol(struct module *mod, struct elf_info *elf,
1081 Elf_Addr faddr, const char *secname,
1084 static const char *prefix = "__export_symbol_";
1085 const char *label_name, *name, *data;
1090 label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1091 label_name = sym_name(elf, label);
1093 if (!strstarts(label_name, prefix)) {
1094 error("%s: .export_symbol section contains strange symbol '%s'\n",
1095 mod->name, label_name);
1099 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1100 ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1101 error("%s: local symbol '%s' was exported\n", mod->name,
1102 label_name + strlen(prefix));
1106 name = sym_name(elf, sym);
1107 if (strcmp(label_name + strlen(prefix), name)) {
1108 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1113 data = sym_get_data(elf, label); /* license */
1114 if (!strcmp(data, "GPL")) {
1116 } else if (!strcmp(data, "")) {
1119 error("%s: unknown license '%s' was specified for '%s'\n",
1120 mod->name, data, name);
1124 data += strlen(data) + 1; /* namespace */
1125 s = sym_add_exported(name, mod, is_gpl, data);
1128 * We need to be aware whether we are exporting a function or
1129 * a data on some architectures.
1131 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1134 * For parisc64, symbols prefixed $$ from the library have the symbol type
1135 * STT_LOPROC. They should be handled as functions too.
1137 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1138 elf->hdr->e_machine == EM_PARISC &&
1139 ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1142 if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1143 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1145 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1146 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1150 static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1152 unsigned int fsecndx, const char *fromsec,
1153 Elf_Addr faddr, Elf_Addr taddr)
1155 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1156 const struct sectioncheck *mismatch;
1158 if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1159 check_export_symbol(mod, elf, faddr, tosec, sym);
1163 mismatch = section_mismatch(fromsec, tosec);
1167 default_mismatch_handler(mod->name, elf, mismatch, sym,
1168 fsecndx, fromsec, faddr,
1172 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1176 return TO_NATIVE(*location);
1178 return TO_NATIVE(*location) + 4;
1181 return (Elf_Addr)(-1);
1185 #define R_ARM_CALL 28
1187 #ifndef R_ARM_JUMP24
1188 #define R_ARM_JUMP24 29
1191 #ifndef R_ARM_THM_CALL
1192 #define R_ARM_THM_CALL 10
1194 #ifndef R_ARM_THM_JUMP24
1195 #define R_ARM_THM_JUMP24 30
1198 #ifndef R_ARM_MOVW_ABS_NC
1199 #define R_ARM_MOVW_ABS_NC 43
1202 #ifndef R_ARM_MOVT_ABS
1203 #define R_ARM_MOVT_ABS 44
1206 #ifndef R_ARM_THM_MOVW_ABS_NC
1207 #define R_ARM_THM_MOVW_ABS_NC 47
1210 #ifndef R_ARM_THM_MOVT_ABS
1211 #define R_ARM_THM_MOVT_ABS 48
1214 #ifndef R_ARM_THM_JUMP19
1215 #define R_ARM_THM_JUMP19 51
1218 static int32_t sign_extend32(int32_t value, int index)
1220 uint8_t shift = 31 - index;
1222 return (int32_t)(value << shift) >> shift;
1225 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1227 uint32_t inst, upper, lower, sign, j1, j2;
1233 inst = TO_NATIVE(*(uint32_t *)loc);
1234 return inst + sym->st_value;
1235 case R_ARM_MOVW_ABS_NC:
1236 case R_ARM_MOVT_ABS:
1237 inst = TO_NATIVE(*(uint32_t *)loc);
1238 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1240 return offset + sym->st_value;
1244 inst = TO_NATIVE(*(uint32_t *)loc);
1245 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1246 return offset + sym->st_value + 8;
1247 case R_ARM_THM_MOVW_ABS_NC:
1248 case R_ARM_THM_MOVT_ABS:
1249 upper = TO_NATIVE(*(uint16_t *)loc);
1250 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1251 offset = sign_extend32(((upper & 0x000f) << 12) |
1252 ((upper & 0x0400) << 1) |
1253 ((lower & 0x7000) >> 4) |
1256 return offset + sym->st_value;
1257 case R_ARM_THM_JUMP19:
1264 * imm11 = lower[10:0]
1265 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1267 upper = TO_NATIVE(*(uint16_t *)loc);
1268 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1270 sign = (upper >> 10) & 1;
1271 j1 = (lower >> 13) & 1;
1272 j2 = (lower >> 11) & 1;
1273 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1274 ((upper & 0x03f) << 12) |
1275 ((lower & 0x07ff) << 1),
1277 return offset + sym->st_value + 4;
1278 case R_ARM_THM_CALL:
1279 case R_ARM_THM_JUMP24:
1283 * imm10 = upper[9:0]
1286 * imm11 = lower[10:0]
1287 * I1 = NOT(J1 XOR S)
1288 * I2 = NOT(J2 XOR S)
1289 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1291 upper = TO_NATIVE(*(uint16_t *)loc);
1292 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1294 sign = (upper >> 10) & 1;
1295 j1 = (lower >> 13) & 1;
1296 j2 = (lower >> 11) & 1;
1297 offset = sign_extend32((sign << 24) |
1298 ((~(j1 ^ sign) & 1) << 23) |
1299 ((~(j2 ^ sign) & 1) << 22) |
1300 ((upper & 0x03ff) << 12) |
1301 ((lower & 0x07ff) << 1),
1303 return offset + sym->st_value + 4;
1306 return (Elf_Addr)(-1);
1309 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1313 inst = TO_NATIVE(*location);
1316 return inst & 0xffff;
1318 return (inst & 0x03ffffff) << 2;
1322 return (Elf_Addr)(-1);
1326 #define EM_RISCV 243
1329 #ifndef R_RISCV_SUB32
1330 #define R_RISCV_SUB32 39
1333 #ifndef EM_LOONGARCH
1334 #define EM_LOONGARCH 258
1337 #ifndef R_LARCH_SUB32
1338 #define R_LARCH_SUB32 55
1341 #ifndef R_LARCH_RELAX
1342 #define R_LARCH_RELAX 100
1345 #ifndef R_LARCH_ALIGN
1346 #define R_LARCH_ALIGN 102
1349 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1350 unsigned int *r_type, unsigned int *r_sym)
1353 Elf64_Word r_sym; /* Symbol index */
1354 unsigned char r_ssym; /* Special symbol for 2nd relocation */
1355 unsigned char r_type3; /* 3rd relocation type */
1356 unsigned char r_type2; /* 2nd relocation type */
1357 unsigned char r_type; /* 1st relocation type */
1358 } Elf64_Mips_R_Info;
1360 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1362 if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1363 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1365 *r_type = mips64_r_info->r_type;
1366 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1371 r_info = TO_NATIVE((Elf64_Xword)r_info);
1373 r_info = TO_NATIVE((Elf32_Word)r_info);
1375 *r_type = ELF_R_TYPE(r_info);
1376 *r_sym = ELF_R_SYM(r_info);
1379 static void section_rela(struct module *mod, struct elf_info *elf,
1380 unsigned int fsecndx, const char *fromsec,
1381 const Elf_Rela *start, const Elf_Rela *stop)
1383 const Elf_Rela *rela;
1385 for (rela = start; rela < stop; rela++) {
1387 Elf_Addr taddr, r_offset;
1388 unsigned int r_type, r_sym;
1390 r_offset = TO_NATIVE(rela->r_offset);
1391 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1393 tsym = elf->symtab_start + r_sym;
1394 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1396 switch (elf->hdr->e_machine) {
1398 if (!strcmp("__ex_table", fromsec) &&
1399 r_type == R_RISCV_SUB32)
1405 if (!strcmp("__ex_table", fromsec))
1410 /* These relocs do not refer to symbols */
1416 check_section_mismatch(mod, elf, tsym,
1417 fsecndx, fromsec, r_offset, taddr);
1421 static void section_rel(struct module *mod, struct elf_info *elf,
1422 unsigned int fsecndx, const char *fromsec,
1423 const Elf_Rel *start, const Elf_Rel *stop)
1427 for (rel = start; rel < stop; rel++) {
1429 Elf_Addr taddr, r_offset;
1430 unsigned int r_type, r_sym;
1433 r_offset = TO_NATIVE(rel->r_offset);
1434 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1436 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1437 tsym = elf->symtab_start + r_sym;
1439 switch (elf->hdr->e_machine) {
1441 taddr = addend_386_rel(loc, r_type);
1444 taddr = addend_arm_rel(loc, tsym, r_type);
1447 taddr = addend_mips_rel(loc, r_type);
1450 fatal("Please add code to calculate addend for this architecture\n");
1453 check_section_mismatch(mod, elf, tsym,
1454 fsecndx, fromsec, r_offset, taddr);
1459 * A module includes a number of sections that are discarded
1460 * either when loaded or when used as built-in.
1461 * For loaded modules all functions marked __init and all data
1462 * marked __initdata will be discarded when the module has been initialized.
1463 * Likewise for modules used built-in the sections marked __exit
1464 * are discarded because __exit marked function are supposed to be called
1465 * only when a module is unloaded which never happens for built-in modules.
1466 * The check_sec_ref() function traverses all relocation records
1467 * to find all references to a section that reference a section that will
1468 * be discarded and warns about it.
1470 static void check_sec_ref(struct module *mod, struct elf_info *elf)
1474 /* Walk through all sections */
1475 for (i = 0; i < elf->num_sections; i++) {
1476 Elf_Shdr *sechdr = &elf->sechdrs[i];
1478 check_section(mod->name, elf, sechdr);
1479 /* We want to process only relocation sections and not .init */
1480 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1481 /* section to which the relocation applies */
1482 unsigned int secndx = sechdr->sh_info;
1483 const char *secname = sec_name(elf, secndx);
1484 const void *start, *stop;
1486 /* If the section is known good, skip it */
1487 if (match(secname, section_white_list))
1490 start = sym_get_data_by_offset(elf, i, 0);
1491 stop = start + sechdr->sh_size;
1493 if (sechdr->sh_type == SHT_RELA)
1494 section_rela(mod, elf, secndx, secname,
1497 section_rel(mod, elf, secndx, secname,
1503 static char *remove_dot(char *s)
1505 size_t n = strcspn(s, ".");
1508 size_t m = strspn(s + n + 1, "0123456789");
1509 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1516 * The CRCs are recorded in .*.cmd files in the form of:
1517 * #SYMVER <name> <crc>
1519 static void extract_crcs_for_object(const char *object, struct module *mod)
1521 char cmd_file[PATH_MAX];
1526 base = strrchr(object, '/');
1529 dirlen = base - object;
1535 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1536 dirlen, object, base);
1537 if (ret >= sizeof(cmd_file)) {
1538 error("%s: too long path was truncated\n", cmd_file);
1542 buf = read_text_file(cmd_file);
1545 while ((p = strstr(p, "\n#SYMVER "))) {
1551 name = p + strlen("\n#SYMVER ");
1553 p = strchr(name, ' ');
1561 continue; /* skip this line */
1563 crc = strtoul(p, &p, 0);
1565 continue; /* skip this line */
1567 name[namelen] = '\0';
1570 * sym_find_with_module() may return NULL here.
1571 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1572 * Since commit e1327a127703, genksyms calculates CRCs of all
1573 * symbols, including trimmed ones. Ignore orphan CRCs.
1575 sym = sym_find_with_module(name, mod);
1577 sym_set_crc(sym, crc);
1584 * The symbol versions (CRC) are recorded in the .*.cmd files.
1585 * Parse them to retrieve CRCs for the current module.
1587 static void mod_set_crcs(struct module *mod)
1589 char objlist[PATH_MAX];
1590 char *buf, *p, *obj;
1593 if (mod->is_vmlinux) {
1594 strcpy(objlist, ".vmlinux.objs");
1596 /* objects for a module are listed in the *.mod file. */
1597 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1598 if (ret >= sizeof(objlist)) {
1599 error("%s: too long path was truncated\n", objlist);
1604 buf = read_text_file(objlist);
1607 while ((obj = strsep(&p, "\n")) && obj[0])
1608 extract_crcs_for_object(obj, mod);
1613 static void read_symbols(const char *modname)
1615 const char *symname;
1620 struct elf_info info = { };
1623 if (!parse_elf(&info, modname))
1626 if (!strends(modname, ".o")) {
1627 error("%s: filename must be suffixed with .o\n", modname);
1631 /* strip trailing .o */
1632 mod = new_module(modname, strlen(modname) - strlen(".o"));
1634 if (!mod->is_vmlinux) {
1635 license = get_modinfo(&info, "license");
1637 error("missing MODULE_LICENSE() in %s\n", modname);
1639 if (!license_is_gpl_compatible(license)) {
1640 mod->is_gpl_compatible = false;
1643 license = get_next_modinfo(&info, "license", license);
1646 namespace = get_modinfo(&info, "import_ns");
1648 add_namespace(&mod->imported_namespaces, namespace);
1649 namespace = get_next_modinfo(&info, "import_ns",
1654 if (extra_warn && !get_modinfo(&info, "description"))
1655 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1656 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1657 symname = remove_dot(info.strtab + sym->st_name);
1659 handle_symbol(mod, &info, sym, symname);
1660 handle_moddevtable(mod, &info, sym, symname);
1663 check_sec_ref(mod, &info);
1665 if (!mod->is_vmlinux) {
1666 version = get_modinfo(&info, "version");
1667 if (version || all_versions)
1668 get_src_version(mod->name, mod->srcversion,
1669 sizeof(mod->srcversion) - 1);
1672 parse_elf_finish(&info);
1676 * Our trick to get versioning for module struct etc. - it's
1677 * never passed as an argument to an exported function, so
1678 * the automatic versioning doesn't pick it up, but it's really
1681 sym_add_unresolved("module_layout", mod, false);
1687 static void read_symbols_from_files(const char *filename)
1690 char fname[PATH_MAX];
1692 in = fopen(filename, "r");
1694 fatal("Can't open filenames file %s: %m", filename);
1696 while (fgets(fname, PATH_MAX, in) != NULL) {
1697 if (strends(fname, "\n"))
1698 fname[strlen(fname)-1] = '\0';
1699 read_symbols(fname);
1707 /* We first write the generated file into memory using the
1708 * following helper, then compare to the file on disk and
1709 * only update the later if anything changed */
1711 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1712 const char *fmt, ...)
1719 len = vsnprintf(tmp, SZ, fmt, ap);
1720 buf_write(buf, tmp, len);
1724 void buf_write(struct buffer *buf, const char *s, int len)
1726 if (buf->size - buf->pos < len) {
1727 buf->size += len + SZ;
1728 buf->p = NOFAIL(realloc(buf->p, buf->size));
1730 strncpy(buf->p + buf->pos, s, len);
1734 static void check_exports(struct module *mod)
1736 struct symbol *s, *exp;
1738 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1739 const char *basename;
1740 exp = find_symbol(s->name);
1742 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1743 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1744 "\"%s\" [%s.ko] undefined!\n",
1745 s->name, mod->name);
1748 if (exp->module == mod) {
1749 error("\"%s\" [%s.ko] was exported without definition\n",
1750 s->name, mod->name);
1755 s->module = exp->module;
1756 s->crc_valid = exp->crc_valid;
1759 basename = strrchr(mod->name, '/');
1763 basename = mod->name;
1765 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1766 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1767 "module %s uses symbol %s from namespace %s, but does not import it.\n",
1768 basename, exp->name, exp->namespace);
1769 add_namespace(&mod->missing_namespaces, exp->namespace);
1772 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1773 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1774 basename, exp->name);
1778 static void handle_white_list_exports(const char *white_list)
1780 char *buf, *p, *name;
1782 buf = read_text_file(white_list);
1785 while ((name = strsep(&p, "\n"))) {
1786 struct symbol *sym = find_symbol(name);
1795 static void check_modname_len(struct module *mod)
1797 const char *mod_name;
1799 mod_name = strrchr(mod->name, '/');
1800 if (mod_name == NULL)
1801 mod_name = mod->name;
1804 if (strlen(mod_name) >= MODULE_NAME_LEN)
1805 error("module name is too long [%s.ko]\n", mod->name);
1809 * Header for the generated file
1811 static void add_header(struct buffer *b, struct module *mod)
1813 buf_printf(b, "#include <linux/module.h>\n");
1815 * Include build-salt.h after module.h in order to
1816 * inherit the definitions.
1818 buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1819 buf_printf(b, "#include <linux/build-salt.h>\n");
1820 buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1821 buf_printf(b, "#include <linux/export-internal.h>\n");
1822 buf_printf(b, "#include <linux/vermagic.h>\n");
1823 buf_printf(b, "#include <linux/compiler.h>\n");
1824 buf_printf(b, "\n");
1825 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1826 buf_printf(b, "#include <asm/orc_header.h>\n");
1827 buf_printf(b, "ORC_HEADER;\n");
1828 buf_printf(b, "#endif\n");
1829 buf_printf(b, "\n");
1830 buf_printf(b, "BUILD_SALT;\n");
1831 buf_printf(b, "BUILD_LTO_INFO;\n");
1832 buf_printf(b, "\n");
1833 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1834 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1835 buf_printf(b, "\n");
1836 buf_printf(b, "__visible struct module __this_module\n");
1837 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1838 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1840 buf_printf(b, "\t.init = init_module,\n");
1841 if (mod->has_cleanup)
1842 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1843 "\t.exit = cleanup_module,\n"
1845 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1846 buf_printf(b, "};\n");
1848 if (!external_module)
1849 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1853 "#ifdef CONFIG_MITIGATION_RETPOLINE\n"
1854 "MODULE_INFO(retpoline, \"Y\");\n"
1857 if (strstarts(mod->name, "drivers/staging"))
1858 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1860 if (strstarts(mod->name, "tools/testing"))
1861 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1864 static void add_exported_symbols(struct buffer *buf, struct module *mod)
1868 /* generate struct for exported symbols */
1869 buf_printf(buf, "\n");
1870 list_for_each_entry(sym, &mod->exported_symbols, list) {
1871 if (trim_unused_exports && !sym->used)
1874 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1875 sym->is_func ? "FUNC" : "DATA", sym->name,
1876 sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1882 /* record CRCs for exported symbols */
1883 buf_printf(buf, "\n");
1884 list_for_each_entry(sym, &mod->exported_symbols, list) {
1885 if (trim_unused_exports && !sym->used)
1888 if (!sym->crc_valid)
1889 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1890 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1891 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1894 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1895 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1900 * Record CRCs for unresolved symbols
1902 static void add_versions(struct buffer *b, struct module *mod)
1909 buf_printf(b, "\n");
1910 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1911 buf_printf(b, "__used __section(\"__versions\") = {\n");
1913 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1916 if (!s->crc_valid) {
1917 warn("\"%s\" [%s.ko] has no CRC!\n",
1918 s->name, mod->name);
1921 if (strlen(s->name) >= MODULE_NAME_LEN) {
1922 error("too long symbol \"%s\" [%s.ko]\n",
1923 s->name, mod->name);
1926 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1930 buf_printf(b, "};\n");
1933 static void add_depends(struct buffer *b, struct module *mod)
1938 /* Clear ->seen flag of modules that own symbols needed by this. */
1939 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1941 s->module->seen = s->module->is_vmlinux;
1944 buf_printf(b, "\n");
1945 buf_printf(b, "MODULE_INFO(depends, \"");
1946 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1951 if (s->module->seen)
1954 s->module->seen = true;
1955 p = strrchr(s->module->name, '/');
1959 p = s->module->name;
1960 buf_printf(b, "%s%s", first ? "" : ",", p);
1963 buf_printf(b, "\");\n");
1966 static void add_srcversion(struct buffer *b, struct module *mod)
1968 if (mod->srcversion[0]) {
1969 buf_printf(b, "\n");
1970 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1975 static void write_buf(struct buffer *b, const char *fname)
1982 file = fopen(fname, "w");
1987 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1991 if (fclose(file) != 0) {
1997 static void write_if_changed(struct buffer *b, const char *fname)
2003 file = fopen(fname, "r");
2007 if (fstat(fileno(file), &st) < 0)
2010 if (st.st_size != b->pos)
2013 tmp = NOFAIL(malloc(b->pos));
2014 if (fread(tmp, 1, b->pos, file) != b->pos)
2017 if (memcmp(tmp, b->p, b->pos) != 0)
2029 write_buf(b, fname);
2032 static void write_vmlinux_export_c_file(struct module *mod)
2034 struct buffer buf = { };
2037 "#include <linux/export-internal.h>\n");
2039 add_exported_symbols(&buf, mod);
2040 write_if_changed(&buf, ".vmlinux.export.c");
2044 /* do sanity checks, and generate *.mod.c file */
2045 static void write_mod_c_file(struct module *mod)
2047 struct buffer buf = { };
2048 char fname[PATH_MAX];
2051 add_header(&buf, mod);
2052 add_exported_symbols(&buf, mod);
2053 add_versions(&buf, mod);
2054 add_depends(&buf, mod);
2055 add_moddevtable(&buf, mod);
2056 add_srcversion(&buf, mod);
2058 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2059 if (ret >= sizeof(fname)) {
2060 error("%s: too long path was truncated\n", fname);
2064 write_if_changed(&buf, fname);
2070 /* parse Module.symvers file. line format:
2071 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2073 static void read_dump(const char *fname)
2075 char *buf, *pos, *line;
2077 buf = read_text_file(fname);
2079 /* No symbol versions, silently ignore */
2084 while ((line = get_line(&pos))) {
2085 char *symname, *namespace, *modname, *d, *export;
2091 if (!(symname = strchr(line, '\t')))
2094 if (!(modname = strchr(symname, '\t')))
2097 if (!(export = strchr(modname, '\t')))
2100 if (!(namespace = strchr(export, '\t')))
2102 *namespace++ = '\0';
2104 crc = strtoul(line, &d, 16);
2105 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2108 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2110 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2113 error("%s: unknown license %s. skip", symname, export);
2117 mod = find_module(modname);
2119 mod = new_module(modname, strlen(modname));
2120 mod->from_dump = true;
2122 s = sym_add_exported(symname, mod, gpl_only, namespace);
2123 sym_set_crc(s, crc);
2129 fatal("parse error in symbol dump file\n");
2132 static void write_dump(const char *fname)
2134 struct buffer buf = { };
2138 list_for_each_entry(mod, &modules, list) {
2141 list_for_each_entry(sym, &mod->exported_symbols, list) {
2142 if (trim_unused_exports && !sym->used)
2145 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2146 sym->crc, sym->name, mod->name,
2147 sym->is_gpl_only ? "_GPL" : "",
2151 write_buf(&buf, fname);
2155 static void write_namespace_deps_files(const char *fname)
2158 struct namespace_list *ns;
2159 struct buffer ns_deps_buf = {};
2161 list_for_each_entry(mod, &modules, list) {
2163 if (mod->from_dump || list_empty(&mod->missing_namespaces))
2166 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2168 list_for_each_entry(ns, &mod->missing_namespaces, list)
2169 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2171 buf_printf(&ns_deps_buf, "\n");
2174 write_if_changed(&ns_deps_buf, fname);
2175 free(ns_deps_buf.p);
2179 struct list_head list;
2183 int main(int argc, char **argv)
2186 char *missing_namespace_deps = NULL;
2187 char *unused_exports_white_list = NULL;
2188 char *dump_write = NULL, *files_source = NULL;
2190 LIST_HEAD(dump_lists);
2191 struct dump_list *dl, *dl2;
2193 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2196 external_module = true;
2199 dl = NOFAIL(malloc(sizeof(*dl)));
2201 list_add_tail(&dl->list, &dump_lists);
2204 module_enabled = true;
2210 ignore_missing_files = true;
2213 dump_write = optarg;
2216 all_versions = true;
2219 files_source = optarg;
2222 trim_unused_exports = true;
2225 unused_exports_white_list = optarg;
2231 warn_unresolved = true;
2234 sec_mismatch_warn_only = false;
2237 allow_missing_ns_imports = true;
2240 missing_namespace_deps = optarg;
2247 list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2248 read_dump(dl->file);
2249 list_del(&dl->list);
2253 while (optind < argc)
2254 read_symbols(argv[optind++]);
2257 read_symbols_from_files(files_source);
2259 list_for_each_entry(mod, &modules, list) {
2260 if (mod->from_dump || mod->is_vmlinux)
2263 check_modname_len(mod);
2267 if (unused_exports_white_list)
2268 handle_white_list_exports(unused_exports_white_list);
2270 list_for_each_entry(mod, &modules, list) {
2274 if (mod->is_vmlinux)
2275 write_vmlinux_export_c_file(mod);
2277 write_mod_c_file(mod);
2280 if (missing_namespace_deps)
2281 write_namespace_deps_files(missing_namespace_deps);
2284 write_dump(dump_write);
2285 if (sec_mismatch_count && !sec_mismatch_warn_only)
2286 error("Section mismatches detected.\n"
2287 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2289 if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2290 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2291 nr_unresolved - MAX_UNRESOLVED_REPORTS);
2293 return error_occurred ? 1 : 0;