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? */
28 /* Warn about undefined symbols? (do so if we have vmlinux) */
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 /* ignore missing files */
42 static int ignore_missing_files;
45 export_plain, export_unused, export_gpl,
46 export_unused_gpl, export_gpl_future, export_unknown
49 #define PRINTF __attribute__ ((format (printf, 1, 2)))
51 PRINTF void fatal(const char *fmt, ...)
55 fprintf(stderr, "FATAL: ");
57 va_start(arglist, fmt);
58 vfprintf(stderr, fmt, arglist);
64 PRINTF void warn(const char *fmt, ...)
68 fprintf(stderr, "WARNING: ");
70 va_start(arglist, fmt);
71 vfprintf(stderr, fmt, arglist);
75 PRINTF void merror(const char *fmt, ...)
79 fprintf(stderr, "ERROR: ");
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 static int is_vmlinux(const char *modname)
98 myname = strrchr(modname, '/');
104 return (strcmp(myname, "vmlinux") == 0) ||
105 (strcmp(myname, "vmlinux.o") == 0);
108 void *do_nofail(void *ptr, const char *expr)
111 fatal("modpost: Memory allocation failure: %s.\n", expr);
116 /* A list of all modules we processed */
117 static struct module *modules;
119 static struct module *find_module(char *modname)
123 for (mod = modules; mod; mod = mod->next)
124 if (strcmp(mod->name, modname) == 0)
129 static struct module *new_module(const char *modname)
134 mod = NOFAIL(malloc(sizeof(*mod)));
135 memset(mod, 0, sizeof(*mod));
136 p = NOFAIL(strdup(modname));
138 /* strip trailing .o */
139 if (strends(p, ".o")) {
140 p[strlen(p) - 2] = '\0';
146 mod->gpl_compatible = -1;
153 /* A hash of all exported symbols,
154 * struct symbol is also used for lists of unresolved symbols */
156 #define SYMBOL_HASH_SIZE 1024
160 struct module *module;
164 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
165 unsigned int kernel:1; /* 1 if symbol is from kernel
166 * (only for external modules) **/
167 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
168 enum export export; /* Type of export */
172 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
174 /* This is based on the hash agorithm from gdbm, via tdb */
175 static inline unsigned int tdb_hash(const char *name)
177 unsigned value; /* Used to compute the hash value. */
178 unsigned i; /* Used to cycle through random values. */
180 /* Set the initial value from the key size. */
181 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
182 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
184 return (1103515243 * value + 12345);
188 * Allocate a new symbols for use in the hash of exported symbols or
189 * the list of unresolved symbols per module
191 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
194 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
196 memset(s, 0, sizeof(*s));
197 strcpy(s->name, name);
203 /* For the hash of exported symbols */
204 static struct symbol *new_symbol(const char *name, struct module *module,
210 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
211 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
212 new->module = module;
213 new->export = export;
217 static struct symbol *find_symbol(const char *name)
221 /* For our purposes, .foo matches foo. PPC64 needs this. */
225 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
226 if (strcmp(s->name, name) == 0)
236 { .str = "EXPORT_SYMBOL", .export = export_plain },
237 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
238 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
239 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
240 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
241 { .str = "(unknown)", .export = export_unknown },
245 static const char *export_str(enum export ex)
247 return export_list[ex].str;
250 static enum export export_no(const char *s)
255 return export_unknown;
256 for (i = 0; export_list[i].export != export_unknown; i++) {
257 if (strcmp(export_list[i].str, s) == 0)
258 return export_list[i].export;
260 return export_unknown;
263 static const char *sec_name(struct elf_info *elf, int secindex);
265 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
267 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
269 const char *secname = sec_name(elf, sec);
271 if (strstarts(secname, "___ksymtab+"))
273 else if (strstarts(secname, "___ksymtab_unused+"))
274 return export_unused;
275 else if (strstarts(secname, "___ksymtab_gpl+"))
277 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
278 return export_unused_gpl;
279 else if (strstarts(secname, "___ksymtab_gpl_future+"))
280 return export_gpl_future;
282 return export_unknown;
285 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
287 if (sec == elf->export_sec)
289 else if (sec == elf->export_unused_sec)
290 return export_unused;
291 else if (sec == elf->export_gpl_sec)
293 else if (sec == elf->export_unused_gpl_sec)
294 return export_unused_gpl;
295 else if (sec == elf->export_gpl_future_sec)
296 return export_gpl_future;
298 return export_unknown;
302 * Add an exported symbol - it may have already been added without a
303 * CRC, in this case just update the CRC
305 static struct symbol *sym_add_exported(const char *name, struct module *mod,
308 struct symbol *s = find_symbol(name);
311 s = new_symbol(name, mod, export);
314 warn("%s: '%s' exported twice. Previous export "
315 "was in %s%s\n", mod->name, name,
317 is_vmlinux(s->module->name) ?"":".ko");
319 /* In case Modules.symvers was out of date */
324 s->vmlinux = is_vmlinux(mod->name);
330 static void sym_update_crc(const char *name, struct module *mod,
331 unsigned int crc, enum export export)
333 struct symbol *s = find_symbol(name);
336 s = new_symbol(name, mod, export);
337 /* Don't complain when we find it later. */
344 void *grab_file(const char *filename, unsigned long *size)
347 void *map = MAP_FAILED;
350 fd = open(filename, O_RDONLY);
357 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
361 if (map == MAP_FAILED)
367 * Return a copy of the next line in a mmap'ed file.
368 * spaces in the beginning of the line is trimmed away.
369 * Return a pointer to a static buffer.
371 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
373 static char line[4096];
376 signed char *p = (signed char *)file + *pos;
379 for (; *pos < size ; (*pos)++) {
380 if (skip && isspace(*p)) {
385 if (*p != '\n' && (*pos < size)) {
389 break; /* Too long, stop */
400 void release_file(void *file, unsigned long size)
405 static int parse_elf(struct elf_info *info, const char *filename)
411 const char *secstrings;
412 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
414 hdr = grab_file(filename, &info->size);
416 if (ignore_missing_files) {
417 fprintf(stderr, "%s: %s (ignored)\n", filename,
425 if (info->size < sizeof(*hdr)) {
426 /* file too small, assume this is an empty .o file */
429 /* Is this a valid ELF file? */
430 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
431 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
432 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
433 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
434 /* Not an ELF file - silently ignore it */
437 /* Fix endianness in ELF header */
438 hdr->e_type = TO_NATIVE(hdr->e_type);
439 hdr->e_machine = TO_NATIVE(hdr->e_machine);
440 hdr->e_version = TO_NATIVE(hdr->e_version);
441 hdr->e_entry = TO_NATIVE(hdr->e_entry);
442 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
443 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
444 hdr->e_flags = TO_NATIVE(hdr->e_flags);
445 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
446 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
447 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
448 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
449 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
450 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
451 sechdrs = (void *)hdr + hdr->e_shoff;
452 info->sechdrs = sechdrs;
454 /* Check if file offset is correct */
455 if (hdr->e_shoff > info->size) {
456 fatal("section header offset=%lu in file '%s' is bigger than "
457 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
458 filename, info->size);
462 if (hdr->e_shnum == SHN_UNDEF) {
464 * There are more than 64k sections,
465 * read count from .sh_size.
467 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
470 info->num_sections = hdr->e_shnum;
472 if (hdr->e_shstrndx == SHN_XINDEX) {
473 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
476 info->secindex_strings = hdr->e_shstrndx;
479 /* Fix endianness in section headers */
480 for (i = 0; i < info->num_sections; i++) {
481 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
482 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
483 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
484 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
485 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
486 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
487 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
488 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
489 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
490 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
492 /* Find symbol table. */
493 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
494 for (i = 1; i < info->num_sections; i++) {
496 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
498 if (!nobits && sechdrs[i].sh_offset > info->size) {
499 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
500 "sizeof(*hrd)=%zu\n", filename,
501 (unsigned long)sechdrs[i].sh_offset,
505 secname = secstrings + sechdrs[i].sh_name;
506 if (strcmp(secname, ".modinfo") == 0) {
508 fatal("%s has NOBITS .modinfo\n", filename);
509 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
510 info->modinfo_len = sechdrs[i].sh_size;
511 } else if (strcmp(secname, "__ksymtab") == 0)
512 info->export_sec = i;
513 else if (strcmp(secname, "__ksymtab_unused") == 0)
514 info->export_unused_sec = i;
515 else if (strcmp(secname, "__ksymtab_gpl") == 0)
516 info->export_gpl_sec = i;
517 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
518 info->export_unused_gpl_sec = i;
519 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
520 info->export_gpl_future_sec = i;
522 if (sechdrs[i].sh_type == SHT_SYMTAB) {
523 unsigned int sh_link_idx;
525 info->symtab_start = (void *)hdr +
526 sechdrs[i].sh_offset;
527 info->symtab_stop = (void *)hdr +
528 sechdrs[i].sh_offset + sechdrs[i].sh_size;
529 sh_link_idx = sechdrs[i].sh_link;
530 info->strtab = (void *)hdr +
531 sechdrs[sh_link_idx].sh_offset;
534 /* 32bit section no. table? ("more than 64k sections") */
535 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
536 symtab_shndx_idx = i;
537 info->symtab_shndx_start = (void *)hdr +
538 sechdrs[i].sh_offset;
539 info->symtab_shndx_stop = (void *)hdr +
540 sechdrs[i].sh_offset + sechdrs[i].sh_size;
543 if (!info->symtab_start)
544 fatal("%s has no symtab?\n", filename);
546 /* Fix endianness in symbols */
547 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
548 sym->st_shndx = TO_NATIVE(sym->st_shndx);
549 sym->st_name = TO_NATIVE(sym->st_name);
550 sym->st_value = TO_NATIVE(sym->st_value);
551 sym->st_size = TO_NATIVE(sym->st_size);
554 if (symtab_shndx_idx != ~0U) {
556 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
557 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
558 filename, sechdrs[symtab_shndx_idx].sh_link,
561 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
569 static void parse_elf_finish(struct elf_info *info)
571 release_file(info->hdr, info->size);
574 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
576 /* ignore __this_module, it will be resolved shortly */
577 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
579 /* ignore global offset table */
580 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
582 if (info->hdr->e_machine == EM_PPC)
583 /* Special register function linked on all modules during final link of .ko */
584 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
585 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
586 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
587 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
589 if (info->hdr->e_machine == EM_PPC64)
590 /* Special register function linked on all modules during final link of .ko */
591 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
592 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
594 /* Do not ignore this symbol */
598 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
599 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
601 static void handle_modversions(struct module *mod, struct elf_info *info,
602 Elf_Sym *sym, const char *symname)
607 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
608 strncmp(symname, "__ksymtab", 9) == 0)
609 export = export_from_secname(info, get_secindex(info, sym));
611 export = export_from_sec(info, get_secindex(info, sym));
614 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
615 crc = (unsigned int) sym->st_value;
616 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
620 switch (sym->st_shndx) {
622 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
625 /* undefined symbol */
626 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
627 ELF_ST_BIND(sym->st_info) != STB_WEAK)
629 if (ignore_undef_symbol(info, symname))
631 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
632 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
633 /* add compatibility with older glibc */
634 #ifndef STT_SPARC_REGISTER
635 #define STT_SPARC_REGISTER STT_REGISTER
637 if (info->hdr->e_machine == EM_SPARC ||
638 info->hdr->e_machine == EM_SPARCV9) {
639 /* Ignore register directives. */
640 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
642 if (symname[0] == '.') {
643 char *munged = strdup(symname);
645 munged[1] = toupper(munged[1]);
651 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
652 if (symname[0] != '_')
657 mod->unres = alloc_symbol(symname,
658 ELF_ST_BIND(sym->st_info) == STB_WEAK,
662 /* All exported symbols */
663 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
664 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
667 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
669 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
670 mod->has_cleanup = 1;
676 * Parse tag=value strings from .modinfo section
678 static char *next_string(char *string, unsigned long *secsize)
680 /* Skip non-zero chars */
683 if ((*secsize)-- <= 1)
687 /* Skip any zero padding. */
690 if ((*secsize)-- <= 1)
696 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
697 const char *tag, char *info)
700 unsigned int taglen = strlen(tag);
701 unsigned long size = modinfo_len;
704 size -= info - (char *)modinfo;
705 modinfo = next_string(info, &size);
708 for (p = modinfo; p; p = next_string(p, &size)) {
709 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
710 return p + taglen + 1;
715 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
719 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
723 * Test if string s ends in string sub
726 static int strrcmp(const char *s, const char *sub)
734 sublen = strlen(sub);
736 if ((slen == 0) || (sublen == 0))
742 return memcmp(s + slen - sublen, sub, sublen);
745 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
748 return elf->strtab + sym->st_name;
753 static const char *sec_name(struct elf_info *elf, int secindex)
755 Elf_Shdr *sechdrs = elf->sechdrs;
756 return (void *)elf->hdr +
757 elf->sechdrs[elf->secindex_strings].sh_offset +
758 sechdrs[secindex].sh_name;
761 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
763 return (void *)elf->hdr +
764 elf->sechdrs[elf->secindex_strings].sh_offset +
768 /* if sym is empty or point to a string
769 * like ".[0-9]+" then return 1.
770 * This is the optional prefix added by ld to some sections
772 static int number_prefix(const char *sym)
780 if (c < '0' || c > '9')
786 /* The pattern is an array of simple patterns.
787 * "foo" will match an exact string equal to "foo"
788 * "*foo" will match a string that ends with "foo"
789 * "foo*" will match a string that begins with "foo"
790 * "foo$" will match a string equal to "foo" or "foo.1"
791 * where the '1' can be any number including several digits.
792 * The $ syntax is for sections where ld append a dot number
793 * to make section name unique.
795 static int match(const char *sym, const char * const pat[])
800 const char *endp = p + strlen(p) - 1;
804 if (strrcmp(sym, p + 1) == 0)
808 else if (*endp == '*') {
809 if (strncmp(sym, p, strlen(p) - 1) == 0)
813 else if (*endp == '$') {
814 if (strncmp(sym, p, strlen(p) - 1) == 0) {
815 if (number_prefix(sym + strlen(p) - 1))
821 if (strcmp(p, sym) == 0)
829 /* sections that we do not want to do full section mismatch check on */
830 static const char *section_white_list[] =
834 ".cranges", /* sh64 */
835 ".zdebug*", /* Compressed debug sections. */
836 ".GCC-command-line", /* mn10300 */
837 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
838 ".mdebug*", /* alpha, score, mips etc. */
839 ".pdr", /* alpha, score, mips etc. */
844 ".xt.prop", /* xtensa */
845 ".xt.lit", /* xtensa */
846 ".arcextmap*", /* arc */
847 ".gnu.linkonce.arcext*", /* arc : modules */
852 * This is used to find sections missing the SHF_ALLOC flag.
853 * The cause of this is often a section specified in assembler
854 * without "ax" / "aw".
856 static void check_section(const char *modname, struct elf_info *elf,
859 const char *sec = sech_name(elf, sechdr);
861 if (sechdr->sh_type == SHT_PROGBITS &&
862 !(sechdr->sh_flags & SHF_ALLOC) &&
863 !match(sec, section_white_list)) {
864 warn("%s (%s): unexpected non-allocatable section.\n"
865 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
866 "Note that for example <linux/init.h> contains\n"
867 "section definitions for use in .S files.\n\n",
874 #define ALL_INIT_DATA_SECTIONS \
875 ".init.setup$", ".init.rodata$", ".meminit.rodata$", \
876 ".init.data$", ".meminit.data$"
877 #define ALL_EXIT_DATA_SECTIONS \
878 ".exit.data$", ".memexit.data$"
880 #define ALL_INIT_TEXT_SECTIONS \
881 ".init.text$", ".meminit.text$"
882 #define ALL_EXIT_TEXT_SECTIONS \
883 ".exit.text$", ".memexit.text$"
885 #define ALL_PCI_INIT_SECTIONS \
886 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
887 ".pci_fixup_enable$", ".pci_fixup_resume$", \
888 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
890 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
891 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
893 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
894 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
896 #define DATA_SECTIONS ".data$", ".data.rel$"
897 #define TEXT_SECTIONS ".text$", ".text.unlikely$"
899 #define INIT_SECTIONS ".init.*"
900 #define MEM_INIT_SECTIONS ".meminit.*"
902 #define EXIT_SECTIONS ".exit.*"
903 #define MEM_EXIT_SECTIONS ".memexit.*"
905 /* init data sections */
906 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
908 /* all init sections */
909 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
911 /* All init and exit sections (code + data) */
912 static const char *init_exit_sections[] =
913 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
916 static const char *data_sections[] = { DATA_SECTIONS, NULL };
919 /* symbols in .data that may refer to init/exit sections */
920 #define DEFAULT_SYMBOL_WHITE_LIST \
922 "*_template", /* scsi uses *_template a lot */ \
923 "*_timer", /* arm uses ops structures named _timer a lot */ \
924 "*_sht", /* scsi also used *_sht to some extent */ \
930 static const char *head_sections[] = { ".head.text*", NULL };
931 static const char *linker_symbols[] =
932 { "__init_begin", "_sinittext", "_einittext", NULL };
939 XXXINIT_TO_SOME_INIT,
940 XXXEXIT_TO_SOME_EXIT,
941 ANY_INIT_TO_ANY_EXIT,
942 ANY_EXIT_TO_ANY_INIT,
946 struct sectioncheck {
947 const char *fromsec[20];
948 const char *tosec[20];
949 enum mismatch mismatch;
950 const char *symbol_white_list[20];
953 const struct sectioncheck sectioncheck[] = {
954 /* Do not reference init/exit code/data from
955 * normal code and data
958 .fromsec = { TEXT_SECTIONS, NULL },
959 .tosec = { ALL_INIT_SECTIONS, NULL },
960 .mismatch = TEXT_TO_ANY_INIT,
961 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
964 .fromsec = { DATA_SECTIONS, NULL },
965 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
966 .mismatch = DATA_TO_ANY_INIT,
967 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
970 .fromsec = { DATA_SECTIONS, NULL },
971 .tosec = { INIT_SECTIONS, NULL },
972 .mismatch = DATA_TO_ANY_INIT,
973 .symbol_white_list = {
974 "*_template", "*_timer", "*_sht", "*_ops",
975 "*_probe", "*_probe_one", "*_console", NULL
979 .fromsec = { TEXT_SECTIONS, NULL },
980 .tosec = { ALL_EXIT_SECTIONS, NULL },
981 .mismatch = TEXT_TO_ANY_EXIT,
982 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
985 .fromsec = { DATA_SECTIONS, NULL },
986 .tosec = { ALL_EXIT_SECTIONS, NULL },
987 .mismatch = DATA_TO_ANY_EXIT,
988 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
990 /* Do not reference init code/data from meminit code/data */
992 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
993 .tosec = { INIT_SECTIONS, NULL },
994 .mismatch = XXXINIT_TO_SOME_INIT,
995 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
997 /* Do not reference exit code/data from memexit code/data */
999 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1000 .tosec = { EXIT_SECTIONS, NULL },
1001 .mismatch = XXXEXIT_TO_SOME_EXIT,
1002 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1004 /* Do not use exit code/data from init code */
1006 .fromsec = { ALL_INIT_SECTIONS, NULL },
1007 .tosec = { ALL_EXIT_SECTIONS, NULL },
1008 .mismatch = ANY_INIT_TO_ANY_EXIT,
1009 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1011 /* Do not use init code/data from exit code */
1013 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1014 .tosec = { ALL_INIT_SECTIONS, NULL },
1015 .mismatch = ANY_EXIT_TO_ANY_INIT,
1016 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1019 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1020 .tosec = { INIT_SECTIONS, NULL },
1021 .mismatch = ANY_INIT_TO_ANY_EXIT,
1022 .symbol_white_list = { NULL },
1024 /* Do not export init/exit functions or data */
1026 .fromsec = { "__ksymtab*", NULL },
1027 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1028 .mismatch = EXPORT_TO_INIT_EXIT,
1029 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1033 static const struct sectioncheck *section_mismatch(
1034 const char *fromsec, const char *tosec)
1037 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1038 const struct sectioncheck *check = §ioncheck[0];
1040 for (i = 0; i < elems; i++) {
1041 if (match(fromsec, check->fromsec) &&
1042 match(tosec, check->tosec))
1050 * Whitelist to allow certain references to pass with no warning.
1053 * If a module parameter is declared __initdata and permissions=0
1054 * then this is legal despite the warning generated.
1055 * We cannot see value of permissions here, so just ignore
1057 * The pattern is identified by:
1058 * tosec = .init.data
1063 * module_param_call() ops can refer to __init set function if permissions=0
1064 * The pattern is identified by:
1065 * tosec = .init.text
1067 * atsym = __param_ops_*
1070 * Many drivers utilise a *driver container with references to
1071 * add, remove, probe functions etc.
1072 * the pattern is identified by:
1073 * tosec = init or exit section
1074 * fromsec = data section
1075 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1076 * *probe_one, *_console, *_timer
1079 * Whitelist all references from .head.text to any init section
1082 * Some symbols belong to init section but still it is ok to reference
1083 * these from non-init sections as these symbols don't have any memory
1084 * allocated for them and symbol address and value are same. So even
1085 * if init section is freed, its ok to reference those symbols.
1086 * For ex. symbols marking the init section boundaries.
1087 * This pattern is identified by
1088 * refsymname = __init_begin, _sinittext, _einittext
1091 static int secref_whitelist(const struct sectioncheck *mismatch,
1092 const char *fromsec, const char *fromsym,
1093 const char *tosec, const char *tosym)
1095 /* Check for pattern 1 */
1096 if (match(tosec, init_data_sections) &&
1097 match(fromsec, data_sections) &&
1098 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1101 /* Check for pattern 1a */
1102 if (strcmp(tosec, ".init.text") == 0 &&
1103 match(fromsec, data_sections) &&
1104 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1107 /* Check for pattern 2 */
1108 if (match(tosec, init_exit_sections) &&
1109 match(fromsec, data_sections) &&
1110 match(fromsym, mismatch->symbol_white_list))
1113 /* Check for pattern 3 */
1114 if (match(fromsec, head_sections) &&
1115 match(tosec, init_sections))
1118 /* Check for pattern 4 */
1119 if (match(tosym, linker_symbols))
1126 * Find symbol based on relocation record info.
1127 * In some cases the symbol supplied is a valid symbol so
1128 * return refsym. If st_name != 0 we assume this is a valid symbol.
1129 * In other cases the symbol needs to be looked up in the symbol table
1130 * based on section and address.
1132 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1136 Elf_Sym *near = NULL;
1137 Elf64_Sword distance = 20;
1139 unsigned int relsym_secindex;
1141 if (relsym->st_name != 0)
1144 relsym_secindex = get_secindex(elf, relsym);
1145 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1146 if (get_secindex(elf, sym) != relsym_secindex)
1148 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1150 if (sym->st_value == addr)
1152 /* Find a symbol nearby - addr are maybe negative */
1153 d = sym->st_value - addr;
1155 d = addr - sym->st_value;
1161 /* We need a close match */
1168 static inline int is_arm_mapping_symbol(const char *str)
1170 return str[0] == '$' && strchr("atd", str[1])
1171 && (str[2] == '\0' || str[2] == '.');
1175 * If there's no name there, ignore it; likewise, ignore it if it's
1176 * one of the magic symbols emitted used by current ARM tools.
1178 * Otherwise if find_symbols_between() returns those symbols, they'll
1179 * fail the whitelist tests and cause lots of false alarms ... fixable
1180 * only by merging __exit and __init sections into __text, bloating
1181 * the kernel (which is especially evil on embedded platforms).
1183 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1185 const char *name = elf->strtab + sym->st_name;
1187 if (!name || !strlen(name))
1189 return !is_arm_mapping_symbol(name);
1193 * Find symbols before or equal addr and after addr - in the section sec.
1194 * If we find two symbols with equal offset prefer one with a valid name.
1195 * The ELF format may have a better way to detect what type of symbol
1196 * it is, but this works for now.
1198 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1202 Elf_Sym *near = NULL;
1203 Elf_Addr distance = ~0;
1205 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1208 if (is_shndx_special(sym->st_shndx))
1210 symsec = sec_name(elf, get_secindex(elf, sym));
1211 if (strcmp(symsec, sec) != 0)
1213 if (!is_valid_name(elf, sym))
1215 if (sym->st_value <= addr) {
1216 if ((addr - sym->st_value) < distance) {
1217 distance = addr - sym->st_value;
1219 } else if ((addr - sym->st_value) == distance) {
1228 * Convert a section name to the function/data attribute
1229 * .init.text => __init
1230 * .memexitconst => __memconst
1233 * The memory of returned value has been allocated on a heap. The user of this
1234 * method should free it after usage.
1236 static char *sec2annotation(const char *s)
1238 if (match(s, init_exit_sections)) {
1239 char *p = malloc(20);
1246 while (*s && *s != '.')
1251 if (strstr(s, "rodata") != NULL)
1252 strcat(p, "const ");
1253 else if (strstr(s, "data") != NULL)
1263 static int is_function(Elf_Sym *sym)
1266 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1271 static void print_section_list(const char * const list[20])
1273 const char *const *s = list;
1276 fprintf(stderr, "%s", *s);
1279 fprintf(stderr, ", ");
1281 fprintf(stderr, "\n");
1285 * Print a warning about a section mismatch.
1286 * Try to find symbols near it so user can find it.
1287 * Check whitelist before warning - it may be a false positive.
1289 static void report_sec_mismatch(const char *modname,
1290 const struct sectioncheck *mismatch,
1291 const char *fromsec,
1292 unsigned long long fromaddr,
1293 const char *fromsym,
1295 const char *tosec, const char *tosym,
1298 const char *from, *from_p;
1299 const char *to, *to_p;
1303 switch (from_is_func) {
1304 case 0: from = "variable"; from_p = ""; break;
1305 case 1: from = "function"; from_p = "()"; break;
1306 default: from = "(unknown reference)"; from_p = ""; break;
1308 switch (to_is_func) {
1309 case 0: to = "variable"; to_p = ""; break;
1310 case 1: to = "function"; to_p = "()"; break;
1311 default: to = "(unknown reference)"; to_p = ""; break;
1314 sec_mismatch_count++;
1315 if (!sec_mismatch_verbose)
1318 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1319 "to the %s %s:%s%s\n",
1320 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1323 switch (mismatch->mismatch) {
1324 case TEXT_TO_ANY_INIT:
1325 prl_from = sec2annotation(fromsec);
1326 prl_to = sec2annotation(tosec);
1328 "The function %s%s() references\n"
1330 "This is often because %s lacks a %s\n"
1331 "annotation or the annotation of %s is wrong.\n",
1333 to, prl_to, tosym, to_p,
1334 fromsym, prl_to, tosym);
1338 case DATA_TO_ANY_INIT: {
1339 prl_to = sec2annotation(tosec);
1341 "The variable %s references\n"
1343 "If the reference is valid then annotate the\n"
1344 "variable with __init* or __refdata (see linux/init.h) "
1345 "or name the variable:\n",
1346 fromsym, to, prl_to, tosym, to_p);
1347 print_section_list(mismatch->symbol_white_list);
1351 case TEXT_TO_ANY_EXIT:
1352 prl_to = sec2annotation(tosec);
1354 "The function %s() references a %s in an exit section.\n"
1355 "Often the %s %s%s has valid usage outside the exit section\n"
1356 "and the fix is to remove the %sannotation of %s.\n",
1357 fromsym, to, to, tosym, to_p, prl_to, tosym);
1360 case DATA_TO_ANY_EXIT: {
1361 prl_to = sec2annotation(tosec);
1363 "The variable %s references\n"
1365 "If the reference is valid then annotate the\n"
1366 "variable with __exit* (see linux/init.h) or "
1367 "name the variable:\n",
1368 fromsym, to, prl_to, tosym, to_p);
1369 print_section_list(mismatch->symbol_white_list);
1373 case XXXINIT_TO_SOME_INIT:
1374 case XXXEXIT_TO_SOME_EXIT:
1375 prl_from = sec2annotation(fromsec);
1376 prl_to = sec2annotation(tosec);
1378 "The %s %s%s%s references\n"
1380 "If %s is only used by %s then\n"
1381 "annotate %s with a matching annotation.\n",
1382 from, prl_from, fromsym, from_p,
1383 to, prl_to, tosym, to_p,
1384 tosym, fromsym, tosym);
1388 case ANY_INIT_TO_ANY_EXIT:
1389 prl_from = sec2annotation(fromsec);
1390 prl_to = sec2annotation(tosec);
1392 "The %s %s%s%s references\n"
1394 "This is often seen when error handling "
1395 "in the init function\n"
1396 "uses functionality in the exit path.\n"
1397 "The fix is often to remove the %sannotation of\n"
1398 "%s%s so it may be used outside an exit section.\n",
1399 from, prl_from, fromsym, from_p,
1400 to, prl_to, tosym, to_p,
1401 prl_to, tosym, to_p);
1405 case ANY_EXIT_TO_ANY_INIT:
1406 prl_from = sec2annotation(fromsec);
1407 prl_to = sec2annotation(tosec);
1409 "The %s %s%s%s references\n"
1411 "This is often seen when error handling "
1412 "in the exit function\n"
1413 "uses functionality in the init path.\n"
1414 "The fix is often to remove the %sannotation of\n"
1415 "%s%s so it may be used outside an init section.\n",
1416 from, prl_from, fromsym, from_p,
1417 to, prl_to, tosym, to_p,
1418 prl_to, tosym, to_p);
1422 case EXPORT_TO_INIT_EXIT:
1423 prl_to = sec2annotation(tosec);
1425 "The symbol %s is exported and annotated %s\n"
1426 "Fix this by removing the %sannotation of %s "
1427 "or drop the export.\n",
1428 tosym, prl_to, prl_to, tosym);
1432 fprintf(stderr, "\n");
1435 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1436 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1439 const struct sectioncheck *mismatch;
1441 tosec = sec_name(elf, get_secindex(elf, sym));
1442 mismatch = section_mismatch(fromsec, tosec);
1447 const char *fromsym;
1449 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1450 fromsym = sym_name(elf, from);
1451 to = find_elf_symbol(elf, r->r_addend, sym);
1452 tosym = sym_name(elf, to);
1454 /* check whitelist - we may ignore it */
1455 if (secref_whitelist(mismatch,
1456 fromsec, fromsym, tosec, tosym)) {
1457 report_sec_mismatch(modname, mismatch,
1458 fromsec, r->r_offset, fromsym,
1459 is_function(from), tosec, tosym,
1465 static unsigned int *reloc_location(struct elf_info *elf,
1466 Elf_Shdr *sechdr, Elf_Rela *r)
1468 Elf_Shdr *sechdrs = elf->sechdrs;
1469 int section = sechdr->sh_info;
1471 return (void *)elf->hdr + sechdrs[section].sh_offset +
1475 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1477 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1478 unsigned int *location = reloc_location(elf, sechdr, r);
1482 r->r_addend = TO_NATIVE(*location);
1485 r->r_addend = TO_NATIVE(*location) + 4;
1486 /* For CONFIG_RELOCATABLE=y */
1487 if (elf->hdr->e_type == ET_EXEC)
1488 r->r_addend += r->r_offset;
1495 #define R_ARM_CALL 28
1497 #ifndef R_ARM_JUMP24
1498 #define R_ARM_JUMP24 29
1501 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1503 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1507 /* From ARM ABI: (S + A) | T */
1508 r->r_addend = (int)(long)
1509 (elf->symtab_start + ELF_R_SYM(r->r_info));
1514 /* From ARM ABI: ((S + A) | T) - P */
1515 r->r_addend = (int)(long)(elf->hdr +
1517 (r->r_offset - sechdr->sh_addr));
1525 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1527 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1528 unsigned int *location = reloc_location(elf, sechdr, r);
1531 if (r_typ == R_MIPS_HI16)
1532 return 1; /* skip this */
1533 inst = TO_NATIVE(*location);
1536 r->r_addend = inst & 0xffff;
1539 r->r_addend = (inst & 0x03ffffff) << 2;
1548 static void section_rela(const char *modname, struct elf_info *elf,
1555 const char *fromsec;
1557 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1558 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1560 fromsec = sech_name(elf, sechdr);
1561 fromsec += strlen(".rela");
1562 /* if from section (name) is know good then skip it */
1563 if (match(fromsec, section_white_list))
1566 for (rela = start; rela < stop; rela++) {
1567 r.r_offset = TO_NATIVE(rela->r_offset);
1568 #if KERNEL_ELFCLASS == ELFCLASS64
1569 if (elf->hdr->e_machine == EM_MIPS) {
1571 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1572 r_sym = TO_NATIVE(r_sym);
1573 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1574 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1576 r.r_info = TO_NATIVE(rela->r_info);
1577 r_sym = ELF_R_SYM(r.r_info);
1580 r.r_info = TO_NATIVE(rela->r_info);
1581 r_sym = ELF_R_SYM(r.r_info);
1583 r.r_addend = TO_NATIVE(rela->r_addend);
1584 sym = elf->symtab_start + r_sym;
1585 /* Skip special sections */
1586 if (is_shndx_special(sym->st_shndx))
1588 check_section_mismatch(modname, elf, &r, sym, fromsec);
1592 static void section_rel(const char *modname, struct elf_info *elf,
1599 const char *fromsec;
1601 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1602 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1604 fromsec = sech_name(elf, sechdr);
1605 fromsec += strlen(".rel");
1606 /* if from section (name) is know good then skip it */
1607 if (match(fromsec, section_white_list))
1610 for (rel = start; rel < stop; rel++) {
1611 r.r_offset = TO_NATIVE(rel->r_offset);
1612 #if KERNEL_ELFCLASS == ELFCLASS64
1613 if (elf->hdr->e_machine == EM_MIPS) {
1615 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1616 r_sym = TO_NATIVE(r_sym);
1617 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1618 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1620 r.r_info = TO_NATIVE(rel->r_info);
1621 r_sym = ELF_R_SYM(r.r_info);
1624 r.r_info = TO_NATIVE(rel->r_info);
1625 r_sym = ELF_R_SYM(r.r_info);
1628 switch (elf->hdr->e_machine) {
1630 if (addend_386_rel(elf, sechdr, &r))
1634 if (addend_arm_rel(elf, sechdr, &r))
1638 if (addend_mips_rel(elf, sechdr, &r))
1642 sym = elf->symtab_start + r_sym;
1643 /* Skip special sections */
1644 if (is_shndx_special(sym->st_shndx))
1646 check_section_mismatch(modname, elf, &r, sym, fromsec);
1651 * A module includes a number of sections that are discarded
1652 * either when loaded or when used as built-in.
1653 * For loaded modules all functions marked __init and all data
1654 * marked __initdata will be discarded when the module has been initialized.
1655 * Likewise for modules used built-in the sections marked __exit
1656 * are discarded because __exit marked function are supposed to be called
1657 * only when a module is unloaded which never happens for built-in modules.
1658 * The check_sec_ref() function traverses all relocation records
1659 * to find all references to a section that reference a section that will
1660 * be discarded and warns about it.
1662 static void check_sec_ref(struct module *mod, const char *modname,
1663 struct elf_info *elf)
1666 Elf_Shdr *sechdrs = elf->sechdrs;
1668 /* Walk through all sections */
1669 for (i = 0; i < elf->num_sections; i++) {
1670 check_section(modname, elf, &elf->sechdrs[i]);
1671 /* We want to process only relocation sections and not .init */
1672 if (sechdrs[i].sh_type == SHT_RELA)
1673 section_rela(modname, elf, &elf->sechdrs[i]);
1674 else if (sechdrs[i].sh_type == SHT_REL)
1675 section_rel(modname, elf, &elf->sechdrs[i]);
1679 static void read_symbols(char *modname)
1681 const char *symname;
1685 struct elf_info info = { };
1688 if (!parse_elf(&info, modname))
1691 mod = new_module(modname);
1693 /* When there's no vmlinux, don't print warnings about
1694 * unresolved symbols (since there'll be too many ;) */
1695 if (is_vmlinux(modname)) {
1700 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1701 if (info.modinfo && !license && !is_vmlinux(modname))
1702 warn("modpost: missing MODULE_LICENSE() in %s\n"
1703 "see include/linux/module.h for "
1704 "more information\n", modname);
1706 if (license_is_gpl_compatible(license))
1707 mod->gpl_compatible = 1;
1709 mod->gpl_compatible = 0;
1712 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1713 "license", license);
1716 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1717 symname = info.strtab + sym->st_name;
1719 handle_modversions(mod, &info, sym, symname);
1720 handle_moddevtable(mod, &info, sym, symname);
1722 if (!is_vmlinux(modname) ||
1723 (is_vmlinux(modname) && vmlinux_section_warnings))
1724 check_sec_ref(mod, modname, &info);
1726 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1728 maybe_frob_rcs_version(modname, version, info.modinfo,
1729 version - (char *)info.hdr);
1730 if (version || (all_versions && !is_vmlinux(modname)))
1731 get_src_version(modname, mod->srcversion,
1732 sizeof(mod->srcversion)-1);
1734 parse_elf_finish(&info);
1736 /* Our trick to get versioning for module struct etc. - it's
1737 * never passed as an argument to an exported function, so
1738 * the automatic versioning doesn't pick it up, but it's really
1739 * important anyhow */
1741 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1744 static void read_symbols_from_files(const char *filename)
1747 char fname[PATH_MAX];
1749 if (strcmp(filename, "-") != 0) {
1750 in = fopen(filename, "r");
1752 fatal("Can't open filenames file %s: %m", filename);
1755 while (fgets(fname, PATH_MAX, in) != NULL) {
1756 if (strends(fname, "\n"))
1757 fname[strlen(fname)-1] = '\0';
1758 read_symbols(fname);
1767 /* We first write the generated file into memory using the
1768 * following helper, then compare to the file on disk and
1769 * only update the later if anything changed */
1771 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1772 const char *fmt, ...)
1779 len = vsnprintf(tmp, SZ, fmt, ap);
1780 buf_write(buf, tmp, len);
1784 void buf_write(struct buffer *buf, const char *s, int len)
1786 if (buf->size - buf->pos < len) {
1787 buf->size += len + SZ;
1788 buf->p = realloc(buf->p, buf->size);
1790 strncpy(buf->p + buf->pos, s, len);
1794 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1796 const char *e = is_vmlinux(m) ?"":".ko";
1800 fatal("modpost: GPL-incompatible module %s%s "
1801 "uses GPL-only symbol '%s'\n", m, e, s);
1803 case export_unused_gpl:
1804 fatal("modpost: GPL-incompatible module %s%s "
1805 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1807 case export_gpl_future:
1808 warn("modpost: GPL-incompatible module %s%s "
1809 "uses future GPL-only symbol '%s'\n", m, e, s);
1813 case export_unknown:
1819 static void check_for_unused(enum export exp, const char *m, const char *s)
1821 const char *e = is_vmlinux(m) ?"":".ko";
1825 case export_unused_gpl:
1826 warn("modpost: module %s%s "
1827 "uses symbol '%s' marked UNUSED\n", m, e, s);
1835 static void check_exports(struct module *mod)
1837 struct symbol *s, *exp;
1839 for (s = mod->unres; s; s = s->next) {
1840 const char *basename;
1841 exp = find_symbol(s->name);
1842 if (!exp || exp->module == mod)
1844 basename = strrchr(mod->name, '/');
1848 basename = mod->name;
1849 if (!mod->gpl_compatible)
1850 check_for_gpl_usage(exp->export, basename, exp->name);
1851 check_for_unused(exp->export, basename, exp->name);
1856 * Header for the generated file
1858 static void add_header(struct buffer *b, struct module *mod)
1860 buf_printf(b, "#include <linux/module.h>\n");
1861 buf_printf(b, "#include <linux/vermagic.h>\n");
1862 buf_printf(b, "#include <linux/compiler.h>\n");
1863 buf_printf(b, "\n");
1864 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1865 buf_printf(b, "\n");
1866 buf_printf(b, "__visible struct module __this_module\n");
1867 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1868 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1870 buf_printf(b, "\t.init = init_module,\n");
1871 if (mod->has_cleanup)
1872 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1873 "\t.exit = cleanup_module,\n"
1875 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1876 buf_printf(b, "};\n");
1879 static void add_intree_flag(struct buffer *b, int is_intree)
1882 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1885 static void add_staging_flag(struct buffer *b, const char *name)
1887 static const char *staging_dir = "drivers/staging";
1889 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1890 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1894 * Record CRCs for unresolved symbols
1896 static int add_versions(struct buffer *b, struct module *mod)
1898 struct symbol *s, *exp;
1901 for (s = mod->unres; s; s = s->next) {
1902 exp = find_symbol(s->name);
1903 if (!exp || exp->module == mod) {
1904 if (have_vmlinux && !s->weak) {
1905 if (warn_unresolved) {
1906 warn("\"%s\" [%s.ko] undefined!\n",
1907 s->name, mod->name);
1909 merror("\"%s\" [%s.ko] undefined!\n",
1910 s->name, mod->name);
1916 s->module = exp->module;
1917 s->crc_valid = exp->crc_valid;
1924 buf_printf(b, "\n");
1925 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1926 buf_printf(b, "__used\n");
1927 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1929 for (s = mod->unres; s; s = s->next) {
1932 if (!s->crc_valid) {
1933 warn("\"%s\" [%s.ko] has no CRC!\n",
1934 s->name, mod->name);
1937 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1941 buf_printf(b, "};\n");
1946 static void add_depends(struct buffer *b, struct module *mod,
1947 struct module *modules)
1953 for (m = modules; m; m = m->next)
1954 m->seen = is_vmlinux(m->name);
1956 buf_printf(b, "\n");
1957 buf_printf(b, "static const char __module_depends[]\n");
1958 buf_printf(b, "__used\n");
1959 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1960 buf_printf(b, "\"depends=");
1961 for (s = mod->unres; s; s = s->next) {
1966 if (s->module->seen)
1969 s->module->seen = 1;
1970 p = strrchr(s->module->name, '/');
1974 p = s->module->name;
1975 buf_printf(b, "%s%s", first ? "" : ",", p);
1978 buf_printf(b, "\";\n");
1981 static void add_srcversion(struct buffer *b, struct module *mod)
1983 if (mod->srcversion[0]) {
1984 buf_printf(b, "\n");
1985 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1990 static void write_if_changed(struct buffer *b, const char *fname)
1996 file = fopen(fname, "r");
2000 if (fstat(fileno(file), &st) < 0)
2003 if (st.st_size != b->pos)
2006 tmp = NOFAIL(malloc(b->pos));
2007 if (fread(tmp, 1, b->pos, file) != b->pos)
2010 if (memcmp(tmp, b->p, b->pos) != 0)
2022 file = fopen(fname, "w");
2027 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2034 /* parse Module.symvers file. line format:
2035 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2037 static void read_dump(const char *fname, unsigned int kernel)
2039 unsigned long size, pos = 0;
2040 void *file = grab_file(fname, &size);
2044 /* No symbol versions, silently ignore */
2047 while ((line = get_next_line(&pos, file, size))) {
2048 char *symname, *modname, *d, *export, *end;
2053 if (!(symname = strchr(line, '\t')))
2056 if (!(modname = strchr(symname, '\t')))
2059 if ((export = strchr(modname, '\t')) != NULL)
2061 if (export && ((end = strchr(export, '\t')) != NULL))
2063 crc = strtoul(line, &d, 16);
2064 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2066 mod = find_module(modname);
2068 if (is_vmlinux(modname))
2070 mod = new_module(modname);
2073 s = sym_add_exported(symname, mod, export_no(export));
2076 sym_update_crc(symname, mod, crc, export_no(export));
2080 fatal("parse error in symbol dump file\n");
2083 /* For normal builds always dump all symbols.
2084 * For external modules only dump symbols
2085 * that are not read from kernel Module.symvers.
2087 static int dump_sym(struct symbol *sym)
2089 if (!external_module)
2091 if (sym->vmlinux || sym->kernel)
2096 static void write_dump(const char *fname)
2098 struct buffer buf = { };
2099 struct symbol *symbol;
2102 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2103 symbol = symbolhash[n];
2105 if (dump_sym(symbol))
2106 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2107 symbol->crc, symbol->name,
2108 symbol->module->name,
2109 export_str(symbol->export));
2110 symbol = symbol->next;
2113 write_if_changed(&buf, fname);
2116 struct ext_sym_list {
2117 struct ext_sym_list *next;
2121 int main(int argc, char **argv)
2124 struct buffer buf = { };
2125 char *kernel_read = NULL, *module_read = NULL;
2126 char *dump_write = NULL, *files_source = NULL;
2129 struct ext_sym_list *extsym_iter;
2130 struct ext_sym_list *extsym_start = NULL;
2132 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:")) != -1) {
2135 kernel_read = optarg;
2138 module_read = optarg;
2139 external_module = 1;
2142 external_module = 1;
2144 NOFAIL(malloc(sizeof(*extsym_iter)));
2145 extsym_iter->next = extsym_start;
2146 extsym_iter->file = optarg;
2147 extsym_start = extsym_iter;
2153 ignore_missing_files = 1;
2156 dump_write = optarg;
2162 vmlinux_section_warnings = 0;
2165 sec_mismatch_verbose = 0;
2168 files_source = optarg;
2171 warn_unresolved = 1;
2179 read_dump(kernel_read, 1);
2181 read_dump(module_read, 0);
2182 while (extsym_start) {
2183 read_dump(extsym_start->file, 0);
2184 extsym_iter = extsym_start->next;
2186 extsym_start = extsym_iter;
2189 while (optind < argc)
2190 read_symbols(argv[optind++]);
2193 read_symbols_from_files(files_source);
2195 for (mod = modules; mod; mod = mod->next) {
2203 for (mod = modules; mod; mod = mod->next) {
2204 char fname[strlen(mod->name) + 10];
2211 add_header(&buf, mod);
2212 add_intree_flag(&buf, !external_module);
2213 add_staging_flag(&buf, mod->name);
2214 err |= add_versions(&buf, mod);
2215 add_depends(&buf, mod, modules);
2216 add_moddevtable(&buf, mod);
2217 add_srcversion(&buf, mod);
2219 sprintf(fname, "%s.mod.c", mod->name);
2220 write_if_changed(&buf, fname);
2224 write_dump(dump_write);
2225 if (sec_mismatch_count && !sec_mismatch_verbose)
2226 warn("modpost: Found %d section mismatch(es).\n"
2227 "To see full details build your kernel with:\n"
2228 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2229 sec_mismatch_count);