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 ...
18 #include "../../include/generated/autoconf.h"
19 #include "../../include/linux/license.h"
21 /* Some toolchains use a `_' prefix for all user symbols. */
22 #ifdef CONFIG_SYMBOL_PREFIX
23 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
25 #define MODULE_SYMBOL_PREFIX ""
29 /* Are we using CONFIG_MODVERSIONS? */
31 /* Warn about undefined symbols? (do so if we have vmlinux) */
33 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
34 static int all_versions = 0;
35 /* If we are modposting external module set to 1 */
36 static int external_module = 0;
37 /* Warn about section mismatch in vmlinux if set to 1 */
38 static int vmlinux_section_warnings = 1;
39 /* Only warn about unresolved symbols */
40 static int warn_unresolved = 0;
41 /* How a symbol is exported */
42 static int sec_mismatch_count = 0;
43 static int sec_mismatch_verbose = 1;
46 export_plain, export_unused, export_gpl,
47 export_unused_gpl, export_gpl_future, export_unknown
50 #define PRINTF __attribute__ ((format (printf, 1, 2)))
52 PRINTF void fatal(const char *fmt, ...)
56 fprintf(stderr, "FATAL: ");
58 va_start(arglist, fmt);
59 vfprintf(stderr, fmt, arglist);
65 PRINTF void warn(const char *fmt, ...)
69 fprintf(stderr, "WARNING: ");
71 va_start(arglist, fmt);
72 vfprintf(stderr, fmt, arglist);
76 PRINTF void merror(const char *fmt, ...)
80 fprintf(stderr, "ERROR: ");
82 va_start(arglist, fmt);
83 vfprintf(stderr, fmt, arglist);
87 static int is_vmlinux(const char *modname)
91 myname = strrchr(modname, '/');
97 return (strcmp(myname, "vmlinux") == 0) ||
98 (strcmp(myname, "vmlinux.o") == 0);
101 void *do_nofail(void *ptr, const char *expr)
104 fatal("modpost: Memory allocation failure: %s.\n", expr);
109 /* A list of all modules we processed */
110 static struct module *modules;
112 static struct module *find_module(char *modname)
116 for (mod = modules; mod; mod = mod->next)
117 if (strcmp(mod->name, modname) == 0)
122 static struct module *new_module(char *modname)
127 mod = NOFAIL(malloc(sizeof(*mod)));
128 memset(mod, 0, sizeof(*mod));
129 p = NOFAIL(strdup(modname));
131 /* strip trailing .o */
134 if (strcmp(s, ".o") == 0)
139 mod->gpl_compatible = -1;
146 /* A hash of all exported symbols,
147 * struct symbol is also used for lists of unresolved symbols */
149 #define SYMBOL_HASH_SIZE 1024
153 struct module *module;
157 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
158 unsigned int kernel:1; /* 1 if symbol is from kernel
159 * (only for external modules) **/
160 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
161 enum export export; /* Type of export */
165 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
167 /* This is based on the hash agorithm from gdbm, via tdb */
168 static inline unsigned int tdb_hash(const char *name)
170 unsigned value; /* Used to compute the hash value. */
171 unsigned i; /* Used to cycle through random values. */
173 /* Set the initial value from the key size. */
174 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
175 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
177 return (1103515243 * value + 12345);
181 * Allocate a new symbols for use in the hash of exported symbols or
182 * the list of unresolved symbols per module
184 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
187 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
189 memset(s, 0, sizeof(*s));
190 strcpy(s->name, name);
196 /* For the hash of exported symbols */
197 static struct symbol *new_symbol(const char *name, struct module *module,
203 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
204 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
205 new->module = module;
206 new->export = export;
210 static struct symbol *find_symbol(const char *name)
214 /* For our purposes, .foo matches foo. PPC64 needs this. */
218 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
219 if (strcmp(s->name, name) == 0)
229 { .str = "EXPORT_SYMBOL", .export = export_plain },
230 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
231 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
232 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
233 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
234 { .str = "(unknown)", .export = export_unknown },
238 static const char *export_str(enum export ex)
240 return export_list[ex].str;
243 static enum export export_no(const char *s)
248 return export_unknown;
249 for (i = 0; export_list[i].export != export_unknown; i++) {
250 if (strcmp(export_list[i].str, s) == 0)
251 return export_list[i].export;
253 return export_unknown;
256 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
258 if (sec == elf->export_sec)
260 else if (sec == elf->export_unused_sec)
261 return export_unused;
262 else if (sec == elf->export_gpl_sec)
264 else if (sec == elf->export_unused_gpl_sec)
265 return export_unused_gpl;
266 else if (sec == elf->export_gpl_future_sec)
267 return export_gpl_future;
269 return export_unknown;
273 * Add an exported symbol - it may have already been added without a
274 * CRC, in this case just update the CRC
276 static struct symbol *sym_add_exported(const char *name, struct module *mod,
279 struct symbol *s = find_symbol(name);
282 s = new_symbol(name, mod, export);
285 warn("%s: '%s' exported twice. Previous export "
286 "was in %s%s\n", mod->name, name,
288 is_vmlinux(s->module->name) ?"":".ko");
290 /* In case Modules.symvers was out of date */
295 s->vmlinux = is_vmlinux(mod->name);
301 static void sym_update_crc(const char *name, struct module *mod,
302 unsigned int crc, enum export export)
304 struct symbol *s = find_symbol(name);
307 s = new_symbol(name, mod, export);
312 void *grab_file(const char *filename, unsigned long *size)
318 fd = open(filename, O_RDONLY);
319 if (fd < 0 || fstat(fd, &st) != 0)
323 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
326 if (map == MAP_FAILED)
332 * Return a copy of the next line in a mmap'ed file.
333 * spaces in the beginning of the line is trimmed away.
334 * Return a pointer to a static buffer.
336 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
338 static char line[4096];
341 signed char *p = (signed char *)file + *pos;
344 for (; *pos < size ; (*pos)++) {
345 if (skip && isspace(*p)) {
350 if (*p != '\n' && (*pos < size)) {
354 break; /* Too long, stop */
365 void release_file(void *file, unsigned long size)
370 static int parse_elf(struct elf_info *info, const char *filename)
377 hdr = grab_file(filename, &info->size);
383 if (info->size < sizeof(*hdr)) {
384 /* file too small, assume this is an empty .o file */
387 /* Is this a valid ELF file? */
388 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
389 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
390 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
391 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
392 /* Not an ELF file - silently ignore it */
395 /* Fix endianness in ELF header */
396 hdr->e_type = TO_NATIVE(hdr->e_type);
397 hdr->e_machine = TO_NATIVE(hdr->e_machine);
398 hdr->e_version = TO_NATIVE(hdr->e_version);
399 hdr->e_entry = TO_NATIVE(hdr->e_entry);
400 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
401 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
402 hdr->e_flags = TO_NATIVE(hdr->e_flags);
403 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
404 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
405 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
406 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
407 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
408 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
409 sechdrs = (void *)hdr + hdr->e_shoff;
410 info->sechdrs = sechdrs;
412 /* Check if file offset is correct */
413 if (hdr->e_shoff > info->size) {
414 fatal("section header offset=%lu in file '%s' is bigger than "
415 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
416 filename, info->size);
420 /* Fix endianness in section headers */
421 for (i = 0; i < hdr->e_shnum; i++) {
422 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
423 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
424 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
425 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
426 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
427 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
428 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
429 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
430 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
431 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
433 /* Find symbol table. */
434 for (i = 1; i < hdr->e_shnum; i++) {
435 const char *secstrings
436 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
438 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
440 if (!nobits && sechdrs[i].sh_offset > info->size) {
441 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
442 "sizeof(*hrd)=%zu\n", filename,
443 (unsigned long)sechdrs[i].sh_offset,
447 secname = secstrings + sechdrs[i].sh_name;
448 if (strcmp(secname, ".modinfo") == 0) {
450 fatal("%s has NOBITS .modinfo\n", filename);
451 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
452 info->modinfo_len = sechdrs[i].sh_size;
453 } else if (strcmp(secname, "__ksymtab") == 0)
454 info->export_sec = i;
455 else if (strcmp(secname, "__ksymtab_unused") == 0)
456 info->export_unused_sec = i;
457 else if (strcmp(secname, "__ksymtab_gpl") == 0)
458 info->export_gpl_sec = i;
459 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
460 info->export_unused_gpl_sec = i;
461 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
462 info->export_gpl_future_sec = i;
464 if (sechdrs[i].sh_type != SHT_SYMTAB)
467 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
468 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
469 + sechdrs[i].sh_size;
470 info->strtab = (void *)hdr +
471 sechdrs[sechdrs[i].sh_link].sh_offset;
473 if (!info->symtab_start)
474 fatal("%s has no symtab?\n", filename);
476 /* Fix endianness in symbols */
477 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
478 sym->st_shndx = TO_NATIVE(sym->st_shndx);
479 sym->st_name = TO_NATIVE(sym->st_name);
480 sym->st_value = TO_NATIVE(sym->st_value);
481 sym->st_size = TO_NATIVE(sym->st_size);
486 static void parse_elf_finish(struct elf_info *info)
488 release_file(info->hdr, info->size);
491 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
493 /* ignore __this_module, it will be resolved shortly */
494 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
496 /* ignore global offset table */
497 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
499 if (info->hdr->e_machine == EM_PPC)
500 /* Special register function linked on all modules during final link of .ko */
501 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
502 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
503 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
504 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
506 if (info->hdr->e_machine == EM_PPC64)
507 /* Special register function linked on all modules during final link of .ko */
508 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
509 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
511 /* Do not ignore this symbol */
515 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
516 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
518 static void handle_modversions(struct module *mod, struct elf_info *info,
519 Elf_Sym *sym, const char *symname)
522 enum export export = export_from_sec(info, sym->st_shndx);
524 switch (sym->st_shndx) {
526 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
530 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
531 crc = (unsigned int) sym->st_value;
532 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
537 /* undefined symbol */
538 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
539 ELF_ST_BIND(sym->st_info) != STB_WEAK)
541 if (ignore_undef_symbol(info, symname))
543 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
544 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
545 /* add compatibility with older glibc */
546 #ifndef STT_SPARC_REGISTER
547 #define STT_SPARC_REGISTER STT_REGISTER
549 if (info->hdr->e_machine == EM_SPARC ||
550 info->hdr->e_machine == EM_SPARCV9) {
551 /* Ignore register directives. */
552 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
554 if (symname[0] == '.') {
555 char *munged = strdup(symname);
557 munged[1] = toupper(munged[1]);
563 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
564 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
566 alloc_symbol(symname +
567 strlen(MODULE_SYMBOL_PREFIX),
568 ELF_ST_BIND(sym->st_info) == STB_WEAK,
573 /* All exported symbols */
574 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
575 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
578 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
580 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
581 mod->has_cleanup = 1;
587 * Parse tag=value strings from .modinfo section
589 static char *next_string(char *string, unsigned long *secsize)
591 /* Skip non-zero chars */
594 if ((*secsize)-- <= 1)
598 /* Skip any zero padding. */
601 if ((*secsize)-- <= 1)
607 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
608 const char *tag, char *info)
611 unsigned int taglen = strlen(tag);
612 unsigned long size = modinfo_len;
615 size -= info - (char *)modinfo;
616 modinfo = next_string(info, &size);
619 for (p = modinfo; p; p = next_string(p, &size)) {
620 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
621 return p + taglen + 1;
626 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
630 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
634 * Test if string s ends in string sub
637 static int strrcmp(const char *s, const char *sub)
645 sublen = strlen(sub);
647 if ((slen == 0) || (sublen == 0))
653 return memcmp(s + slen - sublen, sub, sublen);
656 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
659 return elf->strtab + sym->st_name;
664 static const char *sec_name(struct elf_info *elf, int shndx)
666 Elf_Shdr *sechdrs = elf->sechdrs;
667 return (void *)elf->hdr +
668 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
669 sechdrs[shndx].sh_name;
672 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
674 return (void *)elf->hdr +
675 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
679 /* if sym is empty or point to a string
680 * like ".[0-9]+" then return 1.
681 * This is the optional prefix added by ld to some sections
683 static int number_prefix(const char *sym)
691 if (c < '0' || c > '9')
697 /* The pattern is an array of simple patterns.
698 * "foo" will match an exact string equal to "foo"
699 * "*foo" will match a string that ends with "foo"
700 * "foo*" will match a string that begins with "foo"
701 * "foo$" will match a string equal to "foo" or "foo.1"
702 * where the '1' can be any number including several digits.
703 * The $ syntax is for sections where ld append a dot number
704 * to make section name unique.
706 static int match(const char *sym, const char * const pat[])
711 const char *endp = p + strlen(p) - 1;
715 if (strrcmp(sym, p + 1) == 0)
719 else if (*endp == '*') {
720 if (strncmp(sym, p, strlen(p) - 1) == 0)
724 else if (*endp == '$') {
725 if (strncmp(sym, p, strlen(p) - 1) == 0) {
726 if (number_prefix(sym + strlen(p) - 1))
732 if (strcmp(p, sym) == 0)
740 /* sections that we do not want to do full section mismatch check on */
741 static const char *section_white_list[] =
745 ".mdebug*", /* alpha, score, mips etc. */
746 ".pdr", /* alpha, score, mips etc. */
755 * This is used to find sections missing the SHF_ALLOC flag.
756 * The cause of this is often a section specified in assembler
757 * without "ax" / "aw".
759 static void check_section(const char *modname, struct elf_info *elf,
762 const char *sec = sech_name(elf, sechdr);
764 if (sechdr->sh_type == SHT_PROGBITS &&
765 !(sechdr->sh_flags & SHF_ALLOC) &&
766 !match(sec, section_white_list)) {
767 warn("%s (%s): unexpected non-allocatable section.\n"
768 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
769 "Note that for example <linux/init.h> contains\n"
770 "section definitions for use in .S files.\n\n",
777 #define ALL_INIT_DATA_SECTIONS \
778 ".init.setup$", ".init.rodata$", \
779 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
780 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
781 #define ALL_EXIT_DATA_SECTIONS \
782 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
784 #define ALL_INIT_TEXT_SECTIONS \
785 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
786 #define ALL_EXIT_TEXT_SECTIONS \
787 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
789 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
791 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
794 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
795 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
797 #define DATA_SECTIONS ".data$", ".data.rel$"
798 #define TEXT_SECTIONS ".text$"
800 #define INIT_SECTIONS ".init.*"
801 #define DEV_INIT_SECTIONS ".devinit.*"
802 #define CPU_INIT_SECTIONS ".cpuinit.*"
803 #define MEM_INIT_SECTIONS ".meminit.*"
805 #define EXIT_SECTIONS ".exit.*"
806 #define DEV_EXIT_SECTIONS ".devexit.*"
807 #define CPU_EXIT_SECTIONS ".cpuexit.*"
808 #define MEM_EXIT_SECTIONS ".memexit.*"
810 /* init data sections */
811 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
813 /* all init sections */
814 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
816 /* All init and exit sections (code + data) */
817 static const char *init_exit_sections[] =
818 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
821 static const char *data_sections[] = { DATA_SECTIONS, NULL };
824 /* symbols in .data that may refer to init/exit sections */
825 #define DEFAULT_SYMBOL_WHITE_LIST \
827 "*_template", /* scsi uses *_template a lot */ \
828 "*_timer", /* arm uses ops structures named _timer a lot */ \
829 "*_sht", /* scsi also used *_sht to some extent */ \
835 static const char *head_sections[] = { ".head.text*", NULL };
836 static const char *linker_symbols[] =
837 { "__init_begin", "_sinittext", "_einittext", NULL };
844 XXXINIT_TO_SOME_INIT,
845 XXXEXIT_TO_SOME_EXIT,
846 ANY_INIT_TO_ANY_EXIT,
847 ANY_EXIT_TO_ANY_INIT,
851 struct sectioncheck {
852 const char *fromsec[20];
853 const char *tosec[20];
854 enum mismatch mismatch;
855 const char *symbol_white_list[20];
858 const struct sectioncheck sectioncheck[] = {
859 /* Do not reference init/exit code/data from
860 * normal code and data
863 .fromsec = { TEXT_SECTIONS, NULL },
864 .tosec = { ALL_INIT_SECTIONS, NULL },
865 .mismatch = TEXT_TO_ANY_INIT,
866 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
869 .fromsec = { DATA_SECTIONS, NULL },
870 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
871 .mismatch = DATA_TO_ANY_INIT,
872 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
875 .fromsec = { DATA_SECTIONS, NULL },
876 .tosec = { INIT_SECTIONS, NULL },
877 .mismatch = DATA_TO_ANY_INIT,
878 .symbol_white_list = {
879 "*_template", "*_timer", "*_sht", "*_ops",
880 "*_probe", "*_probe_one", "*_console", NULL
884 .fromsec = { TEXT_SECTIONS, NULL },
885 .tosec = { ALL_EXIT_SECTIONS, NULL },
886 .mismatch = TEXT_TO_ANY_EXIT,
887 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
890 .fromsec = { DATA_SECTIONS, NULL },
891 .tosec = { ALL_EXIT_SECTIONS, NULL },
892 .mismatch = DATA_TO_ANY_EXIT,
893 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
895 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
897 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
898 .tosec = { INIT_SECTIONS, NULL },
899 .mismatch = XXXINIT_TO_SOME_INIT,
900 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
902 /* Do not reference cpuinit code/data from meminit code/data */
904 .fromsec = { MEM_INIT_SECTIONS, NULL },
905 .tosec = { CPU_INIT_SECTIONS, NULL },
906 .mismatch = XXXINIT_TO_SOME_INIT,
907 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
909 /* Do not reference meminit code/data from cpuinit code/data */
911 .fromsec = { CPU_INIT_SECTIONS, NULL },
912 .tosec = { MEM_INIT_SECTIONS, NULL },
913 .mismatch = XXXINIT_TO_SOME_INIT,
914 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
916 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
918 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
919 .tosec = { EXIT_SECTIONS, NULL },
920 .mismatch = XXXEXIT_TO_SOME_EXIT,
921 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
923 /* Do not reference cpuexit code/data from memexit code/data */
925 .fromsec = { MEM_EXIT_SECTIONS, NULL },
926 .tosec = { CPU_EXIT_SECTIONS, NULL },
927 .mismatch = XXXEXIT_TO_SOME_EXIT,
928 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
930 /* Do not reference memexit code/data from cpuexit code/data */
932 .fromsec = { CPU_EXIT_SECTIONS, NULL },
933 .tosec = { MEM_EXIT_SECTIONS, NULL },
934 .mismatch = XXXEXIT_TO_SOME_EXIT,
935 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
937 /* Do not use exit code/data from init code */
939 .fromsec = { ALL_INIT_SECTIONS, NULL },
940 .tosec = { ALL_EXIT_SECTIONS, NULL },
941 .mismatch = ANY_INIT_TO_ANY_EXIT,
942 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
944 /* Do not use init code/data from exit code */
946 .fromsec = { ALL_EXIT_SECTIONS, NULL },
947 .tosec = { ALL_INIT_SECTIONS, NULL },
948 .mismatch = ANY_EXIT_TO_ANY_INIT,
949 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
951 /* Do not export init/exit functions or data */
953 .fromsec = { "__ksymtab*", NULL },
954 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
955 .mismatch = EXPORT_TO_INIT_EXIT,
956 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
960 static const struct sectioncheck *section_mismatch(
961 const char *fromsec, const char *tosec)
964 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
965 const struct sectioncheck *check = §ioncheck[0];
967 for (i = 0; i < elems; i++) {
968 if (match(fromsec, check->fromsec) &&
969 match(tosec, check->tosec))
977 * Whitelist to allow certain references to pass with no warning.
980 * If a module parameter is declared __initdata and permissions=0
981 * then this is legal despite the warning generated.
982 * We cannot see value of permissions here, so just ignore
984 * The pattern is identified by:
990 * Many drivers utilise a *driver container with references to
991 * add, remove, probe functions etc.
992 * These functions may often be marked __devinit and we do not want to
994 * the pattern is identified by:
995 * tosec = init or exit section
996 * fromsec = data section
997 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
998 * *probe_one, *_console, *_timer
1001 * Whitelist all references from .head.text to any init section
1004 * Some symbols belong to init section but still it is ok to reference
1005 * these from non-init sections as these symbols don't have any memory
1006 * allocated for them and symbol address and value are same. So even
1007 * if init section is freed, its ok to reference those symbols.
1008 * For ex. symbols marking the init section boundaries.
1009 * This pattern is identified by
1010 * refsymname = __init_begin, _sinittext, _einittext
1013 static int secref_whitelist(const struct sectioncheck *mismatch,
1014 const char *fromsec, const char *fromsym,
1015 const char *tosec, const char *tosym)
1017 /* Check for pattern 1 */
1018 if (match(tosec, init_data_sections) &&
1019 match(fromsec, data_sections) &&
1020 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1023 /* Check for pattern 2 */
1024 if (match(tosec, init_exit_sections) &&
1025 match(fromsec, data_sections) &&
1026 match(fromsym, mismatch->symbol_white_list))
1029 /* Check for pattern 3 */
1030 if (match(fromsec, head_sections) &&
1031 match(tosec, init_sections))
1034 /* Check for pattern 4 */
1035 if (match(tosym, linker_symbols))
1042 * Find symbol based on relocation record info.
1043 * In some cases the symbol supplied is a valid symbol so
1044 * return refsym. If st_name != 0 we assume this is a valid symbol.
1045 * In other cases the symbol needs to be looked up in the symbol table
1046 * based on section and address.
1048 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1052 Elf_Sym *near = NULL;
1053 Elf64_Sword distance = 20;
1056 if (relsym->st_name != 0)
1058 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1059 if (sym->st_shndx != relsym->st_shndx)
1061 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1063 if (sym->st_value == addr)
1065 /* Find a symbol nearby - addr are maybe negative */
1066 d = sym->st_value - addr;
1068 d = addr - sym->st_value;
1074 /* We need a close match */
1081 static inline int is_arm_mapping_symbol(const char *str)
1083 return str[0] == '$' && strchr("atd", str[1])
1084 && (str[2] == '\0' || str[2] == '.');
1088 * If there's no name there, ignore it; likewise, ignore it if it's
1089 * one of the magic symbols emitted used by current ARM tools.
1091 * Otherwise if find_symbols_between() returns those symbols, they'll
1092 * fail the whitelist tests and cause lots of false alarms ... fixable
1093 * only by merging __exit and __init sections into __text, bloating
1094 * the kernel (which is especially evil on embedded platforms).
1096 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1098 const char *name = elf->strtab + sym->st_name;
1100 if (!name || !strlen(name))
1102 return !is_arm_mapping_symbol(name);
1106 * Find symbols before or equal addr and after addr - in the section sec.
1107 * If we find two symbols with equal offset prefer one with a valid name.
1108 * The ELF format may have a better way to detect what type of symbol
1109 * it is, but this works for now.
1111 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1115 Elf_Sym *near = NULL;
1116 Elf_Addr distance = ~0;
1118 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1121 if (sym->st_shndx >= SHN_LORESERVE)
1123 symsec = sec_name(elf, sym->st_shndx);
1124 if (strcmp(symsec, sec) != 0)
1126 if (!is_valid_name(elf, sym))
1128 if (sym->st_value <= addr) {
1129 if ((addr - sym->st_value) < distance) {
1130 distance = addr - sym->st_value;
1132 } else if ((addr - sym->st_value) == distance) {
1141 * Convert a section name to the function/data attribute
1142 * .init.text => __init
1143 * .cpuinit.data => __cpudata
1144 * .memexitconst => __memconst
1147 static char *sec2annotation(const char *s)
1149 if (match(s, init_exit_sections)) {
1150 char *p = malloc(20);
1157 while (*s && *s != '.')
1162 if (strstr(s, "rodata") != NULL)
1163 strcat(p, "const ");
1164 else if (strstr(s, "data") != NULL)
1168 return r; /* we leak her but we do not care */
1174 static int is_function(Elf_Sym *sym)
1177 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1183 * Print a warning about a section mismatch.
1184 * Try to find symbols near it so user can find it.
1185 * Check whitelist before warning - it may be a false positive.
1187 static void report_sec_mismatch(const char *modname,
1188 const struct sectioncheck *mismatch,
1189 const char *fromsec,
1190 unsigned long long fromaddr,
1191 const char *fromsym,
1193 const char *tosec, const char *tosym,
1196 const char *from, *from_p;
1197 const char *to, *to_p;
1199 switch (from_is_func) {
1200 case 0: from = "variable"; from_p = ""; break;
1201 case 1: from = "function"; from_p = "()"; break;
1202 default: from = "(unknown reference)"; from_p = ""; break;
1204 switch (to_is_func) {
1205 case 0: to = "variable"; to_p = ""; break;
1206 case 1: to = "function"; to_p = "()"; break;
1207 default: to = "(unknown reference)"; to_p = ""; break;
1210 sec_mismatch_count++;
1211 if (!sec_mismatch_verbose)
1214 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1215 "to the %s %s:%s%s\n",
1216 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1219 switch (mismatch->mismatch) {
1220 case TEXT_TO_ANY_INIT:
1222 "The function %s%s() references\n"
1224 "This is often because %s lacks a %s\n"
1225 "annotation or the annotation of %s is wrong.\n",
1226 sec2annotation(fromsec), fromsym,
1227 to, sec2annotation(tosec), tosym, to_p,
1228 fromsym, sec2annotation(tosec), tosym);
1230 case DATA_TO_ANY_INIT: {
1231 const char *const *s = mismatch->symbol_white_list;
1233 "The variable %s references\n"
1235 "If the reference is valid then annotate the\n"
1236 "variable with __init* or __refdata (see linux/init.h) "
1237 "or name the variable:\n",
1238 fromsym, to, sec2annotation(tosec), tosym, to_p);
1240 fprintf(stderr, "%s, ", *s++);
1241 fprintf(stderr, "\n");
1244 case TEXT_TO_ANY_EXIT:
1246 "The function %s() references a %s in an exit section.\n"
1247 "Often the %s %s%s has valid usage outside the exit section\n"
1248 "and the fix is to remove the %sannotation of %s.\n",
1249 fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1251 case DATA_TO_ANY_EXIT: {
1252 const char *const *s = mismatch->symbol_white_list;
1254 "The variable %s references\n"
1256 "If the reference is valid then annotate the\n"
1257 "variable with __exit* (see linux/init.h) or "
1258 "name the variable:\n",
1259 fromsym, to, sec2annotation(tosec), tosym, to_p);
1261 fprintf(stderr, "%s, ", *s++);
1262 fprintf(stderr, "\n");
1265 case XXXINIT_TO_SOME_INIT:
1266 case XXXEXIT_TO_SOME_EXIT:
1268 "The %s %s%s%s references\n"
1270 "If %s is only used by %s then\n"
1271 "annotate %s with a matching annotation.\n",
1272 from, sec2annotation(fromsec), fromsym, from_p,
1273 to, sec2annotation(tosec), tosym, to_p,
1274 tosym, fromsym, tosym);
1276 case ANY_INIT_TO_ANY_EXIT:
1278 "The %s %s%s%s references\n"
1280 "This is often seen when error handling "
1281 "in the init function\n"
1282 "uses functionality in the exit path.\n"
1283 "The fix is often to remove the %sannotation of\n"
1284 "%s%s so it may be used outside an exit section.\n",
1285 from, sec2annotation(fromsec), fromsym, from_p,
1286 to, sec2annotation(tosec), tosym, to_p,
1287 sec2annotation(tosec), tosym, to_p);
1289 case ANY_EXIT_TO_ANY_INIT:
1291 "The %s %s%s%s references\n"
1293 "This is often seen when error handling "
1294 "in the exit function\n"
1295 "uses functionality in the init path.\n"
1296 "The fix is often to remove the %sannotation of\n"
1297 "%s%s so it may be used outside an init section.\n",
1298 from, sec2annotation(fromsec), fromsym, from_p,
1299 to, sec2annotation(tosec), tosym, to_p,
1300 sec2annotation(tosec), tosym, to_p);
1302 case EXPORT_TO_INIT_EXIT:
1304 "The symbol %s is exported and annotated %s\n"
1305 "Fix this by removing the %sannotation of %s "
1306 "or drop the export.\n",
1307 tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1310 fprintf(stderr, "\n");
1313 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1314 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1317 const struct sectioncheck *mismatch;
1319 tosec = sec_name(elf, sym->st_shndx);
1320 mismatch = section_mismatch(fromsec, tosec);
1325 const char *fromsym;
1327 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1328 fromsym = sym_name(elf, from);
1329 to = find_elf_symbol(elf, r->r_addend, sym);
1330 tosym = sym_name(elf, to);
1332 /* check whitelist - we may ignore it */
1333 if (secref_whitelist(mismatch,
1334 fromsec, fromsym, tosec, tosym)) {
1335 report_sec_mismatch(modname, mismatch,
1336 fromsec, r->r_offset, fromsym,
1337 is_function(from), tosec, tosym,
1343 static unsigned int *reloc_location(struct elf_info *elf,
1344 Elf_Shdr *sechdr, Elf_Rela *r)
1346 Elf_Shdr *sechdrs = elf->sechdrs;
1347 int section = sechdr->sh_info;
1349 return (void *)elf->hdr + sechdrs[section].sh_offset +
1350 r->r_offset - sechdrs[section].sh_addr;
1353 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1355 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1356 unsigned int *location = reloc_location(elf, sechdr, r);
1360 r->r_addend = TO_NATIVE(*location);
1363 r->r_addend = TO_NATIVE(*location) + 4;
1364 /* For CONFIG_RELOCATABLE=y */
1365 if (elf->hdr->e_type == ET_EXEC)
1366 r->r_addend += r->r_offset;
1372 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1374 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1378 /* From ARM ABI: (S + A) | T */
1379 r->r_addend = (int)(long)
1380 (elf->symtab_start + ELF_R_SYM(r->r_info));
1383 /* From ARM ABI: ((S + A) | T) - P */
1384 r->r_addend = (int)(long)(elf->hdr +
1386 (r->r_offset - sechdr->sh_addr));
1394 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1396 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1397 unsigned int *location = reloc_location(elf, sechdr, r);
1400 if (r_typ == R_MIPS_HI16)
1401 return 1; /* skip this */
1402 inst = TO_NATIVE(*location);
1405 r->r_addend = inst & 0xffff;
1408 r->r_addend = (inst & 0x03ffffff) << 2;
1417 static void section_rela(const char *modname, struct elf_info *elf,
1424 const char *fromsec;
1426 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1427 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1429 fromsec = sech_name(elf, sechdr);
1430 fromsec += strlen(".rela");
1431 /* if from section (name) is know good then skip it */
1432 if (match(fromsec, section_white_list))
1435 for (rela = start; rela < stop; rela++) {
1436 r.r_offset = TO_NATIVE(rela->r_offset);
1437 #if KERNEL_ELFCLASS == ELFCLASS64
1438 if (elf->hdr->e_machine == EM_MIPS) {
1440 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1441 r_sym = TO_NATIVE(r_sym);
1442 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1443 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1445 r.r_info = TO_NATIVE(rela->r_info);
1446 r_sym = ELF_R_SYM(r.r_info);
1449 r.r_info = TO_NATIVE(rela->r_info);
1450 r_sym = ELF_R_SYM(r.r_info);
1452 r.r_addend = TO_NATIVE(rela->r_addend);
1453 sym = elf->symtab_start + r_sym;
1454 /* Skip special sections */
1455 if (sym->st_shndx >= SHN_LORESERVE)
1457 check_section_mismatch(modname, elf, &r, sym, fromsec);
1461 static void section_rel(const char *modname, struct elf_info *elf,
1468 const char *fromsec;
1470 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1471 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1473 fromsec = sech_name(elf, sechdr);
1474 fromsec += strlen(".rel");
1475 /* if from section (name) is know good then skip it */
1476 if (match(fromsec, section_white_list))
1479 for (rel = start; rel < stop; rel++) {
1480 r.r_offset = TO_NATIVE(rel->r_offset);
1481 #if KERNEL_ELFCLASS == ELFCLASS64
1482 if (elf->hdr->e_machine == EM_MIPS) {
1484 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1485 r_sym = TO_NATIVE(r_sym);
1486 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1487 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1489 r.r_info = TO_NATIVE(rel->r_info);
1490 r_sym = ELF_R_SYM(r.r_info);
1493 r.r_info = TO_NATIVE(rel->r_info);
1494 r_sym = ELF_R_SYM(r.r_info);
1497 switch (elf->hdr->e_machine) {
1499 if (addend_386_rel(elf, sechdr, &r))
1503 if (addend_arm_rel(elf, sechdr, &r))
1507 if (addend_mips_rel(elf, sechdr, &r))
1511 sym = elf->symtab_start + r_sym;
1512 /* Skip special sections */
1513 if (sym->st_shndx >= SHN_LORESERVE)
1515 check_section_mismatch(modname, elf, &r, sym, fromsec);
1520 * A module includes a number of sections that are discarded
1521 * either when loaded or when used as built-in.
1522 * For loaded modules all functions marked __init and all data
1523 * marked __initdata will be discarded when the module has been intialized.
1524 * Likewise for modules used built-in the sections marked __exit
1525 * are discarded because __exit marked function are supposed to be called
1526 * only when a module is unloaded which never happens for built-in modules.
1527 * The check_sec_ref() function traverses all relocation records
1528 * to find all references to a section that reference a section that will
1529 * be discarded and warns about it.
1531 static void check_sec_ref(struct module *mod, const char *modname,
1532 struct elf_info *elf)
1535 Elf_Shdr *sechdrs = elf->sechdrs;
1537 /* Walk through all sections */
1538 for (i = 0; i < elf->hdr->e_shnum; i++) {
1539 check_section(modname, elf, &elf->sechdrs[i]);
1540 /* We want to process only relocation sections and not .init */
1541 if (sechdrs[i].sh_type == SHT_RELA)
1542 section_rela(modname, elf, &elf->sechdrs[i]);
1543 else if (sechdrs[i].sh_type == SHT_REL)
1544 section_rel(modname, elf, &elf->sechdrs[i]);
1548 static void read_symbols(char *modname)
1550 const char *symname;
1554 struct elf_info info = { };
1557 if (!parse_elf(&info, modname))
1560 mod = new_module(modname);
1562 /* When there's no vmlinux, don't print warnings about
1563 * unresolved symbols (since there'll be too many ;) */
1564 if (is_vmlinux(modname)) {
1569 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1570 if (info.modinfo && !license && !is_vmlinux(modname))
1571 warn("modpost: missing MODULE_LICENSE() in %s\n"
1572 "see include/linux/module.h for "
1573 "more information\n", modname);
1575 if (license_is_gpl_compatible(license))
1576 mod->gpl_compatible = 1;
1578 mod->gpl_compatible = 0;
1581 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1582 "license", license);
1585 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1586 symname = info.strtab + sym->st_name;
1588 handle_modversions(mod, &info, sym, symname);
1589 handle_moddevtable(mod, &info, sym, symname);
1591 if (!is_vmlinux(modname) ||
1592 (is_vmlinux(modname) && vmlinux_section_warnings))
1593 check_sec_ref(mod, modname, &info);
1595 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1597 maybe_frob_rcs_version(modname, version, info.modinfo,
1598 version - (char *)info.hdr);
1599 if (version || (all_versions && !is_vmlinux(modname)))
1600 get_src_version(modname, mod->srcversion,
1601 sizeof(mod->srcversion)-1);
1603 parse_elf_finish(&info);
1605 /* Our trick to get versioning for module struct etc. - it's
1606 * never passed as an argument to an exported function, so
1607 * the automatic versioning doesn't pick it up, but it's really
1608 * important anyhow */
1610 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1615 /* We first write the generated file into memory using the
1616 * following helper, then compare to the file on disk and
1617 * only update the later if anything changed */
1619 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1620 const char *fmt, ...)
1627 len = vsnprintf(tmp, SZ, fmt, ap);
1628 buf_write(buf, tmp, len);
1632 void buf_write(struct buffer *buf, const char *s, int len)
1634 if (buf->size - buf->pos < len) {
1635 buf->size += len + SZ;
1636 buf->p = realloc(buf->p, buf->size);
1638 strncpy(buf->p + buf->pos, s, len);
1642 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1644 const char *e = is_vmlinux(m) ?"":".ko";
1648 fatal("modpost: GPL-incompatible module %s%s "
1649 "uses GPL-only symbol '%s'\n", m, e, s);
1651 case export_unused_gpl:
1652 fatal("modpost: GPL-incompatible module %s%s "
1653 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1655 case export_gpl_future:
1656 warn("modpost: GPL-incompatible module %s%s "
1657 "uses future GPL-only symbol '%s'\n", m, e, s);
1661 case export_unknown:
1667 static void check_for_unused(enum export exp, const char *m, const char *s)
1669 const char *e = is_vmlinux(m) ?"":".ko";
1673 case export_unused_gpl:
1674 warn("modpost: module %s%s "
1675 "uses symbol '%s' marked UNUSED\n", m, e, s);
1683 static void check_exports(struct module *mod)
1685 struct symbol *s, *exp;
1687 for (s = mod->unres; s; s = s->next) {
1688 const char *basename;
1689 exp = find_symbol(s->name);
1690 if (!exp || exp->module == mod)
1692 basename = strrchr(mod->name, '/');
1696 basename = mod->name;
1697 if (!mod->gpl_compatible)
1698 check_for_gpl_usage(exp->export, basename, exp->name);
1699 check_for_unused(exp->export, basename, exp->name);
1704 * Header for the generated file
1706 static void add_header(struct buffer *b, struct module *mod)
1708 buf_printf(b, "#include <linux/module.h>\n");
1709 buf_printf(b, "#include <linux/vermagic.h>\n");
1710 buf_printf(b, "#include <linux/compiler.h>\n");
1711 buf_printf(b, "\n");
1712 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1713 buf_printf(b, "\n");
1714 buf_printf(b, "struct module __this_module\n");
1715 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1716 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1718 buf_printf(b, " .init = init_module,\n");
1719 if (mod->has_cleanup)
1720 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1721 " .exit = cleanup_module,\n"
1723 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1724 buf_printf(b, "};\n");
1727 static void add_staging_flag(struct buffer *b, const char *name)
1729 static const char *staging_dir = "drivers/staging";
1731 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1732 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1736 * Record CRCs for unresolved symbols
1738 static int add_versions(struct buffer *b, struct module *mod)
1740 struct symbol *s, *exp;
1743 for (s = mod->unres; s; s = s->next) {
1744 exp = find_symbol(s->name);
1745 if (!exp || exp->module == mod) {
1746 if (have_vmlinux && !s->weak) {
1747 if (warn_unresolved) {
1748 warn("\"%s\" [%s.ko] undefined!\n",
1749 s->name, mod->name);
1751 merror("\"%s\" [%s.ko] undefined!\n",
1752 s->name, mod->name);
1758 s->module = exp->module;
1759 s->crc_valid = exp->crc_valid;
1766 buf_printf(b, "\n");
1767 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1768 buf_printf(b, "__used\n");
1769 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1771 for (s = mod->unres; s; s = s->next) {
1774 if (!s->crc_valid) {
1775 warn("\"%s\" [%s.ko] has no CRC!\n",
1776 s->name, mod->name);
1779 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1782 buf_printf(b, "};\n");
1787 static void add_depends(struct buffer *b, struct module *mod,
1788 struct module *modules)
1794 for (m = modules; m; m = m->next)
1795 m->seen = is_vmlinux(m->name);
1797 buf_printf(b, "\n");
1798 buf_printf(b, "static const char __module_depends[]\n");
1799 buf_printf(b, "__used\n");
1800 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1801 buf_printf(b, "\"depends=");
1802 for (s = mod->unres; s; s = s->next) {
1807 if (s->module->seen)
1810 s->module->seen = 1;
1811 p = strrchr(s->module->name, '/');
1815 p = s->module->name;
1816 buf_printf(b, "%s%s", first ? "" : ",", p);
1819 buf_printf(b, "\";\n");
1822 static void add_srcversion(struct buffer *b, struct module *mod)
1824 if (mod->srcversion[0]) {
1825 buf_printf(b, "\n");
1826 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1831 static void write_if_changed(struct buffer *b, const char *fname)
1837 file = fopen(fname, "r");
1841 if (fstat(fileno(file), &st) < 0)
1844 if (st.st_size != b->pos)
1847 tmp = NOFAIL(malloc(b->pos));
1848 if (fread(tmp, 1, b->pos, file) != b->pos)
1851 if (memcmp(tmp, b->p, b->pos) != 0)
1863 file = fopen(fname, "w");
1868 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1875 /* parse Module.symvers file. line format:
1876 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1878 static void read_dump(const char *fname, unsigned int kernel)
1880 unsigned long size, pos = 0;
1881 void *file = grab_file(fname, &size);
1885 /* No symbol versions, silently ignore */
1888 while ((line = get_next_line(&pos, file, size))) {
1889 char *symname, *modname, *d, *export, *end;
1894 if (!(symname = strchr(line, '\t')))
1897 if (!(modname = strchr(symname, '\t')))
1900 if ((export = strchr(modname, '\t')) != NULL)
1902 if (export && ((end = strchr(export, '\t')) != NULL))
1904 crc = strtoul(line, &d, 16);
1905 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1907 mod = find_module(modname);
1909 if (is_vmlinux(modname))
1911 mod = new_module(modname);
1914 s = sym_add_exported(symname, mod, export_no(export));
1917 sym_update_crc(symname, mod, crc, export_no(export));
1921 fatal("parse error in symbol dump file\n");
1924 /* For normal builds always dump all symbols.
1925 * For external modules only dump symbols
1926 * that are not read from kernel Module.symvers.
1928 static int dump_sym(struct symbol *sym)
1930 if (!external_module)
1932 if (sym->vmlinux || sym->kernel)
1937 static void write_dump(const char *fname)
1939 struct buffer buf = { };
1940 struct symbol *symbol;
1943 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1944 symbol = symbolhash[n];
1946 if (dump_sym(symbol))
1947 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1948 symbol->crc, symbol->name,
1949 symbol->module->name,
1950 export_str(symbol->export));
1951 symbol = symbol->next;
1954 write_if_changed(&buf, fname);
1957 struct ext_sym_list {
1958 struct ext_sym_list *next;
1962 int main(int argc, char **argv)
1965 struct buffer buf = { };
1966 char *kernel_read = NULL, *module_read = NULL;
1967 char *dump_write = NULL;
1970 struct ext_sym_list *extsym_iter;
1971 struct ext_sym_list *extsym_start = NULL;
1973 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
1976 kernel_read = optarg;
1979 module_read = optarg;
1980 external_module = 1;
1986 external_module = 1;
1988 NOFAIL(malloc(sizeof(*extsym_iter)));
1989 extsym_iter->next = extsym_start;
1990 extsym_iter->file = optarg;
1991 extsym_start = extsym_iter;
1997 dump_write = optarg;
2003 vmlinux_section_warnings = 0;
2006 sec_mismatch_verbose = 0;
2009 warn_unresolved = 1;
2017 read_dump(kernel_read, 1);
2019 read_dump(module_read, 0);
2020 while (extsym_start) {
2021 read_dump(extsym_start->file, 0);
2022 extsym_iter = extsym_start->next;
2024 extsym_start = extsym_iter;
2027 while (optind < argc)
2028 read_symbols(argv[optind++]);
2030 for (mod = modules; mod; mod = mod->next) {
2038 for (mod = modules; mod; mod = mod->next) {
2039 char fname[strlen(mod->name) + 10];
2046 add_header(&buf, mod);
2047 add_staging_flag(&buf, mod->name);
2048 err |= add_versions(&buf, mod);
2049 add_depends(&buf, mod, modules);
2050 add_moddevtable(&buf, mod);
2051 add_srcversion(&buf, mod);
2053 sprintf(fname, "%s.mod.c", mod->name);
2054 write_if_changed(&buf, fname);
2058 write_dump(dump_write);
2059 if (sec_mismatch_count && !sec_mismatch_verbose)
2060 warn("modpost: Found %d section mismatch(es).\n"
2061 "To see full details build your kernel with:\n"
2062 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2063 sec_mismatch_count);