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, unsigned int 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)
376 const char *secstrings;
377 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
379 hdr = grab_file(filename, &info->size);
385 if (info->size < sizeof(*hdr)) {
386 /* file too small, assume this is an empty .o file */
389 /* Is this a valid ELF file? */
390 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
391 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
392 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
393 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
394 /* Not an ELF file - silently ignore it */
397 /* Fix endianness in ELF header */
398 hdr->e_type = TO_NATIVE(hdr->e_type);
399 hdr->e_machine = TO_NATIVE(hdr->e_machine);
400 hdr->e_version = TO_NATIVE(hdr->e_version);
401 hdr->e_entry = TO_NATIVE(hdr->e_entry);
402 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
403 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
404 hdr->e_flags = TO_NATIVE(hdr->e_flags);
405 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
406 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
407 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
408 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
409 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
410 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
411 sechdrs = (void *)hdr + hdr->e_shoff;
412 info->sechdrs = sechdrs;
414 /* Check if file offset is correct */
415 if (hdr->e_shoff > info->size) {
416 fatal("section header offset=%lu in file '%s' is bigger than "
417 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
418 filename, info->size);
422 if (hdr->e_shnum == 0) {
424 * There are more than 64k sections,
425 * read count from .sh_size.
426 * note: it doesn't need shndx2secindex()
428 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
431 info->num_sections = hdr->e_shnum;
433 if (hdr->e_shstrndx == SHN_XINDEX) {
434 info->secindex_strings =
435 shndx2secindex(TO_NATIVE(sechdrs[0].sh_link));
438 info->secindex_strings = hdr->e_shstrndx;
441 /* Fix endianness in section headers */
442 for (i = 0; i < info->num_sections; i++) {
443 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
444 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
445 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
446 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
447 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
448 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
449 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
450 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
451 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
452 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
454 /* Find symbol table. */
455 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
456 for (i = 1; i < info->num_sections; i++) {
458 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
460 if (!nobits && sechdrs[i].sh_offset > info->size) {
461 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
462 "sizeof(*hrd)=%zu\n", filename,
463 (unsigned long)sechdrs[i].sh_offset,
467 secname = secstrings + sechdrs[i].sh_name;
468 if (strcmp(secname, ".modinfo") == 0) {
470 fatal("%s has NOBITS .modinfo\n", filename);
471 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
472 info->modinfo_len = sechdrs[i].sh_size;
473 } else if (strcmp(secname, "__ksymtab") == 0)
474 info->export_sec = i;
475 else if (strcmp(secname, "__ksymtab_unused") == 0)
476 info->export_unused_sec = i;
477 else if (strcmp(secname, "__ksymtab_gpl") == 0)
478 info->export_gpl_sec = i;
479 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
480 info->export_unused_gpl_sec = i;
481 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
482 info->export_gpl_future_sec = i;
484 if (sechdrs[i].sh_type == SHT_SYMTAB) {
485 unsigned int sh_link_idx;
487 info->symtab_start = (void *)hdr +
488 sechdrs[i].sh_offset;
489 info->symtab_stop = (void *)hdr +
490 sechdrs[i].sh_offset + sechdrs[i].sh_size;
491 sh_link_idx = shndx2secindex(sechdrs[i].sh_link);
492 info->strtab = (void *)hdr +
493 sechdrs[sh_link_idx].sh_offset;
496 /* 32bit section no. table? ("more than 64k sections") */
497 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
498 symtab_shndx_idx = i;
499 info->symtab_shndx_start = (void *)hdr +
500 sechdrs[i].sh_offset;
501 info->symtab_shndx_stop = (void *)hdr +
502 sechdrs[i].sh_offset + sechdrs[i].sh_size;
505 if (!info->symtab_start)
506 fatal("%s has no symtab?\n", filename);
508 /* Fix endianness in symbols */
509 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
510 sym->st_shndx = TO_NATIVE(sym->st_shndx);
511 sym->st_name = TO_NATIVE(sym->st_name);
512 sym->st_value = TO_NATIVE(sym->st_value);
513 sym->st_size = TO_NATIVE(sym->st_size);
516 if (symtab_shndx_idx != ~0U) {
519 shndx2secindex(sechdrs[symtab_shndx_idx].sh_link))
520 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
522 shndx2secindex(sechdrs[symtab_shndx_idx].sh_link),
525 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
533 static void parse_elf_finish(struct elf_info *info)
535 release_file(info->hdr, info->size);
538 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
540 /* ignore __this_module, it will be resolved shortly */
541 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
543 /* ignore global offset table */
544 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
546 if (info->hdr->e_machine == EM_PPC)
547 /* Special register function linked on all modules during final link of .ko */
548 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
549 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
550 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
551 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
553 if (info->hdr->e_machine == EM_PPC64)
554 /* Special register function linked on all modules during final link of .ko */
555 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
556 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
558 /* Do not ignore this symbol */
562 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
563 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
565 static void handle_modversions(struct module *mod, struct elf_info *info,
566 Elf_Sym *sym, const char *symname)
569 enum export export = export_from_sec(info, get_secindex(info, sym));
571 switch (sym->st_shndx) {
573 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
577 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
578 crc = (unsigned int) sym->st_value;
579 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
584 /* undefined symbol */
585 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
586 ELF_ST_BIND(sym->st_info) != STB_WEAK)
588 if (ignore_undef_symbol(info, symname))
590 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
591 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
592 /* add compatibility with older glibc */
593 #ifndef STT_SPARC_REGISTER
594 #define STT_SPARC_REGISTER STT_REGISTER
596 if (info->hdr->e_machine == EM_SPARC ||
597 info->hdr->e_machine == EM_SPARCV9) {
598 /* Ignore register directives. */
599 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
601 if (symname[0] == '.') {
602 char *munged = strdup(symname);
604 munged[1] = toupper(munged[1]);
610 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
611 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
613 alloc_symbol(symname +
614 strlen(MODULE_SYMBOL_PREFIX),
615 ELF_ST_BIND(sym->st_info) == STB_WEAK,
620 /* All exported symbols */
621 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
622 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
625 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
627 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
628 mod->has_cleanup = 1;
634 * Parse tag=value strings from .modinfo section
636 static char *next_string(char *string, unsigned long *secsize)
638 /* Skip non-zero chars */
641 if ((*secsize)-- <= 1)
645 /* Skip any zero padding. */
648 if ((*secsize)-- <= 1)
654 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
655 const char *tag, char *info)
658 unsigned int taglen = strlen(tag);
659 unsigned long size = modinfo_len;
662 size -= info - (char *)modinfo;
663 modinfo = next_string(info, &size);
666 for (p = modinfo; p; p = next_string(p, &size)) {
667 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
668 return p + taglen + 1;
673 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
677 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
681 * Test if string s ends in string sub
684 static int strrcmp(const char *s, const char *sub)
692 sublen = strlen(sub);
694 if ((slen == 0) || (sublen == 0))
700 return memcmp(s + slen - sublen, sub, sublen);
703 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
706 return elf->strtab + sym->st_name;
711 static const char *sec_name(struct elf_info *elf, int secindex)
713 Elf_Shdr *sechdrs = elf->sechdrs;
714 return (void *)elf->hdr +
715 elf->sechdrs[elf->secindex_strings].sh_offset +
716 sechdrs[secindex].sh_name;
719 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
721 return (void *)elf->hdr +
722 elf->sechdrs[elf->secindex_strings].sh_offset +
726 /* if sym is empty or point to a string
727 * like ".[0-9]+" then return 1.
728 * This is the optional prefix added by ld to some sections
730 static int number_prefix(const char *sym)
738 if (c < '0' || c > '9')
744 /* The pattern is an array of simple patterns.
745 * "foo" will match an exact string equal to "foo"
746 * "*foo" will match a string that ends with "foo"
747 * "foo*" will match a string that begins with "foo"
748 * "foo$" will match a string equal to "foo" or "foo.1"
749 * where the '1' can be any number including several digits.
750 * The $ syntax is for sections where ld append a dot number
751 * to make section name unique.
753 static int match(const char *sym, const char * const pat[])
758 const char *endp = p + strlen(p) - 1;
762 if (strrcmp(sym, p + 1) == 0)
766 else if (*endp == '*') {
767 if (strncmp(sym, p, strlen(p) - 1) == 0)
771 else if (*endp == '$') {
772 if (strncmp(sym, p, strlen(p) - 1) == 0) {
773 if (number_prefix(sym + strlen(p) - 1))
779 if (strcmp(p, sym) == 0)
787 /* sections that we do not want to do full section mismatch check on */
788 static const char *section_white_list[] =
792 ".mdebug*", /* alpha, score, mips etc. */
793 ".pdr", /* alpha, score, mips etc. */
802 * This is used to find sections missing the SHF_ALLOC flag.
803 * The cause of this is often a section specified in assembler
804 * without "ax" / "aw".
806 static void check_section(const char *modname, struct elf_info *elf,
809 const char *sec = sech_name(elf, sechdr);
811 if (sechdr->sh_type == SHT_PROGBITS &&
812 !(sechdr->sh_flags & SHF_ALLOC) &&
813 !match(sec, section_white_list)) {
814 warn("%s (%s): unexpected non-allocatable section.\n"
815 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
816 "Note that for example <linux/init.h> contains\n"
817 "section definitions for use in .S files.\n\n",
824 #define ALL_INIT_DATA_SECTIONS \
825 ".init.setup$", ".init.rodata$", \
826 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
827 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
828 #define ALL_EXIT_DATA_SECTIONS \
829 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
831 #define ALL_INIT_TEXT_SECTIONS \
832 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
833 #define ALL_EXIT_TEXT_SECTIONS \
834 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
836 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
838 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
841 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
842 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
844 #define DATA_SECTIONS ".data$", ".data.rel$"
845 #define TEXT_SECTIONS ".text$"
847 #define INIT_SECTIONS ".init.*"
848 #define DEV_INIT_SECTIONS ".devinit.*"
849 #define CPU_INIT_SECTIONS ".cpuinit.*"
850 #define MEM_INIT_SECTIONS ".meminit.*"
852 #define EXIT_SECTIONS ".exit.*"
853 #define DEV_EXIT_SECTIONS ".devexit.*"
854 #define CPU_EXIT_SECTIONS ".cpuexit.*"
855 #define MEM_EXIT_SECTIONS ".memexit.*"
857 /* init data sections */
858 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
860 /* all init sections */
861 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
863 /* All init and exit sections (code + data) */
864 static const char *init_exit_sections[] =
865 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
868 static const char *data_sections[] = { DATA_SECTIONS, NULL };
871 /* symbols in .data that may refer to init/exit sections */
872 #define DEFAULT_SYMBOL_WHITE_LIST \
874 "*_template", /* scsi uses *_template a lot */ \
875 "*_timer", /* arm uses ops structures named _timer a lot */ \
876 "*_sht", /* scsi also used *_sht to some extent */ \
882 static const char *head_sections[] = { ".head.text*", NULL };
883 static const char *linker_symbols[] =
884 { "__init_begin", "_sinittext", "_einittext", NULL };
891 XXXINIT_TO_SOME_INIT,
892 XXXEXIT_TO_SOME_EXIT,
893 ANY_INIT_TO_ANY_EXIT,
894 ANY_EXIT_TO_ANY_INIT,
898 struct sectioncheck {
899 const char *fromsec[20];
900 const char *tosec[20];
901 enum mismatch mismatch;
902 const char *symbol_white_list[20];
905 const struct sectioncheck sectioncheck[] = {
906 /* Do not reference init/exit code/data from
907 * normal code and data
910 .fromsec = { TEXT_SECTIONS, NULL },
911 .tosec = { ALL_INIT_SECTIONS, NULL },
912 .mismatch = TEXT_TO_ANY_INIT,
913 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
916 .fromsec = { DATA_SECTIONS, NULL },
917 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
918 .mismatch = DATA_TO_ANY_INIT,
919 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
922 .fromsec = { DATA_SECTIONS, NULL },
923 .tosec = { INIT_SECTIONS, NULL },
924 .mismatch = DATA_TO_ANY_INIT,
925 .symbol_white_list = {
926 "*_template", "*_timer", "*_sht", "*_ops",
927 "*_probe", "*_probe_one", "*_console", NULL
931 .fromsec = { TEXT_SECTIONS, NULL },
932 .tosec = { ALL_EXIT_SECTIONS, NULL },
933 .mismatch = TEXT_TO_ANY_EXIT,
934 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
937 .fromsec = { DATA_SECTIONS, NULL },
938 .tosec = { ALL_EXIT_SECTIONS, NULL },
939 .mismatch = DATA_TO_ANY_EXIT,
940 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
942 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
944 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
945 .tosec = { INIT_SECTIONS, NULL },
946 .mismatch = XXXINIT_TO_SOME_INIT,
947 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
949 /* Do not reference cpuinit code/data from meminit code/data */
951 .fromsec = { MEM_INIT_SECTIONS, NULL },
952 .tosec = { CPU_INIT_SECTIONS, NULL },
953 .mismatch = XXXINIT_TO_SOME_INIT,
954 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
956 /* Do not reference meminit code/data from cpuinit code/data */
958 .fromsec = { CPU_INIT_SECTIONS, NULL },
959 .tosec = { MEM_INIT_SECTIONS, NULL },
960 .mismatch = XXXINIT_TO_SOME_INIT,
961 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
963 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
965 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
966 .tosec = { EXIT_SECTIONS, NULL },
967 .mismatch = XXXEXIT_TO_SOME_EXIT,
968 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
970 /* Do not reference cpuexit code/data from memexit code/data */
972 .fromsec = { MEM_EXIT_SECTIONS, NULL },
973 .tosec = { CPU_EXIT_SECTIONS, NULL },
974 .mismatch = XXXEXIT_TO_SOME_EXIT,
975 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
977 /* Do not reference memexit code/data from cpuexit code/data */
979 .fromsec = { CPU_EXIT_SECTIONS, NULL },
980 .tosec = { MEM_EXIT_SECTIONS, NULL },
981 .mismatch = XXXEXIT_TO_SOME_EXIT,
982 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
984 /* Do not use exit code/data from init code */
986 .fromsec = { ALL_INIT_SECTIONS, NULL },
987 .tosec = { ALL_EXIT_SECTIONS, NULL },
988 .mismatch = ANY_INIT_TO_ANY_EXIT,
989 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
991 /* Do not use init code/data from exit code */
993 .fromsec = { ALL_EXIT_SECTIONS, NULL },
994 .tosec = { ALL_INIT_SECTIONS, NULL },
995 .mismatch = ANY_EXIT_TO_ANY_INIT,
996 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
998 /* Do not export init/exit functions or data */
1000 .fromsec = { "__ksymtab*", NULL },
1001 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1002 .mismatch = EXPORT_TO_INIT_EXIT,
1003 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1007 static const struct sectioncheck *section_mismatch(
1008 const char *fromsec, const char *tosec)
1011 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1012 const struct sectioncheck *check = §ioncheck[0];
1014 for (i = 0; i < elems; i++) {
1015 if (match(fromsec, check->fromsec) &&
1016 match(tosec, check->tosec))
1024 * Whitelist to allow certain references to pass with no warning.
1027 * If a module parameter is declared __initdata and permissions=0
1028 * then this is legal despite the warning generated.
1029 * We cannot see value of permissions here, so just ignore
1031 * The pattern is identified by:
1032 * tosec = .init.data
1037 * Many drivers utilise a *driver container with references to
1038 * add, remove, probe functions etc.
1039 * These functions may often be marked __devinit and we do not want to
1041 * the pattern is identified by:
1042 * tosec = init or exit section
1043 * fromsec = data section
1044 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1045 * *probe_one, *_console, *_timer
1048 * Whitelist all references from .head.text to any init section
1051 * Some symbols belong to init section but still it is ok to reference
1052 * these from non-init sections as these symbols don't have any memory
1053 * allocated for them and symbol address and value are same. So even
1054 * if init section is freed, its ok to reference those symbols.
1055 * For ex. symbols marking the init section boundaries.
1056 * This pattern is identified by
1057 * refsymname = __init_begin, _sinittext, _einittext
1060 static int secref_whitelist(const struct sectioncheck *mismatch,
1061 const char *fromsec, const char *fromsym,
1062 const char *tosec, const char *tosym)
1064 /* Check for pattern 1 */
1065 if (match(tosec, init_data_sections) &&
1066 match(fromsec, data_sections) &&
1067 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1070 /* Check for pattern 2 */
1071 if (match(tosec, init_exit_sections) &&
1072 match(fromsec, data_sections) &&
1073 match(fromsym, mismatch->symbol_white_list))
1076 /* Check for pattern 3 */
1077 if (match(fromsec, head_sections) &&
1078 match(tosec, init_sections))
1081 /* Check for pattern 4 */
1082 if (match(tosym, linker_symbols))
1089 * Find symbol based on relocation record info.
1090 * In some cases the symbol supplied is a valid symbol so
1091 * return refsym. If st_name != 0 we assume this is a valid symbol.
1092 * In other cases the symbol needs to be looked up in the symbol table
1093 * based on section and address.
1095 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1099 Elf_Sym *near = NULL;
1100 Elf64_Sword distance = 20;
1102 unsigned int relsym_secindex;
1104 if (relsym->st_name != 0)
1107 relsym_secindex = get_secindex(elf, relsym);
1108 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1109 if (get_secindex(elf, sym) != relsym_secindex)
1111 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1113 if (sym->st_value == addr)
1115 /* Find a symbol nearby - addr are maybe negative */
1116 d = sym->st_value - addr;
1118 d = addr - sym->st_value;
1124 /* We need a close match */
1131 static inline int is_arm_mapping_symbol(const char *str)
1133 return str[0] == '$' && strchr("atd", str[1])
1134 && (str[2] == '\0' || str[2] == '.');
1138 * If there's no name there, ignore it; likewise, ignore it if it's
1139 * one of the magic symbols emitted used by current ARM tools.
1141 * Otherwise if find_symbols_between() returns those symbols, they'll
1142 * fail the whitelist tests and cause lots of false alarms ... fixable
1143 * only by merging __exit and __init sections into __text, bloating
1144 * the kernel (which is especially evil on embedded platforms).
1146 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1148 const char *name = elf->strtab + sym->st_name;
1150 if (!name || !strlen(name))
1152 return !is_arm_mapping_symbol(name);
1156 * Find symbols before or equal addr and after addr - in the section sec.
1157 * If we find two symbols with equal offset prefer one with a valid name.
1158 * The ELF format may have a better way to detect what type of symbol
1159 * it is, but this works for now.
1161 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1165 Elf_Sym *near = NULL;
1166 Elf_Addr distance = ~0;
1168 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1171 if (is_shndx_special(sym->st_shndx))
1173 symsec = sec_name(elf, get_secindex(elf, sym));
1174 if (strcmp(symsec, sec) != 0)
1176 if (!is_valid_name(elf, sym))
1178 if (sym->st_value <= addr) {
1179 if ((addr - sym->st_value) < distance) {
1180 distance = addr - sym->st_value;
1182 } else if ((addr - sym->st_value) == distance) {
1191 * Convert a section name to the function/data attribute
1192 * .init.text => __init
1193 * .cpuinit.data => __cpudata
1194 * .memexitconst => __memconst
1197 static char *sec2annotation(const char *s)
1199 if (match(s, init_exit_sections)) {
1200 char *p = malloc(20);
1207 while (*s && *s != '.')
1212 if (strstr(s, "rodata") != NULL)
1213 strcat(p, "const ");
1214 else if (strstr(s, "data") != NULL)
1218 return r; /* we leak her but we do not care */
1224 static int is_function(Elf_Sym *sym)
1227 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1233 * Print a warning about a section mismatch.
1234 * Try to find symbols near it so user can find it.
1235 * Check whitelist before warning - it may be a false positive.
1237 static void report_sec_mismatch(const char *modname,
1238 const struct sectioncheck *mismatch,
1239 const char *fromsec,
1240 unsigned long long fromaddr,
1241 const char *fromsym,
1243 const char *tosec, const char *tosym,
1246 const char *from, *from_p;
1247 const char *to, *to_p;
1249 switch (from_is_func) {
1250 case 0: from = "variable"; from_p = ""; break;
1251 case 1: from = "function"; from_p = "()"; break;
1252 default: from = "(unknown reference)"; from_p = ""; break;
1254 switch (to_is_func) {
1255 case 0: to = "variable"; to_p = ""; break;
1256 case 1: to = "function"; to_p = "()"; break;
1257 default: to = "(unknown reference)"; to_p = ""; break;
1260 sec_mismatch_count++;
1261 if (!sec_mismatch_verbose)
1264 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1265 "to the %s %s:%s%s\n",
1266 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1269 switch (mismatch->mismatch) {
1270 case TEXT_TO_ANY_INIT:
1272 "The function %s%s() references\n"
1274 "This is often because %s lacks a %s\n"
1275 "annotation or the annotation of %s is wrong.\n",
1276 sec2annotation(fromsec), fromsym,
1277 to, sec2annotation(tosec), tosym, to_p,
1278 fromsym, sec2annotation(tosec), tosym);
1280 case DATA_TO_ANY_INIT: {
1281 const char *const *s = mismatch->symbol_white_list;
1283 "The variable %s references\n"
1285 "If the reference is valid then annotate the\n"
1286 "variable with __init* or __refdata (see linux/init.h) "
1287 "or name the variable:\n",
1288 fromsym, to, sec2annotation(tosec), tosym, to_p);
1290 fprintf(stderr, "%s, ", *s++);
1291 fprintf(stderr, "\n");
1294 case TEXT_TO_ANY_EXIT:
1296 "The function %s() references a %s in an exit section.\n"
1297 "Often the %s %s%s has valid usage outside the exit section\n"
1298 "and the fix is to remove the %sannotation of %s.\n",
1299 fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1301 case DATA_TO_ANY_EXIT: {
1302 const char *const *s = mismatch->symbol_white_list;
1304 "The variable %s references\n"
1306 "If the reference is valid then annotate the\n"
1307 "variable with __exit* (see linux/init.h) or "
1308 "name the variable:\n",
1309 fromsym, to, sec2annotation(tosec), tosym, to_p);
1311 fprintf(stderr, "%s, ", *s++);
1312 fprintf(stderr, "\n");
1315 case XXXINIT_TO_SOME_INIT:
1316 case XXXEXIT_TO_SOME_EXIT:
1318 "The %s %s%s%s references\n"
1320 "If %s is only used by %s then\n"
1321 "annotate %s with a matching annotation.\n",
1322 from, sec2annotation(fromsec), fromsym, from_p,
1323 to, sec2annotation(tosec), tosym, to_p,
1324 tosym, fromsym, tosym);
1326 case ANY_INIT_TO_ANY_EXIT:
1328 "The %s %s%s%s references\n"
1330 "This is often seen when error handling "
1331 "in the init function\n"
1332 "uses functionality in the exit path.\n"
1333 "The fix is often to remove the %sannotation of\n"
1334 "%s%s so it may be used outside an exit section.\n",
1335 from, sec2annotation(fromsec), fromsym, from_p,
1336 to, sec2annotation(tosec), tosym, to_p,
1337 sec2annotation(tosec), tosym, to_p);
1339 case ANY_EXIT_TO_ANY_INIT:
1341 "The %s %s%s%s references\n"
1343 "This is often seen when error handling "
1344 "in the exit function\n"
1345 "uses functionality in the init path.\n"
1346 "The fix is often to remove the %sannotation of\n"
1347 "%s%s so it may be used outside an init section.\n",
1348 from, sec2annotation(fromsec), fromsym, from_p,
1349 to, sec2annotation(tosec), tosym, to_p,
1350 sec2annotation(tosec), tosym, to_p);
1352 case EXPORT_TO_INIT_EXIT:
1354 "The symbol %s is exported and annotated %s\n"
1355 "Fix this by removing the %sannotation of %s "
1356 "or drop the export.\n",
1357 tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1360 fprintf(stderr, "\n");
1363 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1364 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1367 const struct sectioncheck *mismatch;
1369 tosec = sec_name(elf, get_secindex(elf, sym));
1370 mismatch = section_mismatch(fromsec, tosec);
1375 const char *fromsym;
1377 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1378 fromsym = sym_name(elf, from);
1379 to = find_elf_symbol(elf, r->r_addend, sym);
1380 tosym = sym_name(elf, to);
1382 /* check whitelist - we may ignore it */
1383 if (secref_whitelist(mismatch,
1384 fromsec, fromsym, tosec, tosym)) {
1385 report_sec_mismatch(modname, mismatch,
1386 fromsec, r->r_offset, fromsym,
1387 is_function(from), tosec, tosym,
1393 static unsigned int *reloc_location(struct elf_info *elf,
1394 Elf_Shdr *sechdr, Elf_Rela *r)
1396 Elf_Shdr *sechdrs = elf->sechdrs;
1397 int section = shndx2secindex(sechdr->sh_info);
1399 return (void *)elf->hdr + sechdrs[section].sh_offset +
1400 r->r_offset - sechdrs[section].sh_addr;
1403 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1405 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1406 unsigned int *location = reloc_location(elf, sechdr, r);
1410 r->r_addend = TO_NATIVE(*location);
1413 r->r_addend = TO_NATIVE(*location) + 4;
1414 /* For CONFIG_RELOCATABLE=y */
1415 if (elf->hdr->e_type == ET_EXEC)
1416 r->r_addend += r->r_offset;
1422 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1424 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1428 /* From ARM ABI: (S + A) | T */
1429 r->r_addend = (int)(long)
1430 (elf->symtab_start + ELF_R_SYM(r->r_info));
1433 /* From ARM ABI: ((S + A) | T) - P */
1434 r->r_addend = (int)(long)(elf->hdr +
1436 (r->r_offset - sechdr->sh_addr));
1444 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1446 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1447 unsigned int *location = reloc_location(elf, sechdr, r);
1450 if (r_typ == R_MIPS_HI16)
1451 return 1; /* skip this */
1452 inst = TO_NATIVE(*location);
1455 r->r_addend = inst & 0xffff;
1458 r->r_addend = (inst & 0x03ffffff) << 2;
1467 static void section_rela(const char *modname, struct elf_info *elf,
1474 const char *fromsec;
1476 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1477 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1479 fromsec = sech_name(elf, sechdr);
1480 fromsec += strlen(".rela");
1481 /* if from section (name) is know good then skip it */
1482 if (match(fromsec, section_white_list))
1485 for (rela = start; rela < stop; rela++) {
1486 r.r_offset = TO_NATIVE(rela->r_offset);
1487 #if KERNEL_ELFCLASS == ELFCLASS64
1488 if (elf->hdr->e_machine == EM_MIPS) {
1490 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1491 r_sym = TO_NATIVE(r_sym);
1492 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1493 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1495 r.r_info = TO_NATIVE(rela->r_info);
1496 r_sym = ELF_R_SYM(r.r_info);
1499 r.r_info = TO_NATIVE(rela->r_info);
1500 r_sym = ELF_R_SYM(r.r_info);
1502 r.r_addend = TO_NATIVE(rela->r_addend);
1503 sym = elf->symtab_start + r_sym;
1504 /* Skip special sections */
1505 if (is_shndx_special(sym->st_shndx))
1507 check_section_mismatch(modname, elf, &r, sym, fromsec);
1511 static void section_rel(const char *modname, struct elf_info *elf,
1518 const char *fromsec;
1520 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1521 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1523 fromsec = sech_name(elf, sechdr);
1524 fromsec += strlen(".rel");
1525 /* if from section (name) is know good then skip it */
1526 if (match(fromsec, section_white_list))
1529 for (rel = start; rel < stop; rel++) {
1530 r.r_offset = TO_NATIVE(rel->r_offset);
1531 #if KERNEL_ELFCLASS == ELFCLASS64
1532 if (elf->hdr->e_machine == EM_MIPS) {
1534 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1535 r_sym = TO_NATIVE(r_sym);
1536 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1537 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1539 r.r_info = TO_NATIVE(rel->r_info);
1540 r_sym = ELF_R_SYM(r.r_info);
1543 r.r_info = TO_NATIVE(rel->r_info);
1544 r_sym = ELF_R_SYM(r.r_info);
1547 switch (elf->hdr->e_machine) {
1549 if (addend_386_rel(elf, sechdr, &r))
1553 if (addend_arm_rel(elf, sechdr, &r))
1557 if (addend_mips_rel(elf, sechdr, &r))
1561 sym = elf->symtab_start + r_sym;
1562 /* Skip special sections */
1563 if (is_shndx_special(sym->st_shndx))
1565 check_section_mismatch(modname, elf, &r, sym, fromsec);
1570 * A module includes a number of sections that are discarded
1571 * either when loaded or when used as built-in.
1572 * For loaded modules all functions marked __init and all data
1573 * marked __initdata will be discarded when the module has been intialized.
1574 * Likewise for modules used built-in the sections marked __exit
1575 * are discarded because __exit marked function are supposed to be called
1576 * only when a module is unloaded which never happens for built-in modules.
1577 * The check_sec_ref() function traverses all relocation records
1578 * to find all references to a section that reference a section that will
1579 * be discarded and warns about it.
1581 static void check_sec_ref(struct module *mod, const char *modname,
1582 struct elf_info *elf)
1585 Elf_Shdr *sechdrs = elf->sechdrs;
1587 /* Walk through all sections */
1588 for (i = 0; i < elf->num_sections; i++) {
1589 check_section(modname, elf, &elf->sechdrs[i]);
1590 /* We want to process only relocation sections and not .init */
1591 if (sechdrs[i].sh_type == SHT_RELA)
1592 section_rela(modname, elf, &elf->sechdrs[i]);
1593 else if (sechdrs[i].sh_type == SHT_REL)
1594 section_rel(modname, elf, &elf->sechdrs[i]);
1598 static void read_symbols(char *modname)
1600 const char *symname;
1604 struct elf_info info = { };
1607 if (!parse_elf(&info, modname))
1610 mod = new_module(modname);
1612 /* When there's no vmlinux, don't print warnings about
1613 * unresolved symbols (since there'll be too many ;) */
1614 if (is_vmlinux(modname)) {
1619 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1620 if (info.modinfo && !license && !is_vmlinux(modname))
1621 warn("modpost: missing MODULE_LICENSE() in %s\n"
1622 "see include/linux/module.h for "
1623 "more information\n", modname);
1625 if (license_is_gpl_compatible(license))
1626 mod->gpl_compatible = 1;
1628 mod->gpl_compatible = 0;
1631 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1632 "license", license);
1635 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1636 symname = info.strtab + sym->st_name;
1638 handle_modversions(mod, &info, sym, symname);
1639 handle_moddevtable(mod, &info, sym, symname);
1641 if (!is_vmlinux(modname) ||
1642 (is_vmlinux(modname) && vmlinux_section_warnings))
1643 check_sec_ref(mod, modname, &info);
1645 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1647 maybe_frob_rcs_version(modname, version, info.modinfo,
1648 version - (char *)info.hdr);
1649 if (version || (all_versions && !is_vmlinux(modname)))
1650 get_src_version(modname, mod->srcversion,
1651 sizeof(mod->srcversion)-1);
1653 parse_elf_finish(&info);
1655 /* Our trick to get versioning for module struct etc. - it's
1656 * never passed as an argument to an exported function, so
1657 * the automatic versioning doesn't pick it up, but it's really
1658 * important anyhow */
1660 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1665 /* We first write the generated file into memory using the
1666 * following helper, then compare to the file on disk and
1667 * only update the later if anything changed */
1669 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1670 const char *fmt, ...)
1677 len = vsnprintf(tmp, SZ, fmt, ap);
1678 buf_write(buf, tmp, len);
1682 void buf_write(struct buffer *buf, const char *s, int len)
1684 if (buf->size - buf->pos < len) {
1685 buf->size += len + SZ;
1686 buf->p = realloc(buf->p, buf->size);
1688 strncpy(buf->p + buf->pos, s, len);
1692 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1694 const char *e = is_vmlinux(m) ?"":".ko";
1698 fatal("modpost: GPL-incompatible module %s%s "
1699 "uses GPL-only symbol '%s'\n", m, e, s);
1701 case export_unused_gpl:
1702 fatal("modpost: GPL-incompatible module %s%s "
1703 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1705 case export_gpl_future:
1706 warn("modpost: GPL-incompatible module %s%s "
1707 "uses future GPL-only symbol '%s'\n", m, e, s);
1711 case export_unknown:
1717 static void check_for_unused(enum export exp, const char *m, const char *s)
1719 const char *e = is_vmlinux(m) ?"":".ko";
1723 case export_unused_gpl:
1724 warn("modpost: module %s%s "
1725 "uses symbol '%s' marked UNUSED\n", m, e, s);
1733 static void check_exports(struct module *mod)
1735 struct symbol *s, *exp;
1737 for (s = mod->unres; s; s = s->next) {
1738 const char *basename;
1739 exp = find_symbol(s->name);
1740 if (!exp || exp->module == mod)
1742 basename = strrchr(mod->name, '/');
1746 basename = mod->name;
1747 if (!mod->gpl_compatible)
1748 check_for_gpl_usage(exp->export, basename, exp->name);
1749 check_for_unused(exp->export, basename, exp->name);
1754 * Header for the generated file
1756 static void add_header(struct buffer *b, struct module *mod)
1758 buf_printf(b, "#include <linux/module.h>\n");
1759 buf_printf(b, "#include <linux/vermagic.h>\n");
1760 buf_printf(b, "#include <linux/compiler.h>\n");
1761 buf_printf(b, "\n");
1762 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1763 buf_printf(b, "\n");
1764 buf_printf(b, "struct module __this_module\n");
1765 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1766 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1768 buf_printf(b, " .init = init_module,\n");
1769 if (mod->has_cleanup)
1770 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1771 " .exit = cleanup_module,\n"
1773 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1774 buf_printf(b, "};\n");
1777 static void add_staging_flag(struct buffer *b, const char *name)
1779 static const char *staging_dir = "drivers/staging";
1781 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1782 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1786 * Record CRCs for unresolved symbols
1788 static int add_versions(struct buffer *b, struct module *mod)
1790 struct symbol *s, *exp;
1793 for (s = mod->unres; s; s = s->next) {
1794 exp = find_symbol(s->name);
1795 if (!exp || exp->module == mod) {
1796 if (have_vmlinux && !s->weak) {
1797 if (warn_unresolved) {
1798 warn("\"%s\" [%s.ko] undefined!\n",
1799 s->name, mod->name);
1801 merror("\"%s\" [%s.ko] undefined!\n",
1802 s->name, mod->name);
1808 s->module = exp->module;
1809 s->crc_valid = exp->crc_valid;
1816 buf_printf(b, "\n");
1817 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1818 buf_printf(b, "__used\n");
1819 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1821 for (s = mod->unres; s; s = s->next) {
1824 if (!s->crc_valid) {
1825 warn("\"%s\" [%s.ko] has no CRC!\n",
1826 s->name, mod->name);
1829 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1832 buf_printf(b, "};\n");
1837 static void add_depends(struct buffer *b, struct module *mod,
1838 struct module *modules)
1844 for (m = modules; m; m = m->next)
1845 m->seen = is_vmlinux(m->name);
1847 buf_printf(b, "\n");
1848 buf_printf(b, "static const char __module_depends[]\n");
1849 buf_printf(b, "__used\n");
1850 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1851 buf_printf(b, "\"depends=");
1852 for (s = mod->unres; s; s = s->next) {
1857 if (s->module->seen)
1860 s->module->seen = 1;
1861 p = strrchr(s->module->name, '/');
1865 p = s->module->name;
1866 buf_printf(b, "%s%s", first ? "" : ",", p);
1869 buf_printf(b, "\";\n");
1872 static void add_srcversion(struct buffer *b, struct module *mod)
1874 if (mod->srcversion[0]) {
1875 buf_printf(b, "\n");
1876 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1881 static void write_if_changed(struct buffer *b, const char *fname)
1887 file = fopen(fname, "r");
1891 if (fstat(fileno(file), &st) < 0)
1894 if (st.st_size != b->pos)
1897 tmp = NOFAIL(malloc(b->pos));
1898 if (fread(tmp, 1, b->pos, file) != b->pos)
1901 if (memcmp(tmp, b->p, b->pos) != 0)
1913 file = fopen(fname, "w");
1918 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1925 /* parse Module.symvers file. line format:
1926 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1928 static void read_dump(const char *fname, unsigned int kernel)
1930 unsigned long size, pos = 0;
1931 void *file = grab_file(fname, &size);
1935 /* No symbol versions, silently ignore */
1938 while ((line = get_next_line(&pos, file, size))) {
1939 char *symname, *modname, *d, *export, *end;
1944 if (!(symname = strchr(line, '\t')))
1947 if (!(modname = strchr(symname, '\t')))
1950 if ((export = strchr(modname, '\t')) != NULL)
1952 if (export && ((end = strchr(export, '\t')) != NULL))
1954 crc = strtoul(line, &d, 16);
1955 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1957 mod = find_module(modname);
1959 if (is_vmlinux(modname))
1961 mod = new_module(modname);
1964 s = sym_add_exported(symname, mod, export_no(export));
1967 sym_update_crc(symname, mod, crc, export_no(export));
1971 fatal("parse error in symbol dump file\n");
1974 /* For normal builds always dump all symbols.
1975 * For external modules only dump symbols
1976 * that are not read from kernel Module.symvers.
1978 static int dump_sym(struct symbol *sym)
1980 if (!external_module)
1982 if (sym->vmlinux || sym->kernel)
1987 static void write_dump(const char *fname)
1989 struct buffer buf = { };
1990 struct symbol *symbol;
1993 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1994 symbol = symbolhash[n];
1996 if (dump_sym(symbol))
1997 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1998 symbol->crc, symbol->name,
1999 symbol->module->name,
2000 export_str(symbol->export));
2001 symbol = symbol->next;
2004 write_if_changed(&buf, fname);
2007 struct ext_sym_list {
2008 struct ext_sym_list *next;
2012 int main(int argc, char **argv)
2015 struct buffer buf = { };
2016 char *kernel_read = NULL, *module_read = NULL;
2017 char *dump_write = NULL;
2020 struct ext_sym_list *extsym_iter;
2021 struct ext_sym_list *extsym_start = NULL;
2023 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2026 kernel_read = optarg;
2029 module_read = optarg;
2030 external_module = 1;
2036 external_module = 1;
2038 NOFAIL(malloc(sizeof(*extsym_iter)));
2039 extsym_iter->next = extsym_start;
2040 extsym_iter->file = optarg;
2041 extsym_start = extsym_iter;
2047 dump_write = optarg;
2053 vmlinux_section_warnings = 0;
2056 sec_mismatch_verbose = 0;
2059 warn_unresolved = 1;
2067 read_dump(kernel_read, 1);
2069 read_dump(module_read, 0);
2070 while (extsym_start) {
2071 read_dump(extsym_start->file, 0);
2072 extsym_iter = extsym_start->next;
2074 extsym_start = extsym_iter;
2077 while (optind < argc)
2078 read_symbols(argv[optind++]);
2080 for (mod = modules; mod; mod = mod->next) {
2088 for (mod = modules; mod; mod = mod->next) {
2089 char fname[strlen(mod->name) + 10];
2096 add_header(&buf, mod);
2097 add_staging_flag(&buf, mod->name);
2098 err |= add_versions(&buf, mod);
2099 add_depends(&buf, mod, modules);
2100 add_moddevtable(&buf, mod);
2101 add_srcversion(&buf, mod);
2103 sprintf(fname, "%s.mod.c", mod->name);
2104 write_if_changed(&buf, fname);
2108 write_dump(dump_write);
2109 if (sec_mismatch_count && !sec_mismatch_verbose)
2110 warn("modpost: Found %d section mismatch(es).\n"
2111 "To see full details build your kernel with:\n"
2112 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2113 sec_mismatch_count);