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 /* Do not ignore this symbol */
557 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
558 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
560 static void handle_modversions(struct module *mod, struct elf_info *info,
561 Elf_Sym *sym, const char *symname)
564 enum export export = export_from_sec(info, get_secindex(info, sym));
566 switch (sym->st_shndx) {
568 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
572 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
573 crc = (unsigned int) sym->st_value;
574 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
579 /* undefined symbol */
580 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
581 ELF_ST_BIND(sym->st_info) != STB_WEAK)
583 if (ignore_undef_symbol(info, symname))
585 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
586 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
587 /* add compatibility with older glibc */
588 #ifndef STT_SPARC_REGISTER
589 #define STT_SPARC_REGISTER STT_REGISTER
591 if (info->hdr->e_machine == EM_SPARC ||
592 info->hdr->e_machine == EM_SPARCV9) {
593 /* Ignore register directives. */
594 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
596 if (symname[0] == '.') {
597 char *munged = strdup(symname);
599 munged[1] = toupper(munged[1]);
605 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
606 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
608 alloc_symbol(symname +
609 strlen(MODULE_SYMBOL_PREFIX),
610 ELF_ST_BIND(sym->st_info) == STB_WEAK,
615 /* All exported symbols */
616 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
617 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
620 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
622 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
623 mod->has_cleanup = 1;
629 * Parse tag=value strings from .modinfo section
631 static char *next_string(char *string, unsigned long *secsize)
633 /* Skip non-zero chars */
636 if ((*secsize)-- <= 1)
640 /* Skip any zero padding. */
643 if ((*secsize)-- <= 1)
649 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
650 const char *tag, char *info)
653 unsigned int taglen = strlen(tag);
654 unsigned long size = modinfo_len;
657 size -= info - (char *)modinfo;
658 modinfo = next_string(info, &size);
661 for (p = modinfo; p; p = next_string(p, &size)) {
662 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
663 return p + taglen + 1;
668 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
672 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
676 * Test if string s ends in string sub
679 static int strrcmp(const char *s, const char *sub)
687 sublen = strlen(sub);
689 if ((slen == 0) || (sublen == 0))
695 return memcmp(s + slen - sublen, sub, sublen);
698 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
701 return elf->strtab + sym->st_name;
706 static const char *sec_name(struct elf_info *elf, int secindex)
708 Elf_Shdr *sechdrs = elf->sechdrs;
709 return (void *)elf->hdr +
710 elf->sechdrs[elf->secindex_strings].sh_offset +
711 sechdrs[secindex].sh_name;
714 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
716 return (void *)elf->hdr +
717 elf->sechdrs[elf->secindex_strings].sh_offset +
721 /* if sym is empty or point to a string
722 * like ".[0-9]+" then return 1.
723 * This is the optional prefix added by ld to some sections
725 static int number_prefix(const char *sym)
733 if (c < '0' || c > '9')
739 /* The pattern is an array of simple patterns.
740 * "foo" will match an exact string equal to "foo"
741 * "*foo" will match a string that ends with "foo"
742 * "foo*" will match a string that begins with "foo"
743 * "foo$" will match a string equal to "foo" or "foo.1"
744 * where the '1' can be any number including several digits.
745 * The $ syntax is for sections where ld append a dot number
746 * to make section name unique.
748 static int match(const char *sym, const char * const pat[])
753 const char *endp = p + strlen(p) - 1;
757 if (strrcmp(sym, p + 1) == 0)
761 else if (*endp == '*') {
762 if (strncmp(sym, p, strlen(p) - 1) == 0)
766 else if (*endp == '$') {
767 if (strncmp(sym, p, strlen(p) - 1) == 0) {
768 if (number_prefix(sym + strlen(p) - 1))
774 if (strcmp(p, sym) == 0)
782 /* sections that we do not want to do full section mismatch check on */
783 static const char *section_white_list[] =
787 ".mdebug*", /* alpha, score, mips etc. */
788 ".pdr", /* alpha, score, mips etc. */
797 * This is used to find sections missing the SHF_ALLOC flag.
798 * The cause of this is often a section specified in assembler
799 * without "ax" / "aw".
801 static void check_section(const char *modname, struct elf_info *elf,
804 const char *sec = sech_name(elf, sechdr);
806 if (sechdr->sh_type == SHT_PROGBITS &&
807 !(sechdr->sh_flags & SHF_ALLOC) &&
808 !match(sec, section_white_list)) {
809 warn("%s (%s): unexpected non-allocatable section.\n"
810 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
811 "Note that for example <linux/init.h> contains\n"
812 "section definitions for use in .S files.\n\n",
819 #define ALL_INIT_DATA_SECTIONS \
820 ".init.setup$", ".init.rodata$", \
821 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
822 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
823 #define ALL_EXIT_DATA_SECTIONS \
824 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
826 #define ALL_INIT_TEXT_SECTIONS \
827 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
828 #define ALL_EXIT_TEXT_SECTIONS \
829 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
831 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
833 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
836 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
837 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
839 #define DATA_SECTIONS ".data$", ".data.rel$"
840 #define TEXT_SECTIONS ".text$"
842 #define INIT_SECTIONS ".init.*"
843 #define DEV_INIT_SECTIONS ".devinit.*"
844 #define CPU_INIT_SECTIONS ".cpuinit.*"
845 #define MEM_INIT_SECTIONS ".meminit.*"
847 #define EXIT_SECTIONS ".exit.*"
848 #define DEV_EXIT_SECTIONS ".devexit.*"
849 #define CPU_EXIT_SECTIONS ".cpuexit.*"
850 #define MEM_EXIT_SECTIONS ".memexit.*"
852 /* init data sections */
853 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
855 /* all init sections */
856 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
858 /* All init and exit sections (code + data) */
859 static const char *init_exit_sections[] =
860 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
863 static const char *data_sections[] = { DATA_SECTIONS, NULL };
866 /* symbols in .data that may refer to init/exit sections */
867 #define DEFAULT_SYMBOL_WHITE_LIST \
869 "*_template", /* scsi uses *_template a lot */ \
870 "*_timer", /* arm uses ops structures named _timer a lot */ \
871 "*_sht", /* scsi also used *_sht to some extent */ \
877 static const char *head_sections[] = { ".head.text*", NULL };
878 static const char *linker_symbols[] =
879 { "__init_begin", "_sinittext", "_einittext", NULL };
886 XXXINIT_TO_SOME_INIT,
887 XXXEXIT_TO_SOME_EXIT,
888 ANY_INIT_TO_ANY_EXIT,
889 ANY_EXIT_TO_ANY_INIT,
893 struct sectioncheck {
894 const char *fromsec[20];
895 const char *tosec[20];
896 enum mismatch mismatch;
897 const char *symbol_white_list[20];
900 const struct sectioncheck sectioncheck[] = {
901 /* Do not reference init/exit code/data from
902 * normal code and data
905 .fromsec = { TEXT_SECTIONS, NULL },
906 .tosec = { ALL_INIT_SECTIONS, NULL },
907 .mismatch = TEXT_TO_ANY_INIT,
908 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
911 .fromsec = { DATA_SECTIONS, NULL },
912 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
913 .mismatch = DATA_TO_ANY_INIT,
914 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
917 .fromsec = { DATA_SECTIONS, NULL },
918 .tosec = { INIT_SECTIONS, NULL },
919 .mismatch = DATA_TO_ANY_INIT,
920 .symbol_white_list = {
921 "*_template", "*_timer", "*_sht", "*_ops",
922 "*_probe", "*_probe_one", "*_console", NULL
926 .fromsec = { TEXT_SECTIONS, NULL },
927 .tosec = { ALL_EXIT_SECTIONS, NULL },
928 .mismatch = TEXT_TO_ANY_EXIT,
929 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
932 .fromsec = { DATA_SECTIONS, NULL },
933 .tosec = { ALL_EXIT_SECTIONS, NULL },
934 .mismatch = DATA_TO_ANY_EXIT,
935 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
937 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
939 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
940 .tosec = { INIT_SECTIONS, NULL },
941 .mismatch = XXXINIT_TO_SOME_INIT,
942 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
944 /* Do not reference cpuinit code/data from meminit code/data */
946 .fromsec = { MEM_INIT_SECTIONS, NULL },
947 .tosec = { CPU_INIT_SECTIONS, NULL },
948 .mismatch = XXXINIT_TO_SOME_INIT,
949 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
951 /* Do not reference meminit code/data from cpuinit code/data */
953 .fromsec = { CPU_INIT_SECTIONS, NULL },
954 .tosec = { MEM_INIT_SECTIONS, NULL },
955 .mismatch = XXXINIT_TO_SOME_INIT,
956 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
958 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
960 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
961 .tosec = { EXIT_SECTIONS, NULL },
962 .mismatch = XXXEXIT_TO_SOME_EXIT,
963 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
965 /* Do not reference cpuexit code/data from memexit code/data */
967 .fromsec = { MEM_EXIT_SECTIONS, NULL },
968 .tosec = { CPU_EXIT_SECTIONS, NULL },
969 .mismatch = XXXEXIT_TO_SOME_EXIT,
970 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
972 /* Do not reference memexit code/data from cpuexit code/data */
974 .fromsec = { CPU_EXIT_SECTIONS, NULL },
975 .tosec = { MEM_EXIT_SECTIONS, NULL },
976 .mismatch = XXXEXIT_TO_SOME_EXIT,
977 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
979 /* Do not use exit code/data from init code */
981 .fromsec = { ALL_INIT_SECTIONS, NULL },
982 .tosec = { ALL_EXIT_SECTIONS, NULL },
983 .mismatch = ANY_INIT_TO_ANY_EXIT,
984 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
986 /* Do not use init code/data from exit code */
988 .fromsec = { ALL_EXIT_SECTIONS, NULL },
989 .tosec = { ALL_INIT_SECTIONS, NULL },
990 .mismatch = ANY_EXIT_TO_ANY_INIT,
991 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
993 /* Do not export init/exit functions or data */
995 .fromsec = { "__ksymtab*", NULL },
996 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
997 .mismatch = EXPORT_TO_INIT_EXIT,
998 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1002 static const struct sectioncheck *section_mismatch(
1003 const char *fromsec, const char *tosec)
1006 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1007 const struct sectioncheck *check = §ioncheck[0];
1009 for (i = 0; i < elems; i++) {
1010 if (match(fromsec, check->fromsec) &&
1011 match(tosec, check->tosec))
1019 * Whitelist to allow certain references to pass with no warning.
1022 * If a module parameter is declared __initdata and permissions=0
1023 * then this is legal despite the warning generated.
1024 * We cannot see value of permissions here, so just ignore
1026 * The pattern is identified by:
1027 * tosec = .init.data
1032 * Many drivers utilise a *driver container with references to
1033 * add, remove, probe functions etc.
1034 * These functions may often be marked __devinit and we do not want to
1036 * the pattern is identified by:
1037 * tosec = init or exit section
1038 * fromsec = data section
1039 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1040 * *probe_one, *_console, *_timer
1043 * Whitelist all references from .head.text to any init section
1046 * Some symbols belong to init section but still it is ok to reference
1047 * these from non-init sections as these symbols don't have any memory
1048 * allocated for them and symbol address and value are same. So even
1049 * if init section is freed, its ok to reference those symbols.
1050 * For ex. symbols marking the init section boundaries.
1051 * This pattern is identified by
1052 * refsymname = __init_begin, _sinittext, _einittext
1055 static int secref_whitelist(const struct sectioncheck *mismatch,
1056 const char *fromsec, const char *fromsym,
1057 const char *tosec, const char *tosym)
1059 /* Check for pattern 1 */
1060 if (match(tosec, init_data_sections) &&
1061 match(fromsec, data_sections) &&
1062 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1065 /* Check for pattern 2 */
1066 if (match(tosec, init_exit_sections) &&
1067 match(fromsec, data_sections) &&
1068 match(fromsym, mismatch->symbol_white_list))
1071 /* Check for pattern 3 */
1072 if (match(fromsec, head_sections) &&
1073 match(tosec, init_sections))
1076 /* Check for pattern 4 */
1077 if (match(tosym, linker_symbols))
1084 * Find symbol based on relocation record info.
1085 * In some cases the symbol supplied is a valid symbol so
1086 * return refsym. If st_name != 0 we assume this is a valid symbol.
1087 * In other cases the symbol needs to be looked up in the symbol table
1088 * based on section and address.
1090 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1094 Elf_Sym *near = NULL;
1095 Elf64_Sword distance = 20;
1097 unsigned int relsym_secindex;
1099 if (relsym->st_name != 0)
1102 relsym_secindex = get_secindex(elf, relsym);
1103 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1104 if (get_secindex(elf, sym) != relsym_secindex)
1106 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1108 if (sym->st_value == addr)
1110 /* Find a symbol nearby - addr are maybe negative */
1111 d = sym->st_value - addr;
1113 d = addr - sym->st_value;
1119 /* We need a close match */
1126 static inline int is_arm_mapping_symbol(const char *str)
1128 return str[0] == '$' && strchr("atd", str[1])
1129 && (str[2] == '\0' || str[2] == '.');
1133 * If there's no name there, ignore it; likewise, ignore it if it's
1134 * one of the magic symbols emitted used by current ARM tools.
1136 * Otherwise if find_symbols_between() returns those symbols, they'll
1137 * fail the whitelist tests and cause lots of false alarms ... fixable
1138 * only by merging __exit and __init sections into __text, bloating
1139 * the kernel (which is especially evil on embedded platforms).
1141 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1143 const char *name = elf->strtab + sym->st_name;
1145 if (!name || !strlen(name))
1147 return !is_arm_mapping_symbol(name);
1151 * Find symbols before or equal addr and after addr - in the section sec.
1152 * If we find two symbols with equal offset prefer one with a valid name.
1153 * The ELF format may have a better way to detect what type of symbol
1154 * it is, but this works for now.
1156 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1160 Elf_Sym *near = NULL;
1161 Elf_Addr distance = ~0;
1163 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1166 if (is_shndx_special(sym->st_shndx))
1168 symsec = sec_name(elf, get_secindex(elf, sym));
1169 if (strcmp(symsec, sec) != 0)
1171 if (!is_valid_name(elf, sym))
1173 if (sym->st_value <= addr) {
1174 if ((addr - sym->st_value) < distance) {
1175 distance = addr - sym->st_value;
1177 } else if ((addr - sym->st_value) == distance) {
1186 * Convert a section name to the function/data attribute
1187 * .init.text => __init
1188 * .cpuinit.data => __cpudata
1189 * .memexitconst => __memconst
1192 static char *sec2annotation(const char *s)
1194 if (match(s, init_exit_sections)) {
1195 char *p = malloc(20);
1202 while (*s && *s != '.')
1207 if (strstr(s, "rodata") != NULL)
1208 strcat(p, "const ");
1209 else if (strstr(s, "data") != NULL)
1213 return r; /* we leak her but we do not care */
1219 static int is_function(Elf_Sym *sym)
1222 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1228 * Print a warning about a section mismatch.
1229 * Try to find symbols near it so user can find it.
1230 * Check whitelist before warning - it may be a false positive.
1232 static void report_sec_mismatch(const char *modname,
1233 const struct sectioncheck *mismatch,
1234 const char *fromsec,
1235 unsigned long long fromaddr,
1236 const char *fromsym,
1238 const char *tosec, const char *tosym,
1241 const char *from, *from_p;
1242 const char *to, *to_p;
1244 switch (from_is_func) {
1245 case 0: from = "variable"; from_p = ""; break;
1246 case 1: from = "function"; from_p = "()"; break;
1247 default: from = "(unknown reference)"; from_p = ""; break;
1249 switch (to_is_func) {
1250 case 0: to = "variable"; to_p = ""; break;
1251 case 1: to = "function"; to_p = "()"; break;
1252 default: to = "(unknown reference)"; to_p = ""; break;
1255 sec_mismatch_count++;
1256 if (!sec_mismatch_verbose)
1259 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1260 "to the %s %s:%s%s\n",
1261 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1264 switch (mismatch->mismatch) {
1265 case TEXT_TO_ANY_INIT:
1267 "The function %s%s() references\n"
1269 "This is often because %s lacks a %s\n"
1270 "annotation or the annotation of %s is wrong.\n",
1271 sec2annotation(fromsec), fromsym,
1272 to, sec2annotation(tosec), tosym, to_p,
1273 fromsym, sec2annotation(tosec), tosym);
1275 case DATA_TO_ANY_INIT: {
1276 const char *const *s = mismatch->symbol_white_list;
1278 "The variable %s references\n"
1280 "If the reference is valid then annotate the\n"
1281 "variable with __init* or __refdata (see linux/init.h) "
1282 "or name the variable:\n",
1283 fromsym, to, sec2annotation(tosec), tosym, to_p);
1285 fprintf(stderr, "%s, ", *s++);
1286 fprintf(stderr, "\n");
1289 case TEXT_TO_ANY_EXIT:
1291 "The function %s() references a %s in an exit section.\n"
1292 "Often the %s %s%s has valid usage outside the exit section\n"
1293 "and the fix is to remove the %sannotation of %s.\n",
1294 fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1296 case DATA_TO_ANY_EXIT: {
1297 const char *const *s = mismatch->symbol_white_list;
1299 "The variable %s references\n"
1301 "If the reference is valid then annotate the\n"
1302 "variable with __exit* (see linux/init.h) or "
1303 "name the variable:\n",
1304 fromsym, to, sec2annotation(tosec), tosym, to_p);
1306 fprintf(stderr, "%s, ", *s++);
1307 fprintf(stderr, "\n");
1310 case XXXINIT_TO_SOME_INIT:
1311 case XXXEXIT_TO_SOME_EXIT:
1313 "The %s %s%s%s references\n"
1315 "If %s is only used by %s then\n"
1316 "annotate %s with a matching annotation.\n",
1317 from, sec2annotation(fromsec), fromsym, from_p,
1318 to, sec2annotation(tosec), tosym, to_p,
1319 tosym, fromsym, tosym);
1321 case ANY_INIT_TO_ANY_EXIT:
1323 "The %s %s%s%s references\n"
1325 "This is often seen when error handling "
1326 "in the init function\n"
1327 "uses functionality in the exit path.\n"
1328 "The fix is often to remove the %sannotation of\n"
1329 "%s%s so it may be used outside an exit section.\n",
1330 from, sec2annotation(fromsec), fromsym, from_p,
1331 to, sec2annotation(tosec), tosym, to_p,
1332 sec2annotation(tosec), tosym, to_p);
1334 case ANY_EXIT_TO_ANY_INIT:
1336 "The %s %s%s%s references\n"
1338 "This is often seen when error handling "
1339 "in the exit function\n"
1340 "uses functionality in the init path.\n"
1341 "The fix is often to remove the %sannotation of\n"
1342 "%s%s so it may be used outside an init section.\n",
1343 from, sec2annotation(fromsec), fromsym, from_p,
1344 to, sec2annotation(tosec), tosym, to_p,
1345 sec2annotation(tosec), tosym, to_p);
1347 case EXPORT_TO_INIT_EXIT:
1349 "The symbol %s is exported and annotated %s\n"
1350 "Fix this by removing the %sannotation of %s "
1351 "or drop the export.\n",
1352 tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1355 fprintf(stderr, "\n");
1358 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1359 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1362 const struct sectioncheck *mismatch;
1364 tosec = sec_name(elf, get_secindex(elf, sym));
1365 mismatch = section_mismatch(fromsec, tosec);
1370 const char *fromsym;
1372 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1373 fromsym = sym_name(elf, from);
1374 to = find_elf_symbol(elf, r->r_addend, sym);
1375 tosym = sym_name(elf, to);
1377 /* check whitelist - we may ignore it */
1378 if (secref_whitelist(mismatch,
1379 fromsec, fromsym, tosec, tosym)) {
1380 report_sec_mismatch(modname, mismatch,
1381 fromsec, r->r_offset, fromsym,
1382 is_function(from), tosec, tosym,
1388 static unsigned int *reloc_location(struct elf_info *elf,
1389 Elf_Shdr *sechdr, Elf_Rela *r)
1391 Elf_Shdr *sechdrs = elf->sechdrs;
1392 int section = shndx2secindex(sechdr->sh_info);
1394 return (void *)elf->hdr + sechdrs[section].sh_offset +
1395 (r->r_offset - sechdrs[section].sh_addr);
1398 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1400 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1401 unsigned int *location = reloc_location(elf, sechdr, r);
1405 r->r_addend = TO_NATIVE(*location);
1408 r->r_addend = TO_NATIVE(*location) + 4;
1409 /* For CONFIG_RELOCATABLE=y */
1410 if (elf->hdr->e_type == ET_EXEC)
1411 r->r_addend += r->r_offset;
1417 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1419 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1423 /* From ARM ABI: (S + A) | T */
1424 r->r_addend = (int)(long)
1425 (elf->symtab_start + ELF_R_SYM(r->r_info));
1428 /* From ARM ABI: ((S + A) | T) - P */
1429 r->r_addend = (int)(long)(elf->hdr +
1431 (r->r_offset - sechdr->sh_addr));
1439 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1441 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1442 unsigned int *location = reloc_location(elf, sechdr, r);
1445 if (r_typ == R_MIPS_HI16)
1446 return 1; /* skip this */
1447 inst = TO_NATIVE(*location);
1450 r->r_addend = inst & 0xffff;
1453 r->r_addend = (inst & 0x03ffffff) << 2;
1462 static void section_rela(const char *modname, struct elf_info *elf,
1469 const char *fromsec;
1471 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1472 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1474 fromsec = sech_name(elf, sechdr);
1475 fromsec += strlen(".rela");
1476 /* if from section (name) is know good then skip it */
1477 if (match(fromsec, section_white_list))
1480 for (rela = start; rela < stop; rela++) {
1481 r.r_offset = TO_NATIVE(rela->r_offset);
1482 #if KERNEL_ELFCLASS == ELFCLASS64
1483 if (elf->hdr->e_machine == EM_MIPS) {
1485 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1486 r_sym = TO_NATIVE(r_sym);
1487 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1488 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1490 r.r_info = TO_NATIVE(rela->r_info);
1491 r_sym = ELF_R_SYM(r.r_info);
1494 r.r_info = TO_NATIVE(rela->r_info);
1495 r_sym = ELF_R_SYM(r.r_info);
1497 r.r_addend = TO_NATIVE(rela->r_addend);
1498 sym = elf->symtab_start + r_sym;
1499 /* Skip special sections */
1500 if (is_shndx_special(sym->st_shndx))
1502 check_section_mismatch(modname, elf, &r, sym, fromsec);
1506 static void section_rel(const char *modname, struct elf_info *elf,
1513 const char *fromsec;
1515 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1516 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1518 fromsec = sech_name(elf, sechdr);
1519 fromsec += strlen(".rel");
1520 /* if from section (name) is know good then skip it */
1521 if (match(fromsec, section_white_list))
1524 for (rel = start; rel < stop; rel++) {
1525 r.r_offset = TO_NATIVE(rel->r_offset);
1526 #if KERNEL_ELFCLASS == ELFCLASS64
1527 if (elf->hdr->e_machine == EM_MIPS) {
1529 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1530 r_sym = TO_NATIVE(r_sym);
1531 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1532 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1534 r.r_info = TO_NATIVE(rel->r_info);
1535 r_sym = ELF_R_SYM(r.r_info);
1538 r.r_info = TO_NATIVE(rel->r_info);
1539 r_sym = ELF_R_SYM(r.r_info);
1542 switch (elf->hdr->e_machine) {
1544 if (addend_386_rel(elf, sechdr, &r))
1548 if (addend_arm_rel(elf, sechdr, &r))
1552 if (addend_mips_rel(elf, sechdr, &r))
1556 sym = elf->symtab_start + r_sym;
1557 /* Skip special sections */
1558 if (is_shndx_special(sym->st_shndx))
1560 check_section_mismatch(modname, elf, &r, sym, fromsec);
1565 * A module includes a number of sections that are discarded
1566 * either when loaded or when used as built-in.
1567 * For loaded modules all functions marked __init and all data
1568 * marked __initdata will be discarded when the module has been intialized.
1569 * Likewise for modules used built-in the sections marked __exit
1570 * are discarded because __exit marked function are supposed to be called
1571 * only when a module is unloaded which never happens for built-in modules.
1572 * The check_sec_ref() function traverses all relocation records
1573 * to find all references to a section that reference a section that will
1574 * be discarded and warns about it.
1576 static void check_sec_ref(struct module *mod, const char *modname,
1577 struct elf_info *elf)
1580 Elf_Shdr *sechdrs = elf->sechdrs;
1582 /* Walk through all sections */
1583 for (i = 0; i < elf->num_sections; i++) {
1584 check_section(modname, elf, &elf->sechdrs[i]);
1585 /* We want to process only relocation sections and not .init */
1586 if (sechdrs[i].sh_type == SHT_RELA)
1587 section_rela(modname, elf, &elf->sechdrs[i]);
1588 else if (sechdrs[i].sh_type == SHT_REL)
1589 section_rel(modname, elf, &elf->sechdrs[i]);
1593 static void read_symbols(char *modname)
1595 const char *symname;
1599 struct elf_info info = { };
1602 if (!parse_elf(&info, modname))
1605 mod = new_module(modname);
1607 /* When there's no vmlinux, don't print warnings about
1608 * unresolved symbols (since there'll be too many ;) */
1609 if (is_vmlinux(modname)) {
1614 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1615 if (info.modinfo && !license && !is_vmlinux(modname))
1616 warn("modpost: missing MODULE_LICENSE() in %s\n"
1617 "see include/linux/module.h for "
1618 "more information\n", modname);
1620 if (license_is_gpl_compatible(license))
1621 mod->gpl_compatible = 1;
1623 mod->gpl_compatible = 0;
1626 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1627 "license", license);
1630 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1631 symname = info.strtab + sym->st_name;
1633 handle_modversions(mod, &info, sym, symname);
1634 handle_moddevtable(mod, &info, sym, symname);
1636 if (!is_vmlinux(modname) ||
1637 (is_vmlinux(modname) && vmlinux_section_warnings))
1638 check_sec_ref(mod, modname, &info);
1640 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1642 maybe_frob_rcs_version(modname, version, info.modinfo,
1643 version - (char *)info.hdr);
1644 if (version || (all_versions && !is_vmlinux(modname)))
1645 get_src_version(modname, mod->srcversion,
1646 sizeof(mod->srcversion)-1);
1648 parse_elf_finish(&info);
1650 /* Our trick to get versioning for module struct etc. - it's
1651 * never passed as an argument to an exported function, so
1652 * the automatic versioning doesn't pick it up, but it's really
1653 * important anyhow */
1655 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1660 /* We first write the generated file into memory using the
1661 * following helper, then compare to the file on disk and
1662 * only update the later if anything changed */
1664 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1665 const char *fmt, ...)
1672 len = vsnprintf(tmp, SZ, fmt, ap);
1673 buf_write(buf, tmp, len);
1677 void buf_write(struct buffer *buf, const char *s, int len)
1679 if (buf->size - buf->pos < len) {
1680 buf->size += len + SZ;
1681 buf->p = realloc(buf->p, buf->size);
1683 strncpy(buf->p + buf->pos, s, len);
1687 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1689 const char *e = is_vmlinux(m) ?"":".ko";
1693 fatal("modpost: GPL-incompatible module %s%s "
1694 "uses GPL-only symbol '%s'\n", m, e, s);
1696 case export_unused_gpl:
1697 fatal("modpost: GPL-incompatible module %s%s "
1698 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1700 case export_gpl_future:
1701 warn("modpost: GPL-incompatible module %s%s "
1702 "uses future GPL-only symbol '%s'\n", m, e, s);
1706 case export_unknown:
1712 static void check_for_unused(enum export exp, const char *m, const char *s)
1714 const char *e = is_vmlinux(m) ?"":".ko";
1718 case export_unused_gpl:
1719 warn("modpost: module %s%s "
1720 "uses symbol '%s' marked UNUSED\n", m, e, s);
1728 static void check_exports(struct module *mod)
1730 struct symbol *s, *exp;
1732 for (s = mod->unres; s; s = s->next) {
1733 const char *basename;
1734 exp = find_symbol(s->name);
1735 if (!exp || exp->module == mod)
1737 basename = strrchr(mod->name, '/');
1741 basename = mod->name;
1742 if (!mod->gpl_compatible)
1743 check_for_gpl_usage(exp->export, basename, exp->name);
1744 check_for_unused(exp->export, basename, exp->name);
1749 * Header for the generated file
1751 static void add_header(struct buffer *b, struct module *mod)
1753 buf_printf(b, "#include <linux/module.h>\n");
1754 buf_printf(b, "#include <linux/vermagic.h>\n");
1755 buf_printf(b, "#include <linux/compiler.h>\n");
1756 buf_printf(b, "\n");
1757 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1758 buf_printf(b, "\n");
1759 buf_printf(b, "struct module __this_module\n");
1760 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1761 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1763 buf_printf(b, " .init = init_module,\n");
1764 if (mod->has_cleanup)
1765 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1766 " .exit = cleanup_module,\n"
1768 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1769 buf_printf(b, "};\n");
1772 static void add_staging_flag(struct buffer *b, const char *name)
1774 static const char *staging_dir = "drivers/staging";
1776 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1777 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1781 * Record CRCs for unresolved symbols
1783 static int add_versions(struct buffer *b, struct module *mod)
1785 struct symbol *s, *exp;
1788 for (s = mod->unres; s; s = s->next) {
1789 exp = find_symbol(s->name);
1790 if (!exp || exp->module == mod) {
1791 if (have_vmlinux && !s->weak) {
1792 if (warn_unresolved) {
1793 warn("\"%s\" [%s.ko] undefined!\n",
1794 s->name, mod->name);
1796 merror("\"%s\" [%s.ko] undefined!\n",
1797 s->name, mod->name);
1803 s->module = exp->module;
1804 s->crc_valid = exp->crc_valid;
1811 buf_printf(b, "\n");
1812 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1813 buf_printf(b, "__used\n");
1814 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1816 for (s = mod->unres; s; s = s->next) {
1819 if (!s->crc_valid) {
1820 warn("\"%s\" [%s.ko] has no CRC!\n",
1821 s->name, mod->name);
1824 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1827 buf_printf(b, "};\n");
1832 static void add_depends(struct buffer *b, struct module *mod,
1833 struct module *modules)
1839 for (m = modules; m; m = m->next)
1840 m->seen = is_vmlinux(m->name);
1842 buf_printf(b, "\n");
1843 buf_printf(b, "static const char __module_depends[]\n");
1844 buf_printf(b, "__used\n");
1845 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1846 buf_printf(b, "\"depends=");
1847 for (s = mod->unres; s; s = s->next) {
1852 if (s->module->seen)
1855 s->module->seen = 1;
1856 p = strrchr(s->module->name, '/');
1860 p = s->module->name;
1861 buf_printf(b, "%s%s", first ? "" : ",", p);
1864 buf_printf(b, "\";\n");
1867 static void add_srcversion(struct buffer *b, struct module *mod)
1869 if (mod->srcversion[0]) {
1870 buf_printf(b, "\n");
1871 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1876 static void write_if_changed(struct buffer *b, const char *fname)
1882 file = fopen(fname, "r");
1886 if (fstat(fileno(file), &st) < 0)
1889 if (st.st_size != b->pos)
1892 tmp = NOFAIL(malloc(b->pos));
1893 if (fread(tmp, 1, b->pos, file) != b->pos)
1896 if (memcmp(tmp, b->p, b->pos) != 0)
1908 file = fopen(fname, "w");
1913 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1920 /* parse Module.symvers file. line format:
1921 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1923 static void read_dump(const char *fname, unsigned int kernel)
1925 unsigned long size, pos = 0;
1926 void *file = grab_file(fname, &size);
1930 /* No symbol versions, silently ignore */
1933 while ((line = get_next_line(&pos, file, size))) {
1934 char *symname, *modname, *d, *export, *end;
1939 if (!(symname = strchr(line, '\t')))
1942 if (!(modname = strchr(symname, '\t')))
1945 if ((export = strchr(modname, '\t')) != NULL)
1947 if (export && ((end = strchr(export, '\t')) != NULL))
1949 crc = strtoul(line, &d, 16);
1950 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1952 mod = find_module(modname);
1954 if (is_vmlinux(modname))
1956 mod = new_module(modname);
1959 s = sym_add_exported(symname, mod, export_no(export));
1962 sym_update_crc(symname, mod, crc, export_no(export));
1966 fatal("parse error in symbol dump file\n");
1969 /* For normal builds always dump all symbols.
1970 * For external modules only dump symbols
1971 * that are not read from kernel Module.symvers.
1973 static int dump_sym(struct symbol *sym)
1975 if (!external_module)
1977 if (sym->vmlinux || sym->kernel)
1982 static void write_dump(const char *fname)
1984 struct buffer buf = { };
1985 struct symbol *symbol;
1988 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1989 symbol = symbolhash[n];
1991 if (dump_sym(symbol))
1992 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1993 symbol->crc, symbol->name,
1994 symbol->module->name,
1995 export_str(symbol->export));
1996 symbol = symbol->next;
1999 write_if_changed(&buf, fname);
2002 struct ext_sym_list {
2003 struct ext_sym_list *next;
2007 int main(int argc, char **argv)
2010 struct buffer buf = { };
2011 char *kernel_read = NULL, *module_read = NULL;
2012 char *dump_write = NULL;
2015 struct ext_sym_list *extsym_iter;
2016 struct ext_sym_list *extsym_start = NULL;
2018 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2021 kernel_read = optarg;
2024 module_read = optarg;
2025 external_module = 1;
2031 external_module = 1;
2033 NOFAIL(malloc(sizeof(*extsym_iter)));
2034 extsym_iter->next = extsym_start;
2035 extsym_iter->file = optarg;
2036 extsym_start = extsym_iter;
2042 dump_write = optarg;
2048 vmlinux_section_warnings = 0;
2051 sec_mismatch_verbose = 0;
2054 warn_unresolved = 1;
2062 read_dump(kernel_read, 1);
2064 read_dump(module_read, 0);
2065 while (extsym_start) {
2066 read_dump(extsym_start->file, 0);
2067 extsym_iter = extsym_start->next;
2069 extsym_start = extsym_iter;
2072 while (optind < argc)
2073 read_symbols(argv[optind++]);
2075 for (mod = modules; mod; mod = mod->next) {
2083 for (mod = modules; mod; mod = mod->next) {
2084 char fname[strlen(mod->name) + 10];
2091 add_header(&buf, mod);
2092 add_staging_flag(&buf, mod->name);
2093 err |= add_versions(&buf, mod);
2094 add_depends(&buf, mod, modules);
2095 add_moddevtable(&buf, mod);
2096 add_srcversion(&buf, mod);
2098 sprintf(fname, "%s.mod.c", mod->name);
2099 write_if_changed(&buf, fname);
2103 write_dump(dump_write);
2104 if (sec_mismatch_count && !sec_mismatch_verbose)
2105 warn("modpost: Found %d section mismatch(es).\n"
2106 "To see full details build your kernel with:\n"
2107 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2108 sec_mismatch_count);