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 ...
19 #include "../../include/generated/autoconf.h"
20 #include "../../include/linux/license.h"
22 /* Some toolchains use a `_' prefix for all user symbols. */
23 #ifdef CONFIG_SYMBOL_PREFIX
24 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
26 #define MODULE_SYMBOL_PREFIX ""
30 /* Are we using CONFIG_MODVERSIONS? */
32 /* Warn about undefined symbols? (do so if we have vmlinux) */
34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35 static int all_versions = 0;
36 /* If we are modposting external module set to 1 */
37 static int external_module = 0;
38 /* Warn about section mismatch in vmlinux if set to 1 */
39 static int vmlinux_section_warnings = 1;
40 /* Only warn about unresolved symbols */
41 static int warn_unresolved = 0;
42 /* How a symbol is exported */
43 static int sec_mismatch_count = 0;
44 static int sec_mismatch_verbose = 1;
47 export_plain, export_unused, export_gpl,
48 export_unused_gpl, export_gpl_future, export_unknown
51 #define PRINTF __attribute__ ((format (printf, 1, 2)))
53 PRINTF void fatal(const char *fmt, ...)
57 fprintf(stderr, "FATAL: ");
59 va_start(arglist, fmt);
60 vfprintf(stderr, fmt, arglist);
66 PRINTF void warn(const char *fmt, ...)
70 fprintf(stderr, "WARNING: ");
72 va_start(arglist, fmt);
73 vfprintf(stderr, fmt, arglist);
77 PRINTF void merror(const char *fmt, ...)
81 fprintf(stderr, "ERROR: ");
83 va_start(arglist, fmt);
84 vfprintf(stderr, fmt, arglist);
88 static int is_vmlinux(const char *modname)
92 myname = strrchr(modname, '/');
98 return (strcmp(myname, "vmlinux") == 0) ||
99 (strcmp(myname, "vmlinux.o") == 0);
102 void *do_nofail(void *ptr, const char *expr)
105 fatal("modpost: Memory allocation failure: %s.\n", expr);
110 /* A list of all modules we processed */
111 static struct module *modules;
113 static struct module *find_module(char *modname)
117 for (mod = modules; mod; mod = mod->next)
118 if (strcmp(mod->name, modname) == 0)
123 static struct module *new_module(char *modname)
128 mod = NOFAIL(malloc(sizeof(*mod)));
129 memset(mod, 0, sizeof(*mod));
130 p = NOFAIL(strdup(modname));
132 /* strip trailing .o */
135 if (strcmp(s, ".o") == 0) {
142 mod->gpl_compatible = -1;
149 /* A hash of all exported symbols,
150 * struct symbol is also used for lists of unresolved symbols */
152 #define SYMBOL_HASH_SIZE 1024
156 struct module *module;
160 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
161 unsigned int kernel:1; /* 1 if symbol is from kernel
162 * (only for external modules) **/
163 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
164 enum export export; /* Type of export */
168 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
170 /* This is based on the hash agorithm from gdbm, via tdb */
171 static inline unsigned int tdb_hash(const char *name)
173 unsigned value; /* Used to compute the hash value. */
174 unsigned i; /* Used to cycle through random values. */
176 /* Set the initial value from the key size. */
177 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
178 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
180 return (1103515243 * value + 12345);
184 * Allocate a new symbols for use in the hash of exported symbols or
185 * the list of unresolved symbols per module
187 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
190 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
192 memset(s, 0, sizeof(*s));
193 strcpy(s->name, name);
199 /* For the hash of exported symbols */
200 static struct symbol *new_symbol(const char *name, struct module *module,
206 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
207 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
208 new->module = module;
209 new->export = export;
213 static struct symbol *find_symbol(const char *name)
217 /* For our purposes, .foo matches foo. PPC64 needs this. */
221 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
222 if (strcmp(s->name, name) == 0)
232 { .str = "EXPORT_SYMBOL", .export = export_plain },
233 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
234 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
235 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
236 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
237 { .str = "(unknown)", .export = export_unknown },
241 static const char *export_str(enum export ex)
243 return export_list[ex].str;
246 static enum export export_no(const char *s)
251 return export_unknown;
252 for (i = 0; export_list[i].export != export_unknown; i++) {
253 if (strcmp(export_list[i].str, s) == 0)
254 return export_list[i].export;
256 return export_unknown;
259 static const char *sec_name(struct elf_info *elf, int secindex);
261 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
263 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
265 const char *secname = sec_name(elf, sec);
267 if (strstarts(secname, "___ksymtab+"))
269 else if (strstarts(secname, "___ksymtab_unused+"))
270 return export_unused;
271 else if (strstarts(secname, "___ksymtab_gpl+"))
273 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
274 return export_unused_gpl;
275 else if (strstarts(secname, "___ksymtab_gpl_future+"))
276 return export_gpl_future;
278 return export_unknown;
281 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
283 if (sec == elf->export_sec)
285 else if (sec == elf->export_unused_sec)
286 return export_unused;
287 else if (sec == elf->export_gpl_sec)
289 else if (sec == elf->export_unused_gpl_sec)
290 return export_unused_gpl;
291 else if (sec == elf->export_gpl_future_sec)
292 return export_gpl_future;
294 return export_unknown;
298 * Add an exported symbol - it may have already been added without a
299 * CRC, in this case just update the CRC
301 static struct symbol *sym_add_exported(const char *name, struct module *mod,
304 struct symbol *s = find_symbol(name);
307 s = new_symbol(name, mod, export);
310 warn("%s: '%s' exported twice. Previous export "
311 "was in %s%s\n", mod->name, name,
313 is_vmlinux(s->module->name) ?"":".ko");
315 /* In case Modules.symvers was out of date */
320 s->vmlinux = is_vmlinux(mod->name);
326 static void sym_update_crc(const char *name, struct module *mod,
327 unsigned int crc, enum export export)
329 struct symbol *s = find_symbol(name);
332 s = new_symbol(name, mod, export);
337 void *grab_file(const char *filename, unsigned long *size)
340 void *map = MAP_FAILED;
343 fd = open(filename, O_RDONLY);
350 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
354 if (map == MAP_FAILED)
360 * Return a copy of the next line in a mmap'ed file.
361 * spaces in the beginning of the line is trimmed away.
362 * Return a pointer to a static buffer.
364 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
366 static char line[4096];
369 signed char *p = (signed char *)file + *pos;
372 for (; *pos < size ; (*pos)++) {
373 if (skip && isspace(*p)) {
378 if (*p != '\n' && (*pos < size)) {
382 break; /* Too long, stop */
393 void release_file(void *file, unsigned long size)
398 static int parse_elf(struct elf_info *info, const char *filename)
404 const char *secstrings;
405 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
407 hdr = grab_file(filename, &info->size);
413 if (info->size < sizeof(*hdr)) {
414 /* file too small, assume this is an empty .o file */
417 /* Is this a valid ELF file? */
418 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
419 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
420 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
421 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
422 /* Not an ELF file - silently ignore it */
425 /* Fix endianness in ELF header */
426 hdr->e_type = TO_NATIVE(hdr->e_type);
427 hdr->e_machine = TO_NATIVE(hdr->e_machine);
428 hdr->e_version = TO_NATIVE(hdr->e_version);
429 hdr->e_entry = TO_NATIVE(hdr->e_entry);
430 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
431 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
432 hdr->e_flags = TO_NATIVE(hdr->e_flags);
433 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
434 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
435 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
436 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
437 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
438 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
439 sechdrs = (void *)hdr + hdr->e_shoff;
440 info->sechdrs = sechdrs;
442 /* Check if file offset is correct */
443 if (hdr->e_shoff > info->size) {
444 fatal("section header offset=%lu in file '%s' is bigger than "
445 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
446 filename, info->size);
450 if (hdr->e_shnum == SHN_UNDEF) {
452 * There are more than 64k sections,
453 * read count from .sh_size.
455 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
458 info->num_sections = hdr->e_shnum;
460 if (hdr->e_shstrndx == SHN_XINDEX) {
461 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
464 info->secindex_strings = hdr->e_shstrndx;
467 /* Fix endianness in section headers */
468 for (i = 0; i < info->num_sections; i++) {
469 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
470 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
471 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
472 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
473 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
474 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
475 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
476 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
477 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
478 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
480 /* Find symbol table. */
481 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
482 for (i = 1; i < info->num_sections; i++) {
484 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
486 if (!nobits && sechdrs[i].sh_offset > info->size) {
487 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
488 "sizeof(*hrd)=%zu\n", filename,
489 (unsigned long)sechdrs[i].sh_offset,
493 secname = secstrings + sechdrs[i].sh_name;
494 if (strcmp(secname, ".modinfo") == 0) {
496 fatal("%s has NOBITS .modinfo\n", filename);
497 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
498 info->modinfo_len = sechdrs[i].sh_size;
499 } else if (strcmp(secname, "__ksymtab") == 0)
500 info->export_sec = i;
501 else if (strcmp(secname, "__ksymtab_unused") == 0)
502 info->export_unused_sec = i;
503 else if (strcmp(secname, "__ksymtab_gpl") == 0)
504 info->export_gpl_sec = i;
505 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
506 info->export_unused_gpl_sec = i;
507 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
508 info->export_gpl_future_sec = i;
510 if (sechdrs[i].sh_type == SHT_SYMTAB) {
511 unsigned int sh_link_idx;
513 info->symtab_start = (void *)hdr +
514 sechdrs[i].sh_offset;
515 info->symtab_stop = (void *)hdr +
516 sechdrs[i].sh_offset + sechdrs[i].sh_size;
517 sh_link_idx = sechdrs[i].sh_link;
518 info->strtab = (void *)hdr +
519 sechdrs[sh_link_idx].sh_offset;
522 /* 32bit section no. table? ("more than 64k sections") */
523 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
524 symtab_shndx_idx = i;
525 info->symtab_shndx_start = (void *)hdr +
526 sechdrs[i].sh_offset;
527 info->symtab_shndx_stop = (void *)hdr +
528 sechdrs[i].sh_offset + sechdrs[i].sh_size;
531 if (!info->symtab_start)
532 fatal("%s has no symtab?\n", filename);
534 /* Fix endianness in symbols */
535 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
536 sym->st_shndx = TO_NATIVE(sym->st_shndx);
537 sym->st_name = TO_NATIVE(sym->st_name);
538 sym->st_value = TO_NATIVE(sym->st_value);
539 sym->st_size = TO_NATIVE(sym->st_size);
542 if (symtab_shndx_idx != ~0U) {
544 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
545 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
546 filename, sechdrs[symtab_shndx_idx].sh_link,
549 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
557 static void parse_elf_finish(struct elf_info *info)
559 release_file(info->hdr, info->size);
562 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
564 /* ignore __this_module, it will be resolved shortly */
565 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
567 /* ignore global offset table */
568 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
570 if (info->hdr->e_machine == EM_PPC)
571 /* Special register function linked on all modules during final link of .ko */
572 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
573 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
574 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
575 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
577 if (info->hdr->e_machine == EM_PPC64)
578 /* Special register function linked on all modules during final link of .ko */
579 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
580 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
582 /* Do not ignore this symbol */
586 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
587 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
589 static void handle_modversions(struct module *mod, struct elf_info *info,
590 Elf_Sym *sym, const char *symname)
595 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
596 strncmp(symname, "__ksymtab", 9) == 0)
597 export = export_from_secname(info, get_secindex(info, sym));
599 export = export_from_sec(info, get_secindex(info, sym));
601 switch (sym->st_shndx) {
603 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
607 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
608 crc = (unsigned int) sym->st_value;
609 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
614 /* undefined symbol */
615 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
616 ELF_ST_BIND(sym->st_info) != STB_WEAK)
618 if (ignore_undef_symbol(info, symname))
620 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
621 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
622 /* add compatibility with older glibc */
623 #ifndef STT_SPARC_REGISTER
624 #define STT_SPARC_REGISTER STT_REGISTER
626 if (info->hdr->e_machine == EM_SPARC ||
627 info->hdr->e_machine == EM_SPARCV9) {
628 /* Ignore register directives. */
629 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
631 if (symname[0] == '.') {
632 char *munged = strdup(symname);
634 munged[1] = toupper(munged[1]);
640 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
641 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
643 alloc_symbol(symname +
644 strlen(MODULE_SYMBOL_PREFIX),
645 ELF_ST_BIND(sym->st_info) == STB_WEAK,
650 /* All exported symbols */
651 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
652 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
655 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
657 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
658 mod->has_cleanup = 1;
664 * Parse tag=value strings from .modinfo section
666 static char *next_string(char *string, unsigned long *secsize)
668 /* Skip non-zero chars */
671 if ((*secsize)-- <= 1)
675 /* Skip any zero padding. */
678 if ((*secsize)-- <= 1)
684 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
685 const char *tag, char *info)
688 unsigned int taglen = strlen(tag);
689 unsigned long size = modinfo_len;
692 size -= info - (char *)modinfo;
693 modinfo = next_string(info, &size);
696 for (p = modinfo; p; p = next_string(p, &size)) {
697 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
698 return p + taglen + 1;
703 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
707 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
711 * Test if string s ends in string sub
714 static int strrcmp(const char *s, const char *sub)
722 sublen = strlen(sub);
724 if ((slen == 0) || (sublen == 0))
730 return memcmp(s + slen - sublen, sub, sublen);
733 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
736 return elf->strtab + sym->st_name;
741 static const char *sec_name(struct elf_info *elf, int secindex)
743 Elf_Shdr *sechdrs = elf->sechdrs;
744 return (void *)elf->hdr +
745 elf->sechdrs[elf->secindex_strings].sh_offset +
746 sechdrs[secindex].sh_name;
749 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
751 return (void *)elf->hdr +
752 elf->sechdrs[elf->secindex_strings].sh_offset +
756 /* if sym is empty or point to a string
757 * like ".[0-9]+" then return 1.
758 * This is the optional prefix added by ld to some sections
760 static int number_prefix(const char *sym)
768 if (c < '0' || c > '9')
774 /* The pattern is an array of simple patterns.
775 * "foo" will match an exact string equal to "foo"
776 * "*foo" will match a string that ends with "foo"
777 * "foo*" will match a string that begins with "foo"
778 * "foo$" will match a string equal to "foo" or "foo.1"
779 * where the '1' can be any number including several digits.
780 * The $ syntax is for sections where ld append a dot number
781 * to make section name unique.
783 static int match(const char *sym, const char * const pat[])
788 const char *endp = p + strlen(p) - 1;
792 if (strrcmp(sym, p + 1) == 0)
796 else if (*endp == '*') {
797 if (strncmp(sym, p, strlen(p) - 1) == 0)
801 else if (*endp == '$') {
802 if (strncmp(sym, p, strlen(p) - 1) == 0) {
803 if (number_prefix(sym + strlen(p) - 1))
809 if (strcmp(p, sym) == 0)
817 /* sections that we do not want to do full section mismatch check on */
818 static const char *section_white_list[] =
822 ".zdebug*", /* Compressed debug sections. */
823 ".GCC-command-line", /* mn10300 */
824 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
825 ".mdebug*", /* alpha, score, mips etc. */
826 ".pdr", /* alpha, score, mips etc. */
831 ".xt.prop", /* xtensa */
832 ".xt.lit", /* xtensa */
837 * This is used to find sections missing the SHF_ALLOC flag.
838 * The cause of this is often a section specified in assembler
839 * without "ax" / "aw".
841 static void check_section(const char *modname, struct elf_info *elf,
844 const char *sec = sech_name(elf, sechdr);
846 if (sechdr->sh_type == SHT_PROGBITS &&
847 !(sechdr->sh_flags & SHF_ALLOC) &&
848 !match(sec, section_white_list)) {
849 warn("%s (%s): unexpected non-allocatable section.\n"
850 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
851 "Note that for example <linux/init.h> contains\n"
852 "section definitions for use in .S files.\n\n",
859 #define ALL_INIT_DATA_SECTIONS \
860 ".init.setup$", ".init.rodata$", \
861 ".cpuinit.rodata$", ".meminit.rodata$", \
862 ".init.data$", ".cpuinit.data$", ".meminit.data$"
863 #define ALL_EXIT_DATA_SECTIONS \
864 ".exit.data$", ".cpuexit.data$", ".memexit.data$"
866 #define ALL_INIT_TEXT_SECTIONS \
867 ".init.text$", ".cpuinit.text$", ".meminit.text$"
868 #define ALL_EXIT_TEXT_SECTIONS \
869 ".exit.text$", ".cpuexit.text$", ".memexit.text$"
871 #define ALL_PCI_INIT_SECTIONS \
872 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
873 ".pci_fixup_enable$", ".pci_fixup_resume$", \
874 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
876 #define ALL_XXXINIT_SECTIONS CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
877 #define ALL_XXXEXIT_SECTIONS CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS
879 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
880 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
882 #define DATA_SECTIONS ".data$", ".data.rel$"
883 #define TEXT_SECTIONS ".text$"
885 #define INIT_SECTIONS ".init.*"
886 #define CPU_INIT_SECTIONS ".cpuinit.*"
887 #define MEM_INIT_SECTIONS ".meminit.*"
889 #define EXIT_SECTIONS ".exit.*"
890 #define CPU_EXIT_SECTIONS ".cpuexit.*"
891 #define MEM_EXIT_SECTIONS ".memexit.*"
893 /* init data sections */
894 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
896 /* all init sections */
897 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
899 /* All init and exit sections (code + data) */
900 static const char *init_exit_sections[] =
901 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
904 static const char *data_sections[] = { DATA_SECTIONS, NULL };
907 /* symbols in .data that may refer to init/exit sections */
908 #define DEFAULT_SYMBOL_WHITE_LIST \
910 "*_template", /* scsi uses *_template a lot */ \
911 "*_timer", /* arm uses ops structures named _timer a lot */ \
912 "*_sht", /* scsi also used *_sht to some extent */ \
918 static const char *head_sections[] = { ".head.text*", NULL };
919 static const char *linker_symbols[] =
920 { "__init_begin", "_sinittext", "_einittext", NULL };
927 XXXINIT_TO_SOME_INIT,
928 XXXEXIT_TO_SOME_EXIT,
929 ANY_INIT_TO_ANY_EXIT,
930 ANY_EXIT_TO_ANY_INIT,
934 struct sectioncheck {
935 const char *fromsec[20];
936 const char *tosec[20];
937 enum mismatch mismatch;
938 const char *symbol_white_list[20];
941 const struct sectioncheck sectioncheck[] = {
942 /* Do not reference init/exit code/data from
943 * normal code and data
946 .fromsec = { TEXT_SECTIONS, NULL },
947 .tosec = { ALL_INIT_SECTIONS, NULL },
948 .mismatch = TEXT_TO_ANY_INIT,
949 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
952 .fromsec = { DATA_SECTIONS, NULL },
953 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
954 .mismatch = DATA_TO_ANY_INIT,
955 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
958 .fromsec = { DATA_SECTIONS, NULL },
959 .tosec = { INIT_SECTIONS, NULL },
960 .mismatch = DATA_TO_ANY_INIT,
961 .symbol_white_list = {
962 "*_template", "*_timer", "*_sht", "*_ops",
963 "*_probe", "*_probe_one", "*_console", NULL
967 .fromsec = { TEXT_SECTIONS, NULL },
968 .tosec = { ALL_EXIT_SECTIONS, NULL },
969 .mismatch = TEXT_TO_ANY_EXIT,
970 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
973 .fromsec = { DATA_SECTIONS, NULL },
974 .tosec = { ALL_EXIT_SECTIONS, NULL },
975 .mismatch = DATA_TO_ANY_EXIT,
976 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
978 /* Do not reference init code/data from cpuinit/meminit code/data */
980 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
981 .tosec = { INIT_SECTIONS, NULL },
982 .mismatch = XXXINIT_TO_SOME_INIT,
983 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
985 /* Do not reference cpuinit code/data from meminit code/data */
987 .fromsec = { MEM_INIT_SECTIONS, NULL },
988 .tosec = { CPU_INIT_SECTIONS, NULL },
989 .mismatch = XXXINIT_TO_SOME_INIT,
990 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
992 /* Do not reference meminit code/data from cpuinit code/data */
994 .fromsec = { CPU_INIT_SECTIONS, NULL },
995 .tosec = { MEM_INIT_SECTIONS, NULL },
996 .mismatch = XXXINIT_TO_SOME_INIT,
997 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
999 /* Do not reference exit code/data from cpuexit/memexit code/data */
1001 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1002 .tosec = { EXIT_SECTIONS, NULL },
1003 .mismatch = XXXEXIT_TO_SOME_EXIT,
1004 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1006 /* Do not reference cpuexit code/data from memexit code/data */
1008 .fromsec = { MEM_EXIT_SECTIONS, NULL },
1009 .tosec = { CPU_EXIT_SECTIONS, NULL },
1010 .mismatch = XXXEXIT_TO_SOME_EXIT,
1011 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1013 /* Do not reference memexit code/data from cpuexit code/data */
1015 .fromsec = { CPU_EXIT_SECTIONS, NULL },
1016 .tosec = { MEM_EXIT_SECTIONS, NULL },
1017 .mismatch = XXXEXIT_TO_SOME_EXIT,
1018 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1020 /* Do not use exit code/data from init code */
1022 .fromsec = { ALL_INIT_SECTIONS, NULL },
1023 .tosec = { ALL_EXIT_SECTIONS, NULL },
1024 .mismatch = ANY_INIT_TO_ANY_EXIT,
1025 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1027 /* Do not use init code/data from exit code */
1029 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1030 .tosec = { ALL_INIT_SECTIONS, NULL },
1031 .mismatch = ANY_EXIT_TO_ANY_INIT,
1032 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1035 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1036 .tosec = { INIT_SECTIONS, NULL },
1037 .mismatch = ANY_INIT_TO_ANY_EXIT,
1038 .symbol_white_list = { NULL },
1040 /* Do not export init/exit functions or data */
1042 .fromsec = { "__ksymtab*", NULL },
1043 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1044 .mismatch = EXPORT_TO_INIT_EXIT,
1045 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1049 static const struct sectioncheck *section_mismatch(
1050 const char *fromsec, const char *tosec)
1053 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1054 const struct sectioncheck *check = §ioncheck[0];
1056 for (i = 0; i < elems; i++) {
1057 if (match(fromsec, check->fromsec) &&
1058 match(tosec, check->tosec))
1066 * Whitelist to allow certain references to pass with no warning.
1069 * If a module parameter is declared __initdata and permissions=0
1070 * then this is legal despite the warning generated.
1071 * We cannot see value of permissions here, so just ignore
1073 * The pattern is identified by:
1074 * tosec = .init.data
1079 * module_param_call() ops can refer to __init set function if permissions=0
1080 * The pattern is identified by:
1081 * tosec = .init.text
1083 * atsym = __param_ops_*
1086 * Many drivers utilise a *driver container with references to
1087 * add, remove, probe functions etc.
1088 * These functions may often be marked __cpuinit and we do not want to
1090 * the pattern is identified by:
1091 * tosec = init or exit section
1092 * fromsec = data section
1093 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1094 * *probe_one, *_console, *_timer
1097 * Whitelist all references from .head.text to any init section
1100 * Some symbols belong to init section but still it is ok to reference
1101 * these from non-init sections as these symbols don't have any memory
1102 * allocated for them and symbol address and value are same. So even
1103 * if init section is freed, its ok to reference those symbols.
1104 * For ex. symbols marking the init section boundaries.
1105 * This pattern is identified by
1106 * refsymname = __init_begin, _sinittext, _einittext
1109 static int secref_whitelist(const struct sectioncheck *mismatch,
1110 const char *fromsec, const char *fromsym,
1111 const char *tosec, const char *tosym)
1113 /* Check for pattern 1 */
1114 if (match(tosec, init_data_sections) &&
1115 match(fromsec, data_sections) &&
1116 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1119 /* Check for pattern 1a */
1120 if (strcmp(tosec, ".init.text") == 0 &&
1121 match(fromsec, data_sections) &&
1122 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1125 /* Check for pattern 2 */
1126 if (match(tosec, init_exit_sections) &&
1127 match(fromsec, data_sections) &&
1128 match(fromsym, mismatch->symbol_white_list))
1131 /* Check for pattern 3 */
1132 if (match(fromsec, head_sections) &&
1133 match(tosec, init_sections))
1136 /* Check for pattern 4 */
1137 if (match(tosym, linker_symbols))
1144 * Find symbol based on relocation record info.
1145 * In some cases the symbol supplied is a valid symbol so
1146 * return refsym. If st_name != 0 we assume this is a valid symbol.
1147 * In other cases the symbol needs to be looked up in the symbol table
1148 * based on section and address.
1150 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1154 Elf_Sym *near = NULL;
1155 Elf64_Sword distance = 20;
1157 unsigned int relsym_secindex;
1159 if (relsym->st_name != 0)
1162 relsym_secindex = get_secindex(elf, relsym);
1163 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1164 if (get_secindex(elf, sym) != relsym_secindex)
1166 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1168 if (sym->st_value == addr)
1170 /* Find a symbol nearby - addr are maybe negative */
1171 d = sym->st_value - addr;
1173 d = addr - sym->st_value;
1179 /* We need a close match */
1186 static inline int is_arm_mapping_symbol(const char *str)
1188 return str[0] == '$' && strchr("atd", str[1])
1189 && (str[2] == '\0' || str[2] == '.');
1193 * If there's no name there, ignore it; likewise, ignore it if it's
1194 * one of the magic symbols emitted used by current ARM tools.
1196 * Otherwise if find_symbols_between() returns those symbols, they'll
1197 * fail the whitelist tests and cause lots of false alarms ... fixable
1198 * only by merging __exit and __init sections into __text, bloating
1199 * the kernel (which is especially evil on embedded platforms).
1201 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1203 const char *name = elf->strtab + sym->st_name;
1205 if (!name || !strlen(name))
1207 return !is_arm_mapping_symbol(name);
1211 * Find symbols before or equal addr and after addr - in the section sec.
1212 * If we find two symbols with equal offset prefer one with a valid name.
1213 * The ELF format may have a better way to detect what type of symbol
1214 * it is, but this works for now.
1216 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1220 Elf_Sym *near = NULL;
1221 Elf_Addr distance = ~0;
1223 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1226 if (is_shndx_special(sym->st_shndx))
1228 symsec = sec_name(elf, get_secindex(elf, sym));
1229 if (strcmp(symsec, sec) != 0)
1231 if (!is_valid_name(elf, sym))
1233 if (sym->st_value <= addr) {
1234 if ((addr - sym->st_value) < distance) {
1235 distance = addr - sym->st_value;
1237 } else if ((addr - sym->st_value) == distance) {
1246 * Convert a section name to the function/data attribute
1247 * .init.text => __init
1248 * .cpuinit.data => __cpudata
1249 * .memexitconst => __memconst
1252 * The memory of returned value has been allocated on a heap. The user of this
1253 * method should free it after usage.
1255 static char *sec2annotation(const char *s)
1257 if (match(s, init_exit_sections)) {
1258 char *p = malloc(20);
1265 while (*s && *s != '.')
1270 if (strstr(s, "rodata") != NULL)
1271 strcat(p, "const ");
1272 else if (strstr(s, "data") != NULL)
1282 static int is_function(Elf_Sym *sym)
1285 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1290 static void print_section_list(const char * const list[20])
1292 const char *const *s = list;
1295 fprintf(stderr, "%s", *s);
1298 fprintf(stderr, ", ");
1300 fprintf(stderr, "\n");
1304 * Print a warning about a section mismatch.
1305 * Try to find symbols near it so user can find it.
1306 * Check whitelist before warning - it may be a false positive.
1308 static void report_sec_mismatch(const char *modname,
1309 const struct sectioncheck *mismatch,
1310 const char *fromsec,
1311 unsigned long long fromaddr,
1312 const char *fromsym,
1314 const char *tosec, const char *tosym,
1317 const char *from, *from_p;
1318 const char *to, *to_p;
1322 switch (from_is_func) {
1323 case 0: from = "variable"; from_p = ""; break;
1324 case 1: from = "function"; from_p = "()"; break;
1325 default: from = "(unknown reference)"; from_p = ""; break;
1327 switch (to_is_func) {
1328 case 0: to = "variable"; to_p = ""; break;
1329 case 1: to = "function"; to_p = "()"; break;
1330 default: to = "(unknown reference)"; to_p = ""; break;
1333 sec_mismatch_count++;
1334 if (!sec_mismatch_verbose)
1337 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1338 "to the %s %s:%s%s\n",
1339 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1342 switch (mismatch->mismatch) {
1343 case TEXT_TO_ANY_INIT:
1344 prl_from = sec2annotation(fromsec);
1345 prl_to = sec2annotation(tosec);
1347 "The function %s%s() references\n"
1349 "This is often because %s lacks a %s\n"
1350 "annotation or the annotation of %s is wrong.\n",
1352 to, prl_to, tosym, to_p,
1353 fromsym, prl_to, tosym);
1357 case DATA_TO_ANY_INIT: {
1358 prl_to = sec2annotation(tosec);
1360 "The variable %s references\n"
1362 "If the reference is valid then annotate the\n"
1363 "variable with __init* or __refdata (see linux/init.h) "
1364 "or name the variable:\n",
1365 fromsym, to, prl_to, tosym, to_p);
1366 print_section_list(mismatch->symbol_white_list);
1370 case TEXT_TO_ANY_EXIT:
1371 prl_to = sec2annotation(tosec);
1373 "The function %s() references a %s in an exit section.\n"
1374 "Often the %s %s%s has valid usage outside the exit section\n"
1375 "and the fix is to remove the %sannotation of %s.\n",
1376 fromsym, to, to, tosym, to_p, prl_to, tosym);
1379 case DATA_TO_ANY_EXIT: {
1380 prl_to = sec2annotation(tosec);
1382 "The variable %s references\n"
1384 "If the reference is valid then annotate the\n"
1385 "variable with __exit* (see linux/init.h) or "
1386 "name the variable:\n",
1387 fromsym, to, prl_to, tosym, to_p);
1388 print_section_list(mismatch->symbol_white_list);
1392 case XXXINIT_TO_SOME_INIT:
1393 case XXXEXIT_TO_SOME_EXIT:
1394 prl_from = sec2annotation(fromsec);
1395 prl_to = sec2annotation(tosec);
1397 "The %s %s%s%s references\n"
1399 "If %s is only used by %s then\n"
1400 "annotate %s with a matching annotation.\n",
1401 from, prl_from, fromsym, from_p,
1402 to, prl_to, tosym, to_p,
1403 tosym, fromsym, tosym);
1407 case ANY_INIT_TO_ANY_EXIT:
1408 prl_from = sec2annotation(fromsec);
1409 prl_to = sec2annotation(tosec);
1411 "The %s %s%s%s references\n"
1413 "This is often seen when error handling "
1414 "in the init function\n"
1415 "uses functionality in the exit path.\n"
1416 "The fix is often to remove the %sannotation of\n"
1417 "%s%s so it may be used outside an exit section.\n",
1418 from, prl_from, fromsym, from_p,
1419 to, prl_to, tosym, to_p,
1420 prl_to, tosym, to_p);
1424 case ANY_EXIT_TO_ANY_INIT:
1425 prl_from = sec2annotation(fromsec);
1426 prl_to = sec2annotation(tosec);
1428 "The %s %s%s%s references\n"
1430 "This is often seen when error handling "
1431 "in the exit function\n"
1432 "uses functionality in the init path.\n"
1433 "The fix is often to remove the %sannotation of\n"
1434 "%s%s so it may be used outside an init section.\n",
1435 from, prl_from, fromsym, from_p,
1436 to, prl_to, tosym, to_p,
1437 prl_to, tosym, to_p);
1441 case EXPORT_TO_INIT_EXIT:
1442 prl_to = sec2annotation(tosec);
1444 "The symbol %s is exported and annotated %s\n"
1445 "Fix this by removing the %sannotation of %s "
1446 "or drop the export.\n",
1447 tosym, prl_to, prl_to, tosym);
1451 fprintf(stderr, "\n");
1454 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1455 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1458 const struct sectioncheck *mismatch;
1460 tosec = sec_name(elf, get_secindex(elf, sym));
1461 mismatch = section_mismatch(fromsec, tosec);
1466 const char *fromsym;
1468 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1469 fromsym = sym_name(elf, from);
1470 to = find_elf_symbol(elf, r->r_addend, sym);
1471 tosym = sym_name(elf, to);
1473 /* check whitelist - we may ignore it */
1474 if (secref_whitelist(mismatch,
1475 fromsec, fromsym, tosec, tosym)) {
1476 report_sec_mismatch(modname, mismatch,
1477 fromsec, r->r_offset, fromsym,
1478 is_function(from), tosec, tosym,
1484 static unsigned int *reloc_location(struct elf_info *elf,
1485 Elf_Shdr *sechdr, Elf_Rela *r)
1487 Elf_Shdr *sechdrs = elf->sechdrs;
1488 int section = sechdr->sh_info;
1490 return (void *)elf->hdr + sechdrs[section].sh_offset +
1494 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1496 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1497 unsigned int *location = reloc_location(elf, sechdr, r);
1501 r->r_addend = TO_NATIVE(*location);
1504 r->r_addend = TO_NATIVE(*location) + 4;
1505 /* For CONFIG_RELOCATABLE=y */
1506 if (elf->hdr->e_type == ET_EXEC)
1507 r->r_addend += r->r_offset;
1514 #define R_ARM_CALL 28
1516 #ifndef R_ARM_JUMP24
1517 #define R_ARM_JUMP24 29
1520 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1522 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1526 /* From ARM ABI: (S + A) | T */
1527 r->r_addend = (int)(long)
1528 (elf->symtab_start + ELF_R_SYM(r->r_info));
1533 /* From ARM ABI: ((S + A) | T) - P */
1534 r->r_addend = (int)(long)(elf->hdr +
1536 (r->r_offset - sechdr->sh_addr));
1544 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1546 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1547 unsigned int *location = reloc_location(elf, sechdr, r);
1550 if (r_typ == R_MIPS_HI16)
1551 return 1; /* skip this */
1552 inst = TO_NATIVE(*location);
1555 r->r_addend = inst & 0xffff;
1558 r->r_addend = (inst & 0x03ffffff) << 2;
1567 static void section_rela(const char *modname, struct elf_info *elf,
1574 const char *fromsec;
1576 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1577 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1579 fromsec = sech_name(elf, sechdr);
1580 fromsec += strlen(".rela");
1581 /* if from section (name) is know good then skip it */
1582 if (match(fromsec, section_white_list))
1585 for (rela = start; rela < stop; rela++) {
1586 r.r_offset = TO_NATIVE(rela->r_offset);
1587 #if KERNEL_ELFCLASS == ELFCLASS64
1588 if (elf->hdr->e_machine == EM_MIPS) {
1590 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1591 r_sym = TO_NATIVE(r_sym);
1592 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1593 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1595 r.r_info = TO_NATIVE(rela->r_info);
1596 r_sym = ELF_R_SYM(r.r_info);
1599 r.r_info = TO_NATIVE(rela->r_info);
1600 r_sym = ELF_R_SYM(r.r_info);
1602 r.r_addend = TO_NATIVE(rela->r_addend);
1603 sym = elf->symtab_start + r_sym;
1604 /* Skip special sections */
1605 if (is_shndx_special(sym->st_shndx))
1607 check_section_mismatch(modname, elf, &r, sym, fromsec);
1611 static void section_rel(const char *modname, struct elf_info *elf,
1618 const char *fromsec;
1620 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1621 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1623 fromsec = sech_name(elf, sechdr);
1624 fromsec += strlen(".rel");
1625 /* if from section (name) is know good then skip it */
1626 if (match(fromsec, section_white_list))
1629 for (rel = start; rel < stop; rel++) {
1630 r.r_offset = TO_NATIVE(rel->r_offset);
1631 #if KERNEL_ELFCLASS == ELFCLASS64
1632 if (elf->hdr->e_machine == EM_MIPS) {
1634 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1635 r_sym = TO_NATIVE(r_sym);
1636 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1637 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1639 r.r_info = TO_NATIVE(rel->r_info);
1640 r_sym = ELF_R_SYM(r.r_info);
1643 r.r_info = TO_NATIVE(rel->r_info);
1644 r_sym = ELF_R_SYM(r.r_info);
1647 switch (elf->hdr->e_machine) {
1649 if (addend_386_rel(elf, sechdr, &r))
1653 if (addend_arm_rel(elf, sechdr, &r))
1657 if (addend_mips_rel(elf, sechdr, &r))
1661 sym = elf->symtab_start + r_sym;
1662 /* Skip special sections */
1663 if (is_shndx_special(sym->st_shndx))
1665 check_section_mismatch(modname, elf, &r, sym, fromsec);
1670 * A module includes a number of sections that are discarded
1671 * either when loaded or when used as built-in.
1672 * For loaded modules all functions marked __init and all data
1673 * marked __initdata will be discarded when the module has been initialized.
1674 * Likewise for modules used built-in the sections marked __exit
1675 * are discarded because __exit marked function are supposed to be called
1676 * only when a module is unloaded which never happens for built-in modules.
1677 * The check_sec_ref() function traverses all relocation records
1678 * to find all references to a section that reference a section that will
1679 * be discarded and warns about it.
1681 static void check_sec_ref(struct module *mod, const char *modname,
1682 struct elf_info *elf)
1685 Elf_Shdr *sechdrs = elf->sechdrs;
1687 /* Walk through all sections */
1688 for (i = 0; i < elf->num_sections; i++) {
1689 check_section(modname, elf, &elf->sechdrs[i]);
1690 /* We want to process only relocation sections and not .init */
1691 if (sechdrs[i].sh_type == SHT_RELA)
1692 section_rela(modname, elf, &elf->sechdrs[i]);
1693 else if (sechdrs[i].sh_type == SHT_REL)
1694 section_rel(modname, elf, &elf->sechdrs[i]);
1698 static void read_symbols(char *modname)
1700 const char *symname;
1704 struct elf_info info = { };
1707 if (!parse_elf(&info, modname))
1710 mod = new_module(modname);
1712 /* When there's no vmlinux, don't print warnings about
1713 * unresolved symbols (since there'll be too many ;) */
1714 if (is_vmlinux(modname)) {
1719 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1720 if (info.modinfo && !license && !is_vmlinux(modname))
1721 warn("modpost: missing MODULE_LICENSE() in %s\n"
1722 "see include/linux/module.h for "
1723 "more information\n", modname);
1725 if (license_is_gpl_compatible(license))
1726 mod->gpl_compatible = 1;
1728 mod->gpl_compatible = 0;
1731 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1732 "license", license);
1735 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1736 symname = info.strtab + sym->st_name;
1738 handle_modversions(mod, &info, sym, symname);
1739 handle_moddevtable(mod, &info, sym, symname);
1741 if (!is_vmlinux(modname) ||
1742 (is_vmlinux(modname) && vmlinux_section_warnings))
1743 check_sec_ref(mod, modname, &info);
1745 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1747 maybe_frob_rcs_version(modname, version, info.modinfo,
1748 version - (char *)info.hdr);
1749 if (version || (all_versions && !is_vmlinux(modname)))
1750 get_src_version(modname, mod->srcversion,
1751 sizeof(mod->srcversion)-1);
1753 parse_elf_finish(&info);
1755 /* Our trick to get versioning for module struct etc. - it's
1756 * never passed as an argument to an exported function, so
1757 * the automatic versioning doesn't pick it up, but it's really
1758 * important anyhow */
1760 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1765 /* We first write the generated file into memory using the
1766 * following helper, then compare to the file on disk and
1767 * only update the later if anything changed */
1769 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1770 const char *fmt, ...)
1777 len = vsnprintf(tmp, SZ, fmt, ap);
1778 buf_write(buf, tmp, len);
1782 void buf_write(struct buffer *buf, const char *s, int len)
1784 if (buf->size - buf->pos < len) {
1785 buf->size += len + SZ;
1786 buf->p = realloc(buf->p, buf->size);
1788 strncpy(buf->p + buf->pos, s, len);
1792 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1794 const char *e = is_vmlinux(m) ?"":".ko";
1798 fatal("modpost: GPL-incompatible module %s%s "
1799 "uses GPL-only symbol '%s'\n", m, e, s);
1801 case export_unused_gpl:
1802 fatal("modpost: GPL-incompatible module %s%s "
1803 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1805 case export_gpl_future:
1806 warn("modpost: GPL-incompatible module %s%s "
1807 "uses future GPL-only symbol '%s'\n", m, e, s);
1811 case export_unknown:
1817 static void check_for_unused(enum export exp, const char *m, const char *s)
1819 const char *e = is_vmlinux(m) ?"":".ko";
1823 case export_unused_gpl:
1824 warn("modpost: module %s%s "
1825 "uses symbol '%s' marked UNUSED\n", m, e, s);
1833 static void check_exports(struct module *mod)
1835 struct symbol *s, *exp;
1837 for (s = mod->unres; s; s = s->next) {
1838 const char *basename;
1839 exp = find_symbol(s->name);
1840 if (!exp || exp->module == mod)
1842 basename = strrchr(mod->name, '/');
1846 basename = mod->name;
1847 if (!mod->gpl_compatible)
1848 check_for_gpl_usage(exp->export, basename, exp->name);
1849 check_for_unused(exp->export, basename, exp->name);
1854 * Header for the generated file
1856 static void add_header(struct buffer *b, struct module *mod)
1858 buf_printf(b, "#include <linux/module.h>\n");
1859 buf_printf(b, "#include <linux/vermagic.h>\n");
1860 buf_printf(b, "#include <linux/compiler.h>\n");
1861 buf_printf(b, "\n");
1862 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1863 buf_printf(b, "\n");
1864 buf_printf(b, "struct module __this_module\n");
1865 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1866 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1868 buf_printf(b, "\t.init = init_module,\n");
1869 if (mod->has_cleanup)
1870 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1871 "\t.exit = cleanup_module,\n"
1873 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1874 buf_printf(b, "};\n");
1877 static void add_intree_flag(struct buffer *b, int is_intree)
1880 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1883 static void add_staging_flag(struct buffer *b, const char *name)
1885 static const char *staging_dir = "drivers/staging";
1887 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1888 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1892 * Record CRCs for unresolved symbols
1894 static int add_versions(struct buffer *b, struct module *mod)
1896 struct symbol *s, *exp;
1899 for (s = mod->unres; s; s = s->next) {
1900 exp = find_symbol(s->name);
1901 if (!exp || exp->module == mod) {
1902 if (have_vmlinux && !s->weak) {
1903 if (warn_unresolved) {
1904 warn("\"%s\" [%s.ko] undefined!\n",
1905 s->name, mod->name);
1907 merror("\"%s\" [%s.ko] undefined!\n",
1908 s->name, mod->name);
1914 s->module = exp->module;
1915 s->crc_valid = exp->crc_valid;
1922 buf_printf(b, "\n");
1923 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1924 buf_printf(b, "__used\n");
1925 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1927 for (s = mod->unres; s; s = s->next) {
1930 if (!s->crc_valid) {
1931 warn("\"%s\" [%s.ko] has no CRC!\n",
1932 s->name, mod->name);
1935 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1938 buf_printf(b, "};\n");
1943 static void add_depends(struct buffer *b, struct module *mod,
1944 struct module *modules)
1950 for (m = modules; m; m = m->next)
1951 m->seen = is_vmlinux(m->name);
1953 buf_printf(b, "\n");
1954 buf_printf(b, "static const char __module_depends[]\n");
1955 buf_printf(b, "__used\n");
1956 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1957 buf_printf(b, "\"depends=");
1958 for (s = mod->unres; s; s = s->next) {
1963 if (s->module->seen)
1966 s->module->seen = 1;
1967 p = strrchr(s->module->name, '/');
1971 p = s->module->name;
1972 buf_printf(b, "%s%s", first ? "" : ",", p);
1975 buf_printf(b, "\";\n");
1978 static void add_srcversion(struct buffer *b, struct module *mod)
1980 if (mod->srcversion[0]) {
1981 buf_printf(b, "\n");
1982 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1987 static void write_if_changed(struct buffer *b, const char *fname)
1993 file = fopen(fname, "r");
1997 if (fstat(fileno(file), &st) < 0)
2000 if (st.st_size != b->pos)
2003 tmp = NOFAIL(malloc(b->pos));
2004 if (fread(tmp, 1, b->pos, file) != b->pos)
2007 if (memcmp(tmp, b->p, b->pos) != 0)
2019 file = fopen(fname, "w");
2024 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2031 /* parse Module.symvers file. line format:
2032 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2034 static void read_dump(const char *fname, unsigned int kernel)
2036 unsigned long size, pos = 0;
2037 void *file = grab_file(fname, &size);
2041 /* No symbol versions, silently ignore */
2044 while ((line = get_next_line(&pos, file, size))) {
2045 char *symname, *modname, *d, *export, *end;
2050 if (!(symname = strchr(line, '\t')))
2053 if (!(modname = strchr(symname, '\t')))
2056 if ((export = strchr(modname, '\t')) != NULL)
2058 if (export && ((end = strchr(export, '\t')) != NULL))
2060 crc = strtoul(line, &d, 16);
2061 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2063 mod = find_module(modname);
2065 if (is_vmlinux(modname))
2067 mod = new_module(modname);
2070 s = sym_add_exported(symname, mod, export_no(export));
2073 sym_update_crc(symname, mod, crc, export_no(export));
2077 fatal("parse error in symbol dump file\n");
2080 /* For normal builds always dump all symbols.
2081 * For external modules only dump symbols
2082 * that are not read from kernel Module.symvers.
2084 static int dump_sym(struct symbol *sym)
2086 if (!external_module)
2088 if (sym->vmlinux || sym->kernel)
2093 static void write_dump(const char *fname)
2095 struct buffer buf = { };
2096 struct symbol *symbol;
2099 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2100 symbol = symbolhash[n];
2102 if (dump_sym(symbol))
2103 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2104 symbol->crc, symbol->name,
2105 symbol->module->name,
2106 export_str(symbol->export));
2107 symbol = symbol->next;
2110 write_if_changed(&buf, fname);
2113 struct ext_sym_list {
2114 struct ext_sym_list *next;
2118 int main(int argc, char **argv)
2121 struct buffer buf = { };
2122 char *kernel_read = NULL, *module_read = NULL;
2123 char *dump_write = NULL;
2126 struct ext_sym_list *extsym_iter;
2127 struct ext_sym_list *extsym_start = NULL;
2129 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2132 kernel_read = optarg;
2135 module_read = optarg;
2136 external_module = 1;
2142 external_module = 1;
2144 NOFAIL(malloc(sizeof(*extsym_iter)));
2145 extsym_iter->next = extsym_start;
2146 extsym_iter->file = optarg;
2147 extsym_start = extsym_iter;
2153 dump_write = optarg;
2159 vmlinux_section_warnings = 0;
2162 sec_mismatch_verbose = 0;
2165 warn_unresolved = 1;
2173 read_dump(kernel_read, 1);
2175 read_dump(module_read, 0);
2176 while (extsym_start) {
2177 read_dump(extsym_start->file, 0);
2178 extsym_iter = extsym_start->next;
2180 extsym_start = extsym_iter;
2183 while (optind < argc)
2184 read_symbols(argv[optind++]);
2186 for (mod = modules; mod; mod = mod->next) {
2194 for (mod = modules; mod; mod = mod->next) {
2195 char fname[strlen(mod->name) + 10];
2202 add_header(&buf, mod);
2203 add_intree_flag(&buf, !external_module);
2204 add_staging_flag(&buf, mod->name);
2205 err |= add_versions(&buf, mod);
2206 add_depends(&buf, mod, modules);
2207 add_moddevtable(&buf, mod);
2208 add_srcversion(&buf, mod);
2210 sprintf(fname, "%s.mod.c", mod->name);
2211 write_if_changed(&buf, fname);
2215 write_dump(dump_write);
2216 if (sec_mismatch_count && !sec_mismatch_verbose)
2217 warn("modpost: Found %d section mismatch(es).\n"
2218 "To see full details build your kernel with:\n"
2219 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2220 sec_mismatch_count);