1 /* Postprocess module symbol versions
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006 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 ...
17 /* Are we using CONFIG_MODVERSIONS? */
19 /* Warn about undefined symbols? (do so if we have vmlinux) */
21 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
22 static int all_versions = 0;
23 /* If we are modposting external module set to 1 */
24 static int external_module = 0;
26 void fatal(const char *fmt, ...)
30 fprintf(stderr, "FATAL: ");
32 va_start(arglist, fmt);
33 vfprintf(stderr, fmt, arglist);
39 void warn(const char *fmt, ...)
43 fprintf(stderr, "WARNING: ");
45 va_start(arglist, fmt);
46 vfprintf(stderr, fmt, arglist);
50 static int is_vmlinux(const char *modname)
54 if ((myname = strrchr(modname, '/')))
59 return strcmp(myname, "vmlinux") == 0;
62 void *do_nofail(void *ptr, const char *expr)
65 fatal("modpost: Memory allocation failure: %s.\n", expr);
70 /* A list of all modules we processed */
72 static struct module *modules;
74 static struct module *find_module(char *modname)
78 for (mod = modules; mod; mod = mod->next)
79 if (strcmp(mod->name, modname) == 0)
84 static struct module *new_module(char *modname)
89 mod = NOFAIL(malloc(sizeof(*mod)));
90 memset(mod, 0, sizeof(*mod));
91 p = NOFAIL(strdup(modname));
93 /* strip trailing .o */
94 if ((s = strrchr(p, '.')) != NULL)
95 if (strcmp(s, ".o") == 0)
106 /* A hash of all exported symbols,
107 * struct symbol is also used for lists of unresolved symbols */
109 #define SYMBOL_HASH_SIZE 1024
113 struct module *module;
117 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
118 unsigned int kernel:1; /* 1 if symbol is from kernel
119 * (only for external modules) **/
120 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
124 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
126 /* This is based on the hash agorithm from gdbm, via tdb */
127 static inline unsigned int tdb_hash(const char *name)
129 unsigned value; /* Used to compute the hash value. */
130 unsigned i; /* Used to cycle through random values. */
132 /* Set the initial value from the key size. */
133 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
134 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
136 return (1103515243 * value + 12345);
140 * Allocate a new symbols for use in the hash of exported symbols or
141 * the list of unresolved symbols per module
143 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
146 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
148 memset(s, 0, sizeof(*s));
149 strcpy(s->name, name);
155 /* For the hash of exported symbols */
156 static struct symbol *new_symbol(const char *name, struct module *module)
161 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
162 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
163 new->module = module;
167 static struct symbol *find_symbol(const char *name)
171 /* For our purposes, .foo matches foo. PPC64 needs this. */
175 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) {
176 if (strcmp(s->name, name) == 0)
183 * Add an exported symbol - it may have already been added without a
184 * CRC, in this case just update the CRC
186 static struct symbol *sym_add_exported(const char *name, struct module *mod)
188 struct symbol *s = find_symbol(name);
191 s = new_symbol(name, mod);
194 warn("%s: '%s' exported twice. Previous export "
195 "was in %s%s\n", mod->name, name,
197 is_vmlinux(s->module->name) ?"":".ko");
201 s->vmlinux = is_vmlinux(mod->name);
206 static void sym_update_crc(const char *name, struct module *mod,
209 struct symbol *s = find_symbol(name);
212 s = new_symbol(name, mod);
217 void *grab_file(const char *filename, unsigned long *size)
223 fd = open(filename, O_RDONLY);
224 if (fd < 0 || fstat(fd, &st) != 0)
228 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
231 if (map == MAP_FAILED)
237 * Return a copy of the next line in a mmap'ed file.
238 * spaces in the beginning of the line is trimmed away.
239 * Return a pointer to a static buffer.
241 char* get_next_line(unsigned long *pos, void *file, unsigned long size)
243 static char line[4096];
246 signed char *p = (signed char *)file + *pos;
249 for (; *pos < size ; (*pos)++)
251 if (skip && isspace(*p)) {
256 if (*p != '\n' && (*pos < size)) {
260 break; /* Too long, stop */
271 void release_file(void *file, unsigned long size)
276 static void parse_elf(struct elf_info *info, const char *filename)
279 Elf_Ehdr *hdr = info->hdr;
283 hdr = grab_file(filename, &info->size);
289 if (info->size < sizeof(*hdr))
292 /* Fix endianness in ELF header */
293 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
294 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
295 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
296 hdr->e_machine = TO_NATIVE(hdr->e_machine);
297 sechdrs = (void *)hdr + hdr->e_shoff;
298 info->sechdrs = sechdrs;
300 /* Fix endianness in section headers */
301 for (i = 0; i < hdr->e_shnum; i++) {
302 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
303 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
304 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
305 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
306 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
308 /* Find symbol table. */
309 for (i = 1; i < hdr->e_shnum; i++) {
310 const char *secstrings
311 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
313 if (sechdrs[i].sh_offset > info->size)
315 if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) {
316 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
317 info->modinfo_len = sechdrs[i].sh_size;
319 if (sechdrs[i].sh_type != SHT_SYMTAB)
322 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
323 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
324 + sechdrs[i].sh_size;
325 info->strtab = (void *)hdr +
326 sechdrs[sechdrs[i].sh_link].sh_offset;
328 if (!info->symtab_start) {
329 fatal("%s has no symtab?\n", filename);
331 /* Fix endianness in symbols */
332 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
333 sym->st_shndx = TO_NATIVE(sym->st_shndx);
334 sym->st_name = TO_NATIVE(sym->st_name);
335 sym->st_value = TO_NATIVE(sym->st_value);
336 sym->st_size = TO_NATIVE(sym->st_size);
341 fatal("%s is truncated.\n", filename);
344 static void parse_elf_finish(struct elf_info *info)
346 release_file(info->hdr, info->size);
349 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
350 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
352 static void handle_modversions(struct module *mod, struct elf_info *info,
353 Elf_Sym *sym, const char *symname)
357 switch (sym->st_shndx) {
359 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
363 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
364 crc = (unsigned int) sym->st_value;
365 sym_update_crc(symname + strlen(CRC_PFX), mod, crc);
369 /* undefined symbol */
370 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
371 ELF_ST_BIND(sym->st_info) != STB_WEAK)
373 /* ignore global offset table */
374 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
376 /* ignore __this_module, it will be resolved shortly */
377 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
379 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
380 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
381 /* add compatibility with older glibc */
382 #ifndef STT_SPARC_REGISTER
383 #define STT_SPARC_REGISTER STT_REGISTER
385 if (info->hdr->e_machine == EM_SPARC ||
386 info->hdr->e_machine == EM_SPARCV9) {
387 /* Ignore register directives. */
388 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
390 if (symname[0] == '.') {
391 char *munged = strdup(symname);
393 munged[1] = toupper(munged[1]);
399 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
400 strlen(MODULE_SYMBOL_PREFIX)) == 0)
401 mod->unres = alloc_symbol(symname +
402 strlen(MODULE_SYMBOL_PREFIX),
403 ELF_ST_BIND(sym->st_info) == STB_WEAK,
407 /* All exported symbols */
408 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
409 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod);
411 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
413 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
414 mod->has_cleanup = 1;
420 * Parse tag=value strings from .modinfo section
422 static char *next_string(char *string, unsigned long *secsize)
424 /* Skip non-zero chars */
427 if ((*secsize)-- <= 1)
431 /* Skip any zero padding. */
434 if ((*secsize)-- <= 1)
440 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
444 unsigned int taglen = strlen(tag);
445 unsigned long size = modinfo_len;
447 for (p = modinfo; p; p = next_string(p, &size)) {
448 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
449 return p + taglen + 1;
455 * Test if string s ends in string sub
458 static int strrcmp(const char *s, const char *sub)
466 sublen = strlen(sub);
468 if ((slen == 0) || (sublen == 0))
474 return memcmp(s + slen - sublen, sub, sublen);
478 * Whitelist to allow certain references to pass with no warning.
480 * If a module parameter is declared __initdata and permissions=0
481 * then this is legal despite the warning generated.
482 * We cannot see value of permissions here, so just ignore
484 * The pattern is identified by:
490 * Many drivers utilise a *driver container with references to
491 * add, remove, probe functions etc.
492 * These functions may often be marked __init and we do not want to
494 * the pattern is identified by:
495 * tosec = .init.text | .exit.text | .init.data
497 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one
499 static int secref_whitelist(const char *tosec, const char *fromsec,
504 const char *pat2sym[] = {
506 "_template", /* scsi uses *_template a lot */
507 "_sht", /* scsi also used *_sht to some extent */
514 /* Check for pattern 1 */
515 if (strcmp(tosec, ".init.data") != 0)
517 if (strncmp(fromsec, ".data", strlen(".data")) != 0)
519 if (strncmp(atsym, "__param", strlen("__param")) != 0)
525 /* Check for pattern 2 */
526 if ((strcmp(tosec, ".init.text") != 0) &&
527 (strcmp(tosec, ".exit.text") != 0) &&
528 (strcmp(tosec, ".init.data") != 0))
530 if (strcmp(fromsec, ".data") != 0)
533 for (s = pat2sym; *s; s++)
534 if (strrcmp(atsym, *s) == 0)
541 * Find symbol based on relocation record info.
542 * In some cases the symbol supplied is a valid symbol so
543 * return refsym. If st_name != 0 we assume this is a valid symbol.
544 * In other cases the symbol needs to be looked up in the symbol table
545 * based on section and address.
547 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr,
552 if (relsym->st_name != 0)
554 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
555 if (sym->st_shndx != relsym->st_shndx)
557 if (sym->st_value == addr)
564 * Find symbols before or equal addr and after addr - in the section sec.
565 * If we find two symbols with equal offset prefer one with a valid name.
566 * The ELF format may have a better way to detect what type of symbol
567 * it is, but this works for now.
569 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
571 Elf_Sym **before, Elf_Sym **after)
574 Elf_Ehdr *hdr = elf->hdr;
575 Elf_Addr beforediff = ~0;
576 Elf_Addr afterdiff = ~0;
577 const char *secstrings = (void *)hdr +
578 elf->sechdrs[hdr->e_shstrndx].sh_offset;
583 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
586 if (sym->st_shndx >= SHN_LORESERVE)
588 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;
589 if (strcmp(symsec, sec) != 0)
591 if (sym->st_value <= addr) {
592 if ((addr - sym->st_value) < beforediff) {
593 beforediff = addr - sym->st_value;
596 else if ((addr - sym->st_value) == beforediff) {
597 /* equal offset, valid name? */
598 const char *name = elf->strtab + sym->st_name;
599 if (name && strlen(name))
605 if ((sym->st_value - addr) < afterdiff) {
606 afterdiff = sym->st_value - addr;
609 else if ((sym->st_value - addr) == afterdiff) {
610 /* equal offset, valid name? */
611 const char *name = elf->strtab + sym->st_name;
612 if (name && strlen(name))
620 * Print a warning about a section mismatch.
621 * Try to find symbols near it so user can find it.
622 * Check whitelist before warning - it may be a false positive.
624 static void warn_sec_mismatch(const char *modname, const char *fromsec,
625 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
627 const char *refsymname = "";
628 Elf_Sym *before, *after;
630 Elf_Ehdr *hdr = elf->hdr;
631 Elf_Shdr *sechdrs = elf->sechdrs;
632 const char *secstrings = (void *)hdr +
633 sechdrs[hdr->e_shstrndx].sh_offset;
634 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;
636 find_symbols_between(elf, r.r_offset, fromsec, &before, &after);
638 refsym = find_elf_symbol(elf, r.r_addend, sym);
639 if (refsym && strlen(elf->strtab + refsym->st_name))
640 refsymname = elf->strtab + refsym->st_name;
642 /* check whitelist - we may ignore it */
644 secref_whitelist(secname, fromsec, elf->strtab + before->st_name))
647 if (before && after) {
648 warn("%s - Section mismatch: reference to %s:%s from %s "
649 "between '%s' (at offset 0x%llx) and '%s'\n",
650 modname, secname, refsymname, fromsec,
651 elf->strtab + before->st_name,
652 (long long)r.r_offset,
653 elf->strtab + after->st_name);
655 warn("%s - Section mismatch: reference to %s:%s from %s "
656 "after '%s' (at offset 0x%llx)\n",
657 modname, secname, refsymname, fromsec,
658 elf->strtab + before->st_name,
659 (long long)r.r_offset);
661 warn("%s - Section mismatch: reference to %s:%s from %s "
662 "before '%s' (at offset -0x%llx)\n",
663 modname, secname, refsymname, fromsec,
664 elf->strtab + after->st_name,
665 (long long)r.r_offset);
667 warn("%s - Section mismatch: reference to %s:%s from %s "
669 modname, secname, fromsec, refsymname,
670 (long long)r.r_offset);
675 * A module includes a number of sections that are discarded
676 * either when loaded or when used as built-in.
677 * For loaded modules all functions marked __init and all data
678 * marked __initdata will be discarded when the module has been intialized.
679 * Likewise for modules used built-in the sections marked __exit
680 * are discarded because __exit marked function are supposed to be called
681 * only when a moduel is unloaded which never happes for built-in modules.
682 * The check_sec_ref() function traverses all relocation records
683 * to find all references to a section that reference a section that will
684 * be discarded and warns about it.
686 static void check_sec_ref(struct module *mod, const char *modname,
687 struct elf_info *elf,
688 int section(const char*),
689 int section_ref_ok(const char *))
693 Elf_Ehdr *hdr = elf->hdr;
694 Elf_Shdr *sechdrs = elf->sechdrs;
695 const char *secstrings = (void *)hdr +
696 sechdrs[hdr->e_shstrndx].sh_offset;
698 /* Walk through all sections */
699 for (i = 0; i < hdr->e_shnum; i++) {
701 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
702 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size;
703 const char *name = secstrings + sechdrs[i].sh_name +
705 /* We want to process only relocation sections and not .init */
706 if (section_ref_ok(name) || (sechdrs[i].sh_type != SHT_RELA))
709 for (rela = start; rela < stop; rela++) {
713 r.r_offset = TO_NATIVE(rela->r_offset);
714 if (hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
715 hdr->e_machine == EM_MIPS) {
716 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
717 r_sym = TO_NATIVE(r_sym);
719 r_sym = ELF_R_SYM(TO_NATIVE(rela->r_info));
721 r.r_addend = TO_NATIVE(rela->r_addend);
722 sym = elf->symtab_start + r_sym;
723 /* Skip special sections */
724 if (sym->st_shndx >= SHN_LORESERVE)
727 secname = secstrings + sechdrs[sym->st_shndx].sh_name;
728 if (section(secname))
729 warn_sec_mismatch(modname, name, elf, sym, r);
735 * Functions used only during module init is marked __init and is stored in
736 * a .init.text section. Likewise data is marked __initdata and stored in
737 * a .init.data section.
738 * If this section is one of these sections return 1
739 * See include/linux/init.h for the details
741 static int init_section(const char *name)
743 if (strcmp(name, ".init") == 0)
745 if (strncmp(name, ".init.", strlen(".init.")) == 0)
751 * Identify sections from which references to a .init section is OK.
753 * Unfortunately references to read only data that referenced .init
754 * sections had to be excluded. Almost all of these are false
755 * positives, they are created by gcc. The downside of excluding rodata
756 * is that there really are some user references from rodata to
757 * init code, e.g. drivers/video/vgacon.c:
759 * const struct consw vga_con = {
760 * con_startup: vgacon_startup,
762 * where vgacon_startup is __init. If you want to wade through the false
763 * positives, take out the check for rodata.
765 static int init_section_ref_ok(const char *name)
768 /* Absolute section names */
769 const char *namelist1[] = {
771 ".opd", /* see comment [OPD] at exit_section_ref_ok() */
772 ".toc1", /* used by ppc64 */
776 "__bug_table", /* used by powerpc for BUG() */
783 /* Start of section names */
784 const char *namelist2[] = {
791 /* part of section name */
792 const char *namelist3 [] = {
793 ".unwind", /* sample: IA_64.unwind.init.text */
797 for (s = namelist1; *s; s++)
798 if (strcmp(*s, name) == 0)
800 for (s = namelist2; *s; s++)
801 if (strncmp(*s, name, strlen(*s)) == 0)
803 for (s = namelist3; *s; s++)
804 if (strstr(name, *s) != NULL)
810 * Functions used only during module exit is marked __exit and is stored in
811 * a .exit.text section. Likewise data is marked __exitdata and stored in
812 * a .exit.data section.
813 * If this section is one of these sections return 1
814 * See include/linux/init.h for the details
816 static int exit_section(const char *name)
818 if (strcmp(name, ".exit.text") == 0)
820 if (strcmp(name, ".exit.data") == 0)
827 * Identify sections from which references to a .exit section is OK.
829 * [OPD] Keith Ownes <kaos@sgi.com> commented:
830 * For our future {in}sanity, add a comment that this is the ppc .opd
831 * section, not the ia64 .opd section.
832 * ia64 .opd should not point to discarded sections.
833 * [.rodata] like for .init.text we ignore .rodata references -same reason
835 static int exit_section_ref_ok(const char *name)
838 /* Absolute section names */
839 const char *namelist1[] = {
844 ".opd", /* See comment [OPD] */
845 ".toc1", /* used by ppc64 */
848 "__bug_table", /* used by powerpc for BUG() */
854 /* Start of section names */
855 const char *namelist2[] = {
859 /* part of section name */
860 const char *namelist3 [] = {
861 ".unwind", /* Sample: IA_64.unwind.exit.text */
865 for (s = namelist1; *s; s++)
866 if (strcmp(*s, name) == 0)
868 for (s = namelist2; *s; s++)
869 if (strncmp(*s, name, strlen(*s)) == 0)
871 for (s = namelist3; *s; s++)
872 if (strstr(name, *s) != NULL)
877 static void read_symbols(char *modname)
882 struct elf_info info = { };
885 parse_elf(&info, modname);
887 mod = new_module(modname);
889 /* When there's no vmlinux, don't print warnings about
890 * unresolved symbols (since there'll be too many ;) */
891 if (is_vmlinux(modname)) {
896 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
897 symname = info.strtab + sym->st_name;
899 handle_modversions(mod, &info, sym, symname);
900 handle_moddevtable(mod, &info, sym, symname);
902 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
903 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
905 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
907 maybe_frob_rcs_version(modname, version, info.modinfo,
908 version - (char *)info.hdr);
909 if (version || (all_versions && !is_vmlinux(modname)))
910 get_src_version(modname, mod->srcversion,
911 sizeof(mod->srcversion)-1);
913 parse_elf_finish(&info);
915 /* Our trick to get versioning for struct_module - it's
916 * never passed as an argument to an exported function, so
917 * the automatic versioning doesn't pick it up, but it's really
918 * important anyhow */
920 mod->unres = alloc_symbol("struct_module", 0, mod->unres);
925 /* We first write the generated file into memory using the
926 * following helper, then compare to the file on disk and
927 * only update the later if anything changed */
929 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
930 const char *fmt, ...)
937 len = vsnprintf(tmp, SZ, fmt, ap);
938 buf_write(buf, tmp, len);
942 void buf_write(struct buffer *buf, const char *s, int len)
944 if (buf->size - buf->pos < len) {
945 buf->size += len + SZ;
946 buf->p = realloc(buf->p, buf->size);
948 strncpy(buf->p + buf->pos, s, len);
953 * Header for the generated file
955 static void add_header(struct buffer *b, struct module *mod)
957 buf_printf(b, "#include <linux/module.h>\n");
958 buf_printf(b, "#include <linux/vermagic.h>\n");
959 buf_printf(b, "#include <linux/compiler.h>\n");
961 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
963 buf_printf(b, "struct module __this_module\n");
964 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
965 buf_printf(b, " .name = KBUILD_MODNAME,\n");
967 buf_printf(b, " .init = init_module,\n");
968 if (mod->has_cleanup)
969 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
970 " .exit = cleanup_module,\n"
972 buf_printf(b, "};\n");
976 * Record CRCs for unresolved symbols
978 static void add_versions(struct buffer *b, struct module *mod)
980 struct symbol *s, *exp;
982 for (s = mod->unres; s; s = s->next) {
983 exp = find_symbol(s->name);
984 if (!exp || exp->module == mod) {
985 if (have_vmlinux && !s->weak)
986 warn("\"%s\" [%s.ko] undefined!\n",
990 s->module = exp->module;
991 s->crc_valid = exp->crc_valid;
999 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1000 buf_printf(b, "__attribute_used__\n");
1001 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1003 for (s = mod->unres; s; s = s->next) {
1007 if (!s->crc_valid) {
1008 warn("\"%s\" [%s.ko] has no CRC!\n",
1009 s->name, mod->name);
1012 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1015 buf_printf(b, "};\n");
1018 static void add_depends(struct buffer *b, struct module *mod,
1019 struct module *modules)
1025 for (m = modules; m; m = m->next) {
1026 m->seen = is_vmlinux(m->name);
1029 buf_printf(b, "\n");
1030 buf_printf(b, "static const char __module_depends[]\n");
1031 buf_printf(b, "__attribute_used__\n");
1032 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1033 buf_printf(b, "\"depends=");
1034 for (s = mod->unres; s; s = s->next) {
1038 if (s->module->seen)
1041 s->module->seen = 1;
1042 buf_printf(b, "%s%s", first ? "" : ",",
1043 strrchr(s->module->name, '/') + 1);
1046 buf_printf(b, "\";\n");
1049 static void add_srcversion(struct buffer *b, struct module *mod)
1051 if (mod->srcversion[0]) {
1052 buf_printf(b, "\n");
1053 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1058 static void write_if_changed(struct buffer *b, const char *fname)
1064 file = fopen(fname, "r");
1068 if (fstat(fileno(file), &st) < 0)
1071 if (st.st_size != b->pos)
1074 tmp = NOFAIL(malloc(b->pos));
1075 if (fread(tmp, 1, b->pos, file) != b->pos)
1078 if (memcmp(tmp, b->p, b->pos) != 0)
1090 file = fopen(fname, "w");
1095 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1102 static void read_dump(const char *fname, unsigned int kernel)
1104 unsigned long size, pos = 0;
1105 void *file = grab_file(fname, &size);
1109 /* No symbol versions, silently ignore */
1112 while ((line = get_next_line(&pos, file, size))) {
1113 char *symname, *modname, *d;
1118 if (!(symname = strchr(line, '\t')))
1121 if (!(modname = strchr(symname, '\t')))
1124 if (strchr(modname, '\t'))
1126 crc = strtoul(line, &d, 16);
1127 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1130 if (!(mod = find_module(modname))) {
1131 if (is_vmlinux(modname)) {
1134 mod = new_module(NOFAIL(strdup(modname)));
1137 s = sym_add_exported(symname, mod);
1140 sym_update_crc(symname, mod, crc);
1144 fatal("parse error in symbol dump file\n");
1147 /* For normal builds always dump all symbols.
1148 * For external modules only dump symbols
1149 * that are not read from kernel Module.symvers.
1151 static int dump_sym(struct symbol *sym)
1153 if (!external_module)
1155 if (sym->vmlinux || sym->kernel)
1160 static void write_dump(const char *fname)
1162 struct buffer buf = { };
1163 struct symbol *symbol;
1166 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1167 symbol = symbolhash[n];
1169 if (dump_sym(symbol))
1170 buf_printf(&buf, "0x%08x\t%s\t%s\n",
1171 symbol->crc, symbol->name,
1172 symbol->module->name);
1173 symbol = symbol->next;
1176 write_if_changed(&buf, fname);
1179 int main(int argc, char **argv)
1182 struct buffer buf = { };
1184 char *kernel_read = NULL, *module_read = NULL;
1185 char *dump_write = NULL;
1188 while ((opt = getopt(argc, argv, "i:I:mo:a")) != -1) {
1191 kernel_read = optarg;
1194 module_read = optarg;
1195 external_module = 1;
1201 dump_write = optarg;
1212 read_dump(kernel_read, 1);
1214 read_dump(module_read, 0);
1216 while (optind < argc) {
1217 read_symbols(argv[optind++]);
1220 for (mod = modules; mod; mod = mod->next) {
1226 add_header(&buf, mod);
1227 add_versions(&buf, mod);
1228 add_depends(&buf, mod, modules);
1229 add_moddevtable(&buf, mod);
1230 add_srcversion(&buf, mod);
1232 sprintf(fname, "%s.mod.c", mod->name);
1233 write_if_changed(&buf, fname);
1237 write_dump(dump_write);