vfs: add fs.h to define struct file
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / scripts / mod / modpost.c
blob3318692e4e761ffecaf1849693e376291b5a7655
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 ...
14 #define _GNU_SOURCE
15 #include <stdio.h>
16 #include <ctype.h>
17 #include "modpost.h"
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
24 #else
25 #define MODULE_SYMBOL_PREFIX ""
26 #endif
29 /* Are we using CONFIG_MODVERSIONS? */
30 int modversions = 0;
31 /* Warn about undefined symbols? (do so if we have vmlinux) */
32 int have_vmlinux = 0;
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;
45 enum export {
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, ...)
54 va_list arglist;
56 fprintf(stderr, "FATAL: ");
58 va_start(arglist, fmt);
59 vfprintf(stderr, fmt, arglist);
60 va_end(arglist);
62 exit(1);
65 PRINTF void warn(const char *fmt, ...)
67 va_list arglist;
69 fprintf(stderr, "WARNING: ");
71 va_start(arglist, fmt);
72 vfprintf(stderr, fmt, arglist);
73 va_end(arglist);
76 PRINTF void merror(const char *fmt, ...)
78 va_list arglist;
80 fprintf(stderr, "ERROR: ");
82 va_start(arglist, fmt);
83 vfprintf(stderr, fmt, arglist);
84 va_end(arglist);
87 static int is_vmlinux(const char *modname)
89 const char *myname;
91 myname = strrchr(modname, '/');
92 if (myname)
93 myname++;
94 else
95 myname = modname;
97 return (strcmp(myname, "vmlinux") == 0) ||
98 (strcmp(myname, "vmlinux.o") == 0);
101 void *do_nofail(void *ptr, const char *expr)
103 if (!ptr)
104 fatal("modpost: Memory allocation failure: %s.\n", expr);
106 return ptr;
109 /* A list of all modules we processed */
110 static struct module *modules;
112 static struct module *find_module(char *modname)
114 struct module *mod;
116 for (mod = modules; mod; mod = mod->next)
117 if (strcmp(mod->name, modname) == 0)
118 break;
119 return mod;
122 static struct module *new_module(char *modname)
124 struct module *mod;
125 char *p, *s;
127 mod = NOFAIL(malloc(sizeof(*mod)));
128 memset(mod, 0, sizeof(*mod));
129 p = NOFAIL(strdup(modname));
131 /* strip trailing .o */
132 s = strrchr(p, '.');
133 if (s != NULL)
134 if (strcmp(s, ".o") == 0)
135 *s = '\0';
137 /* add to list */
138 mod->name = p;
139 mod->gpl_compatible = -1;
140 mod->next = modules;
141 modules = mod;
143 return mod;
146 /* A hash of all exported symbols,
147 * struct symbol is also used for lists of unresolved symbols */
149 #define SYMBOL_HASH_SIZE 1024
151 struct symbol {
152 struct symbol *next;
153 struct module *module;
154 unsigned int crc;
155 int crc_valid;
156 unsigned int weak:1;
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 */
162 char name[0];
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,
185 struct symbol *next)
187 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
189 memset(s, 0, sizeof(*s));
190 strcpy(s->name, name);
191 s->weak = weak;
192 s->next = next;
193 return s;
196 /* For the hash of exported symbols */
197 static struct symbol *new_symbol(const char *name, struct module *module,
198 enum export export)
200 unsigned int hash;
201 struct symbol *new;
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;
207 return new;
210 static struct symbol *find_symbol(const char *name)
212 struct symbol *s;
214 /* For our purposes, .foo matches foo. PPC64 needs this. */
215 if (name[0] == '.')
216 name++;
218 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
219 if (strcmp(s->name, name) == 0)
220 return s;
222 return NULL;
225 static struct {
226 const char *str;
227 enum export export;
228 } export_list[] = {
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)
245 int i;
247 if (!s)
248 return export_unknown;
249 for (i = 0; export_list[i].export != export_unknown; i++) {
250 if (strcmp(export_list[i].str, s) == 0)
251 return export_list[i].export;
253 return export_unknown;
256 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
258 if (sec == elf->export_sec)
259 return export_plain;
260 else if (sec == elf->export_unused_sec)
261 return export_unused;
262 else if (sec == elf->export_gpl_sec)
263 return export_gpl;
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;
268 else
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,
277 enum export export)
279 struct symbol *s = find_symbol(name);
281 if (!s) {
282 s = new_symbol(name, mod, export);
283 } else {
284 if (!s->preloaded) {
285 warn("%s: '%s' exported twice. Previous export "
286 "was in %s%s\n", mod->name, name,
287 s->module->name,
288 is_vmlinux(s->module->name) ?"":".ko");
289 } else {
290 /* In case Modules.symvers was out of date */
291 s->module = mod;
294 s->preloaded = 0;
295 s->vmlinux = is_vmlinux(mod->name);
296 s->kernel = 0;
297 s->export = export;
298 return s;
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);
306 if (!s)
307 s = new_symbol(name, mod, export);
308 s->crc = crc;
309 s->crc_valid = 1;
312 void *grab_file(const char *filename, unsigned long *size)
314 struct stat st;
315 void *map;
316 int fd;
318 fd = open(filename, O_RDONLY);
319 if (fd < 0 || fstat(fd, &st) != 0)
320 return NULL;
322 *size = st.st_size;
323 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
324 close(fd);
326 if (map == MAP_FAILED)
327 return NULL;
328 return map;
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];
339 int skip = 1;
340 size_t len = 0;
341 signed char *p = (signed char *)file + *pos;
342 char *s = line;
344 for (; *pos < size ; (*pos)++) {
345 if (skip && isspace(*p)) {
346 p++;
347 continue;
349 skip = 0;
350 if (*p != '\n' && (*pos < size)) {
351 len++;
352 *s++ = *p++;
353 if (len > 4095)
354 break; /* Too long, stop */
355 } else {
356 /* End of string */
357 *s = '\0';
358 return line;
361 /* End of buffer */
362 return NULL;
365 void release_file(void *file, unsigned long size)
367 munmap(file, size);
370 static int parse_elf(struct elf_info *info, const char *filename)
372 unsigned int i;
373 Elf_Ehdr *hdr;
374 Elf_Shdr *sechdrs;
375 Elf_Sym *sym;
377 hdr = grab_file(filename, &info->size);
378 if (!hdr) {
379 perror(filename);
380 exit(1);
382 info->hdr = hdr;
383 if (info->size < sizeof(*hdr)) {
384 /* file too small, assume this is an empty .o file */
385 return 0;
387 /* Is this a valid ELF file? */
388 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
389 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
390 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
391 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
392 /* Not an ELF file - silently ignore it */
393 return 0;
395 /* Fix endianness in ELF header */
396 hdr->e_type = TO_NATIVE(hdr->e_type);
397 hdr->e_machine = TO_NATIVE(hdr->e_machine);
398 hdr->e_version = TO_NATIVE(hdr->e_version);
399 hdr->e_entry = TO_NATIVE(hdr->e_entry);
400 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
401 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
402 hdr->e_flags = TO_NATIVE(hdr->e_flags);
403 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
404 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
405 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
406 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
407 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
408 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
409 sechdrs = (void *)hdr + hdr->e_shoff;
410 info->sechdrs = sechdrs;
412 /* Check if file offset is correct */
413 if (hdr->e_shoff > info->size) {
414 fatal("section header offset=%lu in file '%s' is bigger than "
415 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
416 filename, info->size);
417 return 0;
420 /* Fix endianness in section headers */
421 for (i = 0; i < hdr->e_shnum; i++) {
422 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
423 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
424 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
425 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
426 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
427 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
428 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
429 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
430 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
431 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
433 /* Find symbol table. */
434 for (i = 1; i < hdr->e_shnum; i++) {
435 const char *secstrings
436 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
437 const char *secname;
438 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
440 if (!nobits && sechdrs[i].sh_offset > info->size) {
441 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
442 "sizeof(*hrd)=%zu\n", filename,
443 (unsigned long)sechdrs[i].sh_offset,
444 sizeof(*hdr));
445 return 0;
447 secname = secstrings + sechdrs[i].sh_name;
448 if (strcmp(secname, ".modinfo") == 0) {
449 if (nobits)
450 fatal("%s has NOBITS .modinfo\n", filename);
451 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
452 info->modinfo_len = sechdrs[i].sh_size;
453 } else if (strcmp(secname, "__ksymtab") == 0)
454 info->export_sec = i;
455 else if (strcmp(secname, "__ksymtab_unused") == 0)
456 info->export_unused_sec = i;
457 else if (strcmp(secname, "__ksymtab_gpl") == 0)
458 info->export_gpl_sec = i;
459 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
460 info->export_unused_gpl_sec = i;
461 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
462 info->export_gpl_future_sec = i;
464 if (sechdrs[i].sh_type != SHT_SYMTAB)
465 continue;
467 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
468 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
469 + sechdrs[i].sh_size;
470 info->strtab = (void *)hdr +
471 sechdrs[sechdrs[i].sh_link].sh_offset;
473 if (!info->symtab_start)
474 fatal("%s has no symtab?\n", filename);
476 /* Fix endianness in symbols */
477 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
478 sym->st_shndx = TO_NATIVE(sym->st_shndx);
479 sym->st_name = TO_NATIVE(sym->st_name);
480 sym->st_value = TO_NATIVE(sym->st_value);
481 sym->st_size = TO_NATIVE(sym->st_size);
483 return 1;
486 static void parse_elf_finish(struct elf_info *info)
488 release_file(info->hdr, info->size);
491 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
493 /* ignore __this_module, it will be resolved shortly */
494 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
495 return 1;
496 /* ignore global offset table */
497 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
498 return 1;
499 if (info->hdr->e_machine == EM_PPC)
500 /* Special register function linked on all modules during final link of .ko */
501 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
502 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
503 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
504 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
505 return 1;
506 /* Do not ignore this symbol */
507 return 0;
510 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
511 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
513 static void handle_modversions(struct module *mod, struct elf_info *info,
514 Elf_Sym *sym, const char *symname)
516 unsigned int crc;
517 enum export export = export_from_sec(info, sym->st_shndx);
519 switch (sym->st_shndx) {
520 case SHN_COMMON:
521 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
522 break;
523 case SHN_ABS:
524 /* CRC'd symbol */
525 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
526 crc = (unsigned int) sym->st_value;
527 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
528 export);
530 break;
531 case SHN_UNDEF:
532 /* undefined symbol */
533 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
534 ELF_ST_BIND(sym->st_info) != STB_WEAK)
535 break;
536 if (ignore_undef_symbol(info, symname))
537 break;
538 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
539 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
540 /* add compatibility with older glibc */
541 #ifndef STT_SPARC_REGISTER
542 #define STT_SPARC_REGISTER STT_REGISTER
543 #endif
544 if (info->hdr->e_machine == EM_SPARC ||
545 info->hdr->e_machine == EM_SPARCV9) {
546 /* Ignore register directives. */
547 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
548 break;
549 if (symname[0] == '.') {
550 char *munged = strdup(symname);
551 munged[0] = '_';
552 munged[1] = toupper(munged[1]);
553 symname = munged;
556 #endif
558 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
559 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
560 mod->unres =
561 alloc_symbol(symname +
562 strlen(MODULE_SYMBOL_PREFIX),
563 ELF_ST_BIND(sym->st_info) == STB_WEAK,
564 mod->unres);
566 break;
567 default:
568 /* All exported symbols */
569 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
570 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
571 export);
573 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
574 mod->has_init = 1;
575 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
576 mod->has_cleanup = 1;
577 break;
582 * Parse tag=value strings from .modinfo section
584 static char *next_string(char *string, unsigned long *secsize)
586 /* Skip non-zero chars */
587 while (string[0]) {
588 string++;
589 if ((*secsize)-- <= 1)
590 return NULL;
593 /* Skip any zero padding. */
594 while (!string[0]) {
595 string++;
596 if ((*secsize)-- <= 1)
597 return NULL;
599 return string;
602 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
603 const char *tag, char *info)
605 char *p;
606 unsigned int taglen = strlen(tag);
607 unsigned long size = modinfo_len;
609 if (info) {
610 size -= info - (char *)modinfo;
611 modinfo = next_string(info, &size);
614 for (p = modinfo; p; p = next_string(p, &size)) {
615 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
616 return p + taglen + 1;
618 return NULL;
621 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
622 const char *tag)
625 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
629 * Test if string s ends in string sub
630 * return 0 if match
632 static int strrcmp(const char *s, const char *sub)
634 int slen, sublen;
636 if (!s || !sub)
637 return 1;
639 slen = strlen(s);
640 sublen = strlen(sub);
642 if ((slen == 0) || (sublen == 0))
643 return 1;
645 if (sublen > slen)
646 return 1;
648 return memcmp(s + slen - sublen, sub, sublen);
651 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
653 if (sym)
654 return elf->strtab + sym->st_name;
655 else
656 return "(unknown)";
659 static const char *sec_name(struct elf_info *elf, int shndx)
661 Elf_Shdr *sechdrs = elf->sechdrs;
662 return (void *)elf->hdr +
663 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
664 sechdrs[shndx].sh_name;
667 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
669 return (void *)elf->hdr +
670 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
671 sechdr->sh_name;
674 /* if sym is empty or point to a string
675 * like ".[0-9]+" then return 1.
676 * This is the optional prefix added by ld to some sections
678 static int number_prefix(const char *sym)
680 if (*sym++ == '\0')
681 return 1;
682 if (*sym != '.')
683 return 0;
684 do {
685 char c = *sym++;
686 if (c < '0' || c > '9')
687 return 0;
688 } while (*sym);
689 return 1;
692 /* The pattern is an array of simple patterns.
693 * "foo" will match an exact string equal to "foo"
694 * "*foo" will match a string that ends with "foo"
695 * "foo*" will match a string that begins with "foo"
696 * "foo$" will match a string equal to "foo" or "foo.1"
697 * where the '1' can be any number including several digits.
698 * The $ syntax is for sections where ld append a dot number
699 * to make section name unique.
701 static int match(const char *sym, const char * const pat[])
703 const char *p;
704 while (*pat) {
705 p = *pat++;
706 const char *endp = p + strlen(p) - 1;
708 /* "*foo" */
709 if (*p == '*') {
710 if (strrcmp(sym, p + 1) == 0)
711 return 1;
713 /* "foo*" */
714 else if (*endp == '*') {
715 if (strncmp(sym, p, strlen(p) - 1) == 0)
716 return 1;
718 /* "foo$" */
719 else if (*endp == '$') {
720 if (strncmp(sym, p, strlen(p) - 1) == 0) {
721 if (number_prefix(sym + strlen(p) - 1))
722 return 1;
725 /* no wildcards */
726 else {
727 if (strcmp(p, sym) == 0)
728 return 1;
731 /* no match */
732 return 0;
735 /* sections that we do not want to do full section mismatch check on */
736 static const char *section_white_list[] =
738 ".comment*",
739 ".debug*",
740 ".mdebug*", /* alpha, score, mips etc. */
741 ".pdr", /* alpha, score, mips etc. */
742 ".stab*",
743 ".note*",
744 ".got*",
745 ".toc*",
746 NULL
750 * This is used to find sections missing the SHF_ALLOC flag.
751 * The cause of this is often a section specified in assembler
752 * without "ax" / "aw".
754 static void check_section(const char *modname, struct elf_info *elf,
755 Elf_Shdr *sechdr)
757 const char *sec = sech_name(elf, sechdr);
759 if (sechdr->sh_type == SHT_PROGBITS &&
760 !(sechdr->sh_flags & SHF_ALLOC) &&
761 !match(sec, section_white_list)) {
762 warn("%s (%s): unexpected non-allocatable section.\n"
763 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
764 "Note that for example <linux/init.h> contains\n"
765 "section definitions for use in .S files.\n\n",
766 modname, sec);
772 #define ALL_INIT_DATA_SECTIONS \
773 ".init.setup$", ".init.rodata$", \
774 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
775 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
776 #define ALL_EXIT_DATA_SECTIONS \
777 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
779 #define ALL_INIT_TEXT_SECTIONS \
780 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
781 #define ALL_EXIT_TEXT_SECTIONS \
782 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
784 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
785 MEM_INIT_SECTIONS
786 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
787 MEM_EXIT_SECTIONS
789 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
790 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
792 #define DATA_SECTIONS ".data$", ".data.rel$"
793 #define TEXT_SECTIONS ".text$"
795 #define INIT_SECTIONS ".init.*"
796 #define DEV_INIT_SECTIONS ".devinit.*"
797 #define CPU_INIT_SECTIONS ".cpuinit.*"
798 #define MEM_INIT_SECTIONS ".meminit.*"
800 #define EXIT_SECTIONS ".exit.*"
801 #define DEV_EXIT_SECTIONS ".devexit.*"
802 #define CPU_EXIT_SECTIONS ".cpuexit.*"
803 #define MEM_EXIT_SECTIONS ".memexit.*"
805 /* init data sections */
806 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
808 /* all init sections */
809 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
811 /* All init and exit sections (code + data) */
812 static const char *init_exit_sections[] =
813 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
815 /* data section */
816 static const char *data_sections[] = { DATA_SECTIONS, NULL };
819 /* symbols in .data that may refer to init/exit sections */
820 #define DEFAULT_SYMBOL_WHITE_LIST \
821 "*driver", \
822 "*_template", /* scsi uses *_template a lot */ \
823 "*_timer", /* arm uses ops structures named _timer a lot */ \
824 "*_sht", /* scsi also used *_sht to some extent */ \
825 "*_ops", \
826 "*_probe", \
827 "*_probe_one", \
828 "*_console"
830 static const char *head_sections[] = { ".head.text*", NULL };
831 static const char *linker_symbols[] =
832 { "__init_begin", "_sinittext", "_einittext", NULL };
834 enum mismatch {
835 TEXT_TO_ANY_INIT,
836 DATA_TO_ANY_INIT,
837 TEXT_TO_ANY_EXIT,
838 DATA_TO_ANY_EXIT,
839 XXXINIT_TO_SOME_INIT,
840 XXXEXIT_TO_SOME_EXIT,
841 ANY_INIT_TO_ANY_EXIT,
842 ANY_EXIT_TO_ANY_INIT,
843 EXPORT_TO_INIT_EXIT,
846 struct sectioncheck {
847 const char *fromsec[20];
848 const char *tosec[20];
849 enum mismatch mismatch;
850 const char *symbol_white_list[20];
853 const struct sectioncheck sectioncheck[] = {
854 /* Do not reference init/exit code/data from
855 * normal code and data
858 .fromsec = { TEXT_SECTIONS, NULL },
859 .tosec = { ALL_INIT_SECTIONS, NULL },
860 .mismatch = TEXT_TO_ANY_INIT,
861 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
864 .fromsec = { DATA_SECTIONS, NULL },
865 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
866 .mismatch = DATA_TO_ANY_INIT,
867 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
870 .fromsec = { DATA_SECTIONS, NULL },
871 .tosec = { INIT_SECTIONS, NULL },
872 .mismatch = DATA_TO_ANY_INIT,
873 .symbol_white_list = {
874 "*_template", "*_timer", "*_sht", "*_ops",
875 "*_probe", "*_probe_one", "*_console", NULL
879 .fromsec = { TEXT_SECTIONS, NULL },
880 .tosec = { ALL_EXIT_SECTIONS, NULL },
881 .mismatch = TEXT_TO_ANY_EXIT,
882 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
885 .fromsec = { DATA_SECTIONS, NULL },
886 .tosec = { ALL_EXIT_SECTIONS, NULL },
887 .mismatch = DATA_TO_ANY_EXIT,
888 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
890 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
892 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
893 .tosec = { INIT_SECTIONS, NULL },
894 .mismatch = XXXINIT_TO_SOME_INIT,
895 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
897 /* Do not reference cpuinit code/data from meminit code/data */
899 .fromsec = { MEM_INIT_SECTIONS, NULL },
900 .tosec = { CPU_INIT_SECTIONS, NULL },
901 .mismatch = XXXINIT_TO_SOME_INIT,
902 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
904 /* Do not reference meminit code/data from cpuinit code/data */
906 .fromsec = { CPU_INIT_SECTIONS, NULL },
907 .tosec = { MEM_INIT_SECTIONS, NULL },
908 .mismatch = XXXINIT_TO_SOME_INIT,
909 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
911 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
913 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
914 .tosec = { EXIT_SECTIONS, NULL },
915 .mismatch = XXXEXIT_TO_SOME_EXIT,
916 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
918 /* Do not reference cpuexit code/data from memexit code/data */
920 .fromsec = { MEM_EXIT_SECTIONS, NULL },
921 .tosec = { CPU_EXIT_SECTIONS, NULL },
922 .mismatch = XXXEXIT_TO_SOME_EXIT,
923 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
925 /* Do not reference memexit code/data from cpuexit code/data */
927 .fromsec = { CPU_EXIT_SECTIONS, NULL },
928 .tosec = { MEM_EXIT_SECTIONS, NULL },
929 .mismatch = XXXEXIT_TO_SOME_EXIT,
930 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
932 /* Do not use exit code/data from init code */
934 .fromsec = { ALL_INIT_SECTIONS, NULL },
935 .tosec = { ALL_EXIT_SECTIONS, NULL },
936 .mismatch = ANY_INIT_TO_ANY_EXIT,
937 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
939 /* Do not use init code/data from exit code */
941 .fromsec = { ALL_EXIT_SECTIONS, NULL },
942 .tosec = { ALL_INIT_SECTIONS, NULL },
943 .mismatch = ANY_EXIT_TO_ANY_INIT,
944 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
946 /* Do not export init/exit functions or data */
948 .fromsec = { "__ksymtab*", NULL },
949 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
950 .mismatch = EXPORT_TO_INIT_EXIT,
951 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
955 static const struct sectioncheck *section_mismatch(
956 const char *fromsec, const char *tosec)
958 int i;
959 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
960 const struct sectioncheck *check = &sectioncheck[0];
962 for (i = 0; i < elems; i++) {
963 if (match(fromsec, check->fromsec) &&
964 match(tosec, check->tosec))
965 return check;
966 check++;
968 return NULL;
972 * Whitelist to allow certain references to pass with no warning.
974 * Pattern 1:
975 * If a module parameter is declared __initdata and permissions=0
976 * then this is legal despite the warning generated.
977 * We cannot see value of permissions here, so just ignore
978 * this pattern.
979 * The pattern is identified by:
980 * tosec = .init.data
981 * fromsec = .data*
982 * atsym =__param*
984 * Pattern 2:
985 * Many drivers utilise a *driver container with references to
986 * add, remove, probe functions etc.
987 * These functions may often be marked __devinit and we do not want to
988 * warn here.
989 * the pattern is identified by:
990 * tosec = init or exit section
991 * fromsec = data section
992 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
993 * *probe_one, *_console, *_timer
995 * Pattern 3:
996 * Whitelist all references from .head.text to any init section
998 * Pattern 4:
999 * Some symbols belong to init section but still it is ok to reference
1000 * these from non-init sections as these symbols don't have any memory
1001 * allocated for them and symbol address and value are same. So even
1002 * if init section is freed, its ok to reference those symbols.
1003 * For ex. symbols marking the init section boundaries.
1004 * This pattern is identified by
1005 * refsymname = __init_begin, _sinittext, _einittext
1008 static int secref_whitelist(const struct sectioncheck *mismatch,
1009 const char *fromsec, const char *fromsym,
1010 const char *tosec, const char *tosym)
1012 /* Check for pattern 1 */
1013 if (match(tosec, init_data_sections) &&
1014 match(fromsec, data_sections) &&
1015 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1016 return 0;
1018 /* Check for pattern 2 */
1019 if (match(tosec, init_exit_sections) &&
1020 match(fromsec, data_sections) &&
1021 match(fromsym, mismatch->symbol_white_list))
1022 return 0;
1024 /* Check for pattern 3 */
1025 if (match(fromsec, head_sections) &&
1026 match(tosec, init_sections))
1027 return 0;
1029 /* Check for pattern 4 */
1030 if (match(tosym, linker_symbols))
1031 return 0;
1033 return 1;
1037 * Find symbol based on relocation record info.
1038 * In some cases the symbol supplied is a valid symbol so
1039 * return refsym. If st_name != 0 we assume this is a valid symbol.
1040 * In other cases the symbol needs to be looked up in the symbol table
1041 * based on section and address.
1042 * **/
1043 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1044 Elf_Sym *relsym)
1046 Elf_Sym *sym;
1047 Elf_Sym *near = NULL;
1048 Elf64_Sword distance = 20;
1049 Elf64_Sword d;
1051 if (relsym->st_name != 0)
1052 return relsym;
1053 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1054 if (sym->st_shndx != relsym->st_shndx)
1055 continue;
1056 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1057 continue;
1058 if (sym->st_value == addr)
1059 return sym;
1060 /* Find a symbol nearby - addr are maybe negative */
1061 d = sym->st_value - addr;
1062 if (d < 0)
1063 d = addr - sym->st_value;
1064 if (d < distance) {
1065 distance = d;
1066 near = sym;
1069 /* We need a close match */
1070 if (distance < 20)
1071 return near;
1072 else
1073 return NULL;
1076 static inline int is_arm_mapping_symbol(const char *str)
1078 return str[0] == '$' && strchr("atd", str[1])
1079 && (str[2] == '\0' || str[2] == '.');
1083 * If there's no name there, ignore it; likewise, ignore it if it's
1084 * one of the magic symbols emitted used by current ARM tools.
1086 * Otherwise if find_symbols_between() returns those symbols, they'll
1087 * fail the whitelist tests and cause lots of false alarms ... fixable
1088 * only by merging __exit and __init sections into __text, bloating
1089 * the kernel (which is especially evil on embedded platforms).
1091 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1093 const char *name = elf->strtab + sym->st_name;
1095 if (!name || !strlen(name))
1096 return 0;
1097 return !is_arm_mapping_symbol(name);
1101 * Find symbols before or equal addr and after addr - in the section sec.
1102 * If we find two symbols with equal offset prefer one with a valid name.
1103 * The ELF format may have a better way to detect what type of symbol
1104 * it is, but this works for now.
1106 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1107 const char *sec)
1109 Elf_Sym *sym;
1110 Elf_Sym *near = NULL;
1111 Elf_Addr distance = ~0;
1113 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1114 const char *symsec;
1116 if (sym->st_shndx >= SHN_LORESERVE)
1117 continue;
1118 symsec = sec_name(elf, sym->st_shndx);
1119 if (strcmp(symsec, sec) != 0)
1120 continue;
1121 if (!is_valid_name(elf, sym))
1122 continue;
1123 if (sym->st_value <= addr) {
1124 if ((addr - sym->st_value) < distance) {
1125 distance = addr - sym->st_value;
1126 near = sym;
1127 } else if ((addr - sym->st_value) == distance) {
1128 near = sym;
1132 return near;
1136 * Convert a section name to the function/data attribute
1137 * .init.text => __init
1138 * .cpuinit.data => __cpudata
1139 * .memexitconst => __memconst
1140 * etc.
1142 static char *sec2annotation(const char *s)
1144 if (match(s, init_exit_sections)) {
1145 char *p = malloc(20);
1146 char *r = p;
1148 *p++ = '_';
1149 *p++ = '_';
1150 if (*s == '.')
1151 s++;
1152 while (*s && *s != '.')
1153 *p++ = *s++;
1154 *p = '\0';
1155 if (*s == '.')
1156 s++;
1157 if (strstr(s, "rodata") != NULL)
1158 strcat(p, "const ");
1159 else if (strstr(s, "data") != NULL)
1160 strcat(p, "data ");
1161 else
1162 strcat(p, " ");
1163 return r; /* we leak her but we do not care */
1164 } else {
1165 return "";
1169 static int is_function(Elf_Sym *sym)
1171 if (sym)
1172 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1173 else
1174 return -1;
1178 * Print a warning about a section mismatch.
1179 * Try to find symbols near it so user can find it.
1180 * Check whitelist before warning - it may be a false positive.
1182 static void report_sec_mismatch(const char *modname,
1183 const struct sectioncheck *mismatch,
1184 const char *fromsec,
1185 unsigned long long fromaddr,
1186 const char *fromsym,
1187 int from_is_func,
1188 const char *tosec, const char *tosym,
1189 int to_is_func)
1191 const char *from, *from_p;
1192 const char *to, *to_p;
1194 switch (from_is_func) {
1195 case 0: from = "variable"; from_p = ""; break;
1196 case 1: from = "function"; from_p = "()"; break;
1197 default: from = "(unknown reference)"; from_p = ""; break;
1199 switch (to_is_func) {
1200 case 0: to = "variable"; to_p = ""; break;
1201 case 1: to = "function"; to_p = "()"; break;
1202 default: to = "(unknown reference)"; to_p = ""; break;
1205 sec_mismatch_count++;
1206 if (!sec_mismatch_verbose)
1207 return;
1209 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1210 "to the %s %s:%s%s\n",
1211 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1212 tosym, to_p);
1214 switch (mismatch->mismatch) {
1215 case TEXT_TO_ANY_INIT:
1216 fprintf(stderr,
1217 "The function %s%s() references\n"
1218 "the %s %s%s%s.\n"
1219 "This is often because %s lacks a %s\n"
1220 "annotation or the annotation of %s is wrong.\n",
1221 sec2annotation(fromsec), fromsym,
1222 to, sec2annotation(tosec), tosym, to_p,
1223 fromsym, sec2annotation(tosec), tosym);
1224 break;
1225 case DATA_TO_ANY_INIT: {
1226 const char *const *s = mismatch->symbol_white_list;
1227 fprintf(stderr,
1228 "The variable %s references\n"
1229 "the %s %s%s%s\n"
1230 "If the reference is valid then annotate the\n"
1231 "variable with __init* or __refdata (see linux/init.h) "
1232 "or name the variable:\n",
1233 fromsym, to, sec2annotation(tosec), tosym, to_p);
1234 while (*s)
1235 fprintf(stderr, "%s, ", *s++);
1236 fprintf(stderr, "\n");
1237 break;
1239 case TEXT_TO_ANY_EXIT:
1240 fprintf(stderr,
1241 "The function %s() references a %s in an exit section.\n"
1242 "Often the %s %s%s has valid usage outside the exit section\n"
1243 "and the fix is to remove the %sannotation of %s.\n",
1244 fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1245 break;
1246 case DATA_TO_ANY_EXIT: {
1247 const char *const *s = mismatch->symbol_white_list;
1248 fprintf(stderr,
1249 "The variable %s references\n"
1250 "the %s %s%s%s\n"
1251 "If the reference is valid then annotate the\n"
1252 "variable with __exit* (see linux/init.h) or "
1253 "name the variable:\n",
1254 fromsym, to, sec2annotation(tosec), tosym, to_p);
1255 while (*s)
1256 fprintf(stderr, "%s, ", *s++);
1257 fprintf(stderr, "\n");
1258 break;
1260 case XXXINIT_TO_SOME_INIT:
1261 case XXXEXIT_TO_SOME_EXIT:
1262 fprintf(stderr,
1263 "The %s %s%s%s references\n"
1264 "a %s %s%s%s.\n"
1265 "If %s is only used by %s then\n"
1266 "annotate %s with a matching annotation.\n",
1267 from, sec2annotation(fromsec), fromsym, from_p,
1268 to, sec2annotation(tosec), tosym, to_p,
1269 tosym, fromsym, tosym);
1270 break;
1271 case ANY_INIT_TO_ANY_EXIT:
1272 fprintf(stderr,
1273 "The %s %s%s%s references\n"
1274 "a %s %s%s%s.\n"
1275 "This is often seen when error handling "
1276 "in the init function\n"
1277 "uses functionality in the exit path.\n"
1278 "The fix is often to remove the %sannotation of\n"
1279 "%s%s so it may be used outside an exit section.\n",
1280 from, sec2annotation(fromsec), fromsym, from_p,
1281 to, sec2annotation(tosec), tosym, to_p,
1282 sec2annotation(tosec), tosym, to_p);
1283 break;
1284 case ANY_EXIT_TO_ANY_INIT:
1285 fprintf(stderr,
1286 "The %s %s%s%s references\n"
1287 "a %s %s%s%s.\n"
1288 "This is often seen when error handling "
1289 "in the exit function\n"
1290 "uses functionality in the init path.\n"
1291 "The fix is often to remove the %sannotation of\n"
1292 "%s%s so it may be used outside an init section.\n",
1293 from, sec2annotation(fromsec), fromsym, from_p,
1294 to, sec2annotation(tosec), tosym, to_p,
1295 sec2annotation(tosec), tosym, to_p);
1296 break;
1297 case EXPORT_TO_INIT_EXIT:
1298 fprintf(stderr,
1299 "The symbol %s is exported and annotated %s\n"
1300 "Fix this by removing the %sannotation of %s "
1301 "or drop the export.\n",
1302 tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1303 break;
1305 fprintf(stderr, "\n");
1308 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1309 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1311 const char *tosec;
1312 const struct sectioncheck *mismatch;
1314 tosec = sec_name(elf, sym->st_shndx);
1315 mismatch = section_mismatch(fromsec, tosec);
1316 if (mismatch) {
1317 Elf_Sym *to;
1318 Elf_Sym *from;
1319 const char *tosym;
1320 const char *fromsym;
1322 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1323 fromsym = sym_name(elf, from);
1324 to = find_elf_symbol(elf, r->r_addend, sym);
1325 tosym = sym_name(elf, to);
1327 /* check whitelist - we may ignore it */
1328 if (secref_whitelist(mismatch,
1329 fromsec, fromsym, tosec, tosym)) {
1330 report_sec_mismatch(modname, mismatch,
1331 fromsec, r->r_offset, fromsym,
1332 is_function(from), tosec, tosym,
1333 is_function(to));
1338 static unsigned int *reloc_location(struct elf_info *elf,
1339 Elf_Shdr *sechdr, Elf_Rela *r)
1341 Elf_Shdr *sechdrs = elf->sechdrs;
1342 int section = sechdr->sh_info;
1344 return (void *)elf->hdr + sechdrs[section].sh_offset +
1345 (r->r_offset - sechdrs[section].sh_addr);
1348 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1350 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1351 unsigned int *location = reloc_location(elf, sechdr, r);
1353 switch (r_typ) {
1354 case R_386_32:
1355 r->r_addend = TO_NATIVE(*location);
1356 break;
1357 case R_386_PC32:
1358 r->r_addend = TO_NATIVE(*location) + 4;
1359 /* For CONFIG_RELOCATABLE=y */
1360 if (elf->hdr->e_type == ET_EXEC)
1361 r->r_addend += r->r_offset;
1362 break;
1364 return 0;
1367 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1369 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1371 switch (r_typ) {
1372 case R_ARM_ABS32:
1373 /* From ARM ABI: (S + A) | T */
1374 r->r_addend = (int)(long)
1375 (elf->symtab_start + ELF_R_SYM(r->r_info));
1376 break;
1377 case R_ARM_PC24:
1378 /* From ARM ABI: ((S + A) | T) - P */
1379 r->r_addend = (int)(long)(elf->hdr +
1380 sechdr->sh_offset +
1381 (r->r_offset - sechdr->sh_addr));
1382 break;
1383 default:
1384 return 1;
1386 return 0;
1389 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1391 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1392 unsigned int *location = reloc_location(elf, sechdr, r);
1393 unsigned int inst;
1395 if (r_typ == R_MIPS_HI16)
1396 return 1; /* skip this */
1397 inst = TO_NATIVE(*location);
1398 switch (r_typ) {
1399 case R_MIPS_LO16:
1400 r->r_addend = inst & 0xffff;
1401 break;
1402 case R_MIPS_26:
1403 r->r_addend = (inst & 0x03ffffff) << 2;
1404 break;
1405 case R_MIPS_32:
1406 r->r_addend = inst;
1407 break;
1409 return 0;
1412 static void section_rela(const char *modname, struct elf_info *elf,
1413 Elf_Shdr *sechdr)
1415 Elf_Sym *sym;
1416 Elf_Rela *rela;
1417 Elf_Rela r;
1418 unsigned int r_sym;
1419 const char *fromsec;
1421 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1422 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1424 fromsec = sech_name(elf, sechdr);
1425 fromsec += strlen(".rela");
1426 /* if from section (name) is know good then skip it */
1427 if (match(fromsec, section_white_list))
1428 return;
1430 for (rela = start; rela < stop; rela++) {
1431 r.r_offset = TO_NATIVE(rela->r_offset);
1432 #if KERNEL_ELFCLASS == ELFCLASS64
1433 if (elf->hdr->e_machine == EM_MIPS) {
1434 unsigned int r_typ;
1435 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1436 r_sym = TO_NATIVE(r_sym);
1437 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1438 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1439 } else {
1440 r.r_info = TO_NATIVE(rela->r_info);
1441 r_sym = ELF_R_SYM(r.r_info);
1443 #else
1444 r.r_info = TO_NATIVE(rela->r_info);
1445 r_sym = ELF_R_SYM(r.r_info);
1446 #endif
1447 r.r_addend = TO_NATIVE(rela->r_addend);
1448 sym = elf->symtab_start + r_sym;
1449 /* Skip special sections */
1450 if (sym->st_shndx >= SHN_LORESERVE)
1451 continue;
1452 check_section_mismatch(modname, elf, &r, sym, fromsec);
1456 static void section_rel(const char *modname, struct elf_info *elf,
1457 Elf_Shdr *sechdr)
1459 Elf_Sym *sym;
1460 Elf_Rel *rel;
1461 Elf_Rela r;
1462 unsigned int r_sym;
1463 const char *fromsec;
1465 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1466 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1468 fromsec = sech_name(elf, sechdr);
1469 fromsec += strlen(".rel");
1470 /* if from section (name) is know good then skip it */
1471 if (match(fromsec, section_white_list))
1472 return;
1474 for (rel = start; rel < stop; rel++) {
1475 r.r_offset = TO_NATIVE(rel->r_offset);
1476 #if KERNEL_ELFCLASS == ELFCLASS64
1477 if (elf->hdr->e_machine == EM_MIPS) {
1478 unsigned int r_typ;
1479 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1480 r_sym = TO_NATIVE(r_sym);
1481 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1482 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1483 } else {
1484 r.r_info = TO_NATIVE(rel->r_info);
1485 r_sym = ELF_R_SYM(r.r_info);
1487 #else
1488 r.r_info = TO_NATIVE(rel->r_info);
1489 r_sym = ELF_R_SYM(r.r_info);
1490 #endif
1491 r.r_addend = 0;
1492 switch (elf->hdr->e_machine) {
1493 case EM_386:
1494 if (addend_386_rel(elf, sechdr, &r))
1495 continue;
1496 break;
1497 case EM_ARM:
1498 if (addend_arm_rel(elf, sechdr, &r))
1499 continue;
1500 break;
1501 case EM_MIPS:
1502 if (addend_mips_rel(elf, sechdr, &r))
1503 continue;
1504 break;
1506 sym = elf->symtab_start + r_sym;
1507 /* Skip special sections */
1508 if (sym->st_shndx >= SHN_LORESERVE)
1509 continue;
1510 check_section_mismatch(modname, elf, &r, sym, fromsec);
1515 * A module includes a number of sections that are discarded
1516 * either when loaded or when used as built-in.
1517 * For loaded modules all functions marked __init and all data
1518 * marked __initdata will be discarded when the module has been intialized.
1519 * Likewise for modules used built-in the sections marked __exit
1520 * are discarded because __exit marked function are supposed to be called
1521 * only when a module is unloaded which never happens for built-in modules.
1522 * The check_sec_ref() function traverses all relocation records
1523 * to find all references to a section that reference a section that will
1524 * be discarded and warns about it.
1526 static void check_sec_ref(struct module *mod, const char *modname,
1527 struct elf_info *elf)
1529 int i;
1530 Elf_Shdr *sechdrs = elf->sechdrs;
1532 /* Walk through all sections */
1533 for (i = 0; i < elf->hdr->e_shnum; i++) {
1534 check_section(modname, elf, &elf->sechdrs[i]);
1535 /* We want to process only relocation sections and not .init */
1536 if (sechdrs[i].sh_type == SHT_RELA)
1537 section_rela(modname, elf, &elf->sechdrs[i]);
1538 else if (sechdrs[i].sh_type == SHT_REL)
1539 section_rel(modname, elf, &elf->sechdrs[i]);
1543 static void read_symbols(char *modname)
1545 const char *symname;
1546 char *version;
1547 char *license;
1548 struct module *mod;
1549 struct elf_info info = { };
1550 Elf_Sym *sym;
1552 if (!parse_elf(&info, modname))
1553 return;
1555 mod = new_module(modname);
1557 /* When there's no vmlinux, don't print warnings about
1558 * unresolved symbols (since there'll be too many ;) */
1559 if (is_vmlinux(modname)) {
1560 have_vmlinux = 1;
1561 mod->skip = 1;
1564 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1565 if (info.modinfo && !license && !is_vmlinux(modname))
1566 warn("modpost: missing MODULE_LICENSE() in %s\n"
1567 "see include/linux/module.h for "
1568 "more information\n", modname);
1569 while (license) {
1570 if (license_is_gpl_compatible(license))
1571 mod->gpl_compatible = 1;
1572 else {
1573 mod->gpl_compatible = 0;
1574 break;
1576 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1577 "license", license);
1580 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1581 symname = info.strtab + sym->st_name;
1583 handle_modversions(mod, &info, sym, symname);
1584 handle_moddevtable(mod, &info, sym, symname);
1586 if (!is_vmlinux(modname) ||
1587 (is_vmlinux(modname) && vmlinux_section_warnings))
1588 check_sec_ref(mod, modname, &info);
1590 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1591 if (version)
1592 maybe_frob_rcs_version(modname, version, info.modinfo,
1593 version - (char *)info.hdr);
1594 if (version || (all_versions && !is_vmlinux(modname)))
1595 get_src_version(modname, mod->srcversion,
1596 sizeof(mod->srcversion)-1);
1598 parse_elf_finish(&info);
1600 /* Our trick to get versioning for module struct etc. - it's
1601 * never passed as an argument to an exported function, so
1602 * the automatic versioning doesn't pick it up, but it's really
1603 * important anyhow */
1604 if (modversions)
1605 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1608 #define SZ 500
1610 /* We first write the generated file into memory using the
1611 * following helper, then compare to the file on disk and
1612 * only update the later if anything changed */
1614 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1615 const char *fmt, ...)
1617 char tmp[SZ];
1618 int len;
1619 va_list ap;
1621 va_start(ap, fmt);
1622 len = vsnprintf(tmp, SZ, fmt, ap);
1623 buf_write(buf, tmp, len);
1624 va_end(ap);
1627 void buf_write(struct buffer *buf, const char *s, int len)
1629 if (buf->size - buf->pos < len) {
1630 buf->size += len + SZ;
1631 buf->p = realloc(buf->p, buf->size);
1633 strncpy(buf->p + buf->pos, s, len);
1634 buf->pos += len;
1637 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1639 const char *e = is_vmlinux(m) ?"":".ko";
1641 switch (exp) {
1642 case export_gpl:
1643 fatal("modpost: GPL-incompatible module %s%s "
1644 "uses GPL-only symbol '%s'\n", m, e, s);
1645 break;
1646 case export_unused_gpl:
1647 fatal("modpost: GPL-incompatible module %s%s "
1648 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1649 break;
1650 case export_gpl_future:
1651 warn("modpost: GPL-incompatible module %s%s "
1652 "uses future GPL-only symbol '%s'\n", m, e, s);
1653 break;
1654 case export_plain:
1655 case export_unused:
1656 case export_unknown:
1657 /* ignore */
1658 break;
1662 static void check_for_unused(enum export exp, const char *m, const char *s)
1664 const char *e = is_vmlinux(m) ?"":".ko";
1666 switch (exp) {
1667 case export_unused:
1668 case export_unused_gpl:
1669 warn("modpost: module %s%s "
1670 "uses symbol '%s' marked UNUSED\n", m, e, s);
1671 break;
1672 default:
1673 /* ignore */
1674 break;
1678 static void check_exports(struct module *mod)
1680 struct symbol *s, *exp;
1682 for (s = mod->unres; s; s = s->next) {
1683 const char *basename;
1684 exp = find_symbol(s->name);
1685 if (!exp || exp->module == mod)
1686 continue;
1687 basename = strrchr(mod->name, '/');
1688 if (basename)
1689 basename++;
1690 else
1691 basename = mod->name;
1692 if (!mod->gpl_compatible)
1693 check_for_gpl_usage(exp->export, basename, exp->name);
1694 check_for_unused(exp->export, basename, exp->name);
1699 * Header for the generated file
1701 static void add_header(struct buffer *b, struct module *mod)
1703 buf_printf(b, "#include <linux/module.h>\n");
1704 buf_printf(b, "#include <linux/vermagic.h>\n");
1705 buf_printf(b, "#include <linux/compiler.h>\n");
1706 buf_printf(b, "\n");
1707 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1708 buf_printf(b, "\n");
1709 buf_printf(b, "struct module __this_module\n");
1710 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1711 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1712 if (mod->has_init)
1713 buf_printf(b, " .init = init_module,\n");
1714 if (mod->has_cleanup)
1715 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1716 " .exit = cleanup_module,\n"
1717 "#endif\n");
1718 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1719 buf_printf(b, "};\n");
1722 static void add_staging_flag(struct buffer *b, const char *name)
1724 static const char *staging_dir = "drivers/staging";
1726 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1727 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1731 * Record CRCs for unresolved symbols
1733 static int add_versions(struct buffer *b, struct module *mod)
1735 struct symbol *s, *exp;
1736 int err = 0;
1738 for (s = mod->unres; s; s = s->next) {
1739 exp = find_symbol(s->name);
1740 if (!exp || exp->module == mod) {
1741 if (have_vmlinux && !s->weak) {
1742 if (warn_unresolved) {
1743 warn("\"%s\" [%s.ko] undefined!\n",
1744 s->name, mod->name);
1745 } else {
1746 merror("\"%s\" [%s.ko] undefined!\n",
1747 s->name, mod->name);
1748 err = 1;
1751 continue;
1753 s->module = exp->module;
1754 s->crc_valid = exp->crc_valid;
1755 s->crc = exp->crc;
1758 if (!modversions)
1759 return err;
1761 buf_printf(b, "\n");
1762 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1763 buf_printf(b, "__used\n");
1764 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1766 for (s = mod->unres; s; s = s->next) {
1767 if (!s->module)
1768 continue;
1769 if (!s->crc_valid) {
1770 warn("\"%s\" [%s.ko] has no CRC!\n",
1771 s->name, mod->name);
1772 continue;
1774 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1777 buf_printf(b, "};\n");
1779 return err;
1782 static void add_depends(struct buffer *b, struct module *mod,
1783 struct module *modules)
1785 struct symbol *s;
1786 struct module *m;
1787 int first = 1;
1789 for (m = modules; m; m = m->next)
1790 m->seen = is_vmlinux(m->name);
1792 buf_printf(b, "\n");
1793 buf_printf(b, "static const char __module_depends[]\n");
1794 buf_printf(b, "__used\n");
1795 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1796 buf_printf(b, "\"depends=");
1797 for (s = mod->unres; s; s = s->next) {
1798 const char *p;
1799 if (!s->module)
1800 continue;
1802 if (s->module->seen)
1803 continue;
1805 s->module->seen = 1;
1806 p = strrchr(s->module->name, '/');
1807 if (p)
1808 p++;
1809 else
1810 p = s->module->name;
1811 buf_printf(b, "%s%s", first ? "" : ",", p);
1812 first = 0;
1814 buf_printf(b, "\";\n");
1817 static void add_srcversion(struct buffer *b, struct module *mod)
1819 if (mod->srcversion[0]) {
1820 buf_printf(b, "\n");
1821 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1822 mod->srcversion);
1826 static void write_if_changed(struct buffer *b, const char *fname)
1828 char *tmp;
1829 FILE *file;
1830 struct stat st;
1832 file = fopen(fname, "r");
1833 if (!file)
1834 goto write;
1836 if (fstat(fileno(file), &st) < 0)
1837 goto close_write;
1839 if (st.st_size != b->pos)
1840 goto close_write;
1842 tmp = NOFAIL(malloc(b->pos));
1843 if (fread(tmp, 1, b->pos, file) != b->pos)
1844 goto free_write;
1846 if (memcmp(tmp, b->p, b->pos) != 0)
1847 goto free_write;
1849 free(tmp);
1850 fclose(file);
1851 return;
1853 free_write:
1854 free(tmp);
1855 close_write:
1856 fclose(file);
1857 write:
1858 file = fopen(fname, "w");
1859 if (!file) {
1860 perror(fname);
1861 exit(1);
1863 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1864 perror(fname);
1865 exit(1);
1867 fclose(file);
1870 /* parse Module.symvers file. line format:
1871 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1873 static void read_dump(const char *fname, unsigned int kernel)
1875 unsigned long size, pos = 0;
1876 void *file = grab_file(fname, &size);
1877 char *line;
1879 if (!file)
1880 /* No symbol versions, silently ignore */
1881 return;
1883 while ((line = get_next_line(&pos, file, size))) {
1884 char *symname, *modname, *d, *export, *end;
1885 unsigned int crc;
1886 struct module *mod;
1887 struct symbol *s;
1889 if (!(symname = strchr(line, '\t')))
1890 goto fail;
1891 *symname++ = '\0';
1892 if (!(modname = strchr(symname, '\t')))
1893 goto fail;
1894 *modname++ = '\0';
1895 if ((export = strchr(modname, '\t')) != NULL)
1896 *export++ = '\0';
1897 if (export && ((end = strchr(export, '\t')) != NULL))
1898 *end = '\0';
1899 crc = strtoul(line, &d, 16);
1900 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1901 goto fail;
1902 mod = find_module(modname);
1903 if (!mod) {
1904 if (is_vmlinux(modname))
1905 have_vmlinux = 1;
1906 mod = new_module(modname);
1907 mod->skip = 1;
1909 s = sym_add_exported(symname, mod, export_no(export));
1910 s->kernel = kernel;
1911 s->preloaded = 1;
1912 sym_update_crc(symname, mod, crc, export_no(export));
1914 return;
1915 fail:
1916 fatal("parse error in symbol dump file\n");
1919 /* For normal builds always dump all symbols.
1920 * For external modules only dump symbols
1921 * that are not read from kernel Module.symvers.
1923 static int dump_sym(struct symbol *sym)
1925 if (!external_module)
1926 return 1;
1927 if (sym->vmlinux || sym->kernel)
1928 return 0;
1929 return 1;
1932 static void write_dump(const char *fname)
1934 struct buffer buf = { };
1935 struct symbol *symbol;
1936 int n;
1938 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1939 symbol = symbolhash[n];
1940 while (symbol) {
1941 if (dump_sym(symbol))
1942 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1943 symbol->crc, symbol->name,
1944 symbol->module->name,
1945 export_str(symbol->export));
1946 symbol = symbol->next;
1949 write_if_changed(&buf, fname);
1952 struct ext_sym_list {
1953 struct ext_sym_list *next;
1954 const char *file;
1957 int main(int argc, char **argv)
1959 struct module *mod;
1960 struct buffer buf = { };
1961 char *kernel_read = NULL, *module_read = NULL;
1962 char *dump_write = NULL;
1963 int opt;
1964 int err;
1965 struct ext_sym_list *extsym_iter;
1966 struct ext_sym_list *extsym_start = NULL;
1968 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
1969 switch (opt) {
1970 case 'i':
1971 kernel_read = optarg;
1972 break;
1973 case 'I':
1974 module_read = optarg;
1975 external_module = 1;
1976 break;
1977 case 'c':
1978 cross_build = 1;
1979 break;
1980 case 'e':
1981 external_module = 1;
1982 extsym_iter =
1983 NOFAIL(malloc(sizeof(*extsym_iter)));
1984 extsym_iter->next = extsym_start;
1985 extsym_iter->file = optarg;
1986 extsym_start = extsym_iter;
1987 break;
1988 case 'm':
1989 modversions = 1;
1990 break;
1991 case 'o':
1992 dump_write = optarg;
1993 break;
1994 case 'a':
1995 all_versions = 1;
1996 break;
1997 case 's':
1998 vmlinux_section_warnings = 0;
1999 break;
2000 case 'S':
2001 sec_mismatch_verbose = 0;
2002 break;
2003 case 'w':
2004 warn_unresolved = 1;
2005 break;
2006 default:
2007 exit(1);
2011 if (kernel_read)
2012 read_dump(kernel_read, 1);
2013 if (module_read)
2014 read_dump(module_read, 0);
2015 while (extsym_start) {
2016 read_dump(extsym_start->file, 0);
2017 extsym_iter = extsym_start->next;
2018 free(extsym_start);
2019 extsym_start = extsym_iter;
2022 while (optind < argc)
2023 read_symbols(argv[optind++]);
2025 for (mod = modules; mod; mod = mod->next) {
2026 if (mod->skip)
2027 continue;
2028 check_exports(mod);
2031 err = 0;
2033 for (mod = modules; mod; mod = mod->next) {
2034 char fname[strlen(mod->name) + 10];
2036 if (mod->skip)
2037 continue;
2039 buf.pos = 0;
2041 add_header(&buf, mod);
2042 add_staging_flag(&buf, mod->name);
2043 err |= add_versions(&buf, mod);
2044 add_depends(&buf, mod, modules);
2045 add_moddevtable(&buf, mod);
2046 add_srcversion(&buf, mod);
2048 sprintf(fname, "%s.mod.c", mod->name);
2049 write_if_changed(&buf, fname);
2052 if (dump_write)
2053 write_dump(dump_write);
2054 if (sec_mismatch_count && !sec_mismatch_verbose)
2055 warn("modpost: Found %d section mismatch(es).\n"
2056 "To see full details build your kernel with:\n"
2057 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2058 sec_mismatch_count);
2060 return err;