1 /* Postprocess module symbol versions
2 *
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
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14 #define _GNU_SOURCE
15 #include <stdio.h>
16 #include <ctype.h>
17 #include <string.h>
18 #include <limits.h>
19 #include <stdbool.h>
20 #include "modpost.h"
21 #include "../../include/generated/autoconf.h"
22 #include "../../include/linux/license.h"
23 #include "../../include/linux/export.h"
24
25 /* Are we using CONFIG_MODVERSIONS? */
26 int modversions = 0;
27 /* Warn about undefined symbols? (do so if we have vmlinux) */
28 int have_vmlinux = 0;
29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
30 static int all_versions = 0;
31 /* If we are modposting external module set to 1 */
32 static int external_module = 0;
33 /* Warn about section mismatch in vmlinux if set to 1 */
34 static int vmlinux_section_warnings = 1;
35 /* Only warn about unresolved symbols */
36 static int warn_unresolved = 0;
37 /* How a symbol is exported */
38 static int sec_mismatch_count = 0;
39 static int sec_mismatch_verbose = 1;
40
41 enum export {
42 export_plain, export_unused, export_gpl,
43 export_unused_gpl, export_gpl_future, export_unknown
44 };
45
46 #define PRINTF __attribute__ ((format (printf, 1, 2)))
47
48 PRINTF void fatal(const char *fmt, ...)
49 {
50 va_list arglist;
51
52 fprintf(stderr, "FATAL: ");
53
54 va_start(arglist, fmt);
55 vfprintf(stderr, fmt, arglist);
56 va_end(arglist);
57
58 exit(1);
59 }
60
61 PRINTF void warn(const char *fmt, ...)
62 {
63 va_list arglist;
64
65 fprintf(stderr, "WARNING: ");
66
67 va_start(arglist, fmt);
68 vfprintf(stderr, fmt, arglist);
69 va_end(arglist);
70 }
71
72 PRINTF void merror(const char *fmt, ...)
73 {
74 va_list arglist;
75
76 fprintf(stderr, "ERROR: ");
77
78 va_start(arglist, fmt);
79 vfprintf(stderr, fmt, arglist);
80 va_end(arglist);
81 }
82
83 static inline bool strends(const char *str, const char *postfix)
84 {
85 if (strlen(str) < strlen(postfix))
86 return false;
87
88 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
89 }
90
91 static int is_vmlinux(const char *modname)
92 {
93 const char *myname;
94
95 myname = strrchr(modname, '/');
96 if (myname)
97 myname++;
98 else
99 myname = modname;
100
101 return (strcmp(myname, "vmlinux") == 0) ||
102 (strcmp(myname, "vmlinux.o") == 0);
103 }
104
105 void *do_nofail(void *ptr, const char *expr)
106 {
107 if (!ptr)
108 fatal("modpost: Memory allocation failure: %s.\n", expr);
109
110 return ptr;
111 }
112
113 /* A list of all modules we processed */
114 static struct module *modules;
115
116 static struct module *find_module(char *modname)
117 {
118 struct module *mod;
119
120 for (mod = modules; mod; mod = mod->next)
121 if (strcmp(mod->name, modname) == 0)
122 break;
123 return mod;
124 }
125
126 static struct module *new_module(const char *modname)
127 {
128 struct module *mod;
129 char *p;
130
131 mod = NOFAIL(malloc(sizeof(*mod)));
132 memset(mod, 0, sizeof(*mod));
133 p = NOFAIL(strdup(modname));
134
135 /* strip trailing .o */
136 if (strends(p, ".o")) {
137 p[strlen(p) - 2] = '\0';
138 mod->is_dot_o = 1;
139 }
140
141 /* add to list */
142 mod->name = p;
143 mod->gpl_compatible = -1;
144 mod->next = modules;
145 modules = mod;
146
147 return mod;
148 }
149
150 /* A hash of all exported symbols,
151 * struct symbol is also used for lists of unresolved symbols */
152
153 #define SYMBOL_HASH_SIZE 1024
154
155 struct symbol {
156 struct symbol *next;
157 struct module *module;
158 unsigned int crc;
159 int crc_valid;
160 unsigned int weak:1;
161 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
162 unsigned int kernel:1; /* 1 if symbol is from kernel
163 * (only for external modules) **/
164 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
165 enum export export; /* Type of export */
166 char name[0];
167 };
168
169 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
170
171 /* This is based on the hash agorithm from gdbm, via tdb */
172 static inline unsigned int tdb_hash(const char *name)
173 {
174 unsigned value; /* Used to compute the hash value. */
175 unsigned i; /* Used to cycle through random values. */
176
177 /* Set the initial value from the key size. */
178 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
179 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
180
181 return (1103515243 * value + 12345);
182 }
183
184 /**
185 * Allocate a new symbols for use in the hash of exported symbols or
186 * the list of unresolved symbols per module
187 **/
188 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
189 struct symbol *next)
190 {
191 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
192
193 memset(s, 0, sizeof(*s));
194 strcpy(s->name, name);
195 s->weak = weak;
196 s->next = next;
197 return s;
198 }
199
200 /* For the hash of exported symbols */
201 static struct symbol *new_symbol(const char *name, struct module *module,
202 enum export export)
203 {
204 unsigned int hash;
205 struct symbol *new;
206
207 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
208 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
209 new->module = module;
210 new->export = export;
211 return new;
212 }
213
214 static struct symbol *find_symbol(const char *name)
215 {
216 struct symbol *s;
217
218 /* For our purposes, .foo matches foo. PPC64 needs this. */
219 if (name[0] == '.')
220 name++;
221
222 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
223 if (strcmp(s->name, name) == 0)
224 return s;
225 }
226 return NULL;
227 }
228
229 static struct {
230 const char *str;
231 enum export export;
232 } export_list[] = {
233 { .str = "EXPORT_SYMBOL", .export = export_plain },
234 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
235 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
236 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
237 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
238 { .str = "(unknown)", .export = export_unknown },
239 };
240
241
242 static const char *export_str(enum export ex)
243 {
244 return export_list[ex].str;
245 }
246
247 static enum export export_no(const char *s)
248 {
249 int i;
250
251 if (!s)
252 return export_unknown;
253 for (i = 0; export_list[i].export != export_unknown; i++) {
254 if (strcmp(export_list[i].str, s) == 0)
255 return export_list[i].export;
256 }
257 return export_unknown;
258 }
259
260 static const char *sec_name(struct elf_info *elf, int secindex);
261
262 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
263
264 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
265 {
266 const char *secname = sec_name(elf, sec);
267
268 if (strstarts(secname, "___ksymtab+"))
269 return export_plain;
270 else if (strstarts(secname, "___ksymtab_unused+"))
271 return export_unused;
272 else if (strstarts(secname, "___ksymtab_gpl+"))
273 return export_gpl;
274 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
275 return export_unused_gpl;
276 else if (strstarts(secname, "___ksymtab_gpl_future+"))
277 return export_gpl_future;
278 else
279 return export_unknown;
280 }
281
282 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
283 {
284 if (sec == elf->export_sec)
285 return export_plain;
286 else if (sec == elf->export_unused_sec)
287 return export_unused;
288 else if (sec == elf->export_gpl_sec)
289 return export_gpl;
290 else if (sec == elf->export_unused_gpl_sec)
291 return export_unused_gpl;
292 else if (sec == elf->export_gpl_future_sec)
293 return export_gpl_future;
294 else
295 return export_unknown;
296 }
297
298 /**
299 * Add an exported symbol - it may have already been added without a
300 * CRC, in this case just update the CRC
301 **/
302 static struct symbol *sym_add_exported(const char *name, struct module *mod,
303 enum export export)
304 {
305 struct symbol *s = find_symbol(name);
306
307 if (!s) {
308 s = new_symbol(name, mod, export);
309 } else {
310 if (!s->preloaded) {
311 warn("%s: '%s' exported twice. Previous export "
312 "was in %s%s\n", mod->name, name,
313 s->module->name,
314 is_vmlinux(s->module->name) ?"":".ko");
315 } else {
316 /* In case Modules.symvers was out of date */
317 s->module = mod;
318 }
319 }
320 s->preloaded = 0;
321 s->vmlinux = is_vmlinux(mod->name);
322 s->kernel = 0;
323 s->export = export;
324 return s;
325 }
326
327 static void sym_update_crc(const char *name, struct module *mod,
328 unsigned int crc, enum export export)
329 {
330 struct symbol *s = find_symbol(name);
331
332 if (!s)
333 s = new_symbol(name, mod, export);
334 s->crc = crc;
335 s->crc_valid = 1;
336 }
337
338 void *grab_file(const char *filename, unsigned long *size)
339 {
340 struct stat st;
341 void *map = MAP_FAILED;
342 int fd;
343
344 fd = open(filename, O_RDONLY);
345 if (fd < 0)
346 return NULL;
347 if (fstat(fd, &st))
348 goto failed;
349
350 *size = st.st_size;
351 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
352
353 failed:
354 close(fd);
355 if (map == MAP_FAILED)
356 return NULL;
357 return map;
358 }
359
360 /**
361 * Return a copy of the next line in a mmap'ed file.
362 * spaces in the beginning of the line is trimmed away.
363 * Return a pointer to a static buffer.
364 **/
365 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
366 {
367 static char line[4096];
368 int skip = 1;
369 size_t len = 0;
370 signed char *p = (signed char *)file + *pos;
371 char *s = line;
372
373 for (; *pos < size ; (*pos)++) {
374 if (skip && isspace(*p)) {
375 p++;
376 continue;
377 }
378 skip = 0;
379 if (*p != '\n' && (*pos < size)) {
380 len++;
381 *s++ = *p++;
382 if (len > 4095)
383 break; /* Too long, stop */
384 } else {
385 /* End of string */
386 *s = '\0';
387 return line;
388 }
389 }
390 /* End of buffer */
391 return NULL;
392 }
393
394 void release_file(void *file, unsigned long size)
395 {
396 munmap(file, size);
397 }
398
399 static int parse_elf(struct elf_info *info, const char *filename)
400 {
401 unsigned int i;
402 Elf_Ehdr *hdr;
403 Elf_Shdr *sechdrs;
404 Elf_Sym *sym;
405 const char *secstrings;
406 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
407
408 hdr = grab_file(filename, &info->size);
409 if (!hdr) {
410 perror(filename);
411 exit(1);
412 }
413 info->hdr = hdr;
414 if (info->size < sizeof(*hdr)) {
415 /* file too small, assume this is an empty .o file */
416 return 0;
417 }
418 /* Is this a valid ELF file? */
419 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
420 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
421 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
422 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
423 /* Not an ELF file - silently ignore it */
424 return 0;
425 }
426 /* Fix endianness in ELF header */
427 hdr->e_type = TO_NATIVE(hdr->e_type);
428 hdr->e_machine = TO_NATIVE(hdr->e_machine);
429 hdr->e_version = TO_NATIVE(hdr->e_version);
430 hdr->e_entry = TO_NATIVE(hdr->e_entry);
431 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
432 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
433 hdr->e_flags = TO_NATIVE(hdr->e_flags);
434 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
435 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
436 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
437 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
438 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
439 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
440 sechdrs = (void *)hdr + hdr->e_shoff;
441 info->sechdrs = sechdrs;
442
443 /* Check if file offset is correct */
444 if (hdr->e_shoff > info->size) {
445 fatal("section header offset=%lu in file '%s' is bigger than "
446 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
447 filename, info->size);
448 return 0;
449 }
450
451 if (hdr->e_shnum == SHN_UNDEF) {
452 /*
453 * There are more than 64k sections,
454 * read count from .sh_size.
455 */
456 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
457 }
458 else {
459 info->num_sections = hdr->e_shnum;
460 }
461 if (hdr->e_shstrndx == SHN_XINDEX) {
462 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
463 }
464 else {
465 info->secindex_strings = hdr->e_shstrndx;
466 }
467
468 /* Fix endianness in section headers */
469 for (i = 0; i < info->num_sections; i++) {
470 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
471 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
472 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
473 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
474 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
475 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
476 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
477 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
478 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
479 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
480 }
481 /* Find symbol table. */
482 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
483 for (i = 1; i < info->num_sections; i++) {
484 const char *secname;
485 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
486
487 if (!nobits && sechdrs[i].sh_offset > info->size) {
488 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
489 "sizeof(*hrd)=%zu\n", filename,
490 (unsigned long)sechdrs[i].sh_offset,
491 sizeof(*hdr));
492 return 0;
493 }
494 secname = secstrings + sechdrs[i].sh_name;
495 if (strcmp(secname, ".modinfo") == 0) {
496 if (nobits)
497 fatal("%s has NOBITS .modinfo\n", filename);
498 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
499 info->modinfo_len = sechdrs[i].sh_size;
500 } else if (strcmp(secname, "__ksymtab") == 0)
501 info->export_sec = i;
502 else if (strcmp(secname, "__ksymtab_unused") == 0)
503 info->export_unused_sec = i;
504 else if (strcmp(secname, "__ksymtab_gpl") == 0)
505 info->export_gpl_sec = i;
506 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
507 info->export_unused_gpl_sec = i;
508 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
509 info->export_gpl_future_sec = i;
510
511 if (sechdrs[i].sh_type == SHT_SYMTAB) {
512 unsigned int sh_link_idx;
513 symtab_idx = i;
514 info->symtab_start = (void *)hdr +
515 sechdrs[i].sh_offset;
516 info->symtab_stop = (void *)hdr +
517 sechdrs[i].sh_offset + sechdrs[i].sh_size;
518 sh_link_idx = sechdrs[i].sh_link;
519 info->strtab = (void *)hdr +
520 sechdrs[sh_link_idx].sh_offset;
521 }
522
523 /* 32bit section no. table? ("more than 64k sections") */
524 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
525 symtab_shndx_idx = i;
526 info->symtab_shndx_start = (void *)hdr +
527 sechdrs[i].sh_offset;
528 info->symtab_shndx_stop = (void *)hdr +
529 sechdrs[i].sh_offset + sechdrs[i].sh_size;
530 }
531 }
532 if (!info->symtab_start)
533 fatal("%s has no symtab?\n", filename);
534
535 /* Fix endianness in symbols */
536 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
537 sym->st_shndx = TO_NATIVE(sym->st_shndx);
538 sym->st_name = TO_NATIVE(sym->st_name);
539 sym->st_value = TO_NATIVE(sym->st_value);
540 sym->st_size = TO_NATIVE(sym->st_size);
541 }
542
543 if (symtab_shndx_idx != ~0U) {
544 Elf32_Word *p;
545 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
546 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
547 filename, sechdrs[symtab_shndx_idx].sh_link,
548 symtab_idx);
549 /* Fix endianness */
550 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
551 p++)
552 *p = TO_NATIVE(*p);
553 }
554
555 return 1;
556 }
557
558 static void parse_elf_finish(struct elf_info *info)
559 {
560 release_file(info->hdr, info->size);
561 }
562
563 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
564 {
565 /* ignore __this_module, it will be resolved shortly */
566 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
567 return 1;
568 /* ignore global offset table */
569 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
570 return 1;
571 if (info->hdr->e_machine == EM_PPC)
572 /* Special register function linked on all modules during final link of .ko */
573 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
574 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
575 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
576 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
577 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
578 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
579 return 1;
580 if (info->hdr->e_machine == EM_PPC64)
581 /* Special register function linked on all modules during final link of .ko */
582 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
583 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
584 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
585 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
586 return 1;
587 /* Do not ignore this symbol */
588 return 0;
589 }
590
591 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
592 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
593
594 static void handle_modversions(struct module *mod, struct elf_info *info,
595 Elf_Sym *sym, const char *symname)
596 {
597 unsigned int crc;
598 enum export export;
599
600 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
601 strncmp(symname, "__ksymtab", 9) == 0)
602 export = export_from_secname(info, get_secindex(info, sym));
603 else
604 export = export_from_sec(info, get_secindex(info, sym));
605
606 switch (sym->st_shndx) {
607 case SHN_COMMON:
608 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
609 break;
610 case SHN_ABS:
611 /* CRC'd symbol */
612 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
613 crc = (unsigned int) sym->st_value;
614 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
615 export);
616 }
617 break;
618 case SHN_UNDEF:
619 /* undefined symbol */
620 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
621 ELF_ST_BIND(sym->st_info) != STB_WEAK)
622 break;
623 if (ignore_undef_symbol(info, symname))
624 break;
625 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
626 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
627 /* add compatibility with older glibc */
628 #ifndef STT_SPARC_REGISTER
629 #define STT_SPARC_REGISTER STT_REGISTER
630 #endif
631 if (info->hdr->e_machine == EM_SPARC ||
632 info->hdr->e_machine == EM_SPARCV9) {
633 /* Ignore register directives. */
634 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
635 break;
636 if (symname[0] == '.') {
637 char *munged = strdup(symname);
638 munged[0] = '_';
639 munged[1] = toupper(munged[1]);
640 symname = munged;
641 }
642 }
643 #endif
644
645 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
646 if (symname[0] != '_')
647 break;
648 else
649 symname++;
650 #endif
651 mod->unres = alloc_symbol(symname,
652 ELF_ST_BIND(sym->st_info) == STB_WEAK,
653 mod->unres);
654 break;
655 default:
656 /* All exported symbols */
657 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
658 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
659 export);
660 }
661 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
662 mod->has_init = 1;
663 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
664 mod->has_cleanup = 1;
665 break;
666 }
667 }
668
669 /**
670 * Parse tag=value strings from .modinfo section
671 **/
672 static char *next_string(char *string, unsigned long *secsize)
673 {
674 /* Skip non-zero chars */
675 while (string[0]) {
676 string++;
677 if ((*secsize)-- <= 1)
678 return NULL;
679 }
680
681 /* Skip any zero padding. */
682 while (!string[0]) {
683 string++;
684 if ((*secsize)-- <= 1)
685 return NULL;
686 }
687 return string;
688 }
689
690 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
691 const char *tag, char *info)
692 {
693 char *p;
694 unsigned int taglen = strlen(tag);
695 unsigned long size = modinfo_len;
696
697 if (info) {
698 size -= info - (char *)modinfo;
699 modinfo = next_string(info, &size);
700 }
701
702 for (p = modinfo; p; p = next_string(p, &size)) {
703 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
704 return p + taglen + 1;
705 }
706 return NULL;
707 }
708
709 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
710 const char *tag)
711
712 {
713 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
714 }
715
716 /**
717 * Test if string s ends in string sub
718 * return 0 if match
719 **/
720 static int strrcmp(const char *s, const char *sub)
721 {
722 int slen, sublen;
723
724 if (!s || !sub)
725 return 1;
726
727 slen = strlen(s);
728 sublen = strlen(sub);
729
730 if ((slen == 0) || (sublen == 0))
731 return 1;
732
733 if (sublen > slen)
734 return 1;
735
736 return memcmp(s + slen - sublen, sub, sublen);
737 }
738
739 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
740 {
741 if (sym)
742 return elf->strtab + sym->st_name;
743 else
744 return "(unknown)";
745 }
746
747 static const char *sec_name(struct elf_info *elf, int secindex)
748 {
749 Elf_Shdr *sechdrs = elf->sechdrs;
750 return (void *)elf->hdr +
751 elf->sechdrs[elf->secindex_strings].sh_offset +
752 sechdrs[secindex].sh_name;
753 }
754
755 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
756 {
757 return (void *)elf->hdr +
758 elf->sechdrs[elf->secindex_strings].sh_offset +
759 sechdr->sh_name;
760 }
761
762 /* if sym is empty or point to a string
763 * like ".[0-9]+" then return 1.
764 * This is the optional prefix added by ld to some sections
765 */
766 static int number_prefix(const char *sym)
767 {
768 if (*sym++ == '\0')
769 return 1;
770 if (*sym != '.')
771 return 0;
772 do {
773 char c = *sym++;
774 if (c < '' || c > '9')
775 return 0;
776 } while (*sym);
777 return 1;
778 }
779
780 /* The pattern is an array of simple patterns.
781 * "foo" will match an exact string equal to "foo"
782 * "*foo" will match a string that ends with "foo"
783 * "foo*" will match a string that begins with "foo"
784 * "foo$" will match a string equal to "foo" or "foo.1"
785 * where the '1' can be any number including several digits.
786 * The $ syntax is for sections where ld append a dot number
787 * to make section name unique.
788 */
789 static int match(const char *sym, const char * const pat[])
790 {
791 const char *p;
792 while (*pat) {
793 p = *pat++;
794 const char *endp = p + strlen(p) - 1;
795
796 /* "*foo" */
797 if (*p == '*') {
798 if (strrcmp(sym, p + 1) == 0)
799 return 1;
800 }
801 /* "foo*" */
802 else if (*endp == '*') {
803 if (strncmp(sym, p, strlen(p) - 1) == 0)
804 return 1;
805 }
806 /* "foo$" */
807 else if (*endp == '$') {
808 if (strncmp(sym, p, strlen(p) - 1) == 0) {
809 if (number_prefix(sym + strlen(p) - 1))
810 return 1;
811 }
812 }
813 /* no wildcards */
814 else {
815 if (strcmp(p, sym) == 0)
816 return 1;
817 }
818 }
819 /* no match */
820 return 0;
821 }
822
823 /* sections that we do not want to do full section mismatch check on */
824 static const char *section_white_list[] =
825 {
826 ".comment*",
827 ".debug*",
828 ".zdebug*", /* Compressed debug sections. */
829 ".GCC-command-line", /* mn10300 */
830 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
831 ".mdebug*", /* alpha, score, mips etc. */
832 ".pdr", /* alpha, score, mips etc. */
833 ".stab*",
834 ".note*",
835 ".got*",
836 ".toc*",
837 ".xt.prop", /* xtensa */
838 ".xt.lit", /* xtensa */
839 ".arcextmap*", /* arc */
840 ".gnu.linkonce.arcext*", /* arc : modules */
841 NULL
842 };
843
844 /*
845 * This is used to find sections missing the SHF_ALLOC flag.
846 * The cause of this is often a section specified in assembler
847 * without "ax" / "aw".
848 */
849 static void check_section(const char *modname, struct elf_info *elf,
850 Elf_Shdr *sechdr)
851 {
852 const char *sec = sech_name(elf, sechdr);
853
854 if (sechdr->sh_type == SHT_PROGBITS &&
855 !(sechdr->sh_flags & SHF_ALLOC) &&
856 !match(sec, section_white_list)) {
857 warn("%s (%s): unexpected non-allocatable section.\n"
858 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
859 "Note that for example <linux/init.h> contains\n"
860 "section definitions for use in .S files.\n\n",
861 modname, sec);
862 }
863 }
864
865
866
867 #define ALL_INIT_DATA_SECTIONS \
868 ".init.setup$", ".init.rodata$", \
869 ".cpuinit.rodata$", ".meminit.rodata$", \
870 ".init.data$", ".cpuinit.data$", ".meminit.data$"
871 #define ALL_EXIT_DATA_SECTIONS \
872 ".exit.data$", ".cpuexit.data$", ".memexit.data$"
873
874 #define ALL_INIT_TEXT_SECTIONS \
875 ".init.text$", ".cpuinit.text$", ".meminit.text$"
876 #define ALL_EXIT_TEXT_SECTIONS \
877 ".exit.text$", ".cpuexit.text$", ".memexit.text$"
878
879 #define ALL_PCI_INIT_SECTIONS \
880 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
881 ".pci_fixup_enable$", ".pci_fixup_resume$", \
882 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
883
884 #define ALL_XXXINIT_SECTIONS CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
885 #define ALL_XXXEXIT_SECTIONS CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS
886
887 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
888 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
889
890 #define DATA_SECTIONS ".data$", ".data.rel$"
891 #define TEXT_SECTIONS ".text$"
892
893 #define INIT_SECTIONS ".init.*"
894 #define CPU_INIT_SECTIONS ".cpuinit.*"
895 #define MEM_INIT_SECTIONS ".meminit.*"
896
897 #define EXIT_SECTIONS ".exit.*"
898 #define CPU_EXIT_SECTIONS ".cpuexit.*"
899 #define MEM_EXIT_SECTIONS ".memexit.*"
900
901 /* init data sections */
902 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
903
904 /* all init sections */
905 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
906
907 /* All init and exit sections (code + data) */
908 static const char *init_exit_sections[] =
909 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
910
911 /* data section */
912 static const char *data_sections[] = { DATA_SECTIONS, NULL };
913
914
915 /* symbols in .data that may refer to init/exit sections */
916 #define DEFAULT_SYMBOL_WHITE_LIST \
917 "*driver", \
918 "*_template", /* scsi uses *_template a lot */ \
919 "*_timer", /* arm uses ops structures named _timer a lot */ \
920 "*_sht", /* scsi also used *_sht to some extent */ \
921 "*_ops", \
922 "*_probe", \
923 "*_probe_one", \
924 "*_console"
925
926 static const char *head_sections[] = { ".head.text*", NULL };
927 static const char *linker_symbols[] =
928 { "__init_begin", "_sinittext", "_einittext", NULL };
929
930 enum mismatch {
931 TEXT_TO_ANY_INIT,
932 DATA_TO_ANY_INIT,
933 TEXT_TO_ANY_EXIT,
934 DATA_TO_ANY_EXIT,
935 XXXINIT_TO_SOME_INIT,
936 XXXEXIT_TO_SOME_EXIT,
937 ANY_INIT_TO_ANY_EXIT,
938 ANY_EXIT_TO_ANY_INIT,
939 EXPORT_TO_INIT_EXIT,
940 };
941
942 struct sectioncheck {
943 const char *fromsec[20];
944 const char *tosec[20];
945 enum mismatch mismatch;
946 const char *symbol_white_list[20];
947 };
948
949 const struct sectioncheck sectioncheck[] = {
950 /* Do not reference init/exit code/data from
951 * normal code and data
952 */
953 {
954 .fromsec = { TEXT_SECTIONS, NULL },
955 .tosec = { ALL_INIT_SECTIONS, NULL },
956 .mismatch = TEXT_TO_ANY_INIT,
957 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
958 },
959 {
960 .fromsec = { DATA_SECTIONS, NULL },
961 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
962 .mismatch = DATA_TO_ANY_INIT,
963 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
964 },
965 {
966 .fromsec = { DATA_SECTIONS, NULL },
967 .tosec = { INIT_SECTIONS, NULL },
968 .mismatch = DATA_TO_ANY_INIT,
969 .symbol_white_list = {
970 "*_template", "*_timer", "*_sht", "*_ops",
971 "*_probe", "*_probe_one", "*_console", NULL
972 },
973 },
974 {
975 .fromsec = { TEXT_SECTIONS, NULL },
976 .tosec = { ALL_EXIT_SECTIONS, NULL },
977 .mismatch = TEXT_TO_ANY_EXIT,
978 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
979 },
980 {
981 .fromsec = { DATA_SECTIONS, NULL },
982 .tosec = { ALL_EXIT_SECTIONS, NULL },
983 .mismatch = DATA_TO_ANY_EXIT,
984 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
985 },
986 /* Do not reference init code/data from cpuinit/meminit code/data */
987 {
988 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
989 .tosec = { INIT_SECTIONS, NULL },
990 .mismatch = XXXINIT_TO_SOME_INIT,
991 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
992 },
993 /* Do not reference cpuinit code/data from meminit code/data */
994 {
995 .fromsec = { MEM_INIT_SECTIONS, NULL },
996 .tosec = { CPU_INIT_SECTIONS, NULL },
997 .mismatch = XXXINIT_TO_SOME_INIT,
998 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
999 },
1000 /* Do not reference meminit code/data from cpuinit code/data */
1001 {
1002 .fromsec = { CPU_INIT_SECTIONS, NULL },
1003 .tosec = { MEM_INIT_SECTIONS, NULL },
1004 .mismatch = XXXINIT_TO_SOME_INIT,
1005 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1006 },
1007 /* Do not reference exit code/data from cpuexit/memexit code/data */
1008 {
1009 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1010 .tosec = { EXIT_SECTIONS, NULL },
1011 .mismatch = XXXEXIT_TO_SOME_EXIT,
1012 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1013 },
1014 /* Do not reference cpuexit code/data from memexit code/data */
1015 {
1016 .fromsec = { MEM_EXIT_SECTIONS, NULL },
1017 .tosec = { CPU_EXIT_SECTIONS, NULL },
1018 .mismatch = XXXEXIT_TO_SOME_EXIT,
1019 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1020 },
1021 /* Do not reference memexit code/data from cpuexit code/data */
1022 {
1023 .fromsec = { CPU_EXIT_SECTIONS, NULL },
1024 .tosec = { MEM_EXIT_SECTIONS, NULL },
1025 .mismatch = XXXEXIT_TO_SOME_EXIT,
1026 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1027 },
1028 /* Do not use exit code/data from init code */
1029 {
1030 .fromsec = { ALL_INIT_SECTIONS, NULL },
1031 .tosec = { ALL_EXIT_SECTIONS, NULL },
1032 .mismatch = ANY_INIT_TO_ANY_EXIT,
1033 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1034 },
1035 /* Do not use init code/data from exit code */
1036 {
1037 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1038 .tosec = { ALL_INIT_SECTIONS, NULL },
1039 .mismatch = ANY_EXIT_TO_ANY_INIT,
1040 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1041 },
1042 {
1043 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1044 .tosec = { INIT_SECTIONS, NULL },
1045 .mismatch = ANY_INIT_TO_ANY_EXIT,
1046 .symbol_white_list = { NULL },
1047 },
1048 /* Do not export init/exit functions or data */
1049 {
1050 .fromsec = { "__ksymtab*", NULL },
1051 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1052 .mismatch = EXPORT_TO_INIT_EXIT,
1053 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1054 }
1055 };
1056
1057 static const struct sectioncheck *section_mismatch(
1058 const char *fromsec, const char *tosec)
1059 {
1060 int i;
1061 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1062 const struct sectioncheck *check = §ioncheck[0];
1063
1064 for (i = 0; i < elems; i++) {
1065 if (match(fromsec, check->fromsec) &&
1066 match(tosec, check->tosec))
1067 return check;
1068 check++;
1069 }
1070 return NULL;
1071 }
1072
1073 /**
1074 * Whitelist to allow certain references to pass with no warning.
1075 *
1076 * Pattern 1:
1077 * If a module parameter is declared __initdata and permissions=0
1078 * then this is legal despite the warning generated.
1079 * We cannot see value of permissions here, so just ignore
1080 * this pattern.
1081 * The pattern is identified by:
1082 * tosec = .init.data
1083 * fromsec = .data*
1084 * atsym =__param*
1085 *
1086 * Pattern 1a:
1087 * module_param_call() ops can refer to __init set function if permissions=0
1088 * The pattern is identified by:
1089 * tosec = .init.text
1090 * fromsec = .data*
1091 * atsym = __param_ops_*
1092 *
1093 * Pattern 2:
1094 * Many drivers utilise a *driver container with references to
1095 * add, remove, probe functions etc.
1096 * These functions may often be marked __cpuinit and we do not want to
1097 * warn here.
1098 * the pattern is identified by:
1099 * tosec = init or exit section
1100 * fromsec = data section
1101 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1102 * *probe_one, *_console, *_timer
1103 *
1104 * Pattern 3:
1105 * Whitelist all references from .head.text to any init section
1106 *
1107 * Pattern 4:
1108 * Some symbols belong to init section but still it is ok to reference
1109 * these from non-init sections as these symbols don't have any memory
1110 * allocated for them and symbol address and value are same. So even
1111 * if init section is freed, its ok to reference those symbols.
1112 * For ex. symbols marking the init section boundaries.
1113 * This pattern is identified by
1114 * refsymname = __init_begin, _sinittext, _einittext
1115 *
1116 **/
1117 static int secref_whitelist(const struct sectioncheck *mismatch,
1118 const char *fromsec, const char *fromsym,
1119 const char *tosec, const char *tosym)
1120 {
1121 /* Check for pattern 1 */
1122 if (match(tosec, init_data_sections) &&
1123 match(fromsec, data_sections) &&
1124 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1125 return 0;
1126
1127 /* Check for pattern 1a */
1128 if (strcmp(tosec, ".init.text") == 0 &&
1129 match(fromsec, data_sections) &&
1130 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1131 return 0;
1132
1133 /* Check for pattern 2 */
1134 if (match(tosec, init_exit_sections) &&
1135 match(fromsec, data_sections) &&
1136 match(fromsym, mismatch->symbol_white_list))
1137 return 0;
1138
1139 /* Check for pattern 3 */
1140 if (match(fromsec, head_sections) &&
1141 match(tosec, init_sections))
1142 return 0;
1143
1144 /* Check for pattern 4 */
1145 if (match(tosym, linker_symbols))
1146 return 0;
1147
1148 return 1;
1149 }
1150
1151 /**
1152 * Find symbol based on relocation record info.
1153 * In some cases the symbol supplied is a valid symbol so
1154 * return refsym. If st_name != 0 we assume this is a valid symbol.
1155 * In other cases the symbol needs to be looked up in the symbol table
1156 * based on section and address.
1157 * **/
1158 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1159 Elf_Sym *relsym)
1160 {
1161 Elf_Sym *sym;
1162 Elf_Sym *near = NULL;
1163 Elf64_Sword distance = 20;
1164 Elf64_Sword d;
1165 unsigned int relsym_secindex;
1166
1167 if (relsym->st_name != 0)
1168 return relsym;
1169
1170 relsym_secindex = get_secindex(elf, relsym);
1171 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1172 if (get_secindex(elf, sym) != relsym_secindex)
1173 continue;
1174 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1175 continue;
1176 if (sym->st_value == addr)
1177 return sym;
1178 /* Find a symbol nearby - addr are maybe negative */
1179 d = sym->st_value - addr;
1180 if (d < 0)
1181 d = addr - sym->st_value;
1182 if (d < distance) {
1183 distance = d;
1184 near = sym;
1185 }
1186 }
1187 /* We need a close match */
1188 if (distance < 20)
1189 return near;
1190 else
1191 return NULL;
1192 }
1193
1194 static inline int is_arm_mapping_symbol(const char *str)
1195 {
1196 return str[0] == '$' && strchr("atd", str[1])
1197 && (str[2] == '\0' || str[2] == '.');
1198 }
1199
1200 /*
1201 * If there's no name there, ignore it; likewise, ignore it if it's
1202 * one of the magic symbols emitted used by current ARM tools.
1203 *
1204 * Otherwise if find_symbols_between() returns those symbols, they'll
1205 * fail the whitelist tests and cause lots of false alarms ... fixable
1206 * only by merging __exit and __init sections into __text, bloating
1207 * the kernel (which is especially evil on embedded platforms).
1208 */
1209 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1210 {
1211 const char *name = elf->strtab + sym->st_name;
1212
1213 if (!name || !strlen(name))
1214 return 0;
1215 return !is_arm_mapping_symbol(name);
1216 }
1217
1218 /*
1219 * Find symbols before or equal addr and after addr - in the section sec.
1220 * If we find two symbols with equal offset prefer one with a valid name.
1221 * The ELF format may have a better way to detect what type of symbol
1222 * it is, but this works for now.
1223 **/
1224 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1225 const char *sec)
1226 {
1227 Elf_Sym *sym;
1228 Elf_Sym *near = NULL;
1229 Elf_Addr distance = ~0;
1230
1231 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1232 const char *symsec;
1233
1234 if (is_shndx_special(sym->st_shndx))
1235 continue;
1236 symsec = sec_name(elf, get_secindex(elf, sym));
1237 if (strcmp(symsec, sec) != 0)
1238 continue;
1239 if (!is_valid_name(elf, sym))
1240 continue;
1241 if (sym->st_value <= addr) {
1242 if ((addr - sym->st_value) < distance) {
1243 distance = addr - sym->st_value;
1244 near = sym;
1245 } else if ((addr - sym->st_value) == distance) {
1246 near = sym;
1247 }
1248 }
1249 }
1250 return near;
1251 }
1252
1253 /*
1254 * Convert a section name to the function/data attribute
1255 * .init.text => __init
1256 * .cpuinit.data => __cpudata
1257 * .memexitconst => __memconst
1258 * etc.
1259 *
1260 * The memory of returned value has been allocated on a heap. The user of this
1261 * method should free it after usage.
1262 */
1263 static char *sec2annotation(const char *s)
1264 {
1265 if (match(s, init_exit_sections)) {
1266 char *p = malloc(20);
1267 char *r = p;
1268
1269 *p++ = '_';
1270 *p++ = '_';
1271 if (*s == '.')
1272 s++;
1273 while (*s && *s != '.')
1274 *p++ = *s++;
1275 *p = '\0';
1276 if (*s == '.')
1277 s++;
1278 if (strstr(s, "rodata") != NULL)
1279 strcat(p, "const ");
1280 else if (strstr(s, "data") != NULL)
1281 strcat(p, "data ");
1282 else
1283 strcat(p, " ");
1284 return r;
1285 } else {
1286 return strdup("");
1287 }
1288 }
1289
1290 static int is_function(Elf_Sym *sym)
1291 {
1292 if (sym)
1293 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1294 else
1295 return -1;
1296 }
1297
1298 static void print_section_list(const char * const list[20])
1299 {
1300 const char *const *s = list;
1301
1302 while (*s) {
1303 fprintf(stderr, "%s", *s);
1304 s++;
1305 if (*s)
1306 fprintf(stderr, ", ");
1307 }
1308 fprintf(stderr, "\n");
1309 }
1310
1311 /*
1312 * Print a warning about a section mismatch.
1313 * Try to find symbols near it so user can find it.
1314 * Check whitelist before warning - it may be a false positive.
1315 */
1316 static void report_sec_mismatch(const char *modname,
1317 const struct sectioncheck *mismatch,
1318 const char *fromsec,
1319 unsigned long long fromaddr,
1320 const char *fromsym,
1321 int from_is_func,
1322 const char *tosec, const char *tosym,
1323 int to_is_func)
1324 {
1325 const char *from, *from_p;
1326 const char *to, *to_p;
1327 char *prl_from;
1328 char *prl_to;
1329
1330 switch (from_is_func) {
1331 case 0: from = "variable"; from_p = ""; break;
1332 case 1: from = "function"; from_p = "()"; break;
1333 default: from = "(unknown reference)"; from_p = ""; break;
1334 }
1335 switch (to_is_func) {
1336 case 0: to = "variable"; to_p = ""; break;
1337 case 1: to = "function"; to_p = "()"; break;
1338 default: to = "(unknown reference)"; to_p = ""; break;
1339 }
1340
1341 sec_mismatch_count++;
1342 if (!sec_mismatch_verbose)
1343 return;
1344
1345 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1346 "to the %s %s:%s%s\n",
1347 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1348 tosym, to_p);
1349
1350 switch (mismatch->mismatch) {
1351 case TEXT_TO_ANY_INIT:
1352 prl_from = sec2annotation(fromsec);
1353 prl_to = sec2annotation(tosec);
1354 fprintf(stderr,
1355 "The function %s%s() references\n"
1356 "the %s %s%s%s.\n"
1357 "This is often because %s lacks a %s\n"
1358 "annotation or the annotation of %s is wrong.\n",
1359 prl_from, fromsym,
1360 to, prl_to, tosym, to_p,
1361 fromsym, prl_to, tosym);
1362 free(prl_from);
1363 free(prl_to);
1364 break;
1365 case DATA_TO_ANY_INIT: {
1366 prl_to = sec2annotation(tosec);
1367 fprintf(stderr,
1368 "The variable %s references\n"
1369 "the %s %s%s%s\n"
1370 "If the reference is valid then annotate the\n"
1371 "variable with __init* or __refdata (see linux/init.h) "
1372 "or name the variable:\n",
1373 fromsym, to, prl_to, tosym, to_p);
1374 print_section_list(mismatch->symbol_white_list);
1375 free(prl_to);
1376 break;
1377 }
1378 case TEXT_TO_ANY_EXIT:
1379 prl_to = sec2annotation(tosec);
1380 fprintf(stderr,
1381 "The function %s() references a %s in an exit section.\n"
1382 "Often the %s %s%s has valid usage outside the exit section\n"
1383 "and the fix is to remove the %sannotation of %s.\n",
1384 fromsym, to, to, tosym, to_p, prl_to, tosym);
1385 free(prl_to);
1386 break;
1387 case DATA_TO_ANY_EXIT: {
1388 prl_to = sec2annotation(tosec);
1389 fprintf(stderr,
1390 "The variable %s references\n"
1391 "the %s %s%s%s\n"
1392 "If the reference is valid then annotate the\n"
1393 "variable with __exit* (see linux/init.h) or "
1394 "name the variable:\n",
1395 fromsym, to, prl_to, tosym, to_p);
1396 print_section_list(mismatch->symbol_white_list);
1397 free(prl_to);
1398 break;
1399 }
1400 case XXXINIT_TO_SOME_INIT:
1401 case XXXEXIT_TO_SOME_EXIT:
1402 prl_from = sec2annotation(fromsec);
1403 prl_to = sec2annotation(tosec);
1404 fprintf(stderr,
1405 "The %s %s%s%s references\n"
1406 "a %s %s%s%s.\n"
1407 "If %s is only used by %s then\n"
1408 "annotate %s with a matching annotation.\n",
1409 from, prl_from, fromsym, from_p,
1410 to, prl_to, tosym, to_p,
1411 tosym, fromsym, tosym);
1412 free(prl_from);
1413 free(prl_to);
1414 break;
1415 case ANY_INIT_TO_ANY_EXIT:
1416 prl_from = sec2annotation(fromsec);
1417 prl_to = sec2annotation(tosec);
1418 fprintf(stderr,
1419 "The %s %s%s%s references\n"
1420 "a %s %s%s%s.\n"
1421 "This is often seen when error handling "
1422 "in the init function\n"
1423 "uses functionality in the exit path.\n"
1424 "The fix is often to remove the %sannotation of\n"
1425 "%s%s so it may be used outside an exit section.\n",
1426 from, prl_from, fromsym, from_p,
1427 to, prl_to, tosym, to_p,
1428 prl_to, tosym, to_p);
1429 free(prl_from);
1430 free(prl_to);
1431 break;
1432 case ANY_EXIT_TO_ANY_INIT:
1433 prl_from = sec2annotation(fromsec);
1434 prl_to = sec2annotation(tosec);
1435 fprintf(stderr,
1436 "The %s %s%s%s references\n"
1437 "a %s %s%s%s.\n"
1438 "This is often seen when error handling "
1439 "in the exit function\n"
1440 "uses functionality in the init path.\n"
1441 "The fix is often to remove the %sannotation of\n"
1442 "%s%s so it may be used outside an init section.\n",
1443 from, prl_from, fromsym, from_p,
1444 to, prl_to, tosym, to_p,
1445 prl_to, tosym, to_p);
1446 free(prl_from);
1447 free(prl_to);
1448 break;
1449 case EXPORT_TO_INIT_EXIT:
1450 prl_to = sec2annotation(tosec);
1451 fprintf(stderr,
1452 "The symbol %s is exported and annotated %s\n"
1453 "Fix this by removing the %sannotation of %s "
1454 "or drop the export.\n",
1455 tosym, prl_to, prl_to, tosym);
1456 free(prl_to);
1457 break;
1458 }
1459 fprintf(stderr, "\n");
1460 }
1461
1462 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1463 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1464 {
1465 const char *tosec;
1466 const struct sectioncheck *mismatch;
1467
1468 tosec = sec_name(elf, get_secindex(elf, sym));
1469 mismatch = section_mismatch(fromsec, tosec);
1470 if (mismatch) {
1471 Elf_Sym *to;
1472 Elf_Sym *from;
1473 const char *tosym;
1474 const char *fromsym;
1475
1476 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1477 fromsym = sym_name(elf, from);
1478 to = find_elf_symbol(elf, r->r_addend, sym);
1479 tosym = sym_name(elf, to);
1480
1481 /* check whitelist - we may ignore it */
1482 if (secref_whitelist(mismatch,
1483 fromsec, fromsym, tosec, tosym)) {
1484 report_sec_mismatch(modname, mismatch,
1485 fromsec, r->r_offset, fromsym,
1486 is_function(from), tosec, tosym,
1487 is_function(to));
1488 }
1489 }
1490 }
1491
1492 static unsigned int *reloc_location(struct elf_info *elf,
1493 Elf_Shdr *sechdr, Elf_Rela *r)
1494 {
1495 Elf_Shdr *sechdrs = elf->sechdrs;
1496 int section = sechdr->sh_info;
1497
1498 return (void *)elf->hdr + sechdrs[section].sh_offset +
1499 r->r_offset;
1500 }
1501
1502 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1503 {
1504 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1505 unsigned int *location = reloc_location(elf, sechdr, r);
1506
1507 switch (r_typ) {
1508 case R_386_32:
1509 r->r_addend = TO_NATIVE(*location);
1510 break;
1511 case R_386_PC32:
1512 r->r_addend = TO_NATIVE(*location) + 4;
1513 /* For CONFIG_RELOCATABLE=y */
1514 if (elf->hdr->e_type == ET_EXEC)
1515 r->r_addend += r->r_offset;
1516 break;
1517 }
1518 return 0;
1519 }
1520
1521 #ifndef R_ARM_CALL
1522 #define R_ARM_CALL 28
1523 #endif
1524 #ifndef R_ARM_JUMP24
1525 #define R_ARM_JUMP24 29
1526 #endif
1527
1528 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1529 {
1530 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1531
1532 switch (r_typ) {
1533 case R_ARM_ABS32:
1534 /* From ARM ABI: (S + A) | T */
1535 r->r_addend = (int)(long)
1536 (elf->symtab_start + ELF_R_SYM(r->r_info));
1537 break;
1538 case R_ARM_PC24:
1539 case R_ARM_CALL:
1540 case R_ARM_JUMP24:
1541 /* From ARM ABI: ((S + A) | T) - P */
1542 r->r_addend = (int)(long)(elf->hdr +
1543 sechdr->sh_offset +
1544 (r->r_offset - sechdr->sh_addr));
1545 break;
1546 default:
1547 return 1;
1548 }
1549 return 0;
1550 }
1551
1552 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1553 {
1554 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1555 unsigned int *location = reloc_location(elf, sechdr, r);
1556 unsigned int inst;
1557
1558 if (r_typ == R_MIPS_HI16)
1559 return 1; /* skip this */
1560 inst = TO_NATIVE(*location);
1561 switch (r_typ) {
1562 case R_MIPS_LO16:
1563 r->r_addend = inst & 0xffff;
1564 break;
1565 case R_MIPS_26:
1566 r->r_addend = (inst & 0x03ffffff) << 2;
1567 break;
1568 case R_MIPS_32:
1569 r->r_addend = inst;
1570 break;
1571 }
1572 return 0;
1573 }
1574
1575 static void section_rela(const char *modname, struct elf_info *elf,
1576 Elf_Shdr *sechdr)
1577 {
1578 Elf_Sym *sym;
1579 Elf_Rela *rela;
1580 Elf_Rela r;
1581 unsigned int r_sym;
1582 const char *fromsec;
1583
1584 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1585 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1586
1587 fromsec = sech_name(elf, sechdr);
1588 fromsec += strlen(".rela");
1589 /* if from section (name) is know good then skip it */
1590 if (match(fromsec, section_white_list))
1591 return;
1592
1593 for (rela = start; rela < stop; rela++) {
1594 r.r_offset = TO_NATIVE(rela->r_offset);
1595 #if KERNEL_ELFCLASS == ELFCLASS64
1596 if (elf->hdr->e_machine == EM_MIPS) {
1597 unsigned int r_typ;
1598 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1599 r_sym = TO_NATIVE(r_sym);
1600 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1601 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1602 } else {
1603 r.r_info = TO_NATIVE(rela->r_info);
1604 r_sym = ELF_R_SYM(r.r_info);
1605 }
1606 #else
1607 r.r_info = TO_NATIVE(rela->r_info);
1608 r_sym = ELF_R_SYM(r.r_info);
1609 #endif
1610 r.r_addend = TO_NATIVE(rela->r_addend);
1611 sym = elf->symtab_start + r_sym;
1612 /* Skip special sections */
1613 if (is_shndx_special(sym->st_shndx))
1614 continue;
1615 check_section_mismatch(modname, elf, &r, sym, fromsec);
1616 }
1617 }
1618
1619 static void section_rel(const char *modname, struct elf_info *elf,
1620 Elf_Shdr *sechdr)
1621 {
1622 Elf_Sym *sym;
1623 Elf_Rel *rel;
1624 Elf_Rela r;
1625 unsigned int r_sym;
1626 const char *fromsec;
1627
1628 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1629 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1630
1631 fromsec = sech_name(elf, sechdr);
1632 fromsec += strlen(".rel");
1633 /* if from section (name) is know good then skip it */
1634 if (match(fromsec, section_white_list))
1635 return;
1636
1637 for (rel = start; rel < stop; rel++) {
1638 r.r_offset = TO_NATIVE(rel->r_offset);
1639 #if KERNEL_ELFCLASS == ELFCLASS64
1640 if (elf->hdr->e_machine == EM_MIPS) {
1641 unsigned int r_typ;
1642 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1643 r_sym = TO_NATIVE(r_sym);
1644 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1645 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1646 } else {
1647 r.r_info = TO_NATIVE(rel->r_info);
1648 r_sym = ELF_R_SYM(r.r_info);
1649 }
1650 #else
1651 r.r_info = TO_NATIVE(rel->r_info);
1652 r_sym = ELF_R_SYM(r.r_info);
1653 #endif
1654 r.r_addend = 0;
1655 switch (elf->hdr->e_machine) {
1656 case EM_386:
1657 if (addend_386_rel(elf, sechdr, &r))
1658 continue;
1659 break;
1660 case EM_ARM:
1661 if (addend_arm_rel(elf, sechdr, &r))
1662 continue;
1663 break;
1664 case EM_MIPS:
1665 if (addend_mips_rel(elf, sechdr, &r))
1666 continue;
1667 break;
1668 }
1669 sym = elf->symtab_start + r_sym;
1670 /* Skip special sections */
1671 if (is_shndx_special(sym->st_shndx))
1672 continue;
1673 check_section_mismatch(modname, elf, &r, sym, fromsec);
1674 }
1675 }
1676
1677 /**
1678 * A module includes a number of sections that are discarded
1679 * either when loaded or when used as built-in.
1680 * For loaded modules all functions marked __init and all data
1681 * marked __initdata will be discarded when the module has been initialized.
1682 * Likewise for modules used built-in the sections marked __exit
1683 * are discarded because __exit marked function are supposed to be called
1684 * only when a module is unloaded which never happens for built-in modules.
1685 * The check_sec_ref() function traverses all relocation records
1686 * to find all references to a section that reference a section that will
1687 * be discarded and warns about it.
1688 **/
1689 static void check_sec_ref(struct module *mod, const char *modname,
1690 struct elf_info *elf)
1691 {
1692 int i;
1693 Elf_Shdr *sechdrs = elf->sechdrs;
1694
1695 /* Walk through all sections */
1696 for (i = 0; i < elf->num_sections; i++) {
1697 check_section(modname, elf, &elf->sechdrs[i]);
1698 /* We want to process only relocation sections and not .init */
1699 if (sechdrs[i].sh_type == SHT_RELA)
1700 section_rela(modname, elf, &elf->sechdrs[i]);
1701 else if (sechdrs[i].sh_type == SHT_REL)
1702 section_rel(modname, elf, &elf->sechdrs[i]);
1703 }
1704 }
1705
1706 static void read_symbols(char *modname)
1707 {
1708 const char *symname;
1709 char *version;
1710 char *license;
1711 struct module *mod;
1712 struct elf_info info = { };
1713 Elf_Sym *sym;
1714
1715 if (!parse_elf(&info, modname))
1716 return;
1717
1718 mod = new_module(modname);
1719
1720 /* When there's no vmlinux, don't print warnings about
1721 * unresolved symbols (since there'll be too many ;) */
1722 if (is_vmlinux(modname)) {
1723 have_vmlinux = 1;
1724 mod->skip = 1;
1725 }
1726
1727 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1728 if (info.modinfo && !license && !is_vmlinux(modname))
1729 warn("modpost: missing MODULE_LICENSE() in %s\n"
1730 "see include/linux/module.h for "
1731 "more information\n", modname);
1732 while (license) {
1733 if (license_is_gpl_compatible(license))
1734 mod->gpl_compatible = 1;
1735 else {
1736 mod->gpl_compatible = 0;
1737 break;
1738 }
1739 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1740 "license", license);
1741 }
1742
1743 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1744 symname = info.strtab + sym->st_name;
1745
1746 handle_modversions(mod, &info, sym, symname);
1747 handle_moddevtable(mod, &info, sym, symname);
1748 }
1749 if (!is_vmlinux(modname) ||
1750 (is_vmlinux(modname) && vmlinux_section_warnings))
1751 check_sec_ref(mod, modname, &info);
1752
1753 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1754 if (version)
1755 maybe_frob_rcs_version(modname, version, info.modinfo,
1756 version - (char *)info.hdr);
1757 if (version || (all_versions && !is_vmlinux(modname)))
1758 get_src_version(modname, mod->srcversion,
1759 sizeof(mod->srcversion)-1);
1760
1761 parse_elf_finish(&info);
1762
1763 /* Our trick to get versioning for module struct etc. - it's
1764 * never passed as an argument to an exported function, so
1765 * the automatic versioning doesn't pick it up, but it's really
1766 * important anyhow */
1767 if (modversions)
1768 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1769 }
1770
1771 static void read_symbols_from_files(const char *filename)
1772 {
1773 FILE *in = stdin;
1774 char fname[PATH_MAX];
1775
1776 if (strcmp(filename, "-") != 0) {
1777 in = fopen(filename, "r");
1778 if (!in)
1779 fatal("Can't open filenames file %s: %m", filename);
1780 }
1781
1782 while (fgets(fname, PATH_MAX, in) != NULL) {
1783 if (strends(fname, "\n"))
1784 fname[strlen(fname)-1] = '\0';
1785 read_symbols(fname);
1786 }
1787
1788 if (in != stdin)
1789 fclose(in);
1790 }
1791
1792 #define SZ 500
1793
1794 /* We first write the generated file into memory using the
1795 * following helper, then compare to the file on disk and
1796 * only update the later if anything changed */
1797
1798 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1799 const char *fmt, ...)
1800 {
1801 char tmp[SZ];
1802 int len;
1803 va_list ap;
1804
1805 va_start(ap, fmt);
1806 len = vsnprintf(tmp, SZ, fmt, ap);
1807 buf_write(buf, tmp, len);
1808 va_end(ap);
1809 }
1810
1811 void buf_write(struct buffer *buf, const char *s, int len)
1812 {
1813 if (buf->size - buf->pos < len) {
1814 buf->size += len + SZ;
1815 buf->p = realloc(buf->p, buf->size);
1816 }
1817 strncpy(buf->p + buf->pos, s, len);
1818 buf->pos += len;
1819 }
1820
1821 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1822 {
1823 const char *e = is_vmlinux(m) ?"":".ko";
1824
1825 switch (exp) {
1826 case export_gpl:
1827 fatal("modpost: GPL-incompatible module %s%s "
1828 "uses GPL-only symbol '%s'\n", m, e, s);
1829 break;
1830 case export_unused_gpl:
1831 fatal("modpost: GPL-incompatible module %s%s "
1832 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1833 break;
1834 case export_gpl_future:
1835 warn("modpost: GPL-incompatible module %s%s "
1836 "uses future GPL-only symbol '%s'\n", m, e, s);
1837 break;
1838 case export_plain:
1839 case export_unused:
1840 case export_unknown:
1841 /* ignore */
1842 break;
1843 }
1844 }
1845
1846 static void check_for_unused(enum export exp, const char *m, const char *s)
1847 {
1848 const char *e = is_vmlinux(m) ?"":".ko";
1849
1850 switch (exp) {
1851 case export_unused:
1852 case export_unused_gpl:
1853 warn("modpost: module %s%s "
1854 "uses symbol '%s' marked UNUSED\n", m, e, s);
1855 break;
1856 default:
1857 /* ignore */
1858 break;
1859 }
1860 }
1861
1862 static void check_exports(struct module *mod)
1863 {
1864 struct symbol *s, *exp;
1865
1866 for (s = mod->unres; s; s = s->next) {
1867 const char *basename;
1868 exp = find_symbol(s->name);
1869 if (!exp || exp->module == mod)
1870 continue;
1871 basename = strrchr(mod->name, '/');
1872 if (basename)
1873 basename++;
1874 else
1875 basename = mod->name;
1876 if (!mod->gpl_compatible)
1877 check_for_gpl_usage(exp->export, basename, exp->name);
1878 check_for_unused(exp->export, basename, exp->name);
1879 }
1880 }
1881
1882 /**
1883 * Header for the generated file
1884 **/
1885 static void add_header(struct buffer *b, struct module *mod)
1886 {
1887 buf_printf(b, "#include <linux/module.h>\n");
1888 buf_printf(b, "#include <linux/vermagic.h>\n");
1889 buf_printf(b, "#include <linux/compiler.h>\n");
1890 buf_printf(b, "\n");
1891 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1892 buf_printf(b, "\n");
1893 buf_printf(b, "struct module __this_module\n");
1894 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1895 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1896 if (mod->has_init)
1897 buf_printf(b, "\t.init = init_module,\n");
1898 if (mod->has_cleanup)
1899 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1900 "\t.exit = cleanup_module,\n"
1901 "#endif\n");
1902 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1903 buf_printf(b, "};\n");
1904 }
1905
1906 static void add_intree_flag(struct buffer *b, int is_intree)
1907 {
1908 if (is_intree)
1909 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1910 }
1911
1912 static void add_staging_flag(struct buffer *b, const char *name)
1913 {
1914 static const char *staging_dir = "drivers/staging";
1915
1916 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1917 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1918 }
1919
1920 /**
1921 * Record CRCs for unresolved symbols
1922 **/
1923 static int add_versions(struct buffer *b, struct module *mod)
1924 {
1925 struct symbol *s, *exp;
1926 int err = 0;
1927
1928 for (s = mod->unres; s; s = s->next) {
1929 exp = find_symbol(s->name);
1930 if (!exp || exp->module == mod) {
1931 if (have_vmlinux && !s->weak) {
1932 if (warn_unresolved) {
1933 warn("\"%s\" [%s.ko] undefined!\n",
1934 s->name, mod->name);
1935 } else {
1936 merror("\"%s\" [%s.ko] undefined!\n",
1937 s->name, mod->name);
1938 err = 1;
1939 }
1940 }
1941 continue;
1942 }
1943 s->module = exp->module;
1944 s->crc_valid = exp->crc_valid;
1945 s->crc = exp->crc;
1946 }
1947
1948 if (!modversions)
1949 return err;
1950
1951 buf_printf(b, "\n");
1952 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1953 buf_printf(b, "__used\n");
1954 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1955
1956 for (s = mod->unres; s; s = s->next) {
1957 if (!s->module)
1958 continue;
1959 if (!s->crc_valid) {
1960 warn("\"%s\" [%s.ko] has no CRC!\n",
1961 s->name, mod->name);
1962 continue;
1963 }
1964 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1965 s->crc, s->name);
1966 }
1967
1968 buf_printf(b, "};\n");
1969
1970 return err;
1971 }
1972
1973 static void add_depends(struct buffer *b, struct module *mod,
1974 struct module *modules)
1975 {
1976 struct symbol *s;
1977 struct module *m;
1978 int first = 1;
1979
1980 for (m = modules; m; m = m->next)
1981 m->seen = is_vmlinux(m->name);
1982
1983 buf_printf(b, "\n");
1984 buf_printf(b, "static const char __module_depends[]\n");
1985 buf_printf(b, "__used\n");
1986 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1987 buf_printf(b, "\"depends=");
1988 for (s = mod->unres; s; s = s->next) {
1989 const char *p;
1990 if (!s->module)
1991 continue;
1992
1993 if (s->module->seen)
1994 continue;
1995
1996 s->module->seen = 1;
1997 p = strrchr(s->module->name, '/');
1998 if (p)
1999 p++;
2000 else
2001 p = s->module->name;
2002 buf_printf(b, "%s%s", first ? "" : ",", p);
2003 first = 0;
2004 }
2005 buf_printf(b, "\";\n");
2006 }
2007
2008 static void add_srcversion(struct buffer *b, struct module *mod)
2009 {
2010 if (mod->srcversion[0]) {
2011 buf_printf(b, "\n");
2012 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2013 mod->srcversion);
2014 }
2015 }
2016
2017 static void write_if_changed(struct buffer *b, const char *fname)
2018 {
2019 char *tmp;
2020 FILE *file;
2021 struct stat st;
2022
2023 file = fopen(fname, "r");
2024 if (!file)
2025 goto write;
2026
2027 if (fstat(fileno(file), &st) < 0)
2028 goto close_write;
2029
2030 if (st.st_size != b->pos)
2031 goto close_write;
2032
2033 tmp = NOFAIL(malloc(b->pos));
2034 if (fread(tmp, 1, b->pos, file) != b->pos)
2035 goto free_write;
2036
2037 if (memcmp(tmp, b->p, b->pos) != 0)
2038 goto free_write;
2039
2040 free(tmp);
2041 fclose(file);
2042 return;
2043
2044 free_write:
2045 free(tmp);
2046 close_write:
2047 fclose(file);
2048 write:
2049 file = fopen(fname, "w");
2050 if (!file) {
2051 perror(fname);
2052 exit(1);
2053 }
2054 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2055 perror(fname);
2056 exit(1);
2057 }
2058 fclose(file);
2059 }
2060
2061 /* parse Module.symvers file. line format:
2062 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2063 **/
2064 static void read_dump(const char *fname, unsigned int kernel)
2065 {
2066 unsigned long size, pos = 0;
2067 void *file = grab_file(fname, &size);
2068 char *line;
2069
2070 if (!file)
2071 /* No symbol versions, silently ignore */
2072 return;
2073
2074 while ((line = get_next_line(&pos, file, size))) {
2075 char *symname, *modname, *d, *export, *end;
2076 unsigned int crc;
2077 struct module *mod;
2078 struct symbol *s;
2079
2080 if (!(symname = strchr(line, '\t')))
2081 goto fail;
2082 *symname++ = '\0';
2083 if (!(modname = strchr(symname, '\t')))
2084 goto fail;
2085 *modname++ = '\0';
2086 if ((export = strchr(modname, '\t')) != NULL)
2087 *export++ = '\0';
2088 if (export && ((end = strchr(export, '\t')) != NULL))
2089 *end = '\0';
2090 crc = strtoul(line, &d, 16);
2091 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2092 goto fail;
2093 mod = find_module(modname);
2094 if (!mod) {
2095 if (is_vmlinux(modname))
2096 have_vmlinux = 1;
2097 mod = new_module(modname);
2098 mod->skip = 1;
2099 }
2100 s = sym_add_exported(symname, mod, export_no(export));
2101 s->kernel = kernel;
2102 s->preloaded = 1;
2103 sym_update_crc(symname, mod, crc, export_no(export));
2104 }
2105 return;
2106 fail:
2107 fatal("parse error in symbol dump file\n");
2108 }
2109
2110 /* For normal builds always dump all symbols.
2111 * For external modules only dump symbols
2112 * that are not read from kernel Module.symvers.
2113 **/
2114 static int dump_sym(struct symbol *sym)
2115 {
2116 if (!external_module)
2117 return 1;
2118 if (sym->vmlinux || sym->kernel)
2119 return 0;
2120 return 1;
2121 }
2122
2123 static void write_dump(const char *fname)
2124 {
2125 struct buffer buf = { };
2126 struct symbol *symbol;
2127 int n;
2128
2129 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2130 symbol = symbolhash[n];
2131 while (symbol) {
2132 if (dump_sym(symbol))
2133 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2134 symbol->crc, symbol->name,
2135 symbol->module->name,
2136 export_str(symbol->export));
2137 symbol = symbol->next;
2138 }
2139 }
2140 write_if_changed(&buf, fname);
2141 }
2142
2143 struct ext_sym_list {
2144 struct ext_sym_list *next;
2145 const char *file;
2146 };
2147
2148 int main(int argc, char **argv)
2149 {
2150 struct module *mod;
2151 struct buffer buf = { };
2152 char *kernel_read = NULL, *module_read = NULL;
2153 char *dump_write = NULL, *files_source = NULL;
2154 int opt;
2155 int err;
2156 struct ext_sym_list *extsym_iter;
2157 struct ext_sym_list *extsym_start = NULL;
2158
2159 while ((opt = getopt(argc, argv, "i:I:e:msST:o:awM:K:")) != -1) {
2160 switch (opt) {
2161 case 'i':
2162 kernel_read = optarg;
2163 break;
2164 case 'I':
2165 module_read = optarg;
2166 external_module = 1;
2167 break;
2168 case 'e':
2169 external_module = 1;
2170 extsym_iter =
2171 NOFAIL(malloc(sizeof(*extsym_iter)));
2172 extsym_iter->next = extsym_start;
2173 extsym_iter->file = optarg;
2174 extsym_start = extsym_iter;
2175 break;
2176 case 'm':
2177 modversions = 1;
2178 break;
2179 case 'o':
2180 dump_write = optarg;
2181 break;
2182 case 'a':
2183 all_versions = 1;
2184 break;
2185 case 's':
2186 vmlinux_section_warnings = 0;
2187 break;
2188 case 'S':
2189 sec_mismatch_verbose = 0;
2190 break;
2191 case 'T':
2192 files_source = optarg;
2193 break;
2194 case 'w':
2195 warn_unresolved = 1;
2196 break;
2197 default:
2198 exit(1);
2199 }
2200 }
2201
2202 if (kernel_read)
2203 read_dump(kernel_read, 1);
2204 if (module_read)
2205 read_dump(module_read, 0);
2206 while (extsym_start) {
2207 read_dump(extsym_start->file, 0);
2208 extsym_iter = extsym_start->next;
2209 free(extsym_start);
2210 extsym_start = extsym_iter;
2211 }
2212
2213 while (optind < argc)
2214 read_symbols(argv[optind++]);
2215
2216 if (files_source)
2217 read_symbols_from_files(files_source);
2218
2219 for (mod = modules; mod; mod = mod->next) {
2220 if (mod->skip)
2221 continue;
2222 check_exports(mod);
2223 }
2224
2225 err = 0;
2226
2227 for (mod = modules; mod; mod = mod->next) {
2228 char fname[strlen(mod->name) + 10];
2229
2230 if (mod->skip)
2231 continue;
2232
2233 buf.pos = 0;
2234
2235 add_header(&buf, mod);
2236 add_intree_flag(&buf, !external_module);
2237 add_staging_flag(&buf, mod->name);
2238 err |= add_versions(&buf, mod);
2239 add_depends(&buf, mod, modules);
2240 add_moddevtable(&buf, mod);
2241 add_srcversion(&buf, mod);
2242
2243 sprintf(fname, "%s.mod.c", mod->name);
2244 write_if_changed(&buf, fname);
2245 }
2246
2247 if (dump_write)
2248 write_dump(dump_write);
2249 if (sec_mismatch_count && !sec_mismatch_verbose)
2250 warn("modpost: Found %d section mismatch(es).\n"
2251 "To see full details build your kernel with:\n"
2252 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2253 sec_mismatch_count);
2254
2255 return err;
2256 }
2257
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