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Avoid beyond bounds copy while caching ACL
[zen-stable.git] / scripts / mod / modpost.c
blobc4e7d1510f9dfd3136d80e63684b8dc764794950
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 "modpost.h"
19 #include "../../include/generated/autoconf.h"
20 #include "../../include/linux/license.h"
21
22 /* Some toolchains use a `_' prefix for all user symbols. */
23 #ifdef CONFIG_SYMBOL_PREFIX
24 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
25 #else
26 #define MODULE_SYMBOL_PREFIX ""
27 #endif
28
29
30 /* Are we using CONFIG_MODVERSIONS? */
31 int modversions = 0;
32 /* Warn about undefined symbols? (do so if we have vmlinux) */
33 int have_vmlinux = 0;
34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35 static int all_versions = 0;
36 /* If we are modposting external module set to 1 */
37 static int external_module = 0;
38 /* Warn about section mismatch in vmlinux if set to 1 */
39 static int vmlinux_section_warnings = 1;
40 /* Only warn about unresolved symbols */
41 static int warn_unresolved = 0;
42 /* How a symbol is exported */
43 static int sec_mismatch_count = 0;
44 static int sec_mismatch_verbose = 1;
45
46 enum export {
47 export_plain, export_unused, export_gpl,
48 export_unused_gpl, export_gpl_future, export_unknown
49 };
50
51 #define PRINTF __attribute__ ((format (printf, 1, 2)))
52
53 PRINTF void fatal(const char *fmt, ...)
54 {
55 va_list arglist;
56
57 fprintf(stderr, "FATAL: ");
58
59 va_start(arglist, fmt);
60 vfprintf(stderr, fmt, arglist);
61 va_end(arglist);
62
63 exit(1);
64 }
65
66 PRINTF void warn(const char *fmt, ...)
67 {
68 va_list arglist;
69
70 fprintf(stderr, "WARNING: ");
71
72 va_start(arglist, fmt);
73 vfprintf(stderr, fmt, arglist);
74 va_end(arglist);
75 }
76
77 PRINTF void merror(const char *fmt, ...)
78 {
79 va_list arglist;
80
81 fprintf(stderr, "ERROR: ");
82
83 va_start(arglist, fmt);
84 vfprintf(stderr, fmt, arglist);
85 va_end(arglist);
86 }
87
88 static int is_vmlinux(const char *modname)
89 {
90 const char *myname;
91
92 myname = strrchr(modname, '/');
93 if (myname)
94 myname++;
95 else
96 myname = modname;
97
98 return (strcmp(myname, "vmlinux") == 0) ||
99 (strcmp(myname, "vmlinux.o") == 0);
100 }
101
102 void *do_nofail(void *ptr, const char *expr)
103 {
104 if (!ptr)
105 fatal("modpost: Memory allocation failure: %s.\n", expr);
106
107 return ptr;
108 }
109
110 /* A list of all modules we processed */
111 static struct module *modules;
112
113 static struct module *find_module(char *modname)
114 {
115 struct module *mod;
116
117 for (mod = modules; mod; mod = mod->next)
118 if (strcmp(mod->name, modname) == 0)
119 break;
120 return mod;
121 }
122
123 static struct module *new_module(char *modname)
124 {
125 struct module *mod;
126 char *p, *s;
127
128 mod = NOFAIL(malloc(sizeof(*mod)));
129 memset(mod, 0, sizeof(*mod));
130 p = NOFAIL(strdup(modname));
131
132 /* strip trailing .o */
133 s = strrchr(p, '.');
134 if (s != NULL)
135 if (strcmp(s, ".o") == 0) {
136 *s = '\0';
137 mod->is_dot_o = 1;
138 }
139
140 /* add to list */
141 mod->name = p;
142 mod->gpl_compatible = -1;
143 mod->next = modules;
144 modules = mod;
145
146 return mod;
147 }
148
149 /* A hash of all exported symbols,
150 * struct symbol is also used for lists of unresolved symbols */
151
152 #define SYMBOL_HASH_SIZE 1024
153
154 struct symbol {
155 struct symbol *next;
156 struct module *module;
157 unsigned int crc;
158 int crc_valid;
159 unsigned int weak:1;
160 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
161 unsigned int kernel:1; /* 1 if symbol is from kernel
162 * (only for external modules) **/
163 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
164 enum export export; /* Type of export */
165 char name[0];
166 };
167
168 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
169
170 /* This is based on the hash agorithm from gdbm, via tdb */
171 static inline unsigned int tdb_hash(const char *name)
172 {
173 unsigned value; /* Used to compute the hash value. */
174 unsigned i; /* Used to cycle through random values. */
175
176 /* Set the initial value from the key size. */
177 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
178 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
179
180 return (1103515243 * value + 12345);
181 }
182
183 /**
184 * Allocate a new symbols for use in the hash of exported symbols or
185 * the list of unresolved symbols per module
186 **/
187 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
188 struct symbol *next)
189 {
190 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
191
192 memset(s, 0, sizeof(*s));
193 strcpy(s->name, name);
194 s->weak = weak;
195 s->next = next;
196 return s;
197 }
198
199 /* For the hash of exported symbols */
200 static struct symbol *new_symbol(const char *name, struct module *module,
201 enum export export)
202 {
203 unsigned int hash;
204 struct symbol *new;
205
206 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
207 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
208 new->module = module;
209 new->export = export;
210 return new;
211 }
212
213 static struct symbol *find_symbol(const char *name)
214 {
215 struct symbol *s;
216
217 /* For our purposes, .foo matches foo. PPC64 needs this. */
218 if (name[0] == '.')
219 name++;
220
221 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
222 if (strcmp(s->name, name) == 0)
223 return s;
224 }
225 return NULL;
226 }
227
228 static struct {
229 const char *str;
230 enum export export;
231 } export_list[] = {
232 { .str = "EXPORT_SYMBOL", .export = export_plain },
233 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
234 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
235 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
236 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
237 { .str = "(unknown)", .export = export_unknown },
238 };
239
240
241 static const char *export_str(enum export ex)
242 {
243 return export_list[ex].str;
244 }
245
246 static enum export export_no(const char *s)
247 {
248 int i;
249
250 if (!s)
251 return export_unknown;
252 for (i = 0; export_list[i].export != export_unknown; i++) {
253 if (strcmp(export_list[i].str, s) == 0)
254 return export_list[i].export;
255 }
256 return export_unknown;
257 }
258
259 static const char *sec_name(struct elf_info *elf, int secindex);
260
261 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
262
263 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
264 {
265 const char *secname = sec_name(elf, sec);
266
267 if (strstarts(secname, "___ksymtab+"))
268 return export_plain;
269 else if (strstarts(secname, "___ksymtab_unused+"))
270 return export_unused;
271 else if (strstarts(secname, "___ksymtab_gpl+"))
272 return export_gpl;
273 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
274 return export_unused_gpl;
275 else if (strstarts(secname, "___ksymtab_gpl_future+"))
276 return export_gpl_future;
277 else
278 return export_unknown;
279 }
280
281 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
282 {
283 if (sec == elf->export_sec)
284 return export_plain;
285 else if (sec == elf->export_unused_sec)
286 return export_unused;
287 else if (sec == elf->export_gpl_sec)
288 return export_gpl;
289 else if (sec == elf->export_unused_gpl_sec)
290 return export_unused_gpl;
291 else if (sec == elf->export_gpl_future_sec)
292 return export_gpl_future;
293 else
294 return export_unknown;
295 }
296
297 /**
298 * Add an exported symbol - it may have already been added without a
299 * CRC, in this case just update the CRC
300 **/
301 static struct symbol *sym_add_exported(const char *name, struct module *mod,
302 enum export export)
303 {
304 struct symbol *s = find_symbol(name);
305
306 if (!s) {
307 s = new_symbol(name, mod, export);
308 } else {
309 if (!s->preloaded) {
310 warn("%s: '%s' exported twice. Previous export "
311 "was in %s%s\n", mod->name, name,
312 s->module->name,
313 is_vmlinux(s->module->name) ?"":".ko");
314 } else {
315 /* In case Modules.symvers was out of date */
316 s->module = mod;
317 }
318 }
319 s->preloaded = 0;
320 s->vmlinux = is_vmlinux(mod->name);
321 s->kernel = 0;
322 s->export = export;
323 return s;
324 }
325
326 static void sym_update_crc(const char *name, struct module *mod,
327 unsigned int crc, enum export export)
328 {
329 struct symbol *s = find_symbol(name);
330
331 if (!s)
332 s = new_symbol(name, mod, export);
333 s->crc = crc;
334 s->crc_valid = 1;
335 }
336
337 void *grab_file(const char *filename, unsigned long *size)
338 {
339 struct stat st;
340 void *map;
341 int fd;
342
343 fd = open(filename, O_RDONLY);
344 if (fd < 0 || fstat(fd, &st) != 0)
345 return NULL;
346
347 *size = st.st_size;
348 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
349 close(fd);
350
351 if (map == MAP_FAILED)
352 return NULL;
353 return map;
354 }
355
356 /**
357 * Return a copy of the next line in a mmap'ed file.
358 * spaces in the beginning of the line is trimmed away.
359 * Return a pointer to a static buffer.
360 **/
361 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
362 {
363 static char line[4096];
364 int skip = 1;
365 size_t len = 0;
366 signed char *p = (signed char *)file + *pos;
367 char *s = line;
368
369 for (; *pos < size ; (*pos)++) {
370 if (skip && isspace(*p)) {
371 p++;
372 continue;
373 }
374 skip = 0;
375 if (*p != '\n' && (*pos < size)) {
376 len++;
377 *s++ = *p++;
378 if (len > 4095)
379 break; /* Too long, stop */
380 } else {
381 /* End of string */
382 *s = '\0';
383 return line;
384 }
385 }
386 /* End of buffer */
387 return NULL;
388 }
389
390 void release_file(void *file, unsigned long size)
391 {
392 munmap(file, size);
393 }
394
395 static int parse_elf(struct elf_info *info, const char *filename)
396 {
397 unsigned int i;
398 Elf_Ehdr *hdr;
399 Elf_Shdr *sechdrs;
400 Elf_Sym *sym;
401 const char *secstrings;
402 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
403
404 hdr = grab_file(filename, &info->size);
405 if (!hdr) {
406 perror(filename);
407 exit(1);
408 }
409 info->hdr = hdr;
410 if (info->size < sizeof(*hdr)) {
411 /* file too small, assume this is an empty .o file */
412 return 0;
413 }
414 /* Is this a valid ELF file? */
415 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
416 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
417 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
418 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
419 /* Not an ELF file - silently ignore it */
420 return 0;
421 }
422 /* Fix endianness in ELF header */
423 hdr->e_type = TO_NATIVE(hdr->e_type);
424 hdr->e_machine = TO_NATIVE(hdr->e_machine);
425 hdr->e_version = TO_NATIVE(hdr->e_version);
426 hdr->e_entry = TO_NATIVE(hdr->e_entry);
427 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
428 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
429 hdr->e_flags = TO_NATIVE(hdr->e_flags);
430 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
431 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
432 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
433 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
434 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
435 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
436 sechdrs = (void *)hdr + hdr->e_shoff;
437 info->sechdrs = sechdrs;
438
439 /* Check if file offset is correct */
440 if (hdr->e_shoff > info->size) {
441 fatal("section header offset=%lu in file '%s' is bigger than "
442 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
443 filename, info->size);
444 return 0;
445 }
446
447 if (hdr->e_shnum == SHN_UNDEF) {
448 /*
449 * There are more than 64k sections,
450 * read count from .sh_size.
451 */
452 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
453 }
454 else {
455 info->num_sections = hdr->e_shnum;
456 }
457 if (hdr->e_shstrndx == SHN_XINDEX) {
458 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
459 }
460 else {
461 info->secindex_strings = hdr->e_shstrndx;
462 }
463
464 /* Fix endianness in section headers */
465 for (i = 0; i < info->num_sections; i++) {
466 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
467 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
468 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
469 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
470 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
471 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
472 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
473 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
474 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
475 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
476 }
477 /* Find symbol table. */
478 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
479 for (i = 1; i < info->num_sections; i++) {
480 const char *secname;
481 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
482
483 if (!nobits && sechdrs[i].sh_offset > info->size) {
484 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
485 "sizeof(*hrd)=%zu\n", filename,
486 (unsigned long)sechdrs[i].sh_offset,
487 sizeof(*hdr));
488 return 0;
489 }
490 secname = secstrings + sechdrs[i].sh_name;
491 if (strcmp(secname, ".modinfo") == 0) {
492 if (nobits)
493 fatal("%s has NOBITS .modinfo\n", filename);
494 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
495 info->modinfo_len = sechdrs[i].sh_size;
496 } else if (strcmp(secname, "__ksymtab") == 0)
497 info->export_sec = i;
498 else if (strcmp(secname, "__ksymtab_unused") == 0)
499 info->export_unused_sec = i;
500 else if (strcmp(secname, "__ksymtab_gpl") == 0)
501 info->export_gpl_sec = i;
502 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
503 info->export_unused_gpl_sec = i;
504 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
505 info->export_gpl_future_sec = i;
506
507 if (sechdrs[i].sh_type == SHT_SYMTAB) {
508 unsigned int sh_link_idx;
509 symtab_idx = i;
510 info->symtab_start = (void *)hdr +
511 sechdrs[i].sh_offset;
512 info->symtab_stop = (void *)hdr +
513 sechdrs[i].sh_offset + sechdrs[i].sh_size;
514 sh_link_idx = sechdrs[i].sh_link;
515 info->strtab = (void *)hdr +
516 sechdrs[sh_link_idx].sh_offset;
517 }
518
519 /* 32bit section no. table? ("more than 64k sections") */
520 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
521 symtab_shndx_idx = i;
522 info->symtab_shndx_start = (void *)hdr +
523 sechdrs[i].sh_offset;
524 info->symtab_shndx_stop = (void *)hdr +
525 sechdrs[i].sh_offset + sechdrs[i].sh_size;
526 }
527 }
528 if (!info->symtab_start)
529 fatal("%s has no symtab?\n", filename);
530
531 /* Fix endianness in symbols */
532 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
533 sym->st_shndx = TO_NATIVE(sym->st_shndx);
534 sym->st_name = TO_NATIVE(sym->st_name);
535 sym->st_value = TO_NATIVE(sym->st_value);
536 sym->st_size = TO_NATIVE(sym->st_size);
537 }
538
539 if (symtab_shndx_idx != ~0U) {
540 Elf32_Word *p;
541 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
542 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
543 filename, sechdrs[symtab_shndx_idx].sh_link,
544 symtab_idx);
545 /* Fix endianness */
546 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
547 p++)
548 *p = TO_NATIVE(*p);
549 }
550
551 return 1;
552 }
553
554 static void parse_elf_finish(struct elf_info *info)
555 {
556 release_file(info->hdr, info->size);
557 }
558
559 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
560 {
561 /* ignore __this_module, it will be resolved shortly */
562 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
563 return 1;
564 /* ignore global offset table */
565 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
566 return 1;
567 if (info->hdr->e_machine == EM_PPC)
568 /* Special register function linked on all modules during final link of .ko */
569 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
570 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
571 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
572 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
573 return 1;
574 if (info->hdr->e_machine == EM_PPC64)
575 /* Special register function linked on all modules during final link of .ko */
576 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
577 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
578 return 1;
579 /* Do not ignore this symbol */
580 return 0;
581 }
582
583 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
584 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
585
586 static void handle_modversions(struct module *mod, struct elf_info *info,
587 Elf_Sym *sym, const char *symname)
588 {
589 unsigned int crc;
590 enum export export;
591
592 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
593 strncmp(symname, "__ksymtab", 9) == 0)
594 export = export_from_secname(info, get_secindex(info, sym));
595 else
596 export = export_from_sec(info, get_secindex(info, sym));
597
598 switch (sym->st_shndx) {
599 case SHN_COMMON:
600 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
601 break;
602 case SHN_ABS:
603 /* CRC'd symbol */
604 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
605 crc = (unsigned int) sym->st_value;
606 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
607 export);
608 }
609 break;
610 case SHN_UNDEF:
611 /* undefined symbol */
612 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
613 ELF_ST_BIND(sym->st_info) != STB_WEAK)
614 break;
615 if (ignore_undef_symbol(info, symname))
616 break;
617 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
618 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
619 /* add compatibility with older glibc */
620 #ifndef STT_SPARC_REGISTER
621 #define STT_SPARC_REGISTER STT_REGISTER
622 #endif
623 if (info->hdr->e_machine == EM_SPARC ||
624 info->hdr->e_machine == EM_SPARCV9) {
625 /* Ignore register directives. */
626 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
627 break;
628 if (symname[0] == '.') {
629 char *munged = strdup(symname);
630 munged[0] = '_';
631 munged[1] = toupper(munged[1]);
632 symname = munged;
633 }
634 }
635 #endif
636
637 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
638 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
639 mod->unres =
640 alloc_symbol(symname +
641 strlen(MODULE_SYMBOL_PREFIX),
642 ELF_ST_BIND(sym->st_info) == STB_WEAK,
643 mod->unres);
644 }
645 break;
646 default:
647 /* All exported symbols */
648 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
649 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
650 export);
651 }
652 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
653 mod->has_init = 1;
654 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
655 mod->has_cleanup = 1;
656 break;
657 }
658 }
659
660 /**
661 * Parse tag=value strings from .modinfo section
662 **/
663 static char *next_string(char *string, unsigned long *secsize)
664 {
665 /* Skip non-zero chars */
666 while (string[0]) {
667 string++;
668 if ((*secsize)-- <= 1)
669 return NULL;
670 }
671
672 /* Skip any zero padding. */
673 while (!string[0]) {
674 string++;
675 if ((*secsize)-- <= 1)
676 return NULL;
677 }
678 return string;
679 }
680
681 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
682 const char *tag, char *info)
683 {
684 char *p;
685 unsigned int taglen = strlen(tag);
686 unsigned long size = modinfo_len;
687
688 if (info) {
689 size -= info - (char *)modinfo;
690 modinfo = next_string(info, &size);
691 }
692
693 for (p = modinfo; p; p = next_string(p, &size)) {
694 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
695 return p + taglen + 1;
696 }
697 return NULL;
698 }
699
700 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
701 const char *tag)
702
703 {
704 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
705 }
706
707 /**
708 * Test if string s ends in string sub
709 * return 0 if match
710 **/
711 static int strrcmp(const char *s, const char *sub)
712 {
713 int slen, sublen;
714
715 if (!s || !sub)
716 return 1;
717
718 slen = strlen(s);
719 sublen = strlen(sub);
720
721 if ((slen == 0) || (sublen == 0))
722 return 1;
723
724 if (sublen > slen)
725 return 1;
726
727 return memcmp(s + slen - sublen, sub, sublen);
728 }
729
730 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
731 {
732 if (sym)
733 return elf->strtab + sym->st_name;
734 else
735 return "(unknown)";
736 }
737
738 static const char *sec_name(struct elf_info *elf, int secindex)
739 {
740 Elf_Shdr *sechdrs = elf->sechdrs;
741 return (void *)elf->hdr +
742 elf->sechdrs[elf->secindex_strings].sh_offset +
743 sechdrs[secindex].sh_name;
744 }
745
746 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
747 {
748 return (void *)elf->hdr +
749 elf->sechdrs[elf->secindex_strings].sh_offset +
750 sechdr->sh_name;
751 }
752
753 /* if sym is empty or point to a string
754 * like ".[0-9]+" then return 1.
755 * This is the optional prefix added by ld to some sections
756 */
757 static int number_prefix(const char *sym)
758 {
759 if (*sym++ == '\0')
760 return 1;
761 if (*sym != '.')
762 return 0;
763 do {
764 char c = *sym++;
765 if (c < '0' || c > '9')
766 return 0;
767 } while (*sym);
768 return 1;
769 }
770
771 /* The pattern is an array of simple patterns.
772 * "foo" will match an exact string equal to "foo"
773 * "*foo" will match a string that ends with "foo"
774 * "foo*" will match a string that begins with "foo"
775 * "foo$" will match a string equal to "foo" or "foo.1"
776 * where the '1' can be any number including several digits.
777 * The $ syntax is for sections where ld append a dot number
778 * to make section name unique.
779 */
780 static int match(const char *sym, const char * const pat[])
781 {
782 const char *p;
783 while (*pat) {
784 p = *pat++;
785 const char *endp = p + strlen(p) - 1;
786
787 /* "*foo" */
788 if (*p == '*') {
789 if (strrcmp(sym, p + 1) == 0)
790 return 1;
791 }
792 /* "foo*" */
793 else if (*endp == '*') {
794 if (strncmp(sym, p, strlen(p) - 1) == 0)
795 return 1;
796 }
797 /* "foo$" */
798 else if (*endp == '$') {
799 if (strncmp(sym, p, strlen(p) - 1) == 0) {
800 if (number_prefix(sym + strlen(p) - 1))
801 return 1;
802 }
803 }
804 /* no wildcards */
805 else {
806 if (strcmp(p, sym) == 0)
807 return 1;
808 }
809 }
810 /* no match */
811 return 0;
812 }
813
814 /* sections that we do not want to do full section mismatch check on */
815 static const char *section_white_list[] =
816 {
817 ".comment*",
818 ".debug*",
819 ".zdebug*", /* Compressed debug sections. */
820 ".GCC-command-line", /* mn10300 */
821 ".mdebug*", /* alpha, score, mips etc. */
822 ".pdr", /* alpha, score, mips etc. */
823 ".stab*",
824 ".note*",
825 ".got*",
826 ".toc*",
827 NULL
828 };
829
830 /*
831 * This is used to find sections missing the SHF_ALLOC flag.
832 * The cause of this is often a section specified in assembler
833 * without "ax" / "aw".
834 */
835 static void check_section(const char *modname, struct elf_info *elf,
836 Elf_Shdr *sechdr)
837 {
838 const char *sec = sech_name(elf, sechdr);
839
840 if (sechdr->sh_type == SHT_PROGBITS &&
841 !(sechdr->sh_flags & SHF_ALLOC) &&
842 !match(sec, section_white_list)) {
843 warn("%s (%s): unexpected non-allocatable section.\n"
844 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
845 "Note that for example <linux/init.h> contains\n"
846 "section definitions for use in .S files.\n\n",
847 modname, sec);
848 }
849 }
850
851
852
853 #define ALL_INIT_DATA_SECTIONS \
854 ".init.setup$", ".init.rodata$", \
855 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$", \
856 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
857 #define ALL_EXIT_DATA_SECTIONS \
858 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
859
860 #define ALL_INIT_TEXT_SECTIONS \
861 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
862 #define ALL_EXIT_TEXT_SECTIONS \
863 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
864
865 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
866 MEM_INIT_SECTIONS
867 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
868 MEM_EXIT_SECTIONS
869
870 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
871 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
872
873 #define DATA_SECTIONS ".data$", ".data.rel$"
874 #define TEXT_SECTIONS ".text$"
875
876 #define INIT_SECTIONS ".init.*"
877 #define DEV_INIT_SECTIONS ".devinit.*"
878 #define CPU_INIT_SECTIONS ".cpuinit.*"
879 #define MEM_INIT_SECTIONS ".meminit.*"
880
881 #define EXIT_SECTIONS ".exit.*"
882 #define DEV_EXIT_SECTIONS ".devexit.*"
883 #define CPU_EXIT_SECTIONS ".cpuexit.*"
884 #define MEM_EXIT_SECTIONS ".memexit.*"
885
886 /* init data sections */
887 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
888
889 /* all init sections */
890 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
891
892 /* All init and exit sections (code + data) */
893 static const char *init_exit_sections[] =
894 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
895
896 /* data section */
897 static const char *data_sections[] = { DATA_SECTIONS, NULL };
898
899
900 /* symbols in .data that may refer to init/exit sections */
901 #define DEFAULT_SYMBOL_WHITE_LIST \
902 "*driver", \
903 "*_template", /* scsi uses *_template a lot */ \
904 "*_timer", /* arm uses ops structures named _timer a lot */ \
905 "*_sht", /* scsi also used *_sht to some extent */ \
906 "*_ops", \
907 "*_probe", \
908 "*_probe_one", \
909 "*_console"
910
911 static const char *head_sections[] = { ".head.text*", NULL };
912 static const char *linker_symbols[] =
913 { "__init_begin", "_sinittext", "_einittext", NULL };
914
915 enum mismatch {
916 TEXT_TO_ANY_INIT,
917 DATA_TO_ANY_INIT,
918 TEXT_TO_ANY_EXIT,
919 DATA_TO_ANY_EXIT,
920 XXXINIT_TO_SOME_INIT,
921 XXXEXIT_TO_SOME_EXIT,
922 ANY_INIT_TO_ANY_EXIT,
923 ANY_EXIT_TO_ANY_INIT,
924 EXPORT_TO_INIT_EXIT,
925 };
926
927 struct sectioncheck {
928 const char *fromsec[20];
929 const char *tosec[20];
930 enum mismatch mismatch;
931 const char *symbol_white_list[20];
932 };
933
934 const struct sectioncheck sectioncheck[] = {
935 /* Do not reference init/exit code/data from
936 * normal code and data
937 */
938 {
939 .fromsec = { TEXT_SECTIONS, NULL },
940 .tosec = { ALL_INIT_SECTIONS, NULL },
941 .mismatch = TEXT_TO_ANY_INIT,
942 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
943 },
944 {
945 .fromsec = { DATA_SECTIONS, NULL },
946 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
947 .mismatch = DATA_TO_ANY_INIT,
948 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
949 },
950 {
951 .fromsec = { DATA_SECTIONS, NULL },
952 .tosec = { INIT_SECTIONS, NULL },
953 .mismatch = DATA_TO_ANY_INIT,
954 .symbol_white_list = {
955 "*_template", "*_timer", "*_sht", "*_ops",
956 "*_probe", "*_probe_one", "*_console", NULL
957 },
958 },
959 {
960 .fromsec = { TEXT_SECTIONS, NULL },
961 .tosec = { ALL_EXIT_SECTIONS, NULL },
962 .mismatch = TEXT_TO_ANY_EXIT,
963 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
964 },
965 {
966 .fromsec = { DATA_SECTIONS, NULL },
967 .tosec = { ALL_EXIT_SECTIONS, NULL },
968 .mismatch = DATA_TO_ANY_EXIT,
969 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
970 },
971 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
972 {
973 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
974 .tosec = { INIT_SECTIONS, NULL },
975 .mismatch = XXXINIT_TO_SOME_INIT,
976 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
977 },
978 /* Do not reference cpuinit code/data from meminit code/data */
979 {
980 .fromsec = { MEM_INIT_SECTIONS, NULL },
981 .tosec = { CPU_INIT_SECTIONS, NULL },
982 .mismatch = XXXINIT_TO_SOME_INIT,
983 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
984 },
985 /* Do not reference meminit code/data from cpuinit code/data */
986 {
987 .fromsec = { CPU_INIT_SECTIONS, NULL },
988 .tosec = { MEM_INIT_SECTIONS, NULL },
989 .mismatch = XXXINIT_TO_SOME_INIT,
990 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
991 },
992 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
993 {
994 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
995 .tosec = { EXIT_SECTIONS, NULL },
996 .mismatch = XXXEXIT_TO_SOME_EXIT,
997 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
998 },
999 /* Do not reference cpuexit code/data from memexit code/data */
1000 {
1001 .fromsec = { MEM_EXIT_SECTIONS, NULL },
1002 .tosec = { CPU_EXIT_SECTIONS, NULL },
1003 .mismatch = XXXEXIT_TO_SOME_EXIT,
1004 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1005 },
1006 /* Do not reference memexit code/data from cpuexit code/data */
1007 {
1008 .fromsec = { CPU_EXIT_SECTIONS, NULL },
1009 .tosec = { MEM_EXIT_SECTIONS, NULL },
1010 .mismatch = XXXEXIT_TO_SOME_EXIT,
1011 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1012 },
1013 /* Do not use exit code/data from init code */
1014 {
1015 .fromsec = { ALL_INIT_SECTIONS, NULL },
1016 .tosec = { ALL_EXIT_SECTIONS, NULL },
1017 .mismatch = ANY_INIT_TO_ANY_EXIT,
1018 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1019 },
1020 /* Do not use init code/data from exit code */
1021 {
1022 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1023 .tosec = { ALL_INIT_SECTIONS, NULL },
1024 .mismatch = ANY_EXIT_TO_ANY_INIT,
1025 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1026 },
1027 /* Do not export init/exit functions or data */
1028 {
1029 .fromsec = { "__ksymtab*", NULL },
1030 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1031 .mismatch = EXPORT_TO_INIT_EXIT,
1032 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1033 }
1034 };
1035
1036 static const struct sectioncheck *section_mismatch(
1037 const char *fromsec, const char *tosec)
1038 {
1039 int i;
1040 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1041 const struct sectioncheck *check = &sectioncheck[0];
1042
1043 for (i = 0; i < elems; i++) {
1044 if (match(fromsec, check->fromsec) &&
1045 match(tosec, check->tosec))
1046 return check;
1047 check++;
1048 }
1049 return NULL;
1050 }
1051
1052 /**
1053 * Whitelist to allow certain references to pass with no warning.
1054 *
1055 * Pattern 1:
1056 * If a module parameter is declared __initdata and permissions=0
1057 * then this is legal despite the warning generated.
1058 * We cannot see value of permissions here, so just ignore
1059 * this pattern.
1060 * The pattern is identified by:
1061 * tosec = .init.data
1062 * fromsec = .data*
1063 * atsym =__param*
1064 *
1065 * Pattern 1a:
1066 * module_param_call() ops can refer to __init set function if permissions=0
1067 * The pattern is identified by:
1068 * tosec = .init.text
1069 * fromsec = .data*
1070 * atsym = __param_ops_*
1071 *
1072 * Pattern 2:
1073 * Many drivers utilise a *driver container with references to
1074 * add, remove, probe functions etc.
1075 * These functions may often be marked __devinit and we do not want to
1076 * warn here.
1077 * the pattern is identified by:
1078 * tosec = init or exit section
1079 * fromsec = data section
1080 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1081 * *probe_one, *_console, *_timer
1082 *
1083 * Pattern 3:
1084 * Whitelist all references from .head.text to any init section
1085 *
1086 * Pattern 4:
1087 * Some symbols belong to init section but still it is ok to reference
1088 * these from non-init sections as these symbols don't have any memory
1089 * allocated for them and symbol address and value are same. So even
1090 * if init section is freed, its ok to reference those symbols.
1091 * For ex. symbols marking the init section boundaries.
1092 * This pattern is identified by
1093 * refsymname = __init_begin, _sinittext, _einittext
1094 *
1095 **/
1096 static int secref_whitelist(const struct sectioncheck *mismatch,
1097 const char *fromsec, const char *fromsym,
1098 const char *tosec, const char *tosym)
1099 {
1100 /* Check for pattern 1 */
1101 if (match(tosec, init_data_sections) &&
1102 match(fromsec, data_sections) &&
1103 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1104 return 0;
1105
1106 /* Check for pattern 1a */
1107 if (strcmp(tosec, ".init.text") == 0 &&
1108 match(fromsec, data_sections) &&
1109 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1110 return 0;
1111
1112 /* Check for pattern 2 */
1113 if (match(tosec, init_exit_sections) &&
1114 match(fromsec, data_sections) &&
1115 match(fromsym, mismatch->symbol_white_list))
1116 return 0;
1117
1118 /* Check for pattern 3 */
1119 if (match(fromsec, head_sections) &&
1120 match(tosec, init_sections))
1121 return 0;
1122
1123 /* Check for pattern 4 */
1124 if (match(tosym, linker_symbols))
1125 return 0;
1126
1127 return 1;
1128 }
1129
1130 /**
1131 * Find symbol based on relocation record info.
1132 * In some cases the symbol supplied is a valid symbol so
1133 * return refsym. If st_name != 0 we assume this is a valid symbol.
1134 * In other cases the symbol needs to be looked up in the symbol table
1135 * based on section and address.
1136 * **/
1137 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1138 Elf_Sym *relsym)
1139 {
1140 Elf_Sym *sym;
1141 Elf_Sym *near = NULL;
1142 Elf64_Sword distance = 20;
1143 Elf64_Sword d;
1144 unsigned int relsym_secindex;
1145
1146 if (relsym->st_name != 0)
1147 return relsym;
1148
1149 relsym_secindex = get_secindex(elf, relsym);
1150 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1151 if (get_secindex(elf, sym) != relsym_secindex)
1152 continue;
1153 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1154 continue;
1155 if (sym->st_value == addr)
1156 return sym;
1157 /* Find a symbol nearby - addr are maybe negative */
1158 d = sym->st_value - addr;
1159 if (d < 0)
1160 d = addr - sym->st_value;
1161 if (d < distance) {
1162 distance = d;
1163 near = sym;
1164 }
1165 }
1166 /* We need a close match */
1167 if (distance < 20)
1168 return near;
1169 else
1170 return NULL;
1171 }
1172
1173 static inline int is_arm_mapping_symbol(const char *str)
1174 {
1175 return str[0] == '$' && strchr("atd", str[1])
1176 && (str[2] == '\0' || str[2] == '.');
1177 }
1178
1179 /*
1180 * If there's no name there, ignore it; likewise, ignore it if it's
1181 * one of the magic symbols emitted used by current ARM tools.
1182 *
1183 * Otherwise if find_symbols_between() returns those symbols, they'll
1184 * fail the whitelist tests and cause lots of false alarms ... fixable
1185 * only by merging __exit and __init sections into __text, bloating
1186 * the kernel (which is especially evil on embedded platforms).
1187 */
1188 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1189 {
1190 const char *name = elf->strtab + sym->st_name;
1191
1192 if (!name || !strlen(name))
1193 return 0;
1194 return !is_arm_mapping_symbol(name);
1195 }
1196
1197 /*
1198 * Find symbols before or equal addr and after addr - in the section sec.
1199 * If we find two symbols with equal offset prefer one with a valid name.
1200 * The ELF format may have a better way to detect what type of symbol
1201 * it is, but this works for now.
1202 **/
1203 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1204 const char *sec)
1205 {
1206 Elf_Sym *sym;
1207 Elf_Sym *near = NULL;
1208 Elf_Addr distance = ~0;
1209
1210 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1211 const char *symsec;
1212
1213 if (is_shndx_special(sym->st_shndx))
1214 continue;
1215 symsec = sec_name(elf, get_secindex(elf, sym));
1216 if (strcmp(symsec, sec) != 0)
1217 continue;
1218 if (!is_valid_name(elf, sym))
1219 continue;
1220 if (sym->st_value <= addr) {
1221 if ((addr - sym->st_value) < distance) {
1222 distance = addr - sym->st_value;
1223 near = sym;
1224 } else if ((addr - sym->st_value) == distance) {
1225 near = sym;
1226 }
1227 }
1228 }
1229 return near;
1230 }
1231
1232 /*
1233 * Convert a section name to the function/data attribute
1234 * .init.text => __init
1235 * .cpuinit.data => __cpudata
1236 * .memexitconst => __memconst
1237 * etc.
1238 *
1239 * The memory of returned value has been allocated on a heap. The user of this
1240 * method should free it after usage.
1241 */
1242 static char *sec2annotation(const char *s)
1243 {
1244 if (match(s, init_exit_sections)) {
1245 char *p = malloc(20);
1246 char *r = p;
1247
1248 *p++ = '_';
1249 *p++ = '_';
1250 if (*s == '.')
1251 s++;
1252 while (*s && *s != '.')
1253 *p++ = *s++;
1254 *p = '\0';
1255 if (*s == '.')
1256 s++;
1257 if (strstr(s, "rodata") != NULL)
1258 strcat(p, "const ");
1259 else if (strstr(s, "data") != NULL)
1260 strcat(p, "data ");
1261 else
1262 strcat(p, " ");
1263 return r;
1264 } else {
1265 return strdup("");
1266 }
1267 }
1268
1269 static int is_function(Elf_Sym *sym)
1270 {
1271 if (sym)
1272 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1273 else
1274 return -1;
1275 }
1276
1277 static void print_section_list(const char * const list[20])
1278 {
1279 const char *const *s = list;
1280
1281 while (*s) {
1282 fprintf(stderr, "%s", *s);
1283 s++;
1284 if (*s)
1285 fprintf(stderr, ", ");
1286 }
1287 fprintf(stderr, "\n");
1288 }
1289
1290 /*
1291 * Print a warning about a section mismatch.
1292 * Try to find symbols near it so user can find it.
1293 * Check whitelist before warning - it may be a false positive.
1294 */
1295 static void report_sec_mismatch(const char *modname,
1296 const struct sectioncheck *mismatch,
1297 const char *fromsec,
1298 unsigned long long fromaddr,
1299 const char *fromsym,
1300 int from_is_func,
1301 const char *tosec, const char *tosym,
1302 int to_is_func)
1303 {
1304 const char *from, *from_p;
1305 const char *to, *to_p;
1306 char *prl_from;
1307 char *prl_to;
1308
1309 switch (from_is_func) {
1310 case 0: from = "variable"; from_p = ""; break;
1311 case 1: from = "function"; from_p = "()"; break;
1312 default: from = "(unknown reference)"; from_p = ""; break;
1313 }
1314 switch (to_is_func) {
1315 case 0: to = "variable"; to_p = ""; break;
1316 case 1: to = "function"; to_p = "()"; break;
1317 default: to = "(unknown reference)"; to_p = ""; break;
1318 }
1319
1320 sec_mismatch_count++;
1321 if (!sec_mismatch_verbose)
1322 return;
1323
1324 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1325 "to the %s %s:%s%s\n",
1326 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1327 tosym, to_p);
1328
1329 switch (mismatch->mismatch) {
1330 case TEXT_TO_ANY_INIT:
1331 prl_from = sec2annotation(fromsec);
1332 prl_to = sec2annotation(tosec);
1333 fprintf(stderr,
1334 "The function %s%s() references\n"
1335 "the %s %s%s%s.\n"
1336 "This is often because %s lacks a %s\n"
1337 "annotation or the annotation of %s is wrong.\n",
1338 prl_from, fromsym,
1339 to, prl_to, tosym, to_p,
1340 fromsym, prl_to, tosym);
1341 free(prl_from);
1342 free(prl_to);
1343 break;
1344 case DATA_TO_ANY_INIT: {
1345 prl_to = sec2annotation(tosec);
1346 fprintf(stderr,
1347 "The variable %s references\n"
1348 "the %s %s%s%s\n"
1349 "If the reference is valid then annotate the\n"
1350 "variable with __init* or __refdata (see linux/init.h) "
1351 "or name the variable:\n",
1352 fromsym, to, prl_to, tosym, to_p);
1353 print_section_list(mismatch->symbol_white_list);
1354 free(prl_to);
1355 break;
1356 }
1357 case TEXT_TO_ANY_EXIT:
1358 prl_to = sec2annotation(tosec);
1359 fprintf(stderr,
1360 "The function %s() references a %s in an exit section.\n"
1361 "Often the %s %s%s has valid usage outside the exit section\n"
1362 "and the fix is to remove the %sannotation of %s.\n",
1363 fromsym, to, to, tosym, to_p, prl_to, tosym);
1364 free(prl_to);
1365 break;
1366 case DATA_TO_ANY_EXIT: {
1367 prl_to = sec2annotation(tosec);
1368 fprintf(stderr,
1369 "The variable %s references\n"
1370 "the %s %s%s%s\n"
1371 "If the reference is valid then annotate the\n"
1372 "variable with __exit* (see linux/init.h) or "
1373 "name the variable:\n",
1374 fromsym, to, prl_to, tosym, to_p);
1375 print_section_list(mismatch->symbol_white_list);
1376 free(prl_to);
1377 break;
1378 }
1379 case XXXINIT_TO_SOME_INIT:
1380 case XXXEXIT_TO_SOME_EXIT:
1381 prl_from = sec2annotation(fromsec);
1382 prl_to = sec2annotation(tosec);
1383 fprintf(stderr,
1384 "The %s %s%s%s references\n"
1385 "a %s %s%s%s.\n"
1386 "If %s is only used by %s then\n"
1387 "annotate %s with a matching annotation.\n",
1388 from, prl_from, fromsym, from_p,
1389 to, prl_to, tosym, to_p,
1390 tosym, fromsym, tosym);
1391 free(prl_from);
1392 free(prl_to);
1393 break;
1394 case ANY_INIT_TO_ANY_EXIT:
1395 prl_from = sec2annotation(fromsec);
1396 prl_to = sec2annotation(tosec);
1397 fprintf(stderr,
1398 "The %s %s%s%s references\n"
1399 "a %s %s%s%s.\n"
1400 "This is often seen when error handling "
1401 "in the init function\n"
1402 "uses functionality in the exit path.\n"
1403 "The fix is often to remove the %sannotation of\n"
1404 "%s%s so it may be used outside an exit section.\n",
1405 from, prl_from, fromsym, from_p,
1406 to, prl_to, tosym, to_p,
1407 prl_to, tosym, to_p);
1408 free(prl_from);
1409 free(prl_to);
1410 break;
1411 case ANY_EXIT_TO_ANY_INIT:
1412 prl_from = sec2annotation(fromsec);
1413 prl_to = sec2annotation(tosec);
1414 fprintf(stderr,
1415 "The %s %s%s%s references\n"
1416 "a %s %s%s%s.\n"
1417 "This is often seen when error handling "
1418 "in the exit function\n"
1419 "uses functionality in the init path.\n"
1420 "The fix is often to remove the %sannotation of\n"
1421 "%s%s so it may be used outside an init section.\n",
1422 from, prl_from, fromsym, from_p,
1423 to, prl_to, tosym, to_p,
1424 prl_to, tosym, to_p);
1425 free(prl_from);
1426 free(prl_to);
1427 break;
1428 case EXPORT_TO_INIT_EXIT:
1429 prl_to = sec2annotation(tosec);
1430 fprintf(stderr,
1431 "The symbol %s is exported and annotated %s\n"
1432 "Fix this by removing the %sannotation of %s "
1433 "or drop the export.\n",
1434 tosym, prl_to, prl_to, tosym);
1435 free(prl_to);
1436 break;
1437 }
1438 fprintf(stderr, "\n");
1439 }
1440
1441 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1442 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1443 {
1444 const char *tosec;
1445 const struct sectioncheck *mismatch;
1446
1447 tosec = sec_name(elf, get_secindex(elf, sym));
1448 mismatch = section_mismatch(fromsec, tosec);
1449 if (mismatch) {
1450 Elf_Sym *to;
1451 Elf_Sym *from;
1452 const char *tosym;
1453 const char *fromsym;
1454
1455 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1456 fromsym = sym_name(elf, from);
1457 to = find_elf_symbol(elf, r->r_addend, sym);
1458 tosym = sym_name(elf, to);
1459
1460 /* check whitelist - we may ignore it */
1461 if (secref_whitelist(mismatch,
1462 fromsec, fromsym, tosec, tosym)) {
1463 report_sec_mismatch(modname, mismatch,
1464 fromsec, r->r_offset, fromsym,
1465 is_function(from), tosec, tosym,
1466 is_function(to));
1467 }
1468 }
1469 }
1470
1471 static unsigned int *reloc_location(struct elf_info *elf,
1472 Elf_Shdr *sechdr, Elf_Rela *r)
1473 {
1474 Elf_Shdr *sechdrs = elf->sechdrs;
1475 int section = sechdr->sh_info;
1476
1477 return (void *)elf->hdr + sechdrs[section].sh_offset +
1478 r->r_offset;
1479 }
1480
1481 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1482 {
1483 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1484 unsigned int *location = reloc_location(elf, sechdr, r);
1485
1486 switch (r_typ) {
1487 case R_386_32:
1488 r->r_addend = TO_NATIVE(*location);
1489 break;
1490 case R_386_PC32:
1491 r->r_addend = TO_NATIVE(*location) + 4;
1492 /* For CONFIG_RELOCATABLE=y */
1493 if (elf->hdr->e_type == ET_EXEC)
1494 r->r_addend += r->r_offset;
1495 break;
1496 }
1497 return 0;
1498 }
1499
1500 #ifndef R_ARM_CALL
1501 #define R_ARM_CALL 28
1502 #endif
1503 #ifndef R_ARM_JUMP24
1504 #define R_ARM_JUMP24 29
1505 #endif
1506
1507 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1508 {
1509 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1510
1511 switch (r_typ) {
1512 case R_ARM_ABS32:
1513 /* From ARM ABI: (S + A) | T */
1514 r->r_addend = (int)(long)
1515 (elf->symtab_start + ELF_R_SYM(r->r_info));
1516 break;
1517 case R_ARM_PC24:
1518 case R_ARM_CALL:
1519 case R_ARM_JUMP24:
1520 /* From ARM ABI: ((S + A) | T) - P */
1521 r->r_addend = (int)(long)(elf->hdr +
1522 sechdr->sh_offset +
1523 (r->r_offset - sechdr->sh_addr));
1524 break;
1525 default:
1526 return 1;
1527 }
1528 return 0;
1529 }
1530
1531 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1532 {
1533 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1534 unsigned int *location = reloc_location(elf, sechdr, r);
1535 unsigned int inst;
1536
1537 if (r_typ == R_MIPS_HI16)
1538 return 1; /* skip this */
1539 inst = TO_NATIVE(*location);
1540 switch (r_typ) {
1541 case R_MIPS_LO16:
1542 r->r_addend = inst & 0xffff;
1543 break;
1544 case R_MIPS_26:
1545 r->r_addend = (inst & 0x03ffffff) << 2;
1546 break;
1547 case R_MIPS_32:
1548 r->r_addend = inst;
1549 break;
1550 }
1551 return 0;
1552 }
1553
1554 static void section_rela(const char *modname, struct elf_info *elf,
1555 Elf_Shdr *sechdr)
1556 {
1557 Elf_Sym *sym;
1558 Elf_Rela *rela;
1559 Elf_Rela r;
1560 unsigned int r_sym;
1561 const char *fromsec;
1562
1563 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1564 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1565
1566 fromsec = sech_name(elf, sechdr);
1567 fromsec += strlen(".rela");
1568 /* if from section (name) is know good then skip it */
1569 if (match(fromsec, section_white_list))
1570 return;
1571
1572 for (rela = start; rela < stop; rela++) {
1573 r.r_offset = TO_NATIVE(rela->r_offset);
1574 #if KERNEL_ELFCLASS == ELFCLASS64
1575 if (elf->hdr->e_machine == EM_MIPS) {
1576 unsigned int r_typ;
1577 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1578 r_sym = TO_NATIVE(r_sym);
1579 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1580 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1581 } else {
1582 r.r_info = TO_NATIVE(rela->r_info);
1583 r_sym = ELF_R_SYM(r.r_info);
1584 }
1585 #else
1586 r.r_info = TO_NATIVE(rela->r_info);
1587 r_sym = ELF_R_SYM(r.r_info);
1588 #endif
1589 r.r_addend = TO_NATIVE(rela->r_addend);
1590 sym = elf->symtab_start + r_sym;
1591 /* Skip special sections */
1592 if (is_shndx_special(sym->st_shndx))
1593 continue;
1594 check_section_mismatch(modname, elf, &r, sym, fromsec);
1595 }
1596 }
1597
1598 static void section_rel(const char *modname, struct elf_info *elf,
1599 Elf_Shdr *sechdr)
1600 {
1601 Elf_Sym *sym;
1602 Elf_Rel *rel;
1603 Elf_Rela r;
1604 unsigned int r_sym;
1605 const char *fromsec;
1606
1607 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1608 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1609
1610 fromsec = sech_name(elf, sechdr);
1611 fromsec += strlen(".rel");
1612 /* if from section (name) is know good then skip it */
1613 if (match(fromsec, section_white_list))
1614 return;
1615
1616 for (rel = start; rel < stop; rel++) {
1617 r.r_offset = TO_NATIVE(rel->r_offset);
1618 #if KERNEL_ELFCLASS == ELFCLASS64
1619 if (elf->hdr->e_machine == EM_MIPS) {
1620 unsigned int r_typ;
1621 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1622 r_sym = TO_NATIVE(r_sym);
1623 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1624 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1625 } else {
1626 r.r_info = TO_NATIVE(rel->r_info);
1627 r_sym = ELF_R_SYM(r.r_info);
1628 }
1629 #else
1630 r.r_info = TO_NATIVE(rel->r_info);
1631 r_sym = ELF_R_SYM(r.r_info);
1632 #endif
1633 r.r_addend = 0;
1634 switch (elf->hdr->e_machine) {
1635 case EM_386:
1636 if (addend_386_rel(elf, sechdr, &r))
1637 continue;
1638 break;
1639 case EM_ARM:
1640 if (addend_arm_rel(elf, sechdr, &r))
1641 continue;
1642 break;
1643 case EM_MIPS:
1644 if (addend_mips_rel(elf, sechdr, &r))
1645 continue;
1646 break;
1647 }
1648 sym = elf->symtab_start + r_sym;
1649 /* Skip special sections */
1650 if (is_shndx_special(sym->st_shndx))
1651 continue;
1652 check_section_mismatch(modname, elf, &r, sym, fromsec);
1653 }
1654 }
1655
1656 /**
1657 * A module includes a number of sections that are discarded
1658 * either when loaded or when used as built-in.
1659 * For loaded modules all functions marked __init and all data
1660 * marked __initdata will be discarded when the module has been initialized.
1661 * Likewise for modules used built-in the sections marked __exit
1662 * are discarded because __exit marked function are supposed to be called
1663 * only when a module is unloaded which never happens for built-in modules.
1664 * The check_sec_ref() function traverses all relocation records
1665 * to find all references to a section that reference a section that will
1666 * be discarded and warns about it.
1667 **/
1668 static void check_sec_ref(struct module *mod, const char *modname,
1669 struct elf_info *elf)
1670 {
1671 int i;
1672 Elf_Shdr *sechdrs = elf->sechdrs;
1673
1674 /* Walk through all sections */
1675 for (i = 0; i < elf->num_sections; i++) {
1676 check_section(modname, elf, &elf->sechdrs[i]);
1677 /* We want to process only relocation sections and not .init */
1678 if (sechdrs[i].sh_type == SHT_RELA)
1679 section_rela(modname, elf, &elf->sechdrs[i]);
1680 else if (sechdrs[i].sh_type == SHT_REL)
1681 section_rel(modname, elf, &elf->sechdrs[i]);
1682 }
1683 }
1684
1685 static void read_symbols(char *modname)
1686 {
1687 const char *symname;
1688 char *version;
1689 char *license;
1690 struct module *mod;
1691 struct elf_info info = { };
1692 Elf_Sym *sym;
1693
1694 if (!parse_elf(&info, modname))
1695 return;
1696
1697 mod = new_module(modname);
1698
1699 /* When there's no vmlinux, don't print warnings about
1700 * unresolved symbols (since there'll be too many ;) */
1701 if (is_vmlinux(modname)) {
1702 have_vmlinux = 1;
1703 mod->skip = 1;
1704 }
1705
1706 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1707 if (info.modinfo && !license && !is_vmlinux(modname))
1708 warn("modpost: missing MODULE_LICENSE() in %s\n"
1709 "see include/linux/module.h for "
1710 "more information\n", modname);
1711 while (license) {
1712 if (license_is_gpl_compatible(license))
1713 mod->gpl_compatible = 1;
1714 else {
1715 mod->gpl_compatible = 0;
1716 break;
1717 }
1718 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1719 "license", license);
1720 }
1721
1722 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1723 symname = info.strtab + sym->st_name;
1724
1725 handle_modversions(mod, &info, sym, symname);
1726 handle_moddevtable(mod, &info, sym, symname);
1727 }
1728 if (!is_vmlinux(modname) ||
1729 (is_vmlinux(modname) && vmlinux_section_warnings))
1730 check_sec_ref(mod, modname, &info);
1731
1732 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1733 if (version)
1734 maybe_frob_rcs_version(modname, version, info.modinfo,
1735 version - (char *)info.hdr);
1736 if (version || (all_versions && !is_vmlinux(modname)))
1737 get_src_version(modname, mod->srcversion,
1738 sizeof(mod->srcversion)-1);
1739
1740 parse_elf_finish(&info);
1741
1742 /* Our trick to get versioning for module struct etc. - it's
1743 * never passed as an argument to an exported function, so
1744 * the automatic versioning doesn't pick it up, but it's really
1745 * important anyhow */
1746 if (modversions)
1747 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1748 }
1749
1750 #define SZ 500
1751
1752 /* We first write the generated file into memory using the
1753 * following helper, then compare to the file on disk and
1754 * only update the later if anything changed */
1755
1756 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1757 const char *fmt, ...)
1758 {
1759 char tmp[SZ];
1760 int len;
1761 va_list ap;
1762
1763 va_start(ap, fmt);
1764 len = vsnprintf(tmp, SZ, fmt, ap);
1765 buf_write(buf, tmp, len);
1766 va_end(ap);
1767 }
1768
1769 void buf_write(struct buffer *buf, const char *s, int len)
1770 {
1771 if (buf->size - buf->pos < len) {
1772 buf->size += len + SZ;
1773 buf->p = realloc(buf->p, buf->size);
1774 }
1775 strncpy(buf->p + buf->pos, s, len);
1776 buf->pos += len;
1777 }
1778
1779 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1780 {
1781 const char *e = is_vmlinux(m) ?"":".ko";
1782
1783 switch (exp) {
1784 case export_gpl:
1785 fatal("modpost: GPL-incompatible module %s%s "
1786 "uses GPL-only symbol '%s'\n", m, e, s);
1787 break;
1788 case export_unused_gpl:
1789 fatal("modpost: GPL-incompatible module %s%s "
1790 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1791 break;
1792 case export_gpl_future:
1793 warn("modpost: GPL-incompatible module %s%s "
1794 "uses future GPL-only symbol '%s'\n", m, e, s);
1795 break;
1796 case export_plain:
1797 case export_unused:
1798 case export_unknown:
1799 /* ignore */
1800 break;
1801 }
1802 }
1803
1804 static void check_for_unused(enum export exp, const char *m, const char *s)
1805 {
1806 const char *e = is_vmlinux(m) ?"":".ko";
1807
1808 switch (exp) {
1809 case export_unused:
1810 case export_unused_gpl:
1811 warn("modpost: module %s%s "
1812 "uses symbol '%s' marked UNUSED\n", m, e, s);
1813 break;
1814 default:
1815 /* ignore */
1816 break;
1817 }
1818 }
1819
1820 static void check_exports(struct module *mod)
1821 {
1822 struct symbol *s, *exp;
1823
1824 for (s = mod->unres; s; s = s->next) {
1825 const char *basename;
1826 exp = find_symbol(s->name);
1827 if (!exp || exp->module == mod)
1828 continue;
1829 basename = strrchr(mod->name, '/');
1830 if (basename)
1831 basename++;
1832 else
1833 basename = mod->name;
1834 if (!mod->gpl_compatible)
1835 check_for_gpl_usage(exp->export, basename, exp->name);
1836 check_for_unused(exp->export, basename, exp->name);
1837 }
1838 }
1839
1840 /**
1841 * Header for the generated file
1842 **/
1843 static void add_header(struct buffer *b, struct module *mod)
1844 {
1845 buf_printf(b, "#include <linux/module.h>\n");
1846 buf_printf(b, "#include <linux/vermagic.h>\n");
1847 buf_printf(b, "#include <linux/compiler.h>\n");
1848 buf_printf(b, "\n");
1849 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1850 buf_printf(b, "\n");
1851 buf_printf(b, "struct module __this_module\n");
1852 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1853 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1854 if (mod->has_init)
1855 buf_printf(b, " .init = init_module,\n");
1856 if (mod->has_cleanup)
1857 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1858 " .exit = cleanup_module,\n"
1859 "#endif\n");
1860 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1861 buf_printf(b, "};\n");
1862 }
1863
1864 static void add_intree_flag(struct buffer *b, int is_intree)
1865 {
1866 if (is_intree)
1867 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1868 }
1869
1870 static void add_staging_flag(struct buffer *b, const char *name)
1871 {
1872 static const char *staging_dir = "drivers/staging";
1873
1874 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1875 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1876 }
1877
1878 /**
1879 * Record CRCs for unresolved symbols
1880 **/
1881 static int add_versions(struct buffer *b, struct module *mod)
1882 {
1883 struct symbol *s, *exp;
1884 int err = 0;
1885
1886 for (s = mod->unres; s; s = s->next) {
1887 exp = find_symbol(s->name);
1888 if (!exp || exp->module == mod) {
1889 if (have_vmlinux && !s->weak) {
1890 if (warn_unresolved) {
1891 warn("\"%s\" [%s.ko] undefined!\n",
1892 s->name, mod->name);
1893 } else {
1894 merror("\"%s\" [%s.ko] undefined!\n",
1895 s->name, mod->name);
1896 err = 1;
1897 }
1898 }
1899 continue;
1900 }
1901 s->module = exp->module;
1902 s->crc_valid = exp->crc_valid;
1903 s->crc = exp->crc;
1904 }
1905
1906 if (!modversions)
1907 return err;
1908
1909 buf_printf(b, "\n");
1910 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1911 buf_printf(b, "__used\n");
1912 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1913
1914 for (s = mod->unres; s; s = s->next) {
1915 if (!s->module)
1916 continue;
1917 if (!s->crc_valid) {
1918 warn("\"%s\" [%s.ko] has no CRC!\n",
1919 s->name, mod->name);
1920 continue;
1921 }
1922 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1923 }
1924
1925 buf_printf(b, "};\n");
1926
1927 return err;
1928 }
1929
1930 static void add_depends(struct buffer *b, struct module *mod,
1931 struct module *modules)
1932 {
1933 struct symbol *s;
1934 struct module *m;
1935 int first = 1;
1936
1937 for (m = modules; m; m = m->next)
1938 m->seen = is_vmlinux(m->name);
1939
1940 buf_printf(b, "\n");
1941 buf_printf(b, "static const char __module_depends[]\n");
1942 buf_printf(b, "__used\n");
1943 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1944 buf_printf(b, "\"depends=");
1945 for (s = mod->unres; s; s = s->next) {
1946 const char *p;
1947 if (!s->module)
1948 continue;
1949
1950 if (s->module->seen)
1951 continue;
1952
1953 s->module->seen = 1;
1954 p = strrchr(s->module->name, '/');
1955 if (p)
1956 p++;
1957 else
1958 p = s->module->name;
1959 buf_printf(b, "%s%s", first ? "" : ",", p);
1960 first = 0;
1961 }
1962 buf_printf(b, "\";\n");
1963 }
1964
1965 static void add_srcversion(struct buffer *b, struct module *mod)
1966 {
1967 if (mod->srcversion[0]) {
1968 buf_printf(b, "\n");
1969 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1970 mod->srcversion);
1971 }
1972 }
1973
1974 static void write_if_changed(struct buffer *b, const char *fname)
1975 {
1976 char *tmp;
1977 FILE *file;
1978 struct stat st;
1979
1980 file = fopen(fname, "r");
1981 if (!file)
1982 goto write;
1983
1984 if (fstat(fileno(file), &st) < 0)
1985 goto close_write;
1986
1987 if (st.st_size != b->pos)
1988 goto close_write;
1989
1990 tmp = NOFAIL(malloc(b->pos));
1991 if (fread(tmp, 1, b->pos, file) != b->pos)
1992 goto free_write;
1993
1994 if (memcmp(tmp, b->p, b->pos) != 0)
1995 goto free_write;
1996
1997 free(tmp);
1998 fclose(file);
1999 return;
2000
2001 free_write:
2002 free(tmp);
2003 close_write:
2004 fclose(file);
2005 write:
2006 file = fopen(fname, "w");
2007 if (!file) {
2008 perror(fname);
2009 exit(1);
2010 }
2011 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2012 perror(fname);
2013 exit(1);
2014 }
2015 fclose(file);
2016 }
2017
2018 /* parse Module.symvers file. line format:
2019 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2020 **/
2021 static void read_dump(const char *fname, unsigned int kernel)
2022 {
2023 unsigned long size, pos = 0;
2024 void *file = grab_file(fname, &size);
2025 char *line;
2026
2027 if (!file)
2028 /* No symbol versions, silently ignore */
2029 return;
2030
2031 while ((line = get_next_line(&pos, file, size))) {
2032 char *symname, *modname, *d, *export, *end;
2033 unsigned int crc;
2034 struct module *mod;
2035 struct symbol *s;
2036
2037 if (!(symname = strchr(line, '\t')))
2038 goto fail;
2039 *symname++ = '\0';
2040 if (!(modname = strchr(symname, '\t')))
2041 goto fail;
2042 *modname++ = '\0';
2043 if ((export = strchr(modname, '\t')) != NULL)
2044 *export++ = '\0';
2045 if (export && ((end = strchr(export, '\t')) != NULL))
2046 *end = '\0';
2047 crc = strtoul(line, &d, 16);
2048 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2049 goto fail;
2050 mod = find_module(modname);
2051 if (!mod) {
2052 if (is_vmlinux(modname))
2053 have_vmlinux = 1;
2054 mod = new_module(modname);
2055 mod->skip = 1;
2056 }
2057 s = sym_add_exported(symname, mod, export_no(export));
2058 s->kernel = kernel;
2059 s->preloaded = 1;
2060 sym_update_crc(symname, mod, crc, export_no(export));
2061 }
2062 return;
2063 fail:
2064 fatal("parse error in symbol dump file\n");
2065 }
2066
2067 /* For normal builds always dump all symbols.
2068 * For external modules only dump symbols
2069 * that are not read from kernel Module.symvers.
2070 **/
2071 static int dump_sym(struct symbol *sym)
2072 {
2073 if (!external_module)
2074 return 1;
2075 if (sym->vmlinux || sym->kernel)
2076 return 0;
2077 return 1;
2078 }
2079
2080 static void write_dump(const char *fname)
2081 {
2082 struct buffer buf = { };
2083 struct symbol *symbol;
2084 int n;
2085
2086 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2087 symbol = symbolhash[n];
2088 while (symbol) {
2089 if (dump_sym(symbol))
2090 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2091 symbol->crc, symbol->name,
2092 symbol->module->name,
2093 export_str(symbol->export));
2094 symbol = symbol->next;
2095 }
2096 }
2097 write_if_changed(&buf, fname);
2098 }
2099
2100 struct ext_sym_list {
2101 struct ext_sym_list *next;
2102 const char *file;
2103 };
2104
2105 int main(int argc, char **argv)
2106 {
2107 struct module *mod;
2108 struct buffer buf = { };
2109 char *kernel_read = NULL, *module_read = NULL;
2110 char *dump_write = NULL;
2111 int opt;
2112 int err;
2113 struct ext_sym_list *extsym_iter;
2114 struct ext_sym_list *extsym_start = NULL;
2115
2116 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2117 switch (opt) {
2118 case 'i':
2119 kernel_read = optarg;
2120 break;
2121 case 'I':
2122 module_read = optarg;
2123 external_module = 1;
2124 break;
2125 case 'c':
2126 cross_build = 1;
2127 break;
2128 case 'e':
2129 external_module = 1;
2130 extsym_iter =
2131 NOFAIL(malloc(sizeof(*extsym_iter)));
2132 extsym_iter->next = extsym_start;
2133 extsym_iter->file = optarg;
2134 extsym_start = extsym_iter;
2135 break;
2136 case 'm':
2137 modversions = 1;
2138 break;
2139 case 'o':
2140 dump_write = optarg;
2141 break;
2142 case 'a':
2143 all_versions = 1;
2144 break;
2145 case 's':
2146 vmlinux_section_warnings = 0;
2147 break;
2148 case 'S':
2149 sec_mismatch_verbose = 0;
2150 break;
2151 case 'w':
2152 warn_unresolved = 1;
2153 break;
2154 default:
2155 exit(1);
2156 }
2157 }
2158
2159 if (kernel_read)
2160 read_dump(kernel_read, 1);
2161 if (module_read)
2162 read_dump(module_read, 0);
2163 while (extsym_start) {
2164 read_dump(extsym_start->file, 0);
2165 extsym_iter = extsym_start->next;
2166 free(extsym_start);
2167 extsym_start = extsym_iter;
2168 }
2169
2170 while (optind < argc)
2171 read_symbols(argv[optind++]);
2172
2173 for (mod = modules; mod; mod = mod->next) {
2174 if (mod->skip)
2175 continue;
2176 check_exports(mod);
2177 }
2178
2179 err = 0;
2180
2181 for (mod = modules; mod; mod = mod->next) {
2182 char fname[strlen(mod->name) + 10];
2183
2184 if (mod->skip)
2185 continue;
2186
2187 buf.pos = 0;
2188
2189 add_header(&buf, mod);
2190 add_intree_flag(&buf, !external_module);
2191 add_staging_flag(&buf, mod->name);
2192 err |= add_versions(&buf, mod);
2193 add_depends(&buf, mod, modules);
2194 add_moddevtable(&buf, mod);
2195 add_srcversion(&buf, mod);
2196
2197 sprintf(fname, "%s.mod.c", mod->name);
2198 write_if_changed(&buf, fname);
2199 }
2200
2201 if (dump_write)
2202 write_dump(dump_write);
2203 if (sec_mismatch_count && !sec_mismatch_verbose)
2204 warn("modpost: Found %d section mismatch(es).\n"
2205 "To see full details build your kernel with:\n"
2206 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2207 sec_mismatch_count);
2208
2209 return err;
2210 }