a4be8e112bb63c2ece5baa423e9aef65c92a1ad1
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / scripts / mod / modpost.c
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 return 1;
578 if (info->hdr->e_machine == EM_PPC64)
579 /* Special register function linked on all modules during final link of .ko */
580 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
581 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
582 return 1;
583 /* Do not ignore this symbol */
584 return 0;
585 }
586
587 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
588 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
589
590 static void handle_modversions(struct module *mod, struct elf_info *info,
591 Elf_Sym *sym, const char *symname)
592 {
593 unsigned int crc;
594 enum export export;
595
596 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
597 strncmp(symname, "__ksymtab", 9) == 0)
598 export = export_from_secname(info, get_secindex(info, sym));
599 else
600 export = export_from_sec(info, get_secindex(info, sym));
601
602 switch (sym->st_shndx) {
603 case SHN_COMMON:
604 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
605 break;
606 case SHN_ABS:
607 /* CRC'd symbol */
608 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
609 crc = (unsigned int) sym->st_value;
610 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
611 export);
612 }
613 break;
614 case SHN_UNDEF:
615 /* undefined symbol */
616 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
617 ELF_ST_BIND(sym->st_info) != STB_WEAK)
618 break;
619 if (ignore_undef_symbol(info, symname))
620 break;
621 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
622 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
623 /* add compatibility with older glibc */
624 #ifndef STT_SPARC_REGISTER
625 #define STT_SPARC_REGISTER STT_REGISTER
626 #endif
627 if (info->hdr->e_machine == EM_SPARC ||
628 info->hdr->e_machine == EM_SPARCV9) {
629 /* Ignore register directives. */
630 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
631 break;
632 if (symname[0] == '.') {
633 char *munged = strdup(symname);
634 munged[0] = '_';
635 munged[1] = toupper(munged[1]);
636 symname = munged;
637 }
638 }
639 #endif
640
641 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
642 if (symname[0] != '_')
643 break;
644 else
645 symname++;
646 #endif
647 mod->unres = alloc_symbol(symname,
648 ELF_ST_BIND(sym->st_info) == STB_WEAK,
649 mod->unres);
650 break;
651 default:
652 /* All exported symbols */
653 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
654 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
655 export);
656 }
657 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
658 mod->has_init = 1;
659 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
660 mod->has_cleanup = 1;
661 break;
662 }
663 }
664
665 /**
666 * Parse tag=value strings from .modinfo section
667 **/
668 static char *next_string(char *string, unsigned long *secsize)
669 {
670 /* Skip non-zero chars */
671 while (string[0]) {
672 string++;
673 if ((*secsize)-- <= 1)
674 return NULL;
675 }
676
677 /* Skip any zero padding. */
678 while (!string[0]) {
679 string++;
680 if ((*secsize)-- <= 1)
681 return NULL;
682 }
683 return string;
684 }
685
686 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
687 const char *tag, char *info)
688 {
689 char *p;
690 unsigned int taglen = strlen(tag);
691 unsigned long size = modinfo_len;
692
693 if (info) {
694 size -= info - (char *)modinfo;
695 modinfo = next_string(info, &size);
696 }
697
698 for (p = modinfo; p; p = next_string(p, &size)) {
699 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
700 return p + taglen + 1;
701 }
702 return NULL;
703 }
704
705 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
706 const char *tag)
707
708 {
709 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
710 }
711
712 /**
713 * Test if string s ends in string sub
714 * return 0 if match
715 **/
716 static int strrcmp(const char *s, const char *sub)
717 {
718 int slen, sublen;
719
720 if (!s || !sub)
721 return 1;
722
723 slen = strlen(s);
724 sublen = strlen(sub);
725
726 if ((slen == 0) || (sublen == 0))
727 return 1;
728
729 if (sublen > slen)
730 return 1;
731
732 return memcmp(s + slen - sublen, sub, sublen);
733 }
734
735 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
736 {
737 if (sym)
738 return elf->strtab + sym->st_name;
739 else
740 return "(unknown)";
741 }
742
743 static const char *sec_name(struct elf_info *elf, int secindex)
744 {
745 Elf_Shdr *sechdrs = elf->sechdrs;
746 return (void *)elf->hdr +
747 elf->sechdrs[elf->secindex_strings].sh_offset +
748 sechdrs[secindex].sh_name;
749 }
750
751 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
752 {
753 return (void *)elf->hdr +
754 elf->sechdrs[elf->secindex_strings].sh_offset +
755 sechdr->sh_name;
756 }
757
758 /* if sym is empty or point to a string
759 * like ".[0-9]+" then return 1.
760 * This is the optional prefix added by ld to some sections
761 */
762 static int number_prefix(const char *sym)
763 {
764 if (*sym++ == '\0')
765 return 1;
766 if (*sym != '.')
767 return 0;
768 do {
769 char c = *sym++;
770 if (c < '0' || c > '9')
771 return 0;
772 } while (*sym);
773 return 1;
774 }
775
776 /* The pattern is an array of simple patterns.
777 * "foo" will match an exact string equal to "foo"
778 * "*foo" will match a string that ends with "foo"
779 * "foo*" will match a string that begins with "foo"
780 * "foo$" will match a string equal to "foo" or "foo.1"
781 * where the '1' can be any number including several digits.
782 * The $ syntax is for sections where ld append a dot number
783 * to make section name unique.
784 */
785 static int match(const char *sym, const char * const pat[])
786 {
787 const char *p;
788 while (*pat) {
789 p = *pat++;
790 const char *endp = p + strlen(p) - 1;
791
792 /* "*foo" */
793 if (*p == '*') {
794 if (strrcmp(sym, p + 1) == 0)
795 return 1;
796 }
797 /* "foo*" */
798 else if (*endp == '*') {
799 if (strncmp(sym, p, strlen(p) - 1) == 0)
800 return 1;
801 }
802 /* "foo$" */
803 else if (*endp == '$') {
804 if (strncmp(sym, p, strlen(p) - 1) == 0) {
805 if (number_prefix(sym + strlen(p) - 1))
806 return 1;
807 }
808 }
809 /* no wildcards */
810 else {
811 if (strcmp(p, sym) == 0)
812 return 1;
813 }
814 }
815 /* no match */
816 return 0;
817 }
818
819 /* sections that we do not want to do full section mismatch check on */
820 static const char *section_white_list[] =
821 {
822 ".comment*",
823 ".debug*",
824 ".zdebug*", /* Compressed debug sections. */
825 ".GCC-command-line", /* mn10300 */
826 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
827 ".mdebug*", /* alpha, score, mips etc. */
828 ".pdr", /* alpha, score, mips etc. */
829 ".stab*",
830 ".note*",
831 ".got*",
832 ".toc*",
833 ".xt.prop", /* xtensa */
834 ".xt.lit", /* xtensa */
835 ".arcextmap*", /* arc */
836 ".gnu.linkonce.arcext*", /* arc : modules */
837 NULL
838 };
839
840 /*
841 * This is used to find sections missing the SHF_ALLOC flag.
842 * The cause of this is often a section specified in assembler
843 * without "ax" / "aw".
844 */
845 static void check_section(const char *modname, struct elf_info *elf,
846 Elf_Shdr *sechdr)
847 {
848 const char *sec = sech_name(elf, sechdr);
849
850 if (sechdr->sh_type == SHT_PROGBITS &&
851 !(sechdr->sh_flags & SHF_ALLOC) &&
852 !match(sec, section_white_list)) {
853 warn("%s (%s): unexpected non-allocatable section.\n"
854 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
855 "Note that for example <linux/init.h> contains\n"
856 "section definitions for use in .S files.\n\n",
857 modname, sec);
858 }
859 }
860
861
862
863 #define ALL_INIT_DATA_SECTIONS \
864 ".init.setup$", ".init.rodata$", \
865 ".cpuinit.rodata$", ".meminit.rodata$", \
866 ".init.data$", ".cpuinit.data$", ".meminit.data$"
867 #define ALL_EXIT_DATA_SECTIONS \
868 ".exit.data$", ".cpuexit.data$", ".memexit.data$"
869
870 #define ALL_INIT_TEXT_SECTIONS \
871 ".init.text$", ".cpuinit.text$", ".meminit.text$"
872 #define ALL_EXIT_TEXT_SECTIONS \
873 ".exit.text$", ".cpuexit.text$", ".memexit.text$"
874
875 #define ALL_PCI_INIT_SECTIONS \
876 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
877 ".pci_fixup_enable$", ".pci_fixup_resume$", \
878 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
879
880 #define ALL_XXXINIT_SECTIONS CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
881 #define ALL_XXXEXIT_SECTIONS CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS
882
883 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
884 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
885
886 #define DATA_SECTIONS ".data$", ".data.rel$"
887 #define TEXT_SECTIONS ".text$"
888
889 #define INIT_SECTIONS ".init.*"
890 #define CPU_INIT_SECTIONS ".cpuinit.*"
891 #define MEM_INIT_SECTIONS ".meminit.*"
892
893 #define EXIT_SECTIONS ".exit.*"
894 #define CPU_EXIT_SECTIONS ".cpuexit.*"
895 #define MEM_EXIT_SECTIONS ".memexit.*"
896
897 /* init data sections */
898 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
899
900 /* all init sections */
901 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
902
903 /* All init and exit sections (code + data) */
904 static const char *init_exit_sections[] =
905 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
906
907 /* data section */
908 static const char *data_sections[] = { DATA_SECTIONS, NULL };
909
910
911 /* symbols in .data that may refer to init/exit sections */
912 #define DEFAULT_SYMBOL_WHITE_LIST \
913 "*driver", \
914 "*_template", /* scsi uses *_template a lot */ \
915 "*_timer", /* arm uses ops structures named _timer a lot */ \
916 "*_sht", /* scsi also used *_sht to some extent */ \
917 "*_ops", \
918 "*_probe", \
919 "*_probe_one", \
920 "*_console"
921
922 static const char *head_sections[] = { ".head.text*", NULL };
923 static const char *linker_symbols[] =
924 { "__init_begin", "_sinittext", "_einittext", NULL };
925
926 enum mismatch {
927 TEXT_TO_ANY_INIT,
928 DATA_TO_ANY_INIT,
929 TEXT_TO_ANY_EXIT,
930 DATA_TO_ANY_EXIT,
931 XXXINIT_TO_SOME_INIT,
932 XXXEXIT_TO_SOME_EXIT,
933 ANY_INIT_TO_ANY_EXIT,
934 ANY_EXIT_TO_ANY_INIT,
935 EXPORT_TO_INIT_EXIT,
936 };
937
938 struct sectioncheck {
939 const char *fromsec[20];
940 const char *tosec[20];
941 enum mismatch mismatch;
942 const char *symbol_white_list[20];
943 };
944
945 const struct sectioncheck sectioncheck[] = {
946 /* Do not reference init/exit code/data from
947 * normal code and data
948 */
949 {
950 .fromsec = { TEXT_SECTIONS, NULL },
951 .tosec = { ALL_INIT_SECTIONS, NULL },
952 .mismatch = TEXT_TO_ANY_INIT,
953 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
954 },
955 {
956 .fromsec = { DATA_SECTIONS, NULL },
957 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
958 .mismatch = DATA_TO_ANY_INIT,
959 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
960 },
961 {
962 .fromsec = { DATA_SECTIONS, NULL },
963 .tosec = { INIT_SECTIONS, NULL },
964 .mismatch = DATA_TO_ANY_INIT,
965 .symbol_white_list = {
966 "*_template", "*_timer", "*_sht", "*_ops",
967 "*_probe", "*_probe_one", "*_console", NULL
968 },
969 },
970 {
971 .fromsec = { TEXT_SECTIONS, NULL },
972 .tosec = { ALL_EXIT_SECTIONS, NULL },
973 .mismatch = TEXT_TO_ANY_EXIT,
974 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
975 },
976 {
977 .fromsec = { DATA_SECTIONS, NULL },
978 .tosec = { ALL_EXIT_SECTIONS, NULL },
979 .mismatch = DATA_TO_ANY_EXIT,
980 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
981 },
982 /* Do not reference init code/data from cpuinit/meminit code/data */
983 {
984 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
985 .tosec = { INIT_SECTIONS, NULL },
986 .mismatch = XXXINIT_TO_SOME_INIT,
987 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
988 },
989 /* Do not reference cpuinit code/data from meminit code/data */
990 {
991 .fromsec = { MEM_INIT_SECTIONS, NULL },
992 .tosec = { CPU_INIT_SECTIONS, NULL },
993 .mismatch = XXXINIT_TO_SOME_INIT,
994 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
995 },
996 /* Do not reference meminit code/data from cpuinit code/data */
997 {
998 .fromsec = { CPU_INIT_SECTIONS, NULL },
999 .tosec = { MEM_INIT_SECTIONS, NULL },
1000 .mismatch = XXXINIT_TO_SOME_INIT,
1001 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1002 },
1003 /* Do not reference exit code/data from cpuexit/memexit code/data */
1004 {
1005 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1006 .tosec = { EXIT_SECTIONS, NULL },
1007 .mismatch = XXXEXIT_TO_SOME_EXIT,
1008 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1009 },
1010 /* Do not reference cpuexit code/data from memexit code/data */
1011 {
1012 .fromsec = { MEM_EXIT_SECTIONS, NULL },
1013 .tosec = { CPU_EXIT_SECTIONS, NULL },
1014 .mismatch = XXXEXIT_TO_SOME_EXIT,
1015 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1016 },
1017 /* Do not reference memexit code/data from cpuexit code/data */
1018 {
1019 .fromsec = { CPU_EXIT_SECTIONS, NULL },
1020 .tosec = { MEM_EXIT_SECTIONS, NULL },
1021 .mismatch = XXXEXIT_TO_SOME_EXIT,
1022 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1023 },
1024 /* Do not use exit code/data from init code */
1025 {
1026 .fromsec = { ALL_INIT_SECTIONS, NULL },
1027 .tosec = { ALL_EXIT_SECTIONS, NULL },
1028 .mismatch = ANY_INIT_TO_ANY_EXIT,
1029 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1030 },
1031 /* Do not use init code/data from exit code */
1032 {
1033 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1034 .tosec = { ALL_INIT_SECTIONS, NULL },
1035 .mismatch = ANY_EXIT_TO_ANY_INIT,
1036 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1037 },
1038 {
1039 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1040 .tosec = { INIT_SECTIONS, NULL },
1041 .mismatch = ANY_INIT_TO_ANY_EXIT,
1042 .symbol_white_list = { NULL },
1043 },
1044 /* Do not export init/exit functions or data */
1045 {
1046 .fromsec = { "__ksymtab*", NULL },
1047 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1048 .mismatch = EXPORT_TO_INIT_EXIT,
1049 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1050 }
1051 };
1052
1053 static const struct sectioncheck *section_mismatch(
1054 const char *fromsec, const char *tosec)
1055 {
1056 int i;
1057 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1058 const struct sectioncheck *check = &sectioncheck[0];
1059
1060 for (i = 0; i < elems; i++) {
1061 if (match(fromsec, check->fromsec) &&
1062 match(tosec, check->tosec))
1063 return check;
1064 check++;
1065 }
1066 return NULL;
1067 }
1068
1069 /**
1070 * Whitelist to allow certain references to pass with no warning.
1071 *
1072 * Pattern 1:
1073 * If a module parameter is declared __initdata and permissions=0
1074 * then this is legal despite the warning generated.
1075 * We cannot see value of permissions here, so just ignore
1076 * this pattern.
1077 * The pattern is identified by:
1078 * tosec = .init.data
1079 * fromsec = .data*
1080 * atsym =__param*
1081 *
1082 * Pattern 1a:
1083 * module_param_call() ops can refer to __init set function if permissions=0
1084 * The pattern is identified by:
1085 * tosec = .init.text
1086 * fromsec = .data*
1087 * atsym = __param_ops_*
1088 *
1089 * Pattern 2:
1090 * Many drivers utilise a *driver container with references to
1091 * add, remove, probe functions etc.
1092 * These functions may often be marked __cpuinit and we do not want to
1093 * warn here.
1094 * the pattern is identified by:
1095 * tosec = init or exit section
1096 * fromsec = data section
1097 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1098 * *probe_one, *_console, *_timer
1099 *
1100 * Pattern 3:
1101 * Whitelist all references from .head.text to any init section
1102 *
1103 * Pattern 4:
1104 * Some symbols belong to init section but still it is ok to reference
1105 * these from non-init sections as these symbols don't have any memory
1106 * allocated for them and symbol address and value are same. So even
1107 * if init section is freed, its ok to reference those symbols.
1108 * For ex. symbols marking the init section boundaries.
1109 * This pattern is identified by
1110 * refsymname = __init_begin, _sinittext, _einittext
1111 *
1112 **/
1113 static int secref_whitelist(const struct sectioncheck *mismatch,
1114 const char *fromsec, const char *fromsym,
1115 const char *tosec, const char *tosym)
1116 {
1117 /* Check for pattern 1 */
1118 if (match(tosec, init_data_sections) &&
1119 match(fromsec, data_sections) &&
1120 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1121 return 0;
1122
1123 /* Check for pattern 1a */
1124 if (strcmp(tosec, ".init.text") == 0 &&
1125 match(fromsec, data_sections) &&
1126 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1127 return 0;
1128
1129 /* Check for pattern 2 */
1130 if (match(tosec, init_exit_sections) &&
1131 match(fromsec, data_sections) &&
1132 match(fromsym, mismatch->symbol_white_list))
1133 return 0;
1134
1135 /* Check for pattern 3 */
1136 if (match(fromsec, head_sections) &&
1137 match(tosec, init_sections))
1138 return 0;
1139
1140 /* Check for pattern 4 */
1141 if (match(tosym, linker_symbols))
1142 return 0;
1143
1144 return 1;
1145 }
1146
1147 /**
1148 * Find symbol based on relocation record info.
1149 * In some cases the symbol supplied is a valid symbol so
1150 * return refsym. If st_name != 0 we assume this is a valid symbol.
1151 * In other cases the symbol needs to be looked up in the symbol table
1152 * based on section and address.
1153 * **/
1154 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1155 Elf_Sym *relsym)
1156 {
1157 Elf_Sym *sym;
1158 Elf_Sym *near = NULL;
1159 Elf64_Sword distance = 20;
1160 Elf64_Sword d;
1161 unsigned int relsym_secindex;
1162
1163 if (relsym->st_name != 0)
1164 return relsym;
1165
1166 relsym_secindex = get_secindex(elf, relsym);
1167 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1168 if (get_secindex(elf, sym) != relsym_secindex)
1169 continue;
1170 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1171 continue;
1172 if (sym->st_value == addr)
1173 return sym;
1174 /* Find a symbol nearby - addr are maybe negative */
1175 d = sym->st_value - addr;
1176 if (d < 0)
1177 d = addr - sym->st_value;
1178 if (d < distance) {
1179 distance = d;
1180 near = sym;
1181 }
1182 }
1183 /* We need a close match */
1184 if (distance < 20)
1185 return near;
1186 else
1187 return NULL;
1188 }
1189
1190 static inline int is_arm_mapping_symbol(const char *str)
1191 {
1192 return str[0] == '$' && strchr("atd", str[1])
1193 && (str[2] == '\0' || str[2] == '.');
1194 }
1195
1196 /*
1197 * If there's no name there, ignore it; likewise, ignore it if it's
1198 * one of the magic symbols emitted used by current ARM tools.
1199 *
1200 * Otherwise if find_symbols_between() returns those symbols, they'll
1201 * fail the whitelist tests and cause lots of false alarms ... fixable
1202 * only by merging __exit and __init sections into __text, bloating
1203 * the kernel (which is especially evil on embedded platforms).
1204 */
1205 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1206 {
1207 const char *name = elf->strtab + sym->st_name;
1208
1209 if (!name || !strlen(name))
1210 return 0;
1211 return !is_arm_mapping_symbol(name);
1212 }
1213
1214 /*
1215 * Find symbols before or equal addr and after addr - in the section sec.
1216 * If we find two symbols with equal offset prefer one with a valid name.
1217 * The ELF format may have a better way to detect what type of symbol
1218 * it is, but this works for now.
1219 **/
1220 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1221 const char *sec)
1222 {
1223 Elf_Sym *sym;
1224 Elf_Sym *near = NULL;
1225 Elf_Addr distance = ~0;
1226
1227 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1228 const char *symsec;
1229
1230 if (is_shndx_special(sym->st_shndx))
1231 continue;
1232 symsec = sec_name(elf, get_secindex(elf, sym));
1233 if (strcmp(symsec, sec) != 0)
1234 continue;
1235 if (!is_valid_name(elf, sym))
1236 continue;
1237 if (sym->st_value <= addr) {
1238 if ((addr - sym->st_value) < distance) {
1239 distance = addr - sym->st_value;
1240 near = sym;
1241 } else if ((addr - sym->st_value) == distance) {
1242 near = sym;
1243 }
1244 }
1245 }
1246 return near;
1247 }
1248
1249 /*
1250 * Convert a section name to the function/data attribute
1251 * .init.text => __init
1252 * .cpuinit.data => __cpudata
1253 * .memexitconst => __memconst
1254 * etc.
1255 *
1256 * The memory of returned value has been allocated on a heap. The user of this
1257 * method should free it after usage.
1258 */
1259 static char *sec2annotation(const char *s)
1260 {
1261 if (match(s, init_exit_sections)) {
1262 char *p = malloc(20);
1263 char *r = p;
1264
1265 *p++ = '_';
1266 *p++ = '_';
1267 if (*s == '.')
1268 s++;
1269 while (*s && *s != '.')
1270 *p++ = *s++;
1271 *p = '\0';
1272 if (*s == '.')
1273 s++;
1274 if (strstr(s, "rodata") != NULL)
1275 strcat(p, "const ");
1276 else if (strstr(s, "data") != NULL)
1277 strcat(p, "data ");
1278 else
1279 strcat(p, " ");
1280 return r;
1281 } else {
1282 return strdup("");
1283 }
1284 }
1285
1286 static int is_function(Elf_Sym *sym)
1287 {
1288 if (sym)
1289 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1290 else
1291 return -1;
1292 }
1293
1294 static void print_section_list(const char * const list[20])
1295 {
1296 const char *const *s = list;
1297
1298 while (*s) {
1299 fprintf(stderr, "%s", *s);
1300 s++;
1301 if (*s)
1302 fprintf(stderr, ", ");
1303 }
1304 fprintf(stderr, "\n");
1305 }
1306
1307 /*
1308 * Print a warning about a section mismatch.
1309 * Try to find symbols near it so user can find it.
1310 * Check whitelist before warning - it may be a false positive.
1311 */
1312 static void report_sec_mismatch(const char *modname,
1313 const struct sectioncheck *mismatch,
1314 const char *fromsec,
1315 unsigned long long fromaddr,
1316 const char *fromsym,
1317 int from_is_func,
1318 const char *tosec, const char *tosym,
1319 int to_is_func)
1320 {
1321 const char *from, *from_p;
1322 const char *to, *to_p;
1323 char *prl_from;
1324 char *prl_to;
1325
1326 switch (from_is_func) {
1327 case 0: from = "variable"; from_p = ""; break;
1328 case 1: from = "function"; from_p = "()"; break;
1329 default: from = "(unknown reference)"; from_p = ""; break;
1330 }
1331 switch (to_is_func) {
1332 case 0: to = "variable"; to_p = ""; break;
1333 case 1: to = "function"; to_p = "()"; break;
1334 default: to = "(unknown reference)"; to_p = ""; break;
1335 }
1336
1337 sec_mismatch_count++;
1338 if (!sec_mismatch_verbose)
1339 return;
1340
1341 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1342 "to the %s %s:%s%s\n",
1343 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1344 tosym, to_p);
1345
1346 switch (mismatch->mismatch) {
1347 case TEXT_TO_ANY_INIT:
1348 prl_from = sec2annotation(fromsec);
1349 prl_to = sec2annotation(tosec);
1350 fprintf(stderr,
1351 "The function %s%s() references\n"
1352 "the %s %s%s%s.\n"
1353 "This is often because %s lacks a %s\n"
1354 "annotation or the annotation of %s is wrong.\n",
1355 prl_from, fromsym,
1356 to, prl_to, tosym, to_p,
1357 fromsym, prl_to, tosym);
1358 free(prl_from);
1359 free(prl_to);
1360 break;
1361 case DATA_TO_ANY_INIT: {
1362 prl_to = sec2annotation(tosec);
1363 fprintf(stderr,
1364 "The variable %s references\n"
1365 "the %s %s%s%s\n"
1366 "If the reference is valid then annotate the\n"
1367 "variable with __init* or __refdata (see linux/init.h) "
1368 "or name the variable:\n",
1369 fromsym, to, prl_to, tosym, to_p);
1370 print_section_list(mismatch->symbol_white_list);
1371 free(prl_to);
1372 break;
1373 }
1374 case TEXT_TO_ANY_EXIT:
1375 prl_to = sec2annotation(tosec);
1376 fprintf(stderr,
1377 "The function %s() references a %s in an exit section.\n"
1378 "Often the %s %s%s has valid usage outside the exit section\n"
1379 "and the fix is to remove the %sannotation of %s.\n",
1380 fromsym, to, to, tosym, to_p, prl_to, tosym);
1381 free(prl_to);
1382 break;
1383 case DATA_TO_ANY_EXIT: {
1384 prl_to = sec2annotation(tosec);
1385 fprintf(stderr,
1386 "The variable %s references\n"
1387 "the %s %s%s%s\n"
1388 "If the reference is valid then annotate the\n"
1389 "variable with __exit* (see linux/init.h) or "
1390 "name the variable:\n",
1391 fromsym, to, prl_to, tosym, to_p);
1392 print_section_list(mismatch->symbol_white_list);
1393 free(prl_to);
1394 break;
1395 }
1396 case XXXINIT_TO_SOME_INIT:
1397 case XXXEXIT_TO_SOME_EXIT:
1398 prl_from = sec2annotation(fromsec);
1399 prl_to = sec2annotation(tosec);
1400 fprintf(stderr,
1401 "The %s %s%s%s references\n"
1402 "a %s %s%s%s.\n"
1403 "If %s is only used by %s then\n"
1404 "annotate %s with a matching annotation.\n",
1405 from, prl_from, fromsym, from_p,
1406 to, prl_to, tosym, to_p,
1407 tosym, fromsym, tosym);
1408 free(prl_from);
1409 free(prl_to);
1410 break;
1411 case ANY_INIT_TO_ANY_EXIT:
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 init function\n"
1419 "uses functionality in the exit path.\n"
1420 "The fix is often to remove the %sannotation of\n"
1421 "%s%s so it may be used outside an exit 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 ANY_EXIT_TO_ANY_INIT:
1429 prl_from = sec2annotation(fromsec);
1430 prl_to = sec2annotation(tosec);
1431 fprintf(stderr,
1432 "The %s %s%s%s references\n"
1433 "a %s %s%s%s.\n"
1434 "This is often seen when error handling "
1435 "in the exit function\n"
1436 "uses functionality in the init path.\n"
1437 "The fix is often to remove the %sannotation of\n"
1438 "%s%s so it may be used outside an init section.\n",
1439 from, prl_from, fromsym, from_p,
1440 to, prl_to, tosym, to_p,
1441 prl_to, tosym, to_p);
1442 free(prl_from);
1443 free(prl_to);
1444 break;
1445 case EXPORT_TO_INIT_EXIT:
1446 prl_to = sec2annotation(tosec);
1447 fprintf(stderr,
1448 "The symbol %s is exported and annotated %s\n"
1449 "Fix this by removing the %sannotation of %s "
1450 "or drop the export.\n",
1451 tosym, prl_to, prl_to, tosym);
1452 free(prl_to);
1453 break;
1454 }
1455 fprintf(stderr, "\n");
1456 }
1457
1458 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1459 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1460 {
1461 const char *tosec;
1462 const struct sectioncheck *mismatch;
1463
1464 tosec = sec_name(elf, get_secindex(elf, sym));
1465 mismatch = section_mismatch(fromsec, tosec);
1466 if (mismatch) {
1467 Elf_Sym *to;
1468 Elf_Sym *from;
1469 const char *tosym;
1470 const char *fromsym;
1471
1472 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1473 fromsym = sym_name(elf, from);
1474 to = find_elf_symbol(elf, r->r_addend, sym);
1475 tosym = sym_name(elf, to);
1476
1477 /* check whitelist - we may ignore it */
1478 if (secref_whitelist(mismatch,
1479 fromsec, fromsym, tosec, tosym)) {
1480 report_sec_mismatch(modname, mismatch,
1481 fromsec, r->r_offset, fromsym,
1482 is_function(from), tosec, tosym,
1483 is_function(to));
1484 }
1485 }
1486 }
1487
1488 static unsigned int *reloc_location(struct elf_info *elf,
1489 Elf_Shdr *sechdr, Elf_Rela *r)
1490 {
1491 Elf_Shdr *sechdrs = elf->sechdrs;
1492 int section = sechdr->sh_info;
1493
1494 return (void *)elf->hdr + sechdrs[section].sh_offset +
1495 r->r_offset;
1496 }
1497
1498 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1499 {
1500 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1501 unsigned int *location = reloc_location(elf, sechdr, r);
1502
1503 switch (r_typ) {
1504 case R_386_32:
1505 r->r_addend = TO_NATIVE(*location);
1506 break;
1507 case R_386_PC32:
1508 r->r_addend = TO_NATIVE(*location) + 4;
1509 /* For CONFIG_RELOCATABLE=y */
1510 if (elf->hdr->e_type == ET_EXEC)
1511 r->r_addend += r->r_offset;
1512 break;
1513 }
1514 return 0;
1515 }
1516
1517 #ifndef R_ARM_CALL
1518 #define R_ARM_CALL 28
1519 #endif
1520 #ifndef R_ARM_JUMP24
1521 #define R_ARM_JUMP24 29
1522 #endif
1523
1524 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1525 {
1526 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1527
1528 switch (r_typ) {
1529 case R_ARM_ABS32:
1530 /* From ARM ABI: (S + A) | T */
1531 r->r_addend = (int)(long)
1532 (elf->symtab_start + ELF_R_SYM(r->r_info));
1533 break;
1534 case R_ARM_PC24:
1535 case R_ARM_CALL:
1536 case R_ARM_JUMP24:
1537 /* From ARM ABI: ((S + A) | T) - P */
1538 r->r_addend = (int)(long)(elf->hdr +
1539 sechdr->sh_offset +
1540 (r->r_offset - sechdr->sh_addr));
1541 break;
1542 default:
1543 return 1;
1544 }
1545 return 0;
1546 }
1547
1548 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1549 {
1550 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1551 unsigned int *location = reloc_location(elf, sechdr, r);
1552 unsigned int inst;
1553
1554 if (r_typ == R_MIPS_HI16)
1555 return 1; /* skip this */
1556 inst = TO_NATIVE(*location);
1557 switch (r_typ) {
1558 case R_MIPS_LO16:
1559 r->r_addend = inst & 0xffff;
1560 break;
1561 case R_MIPS_26:
1562 r->r_addend = (inst & 0x03ffffff) << 2;
1563 break;
1564 case R_MIPS_32:
1565 r->r_addend = inst;
1566 break;
1567 }
1568 return 0;
1569 }
1570
1571 static void section_rela(const char *modname, struct elf_info *elf,
1572 Elf_Shdr *sechdr)
1573 {
1574 Elf_Sym *sym;
1575 Elf_Rela *rela;
1576 Elf_Rela r;
1577 unsigned int r_sym;
1578 const char *fromsec;
1579
1580 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1581 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1582
1583 fromsec = sech_name(elf, sechdr);
1584 fromsec += strlen(".rela");
1585 /* if from section (name) is know good then skip it */
1586 if (match(fromsec, section_white_list))
1587 return;
1588
1589 for (rela = start; rela < stop; rela++) {
1590 r.r_offset = TO_NATIVE(rela->r_offset);
1591 #if KERNEL_ELFCLASS == ELFCLASS64
1592 if (elf->hdr->e_machine == EM_MIPS) {
1593 unsigned int r_typ;
1594 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1595 r_sym = TO_NATIVE(r_sym);
1596 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1597 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1598 } else {
1599 r.r_info = TO_NATIVE(rela->r_info);
1600 r_sym = ELF_R_SYM(r.r_info);
1601 }
1602 #else
1603 r.r_info = TO_NATIVE(rela->r_info);
1604 r_sym = ELF_R_SYM(r.r_info);
1605 #endif
1606 r.r_addend = TO_NATIVE(rela->r_addend);
1607 sym = elf->symtab_start + r_sym;
1608 /* Skip special sections */
1609 if (is_shndx_special(sym->st_shndx))
1610 continue;
1611 check_section_mismatch(modname, elf, &r, sym, fromsec);
1612 }
1613 }
1614
1615 static void section_rel(const char *modname, struct elf_info *elf,
1616 Elf_Shdr *sechdr)
1617 {
1618 Elf_Sym *sym;
1619 Elf_Rel *rel;
1620 Elf_Rela r;
1621 unsigned int r_sym;
1622 const char *fromsec;
1623
1624 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1625 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1626
1627 fromsec = sech_name(elf, sechdr);
1628 fromsec += strlen(".rel");
1629 /* if from section (name) is know good then skip it */
1630 if (match(fromsec, section_white_list))
1631 return;
1632
1633 for (rel = start; rel < stop; rel++) {
1634 r.r_offset = TO_NATIVE(rel->r_offset);
1635 #if KERNEL_ELFCLASS == ELFCLASS64
1636 if (elf->hdr->e_machine == EM_MIPS) {
1637 unsigned int r_typ;
1638 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1639 r_sym = TO_NATIVE(r_sym);
1640 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1641 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1642 } else {
1643 r.r_info = TO_NATIVE(rel->r_info);
1644 r_sym = ELF_R_SYM(r.r_info);
1645 }
1646 #else
1647 r.r_info = TO_NATIVE(rel->r_info);
1648 r_sym = ELF_R_SYM(r.r_info);
1649 #endif
1650 r.r_addend = 0;
1651 switch (elf->hdr->e_machine) {
1652 case EM_386:
1653 if (addend_386_rel(elf, sechdr, &r))
1654 continue;
1655 break;
1656 case EM_ARM:
1657 if (addend_arm_rel(elf, sechdr, &r))
1658 continue;
1659 break;
1660 case EM_MIPS:
1661 if (addend_mips_rel(elf, sechdr, &r))
1662 continue;
1663 break;
1664 }
1665 sym = elf->symtab_start + r_sym;
1666 /* Skip special sections */
1667 if (is_shndx_special(sym->st_shndx))
1668 continue;
1669 check_section_mismatch(modname, elf, &r, sym, fromsec);
1670 }
1671 }
1672
1673 /**
1674 * A module includes a number of sections that are discarded
1675 * either when loaded or when used as built-in.
1676 * For loaded modules all functions marked __init and all data
1677 * marked __initdata will be discarded when the module has been initialized.
1678 * Likewise for modules used built-in the sections marked __exit
1679 * are discarded because __exit marked function are supposed to be called
1680 * only when a module is unloaded which never happens for built-in modules.
1681 * The check_sec_ref() function traverses all relocation records
1682 * to find all references to a section that reference a section that will
1683 * be discarded and warns about it.
1684 **/
1685 static void check_sec_ref(struct module *mod, const char *modname,
1686 struct elf_info *elf)
1687 {
1688 int i;
1689 Elf_Shdr *sechdrs = elf->sechdrs;
1690
1691 /* Walk through all sections */
1692 for (i = 0; i < elf->num_sections; i++) {
1693 check_section(modname, elf, &elf->sechdrs[i]);
1694 /* We want to process only relocation sections and not .init */
1695 if (sechdrs[i].sh_type == SHT_RELA)
1696 section_rela(modname, elf, &elf->sechdrs[i]);
1697 else if (sechdrs[i].sh_type == SHT_REL)
1698 section_rel(modname, elf, &elf->sechdrs[i]);
1699 }
1700 }
1701
1702 static void read_symbols(char *modname)
1703 {
1704 const char *symname;
1705 char *version;
1706 char *license;
1707 struct module *mod;
1708 struct elf_info info = { };
1709 Elf_Sym *sym;
1710
1711 if (!parse_elf(&info, modname))
1712 return;
1713
1714 mod = new_module(modname);
1715
1716 /* When there's no vmlinux, don't print warnings about
1717 * unresolved symbols (since there'll be too many ;) */
1718 if (is_vmlinux(modname)) {
1719 have_vmlinux = 1;
1720 mod->skip = 1;
1721 }
1722
1723 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1724 if (info.modinfo && !license && !is_vmlinux(modname))
1725 warn("modpost: missing MODULE_LICENSE() in %s\n"
1726 "see include/linux/module.h for "
1727 "more information\n", modname);
1728 while (license) {
1729 if (license_is_gpl_compatible(license))
1730 mod->gpl_compatible = 1;
1731 else {
1732 mod->gpl_compatible = 0;
1733 break;
1734 }
1735 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1736 "license", license);
1737 }
1738
1739 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1740 symname = info.strtab + sym->st_name;
1741
1742 handle_modversions(mod, &info, sym, symname);
1743 handle_moddevtable(mod, &info, sym, symname);
1744 }
1745 if (!is_vmlinux(modname) ||
1746 (is_vmlinux(modname) && vmlinux_section_warnings))
1747 check_sec_ref(mod, modname, &info);
1748
1749 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1750 if (version)
1751 maybe_frob_rcs_version(modname, version, info.modinfo,
1752 version - (char *)info.hdr);
1753 if (version || (all_versions && !is_vmlinux(modname)))
1754 get_src_version(modname, mod->srcversion,
1755 sizeof(mod->srcversion)-1);
1756
1757 parse_elf_finish(&info);
1758
1759 /* Our trick to get versioning for module struct etc. - it's
1760 * never passed as an argument to an exported function, so
1761 * the automatic versioning doesn't pick it up, but it's really
1762 * important anyhow */
1763 if (modversions)
1764 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1765 }
1766
1767 static void read_symbols_from_files(const char *filename)
1768 {
1769 FILE *in = stdin;
1770 char fname[PATH_MAX];
1771
1772 if (strcmp(filename, "-") != 0) {
1773 in = fopen(filename, "r");
1774 if (!in)
1775 fatal("Can't open filenames file %s: %m", filename);
1776 }
1777
1778 while (fgets(fname, PATH_MAX, in) != NULL) {
1779 if (strends(fname, "\n"))
1780 fname[strlen(fname)-1] = '\0';
1781 read_symbols(fname);
1782 }
1783
1784 if (in != stdin)
1785 fclose(in);
1786 }
1787
1788 #define SZ 500
1789
1790 /* We first write the generated file into memory using the
1791 * following helper, then compare to the file on disk and
1792 * only update the later if anything changed */
1793
1794 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1795 const char *fmt, ...)
1796 {
1797 char tmp[SZ];
1798 int len;
1799 va_list ap;
1800
1801 va_start(ap, fmt);
1802 len = vsnprintf(tmp, SZ, fmt, ap);
1803 buf_write(buf, tmp, len);
1804 va_end(ap);
1805 }
1806
1807 void buf_write(struct buffer *buf, const char *s, int len)
1808 {
1809 if (buf->size - buf->pos < len) {
1810 buf->size += len + SZ;
1811 buf->p = realloc(buf->p, buf->size);
1812 }
1813 strncpy(buf->p + buf->pos, s, len);
1814 buf->pos += len;
1815 }
1816
1817 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1818 {
1819 const char *e = is_vmlinux(m) ?"":".ko";
1820
1821 switch (exp) {
1822 case export_gpl:
1823 fatal("modpost: GPL-incompatible module %s%s "
1824 "uses GPL-only symbol '%s'\n", m, e, s);
1825 break;
1826 case export_unused_gpl:
1827 fatal("modpost: GPL-incompatible module %s%s "
1828 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1829 break;
1830 case export_gpl_future:
1831 warn("modpost: GPL-incompatible module %s%s "
1832 "uses future GPL-only symbol '%s'\n", m, e, s);
1833 break;
1834 case export_plain:
1835 case export_unused:
1836 case export_unknown:
1837 /* ignore */
1838 break;
1839 }
1840 }
1841
1842 static void check_for_unused(enum export exp, const char *m, const char *s)
1843 {
1844 const char *e = is_vmlinux(m) ?"":".ko";
1845
1846 switch (exp) {
1847 case export_unused:
1848 case export_unused_gpl:
1849 warn("modpost: module %s%s "
1850 "uses symbol '%s' marked UNUSED\n", m, e, s);
1851 break;
1852 default:
1853 /* ignore */
1854 break;
1855 }
1856 }
1857
1858 static void check_exports(struct module *mod)
1859 {
1860 struct symbol *s, *exp;
1861
1862 for (s = mod->unres; s; s = s->next) {
1863 const char *basename;
1864 exp = find_symbol(s->name);
1865 if (!exp || exp->module == mod)
1866 continue;
1867 basename = strrchr(mod->name, '/');
1868 if (basename)
1869 basename++;
1870 else
1871 basename = mod->name;
1872 if (!mod->gpl_compatible)
1873 check_for_gpl_usage(exp->export, basename, exp->name);
1874 check_for_unused(exp->export, basename, exp->name);
1875 }
1876 }
1877
1878 /**
1879 * Header for the generated file
1880 **/
1881 static void add_header(struct buffer *b, struct module *mod)
1882 {
1883 buf_printf(b, "#include <linux/module.h>\n");
1884 buf_printf(b, "#include <linux/vermagic.h>\n");
1885 buf_printf(b, "#include <linux/compiler.h>\n");
1886 buf_printf(b, "\n");
1887 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1888 buf_printf(b, "\n");
1889 buf_printf(b, "struct module __this_module\n");
1890 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1891 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1892 if (mod->has_init)
1893 buf_printf(b, "\t.init = init_module,\n");
1894 if (mod->has_cleanup)
1895 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1896 "\t.exit = cleanup_module,\n"
1897 "#endif\n");
1898 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1899 buf_printf(b, "};\n");
1900 }
1901
1902 static void add_intree_flag(struct buffer *b, int is_intree)
1903 {
1904 if (is_intree)
1905 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1906 }
1907
1908 static void add_staging_flag(struct buffer *b, const char *name)
1909 {
1910 static const char *staging_dir = "drivers/staging";
1911
1912 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1913 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1914 }
1915
1916 /**
1917 * Record CRCs for unresolved symbols
1918 **/
1919 static int add_versions(struct buffer *b, struct module *mod)
1920 {
1921 struct symbol *s, *exp;
1922 int err = 0;
1923
1924 for (s = mod->unres; s; s = s->next) {
1925 exp = find_symbol(s->name);
1926 if (!exp || exp->module == mod) {
1927 if (have_vmlinux && !s->weak) {
1928 if (warn_unresolved) {
1929 warn("\"%s\" [%s.ko] undefined!\n",
1930 s->name, mod->name);
1931 } else {
1932 merror("\"%s\" [%s.ko] undefined!\n",
1933 s->name, mod->name);
1934 err = 1;
1935 }
1936 }
1937 continue;
1938 }
1939 s->module = exp->module;
1940 s->crc_valid = exp->crc_valid;
1941 s->crc = exp->crc;
1942 }
1943
1944 if (!modversions)
1945 return err;
1946
1947 buf_printf(b, "\n");
1948 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1949 buf_printf(b, "__used\n");
1950 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1951
1952 for (s = mod->unres; s; s = s->next) {
1953 if (!s->module)
1954 continue;
1955 if (!s->crc_valid) {
1956 warn("\"%s\" [%s.ko] has no CRC!\n",
1957 s->name, mod->name);
1958 continue;
1959 }
1960 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1961 s->crc, s->name);
1962 }
1963
1964 buf_printf(b, "};\n");
1965
1966 return err;
1967 }
1968
1969 static void add_depends(struct buffer *b, struct module *mod,
1970 struct module *modules)
1971 {
1972 struct symbol *s;
1973 struct module *m;
1974 int first = 1;
1975
1976 for (m = modules; m; m = m->next)
1977 m->seen = is_vmlinux(m->name);
1978
1979 buf_printf(b, "\n");
1980 buf_printf(b, "static const char __module_depends[]\n");
1981 buf_printf(b, "__used\n");
1982 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1983 buf_printf(b, "\"depends=");
1984 for (s = mod->unres; s; s = s->next) {
1985 const char *p;
1986 if (!s->module)
1987 continue;
1988
1989 if (s->module->seen)
1990 continue;
1991
1992 s->module->seen = 1;
1993 p = strrchr(s->module->name, '/');
1994 if (p)
1995 p++;
1996 else
1997 p = s->module->name;
1998 buf_printf(b, "%s%s", first ? "" : ",", p);
1999 first = 0;
2000 }
2001 buf_printf(b, "\";\n");
2002 }
2003
2004 static void add_srcversion(struct buffer *b, struct module *mod)
2005 {
2006 if (mod->srcversion[0]) {
2007 buf_printf(b, "\n");
2008 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2009 mod->srcversion);
2010 }
2011 }
2012
2013 static void write_if_changed(struct buffer *b, const char *fname)
2014 {
2015 char *tmp;
2016 FILE *file;
2017 struct stat st;
2018
2019 file = fopen(fname, "r");
2020 if (!file)
2021 goto write;
2022
2023 if (fstat(fileno(file), &st) < 0)
2024 goto close_write;
2025
2026 if (st.st_size != b->pos)
2027 goto close_write;
2028
2029 tmp = NOFAIL(malloc(b->pos));
2030 if (fread(tmp, 1, b->pos, file) != b->pos)
2031 goto free_write;
2032
2033 if (memcmp(tmp, b->p, b->pos) != 0)
2034 goto free_write;
2035
2036 free(tmp);
2037 fclose(file);
2038 return;
2039
2040 free_write:
2041 free(tmp);
2042 close_write:
2043 fclose(file);
2044 write:
2045 file = fopen(fname, "w");
2046 if (!file) {
2047 perror(fname);
2048 exit(1);
2049 }
2050 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2051 perror(fname);
2052 exit(1);
2053 }
2054 fclose(file);
2055 }
2056
2057 /* parse Module.symvers file. line format:
2058 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2059 **/
2060 static void read_dump(const char *fname, unsigned int kernel)
2061 {
2062 unsigned long size, pos = 0;
2063 void *file = grab_file(fname, &size);
2064 char *line;
2065
2066 if (!file)
2067 /* No symbol versions, silently ignore */
2068 return;
2069
2070 while ((line = get_next_line(&pos, file, size))) {
2071 char *symname, *modname, *d, *export, *end;
2072 unsigned int crc;
2073 struct module *mod;
2074 struct symbol *s;
2075
2076 if (!(symname = strchr(line, '\t')))
2077 goto fail;
2078 *symname++ = '\0';
2079 if (!(modname = strchr(symname, '\t')))
2080 goto fail;
2081 *modname++ = '\0';
2082 if ((export = strchr(modname, '\t')) != NULL)
2083 *export++ = '\0';
2084 if (export && ((end = strchr(export, '\t')) != NULL))
2085 *end = '\0';
2086 crc = strtoul(line, &d, 16);
2087 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2088 goto fail;
2089 mod = find_module(modname);
2090 if (!mod) {
2091 if (is_vmlinux(modname))
2092 have_vmlinux = 1;
2093 mod = new_module(modname);
2094 mod->skip = 1;
2095 }
2096 s = sym_add_exported(symname, mod, export_no(export));
2097 s->kernel = kernel;
2098 s->preloaded = 1;
2099 sym_update_crc(symname, mod, crc, export_no(export));
2100 }
2101 return;
2102 fail:
2103 fatal("parse error in symbol dump file\n");
2104 }
2105
2106 /* For normal builds always dump all symbols.
2107 * For external modules only dump symbols
2108 * that are not read from kernel Module.symvers.
2109 **/
2110 static int dump_sym(struct symbol *sym)
2111 {
2112 if (!external_module)
2113 return 1;
2114 if (sym->vmlinux || sym->kernel)
2115 return 0;
2116 return 1;
2117 }
2118
2119 static void write_dump(const char *fname)
2120 {
2121 struct buffer buf = { };
2122 struct symbol *symbol;
2123 int n;
2124
2125 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2126 symbol = symbolhash[n];
2127 while (symbol) {
2128 if (dump_sym(symbol))
2129 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2130 symbol->crc, symbol->name,
2131 symbol->module->name,
2132 export_str(symbol->export));
2133 symbol = symbol->next;
2134 }
2135 }
2136 write_if_changed(&buf, fname);
2137 }
2138
2139 struct ext_sym_list {
2140 struct ext_sym_list *next;
2141 const char *file;
2142 };
2143
2144 int main(int argc, char **argv)
2145 {
2146 struct module *mod;
2147 struct buffer buf = { };
2148 char *kernel_read = NULL, *module_read = NULL;
2149 char *dump_write = NULL, *files_source = NULL;
2150 int opt;
2151 int err;
2152 struct ext_sym_list *extsym_iter;
2153 struct ext_sym_list *extsym_start = NULL;
2154
2155 while ((opt = getopt(argc, argv, "i:I:e:msST:o:awM:K:")) != -1) {
2156 switch (opt) {
2157 case 'i':
2158 kernel_read = optarg;
2159 break;
2160 case 'I':
2161 module_read = optarg;
2162 external_module = 1;
2163 break;
2164 case 'e':
2165 external_module = 1;
2166 extsym_iter =
2167 NOFAIL(malloc(sizeof(*extsym_iter)));
2168 extsym_iter->next = extsym_start;
2169 extsym_iter->file = optarg;
2170 extsym_start = extsym_iter;
2171 break;
2172 case 'm':
2173 modversions = 1;
2174 break;
2175 case 'o':
2176 dump_write = optarg;
2177 break;
2178 case 'a':
2179 all_versions = 1;
2180 break;
2181 case 's':
2182 vmlinux_section_warnings = 0;
2183 break;
2184 case 'S':
2185 sec_mismatch_verbose = 0;
2186 break;
2187 case 'T':
2188 files_source = optarg;
2189 break;
2190 case 'w':
2191 warn_unresolved = 1;
2192 break;
2193 default:
2194 exit(1);
2195 }
2196 }
2197
2198 if (kernel_read)
2199 read_dump(kernel_read, 1);
2200 if (module_read)
2201 read_dump(module_read, 0);
2202 while (extsym_start) {
2203 read_dump(extsym_start->file, 0);
2204 extsym_iter = extsym_start->next;
2205 free(extsym_start);
2206 extsym_start = extsym_iter;
2207 }
2208
2209 while (optind < argc)
2210 read_symbols(argv[optind++]);
2211
2212 if (files_source)
2213 read_symbols_from_files(files_source);
2214
2215 for (mod = modules; mod; mod = mod->next) {
2216 if (mod->skip)
2217 continue;
2218 check_exports(mod);
2219 }
2220
2221 err = 0;
2222
2223 for (mod = modules; mod; mod = mod->next) {
2224 char fname[strlen(mod->name) + 10];
2225
2226 if (mod->skip)
2227 continue;
2228
2229 buf.pos = 0;
2230
2231 add_header(&buf, mod);
2232 add_intree_flag(&buf, !external_module);
2233 add_staging_flag(&buf, mod->name);
2234 err |= add_versions(&buf, mod);
2235 add_depends(&buf, mod, modules);
2236 add_moddevtable(&buf, mod);
2237 add_srcversion(&buf, mod);
2238
2239 sprintf(fname, "%s.mod.c", mod->name);
2240 write_if_changed(&buf, fname);
2241 }
2242
2243 if (dump_write)
2244 write_dump(dump_write);
2245 if (sec_mismatch_count && !sec_mismatch_verbose)
2246 warn("modpost: Found %d section mismatch(es).\n"
2247 "To see full details build your kernel with:\n"
2248 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2249 sec_mismatch_count);
2250
2251 return err;
2252 }