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