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Merge branch 'for-linus' of git://git.kernel.dk/linux-block into next
[mirror_ubuntu-bionic-kernel.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 <errno.h>
21 #include "modpost.h"
22 #include "../../include/generated/autoconf.h"
23 #include "../../include/linux/license.h"
24 #include "../../include/linux/export.h"
25
26 /* Are we using CONFIG_MODVERSIONS? */
27 int modversions = 0;
28 /* Warn about undefined symbols? (do so if we have vmlinux) */
29 int have_vmlinux = 0;
30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
31 static int all_versions = 0;
32 /* If we are modposting external module set to 1 */
33 static int external_module = 0;
34 /* Warn about section mismatch in vmlinux if set to 1 */
35 static int vmlinux_section_warnings = 1;
36 /* Only warn about unresolved symbols */
37 static int warn_unresolved = 0;
38 /* How a symbol is exported */
39 static int sec_mismatch_count = 0;
40 static int sec_mismatch_verbose = 1;
41 /* ignore missing files */
42 static int ignore_missing_files;
43
44 enum export {
45 export_plain, export_unused, export_gpl,
46 export_unused_gpl, export_gpl_future, export_unknown
47 };
48
49 #define PRINTF __attribute__ ((format (printf, 1, 2)))
50
51 PRINTF void fatal(const char *fmt, ...)
52 {
53 va_list arglist;
54
55 fprintf(stderr, "FATAL: ");
56
57 va_start(arglist, fmt);
58 vfprintf(stderr, fmt, arglist);
59 va_end(arglist);
60
61 exit(1);
62 }
63
64 PRINTF void warn(const char *fmt, ...)
65 {
66 va_list arglist;
67
68 fprintf(stderr, "WARNING: ");
69
70 va_start(arglist, fmt);
71 vfprintf(stderr, fmt, arglist);
72 va_end(arglist);
73 }
74
75 PRINTF void merror(const char *fmt, ...)
76 {
77 va_list arglist;
78
79 fprintf(stderr, "ERROR: ");
80
81 va_start(arglist, fmt);
82 vfprintf(stderr, fmt, arglist);
83 va_end(arglist);
84 }
85
86 static inline bool strends(const char *str, const char *postfix)
87 {
88 if (strlen(str) < strlen(postfix))
89 return false;
90
91 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
92 }
93
94 static int is_vmlinux(const char *modname)
95 {
96 const char *myname;
97
98 myname = strrchr(modname, '/');
99 if (myname)
100 myname++;
101 else
102 myname = modname;
103
104 return (strcmp(myname, "vmlinux") == 0) ||
105 (strcmp(myname, "vmlinux.o") == 0);
106 }
107
108 void *do_nofail(void *ptr, const char *expr)
109 {
110 if (!ptr)
111 fatal("modpost: Memory allocation failure: %s.\n", expr);
112
113 return ptr;
114 }
115
116 /* A list of all modules we processed */
117 static struct module *modules;
118
119 static struct module *find_module(char *modname)
120 {
121 struct module *mod;
122
123 for (mod = modules; mod; mod = mod->next)
124 if (strcmp(mod->name, modname) == 0)
125 break;
126 return mod;
127 }
128
129 static struct module *new_module(const char *modname)
130 {
131 struct module *mod;
132 char *p;
133
134 mod = NOFAIL(malloc(sizeof(*mod)));
135 memset(mod, 0, sizeof(*mod));
136 p = NOFAIL(strdup(modname));
137
138 /* strip trailing .o */
139 if (strends(p, ".o")) {
140 p[strlen(p) - 2] = '\0';
141 mod->is_dot_o = 1;
142 }
143
144 /* add to list */
145 mod->name = p;
146 mod->gpl_compatible = -1;
147 mod->next = modules;
148 modules = mod;
149
150 return mod;
151 }
152
153 /* A hash of all exported symbols,
154 * struct symbol is also used for lists of unresolved symbols */
155
156 #define SYMBOL_HASH_SIZE 1024
157
158 struct symbol {
159 struct symbol *next;
160 struct module *module;
161 unsigned int crc;
162 int crc_valid;
163 unsigned int weak:1;
164 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
165 unsigned int kernel:1; /* 1 if symbol is from kernel
166 * (only for external modules) **/
167 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
168 enum export export; /* Type of export */
169 char name[0];
170 };
171
172 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
173
174 /* This is based on the hash agorithm from gdbm, via tdb */
175 static inline unsigned int tdb_hash(const char *name)
176 {
177 unsigned value; /* Used to compute the hash value. */
178 unsigned i; /* Used to cycle through random values. */
179
180 /* Set the initial value from the key size. */
181 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
182 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
183
184 return (1103515243 * value + 12345);
185 }
186
187 /**
188 * Allocate a new symbols for use in the hash of exported symbols or
189 * the list of unresolved symbols per module
190 **/
191 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
192 struct symbol *next)
193 {
194 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
195
196 memset(s, 0, sizeof(*s));
197 strcpy(s->name, name);
198 s->weak = weak;
199 s->next = next;
200 return s;
201 }
202
203 /* For the hash of exported symbols */
204 static struct symbol *new_symbol(const char *name, struct module *module,
205 enum export export)
206 {
207 unsigned int hash;
208 struct symbol *new;
209
210 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
211 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
212 new->module = module;
213 new->export = export;
214 return new;
215 }
216
217 static struct symbol *find_symbol(const char *name)
218 {
219 struct symbol *s;
220
221 /* For our purposes, .foo matches foo. PPC64 needs this. */
222 if (name[0] == '.')
223 name++;
224
225 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
226 if (strcmp(s->name, name) == 0)
227 return s;
228 }
229 return NULL;
230 }
231
232 static struct {
233 const char *str;
234 enum export export;
235 } export_list[] = {
236 { .str = "EXPORT_SYMBOL", .export = export_plain },
237 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
238 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
239 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
240 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
241 { .str = "(unknown)", .export = export_unknown },
242 };
243
244
245 static const char *export_str(enum export ex)
246 {
247 return export_list[ex].str;
248 }
249
250 static enum export export_no(const char *s)
251 {
252 int i;
253
254 if (!s)
255 return export_unknown;
256 for (i = 0; export_list[i].export != export_unknown; i++) {
257 if (strcmp(export_list[i].str, s) == 0)
258 return export_list[i].export;
259 }
260 return export_unknown;
261 }
262
263 static const char *sec_name(struct elf_info *elf, int secindex);
264
265 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
266
267 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
268 {
269 const char *secname = sec_name(elf, sec);
270
271 if (strstarts(secname, "___ksymtab+"))
272 return export_plain;
273 else if (strstarts(secname, "___ksymtab_unused+"))
274 return export_unused;
275 else if (strstarts(secname, "___ksymtab_gpl+"))
276 return export_gpl;
277 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
278 return export_unused_gpl;
279 else if (strstarts(secname, "___ksymtab_gpl_future+"))
280 return export_gpl_future;
281 else
282 return export_unknown;
283 }
284
285 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
286 {
287 if (sec == elf->export_sec)
288 return export_plain;
289 else if (sec == elf->export_unused_sec)
290 return export_unused;
291 else if (sec == elf->export_gpl_sec)
292 return export_gpl;
293 else if (sec == elf->export_unused_gpl_sec)
294 return export_unused_gpl;
295 else if (sec == elf->export_gpl_future_sec)
296 return export_gpl_future;
297 else
298 return export_unknown;
299 }
300
301 /**
302 * Add an exported symbol - it may have already been added without a
303 * CRC, in this case just update the CRC
304 **/
305 static struct symbol *sym_add_exported(const char *name, struct module *mod,
306 enum export export)
307 {
308 struct symbol *s = find_symbol(name);
309
310 if (!s) {
311 s = new_symbol(name, mod, export);
312 } else {
313 if (!s->preloaded) {
314 warn("%s: '%s' exported twice. Previous export "
315 "was in %s%s\n", mod->name, name,
316 s->module->name,
317 is_vmlinux(s->module->name) ?"":".ko");
318 } else {
319 /* In case Module.symvers was out of date */
320 s->module = mod;
321 }
322 }
323 s->preloaded = 0;
324 s->vmlinux = is_vmlinux(mod->name);
325 s->kernel = 0;
326 s->export = export;
327 return s;
328 }
329
330 static void sym_update_crc(const char *name, struct module *mod,
331 unsigned int crc, enum export export)
332 {
333 struct symbol *s = find_symbol(name);
334
335 if (!s) {
336 s = new_symbol(name, mod, export);
337 /* Don't complain when we find it later. */
338 s->preloaded = 1;
339 }
340 s->crc = crc;
341 s->crc_valid = 1;
342 }
343
344 void *grab_file(const char *filename, unsigned long *size)
345 {
346 struct stat st;
347 void *map = MAP_FAILED;
348 int fd;
349
350 fd = open(filename, O_RDONLY);
351 if (fd < 0)
352 return NULL;
353 if (fstat(fd, &st))
354 goto failed;
355
356 *size = st.st_size;
357 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
358
359 failed:
360 close(fd);
361 if (map == MAP_FAILED)
362 return NULL;
363 return map;
364 }
365
366 /**
367 * Return a copy of the next line in a mmap'ed file.
368 * spaces in the beginning of the line is trimmed away.
369 * Return a pointer to a static buffer.
370 **/
371 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
372 {
373 static char line[4096];
374 int skip = 1;
375 size_t len = 0;
376 signed char *p = (signed char *)file + *pos;
377 char *s = line;
378
379 for (; *pos < size ; (*pos)++) {
380 if (skip && isspace(*p)) {
381 p++;
382 continue;
383 }
384 skip = 0;
385 if (*p != '\n' && (*pos < size)) {
386 len++;
387 *s++ = *p++;
388 if (len > 4095)
389 break; /* Too long, stop */
390 } else {
391 /* End of string */
392 *s = '\0';
393 return line;
394 }
395 }
396 /* End of buffer */
397 return NULL;
398 }
399
400 void release_file(void *file, unsigned long size)
401 {
402 munmap(file, size);
403 }
404
405 static int parse_elf(struct elf_info *info, const char *filename)
406 {
407 unsigned int i;
408 Elf_Ehdr *hdr;
409 Elf_Shdr *sechdrs;
410 Elf_Sym *sym;
411 const char *secstrings;
412 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
413
414 hdr = grab_file(filename, &info->size);
415 if (!hdr) {
416 if (ignore_missing_files) {
417 fprintf(stderr, "%s: %s (ignored)\n", filename,
418 strerror(errno));
419 return 0;
420 }
421 perror(filename);
422 exit(1);
423 }
424 info->hdr = hdr;
425 if (info->size < sizeof(*hdr)) {
426 /* file too small, assume this is an empty .o file */
427 return 0;
428 }
429 /* Is this a valid ELF file? */
430 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
431 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
432 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
433 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
434 /* Not an ELF file - silently ignore it */
435 return 0;
436 }
437 /* Fix endianness in ELF header */
438 hdr->e_type = TO_NATIVE(hdr->e_type);
439 hdr->e_machine = TO_NATIVE(hdr->e_machine);
440 hdr->e_version = TO_NATIVE(hdr->e_version);
441 hdr->e_entry = TO_NATIVE(hdr->e_entry);
442 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
443 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
444 hdr->e_flags = TO_NATIVE(hdr->e_flags);
445 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
446 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
447 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
448 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
449 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
450 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
451 sechdrs = (void *)hdr + hdr->e_shoff;
452 info->sechdrs = sechdrs;
453
454 /* Check if file offset is correct */
455 if (hdr->e_shoff > info->size) {
456 fatal("section header offset=%lu in file '%s' is bigger than "
457 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
458 filename, info->size);
459 return 0;
460 }
461
462 if (hdr->e_shnum == SHN_UNDEF) {
463 /*
464 * There are more than 64k sections,
465 * read count from .sh_size.
466 */
467 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
468 }
469 else {
470 info->num_sections = hdr->e_shnum;
471 }
472 if (hdr->e_shstrndx == SHN_XINDEX) {
473 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
474 }
475 else {
476 info->secindex_strings = hdr->e_shstrndx;
477 }
478
479 /* Fix endianness in section headers */
480 for (i = 0; i < info->num_sections; i++) {
481 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
482 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
483 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
484 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
485 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
486 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
487 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
488 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
489 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
490 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
491 }
492 /* Find symbol table. */
493 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
494 for (i = 1; i < info->num_sections; i++) {
495 const char *secname;
496 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
497
498 if (!nobits && sechdrs[i].sh_offset > info->size) {
499 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
500 "sizeof(*hrd)=%zu\n", filename,
501 (unsigned long)sechdrs[i].sh_offset,
502 sizeof(*hdr));
503 return 0;
504 }
505 secname = secstrings + sechdrs[i].sh_name;
506 if (strcmp(secname, ".modinfo") == 0) {
507 if (nobits)
508 fatal("%s has NOBITS .modinfo\n", filename);
509 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
510 info->modinfo_len = sechdrs[i].sh_size;
511 } else if (strcmp(secname, "__ksymtab") == 0)
512 info->export_sec = i;
513 else if (strcmp(secname, "__ksymtab_unused") == 0)
514 info->export_unused_sec = i;
515 else if (strcmp(secname, "__ksymtab_gpl") == 0)
516 info->export_gpl_sec = i;
517 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
518 info->export_unused_gpl_sec = i;
519 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
520 info->export_gpl_future_sec = i;
521
522 if (sechdrs[i].sh_type == SHT_SYMTAB) {
523 unsigned int sh_link_idx;
524 symtab_idx = i;
525 info->symtab_start = (void *)hdr +
526 sechdrs[i].sh_offset;
527 info->symtab_stop = (void *)hdr +
528 sechdrs[i].sh_offset + sechdrs[i].sh_size;
529 sh_link_idx = sechdrs[i].sh_link;
530 info->strtab = (void *)hdr +
531 sechdrs[sh_link_idx].sh_offset;
532 }
533
534 /* 32bit section no. table? ("more than 64k sections") */
535 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
536 symtab_shndx_idx = i;
537 info->symtab_shndx_start = (void *)hdr +
538 sechdrs[i].sh_offset;
539 info->symtab_shndx_stop = (void *)hdr +
540 sechdrs[i].sh_offset + sechdrs[i].sh_size;
541 }
542 }
543 if (!info->symtab_start)
544 fatal("%s has no symtab?\n", filename);
545
546 /* Fix endianness in symbols */
547 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
548 sym->st_shndx = TO_NATIVE(sym->st_shndx);
549 sym->st_name = TO_NATIVE(sym->st_name);
550 sym->st_value = TO_NATIVE(sym->st_value);
551 sym->st_size = TO_NATIVE(sym->st_size);
552 }
553
554 if (symtab_shndx_idx != ~0U) {
555 Elf32_Word *p;
556 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
557 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
558 filename, sechdrs[symtab_shndx_idx].sh_link,
559 symtab_idx);
560 /* Fix endianness */
561 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
562 p++)
563 *p = TO_NATIVE(*p);
564 }
565
566 return 1;
567 }
568
569 static void parse_elf_finish(struct elf_info *info)
570 {
571 release_file(info->hdr, info->size);
572 }
573
574 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
575 {
576 /* ignore __this_module, it will be resolved shortly */
577 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
578 return 1;
579 /* ignore global offset table */
580 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
581 return 1;
582 if (info->hdr->e_machine == EM_PPC)
583 /* Special register function linked on all modules during final link of .ko */
584 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
585 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
586 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
587 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
588 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
589 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
590 return 1;
591 if (info->hdr->e_machine == EM_PPC64)
592 /* Special register function linked on all modules during final link of .ko */
593 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
594 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
595 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
596 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
597 return 1;
598 /* Do not ignore this symbol */
599 return 0;
600 }
601
602 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
603 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
604
605 static void handle_modversions(struct module *mod, struct elf_info *info,
606 Elf_Sym *sym, const char *symname)
607 {
608 unsigned int crc;
609 enum export export;
610
611 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
612 strncmp(symname, "__ksymtab", 9) == 0)
613 export = export_from_secname(info, get_secindex(info, sym));
614 else
615 export = export_from_sec(info, get_secindex(info, sym));
616
617 /* CRC'd symbol */
618 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
619 crc = (unsigned int) sym->st_value;
620 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
621 export);
622 }
623
624 switch (sym->st_shndx) {
625 case SHN_COMMON:
626 if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
627 /* Should warn here, but modpost runs before the linker */
628 } else
629 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
630 break;
631 case SHN_UNDEF:
632 /* undefined symbol */
633 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
634 ELF_ST_BIND(sym->st_info) != STB_WEAK)
635 break;
636 if (ignore_undef_symbol(info, symname))
637 break;
638 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
639 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
640 /* add compatibility with older glibc */
641 #ifndef STT_SPARC_REGISTER
642 #define STT_SPARC_REGISTER STT_REGISTER
643 #endif
644 if (info->hdr->e_machine == EM_SPARC ||
645 info->hdr->e_machine == EM_SPARCV9) {
646 /* Ignore register directives. */
647 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
648 break;
649 if (symname[0] == '.') {
650 char *munged = strdup(symname);
651 munged[0] = '_';
652 munged[1] = toupper(munged[1]);
653 symname = munged;
654 }
655 }
656 #endif
657
658 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
659 if (symname[0] != '_')
660 break;
661 else
662 symname++;
663 #endif
664 mod->unres = alloc_symbol(symname,
665 ELF_ST_BIND(sym->st_info) == STB_WEAK,
666 mod->unres);
667 break;
668 default:
669 /* All exported symbols */
670 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
671 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
672 export);
673 }
674 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
675 mod->has_init = 1;
676 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
677 mod->has_cleanup = 1;
678 break;
679 }
680 }
681
682 /**
683 * Parse tag=value strings from .modinfo section
684 **/
685 static char *next_string(char *string, unsigned long *secsize)
686 {
687 /* Skip non-zero chars */
688 while (string[0]) {
689 string++;
690 if ((*secsize)-- <= 1)
691 return NULL;
692 }
693
694 /* Skip any zero padding. */
695 while (!string[0]) {
696 string++;
697 if ((*secsize)-- <= 1)
698 return NULL;
699 }
700 return string;
701 }
702
703 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
704 const char *tag, char *info)
705 {
706 char *p;
707 unsigned int taglen = strlen(tag);
708 unsigned long size = modinfo_len;
709
710 if (info) {
711 size -= info - (char *)modinfo;
712 modinfo = next_string(info, &size);
713 }
714
715 for (p = modinfo; p; p = next_string(p, &size)) {
716 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
717 return p + taglen + 1;
718 }
719 return NULL;
720 }
721
722 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
723 const char *tag)
724
725 {
726 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
727 }
728
729 /**
730 * Test if string s ends in string sub
731 * return 0 if match
732 **/
733 static int strrcmp(const char *s, const char *sub)
734 {
735 int slen, sublen;
736
737 if (!s || !sub)
738 return 1;
739
740 slen = strlen(s);
741 sublen = strlen(sub);
742
743 if ((slen == 0) || (sublen == 0))
744 return 1;
745
746 if (sublen > slen)
747 return 1;
748
749 return memcmp(s + slen - sublen, sub, sublen);
750 }
751
752 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
753 {
754 if (sym)
755 return elf->strtab + sym->st_name;
756 else
757 return "(unknown)";
758 }
759
760 static const char *sec_name(struct elf_info *elf, int secindex)
761 {
762 Elf_Shdr *sechdrs = elf->sechdrs;
763 return (void *)elf->hdr +
764 elf->sechdrs[elf->secindex_strings].sh_offset +
765 sechdrs[secindex].sh_name;
766 }
767
768 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
769 {
770 return (void *)elf->hdr +
771 elf->sechdrs[elf->secindex_strings].sh_offset +
772 sechdr->sh_name;
773 }
774
775 /* if sym is empty or point to a string
776 * like ".[0-9]+" then return 1.
777 * This is the optional prefix added by ld to some sections
778 */
779 static int number_prefix(const char *sym)
780 {
781 if (*sym++ == '\0')
782 return 1;
783 if (*sym != '.')
784 return 0;
785 do {
786 char c = *sym++;
787 if (c < '0' || c > '9')
788 return 0;
789 } while (*sym);
790 return 1;
791 }
792
793 /* The pattern is an array of simple patterns.
794 * "foo" will match an exact string equal to "foo"
795 * "*foo" will match a string that ends with "foo"
796 * "foo*" will match a string that begins with "foo"
797 * "foo$" will match a string equal to "foo" or "foo.1"
798 * where the '1' can be any number including several digits.
799 * The $ syntax is for sections where ld append a dot number
800 * to make section name unique.
801 */
802 static int match(const char *sym, const char * const pat[])
803 {
804 const char *p;
805 while (*pat) {
806 p = *pat++;
807 const char *endp = p + strlen(p) - 1;
808
809 /* "*foo" */
810 if (*p == '*') {
811 if (strrcmp(sym, p + 1) == 0)
812 return 1;
813 }
814 /* "foo*" */
815 else if (*endp == '*') {
816 if (strncmp(sym, p, strlen(p) - 1) == 0)
817 return 1;
818 }
819 /* "foo$" */
820 else if (*endp == '$') {
821 if (strncmp(sym, p, strlen(p) - 1) == 0) {
822 if (number_prefix(sym + strlen(p) - 1))
823 return 1;
824 }
825 }
826 /* no wildcards */
827 else {
828 if (strcmp(p, sym) == 0)
829 return 1;
830 }
831 }
832 /* no match */
833 return 0;
834 }
835
836 /* sections that we do not want to do full section mismatch check on */
837 static const char *section_white_list[] =
838 {
839 ".comment*",
840 ".debug*",
841 ".cranges", /* sh64 */
842 ".zdebug*", /* Compressed debug sections. */
843 ".GCC-command-line", /* mn10300 */
844 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
845 ".mdebug*", /* alpha, score, mips etc. */
846 ".pdr", /* alpha, score, mips etc. */
847 ".stab*",
848 ".note*",
849 ".got*",
850 ".toc*",
851 ".xt.prop", /* xtensa */
852 ".xt.lit", /* xtensa */
853 ".arcextmap*", /* arc */
854 ".gnu.linkonce.arcext*", /* arc : modules */
855 ".gnu.lto*",
856 NULL
857 };
858
859 /*
860 * This is used to find sections missing the SHF_ALLOC flag.
861 * The cause of this is often a section specified in assembler
862 * without "ax" / "aw".
863 */
864 static void check_section(const char *modname, struct elf_info *elf,
865 Elf_Shdr *sechdr)
866 {
867 const char *sec = sech_name(elf, sechdr);
868
869 if (sechdr->sh_type == SHT_PROGBITS &&
870 !(sechdr->sh_flags & SHF_ALLOC) &&
871 !match(sec, section_white_list)) {
872 warn("%s (%s): unexpected non-allocatable section.\n"
873 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
874 "Note that for example <linux/init.h> contains\n"
875 "section definitions for use in .S files.\n\n",
876 modname, sec);
877 }
878 }
879
880
881
882 #define ALL_INIT_DATA_SECTIONS \
883 ".init.setup$", ".init.rodata$", ".meminit.rodata$", \
884 ".init.data$", ".meminit.data$"
885 #define ALL_EXIT_DATA_SECTIONS \
886 ".exit.data$", ".memexit.data$"
887
888 #define ALL_INIT_TEXT_SECTIONS \
889 ".init.text$", ".meminit.text$"
890 #define ALL_EXIT_TEXT_SECTIONS \
891 ".exit.text$", ".memexit.text$"
892
893 #define ALL_PCI_INIT_SECTIONS \
894 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
895 ".pci_fixup_enable$", ".pci_fixup_resume$", \
896 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
897
898 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
899 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
900
901 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
902 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
903
904 #define DATA_SECTIONS ".data$", ".data.rel$"
905 #define TEXT_SECTIONS ".text$", ".text.unlikely$"
906
907 #define INIT_SECTIONS ".init.*"
908 #define MEM_INIT_SECTIONS ".meminit.*"
909
910 #define EXIT_SECTIONS ".exit.*"
911 #define MEM_EXIT_SECTIONS ".memexit.*"
912
913 /* init data sections */
914 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
915
916 /* all init sections */
917 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
918
919 /* All init and exit sections (code + data) */
920 static const char *init_exit_sections[] =
921 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
922
923 /* data section */
924 static const char *data_sections[] = { DATA_SECTIONS, NULL };
925
926
927 /* symbols in .data that may refer to init/exit sections */
928 #define DEFAULT_SYMBOL_WHITE_LIST \
929 "*driver", \
930 "*_template", /* scsi uses *_template a lot */ \
931 "*_timer", /* arm uses ops structures named _timer a lot */ \
932 "*_sht", /* scsi also used *_sht to some extent */ \
933 "*_ops", \
934 "*_probe", \
935 "*_probe_one", \
936 "*_console"
937
938 static const char *head_sections[] = { ".head.text*", NULL };
939 static const char *linker_symbols[] =
940 { "__init_begin", "_sinittext", "_einittext", NULL };
941
942 enum mismatch {
943 TEXT_TO_ANY_INIT,
944 DATA_TO_ANY_INIT,
945 TEXT_TO_ANY_EXIT,
946 DATA_TO_ANY_EXIT,
947 XXXINIT_TO_SOME_INIT,
948 XXXEXIT_TO_SOME_EXIT,
949 ANY_INIT_TO_ANY_EXIT,
950 ANY_EXIT_TO_ANY_INIT,
951 EXPORT_TO_INIT_EXIT,
952 };
953
954 struct sectioncheck {
955 const char *fromsec[20];
956 const char *tosec[20];
957 enum mismatch mismatch;
958 const char *symbol_white_list[20];
959 };
960
961 const struct sectioncheck sectioncheck[] = {
962 /* Do not reference init/exit code/data from
963 * normal code and data
964 */
965 {
966 .fromsec = { TEXT_SECTIONS, NULL },
967 .tosec = { ALL_INIT_SECTIONS, NULL },
968 .mismatch = TEXT_TO_ANY_INIT,
969 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
970 },
971 {
972 .fromsec = { DATA_SECTIONS, NULL },
973 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
974 .mismatch = DATA_TO_ANY_INIT,
975 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
976 },
977 {
978 .fromsec = { DATA_SECTIONS, NULL },
979 .tosec = { INIT_SECTIONS, NULL },
980 .mismatch = DATA_TO_ANY_INIT,
981 .symbol_white_list = {
982 "*_template", "*_timer", "*_sht", "*_ops",
983 "*_probe", "*_probe_one", "*_console", NULL
984 },
985 },
986 {
987 .fromsec = { TEXT_SECTIONS, NULL },
988 .tosec = { ALL_EXIT_SECTIONS, NULL },
989 .mismatch = TEXT_TO_ANY_EXIT,
990 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
991 },
992 {
993 .fromsec = { DATA_SECTIONS, NULL },
994 .tosec = { ALL_EXIT_SECTIONS, NULL },
995 .mismatch = DATA_TO_ANY_EXIT,
996 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
997 },
998 /* Do not reference init code/data from meminit code/data */
999 {
1000 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1001 .tosec = { INIT_SECTIONS, NULL },
1002 .mismatch = XXXINIT_TO_SOME_INIT,
1003 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1004 },
1005 /* Do not reference exit code/data from memexit code/data */
1006 {
1007 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1008 .tosec = { EXIT_SECTIONS, NULL },
1009 .mismatch = XXXEXIT_TO_SOME_EXIT,
1010 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1011 },
1012 /* Do not use exit code/data from init code */
1013 {
1014 .fromsec = { ALL_INIT_SECTIONS, NULL },
1015 .tosec = { ALL_EXIT_SECTIONS, NULL },
1016 .mismatch = ANY_INIT_TO_ANY_EXIT,
1017 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1018 },
1019 /* Do not use init code/data from exit code */
1020 {
1021 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1022 .tosec = { ALL_INIT_SECTIONS, NULL },
1023 .mismatch = ANY_EXIT_TO_ANY_INIT,
1024 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1025 },
1026 {
1027 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1028 .tosec = { INIT_SECTIONS, NULL },
1029 .mismatch = ANY_INIT_TO_ANY_EXIT,
1030 .symbol_white_list = { NULL },
1031 },
1032 /* Do not export init/exit functions or data */
1033 {
1034 .fromsec = { "__ksymtab*", NULL },
1035 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1036 .mismatch = EXPORT_TO_INIT_EXIT,
1037 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1038 }
1039 };
1040
1041 static const struct sectioncheck *section_mismatch(
1042 const char *fromsec, const char *tosec)
1043 {
1044 int i;
1045 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1046 const struct sectioncheck *check = &sectioncheck[0];
1047
1048 for (i = 0; i < elems; i++) {
1049 if (match(fromsec, check->fromsec) &&
1050 match(tosec, check->tosec))
1051 return check;
1052 check++;
1053 }
1054 return NULL;
1055 }
1056
1057 /**
1058 * Whitelist to allow certain references to pass with no warning.
1059 *
1060 * Pattern 1:
1061 * If a module parameter is declared __initdata and permissions=0
1062 * then this is legal despite the warning generated.
1063 * We cannot see value of permissions here, so just ignore
1064 * this pattern.
1065 * The pattern is identified by:
1066 * tosec = .init.data
1067 * fromsec = .data*
1068 * atsym =__param*
1069 *
1070 * Pattern 1a:
1071 * module_param_call() ops can refer to __init set function if permissions=0
1072 * The pattern is identified by:
1073 * tosec = .init.text
1074 * fromsec = .data*
1075 * atsym = __param_ops_*
1076 *
1077 * Pattern 2:
1078 * Many drivers utilise a *driver container with references to
1079 * add, remove, probe functions etc.
1080 * the pattern is identified by:
1081 * tosec = init or exit section
1082 * fromsec = data section
1083 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1084 * *probe_one, *_console, *_timer
1085 *
1086 * Pattern 3:
1087 * Whitelist all references from .head.text to any init section
1088 *
1089 * Pattern 4:
1090 * Some symbols belong to init section but still it is ok to reference
1091 * these from non-init sections as these symbols don't have any memory
1092 * allocated for them and symbol address and value are same. So even
1093 * if init section is freed, its ok to reference those symbols.
1094 * For ex. symbols marking the init section boundaries.
1095 * This pattern is identified by
1096 * refsymname = __init_begin, _sinittext, _einittext
1097 *
1098 **/
1099 static int secref_whitelist(const struct sectioncheck *mismatch,
1100 const char *fromsec, const char *fromsym,
1101 const char *tosec, const char *tosym)
1102 {
1103 /* Check for pattern 1 */
1104 if (match(tosec, init_data_sections) &&
1105 match(fromsec, data_sections) &&
1106 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1107 return 0;
1108
1109 /* Check for pattern 1a */
1110 if (strcmp(tosec, ".init.text") == 0 &&
1111 match(fromsec, data_sections) &&
1112 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1113 return 0;
1114
1115 /* Check for pattern 2 */
1116 if (match(tosec, init_exit_sections) &&
1117 match(fromsec, data_sections) &&
1118 match(fromsym, mismatch->symbol_white_list))
1119 return 0;
1120
1121 /* Check for pattern 3 */
1122 if (match(fromsec, head_sections) &&
1123 match(tosec, init_sections))
1124 return 0;
1125
1126 /* Check for pattern 4 */
1127 if (match(tosym, linker_symbols))
1128 return 0;
1129
1130 return 1;
1131 }
1132
1133 /**
1134 * Find symbol based on relocation record info.
1135 * In some cases the symbol supplied is a valid symbol so
1136 * return refsym. If st_name != 0 we assume this is a valid symbol.
1137 * In other cases the symbol needs to be looked up in the symbol table
1138 * based on section and address.
1139 * **/
1140 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1141 Elf_Sym *relsym)
1142 {
1143 Elf_Sym *sym;
1144 Elf_Sym *near = NULL;
1145 Elf64_Sword distance = 20;
1146 Elf64_Sword d;
1147 unsigned int relsym_secindex;
1148
1149 if (relsym->st_name != 0)
1150 return relsym;
1151
1152 relsym_secindex = get_secindex(elf, relsym);
1153 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1154 if (get_secindex(elf, sym) != relsym_secindex)
1155 continue;
1156 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1157 continue;
1158 if (sym->st_value == addr)
1159 return sym;
1160 /* Find a symbol nearby - addr are maybe negative */
1161 d = sym->st_value - addr;
1162 if (d < 0)
1163 d = addr - sym->st_value;
1164 if (d < distance) {
1165 distance = d;
1166 near = sym;
1167 }
1168 }
1169 /* We need a close match */
1170 if (distance < 20)
1171 return near;
1172 else
1173 return NULL;
1174 }
1175
1176 static inline int is_arm_mapping_symbol(const char *str)
1177 {
1178 return str[0] == '$' && strchr("atd", str[1])
1179 && (str[2] == '\0' || str[2] == '.');
1180 }
1181
1182 /*
1183 * If there's no name there, ignore it; likewise, ignore it if it's
1184 * one of the magic symbols emitted used by current ARM tools.
1185 *
1186 * Otherwise if find_symbols_between() returns those symbols, they'll
1187 * fail the whitelist tests and cause lots of false alarms ... fixable
1188 * only by merging __exit and __init sections into __text, bloating
1189 * the kernel (which is especially evil on embedded platforms).
1190 */
1191 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1192 {
1193 const char *name = elf->strtab + sym->st_name;
1194
1195 if (!name || !strlen(name))
1196 return 0;
1197 return !is_arm_mapping_symbol(name);
1198 }
1199
1200 /*
1201 * Find symbols before or equal addr and after addr - in the section sec.
1202 * If we find two symbols with equal offset prefer one with a valid name.
1203 * The ELF format may have a better way to detect what type of symbol
1204 * it is, but this works for now.
1205 **/
1206 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1207 const char *sec)
1208 {
1209 Elf_Sym *sym;
1210 Elf_Sym *near = NULL;
1211 Elf_Addr distance = ~0;
1212
1213 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1214 const char *symsec;
1215
1216 if (is_shndx_special(sym->st_shndx))
1217 continue;
1218 symsec = sec_name(elf, get_secindex(elf, sym));
1219 if (strcmp(symsec, sec) != 0)
1220 continue;
1221 if (!is_valid_name(elf, sym))
1222 continue;
1223 if (sym->st_value <= addr) {
1224 if ((addr - sym->st_value) < distance) {
1225 distance = addr - sym->st_value;
1226 near = sym;
1227 } else if ((addr - sym->st_value) == distance) {
1228 near = sym;
1229 }
1230 }
1231 }
1232 return near;
1233 }
1234
1235 /*
1236 * Convert a section name to the function/data attribute
1237 * .init.text => __init
1238 * .memexitconst => __memconst
1239 * etc.
1240 *
1241 * The memory of returned value has been allocated on a heap. The user of this
1242 * method should free it after usage.
1243 */
1244 static char *sec2annotation(const char *s)
1245 {
1246 if (match(s, init_exit_sections)) {
1247 char *p = malloc(20);
1248 char *r = p;
1249
1250 *p++ = '_';
1251 *p++ = '_';
1252 if (*s == '.')
1253 s++;
1254 while (*s && *s != '.')
1255 *p++ = *s++;
1256 *p = '\0';
1257 if (*s == '.')
1258 s++;
1259 if (strstr(s, "rodata") != NULL)
1260 strcat(p, "const ");
1261 else if (strstr(s, "data") != NULL)
1262 strcat(p, "data ");
1263 else
1264 strcat(p, " ");
1265 return r;
1266 } else {
1267 return strdup("");
1268 }
1269 }
1270
1271 static int is_function(Elf_Sym *sym)
1272 {
1273 if (sym)
1274 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1275 else
1276 return -1;
1277 }
1278
1279 static void print_section_list(const char * const list[20])
1280 {
1281 const char *const *s = list;
1282
1283 while (*s) {
1284 fprintf(stderr, "%s", *s);
1285 s++;
1286 if (*s)
1287 fprintf(stderr, ", ");
1288 }
1289 fprintf(stderr, "\n");
1290 }
1291
1292 /*
1293 * Print a warning about a section mismatch.
1294 * Try to find symbols near it so user can find it.
1295 * Check whitelist before warning - it may be a false positive.
1296 */
1297 static void report_sec_mismatch(const char *modname,
1298 const struct sectioncheck *mismatch,
1299 const char *fromsec,
1300 unsigned long long fromaddr,
1301 const char *fromsym,
1302 int from_is_func,
1303 const char *tosec, const char *tosym,
1304 int to_is_func)
1305 {
1306 const char *from, *from_p;
1307 const char *to, *to_p;
1308 char *prl_from;
1309 char *prl_to;
1310
1311 switch (from_is_func) {
1312 case 0: from = "variable"; from_p = ""; break;
1313 case 1: from = "function"; from_p = "()"; break;
1314 default: from = "(unknown reference)"; from_p = ""; break;
1315 }
1316 switch (to_is_func) {
1317 case 0: to = "variable"; to_p = ""; break;
1318 case 1: to = "function"; to_p = "()"; break;
1319 default: to = "(unknown reference)"; to_p = ""; break;
1320 }
1321
1322 sec_mismatch_count++;
1323 if (!sec_mismatch_verbose)
1324 return;
1325
1326 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1327 "to the %s %s:%s%s\n",
1328 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1329 tosym, to_p);
1330
1331 switch (mismatch->mismatch) {
1332 case TEXT_TO_ANY_INIT:
1333 prl_from = sec2annotation(fromsec);
1334 prl_to = sec2annotation(tosec);
1335 fprintf(stderr,
1336 "The function %s%s() references\n"
1337 "the %s %s%s%s.\n"
1338 "This is often because %s lacks a %s\n"
1339 "annotation or the annotation of %s is wrong.\n",
1340 prl_from, fromsym,
1341 to, prl_to, tosym, to_p,
1342 fromsym, prl_to, tosym);
1343 free(prl_from);
1344 free(prl_to);
1345 break;
1346 case DATA_TO_ANY_INIT: {
1347 prl_to = sec2annotation(tosec);
1348 fprintf(stderr,
1349 "The variable %s references\n"
1350 "the %s %s%s%s\n"
1351 "If the reference is valid then annotate the\n"
1352 "variable with __init* or __refdata (see linux/init.h) "
1353 "or name the variable:\n",
1354 fromsym, to, prl_to, tosym, to_p);
1355 print_section_list(mismatch->symbol_white_list);
1356 free(prl_to);
1357 break;
1358 }
1359 case TEXT_TO_ANY_EXIT:
1360 prl_to = sec2annotation(tosec);
1361 fprintf(stderr,
1362 "The function %s() references a %s in an exit section.\n"
1363 "Often the %s %s%s has valid usage outside the exit section\n"
1364 "and the fix is to remove the %sannotation of %s.\n",
1365 fromsym, to, to, tosym, to_p, prl_to, tosym);
1366 free(prl_to);
1367 break;
1368 case DATA_TO_ANY_EXIT: {
1369 prl_to = sec2annotation(tosec);
1370 fprintf(stderr,
1371 "The variable %s references\n"
1372 "the %s %s%s%s\n"
1373 "If the reference is valid then annotate the\n"
1374 "variable with __exit* (see linux/init.h) or "
1375 "name the variable:\n",
1376 fromsym, to, prl_to, tosym, to_p);
1377 print_section_list(mismatch->symbol_white_list);
1378 free(prl_to);
1379 break;
1380 }
1381 case XXXINIT_TO_SOME_INIT:
1382 case XXXEXIT_TO_SOME_EXIT:
1383 prl_from = sec2annotation(fromsec);
1384 prl_to = sec2annotation(tosec);
1385 fprintf(stderr,
1386 "The %s %s%s%s references\n"
1387 "a %s %s%s%s.\n"
1388 "If %s is only used by %s then\n"
1389 "annotate %s with a matching annotation.\n",
1390 from, prl_from, fromsym, from_p,
1391 to, prl_to, tosym, to_p,
1392 tosym, fromsym, tosym);
1393 free(prl_from);
1394 free(prl_to);
1395 break;
1396 case ANY_INIT_TO_ANY_EXIT:
1397 prl_from = sec2annotation(fromsec);
1398 prl_to = sec2annotation(tosec);
1399 fprintf(stderr,
1400 "The %s %s%s%s references\n"
1401 "a %s %s%s%s.\n"
1402 "This is often seen when error handling "
1403 "in the init function\n"
1404 "uses functionality in the exit path.\n"
1405 "The fix is often to remove the %sannotation of\n"
1406 "%s%s so it may be used outside an exit section.\n",
1407 from, prl_from, fromsym, from_p,
1408 to, prl_to, tosym, to_p,
1409 prl_to, tosym, to_p);
1410 free(prl_from);
1411 free(prl_to);
1412 break;
1413 case ANY_EXIT_TO_ANY_INIT:
1414 prl_from = sec2annotation(fromsec);
1415 prl_to = sec2annotation(tosec);
1416 fprintf(stderr,
1417 "The %s %s%s%s references\n"
1418 "a %s %s%s%s.\n"
1419 "This is often seen when error handling "
1420 "in the exit function\n"
1421 "uses functionality in the init path.\n"
1422 "The fix is often to remove the %sannotation of\n"
1423 "%s%s so it may be used outside an init section.\n",
1424 from, prl_from, fromsym, from_p,
1425 to, prl_to, tosym, to_p,
1426 prl_to, tosym, to_p);
1427 free(prl_from);
1428 free(prl_to);
1429 break;
1430 case EXPORT_TO_INIT_EXIT:
1431 prl_to = sec2annotation(tosec);
1432 fprintf(stderr,
1433 "The symbol %s is exported and annotated %s\n"
1434 "Fix this by removing the %sannotation of %s "
1435 "or drop the export.\n",
1436 tosym, prl_to, prl_to, tosym);
1437 free(prl_to);
1438 break;
1439 }
1440 fprintf(stderr, "\n");
1441 }
1442
1443 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1444 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1445 {
1446 const char *tosec;
1447 const struct sectioncheck *mismatch;
1448
1449 tosec = sec_name(elf, get_secindex(elf, sym));
1450 mismatch = section_mismatch(fromsec, tosec);
1451 if (mismatch) {
1452 Elf_Sym *to;
1453 Elf_Sym *from;
1454 const char *tosym;
1455 const char *fromsym;
1456
1457 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1458 fromsym = sym_name(elf, from);
1459 to = find_elf_symbol(elf, r->r_addend, sym);
1460 tosym = sym_name(elf, to);
1461
1462 if (!strncmp(fromsym, "reference___initcall",
1463 sizeof("reference___initcall")-1))
1464 return;
1465
1466 /* check whitelist - we may ignore it */
1467 if (secref_whitelist(mismatch,
1468 fromsec, fromsym, tosec, tosym)) {
1469 report_sec_mismatch(modname, mismatch,
1470 fromsec, r->r_offset, fromsym,
1471 is_function(from), tosec, tosym,
1472 is_function(to));
1473 }
1474 }
1475 }
1476
1477 static unsigned int *reloc_location(struct elf_info *elf,
1478 Elf_Shdr *sechdr, Elf_Rela *r)
1479 {
1480 Elf_Shdr *sechdrs = elf->sechdrs;
1481 int section = sechdr->sh_info;
1482
1483 return (void *)elf->hdr + sechdrs[section].sh_offset +
1484 r->r_offset;
1485 }
1486
1487 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1488 {
1489 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1490 unsigned int *location = reloc_location(elf, sechdr, r);
1491
1492 switch (r_typ) {
1493 case R_386_32:
1494 r->r_addend = TO_NATIVE(*location);
1495 break;
1496 case R_386_PC32:
1497 r->r_addend = TO_NATIVE(*location) + 4;
1498 /* For CONFIG_RELOCATABLE=y */
1499 if (elf->hdr->e_type == ET_EXEC)
1500 r->r_addend += r->r_offset;
1501 break;
1502 }
1503 return 0;
1504 }
1505
1506 #ifndef R_ARM_CALL
1507 #define R_ARM_CALL 28
1508 #endif
1509 #ifndef R_ARM_JUMP24
1510 #define R_ARM_JUMP24 29
1511 #endif
1512
1513 #ifndef R_ARM_THM_CALL
1514 #define R_ARM_THM_CALL 10
1515 #endif
1516 #ifndef R_ARM_THM_JUMP24
1517 #define R_ARM_THM_JUMP24 30
1518 #endif
1519 #ifndef R_ARM_THM_JUMP19
1520 #define R_ARM_THM_JUMP19 51
1521 #endif
1522
1523 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1524 {
1525 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1526
1527 switch (r_typ) {
1528 case R_ARM_ABS32:
1529 /* From ARM ABI: (S + A) | T */
1530 r->r_addend = (int)(long)
1531 (elf->symtab_start + ELF_R_SYM(r->r_info));
1532 break;
1533 case R_ARM_PC24:
1534 case R_ARM_CALL:
1535 case R_ARM_JUMP24:
1536 case R_ARM_THM_CALL:
1537 case R_ARM_THM_JUMP24:
1538 case R_ARM_THM_JUMP19:
1539 /* From ARM ABI: ((S + A) | T) - P */
1540 r->r_addend = (int)(long)(elf->hdr +
1541 sechdr->sh_offset +
1542 (r->r_offset - sechdr->sh_addr));
1543 break;
1544 default:
1545 return 1;
1546 }
1547 return 0;
1548 }
1549
1550 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1551 {
1552 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1553 unsigned int *location = reloc_location(elf, sechdr, r);
1554 unsigned int inst;
1555
1556 if (r_typ == R_MIPS_HI16)
1557 return 1; /* skip this */
1558 inst = TO_NATIVE(*location);
1559 switch (r_typ) {
1560 case R_MIPS_LO16:
1561 r->r_addend = inst & 0xffff;
1562 break;
1563 case R_MIPS_26:
1564 r->r_addend = (inst & 0x03ffffff) << 2;
1565 break;
1566 case R_MIPS_32:
1567 r->r_addend = inst;
1568 break;
1569 }
1570 return 0;
1571 }
1572
1573 static void section_rela(const char *modname, struct elf_info *elf,
1574 Elf_Shdr *sechdr)
1575 {
1576 Elf_Sym *sym;
1577 Elf_Rela *rela;
1578 Elf_Rela r;
1579 unsigned int r_sym;
1580 const char *fromsec;
1581
1582 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1583 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1584
1585 fromsec = sech_name(elf, sechdr);
1586 fromsec += strlen(".rela");
1587 /* if from section (name) is know good then skip it */
1588 if (match(fromsec, section_white_list))
1589 return;
1590
1591 for (rela = start; rela < stop; rela++) {
1592 r.r_offset = TO_NATIVE(rela->r_offset);
1593 #if KERNEL_ELFCLASS == ELFCLASS64
1594 if (elf->hdr->e_machine == EM_MIPS) {
1595 unsigned int r_typ;
1596 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1597 r_sym = TO_NATIVE(r_sym);
1598 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1599 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1600 } else {
1601 r.r_info = TO_NATIVE(rela->r_info);
1602 r_sym = ELF_R_SYM(r.r_info);
1603 }
1604 #else
1605 r.r_info = TO_NATIVE(rela->r_info);
1606 r_sym = ELF_R_SYM(r.r_info);
1607 #endif
1608 r.r_addend = TO_NATIVE(rela->r_addend);
1609 sym = elf->symtab_start + r_sym;
1610 /* Skip special sections */
1611 if (is_shndx_special(sym->st_shndx))
1612 continue;
1613 check_section_mismatch(modname, elf, &r, sym, fromsec);
1614 }
1615 }
1616
1617 static void section_rel(const char *modname, struct elf_info *elf,
1618 Elf_Shdr *sechdr)
1619 {
1620 Elf_Sym *sym;
1621 Elf_Rel *rel;
1622 Elf_Rela r;
1623 unsigned int r_sym;
1624 const char *fromsec;
1625
1626 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1627 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1628
1629 fromsec = sech_name(elf, sechdr);
1630 fromsec += strlen(".rel");
1631 /* if from section (name) is know good then skip it */
1632 if (match(fromsec, section_white_list))
1633 return;
1634
1635 for (rel = start; rel < stop; rel++) {
1636 r.r_offset = TO_NATIVE(rel->r_offset);
1637 #if KERNEL_ELFCLASS == ELFCLASS64
1638 if (elf->hdr->e_machine == EM_MIPS) {
1639 unsigned int r_typ;
1640 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1641 r_sym = TO_NATIVE(r_sym);
1642 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1643 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1644 } else {
1645 r.r_info = TO_NATIVE(rel->r_info);
1646 r_sym = ELF_R_SYM(r.r_info);
1647 }
1648 #else
1649 r.r_info = TO_NATIVE(rel->r_info);
1650 r_sym = ELF_R_SYM(r.r_info);
1651 #endif
1652 r.r_addend = 0;
1653 switch (elf->hdr->e_machine) {
1654 case EM_386:
1655 if (addend_386_rel(elf, sechdr, &r))
1656 continue;
1657 break;
1658 case EM_ARM:
1659 if (addend_arm_rel(elf, sechdr, &r))
1660 continue;
1661 break;
1662 case EM_MIPS:
1663 if (addend_mips_rel(elf, sechdr, &r))
1664 continue;
1665 break;
1666 }
1667 sym = elf->symtab_start + r_sym;
1668 /* Skip special sections */
1669 if (is_shndx_special(sym->st_shndx))
1670 continue;
1671 check_section_mismatch(modname, elf, &r, sym, fromsec);
1672 }
1673 }
1674
1675 /**
1676 * A module includes a number of sections that are discarded
1677 * either when loaded or when used as built-in.
1678 * For loaded modules all functions marked __init and all data
1679 * marked __initdata will be discarded when the module has been initialized.
1680 * Likewise for modules used built-in the sections marked __exit
1681 * are discarded because __exit marked function are supposed to be called
1682 * only when a module is unloaded which never happens for built-in modules.
1683 * The check_sec_ref() function traverses all relocation records
1684 * to find all references to a section that reference a section that will
1685 * be discarded and warns about it.
1686 **/
1687 static void check_sec_ref(struct module *mod, const char *modname,
1688 struct elf_info *elf)
1689 {
1690 int i;
1691 Elf_Shdr *sechdrs = elf->sechdrs;
1692
1693 /* Walk through all sections */
1694 for (i = 0; i < elf->num_sections; i++) {
1695 check_section(modname, elf, &elf->sechdrs[i]);
1696 /* We want to process only relocation sections and not .init */
1697 if (sechdrs[i].sh_type == SHT_RELA)
1698 section_rela(modname, elf, &elf->sechdrs[i]);
1699 else if (sechdrs[i].sh_type == SHT_REL)
1700 section_rel(modname, elf, &elf->sechdrs[i]);
1701 }
1702 }
1703
1704 static char *remove_dot(char *s)
1705 {
1706 char *end;
1707 int n = strcspn(s, ".");
1708
1709 if (n > 0 && s[n] != 0) {
1710 strtoul(s + n + 1, &end, 10);
1711 if (end > s + n + 1 && (*end == '.' || *end == 0))
1712 s[n] = 0;
1713 }
1714 return s;
1715 }
1716
1717 static void read_symbols(char *modname)
1718 {
1719 const char *symname;
1720 char *version;
1721 char *license;
1722 struct module *mod;
1723 struct elf_info info = { };
1724 Elf_Sym *sym;
1725
1726 if (!parse_elf(&info, modname))
1727 return;
1728
1729 mod = new_module(modname);
1730
1731 /* When there's no vmlinux, don't print warnings about
1732 * unresolved symbols (since there'll be too many ;) */
1733 if (is_vmlinux(modname)) {
1734 have_vmlinux = 1;
1735 mod->skip = 1;
1736 }
1737
1738 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1739 if (info.modinfo && !license && !is_vmlinux(modname))
1740 warn("modpost: missing MODULE_LICENSE() in %s\n"
1741 "see include/linux/module.h for "
1742 "more information\n", modname);
1743 while (license) {
1744 if (license_is_gpl_compatible(license))
1745 mod->gpl_compatible = 1;
1746 else {
1747 mod->gpl_compatible = 0;
1748 break;
1749 }
1750 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1751 "license", license);
1752 }
1753
1754 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1755 symname = remove_dot(info.strtab + sym->st_name);
1756
1757 handle_modversions(mod, &info, sym, symname);
1758 handle_moddevtable(mod, &info, sym, symname);
1759 }
1760 if (!is_vmlinux(modname) ||
1761 (is_vmlinux(modname) && vmlinux_section_warnings))
1762 check_sec_ref(mod, modname, &info);
1763
1764 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1765 if (version)
1766 maybe_frob_rcs_version(modname, version, info.modinfo,
1767 version - (char *)info.hdr);
1768 if (version || (all_versions && !is_vmlinux(modname)))
1769 get_src_version(modname, mod->srcversion,
1770 sizeof(mod->srcversion)-1);
1771
1772 parse_elf_finish(&info);
1773
1774 /* Our trick to get versioning for module struct etc. - it's
1775 * never passed as an argument to an exported function, so
1776 * the automatic versioning doesn't pick it up, but it's really
1777 * important anyhow */
1778 if (modversions)
1779 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1780 }
1781
1782 static void read_symbols_from_files(const char *filename)
1783 {
1784 FILE *in = stdin;
1785 char fname[PATH_MAX];
1786
1787 if (strcmp(filename, "-") != 0) {
1788 in = fopen(filename, "r");
1789 if (!in)
1790 fatal("Can't open filenames file %s: %m", filename);
1791 }
1792
1793 while (fgets(fname, PATH_MAX, in) != NULL) {
1794 if (strends(fname, "\n"))
1795 fname[strlen(fname)-1] = '\0';
1796 read_symbols(fname);
1797 }
1798
1799 if (in != stdin)
1800 fclose(in);
1801 }
1802
1803 #define SZ 500
1804
1805 /* We first write the generated file into memory using the
1806 * following helper, then compare to the file on disk and
1807 * only update the later if anything changed */
1808
1809 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1810 const char *fmt, ...)
1811 {
1812 char tmp[SZ];
1813 int len;
1814 va_list ap;
1815
1816 va_start(ap, fmt);
1817 len = vsnprintf(tmp, SZ, fmt, ap);
1818 buf_write(buf, tmp, len);
1819 va_end(ap);
1820 }
1821
1822 void buf_write(struct buffer *buf, const char *s, int len)
1823 {
1824 if (buf->size - buf->pos < len) {
1825 buf->size += len + SZ;
1826 buf->p = realloc(buf->p, buf->size);
1827 }
1828 strncpy(buf->p + buf->pos, s, len);
1829 buf->pos += len;
1830 }
1831
1832 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1833 {
1834 const char *e = is_vmlinux(m) ?"":".ko";
1835
1836 switch (exp) {
1837 case export_gpl:
1838 fatal("modpost: GPL-incompatible module %s%s "
1839 "uses GPL-only symbol '%s'\n", m, e, s);
1840 break;
1841 case export_unused_gpl:
1842 fatal("modpost: GPL-incompatible module %s%s "
1843 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1844 break;
1845 case export_gpl_future:
1846 warn("modpost: GPL-incompatible module %s%s "
1847 "uses future GPL-only symbol '%s'\n", m, e, s);
1848 break;
1849 case export_plain:
1850 case export_unused:
1851 case export_unknown:
1852 /* ignore */
1853 break;
1854 }
1855 }
1856
1857 static void check_for_unused(enum export exp, const char *m, const char *s)
1858 {
1859 const char *e = is_vmlinux(m) ?"":".ko";
1860
1861 switch (exp) {
1862 case export_unused:
1863 case export_unused_gpl:
1864 warn("modpost: module %s%s "
1865 "uses symbol '%s' marked UNUSED\n", m, e, s);
1866 break;
1867 default:
1868 /* ignore */
1869 break;
1870 }
1871 }
1872
1873 static void check_exports(struct module *mod)
1874 {
1875 struct symbol *s, *exp;
1876
1877 for (s = mod->unres; s; s = s->next) {
1878 const char *basename;
1879 exp = find_symbol(s->name);
1880 if (!exp || exp->module == mod)
1881 continue;
1882 basename = strrchr(mod->name, '/');
1883 if (basename)
1884 basename++;
1885 else
1886 basename = mod->name;
1887 if (!mod->gpl_compatible)
1888 check_for_gpl_usage(exp->export, basename, exp->name);
1889 check_for_unused(exp->export, basename, exp->name);
1890 }
1891 }
1892
1893 /**
1894 * Header for the generated file
1895 **/
1896 static void add_header(struct buffer *b, struct module *mod)
1897 {
1898 buf_printf(b, "#include <linux/module.h>\n");
1899 buf_printf(b, "#include <linux/vermagic.h>\n");
1900 buf_printf(b, "#include <linux/compiler.h>\n");
1901 buf_printf(b, "\n");
1902 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1903 buf_printf(b, "\n");
1904 buf_printf(b, "__visible struct module __this_module\n");
1905 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1906 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1907 if (mod->has_init)
1908 buf_printf(b, "\t.init = init_module,\n");
1909 if (mod->has_cleanup)
1910 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1911 "\t.exit = cleanup_module,\n"
1912 "#endif\n");
1913 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1914 buf_printf(b, "};\n");
1915 }
1916
1917 static void add_intree_flag(struct buffer *b, int is_intree)
1918 {
1919 if (is_intree)
1920 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1921 }
1922
1923 static void add_staging_flag(struct buffer *b, const char *name)
1924 {
1925 static const char *staging_dir = "drivers/staging";
1926
1927 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1928 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1929 }
1930
1931 /**
1932 * Record CRCs for unresolved symbols
1933 **/
1934 static int add_versions(struct buffer *b, struct module *mod)
1935 {
1936 struct symbol *s, *exp;
1937 int err = 0;
1938
1939 for (s = mod->unres; s; s = s->next) {
1940 exp = find_symbol(s->name);
1941 if (!exp || exp->module == mod) {
1942 if (have_vmlinux && !s->weak) {
1943 if (warn_unresolved) {
1944 warn("\"%s\" [%s.ko] undefined!\n",
1945 s->name, mod->name);
1946 } else {
1947 merror("\"%s\" [%s.ko] undefined!\n",
1948 s->name, mod->name);
1949 err = 1;
1950 }
1951 }
1952 continue;
1953 }
1954 s->module = exp->module;
1955 s->crc_valid = exp->crc_valid;
1956 s->crc = exp->crc;
1957 }
1958
1959 if (!modversions)
1960 return err;
1961
1962 buf_printf(b, "\n");
1963 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1964 buf_printf(b, "__used\n");
1965 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1966
1967 for (s = mod->unres; s; s = s->next) {
1968 if (!s->module)
1969 continue;
1970 if (!s->crc_valid) {
1971 warn("\"%s\" [%s.ko] has no CRC!\n",
1972 s->name, mod->name);
1973 continue;
1974 }
1975 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1976 s->crc, s->name);
1977 }
1978
1979 buf_printf(b, "};\n");
1980
1981 return err;
1982 }
1983
1984 static void add_depends(struct buffer *b, struct module *mod,
1985 struct module *modules)
1986 {
1987 struct symbol *s;
1988 struct module *m;
1989 int first = 1;
1990
1991 for (m = modules; m; m = m->next)
1992 m->seen = is_vmlinux(m->name);
1993
1994 buf_printf(b, "\n");
1995 buf_printf(b, "static const char __module_depends[]\n");
1996 buf_printf(b, "__used\n");
1997 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1998 buf_printf(b, "\"depends=");
1999 for (s = mod->unres; s; s = s->next) {
2000 const char *p;
2001 if (!s->module)
2002 continue;
2003
2004 if (s->module->seen)
2005 continue;
2006
2007 s->module->seen = 1;
2008 p = strrchr(s->module->name, '/');
2009 if (p)
2010 p++;
2011 else
2012 p = s->module->name;
2013 buf_printf(b, "%s%s", first ? "" : ",", p);
2014 first = 0;
2015 }
2016 buf_printf(b, "\";\n");
2017 }
2018
2019 static void add_srcversion(struct buffer *b, struct module *mod)
2020 {
2021 if (mod->srcversion[0]) {
2022 buf_printf(b, "\n");
2023 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2024 mod->srcversion);
2025 }
2026 }
2027
2028 static void write_if_changed(struct buffer *b, const char *fname)
2029 {
2030 char *tmp;
2031 FILE *file;
2032 struct stat st;
2033
2034 file = fopen(fname, "r");
2035 if (!file)
2036 goto write;
2037
2038 if (fstat(fileno(file), &st) < 0)
2039 goto close_write;
2040
2041 if (st.st_size != b->pos)
2042 goto close_write;
2043
2044 tmp = NOFAIL(malloc(b->pos));
2045 if (fread(tmp, 1, b->pos, file) != b->pos)
2046 goto free_write;
2047
2048 if (memcmp(tmp, b->p, b->pos) != 0)
2049 goto free_write;
2050
2051 free(tmp);
2052 fclose(file);
2053 return;
2054
2055 free_write:
2056 free(tmp);
2057 close_write:
2058 fclose(file);
2059 write:
2060 file = fopen(fname, "w");
2061 if (!file) {
2062 perror(fname);
2063 exit(1);
2064 }
2065 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2066 perror(fname);
2067 exit(1);
2068 }
2069 fclose(file);
2070 }
2071
2072 /* parse Module.symvers file. line format:
2073 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2074 **/
2075 static void read_dump(const char *fname, unsigned int kernel)
2076 {
2077 unsigned long size, pos = 0;
2078 void *file = grab_file(fname, &size);
2079 char *line;
2080
2081 if (!file)
2082 /* No symbol versions, silently ignore */
2083 return;
2084
2085 while ((line = get_next_line(&pos, file, size))) {
2086 char *symname, *modname, *d, *export, *end;
2087 unsigned int crc;
2088 struct module *mod;
2089 struct symbol *s;
2090
2091 if (!(symname = strchr(line, '\t')))
2092 goto fail;
2093 *symname++ = '\0';
2094 if (!(modname = strchr(symname, '\t')))
2095 goto fail;
2096 *modname++ = '\0';
2097 if ((export = strchr(modname, '\t')) != NULL)
2098 *export++ = '\0';
2099 if (export && ((end = strchr(export, '\t')) != NULL))
2100 *end = '\0';
2101 crc = strtoul(line, &d, 16);
2102 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2103 goto fail;
2104 mod = find_module(modname);
2105 if (!mod) {
2106 if (is_vmlinux(modname))
2107 have_vmlinux = 1;
2108 mod = new_module(modname);
2109 mod->skip = 1;
2110 }
2111 s = sym_add_exported(symname, mod, export_no(export));
2112 s->kernel = kernel;
2113 s->preloaded = 1;
2114 sym_update_crc(symname, mod, crc, export_no(export));
2115 }
2116 return;
2117 fail:
2118 fatal("parse error in symbol dump file\n");
2119 }
2120
2121 /* For normal builds always dump all symbols.
2122 * For external modules only dump symbols
2123 * that are not read from kernel Module.symvers.
2124 **/
2125 static int dump_sym(struct symbol *sym)
2126 {
2127 if (!external_module)
2128 return 1;
2129 if (sym->vmlinux || sym->kernel)
2130 return 0;
2131 return 1;
2132 }
2133
2134 static void write_dump(const char *fname)
2135 {
2136 struct buffer buf = { };
2137 struct symbol *symbol;
2138 int n;
2139
2140 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2141 symbol = symbolhash[n];
2142 while (symbol) {
2143 if (dump_sym(symbol))
2144 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2145 symbol->crc, symbol->name,
2146 symbol->module->name,
2147 export_str(symbol->export));
2148 symbol = symbol->next;
2149 }
2150 }
2151 write_if_changed(&buf, fname);
2152 }
2153
2154 struct ext_sym_list {
2155 struct ext_sym_list *next;
2156 const char *file;
2157 };
2158
2159 int main(int argc, char **argv)
2160 {
2161 struct module *mod;
2162 struct buffer buf = { };
2163 char *kernel_read = NULL, *module_read = NULL;
2164 char *dump_write = NULL, *files_source = NULL;
2165 int opt;
2166 int err;
2167 struct ext_sym_list *extsym_iter;
2168 struct ext_sym_list *extsym_start = NULL;
2169
2170 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:")) != -1) {
2171 switch (opt) {
2172 case 'i':
2173 kernel_read = optarg;
2174 break;
2175 case 'I':
2176 module_read = optarg;
2177 external_module = 1;
2178 break;
2179 case 'e':
2180 external_module = 1;
2181 extsym_iter =
2182 NOFAIL(malloc(sizeof(*extsym_iter)));
2183 extsym_iter->next = extsym_start;
2184 extsym_iter->file = optarg;
2185 extsym_start = extsym_iter;
2186 break;
2187 case 'm':
2188 modversions = 1;
2189 break;
2190 case 'n':
2191 ignore_missing_files = 1;
2192 break;
2193 case 'o':
2194 dump_write = optarg;
2195 break;
2196 case 'a':
2197 all_versions = 1;
2198 break;
2199 case 's':
2200 vmlinux_section_warnings = 0;
2201 break;
2202 case 'S':
2203 sec_mismatch_verbose = 0;
2204 break;
2205 case 'T':
2206 files_source = optarg;
2207 break;
2208 case 'w':
2209 warn_unresolved = 1;
2210 break;
2211 default:
2212 exit(1);
2213 }
2214 }
2215
2216 if (kernel_read)
2217 read_dump(kernel_read, 1);
2218 if (module_read)
2219 read_dump(module_read, 0);
2220 while (extsym_start) {
2221 read_dump(extsym_start->file, 0);
2222 extsym_iter = extsym_start->next;
2223 free(extsym_start);
2224 extsym_start = extsym_iter;
2225 }
2226
2227 while (optind < argc)
2228 read_symbols(argv[optind++]);
2229
2230 if (files_source)
2231 read_symbols_from_files(files_source);
2232
2233 for (mod = modules; mod; mod = mod->next) {
2234 if (mod->skip)
2235 continue;
2236 check_exports(mod);
2237 }
2238
2239 err = 0;
2240
2241 for (mod = modules; mod; mod = mod->next) {
2242 char fname[strlen(mod->name) + 10];
2243
2244 if (mod->skip)
2245 continue;
2246
2247 buf.pos = 0;
2248
2249 add_header(&buf, mod);
2250 add_intree_flag(&buf, !external_module);
2251 add_staging_flag(&buf, mod->name);
2252 err |= add_versions(&buf, mod);
2253 add_depends(&buf, mod, modules);
2254 add_moddevtable(&buf, mod);
2255 add_srcversion(&buf, mod);
2256
2257 sprintf(fname, "%s.mod.c", mod->name);
2258 write_if_changed(&buf, fname);
2259 }
2260
2261 if (dump_write)
2262 write_dump(dump_write);
2263 if (sec_mismatch_count && !sec_mismatch_verbose)
2264 warn("modpost: Found %d section mismatch(es).\n"
2265 "To see full details build your kernel with:\n"
2266 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2267 sec_mismatch_count);
2268
2269 return err;
2270 }
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