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 <elf.h>
16 #include <fnmatch.h>
17 #include <stdio.h>
18 #include <ctype.h>
19 #include <string.h>
20 #include <limits.h>
21 #include <stdbool.h>
22 #include <errno.h>
23
24 #include <hash.h>
25 #include <hashtable.h>
26 #include <list.h>
27 #include <xalloc.h>
28 #include "modpost.h"
29 #include "../../include/linux/license.h"
30
31 static bool module_enabled;
32 /* Are we using CONFIG_MODVERSIONS? */
33 static bool modversions;
34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35 static bool all_versions;
36 /* Is CONFIG_BASIC_MODVERSIONS set? */
37 static bool basic_modversions;
38 /* Is CONFIG_EXTENDED_MODVERSIONS set? */
39 static bool extended_modversions;
40 /* If we are modposting external module set to 1 */
41 static bool external_module;
42 /* Only warn about unresolved symbols */
43 static bool warn_unresolved;
44
45 static int sec_mismatch_count;
46 static bool sec_mismatch_warn_only = true;
47 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
48 static bool trim_unused_exports;
49
50 /* ignore missing files */
51 static bool ignore_missing_files;
52 /* If set to 1, only warn (instead of error) about missing ns imports */
53 static bool allow_missing_ns_imports;
54
55 static bool error_occurred;
56
57 static bool extra_warn;
58
59 bool target_is_big_endian;
60 bool host_is_big_endian;
61
62 /*
63 * Cut off the warnings when there are too many. This typically occurs when
64 * vmlinux is missing. ('make modules' without building vmlinux.)
65 */
66 #define MAX_UNRESOLVED_REPORTS 10
67 static unsigned int nr_unresolved;
68
69 /* In kernel, this size is defined in linux/module.h;
70 * here we use Elf_Addr instead of long for covering cross-compile
71 */
72
73 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
74
modpost_log(bool is_error,const char * fmt,...)75 void modpost_log(bool is_error, const char *fmt, ...)
76 {
77 va_list arglist;
78
79 if (is_error) {
80 fprintf(stderr, "ERROR: ");
81 error_occurred = true;
82 } else {
83 fprintf(stderr, "WARNING: ");
84 }
85
86 fprintf(stderr, "modpost: ");
87
88 va_start(arglist, fmt);
89 vfprintf(stderr, fmt, arglist);
90 va_end(arglist);
91 }
92
strends(const char * str,const char * postfix)93 static inline bool strends(const char *str, const char *postfix)
94 {
95 if (strlen(str) < strlen(postfix))
96 return false;
97
98 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
99 }
100
101 /**
102 * get_basename - return the last part of a pathname.
103 *
104 * @path: path to extract the filename from.
105 */
get_basename(const char * path)106 const char *get_basename(const char *path)
107 {
108 const char *tail = strrchr(path, '/');
109
110 return tail ? tail + 1 : path;
111 }
112
read_text_file(const char * filename)113 char *read_text_file(const char *filename)
114 {
115 struct stat st;
116 size_t nbytes;
117 int fd;
118 char *buf;
119
120 fd = open(filename, O_RDONLY);
121 if (fd < 0) {
122 perror(filename);
123 exit(1);
124 }
125
126 if (fstat(fd, &st) < 0) {
127 perror(filename);
128 exit(1);
129 }
130
131 buf = xmalloc(st.st_size + 1);
132
133 nbytes = st.st_size;
134
135 while (nbytes) {
136 ssize_t bytes_read;
137
138 bytes_read = read(fd, buf, nbytes);
139 if (bytes_read < 0) {
140 perror(filename);
141 exit(1);
142 }
143
144 nbytes -= bytes_read;
145 }
146 buf[st.st_size] = '\0';
147
148 close(fd);
149
150 return buf;
151 }
152
get_line(char ** stringp)153 char *get_line(char **stringp)
154 {
155 char *orig = *stringp, *next;
156
157 /* do not return the unwanted extra line at EOF */
158 if (!orig || *orig == '\0')
159 return NULL;
160
161 /* don't use strsep here, it is not available everywhere */
162 next = strchr(orig, '\n');
163 if (next)
164 *next++ = '\0';
165
166 *stringp = next;
167
168 return orig;
169 }
170
171 /* A list of all modules we processed */
172 LIST_HEAD(modules);
173
find_module(const char * filename,const char * modname)174 static struct module *find_module(const char *filename, const char *modname)
175 {
176 struct module *mod;
177
178 list_for_each_entry(mod, &modules, list) {
179 if (!strcmp(mod->dump_file, filename) &&
180 !strcmp(mod->name, modname))
181 return mod;
182 }
183 return NULL;
184 }
185
new_module(const char * name,size_t namelen)186 static struct module *new_module(const char *name, size_t namelen)
187 {
188 struct module *mod;
189
190 mod = xmalloc(sizeof(*mod) + namelen + 1);
191 memset(mod, 0, sizeof(*mod));
192
193 INIT_LIST_HEAD(&mod->exported_symbols);
194 INIT_LIST_HEAD(&mod->unresolved_symbols);
195 INIT_LIST_HEAD(&mod->missing_namespaces);
196 INIT_LIST_HEAD(&mod->imported_namespaces);
197 INIT_LIST_HEAD(&mod->aliases);
198
199 memcpy(mod->name, name, namelen);
200 mod->name[namelen] = '\0';
201 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
202
203 /*
204 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
205 * is missing, do not check the use for EXPORT_SYMBOL_GPL() because
206 * modpost will exit with an error anyway.
207 */
208 mod->is_gpl_compatible = true;
209
210 list_add_tail(&mod->list, &modules);
211
212 return mod;
213 }
214
215 struct symbol {
216 struct hlist_node hnode;/* link to hash table */
217 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
218 struct module *module;
219 char *namespace;
220 unsigned int crc;
221 bool crc_valid;
222 bool weak;
223 bool is_func;
224 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
225 bool used; /* there exists a user of this symbol */
226 char name[];
227 };
228
229 static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10);
230
231 /**
232 * Allocate a new symbols for use in the hash of exported symbols or
233 * the list of unresolved symbols per module
234 **/
alloc_symbol(const char * name)235 static struct symbol *alloc_symbol(const char *name)
236 {
237 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1);
238
239 memset(s, 0, sizeof(*s));
240 strcpy(s->name, name);
241
242 return s;
243 }
244
245 /* For the hash of exported symbols */
hash_add_symbol(struct symbol * sym)246 static void hash_add_symbol(struct symbol *sym)
247 {
248 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name));
249 }
250
sym_add_unresolved(const char * name,struct module * mod,bool weak)251 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
252 {
253 struct symbol *sym;
254
255 sym = alloc_symbol(name);
256 sym->weak = weak;
257
258 list_add_tail(&sym->list, &mod->unresolved_symbols);
259 }
260
sym_find_with_module(const char * name,struct module * mod)261 static struct symbol *sym_find_with_module(const char *name, struct module *mod)
262 {
263 struct symbol *s;
264
265 /* For our purposes, .foo matches foo. PPC64 needs this. */
266 if (name[0] == '.')
267 name++;
268
269 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) {
270 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
271 return s;
272 }
273 return NULL;
274 }
275
find_symbol(const char * name)276 static struct symbol *find_symbol(const char *name)
277 {
278 return sym_find_with_module(name, NULL);
279 }
280
281 struct namespace_list {
282 struct list_head list;
283 char namespace[];
284 };
285
contains_namespace(struct list_head * head,const char * namespace)286 static bool contains_namespace(struct list_head *head, const char *namespace)
287 {
288 struct namespace_list *list;
289
290 /*
291 * The default namespace is null string "", which is always implicitly
292 * contained.
293 */
294 if (!namespace[0])
295 return true;
296
297 list_for_each_entry(list, head, list) {
298 if (!strcmp(list->namespace, namespace))
299 return true;
300 }
301
302 return false;
303 }
304
add_namespace(struct list_head * head,const char * namespace)305 static void add_namespace(struct list_head *head, const char *namespace)
306 {
307 struct namespace_list *ns_entry;
308
309 if (!contains_namespace(head, namespace)) {
310 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1);
311 strcpy(ns_entry->namespace, namespace);
312 list_add_tail(&ns_entry->list, head);
313 }
314 }
315
sym_get_data_by_offset(const struct elf_info * info,unsigned int secindex,unsigned long offset)316 static void *sym_get_data_by_offset(const struct elf_info *info,
317 unsigned int secindex, unsigned long offset)
318 {
319 Elf_Shdr *sechdr = &info->sechdrs[secindex];
320
321 return (void *)info->hdr + sechdr->sh_offset + offset;
322 }
323
sym_get_data(const struct elf_info * info,const Elf_Sym * sym)324 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
325 {
326 return sym_get_data_by_offset(info, get_secindex(info, sym),
327 sym->st_value);
328 }
329
sech_name(const struct elf_info * info,Elf_Shdr * sechdr)330 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
331 {
332 return sym_get_data_by_offset(info, info->secindex_strings,
333 sechdr->sh_name);
334 }
335
sec_name(const struct elf_info * info,unsigned int secindex)336 static const char *sec_name(const struct elf_info *info, unsigned int secindex)
337 {
338 /*
339 * If sym->st_shndx is a special section index, there is no
340 * corresponding section header.
341 * Return "" if the index is out of range of info->sechdrs[] array.
342 */
343 if (secindex >= info->num_sections)
344 return "";
345
346 return sech_name(info, &info->sechdrs[secindex]);
347 }
348
sym_add_exported(const char * name,struct module * mod,bool gpl_only,const char * namespace)349 static struct symbol *sym_add_exported(const char *name, struct module *mod,
350 bool gpl_only, const char *namespace)
351 {
352 struct symbol *s = find_symbol(name);
353
354 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
355 error("%s: '%s' exported twice. Previous export was in %s%s\n",
356 mod->name, name, s->module->name,
357 s->module->is_vmlinux ? "" : ".ko");
358 }
359
360 s = alloc_symbol(name);
361 s->module = mod;
362 s->is_gpl_only = gpl_only;
363 s->namespace = xstrdup(namespace);
364 list_add_tail(&s->list, &mod->exported_symbols);
365 hash_add_symbol(s);
366
367 return s;
368 }
369
sym_set_crc(struct symbol * sym,unsigned int crc)370 static void sym_set_crc(struct symbol *sym, unsigned int crc)
371 {
372 sym->crc = crc;
373 sym->crc_valid = true;
374 }
375
grab_file(const char * filename,size_t * size)376 static void *grab_file(const char *filename, size_t *size)
377 {
378 struct stat st;
379 void *map = MAP_FAILED;
380 int fd;
381
382 fd = open(filename, O_RDONLY);
383 if (fd < 0)
384 return NULL;
385 if (fstat(fd, &st))
386 goto failed;
387
388 *size = st.st_size;
389 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
390
391 failed:
392 close(fd);
393 if (map == MAP_FAILED)
394 return NULL;
395 return map;
396 }
397
release_file(void * file,size_t size)398 static void release_file(void *file, size_t size)
399 {
400 munmap(file, size);
401 }
402
parse_elf(struct elf_info * info,const char * filename)403 static int parse_elf(struct elf_info *info, const char *filename)
404 {
405 unsigned int i;
406 Elf_Ehdr *hdr;
407 Elf_Shdr *sechdrs;
408 Elf_Sym *sym;
409 const char *secstrings;
410 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
411
412 hdr = grab_file(filename, &info->size);
413 if (!hdr) {
414 if (ignore_missing_files) {
415 fprintf(stderr, "%s: %s (ignored)\n", filename,
416 strerror(errno));
417 return 0;
418 }
419 perror(filename);
420 exit(1);
421 }
422 info->hdr = hdr;
423 if (info->size < sizeof(*hdr)) {
424 /* file too small, assume this is an empty .o file */
425 return 0;
426 }
427 /* Is this a valid ELF file? */
428 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
429 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
430 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
431 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
432 /* Not an ELF file - silently ignore it */
433 return 0;
434 }
435
436 switch (hdr->e_ident[EI_DATA]) {
437 case ELFDATA2LSB:
438 target_is_big_endian = false;
439 break;
440 case ELFDATA2MSB:
441 target_is_big_endian = true;
442 break;
443 default:
444 fatal("target endian is unknown\n");
445 }
446
447 /* Fix endianness in ELF header */
448 hdr->e_type = TO_NATIVE(hdr->e_type);
449 hdr->e_machine = TO_NATIVE(hdr->e_machine);
450 hdr->e_version = TO_NATIVE(hdr->e_version);
451 hdr->e_entry = TO_NATIVE(hdr->e_entry);
452 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
453 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
454 hdr->e_flags = TO_NATIVE(hdr->e_flags);
455 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
456 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
457 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
458 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
459 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
460 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
461 sechdrs = (void *)hdr + hdr->e_shoff;
462 info->sechdrs = sechdrs;
463
464 /* modpost only works for relocatable objects */
465 if (hdr->e_type != ET_REL)
466 fatal("%s: not relocatable object.", filename);
467
468 /* Check if file offset is correct */
469 if (hdr->e_shoff > info->size)
470 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
471 (unsigned long)hdr->e_shoff, filename, info->size);
472
473 if (hdr->e_shnum == SHN_UNDEF) {
474 /*
475 * There are more than 64k sections,
476 * read count from .sh_size.
477 */
478 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
479 }
480 else {
481 info->num_sections = hdr->e_shnum;
482 }
483 if (hdr->e_shstrndx == SHN_XINDEX) {
484 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
485 }
486 else {
487 info->secindex_strings = hdr->e_shstrndx;
488 }
489
490 /* Fix endianness in section headers */
491 for (i = 0; i < info->num_sections; i++) {
492 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
493 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
494 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
495 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
496 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
497 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
498 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
499 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
500 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
501 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
502 }
503 /* Find symbol table. */
504 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
505 for (i = 1; i < info->num_sections; i++) {
506 const char *secname;
507 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
508
509 if (!nobits && sechdrs[i].sh_offset > info->size)
510 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
511 filename, (unsigned long)sechdrs[i].sh_offset,
512 sizeof(*hdr));
513
514 secname = secstrings + sechdrs[i].sh_name;
515 if (strcmp(secname, ".modinfo") == 0) {
516 if (nobits)
517 fatal("%s has NOBITS .modinfo\n", filename);
518 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
519 info->modinfo_len = sechdrs[i].sh_size;
520 } else if (!strcmp(secname, ".export_symbol")) {
521 info->export_symbol_secndx = i;
522 } else if (!strcmp(secname, ".no_trim_symbol")) {
523 info->no_trim_symbol = (void *)hdr + sechdrs[i].sh_offset;
524 info->no_trim_symbol_len = sechdrs[i].sh_size;
525 }
526
527 if (sechdrs[i].sh_type == SHT_SYMTAB) {
528 unsigned int sh_link_idx;
529 symtab_idx = i;
530 info->symtab_start = (void *)hdr +
531 sechdrs[i].sh_offset;
532 info->symtab_stop = (void *)hdr +
533 sechdrs[i].sh_offset + sechdrs[i].sh_size;
534 sh_link_idx = sechdrs[i].sh_link;
535 info->strtab = (void *)hdr +
536 sechdrs[sh_link_idx].sh_offset;
537 }
538
539 /* 32bit section no. table? ("more than 64k sections") */
540 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
541 symtab_shndx_idx = i;
542 info->symtab_shndx_start = (void *)hdr +
543 sechdrs[i].sh_offset;
544 info->symtab_shndx_stop = (void *)hdr +
545 sechdrs[i].sh_offset + sechdrs[i].sh_size;
546 }
547 }
548 if (!info->symtab_start)
549 fatal("%s has no symtab?\n", filename);
550
551 /* Fix endianness in symbols */
552 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
553 sym->st_shndx = TO_NATIVE(sym->st_shndx);
554 sym->st_name = TO_NATIVE(sym->st_name);
555 sym->st_value = TO_NATIVE(sym->st_value);
556 sym->st_size = TO_NATIVE(sym->st_size);
557 }
558
559 if (symtab_shndx_idx != ~0U) {
560 Elf32_Word *p;
561 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
562 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
563 filename, sechdrs[symtab_shndx_idx].sh_link,
564 symtab_idx);
565 /* Fix endianness */
566 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
567 p++)
568 *p = TO_NATIVE(*p);
569 }
570
571 symsearch_init(info);
572
573 return 1;
574 }
575
parse_elf_finish(struct elf_info * info)576 static void parse_elf_finish(struct elf_info *info)
577 {
578 symsearch_finish(info);
579 release_file(info->hdr, info->size);
580 }
581
ignore_undef_symbol(struct elf_info * info,const char * symname)582 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
583 {
584 /* ignore __this_module, it will be resolved shortly */
585 if (strcmp(symname, "__this_module") == 0)
586 return 1;
587 /* ignore global offset table */
588 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
589 return 1;
590 if (info->hdr->e_machine == EM_PPC)
591 /* Special register function linked on all modules during final link of .ko */
592 if (strstarts(symname, "_restgpr_") ||
593 strstarts(symname, "_savegpr_") ||
594 strstarts(symname, "_rest32gpr_") ||
595 strstarts(symname, "_save32gpr_") ||
596 strstarts(symname, "_restvr_") ||
597 strstarts(symname, "_savevr_"))
598 return 1;
599 if (info->hdr->e_machine == EM_PPC64)
600 /* Special register function linked on all modules during final link of .ko */
601 if (strstarts(symname, "_restgpr0_") ||
602 strstarts(symname, "_savegpr0_") ||
603 strstarts(symname, "_restvr_") ||
604 strstarts(symname, "_savevr_") ||
605 strcmp(symname, ".TOC.") == 0)
606 return 1;
607 /* Do not ignore this symbol */
608 return 0;
609 }
610
handle_symbol(struct module * mod,struct elf_info * info,const Elf_Sym * sym,const char * symname)611 static void handle_symbol(struct module *mod, struct elf_info *info,
612 const Elf_Sym *sym, const char *symname)
613 {
614 switch (sym->st_shndx) {
615 case SHN_COMMON:
616 if (strstarts(symname, "__gnu_lto_")) {
617 /* Should warn here, but modpost runs before the linker */
618 } else
619 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
620 break;
621 case SHN_UNDEF:
622 /* undefined symbol */
623 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
624 ELF_ST_BIND(sym->st_info) != STB_WEAK)
625 break;
626 if (ignore_undef_symbol(info, symname))
627 break;
628 if (info->hdr->e_machine == EM_SPARC ||
629 info->hdr->e_machine == EM_SPARCV9) {
630 /* Ignore register directives. */
631 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
632 break;
633 if (symname[0] == '.') {
634 char *munged = xstrdup(symname);
635 munged[0] = '_';
636 munged[1] = toupper(munged[1]);
637 symname = munged;
638 }
639 }
640
641 sym_add_unresolved(symname, mod,
642 ELF_ST_BIND(sym->st_info) == STB_WEAK);
643 break;
644 default:
645 if (strcmp(symname, "init_module") == 0)
646 mod->has_init = true;
647 if (strcmp(symname, "cleanup_module") == 0)
648 mod->has_cleanup = true;
649 break;
650 }
651 }
652
653 /**
654 * Parse tag=value strings from .modinfo section
655 **/
next_string(char * string,unsigned long * secsize)656 static char *next_string(char *string, unsigned long *secsize)
657 {
658 /* Skip non-zero chars */
659 while (string[0]) {
660 string++;
661 if ((*secsize)-- <= 1)
662 return NULL;
663 }
664
665 /* Skip any zero padding. */
666 while (!string[0]) {
667 string++;
668 if ((*secsize)-- <= 1)
669 return NULL;
670 }
671 return string;
672 }
673
get_next_modinfo(struct elf_info * info,const char * tag,char * prev)674 static char *get_next_modinfo(struct elf_info *info, const char *tag,
675 char *prev)
676 {
677 char *p;
678 unsigned int taglen = strlen(tag);
679 char *modinfo = info->modinfo;
680 unsigned long size = info->modinfo_len;
681
682 if (prev) {
683 size -= prev - modinfo;
684 modinfo = next_string(prev, &size);
685 }
686
687 for (p = modinfo; p; p = next_string(p, &size)) {
688 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
689 return p + taglen + 1;
690 }
691 return NULL;
692 }
693
get_modinfo(struct elf_info * info,const char * tag)694 static char *get_modinfo(struct elf_info *info, const char *tag)
695
696 {
697 return get_next_modinfo(info, tag, NULL);
698 }
699
sym_name(struct elf_info * elf,Elf_Sym * sym)700 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
701 {
702 return sym ? elf->strtab + sym->st_name : "";
703 }
704
705 /*
706 * Check whether the 'string' argument matches one of the 'patterns',
707 * an array of shell wildcard patterns (glob).
708 *
709 * Return true is there is a match.
710 */
match(const char * string,const char * const patterns[])711 static bool match(const char *string, const char *const patterns[])
712 {
713 const char *pattern;
714
715 while ((pattern = *patterns++)) {
716 if (!fnmatch(pattern, string, 0))
717 return true;
718 }
719
720 return false;
721 }
722
723 /* useful to pass patterns to match() directly */
724 #define PATTERNS(...) \
725 ({ \
726 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
727 patterns; \
728 })
729
730 /* sections that we do not want to do full section mismatch check on */
731 static const char *const section_white_list[] =
732 {
733 ".comment*",
734 ".debug*",
735 ".zdebug*", /* Compressed debug sections. */
736 ".GCC.command.line", /* record-gcc-switches */
737 ".mdebug*", /* alpha, score, mips etc. */
738 ".pdr", /* alpha, score, mips etc. */
739 ".stab*",
740 ".note*",
741 ".got*",
742 ".toc*",
743 ".xt.prop", /* xtensa */
744 ".xt.lit", /* xtensa */
745 ".arcextmap*", /* arc */
746 ".gnu.linkonce.arcext*", /* arc : modules */
747 ".cmem*", /* EZchip */
748 ".fmt_slot*", /* EZchip */
749 ".gnu.lto*",
750 ".discard.*",
751 ".llvm.call-graph-profile", /* call graph */
752 NULL
753 };
754
755 /*
756 * This is used to find sections missing the SHF_ALLOC flag.
757 * The cause of this is often a section specified in assembler
758 * without "ax" / "aw".
759 */
check_section(const char * modname,struct elf_info * elf,Elf_Shdr * sechdr)760 static void check_section(const char *modname, struct elf_info *elf,
761 Elf_Shdr *sechdr)
762 {
763 const char *sec = sech_name(elf, sechdr);
764
765 if (sechdr->sh_type == SHT_PROGBITS &&
766 !(sechdr->sh_flags & SHF_ALLOC) &&
767 !match(sec, section_white_list)) {
768 warn("%s (%s): unexpected non-allocatable section.\n"
769 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
770 "Note that for example <linux/init.h> contains\n"
771 "section definitions for use in .S files.\n\n",
772 modname, sec);
773 }
774 }
775
776
777
778 #define ALL_INIT_DATA_SECTIONS \
779 ".init.setup", ".init.rodata", ".init.data"
780
781 #define ALL_PCI_INIT_SECTIONS \
782 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
783 ".pci_fixup_enable", ".pci_fixup_resume", \
784 ".pci_fixup_resume_early", ".pci_fixup_suspend"
785
786 #define ALL_INIT_SECTIONS ".init.*"
787 #define ALL_EXIT_SECTIONS ".exit.*"
788
789 #define DATA_SECTIONS ".data", ".data.rel"
790 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
791 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
792 ".ltext", ".ltext.*"
793 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
794 ".fixup", ".entry.text", ".exception.text", \
795 ".coldtext", ".softirqentry.text", ".irqentry.text"
796
797 #define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \
798 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
799
800 enum mismatch {
801 TEXTDATA_TO_ANY_INIT_EXIT,
802 XXXINIT_TO_SOME_INIT,
803 ANY_INIT_TO_ANY_EXIT,
804 ANY_EXIT_TO_ANY_INIT,
805 EXTABLE_TO_NON_TEXT,
806 };
807
808 /**
809 * Describe how to match sections on different criteria:
810 *
811 * @fromsec: Array of sections to be matched.
812 *
813 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
814 * this array is forbidden (black-list). Can be empty.
815 *
816 * @good_tosec: Relocations applied to a section in @fromsec must be
817 * targeting sections in this array (white-list). Can be empty.
818 *
819 * @mismatch: Type of mismatch.
820 */
821 struct sectioncheck {
822 const char *fromsec[20];
823 const char *bad_tosec[20];
824 const char *good_tosec[20];
825 enum mismatch mismatch;
826 };
827
828 static const struct sectioncheck sectioncheck[] = {
829 /* Do not reference init/exit code/data from
830 * normal code and data
831 */
832 {
833 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
834 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
835 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
836 },
837 /* Do not use exit code/data from init code */
838 {
839 .fromsec = { ALL_INIT_SECTIONS, NULL },
840 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
841 .mismatch = ANY_INIT_TO_ANY_EXIT,
842 },
843 /* Do not use init code/data from exit code */
844 {
845 .fromsec = { ALL_EXIT_SECTIONS, NULL },
846 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
847 .mismatch = ANY_EXIT_TO_ANY_INIT,
848 },
849 {
850 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
851 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
852 .mismatch = ANY_INIT_TO_ANY_EXIT,
853 },
854 {
855 .fromsec = { "__ex_table", NULL },
856 /* If you're adding any new black-listed sections in here, consider
857 * adding a special 'printer' for them in scripts/check_extable.
858 */
859 .bad_tosec = { ".altinstr_replacement", NULL },
860 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
861 .mismatch = EXTABLE_TO_NON_TEXT,
862 }
863 };
864
section_mismatch(const char * fromsec,const char * tosec)865 static const struct sectioncheck *section_mismatch(
866 const char *fromsec, const char *tosec)
867 {
868 int i;
869
870 /*
871 * The target section could be the SHT_NUL section when we're
872 * handling relocations to un-resolved symbols, trying to match it
873 * doesn't make much sense and causes build failures on parisc
874 * architectures.
875 */
876 if (*tosec == '\0')
877 return NULL;
878
879 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
880 const struct sectioncheck *check = §ioncheck[i];
881
882 if (match(fromsec, check->fromsec)) {
883 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
884 return check;
885 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
886 return check;
887 }
888 }
889 return NULL;
890 }
891
892 /**
893 * Whitelist to allow certain references to pass with no warning.
894 *
895 * Pattern 1:
896 * If a module parameter is declared __initdata and permissions=0
897 * then this is legal despite the warning generated.
898 * We cannot see value of permissions here, so just ignore
899 * this pattern.
900 * The pattern is identified by:
901 * tosec = .init.data
902 * fromsec = .data*
903 * atsym =__param*
904 *
905 * Pattern 1a:
906 * module_param_call() ops can refer to __init set function if permissions=0
907 * The pattern is identified by:
908 * tosec = .init.text
909 * fromsec = .data*
910 * atsym = __param_ops_*
911 *
912 * Pattern 3:
913 * Whitelist all references from .head.text to any init section
914 *
915 * Pattern 4:
916 * Some symbols belong to init section but still it is ok to reference
917 * these from non-init sections as these symbols don't have any memory
918 * allocated for them and symbol address and value are same. So even
919 * if init section is freed, its ok to reference those symbols.
920 * For ex. symbols marking the init section boundaries.
921 * This pattern is identified by
922 * refsymname = __init_begin, _sinittext, _einittext
923 *
924 * Pattern 5:
925 * GCC may optimize static inlines when fed constant arg(s) resulting
926 * in functions like cpumask_empty() -- generating an associated symbol
927 * cpumask_empty.constprop.3 that appears in the audit. If the const that
928 * is passed in comes from __init, like say nmi_ipi_mask, we get a
929 * meaningless section warning. May need to add isra symbols too...
930 * This pattern is identified by
931 * tosec = init section
932 * fromsec = text section
933 * refsymname = *.constprop.*
934 *
935 **/
secref_whitelist(const char * fromsec,const char * fromsym,const char * tosec,const char * tosym)936 static int secref_whitelist(const char *fromsec, const char *fromsym,
937 const char *tosec, const char *tosym)
938 {
939 /* Check for pattern 1 */
940 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
941 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
942 strstarts(fromsym, "__param"))
943 return 0;
944
945 /* Check for pattern 1a */
946 if (strcmp(tosec, ".init.text") == 0 &&
947 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
948 strstarts(fromsym, "__param_ops_"))
949 return 0;
950
951 /* symbols in data sections that may refer to any init/exit sections */
952 if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
953 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
954 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
955 return 0;
956
957 /* Check for pattern 3 */
958 if (strstarts(fromsec, ".head.text") &&
959 match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
960 return 0;
961
962 /* Check for pattern 4 */
963 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
964 return 0;
965
966 /* Check for pattern 5 */
967 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
968 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
969 match(fromsym, PATTERNS("*.constprop.*")))
970 return 0;
971
972 return 1;
973 }
974
find_fromsym(struct elf_info * elf,Elf_Addr addr,unsigned int secndx)975 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
976 unsigned int secndx)
977 {
978 return symsearch_find_nearest(elf, addr, secndx, false, ~0);
979 }
980
find_tosym(struct elf_info * elf,Elf_Addr addr,Elf_Sym * sym)981 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
982 {
983 Elf_Sym *new_sym;
984
985 /* If the supplied symbol has a valid name, return it */
986 if (is_valid_name(elf, sym))
987 return sym;
988
989 /*
990 * Strive to find a better symbol name, but the resulting name may not
991 * match the symbol referenced in the original code.
992 */
993 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
994 true, 20);
995 return new_sym ? new_sym : sym;
996 }
997
is_executable_section(struct elf_info * elf,unsigned int secndx)998 static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
999 {
1000 if (secndx >= elf->num_sections)
1001 return false;
1002
1003 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1004 }
1005
default_mismatch_handler(const char * modname,struct elf_info * elf,const struct sectioncheck * const mismatch,Elf_Sym * tsym,unsigned int fsecndx,const char * fromsec,Elf_Addr faddr,const char * tosec,Elf_Addr taddr)1006 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1007 const struct sectioncheck* const mismatch,
1008 Elf_Sym *tsym,
1009 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1010 const char *tosec, Elf_Addr taddr)
1011 {
1012 Elf_Sym *from;
1013 const char *tosym;
1014 const char *fromsym;
1015 char taddr_str[16];
1016
1017 from = find_fromsym(elf, faddr, fsecndx);
1018 fromsym = sym_name(elf, from);
1019
1020 tsym = find_tosym(elf, taddr, tsym);
1021 tosym = sym_name(elf, tsym);
1022
1023 /* check whitelist - we may ignore it */
1024 if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1025 return;
1026
1027 sec_mismatch_count++;
1028
1029 if (!tosym[0])
1030 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr);
1031
1032 /*
1033 * The format for the reference source: <symbol_name>+<offset> or <address>
1034 * The format for the reference destination: <symbol_name> or <address>
1035 */
1036 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n",
1037 modname, fromsym, fromsym[0] ? "+" : "",
1038 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)),
1039 fromsec, tosym[0] ? tosym : taddr_str, tosec);
1040
1041 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1042 if (match(tosec, mismatch->bad_tosec))
1043 fatal("The relocation at %s+0x%lx references\n"
1044 "section \"%s\" which is black-listed.\n"
1045 "Something is seriously wrong and should be fixed.\n"
1046 "You might get more information about where this is\n"
1047 "coming from by using scripts/check_extable.sh %s\n",
1048 fromsec, (long)faddr, tosec, modname);
1049 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1050 warn("The relocation at %s+0x%lx references\n"
1051 "section \"%s\" which is not in the list of\n"
1052 "authorized sections. If you're adding a new section\n"
1053 "and/or if this reference is valid, add \"%s\" to the\n"
1054 "list of authorized sections to jump to on fault.\n"
1055 "This can be achieved by adding \"%s\" to\n"
1056 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1057 fromsec, (long)faddr, tosec, tosec, tosec);
1058 else
1059 error("%s+0x%lx references non-executable section '%s'\n",
1060 fromsec, (long)faddr, tosec);
1061 }
1062 }
1063
check_export_symbol(struct module * mod,struct elf_info * elf,Elf_Addr faddr,const char * secname,Elf_Sym * sym)1064 static void check_export_symbol(struct module *mod, struct elf_info *elf,
1065 Elf_Addr faddr, const char *secname,
1066 Elf_Sym *sym)
1067 {
1068 static const char *prefix = "__export_symbol_";
1069 const char *label_name, *name, *data;
1070 Elf_Sym *label;
1071 struct symbol *s;
1072 bool is_gpl;
1073
1074 label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1075 label_name = sym_name(elf, label);
1076
1077 if (!strstarts(label_name, prefix)) {
1078 error("%s: .export_symbol section contains strange symbol '%s'\n",
1079 mod->name, label_name);
1080 return;
1081 }
1082
1083 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1084 ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1085 error("%s: local symbol '%s' was exported\n", mod->name,
1086 label_name + strlen(prefix));
1087 return;
1088 }
1089
1090 name = sym_name(elf, sym);
1091 if (strcmp(label_name + strlen(prefix), name)) {
1092 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1093 mod->name, name);
1094 return;
1095 }
1096
1097 data = sym_get_data(elf, label); /* license */
1098 if (!strcmp(data, "GPL")) {
1099 is_gpl = true;
1100 } else if (!strcmp(data, "")) {
1101 is_gpl = false;
1102 } else {
1103 error("%s: unknown license '%s' was specified for '%s'\n",
1104 mod->name, data, name);
1105 return;
1106 }
1107
1108 data += strlen(data) + 1; /* namespace */
1109 s = sym_add_exported(name, mod, is_gpl, data);
1110
1111 /*
1112 * We need to be aware whether we are exporting a function or
1113 * a data on some architectures.
1114 */
1115 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1116
1117 /*
1118 * For parisc64, symbols prefixed $$ from the library have the symbol type
1119 * STT_LOPROC. They should be handled as functions too.
1120 */
1121 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1122 elf->hdr->e_machine == EM_PARISC &&
1123 ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1124 s->is_func = true;
1125
1126 if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1127 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1128 mod->name, name);
1129 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1130 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1131 mod->name, name);
1132 }
1133
check_section_mismatch(struct module * mod,struct elf_info * elf,Elf_Sym * sym,unsigned int fsecndx,const char * fromsec,Elf_Addr faddr,Elf_Addr taddr)1134 static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1135 Elf_Sym *sym,
1136 unsigned int fsecndx, const char *fromsec,
1137 Elf_Addr faddr, Elf_Addr taddr)
1138 {
1139 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1140 const struct sectioncheck *mismatch;
1141
1142 if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1143 check_export_symbol(mod, elf, faddr, tosec, sym);
1144 return;
1145 }
1146
1147 mismatch = section_mismatch(fromsec, tosec);
1148 if (!mismatch)
1149 return;
1150
1151 default_mismatch_handler(mod->name, elf, mismatch, sym,
1152 fsecndx, fromsec, faddr,
1153 tosec, taddr);
1154 }
1155
addend_386_rel(uint32_t * location,unsigned int r_type)1156 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1157 {
1158 switch (r_type) {
1159 case R_386_32:
1160 return get_unaligned_native(location);
1161 case R_386_PC32:
1162 return get_unaligned_native(location) + 4;
1163 }
1164
1165 return (Elf_Addr)(-1);
1166 }
1167
sign_extend32(int32_t value,int index)1168 static int32_t sign_extend32(int32_t value, int index)
1169 {
1170 uint8_t shift = 31 - index;
1171
1172 return (int32_t)(value << shift) >> shift;
1173 }
1174
addend_arm_rel(void * loc,Elf_Sym * sym,unsigned int r_type)1175 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1176 {
1177 uint32_t inst, upper, lower, sign, j1, j2;
1178 int32_t offset;
1179
1180 switch (r_type) {
1181 case R_ARM_ABS32:
1182 case R_ARM_REL32:
1183 inst = get_unaligned_native((uint32_t *)loc);
1184 return inst + sym->st_value;
1185 case R_ARM_MOVW_ABS_NC:
1186 case R_ARM_MOVT_ABS:
1187 inst = get_unaligned_native((uint32_t *)loc);
1188 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1189 15);
1190 return offset + sym->st_value;
1191 case R_ARM_PC24:
1192 case R_ARM_CALL:
1193 case R_ARM_JUMP24:
1194 inst = get_unaligned_native((uint32_t *)loc);
1195 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1196 return offset + sym->st_value + 8;
1197 case R_ARM_THM_MOVW_ABS_NC:
1198 case R_ARM_THM_MOVT_ABS:
1199 upper = get_unaligned_native((uint16_t *)loc);
1200 lower = get_unaligned_native((uint16_t *)loc + 1);
1201 offset = sign_extend32(((upper & 0x000f) << 12) |
1202 ((upper & 0x0400) << 1) |
1203 ((lower & 0x7000) >> 4) |
1204 (lower & 0x00ff),
1205 15);
1206 return offset + sym->st_value;
1207 case R_ARM_THM_JUMP19:
1208 /*
1209 * Encoding T3:
1210 * S = upper[10]
1211 * imm6 = upper[5:0]
1212 * J1 = lower[13]
1213 * J2 = lower[11]
1214 * imm11 = lower[10:0]
1215 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1216 */
1217 upper = get_unaligned_native((uint16_t *)loc);
1218 lower = get_unaligned_native((uint16_t *)loc + 1);
1219
1220 sign = (upper >> 10) & 1;
1221 j1 = (lower >> 13) & 1;
1222 j2 = (lower >> 11) & 1;
1223 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1224 ((upper & 0x03f) << 12) |
1225 ((lower & 0x07ff) << 1),
1226 20);
1227 return offset + sym->st_value + 4;
1228 case R_ARM_THM_PC22:
1229 case R_ARM_THM_JUMP24:
1230 /*
1231 * Encoding T4:
1232 * S = upper[10]
1233 * imm10 = upper[9:0]
1234 * J1 = lower[13]
1235 * J2 = lower[11]
1236 * imm11 = lower[10:0]
1237 * I1 = NOT(J1 XOR S)
1238 * I2 = NOT(J2 XOR S)
1239 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1240 */
1241 upper = get_unaligned_native((uint16_t *)loc);
1242 lower = get_unaligned_native((uint16_t *)loc + 1);
1243
1244 sign = (upper >> 10) & 1;
1245 j1 = (lower >> 13) & 1;
1246 j2 = (lower >> 11) & 1;
1247 offset = sign_extend32((sign << 24) |
1248 ((~(j1 ^ sign) & 1) << 23) |
1249 ((~(j2 ^ sign) & 1) << 22) |
1250 ((upper & 0x03ff) << 12) |
1251 ((lower & 0x07ff) << 1),
1252 24);
1253 return offset + sym->st_value + 4;
1254 }
1255
1256 return (Elf_Addr)(-1);
1257 }
1258
addend_mips_rel(uint32_t * location,unsigned int r_type)1259 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1260 {
1261 uint32_t inst;
1262
1263 inst = get_unaligned_native(location);
1264 switch (r_type) {
1265 case R_MIPS_LO16:
1266 return inst & 0xffff;
1267 case R_MIPS_26:
1268 return (inst & 0x03ffffff) << 2;
1269 case R_MIPS_32:
1270 return inst;
1271 }
1272 return (Elf_Addr)(-1);
1273 }
1274
1275 #ifndef EM_RISCV
1276 #define EM_RISCV 243
1277 #endif
1278
1279 #ifndef R_RISCV_SUB32
1280 #define R_RISCV_SUB32 39
1281 #endif
1282
1283 #ifndef EM_LOONGARCH
1284 #define EM_LOONGARCH 258
1285 #endif
1286
1287 #ifndef R_LARCH_SUB32
1288 #define R_LARCH_SUB32 55
1289 #endif
1290
1291 #ifndef R_LARCH_RELAX
1292 #define R_LARCH_RELAX 100
1293 #endif
1294
1295 #ifndef R_LARCH_ALIGN
1296 #define R_LARCH_ALIGN 102
1297 #endif
1298
get_rel_type_and_sym(struct elf_info * elf,uint64_t r_info,unsigned int * r_type,unsigned int * r_sym)1299 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1300 unsigned int *r_type, unsigned int *r_sym)
1301 {
1302 typedef struct {
1303 Elf64_Word r_sym; /* Symbol index */
1304 unsigned char r_ssym; /* Special symbol for 2nd relocation */
1305 unsigned char r_type3; /* 3rd relocation type */
1306 unsigned char r_type2; /* 2nd relocation type */
1307 unsigned char r_type; /* 1st relocation type */
1308 } Elf64_Mips_R_Info;
1309
1310 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1311
1312 if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1313 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1314
1315 *r_type = mips64_r_info->r_type;
1316 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1317 return;
1318 }
1319
1320 if (is_64bit)
1321 r_info = TO_NATIVE((Elf64_Xword)r_info);
1322 else
1323 r_info = TO_NATIVE((Elf32_Word)r_info);
1324
1325 *r_type = ELF_R_TYPE(r_info);
1326 *r_sym = ELF_R_SYM(r_info);
1327 }
1328
section_rela(struct module * mod,struct elf_info * elf,unsigned int fsecndx,const char * fromsec,const Elf_Rela * start,const Elf_Rela * stop)1329 static void section_rela(struct module *mod, struct elf_info *elf,
1330 unsigned int fsecndx, const char *fromsec,
1331 const Elf_Rela *start, const Elf_Rela *stop)
1332 {
1333 const Elf_Rela *rela;
1334
1335 for (rela = start; rela < stop; rela++) {
1336 Elf_Sym *tsym;
1337 Elf_Addr taddr, r_offset;
1338 unsigned int r_type, r_sym;
1339
1340 r_offset = TO_NATIVE(rela->r_offset);
1341 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1342
1343 tsym = elf->symtab_start + r_sym;
1344 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1345
1346 switch (elf->hdr->e_machine) {
1347 case EM_RISCV:
1348 if (!strcmp("__ex_table", fromsec) &&
1349 r_type == R_RISCV_SUB32)
1350 continue;
1351 break;
1352 case EM_LOONGARCH:
1353 switch (r_type) {
1354 case R_LARCH_SUB32:
1355 if (!strcmp("__ex_table", fromsec))
1356 continue;
1357 break;
1358 case R_LARCH_RELAX:
1359 case R_LARCH_ALIGN:
1360 /* These relocs do not refer to symbols */
1361 continue;
1362 }
1363 break;
1364 }
1365
1366 check_section_mismatch(mod, elf, tsym,
1367 fsecndx, fromsec, r_offset, taddr);
1368 }
1369 }
1370
section_rel(struct module * mod,struct elf_info * elf,unsigned int fsecndx,const char * fromsec,const Elf_Rel * start,const Elf_Rel * stop)1371 static void section_rel(struct module *mod, struct elf_info *elf,
1372 unsigned int fsecndx, const char *fromsec,
1373 const Elf_Rel *start, const Elf_Rel *stop)
1374 {
1375 const Elf_Rel *rel;
1376
1377 for (rel = start; rel < stop; rel++) {
1378 Elf_Sym *tsym;
1379 Elf_Addr taddr, r_offset;
1380 unsigned int r_type, r_sym;
1381 void *loc;
1382
1383 r_offset = TO_NATIVE(rel->r_offset);
1384 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1385
1386 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1387 tsym = elf->symtab_start + r_sym;
1388
1389 switch (elf->hdr->e_machine) {
1390 case EM_386:
1391 taddr = addend_386_rel(loc, r_type);
1392 break;
1393 case EM_ARM:
1394 taddr = addend_arm_rel(loc, tsym, r_type);
1395 break;
1396 case EM_MIPS:
1397 taddr = addend_mips_rel(loc, r_type);
1398 break;
1399 default:
1400 fatal("Please add code to calculate addend for this architecture\n");
1401 }
1402
1403 check_section_mismatch(mod, elf, tsym,
1404 fsecndx, fromsec, r_offset, taddr);
1405 }
1406 }
1407
1408 /**
1409 * A module includes a number of sections that are discarded
1410 * either when loaded or when used as built-in.
1411 * For loaded modules all functions marked __init and all data
1412 * marked __initdata will be discarded when the module has been initialized.
1413 * Likewise for modules used built-in the sections marked __exit
1414 * are discarded because __exit marked function are supposed to be called
1415 * only when a module is unloaded which never happens for built-in modules.
1416 * The check_sec_ref() function traverses all relocation records
1417 * to find all references to a section that reference a section that will
1418 * be discarded and warns about it.
1419 **/
check_sec_ref(struct module * mod,struct elf_info * elf)1420 static void check_sec_ref(struct module *mod, struct elf_info *elf)
1421 {
1422 int i;
1423
1424 /* Walk through all sections */
1425 for (i = 0; i < elf->num_sections; i++) {
1426 Elf_Shdr *sechdr = &elf->sechdrs[i];
1427
1428 check_section(mod->name, elf, sechdr);
1429 /* We want to process only relocation sections and not .init */
1430 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1431 /* section to which the relocation applies */
1432 unsigned int secndx = sechdr->sh_info;
1433 const char *secname = sec_name(elf, secndx);
1434 const void *start, *stop;
1435
1436 /* If the section is known good, skip it */
1437 if (match(secname, section_white_list))
1438 continue;
1439
1440 start = sym_get_data_by_offset(elf, i, 0);
1441 stop = start + sechdr->sh_size;
1442
1443 if (sechdr->sh_type == SHT_RELA)
1444 section_rela(mod, elf, secndx, secname,
1445 start, stop);
1446 else
1447 section_rel(mod, elf, secndx, secname,
1448 start, stop);
1449 }
1450 }
1451 }
1452
remove_dot(char * s)1453 static char *remove_dot(char *s)
1454 {
1455 size_t n = strcspn(s, ".");
1456
1457 if (n && s[n]) {
1458 size_t m = strspn(s + n + 1, "0123456789");
1459 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1460 s[n] = 0;
1461 }
1462 return s;
1463 }
1464
1465 /*
1466 * The CRCs are recorded in .*.cmd files in the form of:
1467 * #SYMVER <name> <crc>
1468 */
extract_crcs_for_object(const char * object,struct module * mod)1469 static void extract_crcs_for_object(const char *object, struct module *mod)
1470 {
1471 char cmd_file[PATH_MAX];
1472 char *buf, *p;
1473 const char *base;
1474 int dirlen, ret;
1475
1476 base = get_basename(object);
1477 dirlen = base - object;
1478
1479 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1480 dirlen, object, base);
1481 if (ret >= sizeof(cmd_file)) {
1482 error("%s: too long path was truncated\n", cmd_file);
1483 return;
1484 }
1485
1486 buf = read_text_file(cmd_file);
1487 p = buf;
1488
1489 while ((p = strstr(p, "\n#SYMVER "))) {
1490 char *name;
1491 size_t namelen;
1492 unsigned int crc;
1493 struct symbol *sym;
1494
1495 name = p + strlen("\n#SYMVER ");
1496
1497 p = strchr(name, ' ');
1498 if (!p)
1499 break;
1500
1501 namelen = p - name;
1502 p++;
1503
1504 if (!isdigit(*p))
1505 continue; /* skip this line */
1506
1507 crc = strtoul(p, &p, 0);
1508 if (*p != '\n')
1509 continue; /* skip this line */
1510
1511 name[namelen] = '\0';
1512
1513 /*
1514 * sym_find_with_module() may return NULL here.
1515 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1516 * Since commit e1327a127703, genksyms calculates CRCs of all
1517 * symbols, including trimmed ones. Ignore orphan CRCs.
1518 */
1519 sym = sym_find_with_module(name, mod);
1520 if (sym)
1521 sym_set_crc(sym, crc);
1522 }
1523
1524 free(buf);
1525 }
1526
1527 /*
1528 * The symbol versions (CRC) are recorded in the .*.cmd files.
1529 * Parse them to retrieve CRCs for the current module.
1530 */
mod_set_crcs(struct module * mod)1531 static void mod_set_crcs(struct module *mod)
1532 {
1533 char objlist[PATH_MAX];
1534 char *buf, *p, *obj;
1535 int ret;
1536
1537 if (mod->is_vmlinux) {
1538 strcpy(objlist, ".vmlinux.objs");
1539 } else {
1540 /* objects for a module are listed in the *.mod file. */
1541 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1542 if (ret >= sizeof(objlist)) {
1543 error("%s: too long path was truncated\n", objlist);
1544 return;
1545 }
1546 }
1547
1548 buf = read_text_file(objlist);
1549 p = buf;
1550
1551 while ((obj = strsep(&p, "\n")) && obj[0])
1552 extract_crcs_for_object(obj, mod);
1553
1554 free(buf);
1555 }
1556
read_symbols(const char * modname)1557 static void read_symbols(const char *modname)
1558 {
1559 const char *symname;
1560 char *version;
1561 char *license;
1562 char *namespace;
1563 struct module *mod;
1564 struct elf_info info = { };
1565 Elf_Sym *sym;
1566
1567 if (!parse_elf(&info, modname))
1568 return;
1569
1570 if (!strends(modname, ".o")) {
1571 error("%s: filename must be suffixed with .o\n", modname);
1572 return;
1573 }
1574
1575 /* strip trailing .o */
1576 mod = new_module(modname, strlen(modname) - strlen(".o"));
1577
1578 /* save .no_trim_symbol section for later use */
1579 if (info.no_trim_symbol_len) {
1580 mod->no_trim_symbol = xmalloc(info.no_trim_symbol_len);
1581 memcpy(mod->no_trim_symbol, info.no_trim_symbol,
1582 info.no_trim_symbol_len);
1583 mod->no_trim_symbol_len = info.no_trim_symbol_len;
1584 }
1585
1586 if (!mod->is_vmlinux) {
1587 license = get_modinfo(&info, "license");
1588 if (!license)
1589 error("missing MODULE_LICENSE() in %s\n", modname);
1590 while (license) {
1591 if (!license_is_gpl_compatible(license)) {
1592 mod->is_gpl_compatible = false;
1593 break;
1594 }
1595 license = get_next_modinfo(&info, "license", license);
1596 }
1597
1598 namespace = get_modinfo(&info, "import_ns");
1599 while (namespace) {
1600 add_namespace(&mod->imported_namespaces, namespace);
1601 namespace = get_next_modinfo(&info, "import_ns",
1602 namespace);
1603 }
1604
1605 if (!get_modinfo(&info, "description"))
1606 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1607 }
1608
1609 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1610 symname = remove_dot(info.strtab + sym->st_name);
1611
1612 handle_symbol(mod, &info, sym, symname);
1613 handle_moddevtable(mod, &info, sym, symname);
1614 }
1615
1616 check_sec_ref(mod, &info);
1617
1618 if (!mod->is_vmlinux) {
1619 version = get_modinfo(&info, "version");
1620 if (version || all_versions)
1621 get_src_version(mod->name, mod->srcversion,
1622 sizeof(mod->srcversion) - 1);
1623 }
1624
1625 parse_elf_finish(&info);
1626
1627 if (modversions) {
1628 /*
1629 * Our trick to get versioning for module struct etc. - it's
1630 * never passed as an argument to an exported function, so
1631 * the automatic versioning doesn't pick it up, but it's really
1632 * important anyhow.
1633 */
1634 sym_add_unresolved("module_layout", mod, false);
1635
1636 mod_set_crcs(mod);
1637 }
1638 }
1639
read_symbols_from_files(const char * filename)1640 static void read_symbols_from_files(const char *filename)
1641 {
1642 FILE *in = stdin;
1643 char fname[PATH_MAX];
1644
1645 in = fopen(filename, "r");
1646 if (!in)
1647 fatal("Can't open filenames file %s: %m", filename);
1648
1649 while (fgets(fname, PATH_MAX, in) != NULL) {
1650 if (strends(fname, "\n"))
1651 fname[strlen(fname)-1] = '\0';
1652 read_symbols(fname);
1653 }
1654
1655 fclose(in);
1656 }
1657
1658 #define SZ 500
1659
1660 /* We first write the generated file into memory using the
1661 * following helper, then compare to the file on disk and
1662 * only update the later if anything changed */
1663
buf_printf(struct buffer * buf,const char * fmt,...)1664 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1665 const char *fmt, ...)
1666 {
1667 char tmp[SZ];
1668 int len;
1669 va_list ap;
1670
1671 va_start(ap, fmt);
1672 len = vsnprintf(tmp, SZ, fmt, ap);
1673 buf_write(buf, tmp, len);
1674 va_end(ap);
1675 }
1676
buf_write(struct buffer * buf,const char * s,int len)1677 void buf_write(struct buffer *buf, const char *s, int len)
1678 {
1679 if (buf->size - buf->pos < len) {
1680 buf->size += len + SZ;
1681 buf->p = xrealloc(buf->p, buf->size);
1682 }
1683 strncpy(buf->p + buf->pos, s, len);
1684 buf->pos += len;
1685 }
1686
check_exports(struct module * mod)1687 static void check_exports(struct module *mod)
1688 {
1689 struct symbol *s, *exp;
1690
1691 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1692 const char *basename;
1693 exp = find_symbol(s->name);
1694 if (!exp) {
1695 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1696 modpost_log(!warn_unresolved,
1697 "\"%s\" [%s.ko] undefined!\n",
1698 s->name, mod->name);
1699 continue;
1700 }
1701 if (exp->module == mod) {
1702 error("\"%s\" [%s.ko] was exported without definition\n",
1703 s->name, mod->name);
1704 continue;
1705 }
1706
1707 exp->used = true;
1708 s->module = exp->module;
1709 s->crc_valid = exp->crc_valid;
1710 s->crc = exp->crc;
1711
1712 basename = get_basename(mod->name);
1713
1714 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1715 modpost_log(!allow_missing_ns_imports,
1716 "module %s uses symbol %s from namespace %s, but does not import it.\n",
1717 basename, exp->name, exp->namespace);
1718 add_namespace(&mod->missing_namespaces, exp->namespace);
1719 }
1720
1721 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1722 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1723 basename, exp->name);
1724 }
1725 }
1726
handle_white_list_exports(const char * white_list)1727 static void handle_white_list_exports(const char *white_list)
1728 {
1729 char *buf, *p, *name;
1730
1731 buf = read_text_file(white_list);
1732 p = buf;
1733
1734 while ((name = strsep(&p, "\n"))) {
1735 struct symbol *sym = find_symbol(name);
1736
1737 if (sym)
1738 sym->used = true;
1739 }
1740
1741 free(buf);
1742 }
1743
1744 /*
1745 * Keep symbols recorded in the .no_trim_symbol section. This is necessary to
1746 * prevent CONFIG_TRIM_UNUSED_KSYMS from dropping EXPORT_SYMBOL because
1747 * symbol_get() relies on the symbol being present in the ksymtab for lookups.
1748 */
keep_no_trim_symbols(struct module * mod)1749 static void keep_no_trim_symbols(struct module *mod)
1750 {
1751 unsigned long size = mod->no_trim_symbol_len;
1752
1753 for (char *s = mod->no_trim_symbol; s; s = next_string(s , &size)) {
1754 struct symbol *sym;
1755
1756 /*
1757 * If find_symbol() returns NULL, this symbol is not provided
1758 * by any module, and symbol_get() will fail.
1759 */
1760 sym = find_symbol(s);
1761 if (sym)
1762 sym->used = true;
1763 }
1764 }
1765
check_modname_len(struct module * mod)1766 static void check_modname_len(struct module *mod)
1767 {
1768 const char *mod_name;
1769
1770 mod_name = get_basename(mod->name);
1771
1772 if (strlen(mod_name) >= MODULE_NAME_LEN)
1773 error("module name is too long [%s.ko]\n", mod->name);
1774 }
1775
1776 /**
1777 * Header for the generated file
1778 **/
add_header(struct buffer * b,struct module * mod)1779 static void add_header(struct buffer *b, struct module *mod)
1780 {
1781 buf_printf(b, "#include <linux/module.h>\n");
1782 buf_printf(b, "#include <linux/export-internal.h>\n");
1783 buf_printf(b, "#include <linux/compiler.h>\n");
1784 buf_printf(b, "\n");
1785 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1786 buf_printf(b, "\n");
1787 buf_printf(b, "__visible struct module __this_module\n");
1788 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1789 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1790 if (mod->has_init)
1791 buf_printf(b, "\t.init = init_module,\n");
1792 if (mod->has_cleanup)
1793 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1794 "\t.exit = cleanup_module,\n"
1795 "#endif\n");
1796 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1797 buf_printf(b, "};\n");
1798
1799 if (!external_module)
1800 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1801
1802 if (strstarts(mod->name, "drivers/staging"))
1803 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1804
1805 if (strstarts(mod->name, "tools/testing"))
1806 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1807 }
1808
add_exported_symbols(struct buffer * buf,struct module * mod)1809 static void add_exported_symbols(struct buffer *buf, struct module *mod)
1810 {
1811 struct symbol *sym;
1812
1813 /* generate struct for exported symbols */
1814 buf_printf(buf, "\n");
1815 list_for_each_entry(sym, &mod->exported_symbols, list) {
1816 if (trim_unused_exports && !sym->used)
1817 continue;
1818
1819 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1820 sym->is_func ? "FUNC" : "DATA", sym->name,
1821 sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1822 }
1823
1824 if (!modversions)
1825 return;
1826
1827 /* record CRCs for exported symbols */
1828 buf_printf(buf, "\n");
1829 list_for_each_entry(sym, &mod->exported_symbols, list) {
1830 if (trim_unused_exports && !sym->used)
1831 continue;
1832
1833 if (!sym->crc_valid)
1834 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1835 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1836 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1837 sym->name);
1838
1839 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1840 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1841 }
1842 }
1843
1844 /**
1845 * Record CRCs for unresolved symbols, supporting long names
1846 */
add_extended_versions(struct buffer * b,struct module * mod)1847 static void add_extended_versions(struct buffer *b, struct module *mod)
1848 {
1849 struct symbol *s;
1850
1851 if (!extended_modversions)
1852 return;
1853
1854 buf_printf(b, "\n");
1855 buf_printf(b, "static const u32 ____version_ext_crcs[]\n");
1856 buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n");
1857 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1858 if (!s->module)
1859 continue;
1860 if (!s->crc_valid) {
1861 warn("\"%s\" [%s.ko] has no CRC!\n",
1862 s->name, mod->name);
1863 continue;
1864 }
1865 buf_printf(b, "\t0x%08x,\n", s->crc);
1866 }
1867 buf_printf(b, "};\n");
1868
1869 buf_printf(b, "static const char ____version_ext_names[]\n");
1870 buf_printf(b, "__used __section(\"__version_ext_names\") =\n");
1871 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1872 if (!s->module)
1873 continue;
1874 if (!s->crc_valid)
1875 /*
1876 * We already warned on this when producing the crc
1877 * table.
1878 * We need to skip its name too, as the indexes in
1879 * both tables need to align.
1880 */
1881 continue;
1882 buf_printf(b, "\t\"%s\\0\"\n", s->name);
1883 }
1884 buf_printf(b, ";\n");
1885 }
1886
1887 /**
1888 * Record CRCs for unresolved symbols
1889 **/
add_versions(struct buffer * b,struct module * mod)1890 static void add_versions(struct buffer *b, struct module *mod)
1891 {
1892 struct symbol *s;
1893
1894 if (!basic_modversions)
1895 return;
1896
1897 buf_printf(b, "\n");
1898 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1899 buf_printf(b, "__used __section(\"__versions\") = {\n");
1900
1901 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1902 if (!s->module)
1903 continue;
1904 if (!s->crc_valid) {
1905 warn("\"%s\" [%s.ko] has no CRC!\n",
1906 s->name, mod->name);
1907 continue;
1908 }
1909 if (strlen(s->name) >= MODULE_NAME_LEN) {
1910 if (extended_modversions) {
1911 /* this symbol will only be in the extended info */
1912 continue;
1913 } else {
1914 error("too long symbol \"%s\" [%s.ko]\n",
1915 s->name, mod->name);
1916 break;
1917 }
1918 }
1919 buf_printf(b, "\t{ 0x%08x, \"%s\" },\n",
1920 s->crc, s->name);
1921 }
1922
1923 buf_printf(b, "};\n");
1924 }
1925
add_depends(struct buffer * b,struct module * mod)1926 static void add_depends(struct buffer *b, struct module *mod)
1927 {
1928 struct symbol *s;
1929 int first = 1;
1930
1931 /* Clear ->seen flag of modules that own symbols needed by this. */
1932 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1933 if (s->module)
1934 s->module->seen = s->module->is_vmlinux;
1935 }
1936
1937 buf_printf(b, "\n");
1938 buf_printf(b, "MODULE_INFO(depends, \"");
1939 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1940 const char *p;
1941 if (!s->module)
1942 continue;
1943
1944 if (s->module->seen)
1945 continue;
1946
1947 s->module->seen = true;
1948 p = get_basename(s->module->name);
1949 buf_printf(b, "%s%s", first ? "" : ",", p);
1950 first = 0;
1951 }
1952 buf_printf(b, "\");\n");
1953 }
1954
add_srcversion(struct buffer * b,struct module * mod)1955 static void add_srcversion(struct buffer *b, struct module *mod)
1956 {
1957 if (mod->srcversion[0]) {
1958 buf_printf(b, "\n");
1959 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1960 mod->srcversion);
1961 }
1962 }
1963
write_buf(struct buffer * b,const char * fname)1964 static void write_buf(struct buffer *b, const char *fname)
1965 {
1966 FILE *file;
1967
1968 if (error_occurred)
1969 return;
1970
1971 file = fopen(fname, "w");
1972 if (!file) {
1973 perror(fname);
1974 exit(1);
1975 }
1976 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1977 perror(fname);
1978 exit(1);
1979 }
1980 if (fclose(file) != 0) {
1981 perror(fname);
1982 exit(1);
1983 }
1984 }
1985
write_if_changed(struct buffer * b,const char * fname)1986 static void write_if_changed(struct buffer *b, const char *fname)
1987 {
1988 char *tmp;
1989 FILE *file;
1990 struct stat st;
1991
1992 file = fopen(fname, "r");
1993 if (!file)
1994 goto write;
1995
1996 if (fstat(fileno(file), &st) < 0)
1997 goto close_write;
1998
1999 if (st.st_size != b->pos)
2000 goto close_write;
2001
2002 tmp = xmalloc(b->pos);
2003 if (fread(tmp, 1, b->pos, file) != b->pos)
2004 goto free_write;
2005
2006 if (memcmp(tmp, b->p, b->pos) != 0)
2007 goto free_write;
2008
2009 free(tmp);
2010 fclose(file);
2011 return;
2012
2013 free_write:
2014 free(tmp);
2015 close_write:
2016 fclose(file);
2017 write:
2018 write_buf(b, fname);
2019 }
2020
write_vmlinux_export_c_file(struct module * mod)2021 static void write_vmlinux_export_c_file(struct module *mod)
2022 {
2023 struct buffer buf = { };
2024
2025 buf_printf(&buf,
2026 "#include <linux/export-internal.h>\n");
2027
2028 add_exported_symbols(&buf, mod);
2029 write_if_changed(&buf, ".vmlinux.export.c");
2030 free(buf.p);
2031 }
2032
2033 /* do sanity checks, and generate *.mod.c file */
write_mod_c_file(struct module * mod)2034 static void write_mod_c_file(struct module *mod)
2035 {
2036 struct buffer buf = { };
2037 struct module_alias *alias, *next;
2038 char fname[PATH_MAX];
2039 int ret;
2040
2041 add_header(&buf, mod);
2042 add_exported_symbols(&buf, mod);
2043 add_versions(&buf, mod);
2044 add_extended_versions(&buf, mod);
2045 add_depends(&buf, mod);
2046
2047 buf_printf(&buf, "\n");
2048 list_for_each_entry_safe(alias, next, &mod->aliases, node) {
2049 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str);
2050 list_del(&alias->node);
2051 free(alias);
2052 }
2053
2054 add_srcversion(&buf, mod);
2055
2056 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2057 if (ret >= sizeof(fname)) {
2058 error("%s: too long path was truncated\n", fname);
2059 goto free;
2060 }
2061
2062 write_if_changed(&buf, fname);
2063
2064 free:
2065 free(buf.p);
2066 }
2067
2068 /* parse Module.symvers file. line format:
2069 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2070 **/
read_dump(const char * fname)2071 static void read_dump(const char *fname)
2072 {
2073 char *buf, *pos, *line;
2074
2075 buf = read_text_file(fname);
2076 if (!buf)
2077 /* No symbol versions, silently ignore */
2078 return;
2079
2080 pos = buf;
2081
2082 while ((line = get_line(&pos))) {
2083 char *symname, *namespace, *modname, *d, *export;
2084 unsigned int crc;
2085 struct module *mod;
2086 struct symbol *s;
2087 bool gpl_only;
2088
2089 if (!(symname = strchr(line, '\t')))
2090 goto fail;
2091 *symname++ = '\0';
2092 if (!(modname = strchr(symname, '\t')))
2093 goto fail;
2094 *modname++ = '\0';
2095 if (!(export = strchr(modname, '\t')))
2096 goto fail;
2097 *export++ = '\0';
2098 if (!(namespace = strchr(export, '\t')))
2099 goto fail;
2100 *namespace++ = '\0';
2101
2102 crc = strtoul(line, &d, 16);
2103 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2104 goto fail;
2105
2106 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2107 gpl_only = true;
2108 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2109 gpl_only = false;
2110 } else {
2111 error("%s: unknown license %s. skip", symname, export);
2112 continue;
2113 }
2114
2115 mod = find_module(fname, modname);
2116 if (!mod) {
2117 mod = new_module(modname, strlen(modname));
2118 mod->dump_file = fname;
2119 }
2120 s = sym_add_exported(symname, mod, gpl_only, namespace);
2121 sym_set_crc(s, crc);
2122 }
2123 free(buf);
2124 return;
2125 fail:
2126 free(buf);
2127 fatal("parse error in symbol dump file\n");
2128 }
2129
write_dump(const char * fname)2130 static void write_dump(const char *fname)
2131 {
2132 struct buffer buf = { };
2133 struct module *mod;
2134 struct symbol *sym;
2135
2136 list_for_each_entry(mod, &modules, list) {
2137 if (mod->dump_file)
2138 continue;
2139 list_for_each_entry(sym, &mod->exported_symbols, list) {
2140 if (trim_unused_exports && !sym->used)
2141 continue;
2142
2143 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2144 sym->crc, sym->name, mod->name,
2145 sym->is_gpl_only ? "_GPL" : "",
2146 sym->namespace);
2147 }
2148 }
2149 write_buf(&buf, fname);
2150 free(buf.p);
2151 }
2152
write_namespace_deps_files(const char * fname)2153 static void write_namespace_deps_files(const char *fname)
2154 {
2155 struct module *mod;
2156 struct namespace_list *ns;
2157 struct buffer ns_deps_buf = {};
2158
2159 list_for_each_entry(mod, &modules, list) {
2160
2161 if (mod->dump_file || list_empty(&mod->missing_namespaces))
2162 continue;
2163
2164 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2165
2166 list_for_each_entry(ns, &mod->missing_namespaces, list)
2167 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2168
2169 buf_printf(&ns_deps_buf, "\n");
2170 }
2171
2172 write_if_changed(&ns_deps_buf, fname);
2173 free(ns_deps_buf.p);
2174 }
2175
2176 struct dump_list {
2177 struct list_head list;
2178 const char *file;
2179 };
2180
check_host_endian(void)2181 static void check_host_endian(void)
2182 {
2183 static const union {
2184 short s;
2185 char c[2];
2186 } endian_test = { .c = {0x01, 0x02} };
2187
2188 switch (endian_test.s) {
2189 case 0x0102:
2190 host_is_big_endian = true;
2191 break;
2192 case 0x0201:
2193 host_is_big_endian = false;
2194 break;
2195 default:
2196 fatal("Unknown host endian\n");
2197 }
2198 }
2199
main(int argc,char ** argv)2200 int main(int argc, char **argv)
2201 {
2202 struct module *mod;
2203 char *missing_namespace_deps = NULL;
2204 char *unused_exports_white_list = NULL;
2205 char *dump_write = NULL, *files_source = NULL;
2206 int opt;
2207 LIST_HEAD(dump_lists);
2208 struct dump_list *dl, *dl2;
2209
2210 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) {
2211 switch (opt) {
2212 case 'e':
2213 external_module = true;
2214 break;
2215 case 'i':
2216 dl = xmalloc(sizeof(*dl));
2217 dl->file = optarg;
2218 list_add_tail(&dl->list, &dump_lists);
2219 break;
2220 case 'M':
2221 module_enabled = true;
2222 break;
2223 case 'm':
2224 modversions = true;
2225 break;
2226 case 'n':
2227 ignore_missing_files = true;
2228 break;
2229 case 'o':
2230 dump_write = optarg;
2231 break;
2232 case 'a':
2233 all_versions = true;
2234 break;
2235 case 'T':
2236 files_source = optarg;
2237 break;
2238 case 't':
2239 trim_unused_exports = true;
2240 break;
2241 case 'u':
2242 unused_exports_white_list = optarg;
2243 break;
2244 case 'W':
2245 extra_warn = true;
2246 break;
2247 case 'w':
2248 warn_unresolved = true;
2249 break;
2250 case 'E':
2251 sec_mismatch_warn_only = false;
2252 break;
2253 case 'N':
2254 allow_missing_ns_imports = true;
2255 break;
2256 case 'd':
2257 missing_namespace_deps = optarg;
2258 break;
2259 case 'b':
2260 basic_modversions = true;
2261 break;
2262 case 'x':
2263 extended_modversions = true;
2264 break;
2265 default:
2266 exit(1);
2267 }
2268 }
2269
2270 check_host_endian();
2271
2272 list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2273 read_dump(dl->file);
2274 list_del(&dl->list);
2275 free(dl);
2276 }
2277
2278 while (optind < argc)
2279 read_symbols(argv[optind++]);
2280
2281 if (files_source)
2282 read_symbols_from_files(files_source);
2283
2284 list_for_each_entry(mod, &modules, list) {
2285 keep_no_trim_symbols(mod);
2286
2287 if (mod->dump_file || mod->is_vmlinux)
2288 continue;
2289
2290 check_modname_len(mod);
2291 check_exports(mod);
2292 }
2293
2294 if (unused_exports_white_list)
2295 handle_white_list_exports(unused_exports_white_list);
2296
2297 list_for_each_entry(mod, &modules, list) {
2298 if (mod->dump_file)
2299 continue;
2300
2301 if (mod->is_vmlinux)
2302 write_vmlinux_export_c_file(mod);
2303 else
2304 write_mod_c_file(mod);
2305 }
2306
2307 if (missing_namespace_deps)
2308 write_namespace_deps_files(missing_namespace_deps);
2309
2310 if (dump_write)
2311 write_dump(dump_write);
2312 if (sec_mismatch_count && !sec_mismatch_warn_only)
2313 error("Section mismatches detected.\n"
2314 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2315
2316 if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2317 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2318 nr_unresolved - MAX_UNRESOLVED_REPORTS);
2319
2320 return error_occurred ? 1 : 0;
2321 }
2322