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