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 #include "modpost.h"
24 #include "../../include/linux/license.h"
25
26 static bool module_enabled;
27 /* Are we using CONFIG_MODVERSIONS? */
28 static bool modversions;
29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
30 static bool all_versions;
31 /* If we are modposting external module set to 1 */
32 static bool external_module;
33 /* Only warn about unresolved symbols */
34 static bool warn_unresolved;
35
36 static int sec_mismatch_count;
37 static bool sec_mismatch_warn_only = true;
38 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
39 static bool trim_unused_exports;
40
41 /* ignore missing files */
42 static bool ignore_missing_files;
43 /* If set to 1, only warn (instead of error) about missing ns imports */
44 static bool allow_missing_ns_imports;
45
46 static bool error_occurred;
47
48 static bool extra_warn;
49
50 /*
51 * Cut off the warnings when there are too many. This typically occurs when
52 * vmlinux is missing. ('make modules' without building vmlinux.)
53 */
54 #define MAX_UNRESOLVED_REPORTS 10
55 static unsigned int nr_unresolved;
56
57 /* In kernel, this size is defined in linux/module.h;
58 * here we use Elf_Addr instead of long for covering cross-compile
59 */
60
61 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
62
modpost_log(enum loglevel loglevel,const char * fmt,...)63 void modpost_log(enum loglevel loglevel, const char *fmt, ...)
64 {
65 va_list arglist;
66
67 switch (loglevel) {
68 case LOG_WARN:
69 fprintf(stderr, "WARNING: ");
70 break;
71 case LOG_ERROR:
72 fprintf(stderr, "ERROR: ");
73 error_occurred = true;
74 break;
75 default: /* invalid loglevel, ignore */
76 break;
77 }
78
79 fprintf(stderr, "modpost: ");
80
81 va_start(arglist, fmt);
82 vfprintf(stderr, fmt, arglist);
83 va_end(arglist);
84 }
85
strends(const char * str,const char * postfix)86 static inline bool strends(const char *str, const char *postfix)
87 {
88 if (strlen(str) < strlen(postfix))
89 return false;
90
91 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
92 }
93
do_nofail(void * ptr,const char * expr)94 void *do_nofail(void *ptr, const char *expr)
95 {
96 if (!ptr)
97 fatal("Memory allocation failure: %s.\n", expr);
98
99 return ptr;
100 }
101
read_text_file(const char * filename)102 char *read_text_file(const char *filename)
103 {
104 struct stat st;
105 size_t nbytes;
106 int fd;
107 char *buf;
108
109 fd = open(filename, O_RDONLY);
110 if (fd < 0) {
111 perror(filename);
112 exit(1);
113 }
114
115 if (fstat(fd, &st) < 0) {
116 perror(filename);
117 exit(1);
118 }
119
120 buf = NOFAIL(malloc(st.st_size + 1));
121
122 nbytes = st.st_size;
123
124 while (nbytes) {
125 ssize_t bytes_read;
126
127 bytes_read = read(fd, buf, nbytes);
128 if (bytes_read < 0) {
129 perror(filename);
130 exit(1);
131 }
132
133 nbytes -= bytes_read;
134 }
135 buf[st.st_size] = '\0';
136
137 close(fd);
138
139 return buf;
140 }
141
get_line(char ** stringp)142 char *get_line(char **stringp)
143 {
144 char *orig = *stringp, *next;
145
146 /* do not return the unwanted extra line at EOF */
147 if (!orig || *orig == '\0')
148 return NULL;
149
150 /* don't use strsep here, it is not available everywhere */
151 next = strchr(orig, '\n');
152 if (next)
153 *next++ = '\0';
154
155 *stringp = next;
156
157 return orig;
158 }
159
160 /* A list of all modules we processed */
161 LIST_HEAD(modules);
162
find_module(const char * modname)163 static struct module *find_module(const char *modname)
164 {
165 struct module *mod;
166
167 list_for_each_entry(mod, &modules, list) {
168 if (strcmp(mod->name, modname) == 0)
169 return mod;
170 }
171 return NULL;
172 }
173
new_module(const char * name,size_t namelen)174 static struct module *new_module(const char *name, size_t namelen)
175 {
176 struct module *mod;
177
178 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
179 memset(mod, 0, sizeof(*mod));
180
181 INIT_LIST_HEAD(&mod->exported_symbols);
182 INIT_LIST_HEAD(&mod->unresolved_symbols);
183 INIT_LIST_HEAD(&mod->missing_namespaces);
184 INIT_LIST_HEAD(&mod->imported_namespaces);
185
186 memcpy(mod->name, name, namelen);
187 mod->name[namelen] = '\0';
188 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
189
190 /*
191 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
192 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
193 * modpost will exit wiht error anyway.
194 */
195 mod->is_gpl_compatible = true;
196
197 list_add_tail(&mod->list, &modules);
198
199 return mod;
200 }
201
202 /* A hash of all exported symbols,
203 * struct symbol is also used for lists of unresolved symbols */
204
205 #define SYMBOL_HASH_SIZE 1024
206
207 struct symbol {
208 struct symbol *next;
209 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
210 struct module *module;
211 char *namespace;
212 unsigned int crc;
213 bool crc_valid;
214 bool weak;
215 bool is_func;
216 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
217 bool used; /* there exists a user of this symbol */
218 char name[];
219 };
220
221 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
222
223 /* This is based on the hash algorithm from gdbm, via tdb */
tdb_hash(const char * name)224 static inline unsigned int tdb_hash(const char *name)
225 {
226 unsigned value; /* Used to compute the hash value. */
227 unsigned i; /* Used to cycle through random values. */
228
229 /* Set the initial value from the key size. */
230 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
231 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
232
233 return (1103515243 * value + 12345);
234 }
235
236 /**
237 * Allocate a new symbols for use in the hash of exported symbols or
238 * the list of unresolved symbols per module
239 **/
alloc_symbol(const char * name)240 static struct symbol *alloc_symbol(const char *name)
241 {
242 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
243
244 memset(s, 0, sizeof(*s));
245 strcpy(s->name, name);
246
247 return s;
248 }
249
250 /* For the hash of exported symbols */
hash_add_symbol(struct symbol * sym)251 static void hash_add_symbol(struct symbol *sym)
252 {
253 unsigned int hash;
254
255 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
256 sym->next = symbolhash[hash];
257 symbolhash[hash] = sym;
258 }
259
sym_add_unresolved(const char * name,struct module * mod,bool weak)260 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
261 {
262 struct symbol *sym;
263
264 sym = alloc_symbol(name);
265 sym->weak = weak;
266
267 list_add_tail(&sym->list, &mod->unresolved_symbols);
268 }
269
sym_find_with_module(const char * name,struct module * mod)270 static struct symbol *sym_find_with_module(const char *name, struct module *mod)
271 {
272 struct symbol *s;
273
274 /* For our purposes, .foo matches foo. PPC64 needs this. */
275 if (name[0] == '.')
276 name++;
277
278 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
279 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
280 return s;
281 }
282 return NULL;
283 }
284
find_symbol(const char * name)285 static struct symbol *find_symbol(const char *name)
286 {
287 return sym_find_with_module(name, NULL);
288 }
289
290 struct namespace_list {
291 struct list_head list;
292 char namespace[];
293 };
294
contains_namespace(struct list_head * head,const char * namespace)295 static bool contains_namespace(struct list_head *head, const char *namespace)
296 {
297 struct namespace_list *list;
298
299 /*
300 * The default namespace is null string "", which is always implicitly
301 * contained.
302 */
303 if (!namespace[0])
304 return true;
305
306 list_for_each_entry(list, head, list) {
307 if (!strcmp(list->namespace, namespace))
308 return true;
309 }
310
311 return false;
312 }
313
add_namespace(struct list_head * head,const char * namespace)314 static void add_namespace(struct list_head *head, const char *namespace)
315 {
316 struct namespace_list *ns_entry;
317
318 if (!contains_namespace(head, namespace)) {
319 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
320 strlen(namespace) + 1));
321 strcpy(ns_entry->namespace, namespace);
322 list_add_tail(&ns_entry->list, head);
323 }
324 }
325
sym_get_data_by_offset(const struct elf_info * info,unsigned int secindex,unsigned long offset)326 static void *sym_get_data_by_offset(const struct elf_info *info,
327 unsigned int secindex, unsigned long offset)
328 {
329 Elf_Shdr *sechdr = &info->sechdrs[secindex];
330
331 return (void *)info->hdr + sechdr->sh_offset + offset;
332 }
333
sym_get_data(const struct elf_info * info,const Elf_Sym * sym)334 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
335 {
336 return sym_get_data_by_offset(info, get_secindex(info, sym),
337 sym->st_value);
338 }
339
sech_name(const struct elf_info * info,Elf_Shdr * sechdr)340 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
341 {
342 return sym_get_data_by_offset(info, info->secindex_strings,
343 sechdr->sh_name);
344 }
345
sec_name(const struct elf_info * info,unsigned int secindex)346 static const char *sec_name(const struct elf_info *info, unsigned int secindex)
347 {
348 /*
349 * If sym->st_shndx is a special section index, there is no
350 * corresponding section header.
351 * Return "" if the index is out of range of info->sechdrs[] array.
352 */
353 if (secindex >= info->num_sections)
354 return "";
355
356 return sech_name(info, &info->sechdrs[secindex]);
357 }
358
359 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
360
sym_add_exported(const char * name,struct module * mod,bool gpl_only,const char * namespace)361 static struct symbol *sym_add_exported(const char *name, struct module *mod,
362 bool gpl_only, const char *namespace)
363 {
364 struct symbol *s = find_symbol(name);
365
366 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
367 error("%s: '%s' exported twice. Previous export was in %s%s\n",
368 mod->name, name, s->module->name,
369 s->module->is_vmlinux ? "" : ".ko");
370 }
371
372 s = alloc_symbol(name);
373 s->module = mod;
374 s->is_gpl_only = gpl_only;
375 s->namespace = NOFAIL(strdup(namespace));
376 list_add_tail(&s->list, &mod->exported_symbols);
377 hash_add_symbol(s);
378
379 return s;
380 }
381
sym_set_crc(struct symbol * sym,unsigned int crc)382 static void sym_set_crc(struct symbol *sym, unsigned int crc)
383 {
384 sym->crc = crc;
385 sym->crc_valid = true;
386 }
387
grab_file(const char * filename,size_t * size)388 static void *grab_file(const char *filename, size_t *size)
389 {
390 struct stat st;
391 void *map = MAP_FAILED;
392 int fd;
393
394 fd = open(filename, O_RDONLY);
395 if (fd < 0)
396 return NULL;
397 if (fstat(fd, &st))
398 goto failed;
399
400 *size = st.st_size;
401 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
402
403 failed:
404 close(fd);
405 if (map == MAP_FAILED)
406 return NULL;
407 return map;
408 }
409
release_file(void * file,size_t size)410 static void release_file(void *file, size_t size)
411 {
412 munmap(file, size);
413 }
414
parse_elf(struct elf_info * info,const char * filename)415 static int parse_elf(struct elf_info *info, const char *filename)
416 {
417 unsigned int i;
418 Elf_Ehdr *hdr;
419 Elf_Shdr *sechdrs;
420 Elf_Sym *sym;
421 const char *secstrings;
422 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
423
424 hdr = grab_file(filename, &info->size);
425 if (!hdr) {
426 if (ignore_missing_files) {
427 fprintf(stderr, "%s: %s (ignored)\n", filename,
428 strerror(errno));
429 return 0;
430 }
431 perror(filename);
432 exit(1);
433 }
434 info->hdr = hdr;
435 if (info->size < sizeof(*hdr)) {
436 /* file too small, assume this is an empty .o file */
437 return 0;
438 }
439 /* Is this a valid ELF file? */
440 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
441 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
442 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
443 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
444 /* Not an ELF file - silently ignore it */
445 return 0;
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 }
523
524 if (sechdrs[i].sh_type == SHT_SYMTAB) {
525 unsigned int sh_link_idx;
526 symtab_idx = i;
527 info->symtab_start = (void *)hdr +
528 sechdrs[i].sh_offset;
529 info->symtab_stop = (void *)hdr +
530 sechdrs[i].sh_offset + sechdrs[i].sh_size;
531 sh_link_idx = sechdrs[i].sh_link;
532 info->strtab = (void *)hdr +
533 sechdrs[sh_link_idx].sh_offset;
534 }
535
536 /* 32bit section no. table? ("more than 64k sections") */
537 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
538 symtab_shndx_idx = i;
539 info->symtab_shndx_start = (void *)hdr +
540 sechdrs[i].sh_offset;
541 info->symtab_shndx_stop = (void *)hdr +
542 sechdrs[i].sh_offset + sechdrs[i].sh_size;
543 }
544 }
545 if (!info->symtab_start)
546 fatal("%s has no symtab?\n", filename);
547
548 /* Fix endianness in symbols */
549 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
550 sym->st_shndx = TO_NATIVE(sym->st_shndx);
551 sym->st_name = TO_NATIVE(sym->st_name);
552 sym->st_value = TO_NATIVE(sym->st_value);
553 sym->st_size = TO_NATIVE(sym->st_size);
554 }
555
556 if (symtab_shndx_idx != ~0U) {
557 Elf32_Word *p;
558 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
559 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
560 filename, sechdrs[symtab_shndx_idx].sh_link,
561 symtab_idx);
562 /* Fix endianness */
563 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
564 p++)
565 *p = TO_NATIVE(*p);
566 }
567
568 symsearch_init(info);
569
570 return 1;
571 }
572
parse_elf_finish(struct elf_info * info)573 static void parse_elf_finish(struct elf_info *info)
574 {
575 symsearch_finish(info);
576 release_file(info->hdr, info->size);
577 }
578
ignore_undef_symbol(struct elf_info * info,const char * symname)579 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
580 {
581 /* ignore __this_module, it will be resolved shortly */
582 if (strcmp(symname, "__this_module") == 0)
583 return 1;
584 /* ignore global offset table */
585 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
586 return 1;
587 if (info->hdr->e_machine == EM_PPC)
588 /* Special register function linked on all modules during final link of .ko */
589 if (strstarts(symname, "_restgpr_") ||
590 strstarts(symname, "_savegpr_") ||
591 strstarts(symname, "_rest32gpr_") ||
592 strstarts(symname, "_save32gpr_") ||
593 strstarts(symname, "_restvr_") ||
594 strstarts(symname, "_savevr_"))
595 return 1;
596 if (info->hdr->e_machine == EM_PPC64)
597 /* Special register function linked on all modules during final link of .ko */
598 if (strstarts(symname, "_restgpr0_") ||
599 strstarts(symname, "_savegpr0_") ||
600 strstarts(symname, "_restvr_") ||
601 strstarts(symname, "_savevr_") ||
602 strcmp(symname, ".TOC.") == 0)
603 return 1;
604 /* Do not ignore this symbol */
605 return 0;
606 }
607
handle_symbol(struct module * mod,struct elf_info * info,const Elf_Sym * sym,const char * symname)608 static void handle_symbol(struct module *mod, struct elf_info *info,
609 const Elf_Sym *sym, const char *symname)
610 {
611 switch (sym->st_shndx) {
612 case SHN_COMMON:
613 if (strstarts(symname, "__gnu_lto_")) {
614 /* Should warn here, but modpost runs before the linker */
615 } else
616 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
617 break;
618 case SHN_UNDEF:
619 /* undefined symbol */
620 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
621 ELF_ST_BIND(sym->st_info) != STB_WEAK)
622 break;
623 if (ignore_undef_symbol(info, symname))
624 break;
625 if (info->hdr->e_machine == EM_SPARC ||
626 info->hdr->e_machine == EM_SPARCV9) {
627 /* Ignore register directives. */
628 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
629 break;
630 if (symname[0] == '.') {
631 char *munged = NOFAIL(strdup(symname));
632 munged[0] = '_';
633 munged[1] = toupper(munged[1]);
634 symname = munged;
635 }
636 }
637
638 sym_add_unresolved(symname, mod,
639 ELF_ST_BIND(sym->st_info) == STB_WEAK);
640 break;
641 default:
642 if (strcmp(symname, "init_module") == 0)
643 mod->has_init = true;
644 if (strcmp(symname, "cleanup_module") == 0)
645 mod->has_cleanup = true;
646 break;
647 }
648 }
649
650 /**
651 * Parse tag=value strings from .modinfo section
652 **/
next_string(char * string,unsigned long * secsize)653 static char *next_string(char *string, unsigned long *secsize)
654 {
655 /* Skip non-zero chars */
656 while (string[0]) {
657 string++;
658 if ((*secsize)-- <= 1)
659 return NULL;
660 }
661
662 /* Skip any zero padding. */
663 while (!string[0]) {
664 string++;
665 if ((*secsize)-- <= 1)
666 return NULL;
667 }
668 return string;
669 }
670
get_next_modinfo(struct elf_info * info,const char * tag,char * prev)671 static char *get_next_modinfo(struct elf_info *info, const char *tag,
672 char *prev)
673 {
674 char *p;
675 unsigned int taglen = strlen(tag);
676 char *modinfo = info->modinfo;
677 unsigned long size = info->modinfo_len;
678
679 if (prev) {
680 size -= prev - modinfo;
681 modinfo = next_string(prev, &size);
682 }
683
684 for (p = modinfo; p; p = next_string(p, &size)) {
685 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
686 return p + taglen + 1;
687 }
688 return NULL;
689 }
690
get_modinfo(struct elf_info * info,const char * tag)691 static char *get_modinfo(struct elf_info *info, const char *tag)
692
693 {
694 return get_next_modinfo(info, tag, NULL);
695 }
696
sym_name(struct elf_info * elf,Elf_Sym * sym)697 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
698 {
699 if (sym)
700 return elf->strtab + sym->st_name;
701 else
702 return "(unknown)";
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", ".meminit.rodata", \
780 ".init.data", ".meminit.data"
781
782 #define ALL_PCI_INIT_SECTIONS \
783 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
784 ".pci_fixup_enable", ".pci_fixup_resume", \
785 ".pci_fixup_resume_early", ".pci_fixup_suspend"
786
787 #define ALL_XXXINIT_SECTIONS ".meminit.*"
788
789 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
790 #define ALL_EXIT_SECTIONS ".exit.*"
791
792 #define DATA_SECTIONS ".data", ".data.rel"
793 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
794 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
795 ".ltext", ".ltext.*"
796 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
797 ".fixup", ".entry.text", ".exception.text", \
798 ".coldtext", ".softirqentry.text"
799
800 #define INIT_SECTIONS ".init.*"
801
802 #define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \
803 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
804
805 enum mismatch {
806 TEXTDATA_TO_ANY_INIT_EXIT,
807 XXXINIT_TO_SOME_INIT,
808 ANY_INIT_TO_ANY_EXIT,
809 ANY_EXIT_TO_ANY_INIT,
810 EXTABLE_TO_NON_TEXT,
811 };
812
813 /**
814 * Describe how to match sections on different criteria:
815 *
816 * @fromsec: Array of sections to be matched.
817 *
818 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
819 * this array is forbidden (black-list). Can be empty.
820 *
821 * @good_tosec: Relocations applied to a section in @fromsec must be
822 * targeting sections in this array (white-list). Can be empty.
823 *
824 * @mismatch: Type of mismatch.
825 */
826 struct sectioncheck {
827 const char *fromsec[20];
828 const char *bad_tosec[20];
829 const char *good_tosec[20];
830 enum mismatch mismatch;
831 };
832
833 static const struct sectioncheck sectioncheck[] = {
834 /* Do not reference init/exit code/data from
835 * normal code and data
836 */
837 {
838 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
839 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
840 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
841 },
842 /* Do not reference init code/data from meminit code/data */
843 {
844 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
845 .bad_tosec = { INIT_SECTIONS, NULL },
846 .mismatch = XXXINIT_TO_SOME_INIT,
847 },
848 /* Do not use exit code/data from init code */
849 {
850 .fromsec = { ALL_INIT_SECTIONS, NULL },
851 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
852 .mismatch = ANY_INIT_TO_ANY_EXIT,
853 },
854 /* Do not use init code/data from exit code */
855 {
856 .fromsec = { ALL_EXIT_SECTIONS, NULL },
857 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
858 .mismatch = ANY_EXIT_TO_ANY_INIT,
859 },
860 {
861 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
862 .bad_tosec = { INIT_SECTIONS, NULL },
863 .mismatch = ANY_INIT_TO_ANY_EXIT,
864 },
865 {
866 .fromsec = { "__ex_table", NULL },
867 /* If you're adding any new black-listed sections in here, consider
868 * adding a special 'printer' for them in scripts/check_extable.
869 */
870 .bad_tosec = { ".altinstr_replacement", NULL },
871 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
872 .mismatch = EXTABLE_TO_NON_TEXT,
873 }
874 };
875
section_mismatch(const char * fromsec,const char * tosec)876 static const struct sectioncheck *section_mismatch(
877 const char *fromsec, const char *tosec)
878 {
879 int i;
880
881 /*
882 * The target section could be the SHT_NUL section when we're
883 * handling relocations to un-resolved symbols, trying to match it
884 * doesn't make much sense and causes build failures on parisc
885 * architectures.
886 */
887 if (*tosec == '\0')
888 return NULL;
889
890 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
891 const struct sectioncheck *check = §ioncheck[i];
892
893 if (match(fromsec, check->fromsec)) {
894 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
895 return check;
896 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
897 return check;
898 }
899 }
900 return NULL;
901 }
902
903 /**
904 * Whitelist to allow certain references to pass with no warning.
905 *
906 * Pattern 1:
907 * If a module parameter is declared __initdata and permissions=0
908 * then this is legal despite the warning generated.
909 * We cannot see value of permissions here, so just ignore
910 * this pattern.
911 * The pattern is identified by:
912 * tosec = .init.data
913 * fromsec = .data*
914 * atsym =__param*
915 *
916 * Pattern 1a:
917 * module_param_call() ops can refer to __init set function if permissions=0
918 * The pattern is identified by:
919 * tosec = .init.text
920 * fromsec = .data*
921 * atsym = __param_ops_*
922 *
923 * Pattern 3:
924 * Whitelist all references from .head.text to any init section
925 *
926 * Pattern 4:
927 * Some symbols belong to init section but still it is ok to reference
928 * these from non-init sections as these symbols don't have any memory
929 * allocated for them and symbol address and value are same. So even
930 * if init section is freed, its ok to reference those symbols.
931 * For ex. symbols marking the init section boundaries.
932 * This pattern is identified by
933 * refsymname = __init_begin, _sinittext, _einittext
934 *
935 * Pattern 5:
936 * GCC may optimize static inlines when fed constant arg(s) resulting
937 * in functions like cpumask_empty() -- generating an associated symbol
938 * cpumask_empty.constprop.3 that appears in the audit. If the const that
939 * is passed in comes from __init, like say nmi_ipi_mask, we get a
940 * meaningless section warning. May need to add isra symbols too...
941 * This pattern is identified by
942 * tosec = init section
943 * fromsec = text section
944 * refsymname = *.constprop.*
945 *
946 **/
secref_whitelist(const char * fromsec,const char * fromsym,const char * tosec,const char * tosym)947 static int secref_whitelist(const char *fromsec, const char *fromsym,
948 const char *tosec, const char *tosym)
949 {
950 /* Check for pattern 1 */
951 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
952 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
953 strstarts(fromsym, "__param"))
954 return 0;
955
956 /* Check for pattern 1a */
957 if (strcmp(tosec, ".init.text") == 0 &&
958 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
959 strstarts(fromsym, "__param_ops_"))
960 return 0;
961
962 /* symbols in data sections that may refer to any init/exit sections */
963 if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
964 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
965 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
966 return 0;
967
968 /*
969 * symbols in data sections must not refer to .exit.*, but there are
970 * quite a few offenders, so hide these unless for W=1 builds until
971 * these are fixed.
972 */
973 if (!extra_warn &&
974 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
975 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) &&
976 match(fromsym, PATTERNS("*driver")))
977 return 0;
978
979 /* Check for pattern 3 */
980 if (strstarts(fromsec, ".head.text") &&
981 match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
982 return 0;
983
984 /* Check for pattern 4 */
985 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
986 return 0;
987
988 /* Check for pattern 5 */
989 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
990 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
991 match(fromsym, PATTERNS("*.constprop.*")))
992 return 0;
993
994 return 1;
995 }
996
find_fromsym(struct elf_info * elf,Elf_Addr addr,unsigned int secndx)997 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
998 unsigned int secndx)
999 {
1000 return symsearch_find_nearest(elf, addr, secndx, false, ~0);
1001 }
1002
find_tosym(struct elf_info * elf,Elf_Addr addr,Elf_Sym * sym)1003 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1004 {
1005 Elf_Sym *new_sym;
1006
1007 /* If the supplied symbol has a valid name, return it */
1008 if (is_valid_name(elf, sym))
1009 return sym;
1010
1011 /*
1012 * Strive to find a better symbol name, but the resulting name may not
1013 * match the symbol referenced in the original code.
1014 */
1015 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
1016 true, 20);
1017 return new_sym ? new_sym : sym;
1018 }
1019
is_executable_section(struct elf_info * elf,unsigned int secndx)1020 static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1021 {
1022 if (secndx >= elf->num_sections)
1023 return false;
1024
1025 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1026 }
1027
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)1028 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1029 const struct sectioncheck* const mismatch,
1030 Elf_Sym *tsym,
1031 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1032 const char *tosec, Elf_Addr taddr)
1033 {
1034 Elf_Sym *from;
1035 const char *tosym;
1036 const char *fromsym;
1037
1038 from = find_fromsym(elf, faddr, fsecndx);
1039 fromsym = sym_name(elf, from);
1040
1041 tsym = find_tosym(elf, taddr, tsym);
1042 tosym = sym_name(elf, tsym);
1043
1044 /* check whitelist - we may ignore it */
1045 if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1046 return;
1047
1048 sec_mismatch_count++;
1049
1050 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1051 modname, fromsym,
1052 (unsigned int)(faddr - (from ? from->st_value : 0)),
1053 fromsec, tosym, tosec);
1054
1055 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1056 if (match(tosec, mismatch->bad_tosec))
1057 fatal("The relocation at %s+0x%lx references\n"
1058 "section \"%s\" which is black-listed.\n"
1059 "Something is seriously wrong and should be fixed.\n"
1060 "You might get more information about where this is\n"
1061 "coming from by using scripts/check_extable.sh %s\n",
1062 fromsec, (long)faddr, tosec, modname);
1063 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1064 warn("The relocation at %s+0x%lx references\n"
1065 "section \"%s\" which is not in the list of\n"
1066 "authorized sections. If you're adding a new section\n"
1067 "and/or if this reference is valid, add \"%s\" to the\n"
1068 "list of authorized sections to jump to on fault.\n"
1069 "This can be achieved by adding \"%s\" to\n"
1070 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1071 fromsec, (long)faddr, tosec, tosec, tosec);
1072 else
1073 error("%s+0x%lx references non-executable section '%s'\n",
1074 fromsec, (long)faddr, tosec);
1075 }
1076 }
1077
check_export_symbol(struct module * mod,struct elf_info * elf,Elf_Addr faddr,const char * secname,Elf_Sym * sym)1078 static void check_export_symbol(struct module *mod, struct elf_info *elf,
1079 Elf_Addr faddr, const char *secname,
1080 Elf_Sym *sym)
1081 {
1082 static const char *prefix = "__export_symbol_";
1083 const char *label_name, *name, *data;
1084 Elf_Sym *label;
1085 struct symbol *s;
1086 bool is_gpl;
1087
1088 label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1089 label_name = sym_name(elf, label);
1090
1091 if (!strstarts(label_name, prefix)) {
1092 error("%s: .export_symbol section contains strange symbol '%s'\n",
1093 mod->name, label_name);
1094 return;
1095 }
1096
1097 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1098 ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1099 error("%s: local symbol '%s' was exported\n", mod->name,
1100 label_name + strlen(prefix));
1101 return;
1102 }
1103
1104 name = sym_name(elf, sym);
1105 if (strcmp(label_name + strlen(prefix), name)) {
1106 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1107 mod->name, name);
1108 return;
1109 }
1110
1111 data = sym_get_data(elf, label); /* license */
1112 if (!strcmp(data, "GPL")) {
1113 is_gpl = true;
1114 } else if (!strcmp(data, "")) {
1115 is_gpl = false;
1116 } else {
1117 error("%s: unknown license '%s' was specified for '%s'\n",
1118 mod->name, data, name);
1119 return;
1120 }
1121
1122 data += strlen(data) + 1; /* namespace */
1123 s = sym_add_exported(name, mod, is_gpl, data);
1124
1125 /*
1126 * We need to be aware whether we are exporting a function or
1127 * a data on some architectures.
1128 */
1129 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1130
1131 /*
1132 * For parisc64, symbols prefixed $$ from the library have the symbol type
1133 * STT_LOPROC. They should be handled as functions too.
1134 */
1135 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1136 elf->hdr->e_machine == EM_PARISC &&
1137 ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1138 s->is_func = true;
1139
1140 if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1141 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1142 mod->name, name);
1143 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1144 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1145 mod->name, name);
1146 }
1147
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)1148 static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1149 Elf_Sym *sym,
1150 unsigned int fsecndx, const char *fromsec,
1151 Elf_Addr faddr, Elf_Addr taddr)
1152 {
1153 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1154 const struct sectioncheck *mismatch;
1155
1156 if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1157 check_export_symbol(mod, elf, faddr, tosec, sym);
1158 return;
1159 }
1160
1161 mismatch = section_mismatch(fromsec, tosec);
1162 if (!mismatch)
1163 return;
1164
1165 default_mismatch_handler(mod->name, elf, mismatch, sym,
1166 fsecndx, fromsec, faddr,
1167 tosec, taddr);
1168 }
1169
addend_386_rel(uint32_t * location,unsigned int r_type)1170 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1171 {
1172 switch (r_type) {
1173 case R_386_32:
1174 return TO_NATIVE(*location);
1175 case R_386_PC32:
1176 return TO_NATIVE(*location) + 4;
1177 }
1178
1179 return (Elf_Addr)(-1);
1180 }
1181
1182 #ifndef R_ARM_CALL
1183 #define R_ARM_CALL 28
1184 #endif
1185 #ifndef R_ARM_JUMP24
1186 #define R_ARM_JUMP24 29
1187 #endif
1188
1189 #ifndef R_ARM_THM_CALL
1190 #define R_ARM_THM_CALL 10
1191 #endif
1192 #ifndef R_ARM_THM_JUMP24
1193 #define R_ARM_THM_JUMP24 30
1194 #endif
1195
1196 #ifndef R_ARM_MOVW_ABS_NC
1197 #define R_ARM_MOVW_ABS_NC 43
1198 #endif
1199
1200 #ifndef R_ARM_MOVT_ABS
1201 #define R_ARM_MOVT_ABS 44
1202 #endif
1203
1204 #ifndef R_ARM_THM_MOVW_ABS_NC
1205 #define R_ARM_THM_MOVW_ABS_NC 47
1206 #endif
1207
1208 #ifndef R_ARM_THM_MOVT_ABS
1209 #define R_ARM_THM_MOVT_ABS 48
1210 #endif
1211
1212 #ifndef R_ARM_THM_JUMP19
1213 #define R_ARM_THM_JUMP19 51
1214 #endif
1215
sign_extend32(int32_t value,int index)1216 static int32_t sign_extend32(int32_t value, int index)
1217 {
1218 uint8_t shift = 31 - index;
1219
1220 return (int32_t)(value << shift) >> shift;
1221 }
1222
addend_arm_rel(void * loc,Elf_Sym * sym,unsigned int r_type)1223 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1224 {
1225 uint32_t inst, upper, lower, sign, j1, j2;
1226 int32_t offset;
1227
1228 switch (r_type) {
1229 case R_ARM_ABS32:
1230 case R_ARM_REL32:
1231 inst = TO_NATIVE(*(uint32_t *)loc);
1232 return inst + sym->st_value;
1233 case R_ARM_MOVW_ABS_NC:
1234 case R_ARM_MOVT_ABS:
1235 inst = TO_NATIVE(*(uint32_t *)loc);
1236 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1237 15);
1238 return offset + sym->st_value;
1239 case R_ARM_PC24:
1240 case R_ARM_CALL:
1241 case R_ARM_JUMP24:
1242 inst = TO_NATIVE(*(uint32_t *)loc);
1243 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1244 return offset + sym->st_value + 8;
1245 case R_ARM_THM_MOVW_ABS_NC:
1246 case R_ARM_THM_MOVT_ABS:
1247 upper = TO_NATIVE(*(uint16_t *)loc);
1248 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1249 offset = sign_extend32(((upper & 0x000f) << 12) |
1250 ((upper & 0x0400) << 1) |
1251 ((lower & 0x7000) >> 4) |
1252 (lower & 0x00ff),
1253 15);
1254 return offset + sym->st_value;
1255 case R_ARM_THM_JUMP19:
1256 /*
1257 * Encoding T3:
1258 * S = upper[10]
1259 * imm6 = upper[5:0]
1260 * J1 = lower[13]
1261 * J2 = lower[11]
1262 * imm11 = lower[10:0]
1263 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1264 */
1265 upper = TO_NATIVE(*(uint16_t *)loc);
1266 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1267
1268 sign = (upper >> 10) & 1;
1269 j1 = (lower >> 13) & 1;
1270 j2 = (lower >> 11) & 1;
1271 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1272 ((upper & 0x03f) << 12) |
1273 ((lower & 0x07ff) << 1),
1274 20);
1275 return offset + sym->st_value + 4;
1276 case R_ARM_THM_CALL:
1277 case R_ARM_THM_JUMP24:
1278 /*
1279 * Encoding T4:
1280 * S = upper[10]
1281 * imm10 = upper[9:0]
1282 * J1 = lower[13]
1283 * J2 = lower[11]
1284 * imm11 = lower[10:0]
1285 * I1 = NOT(J1 XOR S)
1286 * I2 = NOT(J2 XOR S)
1287 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1288 */
1289 upper = TO_NATIVE(*(uint16_t *)loc);
1290 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1291
1292 sign = (upper >> 10) & 1;
1293 j1 = (lower >> 13) & 1;
1294 j2 = (lower >> 11) & 1;
1295 offset = sign_extend32((sign << 24) |
1296 ((~(j1 ^ sign) & 1) << 23) |
1297 ((~(j2 ^ sign) & 1) << 22) |
1298 ((upper & 0x03ff) << 12) |
1299 ((lower & 0x07ff) << 1),
1300 24);
1301 return offset + sym->st_value + 4;
1302 }
1303
1304 return (Elf_Addr)(-1);
1305 }
1306
addend_mips_rel(uint32_t * location,unsigned int r_type)1307 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1308 {
1309 uint32_t inst;
1310
1311 inst = TO_NATIVE(*location);
1312 switch (r_type) {
1313 case R_MIPS_LO16:
1314 return inst & 0xffff;
1315 case R_MIPS_26:
1316 return (inst & 0x03ffffff) << 2;
1317 case R_MIPS_32:
1318 return inst;
1319 }
1320 return (Elf_Addr)(-1);
1321 }
1322
1323 #ifndef EM_RISCV
1324 #define EM_RISCV 243
1325 #endif
1326
1327 #ifndef R_RISCV_SUB32
1328 #define R_RISCV_SUB32 39
1329 #endif
1330
1331 #ifndef EM_LOONGARCH
1332 #define EM_LOONGARCH 258
1333 #endif
1334
1335 #ifndef R_LARCH_SUB32
1336 #define R_LARCH_SUB32 55
1337 #endif
1338
1339 #ifndef R_LARCH_RELAX
1340 #define R_LARCH_RELAX 100
1341 #endif
1342
1343 #ifndef R_LARCH_ALIGN
1344 #define R_LARCH_ALIGN 102
1345 #endif
1346
get_rel_type_and_sym(struct elf_info * elf,uint64_t r_info,unsigned int * r_type,unsigned int * r_sym)1347 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1348 unsigned int *r_type, unsigned int *r_sym)
1349 {
1350 typedef struct {
1351 Elf64_Word r_sym; /* Symbol index */
1352 unsigned char r_ssym; /* Special symbol for 2nd relocation */
1353 unsigned char r_type3; /* 3rd relocation type */
1354 unsigned char r_type2; /* 2nd relocation type */
1355 unsigned char r_type; /* 1st relocation type */
1356 } Elf64_Mips_R_Info;
1357
1358 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1359
1360 if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1361 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1362
1363 *r_type = mips64_r_info->r_type;
1364 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1365 return;
1366 }
1367
1368 if (is_64bit)
1369 r_info = TO_NATIVE((Elf64_Xword)r_info);
1370 else
1371 r_info = TO_NATIVE((Elf32_Word)r_info);
1372
1373 *r_type = ELF_R_TYPE(r_info);
1374 *r_sym = ELF_R_SYM(r_info);
1375 }
1376
section_rela(struct module * mod,struct elf_info * elf,unsigned int fsecndx,const char * fromsec,const Elf_Rela * start,const Elf_Rela * stop)1377 static void section_rela(struct module *mod, struct elf_info *elf,
1378 unsigned int fsecndx, const char *fromsec,
1379 const Elf_Rela *start, const Elf_Rela *stop)
1380 {
1381 const Elf_Rela *rela;
1382
1383 for (rela = start; rela < stop; rela++) {
1384 Elf_Sym *tsym;
1385 Elf_Addr taddr, r_offset;
1386 unsigned int r_type, r_sym;
1387
1388 r_offset = TO_NATIVE(rela->r_offset);
1389 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1390
1391 tsym = elf->symtab_start + r_sym;
1392 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1393
1394 switch (elf->hdr->e_machine) {
1395 case EM_RISCV:
1396 if (!strcmp("__ex_table", fromsec) &&
1397 r_type == R_RISCV_SUB32)
1398 continue;
1399 break;
1400 case EM_LOONGARCH:
1401 switch (r_type) {
1402 case R_LARCH_SUB32:
1403 if (!strcmp("__ex_table", fromsec))
1404 continue;
1405 break;
1406 case R_LARCH_RELAX:
1407 case R_LARCH_ALIGN:
1408 /* These relocs do not refer to symbols */
1409 continue;
1410 }
1411 break;
1412 }
1413
1414 check_section_mismatch(mod, elf, tsym,
1415 fsecndx, fromsec, r_offset, taddr);
1416 }
1417 }
1418
section_rel(struct module * mod,struct elf_info * elf,unsigned int fsecndx,const char * fromsec,const Elf_Rel * start,const Elf_Rel * stop)1419 static void section_rel(struct module *mod, struct elf_info *elf,
1420 unsigned int fsecndx, const char *fromsec,
1421 const Elf_Rel *start, const Elf_Rel *stop)
1422 {
1423 const Elf_Rel *rel;
1424
1425 for (rel = start; rel < stop; rel++) {
1426 Elf_Sym *tsym;
1427 Elf_Addr taddr, r_offset;
1428 unsigned int r_type, r_sym;
1429 void *loc;
1430
1431 r_offset = TO_NATIVE(rel->r_offset);
1432 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1433
1434 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1435 tsym = elf->symtab_start + r_sym;
1436
1437 switch (elf->hdr->e_machine) {
1438 case EM_386:
1439 taddr = addend_386_rel(loc, r_type);
1440 break;
1441 case EM_ARM:
1442 taddr = addend_arm_rel(loc, tsym, r_type);
1443 break;
1444 case EM_MIPS:
1445 taddr = addend_mips_rel(loc, r_type);
1446 break;
1447 default:
1448 fatal("Please add code to calculate addend for this architecture\n");
1449 }
1450
1451 check_section_mismatch(mod, elf, tsym,
1452 fsecndx, fromsec, r_offset, taddr);
1453 }
1454 }
1455
1456 /**
1457 * A module includes a number of sections that are discarded
1458 * either when loaded or when used as built-in.
1459 * For loaded modules all functions marked __init and all data
1460 * marked __initdata will be discarded when the module has been initialized.
1461 * Likewise for modules used built-in the sections marked __exit
1462 * are discarded because __exit marked function are supposed to be called
1463 * only when a module is unloaded which never happens for built-in modules.
1464 * The check_sec_ref() function traverses all relocation records
1465 * to find all references to a section that reference a section that will
1466 * be discarded and warns about it.
1467 **/
check_sec_ref(struct module * mod,struct elf_info * elf)1468 static void check_sec_ref(struct module *mod, struct elf_info *elf)
1469 {
1470 int i;
1471
1472 /* Walk through all sections */
1473 for (i = 0; i < elf->num_sections; i++) {
1474 Elf_Shdr *sechdr = &elf->sechdrs[i];
1475
1476 check_section(mod->name, elf, sechdr);
1477 /* We want to process only relocation sections and not .init */
1478 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1479 /* section to which the relocation applies */
1480 unsigned int secndx = sechdr->sh_info;
1481 const char *secname = sec_name(elf, secndx);
1482 const void *start, *stop;
1483
1484 /* If the section is known good, skip it */
1485 if (match(secname, section_white_list))
1486 continue;
1487
1488 start = sym_get_data_by_offset(elf, i, 0);
1489 stop = start + sechdr->sh_size;
1490
1491 if (sechdr->sh_type == SHT_RELA)
1492 section_rela(mod, elf, secndx, secname,
1493 start, stop);
1494 else
1495 section_rel(mod, elf, secndx, secname,
1496 start, stop);
1497 }
1498 }
1499 }
1500
remove_dot(char * s)1501 static char *remove_dot(char *s)
1502 {
1503 size_t n = strcspn(s, ".");
1504
1505 if (n && s[n]) {
1506 size_t m = strspn(s + n + 1, "0123456789");
1507 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1508 s[n] = 0;
1509 }
1510 return s;
1511 }
1512
1513 /*
1514 * The CRCs are recorded in .*.cmd files in the form of:
1515 * #SYMVER <name> <crc>
1516 */
extract_crcs_for_object(const char * object,struct module * mod)1517 static void extract_crcs_for_object(const char *object, struct module *mod)
1518 {
1519 char cmd_file[PATH_MAX];
1520 char *buf, *p;
1521 const char *base;
1522 int dirlen, ret;
1523
1524 base = strrchr(object, '/');
1525 if (base) {
1526 base++;
1527 dirlen = base - object;
1528 } else {
1529 dirlen = 0;
1530 base = object;
1531 }
1532
1533 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1534 dirlen, object, base);
1535 if (ret >= sizeof(cmd_file)) {
1536 error("%s: too long path was truncated\n", cmd_file);
1537 return;
1538 }
1539
1540 buf = read_text_file(cmd_file);
1541 p = buf;
1542
1543 while ((p = strstr(p, "\n#SYMVER "))) {
1544 char *name;
1545 size_t namelen;
1546 unsigned int crc;
1547 struct symbol *sym;
1548
1549 name = p + strlen("\n#SYMVER ");
1550
1551 p = strchr(name, ' ');
1552 if (!p)
1553 break;
1554
1555 namelen = p - name;
1556 p++;
1557
1558 if (!isdigit(*p))
1559 continue; /* skip this line */
1560
1561 crc = strtoul(p, &p, 0);
1562 if (*p != '\n')
1563 continue; /* skip this line */
1564
1565 name[namelen] = '\0';
1566
1567 /*
1568 * sym_find_with_module() may return NULL here.
1569 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1570 * Since commit e1327a127703, genksyms calculates CRCs of all
1571 * symbols, including trimmed ones. Ignore orphan CRCs.
1572 */
1573 sym = sym_find_with_module(name, mod);
1574 if (sym)
1575 sym_set_crc(sym, crc);
1576 }
1577
1578 free(buf);
1579 }
1580
1581 /*
1582 * The symbol versions (CRC) are recorded in the .*.cmd files.
1583 * Parse them to retrieve CRCs for the current module.
1584 */
mod_set_crcs(struct module * mod)1585 static void mod_set_crcs(struct module *mod)
1586 {
1587 char objlist[PATH_MAX];
1588 char *buf, *p, *obj;
1589 int ret;
1590
1591 if (mod->is_vmlinux) {
1592 strcpy(objlist, ".vmlinux.objs");
1593 } else {
1594 /* objects for a module are listed in the *.mod file. */
1595 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1596 if (ret >= sizeof(objlist)) {
1597 error("%s: too long path was truncated\n", objlist);
1598 return;
1599 }
1600 }
1601
1602 buf = read_text_file(objlist);
1603 p = buf;
1604
1605 while ((obj = strsep(&p, "\n")) && obj[0])
1606 extract_crcs_for_object(obj, mod);
1607
1608 free(buf);
1609 }
1610
read_symbols(const char * modname)1611 static void read_symbols(const char *modname)
1612 {
1613 const char *symname;
1614 char *version;
1615 char *license;
1616 char *namespace;
1617 struct module *mod;
1618 struct elf_info info = { };
1619 Elf_Sym *sym;
1620
1621 if (!parse_elf(&info, modname))
1622 return;
1623
1624 if (!strends(modname, ".o")) {
1625 error("%s: filename must be suffixed with .o\n", modname);
1626 return;
1627 }
1628
1629 /* strip trailing .o */
1630 mod = new_module(modname, strlen(modname) - strlen(".o"));
1631
1632 if (!mod->is_vmlinux) {
1633 license = get_modinfo(&info, "license");
1634 if (!license)
1635 error("missing MODULE_LICENSE() in %s\n", modname);
1636 while (license) {
1637 if (!license_is_gpl_compatible(license)) {
1638 mod->is_gpl_compatible = false;
1639 break;
1640 }
1641 license = get_next_modinfo(&info, "license", license);
1642 }
1643
1644 namespace = get_modinfo(&info, "import_ns");
1645 while (namespace) {
1646 add_namespace(&mod->imported_namespaces, namespace);
1647 namespace = get_next_modinfo(&info, "import_ns",
1648 namespace);
1649 }
1650
1651 if (extra_warn && !get_modinfo(&info, "description"))
1652 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1653 }
1654
1655 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1656 symname = remove_dot(info.strtab + sym->st_name);
1657
1658 handle_symbol(mod, &info, sym, symname);
1659 handle_moddevtable(mod, &info, sym, symname);
1660 }
1661
1662 check_sec_ref(mod, &info);
1663
1664 if (!mod->is_vmlinux) {
1665 version = get_modinfo(&info, "version");
1666 if (version || all_versions)
1667 get_src_version(mod->name, mod->srcversion,
1668 sizeof(mod->srcversion) - 1);
1669 }
1670
1671 parse_elf_finish(&info);
1672
1673 if (modversions) {
1674 /*
1675 * Our trick to get versioning for module struct etc. - it's
1676 * never passed as an argument to an exported function, so
1677 * the automatic versioning doesn't pick it up, but it's really
1678 * important anyhow.
1679 */
1680 sym_add_unresolved("module_layout", mod, false);
1681
1682 mod_set_crcs(mod);
1683 }
1684 }
1685
read_symbols_from_files(const char * filename)1686 static void read_symbols_from_files(const char *filename)
1687 {
1688 FILE *in = stdin;
1689 char fname[PATH_MAX];
1690
1691 in = fopen(filename, "r");
1692 if (!in)
1693 fatal("Can't open filenames file %s: %m", filename);
1694
1695 while (fgets(fname, PATH_MAX, in) != NULL) {
1696 if (strends(fname, "\n"))
1697 fname[strlen(fname)-1] = '\0';
1698 read_symbols(fname);
1699 }
1700
1701 fclose(in);
1702 }
1703
1704 #define SZ 500
1705
1706 /* We first write the generated file into memory using the
1707 * following helper, then compare to the file on disk and
1708 * only update the later if anything changed */
1709
buf_printf(struct buffer * buf,const char * fmt,...)1710 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1711 const char *fmt, ...)
1712 {
1713 char tmp[SZ];
1714 int len;
1715 va_list ap;
1716
1717 va_start(ap, fmt);
1718 len = vsnprintf(tmp, SZ, fmt, ap);
1719 buf_write(buf, tmp, len);
1720 va_end(ap);
1721 }
1722
buf_write(struct buffer * buf,const char * s,int len)1723 void buf_write(struct buffer *buf, const char *s, int len)
1724 {
1725 if (buf->size - buf->pos < len) {
1726 buf->size += len + SZ;
1727 buf->p = NOFAIL(realloc(buf->p, buf->size));
1728 }
1729 strncpy(buf->p + buf->pos, s, len);
1730 buf->pos += len;
1731 }
1732
check_exports(struct module * mod)1733 static void check_exports(struct module *mod)
1734 {
1735 struct symbol *s, *exp;
1736
1737 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1738 const char *basename;
1739 exp = find_symbol(s->name);
1740 if (!exp) {
1741 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1742 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1743 "\"%s\" [%s.ko] undefined!\n",
1744 s->name, mod->name);
1745 continue;
1746 }
1747 if (exp->module == mod) {
1748 error("\"%s\" [%s.ko] was exported without definition\n",
1749 s->name, mod->name);
1750 continue;
1751 }
1752
1753 exp->used = true;
1754 s->module = exp->module;
1755 s->crc_valid = exp->crc_valid;
1756 s->crc = exp->crc;
1757
1758 basename = strrchr(mod->name, '/');
1759 if (basename)
1760 basename++;
1761 else
1762 basename = mod->name;
1763
1764 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1765 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1766 "module %s uses symbol %s from namespace %s, but does not import it.\n",
1767 basename, exp->name, exp->namespace);
1768 add_namespace(&mod->missing_namespaces, exp->namespace);
1769 }
1770
1771 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1772 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1773 basename, exp->name);
1774 }
1775 }
1776
handle_white_list_exports(const char * white_list)1777 static void handle_white_list_exports(const char *white_list)
1778 {
1779 char *buf, *p, *name;
1780
1781 buf = read_text_file(white_list);
1782 p = buf;
1783
1784 while ((name = strsep(&p, "\n"))) {
1785 struct symbol *sym = find_symbol(name);
1786
1787 if (sym)
1788 sym->used = true;
1789 }
1790
1791 free(buf);
1792 }
1793
check_modname_len(struct module * mod)1794 static void check_modname_len(struct module *mod)
1795 {
1796 const char *mod_name;
1797
1798 mod_name = strrchr(mod->name, '/');
1799 if (mod_name == NULL)
1800 mod_name = mod->name;
1801 else
1802 mod_name++;
1803 if (strlen(mod_name) >= MODULE_NAME_LEN)
1804 error("module name is too long [%s.ko]\n", mod->name);
1805 }
1806
1807 /**
1808 * Header for the generated file
1809 **/
add_header(struct buffer * b,struct module * mod)1810 static void add_header(struct buffer *b, struct module *mod)
1811 {
1812 buf_printf(b, "#include <linux/module.h>\n");
1813 /*
1814 * Include build-salt.h after module.h in order to
1815 * inherit the definitions.
1816 */
1817 buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1818 buf_printf(b, "#include <linux/build-salt.h>\n");
1819 buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1820 buf_printf(b, "#include <linux/export-internal.h>\n");
1821 buf_printf(b, "#include <linux/vermagic.h>\n");
1822 buf_printf(b, "#include <linux/compiler.h>\n");
1823 buf_printf(b, "\n");
1824 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1825 buf_printf(b, "#include <asm/orc_header.h>\n");
1826 buf_printf(b, "ORC_HEADER;\n");
1827 buf_printf(b, "#endif\n");
1828 buf_printf(b, "\n");
1829 buf_printf(b, "BUILD_SALT;\n");
1830 buf_printf(b, "BUILD_LTO_INFO;\n");
1831 buf_printf(b, "\n");
1832 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1833 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1834 buf_printf(b, "\n");
1835 buf_printf(b, "__visible struct module __this_module\n");
1836 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1837 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1838 if (mod->has_init)
1839 buf_printf(b, "\t.init = init_module,\n");
1840 if (mod->has_cleanup)
1841 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1842 "\t.exit = cleanup_module,\n"
1843 "#endif\n");
1844 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1845 buf_printf(b, "};\n");
1846
1847 if (!external_module)
1848 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1849
1850 buf_printf(b,
1851 "\n"
1852 "#ifdef CONFIG_MITIGATION_RETPOLINE\n"
1853 "MODULE_INFO(retpoline, \"Y\");\n"
1854 "#endif\n");
1855
1856 if (strstarts(mod->name, "drivers/staging"))
1857 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1858
1859 if (strstarts(mod->name, "tools/testing"))
1860 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1861 }
1862
add_exported_symbols(struct buffer * buf,struct module * mod)1863 static void add_exported_symbols(struct buffer *buf, struct module *mod)
1864 {
1865 struct symbol *sym;
1866
1867 /* generate struct for exported symbols */
1868 buf_printf(buf, "\n");
1869 list_for_each_entry(sym, &mod->exported_symbols, list) {
1870 if (trim_unused_exports && !sym->used)
1871 continue;
1872
1873 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1874 sym->is_func ? "FUNC" : "DATA", sym->name,
1875 sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1876 }
1877
1878 if (!modversions)
1879 return;
1880
1881 /* record CRCs for exported symbols */
1882 buf_printf(buf, "\n");
1883 list_for_each_entry(sym, &mod->exported_symbols, list) {
1884 if (trim_unused_exports && !sym->used)
1885 continue;
1886
1887 if (!sym->crc_valid)
1888 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1889 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1890 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1891 sym->name);
1892
1893 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1894 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1895 }
1896 }
1897
1898 /**
1899 * Record CRCs for unresolved symbols
1900 **/
add_versions(struct buffer * b,struct module * mod)1901 static void add_versions(struct buffer *b, struct module *mod)
1902 {
1903 struct symbol *s;
1904
1905 if (!modversions)
1906 return;
1907
1908 buf_printf(b, "\n");
1909 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1910 buf_printf(b, "__used __section(\"__versions\") = {\n");
1911
1912 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1913 if (!s->module)
1914 continue;
1915 if (!s->crc_valid) {
1916 warn("\"%s\" [%s.ko] has no CRC!\n",
1917 s->name, mod->name);
1918 continue;
1919 }
1920 if (strlen(s->name) >= MODULE_NAME_LEN) {
1921 error("too long symbol \"%s\" [%s.ko]\n",
1922 s->name, mod->name);
1923 break;
1924 }
1925 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1926 s->crc, s->name);
1927 }
1928
1929 buf_printf(b, "};\n");
1930 }
1931
add_depends(struct buffer * b,struct module * mod)1932 static void add_depends(struct buffer *b, struct module *mod)
1933 {
1934 struct symbol *s;
1935 int first = 1;
1936
1937 /* Clear ->seen flag of modules that own symbols needed by this. */
1938 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1939 if (s->module)
1940 s->module->seen = s->module->is_vmlinux;
1941 }
1942
1943 buf_printf(b, "\n");
1944 buf_printf(b, "MODULE_INFO(depends, \"");
1945 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1946 const char *p;
1947 if (!s->module)
1948 continue;
1949
1950 if (s->module->seen)
1951 continue;
1952
1953 s->module->seen = true;
1954 p = strrchr(s->module->name, '/');
1955 if (p)
1956 p++;
1957 else
1958 p = s->module->name;
1959 buf_printf(b, "%s%s", first ? "" : ",", p);
1960 first = 0;
1961 }
1962 buf_printf(b, "\");\n");
1963 }
1964
add_srcversion(struct buffer * b,struct module * mod)1965 static void add_srcversion(struct buffer *b, struct module *mod)
1966 {
1967 if (mod->srcversion[0]) {
1968 buf_printf(b, "\n");
1969 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1970 mod->srcversion);
1971 }
1972 }
1973
write_buf(struct buffer * b,const char * fname)1974 static void write_buf(struct buffer *b, const char *fname)
1975 {
1976 FILE *file;
1977
1978 if (error_occurred)
1979 return;
1980
1981 file = fopen(fname, "w");
1982 if (!file) {
1983 perror(fname);
1984 exit(1);
1985 }
1986 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1987 perror(fname);
1988 exit(1);
1989 }
1990 if (fclose(file) != 0) {
1991 perror(fname);
1992 exit(1);
1993 }
1994 }
1995
write_if_changed(struct buffer * b,const char * fname)1996 static void write_if_changed(struct buffer *b, const char *fname)
1997 {
1998 char *tmp;
1999 FILE *file;
2000 struct stat st;
2001
2002 file = fopen(fname, "r");
2003 if (!file)
2004 goto write;
2005
2006 if (fstat(fileno(file), &st) < 0)
2007 goto close_write;
2008
2009 if (st.st_size != b->pos)
2010 goto close_write;
2011
2012 tmp = NOFAIL(malloc(b->pos));
2013 if (fread(tmp, 1, b->pos, file) != b->pos)
2014 goto free_write;
2015
2016 if (memcmp(tmp, b->p, b->pos) != 0)
2017 goto free_write;
2018
2019 free(tmp);
2020 fclose(file);
2021 return;
2022
2023 free_write:
2024 free(tmp);
2025 close_write:
2026 fclose(file);
2027 write:
2028 write_buf(b, fname);
2029 }
2030
write_vmlinux_export_c_file(struct module * mod)2031 static void write_vmlinux_export_c_file(struct module *mod)
2032 {
2033 struct buffer buf = { };
2034
2035 buf_printf(&buf,
2036 "#include <linux/export-internal.h>\n");
2037
2038 add_exported_symbols(&buf, mod);
2039 write_if_changed(&buf, ".vmlinux.export.c");
2040 free(buf.p);
2041 }
2042
2043 /* do sanity checks, and generate *.mod.c file */
write_mod_c_file(struct module * mod)2044 static void write_mod_c_file(struct module *mod)
2045 {
2046 struct buffer buf = { };
2047 char fname[PATH_MAX];
2048 int ret;
2049
2050 add_header(&buf, mod);
2051 add_exported_symbols(&buf, mod);
2052 add_versions(&buf, mod);
2053 add_depends(&buf, mod);
2054 add_moddevtable(&buf, mod);
2055 add_srcversion(&buf, mod);
2056
2057 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2058 if (ret >= sizeof(fname)) {
2059 error("%s: too long path was truncated\n", fname);
2060 goto free;
2061 }
2062
2063 write_if_changed(&buf, fname);
2064
2065 free:
2066 free(buf.p);
2067 }
2068
2069 /* parse Module.symvers file. line format:
2070 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2071 **/
read_dump(const char * fname)2072 static void read_dump(const char *fname)
2073 {
2074 char *buf, *pos, *line;
2075
2076 buf = read_text_file(fname);
2077 if (!buf)
2078 /* No symbol versions, silently ignore */
2079 return;
2080
2081 pos = buf;
2082
2083 while ((line = get_line(&pos))) {
2084 char *symname, *namespace, *modname, *d, *export;
2085 unsigned int crc;
2086 struct module *mod;
2087 struct symbol *s;
2088 bool gpl_only;
2089
2090 if (!(symname = strchr(line, '\t')))
2091 goto fail;
2092 *symname++ = '\0';
2093 if (!(modname = strchr(symname, '\t')))
2094 goto fail;
2095 *modname++ = '\0';
2096 if (!(export = strchr(modname, '\t')))
2097 goto fail;
2098 *export++ = '\0';
2099 if (!(namespace = strchr(export, '\t')))
2100 goto fail;
2101 *namespace++ = '\0';
2102
2103 crc = strtoul(line, &d, 16);
2104 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2105 goto fail;
2106
2107 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2108 gpl_only = true;
2109 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2110 gpl_only = false;
2111 } else {
2112 error("%s: unknown license %s. skip", symname, export);
2113 continue;
2114 }
2115
2116 mod = find_module(modname);
2117 if (!mod) {
2118 mod = new_module(modname, strlen(modname));
2119 mod->from_dump = true;
2120 }
2121 s = sym_add_exported(symname, mod, gpl_only, namespace);
2122 sym_set_crc(s, crc);
2123 }
2124 free(buf);
2125 return;
2126 fail:
2127 free(buf);
2128 fatal("parse error in symbol dump file\n");
2129 }
2130
write_dump(const char * fname)2131 static void write_dump(const char *fname)
2132 {
2133 struct buffer buf = { };
2134 struct module *mod;
2135 struct symbol *sym;
2136
2137 list_for_each_entry(mod, &modules, list) {
2138 if (mod->from_dump)
2139 continue;
2140 list_for_each_entry(sym, &mod->exported_symbols, list) {
2141 if (trim_unused_exports && !sym->used)
2142 continue;
2143
2144 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2145 sym->crc, sym->name, mod->name,
2146 sym->is_gpl_only ? "_GPL" : "",
2147 sym->namespace);
2148 }
2149 }
2150 write_buf(&buf, fname);
2151 free(buf.p);
2152 }
2153
write_namespace_deps_files(const char * fname)2154 static void write_namespace_deps_files(const char *fname)
2155 {
2156 struct module *mod;
2157 struct namespace_list *ns;
2158 struct buffer ns_deps_buf = {};
2159
2160 list_for_each_entry(mod, &modules, list) {
2161
2162 if (mod->from_dump || list_empty(&mod->missing_namespaces))
2163 continue;
2164
2165 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2166
2167 list_for_each_entry(ns, &mod->missing_namespaces, list)
2168 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2169
2170 buf_printf(&ns_deps_buf, "\n");
2171 }
2172
2173 write_if_changed(&ns_deps_buf, fname);
2174 free(ns_deps_buf.p);
2175 }
2176
2177 struct dump_list {
2178 struct list_head list;
2179 const char *file;
2180 };
2181
main(int argc,char ** argv)2182 int main(int argc, char **argv)
2183 {
2184 struct module *mod;
2185 char *missing_namespace_deps = NULL;
2186 char *unused_exports_white_list = NULL;
2187 char *dump_write = NULL, *files_source = NULL;
2188 int opt;
2189 LIST_HEAD(dump_lists);
2190 struct dump_list *dl, *dl2;
2191
2192 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2193 switch (opt) {
2194 case 'e':
2195 external_module = true;
2196 break;
2197 case 'i':
2198 dl = NOFAIL(malloc(sizeof(*dl)));
2199 dl->file = optarg;
2200 list_add_tail(&dl->list, &dump_lists);
2201 break;
2202 case 'M':
2203 module_enabled = true;
2204 break;
2205 case 'm':
2206 modversions = true;
2207 break;
2208 case 'n':
2209 ignore_missing_files = true;
2210 break;
2211 case 'o':
2212 dump_write = optarg;
2213 break;
2214 case 'a':
2215 all_versions = true;
2216 break;
2217 case 'T':
2218 files_source = optarg;
2219 break;
2220 case 't':
2221 trim_unused_exports = true;
2222 break;
2223 case 'u':
2224 unused_exports_white_list = optarg;
2225 break;
2226 case 'W':
2227 extra_warn = true;
2228 break;
2229 case 'w':
2230 warn_unresolved = true;
2231 break;
2232 case 'E':
2233 sec_mismatch_warn_only = false;
2234 break;
2235 case 'N':
2236 allow_missing_ns_imports = true;
2237 break;
2238 case 'd':
2239 missing_namespace_deps = optarg;
2240 break;
2241 default:
2242 exit(1);
2243 }
2244 }
2245
2246 list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2247 read_dump(dl->file);
2248 list_del(&dl->list);
2249 free(dl);
2250 }
2251
2252 while (optind < argc)
2253 read_symbols(argv[optind++]);
2254
2255 if (files_source)
2256 read_symbols_from_files(files_source);
2257
2258 list_for_each_entry(mod, &modules, list) {
2259 if (mod->from_dump || mod->is_vmlinux)
2260 continue;
2261
2262 check_modname_len(mod);
2263 check_exports(mod);
2264 }
2265
2266 if (unused_exports_white_list)
2267 handle_white_list_exports(unused_exports_white_list);
2268
2269 list_for_each_entry(mod, &modules, list) {
2270 if (mod->from_dump)
2271 continue;
2272
2273 if (mod->is_vmlinux)
2274 write_vmlinux_export_c_file(mod);
2275 else
2276 write_mod_c_file(mod);
2277 }
2278
2279 if (missing_namespace_deps)
2280 write_namespace_deps_files(missing_namespace_deps);
2281
2282 if (dump_write)
2283 write_dump(dump_write);
2284 if (sec_mismatch_count && !sec_mismatch_warn_only)
2285 error("Section mismatches detected.\n"
2286 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2287
2288 if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2289 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2290 nr_unresolved - MAX_UNRESOLVED_REPORTS);
2291
2292 return error_occurred ? 1 : 0;
2293 }
2294