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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 <stdio.h>
17#include <ctype.h>
18#include <string.h>
19#include <limits.h>
20#include <stdbool.h>
21#include <errno.h>
22#include "modpost.h"
23#include "../../include/linux/license.h"
24
25/* Are we using CONFIG_MODVERSIONS? */
26static int modversions = 0;
27/* Warn about undefined symbols? (do so if we have vmlinux) */
28static int have_vmlinux = 0;
29/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
30static int all_versions = 0;
31/* If we are modposting external module set to 1 */
32static int external_module = 0;
33/* Only warn about unresolved symbols */
34static int warn_unresolved = 0;
35/* How a symbol is exported */
36static int sec_mismatch_count = 0;
37static int sec_mismatch_fatal = 0;
38/* ignore missing files */
39static int ignore_missing_files;
40/* If set to 1, only warn (instead of error) about missing ns imports */
41static int allow_missing_ns_imports;
42
43enum export {
44 export_plain, export_unused, export_gpl,
45 export_unused_gpl, export_gpl_future, export_unknown
46};
47
48/* In kernel, this size is defined in linux/module.h;
49 * here we use Elf_Addr instead of long for covering cross-compile
50 */
51
52#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
53
54void __attribute__((format(printf, 2, 3)))
55modpost_log(enum loglevel loglevel, const char *fmt, ...)
56{
57 va_list arglist;
58
59 switch (loglevel) {
60 case LOG_WARN:
61 fprintf(stderr, "WARNING: ");
62 break;
63 case LOG_ERROR:
64 fprintf(stderr, "ERROR: ");
65 break;
66 case LOG_FATAL:
67 fprintf(stderr, "FATAL: ");
68 break;
69 default: /* invalid loglevel, ignore */
70 break;
71 }
72
73 fprintf(stderr, "modpost: ");
74
75 va_start(arglist, fmt);
76 vfprintf(stderr, fmt, arglist);
77 va_end(arglist);
78
79 if (loglevel == LOG_FATAL)
80 exit(1);
81}
82
83static inline bool strends(const char *str, const char *postfix)
84{
85 if (strlen(str) < strlen(postfix))
86 return false;
87
88 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
89}
90
91void *do_nofail(void *ptr, const char *expr)
92{
93 if (!ptr)
94 fatal("Memory allocation failure: %s.\n", expr);
95
96 return ptr;
97}
98
99char *read_text_file(const char *filename)
100{
101 struct stat st;
102 size_t nbytes;
103 int fd;
104 char *buf;
105
106 fd = open(filename, O_RDONLY);
107 if (fd < 0) {
108 perror(filename);
109 exit(1);
110 }
111
112 if (fstat(fd, &st) < 0) {
113 perror(filename);
114 exit(1);
115 }
116
117 buf = NOFAIL(malloc(st.st_size + 1));
118
119 nbytes = st.st_size;
120
121 while (nbytes) {
122 ssize_t bytes_read;
123
124 bytes_read = read(fd, buf, nbytes);
125 if (bytes_read < 0) {
126 perror(filename);
127 exit(1);
128 }
129
130 nbytes -= bytes_read;
131 }
132 buf[st.st_size] = '\0';
133
134 close(fd);
135
136 return buf;
137}
138
139char *get_line(char **stringp)
140{
141 char *orig = *stringp, *next;
142
143 /* do not return the unwanted extra line at EOF */
144 if (!orig || *orig == '\0')
145 return NULL;
146
147 /* don't use strsep here, it is not available everywhere */
148 next = strchr(orig, '\n');
149 if (next)
150 *next++ = '\0';
151
152 *stringp = next;
153
154 return orig;
155}
156
157/* A list of all modules we processed */
158static struct module *modules;
159
160static struct module *find_module(const char *modname)
161{
162 struct module *mod;
163
164 for (mod = modules; mod; mod = mod->next)
165 if (strcmp(mod->name, modname) == 0)
166 break;
167 return mod;
168}
169
170static struct module *new_module(const char *modname)
171{
172 struct module *mod;
173
174 mod = NOFAIL(malloc(sizeof(*mod) + strlen(modname) + 1));
175 memset(mod, 0, sizeof(*mod));
176
177 /* add to list */
178 strcpy(mod->name, modname);
179 mod->is_vmlinux = (strcmp(modname, "vmlinux") == 0);
180 mod->gpl_compatible = -1;
181 mod->next = modules;
182 modules = mod;
183
184 if (mod->is_vmlinux)
185 have_vmlinux = 1;
186
187 return mod;
188}
189
190/* A hash of all exported symbols,
191 * struct symbol is also used for lists of unresolved symbols */
192
193#define SYMBOL_HASH_SIZE 1024
194
195struct symbol {
196 struct symbol *next;
197 struct module *module;
198 unsigned int crc;
199 int crc_valid;
200 char *namespace;
201 unsigned int weak:1;
202 unsigned int is_static:1; /* 1 if symbol is not global */
203 enum export export; /* Type of export */
204 char name[];
205};
206
207static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
208
209/* This is based on the hash agorithm from gdbm, via tdb */
210static inline unsigned int tdb_hash(const char *name)
211{
212 unsigned value; /* Used to compute the hash value. */
213 unsigned i; /* Used to cycle through random values. */
214
215 /* Set the initial value from the key size. */
216 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
217 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
218
219 return (1103515243 * value + 12345);
220}
221
222/**
223 * Allocate a new symbols for use in the hash of exported symbols or
224 * the list of unresolved symbols per module
225 **/
226static struct symbol *alloc_symbol(const char *name, unsigned int weak,
227 struct symbol *next)
228{
229 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
230
231 memset(s, 0, sizeof(*s));
232 strcpy(s->name, name);
233 s->weak = weak;
234 s->next = next;
235 s->is_static = 1;
236 return s;
237}
238
239/* For the hash of exported symbols */
240static struct symbol *new_symbol(const char *name, struct module *module,
241 enum export export)
242{
243 unsigned int hash;
244
245 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
246 symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
247
248 return symbolhash[hash];
249}
250
251static struct symbol *find_symbol(const char *name)
252{
253 struct symbol *s;
254
255 /* For our purposes, .foo matches foo. PPC64 needs this. */
256 if (name[0] == '.')
257 name++;
258
259 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
260 if (strcmp(s->name, name) == 0)
261 return s;
262 }
263 return NULL;
264}
265
266static bool contains_namespace(struct namespace_list *list,
267 const char *namespace)
268{
269 for (; list; list = list->next)
270 if (!strcmp(list->namespace, namespace))
271 return true;
272
273 return false;
274}
275
276static void add_namespace(struct namespace_list **list, const char *namespace)
277{
278 struct namespace_list *ns_entry;
279
280 if (!contains_namespace(*list, namespace)) {
281 ns_entry = NOFAIL(malloc(sizeof(struct namespace_list) +
282 strlen(namespace) + 1));
283 strcpy(ns_entry->namespace, namespace);
284 ns_entry->next = *list;
285 *list = ns_entry;
286 }
287}
288
289static bool module_imports_namespace(struct module *module,
290 const char *namespace)
291{
292 return contains_namespace(module->imported_namespaces, namespace);
293}
294
295static const struct {
296 const char *str;
297 enum export export;
298} export_list[] = {
299 { .str = "EXPORT_SYMBOL", .export = export_plain },
300 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
301 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
302 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
303 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
304 { .str = "(unknown)", .export = export_unknown },
305};
306
307
308static const char *export_str(enum export ex)
309{
310 return export_list[ex].str;
311}
312
313static enum export export_no(const char *s)
314{
315 int i;
316
317 if (!s)
318 return export_unknown;
319 for (i = 0; export_list[i].export != export_unknown; i++) {
320 if (strcmp(export_list[i].str, s) == 0)
321 return export_list[i].export;
322 }
323 return export_unknown;
324}
325
326static 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 if (info->hdr->e_type != ET_REL)
332 offset -= sechdr->sh_addr;
333
334 return (void *)info->hdr + sechdr->sh_offset + offset;
335}
336
337static void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
338{
339 return sym_get_data_by_offset(info, get_secindex(info, sym),
340 sym->st_value);
341}
342
343static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
344{
345 return sym_get_data_by_offset(info, info->secindex_strings,
346 sechdr->sh_name);
347}
348
349static const char *sec_name(const struct elf_info *info, int secindex)
350{
351 return sech_name(info, &info->sechdrs[secindex]);
352}
353
354#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
355
356static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
357{
358 const char *secname = sec_name(elf, sec);
359
360 if (strstarts(secname, "___ksymtab+"))
361 return export_plain;
362 else if (strstarts(secname, "___ksymtab_unused+"))
363 return export_unused;
364 else if (strstarts(secname, "___ksymtab_gpl+"))
365 return export_gpl;
366 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
367 return export_unused_gpl;
368 else if (strstarts(secname, "___ksymtab_gpl_future+"))
369 return export_gpl_future;
370 else
371 return export_unknown;
372}
373
374static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
375{
376 if (sec == elf->export_sec)
377 return export_plain;
378 else if (sec == elf->export_unused_sec)
379 return export_unused;
380 else if (sec == elf->export_gpl_sec)
381 return export_gpl;
382 else if (sec == elf->export_unused_gpl_sec)
383 return export_unused_gpl;
384 else if (sec == elf->export_gpl_future_sec)
385 return export_gpl_future;
386 else
387 return export_unknown;
388}
389
390static const char *namespace_from_kstrtabns(const struct elf_info *info,
391 const Elf_Sym *sym)
392{
393 const char *value = sym_get_data(info, sym);
394 return value[0] ? value : NULL;
395}
396
397static void sym_update_namespace(const char *symname, const char *namespace)
398{
399 struct symbol *s = find_symbol(symname);
400
401 /*
402 * That symbol should have been created earlier and thus this is
403 * actually an assertion.
404 */
405 if (!s) {
406 merror("Could not update namespace(%s) for symbol %s\n",
407 namespace, symname);
408 return;
409 }
410
411 free(s->namespace);
412 s->namespace =
413 namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
414}
415
416/**
417 * Add an exported symbol - it may have already been added without a
418 * CRC, in this case just update the CRC
419 **/
420static struct symbol *sym_add_exported(const char *name, struct module *mod,
421 enum export export)
422{
423 struct symbol *s = find_symbol(name);
424
425 if (!s) {
426 s = new_symbol(name, mod, export);
427 } else if (!external_module || s->module->is_vmlinux ||
428 s->module == mod) {
429 warn("%s: '%s' exported twice. Previous export was in %s%s\n",
430 mod->name, name, s->module->name,
431 s->module->is_vmlinux ? "" : ".ko");
432 return s;
433 }
434
435 s->module = mod;
436 s->export = export;
437 return s;
438}
439
440static void sym_set_crc(const char *name, unsigned int crc)
441{
442 struct symbol *s = find_symbol(name);
443
444 /*
445 * Ignore stand-alone __crc_*, which might be auto-generated symbols
446 * such as __*_veneer in ARM ELF.
447 */
448 if (!s)
449 return;
450
451 s->crc = crc;
452 s->crc_valid = 1;
453}
454
455static void *grab_file(const char *filename, size_t *size)
456{
457 struct stat st;
458 void *map = MAP_FAILED;
459 int fd;
460
461 fd = open(filename, O_RDONLY);
462 if (fd < 0)
463 return NULL;
464 if (fstat(fd, &st))
465 goto failed;
466
467 *size = st.st_size;
468 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
469
470failed:
471 close(fd);
472 if (map == MAP_FAILED)
473 return NULL;
474 return map;
475}
476
477static void release_file(void *file, size_t size)
478{
479 munmap(file, size);
480}
481
482static int parse_elf(struct elf_info *info, const char *filename)
483{
484 unsigned int i;
485 Elf_Ehdr *hdr;
486 Elf_Shdr *sechdrs;
487 Elf_Sym *sym;
488 const char *secstrings;
489 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
490
491 hdr = grab_file(filename, &info->size);
492 if (!hdr) {
493 if (ignore_missing_files) {
494 fprintf(stderr, "%s: %s (ignored)\n", filename,
495 strerror(errno));
496 return 0;
497 }
498 perror(filename);
499 exit(1);
500 }
501 info->hdr = hdr;
502 if (info->size < sizeof(*hdr)) {
503 /* file too small, assume this is an empty .o file */
504 return 0;
505 }
506 /* Is this a valid ELF file? */
507 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
508 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
509 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
510 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
511 /* Not an ELF file - silently ignore it */
512 return 0;
513 }
514 /* Fix endianness in ELF header */
515 hdr->e_type = TO_NATIVE(hdr->e_type);
516 hdr->e_machine = TO_NATIVE(hdr->e_machine);
517 hdr->e_version = TO_NATIVE(hdr->e_version);
518 hdr->e_entry = TO_NATIVE(hdr->e_entry);
519 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
520 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
521 hdr->e_flags = TO_NATIVE(hdr->e_flags);
522 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
523 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
524 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
525 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
526 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
527 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
528 sechdrs = (void *)hdr + hdr->e_shoff;
529 info->sechdrs = sechdrs;
530
531 /* Check if file offset is correct */
532 if (hdr->e_shoff > info->size) {
533 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
534 (unsigned long)hdr->e_shoff, filename, info->size);
535 return 0;
536 }
537
538 if (hdr->e_shnum == SHN_UNDEF) {
539 /*
540 * There are more than 64k sections,
541 * read count from .sh_size.
542 */
543 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
544 }
545 else {
546 info->num_sections = hdr->e_shnum;
547 }
548 if (hdr->e_shstrndx == SHN_XINDEX) {
549 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
550 }
551 else {
552 info->secindex_strings = hdr->e_shstrndx;
553 }
554
555 /* Fix endianness in section headers */
556 for (i = 0; i < info->num_sections; i++) {
557 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
558 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
559 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
560 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
561 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
562 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
563 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
564 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
565 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
566 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
567 }
568 /* Find symbol table. */
569 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
570 for (i = 1; i < info->num_sections; i++) {
571 const char *secname;
572 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
573
574 if (!nobits && sechdrs[i].sh_offset > info->size) {
575 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
576 "sizeof(*hrd)=%zu\n", filename,
577 (unsigned long)sechdrs[i].sh_offset,
578 sizeof(*hdr));
579 return 0;
580 }
581 secname = secstrings + sechdrs[i].sh_name;
582 if (strcmp(secname, ".modinfo") == 0) {
583 if (nobits)
584 fatal("%s has NOBITS .modinfo\n", filename);
585 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
586 info->modinfo_len = sechdrs[i].sh_size;
587 } else if (strcmp(secname, "__ksymtab") == 0)
588 info->export_sec = i;
589 else if (strcmp(secname, "__ksymtab_unused") == 0)
590 info->export_unused_sec = i;
591 else if (strcmp(secname, "__ksymtab_gpl") == 0)
592 info->export_gpl_sec = i;
593 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
594 info->export_unused_gpl_sec = i;
595 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
596 info->export_gpl_future_sec = i;
597
598 if (sechdrs[i].sh_type == SHT_SYMTAB) {
599 unsigned int sh_link_idx;
600 symtab_idx = i;
601 info->symtab_start = (void *)hdr +
602 sechdrs[i].sh_offset;
603 info->symtab_stop = (void *)hdr +
604 sechdrs[i].sh_offset + sechdrs[i].sh_size;
605 sh_link_idx = sechdrs[i].sh_link;
606 info->strtab = (void *)hdr +
607 sechdrs[sh_link_idx].sh_offset;
608 }
609
610 /* 32bit section no. table? ("more than 64k sections") */
611 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
612 symtab_shndx_idx = i;
613 info->symtab_shndx_start = (void *)hdr +
614 sechdrs[i].sh_offset;
615 info->symtab_shndx_stop = (void *)hdr +
616 sechdrs[i].sh_offset + sechdrs[i].sh_size;
617 }
618 }
619 if (!info->symtab_start)
620 fatal("%s has no symtab?\n", filename);
621
622 /* Fix endianness in symbols */
623 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
624 sym->st_shndx = TO_NATIVE(sym->st_shndx);
625 sym->st_name = TO_NATIVE(sym->st_name);
626 sym->st_value = TO_NATIVE(sym->st_value);
627 sym->st_size = TO_NATIVE(sym->st_size);
628 }
629
630 if (symtab_shndx_idx != ~0U) {
631 Elf32_Word *p;
632 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
633 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
634 filename, sechdrs[symtab_shndx_idx].sh_link,
635 symtab_idx);
636 /* Fix endianness */
637 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
638 p++)
639 *p = TO_NATIVE(*p);
640 }
641
642 return 1;
643}
644
645static void parse_elf_finish(struct elf_info *info)
646{
647 release_file(info->hdr, info->size);
648}
649
650static int ignore_undef_symbol(struct elf_info *info, const char *symname)
651{
652 /* ignore __this_module, it will be resolved shortly */
653 if (strcmp(symname, "__this_module") == 0)
654 return 1;
655 /* ignore global offset table */
656 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
657 return 1;
658 if (info->hdr->e_machine == EM_PPC)
659 /* Special register function linked on all modules during final link of .ko */
660 if (strstarts(symname, "_restgpr_") ||
661 strstarts(symname, "_savegpr_") ||
662 strstarts(symname, "_rest32gpr_") ||
663 strstarts(symname, "_save32gpr_") ||
664 strstarts(symname, "_restvr_") ||
665 strstarts(symname, "_savevr_"))
666 return 1;
667 if (info->hdr->e_machine == EM_PPC64)
668 /* Special register function linked on all modules during final link of .ko */
669 if (strstarts(symname, "_restgpr0_") ||
670 strstarts(symname, "_savegpr0_") ||
671 strstarts(symname, "_restvr_") ||
672 strstarts(symname, "_savevr_") ||
673 strcmp(symname, ".TOC.") == 0)
674 return 1;
675 /* Do not ignore this symbol */
676 return 0;
677}
678
679static void handle_modversion(const struct module *mod,
680 const struct elf_info *info,
681 const Elf_Sym *sym, const char *symname)
682{
683 unsigned int crc;
684
685 if (sym->st_shndx == SHN_UNDEF) {
686 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n",
687 symname, mod->name, mod->is_vmlinux ? "" : ".ko");
688 return;
689 }
690
691 if (sym->st_shndx == SHN_ABS) {
692 crc = sym->st_value;
693 } else {
694 unsigned int *crcp;
695
696 /* symbol points to the CRC in the ELF object */
697 crcp = sym_get_data(info, sym);
698 crc = TO_NATIVE(*crcp);
699 }
700 sym_set_crc(symname, crc);
701}
702
703static void handle_symbol(struct module *mod, struct elf_info *info,
704 const Elf_Sym *sym, const char *symname)
705{
706 enum export export;
707 const char *name;
708
709 if (strstarts(symname, "__ksymtab"))
710 export = export_from_secname(info, get_secindex(info, sym));
711 else
712 export = export_from_sec(info, get_secindex(info, sym));
713
714 switch (sym->st_shndx) {
715 case SHN_COMMON:
716 if (strstarts(symname, "__gnu_lto_")) {
717 /* Should warn here, but modpost runs before the linker */
718 } else
719 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
720 break;
721 case SHN_UNDEF:
722 /* undefined symbol */
723 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
724 ELF_ST_BIND(sym->st_info) != STB_WEAK)
725 break;
726 if (ignore_undef_symbol(info, symname))
727 break;
728 if (info->hdr->e_machine == EM_SPARC ||
729 info->hdr->e_machine == EM_SPARCV9) {
730 /* Ignore register directives. */
731 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
732 break;
733 if (symname[0] == '.') {
734 char *munged = NOFAIL(strdup(symname));
735 munged[0] = '_';
736 munged[1] = toupper(munged[1]);
737 symname = munged;
738 }
739 }
740
741 mod->unres = alloc_symbol(symname,
742 ELF_ST_BIND(sym->st_info) == STB_WEAK,
743 mod->unres);
744 break;
745 default:
746 /* All exported symbols */
747 if (strstarts(symname, "__ksymtab_")) {
748 name = symname + strlen("__ksymtab_");
749 sym_add_exported(name, mod, export);
750 }
751 if (strcmp(symname, "init_module") == 0)
752 mod->has_init = 1;
753 if (strcmp(symname, "cleanup_module") == 0)
754 mod->has_cleanup = 1;
755 break;
756 }
757}
758
759/**
760 * Parse tag=value strings from .modinfo section
761 **/
762static char *next_string(char *string, unsigned long *secsize)
763{
764 /* Skip non-zero chars */
765 while (string[0]) {
766 string++;
767 if ((*secsize)-- <= 1)
768 return NULL;
769 }
770
771 /* Skip any zero padding. */
772 while (!string[0]) {
773 string++;
774 if ((*secsize)-- <= 1)
775 return NULL;
776 }
777 return string;
778}
779
780static char *get_next_modinfo(struct elf_info *info, const char *tag,
781 char *prev)
782{
783 char *p;
784 unsigned int taglen = strlen(tag);
785 char *modinfo = info->modinfo;
786 unsigned long size = info->modinfo_len;
787
788 if (prev) {
789 size -= prev - modinfo;
790 modinfo = next_string(prev, &size);
791 }
792
793 for (p = modinfo; p; p = next_string(p, &size)) {
794 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
795 return p + taglen + 1;
796 }
797 return NULL;
798}
799
800static char *get_modinfo(struct elf_info *info, const char *tag)
801
802{
803 return get_next_modinfo(info, tag, NULL);
804}
805
806/**
807 * Test if string s ends in string sub
808 * return 0 if match
809 **/
810static int strrcmp(const char *s, const char *sub)
811{
812 int slen, sublen;
813
814 if (!s || !sub)
815 return 1;
816
817 slen = strlen(s);
818 sublen = strlen(sub);
819
820 if ((slen == 0) || (sublen == 0))
821 return 1;
822
823 if (sublen > slen)
824 return 1;
825
826 return memcmp(s + slen - sublen, sub, sublen);
827}
828
829static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
830{
831 if (sym)
832 return elf->strtab + sym->st_name;
833 else
834 return "(unknown)";
835}
836
837/* The pattern is an array of simple patterns.
838 * "foo" will match an exact string equal to "foo"
839 * "*foo" will match a string that ends with "foo"
840 * "foo*" will match a string that begins with "foo"
841 * "*foo*" will match a string that contains "foo"
842 */
843static int match(const char *sym, const char * const pat[])
844{
845 const char *p;
846 while (*pat) {
847 p = *pat++;
848 const char *endp = p + strlen(p) - 1;
849
850 /* "*foo*" */
851 if (*p == '*' && *endp == '*') {
852 char *bare = NOFAIL(strndup(p + 1, strlen(p) - 2));
853 char *here = strstr(sym, bare);
854
855 free(bare);
856 if (here != NULL)
857 return 1;
858 }
859 /* "*foo" */
860 else if (*p == '*') {
861 if (strrcmp(sym, p + 1) == 0)
862 return 1;
863 }
864 /* "foo*" */
865 else if (*endp == '*') {
866 if (strncmp(sym, p, strlen(p) - 1) == 0)
867 return 1;
868 }
869 /* no wildcards */
870 else {
871 if (strcmp(p, sym) == 0)
872 return 1;
873 }
874 }
875 /* no match */
876 return 0;
877}
878
879/* sections that we do not want to do full section mismatch check on */
880static const char *const section_white_list[] =
881{
882 ".comment*",
883 ".debug*",
884 ".cranges", /* sh64 */
885 ".zdebug*", /* Compressed debug sections. */
886 ".GCC.command.line", /* record-gcc-switches */
887 ".mdebug*", /* alpha, score, mips etc. */
888 ".pdr", /* alpha, score, mips etc. */
889 ".stab*",
890 ".note*",
891 ".got*",
892 ".toc*",
893 ".xt.prop", /* xtensa */
894 ".xt.lit", /* xtensa */
895 ".arcextmap*", /* arc */
896 ".gnu.linkonce.arcext*", /* arc : modules */
897 ".cmem*", /* EZchip */
898 ".fmt_slot*", /* EZchip */
899 ".gnu.lto*",
900 ".discard.*",
901 NULL
902};
903
904/*
905 * This is used to find sections missing the SHF_ALLOC flag.
906 * The cause of this is often a section specified in assembler
907 * without "ax" / "aw".
908 */
909static void check_section(const char *modname, struct elf_info *elf,
910 Elf_Shdr *sechdr)
911{
912 const char *sec = sech_name(elf, sechdr);
913
914 if (sechdr->sh_type == SHT_PROGBITS &&
915 !(sechdr->sh_flags & SHF_ALLOC) &&
916 !match(sec, section_white_list)) {
917 warn("%s (%s): unexpected non-allocatable section.\n"
918 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
919 "Note that for example <linux/init.h> contains\n"
920 "section definitions for use in .S files.\n\n",
921 modname, sec);
922 }
923}
924
925
926
927#define ALL_INIT_DATA_SECTIONS \
928 ".init.setup", ".init.rodata", ".meminit.rodata", \
929 ".init.data", ".meminit.data"
930#define ALL_EXIT_DATA_SECTIONS \
931 ".exit.data", ".memexit.data"
932
933#define ALL_INIT_TEXT_SECTIONS \
934 ".init.text", ".meminit.text"
935#define ALL_EXIT_TEXT_SECTIONS \
936 ".exit.text", ".memexit.text"
937
938#define ALL_PCI_INIT_SECTIONS \
939 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
940 ".pci_fixup_enable", ".pci_fixup_resume", \
941 ".pci_fixup_resume_early", ".pci_fixup_suspend"
942
943#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
944#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
945
946#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
947#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
948
949#define DATA_SECTIONS ".data", ".data.rel"
950#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
951 ".kprobes.text", ".cpuidle.text", ".noinstr.text"
952#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
953 ".fixup", ".entry.text", ".exception.text", ".text.*", \
954 ".coldtext"
955
956#define INIT_SECTIONS ".init.*"
957#define MEM_INIT_SECTIONS ".meminit.*"
958
959#define EXIT_SECTIONS ".exit.*"
960#define MEM_EXIT_SECTIONS ".memexit.*"
961
962#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
963 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
964
965/* init data sections */
966static const char *const init_data_sections[] =
967 { ALL_INIT_DATA_SECTIONS, NULL };
968
969/* all init sections */
970static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
971
972/* All init and exit sections (code + data) */
973static const char *const init_exit_sections[] =
974 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
975
976/* all text sections */
977static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
978
979/* data section */
980static const char *const data_sections[] = { DATA_SECTIONS, NULL };
981
982
983/* symbols in .data that may refer to init/exit sections */
984#define DEFAULT_SYMBOL_WHITE_LIST \
985 "*driver", \
986 "*_template", /* scsi uses *_template a lot */ \
987 "*_timer", /* arm uses ops structures named _timer a lot */ \
988 "*_sht", /* scsi also used *_sht to some extent */ \
989 "*_ops", \
990 "*_probe", \
991 "*_probe_one", \
992 "*_console"
993
994static const char *const head_sections[] = { ".head.text*", NULL };
995static const char *const linker_symbols[] =
996 { "__init_begin", "_sinittext", "_einittext", NULL };
997static const char *const optim_symbols[] = { "*.constprop.*", NULL };
998
999enum mismatch {
1000 TEXT_TO_ANY_INIT,
1001 DATA_TO_ANY_INIT,
1002 TEXT_TO_ANY_EXIT,
1003 DATA_TO_ANY_EXIT,
1004 XXXINIT_TO_SOME_INIT,
1005 XXXEXIT_TO_SOME_EXIT,
1006 ANY_INIT_TO_ANY_EXIT,
1007 ANY_EXIT_TO_ANY_INIT,
1008 EXPORT_TO_INIT_EXIT,
1009 EXTABLE_TO_NON_TEXT,
1010};
1011
1012/**
1013 * Describe how to match sections on different criterias:
1014 *
1015 * @fromsec: Array of sections to be matched.
1016 *
1017 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
1018 * this array is forbidden (black-list). Can be empty.
1019 *
1020 * @good_tosec: Relocations applied to a section in @fromsec must be
1021 * targetting sections in this array (white-list). Can be empty.
1022 *
1023 * @mismatch: Type of mismatch.
1024 *
1025 * @symbol_white_list: Do not match a relocation to a symbol in this list
1026 * even if it is targetting a section in @bad_to_sec.
1027 *
1028 * @handler: Specific handler to call when a match is found. If NULL,
1029 * default_mismatch_handler() will be called.
1030 *
1031 */
1032struct sectioncheck {
1033 const char *fromsec[20];
1034 const char *bad_tosec[20];
1035 const char *good_tosec[20];
1036 enum mismatch mismatch;
1037 const char *symbol_white_list[20];
1038 void (*handler)(const char *modname, struct elf_info *elf,
1039 const struct sectioncheck* const mismatch,
1040 Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
1041
1042};
1043
1044static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
1045 const struct sectioncheck* const mismatch,
1046 Elf_Rela *r, Elf_Sym *sym,
1047 const char *fromsec);
1048
1049static const struct sectioncheck sectioncheck[] = {
1050/* Do not reference init/exit code/data from
1051 * normal code and data
1052 */
1053{
1054 .fromsec = { TEXT_SECTIONS, NULL },
1055 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1056 .mismatch = TEXT_TO_ANY_INIT,
1057 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1058},
1059{
1060 .fromsec = { DATA_SECTIONS, NULL },
1061 .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
1062 .mismatch = DATA_TO_ANY_INIT,
1063 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1064},
1065{
1066 .fromsec = { DATA_SECTIONS, NULL },
1067 .bad_tosec = { INIT_SECTIONS, NULL },
1068 .mismatch = DATA_TO_ANY_INIT,
1069 .symbol_white_list = {
1070 "*_template", "*_timer", "*_sht", "*_ops",
1071 "*_probe", "*_probe_one", "*_console", NULL
1072 },
1073},
1074{
1075 .fromsec = { TEXT_SECTIONS, NULL },
1076 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1077 .mismatch = TEXT_TO_ANY_EXIT,
1078 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1079},
1080{
1081 .fromsec = { DATA_SECTIONS, NULL },
1082 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1083 .mismatch = DATA_TO_ANY_EXIT,
1084 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1085},
1086/* Do not reference init code/data from meminit code/data */
1087{
1088 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1089 .bad_tosec = { INIT_SECTIONS, NULL },
1090 .mismatch = XXXINIT_TO_SOME_INIT,
1091 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1092},
1093/* Do not reference exit code/data from memexit code/data */
1094{
1095 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1096 .bad_tosec = { EXIT_SECTIONS, NULL },
1097 .mismatch = XXXEXIT_TO_SOME_EXIT,
1098 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1099},
1100/* Do not use exit code/data from init code */
1101{
1102 .fromsec = { ALL_INIT_SECTIONS, NULL },
1103 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1104 .mismatch = ANY_INIT_TO_ANY_EXIT,
1105 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1106},
1107/* Do not use init code/data from exit code */
1108{
1109 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1110 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1111 .mismatch = ANY_EXIT_TO_ANY_INIT,
1112 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1113},
1114{
1115 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1116 .bad_tosec = { INIT_SECTIONS, NULL },
1117 .mismatch = ANY_INIT_TO_ANY_EXIT,
1118 .symbol_white_list = { NULL },
1119},
1120/* Do not export init/exit functions or data */
1121{
1122 .fromsec = { "__ksymtab*", NULL },
1123 .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1124 .mismatch = EXPORT_TO_INIT_EXIT,
1125 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1126},
1127{
1128 .fromsec = { "__ex_table", NULL },
1129 /* If you're adding any new black-listed sections in here, consider
1130 * adding a special 'printer' for them in scripts/check_extable.
1131 */
1132 .bad_tosec = { ".altinstr_replacement", NULL },
1133 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
1134 .mismatch = EXTABLE_TO_NON_TEXT,
1135 .handler = extable_mismatch_handler,
1136}
1137};
1138
1139static const struct sectioncheck *section_mismatch(
1140 const char *fromsec, const char *tosec)
1141{
1142 int i;
1143 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1144 const struct sectioncheck *check = §ioncheck[0];
1145
1146 /*
1147 * The target section could be the SHT_NUL section when we're
1148 * handling relocations to un-resolved symbols, trying to match it
1149 * doesn't make much sense and causes build failures on parisc
1150 * architectures.
1151 */
1152 if (*tosec == '\0')
1153 return NULL;
1154
1155 for (i = 0; i < elems; i++) {
1156 if (match(fromsec, check->fromsec)) {
1157 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
1158 return check;
1159 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
1160 return check;
1161 }
1162 check++;
1163 }
1164 return NULL;
1165}
1166
1167/**
1168 * Whitelist to allow certain references to pass with no warning.
1169 *
1170 * Pattern 1:
1171 * If a module parameter is declared __initdata and permissions=0
1172 * then this is legal despite the warning generated.
1173 * We cannot see value of permissions here, so just ignore
1174 * this pattern.
1175 * The pattern is identified by:
1176 * tosec = .init.data
1177 * fromsec = .data*
1178 * atsym =__param*
1179 *
1180 * Pattern 1a:
1181 * module_param_call() ops can refer to __init set function if permissions=0
1182 * The pattern is identified by:
1183 * tosec = .init.text
1184 * fromsec = .data*
1185 * atsym = __param_ops_*
1186 *
1187 * Pattern 2:
1188 * Many drivers utilise a *driver container with references to
1189 * add, remove, probe functions etc.
1190 * the pattern is identified by:
1191 * tosec = init or exit section
1192 * fromsec = data section
1193 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1194 * *probe_one, *_console, *_timer
1195 *
1196 * Pattern 3:
1197 * Whitelist all references from .head.text to any init section
1198 *
1199 * Pattern 4:
1200 * Some symbols belong to init section but still it is ok to reference
1201 * these from non-init sections as these symbols don't have any memory
1202 * allocated for them and symbol address and value are same. So even
1203 * if init section is freed, its ok to reference those symbols.
1204 * For ex. symbols marking the init section boundaries.
1205 * This pattern is identified by
1206 * refsymname = __init_begin, _sinittext, _einittext
1207 *
1208 * Pattern 5:
1209 * GCC may optimize static inlines when fed constant arg(s) resulting
1210 * in functions like cpumask_empty() -- generating an associated symbol
1211 * cpumask_empty.constprop.3 that appears in the audit. If the const that
1212 * is passed in comes from __init, like say nmi_ipi_mask, we get a
1213 * meaningless section warning. May need to add isra symbols too...
1214 * This pattern is identified by
1215 * tosec = init section
1216 * fromsec = text section
1217 * refsymname = *.constprop.*
1218 *
1219 * Pattern 6:
1220 * Hide section mismatch warnings for ELF local symbols. The goal
1221 * is to eliminate false positive modpost warnings caused by
1222 * compiler-generated ELF local symbol names such as ".LANCHOR1".
1223 * Autogenerated symbol names bypass modpost's "Pattern 2"
1224 * whitelisting, which relies on pattern-matching against symbol
1225 * names to work. (One situation where gcc can autogenerate ELF
1226 * local symbols is when "-fsection-anchors" is used.)
1227 **/
1228static int secref_whitelist(const struct sectioncheck *mismatch,
1229 const char *fromsec, const char *fromsym,
1230 const char *tosec, const char *tosym)
1231{
1232 /* Check for pattern 1 */
1233 if (match(tosec, init_data_sections) &&
1234 match(fromsec, data_sections) &&
1235 strstarts(fromsym, "__param"))
1236 return 0;
1237
1238 /* Check for pattern 1a */
1239 if (strcmp(tosec, ".init.text") == 0 &&
1240 match(fromsec, data_sections) &&
1241 strstarts(fromsym, "__param_ops_"))
1242 return 0;
1243
1244 /* Check for pattern 2 */
1245 if (match(tosec, init_exit_sections) &&
1246 match(fromsec, data_sections) &&
1247 match(fromsym, mismatch->symbol_white_list))
1248 return 0;
1249
1250 /* Check for pattern 3 */
1251 if (match(fromsec, head_sections) &&
1252 match(tosec, init_sections))
1253 return 0;
1254
1255 /* Check for pattern 4 */
1256 if (match(tosym, linker_symbols))
1257 return 0;
1258
1259 /* Check for pattern 5 */
1260 if (match(fromsec, text_sections) &&
1261 match(tosec, init_sections) &&
1262 match(fromsym, optim_symbols))
1263 return 0;
1264
1265 /* Check for pattern 6 */
1266 if (strstarts(fromsym, ".L"))
1267 return 0;
1268
1269 return 1;
1270}
1271
1272static inline int is_arm_mapping_symbol(const char *str)
1273{
1274 return str[0] == '$' && strchr("axtd", str[1])
1275 && (str[2] == '\0' || str[2] == '.');
1276}
1277
1278/*
1279 * If there's no name there, ignore it; likewise, ignore it if it's
1280 * one of the magic symbols emitted used by current ARM tools.
1281 *
1282 * Otherwise if find_symbols_between() returns those symbols, they'll
1283 * fail the whitelist tests and cause lots of false alarms ... fixable
1284 * only by merging __exit and __init sections into __text, bloating
1285 * the kernel (which is especially evil on embedded platforms).
1286 */
1287static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1288{
1289 const char *name = elf->strtab + sym->st_name;
1290
1291 if (!name || !strlen(name))
1292 return 0;
1293 return !is_arm_mapping_symbol(name);
1294}
1295
1296/**
1297 * Find symbol based on relocation record info.
1298 * In some cases the symbol supplied is a valid symbol so
1299 * return refsym. If st_name != 0 we assume this is a valid symbol.
1300 * In other cases the symbol needs to be looked up in the symbol table
1301 * based on section and address.
1302 * **/
1303static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1304 Elf_Sym *relsym)
1305{
1306 Elf_Sym *sym;
1307 Elf_Sym *near = NULL;
1308 Elf64_Sword distance = 20;
1309 Elf64_Sword d;
1310 unsigned int relsym_secindex;
1311
1312 if (relsym->st_name != 0)
1313 return relsym;
1314
1315 relsym_secindex = get_secindex(elf, relsym);
1316 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1317 if (get_secindex(elf, sym) != relsym_secindex)
1318 continue;
1319 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1320 continue;
1321 if (!is_valid_name(elf, sym))
1322 continue;
1323 if (sym->st_value == addr)
1324 return sym;
1325 /* Find a symbol nearby - addr are maybe negative */
1326 d = sym->st_value - addr;
1327 if (d < 0)
1328 d = addr - sym->st_value;
1329 if (d < distance) {
1330 distance = d;
1331 near = sym;
1332 }
1333 }
1334 /* We need a close match */
1335 if (distance < 20)
1336 return near;
1337 else
1338 return NULL;
1339}
1340
1341/*
1342 * Find symbols before or equal addr and after addr - in the section sec.
1343 * If we find two symbols with equal offset prefer one with a valid name.
1344 * The ELF format may have a better way to detect what type of symbol
1345 * it is, but this works for now.
1346 **/
1347static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1348 const char *sec)
1349{
1350 Elf_Sym *sym;
1351 Elf_Sym *near = NULL;
1352 Elf_Addr distance = ~0;
1353
1354 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1355 const char *symsec;
1356
1357 if (is_shndx_special(sym->st_shndx))
1358 continue;
1359 symsec = sec_name(elf, get_secindex(elf, sym));
1360 if (strcmp(symsec, sec) != 0)
1361 continue;
1362 if (!is_valid_name(elf, sym))
1363 continue;
1364 if (sym->st_value <= addr) {
1365 if ((addr - sym->st_value) < distance) {
1366 distance = addr - sym->st_value;
1367 near = sym;
1368 } else if ((addr - sym->st_value) == distance) {
1369 near = sym;
1370 }
1371 }
1372 }
1373 return near;
1374}
1375
1376/*
1377 * Convert a section name to the function/data attribute
1378 * .init.text => __init
1379 * .memexitconst => __memconst
1380 * etc.
1381 *
1382 * The memory of returned value has been allocated on a heap. The user of this
1383 * method should free it after usage.
1384*/
1385static char *sec2annotation(const char *s)
1386{
1387 if (match(s, init_exit_sections)) {
1388 char *p = NOFAIL(malloc(20));
1389 char *r = p;
1390
1391 *p++ = '_';
1392 *p++ = '_';
1393 if (*s == '.')
1394 s++;
1395 while (*s && *s != '.')
1396 *p++ = *s++;
1397 *p = '\0';
1398 if (*s == '.')
1399 s++;
1400 if (strstr(s, "rodata") != NULL)
1401 strcat(p, "const ");
1402 else if (strstr(s, "data") != NULL)
1403 strcat(p, "data ");
1404 else
1405 strcat(p, " ");
1406 return r;
1407 } else {
1408 return NOFAIL(strdup(""));
1409 }
1410}
1411
1412static int is_function(Elf_Sym *sym)
1413{
1414 if (sym)
1415 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1416 else
1417 return -1;
1418}
1419
1420static void print_section_list(const char * const list[20])
1421{
1422 const char *const *s = list;
1423
1424 while (*s) {
1425 fprintf(stderr, "%s", *s);
1426 s++;
1427 if (*s)
1428 fprintf(stderr, ", ");
1429 }
1430 fprintf(stderr, "\n");
1431}
1432
1433static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1434{
1435 switch (is_func) {
1436 case 0: *name = "variable"; *name_p = ""; break;
1437 case 1: *name = "function"; *name_p = "()"; break;
1438 default: *name = "(unknown reference)"; *name_p = ""; break;
1439 }
1440}
1441
1442/*
1443 * Print a warning about a section mismatch.
1444 * Try to find symbols near it so user can find it.
1445 * Check whitelist before warning - it may be a false positive.
1446 */
1447static void report_sec_mismatch(const char *modname,
1448 const struct sectioncheck *mismatch,
1449 const char *fromsec,
1450 unsigned long long fromaddr,
1451 const char *fromsym,
1452 int from_is_func,
1453 const char *tosec, const char *tosym,
1454 int to_is_func)
1455{
1456 const char *from, *from_p;
1457 const char *to, *to_p;
1458 char *prl_from;
1459 char *prl_to;
1460
1461 sec_mismatch_count++;
1462
1463 get_pretty_name(from_is_func, &from, &from_p);
1464 get_pretty_name(to_is_func, &to, &to_p);
1465
1466 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1467 "to the %s %s:%s%s\n",
1468 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1469 tosym, to_p);
1470
1471 switch (mismatch->mismatch) {
1472 case TEXT_TO_ANY_INIT:
1473 prl_from = sec2annotation(fromsec);
1474 prl_to = sec2annotation(tosec);
1475 fprintf(stderr,
1476 "The function %s%s() references\n"
1477 "the %s %s%s%s.\n"
1478 "This is often because %s lacks a %s\n"
1479 "annotation or the annotation of %s is wrong.\n",
1480 prl_from, fromsym,
1481 to, prl_to, tosym, to_p,
1482 fromsym, prl_to, tosym);
1483 free(prl_from);
1484 free(prl_to);
1485 break;
1486 case DATA_TO_ANY_INIT: {
1487 prl_to = sec2annotation(tosec);
1488 fprintf(stderr,
1489 "The variable %s references\n"
1490 "the %s %s%s%s\n"
1491 "If the reference is valid then annotate the\n"
1492 "variable with __init* or __refdata (see linux/init.h) "
1493 "or name the variable:\n",
1494 fromsym, to, prl_to, tosym, to_p);
1495 print_section_list(mismatch->symbol_white_list);
1496 free(prl_to);
1497 break;
1498 }
1499 case TEXT_TO_ANY_EXIT:
1500 prl_to = sec2annotation(tosec);
1501 fprintf(stderr,
1502 "The function %s() references a %s in an exit section.\n"
1503 "Often the %s %s%s has valid usage outside the exit section\n"
1504 "and the fix is to remove the %sannotation of %s.\n",
1505 fromsym, to, to, tosym, to_p, prl_to, tosym);
1506 free(prl_to);
1507 break;
1508 case DATA_TO_ANY_EXIT: {
1509 prl_to = sec2annotation(tosec);
1510 fprintf(stderr,
1511 "The variable %s references\n"
1512 "the %s %s%s%s\n"
1513 "If the reference is valid then annotate the\n"
1514 "variable with __exit* (see linux/init.h) or "
1515 "name the variable:\n",
1516 fromsym, to, prl_to, tosym, to_p);
1517 print_section_list(mismatch->symbol_white_list);
1518 free(prl_to);
1519 break;
1520 }
1521 case XXXINIT_TO_SOME_INIT:
1522 case XXXEXIT_TO_SOME_EXIT:
1523 prl_from = sec2annotation(fromsec);
1524 prl_to = sec2annotation(tosec);
1525 fprintf(stderr,
1526 "The %s %s%s%s references\n"
1527 "a %s %s%s%s.\n"
1528 "If %s is only used by %s then\n"
1529 "annotate %s with a matching annotation.\n",
1530 from, prl_from, fromsym, from_p,
1531 to, prl_to, tosym, to_p,
1532 tosym, fromsym, tosym);
1533 free(prl_from);
1534 free(prl_to);
1535 break;
1536 case ANY_INIT_TO_ANY_EXIT:
1537 prl_from = sec2annotation(fromsec);
1538 prl_to = sec2annotation(tosec);
1539 fprintf(stderr,
1540 "The %s %s%s%s references\n"
1541 "a %s %s%s%s.\n"
1542 "This is often seen when error handling "
1543 "in the init function\n"
1544 "uses functionality in the exit path.\n"
1545 "The fix is often to remove the %sannotation of\n"
1546 "%s%s so it may be used outside an exit section.\n",
1547 from, prl_from, fromsym, from_p,
1548 to, prl_to, tosym, to_p,
1549 prl_to, tosym, to_p);
1550 free(prl_from);
1551 free(prl_to);
1552 break;
1553 case ANY_EXIT_TO_ANY_INIT:
1554 prl_from = sec2annotation(fromsec);
1555 prl_to = sec2annotation(tosec);
1556 fprintf(stderr,
1557 "The %s %s%s%s references\n"
1558 "a %s %s%s%s.\n"
1559 "This is often seen when error handling "
1560 "in the exit function\n"
1561 "uses functionality in the init path.\n"
1562 "The fix is often to remove the %sannotation of\n"
1563 "%s%s so it may be used outside an init section.\n",
1564 from, prl_from, fromsym, from_p,
1565 to, prl_to, tosym, to_p,
1566 prl_to, tosym, to_p);
1567 free(prl_from);
1568 free(prl_to);
1569 break;
1570 case EXPORT_TO_INIT_EXIT:
1571 prl_to = sec2annotation(tosec);
1572 fprintf(stderr,
1573 "The symbol %s is exported and annotated %s\n"
1574 "Fix this by removing the %sannotation of %s "
1575 "or drop the export.\n",
1576 tosym, prl_to, prl_to, tosym);
1577 free(prl_to);
1578 break;
1579 case EXTABLE_TO_NON_TEXT:
1580 fatal("There's a special handler for this mismatch type, "
1581 "we should never get here.");
1582 break;
1583 }
1584 fprintf(stderr, "\n");
1585}
1586
1587static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1588 const struct sectioncheck* const mismatch,
1589 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1590{
1591 const char *tosec;
1592 Elf_Sym *to;
1593 Elf_Sym *from;
1594 const char *tosym;
1595 const char *fromsym;
1596
1597 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1598 fromsym = sym_name(elf, from);
1599
1600 if (strstarts(fromsym, "reference___initcall"))
1601 return;
1602
1603 tosec = sec_name(elf, get_secindex(elf, sym));
1604 to = find_elf_symbol(elf, r->r_addend, sym);
1605 tosym = sym_name(elf, to);
1606
1607 /* check whitelist - we may ignore it */
1608 if (secref_whitelist(mismatch,
1609 fromsec, fromsym, tosec, tosym)) {
1610 report_sec_mismatch(modname, mismatch,
1611 fromsec, r->r_offset, fromsym,
1612 is_function(from), tosec, tosym,
1613 is_function(to));
1614 }
1615}
1616
1617static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1618{
1619 if (section_index > elf->num_sections)
1620 fatal("section_index is outside elf->num_sections!\n");
1621
1622 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1623}
1624
1625/*
1626 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1627 * to know the sizeof(struct exception_table_entry) for the target architecture.
1628 */
1629static unsigned int extable_entry_size = 0;
1630static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1631{
1632 /*
1633 * If we're currently checking the second relocation within __ex_table,
1634 * that relocation offset tells us the offsetof(struct
1635 * exception_table_entry, fixup) which is equal to sizeof(struct
1636 * exception_table_entry) divided by two. We use that to our advantage
1637 * since there's no portable way to get that size as every architecture
1638 * seems to go with different sized types. Not pretty but better than
1639 * hard-coding the size for every architecture..
1640 */
1641 if (!extable_entry_size)
1642 extable_entry_size = r->r_offset * 2;
1643}
1644
1645static inline bool is_extable_fault_address(Elf_Rela *r)
1646{
1647 /*
1648 * extable_entry_size is only discovered after we've handled the
1649 * _second_ relocation in __ex_table, so only abort when we're not
1650 * handling the first reloc and extable_entry_size is zero.
1651 */
1652 if (r->r_offset && extable_entry_size == 0)
1653 fatal("extable_entry size hasn't been discovered!\n");
1654
1655 return ((r->r_offset == 0) ||
1656 (r->r_offset % extable_entry_size == 0));
1657}
1658
1659#define is_second_extable_reloc(Start, Cur, Sec) \
1660 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1661
1662static void report_extable_warnings(const char* modname, struct elf_info* elf,
1663 const struct sectioncheck* const mismatch,
1664 Elf_Rela* r, Elf_Sym* sym,
1665 const char* fromsec, const char* tosec)
1666{
1667 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1668 const char* fromsym_name = sym_name(elf, fromsym);
1669 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1670 const char* tosym_name = sym_name(elf, tosym);
1671 const char* from_pretty_name;
1672 const char* from_pretty_name_p;
1673 const char* to_pretty_name;
1674 const char* to_pretty_name_p;
1675
1676 get_pretty_name(is_function(fromsym),
1677 &from_pretty_name, &from_pretty_name_p);
1678 get_pretty_name(is_function(tosym),
1679 &to_pretty_name, &to_pretty_name_p);
1680
1681 warn("%s(%s+0x%lx): Section mismatch in reference"
1682 " from the %s %s%s to the %s %s:%s%s\n",
1683 modname, fromsec, (long)r->r_offset, from_pretty_name,
1684 fromsym_name, from_pretty_name_p,
1685 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1686
1687 if (!match(tosec, mismatch->bad_tosec) &&
1688 is_executable_section(elf, get_secindex(elf, sym)))
1689 fprintf(stderr,
1690 "The relocation at %s+0x%lx references\n"
1691 "section \"%s\" which is not in the list of\n"
1692 "authorized sections. If you're adding a new section\n"
1693 "and/or if this reference is valid, add \"%s\" to the\n"
1694 "list of authorized sections to jump to on fault.\n"
1695 "This can be achieved by adding \"%s\" to \n"
1696 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1697 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1698}
1699
1700static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1701 const struct sectioncheck* const mismatch,
1702 Elf_Rela* r, Elf_Sym* sym,
1703 const char *fromsec)
1704{
1705 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1706
1707 sec_mismatch_count++;
1708
1709 report_extable_warnings(modname, elf, mismatch, r, sym, fromsec, tosec);
1710
1711 if (match(tosec, mismatch->bad_tosec))
1712 fatal("The relocation at %s+0x%lx references\n"
1713 "section \"%s\" which is black-listed.\n"
1714 "Something is seriously wrong and should be fixed.\n"
1715 "You might get more information about where this is\n"
1716 "coming from by using scripts/check_extable.sh %s\n",
1717 fromsec, (long)r->r_offset, tosec, modname);
1718 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1719 if (is_extable_fault_address(r))
1720 fatal("The relocation at %s+0x%lx references\n"
1721 "section \"%s\" which is not executable, IOW\n"
1722 "it is not possible for the kernel to fault\n"
1723 "at that address. Something is seriously wrong\n"
1724 "and should be fixed.\n",
1725 fromsec, (long)r->r_offset, tosec);
1726 else
1727 fatal("The relocation at %s+0x%lx references\n"
1728 "section \"%s\" which is not executable, IOW\n"
1729 "the kernel will fault if it ever tries to\n"
1730 "jump to it. Something is seriously wrong\n"
1731 "and should be fixed.\n",
1732 fromsec, (long)r->r_offset, tosec);
1733 }
1734}
1735
1736static void check_section_mismatch(const char *modname, struct elf_info *elf,
1737 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1738{
1739 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1740 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1741
1742 if (mismatch) {
1743 if (mismatch->handler)
1744 mismatch->handler(modname, elf, mismatch,
1745 r, sym, fromsec);
1746 else
1747 default_mismatch_handler(modname, elf, mismatch,
1748 r, sym, fromsec);
1749 }
1750}
1751
1752static unsigned int *reloc_location(struct elf_info *elf,
1753 Elf_Shdr *sechdr, Elf_Rela *r)
1754{
1755 return sym_get_data_by_offset(elf, sechdr->sh_info, r->r_offset);
1756}
1757
1758static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1759{
1760 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1761 unsigned int *location = reloc_location(elf, sechdr, r);
1762
1763 switch (r_typ) {
1764 case R_386_32:
1765 r->r_addend = TO_NATIVE(*location);
1766 break;
1767 case R_386_PC32:
1768 r->r_addend = TO_NATIVE(*location) + 4;
1769 /* For CONFIG_RELOCATABLE=y */
1770 if (elf->hdr->e_type == ET_EXEC)
1771 r->r_addend += r->r_offset;
1772 break;
1773 }
1774 return 0;
1775}
1776
1777#ifndef R_ARM_CALL
1778#define R_ARM_CALL 28
1779#endif
1780#ifndef R_ARM_JUMP24
1781#define R_ARM_JUMP24 29
1782#endif
1783
1784#ifndef R_ARM_THM_CALL
1785#define R_ARM_THM_CALL 10
1786#endif
1787#ifndef R_ARM_THM_JUMP24
1788#define R_ARM_THM_JUMP24 30
1789#endif
1790#ifndef R_ARM_THM_JUMP19
1791#define R_ARM_THM_JUMP19 51
1792#endif
1793
1794static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1795{
1796 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1797
1798 switch (r_typ) {
1799 case R_ARM_ABS32:
1800 /* From ARM ABI: (S + A) | T */
1801 r->r_addend = (int)(long)
1802 (elf->symtab_start + ELF_R_SYM(r->r_info));
1803 break;
1804 case R_ARM_PC24:
1805 case R_ARM_CALL:
1806 case R_ARM_JUMP24:
1807 case R_ARM_THM_CALL:
1808 case R_ARM_THM_JUMP24:
1809 case R_ARM_THM_JUMP19:
1810 /* From ARM ABI: ((S + A) | T) - P */
1811 r->r_addend = (int)(long)(elf->hdr +
1812 sechdr->sh_offset +
1813 (r->r_offset - sechdr->sh_addr));
1814 break;
1815 default:
1816 return 1;
1817 }
1818 return 0;
1819}
1820
1821static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1822{
1823 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1824 unsigned int *location = reloc_location(elf, sechdr, r);
1825 unsigned int inst;
1826
1827 if (r_typ == R_MIPS_HI16)
1828 return 1; /* skip this */
1829 inst = TO_NATIVE(*location);
1830 switch (r_typ) {
1831 case R_MIPS_LO16:
1832 r->r_addend = inst & 0xffff;
1833 break;
1834 case R_MIPS_26:
1835 r->r_addend = (inst & 0x03ffffff) << 2;
1836 break;
1837 case R_MIPS_32:
1838 r->r_addend = inst;
1839 break;
1840 }
1841 return 0;
1842}
1843
1844static void section_rela(const char *modname, struct elf_info *elf,
1845 Elf_Shdr *sechdr)
1846{
1847 Elf_Sym *sym;
1848 Elf_Rela *rela;
1849 Elf_Rela r;
1850 unsigned int r_sym;
1851 const char *fromsec;
1852
1853 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1854 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1855
1856 fromsec = sech_name(elf, sechdr);
1857 fromsec += strlen(".rela");
1858 /* if from section (name) is know good then skip it */
1859 if (match(fromsec, section_white_list))
1860 return;
1861
1862 for (rela = start; rela < stop; rela++) {
1863 r.r_offset = TO_NATIVE(rela->r_offset);
1864#if KERNEL_ELFCLASS == ELFCLASS64
1865 if (elf->hdr->e_machine == EM_MIPS) {
1866 unsigned int r_typ;
1867 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1868 r_sym = TO_NATIVE(r_sym);
1869 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1870 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1871 } else {
1872 r.r_info = TO_NATIVE(rela->r_info);
1873 r_sym = ELF_R_SYM(r.r_info);
1874 }
1875#else
1876 r.r_info = TO_NATIVE(rela->r_info);
1877 r_sym = ELF_R_SYM(r.r_info);
1878#endif
1879 r.r_addend = TO_NATIVE(rela->r_addend);
1880 sym = elf->symtab_start + r_sym;
1881 /* Skip special sections */
1882 if (is_shndx_special(sym->st_shndx))
1883 continue;
1884 if (is_second_extable_reloc(start, rela, fromsec))
1885 find_extable_entry_size(fromsec, &r);
1886 check_section_mismatch(modname, elf, &r, sym, fromsec);
1887 }
1888}
1889
1890static void section_rel(const char *modname, struct elf_info *elf,
1891 Elf_Shdr *sechdr)
1892{
1893 Elf_Sym *sym;
1894 Elf_Rel *rel;
1895 Elf_Rela r;
1896 unsigned int r_sym;
1897 const char *fromsec;
1898
1899 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1900 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1901
1902 fromsec = sech_name(elf, sechdr);
1903 fromsec += strlen(".rel");
1904 /* if from section (name) is know good then skip it */
1905 if (match(fromsec, section_white_list))
1906 return;
1907
1908 for (rel = start; rel < stop; rel++) {
1909 r.r_offset = TO_NATIVE(rel->r_offset);
1910#if KERNEL_ELFCLASS == ELFCLASS64
1911 if (elf->hdr->e_machine == EM_MIPS) {
1912 unsigned int r_typ;
1913 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1914 r_sym = TO_NATIVE(r_sym);
1915 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1916 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1917 } else {
1918 r.r_info = TO_NATIVE(rel->r_info);
1919 r_sym = ELF_R_SYM(r.r_info);
1920 }
1921#else
1922 r.r_info = TO_NATIVE(rel->r_info);
1923 r_sym = ELF_R_SYM(r.r_info);
1924#endif
1925 r.r_addend = 0;
1926 switch (elf->hdr->e_machine) {
1927 case EM_386:
1928 if (addend_386_rel(elf, sechdr, &r))
1929 continue;
1930 break;
1931 case EM_ARM:
1932 if (addend_arm_rel(elf, sechdr, &r))
1933 continue;
1934 break;
1935 case EM_MIPS:
1936 if (addend_mips_rel(elf, sechdr, &r))
1937 continue;
1938 break;
1939 }
1940 sym = elf->symtab_start + r_sym;
1941 /* Skip special sections */
1942 if (is_shndx_special(sym->st_shndx))
1943 continue;
1944 if (is_second_extable_reloc(start, rel, fromsec))
1945 find_extable_entry_size(fromsec, &r);
1946 check_section_mismatch(modname, elf, &r, sym, fromsec);
1947 }
1948}
1949
1950/**
1951 * A module includes a number of sections that are discarded
1952 * either when loaded or when used as built-in.
1953 * For loaded modules all functions marked __init and all data
1954 * marked __initdata will be discarded when the module has been initialized.
1955 * Likewise for modules used built-in the sections marked __exit
1956 * are discarded because __exit marked function are supposed to be called
1957 * only when a module is unloaded which never happens for built-in modules.
1958 * The check_sec_ref() function traverses all relocation records
1959 * to find all references to a section that reference a section that will
1960 * be discarded and warns about it.
1961 **/
1962static void check_sec_ref(struct module *mod, const char *modname,
1963 struct elf_info *elf)
1964{
1965 int i;
1966 Elf_Shdr *sechdrs = elf->sechdrs;
1967
1968 /* Walk through all sections */
1969 for (i = 0; i < elf->num_sections; i++) {
1970 check_section(modname, elf, &elf->sechdrs[i]);
1971 /* We want to process only relocation sections and not .init */
1972 if (sechdrs[i].sh_type == SHT_RELA)
1973 section_rela(modname, elf, &elf->sechdrs[i]);
1974 else if (sechdrs[i].sh_type == SHT_REL)
1975 section_rel(modname, elf, &elf->sechdrs[i]);
1976 }
1977}
1978
1979static char *remove_dot(char *s)
1980{
1981 size_t n = strcspn(s, ".");
1982
1983 if (n && s[n]) {
1984 size_t m = strspn(s + n + 1, "0123456789");
1985 if (m && (s[n + m] == '.' || s[n + m] == 0))
1986 s[n] = 0;
1987 }
1988 return s;
1989}
1990
1991static void read_symbols(const char *modname)
1992{
1993 const char *symname;
1994 char *version;
1995 char *license;
1996 char *namespace;
1997 struct module *mod;
1998 struct elf_info info = { };
1999 Elf_Sym *sym;
2000
2001 if (!parse_elf(&info, modname))
2002 return;
2003
2004 {
2005 char *tmp;
2006
2007 /* strip trailing .o */
2008 tmp = NOFAIL(strdup(modname));
2009 tmp[strlen(tmp) - 2] = '\0';
2010 mod = new_module(tmp);
2011 free(tmp);
2012 }
2013
2014 if (!mod->is_vmlinux) {
2015 license = get_modinfo(&info, "license");
2016 if (!license)
2017 warn("missing MODULE_LICENSE() in %s\n", modname);
2018 while (license) {
2019 if (license_is_gpl_compatible(license))
2020 mod->gpl_compatible = 1;
2021 else {
2022 mod->gpl_compatible = 0;
2023 break;
2024 }
2025 license = get_next_modinfo(&info, "license", license);
2026 }
2027
2028 namespace = get_modinfo(&info, "import_ns");
2029 while (namespace) {
2030 add_namespace(&mod->imported_namespaces, namespace);
2031 namespace = get_next_modinfo(&info, "import_ns",
2032 namespace);
2033 }
2034 }
2035
2036 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2037 symname = remove_dot(info.strtab + sym->st_name);
2038
2039 handle_symbol(mod, &info, sym, symname);
2040 handle_moddevtable(mod, &info, sym, symname);
2041 }
2042
2043 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2044 symname = remove_dot(info.strtab + sym->st_name);
2045
2046 /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
2047 if (strstarts(symname, "__kstrtabns_"))
2048 sym_update_namespace(symname + strlen("__kstrtabns_"),
2049 namespace_from_kstrtabns(&info,
2050 sym));
2051
2052 if (strstarts(symname, "__crc_"))
2053 handle_modversion(mod, &info, sym,
2054 symname + strlen("__crc_"));
2055 }
2056
2057 // check for static EXPORT_SYMBOL_* functions && global vars
2058 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2059 unsigned char bind = ELF_ST_BIND(sym->st_info);
2060
2061 if (bind == STB_GLOBAL || bind == STB_WEAK) {
2062 struct symbol *s =
2063 find_symbol(remove_dot(info.strtab +
2064 sym->st_name));
2065
2066 if (s)
2067 s->is_static = 0;
2068 }
2069 }
2070
2071 check_sec_ref(mod, modname, &info);
2072
2073 if (!mod->is_vmlinux) {
2074 version = get_modinfo(&info, "version");
2075 if (version || all_versions)
2076 get_src_version(modname, mod->srcversion,
2077 sizeof(mod->srcversion) - 1);
2078 }
2079
2080 parse_elf_finish(&info);
2081
2082 /* Our trick to get versioning for module struct etc. - it's
2083 * never passed as an argument to an exported function, so
2084 * the automatic versioning doesn't pick it up, but it's really
2085 * important anyhow */
2086 if (modversions)
2087 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
2088}
2089
2090static void read_symbols_from_files(const char *filename)
2091{
2092 FILE *in = stdin;
2093 char fname[PATH_MAX];
2094
2095 if (strcmp(filename, "-") != 0) {
2096 in = fopen(filename, "r");
2097 if (!in)
2098 fatal("Can't open filenames file %s: %m", filename);
2099 }
2100
2101 while (fgets(fname, PATH_MAX, in) != NULL) {
2102 if (strends(fname, "\n"))
2103 fname[strlen(fname)-1] = '\0';
2104 read_symbols(fname);
2105 }
2106
2107 if (in != stdin)
2108 fclose(in);
2109}
2110
2111#define SZ 500
2112
2113/* We first write the generated file into memory using the
2114 * following helper, then compare to the file on disk and
2115 * only update the later if anything changed */
2116
2117void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2118 const char *fmt, ...)
2119{
2120 char tmp[SZ];
2121 int len;
2122 va_list ap;
2123
2124 va_start(ap, fmt);
2125 len = vsnprintf(tmp, SZ, fmt, ap);
2126 buf_write(buf, tmp, len);
2127 va_end(ap);
2128}
2129
2130void buf_write(struct buffer *buf, const char *s, int len)
2131{
2132 if (buf->size - buf->pos < len) {
2133 buf->size += len + SZ;
2134 buf->p = NOFAIL(realloc(buf->p, buf->size));
2135 }
2136 strncpy(buf->p + buf->pos, s, len);
2137 buf->pos += len;
2138}
2139
2140static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2141{
2142 switch (exp) {
2143 case export_gpl:
2144 fatal("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
2145 m, s);
2146 break;
2147 case export_unused_gpl:
2148 fatal("GPL-incompatible module %s.ko uses GPL-only symbol marked UNUSED '%s'\n",
2149 m, s);
2150 break;
2151 case export_gpl_future:
2152 warn("GPL-incompatible module %s.ko uses future GPL-only symbol '%s'\n",
2153 m, s);
2154 break;
2155 case export_plain:
2156 case export_unused:
2157 case export_unknown:
2158 /* ignore */
2159 break;
2160 }
2161}
2162
2163static void check_for_unused(enum export exp, const char *m, const char *s)
2164{
2165 switch (exp) {
2166 case export_unused:
2167 case export_unused_gpl:
2168 warn("module %s.ko uses symbol '%s' marked UNUSED\n",
2169 m, s);
2170 break;
2171 default:
2172 /* ignore */
2173 break;
2174 }
2175}
2176
2177static int check_exports(struct module *mod)
2178{
2179 struct symbol *s, *exp;
2180 int err = 0;
2181
2182 for (s = mod->unres; s; s = s->next) {
2183 const char *basename;
2184 exp = find_symbol(s->name);
2185 if (!exp || exp->module == mod) {
2186 if (have_vmlinux && !s->weak) {
2187 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
2188 "\"%s\" [%s.ko] undefined!\n",
2189 s->name, mod->name);
2190 if (!warn_unresolved)
2191 err = 1;
2192 }
2193 continue;
2194 }
2195 basename = strrchr(mod->name, '/');
2196 if (basename)
2197 basename++;
2198 else
2199 basename = mod->name;
2200
2201 if (exp->namespace &&
2202 !module_imports_namespace(mod, exp->namespace)) {
2203 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
2204 "module %s uses symbol %s from namespace %s, but does not import it.\n",
2205 basename, exp->name, exp->namespace);
2206 if (!allow_missing_ns_imports)
2207 err = 1;
2208 add_namespace(&mod->missing_namespaces, exp->namespace);
2209 }
2210
2211 if (!mod->gpl_compatible)
2212 check_for_gpl_usage(exp->export, basename, exp->name);
2213 check_for_unused(exp->export, basename, exp->name);
2214 }
2215
2216 return err;
2217}
2218
2219static int check_modname_len(struct module *mod)
2220{
2221 const char *mod_name;
2222
2223 mod_name = strrchr(mod->name, '/');
2224 if (mod_name == NULL)
2225 mod_name = mod->name;
2226 else
2227 mod_name++;
2228 if (strlen(mod_name) >= MODULE_NAME_LEN) {
2229 merror("module name is too long [%s.ko]\n", mod->name);
2230 return 1;
2231 }
2232
2233 return 0;
2234}
2235
2236/**
2237 * Header for the generated file
2238 **/
2239static void add_header(struct buffer *b, struct module *mod)
2240{
2241 buf_printf(b, "#include <linux/module.h>\n");
2242 /*
2243 * Include build-salt.h after module.h in order to
2244 * inherit the definitions.
2245 */
2246 buf_printf(b, "#define INCLUDE_VERMAGIC\n");
2247 buf_printf(b, "#include <linux/build-salt.h>\n");
2248 buf_printf(b, "#include <linux/vermagic.h>\n");
2249 buf_printf(b, "#include <linux/compiler.h>\n");
2250 buf_printf(b, "\n");
2251 buf_printf(b, "BUILD_SALT;\n");
2252 buf_printf(b, "\n");
2253 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2254 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
2255 buf_printf(b, "\n");
2256 buf_printf(b, "__visible struct module __this_module\n");
2257 buf_printf(b, "__section(.gnu.linkonce.this_module) = {\n");
2258 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2259 if (mod->has_init)
2260 buf_printf(b, "\t.init = init_module,\n");
2261 if (mod->has_cleanup)
2262 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2263 "\t.exit = cleanup_module,\n"
2264 "#endif\n");
2265 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2266 buf_printf(b, "};\n");
2267}
2268
2269static void add_intree_flag(struct buffer *b, int is_intree)
2270{
2271 if (is_intree)
2272 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2273}
2274
2275/* Cannot check for assembler */
2276static void add_retpoline(struct buffer *b)
2277{
2278 buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n");
2279 buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
2280 buf_printf(b, "#endif\n");
2281}
2282
2283static void add_staging_flag(struct buffer *b, const char *name)
2284{
2285 if (strstarts(name, "drivers/staging"))
2286 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2287}
2288
2289/**
2290 * Record CRCs for unresolved symbols
2291 **/
2292static int add_versions(struct buffer *b, struct module *mod)
2293{
2294 struct symbol *s, *exp;
2295 int err = 0;
2296
2297 for (s = mod->unres; s; s = s->next) {
2298 exp = find_symbol(s->name);
2299 if (!exp || exp->module == mod)
2300 continue;
2301 s->module = exp->module;
2302 s->crc_valid = exp->crc_valid;
2303 s->crc = exp->crc;
2304 }
2305
2306 if (!modversions)
2307 return err;
2308
2309 buf_printf(b, "\n");
2310 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2311 buf_printf(b, "__used __section(__versions) = {\n");
2312
2313 for (s = mod->unres; s; s = s->next) {
2314 if (!s->module)
2315 continue;
2316 if (!s->crc_valid) {
2317 warn("\"%s\" [%s.ko] has no CRC!\n",
2318 s->name, mod->name);
2319 continue;
2320 }
2321 if (strlen(s->name) >= MODULE_NAME_LEN) {
2322 merror("too long symbol \"%s\" [%s.ko]\n",
2323 s->name, mod->name);
2324 err = 1;
2325 break;
2326 }
2327 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
2328 s->crc, s->name);
2329 }
2330
2331 buf_printf(b, "};\n");
2332
2333 return err;
2334}
2335
2336static void add_depends(struct buffer *b, struct module *mod)
2337{
2338 struct symbol *s;
2339 int first = 1;
2340
2341 /* Clear ->seen flag of modules that own symbols needed by this. */
2342 for (s = mod->unres; s; s = s->next)
2343 if (s->module)
2344 s->module->seen = s->module->is_vmlinux;
2345
2346 buf_printf(b, "\n");
2347 buf_printf(b, "MODULE_INFO(depends, \"");
2348 for (s = mod->unres; s; s = s->next) {
2349 const char *p;
2350 if (!s->module)
2351 continue;
2352
2353 if (s->module->seen)
2354 continue;
2355
2356 s->module->seen = 1;
2357 p = strrchr(s->module->name, '/');
2358 if (p)
2359 p++;
2360 else
2361 p = s->module->name;
2362 buf_printf(b, "%s%s", first ? "" : ",", p);
2363 first = 0;
2364 }
2365 buf_printf(b, "\");\n");
2366}
2367
2368static void add_srcversion(struct buffer *b, struct module *mod)
2369{
2370 if (mod->srcversion[0]) {
2371 buf_printf(b, "\n");
2372 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2373 mod->srcversion);
2374 }
2375}
2376
2377static void write_buf(struct buffer *b, const char *fname)
2378{
2379 FILE *file;
2380
2381 file = fopen(fname, "w");
2382 if (!file) {
2383 perror(fname);
2384 exit(1);
2385 }
2386 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2387 perror(fname);
2388 exit(1);
2389 }
2390 if (fclose(file) != 0) {
2391 perror(fname);
2392 exit(1);
2393 }
2394}
2395
2396static void write_if_changed(struct buffer *b, const char *fname)
2397{
2398 char *tmp;
2399 FILE *file;
2400 struct stat st;
2401
2402 file = fopen(fname, "r");
2403 if (!file)
2404 goto write;
2405
2406 if (fstat(fileno(file), &st) < 0)
2407 goto close_write;
2408
2409 if (st.st_size != b->pos)
2410 goto close_write;
2411
2412 tmp = NOFAIL(malloc(b->pos));
2413 if (fread(tmp, 1, b->pos, file) != b->pos)
2414 goto free_write;
2415
2416 if (memcmp(tmp, b->p, b->pos) != 0)
2417 goto free_write;
2418
2419 free(tmp);
2420 fclose(file);
2421 return;
2422
2423 free_write:
2424 free(tmp);
2425 close_write:
2426 fclose(file);
2427 write:
2428 write_buf(b, fname);
2429}
2430
2431/* parse Module.symvers file. line format:
2432 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2433 **/
2434static void read_dump(const char *fname)
2435{
2436 char *buf, *pos, *line;
2437
2438 buf = read_text_file(fname);
2439 if (!buf)
2440 /* No symbol versions, silently ignore */
2441 return;
2442
2443 pos = buf;
2444
2445 while ((line = get_line(&pos))) {
2446 char *symname, *namespace, *modname, *d, *export;
2447 unsigned int crc;
2448 struct module *mod;
2449 struct symbol *s;
2450
2451 if (!(symname = strchr(line, '\t')))
2452 goto fail;
2453 *symname++ = '\0';
2454 if (!(modname = strchr(symname, '\t')))
2455 goto fail;
2456 *modname++ = '\0';
2457 if (!(export = strchr(modname, '\t')))
2458 goto fail;
2459 *export++ = '\0';
2460 if (!(namespace = strchr(export, '\t')))
2461 goto fail;
2462 *namespace++ = '\0';
2463
2464 crc = strtoul(line, &d, 16);
2465 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2466 goto fail;
2467 mod = find_module(modname);
2468 if (!mod) {
2469 mod = new_module(modname);
2470 mod->from_dump = 1;
2471 }
2472 s = sym_add_exported(symname, mod, export_no(export));
2473 s->is_static = 0;
2474 sym_set_crc(symname, crc);
2475 sym_update_namespace(symname, namespace);
2476 }
2477 free(buf);
2478 return;
2479fail:
2480 free(buf);
2481 fatal("parse error in symbol dump file\n");
2482}
2483
2484/* For normal builds always dump all symbols.
2485 * For external modules only dump symbols
2486 * that are not read from kernel Module.symvers.
2487 **/
2488static int dump_sym(struct symbol *sym)
2489{
2490 if (!external_module)
2491 return 1;
2492 if (sym->module->from_dump)
2493 return 0;
2494 return 1;
2495}
2496
2497static void write_dump(const char *fname)
2498{
2499 struct buffer buf = { };
2500 struct symbol *symbol;
2501 const char *namespace;
2502 int n;
2503
2504 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2505 symbol = symbolhash[n];
2506 while (symbol) {
2507 if (dump_sym(symbol)) {
2508 namespace = symbol->namespace;
2509 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n",
2510 symbol->crc, symbol->name,
2511 symbol->module->name,
2512 export_str(symbol->export),
2513 namespace ? namespace : "");
2514 }
2515 symbol = symbol->next;
2516 }
2517 }
2518 write_buf(&buf, fname);
2519 free(buf.p);
2520}
2521
2522static void write_namespace_deps_files(const char *fname)
2523{
2524 struct module *mod;
2525 struct namespace_list *ns;
2526 struct buffer ns_deps_buf = {};
2527
2528 for (mod = modules; mod; mod = mod->next) {
2529
2530 if (mod->from_dump || !mod->missing_namespaces)
2531 continue;
2532
2533 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2534
2535 for (ns = mod->missing_namespaces; ns; ns = ns->next)
2536 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2537
2538 buf_printf(&ns_deps_buf, "\n");
2539 }
2540
2541 write_if_changed(&ns_deps_buf, fname);
2542 free(ns_deps_buf.p);
2543}
2544
2545struct dump_list {
2546 struct dump_list *next;
2547 const char *file;
2548};
2549
2550int main(int argc, char **argv)
2551{
2552 struct module *mod;
2553 struct buffer buf = { };
2554 char *missing_namespace_deps = NULL;
2555 char *dump_write = NULL, *files_source = NULL;
2556 int opt;
2557 int err;
2558 int n;
2559 struct dump_list *dump_read_start = NULL;
2560 struct dump_list **dump_read_iter = &dump_read_start;
2561
2562 while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) {
2563 switch (opt) {
2564 case 'e':
2565 external_module = 1;
2566 break;
2567 case 'i':
2568 *dump_read_iter =
2569 NOFAIL(calloc(1, sizeof(**dump_read_iter)));
2570 (*dump_read_iter)->file = optarg;
2571 dump_read_iter = &(*dump_read_iter)->next;
2572 break;
2573 case 'm':
2574 modversions = 1;
2575 break;
2576 case 'n':
2577 ignore_missing_files = 1;
2578 break;
2579 case 'o':
2580 dump_write = optarg;
2581 break;
2582 case 'a':
2583 all_versions = 1;
2584 break;
2585 case 'T':
2586 files_source = optarg;
2587 break;
2588 case 'w':
2589 warn_unresolved = 1;
2590 break;
2591 case 'E':
2592 sec_mismatch_fatal = 1;
2593 break;
2594 case 'N':
2595 allow_missing_ns_imports = 1;
2596 break;
2597 case 'd':
2598 missing_namespace_deps = optarg;
2599 break;
2600 default:
2601 exit(1);
2602 }
2603 }
2604
2605 while (dump_read_start) {
2606 struct dump_list *tmp;
2607
2608 read_dump(dump_read_start->file);
2609 tmp = dump_read_start->next;
2610 free(dump_read_start);
2611 dump_read_start = tmp;
2612 }
2613
2614 while (optind < argc)
2615 read_symbols(argv[optind++]);
2616
2617 if (files_source)
2618 read_symbols_from_files(files_source);
2619
2620 /*
2621 * When there's no vmlinux, don't print warnings about
2622 * unresolved symbols (since there'll be too many ;)
2623 */
2624 if (!have_vmlinux)
2625 warn("Symbol info of vmlinux is missing. Unresolved symbol check will be entirely skipped.\n");
2626
2627 err = 0;
2628
2629 for (mod = modules; mod; mod = mod->next) {
2630 char fname[PATH_MAX];
2631
2632 if (mod->is_vmlinux || mod->from_dump)
2633 continue;
2634
2635 buf.pos = 0;
2636
2637 err |= check_modname_len(mod);
2638 err |= check_exports(mod);
2639
2640 add_header(&buf, mod);
2641 add_intree_flag(&buf, !external_module);
2642 add_retpoline(&buf);
2643 add_staging_flag(&buf, mod->name);
2644 err |= add_versions(&buf, mod);
2645 add_depends(&buf, mod);
2646 add_moddevtable(&buf, mod);
2647 add_srcversion(&buf, mod);
2648
2649 sprintf(fname, "%s.mod.c", mod->name);
2650 write_if_changed(&buf, fname);
2651 }
2652
2653 if (missing_namespace_deps)
2654 write_namespace_deps_files(missing_namespace_deps);
2655
2656 if (dump_write)
2657 write_dump(dump_write);
2658 if (sec_mismatch_count && sec_mismatch_fatal)
2659 fatal("Section mismatches detected.\n"
2660 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2661 for (n = 0; n < SYMBOL_HASH_SIZE; n++) {
2662 struct symbol *s;
2663
2664 for (s = symbolhash[n]; s; s = s->next) {
2665 if (s->is_static)
2666 warn("\"%s\" [%s] is a static %s\n",
2667 s->name, s->module->name,
2668 export_str(s->export));
2669 }
2670 }
2671
2672 free(buf.p);
2673
2674 return err;
2675}
1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14#define _GNU_SOURCE
15#include <stdio.h>
16#include <ctype.h>
17#include <string.h>
18#include <limits.h>
19#include <stdbool.h>
20#include <errno.h>
21#include "modpost.h"
22#include "../../include/generated/autoconf.h"
23#include "../../include/linux/license.h"
24#include "../../include/linux/export.h"
25
26/* Are we using CONFIG_MODVERSIONS? */
27static int modversions = 0;
28/* Warn about undefined symbols? (do so if we have vmlinux) */
29static int have_vmlinux = 0;
30/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
31static int all_versions = 0;
32/* If we are modposting external module set to 1 */
33static int external_module = 0;
34/* Warn about section mismatch in vmlinux if set to 1 */
35static int vmlinux_section_warnings = 1;
36/* Only warn about unresolved symbols */
37static int warn_unresolved = 0;
38/* How a symbol is exported */
39static int sec_mismatch_count = 0;
40static int sec_mismatch_verbose = 1;
41static int sec_mismatch_fatal = 0;
42/* ignore missing files */
43static int ignore_missing_files;
44
45enum export {
46 export_plain, export_unused, export_gpl,
47 export_unused_gpl, export_gpl_future, export_unknown
48};
49
50#define PRINTF __attribute__ ((format (printf, 1, 2)))
51
52PRINTF void fatal(const char *fmt, ...)
53{
54 va_list arglist;
55
56 fprintf(stderr, "FATAL: ");
57
58 va_start(arglist, fmt);
59 vfprintf(stderr, fmt, arglist);
60 va_end(arglist);
61
62 exit(1);
63}
64
65PRINTF void warn(const char *fmt, ...)
66{
67 va_list arglist;
68
69 fprintf(stderr, "WARNING: ");
70
71 va_start(arglist, fmt);
72 vfprintf(stderr, fmt, arglist);
73 va_end(arglist);
74}
75
76PRINTF void merror(const char *fmt, ...)
77{
78 va_list arglist;
79
80 fprintf(stderr, "ERROR: ");
81
82 va_start(arglist, fmt);
83 vfprintf(stderr, fmt, arglist);
84 va_end(arglist);
85}
86
87static inline bool strends(const char *str, const char *postfix)
88{
89 if (strlen(str) < strlen(postfix))
90 return false;
91
92 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
93}
94
95static int is_vmlinux(const char *modname)
96{
97 const char *myname;
98
99 myname = strrchr(modname, '/');
100 if (myname)
101 myname++;
102 else
103 myname = modname;
104
105 return (strcmp(myname, "vmlinux") == 0) ||
106 (strcmp(myname, "vmlinux.o") == 0);
107}
108
109void *do_nofail(void *ptr, const char *expr)
110{
111 if (!ptr)
112 fatal("modpost: Memory allocation failure: %s.\n", expr);
113
114 return ptr;
115}
116
117/* A list of all modules we processed */
118static struct module *modules;
119
120static struct module *find_module(char *modname)
121{
122 struct module *mod;
123
124 for (mod = modules; mod; mod = mod->next)
125 if (strcmp(mod->name, modname) == 0)
126 break;
127 return mod;
128}
129
130static struct module *new_module(const char *modname)
131{
132 struct module *mod;
133 char *p;
134
135 mod = NOFAIL(malloc(sizeof(*mod)));
136 memset(mod, 0, sizeof(*mod));
137 p = NOFAIL(strdup(modname));
138
139 /* strip trailing .o */
140 if (strends(p, ".o")) {
141 p[strlen(p) - 2] = '\0';
142 mod->is_dot_o = 1;
143 }
144
145 /* add to list */
146 mod->name = p;
147 mod->gpl_compatible = -1;
148 mod->next = modules;
149 modules = mod;
150
151 return mod;
152}
153
154/* A hash of all exported symbols,
155 * struct symbol is also used for lists of unresolved symbols */
156
157#define SYMBOL_HASH_SIZE 1024
158
159struct symbol {
160 struct symbol *next;
161 struct module *module;
162 unsigned int crc;
163 int crc_valid;
164 unsigned int weak:1;
165 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
166 unsigned int kernel:1; /* 1 if symbol is from kernel
167 * (only for external modules) **/
168 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
169 enum export export; /* Type of export */
170 char name[0];
171};
172
173static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
174
175/* This is based on the hash agorithm from gdbm, via tdb */
176static inline unsigned int tdb_hash(const char *name)
177{
178 unsigned value; /* Used to compute the hash value. */
179 unsigned i; /* Used to cycle through random values. */
180
181 /* Set the initial value from the key size. */
182 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
183 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
184
185 return (1103515243 * value + 12345);
186}
187
188/**
189 * Allocate a new symbols for use in the hash of exported symbols or
190 * the list of unresolved symbols per module
191 **/
192static struct symbol *alloc_symbol(const char *name, unsigned int weak,
193 struct symbol *next)
194{
195 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
196
197 memset(s, 0, sizeof(*s));
198 strcpy(s->name, name);
199 s->weak = weak;
200 s->next = next;
201 return s;
202}
203
204/* For the hash of exported symbols */
205static struct symbol *new_symbol(const char *name, struct module *module,
206 enum export export)
207{
208 unsigned int hash;
209 struct symbol *new;
210
211 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
212 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
213 new->module = module;
214 new->export = export;
215 return new;
216}
217
218static struct symbol *find_symbol(const char *name)
219{
220 struct symbol *s;
221
222 /* For our purposes, .foo matches foo. PPC64 needs this. */
223 if (name[0] == '.')
224 name++;
225
226 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
227 if (strcmp(s->name, name) == 0)
228 return s;
229 }
230 return NULL;
231}
232
233static const struct {
234 const char *str;
235 enum export export;
236} export_list[] = {
237 { .str = "EXPORT_SYMBOL", .export = export_plain },
238 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
239 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
240 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
241 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
242 { .str = "(unknown)", .export = export_unknown },
243};
244
245
246static const char *export_str(enum export ex)
247{
248 return export_list[ex].str;
249}
250
251static enum export export_no(const char *s)
252{
253 int i;
254
255 if (!s)
256 return export_unknown;
257 for (i = 0; export_list[i].export != export_unknown; i++) {
258 if (strcmp(export_list[i].str, s) == 0)
259 return export_list[i].export;
260 }
261 return export_unknown;
262}
263
264static const char *sec_name(struct elf_info *elf, int secindex);
265
266#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
267
268static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
269{
270 const char *secname = sec_name(elf, sec);
271
272 if (strstarts(secname, "___ksymtab+"))
273 return export_plain;
274 else if (strstarts(secname, "___ksymtab_unused+"))
275 return export_unused;
276 else if (strstarts(secname, "___ksymtab_gpl+"))
277 return export_gpl;
278 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
279 return export_unused_gpl;
280 else if (strstarts(secname, "___ksymtab_gpl_future+"))
281 return export_gpl_future;
282 else
283 return export_unknown;
284}
285
286static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
287{
288 if (sec == elf->export_sec)
289 return export_plain;
290 else if (sec == elf->export_unused_sec)
291 return export_unused;
292 else if (sec == elf->export_gpl_sec)
293 return export_gpl;
294 else if (sec == elf->export_unused_gpl_sec)
295 return export_unused_gpl;
296 else if (sec == elf->export_gpl_future_sec)
297 return export_gpl_future;
298 else
299 return export_unknown;
300}
301
302/**
303 * Add an exported symbol - it may have already been added without a
304 * CRC, in this case just update the CRC
305 **/
306static struct symbol *sym_add_exported(const char *name, struct module *mod,
307 enum export export)
308{
309 struct symbol *s = find_symbol(name);
310
311 if (!s) {
312 s = new_symbol(name, mod, export);
313 } else {
314 if (!s->preloaded) {
315 warn("%s: '%s' exported twice. Previous export "
316 "was in %s%s\n", mod->name, name,
317 s->module->name,
318 is_vmlinux(s->module->name) ?"":".ko");
319 } else {
320 /* In case Module.symvers was out of date */
321 s->module = mod;
322 }
323 }
324 s->preloaded = 0;
325 s->vmlinux = is_vmlinux(mod->name);
326 s->kernel = 0;
327 s->export = export;
328 return s;
329}
330
331static void sym_update_crc(const char *name, struct module *mod,
332 unsigned int crc, enum export export)
333{
334 struct symbol *s = find_symbol(name);
335
336 if (!s) {
337 s = new_symbol(name, mod, export);
338 /* Don't complain when we find it later. */
339 s->preloaded = 1;
340 }
341 s->crc = crc;
342 s->crc_valid = 1;
343}
344
345void *grab_file(const char *filename, unsigned long *size)
346{
347 struct stat st;
348 void *map = MAP_FAILED;
349 int fd;
350
351 fd = open(filename, O_RDONLY);
352 if (fd < 0)
353 return NULL;
354 if (fstat(fd, &st))
355 goto failed;
356
357 *size = st.st_size;
358 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
359
360failed:
361 close(fd);
362 if (map == MAP_FAILED)
363 return NULL;
364 return map;
365}
366
367/**
368 * Return a copy of the next line in a mmap'ed file.
369 * spaces in the beginning of the line is trimmed away.
370 * Return a pointer to a static buffer.
371 **/
372char *get_next_line(unsigned long *pos, void *file, unsigned long size)
373{
374 static char line[4096];
375 int skip = 1;
376 size_t len = 0;
377 signed char *p = (signed char *)file + *pos;
378 char *s = line;
379
380 for (; *pos < size ; (*pos)++) {
381 if (skip && isspace(*p)) {
382 p++;
383 continue;
384 }
385 skip = 0;
386 if (*p != '\n' && (*pos < size)) {
387 len++;
388 *s++ = *p++;
389 if (len > 4095)
390 break; /* Too long, stop */
391 } else {
392 /* End of string */
393 *s = '\0';
394 return line;
395 }
396 }
397 /* End of buffer */
398 return NULL;
399}
400
401void release_file(void *file, unsigned long size)
402{
403 munmap(file, size);
404}
405
406static int parse_elf(struct elf_info *info, const char *filename)
407{
408 unsigned int i;
409 Elf_Ehdr *hdr;
410 Elf_Shdr *sechdrs;
411 Elf_Sym *sym;
412 const char *secstrings;
413 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
414
415 hdr = grab_file(filename, &info->size);
416 if (!hdr) {
417 if (ignore_missing_files) {
418 fprintf(stderr, "%s: %s (ignored)\n", filename,
419 strerror(errno));
420 return 0;
421 }
422 perror(filename);
423 exit(1);
424 }
425 info->hdr = hdr;
426 if (info->size < sizeof(*hdr)) {
427 /* file too small, assume this is an empty .o file */
428 return 0;
429 }
430 /* Is this a valid ELF file? */
431 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
432 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
433 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
434 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
435 /* Not an ELF file - silently ignore it */
436 return 0;
437 }
438 /* Fix endianness in ELF header */
439 hdr->e_type = TO_NATIVE(hdr->e_type);
440 hdr->e_machine = TO_NATIVE(hdr->e_machine);
441 hdr->e_version = TO_NATIVE(hdr->e_version);
442 hdr->e_entry = TO_NATIVE(hdr->e_entry);
443 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
444 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
445 hdr->e_flags = TO_NATIVE(hdr->e_flags);
446 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
447 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
448 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
449 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
450 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
451 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
452 sechdrs = (void *)hdr + hdr->e_shoff;
453 info->sechdrs = sechdrs;
454
455 /* Check if file offset is correct */
456 if (hdr->e_shoff > info->size) {
457 fatal("section header offset=%lu in file '%s' is bigger than "
458 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
459 filename, info->size);
460 return 0;
461 }
462
463 if (hdr->e_shnum == SHN_UNDEF) {
464 /*
465 * There are more than 64k sections,
466 * read count from .sh_size.
467 */
468 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
469 }
470 else {
471 info->num_sections = hdr->e_shnum;
472 }
473 if (hdr->e_shstrndx == SHN_XINDEX) {
474 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
475 }
476 else {
477 info->secindex_strings = hdr->e_shstrndx;
478 }
479
480 /* Fix endianness in section headers */
481 for (i = 0; i < info->num_sections; i++) {
482 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
483 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
484 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
485 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
486 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
487 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
488 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
489 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
490 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
491 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
492 }
493 /* Find symbol table. */
494 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
495 for (i = 1; i < info->num_sections; i++) {
496 const char *secname;
497 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
498
499 if (!nobits && sechdrs[i].sh_offset > info->size) {
500 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
501 "sizeof(*hrd)=%zu\n", filename,
502 (unsigned long)sechdrs[i].sh_offset,
503 sizeof(*hdr));
504 return 0;
505 }
506 secname = secstrings + sechdrs[i].sh_name;
507 if (strcmp(secname, ".modinfo") == 0) {
508 if (nobits)
509 fatal("%s has NOBITS .modinfo\n", filename);
510 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
511 info->modinfo_len = sechdrs[i].sh_size;
512 } else if (strcmp(secname, "__ksymtab") == 0)
513 info->export_sec = i;
514 else if (strcmp(secname, "__ksymtab_unused") == 0)
515 info->export_unused_sec = i;
516 else if (strcmp(secname, "__ksymtab_gpl") == 0)
517 info->export_gpl_sec = i;
518 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
519 info->export_unused_gpl_sec = i;
520 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
521 info->export_gpl_future_sec = i;
522
523 if (sechdrs[i].sh_type == SHT_SYMTAB) {
524 unsigned int sh_link_idx;
525 symtab_idx = i;
526 info->symtab_start = (void *)hdr +
527 sechdrs[i].sh_offset;
528 info->symtab_stop = (void *)hdr +
529 sechdrs[i].sh_offset + sechdrs[i].sh_size;
530 sh_link_idx = sechdrs[i].sh_link;
531 info->strtab = (void *)hdr +
532 sechdrs[sh_link_idx].sh_offset;
533 }
534
535 /* 32bit section no. table? ("more than 64k sections") */
536 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
537 symtab_shndx_idx = i;
538 info->symtab_shndx_start = (void *)hdr +
539 sechdrs[i].sh_offset;
540 info->symtab_shndx_stop = (void *)hdr +
541 sechdrs[i].sh_offset + sechdrs[i].sh_size;
542 }
543 }
544 if (!info->symtab_start)
545 fatal("%s has no symtab?\n", filename);
546
547 /* Fix endianness in symbols */
548 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
549 sym->st_shndx = TO_NATIVE(sym->st_shndx);
550 sym->st_name = TO_NATIVE(sym->st_name);
551 sym->st_value = TO_NATIVE(sym->st_value);
552 sym->st_size = TO_NATIVE(sym->st_size);
553 }
554
555 if (symtab_shndx_idx != ~0U) {
556 Elf32_Word *p;
557 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
558 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
559 filename, sechdrs[symtab_shndx_idx].sh_link,
560 symtab_idx);
561 /* Fix endianness */
562 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
563 p++)
564 *p = TO_NATIVE(*p);
565 }
566
567 return 1;
568}
569
570static void parse_elf_finish(struct elf_info *info)
571{
572 release_file(info->hdr, info->size);
573}
574
575static int ignore_undef_symbol(struct elf_info *info, const char *symname)
576{
577 /* ignore __this_module, it will be resolved shortly */
578 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
579 return 1;
580 /* ignore global offset table */
581 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
582 return 1;
583 if (info->hdr->e_machine == EM_PPC)
584 /* Special register function linked on all modules during final link of .ko */
585 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
586 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
587 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
588 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
589 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
590 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
591 return 1;
592 if (info->hdr->e_machine == EM_PPC64)
593 /* Special register function linked on all modules during final link of .ko */
594 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
595 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
596 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
597 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0 ||
598 strcmp(symname, ".TOC.") == 0)
599 return 1;
600 /* Do not ignore this symbol */
601 return 0;
602}
603
604#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
605#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
606
607static void handle_modversions(struct module *mod, struct elf_info *info,
608 Elf_Sym *sym, const char *symname)
609{
610 unsigned int crc;
611 enum export export;
612 bool is_crc = false;
613
614 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
615 strncmp(symname, "__ksymtab", 9) == 0)
616 export = export_from_secname(info, get_secindex(info, sym));
617 else
618 export = export_from_sec(info, get_secindex(info, sym));
619
620 /* CRC'd symbol */
621 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
622 is_crc = true;
623 crc = (unsigned int) sym->st_value;
624 if (sym->st_shndx != SHN_UNDEF && sym->st_shndx != SHN_ABS) {
625 unsigned int *crcp;
626
627 /* symbol points to the CRC in the ELF object */
628 crcp = (void *)info->hdr + sym->st_value +
629 info->sechdrs[sym->st_shndx].sh_offset -
630 (info->hdr->e_type != ET_REL ?
631 info->sechdrs[sym->st_shndx].sh_addr : 0);
632 crc = *crcp;
633 }
634 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
635 export);
636 }
637
638 switch (sym->st_shndx) {
639 case SHN_COMMON:
640 if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
641 /* Should warn here, but modpost runs before the linker */
642 } else
643 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
644 break;
645 case SHN_UNDEF:
646 /* undefined symbol */
647 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
648 ELF_ST_BIND(sym->st_info) != STB_WEAK)
649 break;
650 if (ignore_undef_symbol(info, symname))
651 break;
652/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
653#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
654/* add compatibility with older glibc */
655#ifndef STT_SPARC_REGISTER
656#define STT_SPARC_REGISTER STT_REGISTER
657#endif
658 if (info->hdr->e_machine == EM_SPARC ||
659 info->hdr->e_machine == EM_SPARCV9) {
660 /* Ignore register directives. */
661 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
662 break;
663 if (symname[0] == '.') {
664 char *munged = strdup(symname);
665 munged[0] = '_';
666 munged[1] = toupper(munged[1]);
667 symname = munged;
668 }
669 }
670#endif
671
672#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
673 if (symname[0] != '_')
674 break;
675 else
676 symname++;
677#endif
678 if (is_crc) {
679 const char *e = is_vmlinux(mod->name) ?"":".ko";
680 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", symname + strlen(CRC_PFX), mod->name, e);
681 }
682 mod->unres = alloc_symbol(symname,
683 ELF_ST_BIND(sym->st_info) == STB_WEAK,
684 mod->unres);
685 break;
686 default:
687 /* All exported symbols */
688 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
689 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
690 export);
691 }
692 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
693 mod->has_init = 1;
694 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
695 mod->has_cleanup = 1;
696 break;
697 }
698}
699
700/**
701 * Parse tag=value strings from .modinfo section
702 **/
703static char *next_string(char *string, unsigned long *secsize)
704{
705 /* Skip non-zero chars */
706 while (string[0]) {
707 string++;
708 if ((*secsize)-- <= 1)
709 return NULL;
710 }
711
712 /* Skip any zero padding. */
713 while (!string[0]) {
714 string++;
715 if ((*secsize)-- <= 1)
716 return NULL;
717 }
718 return string;
719}
720
721static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
722 const char *tag, char *info)
723{
724 char *p;
725 unsigned int taglen = strlen(tag);
726 unsigned long size = modinfo_len;
727
728 if (info) {
729 size -= info - (char *)modinfo;
730 modinfo = next_string(info, &size);
731 }
732
733 for (p = modinfo; p; p = next_string(p, &size)) {
734 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
735 return p + taglen + 1;
736 }
737 return NULL;
738}
739
740static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
741 const char *tag)
742
743{
744 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
745}
746
747/**
748 * Test if string s ends in string sub
749 * return 0 if match
750 **/
751static int strrcmp(const char *s, const char *sub)
752{
753 int slen, sublen;
754
755 if (!s || !sub)
756 return 1;
757
758 slen = strlen(s);
759 sublen = strlen(sub);
760
761 if ((slen == 0) || (sublen == 0))
762 return 1;
763
764 if (sublen > slen)
765 return 1;
766
767 return memcmp(s + slen - sublen, sub, sublen);
768}
769
770static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
771{
772 if (sym)
773 return elf->strtab + sym->st_name;
774 else
775 return "(unknown)";
776}
777
778static const char *sec_name(struct elf_info *elf, int secindex)
779{
780 Elf_Shdr *sechdrs = elf->sechdrs;
781 return (void *)elf->hdr +
782 elf->sechdrs[elf->secindex_strings].sh_offset +
783 sechdrs[secindex].sh_name;
784}
785
786static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
787{
788 return (void *)elf->hdr +
789 elf->sechdrs[elf->secindex_strings].sh_offset +
790 sechdr->sh_name;
791}
792
793/* The pattern is an array of simple patterns.
794 * "foo" will match an exact string equal to "foo"
795 * "*foo" will match a string that ends with "foo"
796 * "foo*" will match a string that begins with "foo"
797 * "*foo*" will match a string that contains "foo"
798 */
799static int match(const char *sym, const char * const pat[])
800{
801 const char *p;
802 while (*pat) {
803 p = *pat++;
804 const char *endp = p + strlen(p) - 1;
805
806 /* "*foo*" */
807 if (*p == '*' && *endp == '*') {
808 char *here, *bare = strndup(p + 1, strlen(p) - 2);
809
810 here = strstr(sym, bare);
811 free(bare);
812 if (here != NULL)
813 return 1;
814 }
815 /* "*foo" */
816 else if (*p == '*') {
817 if (strrcmp(sym, p + 1) == 0)
818 return 1;
819 }
820 /* "foo*" */
821 else if (*endp == '*') {
822 if (strncmp(sym, p, strlen(p) - 1) == 0)
823 return 1;
824 }
825 /* no wildcards */
826 else {
827 if (strcmp(p, sym) == 0)
828 return 1;
829 }
830 }
831 /* no match */
832 return 0;
833}
834
835/* sections that we do not want to do full section mismatch check on */
836static const char *const section_white_list[] =
837{
838 ".comment*",
839 ".debug*",
840 ".cranges", /* sh64 */
841 ".zdebug*", /* Compressed debug sections. */
842 ".GCC-command-line", /* mn10300 */
843 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
844 ".mdebug*", /* alpha, score, mips etc. */
845 ".pdr", /* alpha, score, mips etc. */
846 ".stab*",
847 ".note*",
848 ".got*",
849 ".toc*",
850 ".xt.prop", /* xtensa */
851 ".xt.lit", /* xtensa */
852 ".arcextmap*", /* arc */
853 ".gnu.linkonce.arcext*", /* arc : modules */
854 ".cmem*", /* EZchip */
855 ".fmt_slot*", /* EZchip */
856 ".gnu.lto*",
857 NULL
858};
859
860/*
861 * This is used to find sections missing the SHF_ALLOC flag.
862 * The cause of this is often a section specified in assembler
863 * without "ax" / "aw".
864 */
865static void check_section(const char *modname, struct elf_info *elf,
866 Elf_Shdr *sechdr)
867{
868 const char *sec = sech_name(elf, sechdr);
869
870 if (sechdr->sh_type == SHT_PROGBITS &&
871 !(sechdr->sh_flags & SHF_ALLOC) &&
872 !match(sec, section_white_list)) {
873 warn("%s (%s): unexpected non-allocatable section.\n"
874 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
875 "Note that for example <linux/init.h> contains\n"
876 "section definitions for use in .S files.\n\n",
877 modname, sec);
878 }
879}
880
881
882
883#define ALL_INIT_DATA_SECTIONS \
884 ".init.setup", ".init.rodata", ".meminit.rodata", \
885 ".init.data", ".meminit.data"
886#define ALL_EXIT_DATA_SECTIONS \
887 ".exit.data", ".memexit.data"
888
889#define ALL_INIT_TEXT_SECTIONS \
890 ".init.text", ".meminit.text"
891#define ALL_EXIT_TEXT_SECTIONS \
892 ".exit.text", ".memexit.text"
893
894#define ALL_PCI_INIT_SECTIONS \
895 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
896 ".pci_fixup_enable", ".pci_fixup_resume", \
897 ".pci_fixup_resume_early", ".pci_fixup_suspend"
898
899#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
900#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
901
902#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
903#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
904
905#define DATA_SECTIONS ".data", ".data.rel"
906#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
907 ".kprobes.text", ".cpuidle.text"
908#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
909 ".fixup", ".entry.text", ".exception.text", ".text.*", \
910 ".coldtext"
911
912#define INIT_SECTIONS ".init.*"
913#define MEM_INIT_SECTIONS ".meminit.*"
914
915#define EXIT_SECTIONS ".exit.*"
916#define MEM_EXIT_SECTIONS ".memexit.*"
917
918#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
919 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
920
921/* init data sections */
922static const char *const init_data_sections[] =
923 { ALL_INIT_DATA_SECTIONS, NULL };
924
925/* all init sections */
926static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
927
928/* All init and exit sections (code + data) */
929static const char *const init_exit_sections[] =
930 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
931
932/* all text sections */
933static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
934
935/* data section */
936static const char *const data_sections[] = { DATA_SECTIONS, NULL };
937
938
939/* symbols in .data that may refer to init/exit sections */
940#define DEFAULT_SYMBOL_WHITE_LIST \
941 "*driver", \
942 "*_template", /* scsi uses *_template a lot */ \
943 "*_timer", /* arm uses ops structures named _timer a lot */ \
944 "*_sht", /* scsi also used *_sht to some extent */ \
945 "*_ops", \
946 "*_probe", \
947 "*_probe_one", \
948 "*_console"
949
950static const char *const head_sections[] = { ".head.text*", NULL };
951static const char *const linker_symbols[] =
952 { "__init_begin", "_sinittext", "_einittext", NULL };
953static const char *const optim_symbols[] = { "*.constprop.*", NULL };
954
955enum mismatch {
956 TEXT_TO_ANY_INIT,
957 DATA_TO_ANY_INIT,
958 TEXT_TO_ANY_EXIT,
959 DATA_TO_ANY_EXIT,
960 XXXINIT_TO_SOME_INIT,
961 XXXEXIT_TO_SOME_EXIT,
962 ANY_INIT_TO_ANY_EXIT,
963 ANY_EXIT_TO_ANY_INIT,
964 EXPORT_TO_INIT_EXIT,
965 EXTABLE_TO_NON_TEXT,
966};
967
968/**
969 * Describe how to match sections on different criterias:
970 *
971 * @fromsec: Array of sections to be matched.
972 *
973 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
974 * this array is forbidden (black-list). Can be empty.
975 *
976 * @good_tosec: Relocations applied to a section in @fromsec must be
977 * targetting sections in this array (white-list). Can be empty.
978 *
979 * @mismatch: Type of mismatch.
980 *
981 * @symbol_white_list: Do not match a relocation to a symbol in this list
982 * even if it is targetting a section in @bad_to_sec.
983 *
984 * @handler: Specific handler to call when a match is found. If NULL,
985 * default_mismatch_handler() will be called.
986 *
987 */
988struct sectioncheck {
989 const char *fromsec[20];
990 const char *bad_tosec[20];
991 const char *good_tosec[20];
992 enum mismatch mismatch;
993 const char *symbol_white_list[20];
994 void (*handler)(const char *modname, struct elf_info *elf,
995 const struct sectioncheck* const mismatch,
996 Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
997
998};
999
1000static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
1001 const struct sectioncheck* const mismatch,
1002 Elf_Rela *r, Elf_Sym *sym,
1003 const char *fromsec);
1004
1005static const struct sectioncheck sectioncheck[] = {
1006/* Do not reference init/exit code/data from
1007 * normal code and data
1008 */
1009{
1010 .fromsec = { TEXT_SECTIONS, NULL },
1011 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1012 .mismatch = TEXT_TO_ANY_INIT,
1013 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1014},
1015{
1016 .fromsec = { DATA_SECTIONS, NULL },
1017 .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
1018 .mismatch = DATA_TO_ANY_INIT,
1019 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1020},
1021{
1022 .fromsec = { DATA_SECTIONS, NULL },
1023 .bad_tosec = { INIT_SECTIONS, NULL },
1024 .mismatch = DATA_TO_ANY_INIT,
1025 .symbol_white_list = {
1026 "*_template", "*_timer", "*_sht", "*_ops",
1027 "*_probe", "*_probe_one", "*_console", NULL
1028 },
1029},
1030{
1031 .fromsec = { TEXT_SECTIONS, NULL },
1032 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1033 .mismatch = TEXT_TO_ANY_EXIT,
1034 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1035},
1036{
1037 .fromsec = { DATA_SECTIONS, NULL },
1038 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1039 .mismatch = DATA_TO_ANY_EXIT,
1040 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1041},
1042/* Do not reference init code/data from meminit code/data */
1043{
1044 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1045 .bad_tosec = { INIT_SECTIONS, NULL },
1046 .mismatch = XXXINIT_TO_SOME_INIT,
1047 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1048},
1049/* Do not reference exit code/data from memexit code/data */
1050{
1051 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1052 .bad_tosec = { EXIT_SECTIONS, NULL },
1053 .mismatch = XXXEXIT_TO_SOME_EXIT,
1054 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1055},
1056/* Do not use exit code/data from init code */
1057{
1058 .fromsec = { ALL_INIT_SECTIONS, NULL },
1059 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1060 .mismatch = ANY_INIT_TO_ANY_EXIT,
1061 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1062},
1063/* Do not use init code/data from exit code */
1064{
1065 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1066 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1067 .mismatch = ANY_EXIT_TO_ANY_INIT,
1068 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1069},
1070{
1071 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1072 .bad_tosec = { INIT_SECTIONS, NULL },
1073 .mismatch = ANY_INIT_TO_ANY_EXIT,
1074 .symbol_white_list = { NULL },
1075},
1076/* Do not export init/exit functions or data */
1077{
1078 .fromsec = { "__ksymtab*", NULL },
1079 .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1080 .mismatch = EXPORT_TO_INIT_EXIT,
1081 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1082},
1083{
1084 .fromsec = { "__ex_table", NULL },
1085 /* If you're adding any new black-listed sections in here, consider
1086 * adding a special 'printer' for them in scripts/check_extable.
1087 */
1088 .bad_tosec = { ".altinstr_replacement", NULL },
1089 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
1090 .mismatch = EXTABLE_TO_NON_TEXT,
1091 .handler = extable_mismatch_handler,
1092}
1093};
1094
1095static const struct sectioncheck *section_mismatch(
1096 const char *fromsec, const char *tosec)
1097{
1098 int i;
1099 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1100 const struct sectioncheck *check = §ioncheck[0];
1101
1102 /*
1103 * The target section could be the SHT_NUL section when we're
1104 * handling relocations to un-resolved symbols, trying to match it
1105 * doesn't make much sense and causes build failures on parisc and
1106 * mn10300 architectures.
1107 */
1108 if (*tosec == '\0')
1109 return NULL;
1110
1111 for (i = 0; i < elems; i++) {
1112 if (match(fromsec, check->fromsec)) {
1113 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
1114 return check;
1115 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
1116 return check;
1117 }
1118 check++;
1119 }
1120 return NULL;
1121}
1122
1123/**
1124 * Whitelist to allow certain references to pass with no warning.
1125 *
1126 * Pattern 1:
1127 * If a module parameter is declared __initdata and permissions=0
1128 * then this is legal despite the warning generated.
1129 * We cannot see value of permissions here, so just ignore
1130 * this pattern.
1131 * The pattern is identified by:
1132 * tosec = .init.data
1133 * fromsec = .data*
1134 * atsym =__param*
1135 *
1136 * Pattern 1a:
1137 * module_param_call() ops can refer to __init set function if permissions=0
1138 * The pattern is identified by:
1139 * tosec = .init.text
1140 * fromsec = .data*
1141 * atsym = __param_ops_*
1142 *
1143 * Pattern 2:
1144 * Many drivers utilise a *driver container with references to
1145 * add, remove, probe functions etc.
1146 * the pattern is identified by:
1147 * tosec = init or exit section
1148 * fromsec = data section
1149 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1150 * *probe_one, *_console, *_timer
1151 *
1152 * Pattern 3:
1153 * Whitelist all references from .head.text to any init section
1154 *
1155 * Pattern 4:
1156 * Some symbols belong to init section but still it is ok to reference
1157 * these from non-init sections as these symbols don't have any memory
1158 * allocated for them and symbol address and value are same. So even
1159 * if init section is freed, its ok to reference those symbols.
1160 * For ex. symbols marking the init section boundaries.
1161 * This pattern is identified by
1162 * refsymname = __init_begin, _sinittext, _einittext
1163 *
1164 * Pattern 5:
1165 * GCC may optimize static inlines when fed constant arg(s) resulting
1166 * in functions like cpumask_empty() -- generating an associated symbol
1167 * cpumask_empty.constprop.3 that appears in the audit. If the const that
1168 * is passed in comes from __init, like say nmi_ipi_mask, we get a
1169 * meaningless section warning. May need to add isra symbols too...
1170 * This pattern is identified by
1171 * tosec = init section
1172 * fromsec = text section
1173 * refsymname = *.constprop.*
1174 *
1175 **/
1176static int secref_whitelist(const struct sectioncheck *mismatch,
1177 const char *fromsec, const char *fromsym,
1178 const char *tosec, const char *tosym)
1179{
1180 /* Check for pattern 1 */
1181 if (match(tosec, init_data_sections) &&
1182 match(fromsec, data_sections) &&
1183 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1184 return 0;
1185
1186 /* Check for pattern 1a */
1187 if (strcmp(tosec, ".init.text") == 0 &&
1188 match(fromsec, data_sections) &&
1189 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1190 return 0;
1191
1192 /* Check for pattern 2 */
1193 if (match(tosec, init_exit_sections) &&
1194 match(fromsec, data_sections) &&
1195 match(fromsym, mismatch->symbol_white_list))
1196 return 0;
1197
1198 /* Check for pattern 3 */
1199 if (match(fromsec, head_sections) &&
1200 match(tosec, init_sections))
1201 return 0;
1202
1203 /* Check for pattern 4 */
1204 if (match(tosym, linker_symbols))
1205 return 0;
1206
1207 /* Check for pattern 5 */
1208 if (match(fromsec, text_sections) &&
1209 match(tosec, init_sections) &&
1210 match(fromsym, optim_symbols))
1211 return 0;
1212
1213 return 1;
1214}
1215
1216/**
1217 * Find symbol based on relocation record info.
1218 * In some cases the symbol supplied is a valid symbol so
1219 * return refsym. If st_name != 0 we assume this is a valid symbol.
1220 * In other cases the symbol needs to be looked up in the symbol table
1221 * based on section and address.
1222 * **/
1223static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1224 Elf_Sym *relsym)
1225{
1226 Elf_Sym *sym;
1227 Elf_Sym *near = NULL;
1228 Elf64_Sword distance = 20;
1229 Elf64_Sword d;
1230 unsigned int relsym_secindex;
1231
1232 if (relsym->st_name != 0)
1233 return relsym;
1234
1235 relsym_secindex = get_secindex(elf, relsym);
1236 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1237 if (get_secindex(elf, sym) != relsym_secindex)
1238 continue;
1239 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1240 continue;
1241 if (sym->st_value == addr)
1242 return sym;
1243 /* Find a symbol nearby - addr are maybe negative */
1244 d = sym->st_value - addr;
1245 if (d < 0)
1246 d = addr - sym->st_value;
1247 if (d < distance) {
1248 distance = d;
1249 near = sym;
1250 }
1251 }
1252 /* We need a close match */
1253 if (distance < 20)
1254 return near;
1255 else
1256 return NULL;
1257}
1258
1259static inline int is_arm_mapping_symbol(const char *str)
1260{
1261 return str[0] == '$' && strchr("axtd", str[1])
1262 && (str[2] == '\0' || str[2] == '.');
1263}
1264
1265/*
1266 * If there's no name there, ignore it; likewise, ignore it if it's
1267 * one of the magic symbols emitted used by current ARM tools.
1268 *
1269 * Otherwise if find_symbols_between() returns those symbols, they'll
1270 * fail the whitelist tests and cause lots of false alarms ... fixable
1271 * only by merging __exit and __init sections into __text, bloating
1272 * the kernel (which is especially evil on embedded platforms).
1273 */
1274static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1275{
1276 const char *name = elf->strtab + sym->st_name;
1277
1278 if (!name || !strlen(name))
1279 return 0;
1280 return !is_arm_mapping_symbol(name);
1281}
1282
1283/*
1284 * Find symbols before or equal addr and after addr - in the section sec.
1285 * If we find two symbols with equal offset prefer one with a valid name.
1286 * The ELF format may have a better way to detect what type of symbol
1287 * it is, but this works for now.
1288 **/
1289static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1290 const char *sec)
1291{
1292 Elf_Sym *sym;
1293 Elf_Sym *near = NULL;
1294 Elf_Addr distance = ~0;
1295
1296 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1297 const char *symsec;
1298
1299 if (is_shndx_special(sym->st_shndx))
1300 continue;
1301 symsec = sec_name(elf, get_secindex(elf, sym));
1302 if (strcmp(symsec, sec) != 0)
1303 continue;
1304 if (!is_valid_name(elf, sym))
1305 continue;
1306 if (sym->st_value <= addr) {
1307 if ((addr - sym->st_value) < distance) {
1308 distance = addr - sym->st_value;
1309 near = sym;
1310 } else if ((addr - sym->st_value) == distance) {
1311 near = sym;
1312 }
1313 }
1314 }
1315 return near;
1316}
1317
1318/*
1319 * Convert a section name to the function/data attribute
1320 * .init.text => __init
1321 * .memexitconst => __memconst
1322 * etc.
1323 *
1324 * The memory of returned value has been allocated on a heap. The user of this
1325 * method should free it after usage.
1326*/
1327static char *sec2annotation(const char *s)
1328{
1329 if (match(s, init_exit_sections)) {
1330 char *p = malloc(20);
1331 char *r = p;
1332
1333 *p++ = '_';
1334 *p++ = '_';
1335 if (*s == '.')
1336 s++;
1337 while (*s && *s != '.')
1338 *p++ = *s++;
1339 *p = '\0';
1340 if (*s == '.')
1341 s++;
1342 if (strstr(s, "rodata") != NULL)
1343 strcat(p, "const ");
1344 else if (strstr(s, "data") != NULL)
1345 strcat(p, "data ");
1346 else
1347 strcat(p, " ");
1348 return r;
1349 } else {
1350 return strdup("");
1351 }
1352}
1353
1354static int is_function(Elf_Sym *sym)
1355{
1356 if (sym)
1357 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1358 else
1359 return -1;
1360}
1361
1362static void print_section_list(const char * const list[20])
1363{
1364 const char *const *s = list;
1365
1366 while (*s) {
1367 fprintf(stderr, "%s", *s);
1368 s++;
1369 if (*s)
1370 fprintf(stderr, ", ");
1371 }
1372 fprintf(stderr, "\n");
1373}
1374
1375static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1376{
1377 switch (is_func) {
1378 case 0: *name = "variable"; *name_p = ""; break;
1379 case 1: *name = "function"; *name_p = "()"; break;
1380 default: *name = "(unknown reference)"; *name_p = ""; break;
1381 }
1382}
1383
1384/*
1385 * Print a warning about a section mismatch.
1386 * Try to find symbols near it so user can find it.
1387 * Check whitelist before warning - it may be a false positive.
1388 */
1389static void report_sec_mismatch(const char *modname,
1390 const struct sectioncheck *mismatch,
1391 const char *fromsec,
1392 unsigned long long fromaddr,
1393 const char *fromsym,
1394 int from_is_func,
1395 const char *tosec, const char *tosym,
1396 int to_is_func)
1397{
1398 const char *from, *from_p;
1399 const char *to, *to_p;
1400 char *prl_from;
1401 char *prl_to;
1402
1403 sec_mismatch_count++;
1404 if (!sec_mismatch_verbose)
1405 return;
1406
1407 get_pretty_name(from_is_func, &from, &from_p);
1408 get_pretty_name(to_is_func, &to, &to_p);
1409
1410 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1411 "to the %s %s:%s%s\n",
1412 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1413 tosym, to_p);
1414
1415 switch (mismatch->mismatch) {
1416 case TEXT_TO_ANY_INIT:
1417 prl_from = sec2annotation(fromsec);
1418 prl_to = sec2annotation(tosec);
1419 fprintf(stderr,
1420 "The function %s%s() references\n"
1421 "the %s %s%s%s.\n"
1422 "This is often because %s lacks a %s\n"
1423 "annotation or the annotation of %s is wrong.\n",
1424 prl_from, fromsym,
1425 to, prl_to, tosym, to_p,
1426 fromsym, prl_to, tosym);
1427 free(prl_from);
1428 free(prl_to);
1429 break;
1430 case DATA_TO_ANY_INIT: {
1431 prl_to = sec2annotation(tosec);
1432 fprintf(stderr,
1433 "The variable %s references\n"
1434 "the %s %s%s%s\n"
1435 "If the reference is valid then annotate the\n"
1436 "variable with __init* or __refdata (see linux/init.h) "
1437 "or name the variable:\n",
1438 fromsym, to, prl_to, tosym, to_p);
1439 print_section_list(mismatch->symbol_white_list);
1440 free(prl_to);
1441 break;
1442 }
1443 case TEXT_TO_ANY_EXIT:
1444 prl_to = sec2annotation(tosec);
1445 fprintf(stderr,
1446 "The function %s() references a %s in an exit section.\n"
1447 "Often the %s %s%s has valid usage outside the exit section\n"
1448 "and the fix is to remove the %sannotation of %s.\n",
1449 fromsym, to, to, tosym, to_p, prl_to, tosym);
1450 free(prl_to);
1451 break;
1452 case DATA_TO_ANY_EXIT: {
1453 prl_to = sec2annotation(tosec);
1454 fprintf(stderr,
1455 "The variable %s references\n"
1456 "the %s %s%s%s\n"
1457 "If the reference is valid then annotate the\n"
1458 "variable with __exit* (see linux/init.h) or "
1459 "name the variable:\n",
1460 fromsym, to, prl_to, tosym, to_p);
1461 print_section_list(mismatch->symbol_white_list);
1462 free(prl_to);
1463 break;
1464 }
1465 case XXXINIT_TO_SOME_INIT:
1466 case XXXEXIT_TO_SOME_EXIT:
1467 prl_from = sec2annotation(fromsec);
1468 prl_to = sec2annotation(tosec);
1469 fprintf(stderr,
1470 "The %s %s%s%s references\n"
1471 "a %s %s%s%s.\n"
1472 "If %s is only used by %s then\n"
1473 "annotate %s with a matching annotation.\n",
1474 from, prl_from, fromsym, from_p,
1475 to, prl_to, tosym, to_p,
1476 tosym, fromsym, tosym);
1477 free(prl_from);
1478 free(prl_to);
1479 break;
1480 case ANY_INIT_TO_ANY_EXIT:
1481 prl_from = sec2annotation(fromsec);
1482 prl_to = sec2annotation(tosec);
1483 fprintf(stderr,
1484 "The %s %s%s%s references\n"
1485 "a %s %s%s%s.\n"
1486 "This is often seen when error handling "
1487 "in the init function\n"
1488 "uses functionality in the exit path.\n"
1489 "The fix is often to remove the %sannotation of\n"
1490 "%s%s so it may be used outside an exit section.\n",
1491 from, prl_from, fromsym, from_p,
1492 to, prl_to, tosym, to_p,
1493 prl_to, tosym, to_p);
1494 free(prl_from);
1495 free(prl_to);
1496 break;
1497 case ANY_EXIT_TO_ANY_INIT:
1498 prl_from = sec2annotation(fromsec);
1499 prl_to = sec2annotation(tosec);
1500 fprintf(stderr,
1501 "The %s %s%s%s references\n"
1502 "a %s %s%s%s.\n"
1503 "This is often seen when error handling "
1504 "in the exit function\n"
1505 "uses functionality in the init path.\n"
1506 "The fix is often to remove the %sannotation of\n"
1507 "%s%s so it may be used outside an init section.\n",
1508 from, prl_from, fromsym, from_p,
1509 to, prl_to, tosym, to_p,
1510 prl_to, tosym, to_p);
1511 free(prl_from);
1512 free(prl_to);
1513 break;
1514 case EXPORT_TO_INIT_EXIT:
1515 prl_to = sec2annotation(tosec);
1516 fprintf(stderr,
1517 "The symbol %s is exported and annotated %s\n"
1518 "Fix this by removing the %sannotation of %s "
1519 "or drop the export.\n",
1520 tosym, prl_to, prl_to, tosym);
1521 free(prl_to);
1522 break;
1523 case EXTABLE_TO_NON_TEXT:
1524 fatal("There's a special handler for this mismatch type, "
1525 "we should never get here.");
1526 break;
1527 }
1528 fprintf(stderr, "\n");
1529}
1530
1531static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1532 const struct sectioncheck* const mismatch,
1533 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1534{
1535 const char *tosec;
1536 Elf_Sym *to;
1537 Elf_Sym *from;
1538 const char *tosym;
1539 const char *fromsym;
1540
1541 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1542 fromsym = sym_name(elf, from);
1543
1544 if (!strncmp(fromsym, "reference___initcall",
1545 sizeof("reference___initcall")-1))
1546 return;
1547
1548 tosec = sec_name(elf, get_secindex(elf, sym));
1549 to = find_elf_symbol(elf, r->r_addend, sym);
1550 tosym = sym_name(elf, to);
1551
1552 /* check whitelist - we may ignore it */
1553 if (secref_whitelist(mismatch,
1554 fromsec, fromsym, tosec, tosym)) {
1555 report_sec_mismatch(modname, mismatch,
1556 fromsec, r->r_offset, fromsym,
1557 is_function(from), tosec, tosym,
1558 is_function(to));
1559 }
1560}
1561
1562static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1563{
1564 if (section_index > elf->num_sections)
1565 fatal("section_index is outside elf->num_sections!\n");
1566
1567 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1568}
1569
1570/*
1571 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1572 * to know the sizeof(struct exception_table_entry) for the target architecture.
1573 */
1574static unsigned int extable_entry_size = 0;
1575static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1576{
1577 /*
1578 * If we're currently checking the second relocation within __ex_table,
1579 * that relocation offset tells us the offsetof(struct
1580 * exception_table_entry, fixup) which is equal to sizeof(struct
1581 * exception_table_entry) divided by two. We use that to our advantage
1582 * since there's no portable way to get that size as every architecture
1583 * seems to go with different sized types. Not pretty but better than
1584 * hard-coding the size for every architecture..
1585 */
1586 if (!extable_entry_size)
1587 extable_entry_size = r->r_offset * 2;
1588}
1589
1590static inline bool is_extable_fault_address(Elf_Rela *r)
1591{
1592 /*
1593 * extable_entry_size is only discovered after we've handled the
1594 * _second_ relocation in __ex_table, so only abort when we're not
1595 * handling the first reloc and extable_entry_size is zero.
1596 */
1597 if (r->r_offset && extable_entry_size == 0)
1598 fatal("extable_entry size hasn't been discovered!\n");
1599
1600 return ((r->r_offset == 0) ||
1601 (r->r_offset % extable_entry_size == 0));
1602}
1603
1604#define is_second_extable_reloc(Start, Cur, Sec) \
1605 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1606
1607static void report_extable_warnings(const char* modname, struct elf_info* elf,
1608 const struct sectioncheck* const mismatch,
1609 Elf_Rela* r, Elf_Sym* sym,
1610 const char* fromsec, const char* tosec)
1611{
1612 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1613 const char* fromsym_name = sym_name(elf, fromsym);
1614 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1615 const char* tosym_name = sym_name(elf, tosym);
1616 const char* from_pretty_name;
1617 const char* from_pretty_name_p;
1618 const char* to_pretty_name;
1619 const char* to_pretty_name_p;
1620
1621 get_pretty_name(is_function(fromsym),
1622 &from_pretty_name, &from_pretty_name_p);
1623 get_pretty_name(is_function(tosym),
1624 &to_pretty_name, &to_pretty_name_p);
1625
1626 warn("%s(%s+0x%lx): Section mismatch in reference"
1627 " from the %s %s%s to the %s %s:%s%s\n",
1628 modname, fromsec, (long)r->r_offset, from_pretty_name,
1629 fromsym_name, from_pretty_name_p,
1630 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1631
1632 if (!match(tosec, mismatch->bad_tosec) &&
1633 is_executable_section(elf, get_secindex(elf, sym)))
1634 fprintf(stderr,
1635 "The relocation at %s+0x%lx references\n"
1636 "section \"%s\" which is not in the list of\n"
1637 "authorized sections. If you're adding a new section\n"
1638 "and/or if this reference is valid, add \"%s\" to the\n"
1639 "list of authorized sections to jump to on fault.\n"
1640 "This can be achieved by adding \"%s\" to \n"
1641 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1642 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1643}
1644
1645static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1646 const struct sectioncheck* const mismatch,
1647 Elf_Rela* r, Elf_Sym* sym,
1648 const char *fromsec)
1649{
1650 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1651
1652 sec_mismatch_count++;
1653
1654 if (sec_mismatch_verbose)
1655 report_extable_warnings(modname, elf, mismatch, r, sym,
1656 fromsec, tosec);
1657
1658 if (match(tosec, mismatch->bad_tosec))
1659 fatal("The relocation at %s+0x%lx references\n"
1660 "section \"%s\" which is black-listed.\n"
1661 "Something is seriously wrong and should be fixed.\n"
1662 "You might get more information about where this is\n"
1663 "coming from by using scripts/check_extable.sh %s\n",
1664 fromsec, (long)r->r_offset, tosec, modname);
1665 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1666 if (is_extable_fault_address(r))
1667 fatal("The relocation at %s+0x%lx references\n"
1668 "section \"%s\" which is not executable, IOW\n"
1669 "it is not possible for the kernel to fault\n"
1670 "at that address. Something is seriously wrong\n"
1671 "and should be fixed.\n",
1672 fromsec, (long)r->r_offset, tosec);
1673 else
1674 fatal("The relocation at %s+0x%lx references\n"
1675 "section \"%s\" which is not executable, IOW\n"
1676 "the kernel will fault if it ever tries to\n"
1677 "jump to it. Something is seriously wrong\n"
1678 "and should be fixed.\n",
1679 fromsec, (long)r->r_offset, tosec);
1680 }
1681}
1682
1683static void check_section_mismatch(const char *modname, struct elf_info *elf,
1684 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1685{
1686 const char *tosec = sec_name(elf, get_secindex(elf, sym));;
1687 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1688
1689 if (mismatch) {
1690 if (mismatch->handler)
1691 mismatch->handler(modname, elf, mismatch,
1692 r, sym, fromsec);
1693 else
1694 default_mismatch_handler(modname, elf, mismatch,
1695 r, sym, fromsec);
1696 }
1697}
1698
1699static unsigned int *reloc_location(struct elf_info *elf,
1700 Elf_Shdr *sechdr, Elf_Rela *r)
1701{
1702 Elf_Shdr *sechdrs = elf->sechdrs;
1703 int section = sechdr->sh_info;
1704
1705 return (void *)elf->hdr + sechdrs[section].sh_offset +
1706 r->r_offset;
1707}
1708
1709static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1710{
1711 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1712 unsigned int *location = reloc_location(elf, sechdr, r);
1713
1714 switch (r_typ) {
1715 case R_386_32:
1716 r->r_addend = TO_NATIVE(*location);
1717 break;
1718 case R_386_PC32:
1719 r->r_addend = TO_NATIVE(*location) + 4;
1720 /* For CONFIG_RELOCATABLE=y */
1721 if (elf->hdr->e_type == ET_EXEC)
1722 r->r_addend += r->r_offset;
1723 break;
1724 }
1725 return 0;
1726}
1727
1728#ifndef R_ARM_CALL
1729#define R_ARM_CALL 28
1730#endif
1731#ifndef R_ARM_JUMP24
1732#define R_ARM_JUMP24 29
1733#endif
1734
1735#ifndef R_ARM_THM_CALL
1736#define R_ARM_THM_CALL 10
1737#endif
1738#ifndef R_ARM_THM_JUMP24
1739#define R_ARM_THM_JUMP24 30
1740#endif
1741#ifndef R_ARM_THM_JUMP19
1742#define R_ARM_THM_JUMP19 51
1743#endif
1744
1745static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1746{
1747 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1748
1749 switch (r_typ) {
1750 case R_ARM_ABS32:
1751 /* From ARM ABI: (S + A) | T */
1752 r->r_addend = (int)(long)
1753 (elf->symtab_start + ELF_R_SYM(r->r_info));
1754 break;
1755 case R_ARM_PC24:
1756 case R_ARM_CALL:
1757 case R_ARM_JUMP24:
1758 case R_ARM_THM_CALL:
1759 case R_ARM_THM_JUMP24:
1760 case R_ARM_THM_JUMP19:
1761 /* From ARM ABI: ((S + A) | T) - P */
1762 r->r_addend = (int)(long)(elf->hdr +
1763 sechdr->sh_offset +
1764 (r->r_offset - sechdr->sh_addr));
1765 break;
1766 default:
1767 return 1;
1768 }
1769 return 0;
1770}
1771
1772static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1773{
1774 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1775 unsigned int *location = reloc_location(elf, sechdr, r);
1776 unsigned int inst;
1777
1778 if (r_typ == R_MIPS_HI16)
1779 return 1; /* skip this */
1780 inst = TO_NATIVE(*location);
1781 switch (r_typ) {
1782 case R_MIPS_LO16:
1783 r->r_addend = inst & 0xffff;
1784 break;
1785 case R_MIPS_26:
1786 r->r_addend = (inst & 0x03ffffff) << 2;
1787 break;
1788 case R_MIPS_32:
1789 r->r_addend = inst;
1790 break;
1791 }
1792 return 0;
1793}
1794
1795static void section_rela(const char *modname, struct elf_info *elf,
1796 Elf_Shdr *sechdr)
1797{
1798 Elf_Sym *sym;
1799 Elf_Rela *rela;
1800 Elf_Rela r;
1801 unsigned int r_sym;
1802 const char *fromsec;
1803
1804 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1805 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1806
1807 fromsec = sech_name(elf, sechdr);
1808 fromsec += strlen(".rela");
1809 /* if from section (name) is know good then skip it */
1810 if (match(fromsec, section_white_list))
1811 return;
1812
1813 for (rela = start; rela < stop; rela++) {
1814 r.r_offset = TO_NATIVE(rela->r_offset);
1815#if KERNEL_ELFCLASS == ELFCLASS64
1816 if (elf->hdr->e_machine == EM_MIPS) {
1817 unsigned int r_typ;
1818 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1819 r_sym = TO_NATIVE(r_sym);
1820 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1821 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1822 } else {
1823 r.r_info = TO_NATIVE(rela->r_info);
1824 r_sym = ELF_R_SYM(r.r_info);
1825 }
1826#else
1827 r.r_info = TO_NATIVE(rela->r_info);
1828 r_sym = ELF_R_SYM(r.r_info);
1829#endif
1830 r.r_addend = TO_NATIVE(rela->r_addend);
1831 sym = elf->symtab_start + r_sym;
1832 /* Skip special sections */
1833 if (is_shndx_special(sym->st_shndx))
1834 continue;
1835 if (is_second_extable_reloc(start, rela, fromsec))
1836 find_extable_entry_size(fromsec, &r);
1837 check_section_mismatch(modname, elf, &r, sym, fromsec);
1838 }
1839}
1840
1841static void section_rel(const char *modname, struct elf_info *elf,
1842 Elf_Shdr *sechdr)
1843{
1844 Elf_Sym *sym;
1845 Elf_Rel *rel;
1846 Elf_Rela r;
1847 unsigned int r_sym;
1848 const char *fromsec;
1849
1850 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1851 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1852
1853 fromsec = sech_name(elf, sechdr);
1854 fromsec += strlen(".rel");
1855 /* if from section (name) is know good then skip it */
1856 if (match(fromsec, section_white_list))
1857 return;
1858
1859 for (rel = start; rel < stop; rel++) {
1860 r.r_offset = TO_NATIVE(rel->r_offset);
1861#if KERNEL_ELFCLASS == ELFCLASS64
1862 if (elf->hdr->e_machine == EM_MIPS) {
1863 unsigned int r_typ;
1864 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1865 r_sym = TO_NATIVE(r_sym);
1866 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1867 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1868 } else {
1869 r.r_info = TO_NATIVE(rel->r_info);
1870 r_sym = ELF_R_SYM(r.r_info);
1871 }
1872#else
1873 r.r_info = TO_NATIVE(rel->r_info);
1874 r_sym = ELF_R_SYM(r.r_info);
1875#endif
1876 r.r_addend = 0;
1877 switch (elf->hdr->e_machine) {
1878 case EM_386:
1879 if (addend_386_rel(elf, sechdr, &r))
1880 continue;
1881 break;
1882 case EM_ARM:
1883 if (addend_arm_rel(elf, sechdr, &r))
1884 continue;
1885 break;
1886 case EM_MIPS:
1887 if (addend_mips_rel(elf, sechdr, &r))
1888 continue;
1889 break;
1890 }
1891 sym = elf->symtab_start + r_sym;
1892 /* Skip special sections */
1893 if (is_shndx_special(sym->st_shndx))
1894 continue;
1895 if (is_second_extable_reloc(start, rel, fromsec))
1896 find_extable_entry_size(fromsec, &r);
1897 check_section_mismatch(modname, elf, &r, sym, fromsec);
1898 }
1899}
1900
1901/**
1902 * A module includes a number of sections that are discarded
1903 * either when loaded or when used as built-in.
1904 * For loaded modules all functions marked __init and all data
1905 * marked __initdata will be discarded when the module has been initialized.
1906 * Likewise for modules used built-in the sections marked __exit
1907 * are discarded because __exit marked function are supposed to be called
1908 * only when a module is unloaded which never happens for built-in modules.
1909 * The check_sec_ref() function traverses all relocation records
1910 * to find all references to a section that reference a section that will
1911 * be discarded and warns about it.
1912 **/
1913static void check_sec_ref(struct module *mod, const char *modname,
1914 struct elf_info *elf)
1915{
1916 int i;
1917 Elf_Shdr *sechdrs = elf->sechdrs;
1918
1919 /* Walk through all sections */
1920 for (i = 0; i < elf->num_sections; i++) {
1921 check_section(modname, elf, &elf->sechdrs[i]);
1922 /* We want to process only relocation sections and not .init */
1923 if (sechdrs[i].sh_type == SHT_RELA)
1924 section_rela(modname, elf, &elf->sechdrs[i]);
1925 else if (sechdrs[i].sh_type == SHT_REL)
1926 section_rel(modname, elf, &elf->sechdrs[i]);
1927 }
1928}
1929
1930static char *remove_dot(char *s)
1931{
1932 size_t n = strcspn(s, ".");
1933
1934 if (n && s[n]) {
1935 size_t m = strspn(s + n + 1, "0123456789");
1936 if (m && (s[n + m] == '.' || s[n + m] == 0))
1937 s[n] = 0;
1938 }
1939 return s;
1940}
1941
1942static void read_symbols(char *modname)
1943{
1944 const char *symname;
1945 char *version;
1946 char *license;
1947 struct module *mod;
1948 struct elf_info info = { };
1949 Elf_Sym *sym;
1950
1951 if (!parse_elf(&info, modname))
1952 return;
1953
1954 mod = new_module(modname);
1955
1956 /* When there's no vmlinux, don't print warnings about
1957 * unresolved symbols (since there'll be too many ;) */
1958 if (is_vmlinux(modname)) {
1959 have_vmlinux = 1;
1960 mod->skip = 1;
1961 }
1962
1963 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1964 if (info.modinfo && !license && !is_vmlinux(modname))
1965 warn("modpost: missing MODULE_LICENSE() in %s\n"
1966 "see include/linux/module.h for "
1967 "more information\n", modname);
1968 while (license) {
1969 if (license_is_gpl_compatible(license))
1970 mod->gpl_compatible = 1;
1971 else {
1972 mod->gpl_compatible = 0;
1973 break;
1974 }
1975 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1976 "license", license);
1977 }
1978
1979 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1980 symname = remove_dot(info.strtab + sym->st_name);
1981
1982 handle_modversions(mod, &info, sym, symname);
1983 handle_moddevtable(mod, &info, sym, symname);
1984 }
1985 if (!is_vmlinux(modname) ||
1986 (is_vmlinux(modname) && vmlinux_section_warnings))
1987 check_sec_ref(mod, modname, &info);
1988
1989 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1990 if (version)
1991 maybe_frob_rcs_version(modname, version, info.modinfo,
1992 version - (char *)info.hdr);
1993 if (version || (all_versions && !is_vmlinux(modname)))
1994 get_src_version(modname, mod->srcversion,
1995 sizeof(mod->srcversion)-1);
1996
1997 parse_elf_finish(&info);
1998
1999 /* Our trick to get versioning for module struct etc. - it's
2000 * never passed as an argument to an exported function, so
2001 * the automatic versioning doesn't pick it up, but it's really
2002 * important anyhow */
2003 if (modversions)
2004 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
2005}
2006
2007static void read_symbols_from_files(const char *filename)
2008{
2009 FILE *in = stdin;
2010 char fname[PATH_MAX];
2011
2012 if (strcmp(filename, "-") != 0) {
2013 in = fopen(filename, "r");
2014 if (!in)
2015 fatal("Can't open filenames file %s: %m", filename);
2016 }
2017
2018 while (fgets(fname, PATH_MAX, in) != NULL) {
2019 if (strends(fname, "\n"))
2020 fname[strlen(fname)-1] = '\0';
2021 read_symbols(fname);
2022 }
2023
2024 if (in != stdin)
2025 fclose(in);
2026}
2027
2028#define SZ 500
2029
2030/* We first write the generated file into memory using the
2031 * following helper, then compare to the file on disk and
2032 * only update the later if anything changed */
2033
2034void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2035 const char *fmt, ...)
2036{
2037 char tmp[SZ];
2038 int len;
2039 va_list ap;
2040
2041 va_start(ap, fmt);
2042 len = vsnprintf(tmp, SZ, fmt, ap);
2043 buf_write(buf, tmp, len);
2044 va_end(ap);
2045}
2046
2047void buf_write(struct buffer *buf, const char *s, int len)
2048{
2049 if (buf->size - buf->pos < len) {
2050 buf->size += len + SZ;
2051 buf->p = realloc(buf->p, buf->size);
2052 }
2053 strncpy(buf->p + buf->pos, s, len);
2054 buf->pos += len;
2055}
2056
2057static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2058{
2059 const char *e = is_vmlinux(m) ?"":".ko";
2060
2061 switch (exp) {
2062 case export_gpl:
2063 fatal("modpost: GPL-incompatible module %s%s "
2064 "uses GPL-only symbol '%s'\n", m, e, s);
2065 break;
2066 case export_unused_gpl:
2067 fatal("modpost: GPL-incompatible module %s%s "
2068 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
2069 break;
2070 case export_gpl_future:
2071 warn("modpost: GPL-incompatible module %s%s "
2072 "uses future GPL-only symbol '%s'\n", m, e, s);
2073 break;
2074 case export_plain:
2075 case export_unused:
2076 case export_unknown:
2077 /* ignore */
2078 break;
2079 }
2080}
2081
2082static void check_for_unused(enum export exp, const char *m, const char *s)
2083{
2084 const char *e = is_vmlinux(m) ?"":".ko";
2085
2086 switch (exp) {
2087 case export_unused:
2088 case export_unused_gpl:
2089 warn("modpost: module %s%s "
2090 "uses symbol '%s' marked UNUSED\n", m, e, s);
2091 break;
2092 default:
2093 /* ignore */
2094 break;
2095 }
2096}
2097
2098static void check_exports(struct module *mod)
2099{
2100 struct symbol *s, *exp;
2101
2102 for (s = mod->unres; s; s = s->next) {
2103 const char *basename;
2104 exp = find_symbol(s->name);
2105 if (!exp || exp->module == mod)
2106 continue;
2107 basename = strrchr(mod->name, '/');
2108 if (basename)
2109 basename++;
2110 else
2111 basename = mod->name;
2112 if (!mod->gpl_compatible)
2113 check_for_gpl_usage(exp->export, basename, exp->name);
2114 check_for_unused(exp->export, basename, exp->name);
2115 }
2116}
2117
2118/**
2119 * Header for the generated file
2120 **/
2121static void add_header(struct buffer *b, struct module *mod)
2122{
2123 buf_printf(b, "#include <linux/module.h>\n");
2124 buf_printf(b, "#include <linux/vermagic.h>\n");
2125 buf_printf(b, "#include <linux/compiler.h>\n");
2126 buf_printf(b, "\n");
2127 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2128 buf_printf(b, "\n");
2129 buf_printf(b, "__visible struct module __this_module\n");
2130 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
2131 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2132 if (mod->has_init)
2133 buf_printf(b, "\t.init = init_module,\n");
2134 if (mod->has_cleanup)
2135 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2136 "\t.exit = cleanup_module,\n"
2137 "#endif\n");
2138 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2139 buf_printf(b, "};\n");
2140}
2141
2142static void add_intree_flag(struct buffer *b, int is_intree)
2143{
2144 if (is_intree)
2145 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2146}
2147
2148static void add_staging_flag(struct buffer *b, const char *name)
2149{
2150 static const char *staging_dir = "drivers/staging";
2151
2152 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
2153 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2154}
2155
2156/* In kernel, this size is defined in linux/module.h;
2157 * here we use Elf_Addr instead of long for covering cross-compile
2158 */
2159#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
2160
2161/**
2162 * Record CRCs for unresolved symbols
2163 **/
2164static int add_versions(struct buffer *b, struct module *mod)
2165{
2166 struct symbol *s, *exp;
2167 int err = 0;
2168
2169 for (s = mod->unres; s; s = s->next) {
2170 exp = find_symbol(s->name);
2171 if (!exp || exp->module == mod) {
2172 if (have_vmlinux && !s->weak) {
2173 if (warn_unresolved) {
2174 warn("\"%s\" [%s.ko] undefined!\n",
2175 s->name, mod->name);
2176 } else {
2177 merror("\"%s\" [%s.ko] undefined!\n",
2178 s->name, mod->name);
2179 err = 1;
2180 }
2181 }
2182 continue;
2183 }
2184 s->module = exp->module;
2185 s->crc_valid = exp->crc_valid;
2186 s->crc = exp->crc;
2187 }
2188
2189 if (!modversions)
2190 return err;
2191
2192 buf_printf(b, "\n");
2193 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2194 buf_printf(b, "__used\n");
2195 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
2196
2197 for (s = mod->unres; s; s = s->next) {
2198 if (!s->module)
2199 continue;
2200 if (!s->crc_valid) {
2201 warn("\"%s\" [%s.ko] has no CRC!\n",
2202 s->name, mod->name);
2203 continue;
2204 }
2205 if (strlen(s->name) >= MODULE_NAME_LEN) {
2206 merror("too long symbol \"%s\" [%s.ko]\n",
2207 s->name, mod->name);
2208 err = 1;
2209 break;
2210 }
2211 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
2212 s->crc, s->name);
2213 }
2214
2215 buf_printf(b, "};\n");
2216
2217 return err;
2218}
2219
2220static void add_depends(struct buffer *b, struct module *mod,
2221 struct module *modules)
2222{
2223 struct symbol *s;
2224 struct module *m;
2225 int first = 1;
2226
2227 for (m = modules; m; m = m->next)
2228 m->seen = is_vmlinux(m->name);
2229
2230 buf_printf(b, "\n");
2231 buf_printf(b, "static const char __module_depends[]\n");
2232 buf_printf(b, "__used\n");
2233 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
2234 buf_printf(b, "\"depends=");
2235 for (s = mod->unres; s; s = s->next) {
2236 const char *p;
2237 if (!s->module)
2238 continue;
2239
2240 if (s->module->seen)
2241 continue;
2242
2243 s->module->seen = 1;
2244 p = strrchr(s->module->name, '/');
2245 if (p)
2246 p++;
2247 else
2248 p = s->module->name;
2249 buf_printf(b, "%s%s", first ? "" : ",", p);
2250 first = 0;
2251 }
2252 buf_printf(b, "\";\n");
2253}
2254
2255static void add_srcversion(struct buffer *b, struct module *mod)
2256{
2257 if (mod->srcversion[0]) {
2258 buf_printf(b, "\n");
2259 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2260 mod->srcversion);
2261 }
2262}
2263
2264static void write_if_changed(struct buffer *b, const char *fname)
2265{
2266 char *tmp;
2267 FILE *file;
2268 struct stat st;
2269
2270 file = fopen(fname, "r");
2271 if (!file)
2272 goto write;
2273
2274 if (fstat(fileno(file), &st) < 0)
2275 goto close_write;
2276
2277 if (st.st_size != b->pos)
2278 goto close_write;
2279
2280 tmp = NOFAIL(malloc(b->pos));
2281 if (fread(tmp, 1, b->pos, file) != b->pos)
2282 goto free_write;
2283
2284 if (memcmp(tmp, b->p, b->pos) != 0)
2285 goto free_write;
2286
2287 free(tmp);
2288 fclose(file);
2289 return;
2290
2291 free_write:
2292 free(tmp);
2293 close_write:
2294 fclose(file);
2295 write:
2296 file = fopen(fname, "w");
2297 if (!file) {
2298 perror(fname);
2299 exit(1);
2300 }
2301 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2302 perror(fname);
2303 exit(1);
2304 }
2305 fclose(file);
2306}
2307
2308/* parse Module.symvers file. line format:
2309 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2310 **/
2311static void read_dump(const char *fname, unsigned int kernel)
2312{
2313 unsigned long size, pos = 0;
2314 void *file = grab_file(fname, &size);
2315 char *line;
2316
2317 if (!file)
2318 /* No symbol versions, silently ignore */
2319 return;
2320
2321 while ((line = get_next_line(&pos, file, size))) {
2322 char *symname, *modname, *d, *export, *end;
2323 unsigned int crc;
2324 struct module *mod;
2325 struct symbol *s;
2326
2327 if (!(symname = strchr(line, '\t')))
2328 goto fail;
2329 *symname++ = '\0';
2330 if (!(modname = strchr(symname, '\t')))
2331 goto fail;
2332 *modname++ = '\0';
2333 if ((export = strchr(modname, '\t')) != NULL)
2334 *export++ = '\0';
2335 if (export && ((end = strchr(export, '\t')) != NULL))
2336 *end = '\0';
2337 crc = strtoul(line, &d, 16);
2338 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2339 goto fail;
2340 mod = find_module(modname);
2341 if (!mod) {
2342 if (is_vmlinux(modname))
2343 have_vmlinux = 1;
2344 mod = new_module(modname);
2345 mod->skip = 1;
2346 }
2347 s = sym_add_exported(symname, mod, export_no(export));
2348 s->kernel = kernel;
2349 s->preloaded = 1;
2350 sym_update_crc(symname, mod, crc, export_no(export));
2351 }
2352 release_file(file, size);
2353 return;
2354fail:
2355 release_file(file, size);
2356 fatal("parse error in symbol dump file\n");
2357}
2358
2359/* For normal builds always dump all symbols.
2360 * For external modules only dump symbols
2361 * that are not read from kernel Module.symvers.
2362 **/
2363static int dump_sym(struct symbol *sym)
2364{
2365 if (!external_module)
2366 return 1;
2367 if (sym->vmlinux || sym->kernel)
2368 return 0;
2369 return 1;
2370}
2371
2372static void write_dump(const char *fname)
2373{
2374 struct buffer buf = { };
2375 struct symbol *symbol;
2376 int n;
2377
2378 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2379 symbol = symbolhash[n];
2380 while (symbol) {
2381 if (dump_sym(symbol))
2382 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2383 symbol->crc, symbol->name,
2384 symbol->module->name,
2385 export_str(symbol->export));
2386 symbol = symbol->next;
2387 }
2388 }
2389 write_if_changed(&buf, fname);
2390 free(buf.p);
2391}
2392
2393struct ext_sym_list {
2394 struct ext_sym_list *next;
2395 const char *file;
2396};
2397
2398int main(int argc, char **argv)
2399{
2400 struct module *mod;
2401 struct buffer buf = { };
2402 char *kernel_read = NULL, *module_read = NULL;
2403 char *dump_write = NULL, *files_source = NULL;
2404 int opt;
2405 int err;
2406 struct ext_sym_list *extsym_iter;
2407 struct ext_sym_list *extsym_start = NULL;
2408
2409 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:E")) != -1) {
2410 switch (opt) {
2411 case 'i':
2412 kernel_read = optarg;
2413 break;
2414 case 'I':
2415 module_read = optarg;
2416 external_module = 1;
2417 break;
2418 case 'e':
2419 external_module = 1;
2420 extsym_iter =
2421 NOFAIL(malloc(sizeof(*extsym_iter)));
2422 extsym_iter->next = extsym_start;
2423 extsym_iter->file = optarg;
2424 extsym_start = extsym_iter;
2425 break;
2426 case 'm':
2427 modversions = 1;
2428 break;
2429 case 'n':
2430 ignore_missing_files = 1;
2431 break;
2432 case 'o':
2433 dump_write = optarg;
2434 break;
2435 case 'a':
2436 all_versions = 1;
2437 break;
2438 case 's':
2439 vmlinux_section_warnings = 0;
2440 break;
2441 case 'S':
2442 sec_mismatch_verbose = 0;
2443 break;
2444 case 'T':
2445 files_source = optarg;
2446 break;
2447 case 'w':
2448 warn_unresolved = 1;
2449 break;
2450 case 'E':
2451 sec_mismatch_fatal = 1;
2452 break;
2453 default:
2454 exit(1);
2455 }
2456 }
2457
2458 if (kernel_read)
2459 read_dump(kernel_read, 1);
2460 if (module_read)
2461 read_dump(module_read, 0);
2462 while (extsym_start) {
2463 read_dump(extsym_start->file, 0);
2464 extsym_iter = extsym_start->next;
2465 free(extsym_start);
2466 extsym_start = extsym_iter;
2467 }
2468
2469 while (optind < argc)
2470 read_symbols(argv[optind++]);
2471
2472 if (files_source)
2473 read_symbols_from_files(files_source);
2474
2475 for (mod = modules; mod; mod = mod->next) {
2476 if (mod->skip)
2477 continue;
2478 check_exports(mod);
2479 }
2480
2481 err = 0;
2482
2483 for (mod = modules; mod; mod = mod->next) {
2484 char fname[PATH_MAX];
2485
2486 if (mod->skip)
2487 continue;
2488
2489 buf.pos = 0;
2490
2491 add_header(&buf, mod);
2492 add_intree_flag(&buf, !external_module);
2493 add_staging_flag(&buf, mod->name);
2494 err |= add_versions(&buf, mod);
2495 add_depends(&buf, mod, modules);
2496 add_moddevtable(&buf, mod);
2497 add_srcversion(&buf, mod);
2498
2499 sprintf(fname, "%s.mod.c", mod->name);
2500 write_if_changed(&buf, fname);
2501 }
2502 if (dump_write)
2503 write_dump(dump_write);
2504 if (sec_mismatch_count) {
2505 if (!sec_mismatch_verbose) {
2506 warn("modpost: Found %d section mismatch(es).\n"
2507 "To see full details build your kernel with:\n"
2508 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2509 sec_mismatch_count);
2510 }
2511 if (sec_mismatch_fatal) {
2512 fatal("modpost: Section mismatches detected.\n"
2513 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2514 }
2515 }
2516 free(buf.p);
2517
2518 return err;
2519}