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Merge branch 'scsi-target-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel...
[mirror_ubuntu-bionic-kernel.git] / scripts / mod / modpost.c
1 /* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14 #define _GNU_SOURCE
15 #include <stdio.h>
16 #include <ctype.h>
17 #include <string.h>
18 #include <limits.h>
19 #include <stdbool.h>
20 #include <errno.h>
21 #include "modpost.h"
22 #include "../../include/generated/autoconf.h"
23 #include "../../include/linux/license.h"
24 #include "../../include/linux/export.h"
25
26 /* Are we using CONFIG_MODVERSIONS? */
27 static int modversions = 0;
28 /* Warn about undefined symbols? (do so if we have vmlinux) */
29 static int have_vmlinux = 0;
30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
31 static int all_versions = 0;
32 /* If we are modposting external module set to 1 */
33 static int external_module = 0;
34 /* Warn about section mismatch in vmlinux if set to 1 */
35 static int vmlinux_section_warnings = 1;
36 /* Only warn about unresolved symbols */
37 static int warn_unresolved = 0;
38 /* How a symbol is exported */
39 static int sec_mismatch_count = 0;
40 static int sec_mismatch_verbose = 1;
41 static int sec_mismatch_fatal = 0;
42 /* ignore missing files */
43 static int ignore_missing_files;
44
45 enum 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
52 PRINTF 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
65 PRINTF 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
76 PRINTF 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
87 static 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
95 static 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
109 void *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 */
118 static struct module *modules;
119
120 static 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
130 static 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
159 struct 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
173 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
174
175 /* This is based on the hash agorithm from gdbm, via tdb */
176 static 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 **/
192 static 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 */
205 static 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
218 static 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
233 static 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
246 static const char *export_str(enum export ex)
247 {
248 return export_list[ex].str;
249 }
250
251 static 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
264 static const char *sec_name(struct elf_info *elf, int secindex);
265
266 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
267
268 static 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
286 static 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 **/
306 static 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
331 static 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
345 void *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
360 failed:
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 **/
372 char *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
401 void release_file(void *file, unsigned long size)
402 {
403 munmap(file, size);
404 }
405
406 static 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
570 static void parse_elf_finish(struct elf_info *info)
571 {
572 release_file(info->hdr, info->size);
573 }
574
575 static 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
607 static 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 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
625 export);
626 }
627
628 switch (sym->st_shndx) {
629 case SHN_COMMON:
630 if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
631 /* Should warn here, but modpost runs before the linker */
632 } else
633 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
634 break;
635 case SHN_UNDEF:
636 /* undefined symbol */
637 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
638 ELF_ST_BIND(sym->st_info) != STB_WEAK)
639 break;
640 if (ignore_undef_symbol(info, symname))
641 break;
642 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
643 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
644 /* add compatibility with older glibc */
645 #ifndef STT_SPARC_REGISTER
646 #define STT_SPARC_REGISTER STT_REGISTER
647 #endif
648 if (info->hdr->e_machine == EM_SPARC ||
649 info->hdr->e_machine == EM_SPARCV9) {
650 /* Ignore register directives. */
651 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
652 break;
653 if (symname[0] == '.') {
654 char *munged = strdup(symname);
655 munged[0] = '_';
656 munged[1] = toupper(munged[1]);
657 symname = munged;
658 }
659 }
660 #endif
661
662 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
663 if (symname[0] != '_')
664 break;
665 else
666 symname++;
667 #endif
668 if (is_crc) {
669 const char *e = is_vmlinux(mod->name) ?"":".ko";
670 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", symname + strlen(CRC_PFX), mod->name, e);
671 }
672 mod->unres = alloc_symbol(symname,
673 ELF_ST_BIND(sym->st_info) == STB_WEAK,
674 mod->unres);
675 break;
676 default:
677 /* All exported symbols */
678 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
679 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
680 export);
681 }
682 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
683 mod->has_init = 1;
684 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
685 mod->has_cleanup = 1;
686 break;
687 }
688 }
689
690 /**
691 * Parse tag=value strings from .modinfo section
692 **/
693 static char *next_string(char *string, unsigned long *secsize)
694 {
695 /* Skip non-zero chars */
696 while (string[0]) {
697 string++;
698 if ((*secsize)-- <= 1)
699 return NULL;
700 }
701
702 /* Skip any zero padding. */
703 while (!string[0]) {
704 string++;
705 if ((*secsize)-- <= 1)
706 return NULL;
707 }
708 return string;
709 }
710
711 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
712 const char *tag, char *info)
713 {
714 char *p;
715 unsigned int taglen = strlen(tag);
716 unsigned long size = modinfo_len;
717
718 if (info) {
719 size -= info - (char *)modinfo;
720 modinfo = next_string(info, &size);
721 }
722
723 for (p = modinfo; p; p = next_string(p, &size)) {
724 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
725 return p + taglen + 1;
726 }
727 return NULL;
728 }
729
730 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
731 const char *tag)
732
733 {
734 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
735 }
736
737 /**
738 * Test if string s ends in string sub
739 * return 0 if match
740 **/
741 static int strrcmp(const char *s, const char *sub)
742 {
743 int slen, sublen;
744
745 if (!s || !sub)
746 return 1;
747
748 slen = strlen(s);
749 sublen = strlen(sub);
750
751 if ((slen == 0) || (sublen == 0))
752 return 1;
753
754 if (sublen > slen)
755 return 1;
756
757 return memcmp(s + slen - sublen, sub, sublen);
758 }
759
760 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
761 {
762 if (sym)
763 return elf->strtab + sym->st_name;
764 else
765 return "(unknown)";
766 }
767
768 static const char *sec_name(struct elf_info *elf, int secindex)
769 {
770 Elf_Shdr *sechdrs = elf->sechdrs;
771 return (void *)elf->hdr +
772 elf->sechdrs[elf->secindex_strings].sh_offset +
773 sechdrs[secindex].sh_name;
774 }
775
776 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
777 {
778 return (void *)elf->hdr +
779 elf->sechdrs[elf->secindex_strings].sh_offset +
780 sechdr->sh_name;
781 }
782
783 /* The pattern is an array of simple patterns.
784 * "foo" will match an exact string equal to "foo"
785 * "*foo" will match a string that ends with "foo"
786 * "foo*" will match a string that begins with "foo"
787 * "*foo*" will match a string that contains "foo"
788 */
789 static int match(const char *sym, const char * const pat[])
790 {
791 const char *p;
792 while (*pat) {
793 p = *pat++;
794 const char *endp = p + strlen(p) - 1;
795
796 /* "*foo*" */
797 if (*p == '*' && *endp == '*') {
798 char *here, *bare = strndup(p + 1, strlen(p) - 2);
799
800 here = strstr(sym, bare);
801 free(bare);
802 if (here != NULL)
803 return 1;
804 }
805 /* "*foo" */
806 else if (*p == '*') {
807 if (strrcmp(sym, p + 1) == 0)
808 return 1;
809 }
810 /* "foo*" */
811 else if (*endp == '*') {
812 if (strncmp(sym, p, strlen(p) - 1) == 0)
813 return 1;
814 }
815 /* no wildcards */
816 else {
817 if (strcmp(p, sym) == 0)
818 return 1;
819 }
820 }
821 /* no match */
822 return 0;
823 }
824
825 /* sections that we do not want to do full section mismatch check on */
826 static const char *const section_white_list[] =
827 {
828 ".comment*",
829 ".debug*",
830 ".cranges", /* sh64 */
831 ".zdebug*", /* Compressed debug sections. */
832 ".GCC-command-line", /* mn10300 */
833 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
834 ".mdebug*", /* alpha, score, mips etc. */
835 ".pdr", /* alpha, score, mips etc. */
836 ".stab*",
837 ".note*",
838 ".got*",
839 ".toc*",
840 ".xt.prop", /* xtensa */
841 ".xt.lit", /* xtensa */
842 ".arcextmap*", /* arc */
843 ".gnu.linkonce.arcext*", /* arc : modules */
844 ".cmem*", /* EZchip */
845 ".fmt_slot*", /* EZchip */
846 ".gnu.lto*",
847 NULL
848 };
849
850 /*
851 * This is used to find sections missing the SHF_ALLOC flag.
852 * The cause of this is often a section specified in assembler
853 * without "ax" / "aw".
854 */
855 static void check_section(const char *modname, struct elf_info *elf,
856 Elf_Shdr *sechdr)
857 {
858 const char *sec = sech_name(elf, sechdr);
859
860 if (sechdr->sh_type == SHT_PROGBITS &&
861 !(sechdr->sh_flags & SHF_ALLOC) &&
862 !match(sec, section_white_list)) {
863 warn("%s (%s): unexpected non-allocatable section.\n"
864 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
865 "Note that for example <linux/init.h> contains\n"
866 "section definitions for use in .S files.\n\n",
867 modname, sec);
868 }
869 }
870
871
872
873 #define ALL_INIT_DATA_SECTIONS \
874 ".init.setup", ".init.rodata", ".meminit.rodata", \
875 ".init.data", ".meminit.data"
876 #define ALL_EXIT_DATA_SECTIONS \
877 ".exit.data", ".memexit.data"
878
879 #define ALL_INIT_TEXT_SECTIONS \
880 ".init.text", ".meminit.text"
881 #define ALL_EXIT_TEXT_SECTIONS \
882 ".exit.text", ".memexit.text"
883
884 #define ALL_PCI_INIT_SECTIONS \
885 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
886 ".pci_fixup_enable", ".pci_fixup_resume", \
887 ".pci_fixup_resume_early", ".pci_fixup_suspend"
888
889 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
890 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
891
892 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
893 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
894
895 #define DATA_SECTIONS ".data", ".data.rel"
896 #define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
897 ".kprobes.text", ".cpuidle.text"
898 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
899 ".fixup", ".entry.text", ".exception.text", ".text.*", \
900 ".coldtext"
901
902 #define INIT_SECTIONS ".init.*"
903 #define MEM_INIT_SECTIONS ".meminit.*"
904
905 #define EXIT_SECTIONS ".exit.*"
906 #define MEM_EXIT_SECTIONS ".memexit.*"
907
908 #define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
909 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
910
911 /* init data sections */
912 static const char *const init_data_sections[] =
913 { ALL_INIT_DATA_SECTIONS, NULL };
914
915 /* all init sections */
916 static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
917
918 /* All init and exit sections (code + data) */
919 static const char *const init_exit_sections[] =
920 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
921
922 /* all text sections */
923 static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
924
925 /* data section */
926 static const char *const data_sections[] = { DATA_SECTIONS, NULL };
927
928
929 /* symbols in .data that may refer to init/exit sections */
930 #define DEFAULT_SYMBOL_WHITE_LIST \
931 "*driver", \
932 "*_template", /* scsi uses *_template a lot */ \
933 "*_timer", /* arm uses ops structures named _timer a lot */ \
934 "*_sht", /* scsi also used *_sht to some extent */ \
935 "*_ops", \
936 "*_probe", \
937 "*_probe_one", \
938 "*_console"
939
940 static const char *const head_sections[] = { ".head.text*", NULL };
941 static const char *const linker_symbols[] =
942 { "__init_begin", "_sinittext", "_einittext", NULL };
943 static const char *const optim_symbols[] = { "*.constprop.*", NULL };
944
945 enum mismatch {
946 TEXT_TO_ANY_INIT,
947 DATA_TO_ANY_INIT,
948 TEXT_TO_ANY_EXIT,
949 DATA_TO_ANY_EXIT,
950 XXXINIT_TO_SOME_INIT,
951 XXXEXIT_TO_SOME_EXIT,
952 ANY_INIT_TO_ANY_EXIT,
953 ANY_EXIT_TO_ANY_INIT,
954 EXPORT_TO_INIT_EXIT,
955 EXTABLE_TO_NON_TEXT,
956 };
957
958 /**
959 * Describe how to match sections on different criterias:
960 *
961 * @fromsec: Array of sections to be matched.
962 *
963 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
964 * this array is forbidden (black-list). Can be empty.
965 *
966 * @good_tosec: Relocations applied to a section in @fromsec must be
967 * targetting sections in this array (white-list). Can be empty.
968 *
969 * @mismatch: Type of mismatch.
970 *
971 * @symbol_white_list: Do not match a relocation to a symbol in this list
972 * even if it is targetting a section in @bad_to_sec.
973 *
974 * @handler: Specific handler to call when a match is found. If NULL,
975 * default_mismatch_handler() will be called.
976 *
977 */
978 struct sectioncheck {
979 const char *fromsec[20];
980 const char *bad_tosec[20];
981 const char *good_tosec[20];
982 enum mismatch mismatch;
983 const char *symbol_white_list[20];
984 void (*handler)(const char *modname, struct elf_info *elf,
985 const struct sectioncheck* const mismatch,
986 Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
987
988 };
989
990 static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
991 const struct sectioncheck* const mismatch,
992 Elf_Rela *r, Elf_Sym *sym,
993 const char *fromsec);
994
995 static const struct sectioncheck sectioncheck[] = {
996 /* Do not reference init/exit code/data from
997 * normal code and data
998 */
999 {
1000 .fromsec = { TEXT_SECTIONS, NULL },
1001 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1002 .mismatch = TEXT_TO_ANY_INIT,
1003 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1004 },
1005 {
1006 .fromsec = { DATA_SECTIONS, NULL },
1007 .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
1008 .mismatch = DATA_TO_ANY_INIT,
1009 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1010 },
1011 {
1012 .fromsec = { DATA_SECTIONS, NULL },
1013 .bad_tosec = { INIT_SECTIONS, NULL },
1014 .mismatch = DATA_TO_ANY_INIT,
1015 .symbol_white_list = {
1016 "*_template", "*_timer", "*_sht", "*_ops",
1017 "*_probe", "*_probe_one", "*_console", NULL
1018 },
1019 },
1020 {
1021 .fromsec = { TEXT_SECTIONS, NULL },
1022 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1023 .mismatch = TEXT_TO_ANY_EXIT,
1024 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1025 },
1026 {
1027 .fromsec = { DATA_SECTIONS, NULL },
1028 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1029 .mismatch = DATA_TO_ANY_EXIT,
1030 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1031 },
1032 /* Do not reference init code/data from meminit code/data */
1033 {
1034 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1035 .bad_tosec = { INIT_SECTIONS, NULL },
1036 .mismatch = XXXINIT_TO_SOME_INIT,
1037 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1038 },
1039 /* Do not reference exit code/data from memexit code/data */
1040 {
1041 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1042 .bad_tosec = { EXIT_SECTIONS, NULL },
1043 .mismatch = XXXEXIT_TO_SOME_EXIT,
1044 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1045 },
1046 /* Do not use exit code/data from init code */
1047 {
1048 .fromsec = { ALL_INIT_SECTIONS, NULL },
1049 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1050 .mismatch = ANY_INIT_TO_ANY_EXIT,
1051 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1052 },
1053 /* Do not use init code/data from exit code */
1054 {
1055 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1056 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1057 .mismatch = ANY_EXIT_TO_ANY_INIT,
1058 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1059 },
1060 {
1061 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1062 .bad_tosec = { INIT_SECTIONS, NULL },
1063 .mismatch = ANY_INIT_TO_ANY_EXIT,
1064 .symbol_white_list = { NULL },
1065 },
1066 /* Do not export init/exit functions or data */
1067 {
1068 .fromsec = { "__ksymtab*", NULL },
1069 .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1070 .mismatch = EXPORT_TO_INIT_EXIT,
1071 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1072 },
1073 {
1074 .fromsec = { "__ex_table", NULL },
1075 /* If you're adding any new black-listed sections in here, consider
1076 * adding a special 'printer' for them in scripts/check_extable.
1077 */
1078 .bad_tosec = { ".altinstr_replacement", NULL },
1079 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
1080 .mismatch = EXTABLE_TO_NON_TEXT,
1081 .handler = extable_mismatch_handler,
1082 }
1083 };
1084
1085 static const struct sectioncheck *section_mismatch(
1086 const char *fromsec, const char *tosec)
1087 {
1088 int i;
1089 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1090 const struct sectioncheck *check = &sectioncheck[0];
1091
1092 /*
1093 * The target section could be the SHT_NUL section when we're
1094 * handling relocations to un-resolved symbols, trying to match it
1095 * doesn't make much sense and causes build failures on parisc and
1096 * mn10300 architectures.
1097 */
1098 if (*tosec == '\0')
1099 return NULL;
1100
1101 for (i = 0; i < elems; i++) {
1102 if (match(fromsec, check->fromsec)) {
1103 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
1104 return check;
1105 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
1106 return check;
1107 }
1108 check++;
1109 }
1110 return NULL;
1111 }
1112
1113 /**
1114 * Whitelist to allow certain references to pass with no warning.
1115 *
1116 * Pattern 1:
1117 * If a module parameter is declared __initdata and permissions=0
1118 * then this is legal despite the warning generated.
1119 * We cannot see value of permissions here, so just ignore
1120 * this pattern.
1121 * The pattern is identified by:
1122 * tosec = .init.data
1123 * fromsec = .data*
1124 * atsym =__param*
1125 *
1126 * Pattern 1a:
1127 * module_param_call() ops can refer to __init set function if permissions=0
1128 * The pattern is identified by:
1129 * tosec = .init.text
1130 * fromsec = .data*
1131 * atsym = __param_ops_*
1132 *
1133 * Pattern 2:
1134 * Many drivers utilise a *driver container with references to
1135 * add, remove, probe functions etc.
1136 * the pattern is identified by:
1137 * tosec = init or exit section
1138 * fromsec = data section
1139 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1140 * *probe_one, *_console, *_timer
1141 *
1142 * Pattern 3:
1143 * Whitelist all references from .head.text to any init section
1144 *
1145 * Pattern 4:
1146 * Some symbols belong to init section but still it is ok to reference
1147 * these from non-init sections as these symbols don't have any memory
1148 * allocated for them and symbol address and value are same. So even
1149 * if init section is freed, its ok to reference those symbols.
1150 * For ex. symbols marking the init section boundaries.
1151 * This pattern is identified by
1152 * refsymname = __init_begin, _sinittext, _einittext
1153 *
1154 * Pattern 5:
1155 * GCC may optimize static inlines when fed constant arg(s) resulting
1156 * in functions like cpumask_empty() -- generating an associated symbol
1157 * cpumask_empty.constprop.3 that appears in the audit. If the const that
1158 * is passed in comes from __init, like say nmi_ipi_mask, we get a
1159 * meaningless section warning. May need to add isra symbols too...
1160 * This pattern is identified by
1161 * tosec = init section
1162 * fromsec = text section
1163 * refsymname = *.constprop.*
1164 *
1165 **/
1166 static int secref_whitelist(const struct sectioncheck *mismatch,
1167 const char *fromsec, const char *fromsym,
1168 const char *tosec, const char *tosym)
1169 {
1170 /* Check for pattern 1 */
1171 if (match(tosec, init_data_sections) &&
1172 match(fromsec, data_sections) &&
1173 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1174 return 0;
1175
1176 /* Check for pattern 1a */
1177 if (strcmp(tosec, ".init.text") == 0 &&
1178 match(fromsec, data_sections) &&
1179 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1180 return 0;
1181
1182 /* Check for pattern 2 */
1183 if (match(tosec, init_exit_sections) &&
1184 match(fromsec, data_sections) &&
1185 match(fromsym, mismatch->symbol_white_list))
1186 return 0;
1187
1188 /* Check for pattern 3 */
1189 if (match(fromsec, head_sections) &&
1190 match(tosec, init_sections))
1191 return 0;
1192
1193 /* Check for pattern 4 */
1194 if (match(tosym, linker_symbols))
1195 return 0;
1196
1197 /* Check for pattern 5 */
1198 if (match(fromsec, text_sections) &&
1199 match(tosec, init_sections) &&
1200 match(fromsym, optim_symbols))
1201 return 0;
1202
1203 return 1;
1204 }
1205
1206 /**
1207 * Find symbol based on relocation record info.
1208 * In some cases the symbol supplied is a valid symbol so
1209 * return refsym. If st_name != 0 we assume this is a valid symbol.
1210 * In other cases the symbol needs to be looked up in the symbol table
1211 * based on section and address.
1212 * **/
1213 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1214 Elf_Sym *relsym)
1215 {
1216 Elf_Sym *sym;
1217 Elf_Sym *near = NULL;
1218 Elf64_Sword distance = 20;
1219 Elf64_Sword d;
1220 unsigned int relsym_secindex;
1221
1222 if (relsym->st_name != 0)
1223 return relsym;
1224
1225 relsym_secindex = get_secindex(elf, relsym);
1226 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1227 if (get_secindex(elf, sym) != relsym_secindex)
1228 continue;
1229 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1230 continue;
1231 if (sym->st_value == addr)
1232 return sym;
1233 /* Find a symbol nearby - addr are maybe negative */
1234 d = sym->st_value - addr;
1235 if (d < 0)
1236 d = addr - sym->st_value;
1237 if (d < distance) {
1238 distance = d;
1239 near = sym;
1240 }
1241 }
1242 /* We need a close match */
1243 if (distance < 20)
1244 return near;
1245 else
1246 return NULL;
1247 }
1248
1249 static inline int is_arm_mapping_symbol(const char *str)
1250 {
1251 return str[0] == '$' && strchr("axtd", str[1])
1252 && (str[2] == '\0' || str[2] == '.');
1253 }
1254
1255 /*
1256 * If there's no name there, ignore it; likewise, ignore it if it's
1257 * one of the magic symbols emitted used by current ARM tools.
1258 *
1259 * Otherwise if find_symbols_between() returns those symbols, they'll
1260 * fail the whitelist tests and cause lots of false alarms ... fixable
1261 * only by merging __exit and __init sections into __text, bloating
1262 * the kernel (which is especially evil on embedded platforms).
1263 */
1264 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1265 {
1266 const char *name = elf->strtab + sym->st_name;
1267
1268 if (!name || !strlen(name))
1269 return 0;
1270 return !is_arm_mapping_symbol(name);
1271 }
1272
1273 /*
1274 * Find symbols before or equal addr and after addr - in the section sec.
1275 * If we find two symbols with equal offset prefer one with a valid name.
1276 * The ELF format may have a better way to detect what type of symbol
1277 * it is, but this works for now.
1278 **/
1279 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1280 const char *sec)
1281 {
1282 Elf_Sym *sym;
1283 Elf_Sym *near = NULL;
1284 Elf_Addr distance = ~0;
1285
1286 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1287 const char *symsec;
1288
1289 if (is_shndx_special(sym->st_shndx))
1290 continue;
1291 symsec = sec_name(elf, get_secindex(elf, sym));
1292 if (strcmp(symsec, sec) != 0)
1293 continue;
1294 if (!is_valid_name(elf, sym))
1295 continue;
1296 if (sym->st_value <= addr) {
1297 if ((addr - sym->st_value) < distance) {
1298 distance = addr - sym->st_value;
1299 near = sym;
1300 } else if ((addr - sym->st_value) == distance) {
1301 near = sym;
1302 }
1303 }
1304 }
1305 return near;
1306 }
1307
1308 /*
1309 * Convert a section name to the function/data attribute
1310 * .init.text => __init
1311 * .memexitconst => __memconst
1312 * etc.
1313 *
1314 * The memory of returned value has been allocated on a heap. The user of this
1315 * method should free it after usage.
1316 */
1317 static char *sec2annotation(const char *s)
1318 {
1319 if (match(s, init_exit_sections)) {
1320 char *p = malloc(20);
1321 char *r = p;
1322
1323 *p++ = '_';
1324 *p++ = '_';
1325 if (*s == '.')
1326 s++;
1327 while (*s && *s != '.')
1328 *p++ = *s++;
1329 *p = '\0';
1330 if (*s == '.')
1331 s++;
1332 if (strstr(s, "rodata") != NULL)
1333 strcat(p, "const ");
1334 else if (strstr(s, "data") != NULL)
1335 strcat(p, "data ");
1336 else
1337 strcat(p, " ");
1338 return r;
1339 } else {
1340 return strdup("");
1341 }
1342 }
1343
1344 static int is_function(Elf_Sym *sym)
1345 {
1346 if (sym)
1347 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1348 else
1349 return -1;
1350 }
1351
1352 static void print_section_list(const char * const list[20])
1353 {
1354 const char *const *s = list;
1355
1356 while (*s) {
1357 fprintf(stderr, "%s", *s);
1358 s++;
1359 if (*s)
1360 fprintf(stderr, ", ");
1361 }
1362 fprintf(stderr, "\n");
1363 }
1364
1365 static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1366 {
1367 switch (is_func) {
1368 case 0: *name = "variable"; *name_p = ""; break;
1369 case 1: *name = "function"; *name_p = "()"; break;
1370 default: *name = "(unknown reference)"; *name_p = ""; break;
1371 }
1372 }
1373
1374 /*
1375 * Print a warning about a section mismatch.
1376 * Try to find symbols near it so user can find it.
1377 * Check whitelist before warning - it may be a false positive.
1378 */
1379 static void report_sec_mismatch(const char *modname,
1380 const struct sectioncheck *mismatch,
1381 const char *fromsec,
1382 unsigned long long fromaddr,
1383 const char *fromsym,
1384 int from_is_func,
1385 const char *tosec, const char *tosym,
1386 int to_is_func)
1387 {
1388 const char *from, *from_p;
1389 const char *to, *to_p;
1390 char *prl_from;
1391 char *prl_to;
1392
1393 sec_mismatch_count++;
1394 if (!sec_mismatch_verbose)
1395 return;
1396
1397 get_pretty_name(from_is_func, &from, &from_p);
1398 get_pretty_name(to_is_func, &to, &to_p);
1399
1400 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1401 "to the %s %s:%s%s\n",
1402 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1403 tosym, to_p);
1404
1405 switch (mismatch->mismatch) {
1406 case TEXT_TO_ANY_INIT:
1407 prl_from = sec2annotation(fromsec);
1408 prl_to = sec2annotation(tosec);
1409 fprintf(stderr,
1410 "The function %s%s() references\n"
1411 "the %s %s%s%s.\n"
1412 "This is often because %s lacks a %s\n"
1413 "annotation or the annotation of %s is wrong.\n",
1414 prl_from, fromsym,
1415 to, prl_to, tosym, to_p,
1416 fromsym, prl_to, tosym);
1417 free(prl_from);
1418 free(prl_to);
1419 break;
1420 case DATA_TO_ANY_INIT: {
1421 prl_to = sec2annotation(tosec);
1422 fprintf(stderr,
1423 "The variable %s references\n"
1424 "the %s %s%s%s\n"
1425 "If the reference is valid then annotate the\n"
1426 "variable with __init* or __refdata (see linux/init.h) "
1427 "or name the variable:\n",
1428 fromsym, to, prl_to, tosym, to_p);
1429 print_section_list(mismatch->symbol_white_list);
1430 free(prl_to);
1431 break;
1432 }
1433 case TEXT_TO_ANY_EXIT:
1434 prl_to = sec2annotation(tosec);
1435 fprintf(stderr,
1436 "The function %s() references a %s in an exit section.\n"
1437 "Often the %s %s%s has valid usage outside the exit section\n"
1438 "and the fix is to remove the %sannotation of %s.\n",
1439 fromsym, to, to, tosym, to_p, prl_to, tosym);
1440 free(prl_to);
1441 break;
1442 case DATA_TO_ANY_EXIT: {
1443 prl_to = sec2annotation(tosec);
1444 fprintf(stderr,
1445 "The variable %s references\n"
1446 "the %s %s%s%s\n"
1447 "If the reference is valid then annotate the\n"
1448 "variable with __exit* (see linux/init.h) or "
1449 "name the variable:\n",
1450 fromsym, to, prl_to, tosym, to_p);
1451 print_section_list(mismatch->symbol_white_list);
1452 free(prl_to);
1453 break;
1454 }
1455 case XXXINIT_TO_SOME_INIT:
1456 case XXXEXIT_TO_SOME_EXIT:
1457 prl_from = sec2annotation(fromsec);
1458 prl_to = sec2annotation(tosec);
1459 fprintf(stderr,
1460 "The %s %s%s%s references\n"
1461 "a %s %s%s%s.\n"
1462 "If %s is only used by %s then\n"
1463 "annotate %s with a matching annotation.\n",
1464 from, prl_from, fromsym, from_p,
1465 to, prl_to, tosym, to_p,
1466 tosym, fromsym, tosym);
1467 free(prl_from);
1468 free(prl_to);
1469 break;
1470 case ANY_INIT_TO_ANY_EXIT:
1471 prl_from = sec2annotation(fromsec);
1472 prl_to = sec2annotation(tosec);
1473 fprintf(stderr,
1474 "The %s %s%s%s references\n"
1475 "a %s %s%s%s.\n"
1476 "This is often seen when error handling "
1477 "in the init function\n"
1478 "uses functionality in the exit path.\n"
1479 "The fix is often to remove the %sannotation of\n"
1480 "%s%s so it may be used outside an exit section.\n",
1481 from, prl_from, fromsym, from_p,
1482 to, prl_to, tosym, to_p,
1483 prl_to, tosym, to_p);
1484 free(prl_from);
1485 free(prl_to);
1486 break;
1487 case ANY_EXIT_TO_ANY_INIT:
1488 prl_from = sec2annotation(fromsec);
1489 prl_to = sec2annotation(tosec);
1490 fprintf(stderr,
1491 "The %s %s%s%s references\n"
1492 "a %s %s%s%s.\n"
1493 "This is often seen when error handling "
1494 "in the exit function\n"
1495 "uses functionality in the init path.\n"
1496 "The fix is often to remove the %sannotation of\n"
1497 "%s%s so it may be used outside an init section.\n",
1498 from, prl_from, fromsym, from_p,
1499 to, prl_to, tosym, to_p,
1500 prl_to, tosym, to_p);
1501 free(prl_from);
1502 free(prl_to);
1503 break;
1504 case EXPORT_TO_INIT_EXIT:
1505 prl_to = sec2annotation(tosec);
1506 fprintf(stderr,
1507 "The symbol %s is exported and annotated %s\n"
1508 "Fix this by removing the %sannotation of %s "
1509 "or drop the export.\n",
1510 tosym, prl_to, prl_to, tosym);
1511 free(prl_to);
1512 break;
1513 case EXTABLE_TO_NON_TEXT:
1514 fatal("There's a special handler for this mismatch type, "
1515 "we should never get here.");
1516 break;
1517 }
1518 fprintf(stderr, "\n");
1519 }
1520
1521 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1522 const struct sectioncheck* const mismatch,
1523 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1524 {
1525 const char *tosec;
1526 Elf_Sym *to;
1527 Elf_Sym *from;
1528 const char *tosym;
1529 const char *fromsym;
1530
1531 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1532 fromsym = sym_name(elf, from);
1533
1534 if (!strncmp(fromsym, "reference___initcall",
1535 sizeof("reference___initcall")-1))
1536 return;
1537
1538 tosec = sec_name(elf, get_secindex(elf, sym));
1539 to = find_elf_symbol(elf, r->r_addend, sym);
1540 tosym = sym_name(elf, to);
1541
1542 /* check whitelist - we may ignore it */
1543 if (secref_whitelist(mismatch,
1544 fromsec, fromsym, tosec, tosym)) {
1545 report_sec_mismatch(modname, mismatch,
1546 fromsec, r->r_offset, fromsym,
1547 is_function(from), tosec, tosym,
1548 is_function(to));
1549 }
1550 }
1551
1552 static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1553 {
1554 if (section_index > elf->num_sections)
1555 fatal("section_index is outside elf->num_sections!\n");
1556
1557 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1558 }
1559
1560 /*
1561 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1562 * to know the sizeof(struct exception_table_entry) for the target architecture.
1563 */
1564 static unsigned int extable_entry_size = 0;
1565 static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1566 {
1567 /*
1568 * If we're currently checking the second relocation within __ex_table,
1569 * that relocation offset tells us the offsetof(struct
1570 * exception_table_entry, fixup) which is equal to sizeof(struct
1571 * exception_table_entry) divided by two. We use that to our advantage
1572 * since there's no portable way to get that size as every architecture
1573 * seems to go with different sized types. Not pretty but better than
1574 * hard-coding the size for every architecture..
1575 */
1576 if (!extable_entry_size)
1577 extable_entry_size = r->r_offset * 2;
1578 }
1579
1580 static inline bool is_extable_fault_address(Elf_Rela *r)
1581 {
1582 /*
1583 * extable_entry_size is only discovered after we've handled the
1584 * _second_ relocation in __ex_table, so only abort when we're not
1585 * handling the first reloc and extable_entry_size is zero.
1586 */
1587 if (r->r_offset && extable_entry_size == 0)
1588 fatal("extable_entry size hasn't been discovered!\n");
1589
1590 return ((r->r_offset == 0) ||
1591 (r->r_offset % extable_entry_size == 0));
1592 }
1593
1594 #define is_second_extable_reloc(Start, Cur, Sec) \
1595 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1596
1597 static void report_extable_warnings(const char* modname, struct elf_info* elf,
1598 const struct sectioncheck* const mismatch,
1599 Elf_Rela* r, Elf_Sym* sym,
1600 const char* fromsec, const char* tosec)
1601 {
1602 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1603 const char* fromsym_name = sym_name(elf, fromsym);
1604 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1605 const char* tosym_name = sym_name(elf, tosym);
1606 const char* from_pretty_name;
1607 const char* from_pretty_name_p;
1608 const char* to_pretty_name;
1609 const char* to_pretty_name_p;
1610
1611 get_pretty_name(is_function(fromsym),
1612 &from_pretty_name, &from_pretty_name_p);
1613 get_pretty_name(is_function(tosym),
1614 &to_pretty_name, &to_pretty_name_p);
1615
1616 warn("%s(%s+0x%lx): Section mismatch in reference"
1617 " from the %s %s%s to the %s %s:%s%s\n",
1618 modname, fromsec, (long)r->r_offset, from_pretty_name,
1619 fromsym_name, from_pretty_name_p,
1620 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1621
1622 if (!match(tosec, mismatch->bad_tosec) &&
1623 is_executable_section(elf, get_secindex(elf, sym)))
1624 fprintf(stderr,
1625 "The relocation at %s+0x%lx references\n"
1626 "section \"%s\" which is not in the list of\n"
1627 "authorized sections. If you're adding a new section\n"
1628 "and/or if this reference is valid, add \"%s\" to the\n"
1629 "list of authorized sections to jump to on fault.\n"
1630 "This can be achieved by adding \"%s\" to \n"
1631 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1632 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1633 }
1634
1635 static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1636 const struct sectioncheck* const mismatch,
1637 Elf_Rela* r, Elf_Sym* sym,
1638 const char *fromsec)
1639 {
1640 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1641
1642 sec_mismatch_count++;
1643
1644 if (sec_mismatch_verbose)
1645 report_extable_warnings(modname, elf, mismatch, r, sym,
1646 fromsec, tosec);
1647
1648 if (match(tosec, mismatch->bad_tosec))
1649 fatal("The relocation at %s+0x%lx references\n"
1650 "section \"%s\" which is black-listed.\n"
1651 "Something is seriously wrong and should be fixed.\n"
1652 "You might get more information about where this is\n"
1653 "coming from by using scripts/check_extable.sh %s\n",
1654 fromsec, (long)r->r_offset, tosec, modname);
1655 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1656 if (is_extable_fault_address(r))
1657 fatal("The relocation at %s+0x%lx references\n"
1658 "section \"%s\" which is not executable, IOW\n"
1659 "it is not possible for the kernel to fault\n"
1660 "at that address. Something is seriously wrong\n"
1661 "and should be fixed.\n",
1662 fromsec, (long)r->r_offset, tosec);
1663 else
1664 fatal("The relocation at %s+0x%lx references\n"
1665 "section \"%s\" which is not executable, IOW\n"
1666 "the kernel will fault if it ever tries to\n"
1667 "jump to it. Something is seriously wrong\n"
1668 "and should be fixed.\n",
1669 fromsec, (long)r->r_offset, tosec);
1670 }
1671 }
1672
1673 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1674 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1675 {
1676 const char *tosec = sec_name(elf, get_secindex(elf, sym));;
1677 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1678
1679 if (mismatch) {
1680 if (mismatch->handler)
1681 mismatch->handler(modname, elf, mismatch,
1682 r, sym, fromsec);
1683 else
1684 default_mismatch_handler(modname, elf, mismatch,
1685 r, sym, fromsec);
1686 }
1687 }
1688
1689 static unsigned int *reloc_location(struct elf_info *elf,
1690 Elf_Shdr *sechdr, Elf_Rela *r)
1691 {
1692 Elf_Shdr *sechdrs = elf->sechdrs;
1693 int section = sechdr->sh_info;
1694
1695 return (void *)elf->hdr + sechdrs[section].sh_offset +
1696 r->r_offset;
1697 }
1698
1699 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1700 {
1701 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1702 unsigned int *location = reloc_location(elf, sechdr, r);
1703
1704 switch (r_typ) {
1705 case R_386_32:
1706 r->r_addend = TO_NATIVE(*location);
1707 break;
1708 case R_386_PC32:
1709 r->r_addend = TO_NATIVE(*location) + 4;
1710 /* For CONFIG_RELOCATABLE=y */
1711 if (elf->hdr->e_type == ET_EXEC)
1712 r->r_addend += r->r_offset;
1713 break;
1714 }
1715 return 0;
1716 }
1717
1718 #ifndef R_ARM_CALL
1719 #define R_ARM_CALL 28
1720 #endif
1721 #ifndef R_ARM_JUMP24
1722 #define R_ARM_JUMP24 29
1723 #endif
1724
1725 #ifndef R_ARM_THM_CALL
1726 #define R_ARM_THM_CALL 10
1727 #endif
1728 #ifndef R_ARM_THM_JUMP24
1729 #define R_ARM_THM_JUMP24 30
1730 #endif
1731 #ifndef R_ARM_THM_JUMP19
1732 #define R_ARM_THM_JUMP19 51
1733 #endif
1734
1735 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1736 {
1737 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1738
1739 switch (r_typ) {
1740 case R_ARM_ABS32:
1741 /* From ARM ABI: (S + A) | T */
1742 r->r_addend = (int)(long)
1743 (elf->symtab_start + ELF_R_SYM(r->r_info));
1744 break;
1745 case R_ARM_PC24:
1746 case R_ARM_CALL:
1747 case R_ARM_JUMP24:
1748 case R_ARM_THM_CALL:
1749 case R_ARM_THM_JUMP24:
1750 case R_ARM_THM_JUMP19:
1751 /* From ARM ABI: ((S + A) | T) - P */
1752 r->r_addend = (int)(long)(elf->hdr +
1753 sechdr->sh_offset +
1754 (r->r_offset - sechdr->sh_addr));
1755 break;
1756 default:
1757 return 1;
1758 }
1759 return 0;
1760 }
1761
1762 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1763 {
1764 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1765 unsigned int *location = reloc_location(elf, sechdr, r);
1766 unsigned int inst;
1767
1768 if (r_typ == R_MIPS_HI16)
1769 return 1; /* skip this */
1770 inst = TO_NATIVE(*location);
1771 switch (r_typ) {
1772 case R_MIPS_LO16:
1773 r->r_addend = inst & 0xffff;
1774 break;
1775 case R_MIPS_26:
1776 r->r_addend = (inst & 0x03ffffff) << 2;
1777 break;
1778 case R_MIPS_32:
1779 r->r_addend = inst;
1780 break;
1781 }
1782 return 0;
1783 }
1784
1785 static void section_rela(const char *modname, struct elf_info *elf,
1786 Elf_Shdr *sechdr)
1787 {
1788 Elf_Sym *sym;
1789 Elf_Rela *rela;
1790 Elf_Rela r;
1791 unsigned int r_sym;
1792 const char *fromsec;
1793
1794 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1795 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1796
1797 fromsec = sech_name(elf, sechdr);
1798 fromsec += strlen(".rela");
1799 /* if from section (name) is know good then skip it */
1800 if (match(fromsec, section_white_list))
1801 return;
1802
1803 for (rela = start; rela < stop; rela++) {
1804 r.r_offset = TO_NATIVE(rela->r_offset);
1805 #if KERNEL_ELFCLASS == ELFCLASS64
1806 if (elf->hdr->e_machine == EM_MIPS) {
1807 unsigned int r_typ;
1808 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1809 r_sym = TO_NATIVE(r_sym);
1810 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1811 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1812 } else {
1813 r.r_info = TO_NATIVE(rela->r_info);
1814 r_sym = ELF_R_SYM(r.r_info);
1815 }
1816 #else
1817 r.r_info = TO_NATIVE(rela->r_info);
1818 r_sym = ELF_R_SYM(r.r_info);
1819 #endif
1820 r.r_addend = TO_NATIVE(rela->r_addend);
1821 sym = elf->symtab_start + r_sym;
1822 /* Skip special sections */
1823 if (is_shndx_special(sym->st_shndx))
1824 continue;
1825 if (is_second_extable_reloc(start, rela, fromsec))
1826 find_extable_entry_size(fromsec, &r);
1827 check_section_mismatch(modname, elf, &r, sym, fromsec);
1828 }
1829 }
1830
1831 static void section_rel(const char *modname, struct elf_info *elf,
1832 Elf_Shdr *sechdr)
1833 {
1834 Elf_Sym *sym;
1835 Elf_Rel *rel;
1836 Elf_Rela r;
1837 unsigned int r_sym;
1838 const char *fromsec;
1839
1840 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1841 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1842
1843 fromsec = sech_name(elf, sechdr);
1844 fromsec += strlen(".rel");
1845 /* if from section (name) is know good then skip it */
1846 if (match(fromsec, section_white_list))
1847 return;
1848
1849 for (rel = start; rel < stop; rel++) {
1850 r.r_offset = TO_NATIVE(rel->r_offset);
1851 #if KERNEL_ELFCLASS == ELFCLASS64
1852 if (elf->hdr->e_machine == EM_MIPS) {
1853 unsigned int r_typ;
1854 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1855 r_sym = TO_NATIVE(r_sym);
1856 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1857 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1858 } else {
1859 r.r_info = TO_NATIVE(rel->r_info);
1860 r_sym = ELF_R_SYM(r.r_info);
1861 }
1862 #else
1863 r.r_info = TO_NATIVE(rel->r_info);
1864 r_sym = ELF_R_SYM(r.r_info);
1865 #endif
1866 r.r_addend = 0;
1867 switch (elf->hdr->e_machine) {
1868 case EM_386:
1869 if (addend_386_rel(elf, sechdr, &r))
1870 continue;
1871 break;
1872 case EM_ARM:
1873 if (addend_arm_rel(elf, sechdr, &r))
1874 continue;
1875 break;
1876 case EM_MIPS:
1877 if (addend_mips_rel(elf, sechdr, &r))
1878 continue;
1879 break;
1880 }
1881 sym = elf->symtab_start + r_sym;
1882 /* Skip special sections */
1883 if (is_shndx_special(sym->st_shndx))
1884 continue;
1885 if (is_second_extable_reloc(start, rel, fromsec))
1886 find_extable_entry_size(fromsec, &r);
1887 check_section_mismatch(modname, elf, &r, sym, fromsec);
1888 }
1889 }
1890
1891 /**
1892 * A module includes a number of sections that are discarded
1893 * either when loaded or when used as built-in.
1894 * For loaded modules all functions marked __init and all data
1895 * marked __initdata will be discarded when the module has been initialized.
1896 * Likewise for modules used built-in the sections marked __exit
1897 * are discarded because __exit marked function are supposed to be called
1898 * only when a module is unloaded which never happens for built-in modules.
1899 * The check_sec_ref() function traverses all relocation records
1900 * to find all references to a section that reference a section that will
1901 * be discarded and warns about it.
1902 **/
1903 static void check_sec_ref(struct module *mod, const char *modname,
1904 struct elf_info *elf)
1905 {
1906 int i;
1907 Elf_Shdr *sechdrs = elf->sechdrs;
1908
1909 /* Walk through all sections */
1910 for (i = 0; i < elf->num_sections; i++) {
1911 check_section(modname, elf, &elf->sechdrs[i]);
1912 /* We want to process only relocation sections and not .init */
1913 if (sechdrs[i].sh_type == SHT_RELA)
1914 section_rela(modname, elf, &elf->sechdrs[i]);
1915 else if (sechdrs[i].sh_type == SHT_REL)
1916 section_rel(modname, elf, &elf->sechdrs[i]);
1917 }
1918 }
1919
1920 static char *remove_dot(char *s)
1921 {
1922 size_t n = strcspn(s, ".");
1923
1924 if (n && s[n]) {
1925 size_t m = strspn(s + n + 1, "0123456789");
1926 if (m && (s[n + m] == '.' || s[n + m] == 0))
1927 s[n] = 0;
1928 }
1929 return s;
1930 }
1931
1932 static void read_symbols(char *modname)
1933 {
1934 const char *symname;
1935 char *version;
1936 char *license;
1937 struct module *mod;
1938 struct elf_info info = { };
1939 Elf_Sym *sym;
1940
1941 if (!parse_elf(&info, modname))
1942 return;
1943
1944 mod = new_module(modname);
1945
1946 /* When there's no vmlinux, don't print warnings about
1947 * unresolved symbols (since there'll be too many ;) */
1948 if (is_vmlinux(modname)) {
1949 have_vmlinux = 1;
1950 mod->skip = 1;
1951 }
1952
1953 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1954 if (info.modinfo && !license && !is_vmlinux(modname))
1955 warn("modpost: missing MODULE_LICENSE() in %s\n"
1956 "see include/linux/module.h for "
1957 "more information\n", modname);
1958 while (license) {
1959 if (license_is_gpl_compatible(license))
1960 mod->gpl_compatible = 1;
1961 else {
1962 mod->gpl_compatible = 0;
1963 break;
1964 }
1965 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1966 "license", license);
1967 }
1968
1969 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1970 symname = remove_dot(info.strtab + sym->st_name);
1971
1972 handle_modversions(mod, &info, sym, symname);
1973 handle_moddevtable(mod, &info, sym, symname);
1974 }
1975 if (!is_vmlinux(modname) ||
1976 (is_vmlinux(modname) && vmlinux_section_warnings))
1977 check_sec_ref(mod, modname, &info);
1978
1979 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1980 if (version)
1981 maybe_frob_rcs_version(modname, version, info.modinfo,
1982 version - (char *)info.hdr);
1983 if (version || (all_versions && !is_vmlinux(modname)))
1984 get_src_version(modname, mod->srcversion,
1985 sizeof(mod->srcversion)-1);
1986
1987 parse_elf_finish(&info);
1988
1989 /* Our trick to get versioning for module struct etc. - it's
1990 * never passed as an argument to an exported function, so
1991 * the automatic versioning doesn't pick it up, but it's really
1992 * important anyhow */
1993 if (modversions)
1994 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1995 }
1996
1997 static void read_symbols_from_files(const char *filename)
1998 {
1999 FILE *in = stdin;
2000 char fname[PATH_MAX];
2001
2002 if (strcmp(filename, "-") != 0) {
2003 in = fopen(filename, "r");
2004 if (!in)
2005 fatal("Can't open filenames file %s: %m", filename);
2006 }
2007
2008 while (fgets(fname, PATH_MAX, in) != NULL) {
2009 if (strends(fname, "\n"))
2010 fname[strlen(fname)-1] = '\0';
2011 read_symbols(fname);
2012 }
2013
2014 if (in != stdin)
2015 fclose(in);
2016 }
2017
2018 #define SZ 500
2019
2020 /* We first write the generated file into memory using the
2021 * following helper, then compare to the file on disk and
2022 * only update the later if anything changed */
2023
2024 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2025 const char *fmt, ...)
2026 {
2027 char tmp[SZ];
2028 int len;
2029 va_list ap;
2030
2031 va_start(ap, fmt);
2032 len = vsnprintf(tmp, SZ, fmt, ap);
2033 buf_write(buf, tmp, len);
2034 va_end(ap);
2035 }
2036
2037 void buf_write(struct buffer *buf, const char *s, int len)
2038 {
2039 if (buf->size - buf->pos < len) {
2040 buf->size += len + SZ;
2041 buf->p = realloc(buf->p, buf->size);
2042 }
2043 strncpy(buf->p + buf->pos, s, len);
2044 buf->pos += len;
2045 }
2046
2047 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2048 {
2049 const char *e = is_vmlinux(m) ?"":".ko";
2050
2051 switch (exp) {
2052 case export_gpl:
2053 fatal("modpost: GPL-incompatible module %s%s "
2054 "uses GPL-only symbol '%s'\n", m, e, s);
2055 break;
2056 case export_unused_gpl:
2057 fatal("modpost: GPL-incompatible module %s%s "
2058 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
2059 break;
2060 case export_gpl_future:
2061 warn("modpost: GPL-incompatible module %s%s "
2062 "uses future GPL-only symbol '%s'\n", m, e, s);
2063 break;
2064 case export_plain:
2065 case export_unused:
2066 case export_unknown:
2067 /* ignore */
2068 break;
2069 }
2070 }
2071
2072 static void check_for_unused(enum export exp, const char *m, const char *s)
2073 {
2074 const char *e = is_vmlinux(m) ?"":".ko";
2075
2076 switch (exp) {
2077 case export_unused:
2078 case export_unused_gpl:
2079 warn("modpost: module %s%s "
2080 "uses symbol '%s' marked UNUSED\n", m, e, s);
2081 break;
2082 default:
2083 /* ignore */
2084 break;
2085 }
2086 }
2087
2088 static void check_exports(struct module *mod)
2089 {
2090 struct symbol *s, *exp;
2091
2092 for (s = mod->unres; s; s = s->next) {
2093 const char *basename;
2094 exp = find_symbol(s->name);
2095 if (!exp || exp->module == mod)
2096 continue;
2097 basename = strrchr(mod->name, '/');
2098 if (basename)
2099 basename++;
2100 else
2101 basename = mod->name;
2102 if (!mod->gpl_compatible)
2103 check_for_gpl_usage(exp->export, basename, exp->name);
2104 check_for_unused(exp->export, basename, exp->name);
2105 }
2106 }
2107
2108 /**
2109 * Header for the generated file
2110 **/
2111 static void add_header(struct buffer *b, struct module *mod)
2112 {
2113 buf_printf(b, "#include <linux/module.h>\n");
2114 buf_printf(b, "#include <linux/vermagic.h>\n");
2115 buf_printf(b, "#include <linux/compiler.h>\n");
2116 buf_printf(b, "\n");
2117 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2118 buf_printf(b, "\n");
2119 buf_printf(b, "__visible struct module __this_module\n");
2120 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
2121 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2122 if (mod->has_init)
2123 buf_printf(b, "\t.init = init_module,\n");
2124 if (mod->has_cleanup)
2125 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2126 "\t.exit = cleanup_module,\n"
2127 "#endif\n");
2128 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2129 buf_printf(b, "};\n");
2130 }
2131
2132 static void add_intree_flag(struct buffer *b, int is_intree)
2133 {
2134 if (is_intree)
2135 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2136 }
2137
2138 static void add_staging_flag(struct buffer *b, const char *name)
2139 {
2140 static const char *staging_dir = "drivers/staging";
2141
2142 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
2143 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2144 }
2145
2146 /* In kernel, this size is defined in linux/module.h;
2147 * here we use Elf_Addr instead of long for covering cross-compile
2148 */
2149 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
2150
2151 /**
2152 * Record CRCs for unresolved symbols
2153 **/
2154 static int add_versions(struct buffer *b, struct module *mod)
2155 {
2156 struct symbol *s, *exp;
2157 int err = 0;
2158
2159 for (s = mod->unres; s; s = s->next) {
2160 exp = find_symbol(s->name);
2161 if (!exp || exp->module == mod) {
2162 if (have_vmlinux && !s->weak) {
2163 if (warn_unresolved) {
2164 warn("\"%s\" [%s.ko] undefined!\n",
2165 s->name, mod->name);
2166 } else {
2167 merror("\"%s\" [%s.ko] undefined!\n",
2168 s->name, mod->name);
2169 err = 1;
2170 }
2171 }
2172 continue;
2173 }
2174 s->module = exp->module;
2175 s->crc_valid = exp->crc_valid;
2176 s->crc = exp->crc;
2177 }
2178
2179 if (!modversions)
2180 return err;
2181
2182 buf_printf(b, "\n");
2183 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2184 buf_printf(b, "__used\n");
2185 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
2186
2187 for (s = mod->unres; s; s = s->next) {
2188 if (!s->module)
2189 continue;
2190 if (!s->crc_valid) {
2191 warn("\"%s\" [%s.ko] has no CRC!\n",
2192 s->name, mod->name);
2193 continue;
2194 }
2195 if (strlen(s->name) >= MODULE_NAME_LEN) {
2196 merror("too long symbol \"%s\" [%s.ko]\n",
2197 s->name, mod->name);
2198 err = 1;
2199 break;
2200 }
2201 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
2202 s->crc, s->name);
2203 }
2204
2205 buf_printf(b, "};\n");
2206
2207 return err;
2208 }
2209
2210 static void add_depends(struct buffer *b, struct module *mod,
2211 struct module *modules)
2212 {
2213 struct symbol *s;
2214 struct module *m;
2215 int first = 1;
2216
2217 for (m = modules; m; m = m->next)
2218 m->seen = is_vmlinux(m->name);
2219
2220 buf_printf(b, "\n");
2221 buf_printf(b, "static const char __module_depends[]\n");
2222 buf_printf(b, "__used\n");
2223 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
2224 buf_printf(b, "\"depends=");
2225 for (s = mod->unres; s; s = s->next) {
2226 const char *p;
2227 if (!s->module)
2228 continue;
2229
2230 if (s->module->seen)
2231 continue;
2232
2233 s->module->seen = 1;
2234 p = strrchr(s->module->name, '/');
2235 if (p)
2236 p++;
2237 else
2238 p = s->module->name;
2239 buf_printf(b, "%s%s", first ? "" : ",", p);
2240 first = 0;
2241 }
2242 buf_printf(b, "\";\n");
2243 }
2244
2245 static void add_srcversion(struct buffer *b, struct module *mod)
2246 {
2247 if (mod->srcversion[0]) {
2248 buf_printf(b, "\n");
2249 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2250 mod->srcversion);
2251 }
2252 }
2253
2254 static void write_if_changed(struct buffer *b, const char *fname)
2255 {
2256 char *tmp;
2257 FILE *file;
2258 struct stat st;
2259
2260 file = fopen(fname, "r");
2261 if (!file)
2262 goto write;
2263
2264 if (fstat(fileno(file), &st) < 0)
2265 goto close_write;
2266
2267 if (st.st_size != b->pos)
2268 goto close_write;
2269
2270 tmp = NOFAIL(malloc(b->pos));
2271 if (fread(tmp, 1, b->pos, file) != b->pos)
2272 goto free_write;
2273
2274 if (memcmp(tmp, b->p, b->pos) != 0)
2275 goto free_write;
2276
2277 free(tmp);
2278 fclose(file);
2279 return;
2280
2281 free_write:
2282 free(tmp);
2283 close_write:
2284 fclose(file);
2285 write:
2286 file = fopen(fname, "w");
2287 if (!file) {
2288 perror(fname);
2289 exit(1);
2290 }
2291 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2292 perror(fname);
2293 exit(1);
2294 }
2295 fclose(file);
2296 }
2297
2298 /* parse Module.symvers file. line format:
2299 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2300 **/
2301 static void read_dump(const char *fname, unsigned int kernel)
2302 {
2303 unsigned long size, pos = 0;
2304 void *file = grab_file(fname, &size);
2305 char *line;
2306
2307 if (!file)
2308 /* No symbol versions, silently ignore */
2309 return;
2310
2311 while ((line = get_next_line(&pos, file, size))) {
2312 char *symname, *modname, *d, *export, *end;
2313 unsigned int crc;
2314 struct module *mod;
2315 struct symbol *s;
2316
2317 if (!(symname = strchr(line, '\t')))
2318 goto fail;
2319 *symname++ = '\0';
2320 if (!(modname = strchr(symname, '\t')))
2321 goto fail;
2322 *modname++ = '\0';
2323 if ((export = strchr(modname, '\t')) != NULL)
2324 *export++ = '\0';
2325 if (export && ((end = strchr(export, '\t')) != NULL))
2326 *end = '\0';
2327 crc = strtoul(line, &d, 16);
2328 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2329 goto fail;
2330 mod = find_module(modname);
2331 if (!mod) {
2332 if (is_vmlinux(modname))
2333 have_vmlinux = 1;
2334 mod = new_module(modname);
2335 mod->skip = 1;
2336 }
2337 s = sym_add_exported(symname, mod, export_no(export));
2338 s->kernel = kernel;
2339 s->preloaded = 1;
2340 sym_update_crc(symname, mod, crc, export_no(export));
2341 }
2342 release_file(file, size);
2343 return;
2344 fail:
2345 release_file(file, size);
2346 fatal("parse error in symbol dump file\n");
2347 }
2348
2349 /* For normal builds always dump all symbols.
2350 * For external modules only dump symbols
2351 * that are not read from kernel Module.symvers.
2352 **/
2353 static int dump_sym(struct symbol *sym)
2354 {
2355 if (!external_module)
2356 return 1;
2357 if (sym->vmlinux || sym->kernel)
2358 return 0;
2359 return 1;
2360 }
2361
2362 static void write_dump(const char *fname)
2363 {
2364 struct buffer buf = { };
2365 struct symbol *symbol;
2366 int n;
2367
2368 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2369 symbol = symbolhash[n];
2370 while (symbol) {
2371 if (dump_sym(symbol))
2372 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2373 symbol->crc, symbol->name,
2374 symbol->module->name,
2375 export_str(symbol->export));
2376 symbol = symbol->next;
2377 }
2378 }
2379 write_if_changed(&buf, fname);
2380 free(buf.p);
2381 }
2382
2383 struct ext_sym_list {
2384 struct ext_sym_list *next;
2385 const char *file;
2386 };
2387
2388 int main(int argc, char **argv)
2389 {
2390 struct module *mod;
2391 struct buffer buf = { };
2392 char *kernel_read = NULL, *module_read = NULL;
2393 char *dump_write = NULL, *files_source = NULL;
2394 int opt;
2395 int err;
2396 struct ext_sym_list *extsym_iter;
2397 struct ext_sym_list *extsym_start = NULL;
2398
2399 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:E")) != -1) {
2400 switch (opt) {
2401 case 'i':
2402 kernel_read = optarg;
2403 break;
2404 case 'I':
2405 module_read = optarg;
2406 external_module = 1;
2407 break;
2408 case 'e':
2409 external_module = 1;
2410 extsym_iter =
2411 NOFAIL(malloc(sizeof(*extsym_iter)));
2412 extsym_iter->next = extsym_start;
2413 extsym_iter->file = optarg;
2414 extsym_start = extsym_iter;
2415 break;
2416 case 'm':
2417 modversions = 1;
2418 break;
2419 case 'n':
2420 ignore_missing_files = 1;
2421 break;
2422 case 'o':
2423 dump_write = optarg;
2424 break;
2425 case 'a':
2426 all_versions = 1;
2427 break;
2428 case 's':
2429 vmlinux_section_warnings = 0;
2430 break;
2431 case 'S':
2432 sec_mismatch_verbose = 0;
2433 break;
2434 case 'T':
2435 files_source = optarg;
2436 break;
2437 case 'w':
2438 warn_unresolved = 1;
2439 break;
2440 case 'E':
2441 sec_mismatch_fatal = 1;
2442 break;
2443 default:
2444 exit(1);
2445 }
2446 }
2447
2448 if (kernel_read)
2449 read_dump(kernel_read, 1);
2450 if (module_read)
2451 read_dump(module_read, 0);
2452 while (extsym_start) {
2453 read_dump(extsym_start->file, 0);
2454 extsym_iter = extsym_start->next;
2455 free(extsym_start);
2456 extsym_start = extsym_iter;
2457 }
2458
2459 while (optind < argc)
2460 read_symbols(argv[optind++]);
2461
2462 if (files_source)
2463 read_symbols_from_files(files_source);
2464
2465 for (mod = modules; mod; mod = mod->next) {
2466 if (mod->skip)
2467 continue;
2468 check_exports(mod);
2469 }
2470
2471 err = 0;
2472
2473 for (mod = modules; mod; mod = mod->next) {
2474 char fname[PATH_MAX];
2475
2476 if (mod->skip)
2477 continue;
2478
2479 buf.pos = 0;
2480
2481 add_header(&buf, mod);
2482 add_intree_flag(&buf, !external_module);
2483 add_staging_flag(&buf, mod->name);
2484 err |= add_versions(&buf, mod);
2485 add_depends(&buf, mod, modules);
2486 add_moddevtable(&buf, mod);
2487 add_srcversion(&buf, mod);
2488
2489 sprintf(fname, "%s.mod.c", mod->name);
2490 write_if_changed(&buf, fname);
2491 }
2492 if (dump_write)
2493 write_dump(dump_write);
2494 if (sec_mismatch_count) {
2495 if (!sec_mismatch_verbose) {
2496 warn("modpost: Found %d section mismatch(es).\n"
2497 "To see full details build your kernel with:\n"
2498 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2499 sec_mismatch_count);
2500 }
2501 if (sec_mismatch_fatal) {
2502 fatal("modpost: Section mismatches detected.\n"
2503 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2504 }
2505 }
2506 free(buf.p);
2507
2508 return err;
2509 }
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