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x86: 64-bit, add the new split_large_page() function
[wrt350n-kernel.git] / scripts / mod / modpost.c
blobf8efc93eb7004c9ee0004c979acd617ca7d2e8f8
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 #include <ctype.h>
15 #include "modpost.h"
16 #include "../../include/linux/license.h"
17
18 /* Are we using CONFIG_MODVERSIONS? */
19 int modversions = 0;
20 /* Warn about undefined symbols? (do so if we have vmlinux) */
21 int have_vmlinux = 0;
22 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
23 static int all_versions = 0;
24 /* If we are modposting external module set to 1 */
25 static int external_module = 0;
26 /* Warn about section mismatch in vmlinux if set to 1 */
27 static int vmlinux_section_warnings = 1;
28 /* Only warn about unresolved symbols */
29 static int warn_unresolved = 0;
30 /* How a symbol is exported */
31 static int sec_mismatch_count = 0;
32 static int sec_mismatch_verbose = 1;
33
34 enum export {
35 export_plain, export_unused, export_gpl,
36 export_unused_gpl, export_gpl_future, export_unknown
37 };
38
39 #define PRINTF __attribute__ ((format (printf, 1, 2)))
40
41 PRINTF void fatal(const char *fmt, ...)
42 {
43 va_list arglist;
44
45 fprintf(stderr, "FATAL: ");
46
47 va_start(arglist, fmt);
48 vfprintf(stderr, fmt, arglist);
49 va_end(arglist);
50
51 exit(1);
52 }
53
54 PRINTF void warn(const char *fmt, ...)
55 {
56 va_list arglist;
57
58 fprintf(stderr, "WARNING: ");
59
60 va_start(arglist, fmt);
61 vfprintf(stderr, fmt, arglist);
62 va_end(arglist);
63 }
64
65 PRINTF void merror(const char *fmt, ...)
66 {
67 va_list arglist;
68
69 fprintf(stderr, "ERROR: ");
70
71 va_start(arglist, fmt);
72 vfprintf(stderr, fmt, arglist);
73 va_end(arglist);
74 }
75
76 static int is_vmlinux(const char *modname)
77 {
78 const char *myname;
79
80 myname = strrchr(modname, '/');
81 if (myname)
82 myname++;
83 else
84 myname = modname;
85
86 return (strcmp(myname, "vmlinux") == 0) ||
87 (strcmp(myname, "vmlinux.o") == 0);
88 }
89
90 void *do_nofail(void *ptr, const char *expr)
91 {
92 if (!ptr)
93 fatal("modpost: Memory allocation failure: %s.\n", expr);
94
95 return ptr;
96 }
97
98 /* A list of all modules we processed */
99 static struct module *modules;
100
101 static struct module *find_module(char *modname)
102 {
103 struct module *mod;
104
105 for (mod = modules; mod; mod = mod->next)
106 if (strcmp(mod->name, modname) == 0)
107 break;
108 return mod;
109 }
110
111 static struct module *new_module(char *modname)
112 {
113 struct module *mod;
114 char *p, *s;
115
116 mod = NOFAIL(malloc(sizeof(*mod)));
117 memset(mod, 0, sizeof(*mod));
118 p = NOFAIL(strdup(modname));
119
120 /* strip trailing .o */
121 s = strrchr(p, '.');
122 if (s != NULL)
123 if (strcmp(s, ".o") == 0)
124 *s = '\0';
125
126 /* add to list */
127 mod->name = p;
128 mod->gpl_compatible = -1;
129 mod->next = modules;
130 modules = mod;
131
132 return mod;
133 }
134
135 /* A hash of all exported symbols,
136 * struct symbol is also used for lists of unresolved symbols */
137
138 #define SYMBOL_HASH_SIZE 1024
139
140 struct symbol {
141 struct symbol *next;
142 struct module *module;
143 unsigned int crc;
144 int crc_valid;
145 unsigned int weak:1;
146 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
147 unsigned int kernel:1; /* 1 if symbol is from kernel
148 * (only for external modules) **/
149 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
150 enum export export; /* Type of export */
151 char name[0];
152 };
153
154 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
155
156 /* This is based on the hash agorithm from gdbm, via tdb */
157 static inline unsigned int tdb_hash(const char *name)
158 {
159 unsigned value; /* Used to compute the hash value. */
160 unsigned i; /* Used to cycle through random values. */
161
162 /* Set the initial value from the key size. */
163 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
164 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
165
166 return (1103515243 * value + 12345);
167 }
168
169 /**
170 * Allocate a new symbols for use in the hash of exported symbols or
171 * the list of unresolved symbols per module
172 **/
173 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
174 struct symbol *next)
175 {
176 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
177
178 memset(s, 0, sizeof(*s));
179 strcpy(s->name, name);
180 s->weak = weak;
181 s->next = next;
182 return s;
183 }
184
185 /* For the hash of exported symbols */
186 static struct symbol *new_symbol(const char *name, struct module *module,
187 enum export export)
188 {
189 unsigned int hash;
190 struct symbol *new;
191
192 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
193 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
194 new->module = module;
195 new->export = export;
196 return new;
197 }
198
199 static struct symbol *find_symbol(const char *name)
200 {
201 struct symbol *s;
202
203 /* For our purposes, .foo matches foo. PPC64 needs this. */
204 if (name[0] == '.')
205 name++;
206
207 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
208 if (strcmp(s->name, name) == 0)
209 return s;
210 }
211 return NULL;
212 }
213
214 static struct {
215 const char *str;
216 enum export export;
217 } export_list[] = {
218 { .str = "EXPORT_SYMBOL", .export = export_plain },
219 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
220 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
221 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
222 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
223 { .str = "(unknown)", .export = export_unknown },
224 };
225
226
227 static const char *export_str(enum export ex)
228 {
229 return export_list[ex].str;
230 }
231
232 static enum export export_no(const char *s)
233 {
234 int i;
235
236 if (!s)
237 return export_unknown;
238 for (i = 0; export_list[i].export != export_unknown; i++) {
239 if (strcmp(export_list[i].str, s) == 0)
240 return export_list[i].export;
241 }
242 return export_unknown;
243 }
244
245 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
246 {
247 if (sec == elf->export_sec)
248 return export_plain;
249 else if (sec == elf->export_unused_sec)
250 return export_unused;
251 else if (sec == elf->export_gpl_sec)
252 return export_gpl;
253 else if (sec == elf->export_unused_gpl_sec)
254 return export_unused_gpl;
255 else if (sec == elf->export_gpl_future_sec)
256 return export_gpl_future;
257 else
258 return export_unknown;
259 }
260
261 /**
262 * Add an exported symbol - it may have already been added without a
263 * CRC, in this case just update the CRC
264 **/
265 static struct symbol *sym_add_exported(const char *name, struct module *mod,
266 enum export export)
267 {
268 struct symbol *s = find_symbol(name);
269
270 if (!s) {
271 s = new_symbol(name, mod, export);
272 } else {
273 if (!s->preloaded) {
274 warn("%s: '%s' exported twice. Previous export "
275 "was in %s%s\n", mod->name, name,
276 s->module->name,
277 is_vmlinux(s->module->name) ?"":".ko");
278 } else {
279 /* In case Modules.symvers was out of date */
280 s->module = mod;
281 }
282 }
283 s->preloaded = 0;
284 s->vmlinux = is_vmlinux(mod->name);
285 s->kernel = 0;
286 s->export = export;
287 return s;
288 }
289
290 static void sym_update_crc(const char *name, struct module *mod,
291 unsigned int crc, enum export export)
292 {
293 struct symbol *s = find_symbol(name);
294
295 if (!s)
296 s = new_symbol(name, mod, export);
297 s->crc = crc;
298 s->crc_valid = 1;
299 }
300
301 void *grab_file(const char *filename, unsigned long *size)
302 {
303 struct stat st;
304 void *map;
305 int fd;
306
307 fd = open(filename, O_RDONLY);
308 if (fd < 0 || fstat(fd, &st) != 0)
309 return NULL;
310
311 *size = st.st_size;
312 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
313 close(fd);
314
315 if (map == MAP_FAILED)
316 return NULL;
317 return map;
318 }
319
320 /**
321 * Return a copy of the next line in a mmap'ed file.
322 * spaces in the beginning of the line is trimmed away.
323 * Return a pointer to a static buffer.
324 **/
325 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
326 {
327 static char line[4096];
328 int skip = 1;
329 size_t len = 0;
330 signed char *p = (signed char *)file + *pos;
331 char *s = line;
332
333 for (; *pos < size ; (*pos)++) {
334 if (skip && isspace(*p)) {
335 p++;
336 continue;
337 }
338 skip = 0;
339 if (*p != '\n' && (*pos < size)) {
340 len++;
341 *s++ = *p++;
342 if (len > 4095)
343 break; /* Too long, stop */
344 } else {
345 /* End of string */
346 *s = '\0';
347 return line;
348 }
349 }
350 /* End of buffer */
351 return NULL;
352 }
353
354 void release_file(void *file, unsigned long size)
355 {
356 munmap(file, size);
357 }
358
359 static int parse_elf(struct elf_info *info, const char *filename)
360 {
361 unsigned int i;
362 Elf_Ehdr *hdr;
363 Elf_Shdr *sechdrs;
364 Elf_Sym *sym;
365
366 hdr = grab_file(filename, &info->size);
367 if (!hdr) {
368 perror(filename);
369 exit(1);
370 }
371 info->hdr = hdr;
372 if (info->size < sizeof(*hdr)) {
373 /* file too small, assume this is an empty .o file */
374 return 0;
375 }
376 /* Is this a valid ELF file? */
377 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
378 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
379 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
380 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
381 /* Not an ELF file - silently ignore it */
382 return 0;
383 }
384 /* Fix endianness in ELF header */
385 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
386 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
387 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
388 hdr->e_machine = TO_NATIVE(hdr->e_machine);
389 hdr->e_type = TO_NATIVE(hdr->e_type);
390 sechdrs = (void *)hdr + hdr->e_shoff;
391 info->sechdrs = sechdrs;
392
393 /* Check if file offset is correct */
394 if (hdr->e_shoff > info->size) {
395 fatal("section header offset=%lu in file '%s' is bigger than "
396 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
397 filename, info->size);
398 return 0;
399 }
400
401 /* Fix endianness in section headers */
402 for (i = 0; i < hdr->e_shnum; i++) {
403 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
404 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
405 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
406 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
407 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
408 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
409 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
410 }
411 /* Find symbol table. */
412 for (i = 1; i < hdr->e_shnum; i++) {
413 const char *secstrings
414 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
415 const char *secname;
416
417 if (sechdrs[i].sh_offset > info->size) {
418 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
419 "sizeof(*hrd)=%zu\n", filename,
420 (unsigned long)sechdrs[i].sh_offset,
421 sizeof(*hdr));
422 return 0;
423 }
424 secname = secstrings + sechdrs[i].sh_name;
425 if (strcmp(secname, ".modinfo") == 0) {
426 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
427 info->modinfo_len = sechdrs[i].sh_size;
428 } else if (strcmp(secname, "__ksymtab") == 0)
429 info->export_sec = i;
430 else if (strcmp(secname, "__ksymtab_unused") == 0)
431 info->export_unused_sec = i;
432 else if (strcmp(secname, "__ksymtab_gpl") == 0)
433 info->export_gpl_sec = i;
434 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
435 info->export_unused_gpl_sec = i;
436 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
437 info->export_gpl_future_sec = i;
438
439 if (sechdrs[i].sh_type != SHT_SYMTAB)
440 continue;
441
442 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
443 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
444 + sechdrs[i].sh_size;
445 info->strtab = (void *)hdr +
446 sechdrs[sechdrs[i].sh_link].sh_offset;
447 }
448 if (!info->symtab_start)
449 fatal("%s has no symtab?\n", filename);
450
451 /* Fix endianness in symbols */
452 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
453 sym->st_shndx = TO_NATIVE(sym->st_shndx);
454 sym->st_name = TO_NATIVE(sym->st_name);
455 sym->st_value = TO_NATIVE(sym->st_value);
456 sym->st_size = TO_NATIVE(sym->st_size);
457 }
458 return 1;
459 }
460
461 static void parse_elf_finish(struct elf_info *info)
462 {
463 release_file(info->hdr, info->size);
464 }
465
466 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
467 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
468
469 static void handle_modversions(struct module *mod, struct elf_info *info,
470 Elf_Sym *sym, const char *symname)
471 {
472 unsigned int crc;
473 enum export export = export_from_sec(info, sym->st_shndx);
474
475 switch (sym->st_shndx) {
476 case SHN_COMMON:
477 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
478 break;
479 case SHN_ABS:
480 /* CRC'd symbol */
481 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
482 crc = (unsigned int) sym->st_value;
483 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
484 export);
485 }
486 break;
487 case SHN_UNDEF:
488 /* undefined symbol */
489 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
490 ELF_ST_BIND(sym->st_info) != STB_WEAK)
491 break;
492 /* ignore global offset table */
493 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
494 break;
495 /* ignore __this_module, it will be resolved shortly */
496 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
497 break;
498 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
499 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
500 /* add compatibility with older glibc */
501 #ifndef STT_SPARC_REGISTER
502 #define STT_SPARC_REGISTER STT_REGISTER
503 #endif
504 if (info->hdr->e_machine == EM_SPARC ||
505 info->hdr->e_machine == EM_SPARCV9) {
506 /* Ignore register directives. */
507 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
508 break;
509 if (symname[0] == '.') {
510 char *munged = strdup(symname);
511 munged[0] = '_';
512 munged[1] = toupper(munged[1]);
513 symname = munged;
514 }
515 }
516 #endif
517
518 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
519 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
520 mod->unres =
521 alloc_symbol(symname +
522 strlen(MODULE_SYMBOL_PREFIX),
523 ELF_ST_BIND(sym->st_info) == STB_WEAK,
524 mod->unres);
525 }
526 break;
527 default:
528 /* All exported symbols */
529 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
530 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
531 export);
532 }
533 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
534 mod->has_init = 1;
535 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
536 mod->has_cleanup = 1;
537 break;
538 }
539 }
540
541 /**
542 * Parse tag=value strings from .modinfo section
543 **/
544 static char *next_string(char *string, unsigned long *secsize)
545 {
546 /* Skip non-zero chars */
547 while (string[0]) {
548 string++;
549 if ((*secsize)-- <= 1)
550 return NULL;
551 }
552
553 /* Skip any zero padding. */
554 while (!string[0]) {
555 string++;
556 if ((*secsize)-- <= 1)
557 return NULL;
558 }
559 return string;
560 }
561
562 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
563 const char *tag, char *info)
564 {
565 char *p;
566 unsigned int taglen = strlen(tag);
567 unsigned long size = modinfo_len;
568
569 if (info) {
570 size -= info - (char *)modinfo;
571 modinfo = next_string(info, &size);
572 }
573
574 for (p = modinfo; p; p = next_string(p, &size)) {
575 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
576 return p + taglen + 1;
577 }
578 return NULL;
579 }
580
581 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
582 const char *tag)
583
584 {
585 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
586 }
587
588 /**
589 * Test if string s ends in string sub
590 * return 0 if match
591 **/
592 static int strrcmp(const char *s, const char *sub)
593 {
594 int slen, sublen;
595
596 if (!s || !sub)
597 return 1;
598
599 slen = strlen(s);
600 sublen = strlen(sub);
601
602 if ((slen == 0) || (sublen == 0))
603 return 1;
604
605 if (sublen > slen)
606 return 1;
607
608 return memcmp(s + slen - sublen, sub, sublen);
609 }
610
611 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
612 {
613 if (sym)
614 return elf->strtab + sym->st_name;
615 else
616 return "";
617 }
618
619 static const char *sec_name(struct elf_info *elf, int shndx)
620 {
621 Elf_Shdr *sechdrs = elf->sechdrs;
622 return (void *)elf->hdr +
623 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
624 sechdrs[shndx].sh_name;
625 }
626
627 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
628 {
629 return (void *)elf->hdr +
630 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
631 sechdr->sh_name;
632 }
633
634 /* if sym is empty or point to a string
635 * like ".[0-9]+" then return 1.
636 * This is the optional prefix added by ld to some sections
637 */
638 static int number_prefix(const char *sym)
639 {
640 if (*sym++ == '\0')
641 return 1;
642 if (*sym != '.')
643 return 0;
644 do {
645 char c = *sym++;
646 if (c < '0' || c > '9')
647 return 0;
648 } while (*sym);
649 return 1;
650 }
651
652 /* The pattern is an array of simple patterns.
653 * "foo" will match an exact string equal to "foo"
654 * "*foo" will match a string that ends with "foo"
655 * "foo*" will match a string that begins with "foo"
656 * "foo$" will match a string equal to "foo" or "foo.1"
657 * where the '1' can be any number including several digits.
658 * The $ syntax is for sections where ld append a dot number
659 * to make section name unique.
660 */
661 int match(const char *sym, const char * const pat[])
662 {
663 const char *p;
664 while (*pat) {
665 p = *pat++;
666 const char *endp = p + strlen(p) - 1;
667
668 /* "*foo" */
669 if (*p == '*') {
670 if (strrcmp(sym, p + 1) == 0)
671 return 1;
672 }
673 /* "foo*" */
674 else if (*endp == '*') {
675 if (strncmp(sym, p, strlen(p) - 1) == 0)
676 return 1;
677 }
678 /* "foo$" */
679 else if (*endp == '$') {
680 if (strncmp(sym, p, strlen(p) - 1) == 0) {
681 if (number_prefix(sym + strlen(p) - 1))
682 return 1;
683 }
684 }
685 /* no wildcards */
686 else {
687 if (strcmp(p, sym) == 0)
688 return 1;
689 }
690 }
691 /* no match */
692 return 0;
693 }
694
695 /* sections that we do not want to do full section mismatch check on */
696 static const char *section_white_list[] =
697 { ".debug*", ".stab*", ".note*", ".got*", ".toc*", NULL };
698
699 /*
700 * Is this section one we do not want to check?
701 * This is often debug sections.
702 * If we are going to check this section then
703 * test if section name ends with a dot and a number.
704 * This is used to find sections where the linker have
705 * appended a dot-number to make the name unique.
706 * The cause of this is often a section specified in assembler
707 * without "ax" / "aw" and the same section used in .c
708 * code where gcc add these.
709 */
710 static int check_section(const char *modname, const char *sec)
711 {
712 const char *e = sec + strlen(sec) - 1;
713 if (match(sec, section_white_list))
714 return 1;
715
716 if (*e && isdigit(*e)) {
717 /* consume all digits */
718 while (*e && e != sec && isdigit(*e))
719 e--;
720 if (*e == '.') {
721 warn("%s (%s): unexpected section name.\n"
722 "The (.[number]+) following section name are "
723 "ld generated and not expected.\n"
724 "Did you forget to use \"ax\"/\"aw\" "
725 "in a .S file?\n"
726 "Note that for example <linux/init.h> contains\n"
727 "section definitions for use in .S files.\n\n",
728 modname, sec);
729 }
730 }
731 return 0;
732 }
733
734
735
736 #define ALL_INIT_DATA_SECTIONS \
737 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
738 #define ALL_EXIT_DATA_SECTIONS \
739 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
740
741 #define ALL_INIT_TEXT_SECTIONS \
742 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
743 #define ALL_EXIT_TEXT_SECTIONS \
744 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
745
746 #define ALL_INIT_SECTIONS ALL_INIT_DATA_SECTIONS, ALL_INIT_TEXT_SECTIONS
747 #define ALL_EXIT_SECTIONS ALL_EXIT_DATA_SECTIONS, ALL_EXIT_TEXT_SECTIONS
748
749 #define DATA_SECTIONS ".data$", ".data.rel$"
750 #define TEXT_SECTIONS ".text$"
751
752 #define INIT_SECTIONS ".init.data$", ".init.text$"
753 #define DEV_INIT_SECTIONS ".devinit.data$", ".devinit.text$"
754 #define CPU_INIT_SECTIONS ".cpuinit.data$", ".cpuinit.text$"
755 #define MEM_INIT_SECTIONS ".meminit.data$", ".meminit.text$"
756
757 #define EXIT_SECTIONS ".exit.data$", ".exit.text$"
758 #define DEV_EXIT_SECTIONS ".devexit.data$", ".devexit.text$"
759 #define CPU_EXIT_SECTIONS ".cpuexit.data$", ".cpuexit.text$"
760 #define MEM_EXIT_SECTIONS ".memexit.data$", ".memexit.text$"
761
762 /* init data sections */
763 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
764
765 /* all init sections */
766 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
767
768 /* All init and exit sections (code + data) */
769 static const char *init_exit_sections[] =
770 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
771
772 /* data section */
773 static const char *data_sections[] = { DATA_SECTIONS, NULL };
774
775 /* sections that may refer to an init/exit section with no warning */
776 static const char *initref_sections[] =
777 {
778 ".text.init.refok*",
779 ".exit.text.refok*",
780 ".data.init.refok*",
781 NULL
782 };
783
784
785 /* symbols in .data that may refer to init/exit sections */
786 static const char *symbol_white_list[] =
787 {
788 "*driver",
789 "*_template", /* scsi uses *_template a lot */
790 "*_timer", /* arm uses ops structures named _timer a lot */
791 "*_sht", /* scsi also used *_sht to some extent */
792 "*_ops",
793 "*_probe",
794 "*_probe_one",
795 "*_console",
796 NULL
797 };
798
799 static const char *head_sections[] = { ".head.text*", NULL };
800 static const char *linker_symbols[] =
801 { "__init_begin", "_sinittext", "_einittext", NULL };
802
803 enum mismatch {
804 NO_MISMATCH,
805 TEXT_TO_INIT,
806 DATA_TO_INIT,
807 TEXT_TO_EXIT,
808 DATA_TO_EXIT,
809 XXXINIT_TO_INIT,
810 XXXEXIT_TO_EXIT,
811 INIT_TO_EXIT,
812 EXIT_TO_INIT,
813 EXPORT_TO_INIT_EXIT,
814 };
815
816 struct sectioncheck {
817 const char *fromsec[20];
818 const char *tosec[20];
819 enum mismatch mismatch;
820 };
821
822 const struct sectioncheck sectioncheck[] = {
823 /* Do not reference init/exit code/data from
824 * normal code and data
825 */
826 {
827 .fromsec = { TEXT_SECTIONS, NULL },
828 .tosec = { ALL_INIT_SECTIONS, NULL },
829 .mismatch = TEXT_TO_INIT,
830 },
831 {
832 .fromsec = { DATA_SECTIONS, NULL },
833 .tosec = { ALL_INIT_SECTIONS, NULL },
834 .mismatch = DATA_TO_INIT,
835 },
836 {
837 .fromsec = { TEXT_SECTIONS, NULL },
838 .tosec = { ALL_EXIT_SECTIONS, NULL },
839 .mismatch = TEXT_TO_EXIT,
840 },
841 {
842 .fromsec = { DATA_SECTIONS, NULL },
843 .tosec = { ALL_EXIT_SECTIONS, NULL },
844 .mismatch = DATA_TO_EXIT,
845 },
846 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
847 {
848 .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL },
849 .tosec = { INIT_SECTIONS, NULL },
850 .mismatch = XXXINIT_TO_INIT,
851 },
852 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
853 {
854 .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL },
855 .tosec = { EXIT_SECTIONS, NULL },
856 .mismatch = XXXEXIT_TO_EXIT,
857 },
858 /* Do not use exit code/data from init code */
859 {
860 .fromsec = { ALL_INIT_SECTIONS, NULL },
861 .tosec = { ALL_EXIT_SECTIONS, NULL },
862 .mismatch = INIT_TO_EXIT,
863 },
864 /* Do not use init code/data from exit code */
865 {
866 .fromsec = { ALL_EXIT_SECTIONS, NULL },
867 .tosec = { ALL_INIT_SECTIONS, NULL },
868 .mismatch = EXIT_TO_INIT,
869 },
870 /* Do not export init/exit functions or data */
871 {
872 .fromsec = { "__ksymtab*", NULL },
873 .tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
874 .mismatch = EXPORT_TO_INIT_EXIT
875 }
876 };
877
878 static int section_mismatch(const char *fromsec, const char *tosec)
879 {
880 int i;
881 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
882 const struct sectioncheck *check = &sectioncheck[0];
883
884 for (i = 0; i < elems; i++) {
885 if (match(fromsec, check->fromsec) &&
886 match(tosec, check->tosec))
887 return check->mismatch;
888 check++;
889 }
890 return NO_MISMATCH;
891 }
892
893 /**
894 * Whitelist to allow certain references to pass with no warning.
895 *
896 * Pattern 0:
897 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
898 * The pattern is identified by:
899 * fromsec = .text.init.refok* | .data.init.refok*
900 *
901 * Pattern 1:
902 * If a module parameter is declared __initdata and permissions=0
903 * then this is legal despite the warning generated.
904 * We cannot see value of permissions here, so just ignore
905 * this pattern.
906 * The pattern is identified by:
907 * tosec = .init.data
908 * fromsec = .data*
909 * atsym =__param*
910 *
911 * Pattern 2:
912 * Many drivers utilise a *driver container with references to
913 * add, remove, probe functions etc.
914 * These functions may often be marked __init and we do not want to
915 * warn here.
916 * the pattern is identified by:
917 * tosec = init or exit section
918 * fromsec = data section
919 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
920 * *probe_one, *_console, *_timer
921 *
922 * Pattern 3:
923 * Whitelist all refereces from .text.head to .init.data
924 * Whitelist all refereces from .text.head to .init.text
925 *
926 * Pattern 4:
927 * Some symbols belong to init section but still it is ok to reference
928 * these from non-init sections as these symbols don't have any memory
929 * allocated for them and symbol address and value are same. So even
930 * if init section is freed, its ok to reference those symbols.
931 * For ex. symbols marking the init section boundaries.
932 * This pattern is identified by
933 * refsymname = __init_begin, _sinittext, _einittext
934 *
935 **/
936 static int secref_whitelist(const char *fromsec, const char *fromsym,
937 const char *tosec, const char *tosym)
938 {
939 /* Check for pattern 0 */
940 if (match(fromsec, initref_sections))
941 return 0;
942
943 /* Check for pattern 1 */
944 if (match(tosec, init_data_sections) &&
945 match(fromsec, data_sections) &&
946 (strncmp(fromsym, "__param", strlen("__param")) == 0))
947 return 0;
948
949 /* Check for pattern 2 */
950 if (match(tosec, init_exit_sections) &&
951 match(fromsec, data_sections) &&
952 match(fromsym, symbol_white_list))
953 return 0;
954
955 /* Check for pattern 3 */
956 if (match(fromsec, head_sections) &&
957 match(tosec, init_sections))
958 return 0;
959
960 /* Check for pattern 4 */
961 if (match(tosym, linker_symbols))
962 return 0;
963
964 return 1;
965 }
966
967 /**
968 * Find symbol based on relocation record info.
969 * In some cases the symbol supplied is a valid symbol so
970 * return refsym. If st_name != 0 we assume this is a valid symbol.
971 * In other cases the symbol needs to be looked up in the symbol table
972 * based on section and address.
973 * **/
974 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
975 Elf_Sym *relsym)
976 {
977 Elf_Sym *sym;
978 Elf_Sym *near = NULL;
979 Elf64_Sword distance = 20;
980 Elf64_Sword d;
981
982 if (relsym->st_name != 0)
983 return relsym;
984 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
985 if (sym->st_shndx != relsym->st_shndx)
986 continue;
987 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
988 continue;
989 if (sym->st_value == addr)
990 return sym;
991 /* Find a symbol nearby - addr are maybe negative */
992 d = sym->st_value - addr;
993 if (d < 0)
994 d = addr - sym->st_value;
995 if (d < distance) {
996 distance = d;
997 near = sym;
998 }
999 }
1000 /* We need a close match */
1001 if (distance < 20)
1002 return near;
1003 else
1004 return NULL;
1005 }
1006
1007 static inline int is_arm_mapping_symbol(const char *str)
1008 {
1009 return str[0] == '$' && strchr("atd", str[1])
1010 && (str[2] == '\0' || str[2] == '.');
1011 }
1012
1013 /*
1014 * If there's no name there, ignore it; likewise, ignore it if it's
1015 * one of the magic symbols emitted used by current ARM tools.
1016 *
1017 * Otherwise if find_symbols_between() returns those symbols, they'll
1018 * fail the whitelist tests and cause lots of false alarms ... fixable
1019 * only by merging __exit and __init sections into __text, bloating
1020 * the kernel (which is especially evil on embedded platforms).
1021 */
1022 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1023 {
1024 const char *name = elf->strtab + sym->st_name;
1025
1026 if (!name || !strlen(name))
1027 return 0;
1028 return !is_arm_mapping_symbol(name);
1029 }
1030
1031 /*
1032 * Find symbols before or equal addr and after addr - in the section sec.
1033 * If we find two symbols with equal offset prefer one with a valid name.
1034 * The ELF format may have a better way to detect what type of symbol
1035 * it is, but this works for now.
1036 **/
1037 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1038 const char *sec)
1039 {
1040 Elf_Sym *sym;
1041 Elf_Sym *near = NULL;
1042 Elf_Addr distance = ~0;
1043
1044 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1045 const char *symsec;
1046
1047 if (sym->st_shndx >= SHN_LORESERVE)
1048 continue;
1049 symsec = sec_name(elf, sym->st_shndx);
1050 if (strcmp(symsec, sec) != 0)
1051 continue;
1052 if (!is_valid_name(elf, sym))
1053 continue;
1054 if (sym->st_value <= addr) {
1055 if ((addr - sym->st_value) < distance) {
1056 distance = addr - sym->st_value;
1057 near = sym;
1058 } else if ((addr - sym->st_value) == distance) {
1059 near = sym;
1060 }
1061 }
1062 }
1063 return near;
1064 }
1065
1066 /*
1067 * Convert a section name to the function/data attribute
1068 * .init.text => __init
1069 * .cpuinit.data => __cpudata
1070 * .memexitconst => __memconst
1071 * etc.
1072 */
1073 static char *sec2annotation(const char *s)
1074 {
1075 if (match(s, init_exit_sections)) {
1076 char *p = malloc(20);
1077 char *r = p;
1078
1079 *p++ = '_';
1080 *p++ = '_';
1081 if (*s == '.')
1082 s++;
1083 while (*s && *s != '.')
1084 *p++ = *s++;
1085 *p = '\0';
1086 if (*s == '.')
1087 s++;
1088 if (strstr(s, "rodata") != NULL)
1089 strcat(p, "const ");
1090 else if (strstr(s, "data") != NULL)
1091 strcat(p, "data ");
1092 else
1093 strcat(p, " ");
1094 return r; /* we leak her but we do not care */
1095 } else {
1096 return "";
1097 }
1098 }
1099
1100 static int is_function(Elf_Sym *sym)
1101 {
1102 if (sym)
1103 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1104 else
1105 return 0;
1106 }
1107
1108 /*
1109 * Print a warning about a section mismatch.
1110 * Try to find symbols near it so user can find it.
1111 * Check whitelist before warning - it may be a false positive.
1112 */
1113 static void report_sec_mismatch(const char *modname, enum mismatch mismatch,
1114 const char *fromsec,
1115 unsigned long long fromaddr,
1116 const char *fromsym,
1117 int from_is_func,
1118 const char *tosec, const char *tosym,
1119 int to_is_func)
1120 {
1121 const char *from, *from_p;
1122 const char *to, *to_p;
1123 from = from_is_func ? "function" : "variable";
1124 from_p = from_is_func ? "()" : "";
1125 to = to_is_func ? "function" : "variable";
1126 to_p = to_is_func ? "()" : "";
1127
1128 fprintf(stderr, "WARNING: %s(%s+0x%llx): Section mismatch in"
1129 " reference from the %s %s%s to the %s %s:%s%s\n",
1130 modname, fromsec, fromaddr, from, fromsym, from_p,
1131 to, tosec, tosym, to_p);
1132
1133 sec_mismatch_count++;
1134 if (!sec_mismatch_verbose)
1135 return;
1136
1137 switch (mismatch) {
1138 case TEXT_TO_INIT:
1139 fprintf(stderr,
1140 "The function %s %s() references\n"
1141 "the %s %s%s%s.\n"
1142 "This is often because %s lacks a %s\n"
1143 "annotation or the annotation of %s is wrong.\n",
1144 sec2annotation(fromsec), fromsym,
1145 to, sec2annotation(tosec), tosym, to_p,
1146 fromsym, sec2annotation(tosec), tosym);
1147 break;
1148 case DATA_TO_INIT: {
1149 const char **s = symbol_white_list;
1150 fprintf(stderr,
1151 "The variable %s references\n"
1152 "the %s %s%s%s\n"
1153 "If the reference is valid then annotate the\n"
1154 "variable with __init* (see linux/init.h) "
1155 "or name the variable:\n",
1156 fromsym, to, sec2annotation(tosec), tosym, to_p);
1157 while (*s)
1158 fprintf(stderr, "%s, ", *s++);
1159 fprintf(stderr, "\n");
1160 break;
1161 }
1162 case TEXT_TO_EXIT:
1163 fprintf(stderr,
1164 "The function %s() references a %s in an exit section.\n"
1165 "Often the %s %s%s has valid usage outside the exit section\n"
1166 "and the fix is to remove the %sannotation of %s.\n",
1167 fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1168 break;
1169 case DATA_TO_EXIT: {
1170 const char **s = symbol_white_list;
1171 fprintf(stderr,
1172 "The variable %s references\n"
1173 "the %s %s%s%s\n"
1174 "If the reference is valid then annotate the\n"
1175 "variable with __exit* (see linux/init.h) or "
1176 "name the variable:\n",
1177 fromsym, to, sec2annotation(tosec), tosym, to_p);
1178 while (*s)
1179 fprintf(stderr, "%s, ", *s++);
1180 fprintf(stderr, "\n");
1181 break;
1182 }
1183 case XXXINIT_TO_INIT:
1184 case XXXEXIT_TO_EXIT:
1185 fprintf(stderr,
1186 "The %s %s%s%s references\n"
1187 "a %s %s%s%s.\n"
1188 "If %s is only used by %s then\n"
1189 "annotate %s with a matching annotation.\n",
1190 from, sec2annotation(fromsec), fromsym, from_p,
1191 to, sec2annotation(tosec), tosym, to_p,
1192 fromsym, tosym, fromsym);
1193 break;
1194 case INIT_TO_EXIT:
1195 fprintf(stderr,
1196 "The %s %s%s%s references\n"
1197 "a %s %s%s%s.\n"
1198 "This is often seen when error handling "
1199 "in the init function\n"
1200 "uses functionality in the exit path.\n"
1201 "The fix is often to remove the %sannotation of\n"
1202 "%s%s so it may be used outside an exit section.\n",
1203 from, sec2annotation(fromsec), fromsym, from_p,
1204 to, sec2annotation(tosec), tosym, to_p,
1205 sec2annotation(tosec), tosym, to_p);
1206 break;
1207 case EXIT_TO_INIT:
1208 fprintf(stderr,
1209 "The %s %s%s%s references\n"
1210 "a %s %s%s%s.\n"
1211 "This is often seen when error handling "
1212 "in the exit function\n"
1213 "uses functionality in the init path.\n"
1214 "The fix is often to remove the %sannotation of\n"
1215 "%s%s so it may be used outside an init section.\n",
1216 from, sec2annotation(fromsec), fromsym, from_p,
1217 to, sec2annotation(tosec), tosym, to_p,
1218 sec2annotation(tosec), tosym, to_p);
1219 break;
1220 case EXPORT_TO_INIT_EXIT:
1221 fprintf(stderr,
1222 "The symbol %s is exported and annotated %s\n"
1223 "Fix this by removing the %sannotation of %s "
1224 "or drop the export.\n",
1225 tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1226 case NO_MISMATCH:
1227 /* To get warnings on missing members */
1228 break;
1229 }
1230 fprintf(stderr, "\n");
1231 }
1232
1233 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1234 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1235 {
1236 const char *tosec;
1237 enum mismatch mismatch;
1238
1239 tosec = sec_name(elf, sym->st_shndx);
1240 mismatch = section_mismatch(fromsec, tosec);
1241 if (mismatch != NO_MISMATCH) {
1242 Elf_Sym *to;
1243 Elf_Sym *from;
1244 const char *tosym;
1245 const char *fromsym;
1246
1247 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1248 fromsym = sym_name(elf, from);
1249 to = find_elf_symbol(elf, r->r_addend, sym);
1250 tosym = sym_name(elf, to);
1251
1252 /* check whitelist - we may ignore it */
1253 if (secref_whitelist(fromsec, fromsym, tosec, tosym)) {
1254 report_sec_mismatch(modname, mismatch,
1255 fromsec, r->r_offset, fromsym,
1256 is_function(from), tosec, tosym,
1257 is_function(to));
1258 }
1259 }
1260 }
1261
1262 static unsigned int *reloc_location(struct elf_info *elf,
1263 Elf_Shdr *sechdr, Elf_Rela *r)
1264 {
1265 Elf_Shdr *sechdrs = elf->sechdrs;
1266 int section = sechdr->sh_info;
1267
1268 return (void *)elf->hdr + sechdrs[section].sh_offset +
1269 (r->r_offset - sechdrs[section].sh_addr);
1270 }
1271
1272 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1273 {
1274 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1275 unsigned int *location = reloc_location(elf, sechdr, r);
1276
1277 switch (r_typ) {
1278 case R_386_32:
1279 r->r_addend = TO_NATIVE(*location);
1280 break;
1281 case R_386_PC32:
1282 r->r_addend = TO_NATIVE(*location) + 4;
1283 /* For CONFIG_RELOCATABLE=y */
1284 if (elf->hdr->e_type == ET_EXEC)
1285 r->r_addend += r->r_offset;
1286 break;
1287 }
1288 return 0;
1289 }
1290
1291 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1292 {
1293 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1294
1295 switch (r_typ) {
1296 case R_ARM_ABS32:
1297 /* From ARM ABI: (S + A) | T */
1298 r->r_addend = (int)(long)
1299 (elf->symtab_start + ELF_R_SYM(r->r_info));
1300 break;
1301 case R_ARM_PC24:
1302 /* From ARM ABI: ((S + A) | T) - P */
1303 r->r_addend = (int)(long)(elf->hdr +
1304 sechdr->sh_offset +
1305 (r->r_offset - sechdr->sh_addr));
1306 break;
1307 default:
1308 return 1;
1309 }
1310 return 0;
1311 }
1312
1313 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1314 {
1315 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1316 unsigned int *location = reloc_location(elf, sechdr, r);
1317 unsigned int inst;
1318
1319 if (r_typ == R_MIPS_HI16)
1320 return 1; /* skip this */
1321 inst = TO_NATIVE(*location);
1322 switch (r_typ) {
1323 case R_MIPS_LO16:
1324 r->r_addend = inst & 0xffff;
1325 break;
1326 case R_MIPS_26:
1327 r->r_addend = (inst & 0x03ffffff) << 2;
1328 break;
1329 case R_MIPS_32:
1330 r->r_addend = inst;
1331 break;
1332 }
1333 return 0;
1334 }
1335
1336 static void section_rela(const char *modname, struct elf_info *elf,
1337 Elf_Shdr *sechdr)
1338 {
1339 Elf_Sym *sym;
1340 Elf_Rela *rela;
1341 Elf_Rela r;
1342 unsigned int r_sym;
1343 const char *fromsec;
1344
1345 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1346 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1347
1348 fromsec = sech_name(elf, sechdr);
1349 fromsec += strlen(".rela");
1350 /* if from section (name) is know good then skip it */
1351 if (check_section(modname, fromsec))
1352 return;
1353
1354 for (rela = start; rela < stop; rela++) {
1355 r.r_offset = TO_NATIVE(rela->r_offset);
1356 #if KERNEL_ELFCLASS == ELFCLASS64
1357 if (elf->hdr->e_machine == EM_MIPS) {
1358 unsigned int r_typ;
1359 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1360 r_sym = TO_NATIVE(r_sym);
1361 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1362 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1363 } else {
1364 r.r_info = TO_NATIVE(rela->r_info);
1365 r_sym = ELF_R_SYM(r.r_info);
1366 }
1367 #else
1368 r.r_info = TO_NATIVE(rela->r_info);
1369 r_sym = ELF_R_SYM(r.r_info);
1370 #endif
1371 r.r_addend = TO_NATIVE(rela->r_addend);
1372 sym = elf->symtab_start + r_sym;
1373 /* Skip special sections */
1374 if (sym->st_shndx >= SHN_LORESERVE)
1375 continue;
1376 check_section_mismatch(modname, elf, &r, sym, fromsec);
1377 }
1378 }
1379
1380 static void section_rel(const char *modname, struct elf_info *elf,
1381 Elf_Shdr *sechdr)
1382 {
1383 Elf_Sym *sym;
1384 Elf_Rel *rel;
1385 Elf_Rela r;
1386 unsigned int r_sym;
1387 const char *fromsec;
1388
1389 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1390 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1391
1392 fromsec = sech_name(elf, sechdr);
1393 fromsec += strlen(".rel");
1394 /* if from section (name) is know good then skip it */
1395 if (check_section(modname, fromsec))
1396 return;
1397
1398 for (rel = start; rel < stop; rel++) {
1399 r.r_offset = TO_NATIVE(rel->r_offset);
1400 #if KERNEL_ELFCLASS == ELFCLASS64
1401 if (elf->hdr->e_machine == EM_MIPS) {
1402 unsigned int r_typ;
1403 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1404 r_sym = TO_NATIVE(r_sym);
1405 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1406 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1407 } else {
1408 r.r_info = TO_NATIVE(rel->r_info);
1409 r_sym = ELF_R_SYM(r.r_info);
1410 }
1411 #else
1412 r.r_info = TO_NATIVE(rel->r_info);
1413 r_sym = ELF_R_SYM(r.r_info);
1414 #endif
1415 r.r_addend = 0;
1416 switch (elf->hdr->e_machine) {
1417 case EM_386:
1418 if (addend_386_rel(elf, sechdr, &r))
1419 continue;
1420 break;
1421 case EM_ARM:
1422 if (addend_arm_rel(elf, sechdr, &r))
1423 continue;
1424 break;
1425 case EM_MIPS:
1426 if (addend_mips_rel(elf, sechdr, &r))
1427 continue;
1428 break;
1429 }
1430 sym = elf->symtab_start + r_sym;
1431 /* Skip special sections */
1432 if (sym->st_shndx >= SHN_LORESERVE)
1433 continue;
1434 check_section_mismatch(modname, elf, &r, sym, fromsec);
1435 }
1436 }
1437
1438 /**
1439 * A module includes a number of sections that are discarded
1440 * either when loaded or when used as built-in.
1441 * For loaded modules all functions marked __init and all data
1442 * marked __initdata will be discarded when the module has been intialized.
1443 * Likewise for modules used built-in the sections marked __exit
1444 * are discarded because __exit marked function are supposed to be called
1445 * only when a moduel is unloaded which never happes for built-in modules.
1446 * The check_sec_ref() function traverses all relocation records
1447 * to find all references to a section that reference a section that will
1448 * be discarded and warns about it.
1449 **/
1450 static void check_sec_ref(struct module *mod, const char *modname,
1451 struct elf_info *elf)
1452 {
1453 int i;
1454 Elf_Shdr *sechdrs = elf->sechdrs;
1455
1456 /* Walk through all sections */
1457 for (i = 0; i < elf->hdr->e_shnum; i++) {
1458 /* We want to process only relocation sections and not .init */
1459 if (sechdrs[i].sh_type == SHT_RELA)
1460 section_rela(modname, elf, &elf->sechdrs[i]);
1461 else if (sechdrs[i].sh_type == SHT_REL)
1462 section_rel(modname, elf, &elf->sechdrs[i]);
1463 }
1464 }
1465
1466 static void read_symbols(char *modname)
1467 {
1468 const char *symname;
1469 char *version;
1470 char *license;
1471 struct module *mod;
1472 struct elf_info info = { };
1473 Elf_Sym *sym;
1474
1475 if (!parse_elf(&info, modname))
1476 return;
1477
1478 mod = new_module(modname);
1479
1480 /* When there's no vmlinux, don't print warnings about
1481 * unresolved symbols (since there'll be too many ;) */
1482 if (is_vmlinux(modname)) {
1483 have_vmlinux = 1;
1484 mod->skip = 1;
1485 }
1486
1487 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1488 while (license) {
1489 if (license_is_gpl_compatible(license))
1490 mod->gpl_compatible = 1;
1491 else {
1492 mod->gpl_compatible = 0;
1493 break;
1494 }
1495 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1496 "license", license);
1497 }
1498
1499 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1500 symname = info.strtab + sym->st_name;
1501
1502 handle_modversions(mod, &info, sym, symname);
1503 handle_moddevtable(mod, &info, sym, symname);
1504 }
1505 if (!is_vmlinux(modname) ||
1506 (is_vmlinux(modname) && vmlinux_section_warnings))
1507 check_sec_ref(mod, modname, &info);
1508
1509 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1510 if (version)
1511 maybe_frob_rcs_version(modname, version, info.modinfo,
1512 version - (char *)info.hdr);
1513 if (version || (all_versions && !is_vmlinux(modname)))
1514 get_src_version(modname, mod->srcversion,
1515 sizeof(mod->srcversion)-1);
1516
1517 parse_elf_finish(&info);
1518
1519 /* Our trick to get versioning for struct_module - it's
1520 * never passed as an argument to an exported function, so
1521 * the automatic versioning doesn't pick it up, but it's really
1522 * important anyhow */
1523 if (modversions)
1524 mod->unres = alloc_symbol("struct_module", 0, mod->unres);
1525 }
1526
1527 #define SZ 500
1528
1529 /* We first write the generated file into memory using the
1530 * following helper, then compare to the file on disk and
1531 * only update the later if anything changed */
1532
1533 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1534 const char *fmt, ...)
1535 {
1536 char tmp[SZ];
1537 int len;
1538 va_list ap;
1539
1540 va_start(ap, fmt);
1541 len = vsnprintf(tmp, SZ, fmt, ap);
1542 buf_write(buf, tmp, len);
1543 va_end(ap);
1544 }
1545
1546 void buf_write(struct buffer *buf, const char *s, int len)
1547 {
1548 if (buf->size - buf->pos < len) {
1549 buf->size += len + SZ;
1550 buf->p = realloc(buf->p, buf->size);
1551 }
1552 strncpy(buf->p + buf->pos, s, len);
1553 buf->pos += len;
1554 }
1555
1556 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1557 {
1558 const char *e = is_vmlinux(m) ?"":".ko";
1559
1560 switch (exp) {
1561 case export_gpl:
1562 fatal("modpost: GPL-incompatible module %s%s "
1563 "uses GPL-only symbol '%s'\n", m, e, s);
1564 break;
1565 case export_unused_gpl:
1566 fatal("modpost: GPL-incompatible module %s%s "
1567 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1568 break;
1569 case export_gpl_future:
1570 warn("modpost: GPL-incompatible module %s%s "
1571 "uses future GPL-only symbol '%s'\n", m, e, s);
1572 break;
1573 case export_plain:
1574 case export_unused:
1575 case export_unknown:
1576 /* ignore */
1577 break;
1578 }
1579 }
1580
1581 static void check_for_unused(enum export exp, const char *m, const char *s)
1582 {
1583 const char *e = is_vmlinux(m) ?"":".ko";
1584
1585 switch (exp) {
1586 case export_unused:
1587 case export_unused_gpl:
1588 warn("modpost: module %s%s "
1589 "uses symbol '%s' marked UNUSED\n", m, e, s);
1590 break;
1591 default:
1592 /* ignore */
1593 break;
1594 }
1595 }
1596
1597 static void check_exports(struct module *mod)
1598 {
1599 struct symbol *s, *exp;
1600
1601 for (s = mod->unres; s; s = s->next) {
1602 const char *basename;
1603 exp = find_symbol(s->name);
1604 if (!exp || exp->module == mod)
1605 continue;
1606 basename = strrchr(mod->name, '/');
1607 if (basename)
1608 basename++;
1609 else
1610 basename = mod->name;
1611 if (!mod->gpl_compatible)
1612 check_for_gpl_usage(exp->export, basename, exp->name);
1613 check_for_unused(exp->export, basename, exp->name);
1614 }
1615 }
1616
1617 /**
1618 * Header for the generated file
1619 **/
1620 static void add_header(struct buffer *b, struct module *mod)
1621 {
1622 buf_printf(b, "#include <linux/module.h>\n");
1623 buf_printf(b, "#include <linux/vermagic.h>\n");
1624 buf_printf(b, "#include <linux/compiler.h>\n");
1625 buf_printf(b, "\n");
1626 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1627 buf_printf(b, "\n");
1628 buf_printf(b, "struct module __this_module\n");
1629 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1630 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1631 if (mod->has_init)
1632 buf_printf(b, " .init = init_module,\n");
1633 if (mod->has_cleanup)
1634 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1635 " .exit = cleanup_module,\n"
1636 "#endif\n");
1637 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1638 buf_printf(b, "};\n");
1639 }
1640
1641 /**
1642 * Record CRCs for unresolved symbols
1643 **/
1644 static int add_versions(struct buffer *b, struct module *mod)
1645 {
1646 struct symbol *s, *exp;
1647 int err = 0;
1648
1649 for (s = mod->unres; s; s = s->next) {
1650 exp = find_symbol(s->name);
1651 if (!exp || exp->module == mod) {
1652 if (have_vmlinux && !s->weak) {
1653 if (warn_unresolved) {
1654 warn("\"%s\" [%s.ko] undefined!\n",
1655 s->name, mod->name);
1656 } else {
1657 merror("\"%s\" [%s.ko] undefined!\n",
1658 s->name, mod->name);
1659 err = 1;
1660 }
1661 }
1662 continue;
1663 }
1664 s->module = exp->module;
1665 s->crc_valid = exp->crc_valid;
1666 s->crc = exp->crc;
1667 }
1668
1669 if (!modversions)
1670 return err;
1671
1672 buf_printf(b, "\n");
1673 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1674 buf_printf(b, "__used\n");
1675 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1676
1677 for (s = mod->unres; s; s = s->next) {
1678 if (!s->module)
1679 continue;
1680 if (!s->crc_valid) {
1681 warn("\"%s\" [%s.ko] has no CRC!\n",
1682 s->name, mod->name);
1683 continue;
1684 }
1685 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1686 }
1687
1688 buf_printf(b, "};\n");
1689
1690 return err;
1691 }
1692
1693 static void add_depends(struct buffer *b, struct module *mod,
1694 struct module *modules)
1695 {
1696 struct symbol *s;
1697 struct module *m;
1698 int first = 1;
1699
1700 for (m = modules; m; m = m->next)
1701 m->seen = is_vmlinux(m->name);
1702
1703 buf_printf(b, "\n");
1704 buf_printf(b, "static const char __module_depends[]\n");
1705 buf_printf(b, "__used\n");
1706 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1707 buf_printf(b, "\"depends=");
1708 for (s = mod->unres; s; s = s->next) {
1709 const char *p;
1710 if (!s->module)
1711 continue;
1712
1713 if (s->module->seen)
1714 continue;
1715
1716 s->module->seen = 1;
1717 p = strrchr(s->module->name, '/');
1718 if (p)
1719 p++;
1720 else
1721 p = s->module->name;
1722 buf_printf(b, "%s%s", first ? "" : ",", p);
1723 first = 0;
1724 }
1725 buf_printf(b, "\";\n");
1726 }
1727
1728 static void add_srcversion(struct buffer *b, struct module *mod)
1729 {
1730 if (mod->srcversion[0]) {
1731 buf_printf(b, "\n");
1732 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1733 mod->srcversion);
1734 }
1735 }
1736
1737 static void write_if_changed(struct buffer *b, const char *fname)
1738 {
1739 char *tmp;
1740 FILE *file;
1741 struct stat st;
1742
1743 file = fopen(fname, "r");
1744 if (!file)
1745 goto write;
1746
1747 if (fstat(fileno(file), &st) < 0)
1748 goto close_write;
1749
1750 if (st.st_size != b->pos)
1751 goto close_write;
1752
1753 tmp = NOFAIL(malloc(b->pos));
1754 if (fread(tmp, 1, b->pos, file) != b->pos)
1755 goto free_write;
1756
1757 if (memcmp(tmp, b->p, b->pos) != 0)
1758 goto free_write;
1759
1760 free(tmp);
1761 fclose(file);
1762 return;
1763
1764 free_write:
1765 free(tmp);
1766 close_write:
1767 fclose(file);
1768 write:
1769 file = fopen(fname, "w");
1770 if (!file) {
1771 perror(fname);
1772 exit(1);
1773 }
1774 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1775 perror(fname);
1776 exit(1);
1777 }
1778 fclose(file);
1779 }
1780
1781 /* parse Module.symvers file. line format:
1782 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1783 **/
1784 static void read_dump(const char *fname, unsigned int kernel)
1785 {
1786 unsigned long size, pos = 0;
1787 void *file = grab_file(fname, &size);
1788 char *line;
1789
1790 if (!file)
1791 /* No symbol versions, silently ignore */
1792 return;
1793
1794 while ((line = get_next_line(&pos, file, size))) {
1795 char *symname, *modname, *d, *export, *end;
1796 unsigned int crc;
1797 struct module *mod;
1798 struct symbol *s;
1799
1800 if (!(symname = strchr(line, '\t')))
1801 goto fail;
1802 *symname++ = '\0';
1803 if (!(modname = strchr(symname, '\t')))
1804 goto fail;
1805 *modname++ = '\0';
1806 if ((export = strchr(modname, '\t')) != NULL)
1807 *export++ = '\0';
1808 if (export && ((end = strchr(export, '\t')) != NULL))
1809 *end = '\0';
1810 crc = strtoul(line, &d, 16);
1811 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1812 goto fail;
1813 mod = find_module(modname);
1814 if (!mod) {
1815 if (is_vmlinux(modname))
1816 have_vmlinux = 1;
1817 mod = new_module(NOFAIL(strdup(modname)));
1818 mod->skip = 1;
1819 }
1820 s = sym_add_exported(symname, mod, export_no(export));
1821 s->kernel = kernel;
1822 s->preloaded = 1;
1823 sym_update_crc(symname, mod, crc, export_no(export));
1824 }
1825 return;
1826 fail:
1827 fatal("parse error in symbol dump file\n");
1828 }
1829
1830 /* For normal builds always dump all symbols.
1831 * For external modules only dump symbols
1832 * that are not read from kernel Module.symvers.
1833 **/
1834 static int dump_sym(struct symbol *sym)
1835 {
1836 if (!external_module)
1837 return 1;
1838 if (sym->vmlinux || sym->kernel)
1839 return 0;
1840 return 1;
1841 }
1842
1843 static void write_dump(const char *fname)
1844 {
1845 struct buffer buf = { };
1846 struct symbol *symbol;
1847 int n;
1848
1849 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1850 symbol = symbolhash[n];
1851 while (symbol) {
1852 if (dump_sym(symbol))
1853 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1854 symbol->crc, symbol->name,
1855 symbol->module->name,
1856 export_str(symbol->export));
1857 symbol = symbol->next;
1858 }
1859 }
1860 write_if_changed(&buf, fname);
1861 }
1862
1863 int main(int argc, char **argv)
1864 {
1865 struct module *mod;
1866 struct buffer buf = { };
1867 char *kernel_read = NULL, *module_read = NULL;
1868 char *dump_write = NULL;
1869 int opt;
1870 int err;
1871
1872 while ((opt = getopt(argc, argv, "i:I:msSo:aw")) != -1) {
1873 switch (opt) {
1874 case 'i':
1875 kernel_read = optarg;
1876 break;
1877 case 'I':
1878 module_read = optarg;
1879 external_module = 1;
1880 break;
1881 case 'm':
1882 modversions = 1;
1883 break;
1884 case 'o':
1885 dump_write = optarg;
1886 break;
1887 case 'a':
1888 all_versions = 1;
1889 break;
1890 case 's':
1891 vmlinux_section_warnings = 0;
1892 break;
1893 case 'S':
1894 sec_mismatch_verbose = 0;
1895 break;
1896 case 'w':
1897 warn_unresolved = 1;
1898 break;
1899 default:
1900 exit(1);
1901 }
1902 }
1903
1904 if (kernel_read)
1905 read_dump(kernel_read, 1);
1906 if (module_read)
1907 read_dump(module_read, 0);
1908
1909 while (optind < argc)
1910 read_symbols(argv[optind++]);
1911
1912 for (mod = modules; mod; mod = mod->next) {
1913 if (mod->skip)
1914 continue;
1915 check_exports(mod);
1916 }
1917
1918 err = 0;
1919
1920 for (mod = modules; mod; mod = mod->next) {
1921 char fname[strlen(mod->name) + 10];
1922
1923 if (mod->skip)
1924 continue;
1925
1926 buf.pos = 0;
1927
1928 add_header(&buf, mod);
1929 err |= add_versions(&buf, mod);
1930 add_depends(&buf, mod, modules);
1931 add_moddevtable(&buf, mod);
1932 add_srcversion(&buf, mod);
1933
1934 sprintf(fname, "%s.mod.c", mod->name);
1935 write_if_changed(&buf, fname);
1936 }
1937
1938 if (dump_write)
1939 write_dump(dump_write);
1940 if (sec_mismatch_count && !sec_mismatch_verbose)
1941 fprintf(stderr, "modpost: Found %d section mismatch(es).\n"
1942 "To see additional details select \"Enable full "
1943 "Section mismatch analysis\"\n"
1944 "in the Kernel Hacking menu "
1945 "(CONFIG_SECTION_MISMATCH).\n", sec_mismatch_count);
1946
1947 return err;
1948 }
WRT350N Kernel Patches