projects/linux·blob v2.6.24 · refs

1728 lines · 43.2 KiB

1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006 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? */
19int modversions = 0;
20/* Warn about undefined symbols? (do so if we have vmlinux) */
21int have_vmlinux = 0;
22/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
23static int all_versions = 0;
24/* If we are modposting external module set to 1 */
25static int external_module = 0;
26/* Warn about section mismatch in vmlinux if set to 1 */
27static int vmlinux_section_warnings = 1;
28/* Only warn about unresolved symbols */
29static int warn_unresolved = 0;
30/* How a symbol is exported */
31enum export {
32 export_plain, export_unused, export_gpl,
33 export_unused_gpl, export_gpl_future, export_unknown
34};
35
36void fatal(const char *fmt, ...)
37{
38 va_list arglist;
39
40 fprintf(stderr, "FATAL: ");
41
42 va_start(arglist, fmt);
43 vfprintf(stderr, fmt, arglist);
44 va_end(arglist);
45
46 exit(1);
47}
48
49void warn(const char *fmt, ...)
50{
51 va_list arglist;
52
53 fprintf(stderr, "WARNING: ");
54
55 va_start(arglist, fmt);
56 vfprintf(stderr, fmt, arglist);
57 va_end(arglist);
58}
59
60void merror(const char *fmt, ...)
61{
62 va_list arglist;
63
64 fprintf(stderr, "ERROR: ");
65
66 va_start(arglist, fmt);
67 vfprintf(stderr, fmt, arglist);
68 va_end(arglist);
69}
70
71static int is_vmlinux(const char *modname)
72{
73 const char *myname;
74
75 if ((myname = strrchr(modname, '/')))
76 myname++;
77 else
78 myname = modname;
79
80 return (strcmp(myname, "vmlinux") == 0) ||
81 (strcmp(myname, "vmlinux.o") == 0);
82}
83
84void *do_nofail(void *ptr, const char *expr)
85{
86 if (!ptr) {
87 fatal("modpost: Memory allocation failure: %s.\n", expr);
88 }
89 return ptr;
90}
91
92/* A list of all modules we processed */
93
94static struct module *modules;
95
96static struct module *find_module(char *modname)
97{
98 struct module *mod;
99
100 for (mod = modules; mod; mod = mod->next)
101 if (strcmp(mod->name, modname) == 0)
102 break;
103 return mod;
104}
105
106static struct module *new_module(char *modname)
107{
108 struct module *mod;
109 char *p, *s;
110
111 mod = NOFAIL(malloc(sizeof(*mod)));
112 memset(mod, 0, sizeof(*mod));
113 p = NOFAIL(strdup(modname));
114
115 /* strip trailing .o */
116 if ((s = strrchr(p, '.')) != NULL)
117 if (strcmp(s, ".o") == 0)
118 *s = '\0';
119
120 /* add to list */
121 mod->name = p;
122 mod->gpl_compatible = -1;
123 mod->next = modules;
124 modules = mod;
125
126 return mod;
127}
128
129/* A hash of all exported symbols,
130 * struct symbol is also used for lists of unresolved symbols */
131
132#define SYMBOL_HASH_SIZE 1024
133
134struct symbol {
135 struct symbol *next;
136 struct module *module;
137 unsigned int crc;
138 int crc_valid;
139 unsigned int weak:1;
140 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
141 unsigned int kernel:1; /* 1 if symbol is from kernel
142 * (only for external modules) **/
143 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
144 enum export export; /* Type of export */
145 char name[0];
146};
147
148static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
149
150/* This is based on the hash agorithm from gdbm, via tdb */
151static inline unsigned int tdb_hash(const char *name)
152{
153 unsigned value; /* Used to compute the hash value. */
154 unsigned i; /* Used to cycle through random values. */
155
156 /* Set the initial value from the key size. */
157 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
158 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
159
160 return (1103515243 * value + 12345);
161}
162
163/**
164 * Allocate a new symbols for use in the hash of exported symbols or
165 * the list of unresolved symbols per module
166 **/
167static struct symbol *alloc_symbol(const char *name, unsigned int weak,
168 struct symbol *next)
169{
170 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
171
172 memset(s, 0, sizeof(*s));
173 strcpy(s->name, name);
174 s->weak = weak;
175 s->next = next;
176 return s;
177}
178
179/* For the hash of exported symbols */
180static struct symbol *new_symbol(const char *name, struct module *module,
181 enum export export)
182{
183 unsigned int hash;
184 struct symbol *new;
185
186 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
187 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
188 new->module = module;
189 new->export = export;
190 return new;
191}
192
193static struct symbol *find_symbol(const char *name)
194{
195 struct symbol *s;
196
197 /* For our purposes, .foo matches foo. PPC64 needs this. */
198 if (name[0] == '.')
199 name++;
200
201 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) {
202 if (strcmp(s->name, name) == 0)
203 return s;
204 }
205 return NULL;
206}
207
208static struct {
209 const char *str;
210 enum export export;
211} export_list[] = {
212 { .str = "EXPORT_SYMBOL", .export = export_plain },
213 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
214 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
215 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
216 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
217 { .str = "(unknown)", .export = export_unknown },
218};
219
220
221static const char *export_str(enum export ex)
222{
223 return export_list[ex].str;
224}
225
226static enum export export_no(const char * s)
227{
228 int i;
229 if (!s)
230 return export_unknown;
231 for (i = 0; export_list[i].export != export_unknown; i++) {
232 if (strcmp(export_list[i].str, s) == 0)
233 return export_list[i].export;
234 }
235 return export_unknown;
236}
237
238static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
239{
240 if (sec == elf->export_sec)
241 return export_plain;
242 else if (sec == elf->export_unused_sec)
243 return export_unused;
244 else if (sec == elf->export_gpl_sec)
245 return export_gpl;
246 else if (sec == elf->export_unused_gpl_sec)
247 return export_unused_gpl;
248 else if (sec == elf->export_gpl_future_sec)
249 return export_gpl_future;
250 else
251 return export_unknown;
252}
253
254/**
255 * Add an exported symbol - it may have already been added without a
256 * CRC, in this case just update the CRC
257 **/
258static struct symbol *sym_add_exported(const char *name, struct module *mod,
259 enum export export)
260{
261 struct symbol *s = find_symbol(name);
262
263 if (!s) {
264 s = new_symbol(name, mod, export);
265 } else {
266 if (!s->preloaded) {
267 warn("%s: '%s' exported twice. Previous export "
268 "was in %s%s\n", mod->name, name,
269 s->module->name,
270 is_vmlinux(s->module->name) ?"":".ko");
271 } else {
272 /* In case Modules.symvers was out of date */
273 s->module = mod;
274 }
275 }
276 s->preloaded = 0;
277 s->vmlinux = is_vmlinux(mod->name);
278 s->kernel = 0;
279 s->export = export;
280 return s;
281}
282
283static void sym_update_crc(const char *name, struct module *mod,
284 unsigned int crc, enum export export)
285{
286 struct symbol *s = find_symbol(name);
287
288 if (!s)
289 s = new_symbol(name, mod, export);
290 s->crc = crc;
291 s->crc_valid = 1;
292}
293
294void *grab_file(const char *filename, unsigned long *size)
295{
296 struct stat st;
297 void *map;
298 int fd;
299
300 fd = open(filename, O_RDONLY);
301 if (fd < 0 || fstat(fd, &st) != 0)
302 return NULL;
303
304 *size = st.st_size;
305 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
306 close(fd);
307
308 if (map == MAP_FAILED)
309 return NULL;
310 return map;
311}
312
313/**
314 * Return a copy of the next line in a mmap'ed file.
315 * spaces in the beginning of the line is trimmed away.
316 * Return a pointer to a static buffer.
317 **/
318char* get_next_line(unsigned long *pos, void *file, unsigned long size)
319{
320 static char line[4096];
321 int skip = 1;
322 size_t len = 0;
323 signed char *p = (signed char *)file + *pos;
324 char *s = line;
325
326 for (; *pos < size ; (*pos)++)
327 {
328 if (skip && isspace(*p)) {
329 p++;
330 continue;
331 }
332 skip = 0;
333 if (*p != '\n' && (*pos < size)) {
334 len++;
335 *s++ = *p++;
336 if (len > 4095)
337 break; /* Too long, stop */
338 } else {
339 /* End of string */
340 *s = '\0';
341 return line;
342 }
343 }
344 /* End of buffer */
345 return NULL;
346}
347
348void release_file(void *file, unsigned long size)
349{
350 munmap(file, size);
351}
352
353static int parse_elf(struct elf_info *info, const char *filename)
354{
355 unsigned int i;
356 Elf_Ehdr *hdr;
357 Elf_Shdr *sechdrs;
358 Elf_Sym *sym;
359
360 hdr = grab_file(filename, &info->size);
361 if (!hdr) {
362 perror(filename);
363 exit(1);
364 }
365 info->hdr = hdr;
366 if (info->size < sizeof(*hdr)) {
367 /* file too small, assume this is an empty .o file */
368 return 0;
369 }
370 /* Is this a valid ELF file? */
371 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
372 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
373 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
374 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
375 /* Not an ELF file - silently ignore it */
376 return 0;
377 }
378 /* Fix endianness in ELF header */
379 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
380 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
381 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
382 hdr->e_machine = TO_NATIVE(hdr->e_machine);
383 hdr->e_type = TO_NATIVE(hdr->e_type);
384 sechdrs = (void *)hdr + hdr->e_shoff;
385 info->sechdrs = sechdrs;
386
387 /* Check if file offset is correct */
388 if (hdr->e_shoff > info->size) {
389 fatal("section header offset=%u in file '%s' is bigger then filesize=%lu\n", hdr->e_shoff, filename, info->size);
390 return 0;
391 }
392
393 /* Fix endianness in section headers */
394 for (i = 0; i < hdr->e_shnum; i++) {
395 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
396 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
397 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
398 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
399 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
400 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
401 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
402 }
403 /* Find symbol table. */
404 for (i = 1; i < hdr->e_shnum; i++) {
405 const char *secstrings
406 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
407 const char *secname;
408
409 if (sechdrs[i].sh_offset > info->size) {
410 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr));
411 return 0;
412 }
413 secname = secstrings + sechdrs[i].sh_name;
414 if (strcmp(secname, ".modinfo") == 0) {
415 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
416 info->modinfo_len = sechdrs[i].sh_size;
417 } else if (strcmp(secname, "__ksymtab") == 0)
418 info->export_sec = i;
419 else if (strcmp(secname, "__ksymtab_unused") == 0)
420 info->export_unused_sec = i;
421 else if (strcmp(secname, "__ksymtab_gpl") == 0)
422 info->export_gpl_sec = i;
423 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
424 info->export_unused_gpl_sec = i;
425 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
426 info->export_gpl_future_sec = i;
427
428 if (sechdrs[i].sh_type != SHT_SYMTAB)
429 continue;
430
431 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
432 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
433 + sechdrs[i].sh_size;
434 info->strtab = (void *)hdr +
435 sechdrs[sechdrs[i].sh_link].sh_offset;
436 }
437 if (!info->symtab_start) {
438 fatal("%s has no symtab?\n", filename);
439 }
440 /* Fix endianness in symbols */
441 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
442 sym->st_shndx = TO_NATIVE(sym->st_shndx);
443 sym->st_name = TO_NATIVE(sym->st_name);
444 sym->st_value = TO_NATIVE(sym->st_value);
445 sym->st_size = TO_NATIVE(sym->st_size);
446 }
447 return 1;
448}
449
450static void parse_elf_finish(struct elf_info *info)
451{
452 release_file(info->hdr, info->size);
453}
454
455#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
456#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
457
458static void handle_modversions(struct module *mod, struct elf_info *info,
459 Elf_Sym *sym, const char *symname)
460{
461 unsigned int crc;
462 enum export export = export_from_sec(info, sym->st_shndx);
463
464 switch (sym->st_shndx) {
465 case SHN_COMMON:
466 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
467 break;
468 case SHN_ABS:
469 /* CRC'd symbol */
470 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
471 crc = (unsigned int) sym->st_value;
472 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
473 export);
474 }
475 break;
476 case SHN_UNDEF:
477 /* undefined symbol */
478 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
479 ELF_ST_BIND(sym->st_info) != STB_WEAK)
480 break;
481 /* ignore global offset table */
482 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
483 break;
484 /* ignore __this_module, it will be resolved shortly */
485 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
486 break;
487/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
488#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
489/* add compatibility with older glibc */
490#ifndef STT_SPARC_REGISTER
491#define STT_SPARC_REGISTER STT_REGISTER
492#endif
493 if (info->hdr->e_machine == EM_SPARC ||
494 info->hdr->e_machine == EM_SPARCV9) {
495 /* Ignore register directives. */
496 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
497 break;
498 if (symname[0] == '.') {
499 char *munged = strdup(symname);
500 munged[0] = '_';
501 munged[1] = toupper(munged[1]);
502 symname = munged;
503 }
504 }
505#endif
506
507 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
508 strlen(MODULE_SYMBOL_PREFIX)) == 0)
509 mod->unres = alloc_symbol(symname +
510 strlen(MODULE_SYMBOL_PREFIX),
511 ELF_ST_BIND(sym->st_info) == STB_WEAK,
512 mod->unres);
513 break;
514 default:
515 /* All exported symbols */
516 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
517 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
518 export);
519 }
520 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
521 mod->has_init = 1;
522 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
523 mod->has_cleanup = 1;
524 break;
525 }
526}
527
528/**
529 * Parse tag=value strings from .modinfo section
530 **/
531static char *next_string(char *string, unsigned long *secsize)
532{
533 /* Skip non-zero chars */
534 while (string[0]) {
535 string++;
536 if ((*secsize)-- <= 1)
537 return NULL;
538 }
539
540 /* Skip any zero padding. */
541 while (!string[0]) {
542 string++;
543 if ((*secsize)-- <= 1)
544 return NULL;
545 }
546 return string;
547}
548
549static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
550 const char *tag, char *info)
551{
552 char *p;
553 unsigned int taglen = strlen(tag);
554 unsigned long size = modinfo_len;
555
556 if (info) {
557 size -= info - (char *)modinfo;
558 modinfo = next_string(info, &size);
559 }
560
561 for (p = modinfo; p; p = next_string(p, &size)) {
562 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
563 return p + taglen + 1;
564 }
565 return NULL;
566}
567
568static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
569 const char *tag)
570
571{
572 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
573}
574
575/**
576 * Test if string s ends in string sub
577 * return 0 if match
578 **/
579static int strrcmp(const char *s, const char *sub)
580{
581 int slen, sublen;
582
583 if (!s || !sub)
584 return 1;
585
586 slen = strlen(s);
587 sublen = strlen(sub);
588
589 if ((slen == 0) || (sublen == 0))
590 return 1;
591
592 if (sublen > slen)
593 return 1;
594
595 return memcmp(s + slen - sublen, sub, sublen);
596}
597
598/*
599 * Functions used only during module init is marked __init and is stored in
600 * a .init.text section. Likewise data is marked __initdata and stored in
601 * a .init.data section.
602 * If this section is one of these sections return 1
603 * See include/linux/init.h for the details
604 */
605static int init_section(const char *name)
606{
607 if (strcmp(name, ".init") == 0)
608 return 1;
609 if (strncmp(name, ".init.", strlen(".init.")) == 0)
610 return 1;
611 return 0;
612}
613
614/*
615 * Functions used only during module exit is marked __exit and is stored in
616 * a .exit.text section. Likewise data is marked __exitdata and stored in
617 * a .exit.data section.
618 * If this section is one of these sections return 1
619 * See include/linux/init.h for the details
620 **/
621static int exit_section(const char *name)
622{
623 if (strcmp(name, ".exit.text") == 0)
624 return 1;
625 if (strcmp(name, ".exit.data") == 0)
626 return 1;
627 return 0;
628
629}
630
631/*
632 * Data sections are named like this:
633 * .data | .data.rel | .data.rel.*
634 * Return 1 if the specified section is a data section
635 */
636static int data_section(const char *name)
637{
638 if ((strcmp(name, ".data") == 0) ||
639 (strcmp(name, ".data.rel") == 0) ||
640 (strncmp(name, ".data.rel.", strlen(".data.rel.")) == 0))
641 return 1;
642 else
643 return 0;
644}
645
646/**
647 * Whitelist to allow certain references to pass with no warning.
648 *
649 * Pattern 0:
650 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
651 * The pattern is identified by:
652 * fromsec = .text.init.refok* | .data.init.refok*
653 *
654 * Pattern 1:
655 * If a module parameter is declared __initdata and permissions=0
656 * then this is legal despite the warning generated.
657 * We cannot see value of permissions here, so just ignore
658 * this pattern.
659 * The pattern is identified by:
660 * tosec = .init.data
661 * fromsec = .data*
662 * atsym =__param*
663 *
664 * Pattern 2:
665 * Many drivers utilise a *driver container with references to
666 * add, remove, probe functions etc.
667 * These functions may often be marked __init and we do not want to
668 * warn here.
669 * the pattern is identified by:
670 * tosec = init or exit section
671 * fromsec = data section
672 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console, *_timer
673 *
674 * Pattern 3:
675 * Whitelist all refereces from .text.head to .init.data
676 * Whitelist all refereces from .text.head to .init.text
677 *
678 * Pattern 4:
679 * Some symbols belong to init section but still it is ok to reference
680 * these from non-init sections as these symbols don't have any memory
681 * allocated for them and symbol address and value are same. So even
682 * if init section is freed, its ok to reference those symbols.
683 * For ex. symbols marking the init section boundaries.
684 * This pattern is identified by
685 * refsymname = __init_begin, _sinittext, _einittext
686 *
687 * Pattern 5:
688 * Xtensa uses literal sections for constants that are accessed PC-relative.
689 * Literal sections may safely reference their text sections.
690 * (Note that the name for the literal section omits any trailing '.text')
691 * tosec = <section>[.text]
692 * fromsec = <section>.literal
693 **/
694static int secref_whitelist(const char *modname, const char *tosec,
695 const char *fromsec, const char *atsym,
696 const char *refsymname)
697{
698 int len;
699 const char **s;
700 const char *pat2sym[] = {
701 "driver",
702 "_template", /* scsi uses *_template a lot */
703 "_timer", /* arm uses ops structures named _timer a lot */
704 "_sht", /* scsi also used *_sht to some extent */
705 "_ops",
706 "_probe",
707 "_probe_one",
708 "_console",
709 NULL
710 };
711
712 const char *pat3refsym[] = {
713 "__init_begin",
714 "_sinittext",
715 "_einittext",
716 NULL
717 };
718
719 /* Check for pattern 0 */
720 if ((strncmp(fromsec, ".text.init.refok", strlen(".text.init.refok")) == 0) ||
721 (strncmp(fromsec, ".exit.text.refok", strlen(".exit.text.refok")) == 0) ||
722 (strncmp(fromsec, ".data.init.refok", strlen(".data.init.refok")) == 0))
723 return 1;
724
725 /* Check for pattern 1 */
726 if ((strcmp(tosec, ".init.data") == 0) &&
727 (strncmp(fromsec, ".data", strlen(".data")) == 0) &&
728 (strncmp(atsym, "__param", strlen("__param")) == 0))
729 return 1;
730
731 /* Check for pattern 2 */
732 if ((init_section(tosec) || exit_section(tosec)) && data_section(fromsec))
733 for (s = pat2sym; *s; s++)
734 if (strrcmp(atsym, *s) == 0)
735 return 1;
736
737 /* Check for pattern 3 */
738 if ((strcmp(fromsec, ".text.head") == 0) &&
739 ((strcmp(tosec, ".init.data") == 0) ||
740 (strcmp(tosec, ".init.text") == 0)))
741 return 1;
742
743 /* Check for pattern 4 */
744 for (s = pat3refsym; *s; s++)
745 if (strcmp(refsymname, *s) == 0)
746 return 1;
747
748 /* Check for pattern 5 */
749 if (strrcmp(tosec, ".text") == 0)
750 len = strlen(tosec) - strlen(".text");
751 else
752 len = strlen(tosec);
753 if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) &&
754 (strcmp(fromsec + len, ".literal") == 0))
755 return 1;
756
757 return 0;
758}
759
760/**
761 * Find symbol based on relocation record info.
762 * In some cases the symbol supplied is a valid symbol so
763 * return refsym. If st_name != 0 we assume this is a valid symbol.
764 * In other cases the symbol needs to be looked up in the symbol table
765 * based on section and address.
766 * **/
767static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr,
768 Elf_Sym *relsym)
769{
770 Elf_Sym *sym;
771
772 if (relsym->st_name != 0)
773 return relsym;
774 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
775 if (sym->st_shndx != relsym->st_shndx)
776 continue;
777 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
778 continue;
779 if (sym->st_value == addr)
780 return sym;
781 }
782 return NULL;
783}
784
785static inline int is_arm_mapping_symbol(const char *str)
786{
787 return str[0] == '$' && strchr("atd", str[1])
788 && (str[2] == '\0' || str[2] == '.');
789}
790
791/*
792 * If there's no name there, ignore it; likewise, ignore it if it's
793 * one of the magic symbols emitted used by current ARM tools.
794 *
795 * Otherwise if find_symbols_between() returns those symbols, they'll
796 * fail the whitelist tests and cause lots of false alarms ... fixable
797 * only by merging __exit and __init sections into __text, bloating
798 * the kernel (which is especially evil on embedded platforms).
799 */
800static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
801{
802 const char *name = elf->strtab + sym->st_name;
803
804 if (!name || !strlen(name))
805 return 0;
806 return !is_arm_mapping_symbol(name);
807}
808
809/*
810 * Find symbols before or equal addr and after addr - in the section sec.
811 * If we find two symbols with equal offset prefer one with a valid name.
812 * The ELF format may have a better way to detect what type of symbol
813 * it is, but this works for now.
814 **/
815static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
816 const char *sec,
817 Elf_Sym **before, Elf_Sym **after)
818{
819 Elf_Sym *sym;
820 Elf_Ehdr *hdr = elf->hdr;
821 Elf_Addr beforediff = ~0;
822 Elf_Addr afterdiff = ~0;
823 const char *secstrings = (void *)hdr +
824 elf->sechdrs[hdr->e_shstrndx].sh_offset;
825
826 *before = NULL;
827 *after = NULL;
828
829 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
830 const char *symsec;
831
832 if (sym->st_shndx >= SHN_LORESERVE)
833 continue;
834 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;
835 if (strcmp(symsec, sec) != 0)
836 continue;
837 if (!is_valid_name(elf, sym))
838 continue;
839 if (sym->st_value <= addr) {
840 if ((addr - sym->st_value) < beforediff) {
841 beforediff = addr - sym->st_value;
842 *before = sym;
843 }
844 else if ((addr - sym->st_value) == beforediff) {
845 *before = sym;
846 }
847 }
848 else
849 {
850 if ((sym->st_value - addr) < afterdiff) {
851 afterdiff = sym->st_value - addr;
852 *after = sym;
853 }
854 else if ((sym->st_value - addr) == afterdiff) {
855 *after = sym;
856 }
857 }
858 }
859}
860
861/**
862 * Print a warning about a section mismatch.
863 * Try to find symbols near it so user can find it.
864 * Check whitelist before warning - it may be a false positive.
865 **/
866static void warn_sec_mismatch(const char *modname, const char *fromsec,
867 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
868{
869 const char *refsymname = "";
870 Elf_Sym *before, *after;
871 Elf_Sym *refsym;
872 Elf_Ehdr *hdr = elf->hdr;
873 Elf_Shdr *sechdrs = elf->sechdrs;
874 const char *secstrings = (void *)hdr +
875 sechdrs[hdr->e_shstrndx].sh_offset;
876 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;
877
878 find_symbols_between(elf, r.r_offset, fromsec, &before, &after);
879
880 refsym = find_elf_symbol(elf, r.r_addend, sym);
881 if (refsym && strlen(elf->strtab + refsym->st_name))
882 refsymname = elf->strtab + refsym->st_name;
883
884 /* check whitelist - we may ignore it */
885 if (secref_whitelist(modname, secname, fromsec,
886 before ? elf->strtab + before->st_name : "",
887 refsymname))
888 return;
889
890 if (before && after) {
891 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
892 "(between '%s' and '%s')\n",
893 modname, fromsec, (unsigned long long)r.r_offset,
894 secname, refsymname,
895 elf->strtab + before->st_name,
896 elf->strtab + after->st_name);
897 } else if (before) {
898 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
899 "(after '%s')\n",
900 modname, fromsec, (unsigned long long)r.r_offset,
901 secname, refsymname,
902 elf->strtab + before->st_name);
903 } else if (after) {
904 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
905 "before '%s' (at offset -0x%llx)\n",
906 modname, fromsec, (unsigned long long)r.r_offset,
907 secname, refsymname,
908 elf->strtab + after->st_name);
909 } else {
910 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
911 modname, fromsec, (unsigned long long)r.r_offset,
912 secname, refsymname);
913 }
914}
915
916static unsigned int *reloc_location(struct elf_info *elf,
917 int rsection, Elf_Rela *r)
918{
919 Elf_Shdr *sechdrs = elf->sechdrs;
920 int section = sechdrs[rsection].sh_info;
921
922 return (void *)elf->hdr + sechdrs[section].sh_offset +
923 (r->r_offset - sechdrs[section].sh_addr);
924}
925
926static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
927{
928 unsigned int r_typ = ELF_R_TYPE(r->r_info);
929 unsigned int *location = reloc_location(elf, rsection, r);
930
931 switch (r_typ) {
932 case R_386_32:
933 r->r_addend = TO_NATIVE(*location);
934 break;
935 case R_386_PC32:
936 r->r_addend = TO_NATIVE(*location) + 4;
937 /* For CONFIG_RELOCATABLE=y */
938 if (elf->hdr->e_type == ET_EXEC)
939 r->r_addend += r->r_offset;
940 break;
941 }
942 return 0;
943}
944
945static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
946{
947 unsigned int r_typ = ELF_R_TYPE(r->r_info);
948
949 switch (r_typ) {
950 case R_ARM_ABS32:
951 /* From ARM ABI: (S + A) | T */
952 r->r_addend = (int)(long)(elf->symtab_start + ELF_R_SYM(r->r_info));
953 break;
954 case R_ARM_PC24:
955 /* From ARM ABI: ((S + A) | T) - P */
956 r->r_addend = (int)(long)(elf->hdr + elf->sechdrs[rsection].sh_offset +
957 (r->r_offset - elf->sechdrs[rsection].sh_addr));
958 break;
959 default:
960 return 1;
961 }
962 return 0;
963}
964
965static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
966{
967 unsigned int r_typ = ELF_R_TYPE(r->r_info);
968 unsigned int *location = reloc_location(elf, rsection, r);
969 unsigned int inst;
970
971 if (r_typ == R_MIPS_HI16)
972 return 1; /* skip this */
973 inst = TO_NATIVE(*location);
974 switch (r_typ) {
975 case R_MIPS_LO16:
976 r->r_addend = inst & 0xffff;
977 break;
978 case R_MIPS_26:
979 r->r_addend = (inst & 0x03ffffff) << 2;
980 break;
981 case R_MIPS_32:
982 r->r_addend = inst;
983 break;
984 }
985 return 0;
986}
987
988/**
989 * A module includes a number of sections that are discarded
990 * either when loaded or when used as built-in.
991 * For loaded modules all functions marked __init and all data
992 * marked __initdata will be discarded when the module has been intialized.
993 * Likewise for modules used built-in the sections marked __exit
994 * are discarded because __exit marked function are supposed to be called
995 * only when a moduel is unloaded which never happes for built-in modules.
996 * The check_sec_ref() function traverses all relocation records
997 * to find all references to a section that reference a section that will
998 * be discarded and warns about it.
999 **/
1000static void check_sec_ref(struct module *mod, const char *modname,
1001 struct elf_info *elf,
1002 int section(const char*),
1003 int section_ref_ok(const char *))
1004{
1005 int i;
1006 Elf_Sym *sym;
1007 Elf_Ehdr *hdr = elf->hdr;
1008 Elf_Shdr *sechdrs = elf->sechdrs;
1009 const char *secstrings = (void *)hdr +
1010 sechdrs[hdr->e_shstrndx].sh_offset;
1011
1012 /* Walk through all sections */
1013 for (i = 0; i < hdr->e_shnum; i++) {
1014 const char *name = secstrings + sechdrs[i].sh_name;
1015 const char *secname;
1016 Elf_Rela r;
1017 unsigned int r_sym;
1018 /* We want to process only relocation sections and not .init */
1019 if (sechdrs[i].sh_type == SHT_RELA) {
1020 Elf_Rela *rela;
1021 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
1022 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size;
1023 name += strlen(".rela");
1024 if (section_ref_ok(name))
1025 continue;
1026
1027 for (rela = start; rela < stop; rela++) {
1028 r.r_offset = TO_NATIVE(rela->r_offset);
1029#if KERNEL_ELFCLASS == ELFCLASS64
1030 if (hdr->e_machine == EM_MIPS) {
1031 unsigned int r_typ;
1032 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1033 r_sym = TO_NATIVE(r_sym);
1034 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1035 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1036 } else {
1037 r.r_info = TO_NATIVE(rela->r_info);
1038 r_sym = ELF_R_SYM(r.r_info);
1039 }
1040#else
1041 r.r_info = TO_NATIVE(rela->r_info);
1042 r_sym = ELF_R_SYM(r.r_info);
1043#endif
1044 r.r_addend = TO_NATIVE(rela->r_addend);
1045 sym = elf->symtab_start + r_sym;
1046 /* Skip special sections */
1047 if (sym->st_shndx >= SHN_LORESERVE)
1048 continue;
1049
1050 secname = secstrings +
1051 sechdrs[sym->st_shndx].sh_name;
1052 if (section(secname))
1053 warn_sec_mismatch(modname, name,
1054 elf, sym, r);
1055 }
1056 } else if (sechdrs[i].sh_type == SHT_REL) {
1057 Elf_Rel *rel;
1058 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset;
1059 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size;
1060 name += strlen(".rel");
1061 if (section_ref_ok(name))
1062 continue;
1063
1064 for (rel = start; rel < stop; rel++) {
1065 r.r_offset = TO_NATIVE(rel->r_offset);
1066#if KERNEL_ELFCLASS == ELFCLASS64
1067 if (hdr->e_machine == EM_MIPS) {
1068 unsigned int r_typ;
1069 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1070 r_sym = TO_NATIVE(r_sym);
1071 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1072 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1073 } else {
1074 r.r_info = TO_NATIVE(rel->r_info);
1075 r_sym = ELF_R_SYM(r.r_info);
1076 }
1077#else
1078 r.r_info = TO_NATIVE(rel->r_info);
1079 r_sym = ELF_R_SYM(r.r_info);
1080#endif
1081 r.r_addend = 0;
1082 switch (hdr->e_machine) {
1083 case EM_386:
1084 if (addend_386_rel(elf, i, &r))
1085 continue;
1086 break;
1087 case EM_ARM:
1088 if(addend_arm_rel(elf, i, &r))
1089 continue;
1090 break;
1091 case EM_MIPS:
1092 if (addend_mips_rel(elf, i, &r))
1093 continue;
1094 break;
1095 }
1096 sym = elf->symtab_start + r_sym;
1097 /* Skip special sections */
1098 if (sym->st_shndx >= SHN_LORESERVE)
1099 continue;
1100
1101 secname = secstrings +
1102 sechdrs[sym->st_shndx].sh_name;
1103 if (section(secname))
1104 warn_sec_mismatch(modname, name,
1105 elf, sym, r);
1106 }
1107 }
1108 }
1109}
1110
1111/*
1112 * Identify sections from which references to either a
1113 * .init or a .exit section is OK.
1114 *
1115 * [OPD] Keith Ownes <[email protected]> commented:
1116 * For our future {in}sanity, add a comment that this is the ppc .opd
1117 * section, not the ia64 .opd section.
1118 * ia64 .opd should not point to discarded sections.
1119 * [.rodata] like for .init.text we ignore .rodata references -same reason
1120 */
1121static int initexit_section_ref_ok(const char *name)
1122{
1123 const char **s;
1124 /* Absolute section names */
1125 const char *namelist1[] = {
1126 "__bug_table", /* used by powerpc for BUG() */
1127 "__ex_table",
1128 ".altinstructions",
1129 ".cranges", /* used by sh64 */
1130 ".fixup",
1131 ".machvec", /* ia64 + powerpc uses these */
1132 ".machine.desc",
1133 ".opd", /* See comment [OPD] */
1134 "__dbe_table",
1135 ".parainstructions",
1136 ".pdr",
1137 ".plt", /* seen on ARCH=um build on x86_64. Harmless */
1138 ".smp_locks",
1139 ".stab",
1140 ".m68k_fixup",
1141 ".xt.prop", /* xtensa informational section */
1142 ".xt.lit", /* xtensa informational section */
1143 NULL
1144 };
1145 /* Start of section names */
1146 const char *namelist2[] = {
1147 ".debug",
1148 ".eh_frame",
1149 ".note", /* ignore ELF notes - may contain anything */
1150 ".got", /* powerpc - global offset table */
1151 ".toc", /* powerpc - table of contents */
1152 NULL
1153 };
1154 /* part of section name */
1155 const char *namelist3 [] = {
1156 ".unwind", /* Sample: IA_64.unwind.exit.text */
1157 NULL
1158 };
1159
1160 for (s = namelist1; *s; s++)
1161 if (strcmp(*s, name) == 0)
1162 return 1;
1163 for (s = namelist2; *s; s++)
1164 if (strncmp(*s, name, strlen(*s)) == 0)
1165 return 1;
1166 for (s = namelist3; *s; s++)
1167 if (strstr(name, *s) != NULL)
1168 return 1;
1169 return 0;
1170}
1171
1172
1173/*
1174 * Identify sections from which references to a .init section is OK.
1175 *
1176 * Unfortunately references to read only data that referenced .init
1177 * sections had to be excluded. Almost all of these are false
1178 * positives, they are created by gcc. The downside of excluding rodata
1179 * is that there really are some user references from rodata to
1180 * init code, e.g. drivers/video/vgacon.c:
1181 *
1182 * const struct consw vga_con = {
1183 * con_startup: vgacon_startup,
1184 *
1185 * where vgacon_startup is __init. If you want to wade through the false
1186 * positives, take out the check for rodata.
1187 */
1188static int init_section_ref_ok(const char *name)
1189{
1190 const char **s;
1191 /* Absolute section names */
1192 const char *namelist1[] = {
1193 "__dbe_table", /* MIPS generate these */
1194 "__ftr_fixup", /* powerpc cpu feature fixup */
1195 "__fw_ftr_fixup", /* powerpc firmware feature fixup */
1196 "__param",
1197 ".data.rel.ro", /* used by parisc64 */
1198 ".init",
1199 ".text.lock",
1200 NULL
1201 };
1202 /* Start of section names */
1203 const char *namelist2[] = {
1204 ".init.",
1205 ".pci_fixup",
1206 ".rodata",
1207 NULL
1208 };
1209
1210 if (initexit_section_ref_ok(name))
1211 return 1;
1212
1213 for (s = namelist1; *s; s++)
1214 if (strcmp(*s, name) == 0)
1215 return 1;
1216 for (s = namelist2; *s; s++)
1217 if (strncmp(*s, name, strlen(*s)) == 0)
1218 return 1;
1219
1220 /* If section name ends with ".init" we allow references
1221 * as is the case with .initcallN.init, .early_param.init, .taglist.init etc
1222 */
1223 if (strrcmp(name, ".init") == 0)
1224 return 1;
1225 return 0;
1226}
1227
1228/*
1229 * Identify sections from which references to a .exit section is OK.
1230 */
1231static int exit_section_ref_ok(const char *name)
1232{
1233 const char **s;
1234 /* Absolute section names */
1235 const char *namelist1[] = {
1236 ".exit.data",
1237 ".exit.text",
1238 ".exitcall.exit",
1239 ".rodata",
1240 NULL
1241 };
1242
1243 if (initexit_section_ref_ok(name))
1244 return 1;
1245
1246 for (s = namelist1; *s; s++)
1247 if (strcmp(*s, name) == 0)
1248 return 1;
1249 return 0;
1250}
1251
1252static void read_symbols(char *modname)
1253{
1254 const char *symname;
1255 char *version;
1256 char *license;
1257 struct module *mod;
1258 struct elf_info info = { };
1259 Elf_Sym *sym;
1260
1261 if (!parse_elf(&info, modname))
1262 return;
1263
1264 mod = new_module(modname);
1265
1266 /* When there's no vmlinux, don't print warnings about
1267 * unresolved symbols (since there'll be too many ;) */
1268 if (is_vmlinux(modname)) {
1269 have_vmlinux = 1;
1270 mod->skip = 1;
1271 }
1272
1273 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1274 while (license) {
1275 if (license_is_gpl_compatible(license))
1276 mod->gpl_compatible = 1;
1277 else {
1278 mod->gpl_compatible = 0;
1279 break;
1280 }
1281 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1282 "license", license);
1283 }
1284
1285 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1286 symname = info.strtab + sym->st_name;
1287
1288 handle_modversions(mod, &info, sym, symname);
1289 handle_moddevtable(mod, &info, sym, symname);
1290 }
1291 if (is_vmlinux(modname) && vmlinux_section_warnings) {
1292 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
1293 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
1294 }
1295
1296 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1297 if (version)
1298 maybe_frob_rcs_version(modname, version, info.modinfo,
1299 version - (char *)info.hdr);
1300 if (version || (all_versions && !is_vmlinux(modname)))
1301 get_src_version(modname, mod->srcversion,
1302 sizeof(mod->srcversion)-1);
1303
1304 parse_elf_finish(&info);
1305
1306 /* Our trick to get versioning for struct_module - it's
1307 * never passed as an argument to an exported function, so
1308 * the automatic versioning doesn't pick it up, but it's really
1309 * important anyhow */
1310 if (modversions)
1311 mod->unres = alloc_symbol("struct_module", 0, mod->unres);
1312}
1313
1314#define SZ 500
1315
1316/* We first write the generated file into memory using the
1317 * following helper, then compare to the file on disk and
1318 * only update the later if anything changed */
1319
1320void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1321 const char *fmt, ...)
1322{
1323 char tmp[SZ];
1324 int len;
1325 va_list ap;
1326
1327 va_start(ap, fmt);
1328 len = vsnprintf(tmp, SZ, fmt, ap);
1329 buf_write(buf, tmp, len);
1330 va_end(ap);
1331}
1332
1333void buf_write(struct buffer *buf, const char *s, int len)
1334{
1335 if (buf->size - buf->pos < len) {
1336 buf->size += len + SZ;
1337 buf->p = realloc(buf->p, buf->size);
1338 }
1339 strncpy(buf->p + buf->pos, s, len);
1340 buf->pos += len;
1341}
1342
1343static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1344{
1345 const char *e = is_vmlinux(m) ?"":".ko";
1346
1347 switch (exp) {
1348 case export_gpl:
1349 fatal("modpost: GPL-incompatible module %s%s "
1350 "uses GPL-only symbol '%s'\n", m, e, s);
1351 break;
1352 case export_unused_gpl:
1353 fatal("modpost: GPL-incompatible module %s%s "
1354 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1355 break;
1356 case export_gpl_future:
1357 warn("modpost: GPL-incompatible module %s%s "
1358 "uses future GPL-only symbol '%s'\n", m, e, s);
1359 break;
1360 case export_plain:
1361 case export_unused:
1362 case export_unknown:
1363 /* ignore */
1364 break;
1365 }
1366}
1367
1368static void check_for_unused(enum export exp, const char* m, const char* s)
1369{
1370 const char *e = is_vmlinux(m) ?"":".ko";
1371
1372 switch (exp) {
1373 case export_unused:
1374 case export_unused_gpl:
1375 warn("modpost: module %s%s "
1376 "uses symbol '%s' marked UNUSED\n", m, e, s);
1377 break;
1378 default:
1379 /* ignore */
1380 break;
1381 }
1382}
1383
1384static void check_exports(struct module *mod)
1385{
1386 struct symbol *s, *exp;
1387
1388 for (s = mod->unres; s; s = s->next) {
1389 const char *basename;
1390 exp = find_symbol(s->name);
1391 if (!exp || exp->module == mod)
1392 continue;
1393 basename = strrchr(mod->name, '/');
1394 if (basename)
1395 basename++;
1396 else
1397 basename = mod->name;
1398 if (!mod->gpl_compatible)
1399 check_for_gpl_usage(exp->export, basename, exp->name);
1400 check_for_unused(exp->export, basename, exp->name);
1401 }
1402}
1403
1404/**
1405 * Header for the generated file
1406 **/
1407static void add_header(struct buffer *b, struct module *mod)
1408{
1409 buf_printf(b, "#include <linux/module.h>\n");
1410 buf_printf(b, "#include <linux/vermagic.h>\n");
1411 buf_printf(b, "#include <linux/compiler.h>\n");
1412 buf_printf(b, "\n");
1413 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1414 buf_printf(b, "\n");
1415 buf_printf(b, "struct module __this_module\n");
1416 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1417 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1418 if (mod->has_init)
1419 buf_printf(b, " .init = init_module,\n");
1420 if (mod->has_cleanup)
1421 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1422 " .exit = cleanup_module,\n"
1423 "#endif\n");
1424 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1425 buf_printf(b, "};\n");
1426}
1427
1428/**
1429 * Record CRCs for unresolved symbols
1430 **/
1431static int add_versions(struct buffer *b, struct module *mod)
1432{
1433 struct symbol *s, *exp;
1434 int err = 0;
1435
1436 for (s = mod->unres; s; s = s->next) {
1437 exp = find_symbol(s->name);
1438 if (!exp || exp->module == mod) {
1439 if (have_vmlinux && !s->weak) {
1440 if (warn_unresolved) {
1441 warn("\"%s\" [%s.ko] undefined!\n",
1442 s->name, mod->name);
1443 } else {
1444 merror("\"%s\" [%s.ko] undefined!\n",
1445 s->name, mod->name);
1446 err = 1;
1447 }
1448 }
1449 continue;
1450 }
1451 s->module = exp->module;
1452 s->crc_valid = exp->crc_valid;
1453 s->crc = exp->crc;
1454 }
1455
1456 if (!modversions)
1457 return err;
1458
1459 buf_printf(b, "\n");
1460 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1461 buf_printf(b, "__attribute_used__\n");
1462 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1463
1464 for (s = mod->unres; s; s = s->next) {
1465 if (!s->module) {
1466 continue;
1467 }
1468 if (!s->crc_valid) {
1469 warn("\"%s\" [%s.ko] has no CRC!\n",
1470 s->name, mod->name);
1471 continue;
1472 }
1473 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1474 }
1475
1476 buf_printf(b, "};\n");
1477
1478 return err;
1479}
1480
1481static void add_depends(struct buffer *b, struct module *mod,
1482 struct module *modules)
1483{
1484 struct symbol *s;
1485 struct module *m;
1486 int first = 1;
1487
1488 for (m = modules; m; m = m->next) {
1489 m->seen = is_vmlinux(m->name);
1490 }
1491
1492 buf_printf(b, "\n");
1493 buf_printf(b, "static const char __module_depends[]\n");
1494 buf_printf(b, "__attribute_used__\n");
1495 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1496 buf_printf(b, "\"depends=");
1497 for (s = mod->unres; s; s = s->next) {
1498 const char *p;
1499 if (!s->module)
1500 continue;
1501
1502 if (s->module->seen)
1503 continue;
1504
1505 s->module->seen = 1;
1506 if ((p = strrchr(s->module->name, '/')) != NULL)
1507 p++;
1508 else
1509 p = s->module->name;
1510 buf_printf(b, "%s%s", first ? "" : ",", p);
1511 first = 0;
1512 }
1513 buf_printf(b, "\";\n");
1514}
1515
1516static void add_srcversion(struct buffer *b, struct module *mod)
1517{
1518 if (mod->srcversion[0]) {
1519 buf_printf(b, "\n");
1520 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1521 mod->srcversion);
1522 }
1523}
1524
1525static void write_if_changed(struct buffer *b, const char *fname)
1526{
1527 char *tmp;
1528 FILE *file;
1529 struct stat st;
1530
1531 file = fopen(fname, "r");
1532 if (!file)
1533 goto write;
1534
1535 if (fstat(fileno(file), &st) < 0)
1536 goto close_write;
1537
1538 if (st.st_size != b->pos)
1539 goto close_write;
1540
1541 tmp = NOFAIL(malloc(b->pos));
1542 if (fread(tmp, 1, b->pos, file) != b->pos)
1543 goto free_write;
1544
1545 if (memcmp(tmp, b->p, b->pos) != 0)
1546 goto free_write;
1547
1548 free(tmp);
1549 fclose(file);
1550 return;
1551
1552 free_write:
1553 free(tmp);
1554 close_write:
1555 fclose(file);
1556 write:
1557 file = fopen(fname, "w");
1558 if (!file) {
1559 perror(fname);
1560 exit(1);
1561 }
1562 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1563 perror(fname);
1564 exit(1);
1565 }
1566 fclose(file);
1567}
1568
1569/* parse Module.symvers file. line format:
1570 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1571 **/
1572static void read_dump(const char *fname, unsigned int kernel)
1573{
1574 unsigned long size, pos = 0;
1575 void *file = grab_file(fname, &size);
1576 char *line;
1577
1578 if (!file)
1579 /* No symbol versions, silently ignore */
1580 return;
1581
1582 while ((line = get_next_line(&pos, file, size))) {
1583 char *symname, *modname, *d, *export, *end;
1584 unsigned int crc;
1585 struct module *mod;
1586 struct symbol *s;
1587
1588 if (!(symname = strchr(line, '\t')))
1589 goto fail;
1590 *symname++ = '\0';
1591 if (!(modname = strchr(symname, '\t')))
1592 goto fail;
1593 *modname++ = '\0';
1594 if ((export = strchr(modname, '\t')) != NULL)
1595 *export++ = '\0';
1596 if (export && ((end = strchr(export, '\t')) != NULL))
1597 *end = '\0';
1598 crc = strtoul(line, &d, 16);
1599 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1600 goto fail;
1601
1602 if (!(mod = find_module(modname))) {
1603 if (is_vmlinux(modname)) {
1604 have_vmlinux = 1;
1605 }
1606 mod = new_module(NOFAIL(strdup(modname)));
1607 mod->skip = 1;
1608 }
1609 s = sym_add_exported(symname, mod, export_no(export));
1610 s->kernel = kernel;
1611 s->preloaded = 1;
1612 sym_update_crc(symname, mod, crc, export_no(export));
1613 }
1614 return;
1615fail:
1616 fatal("parse error in symbol dump file\n");
1617}
1618
1619/* For normal builds always dump all symbols.
1620 * For external modules only dump symbols
1621 * that are not read from kernel Module.symvers.
1622 **/
1623static int dump_sym(struct symbol *sym)
1624{
1625 if (!external_module)
1626 return 1;
1627 if (sym->vmlinux || sym->kernel)
1628 return 0;
1629 return 1;
1630}
1631
1632static void write_dump(const char *fname)
1633{
1634 struct buffer buf = { };
1635 struct symbol *symbol;
1636 int n;
1637
1638 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1639 symbol = symbolhash[n];
1640 while (symbol) {
1641 if (dump_sym(symbol))
1642 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1643 symbol->crc, symbol->name,
1644 symbol->module->name,
1645 export_str(symbol->export));
1646 symbol = symbol->next;
1647 }
1648 }
1649 write_if_changed(&buf, fname);
1650}
1651
1652int main(int argc, char **argv)
1653{
1654 struct module *mod;
1655 struct buffer buf = { };
1656 char fname[SZ];
1657 char *kernel_read = NULL, *module_read = NULL;
1658 char *dump_write = NULL;
1659 int opt;
1660 int err;
1661
1662 while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) {
1663 switch(opt) {
1664 case 'i':
1665 kernel_read = optarg;
1666 break;
1667 case 'I':
1668 module_read = optarg;
1669 external_module = 1;
1670 break;
1671 case 'm':
1672 modversions = 1;
1673 break;
1674 case 'o':
1675 dump_write = optarg;
1676 break;
1677 case 'a':
1678 all_versions = 1;
1679 break;
1680 case 's':
1681 vmlinux_section_warnings = 0;
1682 break;
1683 case 'w':
1684 warn_unresolved = 1;
1685 break;
1686 default:
1687 exit(1);
1688 }
1689 }
1690
1691 if (kernel_read)
1692 read_dump(kernel_read, 1);
1693 if (module_read)
1694 read_dump(module_read, 0);
1695
1696 while (optind < argc) {
1697 read_symbols(argv[optind++]);
1698 }
1699
1700 for (mod = modules; mod; mod = mod->next) {
1701 if (mod->skip)
1702 continue;
1703 check_exports(mod);
1704 }
1705
1706 err = 0;
1707
1708 for (mod = modules; mod; mod = mod->next) {
1709 if (mod->skip)
1710 continue;
1711
1712 buf.pos = 0;
1713
1714 add_header(&buf, mod);
1715 err |= add_versions(&buf, mod);
1716 add_depends(&buf, mod, modules);
1717 add_moddevtable(&buf, mod);
1718 add_srcversion(&buf, mod);
1719
1720 sprintf(fname, "%s.mod.c", mod->name);
1721 write_if_changed(&buf, fname);
1722 }
1723
1724 if (dump_write)
1725 write_dump(dump_write);
1726
1727 return err;
1728}