blob: 7e8079a34adf00dfda1839640c63fcda5e4a657f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
Sam Ravnborg382168f2006-02-26 20:11:17 +01005 * Copyright 2006 Sam Ravnborg
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * 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
17/* Are we using CONFIG_MODVERSIONS? */
18int modversions = 0;
19/* Warn about undefined symbols? (do so if we have vmlinux) */
20int have_vmlinux = 0;
21/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
22static int all_versions = 0;
Sam Ravnborg040fcc82006-01-28 22:15:55 +010023/* If we are modposting external module set to 1 */
24static int external_module = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Sam Ravnborg5c3ead82006-01-28 17:19:35 +010026void fatal(const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027{
28 va_list arglist;
29
30 fprintf(stderr, "FATAL: ");
31
32 va_start(arglist, fmt);
33 vfprintf(stderr, fmt, arglist);
34 va_end(arglist);
35
36 exit(1);
37}
38
Sam Ravnborg5c3ead82006-01-28 17:19:35 +010039void warn(const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -070040{
41 va_list arglist;
42
43 fprintf(stderr, "WARNING: ");
44
45 va_start(arglist, fmt);
46 vfprintf(stderr, fmt, arglist);
47 va_end(arglist);
48}
49
Sam Ravnborg040fcc82006-01-28 22:15:55 +010050static int is_vmlinux(const char *modname)
51{
52 const char *myname;
53
54 if ((myname = strrchr(modname, '/')))
55 myname++;
56 else
57 myname = modname;
58
59 return strcmp(myname, "vmlinux") == 0;
60}
61
Linus Torvalds1da177e2005-04-16 15:20:36 -070062void *do_nofail(void *ptr, const char *expr)
63{
64 if (!ptr) {
65 fatal("modpost: Memory allocation failure: %s.\n", expr);
66 }
67 return ptr;
68}
69
70/* A list of all modules we processed */
71
72static struct module *modules;
73
Sam Ravnborg5c3ead82006-01-28 17:19:35 +010074static struct module *find_module(char *modname)
Linus Torvalds1da177e2005-04-16 15:20:36 -070075{
76 struct module *mod;
77
78 for (mod = modules; mod; mod = mod->next)
79 if (strcmp(mod->name, modname) == 0)
80 break;
81 return mod;
82}
83
Sam Ravnborg5c3ead82006-01-28 17:19:35 +010084static struct module *new_module(char *modname)
Linus Torvalds1da177e2005-04-16 15:20:36 -070085{
86 struct module *mod;
87 char *p, *s;
Sam Ravnborg62070fa2006-03-03 16:46:04 +010088
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 mod = NOFAIL(malloc(sizeof(*mod)));
90 memset(mod, 0, sizeof(*mod));
91 p = NOFAIL(strdup(modname));
92
93 /* strip trailing .o */
94 if ((s = strrchr(p, '.')) != NULL)
95 if (strcmp(s, ".o") == 0)
96 *s = '\0';
97
98 /* add to list */
99 mod->name = p;
100 mod->next = modules;
101 modules = mod;
102
103 return mod;
104}
105
106/* A hash of all exported symbols,
107 * struct symbol is also used for lists of unresolved symbols */
108
109#define SYMBOL_HASH_SIZE 1024
110
111struct symbol {
112 struct symbol *next;
113 struct module *module;
114 unsigned int crc;
115 int crc_valid;
116 unsigned int weak:1;
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100117 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
118 unsigned int kernel:1; /* 1 if symbol is from kernel
119 * (only for external modules) **/
Sam Ravnborg8e70c452006-01-28 22:22:33 +0100120 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 char name[0];
122};
123
124static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
125
126/* This is based on the hash agorithm from gdbm, via tdb */
127static inline unsigned int tdb_hash(const char *name)
128{
129 unsigned value; /* Used to compute the hash value. */
130 unsigned i; /* Used to cycle through random values. */
131
132 /* Set the initial value from the key size. */
133 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
134 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
135
136 return (1103515243 * value + 12345);
137}
138
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100139/**
140 * Allocate a new symbols for use in the hash of exported symbols or
141 * the list of unresolved symbols per module
142 **/
143static struct symbol *alloc_symbol(const char *name, unsigned int weak,
144 struct symbol *next)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
146 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
147
148 memset(s, 0, sizeof(*s));
149 strcpy(s->name, name);
150 s->weak = weak;
151 s->next = next;
152 return s;
153}
154
155/* For the hash of exported symbols */
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100156static struct symbol *new_symbol(const char *name, struct module *module)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157{
158 unsigned int hash;
159 struct symbol *new;
160
161 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
162 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
163 new->module = module;
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100164 return new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165}
166
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100167static struct symbol *find_symbol(const char *name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168{
169 struct symbol *s;
170
171 /* For our purposes, .foo matches foo. PPC64 needs this. */
172 if (name[0] == '.')
173 name++;
174
175 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) {
176 if (strcmp(s->name, name) == 0)
177 return s;
178 }
179 return NULL;
180}
181
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100182/**
183 * Add an exported symbol - it may have already been added without a
184 * CRC, in this case just update the CRC
185 **/
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100186static struct symbol *sym_add_exported(const char *name, struct module *mod)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187{
188 struct symbol *s = find_symbol(name);
189
190 if (!s) {
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100191 s = new_symbol(name, mod);
Sam Ravnborg8e70c452006-01-28 22:22:33 +0100192 } else {
193 if (!s->preloaded) {
Sam Ravnborg7b75b132006-03-05 13:48:58 +0100194 warn("%s: '%s' exported twice. Previous export "
Sam Ravnborg8e70c452006-01-28 22:22:33 +0100195 "was in %s%s\n", mod->name, name,
196 s->module->name,
197 is_vmlinux(s->module->name) ?"":".ko");
198 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 }
Sam Ravnborg8e70c452006-01-28 22:22:33 +0100200 s->preloaded = 0;
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100201 s->vmlinux = is_vmlinux(mod->name);
202 s->kernel = 0;
203 return s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204}
205
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100206static void sym_update_crc(const char *name, struct module *mod,
207 unsigned int crc)
208{
209 struct symbol *s = find_symbol(name);
210
211 if (!s)
212 s = new_symbol(name, mod);
213 s->crc = crc;
214 s->crc_valid = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215}
216
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100217void *grab_file(const char *filename, unsigned long *size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218{
219 struct stat st;
220 void *map;
221 int fd;
222
223 fd = open(filename, O_RDONLY);
224 if (fd < 0 || fstat(fd, &st) != 0)
225 return NULL;
226
227 *size = st.st_size;
228 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
229 close(fd);
230
231 if (map == MAP_FAILED)
232 return NULL;
233 return map;
234}
235
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100236/**
237 * Return a copy of the next line in a mmap'ed file.
238 * spaces in the beginning of the line is trimmed away.
239 * Return a pointer to a static buffer.
240 **/
241char* get_next_line(unsigned long *pos, void *file, unsigned long size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
243 static char line[4096];
244 int skip = 1;
245 size_t len = 0;
246 signed char *p = (signed char *)file + *pos;
247 char *s = line;
248
249 for (; *pos < size ; (*pos)++)
250 {
251 if (skip && isspace(*p)) {
252 p++;
253 continue;
254 }
255 skip = 0;
256 if (*p != '\n' && (*pos < size)) {
257 len++;
258 *s++ = *p++;
259 if (len > 4095)
260 break; /* Too long, stop */
261 } else {
262 /* End of string */
263 *s = '\0';
264 return line;
265 }
266 }
267 /* End of buffer */
268 return NULL;
269}
270
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100271void release_file(void *file, unsigned long size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272{
273 munmap(file, size);
274}
275
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100276static void parse_elf(struct elf_info *info, const char *filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277{
278 unsigned int i;
279 Elf_Ehdr *hdr = info->hdr;
280 Elf_Shdr *sechdrs;
281 Elf_Sym *sym;
282
283 hdr = grab_file(filename, &info->size);
284 if (!hdr) {
285 perror(filename);
286 abort();
287 }
288 info->hdr = hdr;
289 if (info->size < sizeof(*hdr))
290 goto truncated;
291
292 /* Fix endianness in ELF header */
293 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
294 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
295 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
296 hdr->e_machine = TO_NATIVE(hdr->e_machine);
297 sechdrs = (void *)hdr + hdr->e_shoff;
298 info->sechdrs = sechdrs;
299
300 /* Fix endianness in section headers */
301 for (i = 0; i < hdr->e_shnum; i++) {
302 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
303 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
304 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
305 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
306 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
307 }
308 /* Find symbol table. */
309 for (i = 1; i < hdr->e_shnum; i++) {
310 const char *secstrings
311 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
312
313 if (sechdrs[i].sh_offset > info->size)
314 goto truncated;
315 if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) {
316 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
317 info->modinfo_len = sechdrs[i].sh_size;
318 }
319 if (sechdrs[i].sh_type != SHT_SYMTAB)
320 continue;
321
322 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100323 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 + sechdrs[i].sh_size;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100325 info->strtab = (void *)hdr +
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 sechdrs[sechdrs[i].sh_link].sh_offset;
327 }
328 if (!info->symtab_start) {
Sam Ravnborgcb805142006-01-28 16:57:26 +0100329 fatal("%s has no symtab?\n", filename);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 }
331 /* Fix endianness in symbols */
332 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
333 sym->st_shndx = TO_NATIVE(sym->st_shndx);
334 sym->st_name = TO_NATIVE(sym->st_name);
335 sym->st_value = TO_NATIVE(sym->st_value);
336 sym->st_size = TO_NATIVE(sym->st_size);
337 }
338 return;
339
340 truncated:
Sam Ravnborgcb805142006-01-28 16:57:26 +0100341 fatal("%s is truncated.\n", filename);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342}
343
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100344static void parse_elf_finish(struct elf_info *info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345{
346 release_file(info->hdr, info->size);
347}
348
Luke Yangf7b05e62006-03-02 18:35:31 +0800349#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
350#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100352static void handle_modversions(struct module *mod, struct elf_info *info,
353 Elf_Sym *sym, const char *symname)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354{
355 unsigned int crc;
356
357 switch (sym->st_shndx) {
358 case SHN_COMMON:
Sam Ravnborgcb805142006-01-28 16:57:26 +0100359 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 break;
361 case SHN_ABS:
362 /* CRC'd symbol */
363 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
364 crc = (unsigned int) sym->st_value;
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100365 sym_update_crc(symname + strlen(CRC_PFX), mod, crc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 }
367 break;
368 case SHN_UNDEF:
369 /* undefined symbol */
370 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
371 ELF_ST_BIND(sym->st_info) != STB_WEAK)
372 break;
373 /* ignore global offset table */
374 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
375 break;
376 /* ignore __this_module, it will be resolved shortly */
377 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
378 break;
Ben Colline8d529012005-08-19 13:44:57 -0700379/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
380#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
381/* add compatibility with older glibc */
382#ifndef STT_SPARC_REGISTER
383#define STT_SPARC_REGISTER STT_REGISTER
384#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 if (info->hdr->e_machine == EM_SPARC ||
386 info->hdr->e_machine == EM_SPARCV9) {
387 /* Ignore register directives. */
Ben Colline8d529012005-08-19 13:44:57 -0700388 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 break;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100390 if (symname[0] == '.') {
391 char *munged = strdup(symname);
392 munged[0] = '_';
393 munged[1] = toupper(munged[1]);
394 symname = munged;
395 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 }
397#endif
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
400 strlen(MODULE_SYMBOL_PREFIX)) == 0)
401 mod->unres = alloc_symbol(symname +
402 strlen(MODULE_SYMBOL_PREFIX),
403 ELF_ST_BIND(sym->st_info) == STB_WEAK,
404 mod->unres);
405 break;
406 default:
407 /* All exported symbols */
408 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
Sam Ravnborg040fcc82006-01-28 22:15:55 +0100409 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 }
411 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
412 mod->has_init = 1;
413 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
414 mod->has_cleanup = 1;
415 break;
416 }
417}
418
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100419/**
420 * Parse tag=value strings from .modinfo section
421 **/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422static char *next_string(char *string, unsigned long *secsize)
423{
424 /* Skip non-zero chars */
425 while (string[0]) {
426 string++;
427 if ((*secsize)-- <= 1)
428 return NULL;
429 }
430
431 /* Skip any zero padding. */
432 while (!string[0]) {
433 string++;
434 if ((*secsize)-- <= 1)
435 return NULL;
436 }
437 return string;
438}
439
440static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
441 const char *tag)
442{
443 char *p;
444 unsigned int taglen = strlen(tag);
445 unsigned long size = modinfo_len;
446
447 for (p = modinfo; p; p = next_string(p, &size)) {
448 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
449 return p + taglen + 1;
450 }
451 return NULL;
452}
453
Sam Ravnborg93684d32006-02-19 11:53:35 +0100454/**
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100455 * Test if string s ends in string sub
456 * return 0 if match
457 **/
458static int strrcmp(const char *s, const char *sub)
459{
460 int slen, sublen;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100461
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100462 if (!s || !sub)
463 return 1;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100464
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100465 slen = strlen(s);
466 sublen = strlen(sub);
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100467
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100468 if ((slen == 0) || (sublen == 0))
469 return 1;
470
471 if (sublen > slen)
472 return 1;
473
474 return memcmp(s + slen - sublen, sub, sublen);
475}
476
477/**
478 * Whitelist to allow certain references to pass with no warning.
479 * Pattern 1:
480 * If a module parameter is declared __initdata and permissions=0
481 * then this is legal despite the warning generated.
482 * We cannot see value of permissions here, so just ignore
483 * this pattern.
484 * The pattern is identified by:
485 * tosec = .init.data
Sam Ravnborg9209aed2006-03-05 00:16:26 +0100486 * fromsec = .data*
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100487 * atsym =__param*
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100488 *
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100489 * Pattern 2:
490 * Many drivers utilise a *_driver container with references to
491 * add, remove, probe functions etc.
492 * These functions may often be marked __init and we do not want to
493 * warn here.
494 * the pattern is identified by:
495 * tosec = .init.text | .exit.text
496 * fromsec = .data
497 * atsym = *_driver, *_ops, *_probe, *probe_one
498 **/
499static int secref_whitelist(const char *tosec, const char *fromsec,
500 const char *atsym)
501{
502 int f1 = 1, f2 = 1;
503 const char **s;
504 const char *pat2sym[] = {
505 "_driver",
506 "_ops",
507 "_probe",
508 "_probe_one",
509 NULL
510 };
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100511
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100512 /* Check for pattern 1 */
513 if (strcmp(tosec, ".init.data") != 0)
514 f1 = 0;
Sam Ravnborg9209aed2006-03-05 00:16:26 +0100515 if (strncmp(fromsec, ".data", strlen(".data")) != 0)
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100516 f1 = 0;
517 if (strncmp(atsym, "__param", strlen("__param")) != 0)
518 f1 = 0;
519
520 if (f1)
521 return f1;
522
523 /* Check for pattern 2 */
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100524 if ((strcmp(tosec, ".init.text") != 0) &&
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100525 (strcmp(tosec, ".exit.text") != 0))
526 f2 = 0;
527 if (strcmp(fromsec, ".data") != 0)
528 f2 = 0;
529
530 for (s = pat2sym; *s; s++)
531 if (strrcmp(atsym, *s) == 0)
532 f1 = 1;
533
534 return f1 && f2;
535}
536
537/**
Sam Ravnborg93684d32006-02-19 11:53:35 +0100538 * Find symbol based on relocation record info.
539 * In some cases the symbol supplied is a valid symbol so
540 * return refsym. If st_name != 0 we assume this is a valid symbol.
541 * In other cases the symbol needs to be looked up in the symbol table
542 * based on section and address.
543 * **/
544static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr,
545 Elf_Sym *relsym)
546{
547 Elf_Sym *sym;
548
549 if (relsym->st_name != 0)
550 return relsym;
551 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
552 if (sym->st_shndx != relsym->st_shndx)
553 continue;
554 if (sym->st_value == addr)
555 return sym;
556 }
557 return NULL;
558}
559
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100560/*
Sam Ravnborg43c74d12006-03-05 12:02:46 +0100561 * Find symbols before or equal addr and after addr - in the section sec.
562 * If we find two symbols with equal offset prefer one with a valid name.
563 * The ELF format may have a better way to detect what type of symbol
564 * it is, but this works for now.
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100565 **/
566static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
567 const char *sec,
568 Elf_Sym **before, Elf_Sym **after)
569{
570 Elf_Sym *sym;
571 Elf_Ehdr *hdr = elf->hdr;
572 Elf_Addr beforediff = ~0;
573 Elf_Addr afterdiff = ~0;
574 const char *secstrings = (void *)hdr +
575 elf->sechdrs[hdr->e_shstrndx].sh_offset;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100576
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100577 *before = NULL;
578 *after = NULL;
579
580 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
581 const char *symsec;
582
583 if (sym->st_shndx >= SHN_LORESERVE)
584 continue;
585 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;
586 if (strcmp(symsec, sec) != 0)
587 continue;
588 if (sym->st_value <= addr) {
589 if ((addr - sym->st_value) < beforediff) {
590 beforediff = addr - sym->st_value;
591 *before = sym;
592 }
Sam Ravnborg43c74d12006-03-05 12:02:46 +0100593 else if ((addr - sym->st_value) == beforediff) {
594 /* equal offset, valid name? */
595 const char *name = elf->strtab + sym->st_name;
596 if (name && strlen(name))
597 *before = sym;
598 }
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100599 }
600 else
601 {
602 if ((sym->st_value - addr) < afterdiff) {
603 afterdiff = sym->st_value - addr;
604 *after = sym;
605 }
Sam Ravnborg43c74d12006-03-05 12:02:46 +0100606 else if ((sym->st_value - addr) == afterdiff) {
607 /* equal offset, valid name? */
608 const char *name = elf->strtab + sym->st_name;
609 if (name && strlen(name))
610 *after = sym;
611 }
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100612 }
613 }
614}
615
616/**
617 * Print a warning about a section mismatch.
618 * Try to find symbols near it so user can find it.
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100619 * Check whitelist before warning - it may be a false positive.
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100620 **/
621static void warn_sec_mismatch(const char *modname, const char *fromsec,
622 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
623{
Sam Ravnborg93684d32006-02-19 11:53:35 +0100624 const char *refsymname = "";
625 Elf_Sym *before, *after;
626 Elf_Sym *refsym;
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100627 Elf_Ehdr *hdr = elf->hdr;
628 Elf_Shdr *sechdrs = elf->sechdrs;
629 const char *secstrings = (void *)hdr +
630 sechdrs[hdr->e_shstrndx].sh_offset;
631 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100632
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100633 find_symbols_between(elf, r.r_offset, fromsec, &before, &after);
634
Sam Ravnborg93684d32006-02-19 11:53:35 +0100635 refsym = find_elf_symbol(elf, r.r_addend, sym);
636 if (refsym && strlen(elf->strtab + refsym->st_name))
637 refsymname = elf->strtab + refsym->st_name;
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100638
639 /* check whitelist - we may ignore it */
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100640 if (before &&
Sam Ravnborg4c8fbca2006-02-26 22:18:11 +0100641 secref_whitelist(secname, fromsec, elf->strtab + before->st_name))
642 return;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100643
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100644 if (before && after) {
Sam Ravnborg93684d32006-02-19 11:53:35 +0100645 warn("%s - Section mismatch: reference to %s:%s from %s "
646 "between '%s' (at offset 0x%llx) and '%s'\n",
647 modname, secname, refsymname, fromsec,
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100648 elf->strtab + before->st_name,
Sam Ravnborg93684d32006-02-19 11:53:35 +0100649 (long long)r.r_offset,
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100650 elf->strtab + after->st_name);
651 } else if (before) {
Sam Ravnborg93684d32006-02-19 11:53:35 +0100652 warn("%s - Section mismatch: reference to %s:%s from %s "
653 "after '%s' (at offset 0x%llx)\n",
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100654 modname, secname, refsymname, fromsec,
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100655 elf->strtab + before->st_name,
Sam Ravnborg93684d32006-02-19 11:53:35 +0100656 (long long)r.r_offset);
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100657 } else if (after) {
Sam Ravnborg93684d32006-02-19 11:53:35 +0100658 warn("%s - Section mismatch: reference to %s:%s from %s "
659 "before '%s' (at offset -0x%llx)\n",
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100660 modname, secname, refsymname, fromsec,
Eric Sesterhenneaaae382006-04-11 00:54:16 +0200661 elf->strtab + after->st_name,
Sam Ravnborg93684d32006-02-19 11:53:35 +0100662 (long long)r.r_offset);
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100663 } else {
Sam Ravnborg93684d32006-02-19 11:53:35 +0100664 warn("%s - Section mismatch: reference to %s:%s from %s "
665 "(offset 0x%llx)\n",
666 modname, secname, fromsec, refsymname,
667 (long long)r.r_offset);
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100668 }
669}
670
671/**
672 * A module includes a number of sections that are discarded
673 * either when loaded or when used as built-in.
674 * For loaded modules all functions marked __init and all data
675 * marked __initdata will be discarded when the module has been intialized.
676 * Likewise for modules used built-in the sections marked __exit
677 * are discarded because __exit marked function are supposed to be called
678 * only when a moduel is unloaded which never happes for built-in modules.
679 * The check_sec_ref() function traverses all relocation records
680 * to find all references to a section that reference a section that will
681 * be discarded and warns about it.
682 **/
683static void check_sec_ref(struct module *mod, const char *modname,
684 struct elf_info *elf,
685 int section(const char*),
686 int section_ref_ok(const char *))
687{
688 int i;
689 Elf_Sym *sym;
690 Elf_Ehdr *hdr = elf->hdr;
691 Elf_Shdr *sechdrs = elf->sechdrs;
692 const char *secstrings = (void *)hdr +
693 sechdrs[hdr->e_shstrndx].sh_offset;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100694
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100695 /* Walk through all sections */
696 for (i = 0; i < hdr->e_shnum; i++) {
akpm@osdl.orgfededcd22006-02-22 03:19:54 -0800697 Elf_Rela *rela;
698 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
699 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size;
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100700 const char *name = secstrings + sechdrs[i].sh_name +
701 strlen(".rela");
702 /* We want to process only relocation sections and not .init */
703 if (section_ref_ok(name) || (sechdrs[i].sh_type != SHT_RELA))
704 continue;
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100705
706 for (rela = start; rela < stop; rela++) {
707 Elf_Rela r;
708 const char *secname;
709 r.r_offset = TO_NATIVE(rela->r_offset);
710 r.r_info = TO_NATIVE(rela->r_info);
Sam Ravnborg93684d32006-02-19 11:53:35 +0100711 r.r_addend = TO_NATIVE(rela->r_addend);
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100712 sym = elf->symtab_start + ELF_R_SYM(r.r_info);
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100713 /* Skip special sections */
714 if (sym->st_shndx >= SHN_LORESERVE)
715 continue;
716
Sam Ravnborg8ea80ca2006-02-19 09:56:18 +0100717 secname = secstrings + sechdrs[sym->st_shndx].sh_name;
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100718 if (section(secname))
719 warn_sec_mismatch(modname, name, elf, sym, r);
720 }
721 }
722}
723
724/**
725 * Functions used only during module init is marked __init and is stored in
726 * a .init.text section. Likewise data is marked __initdata and stored in
727 * a .init.data section.
728 * If this section is one of these sections return 1
729 * See include/linux/init.h for the details
730 **/
731static int init_section(const char *name)
732{
733 if (strcmp(name, ".init") == 0)
734 return 1;
735 if (strncmp(name, ".init.", strlen(".init.")) == 0)
736 return 1;
737 return 0;
738}
739
740/**
741 * Identify sections from which references to a .init section is OK.
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100742 *
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100743 * Unfortunately references to read only data that referenced .init
744 * sections had to be excluded. Almost all of these are false
745 * positives, they are created by gcc. The downside of excluding rodata
746 * is that there really are some user references from rodata to
747 * init code, e.g. drivers/video/vgacon.c:
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100748 *
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100749 * const struct consw vga_con = {
750 * con_startup: vgacon_startup,
751 *
752 * where vgacon_startup is __init. If you want to wade through the false
753 * positives, take out the check for rodata.
754 **/
755static int init_section_ref_ok(const char *name)
756{
757 const char **s;
758 /* Absolute section names */
759 const char *namelist1[] = {
760 ".init",
Sam Ravnborg9209aed2006-03-05 00:16:26 +0100761 ".opd", /* see comment [OPD] at exit_section_ref_ok() */
762 ".toc1", /* used by ppc64 */
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100763 ".stab",
764 ".rodata",
765 ".text.lock",
Sam Ravnborg9209aed2006-03-05 00:16:26 +0100766 "__bug_table", /* used by powerpc for BUG() */
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100767 ".pci_fixup_header",
768 ".pci_fixup_final",
769 ".pdr",
770 "__param",
771 NULL
772 };
773 /* Start of section names */
774 const char *namelist2[] = {
775 ".init.",
776 ".altinstructions",
777 ".eh_frame",
778 ".debug",
779 NULL
780 };
Sam Ravnborg6e101332006-02-22 21:24:50 +0100781 /* part of section name */
782 const char *namelist3 [] = {
783 ".unwind", /* sample: IA_64.unwind.init.text */
784 NULL
785 };
786
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100787 for (s = namelist1; *s; s++)
788 if (strcmp(*s, name) == 0)
789 return 1;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100790 for (s = namelist2; *s; s++)
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100791 if (strncmp(*s, name, strlen(*s)) == 0)
792 return 1;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100793 for (s = namelist3; *s; s++)
Sam Ravnborge835a392006-03-05 11:34:15 +0100794 if (strstr(name, *s) != NULL)
Sam Ravnborg6e101332006-02-22 21:24:50 +0100795 return 1;
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100796 return 0;
797}
798
799/*
800 * Functions used only during module exit is marked __exit and is stored in
801 * a .exit.text section. Likewise data is marked __exitdata and stored in
802 * a .exit.data section.
803 * If this section is one of these sections return 1
804 * See include/linux/init.h for the details
805 **/
806static int exit_section(const char *name)
807{
808 if (strcmp(name, ".exit.text") == 0)
809 return 1;
810 if (strcmp(name, ".exit.data") == 0)
811 return 1;
812 return 0;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100813
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100814}
815
816/*
817 * Identify sections from which references to a .exit section is OK.
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100818 *
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100819 * [OPD] Keith Ownes <kaos@sgi.com> commented:
820 * For our future {in}sanity, add a comment that this is the ppc .opd
821 * section, not the ia64 .opd section.
822 * ia64 .opd should not point to discarded sections.
823 **/
824static int exit_section_ref_ok(const char *name)
825{
826 const char **s;
827 /* Absolute section names */
828 const char *namelist1[] = {
829 ".exit.text",
830 ".exit.data",
831 ".init.text",
832 ".opd", /* See comment [OPD] */
Sam Ravnborg9209aed2006-03-05 00:16:26 +0100833 ".toc1", /* used by ppc64 */
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100834 ".altinstructions",
835 ".pdr",
Sam Ravnborg9209aed2006-03-05 00:16:26 +0100836 "__bug_table", /* used by powerpc for BUG() */
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100837 ".exitcall.exit",
838 ".eh_frame",
839 ".stab",
840 NULL
841 };
842 /* Start of section names */
843 const char *namelist2[] = {
844 ".debug",
845 NULL
846 };
Sam Ravnborg6e101332006-02-22 21:24:50 +0100847 /* part of section name */
848 const char *namelist3 [] = {
849 ".unwind", /* Sample: IA_64.unwind.exit.text */
850 NULL
851 };
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100852
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100853 for (s = namelist1; *s; s++)
854 if (strcmp(*s, name) == 0)
855 return 1;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100856 for (s = namelist2; *s; s++)
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100857 if (strncmp(*s, name, strlen(*s)) == 0)
858 return 1;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100859 for (s = namelist3; *s; s++)
Sam Ravnborge835a392006-03-05 11:34:15 +0100860 if (strstr(name, *s) != NULL)
Sam Ravnborg6e101332006-02-22 21:24:50 +0100861 return 1;
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100862 return 0;
863}
864
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100865static void read_symbols(char *modname)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866{
867 const char *symname;
868 char *version;
869 struct module *mod;
870 struct elf_info info = { };
871 Elf_Sym *sym;
872
873 parse_elf(&info, modname);
874
875 mod = new_module(modname);
876
877 /* When there's no vmlinux, don't print warnings about
878 * unresolved symbols (since there'll be too many ;) */
879 if (is_vmlinux(modname)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 have_vmlinux = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 mod->skip = 1;
882 }
883
884 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
885 symname = info.strtab + sym->st_name;
886
887 handle_modversions(mod, &info, sym, symname);
888 handle_moddevtable(mod, &info, sym, symname);
889 }
Sam Ravnborgb39927c2006-02-17 22:42:02 +0100890 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
891 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
894 if (version)
895 maybe_frob_rcs_version(modname, version, info.modinfo,
896 version - (char *)info.hdr);
897 if (version || (all_versions && !is_vmlinux(modname)))
898 get_src_version(modname, mod->srcversion,
899 sizeof(mod->srcversion)-1);
900
901 parse_elf_finish(&info);
902
903 /* Our trick to get versioning for struct_module - it's
904 * never passed as an argument to an exported function, so
905 * the automatic versioning doesn't pick it up, but it's really
906 * important anyhow */
907 if (modversions)
908 mod->unres = alloc_symbol("struct_module", 0, mod->unres);
909}
910
911#define SZ 500
912
913/* We first write the generated file into memory using the
914 * following helper, then compare to the file on disk and
915 * only update the later if anything changed */
916
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100917void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
918 const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919{
920 char tmp[SZ];
921 int len;
922 va_list ap;
Sam Ravnborg62070fa2006-03-03 16:46:04 +0100923
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 va_start(ap, fmt);
925 len = vsnprintf(tmp, SZ, fmt, ap);
Sam Ravnborg7670f022006-03-16 23:04:08 -0800926 buf_write(buf, tmp, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 va_end(ap);
928}
929
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100930void buf_write(struct buffer *buf, const char *s, int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931{
932 if (buf->size - buf->pos < len) {
Sam Ravnborg7670f022006-03-16 23:04:08 -0800933 buf->size += len + SZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 buf->p = realloc(buf->p, buf->size);
935 }
936 strncpy(buf->p + buf->pos, s, len);
937 buf->pos += len;
938}
939
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100940/**
941 * Header for the generated file
942 **/
943static void add_header(struct buffer *b, struct module *mod)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944{
945 buf_printf(b, "#include <linux/module.h>\n");
946 buf_printf(b, "#include <linux/vermagic.h>\n");
947 buf_printf(b, "#include <linux/compiler.h>\n");
948 buf_printf(b, "\n");
949 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
950 buf_printf(b, "\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951 buf_printf(b, "struct module __this_module\n");
952 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
Ustyugov Romanf83b5e32005-09-23 08:42:11 +0400953 buf_printf(b, " .name = KBUILD_MODNAME,\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 if (mod->has_init)
955 buf_printf(b, " .init = init_module,\n");
956 if (mod->has_cleanup)
957 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
958 " .exit = cleanup_module,\n"
959 "#endif\n");
960 buf_printf(b, "};\n");
961}
962
Sam Ravnborg5c3ead82006-01-28 17:19:35 +0100963/**
964 * Record CRCs for unresolved symbols
965 **/
966static void add_versions(struct buffer *b, struct module *mod)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967{
968 struct symbol *s, *exp;
969
970 for (s = mod->unres; s; s = s->next) {
971 exp = find_symbol(s->name);
972 if (!exp || exp->module == mod) {
973 if (have_vmlinux && !s->weak)
Sam Ravnborgcb805142006-01-28 16:57:26 +0100974 warn("\"%s\" [%s.ko] undefined!\n",
975 s->name, mod->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 continue;
977 }
978 s->module = exp->module;
979 s->crc_valid = exp->crc_valid;
980 s->crc = exp->crc;
981 }
982
983 if (!modversions)
984 return;
985
986 buf_printf(b, "\n");
987 buf_printf(b, "static const struct modversion_info ____versions[]\n");
988 buf_printf(b, "__attribute_used__\n");
989 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
990
991 for (s = mod->unres; s; s = s->next) {
992 if (!s->module) {
993 continue;
994 }
995 if (!s->crc_valid) {
Sam Ravnborgcb805142006-01-28 16:57:26 +0100996 warn("\"%s\" [%s.ko] has no CRC!\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 s->name, mod->name);
998 continue;
999 }
1000 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1001 }
1002
1003 buf_printf(b, "};\n");
1004}
1005
Sam Ravnborg5c3ead82006-01-28 17:19:35 +01001006static void add_depends(struct buffer *b, struct module *mod,
1007 struct module *modules)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008{
1009 struct symbol *s;
1010 struct module *m;
1011 int first = 1;
1012
1013 for (m = modules; m; m = m->next) {
1014 m->seen = is_vmlinux(m->name);
1015 }
1016
1017 buf_printf(b, "\n");
1018 buf_printf(b, "static const char __module_depends[]\n");
1019 buf_printf(b, "__attribute_used__\n");
1020 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1021 buf_printf(b, "\"depends=");
1022 for (s = mod->unres; s; s = s->next) {
1023 if (!s->module)
1024 continue;
1025
1026 if (s->module->seen)
1027 continue;
1028
1029 s->module->seen = 1;
1030 buf_printf(b, "%s%s", first ? "" : ",",
1031 strrchr(s->module->name, '/') + 1);
1032 first = 0;
1033 }
1034 buf_printf(b, "\";\n");
1035}
1036
Sam Ravnborg5c3ead82006-01-28 17:19:35 +01001037static void add_srcversion(struct buffer *b, struct module *mod)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038{
1039 if (mod->srcversion[0]) {
1040 buf_printf(b, "\n");
1041 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1042 mod->srcversion);
1043 }
1044}
1045
Sam Ravnborg5c3ead82006-01-28 17:19:35 +01001046static void write_if_changed(struct buffer *b, const char *fname)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047{
1048 char *tmp;
1049 FILE *file;
1050 struct stat st;
1051
1052 file = fopen(fname, "r");
1053 if (!file)
1054 goto write;
1055
1056 if (fstat(fileno(file), &st) < 0)
1057 goto close_write;
1058
1059 if (st.st_size != b->pos)
1060 goto close_write;
1061
1062 tmp = NOFAIL(malloc(b->pos));
1063 if (fread(tmp, 1, b->pos, file) != b->pos)
1064 goto free_write;
1065
1066 if (memcmp(tmp, b->p, b->pos) != 0)
1067 goto free_write;
1068
1069 free(tmp);
1070 fclose(file);
1071 return;
1072
1073 free_write:
1074 free(tmp);
1075 close_write:
1076 fclose(file);
1077 write:
1078 file = fopen(fname, "w");
1079 if (!file) {
1080 perror(fname);
1081 exit(1);
1082 }
1083 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1084 perror(fname);
1085 exit(1);
1086 }
1087 fclose(file);
1088}
1089
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001090static void read_dump(const char *fname, unsigned int kernel)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091{
1092 unsigned long size, pos = 0;
1093 void *file = grab_file(fname, &size);
1094 char *line;
1095
1096 if (!file)
1097 /* No symbol versions, silently ignore */
1098 return;
1099
1100 while ((line = get_next_line(&pos, file, size))) {
1101 char *symname, *modname, *d;
1102 unsigned int crc;
1103 struct module *mod;
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001104 struct symbol *s;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105
1106 if (!(symname = strchr(line, '\t')))
1107 goto fail;
1108 *symname++ = '\0';
1109 if (!(modname = strchr(symname, '\t')))
1110 goto fail;
1111 *modname++ = '\0';
1112 if (strchr(modname, '\t'))
1113 goto fail;
1114 crc = strtoul(line, &d, 16);
1115 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1116 goto fail;
1117
1118 if (!(mod = find_module(modname))) {
1119 if (is_vmlinux(modname)) {
1120 have_vmlinux = 1;
1121 }
1122 mod = new_module(NOFAIL(strdup(modname)));
1123 mod->skip = 1;
1124 }
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001125 s = sym_add_exported(symname, mod);
Sam Ravnborg8e70c452006-01-28 22:22:33 +01001126 s->kernel = kernel;
1127 s->preloaded = 1;
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001128 sym_update_crc(symname, mod, crc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129 }
1130 return;
1131fail:
1132 fatal("parse error in symbol dump file\n");
1133}
1134
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001135/* For normal builds always dump all symbols.
1136 * For external modules only dump symbols
1137 * that are not read from kernel Module.symvers.
1138 **/
1139static int dump_sym(struct symbol *sym)
1140{
1141 if (!external_module)
1142 return 1;
1143 if (sym->vmlinux || sym->kernel)
1144 return 0;
1145 return 1;
1146}
Sam Ravnborg62070fa2006-03-03 16:46:04 +01001147
Sam Ravnborg5c3ead82006-01-28 17:19:35 +01001148static void write_dump(const char *fname)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149{
1150 struct buffer buf = { };
1151 struct symbol *symbol;
1152 int n;
1153
1154 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1155 symbol = symbolhash[n];
1156 while (symbol) {
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001157 if (dump_sym(symbol))
1158 buf_printf(&buf, "0x%08x\t%s\t%s\n",
Sam Ravnborg62070fa2006-03-03 16:46:04 +01001159 symbol->crc, symbol->name,
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001160 symbol->module->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 symbol = symbol->next;
1162 }
1163 }
1164 write_if_changed(&buf, fname);
1165}
1166
Sam Ravnborg5c3ead82006-01-28 17:19:35 +01001167int main(int argc, char **argv)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168{
1169 struct module *mod;
1170 struct buffer buf = { };
1171 char fname[SZ];
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001172 char *kernel_read = NULL, *module_read = NULL;
1173 char *dump_write = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 int opt;
1175
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001176 while ((opt = getopt(argc, argv, "i:I:mo:a")) != -1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 switch(opt) {
1178 case 'i':
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001179 kernel_read = optarg;
1180 break;
1181 case 'I':
1182 module_read = optarg;
1183 external_module = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184 break;
1185 case 'm':
1186 modversions = 1;
1187 break;
1188 case 'o':
1189 dump_write = optarg;
1190 break;
1191 case 'a':
1192 all_versions = 1;
1193 break;
1194 default:
1195 exit(1);
1196 }
1197 }
1198
Sam Ravnborg040fcc82006-01-28 22:15:55 +01001199 if (kernel_read)
1200 read_dump(kernel_read, 1);
1201 if (module_read)
1202 read_dump(module_read, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203
1204 while (optind < argc) {
1205 read_symbols(argv[optind++]);
1206 }
1207
1208 for (mod = modules; mod; mod = mod->next) {
1209 if (mod->skip)
1210 continue;
1211
1212 buf.pos = 0;
1213
1214 add_header(&buf, mod);
1215 add_versions(&buf, mod);
1216 add_depends(&buf, mod, modules);
1217 add_moddevtable(&buf, mod);
1218 add_srcversion(&buf, mod);
1219
1220 sprintf(fname, "%s.mod.c", mod->name);
1221 write_if_changed(&buf, fname);
1222 }
1223
1224 if (dump_write)
1225 write_dump(dump_write);
1226
1227 return 0;
1228}