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