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Commit | Line | Data |
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1da177e4 LT |
1 | /* Postprocess module symbol versions |
2 | * | |
3 | * Copyright 2003 Kai Germaschewski | |
4 | * Copyright 2002-2004 Rusty Russell, IBM Corporation | |
382168f4 | 5 | * Copyright 2006 Sam Ravnborg |
1da177e4 LT |
6 | * Based in part on module-init-tools/depmod.c,file2alias |
7 | * | |
8 | * This software may be used and distributed according to the terms | |
9 | * of the GNU General Public License, incorporated herein by reference. | |
10 | * | |
11 | * Usage: modpost vmlinux module1.o module2.o ... | |
12 | */ | |
13 | ||
14 | #include <ctype.h> | |
15 | #include "modpost.h" | |
b817f6fe | 16 | #include "../../include/linux/license.h" |
1da177e4 LT |
17 | |
18 | /* Are we using CONFIG_MODVERSIONS? */ | |
19 | int modversions = 0; | |
20 | /* Warn about undefined symbols? (do so if we have vmlinux) */ | |
21 | int have_vmlinux = 0; | |
22 | /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ | |
23 | static int all_versions = 0; | |
040fcc81 SR |
24 | /* If we are modposting external module set to 1 */ |
25 | static int external_module = 0; | |
c53ddacd KK |
26 | /* Only warn about unresolved symbols */ |
27 | static int warn_unresolved = 0; | |
bd5cbced | 28 | /* How a symbol is exported */ |
c96fca21 SR |
29 | enum export { |
30 | export_plain, export_unused, export_gpl, | |
31 | export_unused_gpl, export_gpl_future, export_unknown | |
32 | }; | |
1da177e4 | 33 | |
5c3ead8c | 34 | void fatal(const char *fmt, ...) |
1da177e4 LT |
35 | { |
36 | va_list arglist; | |
37 | ||
38 | fprintf(stderr, "FATAL: "); | |
39 | ||
40 | va_start(arglist, fmt); | |
41 | vfprintf(stderr, fmt, arglist); | |
42 | va_end(arglist); | |
43 | ||
44 | exit(1); | |
45 | } | |
46 | ||
5c3ead8c | 47 | void warn(const char *fmt, ...) |
1da177e4 LT |
48 | { |
49 | va_list arglist; | |
50 | ||
51 | fprintf(stderr, "WARNING: "); | |
52 | ||
53 | va_start(arglist, fmt); | |
54 | vfprintf(stderr, fmt, arglist); | |
55 | va_end(arglist); | |
56 | } | |
57 | ||
040fcc81 SR |
58 | static int is_vmlinux(const char *modname) |
59 | { | |
60 | const char *myname; | |
61 | ||
62 | if ((myname = strrchr(modname, '/'))) | |
63 | myname++; | |
64 | else | |
65 | myname = modname; | |
66 | ||
67 | return strcmp(myname, "vmlinux") == 0; | |
68 | } | |
69 | ||
1da177e4 LT |
70 | void *do_nofail(void *ptr, const char *expr) |
71 | { | |
72 | if (!ptr) { | |
73 | fatal("modpost: Memory allocation failure: %s.\n", expr); | |
74 | } | |
75 | return ptr; | |
76 | } | |
77 | ||
78 | /* A list of all modules we processed */ | |
79 | ||
80 | static struct module *modules; | |
81 | ||
5c3ead8c | 82 | static struct module *find_module(char *modname) |
1da177e4 LT |
83 | { |
84 | struct module *mod; | |
85 | ||
86 | for (mod = modules; mod; mod = mod->next) | |
87 | if (strcmp(mod->name, modname) == 0) | |
88 | break; | |
89 | return mod; | |
90 | } | |
91 | ||
5c3ead8c | 92 | static struct module *new_module(char *modname) |
1da177e4 LT |
93 | { |
94 | struct module *mod; | |
95 | char *p, *s; | |
62070fa4 | 96 | |
1da177e4 LT |
97 | mod = NOFAIL(malloc(sizeof(*mod))); |
98 | memset(mod, 0, sizeof(*mod)); | |
99 | p = NOFAIL(strdup(modname)); | |
100 | ||
101 | /* strip trailing .o */ | |
102 | if ((s = strrchr(p, '.')) != NULL) | |
103 | if (strcmp(s, ".o") == 0) | |
104 | *s = '\0'; | |
105 | ||
106 | /* add to list */ | |
107 | mod->name = p; | |
b817f6fe | 108 | mod->gpl_compatible = -1; |
1da177e4 LT |
109 | mod->next = modules; |
110 | modules = mod; | |
111 | ||
112 | return mod; | |
113 | } | |
114 | ||
115 | /* A hash of all exported symbols, | |
116 | * struct symbol is also used for lists of unresolved symbols */ | |
117 | ||
118 | #define SYMBOL_HASH_SIZE 1024 | |
119 | ||
120 | struct symbol { | |
121 | struct symbol *next; | |
122 | struct module *module; | |
123 | unsigned int crc; | |
124 | int crc_valid; | |
125 | unsigned int weak:1; | |
040fcc81 SR |
126 | unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ |
127 | unsigned int kernel:1; /* 1 if symbol is from kernel | |
128 | * (only for external modules) **/ | |
8e70c458 | 129 | unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ |
bd5cbced | 130 | enum export export; /* Type of export */ |
1da177e4 LT |
131 | char name[0]; |
132 | }; | |
133 | ||
134 | static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; | |
135 | ||
136 | /* This is based on the hash agorithm from gdbm, via tdb */ | |
137 | static inline unsigned int tdb_hash(const char *name) | |
138 | { | |
139 | unsigned value; /* Used to compute the hash value. */ | |
140 | unsigned i; /* Used to cycle through random values. */ | |
141 | ||
142 | /* Set the initial value from the key size. */ | |
143 | for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) | |
144 | value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); | |
145 | ||
146 | return (1103515243 * value + 12345); | |
147 | } | |
148 | ||
5c3ead8c SR |
149 | /** |
150 | * Allocate a new symbols for use in the hash of exported symbols or | |
151 | * the list of unresolved symbols per module | |
152 | **/ | |
153 | static struct symbol *alloc_symbol(const char *name, unsigned int weak, | |
154 | struct symbol *next) | |
1da177e4 LT |
155 | { |
156 | struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); | |
157 | ||
158 | memset(s, 0, sizeof(*s)); | |
159 | strcpy(s->name, name); | |
160 | s->weak = weak; | |
161 | s->next = next; | |
162 | return s; | |
163 | } | |
164 | ||
165 | /* For the hash of exported symbols */ | |
bd5cbced RP |
166 | static struct symbol *new_symbol(const char *name, struct module *module, |
167 | enum export export) | |
1da177e4 LT |
168 | { |
169 | unsigned int hash; | |
170 | struct symbol *new; | |
171 | ||
172 | hash = tdb_hash(name) % SYMBOL_HASH_SIZE; | |
173 | new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); | |
174 | new->module = module; | |
bd5cbced | 175 | new->export = export; |
040fcc81 | 176 | return new; |
1da177e4 LT |
177 | } |
178 | ||
5c3ead8c | 179 | static struct symbol *find_symbol(const char *name) |
1da177e4 LT |
180 | { |
181 | struct symbol *s; | |
182 | ||
183 | /* For our purposes, .foo matches foo. PPC64 needs this. */ | |
184 | if (name[0] == '.') | |
185 | name++; | |
186 | ||
187 | for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { | |
188 | if (strcmp(s->name, name) == 0) | |
189 | return s; | |
190 | } | |
191 | return NULL; | |
192 | } | |
193 | ||
bd5cbced RP |
194 | static struct { |
195 | const char *str; | |
196 | enum export export; | |
197 | } export_list[] = { | |
198 | { .str = "EXPORT_SYMBOL", .export = export_plain }, | |
c96fca21 | 199 | { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, |
bd5cbced | 200 | { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, |
c96fca21 | 201 | { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, |
bd5cbced RP |
202 | { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, |
203 | { .str = "(unknown)", .export = export_unknown }, | |
204 | }; | |
205 | ||
206 | ||
207 | static const char *export_str(enum export ex) | |
208 | { | |
209 | return export_list[ex].str; | |
210 | } | |
211 | ||
212 | static enum export export_no(const char * s) | |
213 | { | |
214 | int i; | |
534b89a9 SR |
215 | if (!s) |
216 | return export_unknown; | |
bd5cbced RP |
217 | for (i = 0; export_list[i].export != export_unknown; i++) { |
218 | if (strcmp(export_list[i].str, s) == 0) | |
219 | return export_list[i].export; | |
220 | } | |
221 | return export_unknown; | |
222 | } | |
223 | ||
224 | static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) | |
225 | { | |
226 | if (sec == elf->export_sec) | |
227 | return export_plain; | |
c96fca21 SR |
228 | else if (sec == elf->export_unused_sec) |
229 | return export_unused; | |
bd5cbced RP |
230 | else if (sec == elf->export_gpl_sec) |
231 | return export_gpl; | |
c96fca21 SR |
232 | else if (sec == elf->export_unused_gpl_sec) |
233 | return export_unused_gpl; | |
bd5cbced RP |
234 | else if (sec == elf->export_gpl_future_sec) |
235 | return export_gpl_future; | |
236 | else | |
237 | return export_unknown; | |
238 | } | |
239 | ||
5c3ead8c SR |
240 | /** |
241 | * Add an exported symbol - it may have already been added without a | |
242 | * CRC, in this case just update the CRC | |
243 | **/ | |
bd5cbced RP |
244 | static struct symbol *sym_add_exported(const char *name, struct module *mod, |
245 | enum export export) | |
1da177e4 LT |
246 | { |
247 | struct symbol *s = find_symbol(name); | |
248 | ||
249 | if (!s) { | |
bd5cbced | 250 | s = new_symbol(name, mod, export); |
8e70c458 SR |
251 | } else { |
252 | if (!s->preloaded) { | |
7b75b13c | 253 | warn("%s: '%s' exported twice. Previous export " |
8e70c458 SR |
254 | "was in %s%s\n", mod->name, name, |
255 | s->module->name, | |
256 | is_vmlinux(s->module->name) ?"":".ko"); | |
257 | } | |
1da177e4 | 258 | } |
8e70c458 | 259 | s->preloaded = 0; |
040fcc81 SR |
260 | s->vmlinux = is_vmlinux(mod->name); |
261 | s->kernel = 0; | |
bd5cbced | 262 | s->export = export; |
040fcc81 SR |
263 | return s; |
264 | } | |
265 | ||
266 | static void sym_update_crc(const char *name, struct module *mod, | |
bd5cbced | 267 | unsigned int crc, enum export export) |
040fcc81 SR |
268 | { |
269 | struct symbol *s = find_symbol(name); | |
270 | ||
271 | if (!s) | |
bd5cbced | 272 | s = new_symbol(name, mod, export); |
040fcc81 SR |
273 | s->crc = crc; |
274 | s->crc_valid = 1; | |
1da177e4 LT |
275 | } |
276 | ||
5c3ead8c | 277 | void *grab_file(const char *filename, unsigned long *size) |
1da177e4 LT |
278 | { |
279 | struct stat st; | |
280 | void *map; | |
281 | int fd; | |
282 | ||
283 | fd = open(filename, O_RDONLY); | |
284 | if (fd < 0 || fstat(fd, &st) != 0) | |
285 | return NULL; | |
286 | ||
287 | *size = st.st_size; | |
288 | map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); | |
289 | close(fd); | |
290 | ||
291 | if (map == MAP_FAILED) | |
292 | return NULL; | |
293 | return map; | |
294 | } | |
295 | ||
5c3ead8c SR |
296 | /** |
297 | * Return a copy of the next line in a mmap'ed file. | |
298 | * spaces in the beginning of the line is trimmed away. | |
299 | * Return a pointer to a static buffer. | |
300 | **/ | |
301 | char* get_next_line(unsigned long *pos, void *file, unsigned long size) | |
1da177e4 LT |
302 | { |
303 | static char line[4096]; | |
304 | int skip = 1; | |
305 | size_t len = 0; | |
306 | signed char *p = (signed char *)file + *pos; | |
307 | char *s = line; | |
308 | ||
309 | for (; *pos < size ; (*pos)++) | |
310 | { | |
311 | if (skip && isspace(*p)) { | |
312 | p++; | |
313 | continue; | |
314 | } | |
315 | skip = 0; | |
316 | if (*p != '\n' && (*pos < size)) { | |
317 | len++; | |
318 | *s++ = *p++; | |
319 | if (len > 4095) | |
320 | break; /* Too long, stop */ | |
321 | } else { | |
322 | /* End of string */ | |
323 | *s = '\0'; | |
324 | return line; | |
325 | } | |
326 | } | |
327 | /* End of buffer */ | |
328 | return NULL; | |
329 | } | |
330 | ||
5c3ead8c | 331 | void release_file(void *file, unsigned long size) |
1da177e4 LT |
332 | { |
333 | munmap(file, size); | |
334 | } | |
335 | ||
85bd2fdd | 336 | static int parse_elf(struct elf_info *info, const char *filename) |
1da177e4 LT |
337 | { |
338 | unsigned int i; | |
85bd2fdd | 339 | Elf_Ehdr *hdr; |
1da177e4 LT |
340 | Elf_Shdr *sechdrs; |
341 | Elf_Sym *sym; | |
342 | ||
343 | hdr = grab_file(filename, &info->size); | |
344 | if (!hdr) { | |
345 | perror(filename); | |
6803dc0e | 346 | exit(1); |
1da177e4 LT |
347 | } |
348 | info->hdr = hdr; | |
85bd2fdd SR |
349 | if (info->size < sizeof(*hdr)) { |
350 | /* file too small, assume this is an empty .o file */ | |
351 | return 0; | |
352 | } | |
353 | /* Is this a valid ELF file? */ | |
354 | if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || | |
355 | (hdr->e_ident[EI_MAG1] != ELFMAG1) || | |
356 | (hdr->e_ident[EI_MAG2] != ELFMAG2) || | |
357 | (hdr->e_ident[EI_MAG3] != ELFMAG3)) { | |
358 | /* Not an ELF file - silently ignore it */ | |
359 | return 0; | |
360 | } | |
1da177e4 LT |
361 | /* Fix endianness in ELF header */ |
362 | hdr->e_shoff = TO_NATIVE(hdr->e_shoff); | |
363 | hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); | |
364 | hdr->e_shnum = TO_NATIVE(hdr->e_shnum); | |
365 | hdr->e_machine = TO_NATIVE(hdr->e_machine); | |
366 | sechdrs = (void *)hdr + hdr->e_shoff; | |
367 | info->sechdrs = sechdrs; | |
368 | ||
369 | /* Fix endianness in section headers */ | |
370 | for (i = 0; i < hdr->e_shnum; i++) { | |
371 | sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); | |
372 | sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); | |
373 | sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); | |
374 | sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); | |
375 | sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); | |
376 | } | |
377 | /* Find symbol table. */ | |
378 | for (i = 1; i < hdr->e_shnum; i++) { | |
379 | const char *secstrings | |
380 | = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
bd5cbced | 381 | const char *secname; |
1da177e4 | 382 | |
85bd2fdd SR |
383 | if (sechdrs[i].sh_offset > info->size) { |
384 | fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr)); | |
385 | return 0; | |
386 | } | |
bd5cbced RP |
387 | secname = secstrings + sechdrs[i].sh_name; |
388 | if (strcmp(secname, ".modinfo") == 0) { | |
1da177e4 LT |
389 | info->modinfo = (void *)hdr + sechdrs[i].sh_offset; |
390 | info->modinfo_len = sechdrs[i].sh_size; | |
bd5cbced RP |
391 | } else if (strcmp(secname, "__ksymtab") == 0) |
392 | info->export_sec = i; | |
c96fca21 SR |
393 | else if (strcmp(secname, "__ksymtab_unused") == 0) |
394 | info->export_unused_sec = i; | |
bd5cbced RP |
395 | else if (strcmp(secname, "__ksymtab_gpl") == 0) |
396 | info->export_gpl_sec = i; | |
c96fca21 SR |
397 | else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) |
398 | info->export_unused_gpl_sec = i; | |
bd5cbced RP |
399 | else if (strcmp(secname, "__ksymtab_gpl_future") == 0) |
400 | info->export_gpl_future_sec = i; | |
401 | ||
1da177e4 LT |
402 | if (sechdrs[i].sh_type != SHT_SYMTAB) |
403 | continue; | |
404 | ||
405 | info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; | |
62070fa4 | 406 | info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset |
1da177e4 | 407 | + sechdrs[i].sh_size; |
62070fa4 | 408 | info->strtab = (void *)hdr + |
1da177e4 LT |
409 | sechdrs[sechdrs[i].sh_link].sh_offset; |
410 | } | |
411 | if (!info->symtab_start) { | |
cb80514d | 412 | fatal("%s has no symtab?\n", filename); |
1da177e4 LT |
413 | } |
414 | /* Fix endianness in symbols */ | |
415 | for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { | |
416 | sym->st_shndx = TO_NATIVE(sym->st_shndx); | |
417 | sym->st_name = TO_NATIVE(sym->st_name); | |
418 | sym->st_value = TO_NATIVE(sym->st_value); | |
419 | sym->st_size = TO_NATIVE(sym->st_size); | |
420 | } | |
85bd2fdd | 421 | return 1; |
1da177e4 LT |
422 | } |
423 | ||
5c3ead8c | 424 | static void parse_elf_finish(struct elf_info *info) |
1da177e4 LT |
425 | { |
426 | release_file(info->hdr, info->size); | |
427 | } | |
428 | ||
f7b05e64 LY |
429 | #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" |
430 | #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" | |
1da177e4 | 431 | |
5c3ead8c SR |
432 | static void handle_modversions(struct module *mod, struct elf_info *info, |
433 | Elf_Sym *sym, const char *symname) | |
1da177e4 LT |
434 | { |
435 | unsigned int crc; | |
bd5cbced | 436 | enum export export = export_from_sec(info, sym->st_shndx); |
1da177e4 LT |
437 | |
438 | switch (sym->st_shndx) { | |
439 | case SHN_COMMON: | |
cb80514d | 440 | warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); |
1da177e4 LT |
441 | break; |
442 | case SHN_ABS: | |
443 | /* CRC'd symbol */ | |
444 | if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { | |
445 | crc = (unsigned int) sym->st_value; | |
bd5cbced RP |
446 | sym_update_crc(symname + strlen(CRC_PFX), mod, crc, |
447 | export); | |
1da177e4 LT |
448 | } |
449 | break; | |
450 | case SHN_UNDEF: | |
451 | /* undefined symbol */ | |
452 | if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && | |
453 | ELF_ST_BIND(sym->st_info) != STB_WEAK) | |
454 | break; | |
455 | /* ignore global offset table */ | |
456 | if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) | |
457 | break; | |
458 | /* ignore __this_module, it will be resolved shortly */ | |
459 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) | |
460 | break; | |
8d529014 BC |
461 | /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ |
462 | #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) | |
463 | /* add compatibility with older glibc */ | |
464 | #ifndef STT_SPARC_REGISTER | |
465 | #define STT_SPARC_REGISTER STT_REGISTER | |
466 | #endif | |
1da177e4 LT |
467 | if (info->hdr->e_machine == EM_SPARC || |
468 | info->hdr->e_machine == EM_SPARCV9) { | |
469 | /* Ignore register directives. */ | |
8d529014 | 470 | if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) |
1da177e4 | 471 | break; |
62070fa4 SR |
472 | if (symname[0] == '.') { |
473 | char *munged = strdup(symname); | |
474 | munged[0] = '_'; | |
475 | munged[1] = toupper(munged[1]); | |
476 | symname = munged; | |
477 | } | |
1da177e4 LT |
478 | } |
479 | #endif | |
62070fa4 | 480 | |
1da177e4 LT |
481 | if (memcmp(symname, MODULE_SYMBOL_PREFIX, |
482 | strlen(MODULE_SYMBOL_PREFIX)) == 0) | |
483 | mod->unres = alloc_symbol(symname + | |
484 | strlen(MODULE_SYMBOL_PREFIX), | |
485 | ELF_ST_BIND(sym->st_info) == STB_WEAK, | |
486 | mod->unres); | |
487 | break; | |
488 | default: | |
489 | /* All exported symbols */ | |
490 | if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { | |
bd5cbced RP |
491 | sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, |
492 | export); | |
1da177e4 LT |
493 | } |
494 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) | |
495 | mod->has_init = 1; | |
496 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) | |
497 | mod->has_cleanup = 1; | |
498 | break; | |
499 | } | |
500 | } | |
501 | ||
5c3ead8c SR |
502 | /** |
503 | * Parse tag=value strings from .modinfo section | |
504 | **/ | |
1da177e4 LT |
505 | static char *next_string(char *string, unsigned long *secsize) |
506 | { | |
507 | /* Skip non-zero chars */ | |
508 | while (string[0]) { | |
509 | string++; | |
510 | if ((*secsize)-- <= 1) | |
511 | return NULL; | |
512 | } | |
513 | ||
514 | /* Skip any zero padding. */ | |
515 | while (!string[0]) { | |
516 | string++; | |
517 | if ((*secsize)-- <= 1) | |
518 | return NULL; | |
519 | } | |
520 | return string; | |
521 | } | |
522 | ||
b817f6fe SR |
523 | static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, |
524 | const char *tag, char *info) | |
1da177e4 LT |
525 | { |
526 | char *p; | |
527 | unsigned int taglen = strlen(tag); | |
528 | unsigned long size = modinfo_len; | |
529 | ||
b817f6fe SR |
530 | if (info) { |
531 | size -= info - (char *)modinfo; | |
532 | modinfo = next_string(info, &size); | |
533 | } | |
534 | ||
1da177e4 LT |
535 | for (p = modinfo; p; p = next_string(p, &size)) { |
536 | if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') | |
537 | return p + taglen + 1; | |
538 | } | |
539 | return NULL; | |
540 | } | |
541 | ||
b817f6fe SR |
542 | static char *get_modinfo(void *modinfo, unsigned long modinfo_len, |
543 | const char *tag) | |
544 | ||
545 | { | |
546 | return get_next_modinfo(modinfo, modinfo_len, tag, NULL); | |
547 | } | |
548 | ||
4c8fbca5 SR |
549 | /** |
550 | * Test if string s ends in string sub | |
551 | * return 0 if match | |
552 | **/ | |
553 | static int strrcmp(const char *s, const char *sub) | |
554 | { | |
555 | int slen, sublen; | |
62070fa4 | 556 | |
4c8fbca5 SR |
557 | if (!s || !sub) |
558 | return 1; | |
62070fa4 | 559 | |
4c8fbca5 SR |
560 | slen = strlen(s); |
561 | sublen = strlen(sub); | |
62070fa4 | 562 | |
4c8fbca5 SR |
563 | if ((slen == 0) || (sublen == 0)) |
564 | return 1; | |
565 | ||
566 | if (sublen > slen) | |
567 | return 1; | |
568 | ||
569 | return memcmp(s + slen - sublen, sub, sublen); | |
570 | } | |
571 | ||
572 | /** | |
573 | * Whitelist to allow certain references to pass with no warning. | |
574 | * Pattern 1: | |
575 | * If a module parameter is declared __initdata and permissions=0 | |
576 | * then this is legal despite the warning generated. | |
577 | * We cannot see value of permissions here, so just ignore | |
578 | * this pattern. | |
579 | * The pattern is identified by: | |
580 | * tosec = .init.data | |
9209aed0 | 581 | * fromsec = .data* |
4c8fbca5 | 582 | * atsym =__param* |
62070fa4 | 583 | * |
4c8fbca5 | 584 | * Pattern 2: |
72ee59b5 | 585 | * Many drivers utilise a *driver container with references to |
4c8fbca5 SR |
586 | * add, remove, probe functions etc. |
587 | * These functions may often be marked __init and we do not want to | |
588 | * warn here. | |
589 | * the pattern is identified by: | |
5ecdd0f6 | 590 | * tosec = .init.text | .exit.text | .init.data |
4c8fbca5 | 591 | * fromsec = .data |
aae5f662 | 592 | * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console |
ee6a8545 VG |
593 | * |
594 | * Pattern 3: | |
595 | * Some symbols belong to init section but still it is ok to reference | |
596 | * these from non-init sections as these symbols don't have any memory | |
597 | * allocated for them and symbol address and value are same. So even | |
598 | * if init section is freed, its ok to reference those symbols. | |
599 | * For ex. symbols marking the init section boundaries. | |
600 | * This pattern is identified by | |
601 | * refsymname = __init_begin, _sinittext, _einittext | |
aae5f662 SR |
602 | * Pattern 4: |
603 | * During the early init phase we have references from .init.text to | |
604 | * .text we have an intended section mismatch - do not warn about it. | |
605 | * See kernel_init() in init/main.c | |
606 | * tosec = .init.text | |
607 | * fromsec = .text | |
608 | * atsym = kernel_init | |
609 | * Some symbols belong to init section but still it is ok to reference | |
4c8fbca5 | 610 | **/ |
9e157a5a | 611 | static int secref_whitelist(const char *modname, const char *tosec, |
ee6a8545 VG |
612 | const char *fromsec, const char *atsym, |
613 | const char *refsymname) | |
4c8fbca5 SR |
614 | { |
615 | int f1 = 1, f2 = 1; | |
616 | const char **s; | |
617 | const char *pat2sym[] = { | |
72ee59b5 | 618 | "driver", |
5ecdd0f6 SR |
619 | "_template", /* scsi uses *_template a lot */ |
620 | "_sht", /* scsi also used *_sht to some extent */ | |
4c8fbca5 SR |
621 | "_ops", |
622 | "_probe", | |
623 | "_probe_one", | |
118c0ace | 624 | "_console", |
4c8fbca5 SR |
625 | NULL |
626 | }; | |
62070fa4 | 627 | |
ee6a8545 VG |
628 | const char *pat3refsym[] = { |
629 | "__init_begin", | |
630 | "_sinittext", | |
631 | "_einittext", | |
632 | NULL | |
633 | }; | |
634 | ||
4c8fbca5 SR |
635 | /* Check for pattern 1 */ |
636 | if (strcmp(tosec, ".init.data") != 0) | |
637 | f1 = 0; | |
9209aed0 | 638 | if (strncmp(fromsec, ".data", strlen(".data")) != 0) |
4c8fbca5 SR |
639 | f1 = 0; |
640 | if (strncmp(atsym, "__param", strlen("__param")) != 0) | |
641 | f1 = 0; | |
642 | ||
643 | if (f1) | |
644 | return f1; | |
645 | ||
646 | /* Check for pattern 2 */ | |
62070fa4 | 647 | if ((strcmp(tosec, ".init.text") != 0) && |
5ecdd0f6 SR |
648 | (strcmp(tosec, ".exit.text") != 0) && |
649 | (strcmp(tosec, ".init.data") != 0)) | |
4c8fbca5 SR |
650 | f2 = 0; |
651 | if (strcmp(fromsec, ".data") != 0) | |
652 | f2 = 0; | |
653 | ||
654 | for (s = pat2sym; *s; s++) | |
655 | if (strrcmp(atsym, *s) == 0) | |
656 | f1 = 1; | |
9e157a5a MD |
657 | if (f1 && f2) |
658 | return 1; | |
4c8fbca5 | 659 | |
f8657e1b VG |
660 | /* Whitelist all references from .pci_fixup section if vmlinux |
661 | * Whitelist all refereces from .text.head to .init.data if vmlinux | |
662 | * Whitelist all refereces from .text.head to .init.text if vmlinux | |
663 | */ | |
9e157a5a MD |
664 | if (is_vmlinux(modname)) { |
665 | if ((strcmp(fromsec, ".pci_fixup") == 0) && | |
666 | (strcmp(tosec, ".init.text") == 0)) | |
667 | return 1; | |
ee6a8545 | 668 | |
f8657e1b VG |
669 | if ((strcmp(fromsec, ".text.head") == 0) && |
670 | ((strcmp(tosec, ".init.data") == 0) || | |
671 | (strcmp(tosec, ".init.text") == 0))) | |
672 | return 1; | |
673 | ||
ee6a8545 VG |
674 | /* Check for pattern 3 */ |
675 | for (s = pat3refsym; *s; s++) | |
676 | if (strcmp(refsymname, *s) == 0) | |
677 | return 1; | |
9e157a5a | 678 | } |
aae5f662 SR |
679 | /* Check for pattern 4 */ |
680 | if ((strcmp(tosec, ".init.text") == 0) && | |
681 | (strcmp(fromsec, ".text") == 0) && | |
682 | (strcmp(refsymname, "kernel_init") == 0)) | |
683 | return 1; | |
93659af1 | 684 | return 0; |
4c8fbca5 SR |
685 | } |
686 | ||
93684d3b SR |
687 | /** |
688 | * Find symbol based on relocation record info. | |
689 | * In some cases the symbol supplied is a valid symbol so | |
690 | * return refsym. If st_name != 0 we assume this is a valid symbol. | |
691 | * In other cases the symbol needs to be looked up in the symbol table | |
692 | * based on section and address. | |
693 | * **/ | |
694 | static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, | |
695 | Elf_Sym *relsym) | |
696 | { | |
697 | Elf_Sym *sym; | |
698 | ||
699 | if (relsym->st_name != 0) | |
700 | return relsym; | |
701 | for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { | |
702 | if (sym->st_shndx != relsym->st_shndx) | |
703 | continue; | |
704 | if (sym->st_value == addr) | |
705 | return sym; | |
706 | } | |
707 | return NULL; | |
708 | } | |
709 | ||
da68d61f DB |
710 | static inline int is_arm_mapping_symbol(const char *str) |
711 | { | |
712 | return str[0] == '$' && strchr("atd", str[1]) | |
713 | && (str[2] == '\0' || str[2] == '.'); | |
714 | } | |
715 | ||
716 | /* | |
717 | * If there's no name there, ignore it; likewise, ignore it if it's | |
718 | * one of the magic symbols emitted used by current ARM tools. | |
719 | * | |
720 | * Otherwise if find_symbols_between() returns those symbols, they'll | |
721 | * fail the whitelist tests and cause lots of false alarms ... fixable | |
722 | * only by merging __exit and __init sections into __text, bloating | |
723 | * the kernel (which is especially evil on embedded platforms). | |
724 | */ | |
725 | static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) | |
726 | { | |
727 | const char *name = elf->strtab + sym->st_name; | |
728 | ||
729 | if (!name || !strlen(name)) | |
730 | return 0; | |
731 | return !is_arm_mapping_symbol(name); | |
732 | } | |
733 | ||
b39927cf | 734 | /* |
43c74d17 SR |
735 | * Find symbols before or equal addr and after addr - in the section sec. |
736 | * If we find two symbols with equal offset prefer one with a valid name. | |
737 | * The ELF format may have a better way to detect what type of symbol | |
738 | * it is, but this works for now. | |
b39927cf SR |
739 | **/ |
740 | static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, | |
741 | const char *sec, | |
742 | Elf_Sym **before, Elf_Sym **after) | |
743 | { | |
744 | Elf_Sym *sym; | |
745 | Elf_Ehdr *hdr = elf->hdr; | |
746 | Elf_Addr beforediff = ~0; | |
747 | Elf_Addr afterdiff = ~0; | |
748 | const char *secstrings = (void *)hdr + | |
749 | elf->sechdrs[hdr->e_shstrndx].sh_offset; | |
62070fa4 | 750 | |
b39927cf SR |
751 | *before = NULL; |
752 | *after = NULL; | |
753 | ||
754 | for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { | |
755 | const char *symsec; | |
756 | ||
757 | if (sym->st_shndx >= SHN_LORESERVE) | |
758 | continue; | |
759 | symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; | |
760 | if (strcmp(symsec, sec) != 0) | |
761 | continue; | |
da68d61f DB |
762 | if (!is_valid_name(elf, sym)) |
763 | continue; | |
b39927cf SR |
764 | if (sym->st_value <= addr) { |
765 | if ((addr - sym->st_value) < beforediff) { | |
766 | beforediff = addr - sym->st_value; | |
767 | *before = sym; | |
768 | } | |
43c74d17 | 769 | else if ((addr - sym->st_value) == beforediff) { |
da68d61f | 770 | *before = sym; |
43c74d17 | 771 | } |
b39927cf SR |
772 | } |
773 | else | |
774 | { | |
775 | if ((sym->st_value - addr) < afterdiff) { | |
776 | afterdiff = sym->st_value - addr; | |
777 | *after = sym; | |
778 | } | |
43c74d17 | 779 | else if ((sym->st_value - addr) == afterdiff) { |
da68d61f | 780 | *after = sym; |
43c74d17 | 781 | } |
b39927cf SR |
782 | } |
783 | } | |
784 | } | |
785 | ||
786 | /** | |
787 | * Print a warning about a section mismatch. | |
788 | * Try to find symbols near it so user can find it. | |
4c8fbca5 | 789 | * Check whitelist before warning - it may be a false positive. |
b39927cf SR |
790 | **/ |
791 | static void warn_sec_mismatch(const char *modname, const char *fromsec, | |
792 | struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) | |
793 | { | |
93684d3b SR |
794 | const char *refsymname = ""; |
795 | Elf_Sym *before, *after; | |
796 | Elf_Sym *refsym; | |
b39927cf SR |
797 | Elf_Ehdr *hdr = elf->hdr; |
798 | Elf_Shdr *sechdrs = elf->sechdrs; | |
799 | const char *secstrings = (void *)hdr + | |
800 | sechdrs[hdr->e_shstrndx].sh_offset; | |
801 | const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; | |
62070fa4 | 802 | |
b39927cf SR |
803 | find_symbols_between(elf, r.r_offset, fromsec, &before, &after); |
804 | ||
93684d3b SR |
805 | refsym = find_elf_symbol(elf, r.r_addend, sym); |
806 | if (refsym && strlen(elf->strtab + refsym->st_name)) | |
807 | refsymname = elf->strtab + refsym->st_name; | |
4c8fbca5 SR |
808 | |
809 | /* check whitelist - we may ignore it */ | |
62070fa4 | 810 | if (before && |
9e157a5a | 811 | secref_whitelist(modname, secname, fromsec, |
ee6a8545 | 812 | elf->strtab + before->st_name, refsymname)) |
4c8fbca5 | 813 | return; |
62070fa4 | 814 | |
b39927cf | 815 | if (before && after) { |
93684d3b SR |
816 | warn("%s - Section mismatch: reference to %s:%s from %s " |
817 | "between '%s' (at offset 0x%llx) and '%s'\n", | |
818 | modname, secname, refsymname, fromsec, | |
b39927cf | 819 | elf->strtab + before->st_name, |
93684d3b | 820 | (long long)r.r_offset, |
b39927cf SR |
821 | elf->strtab + after->st_name); |
822 | } else if (before) { | |
93684d3b SR |
823 | warn("%s - Section mismatch: reference to %s:%s from %s " |
824 | "after '%s' (at offset 0x%llx)\n", | |
62070fa4 | 825 | modname, secname, refsymname, fromsec, |
b39927cf | 826 | elf->strtab + before->st_name, |
93684d3b | 827 | (long long)r.r_offset); |
b39927cf | 828 | } else if (after) { |
93684d3b SR |
829 | warn("%s - Section mismatch: reference to %s:%s from %s " |
830 | "before '%s' (at offset -0x%llx)\n", | |
62070fa4 | 831 | modname, secname, refsymname, fromsec, |
eaaae38c | 832 | elf->strtab + after->st_name, |
93684d3b | 833 | (long long)r.r_offset); |
b39927cf | 834 | } else { |
93684d3b SR |
835 | warn("%s - Section mismatch: reference to %s:%s from %s " |
836 | "(offset 0x%llx)\n", | |
837 | modname, secname, fromsec, refsymname, | |
838 | (long long)r.r_offset); | |
b39927cf SR |
839 | } |
840 | } | |
841 | ||
842 | /** | |
843 | * A module includes a number of sections that are discarded | |
844 | * either when loaded or when used as built-in. | |
845 | * For loaded modules all functions marked __init and all data | |
846 | * marked __initdata will be discarded when the module has been intialized. | |
847 | * Likewise for modules used built-in the sections marked __exit | |
848 | * are discarded because __exit marked function are supposed to be called | |
849 | * only when a moduel is unloaded which never happes for built-in modules. | |
850 | * The check_sec_ref() function traverses all relocation records | |
851 | * to find all references to a section that reference a section that will | |
852 | * be discarded and warns about it. | |
853 | **/ | |
854 | static void check_sec_ref(struct module *mod, const char *modname, | |
855 | struct elf_info *elf, | |
856 | int section(const char*), | |
857 | int section_ref_ok(const char *)) | |
858 | { | |
859 | int i; | |
860 | Elf_Sym *sym; | |
861 | Elf_Ehdr *hdr = elf->hdr; | |
862 | Elf_Shdr *sechdrs = elf->sechdrs; | |
863 | const char *secstrings = (void *)hdr + | |
864 | sechdrs[hdr->e_shstrndx].sh_offset; | |
62070fa4 | 865 | |
b39927cf SR |
866 | /* Walk through all sections */ |
867 | for (i = 0; i < hdr->e_shnum; i++) { | |
2c1a51f3 AN |
868 | const char *name = secstrings + sechdrs[i].sh_name; |
869 | const char *secname; | |
870 | Elf_Rela r; | |
eae07ac6 | 871 | unsigned int r_sym; |
b39927cf | 872 | /* We want to process only relocation sections and not .init */ |
2c1a51f3 AN |
873 | if (sechdrs[i].sh_type == SHT_RELA) { |
874 | Elf_Rela *rela; | |
875 | Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; | |
876 | Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; | |
877 | name += strlen(".rela"); | |
878 | if (section_ref_ok(name)) | |
879 | continue; | |
b39927cf | 880 | |
2c1a51f3 AN |
881 | for (rela = start; rela < stop; rela++) { |
882 | r.r_offset = TO_NATIVE(rela->r_offset); | |
eae07ac6 AN |
883 | #if KERNEL_ELFCLASS == ELFCLASS64 |
884 | if (hdr->e_machine == EM_MIPS) { | |
885 | r_sym = ELF64_MIPS_R_SYM(rela->r_info); | |
886 | r_sym = TO_NATIVE(r_sym); | |
887 | } else { | |
888 | r.r_info = TO_NATIVE(rela->r_info); | |
889 | r_sym = ELF_R_SYM(r.r_info); | |
890 | } | |
891 | #else | |
892 | r.r_info = TO_NATIVE(rela->r_info); | |
893 | r_sym = ELF_R_SYM(r.r_info); | |
894 | #endif | |
2c1a51f3 | 895 | r.r_addend = TO_NATIVE(rela->r_addend); |
eae07ac6 | 896 | sym = elf->symtab_start + r_sym; |
2c1a51f3 AN |
897 | /* Skip special sections */ |
898 | if (sym->st_shndx >= SHN_LORESERVE) | |
899 | continue; | |
900 | ||
901 | secname = secstrings + | |
902 | sechdrs[sym->st_shndx].sh_name; | |
903 | if (section(secname)) | |
904 | warn_sec_mismatch(modname, name, | |
905 | elf, sym, r); | |
906 | } | |
907 | } else if (sechdrs[i].sh_type == SHT_REL) { | |
908 | Elf_Rel *rel; | |
909 | Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; | |
910 | Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; | |
911 | name += strlen(".rel"); | |
912 | if (section_ref_ok(name)) | |
b39927cf SR |
913 | continue; |
914 | ||
2c1a51f3 AN |
915 | for (rel = start; rel < stop; rel++) { |
916 | r.r_offset = TO_NATIVE(rel->r_offset); | |
eae07ac6 AN |
917 | #if KERNEL_ELFCLASS == ELFCLASS64 |
918 | if (hdr->e_machine == EM_MIPS) { | |
919 | r_sym = ELF64_MIPS_R_SYM(rel->r_info); | |
920 | r_sym = TO_NATIVE(r_sym); | |
921 | } else { | |
922 | r.r_info = TO_NATIVE(rel->r_info); | |
923 | r_sym = ELF_R_SYM(r.r_info); | |
924 | } | |
925 | #else | |
926 | r.r_info = TO_NATIVE(rel->r_info); | |
927 | r_sym = ELF_R_SYM(r.r_info); | |
928 | #endif | |
2c1a51f3 | 929 | r.r_addend = 0; |
eae07ac6 | 930 | sym = elf->symtab_start + r_sym; |
2c1a51f3 AN |
931 | /* Skip special sections */ |
932 | if (sym->st_shndx >= SHN_LORESERVE) | |
933 | continue; | |
934 | ||
935 | secname = secstrings + | |
936 | sechdrs[sym->st_shndx].sh_name; | |
937 | if (section(secname)) | |
938 | warn_sec_mismatch(modname, name, | |
939 | elf, sym, r); | |
940 | } | |
b39927cf SR |
941 | } |
942 | } | |
943 | } | |
944 | ||
945 | /** | |
946 | * Functions used only during module init is marked __init and is stored in | |
947 | * a .init.text section. Likewise data is marked __initdata and stored in | |
948 | * a .init.data section. | |
949 | * If this section is one of these sections return 1 | |
950 | * See include/linux/init.h for the details | |
951 | **/ | |
952 | static int init_section(const char *name) | |
953 | { | |
954 | if (strcmp(name, ".init") == 0) | |
955 | return 1; | |
956 | if (strncmp(name, ".init.", strlen(".init.")) == 0) | |
957 | return 1; | |
958 | return 0; | |
959 | } | |
960 | ||
961 | /** | |
962 | * Identify sections from which references to a .init section is OK. | |
62070fa4 | 963 | * |
b39927cf SR |
964 | * Unfortunately references to read only data that referenced .init |
965 | * sections had to be excluded. Almost all of these are false | |
966 | * positives, they are created by gcc. The downside of excluding rodata | |
967 | * is that there really are some user references from rodata to | |
968 | * init code, e.g. drivers/video/vgacon.c: | |
62070fa4 | 969 | * |
b39927cf SR |
970 | * const struct consw vga_con = { |
971 | * con_startup: vgacon_startup, | |
972 | * | |
973 | * where vgacon_startup is __init. If you want to wade through the false | |
974 | * positives, take out the check for rodata. | |
975 | **/ | |
976 | static int init_section_ref_ok(const char *name) | |
977 | { | |
978 | const char **s; | |
979 | /* Absolute section names */ | |
980 | const char *namelist1[] = { | |
981 | ".init", | |
9209aed0 SR |
982 | ".opd", /* see comment [OPD] at exit_section_ref_ok() */ |
983 | ".toc1", /* used by ppc64 */ | |
b39927cf | 984 | ".stab", |
742433b0 | 985 | ".data.rel.ro", /* used by parisc64 */ |
139ec7c4 | 986 | ".parainstructions", |
b39927cf | 987 | ".text.lock", |
9209aed0 | 988 | "__bug_table", /* used by powerpc for BUG() */ |
b39927cf SR |
989 | ".pci_fixup_header", |
990 | ".pci_fixup_final", | |
991 | ".pdr", | |
992 | "__param", | |
468d9494 AV |
993 | "__ex_table", |
994 | ".fixup", | |
35899c57 | 995 | ".smp_locks", |
909252d2 | 996 | ".plt", /* seen on ARCH=um build on x86_64. Harmless */ |
21c4ff80 BH |
997 | "__ftr_fixup", /* powerpc cpu feature fixup */ |
998 | "__fw_ftr_fixup", /* powerpc firmware feature fixup */ | |
b39927cf SR |
999 | NULL |
1000 | }; | |
1001 | /* Start of section names */ | |
1002 | const char *namelist2[] = { | |
1003 | ".init.", | |
1004 | ".altinstructions", | |
1005 | ".eh_frame", | |
1006 | ".debug", | |
139ec7c4 | 1007 | ".parainstructions", |
742433b0 | 1008 | ".rodata", |
b39927cf SR |
1009 | NULL |
1010 | }; | |
6e10133f SR |
1011 | /* part of section name */ |
1012 | const char *namelist3 [] = { | |
1013 | ".unwind", /* sample: IA_64.unwind.init.text */ | |
1014 | NULL | |
1015 | }; | |
1016 | ||
b39927cf SR |
1017 | for (s = namelist1; *s; s++) |
1018 | if (strcmp(*s, name) == 0) | |
1019 | return 1; | |
62070fa4 | 1020 | for (s = namelist2; *s; s++) |
b39927cf SR |
1021 | if (strncmp(*s, name, strlen(*s)) == 0) |
1022 | return 1; | |
62070fa4 | 1023 | for (s = namelist3; *s; s++) |
e835a39c | 1024 | if (strstr(name, *s) != NULL) |
6e10133f | 1025 | return 1; |
468d9494 AV |
1026 | if (strrcmp(name, ".init") == 0) |
1027 | return 1; | |
b39927cf SR |
1028 | return 0; |
1029 | } | |
1030 | ||
1031 | /* | |
1032 | * Functions used only during module exit is marked __exit and is stored in | |
1033 | * a .exit.text section. Likewise data is marked __exitdata and stored in | |
1034 | * a .exit.data section. | |
1035 | * If this section is one of these sections return 1 | |
1036 | * See include/linux/init.h for the details | |
1037 | **/ | |
1038 | static int exit_section(const char *name) | |
1039 | { | |
1040 | if (strcmp(name, ".exit.text") == 0) | |
1041 | return 1; | |
1042 | if (strcmp(name, ".exit.data") == 0) | |
1043 | return 1; | |
1044 | return 0; | |
62070fa4 | 1045 | |
b39927cf SR |
1046 | } |
1047 | ||
1048 | /* | |
1049 | * Identify sections from which references to a .exit section is OK. | |
62070fa4 | 1050 | * |
b39927cf SR |
1051 | * [OPD] Keith Ownes <kaos@sgi.com> commented: |
1052 | * For our future {in}sanity, add a comment that this is the ppc .opd | |
1053 | * section, not the ia64 .opd section. | |
1054 | * ia64 .opd should not point to discarded sections. | |
5ecdd0f6 | 1055 | * [.rodata] like for .init.text we ignore .rodata references -same reason |
b39927cf SR |
1056 | **/ |
1057 | static int exit_section_ref_ok(const char *name) | |
1058 | { | |
1059 | const char **s; | |
1060 | /* Absolute section names */ | |
1061 | const char *namelist1[] = { | |
1062 | ".exit.text", | |
1063 | ".exit.data", | |
1064 | ".init.text", | |
5ecdd0f6 | 1065 | ".rodata", |
b39927cf | 1066 | ".opd", /* See comment [OPD] */ |
9209aed0 | 1067 | ".toc1", /* used by ppc64 */ |
b39927cf SR |
1068 | ".altinstructions", |
1069 | ".pdr", | |
9209aed0 | 1070 | "__bug_table", /* used by powerpc for BUG() */ |
b39927cf SR |
1071 | ".exitcall.exit", |
1072 | ".eh_frame", | |
acd19499 | 1073 | ".parainstructions", |
b39927cf | 1074 | ".stab", |
468d9494 AV |
1075 | "__ex_table", |
1076 | ".fixup", | |
35899c57 | 1077 | ".smp_locks", |
909252d2 | 1078 | ".plt", /* seen on ARCH=um build on x86_64. Harmless */ |
b39927cf SR |
1079 | NULL |
1080 | }; | |
1081 | /* Start of section names */ | |
1082 | const char *namelist2[] = { | |
1083 | ".debug", | |
1084 | NULL | |
1085 | }; | |
6e10133f SR |
1086 | /* part of section name */ |
1087 | const char *namelist3 [] = { | |
1088 | ".unwind", /* Sample: IA_64.unwind.exit.text */ | |
1089 | NULL | |
1090 | }; | |
62070fa4 | 1091 | |
b39927cf SR |
1092 | for (s = namelist1; *s; s++) |
1093 | if (strcmp(*s, name) == 0) | |
1094 | return 1; | |
62070fa4 | 1095 | for (s = namelist2; *s; s++) |
b39927cf SR |
1096 | if (strncmp(*s, name, strlen(*s)) == 0) |
1097 | return 1; | |
62070fa4 | 1098 | for (s = namelist3; *s; s++) |
e835a39c | 1099 | if (strstr(name, *s) != NULL) |
6e10133f | 1100 | return 1; |
b39927cf SR |
1101 | return 0; |
1102 | } | |
1103 | ||
5c3ead8c | 1104 | static void read_symbols(char *modname) |
1da177e4 LT |
1105 | { |
1106 | const char *symname; | |
1107 | char *version; | |
b817f6fe | 1108 | char *license; |
1da177e4 LT |
1109 | struct module *mod; |
1110 | struct elf_info info = { }; | |
1111 | Elf_Sym *sym; | |
1112 | ||
85bd2fdd SR |
1113 | if (!parse_elf(&info, modname)) |
1114 | return; | |
1da177e4 LT |
1115 | |
1116 | mod = new_module(modname); | |
1117 | ||
1118 | /* When there's no vmlinux, don't print warnings about | |
1119 | * unresolved symbols (since there'll be too many ;) */ | |
1120 | if (is_vmlinux(modname)) { | |
1da177e4 | 1121 | have_vmlinux = 1; |
1da177e4 LT |
1122 | mod->skip = 1; |
1123 | } | |
1124 | ||
b817f6fe SR |
1125 | license = get_modinfo(info.modinfo, info.modinfo_len, "license"); |
1126 | while (license) { | |
1127 | if (license_is_gpl_compatible(license)) | |
1128 | mod->gpl_compatible = 1; | |
1129 | else { | |
1130 | mod->gpl_compatible = 0; | |
1131 | break; | |
1132 | } | |
1133 | license = get_next_modinfo(info.modinfo, info.modinfo_len, | |
1134 | "license", license); | |
1135 | } | |
1136 | ||
1da177e4 LT |
1137 | for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { |
1138 | symname = info.strtab + sym->st_name; | |
1139 | ||
1140 | handle_modversions(mod, &info, sym, symname); | |
1141 | handle_moddevtable(mod, &info, sym, symname); | |
1142 | } | |
b39927cf SR |
1143 | check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); |
1144 | check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); | |
1da177e4 LT |
1145 | |
1146 | version = get_modinfo(info.modinfo, info.modinfo_len, "version"); | |
1147 | if (version) | |
1148 | maybe_frob_rcs_version(modname, version, info.modinfo, | |
1149 | version - (char *)info.hdr); | |
1150 | if (version || (all_versions && !is_vmlinux(modname))) | |
1151 | get_src_version(modname, mod->srcversion, | |
1152 | sizeof(mod->srcversion)-1); | |
1153 | ||
1154 | parse_elf_finish(&info); | |
1155 | ||
1156 | /* Our trick to get versioning for struct_module - it's | |
1157 | * never passed as an argument to an exported function, so | |
1158 | * the automatic versioning doesn't pick it up, but it's really | |
1159 | * important anyhow */ | |
1160 | if (modversions) | |
1161 | mod->unres = alloc_symbol("struct_module", 0, mod->unres); | |
1162 | } | |
1163 | ||
1164 | #define SZ 500 | |
1165 | ||
1166 | /* We first write the generated file into memory using the | |
1167 | * following helper, then compare to the file on disk and | |
1168 | * only update the later if anything changed */ | |
1169 | ||
5c3ead8c SR |
1170 | void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, |
1171 | const char *fmt, ...) | |
1da177e4 LT |
1172 | { |
1173 | char tmp[SZ]; | |
1174 | int len; | |
1175 | va_list ap; | |
62070fa4 | 1176 | |
1da177e4 LT |
1177 | va_start(ap, fmt); |
1178 | len = vsnprintf(tmp, SZ, fmt, ap); | |
7670f023 | 1179 | buf_write(buf, tmp, len); |
1da177e4 LT |
1180 | va_end(ap); |
1181 | } | |
1182 | ||
5c3ead8c | 1183 | void buf_write(struct buffer *buf, const char *s, int len) |
1da177e4 LT |
1184 | { |
1185 | if (buf->size - buf->pos < len) { | |
7670f023 | 1186 | buf->size += len + SZ; |
1da177e4 LT |
1187 | buf->p = realloc(buf->p, buf->size); |
1188 | } | |
1189 | strncpy(buf->p + buf->pos, s, len); | |
1190 | buf->pos += len; | |
1191 | } | |
1192 | ||
c96fca21 SR |
1193 | static void check_for_gpl_usage(enum export exp, const char *m, const char *s) |
1194 | { | |
1195 | const char *e = is_vmlinux(m) ?"":".ko"; | |
1196 | ||
1197 | switch (exp) { | |
1198 | case export_gpl: | |
1199 | fatal("modpost: GPL-incompatible module %s%s " | |
1200 | "uses GPL-only symbol '%s'\n", m, e, s); | |
1201 | break; | |
1202 | case export_unused_gpl: | |
1203 | fatal("modpost: GPL-incompatible module %s%s " | |
1204 | "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); | |
1205 | break; | |
1206 | case export_gpl_future: | |
1207 | warn("modpost: GPL-incompatible module %s%s " | |
1208 | "uses future GPL-only symbol '%s'\n", m, e, s); | |
1209 | break; | |
1210 | case export_plain: | |
1211 | case export_unused: | |
1212 | case export_unknown: | |
1213 | /* ignore */ | |
1214 | break; | |
1215 | } | |
1216 | } | |
1217 | ||
1218 | static void check_for_unused(enum export exp, const char* m, const char* s) | |
1219 | { | |
1220 | const char *e = is_vmlinux(m) ?"":".ko"; | |
1221 | ||
1222 | switch (exp) { | |
1223 | case export_unused: | |
1224 | case export_unused_gpl: | |
1225 | warn("modpost: module %s%s " | |
1226 | "uses symbol '%s' marked UNUSED\n", m, e, s); | |
1227 | break; | |
1228 | default: | |
1229 | /* ignore */ | |
1230 | break; | |
1231 | } | |
1232 | } | |
1233 | ||
1234 | static void check_exports(struct module *mod) | |
b817f6fe SR |
1235 | { |
1236 | struct symbol *s, *exp; | |
1237 | ||
1238 | for (s = mod->unres; s; s = s->next) { | |
6449bd62 | 1239 | const char *basename; |
b817f6fe SR |
1240 | exp = find_symbol(s->name); |
1241 | if (!exp || exp->module == mod) | |
1242 | continue; | |
6449bd62 | 1243 | basename = strrchr(mod->name, '/'); |
b817f6fe SR |
1244 | if (basename) |
1245 | basename++; | |
c96fca21 SR |
1246 | else |
1247 | basename = mod->name; | |
1248 | if (!mod->gpl_compatible) | |
1249 | check_for_gpl_usage(exp->export, basename, exp->name); | |
1250 | check_for_unused(exp->export, basename, exp->name); | |
b817f6fe SR |
1251 | } |
1252 | } | |
1253 | ||
5c3ead8c SR |
1254 | /** |
1255 | * Header for the generated file | |
1256 | **/ | |
1257 | static void add_header(struct buffer *b, struct module *mod) | |
1da177e4 LT |
1258 | { |
1259 | buf_printf(b, "#include <linux/module.h>\n"); | |
1260 | buf_printf(b, "#include <linux/vermagic.h>\n"); | |
1261 | buf_printf(b, "#include <linux/compiler.h>\n"); | |
1262 | buf_printf(b, "\n"); | |
1263 | buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); | |
1264 | buf_printf(b, "\n"); | |
1da177e4 LT |
1265 | buf_printf(b, "struct module __this_module\n"); |
1266 | buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); | |
f83b5e32 | 1267 | buf_printf(b, " .name = KBUILD_MODNAME,\n"); |
1da177e4 LT |
1268 | if (mod->has_init) |
1269 | buf_printf(b, " .init = init_module,\n"); | |
1270 | if (mod->has_cleanup) | |
1271 | buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" | |
1272 | " .exit = cleanup_module,\n" | |
1273 | "#endif\n"); | |
1274 | buf_printf(b, "};\n"); | |
1275 | } | |
1276 | ||
5c3ead8c SR |
1277 | /** |
1278 | * Record CRCs for unresolved symbols | |
1279 | **/ | |
c53ddacd | 1280 | static int add_versions(struct buffer *b, struct module *mod) |
1da177e4 LT |
1281 | { |
1282 | struct symbol *s, *exp; | |
c53ddacd | 1283 | int err = 0; |
1da177e4 LT |
1284 | |
1285 | for (s = mod->unres; s; s = s->next) { | |
1286 | exp = find_symbol(s->name); | |
1287 | if (!exp || exp->module == mod) { | |
c53ddacd | 1288 | if (have_vmlinux && !s->weak) { |
cb80514d SR |
1289 | warn("\"%s\" [%s.ko] undefined!\n", |
1290 | s->name, mod->name); | |
c53ddacd KK |
1291 | err = warn_unresolved ? 0 : 1; |
1292 | } | |
1da177e4 LT |
1293 | continue; |
1294 | } | |
1295 | s->module = exp->module; | |
1296 | s->crc_valid = exp->crc_valid; | |
1297 | s->crc = exp->crc; | |
1298 | } | |
1299 | ||
1300 | if (!modversions) | |
c53ddacd | 1301 | return err; |
1da177e4 LT |
1302 | |
1303 | buf_printf(b, "\n"); | |
1304 | buf_printf(b, "static const struct modversion_info ____versions[]\n"); | |
1305 | buf_printf(b, "__attribute_used__\n"); | |
1306 | buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); | |
1307 | ||
1308 | for (s = mod->unres; s; s = s->next) { | |
1309 | if (!s->module) { | |
1310 | continue; | |
1311 | } | |
1312 | if (!s->crc_valid) { | |
cb80514d | 1313 | warn("\"%s\" [%s.ko] has no CRC!\n", |
1da177e4 LT |
1314 | s->name, mod->name); |
1315 | continue; | |
1316 | } | |
1317 | buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); | |
1318 | } | |
1319 | ||
1320 | buf_printf(b, "};\n"); | |
c53ddacd KK |
1321 | |
1322 | return err; | |
1da177e4 LT |
1323 | } |
1324 | ||
5c3ead8c SR |
1325 | static void add_depends(struct buffer *b, struct module *mod, |
1326 | struct module *modules) | |
1da177e4 LT |
1327 | { |
1328 | struct symbol *s; | |
1329 | struct module *m; | |
1330 | int first = 1; | |
1331 | ||
1332 | for (m = modules; m; m = m->next) { | |
1333 | m->seen = is_vmlinux(m->name); | |
1334 | } | |
1335 | ||
1336 | buf_printf(b, "\n"); | |
1337 | buf_printf(b, "static const char __module_depends[]\n"); | |
1338 | buf_printf(b, "__attribute_used__\n"); | |
1339 | buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); | |
1340 | buf_printf(b, "\"depends="); | |
1341 | for (s = mod->unres; s; s = s->next) { | |
1342 | if (!s->module) | |
1343 | continue; | |
1344 | ||
1345 | if (s->module->seen) | |
1346 | continue; | |
1347 | ||
1348 | s->module->seen = 1; | |
1349 | buf_printf(b, "%s%s", first ? "" : ",", | |
1350 | strrchr(s->module->name, '/') + 1); | |
1351 | first = 0; | |
1352 | } | |
1353 | buf_printf(b, "\";\n"); | |
1354 | } | |
1355 | ||
5c3ead8c | 1356 | static void add_srcversion(struct buffer *b, struct module *mod) |
1da177e4 LT |
1357 | { |
1358 | if (mod->srcversion[0]) { | |
1359 | buf_printf(b, "\n"); | |
1360 | buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", | |
1361 | mod->srcversion); | |
1362 | } | |
1363 | } | |
1364 | ||
5c3ead8c | 1365 | static void write_if_changed(struct buffer *b, const char *fname) |
1da177e4 LT |
1366 | { |
1367 | char *tmp; | |
1368 | FILE *file; | |
1369 | struct stat st; | |
1370 | ||
1371 | file = fopen(fname, "r"); | |
1372 | if (!file) | |
1373 | goto write; | |
1374 | ||
1375 | if (fstat(fileno(file), &st) < 0) | |
1376 | goto close_write; | |
1377 | ||
1378 | if (st.st_size != b->pos) | |
1379 | goto close_write; | |
1380 | ||
1381 | tmp = NOFAIL(malloc(b->pos)); | |
1382 | if (fread(tmp, 1, b->pos, file) != b->pos) | |
1383 | goto free_write; | |
1384 | ||
1385 | if (memcmp(tmp, b->p, b->pos) != 0) | |
1386 | goto free_write; | |
1387 | ||
1388 | free(tmp); | |
1389 | fclose(file); | |
1390 | return; | |
1391 | ||
1392 | free_write: | |
1393 | free(tmp); | |
1394 | close_write: | |
1395 | fclose(file); | |
1396 | write: | |
1397 | file = fopen(fname, "w"); | |
1398 | if (!file) { | |
1399 | perror(fname); | |
1400 | exit(1); | |
1401 | } | |
1402 | if (fwrite(b->p, 1, b->pos, file) != b->pos) { | |
1403 | perror(fname); | |
1404 | exit(1); | |
1405 | } | |
1406 | fclose(file); | |
1407 | } | |
1408 | ||
bd5cbced | 1409 | /* parse Module.symvers file. line format: |
534b89a9 | 1410 | * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] |
bd5cbced | 1411 | **/ |
040fcc81 | 1412 | static void read_dump(const char *fname, unsigned int kernel) |
1da177e4 LT |
1413 | { |
1414 | unsigned long size, pos = 0; | |
1415 | void *file = grab_file(fname, &size); | |
1416 | char *line; | |
1417 | ||
1418 | if (!file) | |
1419 | /* No symbol versions, silently ignore */ | |
1420 | return; | |
1421 | ||
1422 | while ((line = get_next_line(&pos, file, size))) { | |
534b89a9 | 1423 | char *symname, *modname, *d, *export, *end; |
1da177e4 LT |
1424 | unsigned int crc; |
1425 | struct module *mod; | |
040fcc81 | 1426 | struct symbol *s; |
1da177e4 LT |
1427 | |
1428 | if (!(symname = strchr(line, '\t'))) | |
1429 | goto fail; | |
1430 | *symname++ = '\0'; | |
1431 | if (!(modname = strchr(symname, '\t'))) | |
1432 | goto fail; | |
1433 | *modname++ = '\0'; | |
9ac545b0 | 1434 | if ((export = strchr(modname, '\t')) != NULL) |
bd5cbced | 1435 | *export++ = '\0'; |
534b89a9 SR |
1436 | if (export && ((end = strchr(export, '\t')) != NULL)) |
1437 | *end = '\0'; | |
1da177e4 LT |
1438 | crc = strtoul(line, &d, 16); |
1439 | if (*symname == '\0' || *modname == '\0' || *d != '\0') | |
1440 | goto fail; | |
1441 | ||
1442 | if (!(mod = find_module(modname))) { | |
1443 | if (is_vmlinux(modname)) { | |
1444 | have_vmlinux = 1; | |
1445 | } | |
1446 | mod = new_module(NOFAIL(strdup(modname))); | |
1447 | mod->skip = 1; | |
1448 | } | |
bd5cbced | 1449 | s = sym_add_exported(symname, mod, export_no(export)); |
8e70c458 SR |
1450 | s->kernel = kernel; |
1451 | s->preloaded = 1; | |
bd5cbced | 1452 | sym_update_crc(symname, mod, crc, export_no(export)); |
1da177e4 LT |
1453 | } |
1454 | return; | |
1455 | fail: | |
1456 | fatal("parse error in symbol dump file\n"); | |
1457 | } | |
1458 | ||
040fcc81 SR |
1459 | /* For normal builds always dump all symbols. |
1460 | * For external modules only dump symbols | |
1461 | * that are not read from kernel Module.symvers. | |
1462 | **/ | |
1463 | static int dump_sym(struct symbol *sym) | |
1464 | { | |
1465 | if (!external_module) | |
1466 | return 1; | |
1467 | if (sym->vmlinux || sym->kernel) | |
1468 | return 0; | |
1469 | return 1; | |
1470 | } | |
62070fa4 | 1471 | |
5c3ead8c | 1472 | static void write_dump(const char *fname) |
1da177e4 LT |
1473 | { |
1474 | struct buffer buf = { }; | |
1475 | struct symbol *symbol; | |
1476 | int n; | |
1477 | ||
1478 | for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { | |
1479 | symbol = symbolhash[n]; | |
1480 | while (symbol) { | |
040fcc81 | 1481 | if (dump_sym(symbol)) |
bd5cbced | 1482 | buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", |
62070fa4 | 1483 | symbol->crc, symbol->name, |
bd5cbced RP |
1484 | symbol->module->name, |
1485 | export_str(symbol->export)); | |
1da177e4 LT |
1486 | symbol = symbol->next; |
1487 | } | |
1488 | } | |
1489 | write_if_changed(&buf, fname); | |
1490 | } | |
1491 | ||
5c3ead8c | 1492 | int main(int argc, char **argv) |
1da177e4 LT |
1493 | { |
1494 | struct module *mod; | |
1495 | struct buffer buf = { }; | |
1496 | char fname[SZ]; | |
040fcc81 SR |
1497 | char *kernel_read = NULL, *module_read = NULL; |
1498 | char *dump_write = NULL; | |
1da177e4 | 1499 | int opt; |
c53ddacd | 1500 | int err; |
1da177e4 | 1501 | |
c53ddacd | 1502 | while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) { |
1da177e4 LT |
1503 | switch(opt) { |
1504 | case 'i': | |
040fcc81 SR |
1505 | kernel_read = optarg; |
1506 | break; | |
1507 | case 'I': | |
1508 | module_read = optarg; | |
1509 | external_module = 1; | |
1da177e4 LT |
1510 | break; |
1511 | case 'm': | |
1512 | modversions = 1; | |
1513 | break; | |
1514 | case 'o': | |
1515 | dump_write = optarg; | |
1516 | break; | |
1517 | case 'a': | |
1518 | all_versions = 1; | |
1519 | break; | |
c53ddacd KK |
1520 | case 'w': |
1521 | warn_unresolved = 1; | |
1522 | break; | |
1da177e4 LT |
1523 | default: |
1524 | exit(1); | |
1525 | } | |
1526 | } | |
1527 | ||
040fcc81 SR |
1528 | if (kernel_read) |
1529 | read_dump(kernel_read, 1); | |
1530 | if (module_read) | |
1531 | read_dump(module_read, 0); | |
1da177e4 LT |
1532 | |
1533 | while (optind < argc) { | |
1534 | read_symbols(argv[optind++]); | |
1535 | } | |
1536 | ||
b817f6fe SR |
1537 | for (mod = modules; mod; mod = mod->next) { |
1538 | if (mod->skip) | |
1539 | continue; | |
c96fca21 | 1540 | check_exports(mod); |
b817f6fe SR |
1541 | } |
1542 | ||
c53ddacd KK |
1543 | err = 0; |
1544 | ||
1da177e4 LT |
1545 | for (mod = modules; mod; mod = mod->next) { |
1546 | if (mod->skip) | |
1547 | continue; | |
1548 | ||
1549 | buf.pos = 0; | |
1550 | ||
1551 | add_header(&buf, mod); | |
c53ddacd | 1552 | err |= add_versions(&buf, mod); |
1da177e4 LT |
1553 | add_depends(&buf, mod, modules); |
1554 | add_moddevtable(&buf, mod); | |
1555 | add_srcversion(&buf, mod); | |
1556 | ||
1557 | sprintf(fname, "%s.mod.c", mod->name); | |
1558 | write_if_changed(&buf, fname); | |
1559 | } | |
1560 | ||
1561 | if (dump_write) | |
1562 | write_dump(dump_write); | |
1563 | ||
c53ddacd | 1564 | return err; |
1da177e4 | 1565 | } |