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TOMOYO Linux Cross Reference
Linux/scripts/mod/modpost.c

Version: ~ [ linux-5.11 ] ~ [ linux-5.10.17 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.99 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.176 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.221 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.257 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.257 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 <limits.h>
 19 #include <stdbool.h>
 20 #include "modpost.h"
 21 #include "../../include/generated/autoconf.h"
 22 #include "../../include/linux/license.h"
 23 #include "../../include/linux/export.h"
 24 
 25 /* Are we using CONFIG_MODVERSIONS? */
 26 int modversions = 0;
 27 /* Warn about undefined symbols? (do so if we have vmlinux) */
 28 int have_vmlinux = 0;
 29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
 30 static int all_versions = 0;
 31 /* If we are modposting external module set to 1 */
 32 static int external_module = 0;
 33 /* Warn about section mismatch in vmlinux if set to 1 */
 34 static int vmlinux_section_warnings = 1;
 35 /* Only warn about unresolved symbols */
 36 static int warn_unresolved = 0;
 37 /* How a symbol is exported */
 38 static int sec_mismatch_count = 0;
 39 static int sec_mismatch_verbose = 1;
 40 
 41 enum export {
 42         export_plain,      export_unused,     export_gpl,
 43         export_unused_gpl, export_gpl_future, export_unknown
 44 };
 45 
 46 #define PRINTF __attribute__ ((format (printf, 1, 2)))
 47 
 48 PRINTF void fatal(const char *fmt, ...)
 49 {
 50         va_list arglist;
 51 
 52         fprintf(stderr, "FATAL: ");
 53 
 54         va_start(arglist, fmt);
 55         vfprintf(stderr, fmt, arglist);
 56         va_end(arglist);
 57 
 58         exit(1);
 59 }
 60 
 61 PRINTF void warn(const char *fmt, ...)
 62 {
 63         va_list arglist;
 64 
 65         fprintf(stderr, "WARNING: ");
 66 
 67         va_start(arglist, fmt);
 68         vfprintf(stderr, fmt, arglist);
 69         va_end(arglist);
 70 }
 71 
 72 PRINTF void merror(const char *fmt, ...)
 73 {
 74         va_list arglist;
 75 
 76         fprintf(stderr, "ERROR: ");
 77 
 78         va_start(arglist, fmt);
 79         vfprintf(stderr, fmt, arglist);
 80         va_end(arglist);
 81 }
 82 
 83 static inline bool strends(const char *str, const char *postfix)
 84 {
 85         if (strlen(str) < strlen(postfix))
 86                 return false;
 87 
 88         return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
 89 }
 90 
 91 static int is_vmlinux(const char *modname)
 92 {
 93         const char *myname;
 94 
 95         myname = strrchr(modname, '/');
 96         if (myname)
 97                 myname++;
 98         else
 99                 myname = modname;
100 
101         return (strcmp(myname, "vmlinux") == 0) ||
102                (strcmp(myname, "vmlinux.o") == 0);
103 }
104 
105 void *do_nofail(void *ptr, const char *expr)
106 {
107         if (!ptr)
108                 fatal("modpost: Memory allocation failure: %s.\n", expr);
109 
110         return ptr;
111 }
112 
113 /* A list of all modules we processed */
114 static struct module *modules;
115 
116 static struct module *find_module(char *modname)
117 {
118         struct module *mod;
119 
120         for (mod = modules; mod; mod = mod->next)
121                 if (strcmp(mod->name, modname) == 0)
122                         break;
123         return mod;
124 }
125 
126 static struct module *new_module(const char *modname)
127 {
128         struct module *mod;
129         char *p;
130 
131         mod = NOFAIL(malloc(sizeof(*mod)));
132         memset(mod, 0, sizeof(*mod));
133         p = NOFAIL(strdup(modname));
134 
135         /* strip trailing .o */
136         if (strends(p, ".o")) {
137                 p[strlen(p) - 2] = '\0';
138                 mod->is_dot_o = 1;
139         }
140 
141         /* add to list */
142         mod->name = p;
143         mod->gpl_compatible = -1;
144         mod->next = modules;
145         modules = mod;
146 
147         return mod;
148 }
149 
150 /* A hash of all exported symbols,
151  * struct symbol is also used for lists of unresolved symbols */
152 
153 #define SYMBOL_HASH_SIZE 1024
154 
155 struct symbol {
156         struct symbol *next;
157         struct module *module;
158         unsigned int crc;
159         int crc_valid;
160         unsigned int weak:1;
161         unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
162         unsigned int kernel:1;     /* 1 if symbol is from kernel
163                                     *  (only for external modules) **/
164         unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
165         enum export  export;       /* Type of export */
166         char name[0];
167 };
168 
169 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
170 
171 /* This is based on the hash agorithm from gdbm, via tdb */
172 static inline unsigned int tdb_hash(const char *name)
173 {
174         unsigned value; /* Used to compute the hash value.  */
175         unsigned   i;   /* Used to cycle through random values. */
176 
177         /* Set the initial value from the key size. */
178         for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
179                 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
180 
181         return (1103515243 * value + 12345);
182 }
183 
184 /**
185  * Allocate a new symbols for use in the hash of exported symbols or
186  * the list of unresolved symbols per module
187  **/
188 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
189                                    struct symbol *next)
190 {
191         struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
192 
193         memset(s, 0, sizeof(*s));
194         strcpy(s->name, name);
195         s->weak = weak;
196         s->next = next;
197         return s;
198 }
199 
200 /* For the hash of exported symbols */
201 static struct symbol *new_symbol(const char *name, struct module *module,
202                                  enum export export)
203 {
204         unsigned int hash;
205         struct symbol *new;
206 
207         hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
208         new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
209         new->module = module;
210         new->export = export;
211         return new;
212 }
213 
214 static struct symbol *find_symbol(const char *name)
215 {
216         struct symbol *s;
217 
218         /* For our purposes, .foo matches foo.  PPC64 needs this. */
219         if (name[0] == '.')
220                 name++;
221 
222         for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
223                 if (strcmp(s->name, name) == 0)
224                         return s;
225         }
226         return NULL;
227 }
228 
229 static struct {
230         const char *str;
231         enum export export;
232 } export_list[] = {
233         { .str = "EXPORT_SYMBOL",            .export = export_plain },
234         { .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
235         { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
236         { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
237         { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
238         { .str = "(unknown)",                .export = export_unknown },
239 };
240 
241 
242 static const char *export_str(enum export ex)
243 {
244         return export_list[ex].str;
245 }
246 
247 static enum export export_no(const char *s)
248 {
249         int i;
250 
251         if (!s)
252                 return export_unknown;
253         for (i = 0; export_list[i].export != export_unknown; i++) {
254                 if (strcmp(export_list[i].str, s) == 0)
255                         return export_list[i].export;
256         }
257         return export_unknown;
258 }
259 
260 static const char *sec_name(struct elf_info *elf, int secindex);
261 
262 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
263 
264 static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
265 {
266         const char *secname = sec_name(elf, sec);
267 
268         if (strstarts(secname, "___ksymtab+"))
269                 return export_plain;
270         else if (strstarts(secname, "___ksymtab_unused+"))
271                 return export_unused;
272         else if (strstarts(secname, "___ksymtab_gpl+"))
273                 return export_gpl;
274         else if (strstarts(secname, "___ksymtab_unused_gpl+"))
275                 return export_unused_gpl;
276         else if (strstarts(secname, "___ksymtab_gpl_future+"))
277                 return export_gpl_future;
278         else
279                 return export_unknown;
280 }
281 
282 static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
283 {
284         if (sec == elf->export_sec)
285                 return export_plain;
286         else if (sec == elf->export_unused_sec)
287                 return export_unused;
288         else if (sec == elf->export_gpl_sec)
289                 return export_gpl;
290         else if (sec == elf->export_unused_gpl_sec)
291                 return export_unused_gpl;
292         else if (sec == elf->export_gpl_future_sec)
293                 return export_gpl_future;
294         else
295                 return export_unknown;
296 }
297 
298 /**
299  * Add an exported symbol - it may have already been added without a
300  * CRC, in this case just update the CRC
301  **/
302 static struct symbol *sym_add_exported(const char *name, struct module *mod,
303                                        enum export export)
304 {
305         struct symbol *s = find_symbol(name);
306 
307         if (!s) {
308                 s = new_symbol(name, mod, export);
309         } else {
310                 if (!s->preloaded) {
311                         warn("%s: '%s' exported twice. Previous export "
312                              "was in %s%s\n", mod->name, name,
313                              s->module->name,
314                              is_vmlinux(s->module->name) ?"":".ko");
315                 } else {
316                         /* In case Modules.symvers was out of date */
317                         s->module = mod;
318                 }
319         }
320         s->preloaded = 0;
321         s->vmlinux   = is_vmlinux(mod->name);
322         s->kernel    = 0;
323         s->export    = export;
324         return s;
325 }
326 
327 static void sym_update_crc(const char *name, struct module *mod,
328                            unsigned int crc, enum export export)
329 {
330         struct symbol *s = find_symbol(name);
331 
332         if (!s)
333                 s = new_symbol(name, mod, export);
334         s->crc = crc;
335         s->crc_valid = 1;
336 }
337 
338 void *grab_file(const char *filename, unsigned long *size)
339 {
340         struct stat st;
341         void *map = MAP_FAILED;
342         int fd;
343 
344         fd = open(filename, O_RDONLY);
345         if (fd < 0)
346                 return NULL;
347         if (fstat(fd, &st))
348                 goto failed;
349 
350         *size = st.st_size;
351         map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
352 
353 failed:
354         close(fd);
355         if (map == MAP_FAILED)
356                 return NULL;
357         return map;
358 }
359 
360 /**
361   * Return a copy of the next line in a mmap'ed file.
362   * spaces in the beginning of the line is trimmed away.
363   * Return a pointer to a static buffer.
364   **/
365 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
366 {
367         static char line[4096];
368         int skip = 1;
369         size_t len = 0;
370         signed char *p = (signed char *)file + *pos;
371         char *s = line;
372 
373         for (; *pos < size ; (*pos)++) {
374                 if (skip && isspace(*p)) {
375                         p++;
376                         continue;
377                 }
378                 skip = 0;
379                 if (*p != '\n' && (*pos < size)) {
380                         len++;
381                         *s++ = *p++;
382                         if (len > 4095)
383                                 break; /* Too long, stop */
384                 } else {
385                         /* End of string */
386                         *s = '\0';
387                         return line;
388                 }
389         }
390         /* End of buffer */
391         return NULL;
392 }
393 
394 void release_file(void *file, unsigned long size)
395 {
396         munmap(file, size);
397 }
398 
399 static int parse_elf(struct elf_info *info, const char *filename)
400 {
401         unsigned int i;
402         Elf_Ehdr *hdr;
403         Elf_Shdr *sechdrs;
404         Elf_Sym  *sym;
405         const char *secstrings;
406         unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
407 
408         hdr = grab_file(filename, &info->size);
409         if (!hdr) {
410                 perror(filename);
411                 exit(1);
412         }
413         info->hdr = hdr;
414         if (info->size < sizeof(*hdr)) {
415                 /* file too small, assume this is an empty .o file */
416                 return 0;
417         }
418         /* Is this a valid ELF file? */
419         if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
420             (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
421             (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
422             (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
423                 /* Not an ELF file - silently ignore it */
424                 return 0;
425         }
426         /* Fix endianness in ELF header */
427         hdr->e_type      = TO_NATIVE(hdr->e_type);
428         hdr->e_machine   = TO_NATIVE(hdr->e_machine);
429         hdr->e_version   = TO_NATIVE(hdr->e_version);
430         hdr->e_entry     = TO_NATIVE(hdr->e_entry);
431         hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
432         hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
433         hdr->e_flags     = TO_NATIVE(hdr->e_flags);
434         hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
435         hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
436         hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
437         hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
438         hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
439         hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
440         sechdrs = (void *)hdr + hdr->e_shoff;
441         info->sechdrs = sechdrs;
442 
443         /* Check if file offset is correct */
444         if (hdr->e_shoff > info->size) {
445                 fatal("section header offset=%lu in file '%s' is bigger than "
446                       "filesize=%lu\n", (unsigned long)hdr->e_shoff,
447                       filename, info->size);
448                 return 0;
449         }
450 
451         if (hdr->e_shnum == SHN_UNDEF) {
452                 /*
453                  * There are more than 64k sections,
454                  * read count from .sh_size.
455                  */
456                 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
457         }
458         else {
459                 info->num_sections = hdr->e_shnum;
460         }
461         if (hdr->e_shstrndx == SHN_XINDEX) {
462                 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
463         }
464         else {
465                 info->secindex_strings = hdr->e_shstrndx;
466         }
467 
468         /* Fix endianness in section headers */
469         for (i = 0; i < info->num_sections; i++) {
470                 sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
471                 sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
472                 sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
473                 sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
474                 sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
475                 sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
476                 sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
477                 sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
478                 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
479                 sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
480         }
481         /* Find symbol table. */
482         secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
483         for (i = 1; i < info->num_sections; i++) {
484                 const char *secname;
485                 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
486 
487                 if (!nobits && sechdrs[i].sh_offset > info->size) {
488                         fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
489                               "sizeof(*hrd)=%zu\n", filename,
490                               (unsigned long)sechdrs[i].sh_offset,
491                               sizeof(*hdr));
492                         return 0;
493                 }
494                 secname = secstrings + sechdrs[i].sh_name;
495                 if (strcmp(secname, ".modinfo") == 0) {
496                         if (nobits)
497                                 fatal("%s has NOBITS .modinfo\n", filename);
498                         info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
499                         info->modinfo_len = sechdrs[i].sh_size;
500                 } else if (strcmp(secname, "__ksymtab") == 0)
501                         info->export_sec = i;
502                 else if (strcmp(secname, "__ksymtab_unused") == 0)
503                         info->export_unused_sec = i;
504                 else if (strcmp(secname, "__ksymtab_gpl") == 0)
505                         info->export_gpl_sec = i;
506                 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
507                         info->export_unused_gpl_sec = i;
508                 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
509                         info->export_gpl_future_sec = i;
510 
511                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
512                         unsigned int sh_link_idx;
513                         symtab_idx = i;
514                         info->symtab_start = (void *)hdr +
515                             sechdrs[i].sh_offset;
516                         info->symtab_stop  = (void *)hdr +
517                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
518                         sh_link_idx = sechdrs[i].sh_link;
519                         info->strtab       = (void *)hdr +
520                             sechdrs[sh_link_idx].sh_offset;
521                 }
522 
523                 /* 32bit section no. table? ("more than 64k sections") */
524                 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
525                         symtab_shndx_idx = i;
526                         info->symtab_shndx_start = (void *)hdr +
527                             sechdrs[i].sh_offset;
528                         info->symtab_shndx_stop  = (void *)hdr +
529                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
530                 }
531         }
532         if (!info->symtab_start)
533                 fatal("%s has no symtab?\n", filename);
534 
535         /* Fix endianness in symbols */
536         for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
537                 sym->st_shndx = TO_NATIVE(sym->st_shndx);
538                 sym->st_name  = TO_NATIVE(sym->st_name);
539                 sym->st_value = TO_NATIVE(sym->st_value);
540                 sym->st_size  = TO_NATIVE(sym->st_size);
541         }
542 
543         if (symtab_shndx_idx != ~0U) {
544                 Elf32_Word *p;
545                 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
546                         fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
547                               filename, sechdrs[symtab_shndx_idx].sh_link,
548                               symtab_idx);
549                 /* Fix endianness */
550                 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
551                      p++)
552                         *p = TO_NATIVE(*p);
553         }
554 
555         return 1;
556 }
557 
558 static void parse_elf_finish(struct elf_info *info)
559 {
560         release_file(info->hdr, info->size);
561 }
562 
563 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
564 {
565         /* ignore __this_module, it will be resolved shortly */
566         if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
567                 return 1;
568         /* ignore global offset table */
569         if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
570                 return 1;
571         if (info->hdr->e_machine == EM_PPC)
572                 /* Special register function linked on all modules during final link of .ko */
573                 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
574                     strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
575                     strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
576                     strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
577                     strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
578                     strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
579                         return 1;
580         if (info->hdr->e_machine == EM_PPC64)
581                 /* Special register function linked on all modules during final link of .ko */
582                 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
583                     strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
584                     strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
585                     strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
586                         return 1;
587         /* Do not ignore this symbol */
588         return 0;
589 }
590 
591 #define CRC_PFX     VMLINUX_SYMBOL_STR(__crc_)
592 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
593 
594 static void handle_modversions(struct module *mod, struct elf_info *info,
595                                Elf_Sym *sym, const char *symname)
596 {
597         unsigned int crc;
598         enum export export;
599 
600         if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
601             strncmp(symname, "__ksymtab", 9) == 0)
602                 export = export_from_secname(info, get_secindex(info, sym));
603         else
604                 export = export_from_sec(info, get_secindex(info, sym));
605 
606         switch (sym->st_shndx) {
607         case SHN_COMMON:
608                 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
609                 break;
610         case SHN_ABS:
611                 /* CRC'd symbol */
612                 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
613                         crc = (unsigned int) sym->st_value;
614                         sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
615                                         export);
616                 }
617                 break;
618         case SHN_UNDEF:
619                 /* undefined symbol */
620                 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
621                     ELF_ST_BIND(sym->st_info) != STB_WEAK)
622                         break;
623                 if (ignore_undef_symbol(info, symname))
624                         break;
625 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
626 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
627 /* add compatibility with older glibc */
628 #ifndef STT_SPARC_REGISTER
629 #define STT_SPARC_REGISTER STT_REGISTER
630 #endif
631                 if (info->hdr->e_machine == EM_SPARC ||
632                     info->hdr->e_machine == EM_SPARCV9) {
633                         /* Ignore register directives. */
634                         if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
635                                 break;
636                         if (symname[0] == '.') {
637                                 char *munged = strdup(symname);
638                                 munged[0] = '_';
639                                 munged[1] = toupper(munged[1]);
640                                 symname = munged;
641                         }
642                 }
643 #endif
644 
645 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
646                 if (symname[0] != '_')
647                         break;
648                 else
649                         symname++;
650 #endif
651                 mod->unres = alloc_symbol(symname,
652                                           ELF_ST_BIND(sym->st_info) == STB_WEAK,
653                                           mod->unres);
654                 break;
655         default:
656                 /* All exported symbols */
657                 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
658                         sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
659                                         export);
660                 }
661                 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
662                         mod->has_init = 1;
663                 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
664                         mod->has_cleanup = 1;
665                 break;
666         }
667 }
668 
669 /**
670  * Parse tag=value strings from .modinfo section
671  **/
672 static char *next_string(char *string, unsigned long *secsize)
673 {
674         /* Skip non-zero chars */
675         while (string[0]) {
676                 string++;
677                 if ((*secsize)-- <= 1)
678                         return NULL;
679         }
680 
681         /* Skip any zero padding. */
682         while (!string[0]) {
683                 string++;
684                 if ((*secsize)-- <= 1)
685                         return NULL;
686         }
687         return string;
688 }
689 
690 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
691                               const char *tag, char *info)
692 {
693         char *p;
694         unsigned int taglen = strlen(tag);
695         unsigned long size = modinfo_len;
696 
697         if (info) {
698                 size -= info - (char *)modinfo;
699                 modinfo = next_string(info, &size);
700         }
701 
702         for (p = modinfo; p; p = next_string(p, &size)) {
703                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
704                         return p + taglen + 1;
705         }
706         return NULL;
707 }
708 
709 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
710                          const char *tag)
711 
712 {
713         return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
714 }
715 
716 /**
717  * Test if string s ends in string sub
718  * return 0 if match
719  **/
720 static int strrcmp(const char *s, const char *sub)
721 {
722         int slen, sublen;
723 
724         if (!s || !sub)
725                 return 1;
726 
727         slen = strlen(s);
728         sublen = strlen(sub);
729 
730         if ((slen == 0) || (sublen == 0))
731                 return 1;
732 
733         if (sublen > slen)
734                 return 1;
735 
736         return memcmp(s + slen - sublen, sub, sublen);
737 }
738 
739 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
740 {
741         if (sym)
742                 return elf->strtab + sym->st_name;
743         else
744                 return "(unknown)";
745 }
746 
747 static const char *sec_name(struct elf_info *elf, int secindex)
748 {
749         Elf_Shdr *sechdrs = elf->sechdrs;
750         return (void *)elf->hdr +
751                 elf->sechdrs[elf->secindex_strings].sh_offset +
752                 sechdrs[secindex].sh_name;
753 }
754 
755 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
756 {
757         return (void *)elf->hdr +
758                 elf->sechdrs[elf->secindex_strings].sh_offset +
759                 sechdr->sh_name;
760 }
761 
762 /* if sym is empty or point to a string
763  * like ".[0-9]+" then return 1.
764  * This is the optional prefix added by ld to some sections
765  */
766 static int number_prefix(const char *sym)
767 {
768         if (*sym++ == '\0')
769                 return 1;
770         if (*sym != '.')
771                 return 0;
772         do {
773                 char c = *sym++;
774                 if (c < '' || c > '9')
775                         return 0;
776         } while (*sym);
777         return 1;
778 }
779 
780 /* The pattern is an array of simple patterns.
781  * "foo" will match an exact string equal to "foo"
782  * "*foo" will match a string that ends with "foo"
783  * "foo*" will match a string that begins with "foo"
784  * "foo$" will match a string equal to "foo" or "foo.1"
785  *   where the '1' can be any number including several digits.
786  *   The $ syntax is for sections where ld append a dot number
787  *   to make section name unique.
788  */
789 static int match(const char *sym, const char * const pat[])
790 {
791         const char *p;
792         while (*pat) {
793                 p = *pat++;
794                 const char *endp = p + strlen(p) - 1;
795 
796                 /* "*foo" */
797                 if (*p == '*') {
798                         if (strrcmp(sym, p + 1) == 0)
799                                 return 1;
800                 }
801                 /* "foo*" */
802                 else if (*endp == '*') {
803                         if (strncmp(sym, p, strlen(p) - 1) == 0)
804                                 return 1;
805                 }
806                 /* "foo$" */
807                 else if (*endp == '$') {
808                         if (strncmp(sym, p, strlen(p) - 1) == 0) {
809                                 if (number_prefix(sym + strlen(p) - 1))
810                                         return 1;
811                         }
812                 }
813                 /* no wildcards */
814                 else {
815                         if (strcmp(p, sym) == 0)
816                                 return 1;
817                 }
818         }
819         /* no match */
820         return 0;
821 }
822 
823 /* sections that we do not want to do full section mismatch check on */
824 static const char *section_white_list[] =
825 {
826         ".comment*",
827         ".debug*",
828         ".zdebug*",             /* Compressed debug sections. */
829         ".GCC-command-line",    /* mn10300 */
830         ".GCC.command.line",    /* record-gcc-switches, non mn10300 */
831         ".mdebug*",        /* alpha, score, mips etc. */
832         ".pdr",            /* alpha, score, mips etc. */
833         ".stab*",
834         ".note*",
835         ".got*",
836         ".toc*",
837         ".xt.prop",                              /* xtensa */
838         ".xt.lit",         /* xtensa */
839         ".arcextmap*",                  /* arc */
840         ".gnu.linkonce.arcext*",        /* arc : modules */
841         NULL
842 };
843 
844 /*
845  * This is used to find sections missing the SHF_ALLOC flag.
846  * The cause of this is often a section specified in assembler
847  * without "ax" / "aw".
848  */
849 static void check_section(const char *modname, struct elf_info *elf,
850                           Elf_Shdr *sechdr)
851 {
852         const char *sec = sech_name(elf, sechdr);
853 
854         if (sechdr->sh_type == SHT_PROGBITS &&
855             !(sechdr->sh_flags & SHF_ALLOC) &&
856             !match(sec, section_white_list)) {
857                 warn("%s (%s): unexpected non-allocatable section.\n"
858                      "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
859                      "Note that for example <linux/init.h> contains\n"
860                      "section definitions for use in .S files.\n\n",
861                      modname, sec);
862         }
863 }
864 
865 
866 
867 #define ALL_INIT_DATA_SECTIONS \
868         ".init.setup$", ".init.rodata$", \
869         ".cpuinit.rodata$", ".meminit.rodata$", \
870         ".init.data$", ".cpuinit.data$", ".meminit.data$"
871 #define ALL_EXIT_DATA_SECTIONS \
872         ".exit.data$", ".cpuexit.data$", ".memexit.data$"
873 
874 #define ALL_INIT_TEXT_SECTIONS \
875         ".init.text$", ".cpuinit.text$", ".meminit.text$"
876 #define ALL_EXIT_TEXT_SECTIONS \
877         ".exit.text$", ".cpuexit.text$", ".memexit.text$"
878 
879 #define ALL_PCI_INIT_SECTIONS   \
880         ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
881         ".pci_fixup_enable$", ".pci_fixup_resume$", \
882         ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
883 
884 #define ALL_XXXINIT_SECTIONS CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
885 #define ALL_XXXEXIT_SECTIONS CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS
886 
887 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
888 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
889 
890 #define DATA_SECTIONS ".data$", ".data.rel$"
891 #define TEXT_SECTIONS ".text$"
892 
893 #define INIT_SECTIONS      ".init.*"
894 #define CPU_INIT_SECTIONS  ".cpuinit.*"
895 #define MEM_INIT_SECTIONS  ".meminit.*"
896 
897 #define EXIT_SECTIONS      ".exit.*"
898 #define CPU_EXIT_SECTIONS  ".cpuexit.*"
899 #define MEM_EXIT_SECTIONS  ".memexit.*"
900 
901 /* init data sections */
902 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
903 
904 /* all init sections */
905 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
906 
907 /* All init and exit sections (code + data) */
908 static const char *init_exit_sections[] =
909         {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
910 
911 /* data section */
912 static const char *data_sections[] = { DATA_SECTIONS, NULL };
913 
914 
915 /* symbols in .data that may refer to init/exit sections */
916 #define DEFAULT_SYMBOL_WHITE_LIST                                       \
917         "*driver",                                                      \
918         "*_template", /* scsi uses *_template a lot */                  \
919         "*_timer",    /* arm uses ops structures named _timer a lot */  \
920         "*_sht",      /* scsi also used *_sht to some extent */         \
921         "*_ops",                                                        \
922         "*_probe",                                                      \
923         "*_probe_one",                                                  \
924         "*_console"
925 
926 static const char *head_sections[] = { ".head.text*", NULL };
927 static const char *linker_symbols[] =
928         { "__init_begin", "_sinittext", "_einittext", NULL };
929 
930 enum mismatch {
931         TEXT_TO_ANY_INIT,
932         DATA_TO_ANY_INIT,
933         TEXT_TO_ANY_EXIT,
934         DATA_TO_ANY_EXIT,
935         XXXINIT_TO_SOME_INIT,
936         XXXEXIT_TO_SOME_EXIT,
937         ANY_INIT_TO_ANY_EXIT,
938         ANY_EXIT_TO_ANY_INIT,
939         EXPORT_TO_INIT_EXIT,
940 };
941 
942 struct sectioncheck {
943         const char *fromsec[20];
944         const char *tosec[20];
945         enum mismatch mismatch;
946         const char *symbol_white_list[20];
947 };
948 
949 const struct sectioncheck sectioncheck[] = {
950 /* Do not reference init/exit code/data from
951  * normal code and data
952  */
953 {
954         .fromsec = { TEXT_SECTIONS, NULL },
955         .tosec   = { ALL_INIT_SECTIONS, NULL },
956         .mismatch = TEXT_TO_ANY_INIT,
957         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
958 },
959 {
960         .fromsec = { DATA_SECTIONS, NULL },
961         .tosec   = { ALL_XXXINIT_SECTIONS, NULL },
962         .mismatch = DATA_TO_ANY_INIT,
963         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
964 },
965 {
966         .fromsec = { DATA_SECTIONS, NULL },
967         .tosec   = { INIT_SECTIONS, NULL },
968         .mismatch = DATA_TO_ANY_INIT,
969         .symbol_white_list = {
970                 "*_template", "*_timer", "*_sht", "*_ops",
971                 "*_probe", "*_probe_one", "*_console", NULL
972         },
973 },
974 {
975         .fromsec = { TEXT_SECTIONS, NULL },
976         .tosec   = { ALL_EXIT_SECTIONS, NULL },
977         .mismatch = TEXT_TO_ANY_EXIT,
978         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
979 },
980 {
981         .fromsec = { DATA_SECTIONS, NULL },
982         .tosec   = { ALL_EXIT_SECTIONS, NULL },
983         .mismatch = DATA_TO_ANY_EXIT,
984         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
985 },
986 /* Do not reference init code/data from cpuinit/meminit code/data */
987 {
988         .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
989         .tosec   = { INIT_SECTIONS, NULL },
990         .mismatch = XXXINIT_TO_SOME_INIT,
991         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
992 },
993 /* Do not reference cpuinit code/data from meminit code/data */
994 {
995         .fromsec = { MEM_INIT_SECTIONS, NULL },
996         .tosec   = { CPU_INIT_SECTIONS, NULL },
997         .mismatch = XXXINIT_TO_SOME_INIT,
998         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
999 },
1000 /* Do not reference meminit code/data from cpuinit code/data */
1001 {
1002         .fromsec = { CPU_INIT_SECTIONS, NULL },
1003         .tosec   = { MEM_INIT_SECTIONS, NULL },
1004         .mismatch = XXXINIT_TO_SOME_INIT,
1005         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1006 },
1007 /* Do not reference exit code/data from cpuexit/memexit code/data */
1008 {
1009         .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1010         .tosec   = { EXIT_SECTIONS, NULL },
1011         .mismatch = XXXEXIT_TO_SOME_EXIT,
1012         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1013 },
1014 /* Do not reference cpuexit code/data from memexit code/data */
1015 {
1016         .fromsec = { MEM_EXIT_SECTIONS, NULL },
1017         .tosec   = { CPU_EXIT_SECTIONS, NULL },
1018         .mismatch = XXXEXIT_TO_SOME_EXIT,
1019         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1020 },
1021 /* Do not reference memexit code/data from cpuexit code/data */
1022 {
1023         .fromsec = { CPU_EXIT_SECTIONS, NULL },
1024         .tosec   = { MEM_EXIT_SECTIONS, NULL },
1025         .mismatch = XXXEXIT_TO_SOME_EXIT,
1026         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1027 },
1028 /* Do not use exit code/data from init code */
1029 {
1030         .fromsec = { ALL_INIT_SECTIONS, NULL },
1031         .tosec   = { ALL_EXIT_SECTIONS, NULL },
1032         .mismatch = ANY_INIT_TO_ANY_EXIT,
1033         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1034 },
1035 /* Do not use init code/data from exit code */
1036 {
1037         .fromsec = { ALL_EXIT_SECTIONS, NULL },
1038         .tosec   = { ALL_INIT_SECTIONS, NULL },
1039         .mismatch = ANY_EXIT_TO_ANY_INIT,
1040         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1041 },
1042 {
1043         .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1044         .tosec   = { INIT_SECTIONS, NULL },
1045         .mismatch = ANY_INIT_TO_ANY_EXIT,
1046         .symbol_white_list = { NULL },
1047 },
1048 /* Do not export init/exit functions or data */
1049 {
1050         .fromsec = { "__ksymtab*", NULL },
1051         .tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1052         .mismatch = EXPORT_TO_INIT_EXIT,
1053         .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1054 }
1055 };
1056 
1057 static const struct sectioncheck *section_mismatch(
1058                 const char *fromsec, const char *tosec)
1059 {
1060         int i;
1061         int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1062         const struct sectioncheck *check = &sectioncheck[0];
1063 
1064         for (i = 0; i < elems; i++) {
1065                 if (match(fromsec, check->fromsec) &&
1066                     match(tosec, check->tosec))
1067                         return check;
1068                 check++;
1069         }
1070         return NULL;
1071 }
1072 
1073 /**
1074  * Whitelist to allow certain references to pass with no warning.
1075  *
1076  * Pattern 1:
1077  *   If a module parameter is declared __initdata and permissions=0
1078  *   then this is legal despite the warning generated.
1079  *   We cannot see value of permissions here, so just ignore
1080  *   this pattern.
1081  *   The pattern is identified by:
1082  *   tosec   = .init.data
1083  *   fromsec = .data*
1084  *   atsym   =__param*
1085  *
1086  * Pattern 1a:
1087  *   module_param_call() ops can refer to __init set function if permissions=0
1088  *   The pattern is identified by:
1089  *   tosec   = .init.text
1090  *   fromsec = .data*
1091  *   atsym   = __param_ops_*
1092  *
1093  * Pattern 2:
1094  *   Many drivers utilise a *driver container with references to
1095  *   add, remove, probe functions etc.
1096  *   These functions may often be marked __cpuinit and we do not want to
1097  *   warn here.
1098  *   the pattern is identified by:
1099  *   tosec   = init or exit section
1100  *   fromsec = data section
1101  *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
1102  *           *probe_one, *_console, *_timer
1103  *
1104  * Pattern 3:
1105  *   Whitelist all references from .head.text to any init section
1106  *
1107  * Pattern 4:
1108  *   Some symbols belong to init section but still it is ok to reference
1109  *   these from non-init sections as these symbols don't have any memory
1110  *   allocated for them and symbol address and value are same. So even
1111  *   if init section is freed, its ok to reference those symbols.
1112  *   For ex. symbols marking the init section boundaries.
1113  *   This pattern is identified by
1114  *   refsymname = __init_begin, _sinittext, _einittext
1115  *
1116  **/
1117 static int secref_whitelist(const struct sectioncheck *mismatch,
1118                             const char *fromsec, const char *fromsym,
1119                             const char *tosec, const char *tosym)
1120 {
1121         /* Check for pattern 1 */
1122         if (match(tosec, init_data_sections) &&
1123             match(fromsec, data_sections) &&
1124             (strncmp(fromsym, "__param", strlen("__param")) == 0))
1125                 return 0;
1126 
1127         /* Check for pattern 1a */
1128         if (strcmp(tosec, ".init.text") == 0 &&
1129             match(fromsec, data_sections) &&
1130             (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1131                 return 0;
1132 
1133         /* Check for pattern 2 */
1134         if (match(tosec, init_exit_sections) &&
1135             match(fromsec, data_sections) &&
1136             match(fromsym, mismatch->symbol_white_list))
1137                 return 0;
1138 
1139         /* Check for pattern 3 */
1140         if (match(fromsec, head_sections) &&
1141             match(tosec, init_sections))
1142                 return 0;
1143 
1144         /* Check for pattern 4 */
1145         if (match(tosym, linker_symbols))
1146                 return 0;
1147 
1148         return 1;
1149 }
1150 
1151 /**
1152  * Find symbol based on relocation record info.
1153  * In some cases the symbol supplied is a valid symbol so
1154  * return refsym. If st_name != 0 we assume this is a valid symbol.
1155  * In other cases the symbol needs to be looked up in the symbol table
1156  * based on section and address.
1157  *  **/
1158 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1159                                 Elf_Sym *relsym)
1160 {
1161         Elf_Sym *sym;
1162         Elf_Sym *near = NULL;
1163         Elf64_Sword distance = 20;
1164         Elf64_Sword d;
1165         unsigned int relsym_secindex;
1166 
1167         if (relsym->st_name != 0)
1168                 return relsym;
1169 
1170         relsym_secindex = get_secindex(elf, relsym);
1171         for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1172                 if (get_secindex(elf, sym) != relsym_secindex)
1173                         continue;
1174                 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1175                         continue;
1176                 if (sym->st_value == addr)
1177                         return sym;
1178                 /* Find a symbol nearby - addr are maybe negative */
1179                 d = sym->st_value - addr;
1180                 if (d < 0)
1181                         d = addr - sym->st_value;
1182                 if (d < distance) {
1183                         distance = d;
1184                         near = sym;
1185                 }
1186         }
1187         /* We need a close match */
1188         if (distance < 20)
1189                 return near;
1190         else
1191                 return NULL;
1192 }
1193 
1194 static inline int is_arm_mapping_symbol(const char *str)
1195 {
1196         return str[0] == '$' && strchr("atd", str[1])
1197                && (str[2] == '\0' || str[2] == '.');
1198 }
1199 
1200 /*
1201  * If there's no name there, ignore it; likewise, ignore it if it's
1202  * one of the magic symbols emitted used by current ARM tools.
1203  *
1204  * Otherwise if find_symbols_between() returns those symbols, they'll
1205  * fail the whitelist tests and cause lots of false alarms ... fixable
1206  * only by merging __exit and __init sections into __text, bloating
1207  * the kernel (which is especially evil on embedded platforms).
1208  */
1209 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1210 {
1211         const char *name = elf->strtab + sym->st_name;
1212 
1213         if (!name || !strlen(name))
1214                 return 0;
1215         return !is_arm_mapping_symbol(name);
1216 }
1217 
1218 /*
1219  * Find symbols before or equal addr and after addr - in the section sec.
1220  * If we find two symbols with equal offset prefer one with a valid name.
1221  * The ELF format may have a better way to detect what type of symbol
1222  * it is, but this works for now.
1223  **/
1224 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1225                                  const char *sec)
1226 {
1227         Elf_Sym *sym;
1228         Elf_Sym *near = NULL;
1229         Elf_Addr distance = ~0;
1230 
1231         for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1232                 const char *symsec;
1233 
1234                 if (is_shndx_special(sym->st_shndx))
1235                         continue;
1236                 symsec = sec_name(elf, get_secindex(elf, sym));
1237                 if (strcmp(symsec, sec) != 0)
1238                         continue;
1239                 if (!is_valid_name(elf, sym))
1240                         continue;
1241                 if (sym->st_value <= addr) {
1242                         if ((addr - sym->st_value) < distance) {
1243                                 distance = addr - sym->st_value;
1244                                 near = sym;
1245                         } else if ((addr - sym->st_value) == distance) {
1246                                 near = sym;
1247                         }
1248                 }
1249         }
1250         return near;
1251 }
1252 
1253 /*
1254  * Convert a section name to the function/data attribute
1255  * .init.text => __init
1256  * .cpuinit.data => __cpudata
1257  * .memexitconst => __memconst
1258  * etc.
1259  *
1260  * The memory of returned value has been allocated on a heap. The user of this
1261  * method should free it after usage.
1262 */
1263 static char *sec2annotation(const char *s)
1264 {
1265         if (match(s, init_exit_sections)) {
1266                 char *p = malloc(20);
1267                 char *r = p;
1268 
1269                 *p++ = '_';
1270                 *p++ = '_';
1271                 if (*s == '.')
1272                         s++;
1273                 while (*s && *s != '.')
1274                         *p++ = *s++;
1275                 *p = '\0';
1276                 if (*s == '.')
1277                         s++;
1278                 if (strstr(s, "rodata") != NULL)
1279                         strcat(p, "const ");
1280                 else if (strstr(s, "data") != NULL)
1281                         strcat(p, "data ");
1282                 else
1283                         strcat(p, " ");
1284                 return r;
1285         } else {
1286                 return strdup("");
1287         }
1288 }
1289 
1290 static int is_function(Elf_Sym *sym)
1291 {
1292         if (sym)
1293                 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1294         else
1295                 return -1;
1296 }
1297 
1298 static void print_section_list(const char * const list[20])
1299 {
1300         const char *const *s = list;
1301 
1302         while (*s) {
1303                 fprintf(stderr, "%s", *s);
1304                 s++;
1305                 if (*s)
1306                         fprintf(stderr, ", ");
1307         }
1308         fprintf(stderr, "\n");
1309 }
1310 
1311 /*
1312  * Print a warning about a section mismatch.
1313  * Try to find symbols near it so user can find it.
1314  * Check whitelist before warning - it may be a false positive.
1315  */
1316 static void report_sec_mismatch(const char *modname,
1317                                 const struct sectioncheck *mismatch,
1318                                 const char *fromsec,
1319                                 unsigned long long fromaddr,
1320                                 const char *fromsym,
1321                                 int from_is_func,
1322                                 const char *tosec, const char *tosym,
1323                                 int to_is_func)
1324 {
1325         const char *from, *from_p;
1326         const char *to, *to_p;
1327         char *prl_from;
1328         char *prl_to;
1329 
1330         switch (from_is_func) {
1331         case 0: from = "variable"; from_p = "";   break;
1332         case 1: from = "function"; from_p = "()"; break;
1333         default: from = "(unknown reference)"; from_p = ""; break;
1334         }
1335         switch (to_is_func) {
1336         case 0: to = "variable"; to_p = "";   break;
1337         case 1: to = "function"; to_p = "()"; break;
1338         default: to = "(unknown reference)"; to_p = ""; break;
1339         }
1340 
1341         sec_mismatch_count++;
1342         if (!sec_mismatch_verbose)
1343                 return;
1344 
1345         warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1346              "to the %s %s:%s%s\n",
1347              modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1348              tosym, to_p);
1349 
1350         switch (mismatch->mismatch) {
1351         case TEXT_TO_ANY_INIT:
1352                 prl_from = sec2annotation(fromsec);
1353                 prl_to = sec2annotation(tosec);
1354                 fprintf(stderr,
1355                 "The function %s%s() references\n"
1356                 "the %s %s%s%s.\n"
1357                 "This is often because %s lacks a %s\n"
1358                 "annotation or the annotation of %s is wrong.\n",
1359                 prl_from, fromsym,
1360                 to, prl_to, tosym, to_p,
1361                 fromsym, prl_to, tosym);
1362                 free(prl_from);
1363                 free(prl_to);
1364                 break;
1365         case DATA_TO_ANY_INIT: {
1366                 prl_to = sec2annotation(tosec);
1367                 fprintf(stderr,
1368                 "The variable %s references\n"
1369                 "the %s %s%s%s\n"
1370                 "If the reference is valid then annotate the\n"
1371                 "variable with __init* or __refdata (see linux/init.h) "
1372                 "or name the variable:\n",
1373                 fromsym, to, prl_to, tosym, to_p);
1374                 print_section_list(mismatch->symbol_white_list);
1375                 free(prl_to);
1376                 break;
1377         }
1378         case TEXT_TO_ANY_EXIT:
1379                 prl_to = sec2annotation(tosec);
1380                 fprintf(stderr,
1381                 "The function %s() references a %s in an exit section.\n"
1382                 "Often the %s %s%s has valid usage outside the exit section\n"
1383                 "and the fix is to remove the %sannotation of %s.\n",
1384                 fromsym, to, to, tosym, to_p, prl_to, tosym);
1385                 free(prl_to);
1386                 break;
1387         case DATA_TO_ANY_EXIT: {
1388                 prl_to = sec2annotation(tosec);
1389                 fprintf(stderr,
1390                 "The variable %s references\n"
1391                 "the %s %s%s%s\n"
1392                 "If the reference is valid then annotate the\n"
1393                 "variable with __exit* (see linux/init.h) or "
1394                 "name the variable:\n",
1395                 fromsym, to, prl_to, tosym, to_p);
1396                 print_section_list(mismatch->symbol_white_list);
1397                 free(prl_to);
1398                 break;
1399         }
1400         case XXXINIT_TO_SOME_INIT:
1401         case XXXEXIT_TO_SOME_EXIT:
1402                 prl_from = sec2annotation(fromsec);
1403                 prl_to = sec2annotation(tosec);
1404                 fprintf(stderr,
1405                 "The %s %s%s%s references\n"
1406                 "a %s %s%s%s.\n"
1407                 "If %s is only used by %s then\n"
1408                 "annotate %s with a matching annotation.\n",
1409                 from, prl_from, fromsym, from_p,
1410                 to, prl_to, tosym, to_p,
1411                 tosym, fromsym, tosym);
1412                 free(prl_from);
1413                 free(prl_to);
1414                 break;
1415         case ANY_INIT_TO_ANY_EXIT:
1416                 prl_from = sec2annotation(fromsec);
1417                 prl_to = sec2annotation(tosec);
1418                 fprintf(stderr,
1419                 "The %s %s%s%s references\n"
1420                 "a %s %s%s%s.\n"
1421                 "This is often seen when error handling "
1422                 "in the init function\n"
1423                 "uses functionality in the exit path.\n"
1424                 "The fix is often to remove the %sannotation of\n"
1425                 "%s%s so it may be used outside an exit section.\n",
1426                 from, prl_from, fromsym, from_p,
1427                 to, prl_to, tosym, to_p,
1428                 prl_to, tosym, to_p);
1429                 free(prl_from);
1430                 free(prl_to);
1431                 break;
1432         case ANY_EXIT_TO_ANY_INIT:
1433                 prl_from = sec2annotation(fromsec);
1434                 prl_to = sec2annotation(tosec);
1435                 fprintf(stderr,
1436                 "The %s %s%s%s references\n"
1437                 "a %s %s%s%s.\n"
1438                 "This is often seen when error handling "
1439                 "in the exit function\n"
1440                 "uses functionality in the init path.\n"
1441                 "The fix is often to remove the %sannotation of\n"
1442                 "%s%s so it may be used outside an init section.\n",
1443                 from, prl_from, fromsym, from_p,
1444                 to, prl_to, tosym, to_p,
1445                 prl_to, tosym, to_p);
1446                 free(prl_from);
1447                 free(prl_to);
1448                 break;
1449         case EXPORT_TO_INIT_EXIT:
1450                 prl_to = sec2annotation(tosec);
1451                 fprintf(stderr,
1452                 "The symbol %s is exported and annotated %s\n"
1453                 "Fix this by removing the %sannotation of %s "
1454                 "or drop the export.\n",
1455                 tosym, prl_to, prl_to, tosym);
1456                 free(prl_to);
1457                 break;
1458         }
1459         fprintf(stderr, "\n");
1460 }
1461 
1462 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1463                                    Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1464 {
1465         const char *tosec;
1466         const struct sectioncheck *mismatch;
1467 
1468         tosec = sec_name(elf, get_secindex(elf, sym));
1469         mismatch = section_mismatch(fromsec, tosec);
1470         if (mismatch) {
1471                 Elf_Sym *to;
1472                 Elf_Sym *from;
1473                 const char *tosym;
1474                 const char *fromsym;
1475 
1476                 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1477                 fromsym = sym_name(elf, from);
1478                 to = find_elf_symbol(elf, r->r_addend, sym);
1479                 tosym = sym_name(elf, to);
1480 
1481                 /* check whitelist - we may ignore it */
1482                 if (secref_whitelist(mismatch,
1483                                         fromsec, fromsym, tosec, tosym)) {
1484                         report_sec_mismatch(modname, mismatch,
1485                            fromsec, r->r_offset, fromsym,
1486                            is_function(from), tosec, tosym,
1487                            is_function(to));
1488                 }
1489         }
1490 }
1491 
1492 static unsigned int *reloc_location(struct elf_info *elf,
1493                                     Elf_Shdr *sechdr, Elf_Rela *r)
1494 {
1495         Elf_Shdr *sechdrs = elf->sechdrs;
1496         int section = sechdr->sh_info;
1497 
1498         return (void *)elf->hdr + sechdrs[section].sh_offset +
1499                 r->r_offset;
1500 }
1501 
1502 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1503 {
1504         unsigned int r_typ = ELF_R_TYPE(r->r_info);
1505         unsigned int *location = reloc_location(elf, sechdr, r);
1506 
1507         switch (r_typ) {
1508         case R_386_32:
1509                 r->r_addend = TO_NATIVE(*location);
1510                 break;
1511         case R_386_PC32:
1512                 r->r_addend = TO_NATIVE(*location) + 4;
1513                 /* For CONFIG_RELOCATABLE=y */
1514                 if (elf->hdr->e_type == ET_EXEC)
1515                         r->r_addend += r->r_offset;
1516                 break;
1517         }
1518         return 0;
1519 }
1520 
1521 #ifndef R_ARM_CALL
1522 #define R_ARM_CALL      28
1523 #endif
1524 #ifndef R_ARM_JUMP24
1525 #define R_ARM_JUMP24    29
1526 #endif
1527 
1528 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1529 {
1530         unsigned int r_typ = ELF_R_TYPE(r->r_info);
1531 
1532         switch (r_typ) {
1533         case R_ARM_ABS32:
1534                 /* From ARM ABI: (S + A) | T */
1535                 r->r_addend = (int)(long)
1536                               (elf->symtab_start + ELF_R_SYM(r->r_info));
1537                 break;
1538         case R_ARM_PC24:
1539         case R_ARM_CALL:
1540         case R_ARM_JUMP24:
1541                 /* From ARM ABI: ((S + A) | T) - P */
1542                 r->r_addend = (int)(long)(elf->hdr +
1543                               sechdr->sh_offset +
1544                               (r->r_offset - sechdr->sh_addr));
1545                 break;
1546         default:
1547                 return 1;
1548         }
1549         return 0;
1550 }
1551 
1552 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1553 {
1554         unsigned int r_typ = ELF_R_TYPE(r->r_info);
1555         unsigned int *location = reloc_location(elf, sechdr, r);
1556         unsigned int inst;
1557 
1558         if (r_typ == R_MIPS_HI16)
1559                 return 1;       /* skip this */
1560         inst = TO_NATIVE(*location);
1561         switch (r_typ) {
1562         case R_MIPS_LO16:
1563                 r->r_addend = inst & 0xffff;
1564                 break;
1565         case R_MIPS_26:
1566                 r->r_addend = (inst & 0x03ffffff) << 2;
1567                 break;
1568         case R_MIPS_32:
1569                 r->r_addend = inst;
1570                 break;
1571         }
1572         return 0;
1573 }
1574 
1575 static void section_rela(const char *modname, struct elf_info *elf,
1576                          Elf_Shdr *sechdr)
1577 {
1578         Elf_Sym  *sym;
1579         Elf_Rela *rela;
1580         Elf_Rela r;
1581         unsigned int r_sym;
1582         const char *fromsec;
1583 
1584         Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1585         Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1586 
1587         fromsec = sech_name(elf, sechdr);
1588         fromsec += strlen(".rela");
1589         /* if from section (name) is know good then skip it */
1590         if (match(fromsec, section_white_list))
1591                 return;
1592 
1593         for (rela = start; rela < stop; rela++) {
1594                 r.r_offset = TO_NATIVE(rela->r_offset);
1595 #if KERNEL_ELFCLASS == ELFCLASS64
1596                 if (elf->hdr->e_machine == EM_MIPS) {
1597                         unsigned int r_typ;
1598                         r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1599                         r_sym = TO_NATIVE(r_sym);
1600                         r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1601                         r.r_info = ELF64_R_INFO(r_sym, r_typ);
1602                 } else {
1603                         r.r_info = TO_NATIVE(rela->r_info);
1604                         r_sym = ELF_R_SYM(r.r_info);
1605                 }
1606 #else
1607                 r.r_info = TO_NATIVE(rela->r_info);
1608                 r_sym = ELF_R_SYM(r.r_info);
1609 #endif
1610                 r.r_addend = TO_NATIVE(rela->r_addend);
1611                 sym = elf->symtab_start + r_sym;
1612                 /* Skip special sections */
1613                 if (is_shndx_special(sym->st_shndx))
1614                         continue;
1615                 check_section_mismatch(modname, elf, &r, sym, fromsec);
1616         }
1617 }
1618 
1619 static void section_rel(const char *modname, struct elf_info *elf,
1620                         Elf_Shdr *sechdr)
1621 {
1622         Elf_Sym *sym;
1623         Elf_Rel *rel;
1624         Elf_Rela r;
1625         unsigned int r_sym;
1626         const char *fromsec;
1627 
1628         Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1629         Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1630 
1631         fromsec = sech_name(elf, sechdr);
1632         fromsec += strlen(".rel");
1633         /* if from section (name) is know good then skip it */
1634         if (match(fromsec, section_white_list))
1635                 return;
1636 
1637         for (rel = start; rel < stop; rel++) {
1638                 r.r_offset = TO_NATIVE(rel->r_offset);
1639 #if KERNEL_ELFCLASS == ELFCLASS64
1640                 if (elf->hdr->e_machine == EM_MIPS) {
1641                         unsigned int r_typ;
1642                         r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1643                         r_sym = TO_NATIVE(r_sym);
1644                         r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1645                         r.r_info = ELF64_R_INFO(r_sym, r_typ);
1646                 } else {
1647                         r.r_info = TO_NATIVE(rel->r_info);
1648                         r_sym = ELF_R_SYM(r.r_info);
1649                 }
1650 #else
1651                 r.r_info = TO_NATIVE(rel->r_info);
1652                 r_sym = ELF_R_SYM(r.r_info);
1653 #endif
1654                 r.r_addend = 0;
1655                 switch (elf->hdr->e_machine) {
1656                 case EM_386:
1657                         if (addend_386_rel(elf, sechdr, &r))
1658                                 continue;
1659                         break;
1660                 case EM_ARM:
1661                         if (addend_arm_rel(elf, sechdr, &r))
1662                                 continue;
1663                         break;
1664                 case EM_MIPS:
1665                         if (addend_mips_rel(elf, sechdr, &r))
1666                                 continue;
1667                         break;
1668                 }
1669                 sym = elf->symtab_start + r_sym;
1670                 /* Skip special sections */
1671                 if (is_shndx_special(sym->st_shndx))
1672                         continue;
1673                 check_section_mismatch(modname, elf, &r, sym, fromsec);
1674         }
1675 }
1676 
1677 /**
1678  * A module includes a number of sections that are discarded
1679  * either when loaded or when used as built-in.
1680  * For loaded modules all functions marked __init and all data
1681  * marked __initdata will be discarded when the module has been initialized.
1682  * Likewise for modules used built-in the sections marked __exit
1683  * are discarded because __exit marked function are supposed to be called
1684  * only when a module is unloaded which never happens for built-in modules.
1685  * The check_sec_ref() function traverses all relocation records
1686  * to find all references to a section that reference a section that will
1687  * be discarded and warns about it.
1688  **/
1689 static void check_sec_ref(struct module *mod, const char *modname,
1690                           struct elf_info *elf)
1691 {
1692         int i;
1693         Elf_Shdr *sechdrs = elf->sechdrs;
1694 
1695         /* Walk through all sections */
1696         for (i = 0; i < elf->num_sections; i++) {
1697                 check_section(modname, elf, &elf->sechdrs[i]);
1698                 /* We want to process only relocation sections and not .init */
1699                 if (sechdrs[i].sh_type == SHT_RELA)
1700                         section_rela(modname, elf, &elf->sechdrs[i]);
1701                 else if (sechdrs[i].sh_type == SHT_REL)
1702                         section_rel(modname, elf, &elf->sechdrs[i]);
1703         }
1704 }
1705 
1706 static void read_symbols(char *modname)
1707 {
1708         const char *symname;
1709         char *version;
1710         char *license;
1711         struct module *mod;
1712         struct elf_info info = { };
1713         Elf_Sym *sym;
1714 
1715         if (!parse_elf(&info, modname))
1716                 return;
1717 
1718         mod = new_module(modname);
1719 
1720         /* When there's no vmlinux, don't print warnings about
1721          * unresolved symbols (since there'll be too many ;) */
1722         if (is_vmlinux(modname)) {
1723                 have_vmlinux = 1;
1724                 mod->skip = 1;
1725         }
1726 
1727         license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1728         if (info.modinfo && !license && !is_vmlinux(modname))
1729                 warn("modpost: missing MODULE_LICENSE() in %s\n"
1730                      "see include/linux/module.h for "
1731                      "more information\n", modname);
1732         while (license) {
1733                 if (license_is_gpl_compatible(license))
1734                         mod->gpl_compatible = 1;
1735                 else {
1736                         mod->gpl_compatible = 0;
1737                         break;
1738                 }
1739                 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1740                                            "license", license);
1741         }
1742 
1743         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1744                 symname = info.strtab + sym->st_name;
1745 
1746                 handle_modversions(mod, &info, sym, symname);
1747                 handle_moddevtable(mod, &info, sym, symname);
1748         }
1749         if (!is_vmlinux(modname) ||
1750              (is_vmlinux(modname) && vmlinux_section_warnings))
1751                 check_sec_ref(mod, modname, &info);
1752 
1753         version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1754         if (version)
1755                 maybe_frob_rcs_version(modname, version, info.modinfo,
1756                                        version - (char *)info.hdr);
1757         if (version || (all_versions && !is_vmlinux(modname)))
1758                 get_src_version(modname, mod->srcversion,
1759                                 sizeof(mod->srcversion)-1);
1760 
1761         parse_elf_finish(&info);
1762 
1763         /* Our trick to get versioning for module struct etc. - it's
1764          * never passed as an argument to an exported function, so
1765          * the automatic versioning doesn't pick it up, but it's really
1766          * important anyhow */
1767         if (modversions)
1768                 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1769 }
1770 
1771 static void read_symbols_from_files(const char *filename)
1772 {
1773         FILE *in = stdin;
1774         char fname[PATH_MAX];
1775 
1776         if (strcmp(filename, "-") != 0) {
1777                 in = fopen(filename, "r");
1778                 if (!in)
1779                         fatal("Can't open filenames file %s: %m", filename);
1780         }
1781 
1782         while (fgets(fname, PATH_MAX, in) != NULL) {
1783                 if (strends(fname, "\n"))
1784                         fname[strlen(fname)-1] = '\0';
1785                 read_symbols(fname);
1786         }
1787 
1788         if (in != stdin)
1789                 fclose(in);
1790 }
1791 
1792 #define SZ 500
1793 
1794 /* We first write the generated file into memory using the
1795  * following helper, then compare to the file on disk and
1796  * only update the later if anything changed */
1797 
1798 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1799                                                       const char *fmt, ...)
1800 {
1801         char tmp[SZ];
1802         int len;
1803         va_list ap;
1804 
1805         va_start(ap, fmt);
1806         len = vsnprintf(tmp, SZ, fmt, ap);
1807         buf_write(buf, tmp, len);
1808         va_end(ap);
1809 }
1810 
1811 void buf_write(struct buffer *buf, const char *s, int len)
1812 {
1813         if (buf->size - buf->pos < len) {
1814                 buf->size += len + SZ;
1815                 buf->p = realloc(buf->p, buf->size);
1816         }
1817         strncpy(buf->p + buf->pos, s, len);
1818         buf->pos += len;
1819 }
1820 
1821 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1822 {
1823         const char *e = is_vmlinux(m) ?"":".ko";
1824 
1825         switch (exp) {
1826         case export_gpl:
1827                 fatal("modpost: GPL-incompatible module %s%s "
1828                       "uses GPL-only symbol '%s'\n", m, e, s);
1829                 break;
1830         case export_unused_gpl:
1831                 fatal("modpost: GPL-incompatible module %s%s "
1832                       "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1833                 break;
1834         case export_gpl_future:
1835                 warn("modpost: GPL-incompatible module %s%s "
1836                       "uses future GPL-only symbol '%s'\n", m, e, s);
1837                 break;
1838         case export_plain:
1839         case export_unused:
1840         case export_unknown:
1841                 /* ignore */
1842                 break;
1843         }
1844 }
1845 
1846 static void check_for_unused(enum export exp, const char *m, const char *s)
1847 {
1848         const char *e = is_vmlinux(m) ?"":".ko";
1849 
1850         switch (exp) {
1851         case export_unused:
1852         case export_unused_gpl:
1853                 warn("modpost: module %s%s "
1854                       "uses symbol '%s' marked UNUSED\n", m, e, s);
1855                 break;
1856         default:
1857                 /* ignore */
1858                 break;
1859         }
1860 }
1861 
1862 static void check_exports(struct module *mod)
1863 {
1864         struct symbol *s, *exp;
1865 
1866         for (s = mod->unres; s; s = s->next) {
1867                 const char *basename;
1868                 exp = find_symbol(s->name);
1869                 if (!exp || exp->module == mod)
1870                         continue;
1871                 basename = strrchr(mod->name, '/');
1872                 if (basename)
1873                         basename++;
1874                 else
1875                         basename = mod->name;
1876                 if (!mod->gpl_compatible)
1877                         check_for_gpl_usage(exp->export, basename, exp->name);
1878                 check_for_unused(exp->export, basename, exp->name);
1879         }
1880 }
1881 
1882 /**
1883  * Header for the generated file
1884  **/
1885 static void add_header(struct buffer *b, struct module *mod)
1886 {
1887         buf_printf(b, "#include <linux/module.h>\n");
1888         buf_printf(b, "#include <linux/vermagic.h>\n");
1889         buf_printf(b, "#include <linux/compiler.h>\n");
1890         buf_printf(b, "\n");
1891         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1892         buf_printf(b, "\n");
1893         buf_printf(b, "struct module __this_module\n");
1894         buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1895         buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1896         if (mod->has_init)
1897                 buf_printf(b, "\t.init = init_module,\n");
1898         if (mod->has_cleanup)
1899                 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1900                               "\t.exit = cleanup_module,\n"
1901                               "#endif\n");
1902         buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1903         buf_printf(b, "};\n");
1904 }
1905 
1906 static void add_intree_flag(struct buffer *b, int is_intree)
1907 {
1908         if (is_intree)
1909                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1910 }
1911 
1912 static void add_staging_flag(struct buffer *b, const char *name)
1913 {
1914         static const char *staging_dir = "drivers/staging";
1915 
1916         if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1917                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1918 }
1919 
1920 /**
1921  * Record CRCs for unresolved symbols
1922  **/
1923 static int add_versions(struct buffer *b, struct module *mod)
1924 {
1925         struct symbol *s, *exp;
1926         int err = 0;
1927 
1928         for (s = mod->unres; s; s = s->next) {
1929                 exp = find_symbol(s->name);
1930                 if (!exp || exp->module == mod) {
1931                         if (have_vmlinux && !s->weak) {
1932                                 if (warn_unresolved) {
1933                                         warn("\"%s\" [%s.ko] undefined!\n",
1934                                              s->name, mod->name);
1935                                 } else {
1936                                         merror("\"%s\" [%s.ko] undefined!\n",
1937                                                   s->name, mod->name);
1938                                         err = 1;
1939                                 }
1940                         }
1941                         continue;
1942                 }
1943                 s->module = exp->module;
1944                 s->crc_valid = exp->crc_valid;
1945                 s->crc = exp->crc;
1946         }
1947 
1948         if (!modversions)
1949                 return err;
1950 
1951         buf_printf(b, "\n");
1952         buf_printf(b, "static const struct modversion_info ____versions[]\n");
1953         buf_printf(b, "__used\n");
1954         buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1955 
1956         for (s = mod->unres; s; s = s->next) {
1957                 if (!s->module)
1958                         continue;
1959                 if (!s->crc_valid) {
1960                         warn("\"%s\" [%s.ko] has no CRC!\n",
1961                                 s->name, mod->name);
1962                         continue;
1963                 }
1964                 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1965                            s->crc, s->name);
1966         }
1967 
1968         buf_printf(b, "};\n");
1969 
1970         return err;
1971 }
1972 
1973 static void add_depends(struct buffer *b, struct module *mod,
1974                         struct module *modules)
1975 {
1976         struct symbol *s;
1977         struct module *m;
1978         int first = 1;
1979 
1980         for (m = modules; m; m = m->next)
1981                 m->seen = is_vmlinux(m->name);
1982 
1983         buf_printf(b, "\n");
1984         buf_printf(b, "static const char __module_depends[]\n");
1985         buf_printf(b, "__used\n");
1986         buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1987         buf_printf(b, "\"depends=");
1988         for (s = mod->unres; s; s = s->next) {
1989                 const char *p;
1990                 if (!s->module)
1991                         continue;
1992 
1993                 if (s->module->seen)
1994                         continue;
1995 
1996                 s->module->seen = 1;
1997                 p = strrchr(s->module->name, '/');
1998                 if (p)
1999                         p++;
2000                 else
2001                         p = s->module->name;
2002                 buf_printf(b, "%s%s", first ? "" : ",", p);
2003                 first = 0;
2004         }
2005         buf_printf(b, "\";\n");
2006 }
2007 
2008 static void add_srcversion(struct buffer *b, struct module *mod)
2009 {
2010         if (mod->srcversion[0]) {
2011                 buf_printf(b, "\n");
2012                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2013                            mod->srcversion);
2014         }
2015 }
2016 
2017 static void write_if_changed(struct buffer *b, const char *fname)
2018 {
2019         char *tmp;
2020         FILE *file;
2021         struct stat st;
2022 
2023         file = fopen(fname, "r");
2024         if (!file)
2025                 goto write;
2026 
2027         if (fstat(fileno(file), &st) < 0)
2028                 goto close_write;
2029 
2030         if (st.st_size != b->pos)
2031                 goto close_write;
2032 
2033         tmp = NOFAIL(malloc(b->pos));
2034         if (fread(tmp, 1, b->pos, file) != b->pos)
2035                 goto free_write;
2036 
2037         if (memcmp(tmp, b->p, b->pos) != 0)
2038                 goto free_write;
2039 
2040         free(tmp);
2041         fclose(file);
2042         return;
2043 
2044  free_write:
2045         free(tmp);
2046  close_write:
2047         fclose(file);
2048  write:
2049         file = fopen(fname, "w");
2050         if (!file) {
2051                 perror(fname);
2052                 exit(1);
2053         }
2054         if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2055                 perror(fname);
2056                 exit(1);
2057         }
2058         fclose(file);
2059 }
2060 
2061 /* parse Module.symvers file. line format:
2062  * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2063  **/
2064 static void read_dump(const char *fname, unsigned int kernel)
2065 {
2066         unsigned long size, pos = 0;
2067         void *file = grab_file(fname, &size);
2068         char *line;
2069 
2070         if (!file)
2071                 /* No symbol versions, silently ignore */
2072                 return;
2073 
2074         while ((line = get_next_line(&pos, file, size))) {
2075                 char *symname, *modname, *d, *export, *end;
2076                 unsigned int crc;
2077                 struct module *mod;
2078                 struct symbol *s;
2079 
2080                 if (!(symname = strchr(line, '\t')))
2081                         goto fail;
2082                 *symname++ = '\0';
2083                 if (!(modname = strchr(symname, '\t')))
2084                         goto fail;
2085                 *modname++ = '\0';
2086                 if ((export = strchr(modname, '\t')) != NULL)
2087                         *export++ = '\0';
2088                 if (export && ((end = strchr(export, '\t')) != NULL))
2089                         *end = '\0';
2090                 crc = strtoul(line, &d, 16);
2091                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2092                         goto fail;
2093                 mod = find_module(modname);
2094                 if (!mod) {
2095                         if (is_vmlinux(modname))
2096                                 have_vmlinux = 1;
2097                         mod = new_module(modname);
2098                         mod->skip = 1;
2099                 }
2100                 s = sym_add_exported(symname, mod, export_no(export));
2101                 s->kernel    = kernel;
2102                 s->preloaded = 1;
2103                 sym_update_crc(symname, mod, crc, export_no(export));
2104         }
2105         return;
2106 fail:
2107         fatal("parse error in symbol dump file\n");
2108 }
2109 
2110 /* For normal builds always dump all symbols.
2111  * For external modules only dump symbols
2112  * that are not read from kernel Module.symvers.
2113  **/
2114 static int dump_sym(struct symbol *sym)
2115 {
2116         if (!external_module)
2117                 return 1;
2118         if (sym->vmlinux || sym->kernel)
2119                 return 0;
2120         return 1;
2121 }
2122 
2123 static void write_dump(const char *fname)
2124 {
2125         struct buffer buf = { };
2126         struct symbol *symbol;
2127         int n;
2128 
2129         for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2130                 symbol = symbolhash[n];
2131                 while (symbol) {
2132                         if (dump_sym(symbol))
2133                                 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2134                                         symbol->crc, symbol->name,
2135                                         symbol->module->name,
2136                                         export_str(symbol->export));
2137                         symbol = symbol->next;
2138                 }
2139         }
2140         write_if_changed(&buf, fname);
2141 }
2142 
2143 struct ext_sym_list {
2144         struct ext_sym_list *next;
2145         const char *file;
2146 };
2147 
2148 int main(int argc, char **argv)
2149 {
2150         struct module *mod;
2151         struct buffer buf = { };
2152         char *kernel_read = NULL, *module_read = NULL;
2153         char *dump_write = NULL, *files_source = NULL;
2154         int opt;
2155         int err;
2156         struct ext_sym_list *extsym_iter;
2157         struct ext_sym_list *extsym_start = NULL;
2158 
2159         while ((opt = getopt(argc, argv, "i:I:e:msST:o:awM:K:")) != -1) {
2160                 switch (opt) {
2161                 case 'i':
2162                         kernel_read = optarg;
2163                         break;
2164                 case 'I':
2165                         module_read = optarg;
2166                         external_module = 1;
2167                         break;
2168                 case 'e':
2169                         external_module = 1;
2170                         extsym_iter =
2171                            NOFAIL(malloc(sizeof(*extsym_iter)));
2172                         extsym_iter->next = extsym_start;
2173                         extsym_iter->file = optarg;
2174                         extsym_start = extsym_iter;
2175                         break;
2176                 case 'm':
2177                         modversions = 1;
2178                         break;
2179                 case 'o':
2180                         dump_write = optarg;
2181                         break;
2182                 case 'a':
2183                         all_versions = 1;
2184                         break;
2185                 case 's':
2186                         vmlinux_section_warnings = 0;
2187                         break;
2188                 case 'S':
2189                         sec_mismatch_verbose = 0;
2190                         break;
2191                 case 'T':
2192                         files_source = optarg;
2193                         break;
2194                 case 'w':
2195                         warn_unresolved = 1;
2196                         break;
2197                 default:
2198                         exit(1);
2199                 }
2200         }
2201 
2202         if (kernel_read)
2203                 read_dump(kernel_read, 1);
2204         if (module_read)
2205                 read_dump(module_read, 0);
2206         while (extsym_start) {
2207                 read_dump(extsym_start->file, 0);
2208                 extsym_iter = extsym_start->next;
2209                 free(extsym_start);
2210                 extsym_start = extsym_iter;
2211         }
2212 
2213         while (optind < argc)
2214                 read_symbols(argv[optind++]);
2215 
2216         if (files_source)
2217                 read_symbols_from_files(files_source);
2218 
2219         for (mod = modules; mod; mod = mod->next) {
2220                 if (mod->skip)
2221                         continue;
2222                 check_exports(mod);
2223         }
2224 
2225         err = 0;
2226 
2227         for (mod = modules; mod; mod = mod->next) {
2228                 char fname[strlen(mod->name) + 10];
2229 
2230                 if (mod->skip)
2231                         continue;
2232 
2233                 buf.pos = 0;
2234 
2235                 add_header(&buf, mod);
2236                 add_intree_flag(&buf, !external_module);
2237                 add_staging_flag(&buf, mod->name);
2238                 err |= add_versions(&buf, mod);
2239                 add_depends(&buf, mod, modules);
2240                 add_moddevtable(&buf, mod);
2241                 add_srcversion(&buf, mod);
2242 
2243                 sprintf(fname, "%s.mod.c", mod->name);
2244                 write_if_changed(&buf, fname);
2245         }
2246 
2247         if (dump_write)
2248                 write_dump(dump_write);
2249         if (sec_mismatch_count && !sec_mismatch_verbose)
2250                 warn("modpost: Found %d section mismatch(es).\n"
2251                      "To see full details build your kernel with:\n"
2252                      "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2253                      sec_mismatch_count);
2254 
2255         return err;
2256 }
2257 

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