usr.sbin/kldxref/kldxref.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause
   3  *
   4  * Copyright (c) 2000, Boris Popov
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *    This product includes software developed by Boris Popov.
  18  * 4. Neither the name of the author nor the names of any co-contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $FreeBSD$
  35  */
  36
  37 #include <sys/types.h>
  38 #include <sys/param.h>
  39 #include <sys/endian.h>
  40 #include <sys/exec.h>
  41 #include <sys/queue.h>
  42 #include <sys/kernel.h>
  43 #include <sys/reboot.h>
  44 #include <sys/linker.h>
  45 #include <sys/stat.h>
  46 #include <sys/module.h>
  47 #define FREEBSD_ELF
  48
  49 #include <ctype.h>
  50 #include <err.h>
  51 #include <errno.h>
  52 #include <fts.h>
  53 #include <stdbool.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <unistd.h>
  58 #include <machine/elf.h>
  59
  60 #include "ef.h"
  61
  62 #define MAXRECSIZE      (64 << 10)      /* 64k */
  63 #define check(val)      if ((error = (val)) != 0) break
  64
  65 static bool dflag;      /* do not create a hint file, only write on stdout */
  66 static int verbose;
  67
  68 static FILE *fxref;     /* current hints file */
  69
  70 static const char *xref_file = "linker.hints";
  71
  72 /*
  73  * A record is stored in the static buffer recbuf before going to disk.
  74  */
  75 static char recbuf[MAXRECSIZE];
  76 static int recpos;      /* current write position */
  77 static int reccnt;      /* total record written to this file so far */
  78
  79 static void
  80 intalign(void)
  81 {
  82
  83         recpos = roundup2(recpos, sizeof(int));
  84 }
  85
  86 static void
  87 record_start(void)
  88 {
  89
  90         recpos = 0;
  91         memset(recbuf, 0, MAXRECSIZE);
  92 }
  93
  94 static int
  95 record_end(void)
  96 {
  97
  98         if (recpos == 0)
  99                 return (0);
 100         reccnt++;
 101         intalign();
 102         fwrite(&recpos, sizeof(recpos), 1, fxref);
 103         return (fwrite(recbuf, recpos, 1, fxref) != 1 ? errno : 0);
 104 }
 105
 106 static int
 107 record_buf(const void *buf, size_t size)
 108 {
 109
 110         if (MAXRECSIZE - recpos < size)
 111                 errx(1, "record buffer overflow");
 112         memcpy(recbuf + recpos, buf, size);
 113         recpos += size;
 114         return (0);
 115 }
 116
 117 /*
 118  * An int is stored in host order and aligned
 119  */
 120 static int
 121 record_int(int val)
 122 {
 123
 124         intalign();
 125         return (record_buf(&val, sizeof(val)));
 126 }
 127
 128 /*
 129  * A string is stored as 1-byte length plus data, no padding
 130  */
 131 static int
 132 record_string(const char *str)
 133 {
 134         int error;
 135         size_t len;
 136         u_char val;
 137
 138         if (dflag)
 139                 return (0);
 140         val = len = strlen(str);
 141         if (len > 255)
 142                 errx(1, "string %s too long", str);
 143         error = record_buf(&val, sizeof(val));
 144         if (error != 0)
 145                 return (error);
 146         return (record_buf(str, len));
 147 }
 148
 149 /* From sys/isa/pnp.c */
 150 static char *
 151 pnp_eisaformat(uint32_t id)
 152 {
 153         uint8_t *data;
 154         static char idbuf[8];
 155         const char  hextoascii[] = "0123456789abcdef";
 156
 157         id = htole32(id);
 158         data = (uint8_t *)&id;
 159         idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
 160         idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
 161         idbuf[2] = '@' + (data[1] & 0x1f);
 162         idbuf[3] = hextoascii[(data[2] >> 4)];
 163         idbuf[4] = hextoascii[(data[2] & 0xf)];
 164         idbuf[5] = hextoascii[(data[3] >> 4)];
 165         idbuf[6] = hextoascii[(data[3] & 0xf)];
 166         idbuf[7] = 0;
 167         return (idbuf);
 168 }
 169
 170 struct pnp_elt
 171 {
 172         int     pe_kind;        /* What kind of entry */
 173 #define TYPE_SZ_MASK    0x0f
 174 #define TYPE_FLAGGED    0x10    /* all f's is a wildcard */
 175 #define TYPE_INT        0x20    /* Is a number */
 176 #define TYPE_PAIRED     0x40
 177 #define TYPE_LE         0x80    /* Matches <= this value */
 178 #define TYPE_GE         0x100   /* Matches >= this value */
 179 #define TYPE_MASK       0x200   /* Specifies a mask to follow */
 180 #define TYPE_U8         (1 | TYPE_INT)
 181 #define TYPE_V8         (1 | TYPE_INT | TYPE_FLAGGED)
 182 #define TYPE_G16        (2 | TYPE_INT | TYPE_GE)
 183 #define TYPE_L16        (2 | TYPE_INT | TYPE_LE)
 184 #define TYPE_M16        (2 | TYPE_INT | TYPE_MASK)
 185 #define TYPE_U16        (2 | TYPE_INT)
 186 #define TYPE_V16        (2 | TYPE_INT | TYPE_FLAGGED)
 187 #define TYPE_U32        (4 | TYPE_INT)
 188 #define TYPE_V32        (4 | TYPE_INT | TYPE_FLAGGED)
 189 #define TYPE_W32        (4 | TYPE_INT | TYPE_PAIRED)
 190 #define TYPE_D          7
 191 #define TYPE_Z          8
 192 #define TYPE_P          9
 193 #define TYPE_E          10
 194 #define TYPE_T          11
 195         int     pe_offset;      /* Offset within the element */
 196         char *  pe_key;         /* pnp key name */
 197         TAILQ_ENTRY(pnp_elt) next; /* Link */
 198 };
 199 typedef TAILQ_HEAD(pnp_head, pnp_elt) pnp_list;
 200
 201 /*
 202  * this function finds the data from the pnp table, as described by the
 203  * the description and creates a new output (new_desc). This output table
 204  * is a form that's easier for the agent that's automatically loading the
 205  * modules.
 206  *
 207  * The format output is the simplified string from this routine in the
 208  * same basic format as the pnp string, as documented in sys/module.h.
 209  * First a string describing the format is output, the a count of the
 210  * number of records, then each record. The format string also describes
 211  * the length of each entry (though it isn't a fixed length when strings
 212  * are present).
 213  *
 214  *      type    Output          Meaning
 215  *      I       uint32_t        Integer equality comparison
 216  *      J       uint32_t        Pair of uint16_t fields converted to native
 217  *                              byte order. The two fields both must match.
 218  *      G       uint32_t        Greater than or equal to
 219  *      L       uint32_t        Less than or equal to
 220  *      M       uint32_t        Mask of which fields to test. Fields that
 221  *                              take up space increment the count. This
 222  *                              field must be first, and resets the count.
 223  *      D       string          Description of the device this pnp info is for
 224  *      Z       string          pnp string must match this
 225  *      T       nothing         T fields set pnp values that must be true for
 226  *                              the entire table.
 227  * Values are packed the same way that other values are packed in this file.
 228  * Strings and int32_t's start on a 32-bit boundary and are padded with 0
 229  * bytes. Objects that are smaller than uint32_t are converted, without
 230  * sign extension to uint32_t to simplify parsing downstream.
 231  */
 232 static int
 233 parse_pnp_list(const char *desc, char **new_desc, pnp_list *list)
 234 {
 235         const char *walker, *ep;
 236         const char *colon, *semi;
 237         struct pnp_elt *elt;
 238         char type[8], key[32];
 239         int off;
 240         size_t new_desc_size;
 241         FILE *fp;
 242
 243         walker = desc;
 244         ep = desc + strlen(desc);
 245         off = 0;
 246         fp = open_memstream(new_desc, &new_desc_size);
 247         if (fp == NULL)
 248                 err(1, "Could not open new memory stream");
 249         if (verbose > 1)
 250                 printf("Converting %s into a list\n", desc);
 251         while (walker < ep) {
 252                 colon = strchr(walker, ':');
 253                 semi = strchr(walker, ';');
 254                 if (semi != NULL && semi < colon)
 255                         goto err;
 256                 if (colon - walker > sizeof(type))
 257                         goto err;
 258                 strncpy(type, walker, colon - walker);
 259                 type[colon - walker] = '\0';
 260                 if (semi != NULL) {
 261                         if (semi - colon >= sizeof(key))
 262                                 goto err;
 263                         strncpy(key, colon + 1, semi - colon - 1);
 264                         key[semi - colon - 1] = '\0';
 265                         walker = semi + 1;
 266                         /* Fail safe if we have spaces after ; */
 267                         while (walker < ep && isspace(*walker))
 268                                 walker++;
 269                 } else {
 270                         if (strlen(colon + 1) >= sizeof(key))
 271                                 goto err;
 272                         strcpy(key, colon + 1);
 273                         walker = ep;
 274                 }
 275                 if (verbose > 1)
 276                         printf("Found type %s for name %s\n", type, key);
 277                 /* Skip pointer place holders */
 278                 if (strcmp(type, "P") == 0) {
 279                         off += sizeof(void *);
 280                         continue;
 281                 }
 282
 283                 /*
 284                  * Add a node of the appropriate type
 285                  */
 286                 elt = malloc(sizeof(struct pnp_elt) + strlen(key) + 1);
 287                 TAILQ_INSERT_TAIL(list, elt, next);
 288                 elt->pe_key = (char *)(elt + 1);
 289                 elt->pe_offset = off;
 290                 if (strcmp(type, "U8") == 0)
 291                         elt->pe_kind = TYPE_U8;
 292                 else if (strcmp(type, "V8") == 0)
 293                         elt->pe_kind = TYPE_V8;
 294                 else if (strcmp(type, "G16") == 0)
 295                         elt->pe_kind = TYPE_G16;
 296                 else if (strcmp(type, "L16") == 0)
 297                         elt->pe_kind = TYPE_L16;
 298                 else if (strcmp(type, "M16") == 0)
 299                         elt->pe_kind = TYPE_M16;
 300                 else if (strcmp(type, "U16") == 0)
 301                         elt->pe_kind = TYPE_U16;
 302                 else if (strcmp(type, "V16") == 0)
 303                         elt->pe_kind = TYPE_V16;
 304                 else if (strcmp(type, "U32") == 0)
 305                         elt->pe_kind = TYPE_U32;
 306                 else if (strcmp(type, "V32") == 0)
 307                         elt->pe_kind = TYPE_V32;
 308                 else if (strcmp(type, "W32") == 0)
 309                         elt->pe_kind = TYPE_W32;
 310                 else if (strcmp(type, "D") == 0)        /* description char * */
 311                         elt->pe_kind = TYPE_D;
 312                 else if (strcmp(type, "Z") == 0)        /* char * to match */
 313                         elt->pe_kind = TYPE_Z;
 314                 else if (strcmp(type, "P") == 0)        /* Pointer -- ignored */
 315                         elt->pe_kind = TYPE_P;
 316                 else if (strcmp(type, "E") == 0)        /* EISA PNP ID, as uint32_t */
 317                         elt->pe_kind = TYPE_E;
 318                 else if (strcmp(type, "T") == 0)
 319                         elt->pe_kind = TYPE_T;
 320                 else
 321                         goto err;
 322                 /*
 323                  * Maybe the rounding here needs to be more nuanced and/or somehow
 324                  * architecture specific. Fortunately, most tables in the system
 325                  * have sane ordering of types.
 326                  */
 327                 if (elt->pe_kind & TYPE_INT) {
 328                         elt->pe_offset = roundup2(elt->pe_offset, elt->pe_kind & TYPE_SZ_MASK);
 329                         off = elt->pe_offset + (elt->pe_kind & TYPE_SZ_MASK);
 330                 } else if (elt->pe_kind == TYPE_E) {
 331                         /* Type E stored as Int, displays as string */
 332                         elt->pe_offset = roundup2(elt->pe_offset, sizeof(uint32_t));
 333                         off = elt->pe_offset + sizeof(uint32_t);
 334                 } else if (elt->pe_kind == TYPE_T) {
 335                         /* doesn't actually consume space in the table */
 336                         off = elt->pe_offset;
 337                 } else {
 338                         elt->pe_offset = roundup2(elt->pe_offset, sizeof(void *));
 339                         off = elt->pe_offset + sizeof(void *);
 340                 }
 341                 if (elt->pe_kind & TYPE_PAIRED) {
 342                         char *word, *ctx, newtype;
 343
 344                         for (word = strtok_r(key, "/", &ctx);
 345                              word; word = strtok_r(NULL, "/", &ctx)) {
 346                                 newtype = elt->pe_kind & TYPE_FLAGGED ? 'J' : 'I';
 347                                 fprintf(fp, "%c:%s;", newtype, word);
 348                         }
 349                 }
 350                 else {
 351                         char newtype;
 352
 353                         if (elt->pe_kind & TYPE_FLAGGED)
 354                                 newtype = 'J';
 355                         else if (elt->pe_kind & TYPE_GE)
 356                                 newtype = 'G';
 357                         else if (elt->pe_kind & TYPE_LE)
 358                                 newtype = 'L';
 359                         else if (elt->pe_kind & TYPE_MASK)
 360                                 newtype = 'M';
 361                         else if (elt->pe_kind & TYPE_INT)
 362                                 newtype = 'I';
 363                         else if (elt->pe_kind == TYPE_D)
 364                                 newtype = 'D';
 365                         else if (elt->pe_kind == TYPE_Z || elt->pe_kind == TYPE_E)
 366                                 newtype = 'Z';
 367                         else if (elt->pe_kind == TYPE_T)
 368                                 newtype = 'T';
 369                         else
 370                                 errx(1, "Impossible type %x\n", elt->pe_kind);
 371                         fprintf(fp, "%c:%s;", newtype, key);
 372                 }
 373         }
 374         if (ferror(fp) != 0) {
 375                 fclose(fp);
 376                 errx(1, "Exhausted space converting description %s", desc);
 377         }
 378         if (fclose(fp) != 0)
 379                 errx(1, "Failed to close memory stream");
 380         return (0);
 381 err:
 382         errx(1, "Parse error of description string %s", desc);
 383 }
 384
 385 static int
 386 parse_entry(struct mod_metadata *md, const char *cval,
 387     struct elf_file *ef, const char *kldname)
 388 {
 389         struct mod_depend mdp;
 390         struct mod_version mdv;
 391         struct mod_pnp_match_info pnp;
 392         char descr[1024];
 393         Elf_Off data;
 394         int error, i;
 395         size_t len;
 396         char *walker;
 397         void *table;
 398
 399         data = (Elf_Off)md->md_data;
 400         error = 0;
 401         record_start();
 402         switch (md->md_type) {
 403         case MDT_DEPEND:
 404                 if (!dflag)
 405                         break;
 406                 check(EF_SEG_READ(ef, data, sizeof(mdp), &mdp));
 407                 printf("  depends on %s.%d (%d,%d)\n", cval,
 408                     mdp.md_ver_preferred, mdp.md_ver_minimum, mdp.md_ver_maximum);
 409                 break;
 410         case MDT_VERSION:
 411                 check(EF_SEG_READ(ef, data, sizeof(mdv), &mdv));
 412                 if (dflag) {
 413                         printf("  interface %s.%d\n", cval, mdv.mv_version);
 414                 } else {
 415                         record_int(MDT_VERSION);
 416                         record_string(cval);
 417                         record_int(mdv.mv_version);
 418                         record_string(kldname);
 419                 }
 420                 break;
 421         case MDT_MODULE:
 422                 if (dflag) {
 423                         printf("  module %s\n", cval);
 424                 } else {
 425                         record_int(MDT_MODULE);
 426                         record_string(cval);
 427                         record_string(kldname);
 428                 }
 429                 break;
 430         case MDT_PNP_INFO:
 431                 check(EF_SEG_READ_REL(ef, data, sizeof(pnp), &pnp));
 432                 check(EF_SEG_READ_STRING(ef, (Elf_Off)pnp.descr, sizeof(descr), descr));
 433                 descr[sizeof(descr) - 1] = '\0';
 434                 if (dflag) {
 435                         printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
 436                             cval, descr, pnp.num_entry, pnp.entry_len);
 437                 } else {
 438                         pnp_list list;
 439                         struct pnp_elt *elt, *elt_tmp;
 440                         char *new_descr;
 441
 442                         if (verbose > 1)
 443                                 printf("  pnp info for bus %s format %s %d entries of %d bytes\n",
 444                                     cval, descr, pnp.num_entry, pnp.entry_len);
 445                         /*
 446                          * Parse descr to weed out the chaff and to create a list
 447                          * of offsets to output.
 448                          */
 449                         TAILQ_INIT(&list);
 450                         parse_pnp_list(descr, &new_descr, &list);
 451                         record_int(MDT_PNP_INFO);
 452                         record_string(cval);
 453                         record_string(new_descr);
 454                         record_int(pnp.num_entry);
 455                         len = pnp.num_entry * pnp.entry_len;
 456                         walker = table = malloc(len);
 457                         check(EF_SEG_READ_REL(ef, (Elf_Off)pnp.table, len, table));
 458
 459                         /*
 460                          * Walk the list and output things. We've collapsed all the
 461                          * variant forms of the table down to just ints and strings.
 462                          */
 463                         for (i = 0; i < pnp.num_entry; i++) {
 464                                 TAILQ_FOREACH(elt, &list, next) {
 465                                         uint8_t v1;
 466                                         uint16_t v2;
 467                                         uint32_t v4;
 468                                         int     value;
 469                                         char buffer[1024];
 470
 471                                         if (elt->pe_kind == TYPE_W32) {
 472                                                 memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
 473                                                 value = v4 & 0xffff;
 474                                                 record_int(value);
 475                                                 if (verbose > 1)
 476                                                         printf("W32:%#x", value);
 477                                                 value = (v4 >> 16) & 0xffff;
 478                                                 record_int(value);
 479                                                 if (verbose > 1)
 480                                                         printf(":%#x;", value);
 481                                         } else if (elt->pe_kind & TYPE_INT) {
 482                                                 switch (elt->pe_kind & TYPE_SZ_MASK) {
 483                                                 case 1:
 484                                                         memcpy(&v1, walker + elt->pe_offset, sizeof(v1));
 485                                                         if ((elt->pe_kind & TYPE_FLAGGED) && v1 == 0xff)
 486                                                                 value = -1;
 487                                                         else
 488                                                                 value = v1;
 489                                                         break;
 490                                                 case 2:
 491                                                         memcpy(&v2, walker + elt->pe_offset, sizeof(v2));
 492                                                         if ((elt->pe_kind & TYPE_FLAGGED) && v2 == 0xffff)
 493                                                                 value = -1;
 494                                                         else
 495                                                                 value = v2;
 496                                                         break;
 497                                                 case 4:
 498                                                         memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
 499                                                         if ((elt->pe_kind & TYPE_FLAGGED) && v4 == 0xffffffff)
 500                                                                 value = -1;
 501                                                         else
 502                                                                 value = v4;
 503                                                         break;
 504                                                 default:
 505                                                         errx(1, "Invalid size somehow %#x", elt->pe_kind);
 506                                                 }
 507                                                 if (verbose > 1)
 508                                                         printf("I:%#x;", value);
 509                                                 record_int(value);
 510                                         } else if (elt->pe_kind == TYPE_T) {
 511                                                 /* Do nothing */
 512                                         } else { /* E, Z or D -- P already filtered */
 513                                                 if (elt->pe_kind == TYPE_E) {
 514                                                         memcpy(&v4, walker + elt->pe_offset, sizeof(v4));
 515                                                         strcpy(buffer, pnp_eisaformat(v4));
 516                                                 } else {
 517                                                         char *ptr;
 518
 519                                                         ptr = *(char **)(walker + elt->pe_offset);
 520                                                         buffer[0] = '\0';
 521                                                         if (ptr != NULL) {
 522                                                                 EF_SEG_READ_STRING(ef, (Elf_Off)ptr,
 523                                                                     sizeof(buffer), buffer);
 524                                                                 buffer[sizeof(buffer) - 1] = '\0';
 525                                                         }
 526                                                 }
 527                                                 if (verbose > 1)
 528                                                         printf("%c:%s;", elt->pe_kind == TYPE_E ? 'E' : (elt->pe_kind == TYPE_Z ? 'Z' : 'D'), buffer);
 529                                                 record_string(buffer);
 530                                         }
 531                                 }
 532                                 if (verbose > 1)
 533                                         printf("\n");
 534                                 walker += pnp.entry_len;
 535                         }
 536                         /* Now free it */
 537                         TAILQ_FOREACH_SAFE(elt, &list, next, elt_tmp) {
 538                                 TAILQ_REMOVE(&list, elt, next);
 539                                 free(elt);
 540                         }
 541                         free(table);
 542                 }
 543                 break;
 544         default:
 545                 warnx("unknown metadata record %d in file %s", md->md_type, kldname);
 546         }
 547         if (!error)
 548                 record_end();
 549         return (error);
 550 }
 551
 552 static int
 553 read_kld(char *filename, char *kldname)
 554 {
 555         struct mod_metadata md;
 556         struct elf_file ef;
 557         void **p;
 558         int error, eftype;
 559         long start, finish, entries, i;
 560         char cval[MAXMODNAME + 1];
 561
 562         if (verbose || dflag)
 563                 printf("%s\n", filename);
 564         error = ef_open(filename, &ef, verbose);
 565         if (error != 0) {
 566                 error = ef_obj_open(filename, &ef, verbose);
 567                 if (error != 0) {
 568                         if (verbose)
 569                                 warnc(error, "elf_open(%s)", filename);
 570                         return (error);
 571                 }
 572         }
 573         eftype = EF_GET_TYPE(&ef);
 574         if (eftype != EFT_KLD && eftype != EFT_KERNEL)  {
 575                 EF_CLOSE(&ef);
 576                 return (0);
 577         }
 578         do {
 579                 check(EF_LOOKUP_SET(&ef, MDT_SETNAME, &start, &finish,
 580                     &entries));
 581                 check(EF_SEG_READ_ENTRY_REL(&ef, start, sizeof(*p) * entries,
 582                     (void *)&p));
 583                 /*
 584                  * Do a first pass to find MDT_MODULE.  It is required to be
 585                  * ordered first in the output linker.hints stream because it
 586                  * serves as an implicit record boundary between distinct klds
 587                  * in the stream.  Other MDTs only make sense in the context of
 588                  * a specific MDT_MODULE.
 589                  *
 590                  * Some compilers (e.g., GCC 6.4.0 xtoolchain) or binutils
 591                  * (e.g., GNU binutils 2.32 objcopy/ld.bfd) can reorder
 592                  * MODULE_METADATA set entries relative to the source ordering.
 593                  * This is permitted by the C standard; memory layout of
 594                  * file-scope objects is left implementation-defined.  There is
 595                  * no requirement that source code ordering is retained.
 596                  *
 597                  * Handle that here by taking two passes to ensure MDT_MODULE
 598                  * records are emitted to linker.hints before other MDT records
 599                  * in the same kld.
 600                  */
 601                 for (i = 0; i < entries; i++) {
 602                         check(EF_SEG_READ_REL(&ef, (Elf_Off)p[i], sizeof(md),
 603                             &md));
 604                         check(EF_SEG_READ_STRING(&ef, (Elf_Off)md.md_cval,
 605                             sizeof(cval), cval));
 606                         if (md.md_type == MDT_MODULE) {
 607                                 parse_entry(&md, cval, &ef, kldname);
 608                                 break;
 609                         }
 610                 }
 611                 if (error != 0) {
 612                         warnc(error, "error while reading %s", filename);
 613                         break;
 614                 }
 615
 616                 /*
 617                  * Second pass for all !MDT_MODULE entries.
 618                  */
 619                 for (i = 0; i < entries; i++) {
 620                         check(EF_SEG_READ_REL(&ef, (Elf_Off)p[i], sizeof(md),
 621                             &md));
 622                         check(EF_SEG_READ_STRING(&ef, (Elf_Off)md.md_cval,
 623                             sizeof(cval), cval));
 624                         if (md.md_type != MDT_MODULE)
 625                                 parse_entry(&md, cval, &ef, kldname);
 626                 }
 627                 if (error != 0)
 628                         warnc(error, "error while reading %s", filename);
 629                 free(p);
 630         } while(0);
 631         EF_CLOSE(&ef);
 632         return (error);
 633 }
 634
 635 /*
 636  * Create a temp file in directory root, make sure we don't
 637  * overflow the buffer for the destination name
 638  */
 639 static FILE *
 640 maketempfile(char *dest, const char *root)
 641 {
 642         char *p;
 643         int n, fd;
 644
 645         p = strrchr(root, '/');
 646         n = p != NULL ? p - root + 1 : 0;
 647         if (snprintf(dest, MAXPATHLEN, "%.*slhint.XXXXXX", n, root) >=
 648             MAXPATHLEN) {
 649                 errno = ENAMETOOLONG;
 650                 return (NULL);
 651         }
 652
 653         fd = mkstemp(dest);
 654         if (fd < 0)
 655                 return (NULL);
 656         fchmod(fd, 0644);       /* nothing secret in the file */
 657         return (fdopen(fd, "w+"));
 658 }
 659
 660 static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
 661
 662 static void
 663 usage(void)
 664 {
 665
 666         fprintf(stderr, "%s\n",
 667             "usage: kldxref [-Rdv] [-f hintsfile] path ..."
 668         );
 669         exit(1);
 670 }
 671
 672 static int
 673 compare(const FTSENT *const *a, const FTSENT *const *b)
 674 {
 675
 676         if ((*a)->fts_info == FTS_D && (*b)->fts_info != FTS_D)
 677                 return (1);
 678         if ((*a)->fts_info != FTS_D && (*b)->fts_info == FTS_D)
 679                 return (-1);
 680         return (strcmp((*a)->fts_name, (*b)->fts_name));
 681 }
 682
 683 int
 684 main(int argc, char *argv[])
 685 {
 686         FTS *ftsp;
 687         FTSENT *p;
 688         int opt, fts_options, ival;
 689         struct stat sb;
 690
 691         fts_options = FTS_PHYSICAL;
 692
 693         while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
 694                 switch (opt) {
 695                 case 'd':       /* no hint file, only print on stdout */
 696                         dflag = true;
 697                         break;
 698                 case 'f':       /* use this name instead of linker.hints */
 699                         xref_file = optarg;
 700                         break;
 701                 case 'v':
 702                         verbose++;
 703                         break;
 704                 case 'R':       /* recurse on directories */
 705                         fts_options |= FTS_COMFOLLOW;
 706                         break;
 707                 default:
 708                         usage();
 709                         /* NOTREACHED */
 710                 }
 711         }
 712         if (argc - optind < 1)
 713                 usage();
 714         argc -= optind;
 715         argv += optind;
 716
 717         if (stat(argv[0], &sb) != 0)
 718                 err(1, "%s", argv[0]);
 719         if ((sb.st_mode & S_IFDIR) == 0) {
 720                 errno = ENOTDIR;
 721                 err(1, "%s", argv[0]);
 722         }
 723
 724         ftsp = fts_open(argv, fts_options, compare);
 725         if (ftsp == NULL)
 726                 exit(1);
 727
 728         for (;;) {
 729                 p = fts_read(ftsp);
 730                 if ((p == NULL || p->fts_info == FTS_D) && fxref) {
 731                         /* close and rename the current hint file */
 732                         fclose(fxref);
 733                         fxref = NULL;
 734                         if (reccnt != 0) {
 735                                 rename(tempname, xrefname);
 736                         } else {
 737                                 /* didn't find any entry, ignore this file */
 738                                 unlink(tempname);
 739                                 unlink(xrefname);
 740                         }
 741                 }
 742                 if (p == NULL)
 743                         break;
 744                 if (p->fts_info == FTS_D && !dflag) {
 745                         /* visiting a new directory, create a new hint file */
 746                         snprintf(xrefname, sizeof(xrefname), "%s/%s",
 747                             ftsp->fts_path, xref_file);
 748                         fxref = maketempfile(tempname, ftsp->fts_path);
 749                         if (fxref == NULL)
 750                                 err(1, "can't create %s", tempname);
 751                         ival = 1;
 752                         fwrite(&ival, sizeof(ival), 1, fxref);
 753                         reccnt = 0;
 754                 }
 755                 /* skip non-files and separate debug files */
 756                 if (p->fts_info != FTS_F)
 757                         continue;
 758                 if (p->fts_namelen >= 6 &&
 759                     strcmp(p->fts_name + p->fts_namelen - 6, ".debug") == 0)
 760                         continue;
 761                 if (p->fts_namelen >= 8 &&
 762                     strcmp(p->fts_name + p->fts_namelen - 8, ".symbols") == 0)
 763                         continue;
 764                 read_kld(p->fts_path, p->fts_name);
 765         }
 766         fts_close(ftsp);
 767         return (0);
 768 }