security/selinux/ss/avtab.c

   1 /*
   2  * Implementation of the access vector table type.
   3  *
   4  * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
   5  */
   6
   7 /* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
   8  *
   9  *      Added conditional policy language extensions
  10  *
  11  * Copyright (C) 2003 Tresys Technology, LLC
  12  *      This program is free software; you can redistribute it and/or modify
  13  *      it under the terms of the GNU General Public License as published by
  14  *      the Free Software Foundation, version 2.
  15  *
  16  * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
  17  *      Tuned number of hash slots for avtab to reduce memory usage
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/slab.h>
  22 #include <linux/errno.h>
  23 #include "avtab.h"
  24 #include "policydb.h"
  25
  26 static struct kmem_cache *avtab_node_cachep;
  27 static struct kmem_cache *avtab_xperms_cachep;
  28
  29 /* Based on MurmurHash3, written by Austin Appleby and placed in the
  30  * public domain.
  31  */
  32 static inline int avtab_hash(struct avtab_key *keyp, u32 mask)
  33 {
  34         static const u32 c1 = 0xcc9e2d51;
  35         static const u32 c2 = 0x1b873593;
  36         static const u32 r1 = 15;
  37         static const u32 r2 = 13;
  38         static const u32 m  = 5;
  39         static const u32 n  = 0xe6546b64;
  40
  41         u32 hash = 0;
  42
  43 #define mix(input) { \
  44         u32 v = input; \
  45         v *= c1; \
  46         v = (v << r1) | (v >> (32 - r1)); \
  47         v *= c2; \
  48         hash ^= v; \
  49         hash = (hash << r2) | (hash >> (32 - r2)); \
  50         hash = hash * m + n; \
  51 }
  52
  53         mix(keyp->target_class);
  54         mix(keyp->target_type);
  55         mix(keyp->source_type);
  56
  57 #undef mix
  58
  59         hash ^= hash >> 16;
  60         hash *= 0x85ebca6b;
  61         hash ^= hash >> 13;
  62         hash *= 0xc2b2ae35;
  63         hash ^= hash >> 16;
  64
  65         return hash & mask;
  66 }
  67
  68 static struct avtab_node*
  69 avtab_insert_node(struct avtab *h, int hvalue,
  70                   struct avtab_node *prev, struct avtab_node *cur,
  71                   struct avtab_key *key, struct avtab_datum *datum)
  72 {
  73         struct avtab_node *newnode;
  74         struct avtab_extended_perms *xperms;
  75         newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
  76         if (newnode == NULL)
  77                 return NULL;
  78         newnode->key = *key;
  79
  80         if (key->specified & AVTAB_XPERMS) {
  81                 xperms = kmem_cache_zalloc(avtab_xperms_cachep, GFP_KERNEL);
  82                 if (xperms == NULL) {
  83                         kmem_cache_free(avtab_node_cachep, newnode);
  84                         return NULL;
  85                 }
  86                 *xperms = *(datum->u.xperms);
  87                 newnode->datum.u.xperms = xperms;
  88         } else {
  89                 newnode->datum.u.data = datum->u.data;
  90         }
  91
  92         if (prev) {
  93                 newnode->next = prev->next;
  94                 prev->next = newnode;
  95         } else {
  96                 newnode->next = flex_array_get_ptr(h->htable, hvalue);
  97                 if (flex_array_put_ptr(h->htable, hvalue, newnode,
  98                                        GFP_KERNEL|__GFP_ZERO)) {
  99                         kmem_cache_free(avtab_node_cachep, newnode);
 100                         return NULL;
 101                 }
 102         }
 103
 104         h->nel++;
 105         return newnode;
 106 }
 107
 108 static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
 109 {
 110         int hvalue;
 111         struct avtab_node *prev, *cur, *newnode;
 112         u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 113
 114         if (!h || !h->htable)
 115                 return -EINVAL;
 116
 117         hvalue = avtab_hash(key, h->mask);
 118         for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
 119              cur;
 120              prev = cur, cur = cur->next) {
 121                 if (key->source_type == cur->key.source_type &&
 122                     key->target_type == cur->key.target_type &&
 123                     key->target_class == cur->key.target_class &&
 124                     (specified & cur->key.specified)) {
 125                         /* extended perms may not be unique */
 126                         if (specified & AVTAB_XPERMS)
 127                                 break;
 128                         return -EEXIST;
 129                 }
 130                 if (key->source_type < cur->key.source_type)
 131                         break;
 132                 if (key->source_type == cur->key.source_type &&
 133                     key->target_type < cur->key.target_type)
 134                         break;
 135                 if (key->source_type == cur->key.source_type &&
 136                     key->target_type == cur->key.target_type &&
 137                     key->target_class < cur->key.target_class)
 138                         break;
 139         }
 140
 141         newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);
 142         if (!newnode)
 143                 return -ENOMEM;
 144
 145         return 0;
 146 }
 147
 148 /* Unlike avtab_insert(), this function allow multiple insertions of the same
 149  * key/specified mask into the table, as needed by the conditional avtab.
 150  * It also returns a pointer to the node inserted.
 151  */
 152 struct avtab_node *
 153 avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
 154 {
 155         int hvalue;
 156         struct avtab_node *prev, *cur;
 157         u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 158
 159         if (!h || !h->htable)
 160                 return NULL;
 161         hvalue = avtab_hash(key, h->mask);
 162         for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
 163              cur;
 164              prev = cur, cur = cur->next) {
 165                 if (key->source_type == cur->key.source_type &&
 166                     key->target_type == cur->key.target_type &&
 167                     key->target_class == cur->key.target_class &&
 168                     (specified & cur->key.specified))
 169                         break;
 170                 if (key->source_type < cur->key.source_type)
 171                         break;
 172                 if (key->source_type == cur->key.source_type &&
 173                     key->target_type < cur->key.target_type)
 174                         break;
 175                 if (key->source_type == cur->key.source_type &&
 176                     key->target_type == cur->key.target_type &&
 177                     key->target_class < cur->key.target_class)
 178                         break;
 179         }
 180         return avtab_insert_node(h, hvalue, prev, cur, key, datum);
 181 }
 182
 183 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
 184 {
 185         int hvalue;
 186         struct avtab_node *cur;
 187         u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 188
 189         if (!h || !h->htable)
 190                 return NULL;
 191
 192         hvalue = avtab_hash(key, h->mask);
 193         for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
 194              cur = cur->next) {
 195                 if (key->source_type == cur->key.source_type &&
 196                     key->target_type == cur->key.target_type &&
 197                     key->target_class == cur->key.target_class &&
 198                     (specified & cur->key.specified))
 199                         return &cur->datum;
 200
 201                 if (key->source_type < cur->key.source_type)
 202                         break;
 203                 if (key->source_type == cur->key.source_type &&
 204                     key->target_type < cur->key.target_type)
 205                         break;
 206                 if (key->source_type == cur->key.source_type &&
 207                     key->target_type == cur->key.target_type &&
 208                     key->target_class < cur->key.target_class)
 209                         break;
 210         }
 211
 212         return NULL;
 213 }
 214
 215 /* This search function returns a node pointer, and can be used in
 216  * conjunction with avtab_search_next_node()
 217  */
 218 struct avtab_node*
 219 avtab_search_node(struct avtab *h, struct avtab_key *key)
 220 {
 221         int hvalue;
 222         struct avtab_node *cur;
 223         u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 224
 225         if (!h || !h->htable)
 226                 return NULL;
 227
 228         hvalue = avtab_hash(key, h->mask);
 229         for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
 230              cur = cur->next) {
 231                 if (key->source_type == cur->key.source_type &&
 232                     key->target_type == cur->key.target_type &&
 233                     key->target_class == cur->key.target_class &&
 234                     (specified & cur->key.specified))
 235                         return cur;
 236
 237                 if (key->source_type < cur->key.source_type)
 238                         break;
 239                 if (key->source_type == cur->key.source_type &&
 240                     key->target_type < cur->key.target_type)
 241                         break;
 242                 if (key->source_type == cur->key.source_type &&
 243                     key->target_type == cur->key.target_type &&
 244                     key->target_class < cur->key.target_class)
 245                         break;
 246         }
 247         return NULL;
 248 }
 249
 250 struct avtab_node*
 251 avtab_search_node_next(struct avtab_node *node, int specified)
 252 {
 253         struct avtab_node *cur;
 254
 255         if (!node)
 256                 return NULL;
 257
 258         specified &= ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 259         for (cur = node->next; cur; cur = cur->next) {
 260                 if (node->key.source_type == cur->key.source_type &&
 261                     node->key.target_type == cur->key.target_type &&
 262                     node->key.target_class == cur->key.target_class &&
 263                     (specified & cur->key.specified))
 264                         return cur;
 265
 266                 if (node->key.source_type < cur->key.source_type)
 267                         break;
 268                 if (node->key.source_type == cur->key.source_type &&
 269                     node->key.target_type < cur->key.target_type)
 270                         break;
 271                 if (node->key.source_type == cur->key.source_type &&
 272                     node->key.target_type == cur->key.target_type &&
 273                     node->key.target_class < cur->key.target_class)
 274                         break;
 275         }
 276         return NULL;
 277 }
 278
 279 void avtab_destroy(struct avtab *h)
 280 {
 281         int i;
 282         struct avtab_node *cur, *temp;
 283
 284         if (!h || !h->htable)
 285                 return;
 286
 287         for (i = 0; i < h->nslot; i++) {
 288                 cur = flex_array_get_ptr(h->htable, i);
 289                 while (cur) {
 290                         temp = cur;
 291                         cur = cur->next;
 292                         if (temp->key.specified & AVTAB_XPERMS)
 293                                 kmem_cache_free(avtab_xperms_cachep,
 294                                                 temp->datum.u.xperms);
 295                         kmem_cache_free(avtab_node_cachep, temp);
 296                 }
 297         }
 298         flex_array_free(h->htable);
 299         h->htable = NULL;
 300         h->nslot = 0;
 301         h->mask = 0;
 302 }
 303
 304 int avtab_init(struct avtab *h)
 305 {
 306         h->htable = NULL;
 307         h->nel = 0;
 308         return 0;
 309 }
 310
 311 int avtab_alloc(struct avtab *h, u32 nrules)
 312 {
 313         u32 mask = 0;
 314         u32 shift = 0;
 315         u32 work = nrules;
 316         u32 nslot = 0;
 317
 318         if (nrules == 0)
 319                 goto avtab_alloc_out;
 320
 321         while (work) {
 322                 work  = work >> 1;
 323                 shift++;
 324         }
 325         if (shift > 2)
 326                 shift = shift - 2;
 327         nslot = 1 << shift;
 328         if (nslot > MAX_AVTAB_HASH_BUCKETS)
 329                 nslot = MAX_AVTAB_HASH_BUCKETS;
 330         mask = nslot - 1;
 331
 332         h->htable = flex_array_alloc(sizeof(struct avtab_node *), nslot,
 333                                      GFP_KERNEL | __GFP_ZERO);
 334         if (!h->htable)
 335                 return -ENOMEM;
 336
 337  avtab_alloc_out:
 338         h->nel = 0;
 339         h->nslot = nslot;
 340         h->mask = mask;
 341         printk(KERN_DEBUG "SELinux: %d avtab hash slots, %d rules.\n",
 342                h->nslot, nrules);
 343         return 0;
 344 }
 345
 346 void avtab_hash_eval(struct avtab *h, char *tag)
 347 {
 348         int i, chain_len, slots_used, max_chain_len;
 349         unsigned long long chain2_len_sum;
 350         struct avtab_node *cur;
 351
 352         slots_used = 0;
 353         max_chain_len = 0;
 354         chain2_len_sum = 0;
 355         for (i = 0; i < h->nslot; i++) {
 356                 cur = flex_array_get_ptr(h->htable, i);
 357                 if (cur) {
 358                         slots_used++;
 359                         chain_len = 0;
 360                         while (cur) {
 361                                 chain_len++;
 362                                 cur = cur->next;
 363                         }
 364
 365                         if (chain_len > max_chain_len)
 366                                 max_chain_len = chain_len;
 367                         chain2_len_sum += chain_len * chain_len;
 368                 }
 369         }
 370
 371         printk(KERN_DEBUG "SELinux: %s:  %d entries and %d/%d buckets used, "
 372                "longest chain length %d sum of chain length^2 %llu\n",
 373                tag, h->nel, slots_used, h->nslot, max_chain_len,
 374                chain2_len_sum);
 375 }
 376
 377 static uint16_t spec_order[] = {
 378         AVTAB_ALLOWED,
 379         AVTAB_AUDITDENY,
 380         AVTAB_AUDITALLOW,
 381         AVTAB_TRANSITION,
 382         AVTAB_CHANGE,
 383         AVTAB_MEMBER,
 384         AVTAB_XPERMS_ALLOWED,
 385         AVTAB_XPERMS_AUDITALLOW,
 386         AVTAB_XPERMS_DONTAUDIT
 387 };
 388
 389 int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
 390                     int (*insertf)(struct avtab *a, struct avtab_key *k,
 391                                    struct avtab_datum *d, void *p),
 392                     void *p)
 393 {
 394         __le16 buf16[4];
 395         u16 enabled;
 396         u32 items, items2, val, vers = pol->policyvers;
 397         struct avtab_key key;
 398         struct avtab_datum datum;
 399         struct avtab_extended_perms xperms;
 400         __le32 buf32[ARRAY_SIZE(xperms.perms.p)];
 401         int i, rc;
 402         unsigned set;
 403
 404         memset(&key, 0, sizeof(struct avtab_key));
 405         memset(&datum, 0, sizeof(struct avtab_datum));
 406
 407         if (vers < POLICYDB_VERSION_AVTAB) {
 408                 rc = next_entry(buf32, fp, sizeof(u32));
 409                 if (rc) {
 410                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
 411                         return rc;
 412                 }
 413                 items2 = le32_to_cpu(buf32[0]);
 414                 if (items2 > ARRAY_SIZE(buf32)) {
 415                         printk(KERN_ERR "SELinux: avtab: entry overflow\n");
 416                         return -EINVAL;
 417
 418                 }
 419                 rc = next_entry(buf32, fp, sizeof(u32)*items2);
 420                 if (rc) {
 421                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
 422                         return rc;
 423                 }
 424                 items = 0;
 425
 426                 val = le32_to_cpu(buf32[items++]);
 427                 key.source_type = (u16)val;
 428                 if (key.source_type != val) {
 429                         printk(KERN_ERR "SELinux: avtab: truncated source type\n");
 430                         return -EINVAL;
 431                 }
 432                 val = le32_to_cpu(buf32[items++]);
 433                 key.target_type = (u16)val;
 434                 if (key.target_type != val) {
 435                         printk(KERN_ERR "SELinux: avtab: truncated target type\n");
 436                         return -EINVAL;
 437                 }
 438                 val = le32_to_cpu(buf32[items++]);
 439                 key.target_class = (u16)val;
 440                 if (key.target_class != val) {
 441                         printk(KERN_ERR "SELinux: avtab: truncated target class\n");
 442                         return -EINVAL;
 443                 }
 444
 445                 val = le32_to_cpu(buf32[items++]);
 446                 enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
 447
 448                 if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
 449                         printk(KERN_ERR "SELinux: avtab: null entry\n");
 450                         return -EINVAL;
 451                 }
 452                 if ((val & AVTAB_AV) &&
 453                     (val & AVTAB_TYPE)) {
 454                         printk(KERN_ERR "SELinux: avtab: entry has both access vectors and types\n");
 455                         return -EINVAL;
 456                 }
 457                 if (val & AVTAB_XPERMS) {
 458                         printk(KERN_ERR "SELinux: avtab: entry has extended permissions\n");
 459                         return -EINVAL;
 460                 }
 461
 462                 for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
 463                         if (val & spec_order[i]) {
 464                                 key.specified = spec_order[i] | enabled;
 465                                 datum.u.data = le32_to_cpu(buf32[items++]);
 466                                 rc = insertf(a, &key, &datum, p);
 467                                 if (rc)
 468                                         return rc;
 469                         }
 470                 }
 471
 472                 if (items != items2) {
 473                         printk(KERN_ERR "SELinux: avtab: entry only had %d items, expected %d\n", items2, items);
 474                         return -EINVAL;
 475                 }
 476                 return 0;
 477         }
 478
 479         rc = next_entry(buf16, fp, sizeof(u16)*4);
 480         if (rc) {
 481                 printk(KERN_ERR "SELinux: avtab: truncated entry\n");
 482                 return rc;
 483         }
 484
 485         items = 0;
 486         key.source_type = le16_to_cpu(buf16[items++]);
 487         key.target_type = le16_to_cpu(buf16[items++]);
 488         key.target_class = le16_to_cpu(buf16[items++]);
 489         key.specified = le16_to_cpu(buf16[items++]);
 490
 491         if (!policydb_type_isvalid(pol, key.source_type) ||
 492             !policydb_type_isvalid(pol, key.target_type) ||
 493             !policydb_class_isvalid(pol, key.target_class)) {
 494                 printk(KERN_ERR "SELinux: avtab: invalid type or class\n");
 495                 return -EINVAL;
 496         }
 497
 498         set = 0;
 499         for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
 500                 if (key.specified & spec_order[i])
 501                         set++;
 502         }
 503         if (!set || set > 1) {
 504                 printk(KERN_ERR "SELinux:  avtab:  more than one specifier\n");
 505                 return -EINVAL;
 506         }
 507
 508         if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
 509                         (key.specified & AVTAB_XPERMS)) {
 510                 printk(KERN_ERR "SELinux:  avtab:  policy version %u does not "
 511                                 "support extended permissions rules and one "
 512                                 "was specified\n", vers);
 513                 return -EINVAL;
 514         } else if (key.specified & AVTAB_XPERMS) {
 515                 memset(&xperms, 0, sizeof(struct avtab_extended_perms));
 516                 rc = next_entry(&xperms.specified, fp, sizeof(u8));
 517                 if (rc) {
 518                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
 519                         return rc;
 520                 }
 521                 rc = next_entry(&xperms.driver, fp, sizeof(u8));
 522                 if (rc) {
 523                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
 524                         return rc;
 525                 }
 526                 rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p));
 527                 if (rc) {
 528                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
 529                         return rc;
 530                 }
 531                 for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++)
 532                         xperms.perms.p[i] = le32_to_cpu(buf32[i]);
 533                 datum.u.xperms = &xperms;
 534         } else {
 535                 rc = next_entry(buf32, fp, sizeof(u32));
 536                 if (rc) {
 537                         printk(KERN_ERR "SELinux: avtab: truncated entry\n");
 538                         return rc;
 539                 }
 540                 datum.u.data = le32_to_cpu(*buf32);
 541         }
 542         if ((key.specified & AVTAB_TYPE) &&
 543             !policydb_type_isvalid(pol, datum.u.data)) {
 544                 printk(KERN_ERR "SELinux: avtab: invalid type\n");
 545                 return -EINVAL;
 546         }
 547         return insertf(a, &key, &datum, p);
 548 }
 549
 550 static int avtab_insertf(struct avtab *a, struct avtab_key *k,
 551                          struct avtab_datum *d, void *p)
 552 {
 553         return avtab_insert(a, k, d);
 554 }
 555
 556 int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
 557 {
 558         int rc;
 559         __le32 buf[1];
 560         u32 nel, i;
 561
 562
 563         rc = next_entry(buf, fp, sizeof(u32));
 564         if (rc < 0) {
 565                 printk(KERN_ERR "SELinux: avtab: truncated table\n");
 566                 goto bad;
 567         }
 568         nel = le32_to_cpu(buf[0]);
 569         if (!nel) {
 570                 printk(KERN_ERR "SELinux: avtab: table is empty\n");
 571                 rc = -EINVAL;
 572                 goto bad;
 573         }
 574
 575         rc = avtab_alloc(a, nel);
 576         if (rc)
 577                 goto bad;
 578
 579         for (i = 0; i < nel; i++) {
 580                 rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
 581                 if (rc) {
 582                         if (rc == -ENOMEM)
 583                                 printk(KERN_ERR "SELinux: avtab: out of memory\n");
 584                         else if (rc == -EEXIST)
 585                                 printk(KERN_ERR "SELinux: avtab: duplicate entry\n");
 586
 587                         goto bad;
 588                 }
 589         }
 590
 591         rc = 0;
 592 out:
 593         return rc;
 594
 595 bad:
 596         avtab_destroy(a);
 597         goto out;
 598 }
 599
 600 int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
 601 {
 602         __le16 buf16[4];
 603         __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)];
 604         int rc;
 605         unsigned int i;
 606
 607         buf16[0] = cpu_to_le16(cur->key.source_type);
 608         buf16[1] = cpu_to_le16(cur->key.target_type);
 609         buf16[2] = cpu_to_le16(cur->key.target_class);
 610         buf16[3] = cpu_to_le16(cur->key.specified);
 611         rc = put_entry(buf16, sizeof(u16), 4, fp);
 612         if (rc)
 613                 return rc;
 614
 615         if (cur->key.specified & AVTAB_XPERMS) {
 616                 rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp);
 617                 if (rc)
 618                         return rc;
 619                 rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp);
 620                 if (rc)
 621                         return rc;
 622                 for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++)
 623                         buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]);
 624                 rc = put_entry(buf32, sizeof(u32),
 625                                 ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp);
 626         } else {
 627                 buf32[0] = cpu_to_le32(cur->datum.u.data);
 628                 rc = put_entry(buf32, sizeof(u32), 1, fp);
 629         }
 630         if (rc)
 631                 return rc;
 632         return 0;
 633 }
 634
 635 int avtab_write(struct policydb *p, struct avtab *a, void *fp)
 636 {
 637         unsigned int i;
 638         int rc = 0;
 639         struct avtab_node *cur;
 640         __le32 buf[1];
 641
 642         buf[0] = cpu_to_le32(a->nel);
 643         rc = put_entry(buf, sizeof(u32), 1, fp);
 644         if (rc)
 645                 return rc;
 646
 647         for (i = 0; i < a->nslot; i++) {
 648                 for (cur = flex_array_get_ptr(a->htable, i); cur;
 649                      cur = cur->next) {
 650                         rc = avtab_write_item(p, cur, fp);
 651                         if (rc)
 652                                 return rc;
 653                 }
 654         }
 655
 656         return rc;
 657 }
 658 void avtab_cache_init(void)
 659 {
 660         avtab_node_cachep = kmem_cache_create("avtab_node",
 661                                               sizeof(struct avtab_node),
 662                                               0, SLAB_PANIC, NULL);
 663         avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms",
 664                                                 sizeof(struct avtab_extended_perms),
 665                                                 0, SLAB_PANIC, NULL);
 666 }
 667
 668 void avtab_cache_destroy(void)
 669 {
 670         kmem_cache_destroy(avtab_node_cachep);
 671         kmem_cache_destroy(avtab_xperms_cachep);
 672 }