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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Implementation of the extensible bitmap type.
4 *
5 * Author : Stephen Smalley, <sds@tycho.nsa.gov>
6 */
7/*
8 * Updated: Hewlett-Packard <paul@paul-moore.com>
9 *
10 * Added support to import/export the NetLabel category bitmap
11 *
12 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
13 */
14/*
15 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
16 * Applied standard bit operations to improve bitmap scanning.
17 */
18
19#include <linux/kernel.h>
20#include <linux/slab.h>
21#include <linux/errno.h>
22#include <net/netlabel.h>
23#include "ebitmap.h"
24#include "policydb.h"
25
26#define BITS_PER_U64 (sizeof(u64) * 8)
27
28static struct kmem_cache *ebitmap_node_cachep;
29
30int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
31{
32 struct ebitmap_node *n1, *n2;
33
34 if (e1->highbit != e2->highbit)
35 return 0;
36
37 n1 = e1->node;
38 n2 = e2->node;
39 while (n1 && n2 &&
40 (n1->startbit == n2->startbit) &&
41 !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) {
42 n1 = n1->next;
43 n2 = n2->next;
44 }
45
46 if (n1 || n2)
47 return 0;
48
49 return 1;
50}
51
52int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src)
53{
54 struct ebitmap_node *n, *new, *prev;
55
56 ebitmap_init(dst);
57 n = src->node;
58 prev = NULL;
59 while (n) {
60 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
61 if (!new) {
62 ebitmap_destroy(dst);
63 return -ENOMEM;
64 }
65 new->startbit = n->startbit;
66 memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
67 new->next = NULL;
68 if (prev)
69 prev->next = new;
70 else
71 dst->node = new;
72 prev = new;
73 n = n->next;
74 }
75
76 dst->highbit = src->highbit;
77 return 0;
78}
79
80#ifdef CONFIG_NETLABEL
81/**
82 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
83 * @ebmap: the ebitmap to export
84 * @catmap: the NetLabel category bitmap
85 *
86 * Description:
87 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
88 * Returns zero on success, negative values on error.
89 *
90 */
91int ebitmap_netlbl_export(struct ebitmap *ebmap,
92 struct netlbl_lsm_catmap **catmap)
93{
94 struct ebitmap_node *e_iter = ebmap->node;
95 unsigned long e_map;
96 u32 offset;
97 unsigned int iter;
98 int rc;
99
100 if (e_iter == NULL) {
101 *catmap = NULL;
102 return 0;
103 }
104
105 if (*catmap != NULL)
106 netlbl_catmap_free(*catmap);
107 *catmap = NULL;
108
109 while (e_iter) {
110 offset = e_iter->startbit;
111 for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) {
112 e_map = e_iter->maps[iter];
113 if (e_map != 0) {
114 rc = netlbl_catmap_setlong(catmap,
115 offset,
116 e_map,
117 GFP_ATOMIC);
118 if (rc != 0)
119 goto netlbl_export_failure;
120 }
121 offset += EBITMAP_UNIT_SIZE;
122 }
123 e_iter = e_iter->next;
124 }
125
126 return 0;
127
128netlbl_export_failure:
129 netlbl_catmap_free(*catmap);
130 return -ENOMEM;
131}
132
133/**
134 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
135 * @ebmap: the ebitmap to import
136 * @catmap: the NetLabel category bitmap
137 *
138 * Description:
139 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
140 * Returns zero on success, negative values on error.
141 *
142 */
143int ebitmap_netlbl_import(struct ebitmap *ebmap,
144 struct netlbl_lsm_catmap *catmap)
145{
146 int rc;
147 struct ebitmap_node *e_iter = NULL;
148 struct ebitmap_node *e_prev = NULL;
149 u32 offset = 0, idx;
150 unsigned long bitmap;
151
152 for (;;) {
153 rc = netlbl_catmap_getlong(catmap, &offset, &bitmap);
154 if (rc < 0)
155 goto netlbl_import_failure;
156 if (offset == (u32)-1)
157 return 0;
158
159 /* don't waste ebitmap space if the netlabel bitmap is empty */
160 if (bitmap == 0) {
161 offset += EBITMAP_UNIT_SIZE;
162 continue;
163 }
164
165 if (e_iter == NULL ||
166 offset >= e_iter->startbit + EBITMAP_SIZE) {
167 e_prev = e_iter;
168 e_iter = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
169 if (e_iter == NULL)
170 goto netlbl_import_failure;
171 e_iter->startbit = offset - (offset % EBITMAP_SIZE);
172 if (e_prev == NULL)
173 ebmap->node = e_iter;
174 else
175 e_prev->next = e_iter;
176 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
177 }
178
179 /* offset will always be aligned to an unsigned long */
180 idx = EBITMAP_NODE_INDEX(e_iter, offset);
181 e_iter->maps[idx] = bitmap;
182
183 /* next */
184 offset += EBITMAP_UNIT_SIZE;
185 }
186
187 /* NOTE: we should never reach this return */
188 return 0;
189
190netlbl_import_failure:
191 ebitmap_destroy(ebmap);
192 return -ENOMEM;
193}
194#endif /* CONFIG_NETLABEL */
195
196/*
197 * Check to see if all the bits set in e2 are also set in e1. Optionally,
198 * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
199 * last_e2bit.
200 */
201int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
202{
203 struct ebitmap_node *n1, *n2;
204 int i;
205
206 if (e1->highbit < e2->highbit)
207 return 0;
208
209 n1 = e1->node;
210 n2 = e2->node;
211
212 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
213 if (n1->startbit < n2->startbit) {
214 n1 = n1->next;
215 continue;
216 }
217 for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; )
218 i--; /* Skip trailing NULL map entries */
219 if (last_e2bit && (i >= 0)) {
220 u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
221 __fls(n2->maps[i]);
222 if (lastsetbit > last_e2bit)
223 return 0;
224 }
225
226 while (i >= 0) {
227 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
228 return 0;
229 i--;
230 }
231
232 n1 = n1->next;
233 n2 = n2->next;
234 }
235
236 if (n2)
237 return 0;
238
239 return 1;
240}
241
242int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
243{
244 struct ebitmap_node *n;
245
246 if (e->highbit < bit)
247 return 0;
248
249 n = e->node;
250 while (n && (n->startbit <= bit)) {
251 if ((n->startbit + EBITMAP_SIZE) > bit)
252 return ebitmap_node_get_bit(n, bit);
253 n = n->next;
254 }
255
256 return 0;
257}
258
259int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
260{
261 struct ebitmap_node *n, *prev, *new;
262
263 prev = NULL;
264 n = e->node;
265 while (n && n->startbit <= bit) {
266 if ((n->startbit + EBITMAP_SIZE) > bit) {
267 if (value) {
268 ebitmap_node_set_bit(n, bit);
269 } else {
270 unsigned int s;
271
272 ebitmap_node_clr_bit(n, bit);
273
274 s = find_first_bit(n->maps, EBITMAP_SIZE);
275 if (s < EBITMAP_SIZE)
276 return 0;
277
278 /* drop this node from the bitmap */
279 if (!n->next) {
280 /*
281 * this was the highest map
282 * within the bitmap
283 */
284 if (prev)
285 e->highbit = prev->startbit
286 + EBITMAP_SIZE;
287 else
288 e->highbit = 0;
289 }
290 if (prev)
291 prev->next = n->next;
292 else
293 e->node = n->next;
294 kmem_cache_free(ebitmap_node_cachep, n);
295 }
296 return 0;
297 }
298 prev = n;
299 n = n->next;
300 }
301
302 if (!value)
303 return 0;
304
305 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
306 if (!new)
307 return -ENOMEM;
308
309 new->startbit = bit - (bit % EBITMAP_SIZE);
310 ebitmap_node_set_bit(new, bit);
311
312 if (!n)
313 /* this node will be the highest map within the bitmap */
314 e->highbit = new->startbit + EBITMAP_SIZE;
315
316 if (prev) {
317 new->next = prev->next;
318 prev->next = new;
319 } else {
320 new->next = e->node;
321 e->node = new;
322 }
323
324 return 0;
325}
326
327void ebitmap_destroy(struct ebitmap *e)
328{
329 struct ebitmap_node *n, *temp;
330
331 if (!e)
332 return;
333
334 n = e->node;
335 while (n) {
336 temp = n;
337 n = n->next;
338 kmem_cache_free(ebitmap_node_cachep, temp);
339 }
340
341 e->highbit = 0;
342 e->node = NULL;
343 return;
344}
345
346int ebitmap_read(struct ebitmap *e, void *fp)
347{
348 struct ebitmap_node *n = NULL;
349 u32 mapunit, count, startbit, index;
350 __le32 ebitmap_start;
351 u64 map;
352 __le64 mapbits;
353 __le32 buf[3];
354 int rc, i;
355
356 ebitmap_init(e);
357
358 rc = next_entry(buf, fp, sizeof buf);
359 if (rc < 0)
360 goto out;
361
362 mapunit = le32_to_cpu(buf[0]);
363 e->highbit = le32_to_cpu(buf[1]);
364 count = le32_to_cpu(buf[2]);
365
366 if (mapunit != BITS_PER_U64) {
367 pr_err("SELinux: ebitmap: map size %u does not "
368 "match my size %zd (high bit was %d)\n",
369 mapunit, BITS_PER_U64, e->highbit);
370 goto bad;
371 }
372
373 /* round up e->highbit */
374 e->highbit += EBITMAP_SIZE - 1;
375 e->highbit -= (e->highbit % EBITMAP_SIZE);
376
377 if (!e->highbit) {
378 e->node = NULL;
379 goto ok;
380 }
381
382 if (e->highbit && !count)
383 goto bad;
384
385 for (i = 0; i < count; i++) {
386 rc = next_entry(&ebitmap_start, fp, sizeof(u32));
387 if (rc < 0) {
388 pr_err("SELinux: ebitmap: truncated map\n");
389 goto bad;
390 }
391 startbit = le32_to_cpu(ebitmap_start);
392
393 if (startbit & (mapunit - 1)) {
394 pr_err("SELinux: ebitmap start bit (%d) is "
395 "not a multiple of the map unit size (%u)\n",
396 startbit, mapunit);
397 goto bad;
398 }
399 if (startbit > e->highbit - mapunit) {
400 pr_err("SELinux: ebitmap start bit (%d) is "
401 "beyond the end of the bitmap (%u)\n",
402 startbit, (e->highbit - mapunit));
403 goto bad;
404 }
405
406 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
407 struct ebitmap_node *tmp;
408 tmp = kmem_cache_zalloc(ebitmap_node_cachep, GFP_KERNEL);
409 if (!tmp) {
410 pr_err("SELinux: ebitmap: out of memory\n");
411 rc = -ENOMEM;
412 goto bad;
413 }
414 /* round down */
415 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
416 if (n)
417 n->next = tmp;
418 else
419 e->node = tmp;
420 n = tmp;
421 } else if (startbit <= n->startbit) {
422 pr_err("SELinux: ebitmap: start bit %d"
423 " comes after start bit %d\n",
424 startbit, n->startbit);
425 goto bad;
426 }
427
428 rc = next_entry(&mapbits, fp, sizeof(u64));
429 if (rc < 0) {
430 pr_err("SELinux: ebitmap: truncated map\n");
431 goto bad;
432 }
433 map = le64_to_cpu(mapbits);
434
435 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
436 while (map) {
437 n->maps[index++] = map & (-1UL);
438 map = EBITMAP_SHIFT_UNIT_SIZE(map);
439 }
440 }
441ok:
442 rc = 0;
443out:
444 return rc;
445bad:
446 if (!rc)
447 rc = -EINVAL;
448 ebitmap_destroy(e);
449 goto out;
450}
451
452int ebitmap_write(struct ebitmap *e, void *fp)
453{
454 struct ebitmap_node *n;
455 u32 count;
456 __le32 buf[3];
457 u64 map;
458 int bit, last_bit, last_startbit, rc;
459
460 buf[0] = cpu_to_le32(BITS_PER_U64);
461
462 count = 0;
463 last_bit = 0;
464 last_startbit = -1;
465 ebitmap_for_each_positive_bit(e, n, bit) {
466 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
467 count++;
468 last_startbit = rounddown(bit, BITS_PER_U64);
469 }
470 last_bit = roundup(bit + 1, BITS_PER_U64);
471 }
472 buf[1] = cpu_to_le32(last_bit);
473 buf[2] = cpu_to_le32(count);
474
475 rc = put_entry(buf, sizeof(u32), 3, fp);
476 if (rc)
477 return rc;
478
479 map = 0;
480 last_startbit = INT_MIN;
481 ebitmap_for_each_positive_bit(e, n, bit) {
482 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
483 __le64 buf64[1];
484
485 /* this is the very first bit */
486 if (!map) {
487 last_startbit = rounddown(bit, BITS_PER_U64);
488 map = (u64)1 << (bit - last_startbit);
489 continue;
490 }
491
492 /* write the last node */
493 buf[0] = cpu_to_le32(last_startbit);
494 rc = put_entry(buf, sizeof(u32), 1, fp);
495 if (rc)
496 return rc;
497
498 buf64[0] = cpu_to_le64(map);
499 rc = put_entry(buf64, sizeof(u64), 1, fp);
500 if (rc)
501 return rc;
502
503 /* set up for the next node */
504 map = 0;
505 last_startbit = rounddown(bit, BITS_PER_U64);
506 }
507 map |= (u64)1 << (bit - last_startbit);
508 }
509 /* write the last node */
510 if (map) {
511 __le64 buf64[1];
512
513 /* write the last node */
514 buf[0] = cpu_to_le32(last_startbit);
515 rc = put_entry(buf, sizeof(u32), 1, fp);
516 if (rc)
517 return rc;
518
519 buf64[0] = cpu_to_le64(map);
520 rc = put_entry(buf64, sizeof(u64), 1, fp);
521 if (rc)
522 return rc;
523 }
524 return 0;
525}
526
527void __init ebitmap_cache_init(void)
528{
529 ebitmap_node_cachep = kmem_cache_create("ebitmap_node",
530 sizeof(struct ebitmap_node),
531 0, SLAB_PANIC, NULL);
532}
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Implementation of the extensible bitmap type.
4 *
5 * Author : Stephen Smalley, <stephen.smalley.work@gmail.com>
6 */
7/*
8 * Updated: Hewlett-Packard <paul@paul-moore.com>
9 * Added support to import/export the NetLabel category bitmap
10 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
11 *
12 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
13 * Applied standard bit operations to improve bitmap scanning.
14 */
15
16#include <linux/kernel.h>
17#include <linux/slab.h>
18#include <linux/errno.h>
19#include <linux/jhash.h>
20#include <net/netlabel.h>
21#include "ebitmap.h"
22#include "policydb.h"
23
24#define BITS_PER_U64 ((u32)(sizeof(u64) * 8))
25
26static struct kmem_cache *ebitmap_node_cachep __ro_after_init;
27
28int ebitmap_cmp(const struct ebitmap *e1, const struct ebitmap *e2)
29{
30 const struct ebitmap_node *n1, *n2;
31
32 if (e1->highbit != e2->highbit)
33 return 0;
34
35 n1 = e1->node;
36 n2 = e2->node;
37 while (n1 && n2 && (n1->startbit == n2->startbit) &&
38 !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) {
39 n1 = n1->next;
40 n2 = n2->next;
41 }
42
43 if (n1 || n2)
44 return 0;
45
46 return 1;
47}
48
49int ebitmap_cpy(struct ebitmap *dst, const struct ebitmap *src)
50{
51 struct ebitmap_node *new, *prev;
52 const struct ebitmap_node *n;
53
54 ebitmap_init(dst);
55 n = src->node;
56 prev = NULL;
57 while (n) {
58 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
59 if (!new) {
60 ebitmap_destroy(dst);
61 return -ENOMEM;
62 }
63 new->startbit = n->startbit;
64 memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
65 new->next = NULL;
66 if (prev)
67 prev->next = new;
68 else
69 dst->node = new;
70 prev = new;
71 n = n->next;
72 }
73
74 dst->highbit = src->highbit;
75 return 0;
76}
77
78int ebitmap_and(struct ebitmap *dst, const struct ebitmap *e1,
79 const struct ebitmap *e2)
80{
81 struct ebitmap_node *n;
82 u32 bit;
83 int rc;
84
85 ebitmap_init(dst);
86
87 ebitmap_for_each_positive_bit(e1, n, bit)
88 {
89 if (ebitmap_get_bit(e2, bit)) {
90 rc = ebitmap_set_bit(dst, bit, 1);
91 if (rc < 0)
92 return rc;
93 }
94 }
95 return 0;
96}
97
98#ifdef CONFIG_NETLABEL
99/**
100 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
101 * @ebmap: the ebitmap to export
102 * @catmap: the NetLabel category bitmap
103 *
104 * Description:
105 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
106 * Returns zero on success, negative values on error.
107 *
108 */
109int ebitmap_netlbl_export(struct ebitmap *ebmap,
110 struct netlbl_lsm_catmap **catmap)
111{
112 struct ebitmap_node *e_iter = ebmap->node;
113 unsigned long e_map;
114 u32 offset;
115 unsigned int iter;
116 int rc;
117
118 if (e_iter == NULL) {
119 *catmap = NULL;
120 return 0;
121 }
122
123 if (*catmap != NULL)
124 netlbl_catmap_free(*catmap);
125 *catmap = NULL;
126
127 while (e_iter) {
128 offset = e_iter->startbit;
129 for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) {
130 e_map = e_iter->maps[iter];
131 if (e_map != 0) {
132 rc = netlbl_catmap_setlong(catmap, offset,
133 e_map, GFP_ATOMIC);
134 if (rc != 0)
135 goto netlbl_export_failure;
136 }
137 offset += EBITMAP_UNIT_SIZE;
138 }
139 e_iter = e_iter->next;
140 }
141
142 return 0;
143
144netlbl_export_failure:
145 netlbl_catmap_free(*catmap);
146 return -ENOMEM;
147}
148
149/**
150 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
151 * @ebmap: the ebitmap to import
152 * @catmap: the NetLabel category bitmap
153 *
154 * Description:
155 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
156 * Returns zero on success, negative values on error.
157 *
158 */
159int ebitmap_netlbl_import(struct ebitmap *ebmap,
160 struct netlbl_lsm_catmap *catmap)
161{
162 int rc;
163 struct ebitmap_node *e_iter = NULL;
164 struct ebitmap_node *e_prev = NULL;
165 u32 offset = 0, idx;
166 unsigned long bitmap;
167
168 for (;;) {
169 rc = netlbl_catmap_getlong(catmap, &offset, &bitmap);
170 if (rc < 0)
171 goto netlbl_import_failure;
172 if (offset == (u32)-1)
173 return 0;
174
175 /* don't waste ebitmap space if the netlabel bitmap is empty */
176 if (bitmap == 0) {
177 offset += EBITMAP_UNIT_SIZE;
178 continue;
179 }
180
181 if (e_iter == NULL ||
182 offset >= e_iter->startbit + EBITMAP_SIZE) {
183 e_prev = e_iter;
184 e_iter = kmem_cache_zalloc(ebitmap_node_cachep,
185 GFP_ATOMIC);
186 if (e_iter == NULL)
187 goto netlbl_import_failure;
188 e_iter->startbit = offset - (offset % EBITMAP_SIZE);
189 if (e_prev == NULL)
190 ebmap->node = e_iter;
191 else
192 e_prev->next = e_iter;
193 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
194 }
195
196 /* offset will always be aligned to an unsigned long */
197 idx = EBITMAP_NODE_INDEX(e_iter, offset);
198 e_iter->maps[idx] = bitmap;
199
200 /* next */
201 offset += EBITMAP_UNIT_SIZE;
202 }
203
204 /* NOTE: we should never reach this return */
205 return 0;
206
207netlbl_import_failure:
208 ebitmap_destroy(ebmap);
209 return -ENOMEM;
210}
211#endif /* CONFIG_NETLABEL */
212
213/*
214 * Check to see if all the bits set in e2 are also set in e1. Optionally,
215 * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
216 * last_e2bit.
217 */
218int ebitmap_contains(const struct ebitmap *e1, const struct ebitmap *e2,
219 u32 last_e2bit)
220{
221 const struct ebitmap_node *n1, *n2;
222 int i;
223
224 if (e1->highbit < e2->highbit)
225 return 0;
226
227 n1 = e1->node;
228 n2 = e2->node;
229
230 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
231 if (n1->startbit < n2->startbit) {
232 n1 = n1->next;
233 continue;
234 }
235 for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i];)
236 i--; /* Skip trailing NULL map entries */
237 if (last_e2bit && (i >= 0)) {
238 u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
239 __fls(n2->maps[i]);
240 if (lastsetbit > last_e2bit)
241 return 0;
242 }
243
244 while (i >= 0) {
245 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
246 return 0;
247 i--;
248 }
249
250 n1 = n1->next;
251 n2 = n2->next;
252 }
253
254 if (n2)
255 return 0;
256
257 return 1;
258}
259
260int ebitmap_get_bit(const struct ebitmap *e, u32 bit)
261{
262 const struct ebitmap_node *n;
263
264 if (e->highbit < bit)
265 return 0;
266
267 n = e->node;
268 while (n && (n->startbit <= bit)) {
269 if ((n->startbit + EBITMAP_SIZE) > bit)
270 return ebitmap_node_get_bit(n, bit);
271 n = n->next;
272 }
273
274 return 0;
275}
276
277int ebitmap_set_bit(struct ebitmap *e, u32 bit, int value)
278{
279 struct ebitmap_node *n, *prev, *new;
280
281 prev = NULL;
282 n = e->node;
283 while (n && n->startbit <= bit) {
284 if ((n->startbit + EBITMAP_SIZE) > bit) {
285 if (value) {
286 ebitmap_node_set_bit(n, bit);
287 } else {
288 u32 s;
289
290 ebitmap_node_clr_bit(n, bit);
291
292 s = find_first_bit(n->maps, EBITMAP_SIZE);
293 if (s < EBITMAP_SIZE)
294 return 0;
295
296 /* drop this node from the bitmap */
297 if (!n->next) {
298 /*
299 * this was the highest map
300 * within the bitmap
301 */
302 if (prev)
303 e->highbit = prev->startbit +
304 EBITMAP_SIZE;
305 else
306 e->highbit = 0;
307 }
308 if (prev)
309 prev->next = n->next;
310 else
311 e->node = n->next;
312 kmem_cache_free(ebitmap_node_cachep, n);
313 }
314 return 0;
315 }
316 prev = n;
317 n = n->next;
318 }
319
320 if (!value)
321 return 0;
322
323 new = kmem_cache_zalloc(ebitmap_node_cachep, GFP_ATOMIC);
324 if (!new)
325 return -ENOMEM;
326
327 new->startbit = bit - (bit % EBITMAP_SIZE);
328 ebitmap_node_set_bit(new, bit);
329
330 if (!n)
331 /* this node will be the highest map within the bitmap */
332 e->highbit = new->startbit + EBITMAP_SIZE;
333
334 if (prev) {
335 new->next = prev->next;
336 prev->next = new;
337 } else {
338 new->next = e->node;
339 e->node = new;
340 }
341
342 return 0;
343}
344
345void ebitmap_destroy(struct ebitmap *e)
346{
347 struct ebitmap_node *n, *temp;
348
349 if (!e)
350 return;
351
352 n = e->node;
353 while (n) {
354 temp = n;
355 n = n->next;
356 kmem_cache_free(ebitmap_node_cachep, temp);
357 }
358
359 e->highbit = 0;
360 e->node = NULL;
361}
362
363int ebitmap_read(struct ebitmap *e, void *fp)
364{
365 struct ebitmap_node *n = NULL;
366 u32 mapunit, count, startbit, index, i;
367 __le32 ebitmap_start;
368 u64 map;
369 __le64 mapbits;
370 __le32 buf[3];
371 int rc;
372
373 ebitmap_init(e);
374
375 rc = next_entry(buf, fp, sizeof buf);
376 if (rc < 0)
377 goto out;
378
379 mapunit = le32_to_cpu(buf[0]);
380 e->highbit = le32_to_cpu(buf[1]);
381 count = le32_to_cpu(buf[2]);
382
383 if (mapunit != BITS_PER_U64) {
384 pr_err("SELinux: ebitmap: map size %u does not "
385 "match my size %u (high bit was %u)\n",
386 mapunit, BITS_PER_U64, e->highbit);
387 goto bad;
388 }
389
390 /* round up e->highbit */
391 e->highbit += EBITMAP_SIZE - 1;
392 e->highbit -= (e->highbit % EBITMAP_SIZE);
393
394 if (!e->highbit) {
395 e->node = NULL;
396 goto ok;
397 }
398
399 if (e->highbit && !count)
400 goto bad;
401
402 for (i = 0; i < count; i++) {
403 rc = next_entry(&ebitmap_start, fp, sizeof(u32));
404 if (rc < 0) {
405 pr_err("SELinux: ebitmap: truncated map\n");
406 goto bad;
407 }
408 startbit = le32_to_cpu(ebitmap_start);
409
410 if (startbit & (mapunit - 1)) {
411 pr_err("SELinux: ebitmap start bit (%u) is "
412 "not a multiple of the map unit size (%u)\n",
413 startbit, mapunit);
414 goto bad;
415 }
416 if (startbit > e->highbit - mapunit) {
417 pr_err("SELinux: ebitmap start bit (%u) is "
418 "beyond the end of the bitmap (%u)\n",
419 startbit, (e->highbit - mapunit));
420 goto bad;
421 }
422
423 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
424 struct ebitmap_node *tmp;
425 tmp = kmem_cache_zalloc(ebitmap_node_cachep,
426 GFP_KERNEL);
427 if (!tmp) {
428 pr_err("SELinux: ebitmap: out of memory\n");
429 rc = -ENOMEM;
430 goto bad;
431 }
432 /* round down */
433 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
434 if (n)
435 n->next = tmp;
436 else
437 e->node = tmp;
438 n = tmp;
439 } else if (startbit <= n->startbit) {
440 pr_err("SELinux: ebitmap: start bit %u"
441 " comes after start bit %u\n",
442 startbit, n->startbit);
443 goto bad;
444 }
445
446 rc = next_entry(&mapbits, fp, sizeof(u64));
447 if (rc < 0) {
448 pr_err("SELinux: ebitmap: truncated map\n");
449 goto bad;
450 }
451 map = le64_to_cpu(mapbits);
452 if (!map) {
453 pr_err("SELinux: ebitmap: empty map\n");
454 goto bad;
455 }
456
457 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
458 while (map) {
459 n->maps[index++] = map & (-1UL);
460 map = EBITMAP_SHIFT_UNIT_SIZE(map);
461 }
462 }
463
464 if (n && n->startbit + EBITMAP_SIZE != e->highbit) {
465 pr_err("SELinux: ebitmap: high bit %u is not equal to the expected value %zu\n",
466 e->highbit, n->startbit + EBITMAP_SIZE);
467 goto bad;
468 }
469
470ok:
471 rc = 0;
472out:
473 return rc;
474bad:
475 if (!rc)
476 rc = -EINVAL;
477 ebitmap_destroy(e);
478 goto out;
479}
480
481int ebitmap_write(const struct ebitmap *e, void *fp)
482{
483 struct ebitmap_node *n;
484 u32 bit, count, last_bit, last_startbit;
485 __le32 buf[3];
486 u64 map;
487 int rc;
488
489 buf[0] = cpu_to_le32(BITS_PER_U64);
490
491 count = 0;
492 last_bit = 0;
493 last_startbit = U32_MAX;
494 ebitmap_for_each_positive_bit(e, n, bit)
495 {
496 if (last_startbit == U32_MAX ||
497 rounddown(bit, BITS_PER_U64) > last_startbit) {
498 count++;
499 last_startbit = rounddown(bit, BITS_PER_U64);
500 }
501 last_bit = roundup(bit + 1, BITS_PER_U64);
502 }
503 buf[1] = cpu_to_le32(last_bit);
504 buf[2] = cpu_to_le32(count);
505
506 rc = put_entry(buf, sizeof(u32), 3, fp);
507 if (rc)
508 return rc;
509
510 map = 0;
511 last_startbit = U32_MAX;
512 ebitmap_for_each_positive_bit(e, n, bit)
513 {
514 if (last_startbit == U32_MAX ||
515 rounddown(bit, BITS_PER_U64) > last_startbit) {
516 __le64 buf64[1];
517
518 /* this is the very first bit */
519 if (!map) {
520 last_startbit = rounddown(bit, BITS_PER_U64);
521 map = (u64)1 << (bit - last_startbit);
522 continue;
523 }
524
525 /* write the last node */
526 buf[0] = cpu_to_le32(last_startbit);
527 rc = put_entry(buf, sizeof(u32), 1, fp);
528 if (rc)
529 return rc;
530
531 buf64[0] = cpu_to_le64(map);
532 rc = put_entry(buf64, sizeof(u64), 1, fp);
533 if (rc)
534 return rc;
535
536 /* set up for the next node */
537 map = 0;
538 last_startbit = rounddown(bit, BITS_PER_U64);
539 }
540 map |= (u64)1 << (bit - last_startbit);
541 }
542 /* write the last node */
543 if (map) {
544 __le64 buf64[1];
545
546 /* write the last node */
547 buf[0] = cpu_to_le32(last_startbit);
548 rc = put_entry(buf, sizeof(u32), 1, fp);
549 if (rc)
550 return rc;
551
552 buf64[0] = cpu_to_le64(map);
553 rc = put_entry(buf64, sizeof(u64), 1, fp);
554 if (rc)
555 return rc;
556 }
557 return 0;
558}
559
560u32 ebitmap_hash(const struct ebitmap *e, u32 hash)
561{
562 struct ebitmap_node *node;
563
564 /* need to change hash even if ebitmap is empty */
565 hash = jhash_1word(e->highbit, hash);
566 for (node = e->node; node; node = node->next) {
567 hash = jhash_1word(node->startbit, hash);
568 hash = jhash(node->maps, sizeof(node->maps), hash);
569 }
570 return hash;
571}
572
573void __init ebitmap_cache_init(void)
574{
575 ebitmap_node_cachep = KMEM_CACHE(ebitmap_node, SLAB_PANIC);
576}