blob: 57644b1dc42e1a38b5f1fd0d24ab75164b3bdbf1 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Implementation of the extensible bitmap type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
Venkat Yekkirala7420ed22006-08-04 23:17:57 -07006/*
Paul Moore82c21bf2011-08-01 11:10:33 +00007 * Updated: Hewlett-Packard <paul@paul-moore.com>
Venkat Yekkirala7420ed22006-08-04 23:17:57 -07008 *
Paul Moore02752762006-11-29 13:18:18 -05009 * Added support to import/export the NetLabel category bitmap
Venkat Yekkirala7420ed22006-08-04 23:17:57 -070010 *
11 * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
12 */
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +090013/*
14 * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
15 * Applied standard bit operations to improve bitmap scanning.
16 */
Venkat Yekkirala7420ed22006-08-04 23:17:57 -070017
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/kernel.h>
19#include <linux/slab.h>
20#include <linux/errno.h>
Paul Moore02752762006-11-29 13:18:18 -050021#include <net/netlabel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "ebitmap.h"
23#include "policydb.h"
24
Eric Pariscee74f42010-10-13 17:50:25 -040025#define BITS_PER_U64 (sizeof(u64) * 8)
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2)
28{
29 struct ebitmap_node *n1, *n2;
30
31 if (e1->highbit != e2->highbit)
32 return 0;
33
34 n1 = e1->node;
35 n2 = e2->node;
36 while (n1 && n2 &&
37 (n1->startbit == n2->startbit) &&
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +090038 !memcmp(n1->maps, n2->maps, EBITMAP_SIZE / 8)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 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, struct ebitmap *src)
50{
51 struct ebitmap_node *n, *new, *prev;
52
53 ebitmap_init(dst);
54 n = src->node;
55 prev = NULL;
56 while (n) {
James Morris89d155e2005-10-30 14:59:21 -080057 new = kzalloc(sizeof(*new), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 if (!new) {
59 ebitmap_destroy(dst);
60 return -ENOMEM;
61 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 new->startbit = n->startbit;
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +090063 memcpy(new->maps, n->maps, EBITMAP_SIZE / 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 new->next = NULL;
65 if (prev)
66 prev->next = new;
67 else
68 dst->node = new;
69 prev = new;
70 n = n->next;
71 }
72
73 dst->highbit = src->highbit;
74 return 0;
75}
76
Paul Moore02752762006-11-29 13:18:18 -050077#ifdef CONFIG_NETLABEL
Venkat Yekkirala7420ed22006-08-04 23:17:57 -070078/**
Paul Moore02752762006-11-29 13:18:18 -050079 * ebitmap_netlbl_export - Export an ebitmap into a NetLabel category bitmap
80 * @ebmap: the ebitmap to export
81 * @catmap: the NetLabel category bitmap
Venkat Yekkirala7420ed22006-08-04 23:17:57 -070082 *
83 * Description:
Paul Moore02752762006-11-29 13:18:18 -050084 * Export a SELinux extensibile bitmap into a NetLabel category bitmap.
85 * Returns zero on success, negative values on error.
Venkat Yekkirala7420ed22006-08-04 23:17:57 -070086 *
87 */
Paul Moore02752762006-11-29 13:18:18 -050088int ebitmap_netlbl_export(struct ebitmap *ebmap,
Paul Moore4fbe63d2014-08-01 11:17:37 -040089 struct netlbl_lsm_catmap **catmap)
Venkat Yekkirala7420ed22006-08-04 23:17:57 -070090{
Paul Moore02752762006-11-29 13:18:18 -050091 struct ebitmap_node *e_iter = ebmap->node;
Paul Moore4b8feff2014-08-01 11:17:17 -040092 unsigned long e_map;
93 u32 offset;
94 unsigned int iter;
95 int rc;
Paul Moore02752762006-11-29 13:18:18 -050096
97 if (e_iter == NULL) {
98 *catmap = NULL;
Paul Moorebf0edf32006-10-11 19:10:48 -040099 return 0;
100 }
101
Paul Moore4b8feff2014-08-01 11:17:17 -0400102 if (*catmap != NULL)
Paul Moore4fbe63d2014-08-01 11:17:37 -0400103 netlbl_catmap_free(*catmap);
Paul Moore4b8feff2014-08-01 11:17:17 -0400104 *catmap = NULL;
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700105
Vesa-Matti Karidbc74c62008-08-07 03:18:20 +0300106 while (e_iter) {
Paul Moore4b8feff2014-08-01 11:17:17 -0400107 offset = e_iter->startbit;
108 for (iter = 0; iter < EBITMAP_UNIT_NUMS; iter++) {
109 e_map = e_iter->maps[iter];
110 if (e_map != 0) {
Paul Moore4fbe63d2014-08-01 11:17:37 -0400111 rc = netlbl_catmap_setlong(catmap,
112 offset,
113 e_map,
114 GFP_ATOMIC);
Paul Moore4b8feff2014-08-01 11:17:17 -0400115 if (rc != 0)
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900116 goto netlbl_export_failure;
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900117 }
Paul Moore4b8feff2014-08-01 11:17:17 -0400118 offset += EBITMAP_UNIT_SIZE;
Paul Moore02752762006-11-29 13:18:18 -0500119 }
KaiGai Kohei6d2b6852007-11-07 01:17:16 +0900120 e_iter = e_iter->next;
Paul Moore02752762006-11-29 13:18:18 -0500121 }
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700122
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700123 return 0;
Paul Moore02752762006-11-29 13:18:18 -0500124
125netlbl_export_failure:
Paul Moore4fbe63d2014-08-01 11:17:37 -0400126 netlbl_catmap_free(*catmap);
Paul Moore02752762006-11-29 13:18:18 -0500127 return -ENOMEM;
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700128}
129
130/**
Paul Moore02752762006-11-29 13:18:18 -0500131 * ebitmap_netlbl_import - Import a NetLabel category bitmap into an ebitmap
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900132 * @ebmap: the ebitmap to import
Paul Moore02752762006-11-29 13:18:18 -0500133 * @catmap: the NetLabel category bitmap
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700134 *
135 * Description:
Paul Moore02752762006-11-29 13:18:18 -0500136 * Import a NetLabel category bitmap into a SELinux extensibile bitmap.
137 * Returns zero on success, negative values on error.
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700138 *
139 */
Paul Moore02752762006-11-29 13:18:18 -0500140int ebitmap_netlbl_import(struct ebitmap *ebmap,
Paul Moore4fbe63d2014-08-01 11:17:37 -0400141 struct netlbl_lsm_catmap *catmap)
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700142{
Paul Moore4b8feff2014-08-01 11:17:17 -0400143 int rc;
Paul Moore02752762006-11-29 13:18:18 -0500144 struct ebitmap_node *e_iter = NULL;
Paul Moore4b8feff2014-08-01 11:17:17 -0400145 struct ebitmap_node *e_prev = NULL;
146 u32 offset = 0, idx;
147 unsigned long bitmap;
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700148
Paul Moore4b8feff2014-08-01 11:17:17 -0400149 for (;;) {
Paul Moore4fbe63d2014-08-01 11:17:37 -0400150 rc = netlbl_catmap_getlong(catmap, &offset, &bitmap);
Paul Moore4b8feff2014-08-01 11:17:17 -0400151 if (rc < 0)
152 goto netlbl_import_failure;
153 if (offset == (u32)-1)
154 return 0;
Paul Moore02752762006-11-29 13:18:18 -0500155
Paul Moore33246032015-07-09 14:20:36 -0400156 /* don't waste ebitmap space if the netlabel bitmap is empty */
157 if (bitmap == 0) {
158 offset += EBITMAP_UNIT_SIZE;
159 continue;
160 }
161
Paul Moore4b8feff2014-08-01 11:17:17 -0400162 if (e_iter == NULL ||
163 offset >= e_iter->startbit + EBITMAP_SIZE) {
164 e_prev = e_iter;
165 e_iter = kzalloc(sizeof(*e_iter), GFP_ATOMIC);
166 if (e_iter == NULL)
167 goto netlbl_import_failure;
168 e_iter->startbit = offset & ~(EBITMAP_SIZE - 1);
169 if (e_prev == NULL)
170 ebmap->node = e_iter;
171 else
172 e_prev->next = e_iter;
173 ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
Paul Moore02752762006-11-29 13:18:18 -0500174 }
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700175
Paul Moore4b8feff2014-08-01 11:17:17 -0400176 /* offset will always be aligned to an unsigned long */
177 idx = EBITMAP_NODE_INDEX(e_iter, offset);
178 e_iter->maps[idx] = bitmap;
179
180 /* next */
181 offset += EBITMAP_UNIT_SIZE;
182 }
183
184 /* NOTE: we should never reach this return */
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700185 return 0;
Paul Moore02752762006-11-29 13:18:18 -0500186
187netlbl_import_failure:
188 ebitmap_destroy(ebmap);
189 return -ENOMEM;
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700190}
Paul Moore02752762006-11-29 13:18:18 -0500191#endif /* CONFIG_NETLABEL */
Venkat Yekkirala7420ed22006-08-04 23:17:57 -0700192
Waiman Longfee71142013-07-23 17:38:41 -0400193/*
194 * Check to see if all the bits set in e2 are also set in e1. Optionally,
195 * if last_e2bit is non-zero, the highest set bit in e2 cannot exceed
196 * last_e2bit.
197 */
198int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2, u32 last_e2bit)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199{
200 struct ebitmap_node *n1, *n2;
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900201 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203 if (e1->highbit < e2->highbit)
204 return 0;
205
206 n1 = e1->node;
207 n2 = e2->node;
Waiman Longfee71142013-07-23 17:38:41 -0400208
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 while (n1 && n2 && (n1->startbit <= n2->startbit)) {
210 if (n1->startbit < n2->startbit) {
211 n1 = n1->next;
212 continue;
213 }
Waiman Longfee71142013-07-23 17:38:41 -0400214 for (i = EBITMAP_UNIT_NUMS - 1; (i >= 0) && !n2->maps[i]; )
215 i--; /* Skip trailing NULL map entries */
216 if (last_e2bit && (i >= 0)) {
217 u32 lastsetbit = n2->startbit + i * EBITMAP_UNIT_SIZE +
218 __fls(n2->maps[i]);
219 if (lastsetbit > last_e2bit)
220 return 0;
221 }
222
223 while (i >= 0) {
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900224 if ((n1->maps[i] & n2->maps[i]) != n2->maps[i])
225 return 0;
Waiman Longfee71142013-07-23 17:38:41 -0400226 i--;
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900227 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 n1 = n1->next;
230 n2 = n2->next;
231 }
232
233 if (n2)
234 return 0;
235
236 return 1;
237}
238
239int ebitmap_get_bit(struct ebitmap *e, unsigned long bit)
240{
241 struct ebitmap_node *n;
242
243 if (e->highbit < bit)
244 return 0;
245
246 n = e->node;
247 while (n && (n->startbit <= bit)) {
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900248 if ((n->startbit + EBITMAP_SIZE) > bit)
249 return ebitmap_node_get_bit(n, bit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 n = n->next;
251 }
252
253 return 0;
254}
255
256int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value)
257{
258 struct ebitmap_node *n, *prev, *new;
259
260 prev = NULL;
261 n = e->node;
262 while (n && n->startbit <= bit) {
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900263 if ((n->startbit + EBITMAP_SIZE) > bit) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 if (value) {
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900265 ebitmap_node_set_bit(n, bit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 } else {
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900267 unsigned int s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900269 ebitmap_node_clr_bit(n, bit);
270
271 s = find_first_bit(n->maps, EBITMAP_SIZE);
272 if (s < EBITMAP_SIZE)
273 return 0;
274
275 /* drop this node from the bitmap */
276 if (!n->next) {
277 /*
278 * this was the highest map
279 * within the bitmap
280 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 if (prev)
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900282 e->highbit = prev->startbit
283 + EBITMAP_SIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 else
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900285 e->highbit = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 }
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900287 if (prev)
288 prev->next = n->next;
289 else
290 e->node = n->next;
291 kfree(n);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 }
293 return 0;
294 }
295 prev = n;
296 n = n->next;
297 }
298
299 if (!value)
300 return 0;
301
James Morris89d155e2005-10-30 14:59:21 -0800302 new = kzalloc(sizeof(*new), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 if (!new)
304 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900306 new->startbit = bit - (bit % EBITMAP_SIZE);
307 ebitmap_node_set_bit(new, bit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308
309 if (!n)
310 /* this node will be the highest map within the bitmap */
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900311 e->highbit = new->startbit + EBITMAP_SIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
313 if (prev) {
314 new->next = prev->next;
315 prev->next = new;
316 } else {
317 new->next = e->node;
318 e->node = new;
319 }
320
321 return 0;
322}
323
324void ebitmap_destroy(struct ebitmap *e)
325{
326 struct ebitmap_node *n, *temp;
327
328 if (!e)
329 return;
330
331 n = e->node;
332 while (n) {
333 temp = n;
334 n = n->next;
335 kfree(temp);
336 }
337
338 e->highbit = 0;
339 e->node = NULL;
340 return;
341}
342
343int ebitmap_read(struct ebitmap *e, void *fp)
344{
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900345 struct ebitmap_node *n = NULL;
346 u32 mapunit, count, startbit, index;
347 u64 map;
Alexey Dobriyanb5bf6c52005-09-03 15:55:17 -0700348 __le32 buf[3];
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900349 int rc, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351 ebitmap_init(e);
352
353 rc = next_entry(buf, fp, sizeof buf);
354 if (rc < 0)
355 goto out;
356
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900357 mapunit = le32_to_cpu(buf[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 e->highbit = le32_to_cpu(buf[1]);
359 count = le32_to_cpu(buf[2]);
360
Eric Pariscee74f42010-10-13 17:50:25 -0400361 if (mapunit != BITS_PER_U64) {
James Morris454d9722008-02-26 20:42:02 +1100362 printk(KERN_ERR "SELinux: ebitmap: map size %u does not "
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900363 "match my size %Zd (high bit was %d)\n",
Eric Pariscee74f42010-10-13 17:50:25 -0400364 mapunit, BITS_PER_U64, e->highbit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 goto bad;
366 }
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900367
368 /* round up e->highbit */
369 e->highbit += EBITMAP_SIZE - 1;
370 e->highbit -= (e->highbit % EBITMAP_SIZE);
371
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 if (!e->highbit) {
373 e->node = NULL;
374 goto ok;
375 }
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900376
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 for (i = 0; i < count; i++) {
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900378 rc = next_entry(&startbit, fp, sizeof(u32));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 if (rc < 0) {
James Morris454d9722008-02-26 20:42:02 +1100380 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 goto bad;
382 }
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900383 startbit = le32_to_cpu(startbit);
384
385 if (startbit & (mapunit - 1)) {
James Morris454d9722008-02-26 20:42:02 +1100386 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
KaiGai Kohei087feb92007-10-03 23:42:56 +0900387 "not a multiple of the map unit size (%u)\n",
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900388 startbit, mapunit);
389 goto bad;
390 }
391 if (startbit > e->highbit - mapunit) {
James Morris454d9722008-02-26 20:42:02 +1100392 printk(KERN_ERR "SELinux: ebitmap start bit (%d) is "
KaiGai Kohei087feb92007-10-03 23:42:56 +0900393 "beyond the end of the bitmap (%u)\n",
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900394 startbit, (e->highbit - mapunit));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 goto bad;
396 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900398 if (!n || startbit >= n->startbit + EBITMAP_SIZE) {
399 struct ebitmap_node *tmp;
400 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
401 if (!tmp) {
402 printk(KERN_ERR
James Morris454d9722008-02-26 20:42:02 +1100403 "SELinux: ebitmap: out of memory\n");
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900404 rc = -ENOMEM;
405 goto bad;
406 }
407 /* round down */
408 tmp->startbit = startbit - (startbit % EBITMAP_SIZE);
Eric Paris7696ee82008-04-18 17:38:30 -0400409 if (n)
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900410 n->next = tmp;
Eric Paris7696ee82008-04-18 17:38:30 -0400411 else
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900412 e->node = tmp;
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900413 n = tmp;
414 } else if (startbit <= n->startbit) {
James Morris454d9722008-02-26 20:42:02 +1100415 printk(KERN_ERR "SELinux: ebitmap: start bit %d"
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900416 " comes after start bit %d\n",
417 startbit, n->startbit);
418 goto bad;
419 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 rc = next_entry(&map, fp, sizeof(u64));
422 if (rc < 0) {
James Morris454d9722008-02-26 20:42:02 +1100423 printk(KERN_ERR "SELinux: ebitmap: truncated map\n");
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900424 goto bad;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 }
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900426 map = le64_to_cpu(map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
KaiGai Kohei9fe79ad2007-09-29 02:20:55 +0900428 index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
429 while (map) {
KaiGai Kohei087feb92007-10-03 23:42:56 +0900430 n->maps[index++] = map & (-1UL);
431 map = EBITMAP_SHIFT_UNIT_SIZE(map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434ok:
435 rc = 0;
436out:
437 return rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438bad:
439 if (!rc)
440 rc = -EINVAL;
441 ebitmap_destroy(e);
442 goto out;
443}
Eric Pariscee74f42010-10-13 17:50:25 -0400444
445int ebitmap_write(struct ebitmap *e, void *fp)
446{
447 struct ebitmap_node *n;
448 u32 count;
449 __le32 buf[3];
450 u64 map;
451 int bit, last_bit, last_startbit, rc;
452
453 buf[0] = cpu_to_le32(BITS_PER_U64);
454
455 count = 0;
456 last_bit = 0;
457 last_startbit = -1;
458 ebitmap_for_each_positive_bit(e, n, bit) {
459 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
460 count++;
461 last_startbit = rounddown(bit, BITS_PER_U64);
462 }
463 last_bit = roundup(bit + 1, BITS_PER_U64);
464 }
465 buf[1] = cpu_to_le32(last_bit);
466 buf[2] = cpu_to_le32(count);
467
468 rc = put_entry(buf, sizeof(u32), 3, fp);
469 if (rc)
470 return rc;
471
472 map = 0;
473 last_startbit = INT_MIN;
474 ebitmap_for_each_positive_bit(e, n, bit) {
475 if (rounddown(bit, (int)BITS_PER_U64) > last_startbit) {
476 __le64 buf64[1];
477
478 /* this is the very first bit */
479 if (!map) {
480 last_startbit = rounddown(bit, BITS_PER_U64);
481 map = (u64)1 << (bit - last_startbit);
482 continue;
483 }
484
485 /* write the last node */
486 buf[0] = cpu_to_le32(last_startbit);
487 rc = put_entry(buf, sizeof(u32), 1, fp);
488 if (rc)
489 return rc;
490
491 buf64[0] = cpu_to_le64(map);
492 rc = put_entry(buf64, sizeof(u64), 1, fp);
493 if (rc)
494 return rc;
495
496 /* set up for the next node */
497 map = 0;
498 last_startbit = rounddown(bit, BITS_PER_U64);
499 }
500 map |= (u64)1 << (bit - last_startbit);
501 }
502 /* write the last node */
503 if (map) {
504 __le64 buf64[1];
505
506 /* write the last node */
507 buf[0] = cpu_to_le32(last_startbit);
508 rc = put_entry(buf, sizeof(u32), 1, fp);
509 if (rc)
510 return rc;
511
512 buf64[0] = cpu_to_le64(map);
513 rc = put_entry(buf64, sizeof(u64), 1, fp);
514 if (rc)
515 return rc;
516 }
517 return 0;
518}