1 |
/* |
2 |
* fs/realpath.c |
3 |
* |
4 |
* Get the canonicalized absolute pathnames. The basis for SAKURA and TOMOYO. |
5 |
* |
6 |
* Copyright (C) 2005-2008 NTT DATA CORPORATION |
7 |
* |
8 |
* Version: 1.6.1-rc 2008/04/24 |
9 |
* |
10 |
* This file is applicable to both 2.4.30 and 2.6.11 and later. |
11 |
* See README.ccs for ChangeLog. |
12 |
* |
13 |
*/ |
14 |
#include <linux/string.h> |
15 |
#include <linux/mm.h> |
16 |
#include <linux/utime.h> |
17 |
#include <linux/file.h> |
18 |
#include <linux/smp_lock.h> |
19 |
#include <linux/module.h> |
20 |
#include <linux/slab.h> |
21 |
#include <asm/uaccess.h> |
22 |
#include <asm/atomic.h> |
23 |
#include <linux/version.h> |
24 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
25 |
#include <linux/namei.h> |
26 |
#include <linux/mount.h> |
27 |
static const int lookup_flags = LOOKUP_FOLLOW; |
28 |
#else |
29 |
static const int lookup_flags = LOOKUP_FOLLOW | LOOKUP_POSITIVE; |
30 |
#endif |
31 |
#include <linux/realpath.h> |
32 |
#include <linux/proc_fs.h> |
33 |
#include <linux/ccs_common.h> |
34 |
|
35 |
/** |
36 |
* get_absolute_path - Get the path of a dentry but ignores chroot'ed root. |
37 |
* |
38 |
* @dentry: Pointer to "struct dentry". |
39 |
* @vfsmnt: Pointer to "struct vfsmount". |
40 |
* @buffer: Pointer to buffer to return value in. |
41 |
* @buflen: Sizeof @buffer. |
42 |
* |
43 |
* Returns 0 on success, -ENOMEM otherwise. |
44 |
* |
45 |
* Caller holds the dcache_lock and vfsmount_lock. |
46 |
* Based on __d_path() in fs/dcache.c |
47 |
* |
48 |
* If dentry is a directory, trailing '/' is appended. |
49 |
* Characters out of 0x20 < c < 0x7F range are converted to |
50 |
* \ooo style octal string. |
51 |
* Character \ is converted to \\ string. |
52 |
*/ |
53 |
static int get_absolute_path(struct dentry *dentry, struct vfsmount *vfsmnt, |
54 |
char *buffer, int buflen) |
55 |
{ |
56 |
/***** CRITICAL SECTION START *****/ |
57 |
char *start = buffer; |
58 |
char *end = buffer + buflen; |
59 |
bool is_dir = (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)); |
60 |
|
61 |
if (buflen < 256) |
62 |
goto out; |
63 |
|
64 |
*--end = '\0'; |
65 |
buflen--; |
66 |
|
67 |
for (;;) { |
68 |
struct dentry *parent; |
69 |
|
70 |
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { |
71 |
/* Global root? */ |
72 |
if (vfsmnt->mnt_parent == vfsmnt) |
73 |
break; |
74 |
dentry = vfsmnt->mnt_mountpoint; |
75 |
vfsmnt = vfsmnt->mnt_parent; |
76 |
continue; |
77 |
} |
78 |
if (is_dir) { |
79 |
is_dir = false; |
80 |
*--end = '/'; |
81 |
buflen--; |
82 |
} |
83 |
parent = dentry->d_parent; |
84 |
{ |
85 |
const char *sp = dentry->d_name.name; |
86 |
const char *cp = sp + dentry->d_name.len - 1; |
87 |
unsigned char c; |
88 |
|
89 |
/* |
90 |
* Exception: Use /proc/self/ rather than |
91 |
* /proc/\$/ for current process. |
92 |
*/ |
93 |
if (IS_ROOT(parent) && *sp > '0' && *sp <= '9' && |
94 |
parent->d_sb && |
95 |
parent->d_sb->s_magic == PROC_SUPER_MAGIC) { |
96 |
char *ep; |
97 |
const pid_t pid |
98 |
= (pid_t) simple_strtoul(sp, &ep, 10); |
99 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
100 |
if (!*ep && pid == current->tgid) { |
101 |
sp = "self"; |
102 |
cp = sp + 3; |
103 |
} |
104 |
#else |
105 |
if (!*ep && pid == current->pid) { |
106 |
sp = "self"; |
107 |
cp = sp + 3; |
108 |
} |
109 |
#endif |
110 |
} |
111 |
|
112 |
while (sp <= cp) { |
113 |
c = *(unsigned char *) cp; |
114 |
if (c == '\\') { |
115 |
buflen -= 2; |
116 |
if (buflen < 0) |
117 |
goto out; |
118 |
*--end = '\\'; |
119 |
*--end = '\\'; |
120 |
} else if (c > ' ' && c < 127) { |
121 |
if (--buflen < 0) |
122 |
goto out; |
123 |
*--end = (char) c; |
124 |
} else { |
125 |
buflen -= 4; |
126 |
if (buflen < 0) |
127 |
goto out; |
128 |
*--end = (c & 7) + '0'; |
129 |
*--end = ((c >> 3) & 7) + '0'; |
130 |
*--end = (c >> 6) + '0'; |
131 |
*--end = '\\'; |
132 |
} |
133 |
cp--; |
134 |
} |
135 |
if (--buflen < 0) |
136 |
goto out; |
137 |
*--end = '/'; |
138 |
} |
139 |
dentry = parent; |
140 |
} |
141 |
if (*end == '/') { |
142 |
buflen++; |
143 |
end++; |
144 |
} |
145 |
{ |
146 |
const char *sp = dentry->d_name.name; |
147 |
const char *cp = sp + dentry->d_name.len - 1; |
148 |
unsigned char c; |
149 |
while (sp <= cp) { |
150 |
c = *(unsigned char *) cp; |
151 |
if (c == '\\') { |
152 |
buflen -= 2; |
153 |
if (buflen < 0) |
154 |
goto out; |
155 |
*--end = '\\'; |
156 |
*--end = '\\'; |
157 |
} else if (c > ' ' && c < 127) { |
158 |
if (--buflen < 0) |
159 |
goto out; |
160 |
*--end = (char) c; |
161 |
} else { |
162 |
buflen -= 4; |
163 |
if (buflen < 0) |
164 |
goto out; |
165 |
*--end = (c & 7) + '0'; |
166 |
*--end = ((c >> 3) & 7) + '0'; |
167 |
*--end = (c >> 6) + '0'; |
168 |
*--end = '\\'; |
169 |
} |
170 |
cp--; |
171 |
} |
172 |
} |
173 |
/* Move the pathname to the top of the buffer. */ |
174 |
memmove(start, end, strlen(end) + 1); |
175 |
return 0; |
176 |
out: |
177 |
return -ENOMEM; |
178 |
/***** CRITICAL SECTION END *****/ |
179 |
} |
180 |
|
181 |
/** |
182 |
* ccs_realpath_from_dentry2 - Returns realpath(3) of the given dentry but ignores chroot'ed root. |
183 |
* |
184 |
* @dentry: Pointer to "struct dentry". |
185 |
* @mnt: Pointer to "struct vfsmount". |
186 |
* @newname: Pointer to buffer to return value in. |
187 |
* @newname_len: Size of @newname. |
188 |
* |
189 |
* Returns 0 on success, negative value otherwise. |
190 |
*/ |
191 |
int ccs_realpath_from_dentry2(struct dentry *dentry, struct vfsmount *mnt, |
192 |
char *newname, int newname_len) |
193 |
{ |
194 |
int error; |
195 |
struct dentry *d_dentry; |
196 |
struct vfsmount *d_mnt; |
197 |
if (!dentry || !mnt || !newname || newname_len <= 0) |
198 |
return -EINVAL; |
199 |
d_dentry = dget(dentry); |
200 |
d_mnt = mntget(mnt); |
201 |
/***** CRITICAL SECTION START *****/ |
202 |
spin_lock(&dcache_lock); |
203 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
204 |
spin_lock(&vfsmount_lock); |
205 |
#endif |
206 |
error = get_absolute_path(d_dentry, d_mnt, newname, newname_len); |
207 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
208 |
spin_unlock(&vfsmount_lock); |
209 |
#endif |
210 |
spin_unlock(&dcache_lock); |
211 |
/***** CRITICAL SECTION END *****/ |
212 |
dput(d_dentry); |
213 |
mntput(d_mnt); |
214 |
if (error) |
215 |
printk(KERN_WARNING "ccs_realpath: Pathname too long.\n"); |
216 |
return error; |
217 |
} |
218 |
|
219 |
/** |
220 |
* ccs_realpath_from_dentry - Returns realpath(3) of the given pathname but ignores chroot'ed root. |
221 |
* |
222 |
* @dentry: Pointer to "struct dentry". |
223 |
* @mnt: Pointer to "struct vfsmount". |
224 |
* |
225 |
* Returns the realpath of the given @dentry and @mnt on success, |
226 |
* NULL otherwise. |
227 |
* |
228 |
* These functions use ccs_alloc(), so caller must ccs_free() |
229 |
* if these functions didn't return NULL. |
230 |
*/ |
231 |
char *ccs_realpath_from_dentry(struct dentry *dentry, struct vfsmount *mnt) |
232 |
{ |
233 |
char *buf = ccs_alloc(sizeof(struct ccs_page_buffer)); |
234 |
if (buf && ccs_realpath_from_dentry2(dentry, mnt, buf, |
235 |
CCS_MAX_PATHNAME_LEN - 1) == 0) |
236 |
return buf; |
237 |
ccs_free(buf); |
238 |
return NULL; |
239 |
} |
240 |
|
241 |
/** |
242 |
* ccs_realpath - Get realpath of a pathname. |
243 |
* |
244 |
* @pathname: The pathname to solve. |
245 |
* |
246 |
* Returns the realpath of @pathname on success, NULL otherwise. |
247 |
*/ |
248 |
char *ccs_realpath(const char *pathname) |
249 |
{ |
250 |
struct nameidata nd; |
251 |
if (pathname && path_lookup(pathname, lookup_flags, &nd) == 0) { |
252 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25) |
253 |
char *buf = ccs_realpath_from_dentry(nd.path.dentry, |
254 |
nd.path.mnt); |
255 |
path_put(&nd.path); |
256 |
#else |
257 |
char *buf = ccs_realpath_from_dentry(nd.dentry, nd.mnt); |
258 |
path_release(&nd); |
259 |
#endif |
260 |
return buf; |
261 |
} |
262 |
return NULL; |
263 |
} |
264 |
|
265 |
/** |
266 |
* ccs_realpath_nofollow - Get realpath of a pathname. |
267 |
* |
268 |
* @pathname: The pathname to solve. |
269 |
* |
270 |
* Returns the realpath of @pathname on success, NULL otherwise. |
271 |
*/ |
272 |
char *ccs_realpath_nofollow(const char *pathname) |
273 |
{ |
274 |
struct nameidata nd; |
275 |
if (pathname && path_lookup(pathname, lookup_flags ^ LOOKUP_FOLLOW, |
276 |
&nd) == 0) { |
277 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 25) |
278 |
char *buf = ccs_realpath_from_dentry(nd.path.dentry, |
279 |
nd.path.mnt); |
280 |
path_put(&nd.path); |
281 |
#else |
282 |
char *buf = ccs_realpath_from_dentry(nd.dentry, nd.mnt); |
283 |
path_release(&nd); |
284 |
#endif |
285 |
return buf; |
286 |
} |
287 |
return NULL; |
288 |
} |
289 |
|
290 |
/** |
291 |
* round_up - Round up an integer so that the returned pointers are appropriately aligned. |
292 |
* |
293 |
* @size: Size in bytes. |
294 |
* |
295 |
* Returns rounded value of @size. |
296 |
* |
297 |
* FIXME: Are there more requirements that is needed for assigning value |
298 |
* atomically? |
299 |
*/ |
300 |
static inline unsigned int round_up(const unsigned int size) |
301 |
{ |
302 |
if (sizeof(void *) >= sizeof(long)) |
303 |
return ((size + sizeof(void *) - 1) |
304 |
/ sizeof(void *)) * sizeof(void *); |
305 |
else |
306 |
return ((size + sizeof(long) - 1) |
307 |
/ sizeof(long)) * sizeof(long); |
308 |
} |
309 |
|
310 |
static unsigned int allocated_memory_for_elements; |
311 |
|
312 |
/** |
313 |
* ccs_get_memory_used_for_elements - Get memory used for keeping ACL structures. |
314 |
* |
315 |
* Returns memory used for keeping ACL structures. |
316 |
*/ |
317 |
unsigned int ccs_get_memory_used_for_elements(void) |
318 |
{ |
319 |
return allocated_memory_for_elements; |
320 |
} |
321 |
|
322 |
/** |
323 |
* ccs_alloc_element - Allocate permanent memory for structures. |
324 |
* |
325 |
* @size: Size in bytes. |
326 |
* |
327 |
* Returns pointer to allocated memory on success, NULL otherwise. |
328 |
* |
329 |
* The RAM is chunked, so NEVER try to kfree() the returned pointer. |
330 |
*/ |
331 |
void *ccs_alloc_element(const unsigned int size) |
332 |
{ |
333 |
static DEFINE_MUTEX(lock); |
334 |
static char *buf; |
335 |
static unsigned int buf_used_len = PAGE_SIZE; |
336 |
char *ptr = NULL; |
337 |
const unsigned int word_aligned_size = round_up(size); |
338 |
if (word_aligned_size > PAGE_SIZE) |
339 |
return NULL; |
340 |
mutex_lock(&lock); |
341 |
if (buf_used_len + word_aligned_size > PAGE_SIZE) { |
342 |
ptr = kzalloc(PAGE_SIZE, GFP_KERNEL); |
343 |
if (!ptr) { |
344 |
printk(KERN_WARNING "ERROR: Out of memory " |
345 |
"for ccs_alloc_element().\n"); |
346 |
if (!sbin_init_started) |
347 |
panic("MAC Initialization failed.\n"); |
348 |
} else { |
349 |
buf = ptr; |
350 |
allocated_memory_for_elements += PAGE_SIZE; |
351 |
buf_used_len = word_aligned_size; |
352 |
ptr = buf; |
353 |
} |
354 |
} else if (word_aligned_size) { |
355 |
int i; |
356 |
ptr = buf + buf_used_len; |
357 |
buf_used_len += word_aligned_size; |
358 |
for (i = 0; i < word_aligned_size; i++) { |
359 |
if (!ptr[i]) |
360 |
continue; |
361 |
printk(KERN_ERR "WARNING: Reserved memory was tainted! " |
362 |
"The system might go wrong.\n"); |
363 |
ptr[i] = '\0'; |
364 |
} |
365 |
} |
366 |
mutex_unlock(&lock); |
367 |
return ptr; |
368 |
} |
369 |
|
370 |
static unsigned int allocated_memory_for_savename; |
371 |
|
372 |
/** |
373 |
* ccs_get_memory_used_for_save_name - Get memory used for keeping string data. |
374 |
* |
375 |
* Returns memory used for keeping string data. |
376 |
*/ |
377 |
unsigned int ccs_get_memory_used_for_save_name(void) |
378 |
{ |
379 |
return allocated_memory_for_savename; |
380 |
} |
381 |
|
382 |
#define MAX_HASH 256 |
383 |
|
384 |
/* Structure for string data. */ |
385 |
struct name_entry { |
386 |
struct list1_head list; |
387 |
struct path_info entry; |
388 |
}; |
389 |
|
390 |
/* Structure for available memory region. */ |
391 |
struct free_memory_block_list { |
392 |
struct list_head list; |
393 |
char *ptr; /* Pointer to a free area. */ |
394 |
int len; /* Length of the area. */ |
395 |
}; |
396 |
|
397 |
/* The list for "struct name_entry". */ |
398 |
static struct list1_head name_list[MAX_HASH]; |
399 |
|
400 |
/** |
401 |
* ccs_save_name - Allocate permanent memory for string data. |
402 |
* |
403 |
* @name: The string to store into the permernent memory. |
404 |
* |
405 |
* Returns pointer to "struct path_info" on success, NULL otherwise. |
406 |
* |
407 |
* The RAM is shared, so NEVER try to modify or kfree() the returned name. |
408 |
*/ |
409 |
const struct path_info *ccs_save_name(const char *name) |
410 |
{ |
411 |
static LIST_HEAD(fmb_list); |
412 |
static DEFINE_MUTEX(lock); |
413 |
struct name_entry *ptr; |
414 |
unsigned int hash; |
415 |
struct free_memory_block_list *fmb; |
416 |
int len; |
417 |
char *cp; |
418 |
if (!name) |
419 |
return NULL; |
420 |
len = strlen(name) + 1; |
421 |
if (len > CCS_MAX_PATHNAME_LEN) { |
422 |
printk(KERN_WARNING "ERROR: Name too long " |
423 |
"for ccs_save_name().\n"); |
424 |
return NULL; |
425 |
} |
426 |
hash = full_name_hash((const unsigned char *) name, len - 1); |
427 |
mutex_lock(&lock); |
428 |
list1_for_each_entry(ptr, &name_list[hash % MAX_HASH], list) { |
429 |
if (hash == ptr->entry.hash && !strcmp(name, ptr->entry.name)) |
430 |
goto out; |
431 |
} |
432 |
list_for_each_entry(fmb, &fmb_list, list) { |
433 |
if (len <= fmb->len) |
434 |
goto ready; |
435 |
} |
436 |
cp = kzalloc(PAGE_SIZE, GFP_KERNEL); |
437 |
fmb = kzalloc(sizeof(*fmb), GFP_KERNEL); |
438 |
if (!cp || !fmb) { |
439 |
kfree(cp); |
440 |
kfree(fmb); |
441 |
printk(KERN_WARNING "ERROR: Out of memory " |
442 |
"for ccs_save_name().\n"); |
443 |
if (!sbin_init_started) |
444 |
panic("MAC Initialization failed.\n"); |
445 |
ptr = NULL; |
446 |
goto out; |
447 |
} |
448 |
allocated_memory_for_savename += PAGE_SIZE; |
449 |
list_add(&fmb->list, &fmb_list); |
450 |
fmb->ptr = cp; |
451 |
fmb->len = PAGE_SIZE; |
452 |
ready: |
453 |
ptr = ccs_alloc_element(sizeof(*ptr)); |
454 |
if (!ptr) |
455 |
goto out; |
456 |
ptr->entry.name = fmb->ptr; |
457 |
memmove(fmb->ptr, name, len); |
458 |
ccs_fill_path_info(&ptr->entry); |
459 |
fmb->ptr += len; |
460 |
fmb->len -= len; |
461 |
list1_add_tail_mb(&ptr->list, &name_list[hash % MAX_HASH]); |
462 |
if (fmb->len == 0) { |
463 |
list_del(&fmb->list); |
464 |
kfree(fmb); |
465 |
} |
466 |
out: |
467 |
mutex_unlock(&lock); |
468 |
return ptr ? &ptr->entry : NULL; |
469 |
} |
470 |
|
471 |
/* Structure for temporarily allocated memory. */ |
472 |
struct cache_entry { |
473 |
struct list_head list; |
474 |
void *ptr; |
475 |
int size; |
476 |
}; |
477 |
|
478 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20) |
479 |
static struct kmem_cache *ccs_cachep; |
480 |
#else |
481 |
static kmem_cache_t *ccs_cachep; |
482 |
#endif |
483 |
|
484 |
/** |
485 |
* ccs_realpath_init - Initialize realpath related code. |
486 |
* |
487 |
* Returns 0. |
488 |
*/ |
489 |
static int __init ccs_realpath_init(void) |
490 |
{ |
491 |
int i; |
492 |
if (CCS_MAX_PATHNAME_LEN > PAGE_SIZE) |
493 |
panic("Bad size."); |
494 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 23) |
495 |
ccs_cachep = kmem_cache_create("ccs_cache", sizeof(struct cache_entry), |
496 |
0, 0, NULL); |
497 |
#else |
498 |
ccs_cachep = kmem_cache_create("ccs_cache", sizeof(struct cache_entry), |
499 |
0, 0, NULL, NULL); |
500 |
#endif |
501 |
if (!ccs_cachep) |
502 |
panic("Can't create cache.\n"); |
503 |
for (i = 0; i < MAX_HASH; i++) |
504 |
INIT_LIST1_HEAD(&name_list[i]); |
505 |
INIT_LIST1_HEAD(&KERNEL_DOMAIN.acl_info_list); |
506 |
KERNEL_DOMAIN.domainname = ccs_save_name(ROOT_NAME); |
507 |
list1_add_tail_mb(&KERNEL_DOMAIN.list, &domain_list); |
508 |
if (ccs_find_domain(ROOT_NAME) != &KERNEL_DOMAIN) |
509 |
panic("Can't register KERNEL_DOMAIN"); |
510 |
return 0; |
511 |
} |
512 |
|
513 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 5, 0) |
514 |
__initcall(ccs_realpath_init); |
515 |
#else |
516 |
core_initcall(ccs_realpath_init); |
517 |
#endif |
518 |
|
519 |
/* The list for "struct cache_entry". */ |
520 |
static LIST_HEAD(cache_list); |
521 |
|
522 |
static DEFINE_SPINLOCK(cache_list_lock); |
523 |
|
524 |
static unsigned int dynamic_memory_size; |
525 |
|
526 |
/** |
527 |
* ccs_get_memory_used_for_dynamic - Get memory used for temporal purpose. |
528 |
* |
529 |
* Returns memory used for temporal purpose. |
530 |
*/ |
531 |
unsigned int ccs_get_memory_used_for_dynamic(void) |
532 |
{ |
533 |
return dynamic_memory_size; |
534 |
} |
535 |
|
536 |
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 5, 0) |
537 |
/** |
538 |
* round2 - Rounded up to power-of-two value. |
539 |
* |
540 |
* @size: Size in bytes. |
541 |
* |
542 |
* Returns power-of-two of @size. |
543 |
*/ |
544 |
static int round2(size_t size) |
545 |
{ |
546 |
#if PAGE_SIZE == 4096 |
547 |
size_t bsize = 32; |
548 |
#else |
549 |
size_t bsize = 64; |
550 |
#endif |
551 |
while (size > bsize) |
552 |
bsize <<= 1; |
553 |
return bsize; |
554 |
} |
555 |
#endif |
556 |
|
557 |
/** |
558 |
* ccs_alloc - Allocate memory for temporal purpose. |
559 |
* |
560 |
* @size: Size in bytes. |
561 |
* |
562 |
* Returns pointer to allocated memory on success, NULL otherwise. |
563 |
*/ |
564 |
void *ccs_alloc(const size_t size) |
565 |
{ |
566 |
struct cache_entry *new_entry; |
567 |
void *ret = kzalloc(size, GFP_KERNEL); |
568 |
if (!ret) |
569 |
goto out; |
570 |
new_entry = kmem_cache_alloc(ccs_cachep, GFP_KERNEL); |
571 |
if (!new_entry) { |
572 |
kfree(ret); |
573 |
ret = NULL; |
574 |
goto out; |
575 |
} |
576 |
INIT_LIST_HEAD(&new_entry->list); |
577 |
new_entry->ptr = ret; |
578 |
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 0) |
579 |
new_entry->size = ksize(ret); |
580 |
#else |
581 |
new_entry->size = round2(size); |
582 |
#endif |
583 |
/***** CRITICAL SECTION START *****/ |
584 |
spin_lock(&cache_list_lock); |
585 |
list_add_tail(&new_entry->list, &cache_list); |
586 |
dynamic_memory_size += new_entry->size; |
587 |
spin_unlock(&cache_list_lock); |
588 |
/***** CRITICAL SECTION END *****/ |
589 |
out: |
590 |
return ret; |
591 |
} |
592 |
|
593 |
/** |
594 |
* ccs_free - Release memory allocated by ccs_alloc(). |
595 |
* |
596 |
* @p: Pointer returned by ccs_alloc(). May be NULL. |
597 |
* |
598 |
* Returns nothing. |
599 |
*/ |
600 |
void ccs_free(const void *p) |
601 |
{ |
602 |
struct list_head *v; |
603 |
struct cache_entry *entry = NULL; |
604 |
if (!p) |
605 |
return; |
606 |
/***** CRITICAL SECTION START *****/ |
607 |
spin_lock(&cache_list_lock); |
608 |
list_for_each(v, &cache_list) { |
609 |
entry = list_entry(v, struct cache_entry, list); |
610 |
if (entry->ptr != p) { |
611 |
entry = NULL; |
612 |
continue; |
613 |
} |
614 |
list_del(&entry->list); |
615 |
dynamic_memory_size -= entry->size; |
616 |
break; |
617 |
} |
618 |
spin_unlock(&cache_list_lock); |
619 |
/***** CRITICAL SECTION END *****/ |
620 |
if (entry) { |
621 |
kfree(p); |
622 |
kmem_cache_free(ccs_cachep, entry); |
623 |
} else { |
624 |
printk(KERN_WARNING "BUG: ccs_free() with invalid pointer.\n"); |
625 |
} |
626 |
} |