Blame view
fs/proc/proc_sysctl.c
40.8 KB
b24413180
|
1 |
// SPDX-License-Identifier: GPL-2.0 |
77b14db50
|
2 3 4 |
/* * /proc/sys support */ |
1e0edd3f6
|
5 |
#include <linux/init.h> |
77b14db50
|
6 |
#include <linux/sysctl.h> |
f1ecf0685
|
7 |
#include <linux/poll.h> |
77b14db50
|
8 |
#include <linux/proc_fs.h> |
87ebdc00e
|
9 |
#include <linux/printk.h> |
77b14db50
|
10 |
#include <linux/security.h> |
404015308
|
11 |
#include <linux/sched.h> |
5b825c3af
|
12 |
#include <linux/cred.h> |
34286d666
|
13 |
#include <linux/namei.h> |
404015308
|
14 |
#include <linux/mm.h> |
1f87f0b52
|
15 |
#include <linux/module.h> |
77b14db50
|
16 |
#include "internal.h" |
d72f71eb0
|
17 |
static const struct dentry_operations proc_sys_dentry_operations; |
77b14db50
|
18 |
static const struct file_operations proc_sys_file_operations; |
03a44825b
|
19 |
static const struct inode_operations proc_sys_inode_operations; |
9043476f7
|
20 21 |
static const struct file_operations proc_sys_dir_file_operations; static const struct inode_operations proc_sys_dir_operations; |
77b14db50
|
22 |
|
f9bd6733d
|
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 |
/* Support for permanently empty directories */ struct ctl_table sysctl_mount_point[] = { { } }; static bool is_empty_dir(struct ctl_table_header *head) { return head->ctl_table[0].child == sysctl_mount_point; } static void set_empty_dir(struct ctl_dir *dir) { dir->header.ctl_table[0].child = sysctl_mount_point; } static void clear_empty_dir(struct ctl_dir *dir) { dir->header.ctl_table[0].child = NULL; } |
f1ecf0685
|
44 45 46 47 48 49 50 51 |
void proc_sys_poll_notify(struct ctl_table_poll *poll) { if (!poll) return; atomic_inc(&poll->event); wake_up_interruptible(&poll->wait); } |
a194558e8
|
52 53 54 |
static struct ctl_table root_table[] = { { .procname = "", |
7ec66d063
|
55 |
.mode = S_IFDIR|S_IRUGO|S_IXUGO, |
a194558e8
|
56 57 58 |
}, { } }; |
0e47c99d7
|
59 |
static struct ctl_table_root sysctl_table_root = { |
0e47c99d7
|
60 |
.default_set.dir.header = { |
7ec66d063
|
61 62 |
{{.count = 1, .nreg = 1, |
ac13ac6f4
|
63 |
.ctl_table = root_table }}, |
0e47c99d7
|
64 |
.ctl_table_arg = root_table, |
7ec66d063
|
65 66 67 |
.root = &sysctl_table_root, .set = &sysctl_table_root.default_set, }, |
1f87f0b52
|
68 |
}; |
1f87f0b52
|
69 70 |
static DEFINE_SPINLOCK(sysctl_lock); |
7ec66d063
|
71 |
static void drop_sysctl_table(struct ctl_table_header *header); |
0e47c99d7
|
72 |
static int sysctl_follow_link(struct ctl_table_header **phead, |
13bcc6a28
|
73 |
struct ctl_table **pentry); |
0e47c99d7
|
74 75 |
static int insert_links(struct ctl_table_header *head); static void put_links(struct ctl_table_header *header); |
7ec66d063
|
76 |
|
6980128fe
|
77 78 79 80 |
static void sysctl_print_dir(struct ctl_dir *dir) { if (dir->header.parent) sysctl_print_dir(dir->header.parent); |
87ebdc00e
|
81 |
pr_cont("%s/", dir->header.ctl_table[0].procname); |
6980128fe
|
82 |
} |
076c3eed2
|
83 84 85 86 87 88 89 90 91 92 93 94 95 96 |
static int namecmp(const char *name1, int len1, const char *name2, int len2) { int minlen; int cmp; minlen = len1; if (minlen > len2) minlen = len2; cmp = memcmp(name1, name2, minlen); if (cmp == 0) cmp = len1 - len2; return cmp; } |
60f126d93
|
97 |
/* Called under sysctl_lock */ |
076c3eed2
|
98 |
static struct ctl_table *find_entry(struct ctl_table_header **phead, |
0e47c99d7
|
99 |
struct ctl_dir *dir, const char *name, int namelen) |
076c3eed2
|
100 101 102 |
{ struct ctl_table_header *head; struct ctl_table *entry; |
ac13ac6f4
|
103 |
struct rb_node *node = dir->root.rb_node; |
076c3eed2
|
104 |
|
ac13ac6f4
|
105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 |
while (node) { struct ctl_node *ctl_node; const char *procname; int cmp; ctl_node = rb_entry(node, struct ctl_node, node); head = ctl_node->header; entry = &head->ctl_table[ctl_node - head->node]; procname = entry->procname; cmp = namecmp(name, namelen, procname, strlen(procname)); if (cmp < 0) node = node->rb_left; else if (cmp > 0) node = node->rb_right; else { *phead = head; return entry; |
076c3eed2
|
124 125 126 127 |
} } return NULL; } |
ac13ac6f4
|
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 |
static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry) { struct rb_node *node = &head->node[entry - head->ctl_table].node; struct rb_node **p = &head->parent->root.rb_node; struct rb_node *parent = NULL; const char *name = entry->procname; int namelen = strlen(name); while (*p) { struct ctl_table_header *parent_head; struct ctl_table *parent_entry; struct ctl_node *parent_node; const char *parent_name; int cmp; parent = *p; parent_node = rb_entry(parent, struct ctl_node, node); parent_head = parent_node->header; parent_entry = &parent_head->ctl_table[parent_node - parent_head->node]; parent_name = parent_entry->procname; cmp = namecmp(name, namelen, parent_name, strlen(parent_name)); if (cmp < 0) p = &(*p)->rb_left; else if (cmp > 0) p = &(*p)->rb_right; else { |
87ebdc00e
|
155 |
pr_err("sysctl duplicate entry: "); |
ac13ac6f4
|
156 |
sysctl_print_dir(head->parent); |
87ebdc00e
|
157 158 |
pr_cont("/%s ", entry->procname); |
ac13ac6f4
|
159 160 161 162 163 |
return -EEXIST; } } rb_link_node(node, parent, p); |
ea5272f5c
|
164 |
rb_insert_color(node, &head->parent->root); |
ac13ac6f4
|
165 166 167 168 169 170 171 172 173 |
return 0; } static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry) { struct rb_node *node = &head->node[entry - head->ctl_table].node; rb_erase(node, &head->parent->root); } |
e0d045290
|
174 175 |
static void init_header(struct ctl_table_header *head, struct ctl_table_root *root, struct ctl_table_set *set, |
ac13ac6f4
|
176 |
struct ctl_node *node, struct ctl_table *table) |
e0d045290
|
177 |
{ |
7ec66d063
|
178 |
head->ctl_table = table; |
e0d045290
|
179 |
head->ctl_table_arg = table; |
e0d045290
|
180 181 182 183 184 185 186 |
head->used = 0; head->count = 1; head->nreg = 1; head->unregistering = NULL; head->root = root; head->set = set; head->parent = NULL; |
ac13ac6f4
|
187 |
head->node = node; |
2fd1d2c4c
|
188 |
INIT_HLIST_HEAD(&head->inodes); |
ac13ac6f4
|
189 190 |
if (node) { struct ctl_table *entry; |
4c199a93a
|
191 |
for (entry = table; entry->procname; entry++, node++) |
ac13ac6f4
|
192 |
node->header = head; |
ac13ac6f4
|
193 |
} |
e0d045290
|
194 |
} |
8425d6aaf
|
195 196 |
static void erase_header(struct ctl_table_header *head) { |
ac13ac6f4
|
197 198 199 |
struct ctl_table *entry; for (entry = head->ctl_table; entry->procname; entry++) erase_entry(head, entry); |
8425d6aaf
|
200 |
} |
0e47c99d7
|
201 |
static int insert_header(struct ctl_dir *dir, struct ctl_table_header *header) |
8425d6aaf
|
202 |
{ |
ac13ac6f4
|
203 |
struct ctl_table *entry; |
0e47c99d7
|
204 |
int err; |
f9bd6733d
|
205 206 207 208 209 210 211 212 213 214 |
/* Is this a permanently empty directory? */ if (is_empty_dir(&dir->header)) return -EROFS; /* Am I creating a permanently empty directory? */ if (header->ctl_table == sysctl_mount_point) { if (!RB_EMPTY_ROOT(&dir->root)) return -EINVAL; set_empty_dir(dir); } |
0e47c99d7
|
215 |
dir->header.nreg++; |
7ec66d063
|
216 |
header->parent = dir; |
0e47c99d7
|
217 218 219 |
err = insert_links(header); if (err) goto fail_links; |
ac13ac6f4
|
220 221 222 223 224 |
for (entry = header->ctl_table; entry->procname; entry++) { err = insert_entry(header, entry); if (err) goto fail; } |
0e47c99d7
|
225 |
return 0; |
ac13ac6f4
|
226 227 228 |
fail: erase_header(header); put_links(header); |
0e47c99d7
|
229 |
fail_links: |
f9bd6733d
|
230 231 |
if (header->ctl_table == sysctl_mount_point) clear_empty_dir(dir); |
0e47c99d7
|
232 233 234 |
header->parent = NULL; drop_sysctl_table(&dir->header); return err; |
8425d6aaf
|
235 |
} |
1f87f0b52
|
236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 |
/* called under sysctl_lock */ static int use_table(struct ctl_table_header *p) { if (unlikely(p->unregistering)) return 0; p->used++; return 1; } /* called under sysctl_lock */ static void unuse_table(struct ctl_table_header *p) { if (!--p->used) if (unlikely(p->unregistering)) complete(p->unregistering); } |
d6cffbbe9
|
252 253 |
static void proc_sys_prune_dcache(struct ctl_table_header *head) { |
2fd1d2c4c
|
254 |
struct inode *inode; |
d6cffbbe9
|
255 |
struct proc_inode *ei; |
2fd1d2c4c
|
256 257 |
struct hlist_node *node; struct super_block *sb; |
d6cffbbe9
|
258 |
|
ace0c791e
|
259 |
rcu_read_lock(); |
2fd1d2c4c
|
260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 |
for (;;) { node = hlist_first_rcu(&head->inodes); if (!node) break; ei = hlist_entry(node, struct proc_inode, sysctl_inodes); spin_lock(&sysctl_lock); hlist_del_init_rcu(&ei->sysctl_inodes); spin_unlock(&sysctl_lock); inode = &ei->vfs_inode; sb = inode->i_sb; if (!atomic_inc_not_zero(&sb->s_active)) continue; inode = igrab(inode); rcu_read_unlock(); if (unlikely(!inode)) { deactivate_super(sb); |
ace0c791e
|
277 |
rcu_read_lock(); |
2fd1d2c4c
|
278 |
continue; |
d6cffbbe9
|
279 |
} |
2fd1d2c4c
|
280 281 282 283 284 285 |
d_prune_aliases(inode); iput(inode); deactivate_super(sb); rcu_read_lock(); |
d6cffbbe9
|
286 |
} |
ace0c791e
|
287 |
rcu_read_unlock(); |
d6cffbbe9
|
288 |
} |
1f87f0b52
|
289 290 291 292 293 294 295 296 297 298 299 300 301 |
/* called under sysctl_lock, will reacquire if has to wait */ static void start_unregistering(struct ctl_table_header *p) { /* * if p->used is 0, nobody will ever touch that entry again; * we'll eliminate all paths to it before dropping sysctl_lock */ if (unlikely(p->used)) { struct completion wait; init_completion(&wait); p->unregistering = &wait; spin_unlock(&sysctl_lock); wait_for_completion(&wait); |
1f87f0b52
|
302 303 304 |
} else { /* anything non-NULL; we'll never dereference it */ p->unregistering = ERR_PTR(-EINVAL); |
ace0c791e
|
305 |
spin_unlock(&sysctl_lock); |
1f87f0b52
|
306 307 |
} /* |
d6cffbbe9
|
308 309 310 311 312 |
* Prune dentries for unregistered sysctls: namespaced sysctls * can have duplicate names and contaminate dcache very badly. */ proc_sys_prune_dcache(p); /* |
1f87f0b52
|
313 314 315 |
* do not remove from the list until nobody holds it; walking the * list in do_sysctl() relies on that. */ |
ace0c791e
|
316 |
spin_lock(&sysctl_lock); |
8425d6aaf
|
317 |
erase_header(p); |
1f87f0b52
|
318 |
} |
1f87f0b52
|
319 320 |
static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) { |
ab4a1f247
|
321 |
BUG_ON(!head); |
1f87f0b52
|
322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 |
spin_lock(&sysctl_lock); if (!use_table(head)) head = ERR_PTR(-ENOENT); spin_unlock(&sysctl_lock); return head; } static void sysctl_head_finish(struct ctl_table_header *head) { if (!head) return; spin_lock(&sysctl_lock); unuse_table(head); spin_unlock(&sysctl_lock); } static struct ctl_table_set * |
13bcc6a28
|
339 |
lookup_header_set(struct ctl_table_root *root) |
1f87f0b52
|
340 341 342 |
{ struct ctl_table_set *set = &root->default_set; if (root->lookup) |
13bcc6a28
|
343 |
set = root->lookup(root); |
1f87f0b52
|
344 345 |
return set; } |
076c3eed2
|
346 |
static struct ctl_table *lookup_entry(struct ctl_table_header **phead, |
7ec66d063
|
347 |
struct ctl_dir *dir, |
076c3eed2
|
348 349 350 351 |
const char *name, int namelen) { struct ctl_table_header *head; struct ctl_table *entry; |
076c3eed2
|
352 353 |
spin_lock(&sysctl_lock); |
0e47c99d7
|
354 355 356 357 358 |
entry = find_entry(&head, dir, name, namelen); if (entry && use_table(head)) *phead = head; else entry = NULL; |
076c3eed2
|
359 360 361 |
spin_unlock(&sysctl_lock); return entry; } |
ac13ac6f4
|
362 |
static struct ctl_node *first_usable_entry(struct rb_node *node) |
1f87f0b52
|
363 |
{ |
ac13ac6f4
|
364 |
struct ctl_node *ctl_node; |
1f87f0b52
|
365 |
|
ac13ac6f4
|
366 367 368 369 |
for (;node; node = rb_next(node)) { ctl_node = rb_entry(node, struct ctl_node, node); if (use_table(ctl_node->header)) return ctl_node; |
1f87f0b52
|
370 |
} |
1f87f0b52
|
371 372 |
return NULL; } |
7ec66d063
|
373 |
static void first_entry(struct ctl_dir *dir, |
6a75ce167
|
374 375 |
struct ctl_table_header **phead, struct ctl_table **pentry) { |
ac13ac6f4
|
376 |
struct ctl_table_header *head = NULL; |
7ec66d063
|
377 |
struct ctl_table *entry = NULL; |
ac13ac6f4
|
378 |
struct ctl_node *ctl_node; |
6a75ce167
|
379 380 |
spin_lock(&sysctl_lock); |
ac13ac6f4
|
381 |
ctl_node = first_usable_entry(rb_first(&dir->root)); |
6a75ce167
|
382 |
spin_unlock(&sysctl_lock); |
ac13ac6f4
|
383 384 385 386 |
if (ctl_node) { head = ctl_node->header; entry = &head->ctl_table[ctl_node - head->node]; } |
6a75ce167
|
387 388 389 |
*phead = head; *pentry = entry; } |
7ec66d063
|
390 |
static void next_entry(struct ctl_table_header **phead, struct ctl_table **pentry) |
1f87f0b52
|
391 |
{ |
6a75ce167
|
392 393 |
struct ctl_table_header *head = *phead; struct ctl_table *entry = *pentry; |
ac13ac6f4
|
394 |
struct ctl_node *ctl_node = &head->node[entry - head->ctl_table]; |
6a75ce167
|
395 |
|
ac13ac6f4
|
396 397 398 399 400 401 402 403 404 |
spin_lock(&sysctl_lock); unuse_table(head); ctl_node = first_usable_entry(rb_next(&ctl_node->node)); spin_unlock(&sysctl_lock); head = NULL; if (ctl_node) { head = ctl_node->header; entry = &head->ctl_table[ctl_node - head->node]; |
6a75ce167
|
405 406 407 |
} *phead = head; *pentry = entry; |
1f87f0b52
|
408 |
} |
1f87f0b52
|
409 410 411 412 413 414 415 |
/* * sysctl_perm does NOT grant the superuser all rights automatically, because * some sysctl variables are readonly even to root. */ static int test_perm(int mode, int op) { |
091bd3ea4
|
416 |
if (uid_eq(current_euid(), GLOBAL_ROOT_UID)) |
1f87f0b52
|
417 |
mode >>= 6; |
091bd3ea4
|
418 |
else if (in_egroup_p(GLOBAL_ROOT_GID)) |
1f87f0b52
|
419 420 421 422 423 |
mode >>= 3; if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) return 0; return -EACCES; } |
73f7ef435
|
424 |
static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op) |
1f87f0b52
|
425 |
{ |
73f7ef435
|
426 |
struct ctl_table_root *root = head->root; |
1f87f0b52
|
427 428 429 |
int mode; if (root->permissions) |
73f7ef435
|
430 |
mode = root->permissions(head, table); |
1f87f0b52
|
431 432 433 434 435 |
else mode = table->mode; return test_perm(mode, op); } |
9043476f7
|
436 437 |
static struct inode *proc_sys_make_inode(struct super_block *sb, struct ctl_table_header *head, struct ctl_table *table) |
77b14db50
|
438 |
{ |
e79c6a4fc
|
439 |
struct ctl_table_root *root = head->root; |
77b14db50
|
440 |
struct inode *inode; |
9043476f7
|
441 |
struct proc_inode *ei; |
77b14db50
|
442 |
|
9043476f7
|
443 |
inode = new_inode(sb); |
77b14db50
|
444 445 |
if (!inode) goto out; |
85fe4025c
|
446 |
inode->i_ino = get_next_ino(); |
77b14db50
|
447 |
ei = PROC_I(inode); |
9043476f7
|
448 |
|
d6cffbbe9
|
449 |
spin_lock(&sysctl_lock); |
ace0c791e
|
450 451 452 453 454 455 456 457 |
if (unlikely(head->unregistering)) { spin_unlock(&sysctl_lock); iput(inode); inode = NULL; goto out; } ei->sysctl = head; ei->sysctl_entry = table; |
2fd1d2c4c
|
458 |
hlist_add_head_rcu(&ei->sysctl_inodes, &head->inodes); |
d6cffbbe9
|
459 460 |
head->count++; spin_unlock(&sysctl_lock); |
078cd8279
|
461 |
inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); |
9043476f7
|
462 |
inode->i_mode = table->mode; |
7ec66d063
|
463 |
if (!S_ISDIR(table->mode)) { |
9043476f7
|
464 465 466 467 468 |
inode->i_mode |= S_IFREG; inode->i_op = &proc_sys_inode_operations; inode->i_fop = &proc_sys_file_operations; } else { inode->i_mode |= S_IFDIR; |
9043476f7
|
469 470 |
inode->i_op = &proc_sys_dir_operations; inode->i_fop = &proc_sys_dir_file_operations; |
f9bd6733d
|
471 472 |
if (is_empty_dir(head)) make_empty_dir_inode(inode); |
9043476f7
|
473 |
} |
e79c6a4fc
|
474 475 476 |
if (root->set_ownership) root->set_ownership(head, table, &inode->i_uid, &inode->i_gid); |
77b14db50
|
477 478 479 |
out: return inode; } |
d6cffbbe9
|
480 481 482 |
void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head) { spin_lock(&sysctl_lock); |
2fd1d2c4c
|
483 |
hlist_del_init_rcu(&PROC_I(inode)->sysctl_inodes); |
d6cffbbe9
|
484 485 486 487 |
if (!--head->count) kfree_rcu(head, rcu); spin_unlock(&sysctl_lock); } |
81324364b
|
488 |
static struct ctl_table_header *grab_header(struct inode *inode) |
77b14db50
|
489 |
{ |
3cc3e0463
|
490 491 |
struct ctl_table_header *head = PROC_I(inode)->sysctl; if (!head) |
0e47c99d7
|
492 |
head = &sysctl_table_root.default_set.dir.header; |
3cc3e0463
|
493 |
return sysctl_head_grab(head); |
9043476f7
|
494 |
} |
77b14db50
|
495 |
|
9043476f7
|
496 |
static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, |
00cd8dd3b
|
497 |
unsigned int flags) |
9043476f7
|
498 499 |
{ struct ctl_table_header *head = grab_header(dir); |
9043476f7
|
500 |
struct ctl_table_header *h = NULL; |
dc12e9094
|
501 |
const struct qstr *name = &dentry->d_name; |
9043476f7
|
502 503 504 |
struct ctl_table *p; struct inode *inode; struct dentry *err = ERR_PTR(-ENOENT); |
7ec66d063
|
505 |
struct ctl_dir *ctl_dir; |
0e47c99d7
|
506 |
int ret; |
77b14db50
|
507 |
|
9043476f7
|
508 509 |
if (IS_ERR(head)) return ERR_CAST(head); |
77b14db50
|
510 |
|
7ec66d063
|
511 |
ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db50
|
512 |
|
7ec66d063
|
513 |
p = lookup_entry(&h, ctl_dir, name->name, name->len); |
9043476f7
|
514 |
if (!p) |
77b14db50
|
515 |
goto out; |
4e7573203
|
516 |
if (S_ISLNK(p->mode)) { |
13bcc6a28
|
517 |
ret = sysctl_follow_link(&h, &p); |
4e7573203
|
518 519 520 521 |
err = ERR_PTR(ret); if (ret) goto out; } |
0e47c99d7
|
522 |
|
77b14db50
|
523 |
err = ERR_PTR(-ENOMEM); |
9043476f7
|
524 |
inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); |
77b14db50
|
525 526 527 528 |
if (!inode) goto out; err = NULL; |
fb045adb9
|
529 |
d_set_d_op(dentry, &proc_sys_dentry_operations); |
77b14db50
|
530 531 532 |
d_add(dentry, inode); out: |
6bf610457
|
533 534 |
if (h) sysctl_head_finish(h); |
77b14db50
|
535 536 537 |
sysctl_head_finish(head); return err; } |
7708bfb1c
|
538 539 |
static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf, size_t count, loff_t *ppos, int write) |
77b14db50
|
540 |
{ |
496ad9aa8
|
541 |
struct inode *inode = file_inode(filp); |
9043476f7
|
542 543 |
struct ctl_table_header *head = grab_header(inode); struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
2a2da53b1
|
544 545 |
ssize_t error; size_t res; |
77b14db50
|
546 |
|
9043476f7
|
547 548 |
if (IS_ERR(head)) return PTR_ERR(head); |
77b14db50
|
549 550 551 552 553 554 |
/* * At this point we know that the sysctl was not unregistered * and won't be until we finish. */ error = -EPERM; |
73f7ef435
|
555 |
if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ)) |
77b14db50
|
556 |
goto out; |
9043476f7
|
557 558 559 560 |
/* if that can happen at all, it should be -EINVAL, not -EISDIR */ error = -EINVAL; if (!table->proc_handler) goto out; |
77b14db50
|
561 562 |
/* careful: calling conventions are nasty here */ res = count; |
8d65af789
|
563 |
error = table->proc_handler(table, write, buf, &res, ppos); |
77b14db50
|
564 565 566 567 568 569 570 |
if (!error) error = res; out: sysctl_head_finish(head); return error; } |
7708bfb1c
|
571 |
static ssize_t proc_sys_read(struct file *filp, char __user *buf, |
77b14db50
|
572 573 |
size_t count, loff_t *ppos) { |
7708bfb1c
|
574 575 |
return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0); } |
77b14db50
|
576 |
|
7708bfb1c
|
577 578 579 580 |
static ssize_t proc_sys_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) { return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1); |
77b14db50
|
581 |
} |
f1ecf0685
|
582 583 |
static int proc_sys_open(struct inode *inode, struct file *filp) { |
4e474a00d
|
584 |
struct ctl_table_header *head = grab_header(inode); |
f1ecf0685
|
585 |
struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
4e474a00d
|
586 587 588 |
/* sysctl was unregistered */ if (IS_ERR(head)) return PTR_ERR(head); |
f1ecf0685
|
589 590 |
if (table->poll) filp->private_data = proc_sys_poll_event(table->poll); |
4e474a00d
|
591 |
sysctl_head_finish(head); |
f1ecf0685
|
592 593 594 595 596 |
return 0; } static unsigned int proc_sys_poll(struct file *filp, poll_table *wait) { |
496ad9aa8
|
597 |
struct inode *inode = file_inode(filp); |
4e474a00d
|
598 |
struct ctl_table_header *head = grab_header(inode); |
f1ecf0685
|
599 |
struct ctl_table *table = PROC_I(inode)->sysctl_entry; |
f1ecf0685
|
600 |
unsigned int ret = DEFAULT_POLLMASK; |
4e474a00d
|
601 602 603 604 605 |
unsigned long event; /* sysctl was unregistered */ if (IS_ERR(head)) return POLLERR | POLLHUP; |
f1ecf0685
|
606 607 608 609 610 611 |
if (!table->proc_handler) goto out; if (!table->poll) goto out; |
4e474a00d
|
612 |
event = (unsigned long)filp->private_data; |
f1ecf0685
|
613 614 615 616 617 618 619 620 |
poll_wait(filp, &table->poll->wait, wait); if (event != atomic_read(&table->poll->event)) { filp->private_data = proc_sys_poll_event(table->poll); ret = POLLIN | POLLRDNORM | POLLERR | POLLPRI; } out: |
4e474a00d
|
621 |
sysctl_head_finish(head); |
f1ecf0685
|
622 623 |
return ret; } |
77b14db50
|
624 |
|
f0c3b5093
|
625 626 |
static bool proc_sys_fill_cache(struct file *file, struct dir_context *ctx, |
9043476f7
|
627 628 |
struct ctl_table_header *head, struct ctl_table *table) |
77b14db50
|
629 |
{ |
f0c3b5093
|
630 |
struct dentry *child, *dir = file->f_path.dentry; |
77b14db50
|
631 632 633 634 |
struct inode *inode; struct qstr qname; ino_t ino = 0; unsigned type = DT_UNKNOWN; |
77b14db50
|
635 636 637 |
qname.name = table->procname; qname.len = strlen(table->procname); |
8387ff257
|
638 |
qname.hash = full_name_hash(dir, qname.name, qname.len); |
77b14db50
|
639 |
|
77b14db50
|
640 641 |
child = d_lookup(dir, &qname); if (!child) { |
76aab3ab6
|
642 643 644 645 646 |
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); child = d_alloc_parallel(dir, &qname, &wq); if (IS_ERR(child)) return false; if (d_in_lookup(child)) { |
9043476f7
|
647 648 |
inode = proc_sys_make_inode(dir->d_sb, head, table); if (!inode) { |
76aab3ab6
|
649 |
d_lookup_done(child); |
9043476f7
|
650 |
dput(child); |
f0c3b5093
|
651 |
return false; |
77b14db50
|
652 |
} |
76aab3ab6
|
653 654 |
d_set_d_op(child, &proc_sys_dentry_operations); d_add(child, inode); |
77b14db50
|
655 656 |
} } |
2b0143b5c
|
657 |
inode = d_inode(child); |
9043476f7
|
658 659 |
ino = inode->i_ino; type = inode->i_mode >> 12; |
77b14db50
|
660 |
dput(child); |
f0c3b5093
|
661 |
return dir_emit(ctx, qname.name, qname.len, ino, type); |
9043476f7
|
662 |
} |
f0c3b5093
|
663 664 |
static bool proc_sys_link_fill_cache(struct file *file, struct dir_context *ctx, |
0e47c99d7
|
665 666 667 |
struct ctl_table_header *head, struct ctl_table *table) { |
f0c3b5093
|
668 |
bool ret = true; |
9c9844d9c
|
669 |
|
0e47c99d7
|
670 |
head = sysctl_head_grab(head); |
9c9844d9c
|
671 672 |
if (IS_ERR(head)) return false; |
0e47c99d7
|
673 |
|
4e7573203
|
674 675 |
if (S_ISLNK(table->mode)) { /* It is not an error if we can not follow the link ignore it */ |
13bcc6a28
|
676 |
int err = sysctl_follow_link(&head, &table); |
4e7573203
|
677 678 679 |
if (err) goto out; } |
0e47c99d7
|
680 |
|
f0c3b5093
|
681 |
ret = proc_sys_fill_cache(file, ctx, head, table); |
0e47c99d7
|
682 683 684 685 |
out: sysctl_head_finish(head); return ret; } |
e5eea0981
|
686 |
static int scan(struct ctl_table_header *head, struct ctl_table *table, |
9043476f7
|
687 |
unsigned long *pos, struct file *file, |
f0c3b5093
|
688 |
struct dir_context *ctx) |
9043476f7
|
689 |
{ |
f0c3b5093
|
690 |
bool res; |
9043476f7
|
691 |
|
f0c3b5093
|
692 693 |
if ((*pos)++ < ctx->pos) return true; |
9043476f7
|
694 |
|
0e47c99d7
|
695 |
if (unlikely(S_ISLNK(table->mode))) |
f0c3b5093
|
696 |
res = proc_sys_link_fill_cache(file, ctx, head, table); |
0e47c99d7
|
697 |
else |
f0c3b5093
|
698 |
res = proc_sys_fill_cache(file, ctx, head, table); |
9043476f7
|
699 |
|
f0c3b5093
|
700 701 |
if (res) ctx->pos = *pos; |
9043476f7
|
702 |
|
6a75ce167
|
703 |
return res; |
77b14db50
|
704 |
} |
f0c3b5093
|
705 |
static int proc_sys_readdir(struct file *file, struct dir_context *ctx) |
77b14db50
|
706 |
{ |
f0c3b5093
|
707 |
struct ctl_table_header *head = grab_header(file_inode(file)); |
9043476f7
|
708 |
struct ctl_table_header *h = NULL; |
6a75ce167
|
709 |
struct ctl_table *entry; |
7ec66d063
|
710 |
struct ctl_dir *ctl_dir; |
77b14db50
|
711 |
unsigned long pos; |
9043476f7
|
712 713 714 |
if (IS_ERR(head)) return PTR_ERR(head); |
77b14db50
|
715 |
|
7ec66d063
|
716 |
ctl_dir = container_of(head, struct ctl_dir, header); |
77b14db50
|
717 |
|
f0c3b5093
|
718 |
if (!dir_emit_dots(file, ctx)) |
93362fa47
|
719 |
goto out; |
f0c3b5093
|
720 |
|
77b14db50
|
721 |
pos = 2; |
7ec66d063
|
722 |
for (first_entry(ctl_dir, &h, &entry); h; next_entry(&h, &entry)) { |
f0c3b5093
|
723 |
if (!scan(h, entry, &pos, file, ctx)) { |
9043476f7
|
724 725 |
sysctl_head_finish(h); break; |
77b14db50
|
726 727 |
} } |
93362fa47
|
728 |
out: |
77b14db50
|
729 |
sysctl_head_finish(head); |
f0c3b5093
|
730 |
return 0; |
77b14db50
|
731 |
} |
10556cb21
|
732 |
static int proc_sys_permission(struct inode *inode, int mask) |
77b14db50
|
733 734 735 736 737 |
{ /* * sysctl entries that are not writeable, * are _NOT_ writeable, capabilities or not. */ |
f696a3659
|
738 739 |
struct ctl_table_header *head; struct ctl_table *table; |
77b14db50
|
740 |
int error; |
f696a3659
|
741 742 743 744 745 |
/* Executable files are not allowed under /proc/sys/ */ if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) return -EACCES; head = grab_header(inode); |
9043476f7
|
746 747 |
if (IS_ERR(head)) return PTR_ERR(head); |
77b14db50
|
748 |
|
f696a3659
|
749 |
table = PROC_I(inode)->sysctl_entry; |
9043476f7
|
750 751 752 |
if (!table) /* global root - r-xr-xr-x */ error = mask & MAY_WRITE ? -EACCES : 0; else /* Use the permissions on the sysctl table entry */ |
73f7ef435
|
753 |
error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK); |
77b14db50
|
754 |
|
77b14db50
|
755 756 757 758 759 760 |
sysctl_head_finish(head); return error; } static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) { |
2b0143b5c
|
761 |
struct inode *inode = d_inode(dentry); |
77b14db50
|
762 763 764 765 |
int error; if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) return -EPERM; |
31051c85b
|
766 |
error = setattr_prepare(dentry, attr); |
1025774ce
|
767 768 |
if (error) return error; |
1025774ce
|
769 770 771 |
setattr_copy(inode, attr); mark_inode_dirty(inode); return 0; |
77b14db50
|
772 |
} |
a528d35e8
|
773 774 |
static int proc_sys_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) |
9043476f7
|
775 |
{ |
a528d35e8
|
776 |
struct inode *inode = d_inode(path->dentry); |
9043476f7
|
777 778 779 780 781 782 783 784 785 786 787 788 789 |
struct ctl_table_header *head = grab_header(inode); struct ctl_table *table = PROC_I(inode)->sysctl_entry; if (IS_ERR(head)) return PTR_ERR(head); generic_fillattr(inode, stat); if (table) stat->mode = (stat->mode & S_IFMT) | table->mode; sysctl_head_finish(head); return 0; } |
77b14db50
|
790 |
static const struct file_operations proc_sys_file_operations = { |
f1ecf0685
|
791 792 |
.open = proc_sys_open, .poll = proc_sys_poll, |
77b14db50
|
793 794 |
.read = proc_sys_read, .write = proc_sys_write, |
6038f373a
|
795 |
.llseek = default_llseek, |
9043476f7
|
796 797 798 |
}; static const struct file_operations proc_sys_dir_file_operations = { |
887df0789
|
799 |
.read = generic_read_dir, |
f50752eaa
|
800 |
.iterate_shared = proc_sys_readdir, |
3222a3e55
|
801 |
.llseek = generic_file_llseek, |
77b14db50
|
802 |
}; |
03a44825b
|
803 |
static const struct inode_operations proc_sys_inode_operations = { |
9043476f7
|
804 805 806 807 808 809 |
.permission = proc_sys_permission, .setattr = proc_sys_setattr, .getattr = proc_sys_getattr, }; static const struct inode_operations proc_sys_dir_operations = { |
77b14db50
|
810 811 812 |
.lookup = proc_sys_lookup, .permission = proc_sys_permission, .setattr = proc_sys_setattr, |
9043476f7
|
813 |
.getattr = proc_sys_getattr, |
77b14db50
|
814 |
}; |
0b728e191
|
815 |
static int proc_sys_revalidate(struct dentry *dentry, unsigned int flags) |
77b14db50
|
816 |
{ |
0b728e191
|
817 |
if (flags & LOOKUP_RCU) |
34286d666
|
818 |
return -ECHILD; |
2b0143b5c
|
819 |
return !PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f7
|
820 |
} |
fe15ce446
|
821 |
static int proc_sys_delete(const struct dentry *dentry) |
9043476f7
|
822 |
{ |
2b0143b5c
|
823 |
return !!PROC_I(d_inode(dentry))->sysctl->unregistering; |
9043476f7
|
824 |
} |
1f87f0b52
|
825 826 827 828 829 830 831 832 833 834 835 836 837 838 |
static int sysctl_is_seen(struct ctl_table_header *p) { struct ctl_table_set *set = p->set; int res; spin_lock(&sysctl_lock); if (p->unregistering) res = 0; else if (!set->is_seen) res = 1; else res = set->is_seen(set); spin_unlock(&sysctl_lock); return res; } |
6fa67e707
|
839 |
static int proc_sys_compare(const struct dentry *dentry, |
621e155a3
|
840 |
unsigned int len, const char *str, const struct qstr *name) |
9043476f7
|
841 |
{ |
dfef6dcd3
|
842 |
struct ctl_table_header *head; |
da53be12b
|
843 |
struct inode *inode; |
31e6b01f4
|
844 845 |
/* Although proc doesn't have negative dentries, rcu-walk means * that inode here can be NULL */ |
dfef6dcd3
|
846 |
/* AV: can it, indeed? */ |
2b0143b5c
|
847 |
inode = d_inode_rcu(dentry); |
31e6b01f4
|
848 |
if (!inode) |
dfef6dcd3
|
849 |
return 1; |
621e155a3
|
850 |
if (name->len != len) |
9043476f7
|
851 |
return 1; |
621e155a3
|
852 |
if (memcmp(name->name, str, len)) |
9043476f7
|
853 |
return 1; |
dfef6dcd3
|
854 855 |
head = rcu_dereference(PROC_I(inode)->sysctl); return !head || !sysctl_is_seen(head); |
77b14db50
|
856 |
} |
d72f71eb0
|
857 |
static const struct dentry_operations proc_sys_dentry_operations = { |
77b14db50
|
858 |
.d_revalidate = proc_sys_revalidate, |
9043476f7
|
859 860 |
.d_delete = proc_sys_delete, .d_compare = proc_sys_compare, |
77b14db50
|
861 |
}; |
0e47c99d7
|
862 863 |
static struct ctl_dir *find_subdir(struct ctl_dir *dir, const char *name, int namelen) |
1f87f0b52
|
864 |
{ |
7ec66d063
|
865 866 |
struct ctl_table_header *head; struct ctl_table *entry; |
1f87f0b52
|
867 |
|
0e47c99d7
|
868 |
entry = find_entry(&head, dir, name, namelen); |
7ec66d063
|
869 870 |
if (!entry) return ERR_PTR(-ENOENT); |
51f72f4a0
|
871 872 873 |
if (!S_ISDIR(entry->mode)) return ERR_PTR(-ENOTDIR); return container_of(head, struct ctl_dir, header); |
7ec66d063
|
874 875 876 |
} static struct ctl_dir *new_dir(struct ctl_table_set *set, |
0e47c99d7
|
877 |
const char *name, int namelen) |
7ec66d063
|
878 879 880 |
{ struct ctl_table *table; struct ctl_dir *new; |
ac13ac6f4
|
881 |
struct ctl_node *node; |
7ec66d063
|
882 |
char *new_name; |
1f87f0b52
|
883 |
|
ac13ac6f4
|
884 885 886 |
new = kzalloc(sizeof(*new) + sizeof(struct ctl_node) + sizeof(struct ctl_table)*2 + namelen + 1, GFP_KERNEL); |
7ec66d063
|
887 |
if (!new) |
1f87f0b52
|
888 |
return NULL; |
ac13ac6f4
|
889 890 |
node = (struct ctl_node *)(new + 1); table = (struct ctl_table *)(node + 1); |
7ec66d063
|
891 892 893 894 895 |
new_name = (char *)(table + 2); memcpy(new_name, name, namelen); new_name[namelen] = '\0'; table[0].procname = new_name; table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO; |
ac13ac6f4
|
896 |
init_header(&new->header, set->dir.header.root, set, node, table); |
7ec66d063
|
897 898 |
return new; |
1f87f0b52
|
899 |
} |
60f126d93
|
900 901 902 903 904 905 906 907 908 909 910 911 |
/** * get_subdir - find or create a subdir with the specified name. * @dir: Directory to create the subdirectory in * @name: The name of the subdirectory to find or create * @namelen: The length of name * * Takes a directory with an elevated reference count so we know that * if we drop the lock the directory will not go away. Upon success * the reference is moved from @dir to the returned subdirectory. * Upon error an error code is returned and the reference on @dir is * simply dropped. */ |
0e47c99d7
|
912 913 |
static struct ctl_dir *get_subdir(struct ctl_dir *dir, const char *name, int namelen) |
1f87f0b52
|
914 |
{ |
0e47c99d7
|
915 |
struct ctl_table_set *set = dir->header.set; |
7ec66d063
|
916 |
struct ctl_dir *subdir, *new = NULL; |
0eb97f38d
|
917 |
int err; |
1f87f0b52
|
918 |
|
7ec66d063
|
919 |
spin_lock(&sysctl_lock); |
0e47c99d7
|
920 |
subdir = find_subdir(dir, name, namelen); |
7ec66d063
|
921 922 923 924 925 926 927 928 929 930 931 |
if (!IS_ERR(subdir)) goto found; if (PTR_ERR(subdir) != -ENOENT) goto failed; spin_unlock(&sysctl_lock); new = new_dir(set, name, namelen); spin_lock(&sysctl_lock); subdir = ERR_PTR(-ENOMEM); if (!new) goto failed; |
60f126d93
|
932 |
/* Was the subdir added while we dropped the lock? */ |
0e47c99d7
|
933 |
subdir = find_subdir(dir, name, namelen); |
7ec66d063
|
934 935 936 937 |
if (!IS_ERR(subdir)) goto found; if (PTR_ERR(subdir) != -ENOENT) goto failed; |
60f126d93
|
938 |
/* Nope. Use the our freshly made directory entry. */ |
0eb97f38d
|
939 940 941 |
err = insert_header(dir, &new->header); subdir = ERR_PTR(err); if (err) |
0e47c99d7
|
942 |
goto failed; |
7ec66d063
|
943 944 945 946 |
subdir = new; found: subdir->header.nreg++; failed: |
a1c83681d
|
947 |
if (IS_ERR(subdir)) { |
87ebdc00e
|
948 |
pr_err("sysctl could not get directory: "); |
6980128fe
|
949 |
sysctl_print_dir(dir); |
87ebdc00e
|
950 951 |
pr_cont("/%*.*s %ld ", |
7ec66d063
|
952 |
namelen, namelen, name, PTR_ERR(subdir)); |
1f87f0b52
|
953 |
} |
7ec66d063
|
954 955 956 957 958 |
drop_sysctl_table(&dir->header); if (new) drop_sysctl_table(&new->header); spin_unlock(&sysctl_lock); return subdir; |
1f87f0b52
|
959 |
} |
0e47c99d7
|
960 961 962 963 964 965 966 967 968 969 970 971 972 973 |
static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) { struct ctl_dir *parent; const char *procname; if (!dir->header.parent) return &set->dir; parent = xlate_dir(set, dir->header.parent); if (IS_ERR(parent)) return parent; procname = dir->header.ctl_table[0].procname; return find_subdir(parent, procname, strlen(procname)); } static int sysctl_follow_link(struct ctl_table_header **phead, |
13bcc6a28
|
974 |
struct ctl_table **pentry) |
0e47c99d7
|
975 976 977 978 979 980 981 |
{ struct ctl_table_header *head; struct ctl_table_root *root; struct ctl_table_set *set; struct ctl_table *entry; struct ctl_dir *dir; int ret; |
0e47c99d7
|
982 983 984 |
ret = 0; spin_lock(&sysctl_lock); root = (*pentry)->data; |
13bcc6a28
|
985 |
set = lookup_header_set(root); |
0e47c99d7
|
986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 |
dir = xlate_dir(set, (*phead)->parent); if (IS_ERR(dir)) ret = PTR_ERR(dir); else { const char *procname = (*pentry)->procname; head = NULL; entry = find_entry(&head, dir, procname, strlen(procname)); ret = -ENOENT; if (entry && use_table(head)) { unuse_table(*phead); *phead = head; *pentry = entry; ret = 0; } } spin_unlock(&sysctl_lock); return ret; } |
7c60c48f5
|
1005 |
static int sysctl_err(const char *path, struct ctl_table *table, char *fmt, ...) |
1f87f0b52
|
1006 |
{ |
7c60c48f5
|
1007 1008 |
struct va_format vaf; va_list args; |
1f87f0b52
|
1009 |
|
7c60c48f5
|
1010 1011 1012 |
va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; |
87ebdc00e
|
1013 1014 1015 |
pr_err("sysctl table check failed: %s/%s %pV ", path, table->procname, &vaf); |
1f87f0b52
|
1016 |
|
7c60c48f5
|
1017 1018 |
va_end(args); return -EINVAL; |
1f87f0b52
|
1019 |
} |
4f2fec00a
|
1020 1021 1022 |
static int sysctl_check_table_array(const char *path, struct ctl_table *table) { int err = 0; |
61d9b56a8
|
1023 1024 |
if ((table->proc_handler == proc_douintvec) || (table->proc_handler == proc_douintvec_minmax)) { |
4f2fec00a
|
1025 1026 1027 1028 1029 1030 |
if (table->maxlen != sizeof(unsigned int)) err |= sysctl_err(path, table, "array now allowed"); } return err; } |
7c60c48f5
|
1031 |
static int sysctl_check_table(const char *path, struct ctl_table *table) |
1f87f0b52
|
1032 |
{ |
7c60c48f5
|
1033 |
int err = 0; |
1f87f0b52
|
1034 |
for (; table->procname; table++) { |
1f87f0b52
|
1035 |
if (table->child) |
89c5b53b1
|
1036 |
err |= sysctl_err(path, table, "Not a file"); |
7c60c48f5
|
1037 1038 1039 |
if ((table->proc_handler == proc_dostring) || (table->proc_handler == proc_dointvec) || |
1680a3868
|
1040 |
(table->proc_handler == proc_douintvec) || |
61d9b56a8
|
1041 |
(table->proc_handler == proc_douintvec_minmax) || |
7c60c48f5
|
1042 1043 1044 1045 1046 1047 1048 |
(table->proc_handler == proc_dointvec_minmax) || (table->proc_handler == proc_dointvec_jiffies) || (table->proc_handler == proc_dointvec_userhz_jiffies) || (table->proc_handler == proc_dointvec_ms_jiffies) || (table->proc_handler == proc_doulongvec_minmax) || (table->proc_handler == proc_doulongvec_ms_jiffies_minmax)) { if (!table->data) |
89c5b53b1
|
1049 |
err |= sysctl_err(path, table, "No data"); |
7c60c48f5
|
1050 |
if (!table->maxlen) |
89c5b53b1
|
1051 |
err |= sysctl_err(path, table, "No maxlen"); |
4f2fec00a
|
1052 1053 |
else err |= sysctl_check_table_array(path, table); |
7c60c48f5
|
1054 1055 |
} if (!table->proc_handler) |
89c5b53b1
|
1056 |
err |= sysctl_err(path, table, "No proc_handler"); |
7c60c48f5
|
1057 1058 |
if ((table->mode & (S_IRUGO|S_IWUGO)) != table->mode) |
89c5b53b1
|
1059 |
err |= sysctl_err(path, table, "bogus .mode 0%o", |
7c60c48f5
|
1060 |
table->mode); |
1f87f0b52
|
1061 |
} |
7c60c48f5
|
1062 |
return err; |
1f87f0b52
|
1063 |
} |
1f87f0b52
|
1064 |
|
0e47c99d7
|
1065 1066 1067 1068 1069 |
static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table *table, struct ctl_table_root *link_root) { struct ctl_table *link_table, *entry, *link; struct ctl_table_header *links; |
ac13ac6f4
|
1070 |
struct ctl_node *node; |
0e47c99d7
|
1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 |
char *link_name; int nr_entries, name_bytes; name_bytes = 0; nr_entries = 0; for (entry = table; entry->procname; entry++) { nr_entries++; name_bytes += strlen(entry->procname) + 1; } links = kzalloc(sizeof(struct ctl_table_header) + |
ac13ac6f4
|
1082 |
sizeof(struct ctl_node)*nr_entries + |
0e47c99d7
|
1083 1084 1085 1086 1087 1088 |
sizeof(struct ctl_table)*(nr_entries + 1) + name_bytes, GFP_KERNEL); if (!links) return NULL; |
ac13ac6f4
|
1089 1090 |
node = (struct ctl_node *)(links + 1); link_table = (struct ctl_table *)(node + nr_entries); |
0e47c99d7
|
1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 |
link_name = (char *)&link_table[nr_entries + 1]; for (link = link_table, entry = table; entry->procname; link++, entry++) { int len = strlen(entry->procname) + 1; memcpy(link_name, entry->procname, len); link->procname = link_name; link->mode = S_IFLNK|S_IRWXUGO; link->data = link_root; link_name += len; } |
ac13ac6f4
|
1101 |
init_header(links, dir->header.root, dir->header.set, node, link_table); |
0e47c99d7
|
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 |
links->nreg = nr_entries; return links; } static bool get_links(struct ctl_dir *dir, struct ctl_table *table, struct ctl_table_root *link_root) { struct ctl_table_header *head; struct ctl_table *entry, *link; /* Are there links available for every entry in table? */ for (entry = table; entry->procname; entry++) { const char *procname = entry->procname; link = find_entry(&head, dir, procname, strlen(procname)); if (!link) return false; if (S_ISDIR(link->mode) && S_ISDIR(entry->mode)) continue; if (S_ISLNK(link->mode) && (link->data == link_root)) continue; return false; } /* The checks passed. Increase the registration count on the links */ for (entry = table; entry->procname; entry++) { const char *procname = entry->procname; link = find_entry(&head, dir, procname, strlen(procname)); head->nreg++; } return true; } static int insert_links(struct ctl_table_header *head) { struct ctl_table_set *root_set = &sysctl_table_root.default_set; struct ctl_dir *core_parent = NULL; struct ctl_table_header *links; int err; if (head->set == root_set) return 0; core_parent = xlate_dir(root_set, head->parent); if (IS_ERR(core_parent)) return 0; if (get_links(core_parent, head->ctl_table, head->root)) return 0; core_parent->header.nreg++; spin_unlock(&sysctl_lock); links = new_links(core_parent, head->ctl_table, head->root); spin_lock(&sysctl_lock); err = -ENOMEM; if (!links) goto out; err = 0; if (get_links(core_parent, head->ctl_table, head->root)) { kfree(links); goto out; } err = insert_header(core_parent, links); if (err) kfree(links); out: drop_sysctl_table(&core_parent->header); return err; } |
1f87f0b52
|
1175 |
/** |
f728019bb
|
1176 |
* __register_sysctl_table - register a leaf sysctl table |
60a47a2e8
|
1177 |
* @set: Sysctl tree to register on |
1f87f0b52
|
1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 |
* @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * The members of the &struct ctl_table structure are used as follows: * * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not * enter a sysctl file * * data - a pointer to data for use by proc_handler * * maxlen - the maximum size in bytes of the data * |
f728019bb
|
1193 |
* mode - the file permissions for the /proc/sys file |
1f87f0b52
|
1194 |
* |
f728019bb
|
1195 |
* child - must be %NULL. |
1f87f0b52
|
1196 1197 1198 |
* * proc_handler - the text handler routine (described below) * |
1f87f0b52
|
1199 1200 1201 1202 1203 |
* extra1, extra2 - extra pointers usable by the proc handler routines * * Leaf nodes in the sysctl tree will be represented by a single file * under /proc; non-leaf nodes will be represented by directories. * |
f728019bb
|
1204 1205 |
* There must be a proc_handler routine for any terminal nodes. * Several default handlers are available to cover common cases - |
1f87f0b52
|
1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 |
* * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() * * It is the handler's job to read the input buffer from user memory * and process it. The handler should return 0 on success. * * This routine returns %NULL on a failure to register, and a pointer * to the table header on success. */ |
6e9d51641
|
1217 |
struct ctl_table_header *__register_sysctl_table( |
60a47a2e8
|
1218 |
struct ctl_table_set *set, |
6e9d51641
|
1219 |
const char *path, struct ctl_table *table) |
1f87f0b52
|
1220 |
{ |
60a47a2e8
|
1221 |
struct ctl_table_root *root = set->dir.header.root; |
1f87f0b52
|
1222 |
struct ctl_table_header *header; |
6e9d51641
|
1223 |
const char *name, *nextname; |
7ec66d063
|
1224 |
struct ctl_dir *dir; |
ac13ac6f4
|
1225 1226 1227 1228 1229 1230 |
struct ctl_table *entry; struct ctl_node *node; int nr_entries = 0; for (entry = table; entry->procname; entry++) nr_entries++; |
1f87f0b52
|
1231 |
|
ac13ac6f4
|
1232 1233 |
header = kzalloc(sizeof(struct ctl_table_header) + sizeof(struct ctl_node)*nr_entries, GFP_KERNEL); |
1f87f0b52
|
1234 1235 |
if (!header) return NULL; |
ac13ac6f4
|
1236 1237 |
node = (struct ctl_node *)(header + 1); init_header(header, root, set, node, table); |
7ec66d063
|
1238 1239 1240 1241 |
if (sysctl_check_table(path, table)) goto fail; spin_lock(&sysctl_lock); |
0e47c99d7
|
1242 |
dir = &set->dir; |
60f126d93
|
1243 |
/* Reference moved down the diretory tree get_subdir */ |
7ec66d063
|
1244 1245 |
dir->header.nreg++; spin_unlock(&sysctl_lock); |
1f87f0b52
|
1246 |
|
7ec66d063
|
1247 |
/* Find the directory for the ctl_table */ |
6e9d51641
|
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 |
for (name = path; name; name = nextname) { int namelen; nextname = strchr(name, '/'); if (nextname) { namelen = nextname - name; nextname++; } else { namelen = strlen(name); } if (namelen == 0) continue; |
1f87f0b52
|
1259 |
|
0e47c99d7
|
1260 |
dir = get_subdir(dir, name, namelen); |
7ec66d063
|
1261 1262 |
if (IS_ERR(dir)) goto fail; |
1f87f0b52
|
1263 |
} |
0e47c99d7
|
1264 |
|
1f87f0b52
|
1265 |
spin_lock(&sysctl_lock); |
0e47c99d7
|
1266 |
if (insert_header(dir, header)) |
7ec66d063
|
1267 |
goto fail_put_dir_locked; |
0e47c99d7
|
1268 |
|
7ec66d063
|
1269 |
drop_sysctl_table(&dir->header); |
1f87f0b52
|
1270 1271 1272 |
spin_unlock(&sysctl_lock); return header; |
0e47c99d7
|
1273 |
|
7ec66d063
|
1274 1275 |
fail_put_dir_locked: drop_sysctl_table(&dir->header); |
7c60c48f5
|
1276 1277 1278 1279 1280 |
spin_unlock(&sysctl_lock); fail: kfree(header); dump_stack(); return NULL; |
1f87f0b52
|
1281 |
} |
fea478d41
|
1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 |
/** * register_sysctl - register a sysctl table * @path: The path to the directory the sysctl table is in. * @table: the table structure * * Register a sysctl table. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * See __register_sysctl_table for more details. */ struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table) { return __register_sysctl_table(&sysctl_table_root.default_set, path, table); } EXPORT_SYMBOL(register_sysctl); |
6e9d51641
|
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 |
static char *append_path(const char *path, char *pos, const char *name) { int namelen; namelen = strlen(name); if (((pos - path) + namelen + 2) >= PATH_MAX) return NULL; memcpy(pos, name, namelen); pos[namelen] = '/'; pos[namelen + 1] = '\0'; pos += namelen + 1; return pos; } |
f728019bb
|
1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 |
static int count_subheaders(struct ctl_table *table) { int has_files = 0; int nr_subheaders = 0; struct ctl_table *entry; /* special case: no directory and empty directory */ if (!table || !table->procname) return 1; for (entry = table; entry->procname; entry++) { if (entry->child) nr_subheaders += count_subheaders(entry->child); else has_files = 1; } return nr_subheaders + has_files; } static int register_leaf_sysctl_tables(const char *path, char *pos, |
60a47a2e8
|
1330 |
struct ctl_table_header ***subheader, struct ctl_table_set *set, |
f728019bb
|
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 |
struct ctl_table *table) { struct ctl_table *ctl_table_arg = NULL; struct ctl_table *entry, *files; int nr_files = 0; int nr_dirs = 0; int err = -ENOMEM; for (entry = table; entry->procname; entry++) { if (entry->child) nr_dirs++; else nr_files++; } files = table; /* If there are mixed files and directories we need a new table */ if (nr_dirs && nr_files) { struct ctl_table *new; files = kzalloc(sizeof(struct ctl_table) * (nr_files + 1), GFP_KERNEL); if (!files) goto out; ctl_table_arg = files; for (new = files, entry = table; entry->procname; entry++) { if (entry->child) continue; *new = *entry; new++; } } /* Register everything except a directory full of subdirectories */ if (nr_files || !nr_dirs) { struct ctl_table_header *header; |
60a47a2e8
|
1367 |
header = __register_sysctl_table(set, path, files); |
f728019bb
|
1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 |
if (!header) { kfree(ctl_table_arg); goto out; } /* Remember if we need to free the file table */ header->ctl_table_arg = ctl_table_arg; **subheader = header; (*subheader)++; } /* Recurse into the subdirectories. */ for (entry = table; entry->procname; entry++) { char *child_pos; if (!entry->child) continue; err = -ENAMETOOLONG; child_pos = append_path(path, pos, entry->procname); if (!child_pos) goto out; err = register_leaf_sysctl_tables(path, child_pos, subheader, |
60a47a2e8
|
1392 |
set, entry->child); |
f728019bb
|
1393 1394 1395 1396 1397 1398 1399 1400 1401 |
pos[0] = '\0'; if (err) goto out; } err = 0; out: /* On failure our caller will unregister all registered subheaders */ return err; } |
6e9d51641
|
1402 1403 |
/** * __register_sysctl_paths - register a sysctl table hierarchy |
60a47a2e8
|
1404 |
* @set: Sysctl tree to register on |
6e9d51641
|
1405 1406 1407 1408 1409 1410 1411 1412 1413 |
* @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * See __register_sysctl_table for more details. */ struct ctl_table_header *__register_sysctl_paths( |
60a47a2e8
|
1414 |
struct ctl_table_set *set, |
6e9d51641
|
1415 1416 |
const struct ctl_path *path, struct ctl_table *table) { |
ec6a52668
|
1417 |
struct ctl_table *ctl_table_arg = table; |
f728019bb
|
1418 1419 |
int nr_subheaders = count_subheaders(table); struct ctl_table_header *header = NULL, **subheaders, **subheader; |
6e9d51641
|
1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 |
const struct ctl_path *component; char *new_path, *pos; pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); if (!new_path) return NULL; pos[0] = '\0'; for (component = path; component->procname; component++) { pos = append_path(new_path, pos, component->procname); if (!pos) goto out; } |
ec6a52668
|
1433 1434 1435 1436 1437 1438 |
while (table->procname && table->child && !table[1].procname) { pos = append_path(new_path, pos, table->procname); if (!pos) goto out; table = table->child; } |
f728019bb
|
1439 |
if (nr_subheaders == 1) { |
60a47a2e8
|
1440 |
header = __register_sysctl_table(set, new_path, table); |
f728019bb
|
1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 |
if (header) header->ctl_table_arg = ctl_table_arg; } else { header = kzalloc(sizeof(*header) + sizeof(*subheaders)*nr_subheaders, GFP_KERNEL); if (!header) goto out; subheaders = (struct ctl_table_header **) (header + 1); subheader = subheaders; |
ec6a52668
|
1451 |
header->ctl_table_arg = ctl_table_arg; |
f728019bb
|
1452 1453 |
if (register_leaf_sysctl_tables(new_path, pos, &subheader, |
60a47a2e8
|
1454 |
set, table)) |
f728019bb
|
1455 1456 |
goto err_register_leaves; } |
6e9d51641
|
1457 1458 1459 |
out: kfree(new_path); return header; |
f728019bb
|
1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 |
err_register_leaves: while (subheader > subheaders) { struct ctl_table_header *subh = *(--subheader); struct ctl_table *table = subh->ctl_table_arg; unregister_sysctl_table(subh); kfree(table); } kfree(header); header = NULL; goto out; |
6e9d51641
|
1471 |
} |
1f87f0b52
|
1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 |
/** * register_sysctl_table_path - register a sysctl table hierarchy * @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * See __register_sysctl_paths for more details. */ struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, struct ctl_table *table) { |
60a47a2e8
|
1485 |
return __register_sysctl_paths(&sysctl_table_root.default_set, |
1f87f0b52
|
1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 |
path, table); } EXPORT_SYMBOL(register_sysctl_paths); /** * register_sysctl_table - register a sysctl table hierarchy * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * See register_sysctl_paths for more details. */ struct ctl_table_header *register_sysctl_table(struct ctl_table *table) { static const struct ctl_path null_path[] = { {} }; return register_sysctl_paths(null_path, table); } EXPORT_SYMBOL(register_sysctl_table); |
0e47c99d7
|
1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 |
static void put_links(struct ctl_table_header *header) { struct ctl_table_set *root_set = &sysctl_table_root.default_set; struct ctl_table_root *root = header->root; struct ctl_dir *parent = header->parent; struct ctl_dir *core_parent; struct ctl_table *entry; if (header->set == root_set) return; core_parent = xlate_dir(root_set, parent); if (IS_ERR(core_parent)) return; for (entry = header->ctl_table; entry->procname; entry++) { struct ctl_table_header *link_head; struct ctl_table *link; const char *name = entry->procname; link = find_entry(&link_head, core_parent, name, strlen(name)); if (link && ((S_ISDIR(link->mode) && S_ISDIR(entry->mode)) || (S_ISLNK(link->mode) && (link->data == root)))) { drop_sysctl_table(link_head); } else { |
87ebdc00e
|
1533 |
pr_err("sysctl link missing during unregister: "); |
0e47c99d7
|
1534 |
sysctl_print_dir(parent); |
87ebdc00e
|
1535 1536 |
pr_cont("/%s ", name); |
0e47c99d7
|
1537 1538 1539 |
} } } |
938aaa4f9
|
1540 1541 |
static void drop_sysctl_table(struct ctl_table_header *header) { |
7ec66d063
|
1542 |
struct ctl_dir *parent = header->parent; |
938aaa4f9
|
1543 1544 |
if (--header->nreg) return; |
0e47c99d7
|
1545 |
put_links(header); |
938aaa4f9
|
1546 |
start_unregistering(header); |
938aaa4f9
|
1547 1548 |
if (!--header->count) kfree_rcu(header, rcu); |
7ec66d063
|
1549 1550 1551 |
if (parent) drop_sysctl_table(&parent->header); |
938aaa4f9
|
1552 |
} |
1f87f0b52
|
1553 1554 1555 1556 1557 1558 1559 1560 1561 |
/** * unregister_sysctl_table - unregister a sysctl table hierarchy * @header: the header returned from register_sysctl_table * * Unregisters the sysctl table and all children. proc entries may not * actually be removed until they are no longer used by anyone. */ void unregister_sysctl_table(struct ctl_table_header * header) { |
f728019bb
|
1562 |
int nr_subheaders; |
1f87f0b52
|
1563 1564 1565 1566 |
might_sleep(); if (header == NULL) return; |
f728019bb
|
1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 |
nr_subheaders = count_subheaders(header->ctl_table_arg); if (unlikely(nr_subheaders > 1)) { struct ctl_table_header **subheaders; int i; subheaders = (struct ctl_table_header **)(header + 1); for (i = nr_subheaders -1; i >= 0; i--) { struct ctl_table_header *subh = subheaders[i]; struct ctl_table *table = subh->ctl_table_arg; unregister_sysctl_table(subh); kfree(table); } kfree(header); return; } |
1f87f0b52
|
1582 |
spin_lock(&sysctl_lock); |
938aaa4f9
|
1583 |
drop_sysctl_table(header); |
1f87f0b52
|
1584 1585 1586 |
spin_unlock(&sysctl_lock); } EXPORT_SYMBOL(unregister_sysctl_table); |
0e47c99d7
|
1587 |
void setup_sysctl_set(struct ctl_table_set *set, |
9eb47c26f
|
1588 |
struct ctl_table_root *root, |
1f87f0b52
|
1589 1590 |
int (*is_seen)(struct ctl_table_set *)) { |
1347440db
|
1591 |
memset(set, 0, sizeof(*set)); |
0e47c99d7
|
1592 |
set->is_seen = is_seen; |
ac13ac6f4
|
1593 |
init_header(&set->dir.header, root, set, NULL, root_table); |
1f87f0b52
|
1594 |
} |
97324cd80
|
1595 1596 |
void retire_sysctl_set(struct ctl_table_set *set) { |
ac13ac6f4
|
1597 |
WARN_ON(!RB_EMPTY_ROOT(&set->dir.root)); |
97324cd80
|
1598 |
} |
1f87f0b52
|
1599 |
|
1e0edd3f6
|
1600 |
int __init proc_sys_init(void) |
77b14db50
|
1601 |
{ |
e1675231c
|
1602 |
struct proc_dir_entry *proc_sys_root; |
77b14db50
|
1603 |
proc_sys_root = proc_mkdir("sys", NULL); |
9043476f7
|
1604 1605 |
proc_sys_root->proc_iops = &proc_sys_dir_operations; proc_sys_root->proc_fops = &proc_sys_dir_file_operations; |
77b14db50
|
1606 |
proc_sys_root->nlink = 0; |
de4e83bd6
|
1607 1608 |
return sysctl_init(); |
77b14db50
|
1609 |
} |