mm, oom: do not rely on TIF_MEMDIE for memory reserves access
[linux/fpc-iii.git] / security / keys / proc.c
blobbf08d02b6646ae2077b15903471bfb4575b04f5a
1 /* procfs files for key database enumeration
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/sched.h>
15 #include <linux/fs.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #include <asm/errno.h>
19 #include "internal.h"
21 static int proc_keys_open(struct inode *inode, struct file *file);
22 static void *proc_keys_start(struct seq_file *p, loff_t *_pos);
23 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos);
24 static void proc_keys_stop(struct seq_file *p, void *v);
25 static int proc_keys_show(struct seq_file *m, void *v);
27 static const struct seq_operations proc_keys_ops = {
28 .start = proc_keys_start,
29 .next = proc_keys_next,
30 .stop = proc_keys_stop,
31 .show = proc_keys_show,
34 static const struct file_operations proc_keys_fops = {
35 .open = proc_keys_open,
36 .read = seq_read,
37 .llseek = seq_lseek,
38 .release = seq_release,
41 static int proc_key_users_open(struct inode *inode, struct file *file);
42 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos);
43 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos);
44 static void proc_key_users_stop(struct seq_file *p, void *v);
45 static int proc_key_users_show(struct seq_file *m, void *v);
47 static const struct seq_operations proc_key_users_ops = {
48 .start = proc_key_users_start,
49 .next = proc_key_users_next,
50 .stop = proc_key_users_stop,
51 .show = proc_key_users_show,
54 static const struct file_operations proc_key_users_fops = {
55 .open = proc_key_users_open,
56 .read = seq_read,
57 .llseek = seq_lseek,
58 .release = seq_release,
62 * Declare the /proc files.
64 static int __init key_proc_init(void)
66 struct proc_dir_entry *p;
68 p = proc_create("keys", 0, NULL, &proc_keys_fops);
69 if (!p)
70 panic("Cannot create /proc/keys\n");
72 p = proc_create("key-users", 0, NULL, &proc_key_users_fops);
73 if (!p)
74 panic("Cannot create /proc/key-users\n");
76 return 0;
79 __initcall(key_proc_init);
82 * Implement "/proc/keys" to provide a list of the keys on the system that
83 * grant View permission to the caller.
85 static struct rb_node *key_serial_next(struct seq_file *p, struct rb_node *n)
87 struct user_namespace *user_ns = seq_user_ns(p);
89 n = rb_next(n);
90 while (n) {
91 struct key *key = rb_entry(n, struct key, serial_node);
92 if (kuid_has_mapping(user_ns, key->user->uid))
93 break;
94 n = rb_next(n);
96 return n;
99 static int proc_keys_open(struct inode *inode, struct file *file)
101 return seq_open(file, &proc_keys_ops);
104 static struct key *find_ge_key(struct seq_file *p, key_serial_t id)
106 struct user_namespace *user_ns = seq_user_ns(p);
107 struct rb_node *n = key_serial_tree.rb_node;
108 struct key *minkey = NULL;
110 while (n) {
111 struct key *key = rb_entry(n, struct key, serial_node);
112 if (id < key->serial) {
113 if (!minkey || minkey->serial > key->serial)
114 minkey = key;
115 n = n->rb_left;
116 } else if (id > key->serial) {
117 n = n->rb_right;
118 } else {
119 minkey = key;
120 break;
122 key = NULL;
125 if (!minkey)
126 return NULL;
128 for (;;) {
129 if (kuid_has_mapping(user_ns, minkey->user->uid))
130 return minkey;
131 n = rb_next(&minkey->serial_node);
132 if (!n)
133 return NULL;
134 minkey = rb_entry(n, struct key, serial_node);
138 static void *proc_keys_start(struct seq_file *p, loff_t *_pos)
139 __acquires(key_serial_lock)
141 key_serial_t pos = *_pos;
142 struct key *key;
144 spin_lock(&key_serial_lock);
146 if (*_pos > INT_MAX)
147 return NULL;
148 key = find_ge_key(p, pos);
149 if (!key)
150 return NULL;
151 *_pos = key->serial;
152 return &key->serial_node;
155 static inline key_serial_t key_node_serial(struct rb_node *n)
157 struct key *key = rb_entry(n, struct key, serial_node);
158 return key->serial;
161 static void *proc_keys_next(struct seq_file *p, void *v, loff_t *_pos)
163 struct rb_node *n;
165 n = key_serial_next(p, v);
166 if (n)
167 *_pos = key_node_serial(n);
168 return n;
171 static void proc_keys_stop(struct seq_file *p, void *v)
172 __releases(key_serial_lock)
174 spin_unlock(&key_serial_lock);
177 static int proc_keys_show(struct seq_file *m, void *v)
179 struct rb_node *_p = v;
180 struct key *key = rb_entry(_p, struct key, serial_node);
181 struct timespec now;
182 unsigned long timo;
183 key_ref_t key_ref, skey_ref;
184 char xbuf[16];
185 int rc;
187 struct keyring_search_context ctx = {
188 .index_key.type = key->type,
189 .index_key.description = key->description,
190 .cred = current_cred(),
191 .match_data.cmp = lookup_user_key_possessed,
192 .match_data.raw_data = key,
193 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
194 .flags = KEYRING_SEARCH_NO_STATE_CHECK,
197 key_ref = make_key_ref(key, 0);
199 /* determine if the key is possessed by this process (a test we can
200 * skip if the key does not indicate the possessor can view it
202 if (key->perm & KEY_POS_VIEW) {
203 skey_ref = search_my_process_keyrings(&ctx);
204 if (!IS_ERR(skey_ref)) {
205 key_ref_put(skey_ref);
206 key_ref = make_key_ref(key, 1);
210 /* check whether the current task is allowed to view the key (assuming
211 * non-possession)
212 * - the caller holds a spinlock, and thus the RCU read lock, making our
213 * access to __current_cred() safe
215 rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
216 if (rc < 0)
217 return 0;
219 now = current_kernel_time();
221 rcu_read_lock();
223 /* come up with a suitable timeout value */
224 if (key->expiry == 0) {
225 memcpy(xbuf, "perm", 5);
226 } else if (now.tv_sec >= key->expiry) {
227 memcpy(xbuf, "expd", 5);
228 } else {
229 timo = key->expiry - now.tv_sec;
231 if (timo < 60)
232 sprintf(xbuf, "%lus", timo);
233 else if (timo < 60*60)
234 sprintf(xbuf, "%lum", timo / 60);
235 else if (timo < 60*60*24)
236 sprintf(xbuf, "%luh", timo / (60*60));
237 else if (timo < 60*60*24*7)
238 sprintf(xbuf, "%lud", timo / (60*60*24));
239 else
240 sprintf(xbuf, "%luw", timo / (60*60*24*7));
243 #define showflag(KEY, LETTER, FLAG) \
244 (test_bit(FLAG, &(KEY)->flags) ? LETTER : '-')
246 seq_printf(m, "%08x %c%c%c%c%c%c%c %5d %4s %08x %5d %5d %-9.9s ",
247 key->serial,
248 showflag(key, 'I', KEY_FLAG_INSTANTIATED),
249 showflag(key, 'R', KEY_FLAG_REVOKED),
250 showflag(key, 'D', KEY_FLAG_DEAD),
251 showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
252 showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
253 showflag(key, 'N', KEY_FLAG_NEGATIVE),
254 showflag(key, 'i', KEY_FLAG_INVALIDATED),
255 refcount_read(&key->usage),
256 xbuf,
257 key->perm,
258 from_kuid_munged(seq_user_ns(m), key->uid),
259 from_kgid_munged(seq_user_ns(m), key->gid),
260 key->type->name);
262 #undef showflag
264 if (key->type->describe)
265 key->type->describe(key, m);
266 seq_putc(m, '\n');
268 rcu_read_unlock();
269 return 0;
272 static struct rb_node *__key_user_next(struct user_namespace *user_ns, struct rb_node *n)
274 while (n) {
275 struct key_user *user = rb_entry(n, struct key_user, node);
276 if (kuid_has_mapping(user_ns, user->uid))
277 break;
278 n = rb_next(n);
280 return n;
283 static struct rb_node *key_user_next(struct user_namespace *user_ns, struct rb_node *n)
285 return __key_user_next(user_ns, rb_next(n));
288 static struct rb_node *key_user_first(struct user_namespace *user_ns, struct rb_root *r)
290 struct rb_node *n = rb_first(r);
291 return __key_user_next(user_ns, n);
295 * Implement "/proc/key-users" to provides a list of the key users and their
296 * quotas.
298 static int proc_key_users_open(struct inode *inode, struct file *file)
300 return seq_open(file, &proc_key_users_ops);
303 static void *proc_key_users_start(struct seq_file *p, loff_t *_pos)
304 __acquires(key_user_lock)
306 struct rb_node *_p;
307 loff_t pos = *_pos;
309 spin_lock(&key_user_lock);
311 _p = key_user_first(seq_user_ns(p), &key_user_tree);
312 while (pos > 0 && _p) {
313 pos--;
314 _p = key_user_next(seq_user_ns(p), _p);
317 return _p;
320 static void *proc_key_users_next(struct seq_file *p, void *v, loff_t *_pos)
322 (*_pos)++;
323 return key_user_next(seq_user_ns(p), (struct rb_node *)v);
326 static void proc_key_users_stop(struct seq_file *p, void *v)
327 __releases(key_user_lock)
329 spin_unlock(&key_user_lock);
332 static int proc_key_users_show(struct seq_file *m, void *v)
334 struct rb_node *_p = v;
335 struct key_user *user = rb_entry(_p, struct key_user, node);
336 unsigned maxkeys = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
337 key_quota_root_maxkeys : key_quota_maxkeys;
338 unsigned maxbytes = uid_eq(user->uid, GLOBAL_ROOT_UID) ?
339 key_quota_root_maxbytes : key_quota_maxbytes;
341 seq_printf(m, "%5u: %5d %d/%d %d/%d %d/%d\n",
342 from_kuid_munged(seq_user_ns(m), user->uid),
343 refcount_read(&user->usage),
344 atomic_read(&user->nkeys),
345 atomic_read(&user->nikeys),
346 user->qnkeys,
347 maxkeys,
348 user->qnbytes,
349 maxbytes);
351 return 0;