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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/ipc/util.c
3 * Copyright (C) 1992 Krishna Balasubramanian
4 *
5 * Sep 1997 - Call suser() last after "normal" permission checks so we
6 * get BSD style process accounting right.
7 * Occurs in several places in the IPC code.
8 * Chris Evans, <chris@ferret.lmh.ox.ac.uk>
9 * Nov 1999 - ipc helper functions, unified SMP locking
Christian Kujau624dffc2006-01-15 02:43:54 +010010 * Manfred Spraul <manfred@colorfullife.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * Oct 2002 - One lock per IPC id. RCU ipc_free for lock-free grow_ary().
12 * Mingming Cao <cmm@us.ibm.com>
Steve Grubb073115d2006-04-02 17:07:33 -040013 * Mar 2006 - support for audit of ipc object properties
14 * Dustin Kirkland <dustin.kirkland@us.ibm.com>
Kirill Korotaev73ea4132006-10-02 02:18:20 -070015 * Jun 2006 - namespaces ssupport
16 * OpenVZ, SWsoft Inc.
17 * Pavel Emelianov <xemul@openvz.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 */
19
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/mm.h>
21#include <linux/shm.h>
22#include <linux/init.h>
23#include <linux/msg.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/vmalloc.h>
25#include <linux/slab.h>
Andrew Morton8f68fa22013-04-29 15:08:05 -070026#include <linux/notifier.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080027#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/highuid.h>
29#include <linux/security.h>
30#include <linux/rcupdate.h>
31#include <linux/workqueue.h>
Mike Waychisonae781772005-09-06 15:17:09 -070032#include <linux/seq_file.h>
33#include <linux/proc_fs.h>
Steve Grubb073115d2006-04-02 17:07:33 -040034#include <linux/audit.h>
Kirill Korotaev73ea4132006-10-02 02:18:20 -070035#include <linux/nsproxy.h>
Nadia Derbey3e148c72007-10-18 23:40:54 -070036#include <linux/rwsem.h>
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070037#include <linux/memory.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080038#include <linux/ipc_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#include <asm/unistd.h>
41
42#include "util.h"
43
Mike Waychisonae781772005-09-06 15:17:09 -070044struct ipc_proc_iface {
45 const char *path;
46 const char *header;
Kirill Korotaev73ea4132006-10-02 02:18:20 -070047 int ids;
Mike Waychisonae781772005-09-06 15:17:09 -070048 int (*show)(struct seq_file *, void *);
49};
50
Nadia Derbey424450c2008-04-29 01:00:43 -070051static void ipc_memory_notifier(struct work_struct *work)
52{
53 ipcns_notify(IPCNS_MEMCHANGED);
54}
55
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070056static int ipc_memory_callback(struct notifier_block *self,
57 unsigned long action, void *arg)
58{
Andrew Morton8f68fa22013-04-29 15:08:05 -070059 static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
60
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070061 switch (action) {
62 case MEM_ONLINE: /* memory successfully brought online */
63 case MEM_OFFLINE: /* or offline: it's time to recompute msgmni */
64 /*
65 * This is done by invoking the ipcns notifier chain with the
66 * IPC_MEMCHANGED event.
Nadia Derbey424450c2008-04-29 01:00:43 -070067 * In order not to keep the lock on the hotplug memory chain
68 * for too long, queue a work item that will, when waken up,
69 * activate the ipcns notification chain.
70 * No need to keep several ipc work items on the queue.
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070071 */
Nadia Derbey424450c2008-04-29 01:00:43 -070072 if (!work_pending(&ipc_memory_wq))
73 schedule_work(&ipc_memory_wq);
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070074 break;
75 case MEM_GOING_ONLINE:
76 case MEM_GOING_OFFLINE:
77 case MEM_CANCEL_ONLINE:
78 case MEM_CANCEL_OFFLINE:
79 default:
80 break;
81 }
82
83 return NOTIFY_OK;
84}
85
Andrew Morton8f68fa22013-04-29 15:08:05 -070086static struct notifier_block ipc_memory_nb = {
87 .notifier_call = ipc_memory_callback,
88 .priority = IPC_CALLBACK_PRI,
89};
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070090
Linus Torvalds1da177e2005-04-16 15:20:36 -070091/**
92 * ipc_init - initialise IPC subsystem
93 *
94 * The various system5 IPC resources (semaphores, messages and shared
Robert P. J. Day72fd4a32007-02-10 01:45:59 -080095 * memory) are initialised
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070096 * A callback routine is registered into the memory hotplug notifier
97 * chain: since msgmni scales to lowmem this callback routine will be
98 * called upon successful memory add / remove to recompute msmgni.
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 */
100
101static int __init ipc_init(void)
102{
103 sem_init();
104 msg_init();
105 shm_init();
Andrew Morton8f68fa22013-04-29 15:08:05 -0700106 register_hotmemory_notifier(&ipc_memory_nb);
Nadia Derbeyb6b337a2008-04-29 01:00:42 -0700107 register_ipcns_notifier(&init_ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 return 0;
109}
110__initcall(ipc_init);
111
112/**
113 * ipc_init_ids - initialise IPC identifiers
114 * @ids: Identifier set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 *
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700116 * Set up the sequence range to use for the ipc identifier range (limited
117 * below IPCMNI) then initialise the ids idr.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 */
119
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700120void ipc_init_ids(struct ipc_ids *ids)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121{
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700122 init_rwsem(&ids->rwsem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 ids->in_use = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 ids->seq = 0;
Stanislav Kinsbursky03f59562013-01-04 15:34:50 -0800126 ids->next_id = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 {
128 int seq_limit = INT_MAX/SEQ_MULTIPLIER;
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700129 if (seq_limit > USHRT_MAX)
130 ids->seq_max = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 else
132 ids->seq_max = seq_limit;
133 }
134
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700135 idr_init(&ids->ipcs_idr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136}
137
Mike Waychisonae781772005-09-06 15:17:09 -0700138#ifdef CONFIG_PROC_FS
Arjan van de Ven9a321442007-02-12 00:55:35 -0800139static const struct file_operations sysvipc_proc_fops;
Mike Waychisonae781772005-09-06 15:17:09 -0700140/**
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800141 * ipc_init_proc_interface - Create a proc interface for sysipc types using a seq_file interface.
Mike Waychisonae781772005-09-06 15:17:09 -0700142 * @path: Path in procfs
143 * @header: Banner to be printed at the beginning of the file.
144 * @ids: ipc id table to iterate.
145 * @show: show routine.
146 */
147void __init ipc_init_proc_interface(const char *path, const char *header,
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700148 int ids, int (*show)(struct seq_file *, void *))
Mike Waychisonae781772005-09-06 15:17:09 -0700149{
150 struct proc_dir_entry *pde;
151 struct ipc_proc_iface *iface;
152
153 iface = kmalloc(sizeof(*iface), GFP_KERNEL);
154 if (!iface)
155 return;
156 iface->path = path;
157 iface->header = header;
158 iface->ids = ids;
159 iface->show = show;
160
Denis V. Lunev6a6375d2008-04-29 01:02:12 -0700161 pde = proc_create_data(path,
162 S_IRUGO, /* world readable */
163 NULL, /* parent dir */
164 &sysvipc_proc_fops,
165 iface);
166 if (!pde) {
Mike Waychisonae781772005-09-06 15:17:09 -0700167 kfree(iface);
168 }
169}
170#endif
171
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172/**
173 * ipc_findkey - find a key in an ipc identifier set
174 * @ids: Identifier set
175 * @key: The key to find
176 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700177 * Requires ipc_ids.rwsem locked.
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700178 * Returns the LOCKED pointer to the ipc structure if found or NULL
179 * if not.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700180 * If key is found ipc points to the owning ipc structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 */
182
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700183static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700185 struct kern_ipc_perm *ipc;
186 int next_id;
187 int total;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700189 for (total = 0, next_id = 0; total < ids->in_use; next_id++) {
190 ipc = idr_find(&ids->ipcs_idr, next_id);
191
192 if (ipc == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 continue;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700194
195 if (ipc->key != key) {
196 total++;
197 continue;
198 }
199
200 ipc_lock_by_ptr(ipc);
201 return ipc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700203
204 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700207/**
208 * ipc_get_maxid - get the last assigned id
209 * @ids: IPC identifier set
210 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700211 * Called with ipc_ids.rwsem held.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700213
214int ipc_get_maxid(struct ipc_ids *ids)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700216 struct kern_ipc_perm *ipc;
217 int max_id = -1;
218 int total, id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700220 if (ids->in_use == 0)
221 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700223 if (ids->in_use == IPCMNI)
224 return IPCMNI - 1;
225
226 /* Look for the last assigned id */
227 total = 0;
228 for (id = 0; id < IPCMNI && total < ids->in_use; id++) {
229 ipc = idr_find(&ids->ipcs_idr, id);
230 if (ipc != NULL) {
231 max_id = id;
232 total++;
233 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700235 return max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236}
237
238/**
239 * ipc_addid - add an IPC identifier
240 * @ids: IPC identifier set
241 * @new: new IPC permission set
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700242 * @size: limit for the number of used ids
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700244 * Add an entry 'new' to the IPC ids idr. The permissions object is
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 * initialised and the first free entry is set up and the id assigned
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700246 * is returned. The 'new' entry is returned in a locked state on success.
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700247 * On failure the entry is not locked and a negative err-code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700249 * Called with writer ipc_ids.rwsem held.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
252{
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800253 kuid_t euid;
254 kgid_t egid;
Tejun Heo54924ea2013-02-27 17:04:53 -0800255 int id;
Stanislav Kinsbursky03f59562013-01-04 15:34:50 -0800256 int next_id = ids->next_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700258 if (size > IPCMNI)
259 size = IPCMNI;
260
261 if (ids->in_use >= size)
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700262 return -ENOSPC;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700263
Tejun Heo54924ea2013-02-27 17:04:53 -0800264 idr_preload(GFP_KERNEL);
265
Nadia Derbeye00b4ff7e2008-11-19 15:36:08 -0800266 spin_lock_init(&new->lock);
267 new->deleted = 0;
268 rcu_read_lock();
269 spin_lock(&new->lock);
270
Tejun Heo54924ea2013-02-27 17:04:53 -0800271 id = idr_alloc(&ids->ipcs_idr, new,
272 (next_id < 0) ? 0 : ipcid_to_idx(next_id), 0,
273 GFP_NOWAIT);
274 idr_preload_end();
275 if (id < 0) {
Nadia Derbeye00b4ff7e2008-11-19 15:36:08 -0800276 spin_unlock(&new->lock);
277 rcu_read_unlock();
Tejun Heo54924ea2013-02-27 17:04:53 -0800278 return id;
Nadia Derbeye00b4ff7e2008-11-19 15:36:08 -0800279 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700280
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 ids->in_use++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
David Howells414c0702008-11-14 10:39:06 +1100283 current_euid_egid(&euid, &egid);
284 new->cuid = new->uid = euid;
285 new->gid = new->cgid = egid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
Stanislav Kinsbursky03f59562013-01-04 15:34:50 -0800287 if (next_id < 0) {
288 new->seq = ids->seq++;
289 if (ids->seq > ids->seq_max)
290 ids->seq = 0;
291 } else {
292 new->seq = ipcid_to_seqx(next_id);
293 ids->next_id = -1;
294 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
Pierre Peiffer48dea402008-04-29 01:00:35 -0700296 new->id = ipc_buildid(id, new->seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 return id;
298}
299
300/**
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700301 * ipcget_new - create a new ipc object
302 * @ns: namespace
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700303 * @ids: IPC identifer set
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700304 * @ops: the actual creation routine to call
305 * @params: its parameters
306 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700307 * This routine is called by sys_msgget, sys_semget() and sys_shmget()
308 * when the key is IPC_PRIVATE.
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700309 */
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800310static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700311 struct ipc_ops *ops, struct ipc_params *params)
312{
313 int err;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700314
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700315 down_write(&ids->rwsem);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700316 err = ops->getnew(ns, params);
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700317 up_write(&ids->rwsem);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700318 return err;
319}
320
321/**
322 * ipc_check_perms - check security and permissions for an IPC
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700323 * @ns: IPC namespace
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700324 * @ipcp: ipc permission set
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700325 * @ops: the actual security routine to call
326 * @params: its parameters
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700327 *
328 * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
329 * when the key is not IPC_PRIVATE and that key already exists in the
330 * ids IDR.
331 *
332 * On success, the IPC id is returned.
333 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700334 * It is called with ipc_ids.rwsem and ipcp->lock held.
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700335 */
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700336static int ipc_check_perms(struct ipc_namespace *ns,
337 struct kern_ipc_perm *ipcp,
338 struct ipc_ops *ops,
339 struct ipc_params *params)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700340{
341 int err;
342
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700343 if (ipcperms(ns, ipcp, params->flg))
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700344 err = -EACCES;
345 else {
346 err = ops->associate(ipcp, params->flg);
347 if (!err)
348 err = ipcp->id;
349 }
350
351 return err;
352}
353
354/**
355 * ipcget_public - get an ipc object or create a new one
356 * @ns: namespace
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700357 * @ids: IPC identifer set
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700358 * @ops: the actual creation routine to call
359 * @params: its parameters
360 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700361 * This routine is called by sys_msgget, sys_semget() and sys_shmget()
362 * when the key is not IPC_PRIVATE.
363 * It adds a new entry if the key is not found and does some permission
364 * / security checkings if the key is found.
365 *
366 * On success, the ipc id is returned.
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700367 */
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800368static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700369 struct ipc_ops *ops, struct ipc_params *params)
370{
371 struct kern_ipc_perm *ipcp;
372 int flg = params->flg;
373 int err;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700374
Nadia Derbey3e148c72007-10-18 23:40:54 -0700375 /*
376 * Take the lock as a writer since we are potentially going to add
377 * a new entry + read locks are not "upgradable"
378 */
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700379 down_write(&ids->rwsem);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700380 ipcp = ipc_findkey(ids, params->key);
381 if (ipcp == NULL) {
382 /* key not used */
383 if (!(flg & IPC_CREAT))
384 err = -ENOENT;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700385 else
386 err = ops->getnew(ns, params);
387 } else {
388 /* ipc object has been locked by ipc_findkey() */
389
390 if (flg & IPC_CREAT && flg & IPC_EXCL)
391 err = -EEXIST;
392 else {
393 err = 0;
394 if (ops->more_checks)
395 err = ops->more_checks(ipcp, params);
396 if (!err)
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700397 /*
398 * ipc_check_perms returns the IPC id on
399 * success
400 */
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700401 err = ipc_check_perms(ns, ipcp, ops, params);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700402 }
403 ipc_unlock(ipcp);
404 }
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700405 up_write(&ids->rwsem);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700406
407 return err;
408}
409
410
411/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 * ipc_rmid - remove an IPC identifier
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700413 * @ids: IPC identifier set
414 * @ipcp: ipc perm structure containing the identifier to remove
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700416 * ipc_ids.rwsem (as a writer) and the spinlock for this ID are held
Nadia Derbey3e148c72007-10-18 23:40:54 -0700417 * before this function is called, and remain locked on the exit.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 */
419
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700420void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421{
Nadia Derbeyce621f52007-10-18 23:40:52 -0700422 int lid = ipcid_to_idx(ipcp->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700424 idr_remove(&ids->ipcs_idr, lid);
425
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 ids->in_use--;
427
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700428 ipcp->deleted = 1;
429
430 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431}
432
433/**
434 * ipc_alloc - allocate ipc space
435 * @size: size desired
436 *
437 * Allocate memory from the appropriate pools and return a pointer to it.
438 * NULL is returned if the allocation fails
439 */
440
Rik van Riel6062a8d2013-04-30 19:15:44 -0700441void *ipc_alloc(int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442{
Rik van Riel6062a8d2013-04-30 19:15:44 -0700443 void *out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 if(size > PAGE_SIZE)
445 out = vmalloc(size);
446 else
447 out = kmalloc(size, GFP_KERNEL);
448 return out;
449}
450
451/**
452 * ipc_free - free ipc space
453 * @ptr: pointer returned by ipc_alloc
454 * @size: size of block
455 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800456 * Free a block created with ipc_alloc(). The caller must know the size
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 * used in the allocation call.
458 */
459
460void ipc_free(void* ptr, int size)
461{
462 if(size > PAGE_SIZE)
463 vfree(ptr);
464 else
465 kfree(ptr);
466}
467
Al Viro600fe972013-04-29 12:42:09 -0400468struct ipc_rcu {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 struct rcu_head rcu;
Al Viro600fe972013-04-29 12:42:09 -0400470 atomic_t refcount;
Manfred Spraul196aa012013-07-08 16:01:20 -0700471} ____cacheline_aligned_in_smp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473/**
474 * ipc_rcu_alloc - allocate ipc and rcu space
475 * @size: size desired
476 *
477 * Allocate memory for the rcu header structure + the object.
Rik van Riel6062a8d2013-04-30 19:15:44 -0700478 * Returns the pointer to the object or NULL upon failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 */
Rik van Riel6062a8d2013-04-30 19:15:44 -0700480void *ipc_rcu_alloc(int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481{
Rik van Riel6062a8d2013-04-30 19:15:44 -0700482 /*
Al Viro600fe972013-04-29 12:42:09 -0400483 * We prepend the allocation with the rcu struct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 */
Al Viro600fe972013-04-29 12:42:09 -0400485 struct ipc_rcu *out = ipc_alloc(sizeof(struct ipc_rcu) + size);
486 if (unlikely(!out))
487 return NULL;
488 atomic_set(&out->refcount, 1);
Manfred Spraul196aa012013-07-08 16:01:20 -0700489 return out + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490}
491
Rik van Riel6062a8d2013-04-30 19:15:44 -0700492int ipc_rcu_getref(void *ptr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493{
Manfred Spraul196aa012013-07-08 16:01:20 -0700494 struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
495
496 return atomic_inc_not_zero(&p->refcount);
David Howells65f27f32006-11-22 14:55:48 +0000497}
498
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499/**
Randy Dunlap1e5d5332005-11-07 01:01:06 -0800500 * ipc_schedule_free - free ipc + rcu space
501 * @head: RCU callback structure for queued work
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 */
503static void ipc_schedule_free(struct rcu_head *head)
504{
Al Viro600fe972013-04-29 12:42:09 -0400505 vfree(container_of(head, struct ipc_rcu, rcu));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506}
507
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508void ipc_rcu_putref(void *ptr)
509{
Manfred Spraul196aa012013-07-08 16:01:20 -0700510 struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
Al Viro600fe972013-04-29 12:42:09 -0400511
512 if (!atomic_dec_and_test(&p->refcount))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 return;
514
Al Viro600fe972013-04-29 12:42:09 -0400515 if (is_vmalloc_addr(ptr)) {
516 call_rcu(&p->rcu, ipc_schedule_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 } else {
Al Viro600fe972013-04-29 12:42:09 -0400518 kfree_rcu(p, rcu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 }
520}
521
522/**
523 * ipcperms - check IPC permissions
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700524 * @ns: IPC namespace
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 * @ipcp: IPC permission set
526 * @flag: desired permission set.
527 *
528 * Check user, group, other permissions for access
529 * to ipc resources. return 0 if allowed
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700530 *
531 * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 */
533
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700534int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
535{
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800536 kuid_t euid = current_euid();
Al Viroa33e6752008-12-10 03:40:06 -0500537 int requested_mode, granted_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538
Al Viroa33e6752008-12-10 03:40:06 -0500539 audit_ipc_obj(ipcp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 requested_mode = (flag >> 6) | (flag >> 3) | flag;
541 granted_mode = ipcp->mode;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800542 if (uid_eq(euid, ipcp->cuid) ||
543 uid_eq(euid, ipcp->uid))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 granted_mode >>= 6;
545 else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
546 granted_mode >>= 3;
547 /* is there some bit set in requested_mode but not in granted_mode? */
548 if ((requested_mode & ~granted_mode & 0007) &&
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700549 !ns_capable(ns->user_ns, CAP_IPC_OWNER))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 return -1;
551
552 return security_ipc_permission(ipcp, flag);
553}
554
555/*
556 * Functions to convert between the kern_ipc_perm structure and the
557 * old/new ipc_perm structures
558 */
559
560/**
561 * kernel_to_ipc64_perm - convert kernel ipc permissions to user
562 * @in: kernel permissions
563 * @out: new style IPC permissions
564 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800565 * Turn the kernel object @in into a set of permissions descriptions
566 * for returning to userspace (@out).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 */
568
569
570void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
571{
572 out->key = in->key;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800573 out->uid = from_kuid_munged(current_user_ns(), in->uid);
574 out->gid = from_kgid_munged(current_user_ns(), in->gid);
575 out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
576 out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 out->mode = in->mode;
578 out->seq = in->seq;
579}
580
581/**
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700582 * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 * @in: new style IPC permissions
584 * @out: old style IPC permissions
585 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800586 * Turn the new style permissions object @in into a compatibility
587 * object and store it into the @out pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 */
589
590void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
591{
592 out->key = in->key;
593 SET_UID(out->uid, in->uid);
594 SET_GID(out->gid, in->gid);
595 SET_UID(out->cuid, in->cuid);
596 SET_GID(out->cgid, in->cgid);
597 out->mode = in->mode;
598 out->seq = in->seq;
599}
600
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700601/**
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700602 * ipc_obtain_object
603 * @ids: ipc identifier set
604 * @id: ipc id to look for
605 *
606 * Look for an id in the ipc ids idr and return associated ipc object.
607 *
608 * Call inside the RCU critical section.
609 * The ipc object is *not* locked on exit.
610 */
611struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id)
612{
613 struct kern_ipc_perm *out;
614 int lid = ipcid_to_idx(id);
615
616 out = idr_find(&ids->ipcs_idr, lid);
617 if (!out)
618 return ERR_PTR(-EINVAL);
619
620 return out;
621}
622
623/**
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700624 * ipc_lock - Lock an ipc structure without rwsem held
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700625 * @ids: IPC identifier set
626 * @id: ipc id to look for
627 *
628 * Look for an id in the ipc ids idr and lock the associated ipc object.
629 *
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700630 * The ipc object is locked on successful exit.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700631 */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700632struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700634 struct kern_ipc_perm *out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
636 rcu_read_lock();
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700637 out = ipc_obtain_object(ids, id);
638 if (IS_ERR(out))
639 goto err1;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700640
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 spin_lock(&out->lock);
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700642
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 /* ipc_rmid() may have already freed the ID while ipc_lock
644 * was spinning: here verify that the structure is still valid
645 */
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700646 if (!out->deleted)
647 return out;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700648
Davidlohr Bueso4d2bff52013-04-30 19:15:19 -0700649 spin_unlock(&out->lock);
650 out = ERR_PTR(-EINVAL);
651err1:
652 rcu_read_unlock();
653 return out;
654}
655
656/**
657 * ipc_obtain_object_check
658 * @ids: ipc identifier set
659 * @id: ipc id to look for
660 *
661 * Similar to ipc_obtain_object() but also checks
662 * the ipc object reference counter.
663 *
664 * Call inside the RCU critical section.
665 * The ipc object is *not* locked on exit.
666 */
667struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
668{
669 struct kern_ipc_perm *out = ipc_obtain_object(ids, id);
670
671 if (IS_ERR(out))
672 goto out;
673
674 if (ipc_checkid(out, id))
675 return ERR_PTR(-EIDRM);
676out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 return out;
678}
679
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800680struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id)
681{
682 struct kern_ipc_perm *out;
683
684 out = ipc_lock(ids, id);
685 if (IS_ERR(out))
686 return out;
687
688 if (ipc_checkid(out, id)) {
689 ipc_unlock(out);
690 return ERR_PTR(-EIDRM);
691 }
692
693 return out;
694}
695
696/**
697 * ipcget - Common sys_*get() code
698 * @ns : namsepace
699 * @ids : IPC identifier set
700 * @ops : operations to be called on ipc object creation, permission checks
701 * and further checks
702 * @params : the parameters needed by the previous operations.
703 *
704 * Common routine called by sys_msgget(), sys_semget() and sys_shmget().
705 */
706int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
707 struct ipc_ops *ops, struct ipc_params *params)
708{
709 if (params->key == IPC_PRIVATE)
710 return ipcget_new(ns, ids, ops, params);
711 else
712 return ipcget_public(ns, ids, ops, params);
713}
714
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700715/**
716 * ipc_update_perm - update the permissions of an IPC.
717 * @in: the permission given as input.
718 * @out: the permission of the ipc to set.
719 */
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800720int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700721{
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800722 kuid_t uid = make_kuid(current_user_ns(), in->uid);
723 kgid_t gid = make_kgid(current_user_ns(), in->gid);
724 if (!uid_valid(uid) || !gid_valid(gid))
725 return -EINVAL;
726
727 out->uid = uid;
728 out->gid = gid;
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700729 out->mode = (out->mode & ~S_IRWXUGO)
730 | (in->mode & S_IRWXUGO);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800731
732 return 0;
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700733}
734
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700735/**
Davidlohr Bueso3b1c4ad2013-09-11 14:26:17 -0700736 * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700737 * @ns: the ipc namespace
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700738 * @ids: the table of ids where to look for the ipc
739 * @id: the id of the ipc to retrieve
740 * @cmd: the cmd to check
741 * @perm: the permission to set
742 * @extra_perm: one extra permission parameter used by msq
743 *
744 * This function does some common audit and permissions check for some IPC_XXX
745 * cmd and is called from semctl_down, shmctl_down and msgctl_down.
746 * It must be called without any lock held and
747 * - retrieves the ipc with the given id in the given table.
748 * - performs some audit and permission check, depending on the given cmd
Davidlohr Bueso3b1c4ad2013-09-11 14:26:17 -0700749 * - returns a pointer to the ipc object or otherwise, the corresponding error.
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700750 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700751 * Call holding the both the rwsem and the rcu read lock.
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700752 */
Davidlohr Bueso444d0f62013-04-30 19:15:24 -0700753struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
Davidlohr Bueso3b1c4ad2013-09-11 14:26:17 -0700754 struct ipc_ids *ids, int id, int cmd,
755 struct ipc64_perm *perm, int extra_perm)
Davidlohr Bueso444d0f62013-04-30 19:15:24 -0700756{
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800757 kuid_t euid;
Davidlohr Bueso444d0f62013-04-30 19:15:24 -0700758 int err = -EPERM;
759 struct kern_ipc_perm *ipcp;
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700760
Davidlohr Bueso444d0f62013-04-30 19:15:24 -0700761 ipcp = ipc_obtain_object_check(ids, id);
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700762 if (IS_ERR(ipcp)) {
763 err = PTR_ERR(ipcp);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700764 goto err;
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700765 }
766
Al Viroa33e6752008-12-10 03:40:06 -0500767 audit_ipc_obj(ipcp);
Al Viroe816f372008-12-10 03:47:15 -0500768 if (cmd == IPC_SET)
769 audit_ipc_set_perm(extra_perm, perm->uid,
Davidlohr Bueso444d0f62013-04-30 19:15:24 -0700770 perm->gid, perm->mode);
David Howells414c0702008-11-14 10:39:06 +1100771
772 euid = current_euid();
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800773 if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700774 ns_capable(ns->user_ns, CAP_SYS_ADMIN))
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700775 return ipcp; /* successful lookup */
776err:
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700777 return ERR_PTR(err);
778}
779
Will Deaconc1d7e012012-07-30 14:42:46 -0700780#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781
782
783/**
784 * ipc_parse_version - IPC call version
785 * @cmd: pointer to command
786 *
787 * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800788 * The @cmd value is turned from an encoding command and version into
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 * just the command code.
790 */
791
792int ipc_parse_version (int *cmd)
793{
794 if (*cmd & IPC_64) {
795 *cmd ^= IPC_64;
796 return IPC_64;
797 } else {
798 return IPC_OLD;
799 }
800}
801
Will Deaconc1d7e012012-07-30 14:42:46 -0700802#endif /* CONFIG_ARCH_WANT_IPC_PARSE_VERSION */
Mike Waychisonae781772005-09-06 15:17:09 -0700803
804#ifdef CONFIG_PROC_FS
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800805struct ipc_proc_iter {
806 struct ipc_namespace *ns;
807 struct ipc_proc_iface *iface;
808};
809
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700810/*
811 * This routine locks the ipc structure found at least at position pos.
812 */
Adrian Bunkb524b9a2008-02-06 01:36:28 -0800813static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
814 loff_t *new_pos)
Mike Waychisonae781772005-09-06 15:17:09 -0700815{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700816 struct kern_ipc_perm *ipc;
817 int total, id;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700818
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700819 total = 0;
820 for (id = 0; id < pos && total < ids->in_use; id++) {
821 ipc = idr_find(&ids->ipcs_idr, id);
822 if (ipc != NULL)
823 total++;
824 }
Mike Waychisonae781772005-09-06 15:17:09 -0700825
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700826 if (total >= ids->in_use)
827 return NULL;
Mike Waychisonae781772005-09-06 15:17:09 -0700828
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700829 for ( ; pos < IPCMNI; pos++) {
830 ipc = idr_find(&ids->ipcs_idr, pos);
831 if (ipc != NULL) {
832 *new_pos = pos + 1;
833 ipc_lock_by_ptr(ipc);
Mike Waychisonae781772005-09-06 15:17:09 -0700834 return ipc;
835 }
836 }
837
838 /* Out of range - return NULL to terminate iteration */
839 return NULL;
840}
841
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700842static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
843{
844 struct ipc_proc_iter *iter = s->private;
845 struct ipc_proc_iface *iface = iter->iface;
846 struct kern_ipc_perm *ipc = it;
847
848 /* If we had an ipc id locked before, unlock it */
849 if (ipc && ipc != SEQ_START_TOKEN)
850 ipc_unlock(ipc);
851
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800852 return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700853}
854
Mike Waychisonae781772005-09-06 15:17:09 -0700855/*
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700856 * File positions: pos 0 -> header, pos n -> ipc id = n - 1.
857 * SeqFile iterator: iterator value locked ipc pointer or SEQ_TOKEN_START.
Mike Waychisonae781772005-09-06 15:17:09 -0700858 */
859static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
860{
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800861 struct ipc_proc_iter *iter = s->private;
862 struct ipc_proc_iface *iface = iter->iface;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700863 struct ipc_ids *ids;
864
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800865 ids = &iter->ns->ids[iface->ids];
Mike Waychisonae781772005-09-06 15:17:09 -0700866
867 /*
868 * Take the lock - this will be released by the corresponding
869 * call to stop().
870 */
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700871 down_read(&ids->rwsem);
Mike Waychisonae781772005-09-06 15:17:09 -0700872
873 /* pos < 0 is invalid */
874 if (*pos < 0)
875 return NULL;
876
877 /* pos == 0 means header */
878 if (*pos == 0)
879 return SEQ_START_TOKEN;
880
881 /* Find the (pos-1)th ipc */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700882 return sysvipc_find_ipc(ids, *pos - 1, pos);
Mike Waychisonae781772005-09-06 15:17:09 -0700883}
884
885static void sysvipc_proc_stop(struct seq_file *s, void *it)
886{
887 struct kern_ipc_perm *ipc = it;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800888 struct ipc_proc_iter *iter = s->private;
889 struct ipc_proc_iface *iface = iter->iface;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700890 struct ipc_ids *ids;
Mike Waychisonae781772005-09-06 15:17:09 -0700891
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700892 /* If we had a locked structure, release it */
Mike Waychisonae781772005-09-06 15:17:09 -0700893 if (ipc && ipc != SEQ_START_TOKEN)
894 ipc_unlock(ipc);
895
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800896 ids = &iter->ns->ids[iface->ids];
Mike Waychisonae781772005-09-06 15:17:09 -0700897 /* Release the lock we took in start() */
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700898 up_read(&ids->rwsem);
Mike Waychisonae781772005-09-06 15:17:09 -0700899}
900
901static int sysvipc_proc_show(struct seq_file *s, void *it)
902{
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800903 struct ipc_proc_iter *iter = s->private;
904 struct ipc_proc_iface *iface = iter->iface;
Mike Waychisonae781772005-09-06 15:17:09 -0700905
906 if (it == SEQ_START_TOKEN)
907 return seq_puts(s, iface->header);
908
909 return iface->show(s, it);
910}
911
James Morris88e9d342009-09-22 16:43:43 -0700912static const struct seq_operations sysvipc_proc_seqops = {
Mike Waychisonae781772005-09-06 15:17:09 -0700913 .start = sysvipc_proc_start,
914 .stop = sysvipc_proc_stop,
915 .next = sysvipc_proc_next,
916 .show = sysvipc_proc_show,
917};
918
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800919static int sysvipc_proc_open(struct inode *inode, struct file *file)
920{
Mike Waychisonae781772005-09-06 15:17:09 -0700921 int ret;
922 struct seq_file *seq;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800923 struct ipc_proc_iter *iter;
924
925 ret = -ENOMEM;
926 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
927 if (!iter)
928 goto out;
Mike Waychisonae781772005-09-06 15:17:09 -0700929
930 ret = seq_open(file, &sysvipc_proc_seqops);
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800931 if (ret)
932 goto out_kfree;
933
934 seq = file->private_data;
935 seq->private = iter;
936
Al Virod9dda782013-03-31 18:16:14 -0400937 iter->iface = PDE_DATA(inode);
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800938 iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
939out:
Mike Waychisonae781772005-09-06 15:17:09 -0700940 return ret;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800941out_kfree:
942 kfree(iter);
943 goto out;
944}
945
946static int sysvipc_proc_release(struct inode *inode, struct file *file)
947{
948 struct seq_file *seq = file->private_data;
949 struct ipc_proc_iter *iter = seq->private;
950 put_ipc_ns(iter->ns);
951 return seq_release_private(inode, file);
Mike Waychisonae781772005-09-06 15:17:09 -0700952}
953
Arjan van de Ven9a321442007-02-12 00:55:35 -0800954static const struct file_operations sysvipc_proc_fops = {
Mike Waychisonae781772005-09-06 15:17:09 -0700955 .open = sysvipc_proc_open,
956 .read = seq_read,
957 .llseek = seq_lseek,
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800958 .release = sysvipc_proc_release,
Mike Waychisonae781772005-09-06 15:17:09 -0700959};
960#endif /* CONFIG_PROC_FS */