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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>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080026#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/highuid.h>
28#include <linux/security.h>
29#include <linux/rcupdate.h>
30#include <linux/workqueue.h>
Mike Waychisonae781772005-09-06 15:17:09 -070031#include <linux/seq_file.h>
32#include <linux/proc_fs.h>
Steve Grubb073115d2006-04-02 17:07:33 -040033#include <linux/audit.h>
Kirill Korotaev73ea4132006-10-02 02:18:20 -070034#include <linux/nsproxy.h>
Nadia Derbey3e148c72007-10-18 23:40:54 -070035#include <linux/rwsem.h>
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070036#include <linux/memory.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080037#include <linux/ipc_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#include <asm/unistd.h>
40
41#include "util.h"
42
Mike Waychisonae781772005-09-06 15:17:09 -070043struct ipc_proc_iface {
44 const char *path;
45 const char *header;
Kirill Korotaev73ea4132006-10-02 02:18:20 -070046 int ids;
Mike Waychisonae781772005-09-06 15:17:09 -070047 int (*show)(struct seq_file *, void *);
48};
49
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070050#ifdef CONFIG_MEMORY_HOTPLUG
51
Nadia Derbey424450c2008-04-29 01:00:43 -070052static void ipc_memory_notifier(struct work_struct *work)
53{
54 ipcns_notify(IPCNS_MEMCHANGED);
55}
56
57static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
58
59
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070060static int ipc_memory_callback(struct notifier_block *self,
61 unsigned long action, void *arg)
62{
63 switch (action) {
64 case MEM_ONLINE: /* memory successfully brought online */
65 case MEM_OFFLINE: /* or offline: it's time to recompute msgmni */
66 /*
67 * This is done by invoking the ipcns notifier chain with the
68 * IPC_MEMCHANGED event.
Nadia Derbey424450c2008-04-29 01:00:43 -070069 * In order not to keep the lock on the hotplug memory chain
70 * for too long, queue a work item that will, when waken up,
71 * activate the ipcns notification chain.
72 * No need to keep several ipc work items on the queue.
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070073 */
Nadia Derbey424450c2008-04-29 01:00:43 -070074 if (!work_pending(&ipc_memory_wq))
75 schedule_work(&ipc_memory_wq);
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070076 break;
77 case MEM_GOING_ONLINE:
78 case MEM_GOING_OFFLINE:
79 case MEM_CANCEL_ONLINE:
80 case MEM_CANCEL_OFFLINE:
81 default:
82 break;
83 }
84
85 return NOTIFY_OK;
86}
87
88#endif /* CONFIG_MEMORY_HOTPLUG */
89
Linus Torvalds1da177e2005-04-16 15:20:36 -070090/**
91 * ipc_init - initialise IPC subsystem
92 *
93 * The various system5 IPC resources (semaphores, messages and shared
Robert P. J. Day72fd4a32007-02-10 01:45:59 -080094 * memory) are initialised
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070095 * A callback routine is registered into the memory hotplug notifier
96 * chain: since msgmni scales to lowmem this callback routine will be
97 * called upon successful memory add / remove to recompute msmgni.
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 */
99
100static int __init ipc_init(void)
101{
102 sem_init();
103 msg_init();
104 shm_init();
Nadia Derbeyb6b337a2008-04-29 01:00:42 -0700105 hotplug_memory_notifier(ipc_memory_callback, IPC_CALLBACK_PRI);
106 register_ipcns_notifier(&init_ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 return 0;
108}
109__initcall(ipc_init);
110
111/**
112 * ipc_init_ids - initialise IPC identifiers
113 * @ids: Identifier set
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 *
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700115 * Set up the sequence range to use for the ipc identifier range (limited
116 * below IPCMNI) then initialise the ids idr.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 */
118
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700119void ipc_init_ids(struct ipc_ids *ids)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120{
Nadia Derbey3e148c72007-10-18 23:40:54 -0700121 init_rwsem(&ids->rw_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 ids->in_use = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 ids->seq = 0;
125 {
126 int seq_limit = INT_MAX/SEQ_MULTIPLIER;
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700127 if (seq_limit > USHRT_MAX)
128 ids->seq_max = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 else
130 ids->seq_max = seq_limit;
131 }
132
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700133 idr_init(&ids->ipcs_idr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134}
135
Mike Waychisonae781772005-09-06 15:17:09 -0700136#ifdef CONFIG_PROC_FS
Arjan van de Ven9a321442007-02-12 00:55:35 -0800137static const struct file_operations sysvipc_proc_fops;
Mike Waychisonae781772005-09-06 15:17:09 -0700138/**
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800139 * ipc_init_proc_interface - Create a proc interface for sysipc types using a seq_file interface.
Mike Waychisonae781772005-09-06 15:17:09 -0700140 * @path: Path in procfs
141 * @header: Banner to be printed at the beginning of the file.
142 * @ids: ipc id table to iterate.
143 * @show: show routine.
144 */
145void __init ipc_init_proc_interface(const char *path, const char *header,
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700146 int ids, int (*show)(struct seq_file *, void *))
Mike Waychisonae781772005-09-06 15:17:09 -0700147{
148 struct proc_dir_entry *pde;
149 struct ipc_proc_iface *iface;
150
151 iface = kmalloc(sizeof(*iface), GFP_KERNEL);
152 if (!iface)
153 return;
154 iface->path = path;
155 iface->header = header;
156 iface->ids = ids;
157 iface->show = show;
158
Denis V. Lunev6a6375d2008-04-29 01:02:12 -0700159 pde = proc_create_data(path,
160 S_IRUGO, /* world readable */
161 NULL, /* parent dir */
162 &sysvipc_proc_fops,
163 iface);
164 if (!pde) {
Mike Waychisonae781772005-09-06 15:17:09 -0700165 kfree(iface);
166 }
167}
168#endif
169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170/**
171 * ipc_findkey - find a key in an ipc identifier set
172 * @ids: Identifier set
173 * @key: The key to find
174 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700175 * Requires ipc_ids.rw_mutex locked.
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700176 * Returns the LOCKED pointer to the ipc structure if found or NULL
177 * if not.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700178 * If key is found ipc points to the owning ipc structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 */
180
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700181static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700183 struct kern_ipc_perm *ipc;
184 int next_id;
185 int total;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700187 for (total = 0, next_id = 0; total < ids->in_use; next_id++) {
188 ipc = idr_find(&ids->ipcs_idr, next_id);
189
190 if (ipc == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 continue;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700192
193 if (ipc->key != key) {
194 total++;
195 continue;
196 }
197
198 ipc_lock_by_ptr(ipc);
199 return ipc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700201
202 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203}
204
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700205/**
206 * ipc_get_maxid - get the last assigned id
207 * @ids: IPC identifier set
208 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700209 * Called with ipc_ids.rw_mutex held.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700211
212int ipc_get_maxid(struct ipc_ids *ids)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700214 struct kern_ipc_perm *ipc;
215 int max_id = -1;
216 int total, id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700218 if (ids->in_use == 0)
219 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700221 if (ids->in_use == IPCMNI)
222 return IPCMNI - 1;
223
224 /* Look for the last assigned id */
225 total = 0;
226 for (id = 0; id < IPCMNI && total < ids->in_use; id++) {
227 ipc = idr_find(&ids->ipcs_idr, id);
228 if (ipc != NULL) {
229 max_id = id;
230 total++;
231 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700233 return max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234}
235
236/**
237 * ipc_addid - add an IPC identifier
238 * @ids: IPC identifier set
239 * @new: new IPC permission set
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700240 * @size: limit for the number of used ids
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700242 * Add an entry 'new' to the IPC ids idr. The permissions object is
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 * initialised and the first free entry is set up and the id assigned
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700244 * is returned. The 'new' entry is returned in a locked state on success.
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700245 * On failure the entry is not locked and a negative err-code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700247 * Called with ipc_ids.rw_mutex held as a writer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 */
249
250int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
251{
David Howells414c0702008-11-14 10:39:06 +1100252 uid_t euid;
253 gid_t egid;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700254 int id, err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700256 if (size > IPCMNI)
257 size = IPCMNI;
258
259 if (ids->in_use >= size)
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700260 return -ENOSPC;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700261
Nadia Derbeye00b4ff7e2008-11-19 15:36:08 -0800262 spin_lock_init(&new->lock);
263 new->deleted = 0;
264 rcu_read_lock();
265 spin_lock(&new->lock);
266
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700267 err = idr_get_new(&ids->ipcs_idr, new, &id);
Nadia Derbeye00b4ff7e2008-11-19 15:36:08 -0800268 if (err) {
269 spin_unlock(&new->lock);
270 rcu_read_unlock();
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700271 return err;
Nadia Derbeye00b4ff7e2008-11-19 15:36:08 -0800272 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 ids->in_use++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
David Howells414c0702008-11-14 10:39:06 +1100276 current_euid_egid(&euid, &egid);
277 new->cuid = new->uid = euid;
278 new->gid = new->cgid = egid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
280 new->seq = ids->seq++;
281 if(ids->seq > ids->seq_max)
282 ids->seq = 0;
283
Pierre Peiffer48dea402008-04-29 01:00:35 -0700284 new->id = ipc_buildid(id, new->seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 return id;
286}
287
288/**
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700289 * ipcget_new - create a new ipc object
290 * @ns: namespace
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700291 * @ids: IPC identifer set
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700292 * @ops: the actual creation routine to call
293 * @params: its parameters
294 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700295 * This routine is called by sys_msgget, sys_semget() and sys_shmget()
296 * when the key is IPC_PRIVATE.
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700297 */
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800298static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700299 struct ipc_ops *ops, struct ipc_params *params)
300{
301 int err;
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700302retry:
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700303 err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
304
305 if (!err)
306 return -ENOMEM;
307
Nadia Derbey3e148c72007-10-18 23:40:54 -0700308 down_write(&ids->rw_mutex);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700309 err = ops->getnew(ns, params);
Nadia Derbey3e148c72007-10-18 23:40:54 -0700310 up_write(&ids->rw_mutex);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700311
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700312 if (err == -EAGAIN)
313 goto retry;
314
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700315 return err;
316}
317
318/**
319 * ipc_check_perms - check security and permissions for an IPC
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700320 * @ns: IPC namespace
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700321 * @ipcp: ipc permission set
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700322 * @ops: the actual security routine to call
323 * @params: its parameters
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700324 *
325 * This routine is called by sys_msgget(), sys_semget() and sys_shmget()
326 * when the key is not IPC_PRIVATE and that key already exists in the
327 * ids IDR.
328 *
329 * On success, the IPC id is returned.
330 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700331 * It is called with ipc_ids.rw_mutex and ipcp->lock held.
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700332 */
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700333static int ipc_check_perms(struct ipc_namespace *ns,
334 struct kern_ipc_perm *ipcp,
335 struct ipc_ops *ops,
336 struct ipc_params *params)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700337{
338 int err;
339
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700340 if (ipcperms(ns, ipcp, params->flg))
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700341 err = -EACCES;
342 else {
343 err = ops->associate(ipcp, params->flg);
344 if (!err)
345 err = ipcp->id;
346 }
347
348 return err;
349}
350
351/**
352 * ipcget_public - get an ipc object or create a new one
353 * @ns: namespace
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700354 * @ids: IPC identifer set
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700355 * @ops: the actual creation routine to call
356 * @params: its parameters
357 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700358 * This routine is called by sys_msgget, sys_semget() and sys_shmget()
359 * when the key is not IPC_PRIVATE.
360 * It adds a new entry if the key is not found and does some permission
361 * / security checkings if the key is found.
362 *
363 * On success, the ipc id is returned.
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700364 */
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800365static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700366 struct ipc_ops *ops, struct ipc_params *params)
367{
368 struct kern_ipc_perm *ipcp;
369 int flg = params->flg;
370 int err;
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700371retry:
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700372 err = idr_pre_get(&ids->ipcs_idr, GFP_KERNEL);
373
Nadia Derbey3e148c72007-10-18 23:40:54 -0700374 /*
375 * Take the lock as a writer since we are potentially going to add
376 * a new entry + read locks are not "upgradable"
377 */
378 down_write(&ids->rw_mutex);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700379 ipcp = ipc_findkey(ids, params->key);
380 if (ipcp == NULL) {
381 /* key not used */
382 if (!(flg & IPC_CREAT))
383 err = -ENOENT;
384 else if (!err)
385 err = -ENOMEM;
386 else
387 err = ops->getnew(ns, params);
388 } else {
389 /* ipc object has been locked by ipc_findkey() */
390
391 if (flg & IPC_CREAT && flg & IPC_EXCL)
392 err = -EEXIST;
393 else {
394 err = 0;
395 if (ops->more_checks)
396 err = ops->more_checks(ipcp, params);
397 if (!err)
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700398 /*
399 * ipc_check_perms returns the IPC id on
400 * success
401 */
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700402 err = ipc_check_perms(ns, ipcp, ops, params);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700403 }
404 ipc_unlock(ipcp);
405 }
Nadia Derbey3e148c72007-10-18 23:40:54 -0700406 up_write(&ids->rw_mutex);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700407
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700408 if (err == -EAGAIN)
409 goto retry;
410
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700411 return err;
412}
413
414
415/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 * ipc_rmid - remove an IPC identifier
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700417 * @ids: IPC identifier set
418 * @ipcp: ipc perm structure containing the identifier to remove
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700420 * ipc_ids.rw_mutex (as a writer) and the spinlock for this ID are held
421 * before this function is called, and remain locked on the exit.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 */
423
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700424void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425{
Nadia Derbeyce621f52007-10-18 23:40:52 -0700426 int lid = ipcid_to_idx(ipcp->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700428 idr_remove(&ids->ipcs_idr, lid);
429
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 ids->in_use--;
431
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700432 ipcp->deleted = 1;
433
434 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435}
436
437/**
438 * ipc_alloc - allocate ipc space
439 * @size: size desired
440 *
441 * Allocate memory from the appropriate pools and return a pointer to it.
442 * NULL is returned if the allocation fails
443 */
444
445void* ipc_alloc(int size)
446{
447 void* out;
448 if(size > PAGE_SIZE)
449 out = vmalloc(size);
450 else
451 out = kmalloc(size, GFP_KERNEL);
452 return out;
453}
454
455/**
456 * ipc_free - free ipc space
457 * @ptr: pointer returned by ipc_alloc
458 * @size: size of block
459 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800460 * Free a block created with ipc_alloc(). The caller must know the size
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 * used in the allocation call.
462 */
463
464void ipc_free(void* ptr, int size)
465{
466 if(size > PAGE_SIZE)
467 vfree(ptr);
468 else
469 kfree(ptr);
470}
471
472/*
473 * rcu allocations:
474 * There are three headers that are prepended to the actual allocation:
475 * - during use: ipc_rcu_hdr.
476 * - during the rcu grace period: ipc_rcu_grace.
477 * - [only if vmalloc]: ipc_rcu_sched.
478 * Their lifetime doesn't overlap, thus the headers share the same memory.
479 * Unlike a normal union, they are right-aligned, thus some container_of
480 * forward/backward casting is necessary:
481 */
482struct ipc_rcu_hdr
483{
484 int refcount;
485 int is_vmalloc;
486 void *data[0];
487};
488
489
490struct ipc_rcu_grace
491{
492 struct rcu_head rcu;
493 /* "void *" makes sure alignment of following data is sane. */
494 void *data[0];
495};
496
497struct ipc_rcu_sched
498{
499 struct work_struct work;
500 /* "void *" makes sure alignment of following data is sane. */
501 void *data[0];
502};
503
504#define HDRLEN_KMALLOC (sizeof(struct ipc_rcu_grace) > sizeof(struct ipc_rcu_hdr) ? \
505 sizeof(struct ipc_rcu_grace) : sizeof(struct ipc_rcu_hdr))
506#define HDRLEN_VMALLOC (sizeof(struct ipc_rcu_sched) > HDRLEN_KMALLOC ? \
507 sizeof(struct ipc_rcu_sched) : HDRLEN_KMALLOC)
508
509static inline int rcu_use_vmalloc(int size)
510{
511 /* Too big for a single page? */
512 if (HDRLEN_KMALLOC + size > PAGE_SIZE)
513 return 1;
514 return 0;
515}
516
517/**
518 * ipc_rcu_alloc - allocate ipc and rcu space
519 * @size: size desired
520 *
521 * Allocate memory for the rcu header structure + the object.
522 * Returns the pointer to the object.
523 * NULL is returned if the allocation fails.
524 */
525
526void* ipc_rcu_alloc(int size)
527{
528 void* out;
529 /*
530 * We prepend the allocation with the rcu struct, and
531 * workqueue if necessary (for vmalloc).
532 */
533 if (rcu_use_vmalloc(size)) {
534 out = vmalloc(HDRLEN_VMALLOC + size);
535 if (out) {
536 out += HDRLEN_VMALLOC;
537 container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 1;
538 container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
539 }
540 } else {
541 out = kmalloc(HDRLEN_KMALLOC + size, GFP_KERNEL);
542 if (out) {
543 out += HDRLEN_KMALLOC;
544 container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 0;
545 container_of(out, struct ipc_rcu_hdr, data)->refcount = 1;
546 }
547 }
548
549 return out;
550}
551
552void ipc_rcu_getref(void *ptr)
553{
554 container_of(ptr, struct ipc_rcu_hdr, data)->refcount++;
555}
556
David Howells65f27f32006-11-22 14:55:48 +0000557static void ipc_do_vfree(struct work_struct *work)
558{
559 vfree(container_of(work, struct ipc_rcu_sched, work));
560}
561
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562/**
Randy Dunlap1e5d5332005-11-07 01:01:06 -0800563 * ipc_schedule_free - free ipc + rcu space
564 * @head: RCU callback structure for queued work
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 *
566 * Since RCU callback function is called in bh,
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800567 * we need to defer the vfree to schedule_work().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 */
569static void ipc_schedule_free(struct rcu_head *head)
570{
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700571 struct ipc_rcu_grace *grace;
572 struct ipc_rcu_sched *sched;
573
574 grace = container_of(head, struct ipc_rcu_grace, rcu);
575 sched = container_of(&(grace->data[0]), struct ipc_rcu_sched,
576 data[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577
David Howells65f27f32006-11-22 14:55:48 +0000578 INIT_WORK(&sched->work, ipc_do_vfree);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 schedule_work(&sched->work);
580}
581
582/**
Randy Dunlap1e5d5332005-11-07 01:01:06 -0800583 * ipc_immediate_free - free ipc + rcu space
584 * @head: RCU callback structure that contains pointer to be freed
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800586 * Free from the RCU callback context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 */
588static void ipc_immediate_free(struct rcu_head *head)
589{
590 struct ipc_rcu_grace *free =
591 container_of(head, struct ipc_rcu_grace, rcu);
592 kfree(free);
593}
594
595void ipc_rcu_putref(void *ptr)
596{
597 if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0)
598 return;
599
600 if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) {
601 call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
602 ipc_schedule_free);
603 } else {
604 call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
605 ipc_immediate_free);
606 }
607}
608
609/**
610 * ipcperms - check IPC permissions
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700611 * @ns: IPC namespace
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 * @ipcp: IPC permission set
613 * @flag: desired permission set.
614 *
615 * Check user, group, other permissions for access
616 * to ipc resources. return 0 if allowed
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700617 *
618 * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 */
620
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700621int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
622{
David Howells414c0702008-11-14 10:39:06 +1100623 uid_t euid = current_euid();
Al Viroa33e6752008-12-10 03:40:06 -0500624 int requested_mode, granted_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
Al Viroa33e6752008-12-10 03:40:06 -0500626 audit_ipc_obj(ipcp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 requested_mode = (flag >> 6) | (flag >> 3) | flag;
628 granted_mode = ipcp->mode;
David Howells414c0702008-11-14 10:39:06 +1100629 if (euid == ipcp->cuid ||
630 euid == ipcp->uid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 granted_mode >>= 6;
632 else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
633 granted_mode >>= 3;
634 /* is there some bit set in requested_mode but not in granted_mode? */
635 if ((requested_mode & ~granted_mode & 0007) &&
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700636 !ns_capable(ns->user_ns, CAP_IPC_OWNER))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 return -1;
638
639 return security_ipc_permission(ipcp, flag);
640}
641
642/*
643 * Functions to convert between the kern_ipc_perm structure and the
644 * old/new ipc_perm structures
645 */
646
647/**
648 * kernel_to_ipc64_perm - convert kernel ipc permissions to user
649 * @in: kernel permissions
650 * @out: new style IPC permissions
651 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800652 * Turn the kernel object @in into a set of permissions descriptions
653 * for returning to userspace (@out).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 */
655
656
657void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
658{
659 out->key = in->key;
660 out->uid = in->uid;
661 out->gid = in->gid;
662 out->cuid = in->cuid;
663 out->cgid = in->cgid;
664 out->mode = in->mode;
665 out->seq = in->seq;
666}
667
668/**
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700669 * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 * @in: new style IPC permissions
671 * @out: old style IPC permissions
672 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800673 * Turn the new style permissions object @in into a compatibility
674 * object and store it into the @out pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 */
676
677void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
678{
679 out->key = in->key;
680 SET_UID(out->uid, in->uid);
681 SET_GID(out->gid, in->gid);
682 SET_UID(out->cuid, in->cuid);
683 SET_GID(out->cgid, in->cgid);
684 out->mode = in->mode;
685 out->seq = in->seq;
686}
687
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700688/**
Nadia Derbey3e148c72007-10-18 23:40:54 -0700689 * ipc_lock - Lock an ipc structure without rw_mutex held
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700690 * @ids: IPC identifier set
691 * @id: ipc id to look for
692 *
693 * Look for an id in the ipc ids idr and lock the associated ipc object.
694 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700695 * The ipc object is locked on exit.
696 */
697
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700698struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700700 struct kern_ipc_perm *out;
Nadia Derbeyce621f52007-10-18 23:40:52 -0700701 int lid = ipcid_to_idx(id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702
703 rcu_read_lock();
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700704 out = idr_find(&ids->ipcs_idr, lid);
705 if (out == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 rcu_read_unlock();
Nadia Derbey023a5352007-10-18 23:40:51 -0700707 return ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700709
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 spin_lock(&out->lock);
711
712 /* ipc_rmid() may have already freed the ID while ipc_lock
713 * was spinning: here verify that the structure is still valid
714 */
715 if (out->deleted) {
716 spin_unlock(&out->lock);
717 rcu_read_unlock();
Nadia Derbey023a5352007-10-18 23:40:51 -0700718 return ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700720
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 return out;
722}
723
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800724struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id)
725{
726 struct kern_ipc_perm *out;
727
728 out = ipc_lock(ids, id);
729 if (IS_ERR(out))
730 return out;
731
732 if (ipc_checkid(out, id)) {
733 ipc_unlock(out);
734 return ERR_PTR(-EIDRM);
735 }
736
737 return out;
738}
739
740/**
741 * ipcget - Common sys_*get() code
742 * @ns : namsepace
743 * @ids : IPC identifier set
744 * @ops : operations to be called on ipc object creation, permission checks
745 * and further checks
746 * @params : the parameters needed by the previous operations.
747 *
748 * Common routine called by sys_msgget(), sys_semget() and sys_shmget().
749 */
750int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
751 struct ipc_ops *ops, struct ipc_params *params)
752{
753 if (params->key == IPC_PRIVATE)
754 return ipcget_new(ns, ids, ops, params);
755 else
756 return ipcget_public(ns, ids, ops, params);
757}
758
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700759/**
760 * ipc_update_perm - update the permissions of an IPC.
761 * @in: the permission given as input.
762 * @out: the permission of the ipc to set.
763 */
764void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
765{
766 out->uid = in->uid;
767 out->gid = in->gid;
768 out->mode = (out->mode & ~S_IRWXUGO)
769 | (in->mode & S_IRWXUGO);
770}
771
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700772/**
773 * ipcctl_pre_down - retrieve an ipc and check permissions for some IPC_XXX cmd
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700774 * @ns: the ipc namespace
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700775 * @ids: the table of ids where to look for the ipc
776 * @id: the id of the ipc to retrieve
777 * @cmd: the cmd to check
778 * @perm: the permission to set
779 * @extra_perm: one extra permission parameter used by msq
780 *
781 * This function does some common audit and permissions check for some IPC_XXX
782 * cmd and is called from semctl_down, shmctl_down and msgctl_down.
783 * It must be called without any lock held and
784 * - retrieves the ipc with the given id in the given table.
785 * - performs some audit and permission check, depending on the given cmd
786 * - returns the ipc with both ipc and rw_mutex locks held in case of success
787 * or an err-code without any lock held otherwise.
788 */
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700789struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
790 struct ipc_ids *ids, int id, int cmd,
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700791 struct ipc64_perm *perm, int extra_perm)
792{
793 struct kern_ipc_perm *ipcp;
David Howells414c0702008-11-14 10:39:06 +1100794 uid_t euid;
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700795 int err;
796
797 down_write(&ids->rw_mutex);
Nadia Derbey00c2bf82008-07-25 01:48:03 -0700798 ipcp = ipc_lock_check(ids, id);
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700799 if (IS_ERR(ipcp)) {
800 err = PTR_ERR(ipcp);
801 goto out_up;
802 }
803
Al Viroa33e6752008-12-10 03:40:06 -0500804 audit_ipc_obj(ipcp);
Al Viroe816f372008-12-10 03:47:15 -0500805 if (cmd == IPC_SET)
806 audit_ipc_set_perm(extra_perm, perm->uid,
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700807 perm->gid, perm->mode);
David Howells414c0702008-11-14 10:39:06 +1100808
809 euid = current_euid();
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700810 if (euid == ipcp->cuid || euid == ipcp->uid ||
811 ns_capable(ns->user_ns, CAP_SYS_ADMIN))
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700812 return ipcp;
813
814 err = -EPERM;
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700815 ipc_unlock(ipcp);
816out_up:
817 up_write(&ids->rw_mutex);
818 return ERR_PTR(err);
819}
820
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821#ifdef __ARCH_WANT_IPC_PARSE_VERSION
822
823
824/**
825 * ipc_parse_version - IPC call version
826 * @cmd: pointer to command
827 *
828 * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800829 * The @cmd value is turned from an encoding command and version into
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830 * just the command code.
831 */
832
833int ipc_parse_version (int *cmd)
834{
835 if (*cmd & IPC_64) {
836 *cmd ^= IPC_64;
837 return IPC_64;
838 } else {
839 return IPC_OLD;
840 }
841}
842
843#endif /* __ARCH_WANT_IPC_PARSE_VERSION */
Mike Waychisonae781772005-09-06 15:17:09 -0700844
845#ifdef CONFIG_PROC_FS
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800846struct ipc_proc_iter {
847 struct ipc_namespace *ns;
848 struct ipc_proc_iface *iface;
849};
850
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700851/*
852 * This routine locks the ipc structure found at least at position pos.
853 */
Adrian Bunkb524b9a2008-02-06 01:36:28 -0800854static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
855 loff_t *new_pos)
Mike Waychisonae781772005-09-06 15:17:09 -0700856{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700857 struct kern_ipc_perm *ipc;
858 int total, id;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700859
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700860 total = 0;
861 for (id = 0; id < pos && total < ids->in_use; id++) {
862 ipc = idr_find(&ids->ipcs_idr, id);
863 if (ipc != NULL)
864 total++;
865 }
Mike Waychisonae781772005-09-06 15:17:09 -0700866
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700867 if (total >= ids->in_use)
868 return NULL;
Mike Waychisonae781772005-09-06 15:17:09 -0700869
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700870 for ( ; pos < IPCMNI; pos++) {
871 ipc = idr_find(&ids->ipcs_idr, pos);
872 if (ipc != NULL) {
873 *new_pos = pos + 1;
874 ipc_lock_by_ptr(ipc);
Mike Waychisonae781772005-09-06 15:17:09 -0700875 return ipc;
876 }
877 }
878
879 /* Out of range - return NULL to terminate iteration */
880 return NULL;
881}
882
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700883static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
884{
885 struct ipc_proc_iter *iter = s->private;
886 struct ipc_proc_iface *iface = iter->iface;
887 struct kern_ipc_perm *ipc = it;
888
889 /* If we had an ipc id locked before, unlock it */
890 if (ipc && ipc != SEQ_START_TOKEN)
891 ipc_unlock(ipc);
892
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800893 return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700894}
895
Mike Waychisonae781772005-09-06 15:17:09 -0700896/*
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700897 * File positions: pos 0 -> header, pos n -> ipc id = n - 1.
898 * SeqFile iterator: iterator value locked ipc pointer or SEQ_TOKEN_START.
Mike Waychisonae781772005-09-06 15:17:09 -0700899 */
900static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
901{
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800902 struct ipc_proc_iter *iter = s->private;
903 struct ipc_proc_iface *iface = iter->iface;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700904 struct ipc_ids *ids;
905
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800906 ids = &iter->ns->ids[iface->ids];
Mike Waychisonae781772005-09-06 15:17:09 -0700907
908 /*
909 * Take the lock - this will be released by the corresponding
910 * call to stop().
911 */
Nadia Derbey3e148c72007-10-18 23:40:54 -0700912 down_read(&ids->rw_mutex);
Mike Waychisonae781772005-09-06 15:17:09 -0700913
914 /* pos < 0 is invalid */
915 if (*pos < 0)
916 return NULL;
917
918 /* pos == 0 means header */
919 if (*pos == 0)
920 return SEQ_START_TOKEN;
921
922 /* Find the (pos-1)th ipc */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700923 return sysvipc_find_ipc(ids, *pos - 1, pos);
Mike Waychisonae781772005-09-06 15:17:09 -0700924}
925
926static void sysvipc_proc_stop(struct seq_file *s, void *it)
927{
928 struct kern_ipc_perm *ipc = it;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800929 struct ipc_proc_iter *iter = s->private;
930 struct ipc_proc_iface *iface = iter->iface;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700931 struct ipc_ids *ids;
Mike Waychisonae781772005-09-06 15:17:09 -0700932
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700933 /* If we had a locked structure, release it */
Mike Waychisonae781772005-09-06 15:17:09 -0700934 if (ipc && ipc != SEQ_START_TOKEN)
935 ipc_unlock(ipc);
936
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800937 ids = &iter->ns->ids[iface->ids];
Mike Waychisonae781772005-09-06 15:17:09 -0700938 /* Release the lock we took in start() */
Nadia Derbey3e148c72007-10-18 23:40:54 -0700939 up_read(&ids->rw_mutex);
Mike Waychisonae781772005-09-06 15:17:09 -0700940}
941
942static int sysvipc_proc_show(struct seq_file *s, void *it)
943{
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800944 struct ipc_proc_iter *iter = s->private;
945 struct ipc_proc_iface *iface = iter->iface;
Mike Waychisonae781772005-09-06 15:17:09 -0700946
947 if (it == SEQ_START_TOKEN)
948 return seq_puts(s, iface->header);
949
950 return iface->show(s, it);
951}
952
James Morris88e9d342009-09-22 16:43:43 -0700953static const struct seq_operations sysvipc_proc_seqops = {
Mike Waychisonae781772005-09-06 15:17:09 -0700954 .start = sysvipc_proc_start,
955 .stop = sysvipc_proc_stop,
956 .next = sysvipc_proc_next,
957 .show = sysvipc_proc_show,
958};
959
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800960static int sysvipc_proc_open(struct inode *inode, struct file *file)
961{
Mike Waychisonae781772005-09-06 15:17:09 -0700962 int ret;
963 struct seq_file *seq;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800964 struct ipc_proc_iter *iter;
965
966 ret = -ENOMEM;
967 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
968 if (!iter)
969 goto out;
Mike Waychisonae781772005-09-06 15:17:09 -0700970
971 ret = seq_open(file, &sysvipc_proc_seqops);
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800972 if (ret)
973 goto out_kfree;
974
975 seq = file->private_data;
976 seq->private = iter;
977
978 iter->iface = PDE(inode)->data;
979 iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
980out:
Mike Waychisonae781772005-09-06 15:17:09 -0700981 return ret;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800982out_kfree:
983 kfree(iter);
984 goto out;
985}
986
987static int sysvipc_proc_release(struct inode *inode, struct file *file)
988{
989 struct seq_file *seq = file->private_data;
990 struct ipc_proc_iter *iter = seq->private;
991 put_ipc_ns(iter->ns);
992 return seq_release_private(inode, file);
Mike Waychisonae781772005-09-06 15:17:09 -0700993}
994
Arjan van de Ven9a321442007-02-12 00:55:35 -0800995static const struct file_operations sysvipc_proc_fops = {
Mike Waychisonae781772005-09-06 15:17:09 -0700996 .open = sysvipc_proc_open,
997 .read = seq_read,
998 .llseek = seq_lseek,
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800999 .release = sysvipc_proc_release,
Mike Waychisonae781772005-09-06 15:17:09 -07001000};
1001#endif /* CONFIG_PROC_FS */