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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{
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800252 kuid_t euid;
253 kgid_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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582void ipc_rcu_putref(void *ptr)
583{
584 if (--container_of(ptr, struct ipc_rcu_hdr, data)->refcount > 0)
585 return;
586
587 if (container_of(ptr, struct ipc_rcu_hdr, data)->is_vmalloc) {
588 call_rcu(&container_of(ptr, struct ipc_rcu_grace, data)->rcu,
589 ipc_schedule_free);
590 } else {
Lai Jiangshand4ee9aa2011-03-18 12:11:44 +0800591 kfree_rcu(container_of(ptr, struct ipc_rcu_grace, data), rcu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 }
593}
594
595/**
596 * ipcperms - check IPC permissions
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700597 * @ns: IPC namespace
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 * @ipcp: IPC permission set
599 * @flag: desired permission set.
600 *
601 * Check user, group, other permissions for access
602 * to ipc resources. return 0 if allowed
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700603 *
604 * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 */
606
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700607int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
608{
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800609 kuid_t euid = current_euid();
Al Viroa33e6752008-12-10 03:40:06 -0500610 int requested_mode, granted_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
Al Viroa33e6752008-12-10 03:40:06 -0500612 audit_ipc_obj(ipcp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 requested_mode = (flag >> 6) | (flag >> 3) | flag;
614 granted_mode = ipcp->mode;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800615 if (uid_eq(euid, ipcp->cuid) ||
616 uid_eq(euid, ipcp->uid))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 granted_mode >>= 6;
618 else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
619 granted_mode >>= 3;
620 /* is there some bit set in requested_mode but not in granted_mode? */
621 if ((requested_mode & ~granted_mode & 0007) &&
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700622 !ns_capable(ns->user_ns, CAP_IPC_OWNER))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 return -1;
624
625 return security_ipc_permission(ipcp, flag);
626}
627
628/*
629 * Functions to convert between the kern_ipc_perm structure and the
630 * old/new ipc_perm structures
631 */
632
633/**
634 * kernel_to_ipc64_perm - convert kernel ipc permissions to user
635 * @in: kernel permissions
636 * @out: new style IPC permissions
637 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800638 * Turn the kernel object @in into a set of permissions descriptions
639 * for returning to userspace (@out).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 */
641
642
643void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
644{
645 out->key = in->key;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800646 out->uid = from_kuid_munged(current_user_ns(), in->uid);
647 out->gid = from_kgid_munged(current_user_ns(), in->gid);
648 out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
649 out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 out->mode = in->mode;
651 out->seq = in->seq;
652}
653
654/**
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700655 * ipc64_perm_to_ipc_perm - convert new ipc permissions to old
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 * @in: new style IPC permissions
657 * @out: old style IPC permissions
658 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800659 * Turn the new style permissions object @in into a compatibility
660 * object and store it into the @out pointer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 */
662
663void ipc64_perm_to_ipc_perm (struct ipc64_perm *in, struct ipc_perm *out)
664{
665 out->key = in->key;
666 SET_UID(out->uid, in->uid);
667 SET_GID(out->gid, in->gid);
668 SET_UID(out->cuid, in->cuid);
669 SET_GID(out->cgid, in->cgid);
670 out->mode = in->mode;
671 out->seq = in->seq;
672}
673
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700674/**
Nadia Derbey3e148c72007-10-18 23:40:54 -0700675 * ipc_lock - Lock an ipc structure without rw_mutex held
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700676 * @ids: IPC identifier set
677 * @id: ipc id to look for
678 *
679 * Look for an id in the ipc ids idr and lock the associated ipc object.
680 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700681 * The ipc object is locked on exit.
682 */
683
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700684struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700686 struct kern_ipc_perm *out;
Nadia Derbeyce621f52007-10-18 23:40:52 -0700687 int lid = ipcid_to_idx(id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
689 rcu_read_lock();
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700690 out = idr_find(&ids->ipcs_idr, lid);
691 if (out == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 rcu_read_unlock();
Nadia Derbey023a5352007-10-18 23:40:51 -0700693 return ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 spin_lock(&out->lock);
697
698 /* ipc_rmid() may have already freed the ID while ipc_lock
699 * was spinning: here verify that the structure is still valid
700 */
701 if (out->deleted) {
702 spin_unlock(&out->lock);
703 rcu_read_unlock();
Nadia Derbey023a5352007-10-18 23:40:51 -0700704 return ERR_PTR(-EINVAL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700706
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 return out;
708}
709
Pavel Emelyanovb2d75cd2008-02-08 04:18:54 -0800710struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id)
711{
712 struct kern_ipc_perm *out;
713
714 out = ipc_lock(ids, id);
715 if (IS_ERR(out))
716 return out;
717
718 if (ipc_checkid(out, id)) {
719 ipc_unlock(out);
720 return ERR_PTR(-EIDRM);
721 }
722
723 return out;
724}
725
726/**
727 * ipcget - Common sys_*get() code
728 * @ns : namsepace
729 * @ids : IPC identifier set
730 * @ops : operations to be called on ipc object creation, permission checks
731 * and further checks
732 * @params : the parameters needed by the previous operations.
733 *
734 * Common routine called by sys_msgget(), sys_semget() and sys_shmget().
735 */
736int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
737 struct ipc_ops *ops, struct ipc_params *params)
738{
739 if (params->key == IPC_PRIVATE)
740 return ipcget_new(ns, ids, ops, params);
741 else
742 return ipcget_public(ns, ids, ops, params);
743}
744
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700745/**
746 * ipc_update_perm - update the permissions of an IPC.
747 * @in: the permission given as input.
748 * @out: the permission of the ipc to set.
749 */
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800750int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700751{
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800752 kuid_t uid = make_kuid(current_user_ns(), in->uid);
753 kgid_t gid = make_kgid(current_user_ns(), in->gid);
754 if (!uid_valid(uid) || !gid_valid(gid))
755 return -EINVAL;
756
757 out->uid = uid;
758 out->gid = gid;
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700759 out->mode = (out->mode & ~S_IRWXUGO)
760 | (in->mode & S_IRWXUGO);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800761
762 return 0;
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700763}
764
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700765/**
766 * ipcctl_pre_down - retrieve an ipc and check permissions for some IPC_XXX cmd
Randy Dunlap6213cfe2011-03-26 13:27:41 -0700767 * @ns: the ipc namespace
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700768 * @ids: the table of ids where to look for the ipc
769 * @id: the id of the ipc to retrieve
770 * @cmd: the cmd to check
771 * @perm: the permission to set
772 * @extra_perm: one extra permission parameter used by msq
773 *
774 * This function does some common audit and permissions check for some IPC_XXX
775 * cmd and is called from semctl_down, shmctl_down and msgctl_down.
776 * It must be called without any lock held and
777 * - retrieves the ipc with the given id in the given table.
778 * - performs some audit and permission check, depending on the given cmd
779 * - returns the ipc with both ipc and rw_mutex locks held in case of success
780 * or an err-code without any lock held otherwise.
781 */
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700782struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
783 struct ipc_ids *ids, int id, int cmd,
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700784 struct ipc64_perm *perm, int extra_perm)
785{
786 struct kern_ipc_perm *ipcp;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800787 kuid_t euid;
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700788 int err;
789
790 down_write(&ids->rw_mutex);
Nadia Derbey00c2bf82008-07-25 01:48:03 -0700791 ipcp = ipc_lock_check(ids, id);
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700792 if (IS_ERR(ipcp)) {
793 err = PTR_ERR(ipcp);
794 goto out_up;
795 }
796
Al Viroa33e6752008-12-10 03:40:06 -0500797 audit_ipc_obj(ipcp);
Al Viroe816f372008-12-10 03:47:15 -0500798 if (cmd == IPC_SET)
799 audit_ipc_set_perm(extra_perm, perm->uid,
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700800 perm->gid, perm->mode);
David Howells414c0702008-11-14 10:39:06 +1100801
802 euid = current_euid();
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800803 if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700804 ns_capable(ns->user_ns, CAP_SYS_ADMIN))
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700805 return ipcp;
806
807 err = -EPERM;
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700808 ipc_unlock(ipcp);
809out_up:
810 up_write(&ids->rw_mutex);
811 return ERR_PTR(err);
812}
813
Will Deaconc1d7e012012-07-30 14:42:46 -0700814#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815
816
817/**
818 * ipc_parse_version - IPC call version
819 * @cmd: pointer to command
820 *
821 * Return IPC_64 for new style IPC and IPC_OLD for old style IPC.
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800822 * The @cmd value is turned from an encoding command and version into
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 * just the command code.
824 */
825
826int ipc_parse_version (int *cmd)
827{
828 if (*cmd & IPC_64) {
829 *cmd ^= IPC_64;
830 return IPC_64;
831 } else {
832 return IPC_OLD;
833 }
834}
835
Will Deaconc1d7e012012-07-30 14:42:46 -0700836#endif /* CONFIG_ARCH_WANT_IPC_PARSE_VERSION */
Mike Waychisonae781772005-09-06 15:17:09 -0700837
838#ifdef CONFIG_PROC_FS
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800839struct ipc_proc_iter {
840 struct ipc_namespace *ns;
841 struct ipc_proc_iface *iface;
842};
843
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700844/*
845 * This routine locks the ipc structure found at least at position pos.
846 */
Adrian Bunkb524b9a2008-02-06 01:36:28 -0800847static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
848 loff_t *new_pos)
Mike Waychisonae781772005-09-06 15:17:09 -0700849{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700850 struct kern_ipc_perm *ipc;
851 int total, id;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700852
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700853 total = 0;
854 for (id = 0; id < pos && total < ids->in_use; id++) {
855 ipc = idr_find(&ids->ipcs_idr, id);
856 if (ipc != NULL)
857 total++;
858 }
Mike Waychisonae781772005-09-06 15:17:09 -0700859
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700860 if (total >= ids->in_use)
861 return NULL;
Mike Waychisonae781772005-09-06 15:17:09 -0700862
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700863 for ( ; pos < IPCMNI; pos++) {
864 ipc = idr_find(&ids->ipcs_idr, pos);
865 if (ipc != NULL) {
866 *new_pos = pos + 1;
867 ipc_lock_by_ptr(ipc);
Mike Waychisonae781772005-09-06 15:17:09 -0700868 return ipc;
869 }
870 }
871
872 /* Out of range - return NULL to terminate iteration */
873 return NULL;
874}
875
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700876static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
877{
878 struct ipc_proc_iter *iter = s->private;
879 struct ipc_proc_iface *iface = iter->iface;
880 struct kern_ipc_perm *ipc = it;
881
882 /* If we had an ipc id locked before, unlock it */
883 if (ipc && ipc != SEQ_START_TOKEN)
884 ipc_unlock(ipc);
885
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800886 return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700887}
888
Mike Waychisonae781772005-09-06 15:17:09 -0700889/*
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700890 * File positions: pos 0 -> header, pos n -> ipc id = n - 1.
891 * SeqFile iterator: iterator value locked ipc pointer or SEQ_TOKEN_START.
Mike Waychisonae781772005-09-06 15:17:09 -0700892 */
893static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
894{
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800895 struct ipc_proc_iter *iter = s->private;
896 struct ipc_proc_iface *iface = iter->iface;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700897 struct ipc_ids *ids;
898
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800899 ids = &iter->ns->ids[iface->ids];
Mike Waychisonae781772005-09-06 15:17:09 -0700900
901 /*
902 * Take the lock - this will be released by the corresponding
903 * call to stop().
904 */
Nadia Derbey3e148c72007-10-18 23:40:54 -0700905 down_read(&ids->rw_mutex);
Mike Waychisonae781772005-09-06 15:17:09 -0700906
907 /* pos < 0 is invalid */
908 if (*pos < 0)
909 return NULL;
910
911 /* pos == 0 means header */
912 if (*pos == 0)
913 return SEQ_START_TOKEN;
914
915 /* Find the (pos-1)th ipc */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700916 return sysvipc_find_ipc(ids, *pos - 1, pos);
Mike Waychisonae781772005-09-06 15:17:09 -0700917}
918
919static void sysvipc_proc_stop(struct seq_file *s, void *it)
920{
921 struct kern_ipc_perm *ipc = it;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800922 struct ipc_proc_iter *iter = s->private;
923 struct ipc_proc_iface *iface = iter->iface;
Kirill Korotaev73ea4132006-10-02 02:18:20 -0700924 struct ipc_ids *ids;
Mike Waychisonae781772005-09-06 15:17:09 -0700925
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700926 /* If we had a locked structure, release it */
Mike Waychisonae781772005-09-06 15:17:09 -0700927 if (ipc && ipc != SEQ_START_TOKEN)
928 ipc_unlock(ipc);
929
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800930 ids = &iter->ns->ids[iface->ids];
Mike Waychisonae781772005-09-06 15:17:09 -0700931 /* Release the lock we took in start() */
Nadia Derbey3e148c72007-10-18 23:40:54 -0700932 up_read(&ids->rw_mutex);
Mike Waychisonae781772005-09-06 15:17:09 -0700933}
934
935static int sysvipc_proc_show(struct seq_file *s, void *it)
936{
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800937 struct ipc_proc_iter *iter = s->private;
938 struct ipc_proc_iface *iface = iter->iface;
Mike Waychisonae781772005-09-06 15:17:09 -0700939
940 if (it == SEQ_START_TOKEN)
941 return seq_puts(s, iface->header);
942
943 return iface->show(s, it);
944}
945
James Morris88e9d342009-09-22 16:43:43 -0700946static const struct seq_operations sysvipc_proc_seqops = {
Mike Waychisonae781772005-09-06 15:17:09 -0700947 .start = sysvipc_proc_start,
948 .stop = sysvipc_proc_stop,
949 .next = sysvipc_proc_next,
950 .show = sysvipc_proc_show,
951};
952
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800953static int sysvipc_proc_open(struct inode *inode, struct file *file)
954{
Mike Waychisonae781772005-09-06 15:17:09 -0700955 int ret;
956 struct seq_file *seq;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800957 struct ipc_proc_iter *iter;
958
959 ret = -ENOMEM;
960 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
961 if (!iter)
962 goto out;
Mike Waychisonae781772005-09-06 15:17:09 -0700963
964 ret = seq_open(file, &sysvipc_proc_seqops);
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800965 if (ret)
966 goto out_kfree;
967
968 seq = file->private_data;
969 seq->private = iter;
970
971 iter->iface = PDE(inode)->data;
972 iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
973out:
Mike Waychisonae781772005-09-06 15:17:09 -0700974 return ret;
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800975out_kfree:
976 kfree(iter);
977 goto out;
978}
979
980static int sysvipc_proc_release(struct inode *inode, struct file *file)
981{
982 struct seq_file *seq = file->private_data;
983 struct ipc_proc_iter *iter = seq->private;
984 put_ipc_ns(iter->ns);
985 return seq_release_private(inode, file);
Mike Waychisonae781772005-09-06 15:17:09 -0700986}
987
Arjan van de Ven9a321442007-02-12 00:55:35 -0800988static const struct file_operations sysvipc_proc_fops = {
Mike Waychisonae781772005-09-06 15:17:09 -0700989 .open = sysvipc_proc_open,
990 .read = seq_read,
991 .llseek = seq_lseek,
Eric W. Biedermanbc1fc6d2007-02-12 00:52:10 -0800992 .release = sysvipc_proc_release,
Mike Waychisonae781772005-09-06 15:17:09 -0700993};
994#endif /* CONFIG_PROC_FS */