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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/ipc/shm.c
3 * Copyright (C) 1992, 1993 Krishna Balasubramanian
4 * Many improvements/fixes by Bruno Haible.
5 * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994.
6 * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli.
7 *
8 * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
9 * BIGMEM support, Andrea Arcangeli <andrea@suse.de>
10 * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr>
11 * HIGHMEM support, Ingo Molnar <mingo@redhat.com>
12 * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com>
13 * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com>
14 * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com>
15 *
Steve Grubb073115d2006-04-02 17:07:33 -040016 * support for audit of ipc object properties and permission changes
17 * Dustin Kirkland <dustin.kirkland@us.ibm.com>
Kirill Korotaev4e982312006-10-02 02:18:22 -070018 *
19 * namespaces support
20 * OpenVZ, SWsoft Inc.
21 * Pavel Emelianov <xemul@openvz.org>
Davidlohr Buesoc2c737a2013-09-11 14:26:23 -070022 *
23 * Better ipc lock (kern_ipc_perm.lock) handling
24 * Davidlohr Bueso <davidlohr.bueso@hp.com>, June 2013.
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 */
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/slab.h>
28#include <linux/mm.h>
29#include <linux/hugetlb.h>
30#include <linux/shm.h>
31#include <linux/init.h>
32#include <linux/file.h>
33#include <linux/mman.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/shmem_fs.h>
35#include <linux/security.h>
36#include <linux/syscalls.h>
37#include <linux/audit.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080038#include <linux/capability.h>
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -070039#include <linux/ptrace.h>
Mike Waychison19b49462005-09-06 15:17:10 -070040#include <linux/seq_file.h>
Nadia Derbey3e148c72007-10-18 23:40:54 -070041#include <linux/rwsem.h>
Kirill Korotaev4e982312006-10-02 02:18:22 -070042#include <linux/nsproxy.h>
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080043#include <linux/mount.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080044#include <linux/ipc_namespace.h>
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -070045
Paul McQuade7153e402014-06-06 14:37:37 -070046#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
48#include "util.h"
49
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080050struct shm_file_data {
51 int id;
52 struct ipc_namespace *ns;
53 struct file *file;
54 const struct vm_operations_struct *vm_ops;
55};
56
57#define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
58
Arjan van de Ven9a321442007-02-12 00:55:35 -080059static const struct file_operations shm_file_operations;
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +040060static const struct vm_operations_struct shm_vm_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080062#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Kirill Korotaev4e982312006-10-02 02:18:22 -070064#define shm_unlock(shp) \
65 ipc_unlock(&(shp)->shm_perm)
Kirill Korotaev4e982312006-10-02 02:18:22 -070066
Nadia Derbey7748dbf2007-10-18 23:40:49 -070067static int newseg(struct ipc_namespace *, struct ipc_params *);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080068static void shm_open(struct vm_area_struct *vma);
69static void shm_close(struct vm_area_struct *vma);
Manfred Spraul239521f2014-01-27 17:07:04 -080070static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -070072static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073#endif
74
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080075void shm_init_ns(struct ipc_namespace *ns)
Kirill Korotaev4e982312006-10-02 02:18:22 -070076{
Kirill Korotaev4e982312006-10-02 02:18:22 -070077 ns->shm_ctlmax = SHMMAX;
78 ns->shm_ctlall = SHMALL;
79 ns->shm_ctlmni = SHMMNI;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -070080 ns->shm_rmid_forced = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -070081 ns->shm_tot = 0;
WANG Conge8148f72009-01-06 14:42:49 -080082 ipc_init_ids(&shm_ids(ns));
Kirill Korotaev4e982312006-10-02 02:18:22 -070083}
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Nadia Derbeyf4566f02007-10-18 23:40:53 -070085/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -070086 * Called with shm_ids.rwsem (writer) and the shp structure locked.
87 * Only shm_ids.rwsem remains locked on exit.
Nadia Derbeyf4566f02007-10-18 23:40:53 -070088 */
Pierre Peiffer01b8b072008-02-08 04:18:57 -080089static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
Kirill Korotaev4e982312006-10-02 02:18:22 -070090{
Pierre Peiffer01b8b072008-02-08 04:18:57 -080091 struct shmid_kernel *shp;
92 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
93
Manfred Spraul239521f2014-01-27 17:07:04 -080094 if (shp->shm_nattch) {
Kirill Korotaev4e982312006-10-02 02:18:22 -070095 shp->shm_perm.mode |= SHM_DEST;
96 /* Do not find it any more */
97 shp->shm_perm.key = IPC_PRIVATE;
98 shm_unlock(shp);
99 } else
100 shm_destroy(ns, shp);
101}
102
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800103#ifdef CONFIG_IPC_NS
Kirill Korotaev4e982312006-10-02 02:18:22 -0700104void shm_exit_ns(struct ipc_namespace *ns)
105{
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800106 free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
Serge E. Hallyn7d6feeb2009-12-15 16:47:27 -0800107 idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700108}
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800109#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
Linus Torvalds140d0b22011-08-04 19:35:59 -1000111static int __init ipc_ns_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800113 shm_init_ns(&init_ipc_ns);
Linus Torvalds140d0b22011-08-04 19:35:59 -1000114 return 0;
115}
116
117pure_initcall(ipc_ns_init);
118
Manfred Spraul239521f2014-01-27 17:07:04 -0800119void __init shm_init(void)
Linus Torvalds140d0b22011-08-04 19:35:59 -1000120{
Mike Waychison19b49462005-09-06 15:17:10 -0700121 ipc_init_proc_interface("sysvipc/shm",
Helge Dellerb7952182010-10-27 15:34:16 -0700122#if BITS_PER_LONG <= 32
123 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
124#else
125 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
126#endif
Kirill Korotaev4e982312006-10-02 02:18:22 -0700127 IPC_SHM_IDS, sysvipc_shm_proc_show);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128}
129
Davidlohr Bueso8b8d52a2013-09-11 14:26:15 -0700130static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id)
131{
132 struct kern_ipc_perm *ipcp = ipc_obtain_object(&shm_ids(ns), id);
133
134 if (IS_ERR(ipcp))
135 return ERR_CAST(ipcp);
136
137 return container_of(ipcp, struct shmid_kernel, shm_perm);
138}
139
140static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id)
141{
142 struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id);
143
144 if (IS_ERR(ipcp))
145 return ERR_CAST(ipcp);
146
147 return container_of(ipcp, struct shmid_kernel, shm_perm);
148}
149
Nadia Derbey3e148c72007-10-18 23:40:54 -0700150/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700151 * shm_lock_(check_) routines are called in the paths where the rwsem
Nadia Derbey00c2bf82008-07-25 01:48:03 -0700152 * is not necessarily held.
Nadia Derbey3e148c72007-10-18 23:40:54 -0700153 */
Nadia Derbey023a5352007-10-18 23:40:51 -0700154static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700156 struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
157
Pierre Peifferb1ed88b2008-02-06 01:36:23 -0800158 if (IS_ERR(ipcp))
159 return (struct shmid_kernel *)ipcp;
160
Nadia Derbey03f02c72007-10-18 23:40:51 -0700161 return container_of(ipcp, struct shmid_kernel, shm_perm);
Nadia Derbey023a5352007-10-18 23:40:51 -0700162}
163
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400164static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
165{
166 rcu_read_lock();
Davidlohr Buesocf9d5d72013-07-08 16:01:11 -0700167 ipc_lock_object(&ipcp->shm_perm);
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400168}
169
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700170static void shm_rcu_free(struct rcu_head *head)
171{
172 struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
173 struct shmid_kernel *shp = ipc_rcu_to_struct(p);
174
175 security_shm_free(shp);
176 ipc_rcu_free(head);
177}
178
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700179static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Jack Millerab602f72014-08-08 14:23:19 -0700181 list_del(&s->shm_clist);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700182 ipc_rmid(&shm_ids(ns), &s->shm_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183}
184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800186/* This is called by fork, once for every shm attach. */
187static void shm_open(struct vm_area_struct *vma)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700188{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800189 struct file *file = vma->vm_file;
190 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 struct shmid_kernel *shp;
192
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800193 shp = shm_lock(sfd->ns, sfd->id);
Nadia Derbey023a5352007-10-18 23:40:51 -0700194 BUG_ON(IS_ERR(shp));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 shp->shm_atim = get_seconds();
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700196 shp->shm_lprid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 shp->shm_nattch++;
198 shm_unlock(shp);
199}
200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201/*
202 * shm_destroy - free the struct shmid_kernel
203 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700204 * @ns: namespace
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 * @shp: struct to free
206 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700207 * It has to be called with shp and shm_ids.rwsem (writer) locked,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 * but returns with shp unlocked and freed.
209 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700210static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
Greg Thelena399b292013-11-21 14:32:00 -0800212 struct file *shm_file;
213
214 shm_file = shp->shm_file;
215 shp->shm_file = NULL;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700216 ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700217 shm_rmid(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 shm_unlock(shp);
Greg Thelena399b292013-11-21 14:32:00 -0800219 if (!is_file_hugepages(shm_file))
220 shmem_lock(shm_file, 0, shp->mlock_user);
Hugh Dickins353d5c32009-08-24 16:30:28 +0100221 else if (shp->mlock_user)
Greg Thelena399b292013-11-21 14:32:00 -0800222 user_shm_unlock(file_inode(shm_file)->i_size, shp->mlock_user);
223 fput(shm_file);
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700224 ipc_rcu_putref(shp, shm_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225}
226
227/*
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700228 * shm_may_destroy - identifies whether shm segment should be destroyed now
229 *
230 * Returns true if and only if there are no active users of the segment and
231 * one of the following is true:
232 *
233 * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
234 *
235 * 2) sysctl kernel.shm_rmid_forced is set to 1.
236 */
237static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
238{
239 return (shp->shm_nattch == 0) &&
240 (ns->shm_rmid_forced ||
241 (shp->shm_perm.mode & SHM_DEST));
242}
243
244/*
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800245 * remove the attach descriptor vma.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 * free memory for segment if it is marked destroyed.
247 * The descriptor has already been removed from the current->mm->mmap list
248 * and will later be kfree()d.
249 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800250static void shm_close(struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251{
Manfred Spraul239521f2014-01-27 17:07:04 -0800252 struct file *file = vma->vm_file;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800253 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 struct shmid_kernel *shp;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800255 struct ipc_namespace *ns = sfd->ns;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700256
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700257 down_write(&shm_ids(ns).rwsem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 /* remove from the list of attaches of the shm segment */
Nadia Derbey00c2bf82008-07-25 01:48:03 -0700259 shp = shm_lock(ns, sfd->id);
Nadia Derbey023a5352007-10-18 23:40:51 -0700260 BUG_ON(IS_ERR(shp));
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700261 shp->shm_lprid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 shp->shm_dtim = get_seconds();
263 shp->shm_nattch--;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700264 if (shm_may_destroy(ns, shp))
Kirill Korotaev4e982312006-10-02 02:18:22 -0700265 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 else
267 shm_unlock(shp);
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700268 up_write(&shm_ids(ns).rwsem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269}
270
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700271/* Called with ns->shm_ids(ns).rwsem locked */
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700272static int shm_try_destroy_orphaned(int id, void *p, void *data)
273{
274 struct ipc_namespace *ns = data;
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400275 struct kern_ipc_perm *ipcp = p;
276 struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700277
278 /*
279 * We want to destroy segments without users and with already
280 * exit'ed originating process.
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400281 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700282 * As shp->* are changed under rwsem, it's safe to skip shp locking.
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700283 */
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400284 if (shp->shm_creator != NULL)
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700285 return 0;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700286
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400287 if (shm_may_destroy(ns, shp)) {
288 shm_lock_by_ptr(shp);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700289 shm_destroy(ns, shp);
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400290 }
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700291 return 0;
292}
293
294void shm_destroy_orphaned(struct ipc_namespace *ns)
295{
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700296 down_write(&shm_ids(ns).rwsem);
Vasiliy Kulikov33a30ed2011-08-03 22:26:55 +0400297 if (shm_ids(ns).in_use)
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400298 idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700299 up_write(&shm_ids(ns).rwsem);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700300}
301
Jack Miller83293c02014-08-08 14:23:21 -0700302/* Locking assumes this will only be called with task == current */
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700303void exit_shm(struct task_struct *task)
304{
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400305 struct ipc_namespace *ns = task->nsproxy->ipc_ns;
Jack Millerab602f72014-08-08 14:23:19 -0700306 struct shmid_kernel *shp, *n;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700307
Jack Miller83293c02014-08-08 14:23:21 -0700308 if (list_empty(&task->sysvshm.shm_clist))
Vasiliy Kulikov298507d2011-08-03 22:28:26 +0400309 return;
310
Jack Miller83293c02014-08-08 14:23:21 -0700311 /*
312 * If kernel.shm_rmid_forced is not set then only keep track of
313 * which shmids are orphaned, so that a later set of the sysctl
314 * can clean them up.
315 */
316 if (!ns->shm_rmid_forced) {
317 down_read(&shm_ids(ns).rwsem);
318 list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
319 shp->shm_creator = NULL;
320 /*
321 * Only under read lock but we are only called on current
322 * so no entry on the list will be shared.
323 */
324 list_del(&task->sysvshm.shm_clist);
325 up_read(&shm_ids(ns).rwsem);
326 return;
327 }
328
329 /*
330 * Destroy all already created segments, that were not yet mapped,
331 * and mark any mapped as orphan to cover the sysctl toggling.
332 * Destroy is skipped if shm_may_destroy() returns false.
333 */
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700334 down_write(&shm_ids(ns).rwsem);
Jack Miller83293c02014-08-08 14:23:21 -0700335 list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
336 shp->shm_creator = NULL;
337
338 if (shm_may_destroy(ns, shp)) {
339 shm_lock_by_ptr(shp);
340 shm_destroy(ns, shp);
341 }
342 }
343
344 /* Remove the list head from any segments still attached. */
Jack Millerab602f72014-08-08 14:23:19 -0700345 list_del(&task->sysvshm.shm_clist);
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700346 up_write(&shm_ids(ns).rwsem);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700347}
348
Nick Piggind0217ac2007-07-19 01:47:03 -0700349static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800350{
351 struct file *file = vma->vm_file;
352 struct shm_file_data *sfd = shm_file_data(file);
353
Nick Piggind0217ac2007-07-19 01:47:03 -0700354 return sfd->vm_ops->fault(vma, vmf);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800355}
356
357#ifdef CONFIG_NUMA
Adrian Bunkd823e3e2007-10-16 23:26:42 -0700358static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800359{
360 struct file *file = vma->vm_file;
361 struct shm_file_data *sfd = shm_file_data(file);
362 int err = 0;
363 if (sfd->vm_ops->set_policy)
364 err = sfd->vm_ops->set_policy(vma, new);
365 return err;
366}
367
Adrian Bunkd823e3e2007-10-16 23:26:42 -0700368static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
369 unsigned long addr)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800370{
371 struct file *file = vma->vm_file;
372 struct shm_file_data *sfd = shm_file_data(file);
373 struct mempolicy *pol = NULL;
374
375 if (sfd->vm_ops->get_policy)
376 pol = sfd->vm_ops->get_policy(vma, addr);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700377 else if (vma->vm_policy)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800378 pol = vma->vm_policy;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700379
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800380 return pol;
381}
382#endif
383
Manfred Spraul239521f2014-01-27 17:07:04 -0800384static int shm_mmap(struct file *file, struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800386 struct shm_file_data *sfd = shm_file_data(file);
David Howellsb0e15192006-01-06 00:11:42 -0800387 int ret;
388
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800389 ret = sfd->file->f_op->mmap(sfd->file, vma);
390 if (ret != 0)
391 return ret;
392 sfd->vm_ops = vma->vm_ops;
David Howells2e92a3b2007-07-31 00:37:24 -0700393#ifdef CONFIG_MMU
Nick Piggin54cb8822007-07-19 01:46:59 -0700394 BUG_ON(!sfd->vm_ops->fault);
David Howells2e92a3b2007-07-31 00:37:24 -0700395#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800396 vma->vm_ops = &shm_vm_ops;
397 shm_open(vma);
David Howellsb0e15192006-01-06 00:11:42 -0800398
399 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400}
401
Kirill Korotaev4e982312006-10-02 02:18:22 -0700402static int shm_release(struct inode *ino, struct file *file)
403{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800404 struct shm_file_data *sfd = shm_file_data(file);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700405
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800406 put_ipc_ns(sfd->ns);
407 shm_file_data(file) = NULL;
408 kfree(sfd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700409 return 0;
410}
411
Josef Bacik02c24a82011-07-16 20:44:56 -0400412static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
Adam Litke516dffd2007-03-01 15:46:08 -0800413{
Adam Litke516dffd2007-03-01 15:46:08 -0800414 struct shm_file_data *sfd = shm_file_data(file);
Adam Litke516dffd2007-03-01 15:46:08 -0800415
Christoph Hellwig7ea80852010-05-26 17:53:25 +0200416 if (!sfd->file->f_op->fsync)
417 return -EINVAL;
Josef Bacik02c24a82011-07-16 20:44:56 -0400418 return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
Adam Litke516dffd2007-03-01 15:46:08 -0800419}
420
Will Deacon7d8a4562012-06-07 14:21:13 -0700421static long shm_fallocate(struct file *file, int mode, loff_t offset,
422 loff_t len)
423{
424 struct shm_file_data *sfd = shm_file_data(file);
425
426 if (!sfd->file->f_op->fallocate)
427 return -EOPNOTSUPP;
428 return sfd->file->f_op->fallocate(file, mode, offset, len);
429}
430
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800431static unsigned long shm_get_unmapped_area(struct file *file,
432 unsigned long addr, unsigned long len, unsigned long pgoff,
433 unsigned long flags)
434{
435 struct shm_file_data *sfd = shm_file_data(file);
Al Viroc4caa772009-11-30 08:38:43 -0500436 return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
437 pgoff, flags);
Adam Litke516dffd2007-03-01 15:46:08 -0800438}
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800439
Arjan van de Ven9a321442007-02-12 00:55:35 -0800440static const struct file_operations shm_file_operations = {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700441 .mmap = shm_mmap,
Adam Litke516dffd2007-03-01 15:46:08 -0800442 .fsync = shm_fsync,
Kirill Korotaev4e982312006-10-02 02:18:22 -0700443 .release = shm_release,
David Howellsed5e5892010-01-15 17:01:32 -0800444#ifndef CONFIG_MMU
445 .get_unmapped_area = shm_get_unmapped_area,
446#endif
Arnd Bergmann6038f372010-08-15 18:52:59 +0200447 .llseek = noop_llseek,
Will Deacon7d8a4562012-06-07 14:21:13 -0700448 .fallocate = shm_fallocate,
Al Viroc4caa772009-11-30 08:38:43 -0500449};
450
451static const struct file_operations shm_file_operations_huge = {
452 .mmap = shm_mmap,
453 .fsync = shm_fsync,
454 .release = shm_release,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800455 .get_unmapped_area = shm_get_unmapped_area,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200456 .llseek = noop_llseek,
Will Deacon7d8a4562012-06-07 14:21:13 -0700457 .fallocate = shm_fallocate,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458};
459
Al Viroc4caa772009-11-30 08:38:43 -0500460int is_file_shm_hugepages(struct file *file)
461{
462 return file->f_op == &shm_file_operations_huge;
463}
464
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +0400465static const struct vm_operations_struct shm_vm_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 .open = shm_open, /* callback for a new vm-area open */
467 .close = shm_close, /* callback for when the vm-area is released */
Nick Piggin54cb8822007-07-19 01:46:59 -0700468 .fault = shm_fault,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800469#if defined(CONFIG_NUMA)
470 .set_policy = shm_set_policy,
471 .get_policy = shm_get_policy,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472#endif
473};
474
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700475/**
476 * newseg - Create a new shared memory segment
477 * @ns: namespace
478 * @params: ptr to the structure that contains key, size and shmflg
479 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700480 * Called with shm_ids.rwsem held as a writer.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700481 */
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700482static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483{
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700484 key_t key = params->key;
485 int shmflg = params->flg;
486 size_t size = params->u.size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 int error;
488 struct shmid_kernel *shp;
Robin Holtd69f3ba2013-04-30 19:15:54 -0700489 size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
Manfred Spraul239521f2014-01-27 17:07:04 -0800490 struct file *file;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 char name[13];
492 int id;
KOSAKI Motohiroca16d142011-05-26 19:16:19 +0900493 vm_flags_t acctflag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494
Kirill Korotaev4e982312006-10-02 02:18:22 -0700495 if (size < SHMMIN || size > ns->shm_ctlmax)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 return -EINVAL;
497
Manfred Spraul13763272014-06-06 14:37:41 -0700498 if (numpages << PAGE_SHIFT < size)
499 return -ENOSPC;
500
Manfred Spraul09c6eb12014-06-06 14:37:40 -0700501 if (ns->shm_tot + numpages < ns->shm_tot ||
502 ns->shm_tot + numpages > ns->shm_ctlall)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 return -ENOSPC;
504
505 shp = ipc_rcu_alloc(sizeof(*shp));
506 if (!shp)
507 return -ENOMEM;
508
509 shp->shm_perm.key = key;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800510 shp->shm_perm.mode = (shmflg & S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 shp->mlock_user = NULL;
512
513 shp->shm_perm.security = NULL;
514 error = security_shm_alloc(shp);
515 if (error) {
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700516 ipc_rcu_putref(shp, ipc_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 return error;
518 }
519
Manfred Spraul239521f2014-01-27 17:07:04 -0800520 sprintf(name, "SYSV%08x", key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 if (shmflg & SHM_HUGETLB) {
Andrew Mortonc103a4d2013-07-08 16:01:08 -0700522 struct hstate *hs;
Li Zefan091d0d52013-05-09 15:08:15 +0800523 size_t hugesize;
524
Andrew Mortonc103a4d2013-07-08 16:01:08 -0700525 hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
Li Zefan091d0d52013-05-09 15:08:15 +0800526 if (!hs) {
527 error = -EINVAL;
528 goto no_file;
529 }
530 hugesize = ALIGN(size, huge_page_size(hs));
Naoya Horiguchiaf73e4d2013-05-07 16:18:13 -0700531
Mel Gorman5a6fe122009-02-10 14:02:27 +0000532 /* hugetlb_file_setup applies strict accounting */
533 if (shmflg & SHM_NORESERVE)
534 acctflag = VM_NORESERVE;
Naoya Horiguchiaf73e4d2013-05-07 16:18:13 -0700535 file = hugetlb_file_setup(name, hugesize, acctflag,
Andi Kleen42d73952012-12-11 16:01:34 -0800536 &shp->mlock_user, HUGETLB_SHMFS_INODE,
537 (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 } else {
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800539 /*
540 * Do not allow no accounting for OVERCOMMIT_NEVER, even
Manfred Spraul239521f2014-01-27 17:07:04 -0800541 * if it's asked for.
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800542 */
543 if ((shmflg & SHM_NORESERVE) &&
544 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
Linus Torvaldsfc8744a2009-01-31 15:08:56 -0800545 acctflag = VM_NORESERVE;
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800546 file = shmem_file_setup(name, size, acctflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 }
548 error = PTR_ERR(file);
549 if (IS_ERR(file))
550 goto no_file;
551
Pierre Peiffer48dea402008-04-29 01:00:35 -0700552 id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700553 if (id < 0) {
554 error = id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 goto no_id;
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700556 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700558 shp->shm_cprid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 shp->shm_lprid = 0;
560 shp->shm_atim = shp->shm_dtim = 0;
561 shp->shm_ctim = get_seconds();
562 shp->shm_segsz = size;
563 shp->shm_nattch = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 shp->shm_file = file;
Vasiliy Kulikov5774ed02011-07-29 03:55:31 +0400565 shp->shm_creator = current;
Jack Millerab602f72014-08-08 14:23:19 -0700566 list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700567
Badari Pulavarty30475cc2007-06-16 10:15:59 -0700568 /*
569 * shmid gets reported as "inode#" in /proc/pid/maps.
570 * proc-ps tools use this. Changing this will break them.
571 */
Al Viro496ad9a2013-01-23 17:07:38 -0500572 file_inode(file)->i_ino = shp->shm_perm.id;
Krishnakumar R551110a2005-10-29 18:16:45 -0700573
Kirill Korotaev4e982312006-10-02 02:18:22 -0700574 ns->shm_tot += numpages;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700575 error = shp->shm_perm.id;
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700576
Davidlohr Buesocf9d5d72013-07-08 16:01:11 -0700577 ipc_unlock_object(&shp->shm_perm);
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700578 rcu_read_unlock();
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700579 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
581no_id:
Hugh Dickins2195d282009-09-12 12:21:27 +0100582 if (is_file_hugepages(file) && shp->mlock_user)
Hugh Dickins353d5c32009-08-24 16:30:28 +0100583 user_shm_unlock(size, shp->mlock_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 fput(file);
585no_file:
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700586 ipc_rcu_putref(shp, shm_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 return error;
588}
589
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700590/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700591 * Called with shm_ids.rwsem and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700592 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700593static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700594{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700595 struct shmid_kernel *shp;
596
597 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
598 return security_shm_associate(shp, shmflg);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700599}
600
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700601/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700602 * Called with shm_ids.rwsem and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700603 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700604static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
605 struct ipc_params *params)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700606{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700607 struct shmid_kernel *shp;
608
609 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
610 if (shp->shm_segsz < params->u.size)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700611 return -EINVAL;
612
613 return 0;
614}
615
Heiko Carstensd5460c92009-01-14 14:14:27 +0100616SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700618 struct ipc_namespace *ns;
Mathias Krauseeb66ec42014-06-06 14:37:36 -0700619 static const struct ipc_ops shm_ops = {
620 .getnew = newseg,
621 .associate = shm_security,
622 .more_checks = shm_more_checks,
623 };
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700624 struct ipc_params shm_params;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
Kirill Korotaev4e982312006-10-02 02:18:22 -0700626 ns = current->nsproxy->ipc_ns;
627
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700628 shm_params.key = key;
629 shm_params.flg = shmflg;
630 shm_params.u.size = size;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700631
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700632 return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633}
634
635static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
636{
Manfred Spraul239521f2014-01-27 17:07:04 -0800637 switch (version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 case IPC_64:
639 return copy_to_user(buf, in, sizeof(*in));
640 case IPC_OLD:
641 {
642 struct shmid_ds out;
643
Vasiliy Kulikov3af54c92010-10-30 18:22:49 +0400644 memset(&out, 0, sizeof(out));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
646 out.shm_segsz = in->shm_segsz;
647 out.shm_atime = in->shm_atime;
648 out.shm_dtime = in->shm_dtime;
649 out.shm_ctime = in->shm_ctime;
650 out.shm_cpid = in->shm_cpid;
651 out.shm_lpid = in->shm_lpid;
652 out.shm_nattch = in->shm_nattch;
653
654 return copy_to_user(buf, &out, sizeof(out));
655 }
656 default:
657 return -EINVAL;
658 }
659}
660
Pierre Peiffer016d7132008-04-29 01:00:50 -0700661static inline unsigned long
662copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663{
Manfred Spraul239521f2014-01-27 17:07:04 -0800664 switch (version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 case IPC_64:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700666 if (copy_from_user(out, buf, sizeof(*out)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 case IPC_OLD:
670 {
671 struct shmid_ds tbuf_old;
672
673 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
674 return -EFAULT;
675
Pierre Peiffer016d7132008-04-29 01:00:50 -0700676 out->shm_perm.uid = tbuf_old.shm_perm.uid;
677 out->shm_perm.gid = tbuf_old.shm_perm.gid;
678 out->shm_perm.mode = tbuf_old.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
680 return 0;
681 }
682 default:
683 return -EINVAL;
684 }
685}
686
687static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
688{
Manfred Spraul239521f2014-01-27 17:07:04 -0800689 switch (version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 case IPC_64:
691 return copy_to_user(buf, in, sizeof(*in));
692 case IPC_OLD:
693 {
694 struct shminfo out;
695
Manfred Spraul239521f2014-01-27 17:07:04 -0800696 if (in->shmmax > INT_MAX)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 out.shmmax = INT_MAX;
698 else
699 out.shmmax = (int)in->shmmax;
700
701 out.shmmin = in->shmmin;
702 out.shmmni = in->shmmni;
703 out.shmseg = in->shmseg;
Paul McQuade46c0a8c2014-06-06 14:37:37 -0700704 out.shmall = in->shmall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705
706 return copy_to_user(buf, &out, sizeof(out));
707 }
708 default:
709 return -EINVAL;
710 }
711}
712
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700713/*
Helge Dellerb7952182010-10-27 15:34:16 -0700714 * Calculate and add used RSS and swap pages of a shm.
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700715 * Called with shm_ids.rwsem held as a reader
Helge Dellerb7952182010-10-27 15:34:16 -0700716 */
717static void shm_add_rss_swap(struct shmid_kernel *shp,
718 unsigned long *rss_add, unsigned long *swp_add)
719{
720 struct inode *inode;
721
Al Viro496ad9a2013-01-23 17:07:38 -0500722 inode = file_inode(shp->shm_file);
Helge Dellerb7952182010-10-27 15:34:16 -0700723
724 if (is_file_hugepages(shp->shm_file)) {
725 struct address_space *mapping = inode->i_mapping;
726 struct hstate *h = hstate_file(shp->shm_file);
727 *rss_add += pages_per_huge_page(h) * mapping->nrpages;
728 } else {
729#ifdef CONFIG_SHMEM
730 struct shmem_inode_info *info = SHMEM_I(inode);
731 spin_lock(&info->lock);
732 *rss_add += inode->i_mapping->nrpages;
733 *swp_add += info->swapped;
734 spin_unlock(&info->lock);
735#else
736 *rss_add += inode->i_mapping->nrpages;
737#endif
738 }
739}
740
741/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700742 * Called with shm_ids.rwsem held as a reader
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700743 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700744static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
745 unsigned long *swp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700747 int next_id;
748 int total, in_use;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749
750 *rss = 0;
751 *swp = 0;
752
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700753 in_use = shm_ids(ns).in_use;
754
755 for (total = 0, next_id = 0; total < in_use; next_id++) {
Tony Battersbye562aeb2009-04-02 16:58:26 -0700756 struct kern_ipc_perm *ipc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 struct shmid_kernel *shp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758
Tony Battersbye562aeb2009-04-02 16:58:26 -0700759 ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
760 if (ipc == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 continue;
Tony Battersbye562aeb2009-04-02 16:58:26 -0700762 shp = container_of(ipc, struct shmid_kernel, shm_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763
Helge Dellerb7952182010-10-27 15:34:16 -0700764 shm_add_rss_swap(shp, rss, swp);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700765
766 total++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 }
768}
769
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700770/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700771 * This function handles some shmctl commands which require the rwsem
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700772 * to be held in write mode.
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700773 * NOTE: no locks must be held, the rwsem is taken inside this function.
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700774 */
775static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
776 struct shmid_ds __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777{
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700778 struct kern_ipc_perm *ipcp;
Pierre Peiffer016d7132008-04-29 01:00:50 -0700779 struct shmid64_ds shmid64;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 struct shmid_kernel *shp;
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700781 int err;
782
783 if (cmd == IPC_SET) {
Pierre Peiffer016d7132008-04-29 01:00:50 -0700784 if (copy_shmid_from_user(&shmid64, buf, version))
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700785 return -EFAULT;
786 }
787
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700788 down_write(&shm_ids(ns).rwsem);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700789 rcu_read_lock();
790
Davidlohr Bueso79ccf0f2013-09-11 14:26:16 -0700791 ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,
792 &shmid64.shm_perm, 0);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700793 if (IS_ERR(ipcp)) {
794 err = PTR_ERR(ipcp);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700795 goto out_unlock1;
796 }
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700797
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700798 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700799
800 err = security_shm_shmctl(shp, cmd);
801 if (err)
Davidlohr Bueso79ccf0f2013-09-11 14:26:16 -0700802 goto out_unlock1;
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700803
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700804 switch (cmd) {
805 case IPC_RMID:
Davidlohr Bueso79ccf0f2013-09-11 14:26:16 -0700806 ipc_lock_object(&shp->shm_perm);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700807 /* do_shm_rmid unlocks the ipc object and rcu */
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700808 do_shm_rmid(ns, ipcp);
809 goto out_up;
810 case IPC_SET:
Davidlohr Bueso79ccf0f2013-09-11 14:26:16 -0700811 ipc_lock_object(&shp->shm_perm);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800812 err = ipc_update_perm(&shmid64.shm_perm, ipcp);
813 if (err)
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700814 goto out_unlock0;
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700815 shp->shm_ctim = get_seconds();
816 break;
817 default:
818 err = -EINVAL;
Davidlohr Bueso79ccf0f2013-09-11 14:26:16 -0700819 goto out_unlock1;
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700820 }
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700821
822out_unlock0:
823 ipc_unlock_object(&shp->shm_perm);
824out_unlock1:
825 rcu_read_unlock();
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700826out_up:
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700827 up_write(&shm_ids(ns).rwsem);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700828 return err;
829}
830
Davidlohr Bueso68eccc12013-09-11 14:26:18 -0700831static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
832 int cmd, int version, void __user *buf)
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700833{
Davidlohr Bueso68eccc12013-09-11 14:26:18 -0700834 int err;
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700835 struct shmid_kernel *shp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
Davidlohr Bueso68eccc12013-09-11 14:26:18 -0700837 /* preliminary security checks for *_INFO */
838 if (cmd == IPC_INFO || cmd == SHM_INFO) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 err = security_shm_shmctl(NULL, cmd);
840 if (err)
841 return err;
Davidlohr Bueso68eccc12013-09-11 14:26:18 -0700842 }
843
844 switch (cmd) {
845 case IPC_INFO:
846 {
847 struct shminfo64 shminfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848
WANG Conge8148f72009-01-06 14:42:49 -0800849 memset(&shminfo, 0, sizeof(shminfo));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700850 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
851 shminfo.shmmax = ns->shm_ctlmax;
852 shminfo.shmall = ns->shm_ctlall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
854 shminfo.shmmin = SHMMIN;
Manfred Spraul239521f2014-01-27 17:07:04 -0800855 if (copy_shminfo_to_user(buf, &shminfo, version))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 return -EFAULT;
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700857
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700858 down_read(&shm_ids(ns).rwsem);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700859 err = ipc_get_maxid(&shm_ids(ns));
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700860 up_read(&shm_ids(ns).rwsem);
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700861
Manfred Spraul239521f2014-01-27 17:07:04 -0800862 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 err = 0;
864 goto out;
865 }
866 case SHM_INFO:
867 {
868 struct shm_info shm_info;
869
WANG Conge8148f72009-01-06 14:42:49 -0800870 memset(&shm_info, 0, sizeof(shm_info));
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700871 down_read(&shm_ids(ns).rwsem);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700872 shm_info.used_ids = shm_ids(ns).in_use;
Manfred Spraul239521f2014-01-27 17:07:04 -0800873 shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700874 shm_info.shm_tot = ns->shm_tot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 shm_info.swap_attempts = 0;
876 shm_info.swap_successes = 0;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700877 err = ipc_get_maxid(&shm_ids(ns));
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700878 up_read(&shm_ids(ns).rwsem);
WANG Conge8148f72009-01-06 14:42:49 -0800879 if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 err = -EFAULT;
881 goto out;
882 }
883
884 err = err < 0 ? 0 : err;
885 goto out;
886 }
887 case SHM_STAT:
888 case IPC_STAT:
889 {
890 struct shmid64_ds tbuf;
891 int result;
Nadia Derbey023a5352007-10-18 23:40:51 -0700892
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700893 rcu_read_lock();
Nadia Derbey023a5352007-10-18 23:40:51 -0700894 if (cmd == SHM_STAT) {
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700895 shp = shm_obtain_object(ns, shmid);
Nadia Derbey023a5352007-10-18 23:40:51 -0700896 if (IS_ERR(shp)) {
897 err = PTR_ERR(shp);
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700898 goto out_unlock;
Nadia Derbey023a5352007-10-18 23:40:51 -0700899 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700900 result = shp->shm_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 } else {
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700902 shp = shm_obtain_object_check(ns, shmid);
Nadia Derbey023a5352007-10-18 23:40:51 -0700903 if (IS_ERR(shp)) {
904 err = PTR_ERR(shp);
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700905 goto out_unlock;
Nadia Derbey023a5352007-10-18 23:40:51 -0700906 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 result = 0;
908 }
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700909
WANG Conge8148f72009-01-06 14:42:49 -0800910 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700911 if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 goto out_unlock;
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 err = security_shm_shmctl(shp, cmd);
915 if (err)
916 goto out_unlock;
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700917
Nadia Derbey023a5352007-10-18 23:40:51 -0700918 memset(&tbuf, 0, sizeof(tbuf));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
920 tbuf.shm_segsz = shp->shm_segsz;
921 tbuf.shm_atime = shp->shm_atim;
922 tbuf.shm_dtime = shp->shm_dtim;
923 tbuf.shm_ctime = shp->shm_ctim;
924 tbuf.shm_cpid = shp->shm_cprid;
925 tbuf.shm_lpid = shp->shm_lprid;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800926 tbuf.shm_nattch = shp->shm_nattch;
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700927 rcu_read_unlock();
928
929 if (copy_shmid_to_user(buf, &tbuf, version))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 err = -EFAULT;
931 else
932 err = result;
933 goto out;
934 }
Davidlohr Bueso68eccc12013-09-11 14:26:18 -0700935 default:
936 return -EINVAL;
937 }
938
939out_unlock:
Davidlohr Buesoc97cb9c2013-09-11 14:26:20 -0700940 rcu_read_unlock();
Davidlohr Bueso68eccc12013-09-11 14:26:18 -0700941out:
942 return err;
943}
944
945SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
946{
947 struct shmid_kernel *shp;
948 int err, version;
949 struct ipc_namespace *ns;
950
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -0700951 if (cmd < 0 || shmid < 0)
952 return -EINVAL;
Davidlohr Bueso68eccc12013-09-11 14:26:18 -0700953
954 version = ipc_parse_version(&cmd);
955 ns = current->nsproxy->ipc_ns;
956
957 switch (cmd) {
958 case IPC_INFO:
959 case SHM_INFO:
960 case SHM_STAT:
961 case IPC_STAT:
962 return shmctl_nolock(ns, shmid, cmd, version, buf);
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -0700963 case IPC_RMID:
964 case IPC_SET:
965 return shmctl_down(ns, shmid, cmd, buf, version);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 case SHM_LOCK:
967 case SHM_UNLOCK:
968 {
Hugh Dickins850465792012-01-20 14:34:19 -0800969 struct file *shm_file;
Lee Schermerhorn89e004ea2008-10-18 20:26:43 -0700970
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -0700971 rcu_read_lock();
972 shp = shm_obtain_object_check(ns, shmid);
Nadia Derbey023a5352007-10-18 23:40:51 -0700973 if (IS_ERR(shp)) {
974 err = PTR_ERR(shp);
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -0700975 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977
Al Viroa33e6752008-12-10 03:40:06 -0500978 audit_ipc_obj(&(shp->shm_perm));
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -0700979 err = security_shm_shmctl(shp, cmd);
980 if (err)
981 goto out_unlock1;
Steve Grubb073115d2006-04-02 17:07:33 -0400982
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -0700983 ipc_lock_object(&shp->shm_perm);
Rafael Aquini0f3d2b02014-01-27 17:07:01 -0800984
985 /* check if shm_destroy() is tearing down shp */
986 if (!ipc_valid_object(&shp->shm_perm)) {
987 err = -EIDRM;
988 goto out_unlock0;
989 }
990
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700991 if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800992 kuid_t euid = current_euid();
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800993 if (!uid_eq(euid, shp->shm_perm.uid) &&
Jesper Nilsson3a726602013-11-21 14:32:08 -0800994 !uid_eq(euid, shp->shm_perm.cuid)) {
995 err = -EPERM;
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -0700996 goto out_unlock0;
Jesper Nilsson3a726602013-11-21 14:32:08 -0800997 }
998 if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
999 err = -EPERM;
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001000 goto out_unlock0;
Jesper Nilsson3a726602013-11-21 14:32:08 -08001001 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 }
1003
Hugh Dickins850465792012-01-20 14:34:19 -08001004 shm_file = shp->shm_file;
1005 if (is_file_hugepages(shm_file))
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001006 goto out_unlock0;
Hugh Dickins850465792012-01-20 14:34:19 -08001007
1008 if (cmd == SHM_LOCK) {
David Howells86a264a2008-11-14 10:39:18 +11001009 struct user_struct *user = current_user();
Hugh Dickins850465792012-01-20 14:34:19 -08001010 err = shmem_lock(shm_file, 1, user);
1011 if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
1012 shp->shm_perm.mode |= SHM_LOCKED;
1013 shp->mlock_user = user;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014 }
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001015 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 }
Hugh Dickins850465792012-01-20 14:34:19 -08001017
1018 /* SHM_UNLOCK */
1019 if (!(shp->shm_perm.mode & SHM_LOCKED))
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001020 goto out_unlock0;
Hugh Dickins850465792012-01-20 14:34:19 -08001021 shmem_lock(shm_file, 0, shp->mlock_user);
1022 shp->shm_perm.mode &= ~SHM_LOCKED;
1023 shp->mlock_user = NULL;
1024 get_file(shm_file);
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001025 ipc_unlock_object(&shp->shm_perm);
1026 rcu_read_unlock();
Hugh Dickins24513262012-01-20 14:34:21 -08001027 shmem_unlock_mapping(shm_file->f_mapping);
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001028
Hugh Dickins850465792012-01-20 14:34:19 -08001029 fput(shm_file);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -07001030 return err;
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001031 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032 default:
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -07001033 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 }
1035
Davidlohr Bueso2caacaa2013-09-11 14:26:21 -07001036out_unlock0:
1037 ipc_unlock_object(&shp->shm_perm);
1038out_unlock1:
1039 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 return err;
1041}
1042
1043/*
1044 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
1045 *
1046 * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
1047 * "raddr" thing points to kernel space, and there has to be a wrapper around
1048 * this.
1049 */
Will Deacon079a96a2012-07-30 14:42:38 -07001050long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
1051 unsigned long shmlba)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052{
1053 struct shmid_kernel *shp;
1054 unsigned long addr;
1055 unsigned long size;
Manfred Spraul239521f2014-01-27 17:07:04 -08001056 struct file *file;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057 int err;
1058 unsigned long flags;
1059 unsigned long prot;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 int acc_mode;
Kirill Korotaev4e982312006-10-02 02:18:22 -07001061 struct ipc_namespace *ns;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001062 struct shm_file_data *sfd;
1063 struct path path;
Al Viroaeb5d722008-09-02 15:28:45 -04001064 fmode_t f_mode;
Michel Lespinasse41badc12013-02-22 16:32:47 -08001065 unsigned long populate = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001067 err = -EINVAL;
1068 if (shmid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069 goto out;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001070 else if ((addr = (ulong)shmaddr)) {
Will Deacon079a96a2012-07-30 14:42:38 -07001071 if (addr & (shmlba - 1)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 if (shmflg & SHM_RND)
Will Deacon079a96a2012-07-30 14:42:38 -07001073 addr &= ~(shmlba - 1); /* round down */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 else
1075#ifndef __ARCH_FORCE_SHMLBA
1076 if (addr & ~PAGE_MASK)
1077#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001078 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079 }
1080 flags = MAP_SHARED | MAP_FIXED;
1081 } else {
1082 if ((shmflg & SHM_REMAP))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001083 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084
1085 flags = MAP_SHARED;
1086 }
1087
1088 if (shmflg & SHM_RDONLY) {
1089 prot = PROT_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 acc_mode = S_IRUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001091 f_mode = FMODE_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 } else {
1093 prot = PROT_READ | PROT_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 acc_mode = S_IRUGO | S_IWUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001095 f_mode = FMODE_READ | FMODE_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096 }
1097 if (shmflg & SHM_EXEC) {
1098 prot |= PROT_EXEC;
1099 acc_mode |= S_IXUGO;
1100 }
1101
1102 /*
1103 * We cannot rely on the fs check since SYSV IPC does have an
1104 * additional creator id...
1105 */
Kirill Korotaev4e982312006-10-02 02:18:22 -07001106 ns = current->nsproxy->ipc_ns;
Davidlohr Buesoc2c737a2013-09-11 14:26:23 -07001107 rcu_read_lock();
1108 shp = shm_obtain_object_check(ns, shmid);
Nadia Derbey023a5352007-10-18 23:40:51 -07001109 if (IS_ERR(shp)) {
1110 err = PTR_ERR(shp);
Davidlohr Buesoc2c737a2013-09-11 14:26:23 -07001111 goto out_unlock;
Nadia Derbey023a5352007-10-18 23:40:51 -07001112 }
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001113
1114 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -07001115 if (ipcperms(ns, &shp->shm_perm, acc_mode))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001116 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117
1118 err = security_shm_shmat(shp, shmaddr, shmflg);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001119 if (err)
1120 goto out_unlock;
1121
Davidlohr Buesoc2c737a2013-09-11 14:26:23 -07001122 ipc_lock_object(&shp->shm_perm);
Greg Thelena399b292013-11-21 14:32:00 -08001123
1124 /* check if shm_destroy() is tearing down shp */
Rafael Aquini0f3d2b02014-01-27 17:07:01 -08001125 if (!ipc_valid_object(&shp->shm_perm)) {
Greg Thelena399b292013-11-21 14:32:00 -08001126 ipc_unlock_object(&shp->shm_perm);
1127 err = -EIDRM;
1128 goto out_unlock;
1129 }
1130
Al Viro2c48b9c2009-08-09 00:52:35 +04001131 path = shp->shm_file->f_path;
1132 path_get(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 shp->shm_nattch++;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001134 size = i_size_read(path.dentry->d_inode);
Davidlohr Buesoc2c737a2013-09-11 14:26:23 -07001135 ipc_unlock_object(&shp->shm_perm);
1136 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001138 err = -ENOMEM;
1139 sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
Davidlohr Buesof42569b2013-09-11 14:26:22 -07001140 if (!sfd) {
1141 path_put(&path);
1142 goto out_nattch;
1143 }
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001144
Al Viro2c48b9c2009-08-09 00:52:35 +04001145 file = alloc_file(&path, f_mode,
1146 is_file_hugepages(shp->shm_file) ?
Al Viroc4caa772009-11-30 08:38:43 -05001147 &shm_file_operations_huge :
1148 &shm_file_operations);
Anatol Pomozov39b65252012-09-12 20:11:55 -07001149 err = PTR_ERR(file);
Davidlohr Buesof42569b2013-09-11 14:26:22 -07001150 if (IS_ERR(file)) {
1151 kfree(sfd);
1152 path_put(&path);
1153 goto out_nattch;
1154 }
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001155
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001156 file->private_data = sfd;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001157 file->f_mapping = shp->shm_file->f_mapping;
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001158 sfd->id = shp->shm_perm.id;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001159 sfd->ns = get_ipc_ns(ns);
1160 sfd->file = shp->shm_file;
1161 sfd->vm_ops = NULL;
1162
Al Viro8b3ec682012-05-30 17:11:23 -04001163 err = security_mmap_file(file, prot, flags);
1164 if (err)
1165 goto out_fput;
1166
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 down_write(&current->mm->mmap_sem);
1168 if (addr && !(shmflg & SHM_REMAP)) {
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001169 err = -EINVAL;
Manfred Spraul247a8ce2014-06-06 14:37:38 -07001170 if (addr + size < addr)
1171 goto invalid;
1172
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 if (find_vma_intersection(current->mm, addr, addr + size))
1174 goto invalid;
1175 /*
1176 * If shm segment goes below stack, make sure there is some
1177 * space left for the stack to grow (at least 4 pages).
1178 */
1179 if (addr < current->mm->start_stack &&
1180 addr > current->mm->start_stack - size - PAGE_SIZE * 5)
1181 goto invalid;
1182 }
Davidlohr Buesof42569b2013-09-11 14:26:22 -07001183
Michel Lespinassebebeb3d2013-02-22 16:32:37 -08001184 addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
1185 *raddr = addr;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001186 err = 0;
Michel Lespinassebebeb3d2013-02-22 16:32:37 -08001187 if (IS_ERR_VALUE(addr))
1188 err = (long)addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189invalid:
1190 up_write(&current->mm->mmap_sem);
Michel Lespinassebebeb3d2013-02-22 16:32:37 -08001191 if (populate)
Michel Lespinasse41badc12013-02-22 16:32:47 -08001192 mm_populate(addr, populate);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193
Al Viro8b3ec682012-05-30 17:11:23 -04001194out_fput:
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001195 fput(file);
1196
1197out_nattch:
Davidlohr Buesod9a605e2013-09-11 14:26:24 -07001198 down_write(&shm_ids(ns).rwsem);
Nadia Derbey00c2bf82008-07-25 01:48:03 -07001199 shp = shm_lock(ns, shmid);
Nadia Derbey023a5352007-10-18 23:40:51 -07001200 BUG_ON(IS_ERR(shp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201 shp->shm_nattch--;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -07001202 if (shm_may_destroy(ns, shp))
Kirill Korotaev4e982312006-10-02 02:18:22 -07001203 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 else
1205 shm_unlock(shp);
Davidlohr Buesod9a605e2013-09-11 14:26:24 -07001206 up_write(&shm_ids(ns).rwsem);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207 return err;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001208
1209out_unlock:
Davidlohr Buesoc2c737a2013-09-11 14:26:23 -07001210 rcu_read_unlock();
Davidlohr Buesof42569b2013-09-11 14:26:22 -07001211out:
1212 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213}
1214
Heiko Carstensd5460c92009-01-14 14:14:27 +01001215SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -07001216{
1217 unsigned long ret;
1218 long err;
1219
Will Deacon079a96a2012-07-30 14:42:38 -07001220 err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -07001221 if (err)
1222 return err;
1223 force_successful_syscall_return();
1224 return (long)ret;
1225}
1226
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227/*
1228 * detach and kill segment if marked destroyed.
1229 * The work is done in shm_close.
1230 */
Heiko Carstensd5460c92009-01-14 14:14:27 +01001231SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232{
1233 struct mm_struct *mm = current->mm;
Mike Frysinger586c7e62009-06-09 16:26:23 -07001234 struct vm_area_struct *vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235 unsigned long addr = (unsigned long)shmaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 int retval = -EINVAL;
Mike Frysinger586c7e62009-06-09 16:26:23 -07001237#ifdef CONFIG_MMU
1238 loff_t size = 0;
1239 struct vm_area_struct *next;
1240#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241
Hugh Dickinsdf1e2fb2006-03-24 03:18:06 -08001242 if (addr & ~PAGE_MASK)
1243 return retval;
1244
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 down_write(&mm->mmap_sem);
1246
1247 /*
1248 * This function tries to be smart and unmap shm segments that
1249 * were modified by partial mlock or munmap calls:
1250 * - It first determines the size of the shm segment that should be
1251 * unmapped: It searches for a vma that is backed by shm and that
1252 * started at address shmaddr. It records it's size and then unmaps
1253 * it.
1254 * - Then it unmaps all shm vmas that started at shmaddr and that
1255 * are within the initially determined size.
1256 * Errors from do_munmap are ignored: the function only fails if
1257 * it's called with invalid parameters or if it's called to unmap
1258 * a part of a vma. Both calls in this function are for full vmas,
1259 * the parameters are directly copied from the vma itself and always
1260 * valid - therefore do_munmap cannot fail. (famous last words?)
1261 */
1262 /*
1263 * If it had been mremap()'d, the starting address would not
1264 * match the usual checks anyway. So assume all vma's are
1265 * above the starting address given.
1266 */
1267 vma = find_vma(mm, addr);
1268
David Howells8feae132009-01-08 12:04:47 +00001269#ifdef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270 while (vma) {
1271 next = vma->vm_next;
1272
1273 /*
1274 * Check if the starting address would match, i.e. it's
1275 * a fragment created by mprotect() and/or munmap(), or it
1276 * otherwise it starts at this address with no hassles.
1277 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001278 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1280
1281
Al Viro496ad9a2013-01-23 17:07:38 -05001282 size = file_inode(vma->vm_file)->i_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1284 /*
1285 * We discovered the size of the shm segment, so
1286 * break out of here and fall through to the next
1287 * loop that uses the size information to stop
1288 * searching for matching vma's.
1289 */
1290 retval = 0;
1291 vma = next;
1292 break;
1293 }
1294 vma = next;
1295 }
1296
1297 /*
1298 * We need look no further than the maximum address a fragment
1299 * could possibly have landed at. Also cast things to loff_t to
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001300 * prevent overflows and make comparisons vs. equal-width types.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 */
KAMEZAWA Hiroyuki8e367092006-02-10 01:51:12 -08001302 size = PAGE_ALIGN(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1304 next = vma->vm_next;
1305
1306 /* finding a matching vma now does not alter retval */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001307 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
1309
1310 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1311 vma = next;
1312 }
1313
David Howells8feae132009-01-08 12:04:47 +00001314#else /* CONFIG_MMU */
1315 /* under NOMMU conditions, the exact address to be destroyed must be
1316 * given */
Davidlohr Bueso530fcd162013-09-11 14:26:28 -07001317 if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
David Howells8feae132009-01-08 12:04:47 +00001318 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1319 retval = 0;
1320 }
1321
1322#endif
1323
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 up_write(&mm->mmap_sem);
1325 return retval;
1326}
1327
1328#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001329static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330{
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001331 struct user_namespace *user_ns = seq_user_ns(s);
Mike Waychison19b49462005-09-06 15:17:10 -07001332 struct shmid_kernel *shp = it;
Helge Dellerb7952182010-10-27 15:34:16 -07001333 unsigned long rss = 0, swp = 0;
1334
1335 shm_add_rss_swap(shp, &rss, &swp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336
Paul Menage6c826812008-06-12 15:21:49 -07001337#if BITS_PER_LONG <= 32
1338#define SIZE_SPEC "%10lu"
1339#else
1340#define SIZE_SPEC "%21lu"
1341#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342
Paul Menage6c826812008-06-12 15:21:49 -07001343 return seq_printf(s,
1344 "%10d %10d %4o " SIZE_SPEC " %5u %5u "
Helge Dellerb7952182010-10-27 15:34:16 -07001345 "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
1346 SIZE_SPEC " " SIZE_SPEC "\n",
Mike Waychison19b49462005-09-06 15:17:10 -07001347 shp->shm_perm.key,
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001348 shp->shm_perm.id,
Andrew Mortonb33291c2006-01-08 01:02:21 -08001349 shp->shm_perm.mode,
Mike Waychison19b49462005-09-06 15:17:10 -07001350 shp->shm_segsz,
1351 shp->shm_cprid,
1352 shp->shm_lprid,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001353 shp->shm_nattch,
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001354 from_kuid_munged(user_ns, shp->shm_perm.uid),
1355 from_kgid_munged(user_ns, shp->shm_perm.gid),
1356 from_kuid_munged(user_ns, shp->shm_perm.cuid),
1357 from_kgid_munged(user_ns, shp->shm_perm.cgid),
Mike Waychison19b49462005-09-06 15:17:10 -07001358 shp->shm_atim,
1359 shp->shm_dtim,
Helge Dellerb7952182010-10-27 15:34:16 -07001360 shp->shm_ctim,
1361 rss * PAGE_SIZE,
1362 swp * PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363}
1364#endif