blob: 7e199fa1960f86087c557bcc39b08d304c2b8f7b [file] [log] [blame]
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 */
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/slab.h>
25#include <linux/mm.h>
26#include <linux/hugetlb.h>
27#include <linux/shm.h>
28#include <linux/init.h>
29#include <linux/file.h>
30#include <linux/mman.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/shmem_fs.h>
32#include <linux/security.h>
33#include <linux/syscalls.h>
34#include <linux/audit.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080035#include <linux/capability.h>
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -070036#include <linux/ptrace.h>
Mike Waychison19b49462005-09-06 15:17:10 -070037#include <linux/seq_file.h>
Nadia Derbey3e148c72007-10-18 23:40:54 -070038#include <linux/rwsem.h>
Kirill Korotaev4e982312006-10-02 02:18:22 -070039#include <linux/nsproxy.h>
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080040#include <linux/mount.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080041#include <linux/ipc_namespace.h>
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -070042
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include <asm/uaccess.h>
44
45#include "util.h"
46
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080047struct shm_file_data {
48 int id;
49 struct ipc_namespace *ns;
50 struct file *file;
51 const struct vm_operations_struct *vm_ops;
52};
53
54#define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
55
Arjan van de Ven9a321442007-02-12 00:55:35 -080056static const struct file_operations shm_file_operations;
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +040057static const struct vm_operations_struct shm_vm_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080059#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
Kirill Korotaev4e982312006-10-02 02:18:22 -070061#define shm_unlock(shp) \
62 ipc_unlock(&(shp)->shm_perm)
Kirill Korotaev4e982312006-10-02 02:18:22 -070063
Nadia Derbey7748dbf2007-10-18 23:40:49 -070064static int newseg(struct ipc_namespace *, struct ipc_params *);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080065static void shm_open(struct vm_area_struct *vma);
66static void shm_close(struct vm_area_struct *vma);
Kirill Korotaev4e982312006-10-02 02:18:22 -070067static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -070069static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070#endif
71
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080072void shm_init_ns(struct ipc_namespace *ns)
Kirill Korotaev4e982312006-10-02 02:18:22 -070073{
Kirill Korotaev4e982312006-10-02 02:18:22 -070074 ns->shm_ctlmax = SHMMAX;
75 ns->shm_ctlall = SHMALL;
76 ns->shm_ctlmni = SHMMNI;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -070077 ns->shm_rmid_forced = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -070078 ns->shm_tot = 0;
WANG Conge8148f72009-01-06 14:42:49 -080079 ipc_init_ids(&shm_ids(ns));
Kirill Korotaev4e982312006-10-02 02:18:22 -070080}
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Nadia Derbeyf4566f02007-10-18 23:40:53 -070082/*
Nadia Derbey3e148c72007-10-18 23:40:54 -070083 * Called with shm_ids.rw_mutex (writer) and the shp structure locked.
84 * Only shm_ids.rw_mutex remains locked on exit.
Nadia Derbeyf4566f02007-10-18 23:40:53 -070085 */
Pierre Peiffer01b8b072008-02-08 04:18:57 -080086static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
Kirill Korotaev4e982312006-10-02 02:18:22 -070087{
Pierre Peiffer01b8b072008-02-08 04:18:57 -080088 struct shmid_kernel *shp;
89 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
90
Kirill Korotaev4e982312006-10-02 02:18:22 -070091 if (shp->shm_nattch){
92 shp->shm_perm.mode |= SHM_DEST;
93 /* Do not find it any more */
94 shp->shm_perm.key = IPC_PRIVATE;
95 shm_unlock(shp);
96 } else
97 shm_destroy(ns, shp);
98}
99
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800100#ifdef CONFIG_IPC_NS
Kirill Korotaev4e982312006-10-02 02:18:22 -0700101void shm_exit_ns(struct ipc_namespace *ns)
102{
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800103 free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
Serge E. Hallyn7d6feeb2009-12-15 16:47:27 -0800104 idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700105}
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800106#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
Linus Torvalds140d0b22011-08-04 19:35:59 -1000108static int __init ipc_ns_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800110 shm_init_ns(&init_ipc_ns);
Linus Torvalds140d0b22011-08-04 19:35:59 -1000111 return 0;
112}
113
114pure_initcall(ipc_ns_init);
115
116void __init shm_init (void)
117{
Mike Waychison19b49462005-09-06 15:17:10 -0700118 ipc_init_proc_interface("sysvipc/shm",
Helge Dellerb7952182010-10-27 15:34:16 -0700119#if BITS_PER_LONG <= 32
120 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
121#else
122 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n",
123#endif
Kirill Korotaev4e982312006-10-02 02:18:22 -0700124 IPC_SHM_IDS, sysvipc_shm_proc_show);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125}
126
Nadia Derbey3e148c72007-10-18 23:40:54 -0700127/*
Nadia Derbey3e148c72007-10-18 23:40:54 -0700128 * shm_lock_(check_) routines are called in the paths where the rw_mutex
Nadia Derbey00c2bf82008-07-25 01:48:03 -0700129 * is not necessarily held.
Nadia Derbey3e148c72007-10-18 23:40:54 -0700130 */
Nadia Derbey023a5352007-10-18 23:40:51 -0700131static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700133 struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
134
Pierre Peifferb1ed88b2008-02-06 01:36:23 -0800135 if (IS_ERR(ipcp))
136 return (struct shmid_kernel *)ipcp;
137
Nadia Derbey03f02c72007-10-18 23:40:51 -0700138 return container_of(ipcp, struct shmid_kernel, shm_perm);
Nadia Derbey023a5352007-10-18 23:40:51 -0700139}
140
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400141static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
142{
143 rcu_read_lock();
144 spin_lock(&ipcp->shm_perm.lock);
145}
146
Nadia Derbey023a5352007-10-18 23:40:51 -0700147static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
148 int id)
149{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700150 struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id);
151
Pierre Peifferb1ed88b2008-02-06 01:36:23 -0800152 if (IS_ERR(ipcp))
153 return (struct shmid_kernel *)ipcp;
154
Nadia Derbey03f02c72007-10-18 23:40:51 -0700155 return container_of(ipcp, struct shmid_kernel, shm_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156}
157
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700158static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700160 ipc_rmid(&shm_ids(ns), &s->shm_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161}
162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800164/* This is called by fork, once for every shm attach. */
165static void shm_open(struct vm_area_struct *vma)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700166{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800167 struct file *file = vma->vm_file;
168 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 struct shmid_kernel *shp;
170
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800171 shp = shm_lock(sfd->ns, sfd->id);
Nadia Derbey023a5352007-10-18 23:40:51 -0700172 BUG_ON(IS_ERR(shp));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 shp->shm_atim = get_seconds();
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700174 shp->shm_lprid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 shp->shm_nattch++;
176 shm_unlock(shp);
177}
178
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179/*
180 * shm_destroy - free the struct shmid_kernel
181 *
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700182 * @ns: namespace
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 * @shp: struct to free
184 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700185 * It has to be called with shp and shm_ids.rw_mutex (writer) locked,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 * but returns with shp unlocked and freed.
187 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700188static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700190 ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700191 shm_rmid(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 shm_unlock(shp);
193 if (!is_file_hugepages(shp->shm_file))
194 shmem_lock(shp->shm_file, 0, shp->mlock_user);
Hugh Dickins353d5c32009-08-24 16:30:28 +0100195 else if (shp->mlock_user)
Al Viro496ad9a2013-01-23 17:07:38 -0500196 user_shm_unlock(file_inode(shp->shm_file)->i_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 shp->mlock_user);
198 fput (shp->shm_file);
199 security_shm_free(shp);
200 ipc_rcu_putref(shp);
201}
202
203/*
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700204 * shm_may_destroy - identifies whether shm segment should be destroyed now
205 *
206 * Returns true if and only if there are no active users of the segment and
207 * one of the following is true:
208 *
209 * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
210 *
211 * 2) sysctl kernel.shm_rmid_forced is set to 1.
212 */
213static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
214{
215 return (shp->shm_nattch == 0) &&
216 (ns->shm_rmid_forced ||
217 (shp->shm_perm.mode & SHM_DEST));
218}
219
220/*
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800221 * remove the attach descriptor vma.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 * free memory for segment if it is marked destroyed.
223 * The descriptor has already been removed from the current->mm->mmap list
224 * and will later be kfree()d.
225 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800226static void shm_close(struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800228 struct file * file = vma->vm_file;
229 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 struct shmid_kernel *shp;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800231 struct ipc_namespace *ns = sfd->ns;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700232
Nadia Derbey3e148c72007-10-18 23:40:54 -0700233 down_write(&shm_ids(ns).rw_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 /* remove from the list of attaches of the shm segment */
Nadia Derbey00c2bf82008-07-25 01:48:03 -0700235 shp = shm_lock(ns, sfd->id);
Nadia Derbey023a5352007-10-18 23:40:51 -0700236 BUG_ON(IS_ERR(shp));
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700237 shp->shm_lprid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 shp->shm_dtim = get_seconds();
239 shp->shm_nattch--;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700240 if (shm_may_destroy(ns, shp))
Kirill Korotaev4e982312006-10-02 02:18:22 -0700241 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 else
243 shm_unlock(shp);
Nadia Derbey3e148c72007-10-18 23:40:54 -0700244 up_write(&shm_ids(ns).rw_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245}
246
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400247/* Called with ns->shm_ids(ns).rw_mutex locked */
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700248static int shm_try_destroy_current(int id, void *p, void *data)
249{
250 struct ipc_namespace *ns = data;
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400251 struct kern_ipc_perm *ipcp = p;
252 struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700253
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400254 if (shp->shm_creator != current)
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700255 return 0;
256
Vasiliy Kulikov5774ed02011-07-29 03:55:31 +0400257 /*
258 * Mark it as orphaned to destroy the segment when
259 * kernel.shm_rmid_forced is changed.
260 * It is noop if the following shm_may_destroy() returns true.
261 */
262 shp->shm_creator = NULL;
263
264 /*
265 * Don't even try to destroy it. If shm_rmid_forced=0 and IPC_RMID
266 * is not set, it shouldn't be deleted here.
267 */
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400268 if (!ns->shm_rmid_forced)
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700269 return 0;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700270
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400271 if (shm_may_destroy(ns, shp)) {
272 shm_lock_by_ptr(shp);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700273 shm_destroy(ns, shp);
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400274 }
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700275 return 0;
276}
277
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400278/* Called with ns->shm_ids(ns).rw_mutex locked */
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700279static int shm_try_destroy_orphaned(int id, void *p, void *data)
280{
281 struct ipc_namespace *ns = data;
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400282 struct kern_ipc_perm *ipcp = p;
283 struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700284
285 /*
286 * We want to destroy segments without users and with already
287 * exit'ed originating process.
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400288 *
289 * As shp->* are changed under rw_mutex, it's safe to skip shp locking.
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700290 */
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400291 if (shp->shm_creator != NULL)
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700292 return 0;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700293
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400294 if (shm_may_destroy(ns, shp)) {
295 shm_lock_by_ptr(shp);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700296 shm_destroy(ns, shp);
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400297 }
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700298 return 0;
299}
300
301void shm_destroy_orphaned(struct ipc_namespace *ns)
302{
303 down_write(&shm_ids(ns).rw_mutex);
Vasiliy Kulikov33a30ed2011-08-03 22:26:55 +0400304 if (shm_ids(ns).in_use)
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400305 idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700306 up_write(&shm_ids(ns).rw_mutex);
307}
308
309
310void exit_shm(struct task_struct *task)
311{
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400312 struct ipc_namespace *ns = task->nsproxy->ipc_ns;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700313
Vasiliy Kulikov298507d2011-08-03 22:28:26 +0400314 if (shm_ids(ns).in_use == 0)
315 return;
316
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700317 /* Destroy all already created segments, but not mapped yet */
318 down_write(&shm_ids(ns).rw_mutex);
Vasiliy Kulikov33a30ed2011-08-03 22:26:55 +0400319 if (shm_ids(ns).in_use)
Vasiliy Kulikov4c677e22011-07-29 03:56:40 +0400320 idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_current, ns);
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -0700321 up_write(&shm_ids(ns).rw_mutex);
322}
323
Nick Piggind0217ac2007-07-19 01:47:03 -0700324static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800325{
326 struct file *file = vma->vm_file;
327 struct shm_file_data *sfd = shm_file_data(file);
328
Nick Piggind0217ac2007-07-19 01:47:03 -0700329 return sfd->vm_ops->fault(vma, vmf);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800330}
331
332#ifdef CONFIG_NUMA
Adrian Bunkd823e3e2007-10-16 23:26:42 -0700333static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800334{
335 struct file *file = vma->vm_file;
336 struct shm_file_data *sfd = shm_file_data(file);
337 int err = 0;
338 if (sfd->vm_ops->set_policy)
339 err = sfd->vm_ops->set_policy(vma, new);
340 return err;
341}
342
Adrian Bunkd823e3e2007-10-16 23:26:42 -0700343static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
344 unsigned long addr)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800345{
346 struct file *file = vma->vm_file;
347 struct shm_file_data *sfd = shm_file_data(file);
348 struct mempolicy *pol = NULL;
349
350 if (sfd->vm_ops->get_policy)
351 pol = sfd->vm_ops->get_policy(vma, addr);
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700352 else if (vma->vm_policy)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800353 pol = vma->vm_policy;
Lee Schermerhorn52cd3b02008-04-28 02:13:16 -0700354
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800355 return pol;
356}
357#endif
358
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359static int shm_mmap(struct file * file, struct vm_area_struct * vma)
360{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800361 struct shm_file_data *sfd = shm_file_data(file);
David Howellsb0e15192006-01-06 00:11:42 -0800362 int ret;
363
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800364 ret = sfd->file->f_op->mmap(sfd->file, vma);
365 if (ret != 0)
366 return ret;
367 sfd->vm_ops = vma->vm_ops;
David Howells2e92a3b2007-07-31 00:37:24 -0700368#ifdef CONFIG_MMU
Nick Piggin54cb8822007-07-19 01:46:59 -0700369 BUG_ON(!sfd->vm_ops->fault);
David Howells2e92a3b2007-07-31 00:37:24 -0700370#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800371 vma->vm_ops = &shm_vm_ops;
372 shm_open(vma);
David Howellsb0e15192006-01-06 00:11:42 -0800373
374 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375}
376
Kirill Korotaev4e982312006-10-02 02:18:22 -0700377static int shm_release(struct inode *ino, struct file *file)
378{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800379 struct shm_file_data *sfd = shm_file_data(file);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700380
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800381 put_ipc_ns(sfd->ns);
382 shm_file_data(file) = NULL;
383 kfree(sfd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700384 return 0;
385}
386
Josef Bacik02c24a82011-07-16 20:44:56 -0400387static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
Adam Litke516dffd2007-03-01 15:46:08 -0800388{
Adam Litke516dffd2007-03-01 15:46:08 -0800389 struct shm_file_data *sfd = shm_file_data(file);
Adam Litke516dffd2007-03-01 15:46:08 -0800390
Christoph Hellwig7ea80852010-05-26 17:53:25 +0200391 if (!sfd->file->f_op->fsync)
392 return -EINVAL;
Josef Bacik02c24a82011-07-16 20:44:56 -0400393 return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
Adam Litke516dffd2007-03-01 15:46:08 -0800394}
395
Will Deacon7d8a4562012-06-07 14:21:13 -0700396static long shm_fallocate(struct file *file, int mode, loff_t offset,
397 loff_t len)
398{
399 struct shm_file_data *sfd = shm_file_data(file);
400
401 if (!sfd->file->f_op->fallocate)
402 return -EOPNOTSUPP;
403 return sfd->file->f_op->fallocate(file, mode, offset, len);
404}
405
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800406static unsigned long shm_get_unmapped_area(struct file *file,
407 unsigned long addr, unsigned long len, unsigned long pgoff,
408 unsigned long flags)
409{
410 struct shm_file_data *sfd = shm_file_data(file);
Al Viroc4caa772009-11-30 08:38:43 -0500411 return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
412 pgoff, flags);
Adam Litke516dffd2007-03-01 15:46:08 -0800413}
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800414
Arjan van de Ven9a321442007-02-12 00:55:35 -0800415static const struct file_operations shm_file_operations = {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700416 .mmap = shm_mmap,
Adam Litke516dffd2007-03-01 15:46:08 -0800417 .fsync = shm_fsync,
Kirill Korotaev4e982312006-10-02 02:18:22 -0700418 .release = shm_release,
David Howellsed5e5892010-01-15 17:01:32 -0800419#ifndef CONFIG_MMU
420 .get_unmapped_area = shm_get_unmapped_area,
421#endif
Arnd Bergmann6038f372010-08-15 18:52:59 +0200422 .llseek = noop_llseek,
Will Deacon7d8a4562012-06-07 14:21:13 -0700423 .fallocate = shm_fallocate,
Al Viroc4caa772009-11-30 08:38:43 -0500424};
425
426static const struct file_operations shm_file_operations_huge = {
427 .mmap = shm_mmap,
428 .fsync = shm_fsync,
429 .release = shm_release,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800430 .get_unmapped_area = shm_get_unmapped_area,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200431 .llseek = noop_llseek,
Will Deacon7d8a4562012-06-07 14:21:13 -0700432 .fallocate = shm_fallocate,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433};
434
Al Viroc4caa772009-11-30 08:38:43 -0500435int is_file_shm_hugepages(struct file *file)
436{
437 return file->f_op == &shm_file_operations_huge;
438}
439
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +0400440static const struct vm_operations_struct shm_vm_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 .open = shm_open, /* callback for a new vm-area open */
442 .close = shm_close, /* callback for when the vm-area is released */
Nick Piggin54cb8822007-07-19 01:46:59 -0700443 .fault = shm_fault,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800444#if defined(CONFIG_NUMA)
445 .set_policy = shm_set_policy,
446 .get_policy = shm_get_policy,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447#endif
448};
449
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700450/**
451 * newseg - Create a new shared memory segment
452 * @ns: namespace
453 * @params: ptr to the structure that contains key, size and shmflg
454 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700455 * Called with shm_ids.rw_mutex held as a writer.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700456 */
457
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700458static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459{
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700460 key_t key = params->key;
461 int shmflg = params->flg;
462 size_t size = params->u.size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 int error;
464 struct shmid_kernel *shp;
Robin Holtd69f3ba2013-04-30 19:15:54 -0700465 size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 struct file * file;
467 char name[13];
468 int id;
KOSAKI Motohiroca16d142011-05-26 19:16:19 +0900469 vm_flags_t acctflag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470
Kirill Korotaev4e982312006-10-02 02:18:22 -0700471 if (size < SHMMIN || size > ns->shm_ctlmax)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 return -EINVAL;
473
Guy Streeterf66d45e2007-01-23 12:20:04 -0600474 if (ns->shm_tot + numpages > ns->shm_ctlall)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 return -ENOSPC;
476
477 shp = ipc_rcu_alloc(sizeof(*shp));
478 if (!shp)
479 return -ENOMEM;
480
481 shp->shm_perm.key = key;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800482 shp->shm_perm.mode = (shmflg & S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 shp->mlock_user = NULL;
484
485 shp->shm_perm.security = NULL;
486 error = security_shm_alloc(shp);
487 if (error) {
488 ipc_rcu_putref(shp);
489 return error;
490 }
491
Eric W. Biederman9d665862007-06-16 10:16:16 -0700492 sprintf (name, "SYSV%08x", key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 if (shmflg & SHM_HUGETLB) {
Naoya Horiguchiaf73e4d2013-05-07 16:18:13 -0700494 struct hstate *hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT)
495 & SHM_HUGE_MASK);
Li Zefan091d0d52013-05-09 15:08:15 +0800496 size_t hugesize;
497
498 if (!hs) {
499 error = -EINVAL;
500 goto no_file;
501 }
502 hugesize = ALIGN(size, huge_page_size(hs));
Naoya Horiguchiaf73e4d2013-05-07 16:18:13 -0700503
Mel Gorman5a6fe122009-02-10 14:02:27 +0000504 /* hugetlb_file_setup applies strict accounting */
505 if (shmflg & SHM_NORESERVE)
506 acctflag = VM_NORESERVE;
Naoya Horiguchiaf73e4d2013-05-07 16:18:13 -0700507 file = hugetlb_file_setup(name, hugesize, acctflag,
Andi Kleen42d73952012-12-11 16:01:34 -0800508 &shp->mlock_user, HUGETLB_SHMFS_INODE,
509 (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 } else {
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800511 /*
512 * Do not allow no accounting for OVERCOMMIT_NEVER, even
513 * if it's asked for.
514 */
515 if ((shmflg & SHM_NORESERVE) &&
516 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
Linus Torvaldsfc8744a2009-01-31 15:08:56 -0800517 acctflag = VM_NORESERVE;
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800518 file = shmem_file_setup(name, size, acctflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 }
520 error = PTR_ERR(file);
521 if (IS_ERR(file))
522 goto no_file;
523
Pierre Peiffer48dea402008-04-29 01:00:35 -0700524 id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700525 if (id < 0) {
526 error = id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 goto no_id;
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700528 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700530 shp->shm_cprid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 shp->shm_lprid = 0;
532 shp->shm_atim = shp->shm_dtim = 0;
533 shp->shm_ctim = get_seconds();
534 shp->shm_segsz = size;
535 shp->shm_nattch = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 shp->shm_file = file;
Vasiliy Kulikov5774ed02011-07-29 03:55:31 +0400537 shp->shm_creator = current;
Badari Pulavarty30475cc2007-06-16 10:15:59 -0700538 /*
539 * shmid gets reported as "inode#" in /proc/pid/maps.
540 * proc-ps tools use this. Changing this will break them.
541 */
Al Viro496ad9a2013-01-23 17:07:38 -0500542 file_inode(file)->i_ino = shp->shm_perm.id;
Krishnakumar R551110a2005-10-29 18:16:45 -0700543
Kirill Korotaev4e982312006-10-02 02:18:22 -0700544 ns->shm_tot += numpages;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700545 error = shp->shm_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 shm_unlock(shp);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700547 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
549no_id:
Hugh Dickins2195d282009-09-12 12:21:27 +0100550 if (is_file_hugepages(file) && shp->mlock_user)
Hugh Dickins353d5c32009-08-24 16:30:28 +0100551 user_shm_unlock(size, shp->mlock_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 fput(file);
553no_file:
554 security_shm_free(shp);
555 ipc_rcu_putref(shp);
556 return error;
557}
558
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700559/*
Nadia Derbey3e148c72007-10-18 23:40:54 -0700560 * Called with shm_ids.rw_mutex and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700561 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700562static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700563{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700564 struct shmid_kernel *shp;
565
566 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
567 return security_shm_associate(shp, shmflg);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700568}
569
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700570/*
Nadia Derbey3e148c72007-10-18 23:40:54 -0700571 * Called with shm_ids.rw_mutex and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700572 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700573static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
574 struct ipc_params *params)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700575{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700576 struct shmid_kernel *shp;
577
578 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
579 if (shp->shm_segsz < params->u.size)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700580 return -EINVAL;
581
582 return 0;
583}
584
Heiko Carstensd5460c92009-01-14 14:14:27 +0100585SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700587 struct ipc_namespace *ns;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700588 struct ipc_ops shm_ops;
589 struct ipc_params shm_params;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
Kirill Korotaev4e982312006-10-02 02:18:22 -0700591 ns = current->nsproxy->ipc_ns;
592
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700593 shm_ops.getnew = newseg;
594 shm_ops.associate = shm_security;
595 shm_ops.more_checks = shm_more_checks;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700596
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700597 shm_params.key = key;
598 shm_params.flg = shmflg;
599 shm_params.u.size = size;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700600
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700601 return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602}
603
604static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
605{
606 switch(version) {
607 case IPC_64:
608 return copy_to_user(buf, in, sizeof(*in));
609 case IPC_OLD:
610 {
611 struct shmid_ds out;
612
Vasiliy Kulikov3af54c92010-10-30 18:22:49 +0400613 memset(&out, 0, sizeof(out));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
615 out.shm_segsz = in->shm_segsz;
616 out.shm_atime = in->shm_atime;
617 out.shm_dtime = in->shm_dtime;
618 out.shm_ctime = in->shm_ctime;
619 out.shm_cpid = in->shm_cpid;
620 out.shm_lpid = in->shm_lpid;
621 out.shm_nattch = in->shm_nattch;
622
623 return copy_to_user(buf, &out, sizeof(out));
624 }
625 default:
626 return -EINVAL;
627 }
628}
629
Pierre Peiffer016d7132008-04-29 01:00:50 -0700630static inline unsigned long
631copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632{
633 switch(version) {
634 case IPC_64:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700635 if (copy_from_user(out, buf, sizeof(*out)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 case IPC_OLD:
639 {
640 struct shmid_ds tbuf_old;
641
642 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
643 return -EFAULT;
644
Pierre Peiffer016d7132008-04-29 01:00:50 -0700645 out->shm_perm.uid = tbuf_old.shm_perm.uid;
646 out->shm_perm.gid = tbuf_old.shm_perm.gid;
647 out->shm_perm.mode = tbuf_old.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
649 return 0;
650 }
651 default:
652 return -EINVAL;
653 }
654}
655
656static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
657{
658 switch(version) {
659 case IPC_64:
660 return copy_to_user(buf, in, sizeof(*in));
661 case IPC_OLD:
662 {
663 struct shminfo out;
664
665 if(in->shmmax > INT_MAX)
666 out.shmmax = INT_MAX;
667 else
668 out.shmmax = (int)in->shmmax;
669
670 out.shmmin = in->shmmin;
671 out.shmmni = in->shmmni;
672 out.shmseg = in->shmseg;
673 out.shmall = in->shmall;
674
675 return copy_to_user(buf, &out, sizeof(out));
676 }
677 default:
678 return -EINVAL;
679 }
680}
681
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700682/*
Helge Dellerb7952182010-10-27 15:34:16 -0700683 * Calculate and add used RSS and swap pages of a shm.
684 * Called with shm_ids.rw_mutex held as a reader
685 */
686static void shm_add_rss_swap(struct shmid_kernel *shp,
687 unsigned long *rss_add, unsigned long *swp_add)
688{
689 struct inode *inode;
690
Al Viro496ad9a2013-01-23 17:07:38 -0500691 inode = file_inode(shp->shm_file);
Helge Dellerb7952182010-10-27 15:34:16 -0700692
693 if (is_file_hugepages(shp->shm_file)) {
694 struct address_space *mapping = inode->i_mapping;
695 struct hstate *h = hstate_file(shp->shm_file);
696 *rss_add += pages_per_huge_page(h) * mapping->nrpages;
697 } else {
698#ifdef CONFIG_SHMEM
699 struct shmem_inode_info *info = SHMEM_I(inode);
700 spin_lock(&info->lock);
701 *rss_add += inode->i_mapping->nrpages;
702 *swp_add += info->swapped;
703 spin_unlock(&info->lock);
704#else
705 *rss_add += inode->i_mapping->nrpages;
706#endif
707 }
708}
709
710/*
Nadia Derbey3e148c72007-10-18 23:40:54 -0700711 * Called with shm_ids.rw_mutex held as a reader
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700712 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700713static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
714 unsigned long *swp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700716 int next_id;
717 int total, in_use;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718
719 *rss = 0;
720 *swp = 0;
721
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700722 in_use = shm_ids(ns).in_use;
723
724 for (total = 0, next_id = 0; total < in_use; next_id++) {
Tony Battersbye562aeb2009-04-02 16:58:26 -0700725 struct kern_ipc_perm *ipc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 struct shmid_kernel *shp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727
Tony Battersbye562aeb2009-04-02 16:58:26 -0700728 ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
729 if (ipc == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 continue;
Tony Battersbye562aeb2009-04-02 16:58:26 -0700731 shp = container_of(ipc, struct shmid_kernel, shm_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732
Helge Dellerb7952182010-10-27 15:34:16 -0700733 shm_add_rss_swap(shp, rss, swp);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700734
735 total++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 }
737}
738
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700739/*
740 * This function handles some shmctl commands which require the rw_mutex
741 * to be held in write mode.
742 * NOTE: no locks must be held, the rw_mutex is taken inside this function.
743 */
744static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
745 struct shmid_ds __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746{
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700747 struct kern_ipc_perm *ipcp;
Pierre Peiffer016d7132008-04-29 01:00:50 -0700748 struct shmid64_ds shmid64;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 struct shmid_kernel *shp;
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700750 int err;
751
752 if (cmd == IPC_SET) {
Pierre Peiffer016d7132008-04-29 01:00:50 -0700753 if (copy_shmid_from_user(&shmid64, buf, version))
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700754 return -EFAULT;
755 }
756
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700757 ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd,
758 &shmid64.shm_perm, 0);
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700759 if (IS_ERR(ipcp))
760 return PTR_ERR(ipcp);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700761
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700762 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700763
764 err = security_shm_shmctl(shp, cmd);
765 if (err)
766 goto out_unlock;
767 switch (cmd) {
768 case IPC_RMID:
769 do_shm_rmid(ns, ipcp);
770 goto out_up;
771 case IPC_SET:
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800772 err = ipc_update_perm(&shmid64.shm_perm, ipcp);
773 if (err)
774 goto out_unlock;
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700775 shp->shm_ctim = get_seconds();
776 break;
777 default:
778 err = -EINVAL;
779 }
780out_unlock:
781 shm_unlock(shp);
782out_up:
783 up_write(&shm_ids(ns).rw_mutex);
784 return err;
785}
786
Heiko Carstensd5460c92009-01-14 14:14:27 +0100787SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700788{
789 struct shmid_kernel *shp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 int err, version;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700791 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792
793 if (cmd < 0 || shmid < 0) {
794 err = -EINVAL;
795 goto out;
796 }
797
798 version = ipc_parse_version(&cmd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700799 ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
801 switch (cmd) { /* replace with proc interface ? */
802 case IPC_INFO:
803 {
804 struct shminfo64 shminfo;
805
806 err = security_shm_shmctl(NULL, cmd);
807 if (err)
808 return err;
809
WANG Conge8148f72009-01-06 14:42:49 -0800810 memset(&shminfo, 0, sizeof(shminfo));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700811 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
812 shminfo.shmmax = ns->shm_ctlmax;
813 shminfo.shmall = ns->shm_ctlall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814
815 shminfo.shmmin = SHMMIN;
816 if(copy_shminfo_to_user (buf, &shminfo, version))
817 return -EFAULT;
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700818
Nadia Derbey3e148c72007-10-18 23:40:54 -0700819 down_read(&shm_ids(ns).rw_mutex);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700820 err = ipc_get_maxid(&shm_ids(ns));
Nadia Derbey3e148c72007-10-18 23:40:54 -0700821 up_read(&shm_ids(ns).rw_mutex);
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700822
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 if(err<0)
824 err = 0;
825 goto out;
826 }
827 case SHM_INFO:
828 {
829 struct shm_info shm_info;
830
831 err = security_shm_shmctl(NULL, cmd);
832 if (err)
833 return err;
834
WANG Conge8148f72009-01-06 14:42:49 -0800835 memset(&shm_info, 0, sizeof(shm_info));
Nadia Derbey3e148c72007-10-18 23:40:54 -0700836 down_read(&shm_ids(ns).rw_mutex);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700837 shm_info.used_ids = shm_ids(ns).in_use;
838 shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
839 shm_info.shm_tot = ns->shm_tot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 shm_info.swap_attempts = 0;
841 shm_info.swap_successes = 0;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700842 err = ipc_get_maxid(&shm_ids(ns));
Nadia Derbey3e148c72007-10-18 23:40:54 -0700843 up_read(&shm_ids(ns).rw_mutex);
WANG Conge8148f72009-01-06 14:42:49 -0800844 if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 err = -EFAULT;
846 goto out;
847 }
848
849 err = err < 0 ? 0 : err;
850 goto out;
851 }
852 case SHM_STAT:
853 case IPC_STAT:
854 {
855 struct shmid64_ds tbuf;
856 int result;
Nadia Derbey023a5352007-10-18 23:40:51 -0700857
Nadia Derbey023a5352007-10-18 23:40:51 -0700858 if (cmd == SHM_STAT) {
859 shp = shm_lock(ns, shmid);
860 if (IS_ERR(shp)) {
861 err = PTR_ERR(shp);
862 goto out;
863 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700864 result = shp->shm_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 } else {
Nadia Derbey023a5352007-10-18 23:40:51 -0700866 shp = shm_lock_check(ns, shmid);
867 if (IS_ERR(shp)) {
868 err = PTR_ERR(shp);
869 goto out;
870 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 result = 0;
872 }
WANG Conge8148f72009-01-06 14:42:49 -0800873 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700874 if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 goto out_unlock;
876 err = security_shm_shmctl(shp, cmd);
877 if (err)
878 goto out_unlock;
Nadia Derbey023a5352007-10-18 23:40:51 -0700879 memset(&tbuf, 0, sizeof(tbuf));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
881 tbuf.shm_segsz = shp->shm_segsz;
882 tbuf.shm_atime = shp->shm_atim;
883 tbuf.shm_dtime = shp->shm_dtim;
884 tbuf.shm_ctime = shp->shm_ctim;
885 tbuf.shm_cpid = shp->shm_cprid;
886 tbuf.shm_lpid = shp->shm_lprid;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800887 tbuf.shm_nattch = shp->shm_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888 shm_unlock(shp);
889 if(copy_shmid_to_user (buf, &tbuf, version))
890 err = -EFAULT;
891 else
892 err = result;
893 goto out;
894 }
895 case SHM_LOCK:
896 case SHM_UNLOCK:
897 {
Hugh Dickins850465792012-01-20 14:34:19 -0800898 struct file *shm_file;
Lee Schermerhorn89e004ea2008-10-18 20:26:43 -0700899
Nadia Derbey023a5352007-10-18 23:40:51 -0700900 shp = shm_lock_check(ns, shmid);
901 if (IS_ERR(shp)) {
902 err = PTR_ERR(shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 goto out;
904 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905
Al Viroa33e6752008-12-10 03:40:06 -0500906 audit_ipc_obj(&(shp->shm_perm));
Steve Grubb073115d2006-04-02 17:07:33 -0400907
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700908 if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800909 kuid_t euid = current_euid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 err = -EPERM;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800911 if (!uid_eq(euid, shp->shm_perm.uid) &&
912 !uid_eq(euid, shp->shm_perm.cuid))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 goto out_unlock;
Jiri Slabyf1eb1332010-03-10 15:23:05 -0800914 if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 goto out_unlock;
916 }
917
918 err = security_shm_shmctl(shp, cmd);
919 if (err)
920 goto out_unlock;
Hugh Dickins850465792012-01-20 14:34:19 -0800921
922 shm_file = shp->shm_file;
923 if (is_file_hugepages(shm_file))
924 goto out_unlock;
925
926 if (cmd == SHM_LOCK) {
David Howells86a264a2008-11-14 10:39:18 +1100927 struct user_struct *user = current_user();
Hugh Dickins850465792012-01-20 14:34:19 -0800928 err = shmem_lock(shm_file, 1, user);
929 if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
930 shp->shm_perm.mode |= SHM_LOCKED;
931 shp->mlock_user = user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 }
Hugh Dickins850465792012-01-20 14:34:19 -0800933 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 }
Hugh Dickins850465792012-01-20 14:34:19 -0800935
936 /* SHM_UNLOCK */
937 if (!(shp->shm_perm.mode & SHM_LOCKED))
938 goto out_unlock;
939 shmem_lock(shm_file, 0, shp->mlock_user);
940 shp->shm_perm.mode &= ~SHM_LOCKED;
941 shp->mlock_user = NULL;
942 get_file(shm_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 shm_unlock(shp);
Hugh Dickins24513262012-01-20 14:34:21 -0800944 shmem_unlock_mapping(shm_file->f_mapping);
Hugh Dickins850465792012-01-20 14:34:19 -0800945 fput(shm_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 goto out;
947 }
948 case IPC_RMID:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 case IPC_SET:
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700950 err = shmctl_down(ns, shmid, cmd, buf, version);
951 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 default:
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700953 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 }
955
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956out_unlock:
957 shm_unlock(shp);
958out:
959 return err;
960}
961
962/*
963 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
964 *
965 * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
966 * "raddr" thing points to kernel space, and there has to be a wrapper around
967 * this.
968 */
Will Deacon079a96a2012-07-30 14:42:38 -0700969long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
970 unsigned long shmlba)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971{
972 struct shmid_kernel *shp;
973 unsigned long addr;
974 unsigned long size;
975 struct file * file;
976 int err;
977 unsigned long flags;
978 unsigned long prot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 int acc_mode;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700980 struct ipc_namespace *ns;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800981 struct shm_file_data *sfd;
982 struct path path;
Al Viroaeb5d722008-09-02 15:28:45 -0400983 fmode_t f_mode;
Michel Lespinasse41badc12013-02-22 16:32:47 -0800984 unsigned long populate = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800986 err = -EINVAL;
987 if (shmid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 goto out;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800989 else if ((addr = (ulong)shmaddr)) {
Will Deacon079a96a2012-07-30 14:42:38 -0700990 if (addr & (shmlba - 1)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 if (shmflg & SHM_RND)
Will Deacon079a96a2012-07-30 14:42:38 -0700992 addr &= ~(shmlba - 1); /* round down */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 else
994#ifndef __ARCH_FORCE_SHMLBA
995 if (addr & ~PAGE_MASK)
996#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800997 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 }
999 flags = MAP_SHARED | MAP_FIXED;
1000 } else {
1001 if ((shmflg & SHM_REMAP))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001002 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003
1004 flags = MAP_SHARED;
1005 }
1006
1007 if (shmflg & SHM_RDONLY) {
1008 prot = PROT_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 acc_mode = S_IRUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001010 f_mode = FMODE_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 } else {
1012 prot = PROT_READ | PROT_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 acc_mode = S_IRUGO | S_IWUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001014 f_mode = FMODE_READ | FMODE_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 }
1016 if (shmflg & SHM_EXEC) {
1017 prot |= PROT_EXEC;
1018 acc_mode |= S_IXUGO;
1019 }
1020
1021 /*
1022 * We cannot rely on the fs check since SYSV IPC does have an
1023 * additional creator id...
1024 */
Kirill Korotaev4e982312006-10-02 02:18:22 -07001025 ns = current->nsproxy->ipc_ns;
Nadia Derbey023a5352007-10-18 23:40:51 -07001026 shp = shm_lock_check(ns, shmid);
1027 if (IS_ERR(shp)) {
1028 err = PTR_ERR(shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 goto out;
Nadia Derbey023a5352007-10-18 23:40:51 -07001030 }
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001031
1032 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -07001033 if (ipcperms(ns, &shp->shm_perm, acc_mode))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001034 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035
1036 err = security_shm_shmat(shp, shmaddr, shmflg);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001037 if (err)
1038 goto out_unlock;
1039
Al Viro2c48b9c2009-08-09 00:52:35 +04001040 path = shp->shm_file->f_path;
1041 path_get(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 shp->shm_nattch++;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001043 size = i_size_read(path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 shm_unlock(shp);
1045
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001046 err = -ENOMEM;
1047 sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
1048 if (!sfd)
Dave Hansence8d2cd2007-10-16 23:31:13 -07001049 goto out_put_dentry;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001050
Al Viro2c48b9c2009-08-09 00:52:35 +04001051 file = alloc_file(&path, f_mode,
1052 is_file_hugepages(shp->shm_file) ?
Al Viroc4caa772009-11-30 08:38:43 -05001053 &shm_file_operations_huge :
1054 &shm_file_operations);
Anatol Pomozov39b65252012-09-12 20:11:55 -07001055 err = PTR_ERR(file);
1056 if (IS_ERR(file))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001057 goto out_free;
1058
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001059 file->private_data = sfd;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001060 file->f_mapping = shp->shm_file->f_mapping;
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001061 sfd->id = shp->shm_perm.id;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001062 sfd->ns = get_ipc_ns(ns);
1063 sfd->file = shp->shm_file;
1064 sfd->vm_ops = NULL;
1065
Al Viro8b3ec682012-05-30 17:11:23 -04001066 err = security_mmap_file(file, prot, flags);
1067 if (err)
1068 goto out_fput;
1069
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070 down_write(&current->mm->mmap_sem);
1071 if (addr && !(shmflg & SHM_REMAP)) {
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001072 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073 if (find_vma_intersection(current->mm, addr, addr + size))
1074 goto invalid;
1075 /*
1076 * If shm segment goes below stack, make sure there is some
1077 * space left for the stack to grow (at least 4 pages).
1078 */
1079 if (addr < current->mm->start_stack &&
1080 addr > current->mm->start_stack - size - PAGE_SIZE * 5)
1081 goto invalid;
1082 }
1083
Michel Lespinassebebeb3d2013-02-22 16:32:37 -08001084 addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
1085 *raddr = addr;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001086 err = 0;
Michel Lespinassebebeb3d2013-02-22 16:32:37 -08001087 if (IS_ERR_VALUE(addr))
1088 err = (long)addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089invalid:
1090 up_write(&current->mm->mmap_sem);
Michel Lespinassebebeb3d2013-02-22 16:32:37 -08001091 if (populate)
Michel Lespinasse41badc12013-02-22 16:32:47 -08001092 mm_populate(addr, populate);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093
Al Viro8b3ec682012-05-30 17:11:23 -04001094out_fput:
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001095 fput(file);
1096
1097out_nattch:
Nadia Derbey3e148c72007-10-18 23:40:54 -07001098 down_write(&shm_ids(ns).rw_mutex);
Nadia Derbey00c2bf82008-07-25 01:48:03 -07001099 shp = shm_lock(ns, shmid);
Nadia Derbey023a5352007-10-18 23:40:51 -07001100 BUG_ON(IS_ERR(shp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 shp->shm_nattch--;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -07001102 if (shm_may_destroy(ns, shp))
Kirill Korotaev4e982312006-10-02 02:18:22 -07001103 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104 else
1105 shm_unlock(shp);
Nadia Derbey3e148c72007-10-18 23:40:54 -07001106 up_write(&shm_ids(ns).rw_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108out:
1109 return err;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001110
1111out_unlock:
1112 shm_unlock(shp);
1113 goto out;
1114
1115out_free:
1116 kfree(sfd);
Dave Hansence8d2cd2007-10-16 23:31:13 -07001117out_put_dentry:
Al Viro2c48b9c2009-08-09 00:52:35 +04001118 path_put(&path);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001119 goto out_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120}
1121
Heiko Carstensd5460c92009-01-14 14:14:27 +01001122SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -07001123{
1124 unsigned long ret;
1125 long err;
1126
Will Deacon079a96a2012-07-30 14:42:38 -07001127 err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -07001128 if (err)
1129 return err;
1130 force_successful_syscall_return();
1131 return (long)ret;
1132}
1133
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134/*
1135 * detach and kill segment if marked destroyed.
1136 * The work is done in shm_close.
1137 */
Heiko Carstensd5460c92009-01-14 14:14:27 +01001138SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139{
1140 struct mm_struct *mm = current->mm;
Mike Frysinger586c7e62009-06-09 16:26:23 -07001141 struct vm_area_struct *vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 unsigned long addr = (unsigned long)shmaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 int retval = -EINVAL;
Mike Frysinger586c7e62009-06-09 16:26:23 -07001144#ifdef CONFIG_MMU
1145 loff_t size = 0;
1146 struct vm_area_struct *next;
1147#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148
Hugh Dickinsdf1e2fb2006-03-24 03:18:06 -08001149 if (addr & ~PAGE_MASK)
1150 return retval;
1151
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 down_write(&mm->mmap_sem);
1153
1154 /*
1155 * This function tries to be smart and unmap shm segments that
1156 * were modified by partial mlock or munmap calls:
1157 * - It first determines the size of the shm segment that should be
1158 * unmapped: It searches for a vma that is backed by shm and that
1159 * started at address shmaddr. It records it's size and then unmaps
1160 * it.
1161 * - Then it unmaps all shm vmas that started at shmaddr and that
1162 * are within the initially determined size.
1163 * Errors from do_munmap are ignored: the function only fails if
1164 * it's called with invalid parameters or if it's called to unmap
1165 * a part of a vma. Both calls in this function are for full vmas,
1166 * the parameters are directly copied from the vma itself and always
1167 * valid - therefore do_munmap cannot fail. (famous last words?)
1168 */
1169 /*
1170 * If it had been mremap()'d, the starting address would not
1171 * match the usual checks anyway. So assume all vma's are
1172 * above the starting address given.
1173 */
1174 vma = find_vma(mm, addr);
1175
David Howells8feae132009-01-08 12:04:47 +00001176#ifdef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 while (vma) {
1178 next = vma->vm_next;
1179
1180 /*
1181 * Check if the starting address would match, i.e. it's
1182 * a fragment created by mprotect() and/or munmap(), or it
1183 * otherwise it starts at this address with no hassles.
1184 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001185 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1187
1188
Al Viro496ad9a2013-01-23 17:07:38 -05001189 size = file_inode(vma->vm_file)->i_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1191 /*
1192 * We discovered the size of the shm segment, so
1193 * break out of here and fall through to the next
1194 * loop that uses the size information to stop
1195 * searching for matching vma's.
1196 */
1197 retval = 0;
1198 vma = next;
1199 break;
1200 }
1201 vma = next;
1202 }
1203
1204 /*
1205 * We need look no further than the maximum address a fragment
1206 * could possibly have landed at. Also cast things to loff_t to
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001207 * prevent overflows and make comparisons vs. equal-width types.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 */
KAMEZAWA Hiroyuki8e367092006-02-10 01:51:12 -08001209 size = PAGE_ALIGN(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1211 next = vma->vm_next;
1212
1213 /* finding a matching vma now does not alter retval */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001214 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
1216
1217 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1218 vma = next;
1219 }
1220
David Howells8feae132009-01-08 12:04:47 +00001221#else /* CONFIG_MMU */
1222 /* under NOMMU conditions, the exact address to be destroyed must be
1223 * given */
1224 retval = -EINVAL;
1225 if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
1226 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1227 retval = 0;
1228 }
1229
1230#endif
1231
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 up_write(&mm->mmap_sem);
1233 return retval;
1234}
1235
1236#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001237static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238{
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001239 struct user_namespace *user_ns = seq_user_ns(s);
Mike Waychison19b49462005-09-06 15:17:10 -07001240 struct shmid_kernel *shp = it;
Helge Dellerb7952182010-10-27 15:34:16 -07001241 unsigned long rss = 0, swp = 0;
1242
1243 shm_add_rss_swap(shp, &rss, &swp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244
Paul Menage6c826812008-06-12 15:21:49 -07001245#if BITS_PER_LONG <= 32
1246#define SIZE_SPEC "%10lu"
1247#else
1248#define SIZE_SPEC "%21lu"
1249#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250
Paul Menage6c826812008-06-12 15:21:49 -07001251 return seq_printf(s,
1252 "%10d %10d %4o " SIZE_SPEC " %5u %5u "
Helge Dellerb7952182010-10-27 15:34:16 -07001253 "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
1254 SIZE_SPEC " " SIZE_SPEC "\n",
Mike Waychison19b49462005-09-06 15:17:10 -07001255 shp->shm_perm.key,
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001256 shp->shm_perm.id,
Andrew Mortonb33291c2006-01-08 01:02:21 -08001257 shp->shm_perm.mode,
Mike Waychison19b49462005-09-06 15:17:10 -07001258 shp->shm_segsz,
1259 shp->shm_cprid,
1260 shp->shm_lprid,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001261 shp->shm_nattch,
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001262 from_kuid_munged(user_ns, shp->shm_perm.uid),
1263 from_kgid_munged(user_ns, shp->shm_perm.gid),
1264 from_kuid_munged(user_ns, shp->shm_perm.cuid),
1265 from_kgid_munged(user_ns, shp->shm_perm.cgid),
Mike Waychison19b49462005-09-06 15:17:10 -07001266 shp->shm_atim,
1267 shp->shm_dtim,
Helge Dellerb7952182010-10-27 15:34:16 -07001268 shp->shm_ctim,
1269 rss * PAGE_SIZE,
1270 swp * PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271}
1272#endif