blob: 00faa05cf72adf914bc40a41113182da964eec31 [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)
Josef Sipek6d630792006-12-08 02:37:11 -0800196 user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->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;
465 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
466 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) {
Mel Gorman5a6fe122009-02-10 14:02:27 +0000494 /* hugetlb_file_setup applies strict accounting */
495 if (shmflg & SHM_NORESERVE)
496 acctflag = VM_NORESERVE;
Steven Truelove40716e22012-03-21 16:34:14 -0700497 file = hugetlb_file_setup(name, 0, size, acctflag,
Eric B Munson6bfde052009-09-21 17:03:43 -0700498 &shp->mlock_user, HUGETLB_SHMFS_INODE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 } else {
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800500 /*
501 * Do not allow no accounting for OVERCOMMIT_NEVER, even
502 * if it's asked for.
503 */
504 if ((shmflg & SHM_NORESERVE) &&
505 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
Linus Torvaldsfc8744a2009-01-31 15:08:56 -0800506 acctflag = VM_NORESERVE;
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800507 file = shmem_file_setup(name, size, acctflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 }
509 error = PTR_ERR(file);
510 if (IS_ERR(file))
511 goto no_file;
512
Pierre Peiffer48dea402008-04-29 01:00:35 -0700513 id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700514 if (id < 0) {
515 error = id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 goto no_id;
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700517 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700519 shp->shm_cprid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 shp->shm_lprid = 0;
521 shp->shm_atim = shp->shm_dtim = 0;
522 shp->shm_ctim = get_seconds();
523 shp->shm_segsz = size;
524 shp->shm_nattch = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 shp->shm_file = file;
Vasiliy Kulikov5774ed02011-07-29 03:55:31 +0400526 shp->shm_creator = current;
Badari Pulavarty30475cc2007-06-16 10:15:59 -0700527 /*
528 * shmid gets reported as "inode#" in /proc/pid/maps.
529 * proc-ps tools use this. Changing this will break them.
530 */
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700531 file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
Krishnakumar R551110a2005-10-29 18:16:45 -0700532
Kirill Korotaev4e982312006-10-02 02:18:22 -0700533 ns->shm_tot += numpages;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700534 error = shp->shm_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 shm_unlock(shp);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700536 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
538no_id:
Hugh Dickins2195d282009-09-12 12:21:27 +0100539 if (is_file_hugepages(file) && shp->mlock_user)
Hugh Dickins353d5c32009-08-24 16:30:28 +0100540 user_shm_unlock(size, shp->mlock_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 fput(file);
542no_file:
543 security_shm_free(shp);
544 ipc_rcu_putref(shp);
545 return error;
546}
547
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700548/*
Nadia Derbey3e148c72007-10-18 23:40:54 -0700549 * Called with shm_ids.rw_mutex and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700550 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700551static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700552{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700553 struct shmid_kernel *shp;
554
555 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
556 return security_shm_associate(shp, shmflg);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700557}
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_more_checks(struct kern_ipc_perm *ipcp,
563 struct ipc_params *params)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700564{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700565 struct shmid_kernel *shp;
566
567 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
568 if (shp->shm_segsz < params->u.size)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700569 return -EINVAL;
570
571 return 0;
572}
573
Heiko Carstensd5460c92009-01-14 14:14:27 +0100574SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700576 struct ipc_namespace *ns;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700577 struct ipc_ops shm_ops;
578 struct ipc_params shm_params;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
Kirill Korotaev4e982312006-10-02 02:18:22 -0700580 ns = current->nsproxy->ipc_ns;
581
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700582 shm_ops.getnew = newseg;
583 shm_ops.associate = shm_security;
584 shm_ops.more_checks = shm_more_checks;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700585
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700586 shm_params.key = key;
587 shm_params.flg = shmflg;
588 shm_params.u.size = size;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700589
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700590 return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591}
592
593static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
594{
595 switch(version) {
596 case IPC_64:
597 return copy_to_user(buf, in, sizeof(*in));
598 case IPC_OLD:
599 {
600 struct shmid_ds out;
601
Vasiliy Kulikov3af54c92010-10-30 18:22:49 +0400602 memset(&out, 0, sizeof(out));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
604 out.shm_segsz = in->shm_segsz;
605 out.shm_atime = in->shm_atime;
606 out.shm_dtime = in->shm_dtime;
607 out.shm_ctime = in->shm_ctime;
608 out.shm_cpid = in->shm_cpid;
609 out.shm_lpid = in->shm_lpid;
610 out.shm_nattch = in->shm_nattch;
611
612 return copy_to_user(buf, &out, sizeof(out));
613 }
614 default:
615 return -EINVAL;
616 }
617}
618
Pierre Peiffer016d7132008-04-29 01:00:50 -0700619static inline unsigned long
620copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621{
622 switch(version) {
623 case IPC_64:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700624 if (copy_from_user(out, buf, sizeof(*out)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 case IPC_OLD:
628 {
629 struct shmid_ds tbuf_old;
630
631 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
632 return -EFAULT;
633
Pierre Peiffer016d7132008-04-29 01:00:50 -0700634 out->shm_perm.uid = tbuf_old.shm_perm.uid;
635 out->shm_perm.gid = tbuf_old.shm_perm.gid;
636 out->shm_perm.mode = tbuf_old.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637
638 return 0;
639 }
640 default:
641 return -EINVAL;
642 }
643}
644
645static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
646{
647 switch(version) {
648 case IPC_64:
649 return copy_to_user(buf, in, sizeof(*in));
650 case IPC_OLD:
651 {
652 struct shminfo out;
653
654 if(in->shmmax > INT_MAX)
655 out.shmmax = INT_MAX;
656 else
657 out.shmmax = (int)in->shmmax;
658
659 out.shmmin = in->shmmin;
660 out.shmmni = in->shmmni;
661 out.shmseg = in->shmseg;
662 out.shmall = in->shmall;
663
664 return copy_to_user(buf, &out, sizeof(out));
665 }
666 default:
667 return -EINVAL;
668 }
669}
670
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700671/*
Helge Dellerb7952182010-10-27 15:34:16 -0700672 * Calculate and add used RSS and swap pages of a shm.
673 * Called with shm_ids.rw_mutex held as a reader
674 */
675static void shm_add_rss_swap(struct shmid_kernel *shp,
676 unsigned long *rss_add, unsigned long *swp_add)
677{
678 struct inode *inode;
679
680 inode = shp->shm_file->f_path.dentry->d_inode;
681
682 if (is_file_hugepages(shp->shm_file)) {
683 struct address_space *mapping = inode->i_mapping;
684 struct hstate *h = hstate_file(shp->shm_file);
685 *rss_add += pages_per_huge_page(h) * mapping->nrpages;
686 } else {
687#ifdef CONFIG_SHMEM
688 struct shmem_inode_info *info = SHMEM_I(inode);
689 spin_lock(&info->lock);
690 *rss_add += inode->i_mapping->nrpages;
691 *swp_add += info->swapped;
692 spin_unlock(&info->lock);
693#else
694 *rss_add += inode->i_mapping->nrpages;
695#endif
696 }
697}
698
699/*
Nadia Derbey3e148c72007-10-18 23:40:54 -0700700 * Called with shm_ids.rw_mutex held as a reader
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700701 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700702static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
703 unsigned long *swp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704{
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700705 int next_id;
706 int total, in_use;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707
708 *rss = 0;
709 *swp = 0;
710
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700711 in_use = shm_ids(ns).in_use;
712
713 for (total = 0, next_id = 0; total < in_use; next_id++) {
Tony Battersbye562aeb2009-04-02 16:58:26 -0700714 struct kern_ipc_perm *ipc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 struct shmid_kernel *shp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716
Tony Battersbye562aeb2009-04-02 16:58:26 -0700717 ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
718 if (ipc == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 continue;
Tony Battersbye562aeb2009-04-02 16:58:26 -0700720 shp = container_of(ipc, struct shmid_kernel, shm_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721
Helge Dellerb7952182010-10-27 15:34:16 -0700722 shm_add_rss_swap(shp, rss, swp);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700723
724 total++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 }
726}
727
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700728/*
729 * This function handles some shmctl commands which require the rw_mutex
730 * to be held in write mode.
731 * NOTE: no locks must be held, the rw_mutex is taken inside this function.
732 */
733static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
734 struct shmid_ds __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735{
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700736 struct kern_ipc_perm *ipcp;
Pierre Peiffer016d7132008-04-29 01:00:50 -0700737 struct shmid64_ds shmid64;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 struct shmid_kernel *shp;
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700739 int err;
740
741 if (cmd == IPC_SET) {
Pierre Peiffer016d7132008-04-29 01:00:50 -0700742 if (copy_shmid_from_user(&shmid64, buf, version))
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700743 return -EFAULT;
744 }
745
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700746 ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd,
747 &shmid64.shm_perm, 0);
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700748 if (IS_ERR(ipcp))
749 return PTR_ERR(ipcp);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700750
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700751 shp = container_of(ipcp, struct shmid_kernel, shm_perm);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700752
753 err = security_shm_shmctl(shp, cmd);
754 if (err)
755 goto out_unlock;
756 switch (cmd) {
757 case IPC_RMID:
758 do_shm_rmid(ns, ipcp);
759 goto out_up;
760 case IPC_SET:
Pierre Peiffer8f4a3802008-04-29 01:00:51 -0700761 ipc_update_perm(&shmid64.shm_perm, ipcp);
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700762 shp->shm_ctim = get_seconds();
763 break;
764 default:
765 err = -EINVAL;
766 }
767out_unlock:
768 shm_unlock(shp);
769out_up:
770 up_write(&shm_ids(ns).rw_mutex);
771 return err;
772}
773
Heiko Carstensd5460c92009-01-14 14:14:27 +0100774SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700775{
776 struct shmid_kernel *shp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 int err, version;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700778 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
780 if (cmd < 0 || shmid < 0) {
781 err = -EINVAL;
782 goto out;
783 }
784
785 version = ipc_parse_version(&cmd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700786 ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787
788 switch (cmd) { /* replace with proc interface ? */
789 case IPC_INFO:
790 {
791 struct shminfo64 shminfo;
792
793 err = security_shm_shmctl(NULL, cmd);
794 if (err)
795 return err;
796
WANG Conge8148f72009-01-06 14:42:49 -0800797 memset(&shminfo, 0, sizeof(shminfo));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700798 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
799 shminfo.shmmax = ns->shm_ctlmax;
800 shminfo.shmall = ns->shm_ctlall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
802 shminfo.shmmin = SHMMIN;
803 if(copy_shminfo_to_user (buf, &shminfo, version))
804 return -EFAULT;
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700805
Nadia Derbey3e148c72007-10-18 23:40:54 -0700806 down_read(&shm_ids(ns).rw_mutex);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700807 err = ipc_get_maxid(&shm_ids(ns));
Nadia Derbey3e148c72007-10-18 23:40:54 -0700808 up_read(&shm_ids(ns).rw_mutex);
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700809
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 if(err<0)
811 err = 0;
812 goto out;
813 }
814 case SHM_INFO:
815 {
816 struct shm_info shm_info;
817
818 err = security_shm_shmctl(NULL, cmd);
819 if (err)
820 return err;
821
WANG Conge8148f72009-01-06 14:42:49 -0800822 memset(&shm_info, 0, sizeof(shm_info));
Nadia Derbey3e148c72007-10-18 23:40:54 -0700823 down_read(&shm_ids(ns).rw_mutex);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700824 shm_info.used_ids = shm_ids(ns).in_use;
825 shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
826 shm_info.shm_tot = ns->shm_tot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 shm_info.swap_attempts = 0;
828 shm_info.swap_successes = 0;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700829 err = ipc_get_maxid(&shm_ids(ns));
Nadia Derbey3e148c72007-10-18 23:40:54 -0700830 up_read(&shm_ids(ns).rw_mutex);
WANG Conge8148f72009-01-06 14:42:49 -0800831 if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 err = -EFAULT;
833 goto out;
834 }
835
836 err = err < 0 ? 0 : err;
837 goto out;
838 }
839 case SHM_STAT:
840 case IPC_STAT:
841 {
842 struct shmid64_ds tbuf;
843 int result;
Nadia Derbey023a5352007-10-18 23:40:51 -0700844
Nadia Derbey023a5352007-10-18 23:40:51 -0700845 if (cmd == SHM_STAT) {
846 shp = shm_lock(ns, shmid);
847 if (IS_ERR(shp)) {
848 err = PTR_ERR(shp);
849 goto out;
850 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700851 result = shp->shm_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 } else {
Nadia Derbey023a5352007-10-18 23:40:51 -0700853 shp = shm_lock_check(ns, shmid);
854 if (IS_ERR(shp)) {
855 err = PTR_ERR(shp);
856 goto out;
857 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 result = 0;
859 }
WANG Conge8148f72009-01-06 14:42:49 -0800860 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700861 if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862 goto out_unlock;
863 err = security_shm_shmctl(shp, cmd);
864 if (err)
865 goto out_unlock;
Nadia Derbey023a5352007-10-18 23:40:51 -0700866 memset(&tbuf, 0, sizeof(tbuf));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
868 tbuf.shm_segsz = shp->shm_segsz;
869 tbuf.shm_atime = shp->shm_atim;
870 tbuf.shm_dtime = shp->shm_dtim;
871 tbuf.shm_ctime = shp->shm_ctim;
872 tbuf.shm_cpid = shp->shm_cprid;
873 tbuf.shm_lpid = shp->shm_lprid;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800874 tbuf.shm_nattch = shp->shm_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 shm_unlock(shp);
876 if(copy_shmid_to_user (buf, &tbuf, version))
877 err = -EFAULT;
878 else
879 err = result;
880 goto out;
881 }
882 case SHM_LOCK:
883 case SHM_UNLOCK:
884 {
Hugh Dickins850465792012-01-20 14:34:19 -0800885 struct file *shm_file;
Lee Schermerhorn89e004ea2008-10-18 20:26:43 -0700886
Nadia Derbey023a5352007-10-18 23:40:51 -0700887 shp = shm_lock_check(ns, shmid);
888 if (IS_ERR(shp)) {
889 err = PTR_ERR(shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 goto out;
891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
Al Viroa33e6752008-12-10 03:40:06 -0500893 audit_ipc_obj(&(shp->shm_perm));
Steve Grubb073115d2006-04-02 17:07:33 -0400894
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700895 if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
David Howells414c0702008-11-14 10:39:06 +1100896 uid_t euid = current_euid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 err = -EPERM;
David Howells414c0702008-11-14 10:39:06 +1100898 if (euid != shp->shm_perm.uid &&
899 euid != shp->shm_perm.cuid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 goto out_unlock;
Jiri Slabyf1eb1332010-03-10 15:23:05 -0800901 if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 goto out_unlock;
903 }
904
905 err = security_shm_shmctl(shp, cmd);
906 if (err)
907 goto out_unlock;
Hugh Dickins850465792012-01-20 14:34:19 -0800908
909 shm_file = shp->shm_file;
910 if (is_file_hugepages(shm_file))
911 goto out_unlock;
912
913 if (cmd == SHM_LOCK) {
David Howells86a264a2008-11-14 10:39:18 +1100914 struct user_struct *user = current_user();
Hugh Dickins850465792012-01-20 14:34:19 -0800915 err = shmem_lock(shm_file, 1, user);
916 if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
917 shp->shm_perm.mode |= SHM_LOCKED;
918 shp->mlock_user = user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 }
Hugh Dickins850465792012-01-20 14:34:19 -0800920 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 }
Hugh Dickins850465792012-01-20 14:34:19 -0800922
923 /* SHM_UNLOCK */
924 if (!(shp->shm_perm.mode & SHM_LOCKED))
925 goto out_unlock;
926 shmem_lock(shm_file, 0, shp->mlock_user);
927 shp->shm_perm.mode &= ~SHM_LOCKED;
928 shp->mlock_user = NULL;
929 get_file(shm_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 shm_unlock(shp);
Hugh Dickins24513262012-01-20 14:34:21 -0800931 shmem_unlock_mapping(shm_file->f_mapping);
Hugh Dickins850465792012-01-20 14:34:19 -0800932 fput(shm_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 goto out;
934 }
935 case IPC_RMID:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 case IPC_SET:
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700937 err = shmctl_down(ns, shmid, cmd, buf, version);
938 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 default:
Pierre Peiffer8d4cc8b2008-04-29 01:00:47 -0700940 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 }
942
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943out_unlock:
944 shm_unlock(shp);
945out:
946 return err;
947}
948
949/*
950 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
951 *
952 * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
953 * "raddr" thing points to kernel space, and there has to be a wrapper around
954 * this.
955 */
Will Deacon079a96a2012-07-30 14:42:38 -0700956long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
957 unsigned long shmlba)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958{
959 struct shmid_kernel *shp;
960 unsigned long addr;
961 unsigned long size;
962 struct file * file;
963 int err;
964 unsigned long flags;
965 unsigned long prot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 int acc_mode;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800967 unsigned long user_addr;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700968 struct ipc_namespace *ns;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800969 struct shm_file_data *sfd;
970 struct path path;
Al Viroaeb5d722008-09-02 15:28:45 -0400971 fmode_t f_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800973 err = -EINVAL;
974 if (shmid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 goto out;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800976 else if ((addr = (ulong)shmaddr)) {
Will Deacon079a96a2012-07-30 14:42:38 -0700977 if (addr & (shmlba - 1)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 if (shmflg & SHM_RND)
Will Deacon079a96a2012-07-30 14:42:38 -0700979 addr &= ~(shmlba - 1); /* round down */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 else
981#ifndef __ARCH_FORCE_SHMLBA
982 if (addr & ~PAGE_MASK)
983#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800984 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 }
986 flags = MAP_SHARED | MAP_FIXED;
987 } else {
988 if ((shmflg & SHM_REMAP))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800989 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990
991 flags = MAP_SHARED;
992 }
993
994 if (shmflg & SHM_RDONLY) {
995 prot = PROT_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 acc_mode = S_IRUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800997 f_mode = FMODE_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 } else {
999 prot = PROT_READ | PROT_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 acc_mode = S_IRUGO | S_IWUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001001 f_mode = FMODE_READ | FMODE_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 }
1003 if (shmflg & SHM_EXEC) {
1004 prot |= PROT_EXEC;
1005 acc_mode |= S_IXUGO;
1006 }
1007
1008 /*
1009 * We cannot rely on the fs check since SYSV IPC does have an
1010 * additional creator id...
1011 */
Kirill Korotaev4e982312006-10-02 02:18:22 -07001012 ns = current->nsproxy->ipc_ns;
Nadia Derbey023a5352007-10-18 23:40:51 -07001013 shp = shm_lock_check(ns, shmid);
1014 if (IS_ERR(shp)) {
1015 err = PTR_ERR(shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 goto out;
Nadia Derbey023a5352007-10-18 23:40:51 -07001017 }
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001018
1019 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -07001020 if (ipcperms(ns, &shp->shm_perm, acc_mode))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001021 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022
1023 err = security_shm_shmat(shp, shmaddr, shmflg);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001024 if (err)
1025 goto out_unlock;
1026
Al Viro2c48b9c2009-08-09 00:52:35 +04001027 path = shp->shm_file->f_path;
1028 path_get(&path);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 shp->shm_nattch++;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001030 size = i_size_read(path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 shm_unlock(shp);
1032
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001033 err = -ENOMEM;
1034 sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
1035 if (!sfd)
Dave Hansence8d2cd2007-10-16 23:31:13 -07001036 goto out_put_dentry;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001037
Al Viro2c48b9c2009-08-09 00:52:35 +04001038 file = alloc_file(&path, f_mode,
1039 is_file_hugepages(shp->shm_file) ?
Al Viroc4caa772009-11-30 08:38:43 -05001040 &shm_file_operations_huge :
1041 &shm_file_operations);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001042 if (!file)
1043 goto out_free;
1044
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001045 file->private_data = sfd;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001046 file->f_mapping = shp->shm_file->f_mapping;
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001047 sfd->id = shp->shm_perm.id;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001048 sfd->ns = get_ipc_ns(ns);
1049 sfd->file = shp->shm_file;
1050 sfd->vm_ops = NULL;
1051
Al Viro8b3ec682012-05-30 17:11:23 -04001052 err = security_mmap_file(file, prot, flags);
1053 if (err)
1054 goto out_fput;
1055
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 down_write(&current->mm->mmap_sem);
1057 if (addr && !(shmflg & SHM_REMAP)) {
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001058 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 if (find_vma_intersection(current->mm, addr, addr + size))
1060 goto invalid;
1061 /*
1062 * If shm segment goes below stack, make sure there is some
1063 * space left for the stack to grow (at least 4 pages).
1064 */
1065 if (addr < current->mm->start_stack &&
1066 addr > current->mm->start_stack - size - PAGE_SIZE * 5)
1067 goto invalid;
1068 }
1069
Al Viroe3fc6292012-05-30 20:08:42 -04001070 user_addr = do_mmap_pgoff(file, addr, size, prot, flags, 0);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001071 *raddr = user_addr;
1072 err = 0;
1073 if (IS_ERR_VALUE(user_addr))
1074 err = (long)user_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075invalid:
1076 up_write(&current->mm->mmap_sem);
1077
Al Viro8b3ec682012-05-30 17:11:23 -04001078out_fput:
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001079 fput(file);
1080
1081out_nattch:
Nadia Derbey3e148c72007-10-18 23:40:54 -07001082 down_write(&shm_ids(ns).rw_mutex);
Nadia Derbey00c2bf82008-07-25 01:48:03 -07001083 shp = shm_lock(ns, shmid);
Nadia Derbey023a5352007-10-18 23:40:51 -07001084 BUG_ON(IS_ERR(shp));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 shp->shm_nattch--;
Vasiliy Kulikovb34a6b12011-07-26 16:08:48 -07001086 if (shm_may_destroy(ns, shp))
Kirill Korotaev4e982312006-10-02 02:18:22 -07001087 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088 else
1089 shm_unlock(shp);
Nadia Derbey3e148c72007-10-18 23:40:54 -07001090 up_write(&shm_ids(ns).rw_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092out:
1093 return err;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001094
1095out_unlock:
1096 shm_unlock(shp);
1097 goto out;
1098
1099out_free:
1100 kfree(sfd);
Dave Hansence8d2cd2007-10-16 23:31:13 -07001101out_put_dentry:
Al Viro2c48b9c2009-08-09 00:52:35 +04001102 path_put(&path);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001103 goto out_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001104}
1105
Heiko Carstensd5460c92009-01-14 14:14:27 +01001106SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -07001107{
1108 unsigned long ret;
1109 long err;
1110
Will Deacon079a96a2012-07-30 14:42:38 -07001111 err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -07001112 if (err)
1113 return err;
1114 force_successful_syscall_return();
1115 return (long)ret;
1116}
1117
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118/*
1119 * detach and kill segment if marked destroyed.
1120 * The work is done in shm_close.
1121 */
Heiko Carstensd5460c92009-01-14 14:14:27 +01001122SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123{
1124 struct mm_struct *mm = current->mm;
Mike Frysinger586c7e62009-06-09 16:26:23 -07001125 struct vm_area_struct *vma;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 unsigned long addr = (unsigned long)shmaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 int retval = -EINVAL;
Mike Frysinger586c7e62009-06-09 16:26:23 -07001128#ifdef CONFIG_MMU
1129 loff_t size = 0;
1130 struct vm_area_struct *next;
1131#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132
Hugh Dickinsdf1e2fb2006-03-24 03:18:06 -08001133 if (addr & ~PAGE_MASK)
1134 return retval;
1135
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 down_write(&mm->mmap_sem);
1137
1138 /*
1139 * This function tries to be smart and unmap shm segments that
1140 * were modified by partial mlock or munmap calls:
1141 * - It first determines the size of the shm segment that should be
1142 * unmapped: It searches for a vma that is backed by shm and that
1143 * started at address shmaddr. It records it's size and then unmaps
1144 * it.
1145 * - Then it unmaps all shm vmas that started at shmaddr and that
1146 * are within the initially determined size.
1147 * Errors from do_munmap are ignored: the function only fails if
1148 * it's called with invalid parameters or if it's called to unmap
1149 * a part of a vma. Both calls in this function are for full vmas,
1150 * the parameters are directly copied from the vma itself and always
1151 * valid - therefore do_munmap cannot fail. (famous last words?)
1152 */
1153 /*
1154 * If it had been mremap()'d, the starting address would not
1155 * match the usual checks anyway. So assume all vma's are
1156 * above the starting address given.
1157 */
1158 vma = find_vma(mm, addr);
1159
David Howells8feae132009-01-08 12:04:47 +00001160#ifdef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 while (vma) {
1162 next = vma->vm_next;
1163
1164 /*
1165 * Check if the starting address would match, i.e. it's
1166 * a fragment created by mprotect() and/or munmap(), or it
1167 * otherwise it starts at this address with no hassles.
1168 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001169 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1171
1172
Josef Sipek6d630792006-12-08 02:37:11 -08001173 size = vma->vm_file->f_path.dentry->d_inode->i_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1175 /*
1176 * We discovered the size of the shm segment, so
1177 * break out of here and fall through to the next
1178 * loop that uses the size information to stop
1179 * searching for matching vma's.
1180 */
1181 retval = 0;
1182 vma = next;
1183 break;
1184 }
1185 vma = next;
1186 }
1187
1188 /*
1189 * We need look no further than the maximum address a fragment
1190 * could possibly have landed at. Also cast things to loff_t to
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001191 * prevent overflows and make comparisons vs. equal-width types.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 */
KAMEZAWA Hiroyuki8e367092006-02-10 01:51:12 -08001193 size = PAGE_ALIGN(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1195 next = vma->vm_next;
1196
1197 /* finding a matching vma now does not alter retval */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001198 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
1200
1201 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1202 vma = next;
1203 }
1204
David Howells8feae132009-01-08 12:04:47 +00001205#else /* CONFIG_MMU */
1206 /* under NOMMU conditions, the exact address to be destroyed must be
1207 * given */
1208 retval = -EINVAL;
1209 if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
1210 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1211 retval = 0;
1212 }
1213
1214#endif
1215
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 up_write(&mm->mmap_sem);
1217 return retval;
1218}
1219
1220#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001221static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222{
Mike Waychison19b49462005-09-06 15:17:10 -07001223 struct shmid_kernel *shp = it;
Helge Dellerb7952182010-10-27 15:34:16 -07001224 unsigned long rss = 0, swp = 0;
1225
1226 shm_add_rss_swap(shp, &rss, &swp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227
Paul Menage6c826812008-06-12 15:21:49 -07001228#if BITS_PER_LONG <= 32
1229#define SIZE_SPEC "%10lu"
1230#else
1231#define SIZE_SPEC "%21lu"
1232#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233
Paul Menage6c826812008-06-12 15:21:49 -07001234 return seq_printf(s,
1235 "%10d %10d %4o " SIZE_SPEC " %5u %5u "
Helge Dellerb7952182010-10-27 15:34:16 -07001236 "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
1237 SIZE_SPEC " " SIZE_SPEC "\n",
Mike Waychison19b49462005-09-06 15:17:10 -07001238 shp->shm_perm.key,
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001239 shp->shm_perm.id,
Andrew Mortonb33291c2006-01-08 01:02:21 -08001240 shp->shm_perm.mode,
Mike Waychison19b49462005-09-06 15:17:10 -07001241 shp->shm_segsz,
1242 shp->shm_cprid,
1243 shp->shm_lprid,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001244 shp->shm_nattch,
Mike Waychison19b49462005-09-06 15:17:10 -07001245 shp->shm_perm.uid,
1246 shp->shm_perm.gid,
1247 shp->shm_perm.cuid,
1248 shp->shm_perm.cgid,
1249 shp->shm_atim,
1250 shp->shm_dtim,
Helge Dellerb7952182010-10-27 15:34:16 -07001251 shp->shm_ctim,
1252 rss * PAGE_SIZE,
1253 swp * PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254}
1255#endif