blob: 4fefbad7096d539d90345621ac6419d2ab904b85 [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 Rothwell7d87e142005-05-01 08:59:12 -070036#include <linux/ptrace.h>
Mike Waychison19b49462005-09-06 15:17:10 -070037#include <linux/seq_file.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080038#include <linux/mutex.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>
Stephen Rothwell7d87e142005-05-01 08:59:12 -070041
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <asm/uaccess.h>
43
44#include "util.h"
45
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080046struct shm_file_data {
47 int id;
48 struct ipc_namespace *ns;
49 struct file *file;
50 const struct vm_operations_struct *vm_ops;
51};
52
53#define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
54
Arjan van de Ven9a321442007-02-12 00:55:35 -080055static const struct file_operations shm_file_operations;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056static struct vm_operations_struct shm_vm_ops;
57
Kirill Korotaev4e982312006-10-02 02:18:22 -070058static struct ipc_ids init_shm_ids;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
Kirill Korotaev4e982312006-10-02 02:18:22 -070060#define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS]))
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Kirill Korotaev4e982312006-10-02 02:18:22 -070062#define shm_lock(ns, id) \
63 ((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id))
64#define shm_unlock(shp) \
65 ipc_unlock(&(shp)->shm_perm)
66#define shm_get(ns, id) \
67 ((struct shmid_kernel*)ipc_get(&shm_ids(ns),id))
68#define shm_buildid(ns, id, seq) \
69 ipc_buildid(&shm_ids(ns), id, seq)
70
71static int newseg (struct ipc_namespace *ns, key_t key,
72 int shmflg, size_t size);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -080073static void shm_open(struct vm_area_struct *vma);
74static void shm_close(struct vm_area_struct *vma);
Kirill Korotaev4e982312006-10-02 02:18:22 -070075static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -070077static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#endif
79
Kirill Korotaev4e982312006-10-02 02:18:22 -070080static void __ipc_init __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
81{
82 ns->ids[IPC_SHM_IDS] = ids;
83 ns->shm_ctlmax = SHMMAX;
84 ns->shm_ctlall = SHMALL;
85 ns->shm_ctlmni = SHMMNI;
86 ns->shm_tot = 0;
87 ipc_init_ids(ids, 1);
88}
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
Kirill Korotaev4e982312006-10-02 02:18:22 -070090static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
91{
92 if (shp->shm_nattch){
93 shp->shm_perm.mode |= SHM_DEST;
94 /* Do not find it any more */
95 shp->shm_perm.key = IPC_PRIVATE;
96 shm_unlock(shp);
97 } else
98 shm_destroy(ns, shp);
99}
100
101#ifdef CONFIG_IPC_NS
102int shm_init_ns(struct ipc_namespace *ns)
103{
104 struct ipc_ids *ids;
105
106 ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
107 if (ids == NULL)
108 return -ENOMEM;
109
110 __shm_init_ns(ns, ids);
111 return 0;
112}
113
114void shm_exit_ns(struct ipc_namespace *ns)
115{
116 int i;
117 struct shmid_kernel *shp;
118
119 mutex_lock(&shm_ids(ns).mutex);
120 for (i = 0; i <= shm_ids(ns).max_id; i++) {
121 shp = shm_lock(ns, i);
122 if (shp == NULL)
123 continue;
124
125 do_shm_rmid(ns, shp);
126 }
127 mutex_unlock(&shm_ids(ns).mutex);
128
Pavel Emelianovc7e12b82006-11-02 22:07:03 -0800129 ipc_fini_ids(ns->ids[IPC_SHM_IDS]);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700130 kfree(ns->ids[IPC_SHM_IDS]);
131 ns->ids[IPC_SHM_IDS] = NULL;
132}
133#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135void __init shm_init (void)
136{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700137 __shm_init_ns(&init_ipc_ns, &init_shm_ids);
Mike Waychison19b49462005-09-06 15:17:10 -0700138 ipc_init_proc_interface("sysvipc/shm",
139 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
Kirill Korotaev4e982312006-10-02 02:18:22 -0700140 IPC_SHM_IDS, sysvipc_shm_proc_show);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141}
142
Kirill Korotaev4e982312006-10-02 02:18:22 -0700143static inline int shm_checkid(struct ipc_namespace *ns,
144 struct shmid_kernel *s, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700146 if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 return -EIDRM;
148 return 0;
149}
150
Kirill Korotaev4e982312006-10-02 02:18:22 -0700151static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700153 return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154}
155
Kirill Korotaev4e982312006-10-02 02:18:22 -0700156static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700158 return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159}
160
161
162
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800163/* This is called by fork, once for every shm attach. */
164static void shm_open(struct vm_area_struct *vma)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700165{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800166 struct file *file = vma->vm_file;
167 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 struct shmid_kernel *shp;
169
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800170 shp = shm_lock(sfd->ns, sfd->id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200171 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 shp->shm_atim = get_seconds();
173 shp->shm_lprid = current->tgid;
174 shp->shm_nattch++;
175 shm_unlock(shp);
176}
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178/*
179 * shm_destroy - free the struct shmid_kernel
180 *
181 * @shp: struct to free
182 *
Ingo Molnar5f921ae2006-03-26 01:37:17 -0800183 * It has to be called with shp and shm_ids.mutex locked,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 * but returns with shp unlocked and freed.
185 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700186static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700188 ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
189 shm_rmid(ns, shp->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 shm_unlock(shp);
191 if (!is_file_hugepages(shp->shm_file))
192 shmem_lock(shp->shm_file, 0, shp->mlock_user);
193 else
Josef Sipek6d630792006-12-08 02:37:11 -0800194 user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 shp->mlock_user);
196 fput (shp->shm_file);
197 security_shm_free(shp);
198 ipc_rcu_putref(shp);
199}
200
201/*
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800202 * remove the attach descriptor vma.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 * free memory for segment if it is marked destroyed.
204 * The descriptor has already been removed from the current->mm->mmap list
205 * and will later be kfree()d.
206 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800207static void shm_close(struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800209 struct file * file = vma->vm_file;
210 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 struct shmid_kernel *shp;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800212 struct ipc_namespace *ns = sfd->ns;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700213
214 mutex_lock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 /* remove from the list of attaches of the shm segment */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800216 shp = shm_lock(ns, sfd->id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200217 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 shp->shm_lprid = current->tgid;
219 shp->shm_dtim = get_seconds();
220 shp->shm_nattch--;
221 if(shp->shm_nattch == 0 &&
Andrew Mortonb33291c2006-01-08 01:02:21 -0800222 shp->shm_perm.mode & SHM_DEST)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700223 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 else
225 shm_unlock(shp);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700226 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227}
228
Adrian Bunkde01bad2007-02-28 20:11:01 -0800229static struct page *shm_nopage(struct vm_area_struct *vma,
230 unsigned long address, int *type)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800231{
232 struct file *file = vma->vm_file;
233 struct shm_file_data *sfd = shm_file_data(file);
234
235 return sfd->vm_ops->nopage(vma, address, type);
236}
237
238#ifdef CONFIG_NUMA
239int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
240{
241 struct file *file = vma->vm_file;
242 struct shm_file_data *sfd = shm_file_data(file);
243 int err = 0;
244 if (sfd->vm_ops->set_policy)
245 err = sfd->vm_ops->set_policy(vma, new);
246 return err;
247}
248
249struct mempolicy *shm_get_policy(struct vm_area_struct *vma, unsigned long addr)
250{
251 struct file *file = vma->vm_file;
252 struct shm_file_data *sfd = shm_file_data(file);
253 struct mempolicy *pol = NULL;
254
255 if (sfd->vm_ops->get_policy)
256 pol = sfd->vm_ops->get_policy(vma, addr);
257 else
258 pol = vma->vm_policy;
259 return pol;
260}
261#endif
262
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263static int shm_mmap(struct file * file, struct vm_area_struct * vma)
264{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800265 struct shm_file_data *sfd = shm_file_data(file);
David Howellsb0e15192006-01-06 00:11:42 -0800266 int ret;
267
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800268 ret = sfd->file->f_op->mmap(sfd->file, vma);
269 if (ret != 0)
270 return ret;
271 sfd->vm_ops = vma->vm_ops;
272 vma->vm_ops = &shm_vm_ops;
273 shm_open(vma);
David Howellsb0e15192006-01-06 00:11:42 -0800274
275 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276}
277
Kirill Korotaev4e982312006-10-02 02:18:22 -0700278static int shm_release(struct inode *ino, struct file *file)
279{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800280 struct shm_file_data *sfd = shm_file_data(file);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700281
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800282 put_ipc_ns(sfd->ns);
283 shm_file_data(file) = NULL;
284 kfree(sfd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700285 return 0;
286}
287
Adam Litke516dffd2007-03-01 15:46:08 -0800288static int shm_fsync(struct file *file, struct dentry *dentry, int datasync)
289{
290 int (*fsync) (struct file *, struct dentry *, int datasync);
291 struct shm_file_data *sfd = shm_file_data(file);
292 int ret = -EINVAL;
293
294 fsync = sfd->file->f_op->fsync;
295 if (fsync)
296 ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync);
297 return ret;
298}
299
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800300static unsigned long shm_get_unmapped_area(struct file *file,
301 unsigned long addr, unsigned long len, unsigned long pgoff,
302 unsigned long flags)
303{
304 struct shm_file_data *sfd = shm_file_data(file);
Adam Litke516dffd2007-03-01 15:46:08 -0800305 return get_unmapped_area(sfd->file, addr, len, pgoff, flags);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800306}
Adam Litke516dffd2007-03-01 15:46:08 -0800307
308int is_file_shm_hugepages(struct file *file)
309{
310 int ret = 0;
311
312 if (file->f_op == &shm_file_operations) {
313 struct shm_file_data *sfd;
314 sfd = shm_file_data(file);
315 ret = is_file_hugepages(sfd->file);
316 }
317 return ret;
318}
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800319
Arjan van de Ven9a321442007-02-12 00:55:35 -0800320static const struct file_operations shm_file_operations = {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700321 .mmap = shm_mmap,
Adam Litke516dffd2007-03-01 15:46:08 -0800322 .fsync = shm_fsync,
Kirill Korotaev4e982312006-10-02 02:18:22 -0700323 .release = shm_release,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800324 .get_unmapped_area = shm_get_unmapped_area,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325};
326
327static struct vm_operations_struct shm_vm_ops = {
328 .open = shm_open, /* callback for a new vm-area open */
329 .close = shm_close, /* callback for when the vm-area is released */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800330 .nopage = shm_nopage,
331#if defined(CONFIG_NUMA)
332 .set_policy = shm_set_policy,
333 .get_policy = shm_get_policy,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334#endif
335};
336
Kirill Korotaev4e982312006-10-02 02:18:22 -0700337static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338{
339 int error;
340 struct shmid_kernel *shp;
341 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
342 struct file * file;
343 char name[13];
344 int id;
345
Kirill Korotaev4e982312006-10-02 02:18:22 -0700346 if (size < SHMMIN || size > ns->shm_ctlmax)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 return -EINVAL;
348
Guy Streeterf66d45e2007-01-23 12:20:04 -0600349 if (ns->shm_tot + numpages > ns->shm_ctlall)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return -ENOSPC;
351
352 shp = ipc_rcu_alloc(sizeof(*shp));
353 if (!shp)
354 return -ENOMEM;
355
356 shp->shm_perm.key = key;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800357 shp->shm_perm.mode = (shmflg & S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 shp->mlock_user = NULL;
359
360 shp->shm_perm.security = NULL;
361 error = security_shm_alloc(shp);
362 if (error) {
363 ipc_rcu_putref(shp);
364 return error;
365 }
366
367 if (shmflg & SHM_HUGETLB) {
368 /* hugetlb_zero_setup takes care of mlock user accounting */
369 file = hugetlb_zero_setup(size);
370 shp->mlock_user = current->user;
371 } else {
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800372 int acctflag = VM_ACCOUNT;
373 /*
374 * Do not allow no accounting for OVERCOMMIT_NEVER, even
375 * if it's asked for.
376 */
377 if ((shmflg & SHM_NORESERVE) &&
378 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
379 acctflag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 sprintf (name, "SYSV%08x", key);
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800381 file = shmem_file_setup(name, size, acctflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 }
383 error = PTR_ERR(file);
384 if (IS_ERR(file))
385 goto no_file;
386
387 error = -ENOSPC;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700388 id = shm_addid(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 if(id == -1)
390 goto no_id;
391
392 shp->shm_cprid = current->tgid;
393 shp->shm_lprid = 0;
394 shp->shm_atim = shp->shm_dtim = 0;
395 shp->shm_ctim = get_seconds();
396 shp->shm_segsz = size;
397 shp->shm_nattch = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700398 shp->id = shm_buildid(ns, id, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 shp->shm_file = file;
Krishnakumar R551110a2005-10-29 18:16:45 -0700400
Kirill Korotaev4e982312006-10-02 02:18:22 -0700401 ns->shm_tot += numpages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 shm_unlock(shp);
403 return shp->id;
404
405no_id:
406 fput(file);
407no_file:
408 security_shm_free(shp);
409 ipc_rcu_putref(shp);
410 return error;
411}
412
413asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
414{
415 struct shmid_kernel *shp;
416 int err, id = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700417 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418
Kirill Korotaev4e982312006-10-02 02:18:22 -0700419 ns = current->nsproxy->ipc_ns;
420
421 mutex_lock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 if (key == IPC_PRIVATE) {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700423 err = newseg(ns, key, shmflg, size);
424 } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 if (!(shmflg & IPC_CREAT))
426 err = -ENOENT;
427 else
Kirill Korotaev4e982312006-10-02 02:18:22 -0700428 err = newseg(ns, key, shmflg, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
430 err = -EEXIST;
431 } else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700432 shp = shm_lock(ns, id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200433 BUG_ON(shp==NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 if (shp->shm_segsz < size)
435 err = -EINVAL;
436 else if (ipcperms(&shp->shm_perm, shmflg))
437 err = -EACCES;
438 else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700439 int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 err = security_shm_associate(shp, shmflg);
441 if (!err)
442 err = shmid;
443 }
444 shm_unlock(shp);
445 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700446 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
448 return err;
449}
450
451static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
452{
453 switch(version) {
454 case IPC_64:
455 return copy_to_user(buf, in, sizeof(*in));
456 case IPC_OLD:
457 {
458 struct shmid_ds out;
459
460 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
461 out.shm_segsz = in->shm_segsz;
462 out.shm_atime = in->shm_atime;
463 out.shm_dtime = in->shm_dtime;
464 out.shm_ctime = in->shm_ctime;
465 out.shm_cpid = in->shm_cpid;
466 out.shm_lpid = in->shm_lpid;
467 out.shm_nattch = in->shm_nattch;
468
469 return copy_to_user(buf, &out, sizeof(out));
470 }
471 default:
472 return -EINVAL;
473 }
474}
475
476struct shm_setbuf {
477 uid_t uid;
478 gid_t gid;
479 mode_t mode;
480};
481
482static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
483{
484 switch(version) {
485 case IPC_64:
486 {
487 struct shmid64_ds tbuf;
488
489 if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
490 return -EFAULT;
491
492 out->uid = tbuf.shm_perm.uid;
493 out->gid = tbuf.shm_perm.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800494 out->mode = tbuf.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495
496 return 0;
497 }
498 case IPC_OLD:
499 {
500 struct shmid_ds tbuf_old;
501
502 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
503 return -EFAULT;
504
505 out->uid = tbuf_old.shm_perm.uid;
506 out->gid = tbuf_old.shm_perm.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800507 out->mode = tbuf_old.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
509 return 0;
510 }
511 default:
512 return -EINVAL;
513 }
514}
515
516static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
517{
518 switch(version) {
519 case IPC_64:
520 return copy_to_user(buf, in, sizeof(*in));
521 case IPC_OLD:
522 {
523 struct shminfo out;
524
525 if(in->shmmax > INT_MAX)
526 out.shmmax = INT_MAX;
527 else
528 out.shmmax = (int)in->shmmax;
529
530 out.shmmin = in->shmmin;
531 out.shmmni = in->shmmni;
532 out.shmseg = in->shmseg;
533 out.shmall = in->shmall;
534
535 return copy_to_user(buf, &out, sizeof(out));
536 }
537 default:
538 return -EINVAL;
539 }
540}
541
Kirill Korotaev4e982312006-10-02 02:18:22 -0700542static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
543 unsigned long *swp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544{
545 int i;
546
547 *rss = 0;
548 *swp = 0;
549
Kirill Korotaev4e982312006-10-02 02:18:22 -0700550 for (i = 0; i <= shm_ids(ns).max_id; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 struct shmid_kernel *shp;
552 struct inode *inode;
553
Kirill Korotaev4e982312006-10-02 02:18:22 -0700554 shp = shm_get(ns, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 if(!shp)
556 continue;
557
Josef Sipek6d630792006-12-08 02:37:11 -0800558 inode = shp->shm_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560 if (is_file_hugepages(shp->shm_file)) {
561 struct address_space *mapping = inode->i_mapping;
562 *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
563 } else {
564 struct shmem_inode_info *info = SHMEM_I(inode);
565 spin_lock(&info->lock);
566 *rss += inode->i_mapping->nrpages;
567 *swp += info->swapped;
568 spin_unlock(&info->lock);
569 }
570 }
571}
572
573asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
574{
575 struct shm_setbuf setbuf;
576 struct shmid_kernel *shp;
577 int err, version;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700578 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
580 if (cmd < 0 || shmid < 0) {
581 err = -EINVAL;
582 goto out;
583 }
584
585 version = ipc_parse_version(&cmd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700586 ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588 switch (cmd) { /* replace with proc interface ? */
589 case IPC_INFO:
590 {
591 struct shminfo64 shminfo;
592
593 err = security_shm_shmctl(NULL, cmd);
594 if (err)
595 return err;
596
597 memset(&shminfo,0,sizeof(shminfo));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700598 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
599 shminfo.shmmax = ns->shm_ctlmax;
600 shminfo.shmall = ns->shm_ctlall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601
602 shminfo.shmmin = SHMMIN;
603 if(copy_shminfo_to_user (buf, &shminfo, version))
604 return -EFAULT;
605 /* reading a integer is always atomic */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700606 err= shm_ids(ns).max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 if(err<0)
608 err = 0;
609 goto out;
610 }
611 case SHM_INFO:
612 {
613 struct shm_info shm_info;
614
615 err = security_shm_shmctl(NULL, cmd);
616 if (err)
617 return err;
618
619 memset(&shm_info,0,sizeof(shm_info));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700620 mutex_lock(&shm_ids(ns).mutex);
621 shm_info.used_ids = shm_ids(ns).in_use;
622 shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
623 shm_info.shm_tot = ns->shm_tot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 shm_info.swap_attempts = 0;
625 shm_info.swap_successes = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700626 err = shm_ids(ns).max_id;
627 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
629 err = -EFAULT;
630 goto out;
631 }
632
633 err = err < 0 ? 0 : err;
634 goto out;
635 }
636 case SHM_STAT:
637 case IPC_STAT:
638 {
639 struct shmid64_ds tbuf;
640 int result;
641 memset(&tbuf, 0, sizeof(tbuf));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700642 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 if(shp==NULL) {
644 err = -EINVAL;
645 goto out;
646 } else if(cmd==SHM_STAT) {
647 err = -EINVAL;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700648 if (shmid > shm_ids(ns).max_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 goto out_unlock;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700650 result = shm_buildid(ns, shmid, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 } else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700652 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 if(err)
654 goto out_unlock;
655 result = 0;
656 }
657 err=-EACCES;
658 if (ipcperms (&shp->shm_perm, S_IRUGO))
659 goto out_unlock;
660 err = security_shm_shmctl(shp, cmd);
661 if (err)
662 goto out_unlock;
663 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
664 tbuf.shm_segsz = shp->shm_segsz;
665 tbuf.shm_atime = shp->shm_atim;
666 tbuf.shm_dtime = shp->shm_dtim;
667 tbuf.shm_ctime = shp->shm_ctim;
668 tbuf.shm_cpid = shp->shm_cprid;
669 tbuf.shm_lpid = shp->shm_lprid;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800670 tbuf.shm_nattch = shp->shm_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 shm_unlock(shp);
672 if(copy_shmid_to_user (buf, &tbuf, version))
673 err = -EFAULT;
674 else
675 err = result;
676 goto out;
677 }
678 case SHM_LOCK:
679 case SHM_UNLOCK:
680 {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700681 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 if(shp==NULL) {
683 err = -EINVAL;
684 goto out;
685 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700686 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 if(err)
688 goto out_unlock;
689
Steve Grubb073115d2006-04-02 17:07:33 -0400690 err = audit_ipc_obj(&(shp->shm_perm));
691 if (err)
692 goto out_unlock;
693
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 if (!capable(CAP_IPC_LOCK)) {
695 err = -EPERM;
696 if (current->euid != shp->shm_perm.uid &&
697 current->euid != shp->shm_perm.cuid)
698 goto out_unlock;
699 if (cmd == SHM_LOCK &&
700 !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
701 goto out_unlock;
702 }
703
704 err = security_shm_shmctl(shp, cmd);
705 if (err)
706 goto out_unlock;
707
708 if(cmd==SHM_LOCK) {
709 struct user_struct * user = current->user;
710 if (!is_file_hugepages(shp->shm_file)) {
711 err = shmem_lock(shp->shm_file, 1, user);
712 if (!err) {
Andrew Mortonb33291c2006-01-08 01:02:21 -0800713 shp->shm_perm.mode |= SHM_LOCKED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 shp->mlock_user = user;
715 }
716 }
717 } else if (!is_file_hugepages(shp->shm_file)) {
718 shmem_lock(shp->shm_file, 0, shp->mlock_user);
Andrew Mortonb33291c2006-01-08 01:02:21 -0800719 shp->shm_perm.mode &= ~SHM_LOCKED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 shp->mlock_user = NULL;
721 }
722 shm_unlock(shp);
723 goto out;
724 }
725 case IPC_RMID:
726 {
727 /*
728 * We cannot simply remove the file. The SVID states
729 * that the block remains until the last person
730 * detaches from it, then is deleted. A shmat() on
731 * an RMID segment is legal in older Linux and if
732 * we change it apps break...
733 *
734 * Instead we set a destroyed flag, and then blow
735 * the name away when the usage hits zero.
736 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700737 mutex_lock(&shm_ids(ns).mutex);
738 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 err = -EINVAL;
740 if (shp == NULL)
741 goto out_up;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700742 err = shm_checkid(ns, shp, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 if(err)
744 goto out_unlock_up;
745
Steve Grubb073115d2006-04-02 17:07:33 -0400746 err = audit_ipc_obj(&(shp->shm_perm));
747 if (err)
748 goto out_unlock_up;
749
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 if (current->euid != shp->shm_perm.uid &&
751 current->euid != shp->shm_perm.cuid &&
752 !capable(CAP_SYS_ADMIN)) {
753 err=-EPERM;
754 goto out_unlock_up;
755 }
756
757 err = security_shm_shmctl(shp, cmd);
758 if (err)
759 goto out_unlock_up;
760
Kirill Korotaev4e982312006-10-02 02:18:22 -0700761 do_shm_rmid(ns, shp);
762 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 goto out;
764 }
765
766 case IPC_SET:
767 {
768 if (copy_shmid_from_user (&setbuf, buf, version)) {
769 err = -EFAULT;
770 goto out;
771 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700772 mutex_lock(&shm_ids(ns).mutex);
773 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 err=-EINVAL;
775 if(shp==NULL)
776 goto out_up;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700777 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 if(err)
779 goto out_unlock_up;
Steve Grubb073115d2006-04-02 17:07:33 -0400780 err = audit_ipc_obj(&(shp->shm_perm));
781 if (err)
782 goto out_unlock_up;
Linda Knippersac032212006-05-16 22:03:48 -0400783 err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
Steve Grubb073115d2006-04-02 17:07:33 -0400784 if (err)
785 goto out_unlock_up;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 err=-EPERM;
787 if (current->euid != shp->shm_perm.uid &&
788 current->euid != shp->shm_perm.cuid &&
789 !capable(CAP_SYS_ADMIN)) {
790 goto out_unlock_up;
791 }
792
793 err = security_shm_shmctl(shp, cmd);
794 if (err)
795 goto out_unlock_up;
796
797 shp->shm_perm.uid = setbuf.uid;
798 shp->shm_perm.gid = setbuf.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800799 shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 | (setbuf.mode & S_IRWXUGO);
801 shp->shm_ctim = get_seconds();
802 break;
803 }
804
805 default:
806 err = -EINVAL;
807 goto out;
808 }
809
810 err = 0;
811out_unlock_up:
812 shm_unlock(shp);
813out_up:
Kirill Korotaev4e982312006-10-02 02:18:22 -0700814 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 goto out;
816out_unlock:
817 shm_unlock(shp);
818out:
819 return err;
820}
821
822/*
823 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
824 *
825 * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
826 * "raddr" thing points to kernel space, and there has to be a wrapper around
827 * this.
828 */
829long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
830{
831 struct shmid_kernel *shp;
832 unsigned long addr;
833 unsigned long size;
834 struct file * file;
835 int err;
836 unsigned long flags;
837 unsigned long prot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 int acc_mode;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800839 unsigned long user_addr;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700840 struct ipc_namespace *ns;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800841 struct shm_file_data *sfd;
842 struct path path;
843 mode_t f_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800845 err = -EINVAL;
846 if (shmid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 goto out;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800848 else if ((addr = (ulong)shmaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 if (addr & (SHMLBA-1)) {
850 if (shmflg & SHM_RND)
851 addr &= ~(SHMLBA-1); /* round down */
852 else
853#ifndef __ARCH_FORCE_SHMLBA
854 if (addr & ~PAGE_MASK)
855#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800856 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 }
858 flags = MAP_SHARED | MAP_FIXED;
859 } else {
860 if ((shmflg & SHM_REMAP))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800861 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862
863 flags = MAP_SHARED;
864 }
865
866 if (shmflg & SHM_RDONLY) {
867 prot = PROT_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 acc_mode = S_IRUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800869 f_mode = FMODE_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 } else {
871 prot = PROT_READ | PROT_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 acc_mode = S_IRUGO | S_IWUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800873 f_mode = FMODE_READ | FMODE_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 }
875 if (shmflg & SHM_EXEC) {
876 prot |= PROT_EXEC;
877 acc_mode |= S_IXUGO;
878 }
879
880 /*
881 * We cannot rely on the fs check since SYSV IPC does have an
882 * additional creator id...
883 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700884 ns = current->nsproxy->ipc_ns;
885 shp = shm_lock(ns, shmid);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800886 if(shp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 goto out;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800888
Kirill Korotaev4e982312006-10-02 02:18:22 -0700889 err = shm_checkid(ns, shp,shmid);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800890 if (err)
891 goto out_unlock;
892
893 err = -EACCES;
894 if (ipcperms(&shp->shm_perm, acc_mode))
895 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896
897 err = security_shm_shmat(shp, shmaddr, shmflg);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800898 if (err)
899 goto out_unlock;
900
901 path.dentry = dget(shp->shm_file->f_path.dentry);
902 path.mnt = mntget(shp->shm_file->f_path.mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 shp->shm_nattch++;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800904 size = i_size_read(path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 shm_unlock(shp);
906
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800907 err = -ENOMEM;
908 sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
909 if (!sfd)
910 goto out_put_path;
911
912 err = -ENOMEM;
913 file = get_empty_filp();
914 if (!file)
915 goto out_free;
916
917 file->f_op = &shm_file_operations;
918 file->private_data = sfd;
919 file->f_path = path;
920 file->f_mapping = shp->shm_file->f_mapping;
921 file->f_mode = f_mode;
922 sfd->id = shp->id;
923 sfd->ns = get_ipc_ns(ns);
924 sfd->file = shp->shm_file;
925 sfd->vm_ops = NULL;
926
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 down_write(&current->mm->mmap_sem);
928 if (addr && !(shmflg & SHM_REMAP)) {
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800929 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 if (find_vma_intersection(current->mm, addr, addr + size))
931 goto invalid;
932 /*
933 * If shm segment goes below stack, make sure there is some
934 * space left for the stack to grow (at least 4 pages).
935 */
936 if (addr < current->mm->start_stack &&
937 addr > current->mm->start_stack - size - PAGE_SIZE * 5)
938 goto invalid;
939 }
940
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800941 user_addr = do_mmap (file, addr, size, prot, flags, 0);
942 *raddr = user_addr;
943 err = 0;
944 if (IS_ERR_VALUE(user_addr))
945 err = (long)user_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946invalid:
947 up_write(&current->mm->mmap_sem);
948
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800949 fput(file);
950
951out_nattch:
Kirill Korotaev4e982312006-10-02 02:18:22 -0700952 mutex_lock(&shm_ids(ns).mutex);
953 shp = shm_lock(ns, shmid);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200954 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 shp->shm_nattch--;
956 if(shp->shm_nattch == 0 &&
Andrew Mortonb33291c2006-01-08 01:02:21 -0800957 shp->shm_perm.mode & SHM_DEST)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700958 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 else
960 shm_unlock(shp);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700961 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963out:
964 return err;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800965
966out_unlock:
967 shm_unlock(shp);
968 goto out;
969
970out_free:
971 kfree(sfd);
972out_put_path:
973 dput(path.dentry);
974 mntput(path.mnt);
975 goto out_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976}
977
Stephen Rothwell7d87e142005-05-01 08:59:12 -0700978asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
979{
980 unsigned long ret;
981 long err;
982
983 err = do_shmat(shmid, shmaddr, shmflg, &ret);
984 if (err)
985 return err;
986 force_successful_syscall_return();
987 return (long)ret;
988}
989
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990/*
991 * detach and kill segment if marked destroyed.
992 * The work is done in shm_close.
993 */
994asmlinkage long sys_shmdt(char __user *shmaddr)
995{
996 struct mm_struct *mm = current->mm;
997 struct vm_area_struct *vma, *next;
998 unsigned long addr = (unsigned long)shmaddr;
999 loff_t size = 0;
1000 int retval = -EINVAL;
1001
Hugh Dickinsdf1e2fb2006-03-24 03:18:06 -08001002 if (addr & ~PAGE_MASK)
1003 return retval;
1004
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 down_write(&mm->mmap_sem);
1006
1007 /*
1008 * This function tries to be smart and unmap shm segments that
1009 * were modified by partial mlock or munmap calls:
1010 * - It first determines the size of the shm segment that should be
1011 * unmapped: It searches for a vma that is backed by shm and that
1012 * started at address shmaddr. It records it's size and then unmaps
1013 * it.
1014 * - Then it unmaps all shm vmas that started at shmaddr and that
1015 * are within the initially determined size.
1016 * Errors from do_munmap are ignored: the function only fails if
1017 * it's called with invalid parameters or if it's called to unmap
1018 * a part of a vma. Both calls in this function are for full vmas,
1019 * the parameters are directly copied from the vma itself and always
1020 * valid - therefore do_munmap cannot fail. (famous last words?)
1021 */
1022 /*
1023 * If it had been mremap()'d, the starting address would not
1024 * match the usual checks anyway. So assume all vma's are
1025 * above the starting address given.
1026 */
1027 vma = find_vma(mm, addr);
1028
1029 while (vma) {
1030 next = vma->vm_next;
1031
1032 /*
1033 * Check if the starting address would match, i.e. it's
1034 * a fragment created by mprotect() and/or munmap(), or it
1035 * otherwise it starts at this address with no hassles.
1036 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001037 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1039
1040
Josef Sipek6d630792006-12-08 02:37:11 -08001041 size = vma->vm_file->f_path.dentry->d_inode->i_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1043 /*
1044 * We discovered the size of the shm segment, so
1045 * break out of here and fall through to the next
1046 * loop that uses the size information to stop
1047 * searching for matching vma's.
1048 */
1049 retval = 0;
1050 vma = next;
1051 break;
1052 }
1053 vma = next;
1054 }
1055
1056 /*
1057 * We need look no further than the maximum address a fragment
1058 * could possibly have landed at. Also cast things to loff_t to
1059 * prevent overflows and make comparisions vs. equal-width types.
1060 */
KAMEZAWA Hiroyuki8e367092006-02-10 01:51:12 -08001061 size = PAGE_ALIGN(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1063 next = vma->vm_next;
1064
1065 /* finding a matching vma now does not alter retval */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001066 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
1068
1069 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1070 vma = next;
1071 }
1072
1073 up_write(&mm->mmap_sem);
1074 return retval;
1075}
1076
1077#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001078static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079{
Mike Waychison19b49462005-09-06 15:17:10 -07001080 struct shmid_kernel *shp = it;
1081 char *format;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083#define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
1084#define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085
Mike Waychison19b49462005-09-06 15:17:10 -07001086 if (sizeof(size_t) <= sizeof(int))
1087 format = SMALL_STRING;
1088 else
1089 format = BIG_STRING;
1090 return seq_printf(s, format,
1091 shp->shm_perm.key,
1092 shp->id,
Andrew Mortonb33291c2006-01-08 01:02:21 -08001093 shp->shm_perm.mode,
Mike Waychison19b49462005-09-06 15:17:10 -07001094 shp->shm_segsz,
1095 shp->shm_cprid,
1096 shp->shm_lprid,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001097 shp->shm_nattch,
Mike Waychison19b49462005-09-06 15:17:10 -07001098 shp->shm_perm.uid,
1099 shp->shm_perm.gid,
1100 shp->shm_perm.cuid,
1101 shp->shm_perm.cgid,
1102 shp->shm_atim,
1103 shp->shm_dtim,
1104 shp->shm_ctim);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105}
1106#endif