blob: 5fc5cf50cf1b847fc630cf2e127f37005337bb94 [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>
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 Rothwell7d87e14c2005-05-01 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
Cedric Le Goater7d69a1f2007-07-15 23:40:58 -070080static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
Kirill Korotaev4e982312006-10-02 02:18:22 -070081{
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
Kirill Korotaev4e982312006-10-02 02:18:22 -0700101int shm_init_ns(struct ipc_namespace *ns)
102{
103 struct ipc_ids *ids;
104
105 ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
106 if (ids == NULL)
107 return -ENOMEM;
108
109 __shm_init_ns(ns, ids);
110 return 0;
111}
112
113void shm_exit_ns(struct ipc_namespace *ns)
114{
115 int i;
116 struct shmid_kernel *shp;
117
118 mutex_lock(&shm_ids(ns).mutex);
119 for (i = 0; i <= shm_ids(ns).max_id; i++) {
120 shp = shm_lock(ns, i);
121 if (shp == NULL)
122 continue;
123
124 do_shm_rmid(ns, shp);
125 }
126 mutex_unlock(&shm_ids(ns).mutex);
127
Pavel Emelianovc7e12b82006-11-02 22:07:03 -0800128 ipc_fini_ids(ns->ids[IPC_SHM_IDS]);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700129 kfree(ns->ids[IPC_SHM_IDS]);
130 ns->ids[IPC_SHM_IDS] = NULL;
131}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133void __init shm_init (void)
134{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700135 __shm_init_ns(&init_ipc_ns, &init_shm_ids);
Mike Waychison19b49462005-09-06 15:17:10 -0700136 ipc_init_proc_interface("sysvipc/shm",
137 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
Kirill Korotaev4e982312006-10-02 02:18:22 -0700138 IPC_SHM_IDS, sysvipc_shm_proc_show);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139}
140
Kirill Korotaev4e982312006-10-02 02:18:22 -0700141static inline int shm_checkid(struct ipc_namespace *ns,
142 struct shmid_kernel *s, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700144 if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 return -EIDRM;
146 return 0;
147}
148
Kirill Korotaev4e982312006-10-02 02:18:22 -0700149static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700151 return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Kirill Korotaev4e982312006-10-02 02:18:22 -0700154static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700156 return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157}
158
159
160
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800161/* This is called by fork, once for every shm attach. */
162static void shm_open(struct vm_area_struct *vma)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700163{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800164 struct file *file = vma->vm_file;
165 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 struct shmid_kernel *shp;
167
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800168 shp = shm_lock(sfd->ns, sfd->id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200169 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 shp->shm_atim = get_seconds();
171 shp->shm_lprid = current->tgid;
172 shp->shm_nattch++;
173 shm_unlock(shp);
174}
175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176/*
177 * shm_destroy - free the struct shmid_kernel
178 *
179 * @shp: struct to free
180 *
Ingo Molnar5f921ae2006-03-26 01:37:17 -0800181 * It has to be called with shp and shm_ids.mutex locked,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 * but returns with shp unlocked and freed.
183 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700184static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700186 ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
187 shm_rmid(ns, shp->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 shm_unlock(shp);
189 if (!is_file_hugepages(shp->shm_file))
190 shmem_lock(shp->shm_file, 0, shp->mlock_user);
191 else
Josef Sipek6d630792006-12-08 02:37:11 -0800192 user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 shp->mlock_user);
194 fput (shp->shm_file);
195 security_shm_free(shp);
196 ipc_rcu_putref(shp);
197}
198
199/*
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800200 * remove the attach descriptor vma.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 * free memory for segment if it is marked destroyed.
202 * The descriptor has already been removed from the current->mm->mmap list
203 * and will later be kfree()d.
204 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800205static void shm_close(struct vm_area_struct *vma)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800207 struct file * file = vma->vm_file;
208 struct shm_file_data *sfd = shm_file_data(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 struct shmid_kernel *shp;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800210 struct ipc_namespace *ns = sfd->ns;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700211
212 mutex_lock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 /* remove from the list of attaches of the shm segment */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800214 shp = shm_lock(ns, sfd->id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200215 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 shp->shm_lprid = current->tgid;
217 shp->shm_dtim = get_seconds();
218 shp->shm_nattch--;
219 if(shp->shm_nattch == 0 &&
Andrew Mortonb33291c2006-01-08 01:02:21 -0800220 shp->shm_perm.mode & SHM_DEST)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700221 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 else
223 shm_unlock(shp);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700224 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225}
226
Nick Piggind0217ac2007-07-19 01:47:03 -0700227static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800228{
229 struct file *file = vma->vm_file;
230 struct shm_file_data *sfd = shm_file_data(file);
231
Nick Piggind0217ac2007-07-19 01:47:03 -0700232 return sfd->vm_ops->fault(vma, vmf);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800233}
234
235#ifdef CONFIG_NUMA
Adrian Bunkd823e3e2007-10-16 23:26:42 -0700236static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800237{
238 struct file *file = vma->vm_file;
239 struct shm_file_data *sfd = shm_file_data(file);
240 int err = 0;
241 if (sfd->vm_ops->set_policy)
242 err = sfd->vm_ops->set_policy(vma, new);
243 return err;
244}
245
Adrian Bunkd823e3e2007-10-16 23:26:42 -0700246static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
247 unsigned long addr)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800248{
249 struct file *file = vma->vm_file;
250 struct shm_file_data *sfd = shm_file_data(file);
251 struct mempolicy *pol = NULL;
252
253 if (sfd->vm_ops->get_policy)
254 pol = sfd->vm_ops->get_policy(vma, addr);
Adam Litke22741922007-06-16 10:16:15 -0700255 else if (vma->vm_policy)
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800256 pol = vma->vm_policy;
Adam Litke22741922007-06-16 10:16:15 -0700257 else
258 pol = current->mempolicy;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800259 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;
David Howells2e92a3b2007-07-31 00:37:24 -0700272#ifdef CONFIG_MMU
Nick Piggin54cb8822007-07-19 01:46:59 -0700273 BUG_ON(!sfd->vm_ops->fault);
David Howells2e92a3b2007-07-31 00:37:24 -0700274#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800275 vma->vm_ops = &shm_vm_ops;
276 shm_open(vma);
David Howellsb0e15192006-01-06 00:11:42 -0800277
278 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279}
280
Kirill Korotaev4e982312006-10-02 02:18:22 -0700281static int shm_release(struct inode *ino, struct file *file)
282{
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800283 struct shm_file_data *sfd = shm_file_data(file);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700284
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800285 put_ipc_ns(sfd->ns);
286 shm_file_data(file) = NULL;
287 kfree(sfd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700288 return 0;
289}
290
Adam Litke516dffd2007-03-01 15:46:08 -0800291static int shm_fsync(struct file *file, struct dentry *dentry, int datasync)
292{
293 int (*fsync) (struct file *, struct dentry *, int datasync);
294 struct shm_file_data *sfd = shm_file_data(file);
295 int ret = -EINVAL;
296
297 fsync = sfd->file->f_op->fsync;
298 if (fsync)
299 ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync);
300 return ret;
301}
302
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800303static unsigned long shm_get_unmapped_area(struct file *file,
304 unsigned long addr, unsigned long len, unsigned long pgoff,
305 unsigned long flags)
306{
307 struct shm_file_data *sfd = shm_file_data(file);
Adam Litke516dffd2007-03-01 15:46:08 -0800308 return get_unmapped_area(sfd->file, addr, len, pgoff, flags);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800309}
Adam Litke516dffd2007-03-01 15:46:08 -0800310
311int is_file_shm_hugepages(struct file *file)
312{
313 int ret = 0;
314
315 if (file->f_op == &shm_file_operations) {
316 struct shm_file_data *sfd;
317 sfd = shm_file_data(file);
318 ret = is_file_hugepages(sfd->file);
319 }
320 return ret;
321}
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800322
Arjan van de Ven9a321442007-02-12 00:55:35 -0800323static const struct file_operations shm_file_operations = {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700324 .mmap = shm_mmap,
Adam Litke516dffd2007-03-01 15:46:08 -0800325 .fsync = shm_fsync,
Kirill Korotaev4e982312006-10-02 02:18:22 -0700326 .release = shm_release,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800327 .get_unmapped_area = shm_get_unmapped_area,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328};
329
330static struct vm_operations_struct shm_vm_ops = {
331 .open = shm_open, /* callback for a new vm-area open */
332 .close = shm_close, /* callback for when the vm-area is released */
Nick Piggin54cb8822007-07-19 01:46:59 -0700333 .fault = shm_fault,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800334#if defined(CONFIG_NUMA)
335 .set_policy = shm_set_policy,
336 .get_policy = shm_get_policy,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337#endif
338};
339
Kirill Korotaev4e982312006-10-02 02:18:22 -0700340static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341{
342 int error;
343 struct shmid_kernel *shp;
344 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
345 struct file * file;
346 char name[13];
347 int id;
348
Kirill Korotaev4e982312006-10-02 02:18:22 -0700349 if (size < SHMMIN || size > ns->shm_ctlmax)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return -EINVAL;
351
Guy Streeterf66d45e2007-01-23 12:20:04 -0600352 if (ns->shm_tot + numpages > ns->shm_ctlall)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 return -ENOSPC;
354
355 shp = ipc_rcu_alloc(sizeof(*shp));
356 if (!shp)
357 return -ENOMEM;
358
359 shp->shm_perm.key = key;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800360 shp->shm_perm.mode = (shmflg & S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 shp->mlock_user = NULL;
362
363 shp->shm_perm.security = NULL;
364 error = security_shm_alloc(shp);
365 if (error) {
366 ipc_rcu_putref(shp);
367 return error;
368 }
369
Eric W. Biederman9d665862007-06-16 10:16:16 -0700370 sprintf (name, "SYSV%08x", key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 if (shmflg & SHM_HUGETLB) {
Eric W. Biederman9d665862007-06-16 10:16:16 -0700372 /* hugetlb_file_setup takes care of mlock user accounting */
373 file = hugetlb_file_setup(name, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 shp->mlock_user = current->user;
375 } else {
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800376 int acctflag = VM_ACCOUNT;
377 /*
378 * Do not allow no accounting for OVERCOMMIT_NEVER, even
379 * if it's asked for.
380 */
381 if ((shmflg & SHM_NORESERVE) &&
382 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
383 acctflag = 0;
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800384 file = shmem_file_setup(name, size, acctflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 }
386 error = PTR_ERR(file);
387 if (IS_ERR(file))
388 goto no_file;
389
390 error = -ENOSPC;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700391 id = shm_addid(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 if(id == -1)
393 goto no_id;
394
395 shp->shm_cprid = current->tgid;
396 shp->shm_lprid = 0;
397 shp->shm_atim = shp->shm_dtim = 0;
398 shp->shm_ctim = get_seconds();
399 shp->shm_segsz = size;
400 shp->shm_nattch = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700401 shp->id = shm_buildid(ns, id, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 shp->shm_file = file;
Badari Pulavarty30475cc2007-06-16 10:15:59 -0700403 /*
404 * shmid gets reported as "inode#" in /proc/pid/maps.
405 * proc-ps tools use this. Changing this will break them.
406 */
407 file->f_dentry->d_inode->i_ino = shp->id;
Krishnakumar R551110a2005-10-29 18:16:45 -0700408
Kirill Korotaev4e982312006-10-02 02:18:22 -0700409 ns->shm_tot += numpages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 shm_unlock(shp);
411 return shp->id;
412
413no_id:
414 fput(file);
415no_file:
416 security_shm_free(shp);
417 ipc_rcu_putref(shp);
418 return error;
419}
420
421asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
422{
423 struct shmid_kernel *shp;
424 int err, id = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700425 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
Kirill Korotaev4e982312006-10-02 02:18:22 -0700427 ns = current->nsproxy->ipc_ns;
428
429 mutex_lock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 if (key == IPC_PRIVATE) {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700431 err = newseg(ns, key, shmflg, size);
432 } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 if (!(shmflg & IPC_CREAT))
434 err = -ENOENT;
435 else
Kirill Korotaev4e982312006-10-02 02:18:22 -0700436 err = newseg(ns, key, shmflg, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
438 err = -EEXIST;
439 } else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700440 shp = shm_lock(ns, id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200441 BUG_ON(shp==NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (shp->shm_segsz < size)
443 err = -EINVAL;
444 else if (ipcperms(&shp->shm_perm, shmflg))
445 err = -EACCES;
446 else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700447 int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 err = security_shm_associate(shp, shmflg);
449 if (!err)
450 err = shmid;
451 }
452 shm_unlock(shp);
453 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700454 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
456 return err;
457}
458
459static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
460{
461 switch(version) {
462 case IPC_64:
463 return copy_to_user(buf, in, sizeof(*in));
464 case IPC_OLD:
465 {
466 struct shmid_ds out;
467
468 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
469 out.shm_segsz = in->shm_segsz;
470 out.shm_atime = in->shm_atime;
471 out.shm_dtime = in->shm_dtime;
472 out.shm_ctime = in->shm_ctime;
473 out.shm_cpid = in->shm_cpid;
474 out.shm_lpid = in->shm_lpid;
475 out.shm_nattch = in->shm_nattch;
476
477 return copy_to_user(buf, &out, sizeof(out));
478 }
479 default:
480 return -EINVAL;
481 }
482}
483
484struct shm_setbuf {
485 uid_t uid;
486 gid_t gid;
487 mode_t mode;
488};
489
490static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
491{
492 switch(version) {
493 case IPC_64:
494 {
495 struct shmid64_ds tbuf;
496
497 if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
498 return -EFAULT;
499
500 out->uid = tbuf.shm_perm.uid;
501 out->gid = tbuf.shm_perm.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800502 out->mode = tbuf.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503
504 return 0;
505 }
506 case IPC_OLD:
507 {
508 struct shmid_ds tbuf_old;
509
510 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
511 return -EFAULT;
512
513 out->uid = tbuf_old.shm_perm.uid;
514 out->gid = tbuf_old.shm_perm.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800515 out->mode = tbuf_old.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 return 0;
518 }
519 default:
520 return -EINVAL;
521 }
522}
523
524static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
525{
526 switch(version) {
527 case IPC_64:
528 return copy_to_user(buf, in, sizeof(*in));
529 case IPC_OLD:
530 {
531 struct shminfo out;
532
533 if(in->shmmax > INT_MAX)
534 out.shmmax = INT_MAX;
535 else
536 out.shmmax = (int)in->shmmax;
537
538 out.shmmin = in->shmmin;
539 out.shmmni = in->shmmni;
540 out.shmseg = in->shmseg;
541 out.shmall = in->shmall;
542
543 return copy_to_user(buf, &out, sizeof(out));
544 }
545 default:
546 return -EINVAL;
547 }
548}
549
Kirill Korotaev4e982312006-10-02 02:18:22 -0700550static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
551 unsigned long *swp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552{
553 int i;
554
555 *rss = 0;
556 *swp = 0;
557
Kirill Korotaev4e982312006-10-02 02:18:22 -0700558 for (i = 0; i <= shm_ids(ns).max_id; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 struct shmid_kernel *shp;
560 struct inode *inode;
561
Kirill Korotaev4e982312006-10-02 02:18:22 -0700562 shp = shm_get(ns, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 if(!shp)
564 continue;
565
Josef Sipek6d630792006-12-08 02:37:11 -0800566 inode = shp->shm_file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 if (is_file_hugepages(shp->shm_file)) {
569 struct address_space *mapping = inode->i_mapping;
570 *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
571 } else {
572 struct shmem_inode_info *info = SHMEM_I(inode);
573 spin_lock(&info->lock);
574 *rss += inode->i_mapping->nrpages;
575 *swp += info->swapped;
576 spin_unlock(&info->lock);
577 }
578 }
579}
580
581asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
582{
583 struct shm_setbuf setbuf;
584 struct shmid_kernel *shp;
585 int err, version;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700586 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587
588 if (cmd < 0 || shmid < 0) {
589 err = -EINVAL;
590 goto out;
591 }
592
593 version = ipc_parse_version(&cmd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700594 ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
596 switch (cmd) { /* replace with proc interface ? */
597 case IPC_INFO:
598 {
599 struct shminfo64 shminfo;
600
601 err = security_shm_shmctl(NULL, cmd);
602 if (err)
603 return err;
604
605 memset(&shminfo,0,sizeof(shminfo));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700606 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
607 shminfo.shmmax = ns->shm_ctlmax;
608 shminfo.shmall = ns->shm_ctlall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
610 shminfo.shmmin = SHMMIN;
611 if(copy_shminfo_to_user (buf, &shminfo, version))
612 return -EFAULT;
613 /* reading a integer is always atomic */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700614 err= shm_ids(ns).max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 if(err<0)
616 err = 0;
617 goto out;
618 }
619 case SHM_INFO:
620 {
621 struct shm_info shm_info;
622
623 err = security_shm_shmctl(NULL, cmd);
624 if (err)
625 return err;
626
627 memset(&shm_info,0,sizeof(shm_info));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700628 mutex_lock(&shm_ids(ns).mutex);
629 shm_info.used_ids = shm_ids(ns).in_use;
630 shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
631 shm_info.shm_tot = ns->shm_tot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 shm_info.swap_attempts = 0;
633 shm_info.swap_successes = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700634 err = shm_ids(ns).max_id;
635 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
637 err = -EFAULT;
638 goto out;
639 }
640
641 err = err < 0 ? 0 : err;
642 goto out;
643 }
644 case SHM_STAT:
645 case IPC_STAT:
646 {
647 struct shmid64_ds tbuf;
648 int result;
649 memset(&tbuf, 0, sizeof(tbuf));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700650 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 if(shp==NULL) {
652 err = -EINVAL;
653 goto out;
654 } else if(cmd==SHM_STAT) {
655 err = -EINVAL;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700656 if (shmid > shm_ids(ns).max_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 goto out_unlock;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700658 result = shm_buildid(ns, shmid, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 } else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700660 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 if(err)
662 goto out_unlock;
663 result = 0;
664 }
665 err=-EACCES;
666 if (ipcperms (&shp->shm_perm, S_IRUGO))
667 goto out_unlock;
668 err = security_shm_shmctl(shp, cmd);
669 if (err)
670 goto out_unlock;
671 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
672 tbuf.shm_segsz = shp->shm_segsz;
673 tbuf.shm_atime = shp->shm_atim;
674 tbuf.shm_dtime = shp->shm_dtim;
675 tbuf.shm_ctime = shp->shm_ctim;
676 tbuf.shm_cpid = shp->shm_cprid;
677 tbuf.shm_lpid = shp->shm_lprid;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800678 tbuf.shm_nattch = shp->shm_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 shm_unlock(shp);
680 if(copy_shmid_to_user (buf, &tbuf, version))
681 err = -EFAULT;
682 else
683 err = result;
684 goto out;
685 }
686 case SHM_LOCK:
687 case SHM_UNLOCK:
688 {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700689 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 if(shp==NULL) {
691 err = -EINVAL;
692 goto out;
693 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700694 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 if(err)
696 goto out_unlock;
697
Steve Grubb073115d2006-04-02 17:07:33 -0400698 err = audit_ipc_obj(&(shp->shm_perm));
699 if (err)
700 goto out_unlock;
701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 if (!capable(CAP_IPC_LOCK)) {
703 err = -EPERM;
704 if (current->euid != shp->shm_perm.uid &&
705 current->euid != shp->shm_perm.cuid)
706 goto out_unlock;
707 if (cmd == SHM_LOCK &&
708 !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
709 goto out_unlock;
710 }
711
712 err = security_shm_shmctl(shp, cmd);
713 if (err)
714 goto out_unlock;
715
716 if(cmd==SHM_LOCK) {
717 struct user_struct * user = current->user;
718 if (!is_file_hugepages(shp->shm_file)) {
719 err = shmem_lock(shp->shm_file, 1, user);
Pavel Emelianov7be77e22007-07-31 00:38:48 -0700720 if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
Andrew Mortonb33291c2006-01-08 01:02:21 -0800721 shp->shm_perm.mode |= SHM_LOCKED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 shp->mlock_user = user;
723 }
724 }
725 } else if (!is_file_hugepages(shp->shm_file)) {
726 shmem_lock(shp->shm_file, 0, shp->mlock_user);
Andrew Mortonb33291c2006-01-08 01:02:21 -0800727 shp->shm_perm.mode &= ~SHM_LOCKED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 shp->mlock_user = NULL;
729 }
730 shm_unlock(shp);
731 goto out;
732 }
733 case IPC_RMID:
734 {
735 /*
736 * We cannot simply remove the file. The SVID states
737 * that the block remains until the last person
738 * detaches from it, then is deleted. A shmat() on
739 * an RMID segment is legal in older Linux and if
740 * we change it apps break...
741 *
742 * Instead we set a destroyed flag, and then blow
743 * the name away when the usage hits zero.
744 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700745 mutex_lock(&shm_ids(ns).mutex);
746 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 err = -EINVAL;
748 if (shp == NULL)
749 goto out_up;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700750 err = shm_checkid(ns, shp, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 if(err)
752 goto out_unlock_up;
753
Steve Grubb073115d2006-04-02 17:07:33 -0400754 err = audit_ipc_obj(&(shp->shm_perm));
755 if (err)
756 goto out_unlock_up;
757
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 if (current->euid != shp->shm_perm.uid &&
759 current->euid != shp->shm_perm.cuid &&
760 !capable(CAP_SYS_ADMIN)) {
761 err=-EPERM;
762 goto out_unlock_up;
763 }
764
765 err = security_shm_shmctl(shp, cmd);
766 if (err)
767 goto out_unlock_up;
768
Kirill Korotaev4e982312006-10-02 02:18:22 -0700769 do_shm_rmid(ns, shp);
770 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 goto out;
772 }
773
774 case IPC_SET:
775 {
776 if (copy_shmid_from_user (&setbuf, buf, version)) {
777 err = -EFAULT;
778 goto out;
779 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700780 mutex_lock(&shm_ids(ns).mutex);
781 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 err=-EINVAL;
783 if(shp==NULL)
784 goto out_up;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700785 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 if(err)
787 goto out_unlock_up;
Steve Grubb073115d2006-04-02 17:07:33 -0400788 err = audit_ipc_obj(&(shp->shm_perm));
789 if (err)
790 goto out_unlock_up;
Linda Knippersac032212006-05-16 22:03:48 -0400791 err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
Steve Grubb073115d2006-04-02 17:07:33 -0400792 if (err)
793 goto out_unlock_up;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 err=-EPERM;
795 if (current->euid != shp->shm_perm.uid &&
796 current->euid != shp->shm_perm.cuid &&
797 !capable(CAP_SYS_ADMIN)) {
798 goto out_unlock_up;
799 }
800
801 err = security_shm_shmctl(shp, cmd);
802 if (err)
803 goto out_unlock_up;
804
805 shp->shm_perm.uid = setbuf.uid;
806 shp->shm_perm.gid = setbuf.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800807 shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 | (setbuf.mode & S_IRWXUGO);
809 shp->shm_ctim = get_seconds();
810 break;
811 }
812
813 default:
814 err = -EINVAL;
815 goto out;
816 }
817
818 err = 0;
819out_unlock_up:
820 shm_unlock(shp);
821out_up:
Kirill Korotaev4e982312006-10-02 02:18:22 -0700822 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 goto out;
824out_unlock:
825 shm_unlock(shp);
826out:
827 return err;
828}
829
830/*
831 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
832 *
833 * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
834 * "raddr" thing points to kernel space, and there has to be a wrapper around
835 * this.
836 */
837long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
838{
839 struct shmid_kernel *shp;
840 unsigned long addr;
841 unsigned long size;
842 struct file * file;
843 int err;
844 unsigned long flags;
845 unsigned long prot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 int acc_mode;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800847 unsigned long user_addr;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700848 struct ipc_namespace *ns;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800849 struct shm_file_data *sfd;
850 struct path path;
851 mode_t f_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800853 err = -EINVAL;
854 if (shmid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 goto out;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800856 else if ((addr = (ulong)shmaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 if (addr & (SHMLBA-1)) {
858 if (shmflg & SHM_RND)
859 addr &= ~(SHMLBA-1); /* round down */
860 else
861#ifndef __ARCH_FORCE_SHMLBA
862 if (addr & ~PAGE_MASK)
863#endif
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800864 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 }
866 flags = MAP_SHARED | MAP_FIXED;
867 } else {
868 if ((shmflg & SHM_REMAP))
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800869 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
871 flags = MAP_SHARED;
872 }
873
874 if (shmflg & SHM_RDONLY) {
875 prot = PROT_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 acc_mode = S_IRUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800877 f_mode = FMODE_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 } else {
879 prot = PROT_READ | PROT_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 acc_mode = S_IRUGO | S_IWUGO;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800881 f_mode = FMODE_READ | FMODE_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 }
883 if (shmflg & SHM_EXEC) {
884 prot |= PROT_EXEC;
885 acc_mode |= S_IXUGO;
886 }
887
888 /*
889 * We cannot rely on the fs check since SYSV IPC does have an
890 * additional creator id...
891 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700892 ns = current->nsproxy->ipc_ns;
893 shp = shm_lock(ns, shmid);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800894 if(shp == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 goto out;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800896
Kirill Korotaev4e982312006-10-02 02:18:22 -0700897 err = shm_checkid(ns, shp,shmid);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800898 if (err)
899 goto out_unlock;
900
901 err = -EACCES;
902 if (ipcperms(&shp->shm_perm, acc_mode))
903 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904
905 err = security_shm_shmat(shp, shmaddr, shmflg);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800906 if (err)
907 goto out_unlock;
908
909 path.dentry = dget(shp->shm_file->f_path.dentry);
Dave Hansence8d2cd2007-10-16 23:31:13 -0700910 path.mnt = shp->shm_file->f_path.mnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 shp->shm_nattch++;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800912 size = i_size_read(path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 shm_unlock(shp);
914
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800915 err = -ENOMEM;
916 sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
917 if (!sfd)
Dave Hansence8d2cd2007-10-16 23:31:13 -0700918 goto out_put_dentry;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800919
920 err = -ENOMEM;
Dave Hansence8d2cd2007-10-16 23:31:13 -0700921
922 file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800923 if (!file)
924 goto out_free;
925
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800926 file->private_data = sfd;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800927 file->f_mapping = shp->shm_file->f_mapping;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800928 sfd->id = shp->id;
929 sfd->ns = get_ipc_ns(ns);
930 sfd->file = shp->shm_file;
931 sfd->vm_ops = NULL;
932
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 down_write(&current->mm->mmap_sem);
934 if (addr && !(shmflg & SHM_REMAP)) {
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800935 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 if (find_vma_intersection(current->mm, addr, addr + size))
937 goto invalid;
938 /*
939 * If shm segment goes below stack, make sure there is some
940 * space left for the stack to grow (at least 4 pages).
941 */
942 if (addr < current->mm->start_stack &&
943 addr > current->mm->start_stack - size - PAGE_SIZE * 5)
944 goto invalid;
945 }
946
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800947 user_addr = do_mmap (file, addr, size, prot, flags, 0);
948 *raddr = user_addr;
949 err = 0;
950 if (IS_ERR_VALUE(user_addr))
951 err = (long)user_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952invalid:
953 up_write(&current->mm->mmap_sem);
954
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800955 fput(file);
956
957out_nattch:
Kirill Korotaev4e982312006-10-02 02:18:22 -0700958 mutex_lock(&shm_ids(ns).mutex);
959 shp = shm_lock(ns, shmid);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200960 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 shp->shm_nattch--;
962 if(shp->shm_nattch == 0 &&
Andrew Mortonb33291c2006-01-08 01:02:21 -0800963 shp->shm_perm.mode & SHM_DEST)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700964 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 else
966 shm_unlock(shp);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700967 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969out:
970 return err;
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800971
972out_unlock:
973 shm_unlock(shp);
974 goto out;
975
976out_free:
977 kfree(sfd);
Dave Hansence8d2cd2007-10-16 23:31:13 -0700978out_put_dentry:
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800979 dput(path.dentry);
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -0800980 goto out_nattch;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981}
982
Stephen Rothwell7d87e14c2005-05-01 08:59:12 -0700983asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
984{
985 unsigned long ret;
986 long err;
987
988 err = do_shmat(shmid, shmaddr, shmflg, &ret);
989 if (err)
990 return err;
991 force_successful_syscall_return();
992 return (long)ret;
993}
994
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995/*
996 * detach and kill segment if marked destroyed.
997 * The work is done in shm_close.
998 */
999asmlinkage long sys_shmdt(char __user *shmaddr)
1000{
1001 struct mm_struct *mm = current->mm;
1002 struct vm_area_struct *vma, *next;
1003 unsigned long addr = (unsigned long)shmaddr;
1004 loff_t size = 0;
1005 int retval = -EINVAL;
1006
Hugh Dickinsdf1e2fb2006-03-24 03:18:06 -08001007 if (addr & ~PAGE_MASK)
1008 return retval;
1009
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 down_write(&mm->mmap_sem);
1011
1012 /*
1013 * This function tries to be smart and unmap shm segments that
1014 * were modified by partial mlock or munmap calls:
1015 * - It first determines the size of the shm segment that should be
1016 * unmapped: It searches for a vma that is backed by shm and that
1017 * started at address shmaddr. It records it's size and then unmaps
1018 * it.
1019 * - Then it unmaps all shm vmas that started at shmaddr and that
1020 * are within the initially determined size.
1021 * Errors from do_munmap are ignored: the function only fails if
1022 * it's called with invalid parameters or if it's called to unmap
1023 * a part of a vma. Both calls in this function are for full vmas,
1024 * the parameters are directly copied from the vma itself and always
1025 * valid - therefore do_munmap cannot fail. (famous last words?)
1026 */
1027 /*
1028 * If it had been mremap()'d, the starting address would not
1029 * match the usual checks anyway. So assume all vma's are
1030 * above the starting address given.
1031 */
1032 vma = find_vma(mm, addr);
1033
1034 while (vma) {
1035 next = vma->vm_next;
1036
1037 /*
1038 * Check if the starting address would match, i.e. it's
1039 * a fragment created by mprotect() and/or munmap(), or it
1040 * otherwise it starts at this address with no hassles.
1041 */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001042 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1044
1045
Josef Sipek6d630792006-12-08 02:37:11 -08001046 size = vma->vm_file->f_path.dentry->d_inode->i_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1048 /*
1049 * We discovered the size of the shm segment, so
1050 * break out of here and fall through to the next
1051 * loop that uses the size information to stop
1052 * searching for matching vma's.
1053 */
1054 retval = 0;
1055 vma = next;
1056 break;
1057 }
1058 vma = next;
1059 }
1060
1061 /*
1062 * We need look no further than the maximum address a fragment
1063 * could possibly have landed at. Also cast things to loff_t to
1064 * prevent overflows and make comparisions vs. equal-width types.
1065 */
KAMEZAWA Hiroyuki8e367092006-02-10 01:51:12 -08001066 size = PAGE_ALIGN(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1068 next = vma->vm_next;
1069
1070 /* finding a matching vma now does not alter retval */
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001071 if ((vma->vm_ops == &shm_vm_ops) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
1073
1074 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1075 vma = next;
1076 }
1077
1078 up_write(&mm->mmap_sem);
1079 return retval;
1080}
1081
1082#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001083static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084{
Mike Waychison19b49462005-09-06 15:17:10 -07001085 struct shmid_kernel *shp = it;
1086 char *format;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088#define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
1089#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 -07001090
Mike Waychison19b49462005-09-06 15:17:10 -07001091 if (sizeof(size_t) <= sizeof(int))
1092 format = SMALL_STRING;
1093 else
1094 format = BIG_STRING;
1095 return seq_printf(s, format,
1096 shp->shm_perm.key,
1097 shp->id,
Andrew Mortonb33291c2006-01-08 01:02:21 -08001098 shp->shm_perm.mode,
Mike Waychison19b49462005-09-06 15:17:10 -07001099 shp->shm_segsz,
1100 shp->shm_cprid,
1101 shp->shm_lprid,
Eric W. Biedermanbc56bba2007-02-20 13:57:53 -08001102 shp->shm_nattch,
Mike Waychison19b49462005-09-06 15:17:10 -07001103 shp->shm_perm.uid,
1104 shp->shm_perm.gid,
1105 shp->shm_perm.cuid,
1106 shp->shm_perm.cgid,
1107 shp->shm_atim,
1108 shp->shm_dtim,
1109 shp->shm_ctim);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110}
1111#endif