blob: bfbd317ec11c0be1a73bc85b82d37ee3bbf33dd3 [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>
Stephen Rothwell7d87e142005-05-01 08:59:12 -070040
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <asm/uaccess.h>
42
43#include "util.h"
44
Linus Torvalds1da177e2005-04-16 15:20:36 -070045static struct file_operations shm_file_operations;
46static struct vm_operations_struct shm_vm_ops;
47
Kirill Korotaev4e982312006-10-02 02:18:22 -070048static struct ipc_ids init_shm_ids;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Kirill Korotaev4e982312006-10-02 02:18:22 -070050#define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS]))
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Kirill Korotaev4e982312006-10-02 02:18:22 -070052#define shm_lock(ns, id) \
53 ((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id))
54#define shm_unlock(shp) \
55 ipc_unlock(&(shp)->shm_perm)
56#define shm_get(ns, id) \
57 ((struct shmid_kernel*)ipc_get(&shm_ids(ns),id))
58#define shm_buildid(ns, id, seq) \
59 ipc_buildid(&shm_ids(ns), id, seq)
60
61static int newseg (struct ipc_namespace *ns, key_t key,
62 int shmflg, size_t size);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063static void shm_open (struct vm_area_struct *shmd);
64static void shm_close (struct vm_area_struct *shmd);
Kirill Korotaev4e982312006-10-02 02:18:22 -070065static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070066#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -070067static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#endif
69
Kirill Korotaev4e982312006-10-02 02:18:22 -070070static void __ipc_init __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
71{
72 ns->ids[IPC_SHM_IDS] = ids;
73 ns->shm_ctlmax = SHMMAX;
74 ns->shm_ctlall = SHMALL;
75 ns->shm_ctlmni = SHMMNI;
76 ns->shm_tot = 0;
77 ipc_init_ids(ids, 1);
78}
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Kirill Korotaev4e982312006-10-02 02:18:22 -070080static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
81{
82 if (shp->shm_nattch){
83 shp->shm_perm.mode |= SHM_DEST;
84 /* Do not find it any more */
85 shp->shm_perm.key = IPC_PRIVATE;
86 shm_unlock(shp);
87 } else
88 shm_destroy(ns, shp);
89}
90
91#ifdef CONFIG_IPC_NS
92int shm_init_ns(struct ipc_namespace *ns)
93{
94 struct ipc_ids *ids;
95
96 ids = kmalloc(sizeof(struct ipc_ids), GFP_KERNEL);
97 if (ids == NULL)
98 return -ENOMEM;
99
100 __shm_init_ns(ns, ids);
101 return 0;
102}
103
104void shm_exit_ns(struct ipc_namespace *ns)
105{
106 int i;
107 struct shmid_kernel *shp;
108
109 mutex_lock(&shm_ids(ns).mutex);
110 for (i = 0; i <= shm_ids(ns).max_id; i++) {
111 shp = shm_lock(ns, i);
112 if (shp == NULL)
113 continue;
114
115 do_shm_rmid(ns, shp);
116 }
117 mutex_unlock(&shm_ids(ns).mutex);
118
119 kfree(ns->ids[IPC_SHM_IDS]);
120 ns->ids[IPC_SHM_IDS] = NULL;
121}
122#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124void __init shm_init (void)
125{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700126 __shm_init_ns(&init_ipc_ns, &init_shm_ids);
Mike Waychison19b49462005-09-06 15:17:10 -0700127 ipc_init_proc_interface("sysvipc/shm",
128 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
Kirill Korotaev4e982312006-10-02 02:18:22 -0700129 IPC_SHM_IDS, sysvipc_shm_proc_show);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130}
131
Kirill Korotaev4e982312006-10-02 02:18:22 -0700132static inline int shm_checkid(struct ipc_namespace *ns,
133 struct shmid_kernel *s, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700135 if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 return -EIDRM;
137 return 0;
138}
139
Kirill Korotaev4e982312006-10-02 02:18:22 -0700140static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700142 return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143}
144
Kirill Korotaev4e982312006-10-02 02:18:22 -0700145static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700147 return ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148}
149
150
151
Kirill Korotaev4e982312006-10-02 02:18:22 -0700152static inline void shm_inc(struct ipc_namespace *ns, int id)
153{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 struct shmid_kernel *shp;
155
Kirill Korotaev4e982312006-10-02 02:18:22 -0700156 shp = shm_lock(ns, id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200157 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 shp->shm_atim = get_seconds();
159 shp->shm_lprid = current->tgid;
160 shp->shm_nattch++;
161 shm_unlock(shp);
162}
163
Kirill Korotaev4e982312006-10-02 02:18:22 -0700164#define shm_file_ns(file) (*((struct ipc_namespace **)&(file)->private_data))
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166/* This is called by fork, once for every shm attach. */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700167static void shm_open(struct vm_area_struct *shmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700169 shm_inc(shm_file_ns(shmd->vm_file),
170 shmd->vm_file->f_dentry->d_inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171}
172
173/*
174 * shm_destroy - free the struct shmid_kernel
175 *
176 * @shp: struct to free
177 *
Ingo Molnar5f921ae2006-03-26 01:37:17 -0800178 * It has to be called with shp and shm_ids.mutex locked,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 * but returns with shp unlocked and freed.
180 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700181static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
Kirill Korotaev4e982312006-10-02 02:18:22 -0700183 ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
184 shm_rmid(ns, shp->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 shm_unlock(shp);
186 if (!is_file_hugepages(shp->shm_file))
187 shmem_lock(shp->shm_file, 0, shp->mlock_user);
188 else
189 user_shm_unlock(shp->shm_file->f_dentry->d_inode->i_size,
190 shp->mlock_user);
191 fput (shp->shm_file);
192 security_shm_free(shp);
193 ipc_rcu_putref(shp);
194}
195
196/*
197 * remove the attach descriptor shmd.
198 * free memory for segment if it is marked destroyed.
199 * The descriptor has already been removed from the current->mm->mmap list
200 * and will later be kfree()d.
201 */
202static void shm_close (struct vm_area_struct *shmd)
203{
204 struct file * file = shmd->vm_file;
205 int id = file->f_dentry->d_inode->i_ino;
206 struct shmid_kernel *shp;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700207 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Kirill Korotaev4e982312006-10-02 02:18:22 -0700209 ns = shm_file_ns(file);
210
211 mutex_lock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 /* remove from the list of attaches of the shm segment */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700213 shp = shm_lock(ns, id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200214 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 shp->shm_lprid = current->tgid;
216 shp->shm_dtim = get_seconds();
217 shp->shm_nattch--;
218 if(shp->shm_nattch == 0 &&
Andrew Mortonb33291c2006-01-08 01:02:21 -0800219 shp->shm_perm.mode & SHM_DEST)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700220 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 else
222 shm_unlock(shp);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700223 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224}
225
226static int shm_mmap(struct file * file, struct vm_area_struct * vma)
227{
David Howellsb0e15192006-01-06 00:11:42 -0800228 int ret;
229
230 ret = shmem_mmap(file, vma);
231 if (ret == 0) {
232 vma->vm_ops = &shm_vm_ops;
Hugh Dickinsb78b6af2006-04-12 14:34:27 -0700233 if (!(vma->vm_flags & VM_WRITE))
234 vma->vm_flags &= ~VM_MAYWRITE;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700235 shm_inc(shm_file_ns(file), file->f_dentry->d_inode->i_ino);
David Howellsb0e15192006-01-06 00:11:42 -0800236 }
237
238 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240
Kirill Korotaev4e982312006-10-02 02:18:22 -0700241static int shm_release(struct inode *ino, struct file *file)
242{
243 struct ipc_namespace *ns;
244
245 ns = shm_file_ns(file);
246 put_ipc_ns(ns);
247 shm_file_ns(file) = NULL;
248 return 0;
249}
250
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251static struct file_operations shm_file_operations = {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700252 .mmap = shm_mmap,
253 .release = shm_release,
David Howellsb0e15192006-01-06 00:11:42 -0800254#ifndef CONFIG_MMU
255 .get_unmapped_area = shmem_get_unmapped_area,
256#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257};
258
259static struct vm_operations_struct shm_vm_ops = {
260 .open = shm_open, /* callback for a new vm-area open */
261 .close = shm_close, /* callback for when the vm-area is released */
262 .nopage = shmem_nopage,
Andrew Morton6ade43f2005-08-01 21:11:45 -0700263#if defined(CONFIG_NUMA) && defined(CONFIG_SHMEM)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 .set_policy = shmem_set_policy,
265 .get_policy = shmem_get_policy,
266#endif
267};
268
Kirill Korotaev4e982312006-10-02 02:18:22 -0700269static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270{
271 int error;
272 struct shmid_kernel *shp;
273 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
274 struct file * file;
275 char name[13];
276 int id;
277
Kirill Korotaev4e982312006-10-02 02:18:22 -0700278 if (size < SHMMIN || size > ns->shm_ctlmax)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 return -EINVAL;
280
Kirill Korotaev4e982312006-10-02 02:18:22 -0700281 if (ns->shm_tot + numpages >= ns->shm_ctlall)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 return -ENOSPC;
283
284 shp = ipc_rcu_alloc(sizeof(*shp));
285 if (!shp)
286 return -ENOMEM;
287
288 shp->shm_perm.key = key;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800289 shp->shm_perm.mode = (shmflg & S_IRWXUGO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 shp->mlock_user = NULL;
291
292 shp->shm_perm.security = NULL;
293 error = security_shm_alloc(shp);
294 if (error) {
295 ipc_rcu_putref(shp);
296 return error;
297 }
298
299 if (shmflg & SHM_HUGETLB) {
300 /* hugetlb_zero_setup takes care of mlock user accounting */
301 file = hugetlb_zero_setup(size);
302 shp->mlock_user = current->user;
303 } else {
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800304 int acctflag = VM_ACCOUNT;
305 /*
306 * Do not allow no accounting for OVERCOMMIT_NEVER, even
307 * if it's asked for.
308 */
309 if ((shmflg & SHM_NORESERVE) &&
310 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
311 acctflag = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 sprintf (name, "SYSV%08x", key);
Badari Pulavartybf8f9722005-11-07 00:59:27 -0800313 file = shmem_file_setup(name, size, acctflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 }
315 error = PTR_ERR(file);
316 if (IS_ERR(file))
317 goto no_file;
318
319 error = -ENOSPC;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700320 id = shm_addid(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 if(id == -1)
322 goto no_id;
323
324 shp->shm_cprid = current->tgid;
325 shp->shm_lprid = 0;
326 shp->shm_atim = shp->shm_dtim = 0;
327 shp->shm_ctim = get_seconds();
328 shp->shm_segsz = size;
329 shp->shm_nattch = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700330 shp->id = shm_buildid(ns, id, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 shp->shm_file = file;
332 file->f_dentry->d_inode->i_ino = shp->id;
Krishnakumar R551110a2005-10-29 18:16:45 -0700333
Kirill Korotaev4e982312006-10-02 02:18:22 -0700334 shm_file_ns(file) = get_ipc_ns(ns);
335
Krishnakumar R551110a2005-10-29 18:16:45 -0700336 /* Hugetlb ops would have already been assigned. */
337 if (!(shmflg & SHM_HUGETLB))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 file->f_op = &shm_file_operations;
Krishnakumar R551110a2005-10-29 18:16:45 -0700339
Kirill Korotaev4e982312006-10-02 02:18:22 -0700340 ns->shm_tot += numpages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 shm_unlock(shp);
342 return shp->id;
343
344no_id:
345 fput(file);
346no_file:
347 security_shm_free(shp);
348 ipc_rcu_putref(shp);
349 return error;
350}
351
352asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
353{
354 struct shmid_kernel *shp;
355 int err, id = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700356 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
Kirill Korotaev4e982312006-10-02 02:18:22 -0700358 ns = current->nsproxy->ipc_ns;
359
360 mutex_lock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 if (key == IPC_PRIVATE) {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700362 err = newseg(ns, key, shmflg, size);
363 } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 if (!(shmflg & IPC_CREAT))
365 err = -ENOENT;
366 else
Kirill Korotaev4e982312006-10-02 02:18:22 -0700367 err = newseg(ns, key, shmflg, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
369 err = -EEXIST;
370 } else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700371 shp = shm_lock(ns, id);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200372 BUG_ON(shp==NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 if (shp->shm_segsz < size)
374 err = -EINVAL;
375 else if (ipcperms(&shp->shm_perm, shmflg))
376 err = -EACCES;
377 else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700378 int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 err = security_shm_associate(shp, shmflg);
380 if (!err)
381 err = shmid;
382 }
383 shm_unlock(shp);
384 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700385 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387 return err;
388}
389
390static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
391{
392 switch(version) {
393 case IPC_64:
394 return copy_to_user(buf, in, sizeof(*in));
395 case IPC_OLD:
396 {
397 struct shmid_ds out;
398
399 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
400 out.shm_segsz = in->shm_segsz;
401 out.shm_atime = in->shm_atime;
402 out.shm_dtime = in->shm_dtime;
403 out.shm_ctime = in->shm_ctime;
404 out.shm_cpid = in->shm_cpid;
405 out.shm_lpid = in->shm_lpid;
406 out.shm_nattch = in->shm_nattch;
407
408 return copy_to_user(buf, &out, sizeof(out));
409 }
410 default:
411 return -EINVAL;
412 }
413}
414
415struct shm_setbuf {
416 uid_t uid;
417 gid_t gid;
418 mode_t mode;
419};
420
421static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version)
422{
423 switch(version) {
424 case IPC_64:
425 {
426 struct shmid64_ds tbuf;
427
428 if (copy_from_user(&tbuf, buf, sizeof(tbuf)))
429 return -EFAULT;
430
431 out->uid = tbuf.shm_perm.uid;
432 out->gid = tbuf.shm_perm.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800433 out->mode = tbuf.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
435 return 0;
436 }
437 case IPC_OLD:
438 {
439 struct shmid_ds tbuf_old;
440
441 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
442 return -EFAULT;
443
444 out->uid = tbuf_old.shm_perm.uid;
445 out->gid = tbuf_old.shm_perm.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800446 out->mode = tbuf_old.shm_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
448 return 0;
449 }
450 default:
451 return -EINVAL;
452 }
453}
454
455static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
456{
457 switch(version) {
458 case IPC_64:
459 return copy_to_user(buf, in, sizeof(*in));
460 case IPC_OLD:
461 {
462 struct shminfo out;
463
464 if(in->shmmax > INT_MAX)
465 out.shmmax = INT_MAX;
466 else
467 out.shmmax = (int)in->shmmax;
468
469 out.shmmin = in->shmmin;
470 out.shmmni = in->shmmni;
471 out.shmseg = in->shmseg;
472 out.shmall = in->shmall;
473
474 return copy_to_user(buf, &out, sizeof(out));
475 }
476 default:
477 return -EINVAL;
478 }
479}
480
Kirill Korotaev4e982312006-10-02 02:18:22 -0700481static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
482 unsigned long *swp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483{
484 int i;
485
486 *rss = 0;
487 *swp = 0;
488
Kirill Korotaev4e982312006-10-02 02:18:22 -0700489 for (i = 0; i <= shm_ids(ns).max_id; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 struct shmid_kernel *shp;
491 struct inode *inode;
492
Kirill Korotaev4e982312006-10-02 02:18:22 -0700493 shp = shm_get(ns, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 if(!shp)
495 continue;
496
497 inode = shp->shm_file->f_dentry->d_inode;
498
499 if (is_file_hugepages(shp->shm_file)) {
500 struct address_space *mapping = inode->i_mapping;
501 *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages;
502 } else {
503 struct shmem_inode_info *info = SHMEM_I(inode);
504 spin_lock(&info->lock);
505 *rss += inode->i_mapping->nrpages;
506 *swp += info->swapped;
507 spin_unlock(&info->lock);
508 }
509 }
510}
511
512asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
513{
514 struct shm_setbuf setbuf;
515 struct shmid_kernel *shp;
516 int err, version;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700517 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518
519 if (cmd < 0 || shmid < 0) {
520 err = -EINVAL;
521 goto out;
522 }
523
524 version = ipc_parse_version(&cmd);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700525 ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526
527 switch (cmd) { /* replace with proc interface ? */
528 case IPC_INFO:
529 {
530 struct shminfo64 shminfo;
531
532 err = security_shm_shmctl(NULL, cmd);
533 if (err)
534 return err;
535
536 memset(&shminfo,0,sizeof(shminfo));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700537 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
538 shminfo.shmmax = ns->shm_ctlmax;
539 shminfo.shmall = ns->shm_ctlall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
541 shminfo.shmmin = SHMMIN;
542 if(copy_shminfo_to_user (buf, &shminfo, version))
543 return -EFAULT;
544 /* reading a integer is always atomic */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700545 err= shm_ids(ns).max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 if(err<0)
547 err = 0;
548 goto out;
549 }
550 case SHM_INFO:
551 {
552 struct shm_info shm_info;
553
554 err = security_shm_shmctl(NULL, cmd);
555 if (err)
556 return err;
557
558 memset(&shm_info,0,sizeof(shm_info));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700559 mutex_lock(&shm_ids(ns).mutex);
560 shm_info.used_ids = shm_ids(ns).in_use;
561 shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp);
562 shm_info.shm_tot = ns->shm_tot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 shm_info.swap_attempts = 0;
564 shm_info.swap_successes = 0;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700565 err = shm_ids(ns).max_id;
566 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 if(copy_to_user (buf, &shm_info, sizeof(shm_info))) {
568 err = -EFAULT;
569 goto out;
570 }
571
572 err = err < 0 ? 0 : err;
573 goto out;
574 }
575 case SHM_STAT:
576 case IPC_STAT:
577 {
578 struct shmid64_ds tbuf;
579 int result;
580 memset(&tbuf, 0, sizeof(tbuf));
Kirill Korotaev4e982312006-10-02 02:18:22 -0700581 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 if(shp==NULL) {
583 err = -EINVAL;
584 goto out;
585 } else if(cmd==SHM_STAT) {
586 err = -EINVAL;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700587 if (shmid > shm_ids(ns).max_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 goto out_unlock;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700589 result = shm_buildid(ns, shmid, shp->shm_perm.seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 } else {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700591 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 if(err)
593 goto out_unlock;
594 result = 0;
595 }
596 err=-EACCES;
597 if (ipcperms (&shp->shm_perm, S_IRUGO))
598 goto out_unlock;
599 err = security_shm_shmctl(shp, cmd);
600 if (err)
601 goto out_unlock;
602 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
603 tbuf.shm_segsz = shp->shm_segsz;
604 tbuf.shm_atime = shp->shm_atim;
605 tbuf.shm_dtime = shp->shm_dtim;
606 tbuf.shm_ctime = shp->shm_ctim;
607 tbuf.shm_cpid = shp->shm_cprid;
608 tbuf.shm_lpid = shp->shm_lprid;
609 if (!is_file_hugepages(shp->shm_file))
610 tbuf.shm_nattch = shp->shm_nattch;
611 else
612 tbuf.shm_nattch = file_count(shp->shm_file) - 1;
613 shm_unlock(shp);
614 if(copy_shmid_to_user (buf, &tbuf, version))
615 err = -EFAULT;
616 else
617 err = result;
618 goto out;
619 }
620 case SHM_LOCK:
621 case SHM_UNLOCK:
622 {
Kirill Korotaev4e982312006-10-02 02:18:22 -0700623 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 if(shp==NULL) {
625 err = -EINVAL;
626 goto out;
627 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700628 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 if(err)
630 goto out_unlock;
631
Steve Grubb073115d2006-04-02 17:07:33 -0400632 err = audit_ipc_obj(&(shp->shm_perm));
633 if (err)
634 goto out_unlock;
635
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 if (!capable(CAP_IPC_LOCK)) {
637 err = -EPERM;
638 if (current->euid != shp->shm_perm.uid &&
639 current->euid != shp->shm_perm.cuid)
640 goto out_unlock;
641 if (cmd == SHM_LOCK &&
642 !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
643 goto out_unlock;
644 }
645
646 err = security_shm_shmctl(shp, cmd);
647 if (err)
648 goto out_unlock;
649
650 if(cmd==SHM_LOCK) {
651 struct user_struct * user = current->user;
652 if (!is_file_hugepages(shp->shm_file)) {
653 err = shmem_lock(shp->shm_file, 1, user);
654 if (!err) {
Andrew Mortonb33291c2006-01-08 01:02:21 -0800655 shp->shm_perm.mode |= SHM_LOCKED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 shp->mlock_user = user;
657 }
658 }
659 } else if (!is_file_hugepages(shp->shm_file)) {
660 shmem_lock(shp->shm_file, 0, shp->mlock_user);
Andrew Mortonb33291c2006-01-08 01:02:21 -0800661 shp->shm_perm.mode &= ~SHM_LOCKED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 shp->mlock_user = NULL;
663 }
664 shm_unlock(shp);
665 goto out;
666 }
667 case IPC_RMID:
668 {
669 /*
670 * We cannot simply remove the file. The SVID states
671 * that the block remains until the last person
672 * detaches from it, then is deleted. A shmat() on
673 * an RMID segment is legal in older Linux and if
674 * we change it apps break...
675 *
676 * Instead we set a destroyed flag, and then blow
677 * the name away when the usage hits zero.
678 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700679 mutex_lock(&shm_ids(ns).mutex);
680 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 err = -EINVAL;
682 if (shp == NULL)
683 goto out_up;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700684 err = shm_checkid(ns, shp, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 if(err)
686 goto out_unlock_up;
687
Steve Grubb073115d2006-04-02 17:07:33 -0400688 err = audit_ipc_obj(&(shp->shm_perm));
689 if (err)
690 goto out_unlock_up;
691
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 if (current->euid != shp->shm_perm.uid &&
693 current->euid != shp->shm_perm.cuid &&
694 !capable(CAP_SYS_ADMIN)) {
695 err=-EPERM;
696 goto out_unlock_up;
697 }
698
699 err = security_shm_shmctl(shp, cmd);
700 if (err)
701 goto out_unlock_up;
702
Kirill Korotaev4e982312006-10-02 02:18:22 -0700703 do_shm_rmid(ns, shp);
704 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 goto out;
706 }
707
708 case IPC_SET:
709 {
710 if (copy_shmid_from_user (&setbuf, buf, version)) {
711 err = -EFAULT;
712 goto out;
713 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700714 mutex_lock(&shm_ids(ns).mutex);
715 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 err=-EINVAL;
717 if(shp==NULL)
718 goto out_up;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700719 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 if(err)
721 goto out_unlock_up;
Steve Grubb073115d2006-04-02 17:07:33 -0400722 err = audit_ipc_obj(&(shp->shm_perm));
723 if (err)
724 goto out_unlock_up;
Linda Knippersac032212006-05-16 22:03:48 -0400725 err = audit_ipc_set_perm(0, setbuf.uid, setbuf.gid, setbuf.mode);
Steve Grubb073115d2006-04-02 17:07:33 -0400726 if (err)
727 goto out_unlock_up;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 err=-EPERM;
729 if (current->euid != shp->shm_perm.uid &&
730 current->euid != shp->shm_perm.cuid &&
731 !capable(CAP_SYS_ADMIN)) {
732 goto out_unlock_up;
733 }
734
735 err = security_shm_shmctl(shp, cmd);
736 if (err)
737 goto out_unlock_up;
738
739 shp->shm_perm.uid = setbuf.uid;
740 shp->shm_perm.gid = setbuf.gid;
Andrew Mortonb33291c2006-01-08 01:02:21 -0800741 shp->shm_perm.mode = (shp->shm_perm.mode & ~S_IRWXUGO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 | (setbuf.mode & S_IRWXUGO);
743 shp->shm_ctim = get_seconds();
744 break;
745 }
746
747 default:
748 err = -EINVAL;
749 goto out;
750 }
751
752 err = 0;
753out_unlock_up:
754 shm_unlock(shp);
755out_up:
Kirill Korotaev4e982312006-10-02 02:18:22 -0700756 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 goto out;
758out_unlock:
759 shm_unlock(shp);
760out:
761 return err;
762}
763
764/*
765 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
766 *
767 * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
768 * "raddr" thing points to kernel space, and there has to be a wrapper around
769 * this.
770 */
771long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
772{
773 struct shmid_kernel *shp;
774 unsigned long addr;
775 unsigned long size;
776 struct file * file;
777 int err;
778 unsigned long flags;
779 unsigned long prot;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 int acc_mode;
781 void *user_addr;
Kirill Korotaev4e982312006-10-02 02:18:22 -0700782 struct ipc_namespace *ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783
784 if (shmid < 0) {
785 err = -EINVAL;
786 goto out;
787 } else if ((addr = (ulong)shmaddr)) {
788 if (addr & (SHMLBA-1)) {
789 if (shmflg & SHM_RND)
790 addr &= ~(SHMLBA-1); /* round down */
791 else
792#ifndef __ARCH_FORCE_SHMLBA
793 if (addr & ~PAGE_MASK)
794#endif
795 return -EINVAL;
796 }
797 flags = MAP_SHARED | MAP_FIXED;
798 } else {
799 if ((shmflg & SHM_REMAP))
800 return -EINVAL;
801
802 flags = MAP_SHARED;
803 }
804
805 if (shmflg & SHM_RDONLY) {
806 prot = PROT_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 acc_mode = S_IRUGO;
808 } else {
809 prot = PROT_READ | PROT_WRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 acc_mode = S_IRUGO | S_IWUGO;
811 }
812 if (shmflg & SHM_EXEC) {
813 prot |= PROT_EXEC;
814 acc_mode |= S_IXUGO;
815 }
816
817 /*
818 * We cannot rely on the fs check since SYSV IPC does have an
819 * additional creator id...
820 */
Kirill Korotaev4e982312006-10-02 02:18:22 -0700821 ns = current->nsproxy->ipc_ns;
822 shp = shm_lock(ns, shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 if(shp == NULL) {
824 err = -EINVAL;
825 goto out;
826 }
Kirill Korotaev4e982312006-10-02 02:18:22 -0700827 err = shm_checkid(ns, shp,shmid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 if (err) {
829 shm_unlock(shp);
830 goto out;
831 }
832 if (ipcperms(&shp->shm_perm, acc_mode)) {
833 shm_unlock(shp);
834 err = -EACCES;
835 goto out;
836 }
837
838 err = security_shm_shmat(shp, shmaddr, shmflg);
839 if (err) {
840 shm_unlock(shp);
841 return err;
842 }
843
844 file = shp->shm_file;
845 size = i_size_read(file->f_dentry->d_inode);
846 shp->shm_nattch++;
847 shm_unlock(shp);
848
849 down_write(&current->mm->mmap_sem);
850 if (addr && !(shmflg & SHM_REMAP)) {
851 user_addr = ERR_PTR(-EINVAL);
852 if (find_vma_intersection(current->mm, addr, addr + size))
853 goto invalid;
854 /*
855 * If shm segment goes below stack, make sure there is some
856 * space left for the stack to grow (at least 4 pages).
857 */
858 if (addr < current->mm->start_stack &&
859 addr > current->mm->start_stack - size - PAGE_SIZE * 5)
860 goto invalid;
861 }
862
863 user_addr = (void*) do_mmap (file, addr, size, prot, flags, 0);
864
865invalid:
866 up_write(&current->mm->mmap_sem);
867
Kirill Korotaev4e982312006-10-02 02:18:22 -0700868 mutex_lock(&shm_ids(ns).mutex);
869 shp = shm_lock(ns, shmid);
Eric Sesterhenn9ba025f2006-04-02 13:42:42 +0200870 BUG_ON(!shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 shp->shm_nattch--;
872 if(shp->shm_nattch == 0 &&
Andrew Mortonb33291c2006-01-08 01:02:21 -0800873 shp->shm_perm.mode & SHM_DEST)
Kirill Korotaev4e982312006-10-02 02:18:22 -0700874 shm_destroy(ns, shp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 else
876 shm_unlock(shp);
Kirill Korotaev4e982312006-10-02 02:18:22 -0700877 mutex_unlock(&shm_ids(ns).mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878
879 *raddr = (unsigned long) user_addr;
880 err = 0;
881 if (IS_ERR(user_addr))
882 err = PTR_ERR(user_addr);
883out:
884 return err;
885}
886
Stephen Rothwell7d87e142005-05-01 08:59:12 -0700887asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg)
888{
889 unsigned long ret;
890 long err;
891
892 err = do_shmat(shmid, shmaddr, shmflg, &ret);
893 if (err)
894 return err;
895 force_successful_syscall_return();
896 return (long)ret;
897}
898
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899/*
900 * detach and kill segment if marked destroyed.
901 * The work is done in shm_close.
902 */
903asmlinkage long sys_shmdt(char __user *shmaddr)
904{
905 struct mm_struct *mm = current->mm;
906 struct vm_area_struct *vma, *next;
907 unsigned long addr = (unsigned long)shmaddr;
908 loff_t size = 0;
909 int retval = -EINVAL;
910
Hugh Dickinsdf1e2fb2006-03-24 03:18:06 -0800911 if (addr & ~PAGE_MASK)
912 return retval;
913
Linus Torvalds1da177e2005-04-16 15:20:36 -0700914 down_write(&mm->mmap_sem);
915
916 /*
917 * This function tries to be smart and unmap shm segments that
918 * were modified by partial mlock or munmap calls:
919 * - It first determines the size of the shm segment that should be
920 * unmapped: It searches for a vma that is backed by shm and that
921 * started at address shmaddr. It records it's size and then unmaps
922 * it.
923 * - Then it unmaps all shm vmas that started at shmaddr and that
924 * are within the initially determined size.
925 * Errors from do_munmap are ignored: the function only fails if
926 * it's called with invalid parameters or if it's called to unmap
927 * a part of a vma. Both calls in this function are for full vmas,
928 * the parameters are directly copied from the vma itself and always
929 * valid - therefore do_munmap cannot fail. (famous last words?)
930 */
931 /*
932 * If it had been mremap()'d, the starting address would not
933 * match the usual checks anyway. So assume all vma's are
934 * above the starting address given.
935 */
936 vma = find_vma(mm, addr);
937
938 while (vma) {
939 next = vma->vm_next;
940
941 /*
942 * Check if the starting address would match, i.e. it's
943 * a fragment created by mprotect() and/or munmap(), or it
944 * otherwise it starts at this address with no hassles.
945 */
946 if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) &&
947 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
948
949
950 size = vma->vm_file->f_dentry->d_inode->i_size;
951 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
952 /*
953 * We discovered the size of the shm segment, so
954 * break out of here and fall through to the next
955 * loop that uses the size information to stop
956 * searching for matching vma's.
957 */
958 retval = 0;
959 vma = next;
960 break;
961 }
962 vma = next;
963 }
964
965 /*
966 * We need look no further than the maximum address a fragment
967 * could possibly have landed at. Also cast things to loff_t to
968 * prevent overflows and make comparisions vs. equal-width types.
969 */
KAMEZAWA Hiroyuki8e367092006-02-10 01:51:12 -0800970 size = PAGE_ALIGN(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 while (vma && (loff_t)(vma->vm_end - addr) <= size) {
972 next = vma->vm_next;
973
974 /* finding a matching vma now does not alter retval */
975 if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) &&
976 (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff)
977
978 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
979 vma = next;
980 }
981
982 up_write(&mm->mmap_sem);
983 return retval;
984}
985
986#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -0700987static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988{
Mike Waychison19b49462005-09-06 15:17:10 -0700989 struct shmid_kernel *shp = it;
990 char *format;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992#define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n"
993#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 -0700994
Mike Waychison19b49462005-09-06 15:17:10 -0700995 if (sizeof(size_t) <= sizeof(int))
996 format = SMALL_STRING;
997 else
998 format = BIG_STRING;
999 return seq_printf(s, format,
1000 shp->shm_perm.key,
1001 shp->id,
Andrew Mortonb33291c2006-01-08 01:02:21 -08001002 shp->shm_perm.mode,
Mike Waychison19b49462005-09-06 15:17:10 -07001003 shp->shm_segsz,
1004 shp->shm_cprid,
1005 shp->shm_lprid,
1006 is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch,
1007 shp->shm_perm.uid,
1008 shp->shm_perm.gid,
1009 shp->shm_perm.cuid,
1010 shp->shm_perm.cgid,
1011 shp->shm_atim,
1012 shp->shm_dtim,
1013 shp->shm_ctim);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014}
1015#endif