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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
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 | * | |
073115d6 SG |
16 | * support for audit of ipc object properties and permission changes |
17 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
4e982311 KK |
18 | * |
19 | * namespaces support | |
20 | * OpenVZ, SWsoft Inc. | |
21 | * Pavel Emelianov <xemul@openvz.org> | |
c2c737a0 DB |
22 | * |
23 | * Better ipc lock (kern_ipc_perm.lock) handling | |
24 | * Davidlohr Bueso <davidlohr.bueso@hp.com>, June 2013. | |
1da177e4 LT |
25 | */ |
26 | ||
1da177e4 LT |
27 | #include <linux/slab.h> |
28 | #include <linux/mm.h> | |
29 | #include <linux/hugetlb.h> | |
30 | #include <linux/shm.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/file.h> | |
33 | #include <linux/mman.h> | |
1da177e4 LT |
34 | #include <linux/shmem_fs.h> |
35 | #include <linux/security.h> | |
36 | #include <linux/syscalls.h> | |
37 | #include <linux/audit.h> | |
c59ede7b | 38 | #include <linux/capability.h> |
7d87e14c | 39 | #include <linux/ptrace.h> |
19b4946c | 40 | #include <linux/seq_file.h> |
3e148c79 | 41 | #include <linux/rwsem.h> |
4e982311 | 42 | #include <linux/nsproxy.h> |
bc56bba8 | 43 | #include <linux/mount.h> |
ae5e1b22 | 44 | #include <linux/ipc_namespace.h> |
7d87e14c | 45 | |
1da177e4 LT |
46 | #include <asm/uaccess.h> |
47 | ||
48 | #include "util.h" | |
49 | ||
bc56bba8 EB |
50 | struct shm_file_data { |
51 | int id; | |
52 | struct ipc_namespace *ns; | |
53 | struct file *file; | |
54 | const struct vm_operations_struct *vm_ops; | |
55 | }; | |
56 | ||
57 | #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) | |
58 | ||
9a32144e | 59 | static const struct file_operations shm_file_operations; |
f0f37e2f | 60 | static const struct vm_operations_struct shm_vm_ops; |
1da177e4 | 61 | |
ed2ddbf8 | 62 | #define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
1da177e4 | 63 | |
4e982311 KK |
64 | #define shm_unlock(shp) \ |
65 | ipc_unlock(&(shp)->shm_perm) | |
1da177e4 | 66 | |
7748dbfa | 67 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
68 | static void shm_open(struct vm_area_struct *vma); |
69 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 70 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 71 | #ifdef CONFIG_PROC_FS |
19b4946c | 72 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
73 | #endif |
74 | ||
ed2ddbf8 | 75 | void shm_init_ns(struct ipc_namespace *ns) |
4e982311 | 76 | { |
4e982311 KK |
77 | ns->shm_ctlmax = SHMMAX; |
78 | ns->shm_ctlall = SHMALL; | |
79 | ns->shm_ctlmni = SHMMNI; | |
b34a6b1d | 80 | ns->shm_rmid_forced = 0; |
4e982311 | 81 | ns->shm_tot = 0; |
e8148f75 | 82 | ipc_init_ids(&shm_ids(ns)); |
4e982311 KK |
83 | } |
84 | ||
f4566f04 | 85 | /* |
d9a605e4 DB |
86 | * Called with shm_ids.rwsem (writer) and the shp structure locked. |
87 | * Only shm_ids.rwsem remains locked on exit. | |
f4566f04 | 88 | */ |
01b8b07a | 89 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
4e982311 | 90 | { |
01b8b07a PP |
91 | struct shmid_kernel *shp; |
92 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
93 | ||
4e982311 KK |
94 | if (shp->shm_nattch){ |
95 | shp->shm_perm.mode |= SHM_DEST; | |
96 | /* Do not find it any more */ | |
97 | shp->shm_perm.key = IPC_PRIVATE; | |
98 | shm_unlock(shp); | |
99 | } else | |
100 | shm_destroy(ns, shp); | |
101 | } | |
102 | ||
ae5e1b22 | 103 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
104 | void shm_exit_ns(struct ipc_namespace *ns) |
105 | { | |
01b8b07a | 106 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
7d6feeb2 | 107 | idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
4e982311 | 108 | } |
ae5e1b22 | 109 | #endif |
1da177e4 | 110 | |
140d0b21 | 111 | static int __init ipc_ns_init(void) |
1da177e4 | 112 | { |
ed2ddbf8 | 113 | shm_init_ns(&init_ipc_ns); |
140d0b21 LT |
114 | return 0; |
115 | } | |
116 | ||
117 | pure_initcall(ipc_ns_init); | |
118 | ||
119 | void __init shm_init (void) | |
120 | { | |
19b4946c | 121 | ipc_init_proc_interface("sysvipc/shm", |
b7952180 HD |
122 | #if BITS_PER_LONG <= 32 |
123 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", | |
124 | #else | |
125 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", | |
126 | #endif | |
4e982311 | 127 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
128 | } |
129 | ||
8b8d52ac DB |
130 | static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id) |
131 | { | |
132 | struct kern_ipc_perm *ipcp = ipc_obtain_object(&shm_ids(ns), id); | |
133 | ||
134 | if (IS_ERR(ipcp)) | |
135 | return ERR_CAST(ipcp); | |
136 | ||
137 | return container_of(ipcp, struct shmid_kernel, shm_perm); | |
138 | } | |
139 | ||
140 | static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id) | |
141 | { | |
142 | struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id); | |
143 | ||
144 | if (IS_ERR(ipcp)) | |
145 | return ERR_CAST(ipcp); | |
146 | ||
147 | return container_of(ipcp, struct shmid_kernel, shm_perm); | |
148 | } | |
149 | ||
3e148c79 | 150 | /* |
d9a605e4 | 151 | * shm_lock_(check_) routines are called in the paths where the rwsem |
00c2bf85 | 152 | * is not necessarily held. |
3e148c79 | 153 | */ |
023a5355 | 154 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 155 | { |
03f02c76 ND |
156 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
157 | ||
b1ed88b4 PP |
158 | if (IS_ERR(ipcp)) |
159 | return (struct shmid_kernel *)ipcp; | |
160 | ||
03f02c76 | 161 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
162 | } |
163 | ||
4c677e2e VK |
164 | static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp) |
165 | { | |
166 | rcu_read_lock(); | |
cf9d5d78 | 167 | ipc_lock_object(&ipcp->shm_perm); |
4c677e2e VK |
168 | } |
169 | ||
7ca7e564 | 170 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 171 | { |
7ca7e564 | 172 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
173 | } |
174 | ||
1da177e4 | 175 | |
bc56bba8 EB |
176 | /* This is called by fork, once for every shm attach. */ |
177 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 178 | { |
bc56bba8 EB |
179 | struct file *file = vma->vm_file; |
180 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
181 | struct shmid_kernel *shp; |
182 | ||
bc56bba8 | 183 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 184 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 185 | shp->shm_atim = get_seconds(); |
b488893a | 186 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
187 | shp->shm_nattch++; |
188 | shm_unlock(shp); | |
189 | } | |
190 | ||
1da177e4 LT |
191 | /* |
192 | * shm_destroy - free the struct shmid_kernel | |
193 | * | |
f4566f04 | 194 | * @ns: namespace |
1da177e4 LT |
195 | * @shp: struct to free |
196 | * | |
d9a605e4 | 197 | * It has to be called with shp and shm_ids.rwsem (writer) locked, |
1da177e4 LT |
198 | * but returns with shp unlocked and freed. |
199 | */ | |
4e982311 | 200 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 201 | { |
4e982311 | 202 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 203 | shm_rmid(ns, shp); |
1da177e4 LT |
204 | shm_unlock(shp); |
205 | if (!is_file_hugepages(shp->shm_file)) | |
206 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
353d5c30 | 207 | else if (shp->mlock_user) |
496ad9aa | 208 | user_shm_unlock(file_inode(shp->shm_file)->i_size, |
1da177e4 LT |
209 | shp->mlock_user); |
210 | fput (shp->shm_file); | |
211 | security_shm_free(shp); | |
212 | ipc_rcu_putref(shp); | |
213 | } | |
214 | ||
b34a6b1d VK |
215 | /* |
216 | * shm_may_destroy - identifies whether shm segment should be destroyed now | |
217 | * | |
218 | * Returns true if and only if there are no active users of the segment and | |
219 | * one of the following is true: | |
220 | * | |
221 | * 1) shmctl(id, IPC_RMID, NULL) was called for this shp | |
222 | * | |
223 | * 2) sysctl kernel.shm_rmid_forced is set to 1. | |
224 | */ | |
225 | static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) | |
226 | { | |
227 | return (shp->shm_nattch == 0) && | |
228 | (ns->shm_rmid_forced || | |
229 | (shp->shm_perm.mode & SHM_DEST)); | |
230 | } | |
231 | ||
1da177e4 | 232 | /* |
bc56bba8 | 233 | * remove the attach descriptor vma. |
1da177e4 LT |
234 | * free memory for segment if it is marked destroyed. |
235 | * The descriptor has already been removed from the current->mm->mmap list | |
236 | * and will later be kfree()d. | |
237 | */ | |
bc56bba8 | 238 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 239 | { |
bc56bba8 EB |
240 | struct file * file = vma->vm_file; |
241 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 242 | struct shmid_kernel *shp; |
bc56bba8 | 243 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 244 | |
d9a605e4 | 245 | down_write(&shm_ids(ns).rwsem); |
1da177e4 | 246 | /* remove from the list of attaches of the shm segment */ |
00c2bf85 | 247 | shp = shm_lock(ns, sfd->id); |
023a5355 | 248 | BUG_ON(IS_ERR(shp)); |
b488893a | 249 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
250 | shp->shm_dtim = get_seconds(); |
251 | shp->shm_nattch--; | |
b34a6b1d VK |
252 | if (shm_may_destroy(ns, shp)) |
253 | shm_destroy(ns, shp); | |
254 | else | |
255 | shm_unlock(shp); | |
d9a605e4 | 256 | up_write(&shm_ids(ns).rwsem); |
b34a6b1d VK |
257 | } |
258 | ||
d9a605e4 | 259 | /* Called with ns->shm_ids(ns).rwsem locked */ |
b34a6b1d VK |
260 | static int shm_try_destroy_current(int id, void *p, void *data) |
261 | { | |
262 | struct ipc_namespace *ns = data; | |
4c677e2e VK |
263 | struct kern_ipc_perm *ipcp = p; |
264 | struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
b34a6b1d | 265 | |
4c677e2e | 266 | if (shp->shm_creator != current) |
5774ed01 | 267 | return 0; |
5774ed01 VK |
268 | |
269 | /* | |
270 | * Mark it as orphaned to destroy the segment when | |
271 | * kernel.shm_rmid_forced is changed. | |
272 | * It is noop if the following shm_may_destroy() returns true. | |
273 | */ | |
274 | shp->shm_creator = NULL; | |
275 | ||
276 | /* | |
277 | * Don't even try to destroy it. If shm_rmid_forced=0 and IPC_RMID | |
278 | * is not set, it shouldn't be deleted here. | |
279 | */ | |
4c677e2e | 280 | if (!ns->shm_rmid_forced) |
b34a6b1d | 281 | return 0; |
b34a6b1d | 282 | |
4c677e2e VK |
283 | if (shm_may_destroy(ns, shp)) { |
284 | shm_lock_by_ptr(shp); | |
b34a6b1d | 285 | shm_destroy(ns, shp); |
4c677e2e | 286 | } |
b34a6b1d VK |
287 | return 0; |
288 | } | |
289 | ||
d9a605e4 | 290 | /* Called with ns->shm_ids(ns).rwsem locked */ |
b34a6b1d VK |
291 | static int shm_try_destroy_orphaned(int id, void *p, void *data) |
292 | { | |
293 | struct ipc_namespace *ns = data; | |
4c677e2e VK |
294 | struct kern_ipc_perm *ipcp = p; |
295 | struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
b34a6b1d VK |
296 | |
297 | /* | |
298 | * We want to destroy segments without users and with already | |
299 | * exit'ed originating process. | |
4c677e2e | 300 | * |
d9a605e4 | 301 | * As shp->* are changed under rwsem, it's safe to skip shp locking. |
b34a6b1d | 302 | */ |
4c677e2e | 303 | if (shp->shm_creator != NULL) |
b34a6b1d | 304 | return 0; |
b34a6b1d | 305 | |
4c677e2e VK |
306 | if (shm_may_destroy(ns, shp)) { |
307 | shm_lock_by_ptr(shp); | |
4e982311 | 308 | shm_destroy(ns, shp); |
4c677e2e | 309 | } |
b34a6b1d VK |
310 | return 0; |
311 | } | |
312 | ||
313 | void shm_destroy_orphaned(struct ipc_namespace *ns) | |
314 | { | |
d9a605e4 | 315 | down_write(&shm_ids(ns).rwsem); |
33a30ed4 | 316 | if (shm_ids(ns).in_use) |
4c677e2e | 317 | idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns); |
d9a605e4 | 318 | up_write(&shm_ids(ns).rwsem); |
b34a6b1d VK |
319 | } |
320 | ||
321 | ||
322 | void exit_shm(struct task_struct *task) | |
323 | { | |
4c677e2e | 324 | struct ipc_namespace *ns = task->nsproxy->ipc_ns; |
b34a6b1d | 325 | |
298507d4 VK |
326 | if (shm_ids(ns).in_use == 0) |
327 | return; | |
328 | ||
b34a6b1d | 329 | /* Destroy all already created segments, but not mapped yet */ |
d9a605e4 | 330 | down_write(&shm_ids(ns).rwsem); |
33a30ed4 | 331 | if (shm_ids(ns).in_use) |
4c677e2e | 332 | idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_current, ns); |
d9a605e4 | 333 | up_write(&shm_ids(ns).rwsem); |
1da177e4 LT |
334 | } |
335 | ||
d0217ac0 | 336 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
337 | { |
338 | struct file *file = vma->vm_file; | |
339 | struct shm_file_data *sfd = shm_file_data(file); | |
340 | ||
d0217ac0 | 341 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
342 | } |
343 | ||
344 | #ifdef CONFIG_NUMA | |
d823e3e7 | 345 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
346 | { |
347 | struct file *file = vma->vm_file; | |
348 | struct shm_file_data *sfd = shm_file_data(file); | |
349 | int err = 0; | |
350 | if (sfd->vm_ops->set_policy) | |
351 | err = sfd->vm_ops->set_policy(vma, new); | |
352 | return err; | |
353 | } | |
354 | ||
d823e3e7 AB |
355 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
356 | unsigned long addr) | |
bc56bba8 EB |
357 | { |
358 | struct file *file = vma->vm_file; | |
359 | struct shm_file_data *sfd = shm_file_data(file); | |
360 | struct mempolicy *pol = NULL; | |
361 | ||
362 | if (sfd->vm_ops->get_policy) | |
363 | pol = sfd->vm_ops->get_policy(vma, addr); | |
52cd3b07 | 364 | else if (vma->vm_policy) |
bc56bba8 | 365 | pol = vma->vm_policy; |
52cd3b07 | 366 | |
bc56bba8 EB |
367 | return pol; |
368 | } | |
369 | #endif | |
370 | ||
1da177e4 LT |
371 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
372 | { | |
bc56bba8 | 373 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
374 | int ret; |
375 | ||
bc56bba8 EB |
376 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
377 | if (ret != 0) | |
378 | return ret; | |
379 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 380 | #ifdef CONFIG_MMU |
54cb8821 | 381 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 382 | #endif |
bc56bba8 EB |
383 | vma->vm_ops = &shm_vm_ops; |
384 | shm_open(vma); | |
b0e15190 DH |
385 | |
386 | return ret; | |
1da177e4 LT |
387 | } |
388 | ||
4e982311 KK |
389 | static int shm_release(struct inode *ino, struct file *file) |
390 | { | |
bc56bba8 | 391 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 392 | |
bc56bba8 EB |
393 | put_ipc_ns(sfd->ns); |
394 | shm_file_data(file) = NULL; | |
395 | kfree(sfd); | |
4e982311 KK |
396 | return 0; |
397 | } | |
398 | ||
02c24a82 | 399 | static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
516dffdc | 400 | { |
516dffdc | 401 | struct shm_file_data *sfd = shm_file_data(file); |
516dffdc | 402 | |
7ea80859 CH |
403 | if (!sfd->file->f_op->fsync) |
404 | return -EINVAL; | |
02c24a82 | 405 | return sfd->file->f_op->fsync(sfd->file, start, end, datasync); |
516dffdc AL |
406 | } |
407 | ||
7d8a4569 WD |
408 | static long shm_fallocate(struct file *file, int mode, loff_t offset, |
409 | loff_t len) | |
410 | { | |
411 | struct shm_file_data *sfd = shm_file_data(file); | |
412 | ||
413 | if (!sfd->file->f_op->fallocate) | |
414 | return -EOPNOTSUPP; | |
415 | return sfd->file->f_op->fallocate(file, mode, offset, len); | |
416 | } | |
417 | ||
bc56bba8 EB |
418 | static unsigned long shm_get_unmapped_area(struct file *file, |
419 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
420 | unsigned long flags) | |
421 | { | |
422 | struct shm_file_data *sfd = shm_file_data(file); | |
c4caa778 AV |
423 | return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
424 | pgoff, flags); | |
bc56bba8 | 425 | } |
bc56bba8 | 426 | |
9a32144e | 427 | static const struct file_operations shm_file_operations = { |
4e982311 | 428 | .mmap = shm_mmap, |
516dffdc | 429 | .fsync = shm_fsync, |
4e982311 | 430 | .release = shm_release, |
ed5e5894 DH |
431 | #ifndef CONFIG_MMU |
432 | .get_unmapped_area = shm_get_unmapped_area, | |
433 | #endif | |
6038f373 | 434 | .llseek = noop_llseek, |
7d8a4569 | 435 | .fallocate = shm_fallocate, |
c4caa778 AV |
436 | }; |
437 | ||
438 | static const struct file_operations shm_file_operations_huge = { | |
439 | .mmap = shm_mmap, | |
440 | .fsync = shm_fsync, | |
441 | .release = shm_release, | |
bc56bba8 | 442 | .get_unmapped_area = shm_get_unmapped_area, |
6038f373 | 443 | .llseek = noop_llseek, |
7d8a4569 | 444 | .fallocate = shm_fallocate, |
1da177e4 LT |
445 | }; |
446 | ||
c4caa778 AV |
447 | int is_file_shm_hugepages(struct file *file) |
448 | { | |
449 | return file->f_op == &shm_file_operations_huge; | |
450 | } | |
451 | ||
f0f37e2f | 452 | static const struct vm_operations_struct shm_vm_ops = { |
1da177e4 LT |
453 | .open = shm_open, /* callback for a new vm-area open */ |
454 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 455 | .fault = shm_fault, |
bc56bba8 EB |
456 | #if defined(CONFIG_NUMA) |
457 | .set_policy = shm_set_policy, | |
458 | .get_policy = shm_get_policy, | |
1da177e4 LT |
459 | #endif |
460 | }; | |
461 | ||
f4566f04 ND |
462 | /** |
463 | * newseg - Create a new shared memory segment | |
464 | * @ns: namespace | |
465 | * @params: ptr to the structure that contains key, size and shmflg | |
466 | * | |
d9a605e4 | 467 | * Called with shm_ids.rwsem held as a writer. |
f4566f04 ND |
468 | */ |
469 | ||
7748dbfa | 470 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 471 | { |
7748dbfa ND |
472 | key_t key = params->key; |
473 | int shmflg = params->flg; | |
474 | size_t size = params->u.size; | |
1da177e4 LT |
475 | int error; |
476 | struct shmid_kernel *shp; | |
d69f3bad | 477 | size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1da177e4 LT |
478 | struct file * file; |
479 | char name[13]; | |
480 | int id; | |
ca16d140 | 481 | vm_flags_t acctflag = 0; |
1da177e4 | 482 | |
4e982311 | 483 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
484 | return -EINVAL; |
485 | ||
f66d45e9 | 486 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
487 | return -ENOSPC; |
488 | ||
489 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
490 | if (!shp) | |
491 | return -ENOMEM; | |
492 | ||
493 | shp->shm_perm.key = key; | |
b33291c0 | 494 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
495 | shp->mlock_user = NULL; |
496 | ||
497 | shp->shm_perm.security = NULL; | |
498 | error = security_shm_alloc(shp); | |
499 | if (error) { | |
500 | ipc_rcu_putref(shp); | |
501 | return error; | |
502 | } | |
503 | ||
9d66586f | 504 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 505 | if (shmflg & SHM_HUGETLB) { |
c103a4dc | 506 | struct hstate *hs; |
091d0d55 LZ |
507 | size_t hugesize; |
508 | ||
c103a4dc | 509 | hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK); |
091d0d55 LZ |
510 | if (!hs) { |
511 | error = -EINVAL; | |
512 | goto no_file; | |
513 | } | |
514 | hugesize = ALIGN(size, huge_page_size(hs)); | |
af73e4d9 | 515 | |
5a6fe125 MG |
516 | /* hugetlb_file_setup applies strict accounting */ |
517 | if (shmflg & SHM_NORESERVE) | |
518 | acctflag = VM_NORESERVE; | |
af73e4d9 | 519 | file = hugetlb_file_setup(name, hugesize, acctflag, |
42d7395f AK |
520 | &shp->mlock_user, HUGETLB_SHMFS_INODE, |
521 | (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK); | |
1da177e4 | 522 | } else { |
bf8f972d BP |
523 | /* |
524 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
525 | * if it's asked for. | |
526 | */ | |
527 | if ((shmflg & SHM_NORESERVE) && | |
528 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
fc8744ad | 529 | acctflag = VM_NORESERVE; |
bf8f972d | 530 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
531 | } |
532 | error = PTR_ERR(file); | |
533 | if (IS_ERR(file)) | |
534 | goto no_file; | |
535 | ||
48dea404 | 536 | id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
283bb7fa PP |
537 | if (id < 0) { |
538 | error = id; | |
1da177e4 | 539 | goto no_id; |
283bb7fa | 540 | } |
1da177e4 | 541 | |
b488893a | 542 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
543 | shp->shm_lprid = 0; |
544 | shp->shm_atim = shp->shm_dtim = 0; | |
545 | shp->shm_ctim = get_seconds(); | |
546 | shp->shm_segsz = size; | |
547 | shp->shm_nattch = 0; | |
1da177e4 | 548 | shp->shm_file = file; |
5774ed01 | 549 | shp->shm_creator = current; |
dbfcd91f | 550 | |
30475cc1 BP |
551 | /* |
552 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
553 | * proc-ps tools use this. Changing this will break them. | |
554 | */ | |
496ad9aa | 555 | file_inode(file)->i_ino = shp->shm_perm.id; |
551110a9 | 556 | |
4e982311 | 557 | ns->shm_tot += numpages; |
7ca7e564 | 558 | error = shp->shm_perm.id; |
dbfcd91f | 559 | |
cf9d5d78 | 560 | ipc_unlock_object(&shp->shm_perm); |
dbfcd91f | 561 | rcu_read_unlock(); |
7ca7e564 | 562 | return error; |
1da177e4 LT |
563 | |
564 | no_id: | |
2195d281 | 565 | if (is_file_hugepages(file) && shp->mlock_user) |
353d5c30 | 566 | user_shm_unlock(size, shp->mlock_user); |
1da177e4 LT |
567 | fput(file); |
568 | no_file: | |
569 | security_shm_free(shp); | |
570 | ipc_rcu_putref(shp); | |
571 | return error; | |
572 | } | |
573 | ||
f4566f04 | 574 | /* |
d9a605e4 | 575 | * Called with shm_ids.rwsem and ipcp locked. |
f4566f04 | 576 | */ |
03f02c76 | 577 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 578 | { |
03f02c76 ND |
579 | struct shmid_kernel *shp; |
580 | ||
581 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
582 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
583 | } |
584 | ||
f4566f04 | 585 | /* |
d9a605e4 | 586 | * Called with shm_ids.rwsem and ipcp locked. |
f4566f04 | 587 | */ |
03f02c76 ND |
588 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
589 | struct ipc_params *params) | |
7748dbfa | 590 | { |
03f02c76 ND |
591 | struct shmid_kernel *shp; |
592 | ||
593 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
594 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
595 | return -EINVAL; |
596 | ||
597 | return 0; | |
598 | } | |
599 | ||
d5460c99 | 600 | SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
1da177e4 | 601 | { |
4e982311 | 602 | struct ipc_namespace *ns; |
7748dbfa ND |
603 | struct ipc_ops shm_ops; |
604 | struct ipc_params shm_params; | |
4e982311 KK |
605 | |
606 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 607 | |
7748dbfa ND |
608 | shm_ops.getnew = newseg; |
609 | shm_ops.associate = shm_security; | |
610 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 611 | |
7748dbfa ND |
612 | shm_params.key = key; |
613 | shm_params.flg = shmflg; | |
614 | shm_params.u.size = size; | |
1da177e4 | 615 | |
7748dbfa | 616 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
617 | } |
618 | ||
619 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
620 | { | |
621 | switch(version) { | |
622 | case IPC_64: | |
623 | return copy_to_user(buf, in, sizeof(*in)); | |
624 | case IPC_OLD: | |
625 | { | |
626 | struct shmid_ds out; | |
627 | ||
3af54c9b | 628 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
629 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); |
630 | out.shm_segsz = in->shm_segsz; | |
631 | out.shm_atime = in->shm_atime; | |
632 | out.shm_dtime = in->shm_dtime; | |
633 | out.shm_ctime = in->shm_ctime; | |
634 | out.shm_cpid = in->shm_cpid; | |
635 | out.shm_lpid = in->shm_lpid; | |
636 | out.shm_nattch = in->shm_nattch; | |
637 | ||
638 | return copy_to_user(buf, &out, sizeof(out)); | |
639 | } | |
640 | default: | |
641 | return -EINVAL; | |
642 | } | |
643 | } | |
644 | ||
016d7132 PP |
645 | static inline unsigned long |
646 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) | |
1da177e4 LT |
647 | { |
648 | switch(version) { | |
649 | case IPC_64: | |
016d7132 | 650 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 651 | return -EFAULT; |
1da177e4 | 652 | return 0; |
1da177e4 LT |
653 | case IPC_OLD: |
654 | { | |
655 | struct shmid_ds tbuf_old; | |
656 | ||
657 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
658 | return -EFAULT; | |
659 | ||
016d7132 PP |
660 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
661 | out->shm_perm.gid = tbuf_old.shm_perm.gid; | |
662 | out->shm_perm.mode = tbuf_old.shm_perm.mode; | |
1da177e4 LT |
663 | |
664 | return 0; | |
665 | } | |
666 | default: | |
667 | return -EINVAL; | |
668 | } | |
669 | } | |
670 | ||
671 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
672 | { | |
673 | switch(version) { | |
674 | case IPC_64: | |
675 | return copy_to_user(buf, in, sizeof(*in)); | |
676 | case IPC_OLD: | |
677 | { | |
678 | struct shminfo out; | |
679 | ||
680 | if(in->shmmax > INT_MAX) | |
681 | out.shmmax = INT_MAX; | |
682 | else | |
683 | out.shmmax = (int)in->shmmax; | |
684 | ||
685 | out.shmmin = in->shmmin; | |
686 | out.shmmni = in->shmmni; | |
687 | out.shmseg = in->shmseg; | |
688 | out.shmall = in->shmall; | |
689 | ||
690 | return copy_to_user(buf, &out, sizeof(out)); | |
691 | } | |
692 | default: | |
693 | return -EINVAL; | |
694 | } | |
695 | } | |
696 | ||
b7952180 HD |
697 | /* |
698 | * Calculate and add used RSS and swap pages of a shm. | |
d9a605e4 | 699 | * Called with shm_ids.rwsem held as a reader |
b7952180 HD |
700 | */ |
701 | static void shm_add_rss_swap(struct shmid_kernel *shp, | |
702 | unsigned long *rss_add, unsigned long *swp_add) | |
703 | { | |
704 | struct inode *inode; | |
705 | ||
496ad9aa | 706 | inode = file_inode(shp->shm_file); |
b7952180 HD |
707 | |
708 | if (is_file_hugepages(shp->shm_file)) { | |
709 | struct address_space *mapping = inode->i_mapping; | |
710 | struct hstate *h = hstate_file(shp->shm_file); | |
711 | *rss_add += pages_per_huge_page(h) * mapping->nrpages; | |
712 | } else { | |
713 | #ifdef CONFIG_SHMEM | |
714 | struct shmem_inode_info *info = SHMEM_I(inode); | |
715 | spin_lock(&info->lock); | |
716 | *rss_add += inode->i_mapping->nrpages; | |
717 | *swp_add += info->swapped; | |
718 | spin_unlock(&info->lock); | |
719 | #else | |
720 | *rss_add += inode->i_mapping->nrpages; | |
721 | #endif | |
722 | } | |
723 | } | |
724 | ||
f4566f04 | 725 | /* |
d9a605e4 | 726 | * Called with shm_ids.rwsem held as a reader |
f4566f04 | 727 | */ |
4e982311 KK |
728 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
729 | unsigned long *swp) | |
1da177e4 | 730 | { |
7ca7e564 ND |
731 | int next_id; |
732 | int total, in_use; | |
1da177e4 LT |
733 | |
734 | *rss = 0; | |
735 | *swp = 0; | |
736 | ||
7ca7e564 ND |
737 | in_use = shm_ids(ns).in_use; |
738 | ||
739 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
e562aebc | 740 | struct kern_ipc_perm *ipc; |
1da177e4 | 741 | struct shmid_kernel *shp; |
1da177e4 | 742 | |
e562aebc TB |
743 | ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
744 | if (ipc == NULL) | |
1da177e4 | 745 | continue; |
e562aebc | 746 | shp = container_of(ipc, struct shmid_kernel, shm_perm); |
1da177e4 | 747 | |
b7952180 | 748 | shm_add_rss_swap(shp, rss, swp); |
7ca7e564 ND |
749 | |
750 | total++; | |
1da177e4 LT |
751 | } |
752 | } | |
753 | ||
8d4cc8b5 | 754 | /* |
d9a605e4 | 755 | * This function handles some shmctl commands which require the rwsem |
8d4cc8b5 | 756 | * to be held in write mode. |
d9a605e4 | 757 | * NOTE: no locks must be held, the rwsem is taken inside this function. |
8d4cc8b5 PP |
758 | */ |
759 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, | |
760 | struct shmid_ds __user *buf, int version) | |
1da177e4 | 761 | { |
8d4cc8b5 | 762 | struct kern_ipc_perm *ipcp; |
016d7132 | 763 | struct shmid64_ds shmid64; |
8d4cc8b5 PP |
764 | struct shmid_kernel *shp; |
765 | int err; | |
766 | ||
767 | if (cmd == IPC_SET) { | |
016d7132 | 768 | if (copy_shmid_from_user(&shmid64, buf, version)) |
8d4cc8b5 PP |
769 | return -EFAULT; |
770 | } | |
771 | ||
d9a605e4 | 772 | down_write(&shm_ids(ns).rwsem); |
7b4cc5d8 DB |
773 | rcu_read_lock(); |
774 | ||
79ccf0f8 DB |
775 | ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd, |
776 | &shmid64.shm_perm, 0); | |
7b4cc5d8 DB |
777 | if (IS_ERR(ipcp)) { |
778 | err = PTR_ERR(ipcp); | |
7b4cc5d8 DB |
779 | goto out_unlock1; |
780 | } | |
8d4cc8b5 | 781 | |
a5f75e7f | 782 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
8d4cc8b5 PP |
783 | |
784 | err = security_shm_shmctl(shp, cmd); | |
785 | if (err) | |
79ccf0f8 | 786 | goto out_unlock1; |
7b4cc5d8 | 787 | |
8d4cc8b5 PP |
788 | switch (cmd) { |
789 | case IPC_RMID: | |
79ccf0f8 | 790 | ipc_lock_object(&shp->shm_perm); |
7b4cc5d8 | 791 | /* do_shm_rmid unlocks the ipc object and rcu */ |
8d4cc8b5 PP |
792 | do_shm_rmid(ns, ipcp); |
793 | goto out_up; | |
794 | case IPC_SET: | |
79ccf0f8 | 795 | ipc_lock_object(&shp->shm_perm); |
1efdb69b EB |
796 | err = ipc_update_perm(&shmid64.shm_perm, ipcp); |
797 | if (err) | |
7b4cc5d8 | 798 | goto out_unlock0; |
8d4cc8b5 PP |
799 | shp->shm_ctim = get_seconds(); |
800 | break; | |
801 | default: | |
802 | err = -EINVAL; | |
79ccf0f8 | 803 | goto out_unlock1; |
8d4cc8b5 | 804 | } |
7b4cc5d8 DB |
805 | |
806 | out_unlock0: | |
807 | ipc_unlock_object(&shp->shm_perm); | |
808 | out_unlock1: | |
809 | rcu_read_unlock(); | |
8d4cc8b5 | 810 | out_up: |
d9a605e4 | 811 | up_write(&shm_ids(ns).rwsem); |
8d4cc8b5 PP |
812 | return err; |
813 | } | |
814 | ||
68eccc1d DB |
815 | static int shmctl_nolock(struct ipc_namespace *ns, int shmid, |
816 | int cmd, int version, void __user *buf) | |
8d4cc8b5 | 817 | { |
68eccc1d | 818 | int err; |
1da177e4 | 819 | struct shmid_kernel *shp; |
1da177e4 | 820 | |
68eccc1d DB |
821 | /* preliminary security checks for *_INFO */ |
822 | if (cmd == IPC_INFO || cmd == SHM_INFO) { | |
823 | err = security_shm_shmctl(NULL, cmd); | |
824 | if (err) | |
825 | return err; | |
1da177e4 LT |
826 | } |
827 | ||
68eccc1d | 828 | switch (cmd) { |
1da177e4 LT |
829 | case IPC_INFO: |
830 | { | |
831 | struct shminfo64 shminfo; | |
832 | ||
e8148f75 | 833 | memset(&shminfo, 0, sizeof(shminfo)); |
4e982311 KK |
834 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
835 | shminfo.shmmax = ns->shm_ctlmax; | |
836 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
837 | |
838 | shminfo.shmmin = SHMMIN; | |
839 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
840 | return -EFAULT; | |
f4566f04 | 841 | |
d9a605e4 | 842 | down_read(&shm_ids(ns).rwsem); |
7ca7e564 | 843 | err = ipc_get_maxid(&shm_ids(ns)); |
d9a605e4 | 844 | up_read(&shm_ids(ns).rwsem); |
f4566f04 | 845 | |
1da177e4 LT |
846 | if(err<0) |
847 | err = 0; | |
848 | goto out; | |
849 | } | |
850 | case SHM_INFO: | |
851 | { | |
852 | struct shm_info shm_info; | |
853 | ||
e8148f75 | 854 | memset(&shm_info, 0, sizeof(shm_info)); |
d9a605e4 | 855 | down_read(&shm_ids(ns).rwsem); |
4e982311 KK |
856 | shm_info.used_ids = shm_ids(ns).in_use; |
857 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
858 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
859 | shm_info.swap_attempts = 0; |
860 | shm_info.swap_successes = 0; | |
7ca7e564 | 861 | err = ipc_get_maxid(&shm_ids(ns)); |
d9a605e4 | 862 | up_read(&shm_ids(ns).rwsem); |
e8148f75 | 863 | if (copy_to_user(buf, &shm_info, sizeof(shm_info))) { |
1da177e4 LT |
864 | err = -EFAULT; |
865 | goto out; | |
866 | } | |
867 | ||
868 | err = err < 0 ? 0 : err; | |
869 | goto out; | |
870 | } | |
871 | case SHM_STAT: | |
872 | case IPC_STAT: | |
873 | { | |
874 | struct shmid64_ds tbuf; | |
875 | int result; | |
023a5355 | 876 | |
c97cb9cc | 877 | rcu_read_lock(); |
023a5355 | 878 | if (cmd == SHM_STAT) { |
c97cb9cc | 879 | shp = shm_obtain_object(ns, shmid); |
023a5355 ND |
880 | if (IS_ERR(shp)) { |
881 | err = PTR_ERR(shp); | |
c97cb9cc | 882 | goto out_unlock; |
023a5355 | 883 | } |
7ca7e564 | 884 | result = shp->shm_perm.id; |
1da177e4 | 885 | } else { |
c97cb9cc | 886 | shp = shm_obtain_object_check(ns, shmid); |
023a5355 ND |
887 | if (IS_ERR(shp)) { |
888 | err = PTR_ERR(shp); | |
c97cb9cc | 889 | goto out_unlock; |
023a5355 | 890 | } |
1da177e4 LT |
891 | result = 0; |
892 | } | |
c97cb9cc | 893 | |
e8148f75 | 894 | err = -EACCES; |
b0e77598 | 895 | if (ipcperms(ns, &shp->shm_perm, S_IRUGO)) |
1da177e4 | 896 | goto out_unlock; |
c97cb9cc | 897 | |
1da177e4 LT |
898 | err = security_shm_shmctl(shp, cmd); |
899 | if (err) | |
900 | goto out_unlock; | |
c97cb9cc | 901 | |
023a5355 | 902 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
903 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
904 | tbuf.shm_segsz = shp->shm_segsz; | |
905 | tbuf.shm_atime = shp->shm_atim; | |
906 | tbuf.shm_dtime = shp->shm_dtim; | |
907 | tbuf.shm_ctime = shp->shm_ctim; | |
908 | tbuf.shm_cpid = shp->shm_cprid; | |
909 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 910 | tbuf.shm_nattch = shp->shm_nattch; |
c97cb9cc DB |
911 | rcu_read_unlock(); |
912 | ||
913 | if (copy_shmid_to_user(buf, &tbuf, version)) | |
1da177e4 LT |
914 | err = -EFAULT; |
915 | else | |
916 | err = result; | |
917 | goto out; | |
918 | } | |
68eccc1d DB |
919 | default: |
920 | return -EINVAL; | |
921 | } | |
922 | ||
923 | out_unlock: | |
c97cb9cc | 924 | rcu_read_unlock(); |
68eccc1d DB |
925 | out: |
926 | return err; | |
927 | } | |
928 | ||
929 | SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) | |
930 | { | |
931 | struct shmid_kernel *shp; | |
932 | int err, version; | |
933 | struct ipc_namespace *ns; | |
934 | ||
2caacaa8 DB |
935 | if (cmd < 0 || shmid < 0) |
936 | return -EINVAL; | |
68eccc1d DB |
937 | |
938 | version = ipc_parse_version(&cmd); | |
939 | ns = current->nsproxy->ipc_ns; | |
940 | ||
941 | switch (cmd) { | |
942 | case IPC_INFO: | |
943 | case SHM_INFO: | |
944 | case SHM_STAT: | |
945 | case IPC_STAT: | |
946 | return shmctl_nolock(ns, shmid, cmd, version, buf); | |
2caacaa8 DB |
947 | case IPC_RMID: |
948 | case IPC_SET: | |
949 | return shmctl_down(ns, shmid, cmd, buf, version); | |
1da177e4 LT |
950 | case SHM_LOCK: |
951 | case SHM_UNLOCK: | |
952 | { | |
85046579 | 953 | struct file *shm_file; |
89e004ea | 954 | |
2caacaa8 DB |
955 | rcu_read_lock(); |
956 | shp = shm_obtain_object_check(ns, shmid); | |
023a5355 ND |
957 | if (IS_ERR(shp)) { |
958 | err = PTR_ERR(shp); | |
2caacaa8 | 959 | goto out_unlock1; |
1da177e4 | 960 | } |
1da177e4 | 961 | |
a33e6751 | 962 | audit_ipc_obj(&(shp->shm_perm)); |
2caacaa8 DB |
963 | err = security_shm_shmctl(shp, cmd); |
964 | if (err) | |
965 | goto out_unlock1; | |
073115d6 | 966 | |
2caacaa8 | 967 | ipc_lock_object(&shp->shm_perm); |
b0e77598 | 968 | if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) { |
1efdb69b | 969 | kuid_t euid = current_euid(); |
1da177e4 | 970 | err = -EPERM; |
1efdb69b EB |
971 | if (!uid_eq(euid, shp->shm_perm.uid) && |
972 | !uid_eq(euid, shp->shm_perm.cuid)) | |
2caacaa8 | 973 | goto out_unlock0; |
f1eb1332 | 974 | if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) |
2caacaa8 | 975 | goto out_unlock0; |
1da177e4 LT |
976 | } |
977 | ||
85046579 HD |
978 | shm_file = shp->shm_file; |
979 | if (is_file_hugepages(shm_file)) | |
2caacaa8 | 980 | goto out_unlock0; |
85046579 HD |
981 | |
982 | if (cmd == SHM_LOCK) { | |
86a264ab | 983 | struct user_struct *user = current_user(); |
85046579 HD |
984 | err = shmem_lock(shm_file, 1, user); |
985 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) { | |
986 | shp->shm_perm.mode |= SHM_LOCKED; | |
987 | shp->mlock_user = user; | |
1da177e4 | 988 | } |
2caacaa8 | 989 | goto out_unlock0; |
1da177e4 | 990 | } |
85046579 HD |
991 | |
992 | /* SHM_UNLOCK */ | |
993 | if (!(shp->shm_perm.mode & SHM_LOCKED)) | |
2caacaa8 | 994 | goto out_unlock0; |
85046579 HD |
995 | shmem_lock(shm_file, 0, shp->mlock_user); |
996 | shp->shm_perm.mode &= ~SHM_LOCKED; | |
997 | shp->mlock_user = NULL; | |
998 | get_file(shm_file); | |
2caacaa8 DB |
999 | ipc_unlock_object(&shp->shm_perm); |
1000 | rcu_read_unlock(); | |
24513264 | 1001 | shmem_unlock_mapping(shm_file->f_mapping); |
2caacaa8 | 1002 | |
85046579 | 1003 | fput(shm_file); |
8d4cc8b5 | 1004 | return err; |
2caacaa8 | 1005 | } |
1da177e4 | 1006 | default: |
8d4cc8b5 | 1007 | return -EINVAL; |
1da177e4 LT |
1008 | } |
1009 | ||
2caacaa8 DB |
1010 | out_unlock0: |
1011 | ipc_unlock_object(&shp->shm_perm); | |
1012 | out_unlock1: | |
1013 | rcu_read_unlock(); | |
1da177e4 LT |
1014 | return err; |
1015 | } | |
1016 | ||
1017 | /* | |
1018 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
1019 | * | |
1020 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
1021 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
1022 | * this. | |
1023 | */ | |
079a96ae WD |
1024 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr, |
1025 | unsigned long shmlba) | |
1da177e4 LT |
1026 | { |
1027 | struct shmid_kernel *shp; | |
1028 | unsigned long addr; | |
1029 | unsigned long size; | |
1030 | struct file * file; | |
1031 | int err; | |
1032 | unsigned long flags; | |
1033 | unsigned long prot; | |
1da177e4 | 1034 | int acc_mode; |
4e982311 | 1035 | struct ipc_namespace *ns; |
bc56bba8 EB |
1036 | struct shm_file_data *sfd; |
1037 | struct path path; | |
aeb5d727 | 1038 | fmode_t f_mode; |
41badc15 | 1039 | unsigned long populate = 0; |
1da177e4 | 1040 | |
bc56bba8 EB |
1041 | err = -EINVAL; |
1042 | if (shmid < 0) | |
1da177e4 | 1043 | goto out; |
bc56bba8 | 1044 | else if ((addr = (ulong)shmaddr)) { |
079a96ae | 1045 | if (addr & (shmlba - 1)) { |
1da177e4 | 1046 | if (shmflg & SHM_RND) |
079a96ae | 1047 | addr &= ~(shmlba - 1); /* round down */ |
1da177e4 LT |
1048 | else |
1049 | #ifndef __ARCH_FORCE_SHMLBA | |
1050 | if (addr & ~PAGE_MASK) | |
1051 | #endif | |
bc56bba8 | 1052 | goto out; |
1da177e4 LT |
1053 | } |
1054 | flags = MAP_SHARED | MAP_FIXED; | |
1055 | } else { | |
1056 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 1057 | goto out; |
1da177e4 LT |
1058 | |
1059 | flags = MAP_SHARED; | |
1060 | } | |
1061 | ||
1062 | if (shmflg & SHM_RDONLY) { | |
1063 | prot = PROT_READ; | |
1da177e4 | 1064 | acc_mode = S_IRUGO; |
bc56bba8 | 1065 | f_mode = FMODE_READ; |
1da177e4 LT |
1066 | } else { |
1067 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 1068 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 1069 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
1070 | } |
1071 | if (shmflg & SHM_EXEC) { | |
1072 | prot |= PROT_EXEC; | |
1073 | acc_mode |= S_IXUGO; | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * We cannot rely on the fs check since SYSV IPC does have an | |
1078 | * additional creator id... | |
1079 | */ | |
4e982311 | 1080 | ns = current->nsproxy->ipc_ns; |
c2c737a0 DB |
1081 | rcu_read_lock(); |
1082 | shp = shm_obtain_object_check(ns, shmid); | |
023a5355 ND |
1083 | if (IS_ERR(shp)) { |
1084 | err = PTR_ERR(shp); | |
c2c737a0 | 1085 | goto out_unlock; |
023a5355 | 1086 | } |
bc56bba8 EB |
1087 | |
1088 | err = -EACCES; | |
b0e77598 | 1089 | if (ipcperms(ns, &shp->shm_perm, acc_mode)) |
bc56bba8 | 1090 | goto out_unlock; |
1da177e4 LT |
1091 | |
1092 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
1093 | if (err) |
1094 | goto out_unlock; | |
1095 | ||
c2c737a0 | 1096 | ipc_lock_object(&shp->shm_perm); |
2c48b9c4 AV |
1097 | path = shp->shm_file->f_path; |
1098 | path_get(&path); | |
1da177e4 | 1099 | shp->shm_nattch++; |
bc56bba8 | 1100 | size = i_size_read(path.dentry->d_inode); |
c2c737a0 DB |
1101 | ipc_unlock_object(&shp->shm_perm); |
1102 | rcu_read_unlock(); | |
1da177e4 | 1103 | |
bc56bba8 EB |
1104 | err = -ENOMEM; |
1105 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
f42569b1 DB |
1106 | if (!sfd) { |
1107 | path_put(&path); | |
1108 | goto out_nattch; | |
1109 | } | |
bc56bba8 | 1110 | |
2c48b9c4 AV |
1111 | file = alloc_file(&path, f_mode, |
1112 | is_file_hugepages(shp->shm_file) ? | |
c4caa778 AV |
1113 | &shm_file_operations_huge : |
1114 | &shm_file_operations); | |
39b65252 | 1115 | err = PTR_ERR(file); |
f42569b1 DB |
1116 | if (IS_ERR(file)) { |
1117 | kfree(sfd); | |
1118 | path_put(&path); | |
1119 | goto out_nattch; | |
1120 | } | |
bc56bba8 | 1121 | |
bc56bba8 | 1122 | file->private_data = sfd; |
bc56bba8 | 1123 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 1124 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
1125 | sfd->ns = get_ipc_ns(ns); |
1126 | sfd->file = shp->shm_file; | |
1127 | sfd->vm_ops = NULL; | |
1128 | ||
8b3ec681 AV |
1129 | err = security_mmap_file(file, prot, flags); |
1130 | if (err) | |
1131 | goto out_fput; | |
1132 | ||
1da177e4 LT |
1133 | down_write(¤t->mm->mmap_sem); |
1134 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 1135 | err = -EINVAL; |
1da177e4 LT |
1136 | if (find_vma_intersection(current->mm, addr, addr + size)) |
1137 | goto invalid; | |
1138 | /* | |
1139 | * If shm segment goes below stack, make sure there is some | |
1140 | * space left for the stack to grow (at least 4 pages). | |
1141 | */ | |
1142 | if (addr < current->mm->start_stack && | |
1143 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
1144 | goto invalid; | |
1145 | } | |
f42569b1 | 1146 | |
bebeb3d6 ML |
1147 | addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate); |
1148 | *raddr = addr; | |
bc56bba8 | 1149 | err = 0; |
bebeb3d6 ML |
1150 | if (IS_ERR_VALUE(addr)) |
1151 | err = (long)addr; | |
1da177e4 LT |
1152 | invalid: |
1153 | up_write(¤t->mm->mmap_sem); | |
bebeb3d6 | 1154 | if (populate) |
41badc15 | 1155 | mm_populate(addr, populate); |
1da177e4 | 1156 | |
8b3ec681 | 1157 | out_fput: |
bc56bba8 EB |
1158 | fput(file); |
1159 | ||
1160 | out_nattch: | |
d9a605e4 | 1161 | down_write(&shm_ids(ns).rwsem); |
00c2bf85 | 1162 | shp = shm_lock(ns, shmid); |
023a5355 | 1163 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 1164 | shp->shm_nattch--; |
b34a6b1d | 1165 | if (shm_may_destroy(ns, shp)) |
4e982311 | 1166 | shm_destroy(ns, shp); |
1da177e4 LT |
1167 | else |
1168 | shm_unlock(shp); | |
d9a605e4 | 1169 | up_write(&shm_ids(ns).rwsem); |
1da177e4 | 1170 | return err; |
bc56bba8 EB |
1171 | |
1172 | out_unlock: | |
c2c737a0 | 1173 | rcu_read_unlock(); |
f42569b1 DB |
1174 | out: |
1175 | return err; | |
1da177e4 LT |
1176 | } |
1177 | ||
d5460c99 | 1178 | SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
7d87e14c SR |
1179 | { |
1180 | unsigned long ret; | |
1181 | long err; | |
1182 | ||
079a96ae | 1183 | err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA); |
7d87e14c SR |
1184 | if (err) |
1185 | return err; | |
1186 | force_successful_syscall_return(); | |
1187 | return (long)ret; | |
1188 | } | |
1189 | ||
1da177e4 LT |
1190 | /* |
1191 | * detach and kill segment if marked destroyed. | |
1192 | * The work is done in shm_close. | |
1193 | */ | |
d5460c99 | 1194 | SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
1da177e4 LT |
1195 | { |
1196 | struct mm_struct *mm = current->mm; | |
586c7e6a | 1197 | struct vm_area_struct *vma; |
1da177e4 | 1198 | unsigned long addr = (unsigned long)shmaddr; |
1da177e4 | 1199 | int retval = -EINVAL; |
586c7e6a MF |
1200 | #ifdef CONFIG_MMU |
1201 | loff_t size = 0; | |
1202 | struct vm_area_struct *next; | |
1203 | #endif | |
1da177e4 | 1204 | |
df1e2fb5 HD |
1205 | if (addr & ~PAGE_MASK) |
1206 | return retval; | |
1207 | ||
1da177e4 LT |
1208 | down_write(&mm->mmap_sem); |
1209 | ||
1210 | /* | |
1211 | * This function tries to be smart and unmap shm segments that | |
1212 | * were modified by partial mlock or munmap calls: | |
1213 | * - It first determines the size of the shm segment that should be | |
1214 | * unmapped: It searches for a vma that is backed by shm and that | |
1215 | * started at address shmaddr. It records it's size and then unmaps | |
1216 | * it. | |
1217 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
1218 | * are within the initially determined size. | |
1219 | * Errors from do_munmap are ignored: the function only fails if | |
1220 | * it's called with invalid parameters or if it's called to unmap | |
1221 | * a part of a vma. Both calls in this function are for full vmas, | |
1222 | * the parameters are directly copied from the vma itself and always | |
1223 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1224 | */ | |
1225 | /* | |
1226 | * If it had been mremap()'d, the starting address would not | |
1227 | * match the usual checks anyway. So assume all vma's are | |
1228 | * above the starting address given. | |
1229 | */ | |
1230 | vma = find_vma(mm, addr); | |
1231 | ||
8feae131 | 1232 | #ifdef CONFIG_MMU |
1da177e4 LT |
1233 | while (vma) { |
1234 | next = vma->vm_next; | |
1235 | ||
1236 | /* | |
1237 | * Check if the starting address would match, i.e. it's | |
1238 | * a fragment created by mprotect() and/or munmap(), or it | |
1239 | * otherwise it starts at this address with no hassles. | |
1240 | */ | |
bc56bba8 | 1241 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1242 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1243 | ||
1244 | ||
496ad9aa | 1245 | size = file_inode(vma->vm_file)->i_size; |
1da177e4 LT |
1246 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1247 | /* | |
1248 | * We discovered the size of the shm segment, so | |
1249 | * break out of here and fall through to the next | |
1250 | * loop that uses the size information to stop | |
1251 | * searching for matching vma's. | |
1252 | */ | |
1253 | retval = 0; | |
1254 | vma = next; | |
1255 | break; | |
1256 | } | |
1257 | vma = next; | |
1258 | } | |
1259 | ||
1260 | /* | |
1261 | * We need look no further than the maximum address a fragment | |
1262 | * could possibly have landed at. Also cast things to loff_t to | |
25985edc | 1263 | * prevent overflows and make comparisons vs. equal-width types. |
1da177e4 | 1264 | */ |
8e36709d | 1265 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1266 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1267 | next = vma->vm_next; | |
1268 | ||
1269 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1270 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1271 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1272 | ||
1273 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1274 | vma = next; | |
1275 | } | |
1276 | ||
8feae131 DH |
1277 | #else /* CONFIG_MMU */ |
1278 | /* under NOMMU conditions, the exact address to be destroyed must be | |
1279 | * given */ | |
530fcd16 | 1280 | if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { |
8feae131 DH |
1281 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1282 | retval = 0; | |
1283 | } | |
1284 | ||
1285 | #endif | |
1286 | ||
1da177e4 LT |
1287 | up_write(&mm->mmap_sem); |
1288 | return retval; | |
1289 | } | |
1290 | ||
1291 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1292 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1293 | { |
1efdb69b | 1294 | struct user_namespace *user_ns = seq_user_ns(s); |
19b4946c | 1295 | struct shmid_kernel *shp = it; |
b7952180 HD |
1296 | unsigned long rss = 0, swp = 0; |
1297 | ||
1298 | shm_add_rss_swap(shp, &rss, &swp); | |
1da177e4 | 1299 | |
6c826818 PM |
1300 | #if BITS_PER_LONG <= 32 |
1301 | #define SIZE_SPEC "%10lu" | |
1302 | #else | |
1303 | #define SIZE_SPEC "%21lu" | |
1304 | #endif | |
1da177e4 | 1305 | |
6c826818 PM |
1306 | return seq_printf(s, |
1307 | "%10d %10d %4o " SIZE_SPEC " %5u %5u " | |
b7952180 HD |
1308 | "%5lu %5u %5u %5u %5u %10lu %10lu %10lu " |
1309 | SIZE_SPEC " " SIZE_SPEC "\n", | |
19b4946c | 1310 | shp->shm_perm.key, |
7ca7e564 | 1311 | shp->shm_perm.id, |
b33291c0 | 1312 | shp->shm_perm.mode, |
19b4946c MW |
1313 | shp->shm_segsz, |
1314 | shp->shm_cprid, | |
1315 | shp->shm_lprid, | |
bc56bba8 | 1316 | shp->shm_nattch, |
1efdb69b EB |
1317 | from_kuid_munged(user_ns, shp->shm_perm.uid), |
1318 | from_kgid_munged(user_ns, shp->shm_perm.gid), | |
1319 | from_kuid_munged(user_ns, shp->shm_perm.cuid), | |
1320 | from_kgid_munged(user_ns, shp->shm_perm.cgid), | |
19b4946c MW |
1321 | shp->shm_atim, |
1322 | shp->shm_dtim, | |
b7952180 HD |
1323 | shp->shm_ctim, |
1324 | rss * PAGE_SIZE, | |
1325 | swp * PAGE_SIZE); | |
1da177e4 LT |
1326 | } |
1327 | #endif |