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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/ipc/shm.c | |
4 | * Copyright (C) 1992, 1993 Krishna Balasubramanian | |
5 | * Many improvements/fixes by Bruno Haible. | |
6 | * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994. | |
7 | * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli. | |
8 | * | |
9 | * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com> | |
10 | * BIGMEM support, Andrea Arcangeli <andrea@suse.de> | |
11 | * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr> | |
12 | * HIGHMEM support, Ingo Molnar <mingo@redhat.com> | |
13 | * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com> | |
14 | * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com> | |
15 | * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com> | |
16 | * | |
073115d6 SG |
17 | * support for audit of ipc object properties and permission changes |
18 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
4e982311 KK |
19 | * |
20 | * namespaces support | |
21 | * OpenVZ, SWsoft Inc. | |
22 | * Pavel Emelianov <xemul@openvz.org> | |
c2c737a0 DB |
23 | * |
24 | * Better ipc lock (kern_ipc_perm.lock) handling | |
25 | * Davidlohr Bueso <davidlohr.bueso@hp.com>, June 2013. | |
1da177e4 LT |
26 | */ |
27 | ||
1da177e4 LT |
28 | #include <linux/slab.h> |
29 | #include <linux/mm.h> | |
30 | #include <linux/hugetlb.h> | |
31 | #include <linux/shm.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/file.h> | |
34 | #include <linux/mman.h> | |
1da177e4 LT |
35 | #include <linux/shmem_fs.h> |
36 | #include <linux/security.h> | |
37 | #include <linux/syscalls.h> | |
38 | #include <linux/audit.h> | |
c59ede7b | 39 | #include <linux/capability.h> |
7d87e14c | 40 | #include <linux/ptrace.h> |
19b4946c | 41 | #include <linux/seq_file.h> |
3e148c79 | 42 | #include <linux/rwsem.h> |
4e982311 | 43 | #include <linux/nsproxy.h> |
bc56bba8 | 44 | #include <linux/mount.h> |
ae5e1b22 | 45 | #include <linux/ipc_namespace.h> |
0eb71a9d | 46 | #include <linux/rhashtable.h> |
7d87e14c | 47 | |
7153e402 | 48 | #include <linux/uaccess.h> |
1da177e4 LT |
49 | |
50 | #include "util.h" | |
51 | ||
a2e102cd EB |
52 | struct shmid_kernel /* private to the kernel */ |
53 | { | |
54 | struct kern_ipc_perm shm_perm; | |
55 | struct file *shm_file; | |
56 | unsigned long shm_nattch; | |
57 | unsigned long shm_segsz; | |
58 | time64_t shm_atim; | |
59 | time64_t shm_dtim; | |
60 | time64_t shm_ctim; | |
98f929b1 EB |
61 | struct pid *shm_cprid; |
62 | struct pid *shm_lprid; | |
d7c9e99a | 63 | struct ucounts *mlock_ucounts; |
a2e102cd | 64 | |
d17415bb AM |
65 | /* |
66 | * The task created the shm object, for | |
67 | * task_lock(shp->shm_creator) | |
68 | */ | |
a2e102cd | 69 | struct task_struct *shm_creator; |
d17415bb AM |
70 | |
71 | /* | |
72 | * List by creator. task_lock(->shm_creator) required for read/write. | |
73 | * If list_empty(), then the creator is dead already. | |
74 | */ | |
75 | struct list_head shm_clist; | |
76 | struct ipc_namespace *ns; | |
a2e102cd EB |
77 | } __randomize_layout; |
78 | ||
79 | /* shm_mode upper byte flags */ | |
80 | #define SHM_DEST 01000 /* segment will be destroyed on last detach */ | |
81 | #define SHM_LOCKED 02000 /* segment will not be swapped */ | |
82 | ||
bc56bba8 EB |
83 | struct shm_file_data { |
84 | int id; | |
85 | struct ipc_namespace *ns; | |
86 | struct file *file; | |
87 | const struct vm_operations_struct *vm_ops; | |
88 | }; | |
89 | ||
90 | #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) | |
91 | ||
9a32144e | 92 | static const struct file_operations shm_file_operations; |
f0f37e2f | 93 | static const struct vm_operations_struct shm_vm_ops; |
1da177e4 | 94 | |
ed2ddbf8 | 95 | #define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
1da177e4 | 96 | |
4e982311 KK |
97 | #define shm_unlock(shp) \ |
98 | ipc_unlock(&(shp)->shm_perm) | |
1da177e4 | 99 | |
7748dbfa | 100 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
101 | static void shm_open(struct vm_area_struct *vma); |
102 | static void shm_close(struct vm_area_struct *vma); | |
239521f3 | 103 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 104 | #ifdef CONFIG_PROC_FS |
19b4946c | 105 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
106 | #endif |
107 | ||
eae04d25 | 108 | void shm_init_ns(struct ipc_namespace *ns) |
4e982311 | 109 | { |
4e982311 KK |
110 | ns->shm_ctlmax = SHMMAX; |
111 | ns->shm_ctlall = SHMALL; | |
112 | ns->shm_ctlmni = SHMMNI; | |
b34a6b1d | 113 | ns->shm_rmid_forced = 0; |
4e982311 | 114 | ns->shm_tot = 0; |
eae04d25 | 115 | ipc_init_ids(&shm_ids(ns)); |
4e982311 KK |
116 | } |
117 | ||
f4566f04 | 118 | /* |
d9a605e4 DB |
119 | * Called with shm_ids.rwsem (writer) and the shp structure locked. |
120 | * Only shm_ids.rwsem remains locked on exit. | |
f4566f04 | 121 | */ |
01b8b07a | 122 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
4e982311 | 123 | { |
01b8b07a | 124 | struct shmid_kernel *shp; |
63980c80 | 125 | |
01b8b07a | 126 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
d17415bb | 127 | WARN_ON(ns != shp->ns); |
01b8b07a | 128 | |
239521f3 | 129 | if (shp->shm_nattch) { |
4e982311 KK |
130 | shp->shm_perm.mode |= SHM_DEST; |
131 | /* Do not find it any more */ | |
0cfb6aee | 132 | ipc_set_key_private(&shm_ids(ns), &shp->shm_perm); |
4e982311 KK |
133 | shm_unlock(shp); |
134 | } else | |
135 | shm_destroy(ns, shp); | |
136 | } | |
137 | ||
ae5e1b22 | 138 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
139 | void shm_exit_ns(struct ipc_namespace *ns) |
140 | { | |
01b8b07a | 141 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
7d6feeb2 | 142 | idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
0cfb6aee | 143 | rhashtable_destroy(&ns->ids[IPC_SHM_IDS].key_ht); |
4e982311 | 144 | } |
ae5e1b22 | 145 | #endif |
1da177e4 | 146 | |
140d0b21 | 147 | static int __init ipc_ns_init(void) |
1da177e4 | 148 | { |
eae04d25 DB |
149 | shm_init_ns(&init_ipc_ns); |
150 | return 0; | |
140d0b21 LT |
151 | } |
152 | ||
153 | pure_initcall(ipc_ns_init); | |
154 | ||
239521f3 | 155 | void __init shm_init(void) |
140d0b21 | 156 | { |
19b4946c | 157 | ipc_init_proc_interface("sysvipc/shm", |
b7952180 HD |
158 | #if BITS_PER_LONG <= 32 |
159 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", | |
160 | #else | |
161 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", | |
162 | #endif | |
4e982311 | 163 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
164 | } |
165 | ||
8b8d52ac DB |
166 | static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id) |
167 | { | |
55b7ae50 | 168 | struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&shm_ids(ns), id); |
8b8d52ac DB |
169 | |
170 | if (IS_ERR(ipcp)) | |
171 | return ERR_CAST(ipcp); | |
172 | ||
173 | return container_of(ipcp, struct shmid_kernel, shm_perm); | |
174 | } | |
175 | ||
176 | static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id) | |
177 | { | |
178 | struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id); | |
179 | ||
180 | if (IS_ERR(ipcp)) | |
181 | return ERR_CAST(ipcp); | |
182 | ||
183 | return container_of(ipcp, struct shmid_kernel, shm_perm); | |
184 | } | |
185 | ||
3e148c79 | 186 | /* |
d9a605e4 | 187 | * shm_lock_(check_) routines are called in the paths where the rwsem |
00c2bf85 | 188 | * is not necessarily held. |
3e148c79 | 189 | */ |
023a5355 | 190 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 191 | { |
82061c57 | 192 | struct kern_ipc_perm *ipcp; |
03f02c76 | 193 | |
82061c57 DB |
194 | rcu_read_lock(); |
195 | ipcp = ipc_obtain_object_idr(&shm_ids(ns), id); | |
196 | if (IS_ERR(ipcp)) | |
197 | goto err; | |
198 | ||
199 | ipc_lock_object(ipcp); | |
200 | /* | |
201 | * ipc_rmid() may have already freed the ID while ipc_lock_object() | |
202 | * was spinning: here verify that the structure is still valid. | |
203 | * Upon races with RMID, return -EIDRM, thus indicating that | |
204 | * the ID points to a removed identifier. | |
205 | */ | |
206 | if (ipc_valid_object(ipcp)) { | |
207 | /* return a locked ipc object upon success */ | |
208 | return container_of(ipcp, struct shmid_kernel, shm_perm); | |
209 | } | |
210 | ||
211 | ipc_unlock_object(ipcp); | |
9c21dae2 | 212 | ipcp = ERR_PTR(-EIDRM); |
82061c57 DB |
213 | err: |
214 | rcu_read_unlock(); | |
c5c8975b | 215 | /* |
1ac0b6de | 216 | * Callers of shm_lock() must validate the status of the returned ipc |
82061c57 | 217 | * object pointer and error out as appropriate. |
c5c8975b | 218 | */ |
59cf0a93 | 219 | return ERR_CAST(ipcp); |
023a5355 ND |
220 | } |
221 | ||
4c677e2e VK |
222 | static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp) |
223 | { | |
224 | rcu_read_lock(); | |
cf9d5d78 | 225 | ipc_lock_object(&ipcp->shm_perm); |
4c677e2e VK |
226 | } |
227 | ||
53dad6d3 DB |
228 | static void shm_rcu_free(struct rcu_head *head) |
229 | { | |
dba4cdd3 MS |
230 | struct kern_ipc_perm *ptr = container_of(head, struct kern_ipc_perm, |
231 | rcu); | |
232 | struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel, | |
233 | shm_perm); | |
7191adff | 234 | security_shm_free(&shp->shm_perm); |
bc8136a5 | 235 | kfree(shp); |
53dad6d3 DB |
236 | } |
237 | ||
d17415bb AM |
238 | /* |
239 | * It has to be called with shp locked. | |
240 | * It must be called before ipc_rmid() | |
241 | */ | |
242 | static inline void shm_clist_rm(struct shmid_kernel *shp) | |
1da177e4 | 243 | { |
d17415bb AM |
244 | struct task_struct *creator; |
245 | ||
246 | /* ensure that shm_creator does not disappear */ | |
247 | rcu_read_lock(); | |
248 | ||
249 | /* | |
250 | * A concurrent exit_shm may do a list_del_init() as well. | |
251 | * Just do nothing if exit_shm already did the work | |
252 | */ | |
253 | if (!list_empty(&shp->shm_clist)) { | |
254 | /* | |
255 | * shp->shm_creator is guaranteed to be valid *only* | |
256 | * if shp->shm_clist is not empty. | |
257 | */ | |
258 | creator = shp->shm_creator; | |
259 | ||
260 | task_lock(creator); | |
261 | /* | |
262 | * list_del_init() is a nop if the entry was already removed | |
263 | * from the list. | |
264 | */ | |
265 | list_del_init(&shp->shm_clist); | |
266 | task_unlock(creator); | |
267 | } | |
268 | rcu_read_unlock(); | |
269 | } | |
270 | ||
271 | static inline void shm_rmid(struct shmid_kernel *s) | |
272 | { | |
273 | shm_clist_rm(s); | |
274 | ipc_rmid(&shm_ids(s->ns), &s->shm_perm); | |
1da177e4 LT |
275 | } |
276 | ||
1da177e4 | 277 | |
1ac0b6de | 278 | static int __shm_open(struct vm_area_struct *vma) |
4e982311 | 279 | { |
bc56bba8 EB |
280 | struct file *file = vma->vm_file; |
281 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
282 | struct shmid_kernel *shp; |
283 | ||
bc56bba8 | 284 | shp = shm_lock(sfd->ns, sfd->id); |
1ac0b6de KS |
285 | |
286 | if (IS_ERR(shp)) | |
287 | return PTR_ERR(shp); | |
288 | ||
3f05317d EB |
289 | if (shp->shm_file != sfd->file) { |
290 | /* ID was reused */ | |
291 | shm_unlock(shp); | |
292 | return -EINVAL; | |
293 | } | |
294 | ||
7ff2819e | 295 | shp->shm_atim = ktime_get_real_seconds(); |
98f929b1 | 296 | ipc_update_pid(&shp->shm_lprid, task_tgid(current)); |
1da177e4 LT |
297 | shp->shm_nattch++; |
298 | shm_unlock(shp); | |
1ac0b6de KS |
299 | return 0; |
300 | } | |
301 | ||
302 | /* This is called by fork, once for every shm attach. */ | |
303 | static void shm_open(struct vm_area_struct *vma) | |
304 | { | |
305 | int err = __shm_open(vma); | |
306 | /* | |
307 | * We raced in the idr lookup or with shm_destroy(). | |
308 | * Either way, the ID is busted. | |
309 | */ | |
310 | WARN_ON_ONCE(err); | |
1da177e4 LT |
311 | } |
312 | ||
1da177e4 LT |
313 | /* |
314 | * shm_destroy - free the struct shmid_kernel | |
315 | * | |
f4566f04 | 316 | * @ns: namespace |
1da177e4 LT |
317 | * @shp: struct to free |
318 | * | |
d9a605e4 | 319 | * It has to be called with shp and shm_ids.rwsem (writer) locked, |
1da177e4 LT |
320 | * but returns with shp unlocked and freed. |
321 | */ | |
4e982311 | 322 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 323 | { |
a399b29d GT |
324 | struct file *shm_file; |
325 | ||
326 | shm_file = shp->shm_file; | |
327 | shp->shm_file = NULL; | |
4e982311 | 328 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
d17415bb | 329 | shm_rmid(shp); |
1da177e4 | 330 | shm_unlock(shp); |
a399b29d | 331 | if (!is_file_hugepages(shm_file)) |
d7c9e99a AG |
332 | shmem_lock(shm_file, 0, shp->mlock_ucounts); |
333 | else if (shp->mlock_ucounts) | |
07a46ed2 | 334 | user_shm_unlock(i_size_read(file_inode(shm_file)), |
d7c9e99a | 335 | shp->mlock_ucounts); |
a399b29d | 336 | fput(shm_file); |
98f929b1 EB |
337 | ipc_update_pid(&shp->shm_cprid, NULL); |
338 | ipc_update_pid(&shp->shm_lprid, NULL); | |
dba4cdd3 | 339 | ipc_rcu_putref(&shp->shm_perm, shm_rcu_free); |
1da177e4 LT |
340 | } |
341 | ||
b34a6b1d VK |
342 | /* |
343 | * shm_may_destroy - identifies whether shm segment should be destroyed now | |
344 | * | |
345 | * Returns true if and only if there are no active users of the segment and | |
346 | * one of the following is true: | |
347 | * | |
348 | * 1) shmctl(id, IPC_RMID, NULL) was called for this shp | |
349 | * | |
350 | * 2) sysctl kernel.shm_rmid_forced is set to 1. | |
351 | */ | |
d17415bb | 352 | static bool shm_may_destroy(struct shmid_kernel *shp) |
b34a6b1d VK |
353 | { |
354 | return (shp->shm_nattch == 0) && | |
d17415bb | 355 | (shp->ns->shm_rmid_forced || |
b34a6b1d VK |
356 | (shp->shm_perm.mode & SHM_DEST)); |
357 | } | |
358 | ||
1da177e4 | 359 | /* |
bc56bba8 | 360 | * remove the attach descriptor vma. |
1da177e4 LT |
361 | * free memory for segment if it is marked destroyed. |
362 | * The descriptor has already been removed from the current->mm->mmap list | |
363 | * and will later be kfree()d. | |
364 | */ | |
bc56bba8 | 365 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 366 | { |
239521f3 | 367 | struct file *file = vma->vm_file; |
bc56bba8 | 368 | struct shm_file_data *sfd = shm_file_data(file); |
1da177e4 | 369 | struct shmid_kernel *shp; |
bc56bba8 | 370 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 371 | |
d9a605e4 | 372 | down_write(&shm_ids(ns).rwsem); |
1da177e4 | 373 | /* remove from the list of attaches of the shm segment */ |
00c2bf85 | 374 | shp = shm_lock(ns, sfd->id); |
1ac0b6de KS |
375 | |
376 | /* | |
377 | * We raced in the idr lookup or with shm_destroy(). | |
378 | * Either way, the ID is busted. | |
379 | */ | |
380 | if (WARN_ON_ONCE(IS_ERR(shp))) | |
381 | goto done; /* no-op */ | |
382 | ||
98f929b1 | 383 | ipc_update_pid(&shp->shm_lprid, task_tgid(current)); |
7ff2819e | 384 | shp->shm_dtim = ktime_get_real_seconds(); |
1da177e4 | 385 | shp->shm_nattch--; |
d17415bb | 386 | if (shm_may_destroy(shp)) |
b34a6b1d VK |
387 | shm_destroy(ns, shp); |
388 | else | |
389 | shm_unlock(shp); | |
1ac0b6de | 390 | done: |
d9a605e4 | 391 | up_write(&shm_ids(ns).rwsem); |
b34a6b1d VK |
392 | } |
393 | ||
d9a605e4 | 394 | /* Called with ns->shm_ids(ns).rwsem locked */ |
b34a6b1d VK |
395 | static int shm_try_destroy_orphaned(int id, void *p, void *data) |
396 | { | |
397 | struct ipc_namespace *ns = data; | |
4c677e2e VK |
398 | struct kern_ipc_perm *ipcp = p; |
399 | struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
b34a6b1d VK |
400 | |
401 | /* | |
402 | * We want to destroy segments without users and with already | |
403 | * exit'ed originating process. | |
4c677e2e | 404 | * |
d9a605e4 | 405 | * As shp->* are changed under rwsem, it's safe to skip shp locking. |
b34a6b1d | 406 | */ |
d17415bb | 407 | if (!list_empty(&shp->shm_clist)) |
b34a6b1d | 408 | return 0; |
b34a6b1d | 409 | |
d17415bb | 410 | if (shm_may_destroy(shp)) { |
4c677e2e | 411 | shm_lock_by_ptr(shp); |
4e982311 | 412 | shm_destroy(ns, shp); |
4c677e2e | 413 | } |
b34a6b1d VK |
414 | return 0; |
415 | } | |
416 | ||
417 | void shm_destroy_orphaned(struct ipc_namespace *ns) | |
418 | { | |
d9a605e4 | 419 | down_write(&shm_ids(ns).rwsem); |
33a30ed4 | 420 | if (shm_ids(ns).in_use) |
4c677e2e | 421 | idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns); |
d9a605e4 | 422 | up_write(&shm_ids(ns).rwsem); |
b34a6b1d VK |
423 | } |
424 | ||
83293c0f | 425 | /* Locking assumes this will only be called with task == current */ |
b34a6b1d VK |
426 | void exit_shm(struct task_struct *task) |
427 | { | |
d17415bb AM |
428 | for (;;) { |
429 | struct shmid_kernel *shp; | |
430 | struct ipc_namespace *ns; | |
b34a6b1d | 431 | |
d17415bb AM |
432 | task_lock(task); |
433 | ||
434 | if (list_empty(&task->sysvshm.shm_clist)) { | |
435 | task_unlock(task); | |
436 | break; | |
437 | } | |
438 | ||
439 | shp = list_first_entry(&task->sysvshm.shm_clist, struct shmid_kernel, | |
440 | shm_clist); | |
83293c0f | 441 | |
83293c0f | 442 | /* |
d17415bb AM |
443 | * 1) Get pointer to the ipc namespace. It is worth to say |
444 | * that this pointer is guaranteed to be valid because | |
445 | * shp lifetime is always shorter than namespace lifetime | |
446 | * in which shp lives. | |
447 | * We taken task_lock it means that shp won't be freed. | |
83293c0f | 448 | */ |
d17415bb | 449 | ns = shp->ns; |
298507d4 | 450 | |
d17415bb AM |
451 | /* |
452 | * 2) If kernel.shm_rmid_forced is not set then only keep track of | |
453 | * which shmids are orphaned, so that a later set of the sysctl | |
454 | * can clean them up. | |
455 | */ | |
456 | if (!ns->shm_rmid_forced) | |
457 | goto unlink_continue; | |
83293c0f | 458 | |
d17415bb AM |
459 | /* |
460 | * 3) get a reference to the namespace. | |
461 | * The refcount could be already 0. If it is 0, then | |
462 | * the shm objects will be free by free_ipc_work(). | |
463 | */ | |
464 | ns = get_ipc_ns_not_zero(ns); | |
465 | if (!ns) { | |
466 | unlink_continue: | |
467 | list_del_init(&shp->shm_clist); | |
468 | task_unlock(task); | |
469 | continue; | |
83293c0f | 470 | } |
83293c0f | 471 | |
d17415bb AM |
472 | /* |
473 | * 4) get a reference to shp. | |
474 | * This cannot fail: shm_clist_rm() is called before | |
475 | * ipc_rmid(), thus the refcount cannot be 0. | |
476 | */ | |
477 | WARN_ON(!ipc_rcu_getref(&shp->shm_perm)); | |
478 | ||
479 | /* | |
480 | * 5) unlink the shm segment from the list of segments | |
481 | * created by current. | |
482 | * This must be done last. After unlinking, | |
483 | * only the refcounts obtained above prevent IPC_RMID | |
484 | * from destroying the segment or the namespace. | |
485 | */ | |
486 | list_del_init(&shp->shm_clist); | |
487 | ||
488 | task_unlock(task); | |
489 | ||
490 | /* | |
491 | * 6) we have all references | |
492 | * Thus lock & if needed destroy shp. | |
493 | */ | |
494 | down_write(&shm_ids(ns).rwsem); | |
495 | shm_lock_by_ptr(shp); | |
496 | /* | |
497 | * rcu_read_lock was implicitly taken in shm_lock_by_ptr, it's | |
498 | * safe to call ipc_rcu_putref here | |
499 | */ | |
500 | ipc_rcu_putref(&shp->shm_perm, shm_rcu_free); | |
501 | ||
502 | if (ipc_valid_object(&shp->shm_perm)) { | |
503 | if (shm_may_destroy(shp)) | |
504 | shm_destroy(ns, shp); | |
505 | else | |
506 | shm_unlock(shp); | |
507 | } else { | |
508 | /* | |
509 | * Someone else deleted the shp from namespace | |
510 | * idr/kht while we have waited. | |
511 | * Just unlock and continue. | |
512 | */ | |
513 | shm_unlock(shp); | |
514 | } | |
515 | ||
516 | up_write(&shm_ids(ns).rwsem); | |
517 | put_ipc_ns(ns); /* paired with get_ipc_ns_not_zero */ | |
518 | } | |
1da177e4 LT |
519 | } |
520 | ||
14f28f57 | 521 | static vm_fault_t shm_fault(struct vm_fault *vmf) |
bc56bba8 | 522 | { |
11bac800 | 523 | struct file *file = vmf->vma->vm_file; |
bc56bba8 EB |
524 | struct shm_file_data *sfd = shm_file_data(file); |
525 | ||
11bac800 | 526 | return sfd->vm_ops->fault(vmf); |
bc56bba8 EB |
527 | } |
528 | ||
dd3b614f | 529 | static int shm_may_split(struct vm_area_struct *vma, unsigned long addr) |
3d942ee0 MK |
530 | { |
531 | struct file *file = vma->vm_file; | |
532 | struct shm_file_data *sfd = shm_file_data(file); | |
533 | ||
dd3b614f DS |
534 | if (sfd->vm_ops->may_split) |
535 | return sfd->vm_ops->may_split(vma, addr); | |
3d942ee0 MK |
536 | |
537 | return 0; | |
538 | } | |
539 | ||
eec3636a JC |
540 | static unsigned long shm_pagesize(struct vm_area_struct *vma) |
541 | { | |
542 | struct file *file = vma->vm_file; | |
543 | struct shm_file_data *sfd = shm_file_data(file); | |
544 | ||
545 | if (sfd->vm_ops->pagesize) | |
546 | return sfd->vm_ops->pagesize(vma); | |
547 | ||
548 | return PAGE_SIZE; | |
549 | } | |
550 | ||
bc56bba8 | 551 | #ifdef CONFIG_NUMA |
d823e3e7 | 552 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
553 | { |
554 | struct file *file = vma->vm_file; | |
555 | struct shm_file_data *sfd = shm_file_data(file); | |
556 | int err = 0; | |
63980c80 | 557 | |
bc56bba8 EB |
558 | if (sfd->vm_ops->set_policy) |
559 | err = sfd->vm_ops->set_policy(vma, new); | |
560 | return err; | |
561 | } | |
562 | ||
d823e3e7 AB |
563 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
564 | unsigned long addr) | |
bc56bba8 EB |
565 | { |
566 | struct file *file = vma->vm_file; | |
567 | struct shm_file_data *sfd = shm_file_data(file); | |
568 | struct mempolicy *pol = NULL; | |
569 | ||
570 | if (sfd->vm_ops->get_policy) | |
571 | pol = sfd->vm_ops->get_policy(vma, addr); | |
52cd3b07 | 572 | else if (vma->vm_policy) |
bc56bba8 | 573 | pol = vma->vm_policy; |
52cd3b07 | 574 | |
bc56bba8 EB |
575 | return pol; |
576 | } | |
577 | #endif | |
578 | ||
239521f3 | 579 | static int shm_mmap(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 580 | { |
bc56bba8 | 581 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
582 | int ret; |
583 | ||
1ac0b6de | 584 | /* |
3f05317d EB |
585 | * In case of remap_file_pages() emulation, the file can represent an |
586 | * IPC ID that was removed, and possibly even reused by another shm | |
587 | * segment already. Propagate this case as an error to caller. | |
1ac0b6de | 588 | */ |
63980c80 | 589 | ret = __shm_open(vma); |
1ac0b6de KS |
590 | if (ret) |
591 | return ret; | |
592 | ||
f74ac015 | 593 | ret = call_mmap(sfd->file, vma); |
1ac0b6de KS |
594 | if (ret) { |
595 | shm_close(vma); | |
bc56bba8 | 596 | return ret; |
1ac0b6de | 597 | } |
bc56bba8 | 598 | sfd->vm_ops = vma->vm_ops; |
2e92a3ba | 599 | #ifdef CONFIG_MMU |
d0edd852 | 600 | WARN_ON(!sfd->vm_ops->fault); |
2e92a3ba | 601 | #endif |
bc56bba8 | 602 | vma->vm_ops = &shm_vm_ops; |
1ac0b6de | 603 | return 0; |
1da177e4 LT |
604 | } |
605 | ||
4e982311 KK |
606 | static int shm_release(struct inode *ino, struct file *file) |
607 | { | |
bc56bba8 | 608 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 609 | |
bc56bba8 | 610 | put_ipc_ns(sfd->ns); |
3f05317d | 611 | fput(sfd->file); |
bc56bba8 EB |
612 | shm_file_data(file) = NULL; |
613 | kfree(sfd); | |
4e982311 KK |
614 | return 0; |
615 | } | |
616 | ||
02c24a82 | 617 | static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
516dffdc | 618 | { |
516dffdc | 619 | struct shm_file_data *sfd = shm_file_data(file); |
516dffdc | 620 | |
7ea80859 CH |
621 | if (!sfd->file->f_op->fsync) |
622 | return -EINVAL; | |
0f41074a | 623 | return sfd->file->f_op->fsync(sfd->file, start, end, datasync); |
516dffdc AL |
624 | } |
625 | ||
7d8a4569 WD |
626 | static long shm_fallocate(struct file *file, int mode, loff_t offset, |
627 | loff_t len) | |
628 | { | |
629 | struct shm_file_data *sfd = shm_file_data(file); | |
630 | ||
631 | if (!sfd->file->f_op->fallocate) | |
632 | return -EOPNOTSUPP; | |
633 | return sfd->file->f_op->fallocate(file, mode, offset, len); | |
634 | } | |
635 | ||
bc56bba8 EB |
636 | static unsigned long shm_get_unmapped_area(struct file *file, |
637 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
638 | unsigned long flags) | |
639 | { | |
640 | struct shm_file_data *sfd = shm_file_data(file); | |
63980c80 | 641 | |
c4caa778 AV |
642 | return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
643 | pgoff, flags); | |
bc56bba8 | 644 | } |
bc56bba8 | 645 | |
9a32144e | 646 | static const struct file_operations shm_file_operations = { |
4e982311 | 647 | .mmap = shm_mmap, |
516dffdc | 648 | .fsync = shm_fsync, |
4e982311 | 649 | .release = shm_release, |
ed5e5894 | 650 | .get_unmapped_area = shm_get_unmapped_area, |
6038f373 | 651 | .llseek = noop_llseek, |
7d8a4569 | 652 | .fallocate = shm_fallocate, |
c4caa778 AV |
653 | }; |
654 | ||
c01d5b30 HD |
655 | /* |
656 | * shm_file_operations_huge is now identical to shm_file_operations, | |
657 | * but we keep it distinct for the sake of is_file_shm_hugepages(). | |
658 | */ | |
c4caa778 AV |
659 | static const struct file_operations shm_file_operations_huge = { |
660 | .mmap = shm_mmap, | |
661 | .fsync = shm_fsync, | |
662 | .release = shm_release, | |
bc56bba8 | 663 | .get_unmapped_area = shm_get_unmapped_area, |
6038f373 | 664 | .llseek = noop_llseek, |
7d8a4569 | 665 | .fallocate = shm_fallocate, |
1da177e4 LT |
666 | }; |
667 | ||
2954e440 | 668 | bool is_file_shm_hugepages(struct file *file) |
c4caa778 AV |
669 | { |
670 | return file->f_op == &shm_file_operations_huge; | |
671 | } | |
672 | ||
f0f37e2f | 673 | static const struct vm_operations_struct shm_vm_ops = { |
1da177e4 LT |
674 | .open = shm_open, /* callback for a new vm-area open */ |
675 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 676 | .fault = shm_fault, |
dd3b614f | 677 | .may_split = shm_may_split, |
eec3636a | 678 | .pagesize = shm_pagesize, |
bc56bba8 EB |
679 | #if defined(CONFIG_NUMA) |
680 | .set_policy = shm_set_policy, | |
681 | .get_policy = shm_get_policy, | |
1da177e4 LT |
682 | #endif |
683 | }; | |
684 | ||
f4566f04 ND |
685 | /** |
686 | * newseg - Create a new shared memory segment | |
687 | * @ns: namespace | |
688 | * @params: ptr to the structure that contains key, size and shmflg | |
689 | * | |
d9a605e4 | 690 | * Called with shm_ids.rwsem held as a writer. |
f4566f04 | 691 | */ |
7748dbfa | 692 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 693 | { |
7748dbfa ND |
694 | key_t key = params->key; |
695 | int shmflg = params->flg; | |
696 | size_t size = params->u.size; | |
1da177e4 LT |
697 | int error; |
698 | struct shmid_kernel *shp; | |
d69f3bad | 699 | size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
239521f3 | 700 | struct file *file; |
1da177e4 | 701 | char name[13]; |
ca16d140 | 702 | vm_flags_t acctflag = 0; |
1da177e4 | 703 | |
4e982311 | 704 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
705 | return -EINVAL; |
706 | ||
1376327c MS |
707 | if (numpages << PAGE_SHIFT < size) |
708 | return -ENOSPC; | |
709 | ||
09c6eb1f MS |
710 | if (ns->shm_tot + numpages < ns->shm_tot || |
711 | ns->shm_tot + numpages > ns->shm_ctlall) | |
1da177e4 LT |
712 | return -ENOSPC; |
713 | ||
18319498 | 714 | shp = kmalloc(sizeof(*shp), GFP_KERNEL_ACCOUNT); |
42e618f7 | 715 | if (unlikely(!shp)) |
1da177e4 LT |
716 | return -ENOMEM; |
717 | ||
718 | shp->shm_perm.key = key; | |
b33291c0 | 719 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
d7c9e99a | 720 | shp->mlock_ucounts = NULL; |
1da177e4 LT |
721 | |
722 | shp->shm_perm.security = NULL; | |
7191adff | 723 | error = security_shm_alloc(&shp->shm_perm); |
1da177e4 | 724 | if (error) { |
bc8136a5 | 725 | kfree(shp); |
1da177e4 LT |
726 | return error; |
727 | } | |
728 | ||
239521f3 | 729 | sprintf(name, "SYSV%08x", key); |
1da177e4 | 730 | if (shmflg & SHM_HUGETLB) { |
c103a4dc | 731 | struct hstate *hs; |
091d0d55 LZ |
732 | size_t hugesize; |
733 | ||
c103a4dc | 734 | hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK); |
091d0d55 LZ |
735 | if (!hs) { |
736 | error = -EINVAL; | |
737 | goto no_file; | |
738 | } | |
739 | hugesize = ALIGN(size, huge_page_size(hs)); | |
af73e4d9 | 740 | |
5a6fe125 MG |
741 | /* hugetlb_file_setup applies strict accounting */ |
742 | if (shmflg & SHM_NORESERVE) | |
743 | acctflag = VM_NORESERVE; | |
af73e4d9 | 744 | file = hugetlb_file_setup(name, hugesize, acctflag, |
d7c9e99a | 745 | &shp->mlock_ucounts, HUGETLB_SHMFS_INODE, |
42d7395f | 746 | (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK); |
1da177e4 | 747 | } else { |
bf8f972d BP |
748 | /* |
749 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
239521f3 | 750 | * if it's asked for. |
bf8f972d BP |
751 | */ |
752 | if ((shmflg & SHM_NORESERVE) && | |
753 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
fc8744ad | 754 | acctflag = VM_NORESERVE; |
e1832f29 | 755 | file = shmem_kernel_file_setup(name, size, acctflag); |
1da177e4 LT |
756 | } |
757 | error = PTR_ERR(file); | |
758 | if (IS_ERR(file)) | |
759 | goto no_file; | |
760 | ||
98f929b1 EB |
761 | shp->shm_cprid = get_pid(task_tgid(current)); |
762 | shp->shm_lprid = NULL; | |
1da177e4 | 763 | shp->shm_atim = shp->shm_dtim = 0; |
7ff2819e | 764 | shp->shm_ctim = ktime_get_real_seconds(); |
1da177e4 LT |
765 | shp->shm_segsz = size; |
766 | shp->shm_nattch = 0; | |
1da177e4 | 767 | shp->shm_file = file; |
5774ed01 | 768 | shp->shm_creator = current; |
b9a53227 | 769 | |
39c96a1b | 770 | /* ipc_addid() locks shp upon success. */ |
a2642f87 MS |
771 | error = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
772 | if (error < 0) | |
b9a53227 | 773 | goto no_id; |
b9a53227 | 774 | |
d17415bb AM |
775 | shp->ns = ns; |
776 | ||
777 | task_lock(current); | |
ab602f79 | 778 | list_add(&shp->shm_clist, ¤t->sysvshm.shm_clist); |
d17415bb | 779 | task_unlock(current); |
dbfcd91f | 780 | |
30475cc1 BP |
781 | /* |
782 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
783 | * proc-ps tools use this. Changing this will break them. | |
784 | */ | |
496ad9aa | 785 | file_inode(file)->i_ino = shp->shm_perm.id; |
551110a9 | 786 | |
4e982311 | 787 | ns->shm_tot += numpages; |
7ca7e564 | 788 | error = shp->shm_perm.id; |
dbfcd91f | 789 | |
cf9d5d78 | 790 | ipc_unlock_object(&shp->shm_perm); |
dbfcd91f | 791 | rcu_read_unlock(); |
7ca7e564 | 792 | return error; |
1da177e4 LT |
793 | |
794 | no_id: | |
2236d4d3 EB |
795 | ipc_update_pid(&shp->shm_cprid, NULL); |
796 | ipc_update_pid(&shp->shm_lprid, NULL); | |
d7c9e99a AG |
797 | if (is_file_hugepages(file) && shp->mlock_ucounts) |
798 | user_shm_unlock(size, shp->mlock_ucounts); | |
1da177e4 | 799 | fput(file); |
39cfffd7 MS |
800 | ipc_rcu_putref(&shp->shm_perm, shm_rcu_free); |
801 | return error; | |
1da177e4 | 802 | no_file: |
a2642f87 | 803 | call_rcu(&shp->shm_perm.rcu, shm_rcu_free); |
1da177e4 LT |
804 | return error; |
805 | } | |
806 | ||
f4566f04 | 807 | /* |
d9a605e4 | 808 | * Called with shm_ids.rwsem and ipcp locked. |
f4566f04 | 809 | */ |
00898e85 | 810 | static int shm_more_checks(struct kern_ipc_perm *ipcp, struct ipc_params *params) |
7748dbfa | 811 | { |
03f02c76 ND |
812 | struct shmid_kernel *shp; |
813 | ||
814 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
815 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
816 | return -EINVAL; |
817 | ||
818 | return 0; | |
819 | } | |
820 | ||
65749e0b | 821 | long ksys_shmget(key_t key, size_t size, int shmflg) |
1da177e4 | 822 | { |
4e982311 | 823 | struct ipc_namespace *ns; |
eb66ec44 MK |
824 | static const struct ipc_ops shm_ops = { |
825 | .getnew = newseg, | |
50ab44b1 | 826 | .associate = security_shm_associate, |
eb66ec44 MK |
827 | .more_checks = shm_more_checks, |
828 | }; | |
7748dbfa | 829 | struct ipc_params shm_params; |
4e982311 KK |
830 | |
831 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 832 | |
7748dbfa ND |
833 | shm_params.key = key; |
834 | shm_params.flg = shmflg; | |
835 | shm_params.u.size = size; | |
1da177e4 | 836 | |
7748dbfa | 837 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
838 | } |
839 | ||
65749e0b DB |
840 | SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
841 | { | |
842 | return ksys_shmget(key, size, shmflg); | |
843 | } | |
844 | ||
1da177e4 LT |
845 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) |
846 | { | |
239521f3 | 847 | switch (version) { |
1da177e4 LT |
848 | case IPC_64: |
849 | return copy_to_user(buf, in, sizeof(*in)); | |
850 | case IPC_OLD: | |
851 | { | |
852 | struct shmid_ds out; | |
853 | ||
3af54c9b | 854 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
855 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); |
856 | out.shm_segsz = in->shm_segsz; | |
857 | out.shm_atime = in->shm_atime; | |
858 | out.shm_dtime = in->shm_dtime; | |
859 | out.shm_ctime = in->shm_ctime; | |
860 | out.shm_cpid = in->shm_cpid; | |
861 | out.shm_lpid = in->shm_lpid; | |
862 | out.shm_nattch = in->shm_nattch; | |
863 | ||
864 | return copy_to_user(buf, &out, sizeof(out)); | |
865 | } | |
866 | default: | |
867 | return -EINVAL; | |
868 | } | |
869 | } | |
870 | ||
016d7132 PP |
871 | static inline unsigned long |
872 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) | |
1da177e4 | 873 | { |
239521f3 | 874 | switch (version) { |
1da177e4 | 875 | case IPC_64: |
016d7132 | 876 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 877 | return -EFAULT; |
1da177e4 | 878 | return 0; |
1da177e4 LT |
879 | case IPC_OLD: |
880 | { | |
881 | struct shmid_ds tbuf_old; | |
882 | ||
883 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
884 | return -EFAULT; | |
885 | ||
016d7132 PP |
886 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
887 | out->shm_perm.gid = tbuf_old.shm_perm.gid; | |
888 | out->shm_perm.mode = tbuf_old.shm_perm.mode; | |
1da177e4 LT |
889 | |
890 | return 0; | |
891 | } | |
892 | default: | |
893 | return -EINVAL; | |
894 | } | |
895 | } | |
896 | ||
897 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
898 | { | |
239521f3 | 899 | switch (version) { |
1da177e4 LT |
900 | case IPC_64: |
901 | return copy_to_user(buf, in, sizeof(*in)); | |
902 | case IPC_OLD: | |
903 | { | |
904 | struct shminfo out; | |
905 | ||
239521f3 | 906 | if (in->shmmax > INT_MAX) |
1da177e4 LT |
907 | out.shmmax = INT_MAX; |
908 | else | |
909 | out.shmmax = (int)in->shmmax; | |
910 | ||
911 | out.shmmin = in->shmmin; | |
912 | out.shmmni = in->shmmni; | |
913 | out.shmseg = in->shmseg; | |
46c0a8ca | 914 | out.shmall = in->shmall; |
1da177e4 LT |
915 | |
916 | return copy_to_user(buf, &out, sizeof(out)); | |
917 | } | |
918 | default: | |
919 | return -EINVAL; | |
920 | } | |
921 | } | |
922 | ||
b7952180 HD |
923 | /* |
924 | * Calculate and add used RSS and swap pages of a shm. | |
d9a605e4 | 925 | * Called with shm_ids.rwsem held as a reader |
b7952180 HD |
926 | */ |
927 | static void shm_add_rss_swap(struct shmid_kernel *shp, | |
928 | unsigned long *rss_add, unsigned long *swp_add) | |
929 | { | |
930 | struct inode *inode; | |
931 | ||
496ad9aa | 932 | inode = file_inode(shp->shm_file); |
b7952180 HD |
933 | |
934 | if (is_file_hugepages(shp->shm_file)) { | |
935 | struct address_space *mapping = inode->i_mapping; | |
936 | struct hstate *h = hstate_file(shp->shm_file); | |
937 | *rss_add += pages_per_huge_page(h) * mapping->nrpages; | |
938 | } else { | |
939 | #ifdef CONFIG_SHMEM | |
940 | struct shmem_inode_info *info = SHMEM_I(inode); | |
63980c80 | 941 | |
4595ef88 | 942 | spin_lock_irq(&info->lock); |
b7952180 HD |
943 | *rss_add += inode->i_mapping->nrpages; |
944 | *swp_add += info->swapped; | |
4595ef88 | 945 | spin_unlock_irq(&info->lock); |
b7952180 HD |
946 | #else |
947 | *rss_add += inode->i_mapping->nrpages; | |
948 | #endif | |
949 | } | |
950 | } | |
951 | ||
f4566f04 | 952 | /* |
d9a605e4 | 953 | * Called with shm_ids.rwsem held as a reader |
f4566f04 | 954 | */ |
4e982311 KK |
955 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
956 | unsigned long *swp) | |
1da177e4 | 957 | { |
7ca7e564 ND |
958 | int next_id; |
959 | int total, in_use; | |
1da177e4 LT |
960 | |
961 | *rss = 0; | |
962 | *swp = 0; | |
963 | ||
7ca7e564 ND |
964 | in_use = shm_ids(ns).in_use; |
965 | ||
966 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
e562aebc | 967 | struct kern_ipc_perm *ipc; |
1da177e4 | 968 | struct shmid_kernel *shp; |
1da177e4 | 969 | |
e562aebc TB |
970 | ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
971 | if (ipc == NULL) | |
1da177e4 | 972 | continue; |
e562aebc | 973 | shp = container_of(ipc, struct shmid_kernel, shm_perm); |
1da177e4 | 974 | |
b7952180 | 975 | shm_add_rss_swap(shp, rss, swp); |
7ca7e564 ND |
976 | |
977 | total++; | |
1da177e4 LT |
978 | } |
979 | } | |
980 | ||
8d4cc8b5 | 981 | /* |
d9a605e4 | 982 | * This function handles some shmctl commands which require the rwsem |
8d4cc8b5 | 983 | * to be held in write mode. |
d9a605e4 | 984 | * NOTE: no locks must be held, the rwsem is taken inside this function. |
8d4cc8b5 PP |
985 | */ |
986 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, | |
9ba720c1 | 987 | struct shmid64_ds *shmid64) |
1da177e4 | 988 | { |
8d4cc8b5 | 989 | struct kern_ipc_perm *ipcp; |
8d4cc8b5 PP |
990 | struct shmid_kernel *shp; |
991 | int err; | |
992 | ||
d9a605e4 | 993 | down_write(&shm_ids(ns).rwsem); |
7b4cc5d8 DB |
994 | rcu_read_lock(); |
995 | ||
4241c1a3 | 996 | ipcp = ipcctl_obtain_check(ns, &shm_ids(ns), shmid, cmd, |
9ba720c1 | 997 | &shmid64->shm_perm, 0); |
7b4cc5d8 DB |
998 | if (IS_ERR(ipcp)) { |
999 | err = PTR_ERR(ipcp); | |
7b4cc5d8 DB |
1000 | goto out_unlock1; |
1001 | } | |
8d4cc8b5 | 1002 | |
a5f75e7f | 1003 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
8d4cc8b5 | 1004 | |
7191adff | 1005 | err = security_shm_shmctl(&shp->shm_perm, cmd); |
8d4cc8b5 | 1006 | if (err) |
79ccf0f8 | 1007 | goto out_unlock1; |
7b4cc5d8 | 1008 | |
8d4cc8b5 PP |
1009 | switch (cmd) { |
1010 | case IPC_RMID: | |
79ccf0f8 | 1011 | ipc_lock_object(&shp->shm_perm); |
7b4cc5d8 | 1012 | /* do_shm_rmid unlocks the ipc object and rcu */ |
8d4cc8b5 PP |
1013 | do_shm_rmid(ns, ipcp); |
1014 | goto out_up; | |
1015 | case IPC_SET: | |
79ccf0f8 | 1016 | ipc_lock_object(&shp->shm_perm); |
9ba720c1 | 1017 | err = ipc_update_perm(&shmid64->shm_perm, ipcp); |
1efdb69b | 1018 | if (err) |
7b4cc5d8 | 1019 | goto out_unlock0; |
7ff2819e | 1020 | shp->shm_ctim = ktime_get_real_seconds(); |
8d4cc8b5 PP |
1021 | break; |
1022 | default: | |
1023 | err = -EINVAL; | |
79ccf0f8 | 1024 | goto out_unlock1; |
8d4cc8b5 | 1025 | } |
7b4cc5d8 DB |
1026 | |
1027 | out_unlock0: | |
1028 | ipc_unlock_object(&shp->shm_perm); | |
1029 | out_unlock1: | |
1030 | rcu_read_unlock(); | |
8d4cc8b5 | 1031 | out_up: |
d9a605e4 | 1032 | up_write(&shm_ids(ns).rwsem); |
8d4cc8b5 PP |
1033 | return err; |
1034 | } | |
1035 | ||
9ba720c1 AV |
1036 | static int shmctl_ipc_info(struct ipc_namespace *ns, |
1037 | struct shminfo64 *shminfo) | |
8d4cc8b5 | 1038 | { |
9ba720c1 AV |
1039 | int err = security_shm_shmctl(NULL, IPC_INFO); |
1040 | if (!err) { | |
1041 | memset(shminfo, 0, sizeof(*shminfo)); | |
1042 | shminfo->shmmni = shminfo->shmseg = ns->shm_ctlmni; | |
1043 | shminfo->shmmax = ns->shm_ctlmax; | |
1044 | shminfo->shmall = ns->shm_ctlall; | |
1045 | shminfo->shmmin = SHMMIN; | |
d9a605e4 | 1046 | down_read(&shm_ids(ns).rwsem); |
27c331a1 | 1047 | err = ipc_get_maxidx(&shm_ids(ns)); |
d9a605e4 | 1048 | up_read(&shm_ids(ns).rwsem); |
239521f3 | 1049 | if (err < 0) |
1da177e4 | 1050 | err = 0; |
1da177e4 | 1051 | } |
9ba720c1 AV |
1052 | return err; |
1053 | } | |
1da177e4 | 1054 | |
9ba720c1 AV |
1055 | static int shmctl_shm_info(struct ipc_namespace *ns, |
1056 | struct shm_info *shm_info) | |
1057 | { | |
1058 | int err = security_shm_shmctl(NULL, SHM_INFO); | |
1059 | if (!err) { | |
1060 | memset(shm_info, 0, sizeof(*shm_info)); | |
d9a605e4 | 1061 | down_read(&shm_ids(ns).rwsem); |
9ba720c1 AV |
1062 | shm_info->used_ids = shm_ids(ns).in_use; |
1063 | shm_get_stat(ns, &shm_info->shm_rss, &shm_info->shm_swp); | |
1064 | shm_info->shm_tot = ns->shm_tot; | |
1065 | shm_info->swap_attempts = 0; | |
1066 | shm_info->swap_successes = 0; | |
27c331a1 | 1067 | err = ipc_get_maxidx(&shm_ids(ns)); |
d9a605e4 | 1068 | up_read(&shm_ids(ns).rwsem); |
9ba720c1 AV |
1069 | if (err < 0) |
1070 | err = 0; | |
1da177e4 | 1071 | } |
9ba720c1 AV |
1072 | return err; |
1073 | } | |
c97cb9cc | 1074 | |
9ba720c1 AV |
1075 | static int shmctl_stat(struct ipc_namespace *ns, int shmid, |
1076 | int cmd, struct shmid64_ds *tbuf) | |
1077 | { | |
1078 | struct shmid_kernel *shp; | |
9ba720c1 | 1079 | int err; |
c97cb9cc | 1080 | |
87ad4b0d PM |
1081 | memset(tbuf, 0, sizeof(*tbuf)); |
1082 | ||
9ba720c1 | 1083 | rcu_read_lock(); |
c21a6970 | 1084 | if (cmd == SHM_STAT || cmd == SHM_STAT_ANY) { |
9ba720c1 AV |
1085 | shp = shm_obtain_object(ns, shmid); |
1086 | if (IS_ERR(shp)) { | |
1087 | err = PTR_ERR(shp); | |
1088 | goto out_unlock; | |
1089 | } | |
c21a6970 | 1090 | } else { /* IPC_STAT */ |
9ba720c1 AV |
1091 | shp = shm_obtain_object_check(ns, shmid); |
1092 | if (IS_ERR(shp)) { | |
1093 | err = PTR_ERR(shp); | |
1da177e4 | 1094 | goto out_unlock; |
1da177e4 | 1095 | } |
9ba720c1 | 1096 | } |
1da177e4 | 1097 | |
c21a6970 DB |
1098 | /* |
1099 | * Semantically SHM_STAT_ANY ought to be identical to | |
1100 | * that functionality provided by the /proc/sysvipc/ | |
1101 | * interface. As such, only audit these calls and | |
1102 | * do not do traditional S_IRUGO permission checks on | |
1103 | * the ipc object. | |
1104 | */ | |
1105 | if (cmd == SHM_STAT_ANY) | |
1106 | audit_ipc_obj(&shp->shm_perm); | |
1107 | else { | |
1108 | err = -EACCES; | |
1109 | if (ipcperms(ns, &shp->shm_perm, S_IRUGO)) | |
1110 | goto out_unlock; | |
1111 | } | |
c97cb9cc | 1112 | |
7191adff | 1113 | err = security_shm_shmctl(&shp->shm_perm, cmd); |
9ba720c1 AV |
1114 | if (err) |
1115 | goto out_unlock; | |
1116 | ||
87ad4b0d PM |
1117 | ipc_lock_object(&shp->shm_perm); |
1118 | ||
1119 | if (!ipc_valid_object(&shp->shm_perm)) { | |
1120 | ipc_unlock_object(&shp->shm_perm); | |
1121 | err = -EIDRM; | |
1122 | goto out_unlock; | |
1123 | } | |
1124 | ||
9ba720c1 AV |
1125 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf->shm_perm); |
1126 | tbuf->shm_segsz = shp->shm_segsz; | |
1127 | tbuf->shm_atime = shp->shm_atim; | |
1128 | tbuf->shm_dtime = shp->shm_dtim; | |
1129 | tbuf->shm_ctime = shp->shm_ctim; | |
c2ab975c AB |
1130 | #ifndef CONFIG_64BIT |
1131 | tbuf->shm_atime_high = shp->shm_atim >> 32; | |
1132 | tbuf->shm_dtime_high = shp->shm_dtim >> 32; | |
1133 | tbuf->shm_ctime_high = shp->shm_ctim >> 32; | |
1134 | #endif | |
98f929b1 EB |
1135 | tbuf->shm_cpid = pid_vnr(shp->shm_cprid); |
1136 | tbuf->shm_lpid = pid_vnr(shp->shm_lprid); | |
9ba720c1 | 1137 | tbuf->shm_nattch = shp->shm_nattch; |
87ad4b0d | 1138 | |
615c999c MS |
1139 | if (cmd == IPC_STAT) { |
1140 | /* | |
1141 | * As defined in SUS: | |
1142 | * Return 0 on success | |
1143 | */ | |
1144 | err = 0; | |
1145 | } else { | |
1146 | /* | |
1147 | * SHM_STAT and SHM_STAT_ANY (both Linux specific) | |
1148 | * Return the full id, including the sequence number | |
1149 | */ | |
1150 | err = shp->shm_perm.id; | |
1151 | } | |
68eccc1d | 1152 | |
615c999c | 1153 | ipc_unlock_object(&shp->shm_perm); |
68eccc1d | 1154 | out_unlock: |
c97cb9cc | 1155 | rcu_read_unlock(); |
68eccc1d DB |
1156 | return err; |
1157 | } | |
1158 | ||
9ba720c1 | 1159 | static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd) |
68eccc1d DB |
1160 | { |
1161 | struct shmid_kernel *shp; | |
9ba720c1 AV |
1162 | struct file *shm_file; |
1163 | int err; | |
68eccc1d | 1164 | |
9ba720c1 AV |
1165 | rcu_read_lock(); |
1166 | shp = shm_obtain_object_check(ns, shmid); | |
1167 | if (IS_ERR(shp)) { | |
1168 | err = PTR_ERR(shp); | |
1169 | goto out_unlock1; | |
1da177e4 | 1170 | } |
c97cb9cc | 1171 | |
9ba720c1 | 1172 | audit_ipc_obj(&(shp->shm_perm)); |
7191adff | 1173 | err = security_shm_shmctl(&shp->shm_perm, cmd); |
9ba720c1 AV |
1174 | if (err) |
1175 | goto out_unlock1; | |
c97cb9cc | 1176 | |
9ba720c1 | 1177 | ipc_lock_object(&shp->shm_perm); |
c97cb9cc | 1178 | |
9ba720c1 AV |
1179 | /* check if shm_destroy() is tearing down shp */ |
1180 | if (!ipc_valid_object(&shp->shm_perm)) { | |
1181 | err = -EIDRM; | |
1182 | goto out_unlock0; | |
1da177e4 | 1183 | } |
073115d6 | 1184 | |
9ba720c1 AV |
1185 | if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) { |
1186 | kuid_t euid = current_euid(); | |
0f3d2b01 | 1187 | |
9ba720c1 AV |
1188 | if (!uid_eq(euid, shp->shm_perm.uid) && |
1189 | !uid_eq(euid, shp->shm_perm.cuid)) { | |
1190 | err = -EPERM; | |
0f3d2b01 RA |
1191 | goto out_unlock0; |
1192 | } | |
9ba720c1 AV |
1193 | if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) { |
1194 | err = -EPERM; | |
1195 | goto out_unlock0; | |
1da177e4 | 1196 | } |
68eccc1d DB |
1197 | } |
1198 | ||
9ba720c1 AV |
1199 | shm_file = shp->shm_file; |
1200 | if (is_file_hugepages(shm_file)) | |
1201 | goto out_unlock0; | |
85046579 | 1202 | |
9ba720c1 | 1203 | if (cmd == SHM_LOCK) { |
d7c9e99a | 1204 | struct ucounts *ucounts = current_ucounts(); |
63980c80 | 1205 | |
d7c9e99a | 1206 | err = shmem_lock(shm_file, 1, ucounts); |
9ba720c1 AV |
1207 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) { |
1208 | shp->shm_perm.mode |= SHM_LOCKED; | |
d7c9e99a | 1209 | shp->mlock_ucounts = ucounts; |
1da177e4 | 1210 | } |
9ba720c1 | 1211 | goto out_unlock0; |
1da177e4 LT |
1212 | } |
1213 | ||
9ba720c1 AV |
1214 | /* SHM_UNLOCK */ |
1215 | if (!(shp->shm_perm.mode & SHM_LOCKED)) | |
1216 | goto out_unlock0; | |
d7c9e99a | 1217 | shmem_lock(shm_file, 0, shp->mlock_ucounts); |
9ba720c1 | 1218 | shp->shm_perm.mode &= ~SHM_LOCKED; |
d7c9e99a | 1219 | shp->mlock_ucounts = NULL; |
9ba720c1 AV |
1220 | get_file(shm_file); |
1221 | ipc_unlock_object(&shp->shm_perm); | |
1222 | rcu_read_unlock(); | |
1223 | shmem_unlock_mapping(shm_file->f_mapping); | |
1224 | ||
1225 | fput(shm_file); | |
1226 | return err; | |
1227 | ||
2caacaa8 DB |
1228 | out_unlock0: |
1229 | ipc_unlock_object(&shp->shm_perm); | |
1230 | out_unlock1: | |
c97cb9cc | 1231 | rcu_read_unlock(); |
68eccc1d DB |
1232 | return err; |
1233 | } | |
1234 | ||
275f2214 | 1235 | static long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf, int version) |
68eccc1d | 1236 | { |
275f2214 | 1237 | int err; |
68eccc1d | 1238 | struct ipc_namespace *ns; |
553f770e | 1239 | struct shmid64_ds sem64; |
68eccc1d | 1240 | |
2caacaa8 DB |
1241 | if (cmd < 0 || shmid < 0) |
1242 | return -EINVAL; | |
68eccc1d | 1243 | |
68eccc1d DB |
1244 | ns = current->nsproxy->ipc_ns; |
1245 | ||
1246 | switch (cmd) { | |
9ba720c1 AV |
1247 | case IPC_INFO: { |
1248 | struct shminfo64 shminfo; | |
1249 | err = shmctl_ipc_info(ns, &shminfo); | |
1250 | if (err < 0) | |
1251 | return err; | |
1252 | if (copy_shminfo_to_user(buf, &shminfo, version)) | |
1253 | err = -EFAULT; | |
1254 | return err; | |
1255 | } | |
1256 | case SHM_INFO: { | |
1257 | struct shm_info shm_info; | |
1258 | err = shmctl_shm_info(ns, &shm_info); | |
1259 | if (err < 0) | |
1260 | return err; | |
1261 | if (copy_to_user(buf, &shm_info, sizeof(shm_info))) | |
1262 | err = -EFAULT; | |
1263 | return err; | |
1264 | } | |
68eccc1d | 1265 | case SHM_STAT: |
c21a6970 | 1266 | case SHM_STAT_ANY: |
9ba720c1 | 1267 | case IPC_STAT: { |
553f770e | 1268 | err = shmctl_stat(ns, shmid, cmd, &sem64); |
9ba720c1 AV |
1269 | if (err < 0) |
1270 | return err; | |
553f770e | 1271 | if (copy_shmid_to_user(buf, &sem64, version)) |
9ba720c1 AV |
1272 | err = -EFAULT; |
1273 | return err; | |
1274 | } | |
2caacaa8 | 1275 | case IPC_SET: |
553f770e | 1276 | if (copy_shmid_from_user(&sem64, buf, version)) |
9ba720c1 | 1277 | return -EFAULT; |
df561f66 | 1278 | fallthrough; |
9ba720c1 | 1279 | case IPC_RMID: |
553f770e | 1280 | return shmctl_down(ns, shmid, cmd, &sem64); |
1da177e4 LT |
1281 | case SHM_LOCK: |
1282 | case SHM_UNLOCK: | |
9ba720c1 AV |
1283 | return shmctl_do_lock(ns, shmid, cmd); |
1284 | default: | |
1285 | return -EINVAL; | |
1286 | } | |
1287 | } | |
89e004ea | 1288 | |
c84d0791 DB |
1289 | SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
1290 | { | |
275f2214 AB |
1291 | return ksys_shmctl(shmid, cmd, buf, IPC_64); |
1292 | } | |
1293 | ||
1294 | #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION | |
1295 | long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) | |
1296 | { | |
1297 | int version = ipc_parse_version(&cmd); | |
1298 | ||
1299 | return ksys_shmctl(shmid, cmd, buf, version); | |
1300 | } | |
1301 | ||
1302 | SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) | |
1303 | { | |
1304 | return ksys_old_shmctl(shmid, cmd, buf); | |
c84d0791 | 1305 | } |
275f2214 | 1306 | #endif |
c84d0791 | 1307 | |
553f770e AV |
1308 | #ifdef CONFIG_COMPAT |
1309 | ||
1310 | struct compat_shmid_ds { | |
1311 | struct compat_ipc_perm shm_perm; | |
1312 | int shm_segsz; | |
9afc5eee AB |
1313 | old_time32_t shm_atime; |
1314 | old_time32_t shm_dtime; | |
1315 | old_time32_t shm_ctime; | |
553f770e AV |
1316 | compat_ipc_pid_t shm_cpid; |
1317 | compat_ipc_pid_t shm_lpid; | |
1318 | unsigned short shm_nattch; | |
1319 | unsigned short shm_unused; | |
1320 | compat_uptr_t shm_unused2; | |
1321 | compat_uptr_t shm_unused3; | |
1322 | }; | |
1da177e4 | 1323 | |
553f770e AV |
1324 | struct compat_shminfo64 { |
1325 | compat_ulong_t shmmax; | |
1326 | compat_ulong_t shmmin; | |
1327 | compat_ulong_t shmmni; | |
1328 | compat_ulong_t shmseg; | |
1329 | compat_ulong_t shmall; | |
1330 | compat_ulong_t __unused1; | |
1331 | compat_ulong_t __unused2; | |
1332 | compat_ulong_t __unused3; | |
1333 | compat_ulong_t __unused4; | |
1334 | }; | |
073115d6 | 1335 | |
553f770e AV |
1336 | struct compat_shm_info { |
1337 | compat_int_t used_ids; | |
1338 | compat_ulong_t shm_tot, shm_rss, shm_swp; | |
1339 | compat_ulong_t swap_attempts, swap_successes; | |
1340 | }; | |
0f3d2b01 | 1341 | |
553f770e AV |
1342 | static int copy_compat_shminfo_to_user(void __user *buf, struct shminfo64 *in, |
1343 | int version) | |
1344 | { | |
1345 | if (in->shmmax > INT_MAX) | |
1346 | in->shmmax = INT_MAX; | |
1347 | if (version == IPC_64) { | |
1348 | struct compat_shminfo64 info; | |
1349 | memset(&info, 0, sizeof(info)); | |
1350 | info.shmmax = in->shmmax; | |
1351 | info.shmmin = in->shmmin; | |
1352 | info.shmmni = in->shmmni; | |
1353 | info.shmseg = in->shmseg; | |
1354 | info.shmall = in->shmall; | |
1355 | return copy_to_user(buf, &info, sizeof(info)); | |
1356 | } else { | |
1357 | struct shminfo info; | |
1358 | memset(&info, 0, sizeof(info)); | |
1359 | info.shmmax = in->shmmax; | |
1360 | info.shmmin = in->shmmin; | |
1361 | info.shmmni = in->shmmni; | |
1362 | info.shmseg = in->shmseg; | |
1363 | info.shmall = in->shmall; | |
1364 | return copy_to_user(buf, &info, sizeof(info)); | |
1365 | } | |
1366 | } | |
0f3d2b01 | 1367 | |
553f770e AV |
1368 | static int put_compat_shm_info(struct shm_info *ip, |
1369 | struct compat_shm_info __user *uip) | |
1370 | { | |
1371 | struct compat_shm_info info; | |
1372 | ||
1373 | memset(&info, 0, sizeof(info)); | |
1374 | info.used_ids = ip->used_ids; | |
1375 | info.shm_tot = ip->shm_tot; | |
1376 | info.shm_rss = ip->shm_rss; | |
1377 | info.shm_swp = ip->shm_swp; | |
1378 | info.swap_attempts = ip->swap_attempts; | |
1379 | info.swap_successes = ip->swap_successes; | |
b776e4b1 | 1380 | return copy_to_user(uip, &info, sizeof(info)); |
553f770e | 1381 | } |
1da177e4 | 1382 | |
553f770e AV |
1383 | static int copy_compat_shmid_to_user(void __user *buf, struct shmid64_ds *in, |
1384 | int version) | |
1385 | { | |
1386 | if (version == IPC_64) { | |
1387 | struct compat_shmid64_ds v; | |
1388 | memset(&v, 0, sizeof(v)); | |
28327fae | 1389 | to_compat_ipc64_perm(&v.shm_perm, &in->shm_perm); |
c2ab975c AB |
1390 | v.shm_atime = lower_32_bits(in->shm_atime); |
1391 | v.shm_atime_high = upper_32_bits(in->shm_atime); | |
1392 | v.shm_dtime = lower_32_bits(in->shm_dtime); | |
1393 | v.shm_dtime_high = upper_32_bits(in->shm_dtime); | |
1394 | v.shm_ctime = lower_32_bits(in->shm_ctime); | |
1395 | v.shm_ctime_high = upper_32_bits(in->shm_ctime); | |
553f770e AV |
1396 | v.shm_segsz = in->shm_segsz; |
1397 | v.shm_nattch = in->shm_nattch; | |
1398 | v.shm_cpid = in->shm_cpid; | |
1399 | v.shm_lpid = in->shm_lpid; | |
1400 | return copy_to_user(buf, &v, sizeof(v)); | |
1401 | } else { | |
1402 | struct compat_shmid_ds v; | |
1403 | memset(&v, 0, sizeof(v)); | |
28327fae | 1404 | to_compat_ipc_perm(&v.shm_perm, &in->shm_perm); |
553f770e | 1405 | v.shm_perm.key = in->shm_perm.key; |
553f770e AV |
1406 | v.shm_atime = in->shm_atime; |
1407 | v.shm_dtime = in->shm_dtime; | |
1408 | v.shm_ctime = in->shm_ctime; | |
1409 | v.shm_segsz = in->shm_segsz; | |
1410 | v.shm_nattch = in->shm_nattch; | |
1411 | v.shm_cpid = in->shm_cpid; | |
1412 | v.shm_lpid = in->shm_lpid; | |
1413 | return copy_to_user(buf, &v, sizeof(v)); | |
1414 | } | |
1415 | } | |
85046579 | 1416 | |
553f770e AV |
1417 | static int copy_compat_shmid_from_user(struct shmid64_ds *out, void __user *buf, |
1418 | int version) | |
1419 | { | |
1420 | memset(out, 0, sizeof(*out)); | |
1421 | if (version == IPC_64) { | |
6aa211e8 | 1422 | struct compat_shmid64_ds __user *p = buf; |
28327fae | 1423 | return get_compat_ipc64_perm(&out->shm_perm, &p->shm_perm); |
553f770e | 1424 | } else { |
6aa211e8 | 1425 | struct compat_shmid_ds __user *p = buf; |
28327fae | 1426 | return get_compat_ipc_perm(&out->shm_perm, &p->shm_perm); |
553f770e | 1427 | } |
553f770e | 1428 | } |
63980c80 | 1429 | |
1cd377ba | 1430 | static long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr, int version) |
553f770e AV |
1431 | { |
1432 | struct ipc_namespace *ns; | |
1433 | struct shmid64_ds sem64; | |
553f770e | 1434 | int err; |
85046579 | 1435 | |
553f770e AV |
1436 | ns = current->nsproxy->ipc_ns; |
1437 | ||
1438 | if (cmd < 0 || shmid < 0) | |
1439 | return -EINVAL; | |
2caacaa8 | 1440 | |
553f770e AV |
1441 | switch (cmd) { |
1442 | case IPC_INFO: { | |
1443 | struct shminfo64 shminfo; | |
1444 | err = shmctl_ipc_info(ns, &shminfo); | |
1445 | if (err < 0) | |
1446 | return err; | |
1447 | if (copy_compat_shminfo_to_user(uptr, &shminfo, version)) | |
1448 | err = -EFAULT; | |
1449 | return err; | |
1450 | } | |
1451 | case SHM_INFO: { | |
1452 | struct shm_info shm_info; | |
1453 | err = shmctl_shm_info(ns, &shm_info); | |
1454 | if (err < 0) | |
1455 | return err; | |
1456 | if (put_compat_shm_info(&shm_info, uptr)) | |
1457 | err = -EFAULT; | |
8d4cc8b5 | 1458 | return err; |
2caacaa8 | 1459 | } |
553f770e | 1460 | case IPC_STAT: |
c21a6970 | 1461 | case SHM_STAT_ANY: |
553f770e AV |
1462 | case SHM_STAT: |
1463 | err = shmctl_stat(ns, shmid, cmd, &sem64); | |
1464 | if (err < 0) | |
1465 | return err; | |
58aff0af | 1466 | if (copy_compat_shmid_to_user(uptr, &sem64, version)) |
553f770e AV |
1467 | err = -EFAULT; |
1468 | return err; | |
1469 | ||
1470 | case IPC_SET: | |
1471 | if (copy_compat_shmid_from_user(&sem64, uptr, version)) | |
1472 | return -EFAULT; | |
df561f66 | 1473 | fallthrough; |
553f770e AV |
1474 | case IPC_RMID: |
1475 | return shmctl_down(ns, shmid, cmd, &sem64); | |
1476 | case SHM_LOCK: | |
1477 | case SHM_UNLOCK: | |
1478 | return shmctl_do_lock(ns, shmid, cmd); | |
1da177e4 | 1479 | default: |
8d4cc8b5 | 1480 | return -EINVAL; |
1da177e4 | 1481 | } |
1da177e4 LT |
1482 | return err; |
1483 | } | |
c84d0791 DB |
1484 | |
1485 | COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr) | |
1486 | { | |
275f2214 | 1487 | return compat_ksys_shmctl(shmid, cmd, uptr, IPC_64); |
c84d0791 | 1488 | } |
275f2214 AB |
1489 | |
1490 | #ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION | |
1491 | long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr) | |
1492 | { | |
1493 | int version = compat_ipc_parse_version(&cmd); | |
1494 | ||
1495 | return compat_ksys_shmctl(shmid, cmd, uptr, version); | |
1496 | } | |
1497 | ||
1498 | COMPAT_SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, void __user *, uptr) | |
1499 | { | |
1500 | return compat_ksys_old_shmctl(shmid, cmd, uptr); | |
1501 | } | |
1502 | #endif | |
553f770e | 1503 | #endif |
1da177e4 LT |
1504 | |
1505 | /* | |
1506 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
1507 | * | |
1508 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
1509 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
1510 | * this. | |
1511 | */ | |
95e91b83 DB |
1512 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, |
1513 | ulong *raddr, unsigned long shmlba) | |
1da177e4 LT |
1514 | { |
1515 | struct shmid_kernel *shp; | |
f0cb8802 | 1516 | unsigned long addr = (unsigned long)shmaddr; |
1da177e4 | 1517 | unsigned long size; |
4f089acc | 1518 | struct file *file, *base; |
1da177e4 | 1519 | int err; |
f0cb8802 | 1520 | unsigned long flags = MAP_SHARED; |
1da177e4 | 1521 | unsigned long prot; |
1da177e4 | 1522 | int acc_mode; |
4e982311 | 1523 | struct ipc_namespace *ns; |
bc56bba8 | 1524 | struct shm_file_data *sfd; |
c9c554f2 | 1525 | int f_flags; |
41badc15 | 1526 | unsigned long populate = 0; |
1da177e4 | 1527 | |
bc56bba8 EB |
1528 | err = -EINVAL; |
1529 | if (shmid < 0) | |
1da177e4 | 1530 | goto out; |
f0cb8802 DB |
1531 | |
1532 | if (addr) { | |
079a96ae | 1533 | if (addr & (shmlba - 1)) { |
8f89c007 | 1534 | if (shmflg & SHM_RND) { |
a73ab244 | 1535 | addr &= ~(shmlba - 1); /* round down */ |
8f89c007 DB |
1536 | |
1537 | /* | |
1538 | * Ensure that the round-down is non-nil | |
1539 | * when remapping. This can happen for | |
1540 | * cases when addr < shmlba. | |
1541 | */ | |
1542 | if (!addr && (shmflg & SHM_REMAP)) | |
1543 | goto out; | |
1544 | } else | |
1da177e4 LT |
1545 | #ifndef __ARCH_FORCE_SHMLBA |
1546 | if (addr & ~PAGE_MASK) | |
1547 | #endif | |
bc56bba8 | 1548 | goto out; |
1da177e4 | 1549 | } |
1da177e4 | 1550 | |
f0cb8802 DB |
1551 | flags |= MAP_FIXED; |
1552 | } else if ((shmflg & SHM_REMAP)) | |
1553 | goto out; | |
1da177e4 LT |
1554 | |
1555 | if (shmflg & SHM_RDONLY) { | |
1556 | prot = PROT_READ; | |
1da177e4 | 1557 | acc_mode = S_IRUGO; |
c9c554f2 | 1558 | f_flags = O_RDONLY; |
1da177e4 LT |
1559 | } else { |
1560 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 1561 | acc_mode = S_IRUGO | S_IWUGO; |
c9c554f2 | 1562 | f_flags = O_RDWR; |
1da177e4 LT |
1563 | } |
1564 | if (shmflg & SHM_EXEC) { | |
1565 | prot |= PROT_EXEC; | |
1566 | acc_mode |= S_IXUGO; | |
1567 | } | |
1568 | ||
1569 | /* | |
1570 | * We cannot rely on the fs check since SYSV IPC does have an | |
1571 | * additional creator id... | |
1572 | */ | |
4e982311 | 1573 | ns = current->nsproxy->ipc_ns; |
c2c737a0 DB |
1574 | rcu_read_lock(); |
1575 | shp = shm_obtain_object_check(ns, shmid); | |
023a5355 ND |
1576 | if (IS_ERR(shp)) { |
1577 | err = PTR_ERR(shp); | |
c2c737a0 | 1578 | goto out_unlock; |
023a5355 | 1579 | } |
bc56bba8 EB |
1580 | |
1581 | err = -EACCES; | |
b0e77598 | 1582 | if (ipcperms(ns, &shp->shm_perm, acc_mode)) |
bc56bba8 | 1583 | goto out_unlock; |
1da177e4 | 1584 | |
7191adff | 1585 | err = security_shm_shmat(&shp->shm_perm, shmaddr, shmflg); |
bc56bba8 EB |
1586 | if (err) |
1587 | goto out_unlock; | |
1588 | ||
c2c737a0 | 1589 | ipc_lock_object(&shp->shm_perm); |
a399b29d GT |
1590 | |
1591 | /* check if shm_destroy() is tearing down shp */ | |
0f3d2b01 | 1592 | if (!ipc_valid_object(&shp->shm_perm)) { |
a399b29d GT |
1593 | ipc_unlock_object(&shp->shm_perm); |
1594 | err = -EIDRM; | |
1595 | goto out_unlock; | |
1596 | } | |
1597 | ||
4f089acc AV |
1598 | /* |
1599 | * We need to take a reference to the real shm file to prevent the | |
1600 | * pointer from becoming stale in cases where the lifetime of the outer | |
1601 | * file extends beyond that of the shm segment. It's not usually | |
1602 | * possible, but it can happen during remap_file_pages() emulation as | |
1603 | * that unmaps the memory, then does ->mmap() via file reference only. | |
1604 | * We'll deny the ->mmap() if the shm segment was since removed, but to | |
1605 | * detect shm ID reuse we need to compare the file pointers. | |
1606 | */ | |
1607 | base = get_file(shp->shm_file); | |
1da177e4 | 1608 | shp->shm_nattch++; |
4f089acc | 1609 | size = i_size_read(file_inode(base)); |
c2c737a0 DB |
1610 | ipc_unlock_object(&shp->shm_perm); |
1611 | rcu_read_unlock(); | |
1da177e4 | 1612 | |
bc56bba8 EB |
1613 | err = -ENOMEM; |
1614 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
f42569b1 | 1615 | if (!sfd) { |
4f089acc | 1616 | fput(base); |
f42569b1 DB |
1617 | goto out_nattch; |
1618 | } | |
bc56bba8 | 1619 | |
4f089acc AV |
1620 | file = alloc_file_clone(base, f_flags, |
1621 | is_file_hugepages(base) ? | |
c4caa778 AV |
1622 | &shm_file_operations_huge : |
1623 | &shm_file_operations); | |
39b65252 | 1624 | err = PTR_ERR(file); |
f42569b1 DB |
1625 | if (IS_ERR(file)) { |
1626 | kfree(sfd); | |
4f089acc | 1627 | fput(base); |
f42569b1 DB |
1628 | goto out_nattch; |
1629 | } | |
bc56bba8 | 1630 | |
7ca7e564 | 1631 | sfd->id = shp->shm_perm.id; |
bc56bba8 | 1632 | sfd->ns = get_ipc_ns(ns); |
4f089acc | 1633 | sfd->file = base; |
bc56bba8 | 1634 | sfd->vm_ops = NULL; |
4f089acc | 1635 | file->private_data = sfd; |
bc56bba8 | 1636 | |
8b3ec681 AV |
1637 | err = security_mmap_file(file, prot, flags); |
1638 | if (err) | |
1639 | goto out_fput; | |
1640 | ||
d8ed45c5 | 1641 | if (mmap_write_lock_killable(current->mm)) { |
91f4f94e MH |
1642 | err = -EINTR; |
1643 | goto out_fput; | |
1644 | } | |
1645 | ||
1da177e4 | 1646 | if (addr && !(shmflg & SHM_REMAP)) { |
bc56bba8 | 1647 | err = -EINVAL; |
247a8ce8 MS |
1648 | if (addr + size < addr) |
1649 | goto invalid; | |
1650 | ||
1da177e4 LT |
1651 | if (find_vma_intersection(current->mm, addr, addr + size)) |
1652 | goto invalid; | |
1da177e4 | 1653 | } |
f42569b1 | 1654 | |
45e55300 | 1655 | addr = do_mmap(file, addr, size, prot, flags, 0, &populate, NULL); |
bebeb3d6 | 1656 | *raddr = addr; |
bc56bba8 | 1657 | err = 0; |
bebeb3d6 ML |
1658 | if (IS_ERR_VALUE(addr)) |
1659 | err = (long)addr; | |
1da177e4 | 1660 | invalid: |
d8ed45c5 | 1661 | mmap_write_unlock(current->mm); |
bebeb3d6 | 1662 | if (populate) |
41badc15 | 1663 | mm_populate(addr, populate); |
1da177e4 | 1664 | |
8b3ec681 | 1665 | out_fput: |
bc56bba8 EB |
1666 | fput(file); |
1667 | ||
1668 | out_nattch: | |
d9a605e4 | 1669 | down_write(&shm_ids(ns).rwsem); |
00c2bf85 | 1670 | shp = shm_lock(ns, shmid); |
1da177e4 | 1671 | shp->shm_nattch--; |
d17415bb AM |
1672 | |
1673 | if (shm_may_destroy(shp)) | |
4e982311 | 1674 | shm_destroy(ns, shp); |
1da177e4 LT |
1675 | else |
1676 | shm_unlock(shp); | |
d9a605e4 | 1677 | up_write(&shm_ids(ns).rwsem); |
1da177e4 | 1678 | return err; |
bc56bba8 EB |
1679 | |
1680 | out_unlock: | |
c2c737a0 | 1681 | rcu_read_unlock(); |
f42569b1 DB |
1682 | out: |
1683 | return err; | |
1da177e4 LT |
1684 | } |
1685 | ||
d5460c99 | 1686 | SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
7d87e14c SR |
1687 | { |
1688 | unsigned long ret; | |
1689 | long err; | |
1690 | ||
079a96ae | 1691 | err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA); |
7d87e14c SR |
1692 | if (err) |
1693 | return err; | |
1694 | force_successful_syscall_return(); | |
1695 | return (long)ret; | |
1696 | } | |
1697 | ||
a78ee9ed AV |
1698 | #ifdef CONFIG_COMPAT |
1699 | ||
1700 | #ifndef COMPAT_SHMLBA | |
1701 | #define COMPAT_SHMLBA SHMLBA | |
1702 | #endif | |
1703 | ||
1704 | COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg) | |
1705 | { | |
1706 | unsigned long ret; | |
1707 | long err; | |
1708 | ||
1709 | err = do_shmat(shmid, compat_ptr(shmaddr), shmflg, &ret, COMPAT_SHMLBA); | |
1710 | if (err) | |
1711 | return err; | |
1712 | force_successful_syscall_return(); | |
1713 | return (long)ret; | |
1714 | } | |
1715 | #endif | |
1716 | ||
1da177e4 LT |
1717 | /* |
1718 | * detach and kill segment if marked destroyed. | |
1719 | * The work is done in shm_close. | |
1720 | */ | |
da1e2744 | 1721 | long ksys_shmdt(char __user *shmaddr) |
1da177e4 LT |
1722 | { |
1723 | struct mm_struct *mm = current->mm; | |
586c7e6a | 1724 | struct vm_area_struct *vma; |
1da177e4 | 1725 | unsigned long addr = (unsigned long)shmaddr; |
1da177e4 | 1726 | int retval = -EINVAL; |
586c7e6a MF |
1727 | #ifdef CONFIG_MMU |
1728 | loff_t size = 0; | |
d3c97900 | 1729 | struct file *file; |
586c7e6a MF |
1730 | struct vm_area_struct *next; |
1731 | #endif | |
1da177e4 | 1732 | |
df1e2fb5 HD |
1733 | if (addr & ~PAGE_MASK) |
1734 | return retval; | |
1735 | ||
d8ed45c5 | 1736 | if (mmap_write_lock_killable(mm)) |
91f4f94e | 1737 | return -EINTR; |
1da177e4 LT |
1738 | |
1739 | /* | |
1740 | * This function tries to be smart and unmap shm segments that | |
1741 | * were modified by partial mlock or munmap calls: | |
1742 | * - It first determines the size of the shm segment that should be | |
1743 | * unmapped: It searches for a vma that is backed by shm and that | |
1744 | * started at address shmaddr. It records it's size and then unmaps | |
1745 | * it. | |
1746 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
d3c97900 DH |
1747 | * are within the initially determined size and that are from the |
1748 | * same shm segment from which we determined the size. | |
1da177e4 LT |
1749 | * Errors from do_munmap are ignored: the function only fails if |
1750 | * it's called with invalid parameters or if it's called to unmap | |
1751 | * a part of a vma. Both calls in this function are for full vmas, | |
1752 | * the parameters are directly copied from the vma itself and always | |
1753 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1754 | */ | |
1755 | /* | |
1756 | * If it had been mremap()'d, the starting address would not | |
1757 | * match the usual checks anyway. So assume all vma's are | |
1758 | * above the starting address given. | |
1759 | */ | |
1760 | vma = find_vma(mm, addr); | |
1761 | ||
8feae131 | 1762 | #ifdef CONFIG_MMU |
1da177e4 LT |
1763 | while (vma) { |
1764 | next = vma->vm_next; | |
1765 | ||
1766 | /* | |
1767 | * Check if the starting address would match, i.e. it's | |
1768 | * a fragment created by mprotect() and/or munmap(), or it | |
1769 | * otherwise it starts at this address with no hassles. | |
1770 | */ | |
bc56bba8 | 1771 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1772 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1773 | ||
d3c97900 DH |
1774 | /* |
1775 | * Record the file of the shm segment being | |
1776 | * unmapped. With mremap(), someone could place | |
1777 | * page from another segment but with equal offsets | |
1778 | * in the range we are unmapping. | |
1779 | */ | |
1780 | file = vma->vm_file; | |
07a46ed2 | 1781 | size = i_size_read(file_inode(vma->vm_file)); |
897ab3e0 | 1782 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); |
1da177e4 LT |
1783 | /* |
1784 | * We discovered the size of the shm segment, so | |
1785 | * break out of here and fall through to the next | |
1786 | * loop that uses the size information to stop | |
1787 | * searching for matching vma's. | |
1788 | */ | |
1789 | retval = 0; | |
1790 | vma = next; | |
1791 | break; | |
1792 | } | |
1793 | vma = next; | |
1794 | } | |
1795 | ||
1796 | /* | |
1797 | * We need look no further than the maximum address a fragment | |
1798 | * could possibly have landed at. Also cast things to loff_t to | |
25985edc | 1799 | * prevent overflows and make comparisons vs. equal-width types. |
1da177e4 | 1800 | */ |
8e36709d | 1801 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1802 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1803 | next = vma->vm_next; | |
1804 | ||
1805 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1806 | if ((vma->vm_ops == &shm_vm_ops) && |
d3c97900 DH |
1807 | ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) && |
1808 | (vma->vm_file == file)) | |
897ab3e0 | 1809 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); |
1da177e4 LT |
1810 | vma = next; |
1811 | } | |
1812 | ||
63980c80 | 1813 | #else /* CONFIG_MMU */ |
8feae131 | 1814 | /* under NOMMU conditions, the exact address to be destroyed must be |
63980c80 SP |
1815 | * given |
1816 | */ | |
530fcd16 | 1817 | if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { |
897ab3e0 | 1818 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); |
8feae131 DH |
1819 | retval = 0; |
1820 | } | |
1821 | ||
1822 | #endif | |
1823 | ||
d8ed45c5 | 1824 | mmap_write_unlock(mm); |
1da177e4 LT |
1825 | return retval; |
1826 | } | |
1827 | ||
da1e2744 DB |
1828 | SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
1829 | { | |
1830 | return ksys_shmdt(shmaddr); | |
1831 | } | |
1832 | ||
1da177e4 | 1833 | #ifdef CONFIG_PROC_FS |
19b4946c | 1834 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1835 | { |
98f929b1 | 1836 | struct pid_namespace *pid_ns = ipc_seq_pid_ns(s); |
1efdb69b | 1837 | struct user_namespace *user_ns = seq_user_ns(s); |
ade9f91b KC |
1838 | struct kern_ipc_perm *ipcp = it; |
1839 | struct shmid_kernel *shp; | |
b7952180 HD |
1840 | unsigned long rss = 0, swp = 0; |
1841 | ||
ade9f91b | 1842 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
b7952180 | 1843 | shm_add_rss_swap(shp, &rss, &swp); |
1da177e4 | 1844 | |
6c826818 PM |
1845 | #if BITS_PER_LONG <= 32 |
1846 | #define SIZE_SPEC "%10lu" | |
1847 | #else | |
1848 | #define SIZE_SPEC "%21lu" | |
1849 | #endif | |
1da177e4 | 1850 | |
7f032d6e JP |
1851 | seq_printf(s, |
1852 | "%10d %10d %4o " SIZE_SPEC " %5u %5u " | |
7ff2819e | 1853 | "%5lu %5u %5u %5u %5u %10llu %10llu %10llu " |
7f032d6e JP |
1854 | SIZE_SPEC " " SIZE_SPEC "\n", |
1855 | shp->shm_perm.key, | |
1856 | shp->shm_perm.id, | |
1857 | shp->shm_perm.mode, | |
1858 | shp->shm_segsz, | |
98f929b1 EB |
1859 | pid_nr_ns(shp->shm_cprid, pid_ns), |
1860 | pid_nr_ns(shp->shm_lprid, pid_ns), | |
7f032d6e JP |
1861 | shp->shm_nattch, |
1862 | from_kuid_munged(user_ns, shp->shm_perm.uid), | |
1863 | from_kgid_munged(user_ns, shp->shm_perm.gid), | |
1864 | from_kuid_munged(user_ns, shp->shm_perm.cuid), | |
1865 | from_kgid_munged(user_ns, shp->shm_perm.cgid), | |
1866 | shp->shm_atim, | |
1867 | shp->shm_dtim, | |
1868 | shp->shm_ctim, | |
1869 | rss * PAGE_SIZE, | |
1870 | swp * PAGE_SIZE); | |
1871 | ||
1872 | return 0; | |
1da177e4 LT |
1873 | } |
1874 | #endif |