Commit | Line | Data |
---|---|---|
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> | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/slab.h> |
25 | #include <linux/mm.h> | |
26 | #include <linux/hugetlb.h> | |
27 | #include <linux/shm.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/file.h> | |
30 | #include <linux/mman.h> | |
1da177e4 LT |
31 | #include <linux/shmem_fs.h> |
32 | #include <linux/security.h> | |
33 | #include <linux/syscalls.h> | |
34 | #include <linux/audit.h> | |
c59ede7b | 35 | #include <linux/capability.h> |
7d87e14c | 36 | #include <linux/ptrace.h> |
19b4946c | 37 | #include <linux/seq_file.h> |
3e148c79 | 38 | #include <linux/rwsem.h> |
4e982311 | 39 | #include <linux/nsproxy.h> |
bc56bba8 | 40 | #include <linux/mount.h> |
ae5e1b22 | 41 | #include <linux/ipc_namespace.h> |
7d87e14c | 42 | |
1da177e4 LT |
43 | #include <asm/uaccess.h> |
44 | ||
45 | #include "util.h" | |
46 | ||
bc56bba8 EB |
47 | struct shm_file_data { |
48 | int id; | |
49 | struct ipc_namespace *ns; | |
50 | struct file *file; | |
51 | const struct vm_operations_struct *vm_ops; | |
52 | }; | |
53 | ||
54 | #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) | |
55 | ||
9a32144e | 56 | static const struct file_operations shm_file_operations; |
f0f37e2f | 57 | static const struct vm_operations_struct shm_vm_ops; |
1da177e4 | 58 | |
ed2ddbf8 | 59 | #define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
1da177e4 | 60 | |
4e982311 KK |
61 | #define shm_unlock(shp) \ |
62 | ipc_unlock(&(shp)->shm_perm) | |
1da177e4 | 63 | |
7748dbfa | 64 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
bc56bba8 EB |
65 | static void shm_open(struct vm_area_struct *vma); |
66 | static void shm_close(struct vm_area_struct *vma); | |
4e982311 | 67 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
1da177e4 | 68 | #ifdef CONFIG_PROC_FS |
19b4946c | 69 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
1da177e4 LT |
70 | #endif |
71 | ||
ed2ddbf8 | 72 | void shm_init_ns(struct ipc_namespace *ns) |
4e982311 | 73 | { |
4e982311 KK |
74 | ns->shm_ctlmax = SHMMAX; |
75 | ns->shm_ctlall = SHMALL; | |
76 | ns->shm_ctlmni = SHMMNI; | |
b34a6b1d | 77 | ns->shm_rmid_forced = 0; |
4e982311 | 78 | ns->shm_tot = 0; |
e8148f75 | 79 | ipc_init_ids(&shm_ids(ns)); |
4e982311 KK |
80 | } |
81 | ||
f4566f04 | 82 | /* |
3e148c79 ND |
83 | * Called with shm_ids.rw_mutex (writer) and the shp structure locked. |
84 | * Only shm_ids.rw_mutex remains locked on exit. | |
f4566f04 | 85 | */ |
01b8b07a | 86 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
4e982311 | 87 | { |
01b8b07a PP |
88 | struct shmid_kernel *shp; |
89 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
90 | ||
4e982311 KK |
91 | if (shp->shm_nattch){ |
92 | shp->shm_perm.mode |= SHM_DEST; | |
93 | /* Do not find it any more */ | |
94 | shp->shm_perm.key = IPC_PRIVATE; | |
95 | shm_unlock(shp); | |
96 | } else | |
97 | shm_destroy(ns, shp); | |
98 | } | |
99 | ||
ae5e1b22 | 100 | #ifdef CONFIG_IPC_NS |
4e982311 KK |
101 | void shm_exit_ns(struct ipc_namespace *ns) |
102 | { | |
01b8b07a | 103 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
7d6feeb2 | 104 | idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
4e982311 | 105 | } |
ae5e1b22 | 106 | #endif |
1da177e4 LT |
107 | |
108 | void __init shm_init (void) | |
109 | { | |
ed2ddbf8 | 110 | shm_init_ns(&init_ipc_ns); |
19b4946c | 111 | ipc_init_proc_interface("sysvipc/shm", |
b7952180 HD |
112 | #if BITS_PER_LONG <= 32 |
113 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", | |
114 | #else | |
115 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", | |
116 | #endif | |
4e982311 | 117 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
1da177e4 LT |
118 | } |
119 | ||
3e148c79 ND |
120 | /* |
121 | * shm_lock_(check_) routines are called in the paths where the rw_mutex | |
00c2bf85 | 122 | * is not necessarily held. |
3e148c79 | 123 | */ |
023a5355 | 124 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
1da177e4 | 125 | { |
03f02c76 ND |
126 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
127 | ||
b1ed88b4 PP |
128 | if (IS_ERR(ipcp)) |
129 | return (struct shmid_kernel *)ipcp; | |
130 | ||
03f02c76 | 131 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
023a5355 ND |
132 | } |
133 | ||
134 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, | |
135 | int id) | |
136 | { | |
03f02c76 ND |
137 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
138 | ||
b1ed88b4 PP |
139 | if (IS_ERR(ipcp)) |
140 | return (struct shmid_kernel *)ipcp; | |
141 | ||
03f02c76 | 142 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
1da177e4 LT |
143 | } |
144 | ||
7ca7e564 | 145 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
1da177e4 | 146 | { |
7ca7e564 | 147 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
1da177e4 LT |
148 | } |
149 | ||
1da177e4 | 150 | |
bc56bba8 EB |
151 | /* This is called by fork, once for every shm attach. */ |
152 | static void shm_open(struct vm_area_struct *vma) | |
4e982311 | 153 | { |
bc56bba8 EB |
154 | struct file *file = vma->vm_file; |
155 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 LT |
156 | struct shmid_kernel *shp; |
157 | ||
bc56bba8 | 158 | shp = shm_lock(sfd->ns, sfd->id); |
023a5355 | 159 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 160 | shp->shm_atim = get_seconds(); |
b488893a | 161 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
162 | shp->shm_nattch++; |
163 | shm_unlock(shp); | |
164 | } | |
165 | ||
1da177e4 LT |
166 | /* |
167 | * shm_destroy - free the struct shmid_kernel | |
168 | * | |
f4566f04 | 169 | * @ns: namespace |
1da177e4 LT |
170 | * @shp: struct to free |
171 | * | |
3e148c79 | 172 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
1da177e4 LT |
173 | * but returns with shp unlocked and freed. |
174 | */ | |
4e982311 | 175 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
1da177e4 | 176 | { |
4e982311 | 177 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
7ca7e564 | 178 | shm_rmid(ns, shp); |
1da177e4 LT |
179 | shm_unlock(shp); |
180 | if (!is_file_hugepages(shp->shm_file)) | |
181 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
353d5c30 | 182 | else if (shp->mlock_user) |
6d63079a | 183 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
1da177e4 LT |
184 | shp->mlock_user); |
185 | fput (shp->shm_file); | |
186 | security_shm_free(shp); | |
187 | ipc_rcu_putref(shp); | |
188 | } | |
189 | ||
b34a6b1d VK |
190 | /* |
191 | * shm_may_destroy - identifies whether shm segment should be destroyed now | |
192 | * | |
193 | * Returns true if and only if there are no active users of the segment and | |
194 | * one of the following is true: | |
195 | * | |
196 | * 1) shmctl(id, IPC_RMID, NULL) was called for this shp | |
197 | * | |
198 | * 2) sysctl kernel.shm_rmid_forced is set to 1. | |
199 | */ | |
200 | static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) | |
201 | { | |
202 | return (shp->shm_nattch == 0) && | |
203 | (ns->shm_rmid_forced || | |
204 | (shp->shm_perm.mode & SHM_DEST)); | |
205 | } | |
206 | ||
1da177e4 | 207 | /* |
bc56bba8 | 208 | * remove the attach descriptor vma. |
1da177e4 LT |
209 | * free memory for segment if it is marked destroyed. |
210 | * The descriptor has already been removed from the current->mm->mmap list | |
211 | * and will later be kfree()d. | |
212 | */ | |
bc56bba8 | 213 | static void shm_close(struct vm_area_struct *vma) |
1da177e4 | 214 | { |
bc56bba8 EB |
215 | struct file * file = vma->vm_file; |
216 | struct shm_file_data *sfd = shm_file_data(file); | |
1da177e4 | 217 | struct shmid_kernel *shp; |
bc56bba8 | 218 | struct ipc_namespace *ns = sfd->ns; |
4e982311 | 219 | |
3e148c79 | 220 | down_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 221 | /* remove from the list of attaches of the shm segment */ |
00c2bf85 | 222 | shp = shm_lock(ns, sfd->id); |
023a5355 | 223 | BUG_ON(IS_ERR(shp)); |
b488893a | 224 | shp->shm_lprid = task_tgid_vnr(current); |
1da177e4 LT |
225 | shp->shm_dtim = get_seconds(); |
226 | shp->shm_nattch--; | |
b34a6b1d VK |
227 | if (shm_may_destroy(ns, shp)) |
228 | shm_destroy(ns, shp); | |
229 | else | |
230 | shm_unlock(shp); | |
231 | up_write(&shm_ids(ns).rw_mutex); | |
232 | } | |
233 | ||
234 | static int shm_try_destroy_current(int id, void *p, void *data) | |
235 | { | |
236 | struct ipc_namespace *ns = data; | |
237 | struct shmid_kernel *shp = shm_lock(ns, id); | |
238 | ||
239 | if (IS_ERR(shp)) | |
240 | return 0; | |
241 | ||
5774ed01 VK |
242 | if (shp->shm_creator != current) { |
243 | shm_unlock(shp); | |
244 | return 0; | |
245 | } | |
246 | ||
247 | /* | |
248 | * Mark it as orphaned to destroy the segment when | |
249 | * kernel.shm_rmid_forced is changed. | |
250 | * It is noop if the following shm_may_destroy() returns true. | |
251 | */ | |
252 | shp->shm_creator = NULL; | |
253 | ||
254 | /* | |
255 | * Don't even try to destroy it. If shm_rmid_forced=0 and IPC_RMID | |
256 | * is not set, it shouldn't be deleted here. | |
257 | */ | |
258 | if (!ns->shm_rmid_forced) { | |
b34a6b1d VK |
259 | shm_unlock(shp); |
260 | return 0; | |
261 | } | |
262 | ||
263 | if (shm_may_destroy(ns, shp)) | |
264 | shm_destroy(ns, shp); | |
265 | else | |
266 | shm_unlock(shp); | |
267 | return 0; | |
268 | } | |
269 | ||
270 | static int shm_try_destroy_orphaned(int id, void *p, void *data) | |
271 | { | |
272 | struct ipc_namespace *ns = data; | |
273 | struct shmid_kernel *shp = shm_lock(ns, id); | |
b34a6b1d VK |
274 | |
275 | if (IS_ERR(shp)) | |
276 | return 0; | |
277 | ||
278 | /* | |
279 | * We want to destroy segments without users and with already | |
280 | * exit'ed originating process. | |
b34a6b1d | 281 | */ |
5774ed01 | 282 | if (shp->shm_creator != NULL) { |
b34a6b1d VK |
283 | shm_unlock(shp); |
284 | return 0; | |
285 | } | |
286 | ||
287 | if (shm_may_destroy(ns, shp)) | |
4e982311 | 288 | shm_destroy(ns, shp); |
1da177e4 LT |
289 | else |
290 | shm_unlock(shp); | |
b34a6b1d VK |
291 | return 0; |
292 | } | |
293 | ||
294 | void shm_destroy_orphaned(struct ipc_namespace *ns) | |
295 | { | |
296 | down_write(&shm_ids(ns).rw_mutex); | |
297 | idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns); | |
298 | up_write(&shm_ids(ns).rw_mutex); | |
299 | } | |
300 | ||
301 | ||
302 | void exit_shm(struct task_struct *task) | |
303 | { | |
304 | struct nsproxy *nsp = task->nsproxy; | |
305 | struct ipc_namespace *ns; | |
306 | ||
307 | if (!nsp) | |
308 | return; | |
309 | ns = nsp->ipc_ns; | |
5774ed01 | 310 | if (!ns) |
b34a6b1d VK |
311 | return; |
312 | ||
313 | /* Destroy all already created segments, but not mapped yet */ | |
314 | down_write(&shm_ids(ns).rw_mutex); | |
315 | idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_current, ns); | |
3e148c79 | 316 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 LT |
317 | } |
318 | ||
d0217ac0 | 319 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
bc56bba8 EB |
320 | { |
321 | struct file *file = vma->vm_file; | |
322 | struct shm_file_data *sfd = shm_file_data(file); | |
323 | ||
d0217ac0 | 324 | return sfd->vm_ops->fault(vma, vmf); |
bc56bba8 EB |
325 | } |
326 | ||
327 | #ifdef CONFIG_NUMA | |
d823e3e7 | 328 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
bc56bba8 EB |
329 | { |
330 | struct file *file = vma->vm_file; | |
331 | struct shm_file_data *sfd = shm_file_data(file); | |
332 | int err = 0; | |
333 | if (sfd->vm_ops->set_policy) | |
334 | err = sfd->vm_ops->set_policy(vma, new); | |
335 | return err; | |
336 | } | |
337 | ||
d823e3e7 AB |
338 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
339 | unsigned long addr) | |
bc56bba8 EB |
340 | { |
341 | struct file *file = vma->vm_file; | |
342 | struct shm_file_data *sfd = shm_file_data(file); | |
343 | struct mempolicy *pol = NULL; | |
344 | ||
345 | if (sfd->vm_ops->get_policy) | |
346 | pol = sfd->vm_ops->get_policy(vma, addr); | |
52cd3b07 | 347 | else if (vma->vm_policy) |
bc56bba8 | 348 | pol = vma->vm_policy; |
52cd3b07 | 349 | |
bc56bba8 EB |
350 | return pol; |
351 | } | |
352 | #endif | |
353 | ||
1da177e4 LT |
354 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
355 | { | |
bc56bba8 | 356 | struct shm_file_data *sfd = shm_file_data(file); |
b0e15190 DH |
357 | int ret; |
358 | ||
bc56bba8 EB |
359 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
360 | if (ret != 0) | |
361 | return ret; | |
362 | sfd->vm_ops = vma->vm_ops; | |
2e92a3ba | 363 | #ifdef CONFIG_MMU |
54cb8821 | 364 | BUG_ON(!sfd->vm_ops->fault); |
2e92a3ba | 365 | #endif |
bc56bba8 EB |
366 | vma->vm_ops = &shm_vm_ops; |
367 | shm_open(vma); | |
b0e15190 DH |
368 | |
369 | return ret; | |
1da177e4 LT |
370 | } |
371 | ||
4e982311 KK |
372 | static int shm_release(struct inode *ino, struct file *file) |
373 | { | |
bc56bba8 | 374 | struct shm_file_data *sfd = shm_file_data(file); |
4e982311 | 375 | |
bc56bba8 EB |
376 | put_ipc_ns(sfd->ns); |
377 | shm_file_data(file) = NULL; | |
378 | kfree(sfd); | |
4e982311 KK |
379 | return 0; |
380 | } | |
381 | ||
02c24a82 | 382 | static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
516dffdc | 383 | { |
516dffdc | 384 | struct shm_file_data *sfd = shm_file_data(file); |
516dffdc | 385 | |
7ea80859 CH |
386 | if (!sfd->file->f_op->fsync) |
387 | return -EINVAL; | |
02c24a82 | 388 | return sfd->file->f_op->fsync(sfd->file, start, end, datasync); |
516dffdc AL |
389 | } |
390 | ||
bc56bba8 EB |
391 | static unsigned long shm_get_unmapped_area(struct file *file, |
392 | unsigned long addr, unsigned long len, unsigned long pgoff, | |
393 | unsigned long flags) | |
394 | { | |
395 | struct shm_file_data *sfd = shm_file_data(file); | |
c4caa778 AV |
396 | return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
397 | pgoff, flags); | |
bc56bba8 | 398 | } |
bc56bba8 | 399 | |
9a32144e | 400 | static const struct file_operations shm_file_operations = { |
4e982311 | 401 | .mmap = shm_mmap, |
516dffdc | 402 | .fsync = shm_fsync, |
4e982311 | 403 | .release = shm_release, |
ed5e5894 DH |
404 | #ifndef CONFIG_MMU |
405 | .get_unmapped_area = shm_get_unmapped_area, | |
406 | #endif | |
6038f373 | 407 | .llseek = noop_llseek, |
c4caa778 AV |
408 | }; |
409 | ||
410 | static const struct file_operations shm_file_operations_huge = { | |
411 | .mmap = shm_mmap, | |
412 | .fsync = shm_fsync, | |
413 | .release = shm_release, | |
bc56bba8 | 414 | .get_unmapped_area = shm_get_unmapped_area, |
6038f373 | 415 | .llseek = noop_llseek, |
1da177e4 LT |
416 | }; |
417 | ||
c4caa778 AV |
418 | int is_file_shm_hugepages(struct file *file) |
419 | { | |
420 | return file->f_op == &shm_file_operations_huge; | |
421 | } | |
422 | ||
f0f37e2f | 423 | static const struct vm_operations_struct shm_vm_ops = { |
1da177e4 LT |
424 | .open = shm_open, /* callback for a new vm-area open */ |
425 | .close = shm_close, /* callback for when the vm-area is released */ | |
54cb8821 | 426 | .fault = shm_fault, |
bc56bba8 EB |
427 | #if defined(CONFIG_NUMA) |
428 | .set_policy = shm_set_policy, | |
429 | .get_policy = shm_get_policy, | |
1da177e4 LT |
430 | #endif |
431 | }; | |
432 | ||
f4566f04 ND |
433 | /** |
434 | * newseg - Create a new shared memory segment | |
435 | * @ns: namespace | |
436 | * @params: ptr to the structure that contains key, size and shmflg | |
437 | * | |
3e148c79 | 438 | * Called with shm_ids.rw_mutex held as a writer. |
f4566f04 ND |
439 | */ |
440 | ||
7748dbfa | 441 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 442 | { |
7748dbfa ND |
443 | key_t key = params->key; |
444 | int shmflg = params->flg; | |
445 | size_t size = params->u.size; | |
1da177e4 LT |
446 | int error; |
447 | struct shmid_kernel *shp; | |
448 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; | |
449 | struct file * file; | |
450 | char name[13]; | |
451 | int id; | |
ca16d140 | 452 | vm_flags_t acctflag = 0; |
1da177e4 | 453 | |
4e982311 | 454 | if (size < SHMMIN || size > ns->shm_ctlmax) |
1da177e4 LT |
455 | return -EINVAL; |
456 | ||
f66d45e9 | 457 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
1da177e4 LT |
458 | return -ENOSPC; |
459 | ||
460 | shp = ipc_rcu_alloc(sizeof(*shp)); | |
461 | if (!shp) | |
462 | return -ENOMEM; | |
463 | ||
464 | shp->shm_perm.key = key; | |
b33291c0 | 465 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
1da177e4 LT |
466 | shp->mlock_user = NULL; |
467 | ||
468 | shp->shm_perm.security = NULL; | |
469 | error = security_shm_alloc(shp); | |
470 | if (error) { | |
471 | ipc_rcu_putref(shp); | |
472 | return error; | |
473 | } | |
474 | ||
9d66586f | 475 | sprintf (name, "SYSV%08x", key); |
1da177e4 | 476 | if (shmflg & SHM_HUGETLB) { |
5a6fe125 MG |
477 | /* hugetlb_file_setup applies strict accounting */ |
478 | if (shmflg & SHM_NORESERVE) | |
479 | acctflag = VM_NORESERVE; | |
353d5c30 | 480 | file = hugetlb_file_setup(name, size, acctflag, |
6bfde05b | 481 | &shp->mlock_user, HUGETLB_SHMFS_INODE); |
1da177e4 | 482 | } else { |
bf8f972d BP |
483 | /* |
484 | * Do not allow no accounting for OVERCOMMIT_NEVER, even | |
485 | * if it's asked for. | |
486 | */ | |
487 | if ((shmflg & SHM_NORESERVE) && | |
488 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) | |
fc8744ad | 489 | acctflag = VM_NORESERVE; |
bf8f972d | 490 | file = shmem_file_setup(name, size, acctflag); |
1da177e4 LT |
491 | } |
492 | error = PTR_ERR(file); | |
493 | if (IS_ERR(file)) | |
494 | goto no_file; | |
495 | ||
48dea404 | 496 | id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
283bb7fa PP |
497 | if (id < 0) { |
498 | error = id; | |
1da177e4 | 499 | goto no_id; |
283bb7fa | 500 | } |
1da177e4 | 501 | |
b488893a | 502 | shp->shm_cprid = task_tgid_vnr(current); |
1da177e4 LT |
503 | shp->shm_lprid = 0; |
504 | shp->shm_atim = shp->shm_dtim = 0; | |
505 | shp->shm_ctim = get_seconds(); | |
506 | shp->shm_segsz = size; | |
507 | shp->shm_nattch = 0; | |
1da177e4 | 508 | shp->shm_file = file; |
5774ed01 | 509 | shp->shm_creator = current; |
30475cc1 BP |
510 | /* |
511 | * shmid gets reported as "inode#" in /proc/pid/maps. | |
512 | * proc-ps tools use this. Changing this will break them. | |
513 | */ | |
7ca7e564 | 514 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
551110a9 | 515 | |
4e982311 | 516 | ns->shm_tot += numpages; |
7ca7e564 | 517 | error = shp->shm_perm.id; |
1da177e4 | 518 | shm_unlock(shp); |
7ca7e564 | 519 | return error; |
1da177e4 LT |
520 | |
521 | no_id: | |
2195d281 | 522 | if (is_file_hugepages(file) && shp->mlock_user) |
353d5c30 | 523 | user_shm_unlock(size, shp->mlock_user); |
1da177e4 LT |
524 | fput(file); |
525 | no_file: | |
526 | security_shm_free(shp); | |
527 | ipc_rcu_putref(shp); | |
528 | return error; | |
529 | } | |
530 | ||
f4566f04 | 531 | /* |
3e148c79 | 532 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 533 | */ |
03f02c76 | 534 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
7748dbfa | 535 | { |
03f02c76 ND |
536 | struct shmid_kernel *shp; |
537 | ||
538 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
539 | return security_shm_associate(shp, shmflg); | |
7748dbfa ND |
540 | } |
541 | ||
f4566f04 | 542 | /* |
3e148c79 | 543 | * Called with shm_ids.rw_mutex and ipcp locked. |
f4566f04 | 544 | */ |
03f02c76 ND |
545 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
546 | struct ipc_params *params) | |
7748dbfa | 547 | { |
03f02c76 ND |
548 | struct shmid_kernel *shp; |
549 | ||
550 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); | |
551 | if (shp->shm_segsz < params->u.size) | |
7748dbfa ND |
552 | return -EINVAL; |
553 | ||
554 | return 0; | |
555 | } | |
556 | ||
d5460c99 | 557 | SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
1da177e4 | 558 | { |
4e982311 | 559 | struct ipc_namespace *ns; |
7748dbfa ND |
560 | struct ipc_ops shm_ops; |
561 | struct ipc_params shm_params; | |
4e982311 KK |
562 | |
563 | ns = current->nsproxy->ipc_ns; | |
1da177e4 | 564 | |
7748dbfa ND |
565 | shm_ops.getnew = newseg; |
566 | shm_ops.associate = shm_security; | |
567 | shm_ops.more_checks = shm_more_checks; | |
7ca7e564 | 568 | |
7748dbfa ND |
569 | shm_params.key = key; |
570 | shm_params.flg = shmflg; | |
571 | shm_params.u.size = size; | |
1da177e4 | 572 | |
7748dbfa | 573 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4 LT |
574 | } |
575 | ||
576 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) | |
577 | { | |
578 | switch(version) { | |
579 | case IPC_64: | |
580 | return copy_to_user(buf, in, sizeof(*in)); | |
581 | case IPC_OLD: | |
582 | { | |
583 | struct shmid_ds out; | |
584 | ||
3af54c9b | 585 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
586 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); |
587 | out.shm_segsz = in->shm_segsz; | |
588 | out.shm_atime = in->shm_atime; | |
589 | out.shm_dtime = in->shm_dtime; | |
590 | out.shm_ctime = in->shm_ctime; | |
591 | out.shm_cpid = in->shm_cpid; | |
592 | out.shm_lpid = in->shm_lpid; | |
593 | out.shm_nattch = in->shm_nattch; | |
594 | ||
595 | return copy_to_user(buf, &out, sizeof(out)); | |
596 | } | |
597 | default: | |
598 | return -EINVAL; | |
599 | } | |
600 | } | |
601 | ||
016d7132 PP |
602 | static inline unsigned long |
603 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) | |
1da177e4 LT |
604 | { |
605 | switch(version) { | |
606 | case IPC_64: | |
016d7132 | 607 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 608 | return -EFAULT; |
1da177e4 | 609 | return 0; |
1da177e4 LT |
610 | case IPC_OLD: |
611 | { | |
612 | struct shmid_ds tbuf_old; | |
613 | ||
614 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) | |
615 | return -EFAULT; | |
616 | ||
016d7132 PP |
617 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
618 | out->shm_perm.gid = tbuf_old.shm_perm.gid; | |
619 | out->shm_perm.mode = tbuf_old.shm_perm.mode; | |
1da177e4 LT |
620 | |
621 | return 0; | |
622 | } | |
623 | default: | |
624 | return -EINVAL; | |
625 | } | |
626 | } | |
627 | ||
628 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) | |
629 | { | |
630 | switch(version) { | |
631 | case IPC_64: | |
632 | return copy_to_user(buf, in, sizeof(*in)); | |
633 | case IPC_OLD: | |
634 | { | |
635 | struct shminfo out; | |
636 | ||
637 | if(in->shmmax > INT_MAX) | |
638 | out.shmmax = INT_MAX; | |
639 | else | |
640 | out.shmmax = (int)in->shmmax; | |
641 | ||
642 | out.shmmin = in->shmmin; | |
643 | out.shmmni = in->shmmni; | |
644 | out.shmseg = in->shmseg; | |
645 | out.shmall = in->shmall; | |
646 | ||
647 | return copy_to_user(buf, &out, sizeof(out)); | |
648 | } | |
649 | default: | |
650 | return -EINVAL; | |
651 | } | |
652 | } | |
653 | ||
b7952180 HD |
654 | /* |
655 | * Calculate and add used RSS and swap pages of a shm. | |
656 | * Called with shm_ids.rw_mutex held as a reader | |
657 | */ | |
658 | static void shm_add_rss_swap(struct shmid_kernel *shp, | |
659 | unsigned long *rss_add, unsigned long *swp_add) | |
660 | { | |
661 | struct inode *inode; | |
662 | ||
663 | inode = shp->shm_file->f_path.dentry->d_inode; | |
664 | ||
665 | if (is_file_hugepages(shp->shm_file)) { | |
666 | struct address_space *mapping = inode->i_mapping; | |
667 | struct hstate *h = hstate_file(shp->shm_file); | |
668 | *rss_add += pages_per_huge_page(h) * mapping->nrpages; | |
669 | } else { | |
670 | #ifdef CONFIG_SHMEM | |
671 | struct shmem_inode_info *info = SHMEM_I(inode); | |
672 | spin_lock(&info->lock); | |
673 | *rss_add += inode->i_mapping->nrpages; | |
674 | *swp_add += info->swapped; | |
675 | spin_unlock(&info->lock); | |
676 | #else | |
677 | *rss_add += inode->i_mapping->nrpages; | |
678 | #endif | |
679 | } | |
680 | } | |
681 | ||
f4566f04 | 682 | /* |
3e148c79 | 683 | * Called with shm_ids.rw_mutex held as a reader |
f4566f04 | 684 | */ |
4e982311 KK |
685 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
686 | unsigned long *swp) | |
1da177e4 | 687 | { |
7ca7e564 ND |
688 | int next_id; |
689 | int total, in_use; | |
1da177e4 LT |
690 | |
691 | *rss = 0; | |
692 | *swp = 0; | |
693 | ||
7ca7e564 ND |
694 | in_use = shm_ids(ns).in_use; |
695 | ||
696 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
e562aebc | 697 | struct kern_ipc_perm *ipc; |
1da177e4 | 698 | struct shmid_kernel *shp; |
1da177e4 | 699 | |
e562aebc TB |
700 | ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
701 | if (ipc == NULL) | |
1da177e4 | 702 | continue; |
e562aebc | 703 | shp = container_of(ipc, struct shmid_kernel, shm_perm); |
1da177e4 | 704 | |
b7952180 | 705 | shm_add_rss_swap(shp, rss, swp); |
7ca7e564 ND |
706 | |
707 | total++; | |
1da177e4 LT |
708 | } |
709 | } | |
710 | ||
8d4cc8b5 PP |
711 | /* |
712 | * This function handles some shmctl commands which require the rw_mutex | |
713 | * to be held in write mode. | |
714 | * NOTE: no locks must be held, the rw_mutex is taken inside this function. | |
715 | */ | |
716 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, | |
717 | struct shmid_ds __user *buf, int version) | |
1da177e4 | 718 | { |
8d4cc8b5 | 719 | struct kern_ipc_perm *ipcp; |
016d7132 | 720 | struct shmid64_ds shmid64; |
8d4cc8b5 PP |
721 | struct shmid_kernel *shp; |
722 | int err; | |
723 | ||
724 | if (cmd == IPC_SET) { | |
016d7132 | 725 | if (copy_shmid_from_user(&shmid64, buf, version)) |
8d4cc8b5 PP |
726 | return -EFAULT; |
727 | } | |
728 | ||
b0e77598 SH |
729 | ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd, |
730 | &shmid64.shm_perm, 0); | |
a5f75e7f PP |
731 | if (IS_ERR(ipcp)) |
732 | return PTR_ERR(ipcp); | |
8d4cc8b5 | 733 | |
a5f75e7f | 734 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
8d4cc8b5 PP |
735 | |
736 | err = security_shm_shmctl(shp, cmd); | |
737 | if (err) | |
738 | goto out_unlock; | |
739 | switch (cmd) { | |
740 | case IPC_RMID: | |
741 | do_shm_rmid(ns, ipcp); | |
742 | goto out_up; | |
743 | case IPC_SET: | |
8f4a3809 | 744 | ipc_update_perm(&shmid64.shm_perm, ipcp); |
8d4cc8b5 PP |
745 | shp->shm_ctim = get_seconds(); |
746 | break; | |
747 | default: | |
748 | err = -EINVAL; | |
749 | } | |
750 | out_unlock: | |
751 | shm_unlock(shp); | |
752 | out_up: | |
753 | up_write(&shm_ids(ns).rw_mutex); | |
754 | return err; | |
755 | } | |
756 | ||
d5460c99 | 757 | SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
8d4cc8b5 | 758 | { |
1da177e4 LT |
759 | struct shmid_kernel *shp; |
760 | int err, version; | |
4e982311 | 761 | struct ipc_namespace *ns; |
1da177e4 LT |
762 | |
763 | if (cmd < 0 || shmid < 0) { | |
764 | err = -EINVAL; | |
765 | goto out; | |
766 | } | |
767 | ||
768 | version = ipc_parse_version(&cmd); | |
4e982311 | 769 | ns = current->nsproxy->ipc_ns; |
1da177e4 LT |
770 | |
771 | switch (cmd) { /* replace with proc interface ? */ | |
772 | case IPC_INFO: | |
773 | { | |
774 | struct shminfo64 shminfo; | |
775 | ||
776 | err = security_shm_shmctl(NULL, cmd); | |
777 | if (err) | |
778 | return err; | |
779 | ||
e8148f75 | 780 | memset(&shminfo, 0, sizeof(shminfo)); |
4e982311 KK |
781 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
782 | shminfo.shmmax = ns->shm_ctlmax; | |
783 | shminfo.shmall = ns->shm_ctlall; | |
1da177e4 LT |
784 | |
785 | shminfo.shmmin = SHMMIN; | |
786 | if(copy_shminfo_to_user (buf, &shminfo, version)) | |
787 | return -EFAULT; | |
f4566f04 | 788 | |
3e148c79 | 789 | down_read(&shm_ids(ns).rw_mutex); |
7ca7e564 | 790 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 791 | up_read(&shm_ids(ns).rw_mutex); |
f4566f04 | 792 | |
1da177e4 LT |
793 | if(err<0) |
794 | err = 0; | |
795 | goto out; | |
796 | } | |
797 | case SHM_INFO: | |
798 | { | |
799 | struct shm_info shm_info; | |
800 | ||
801 | err = security_shm_shmctl(NULL, cmd); | |
802 | if (err) | |
803 | return err; | |
804 | ||
e8148f75 | 805 | memset(&shm_info, 0, sizeof(shm_info)); |
3e148c79 | 806 | down_read(&shm_ids(ns).rw_mutex); |
4e982311 KK |
807 | shm_info.used_ids = shm_ids(ns).in_use; |
808 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); | |
809 | shm_info.shm_tot = ns->shm_tot; | |
1da177e4 LT |
810 | shm_info.swap_attempts = 0; |
811 | shm_info.swap_successes = 0; | |
7ca7e564 | 812 | err = ipc_get_maxid(&shm_ids(ns)); |
3e148c79 | 813 | up_read(&shm_ids(ns).rw_mutex); |
e8148f75 | 814 | if (copy_to_user(buf, &shm_info, sizeof(shm_info))) { |
1da177e4 LT |
815 | err = -EFAULT; |
816 | goto out; | |
817 | } | |
818 | ||
819 | err = err < 0 ? 0 : err; | |
820 | goto out; | |
821 | } | |
822 | case SHM_STAT: | |
823 | case IPC_STAT: | |
824 | { | |
825 | struct shmid64_ds tbuf; | |
826 | int result; | |
023a5355 | 827 | |
023a5355 ND |
828 | if (cmd == SHM_STAT) { |
829 | shp = shm_lock(ns, shmid); | |
830 | if (IS_ERR(shp)) { | |
831 | err = PTR_ERR(shp); | |
832 | goto out; | |
833 | } | |
7ca7e564 | 834 | result = shp->shm_perm.id; |
1da177e4 | 835 | } else { |
023a5355 ND |
836 | shp = shm_lock_check(ns, shmid); |
837 | if (IS_ERR(shp)) { | |
838 | err = PTR_ERR(shp); | |
839 | goto out; | |
840 | } | |
1da177e4 LT |
841 | result = 0; |
842 | } | |
e8148f75 | 843 | err = -EACCES; |
b0e77598 | 844 | if (ipcperms(ns, &shp->shm_perm, S_IRUGO)) |
1da177e4 LT |
845 | goto out_unlock; |
846 | err = security_shm_shmctl(shp, cmd); | |
847 | if (err) | |
848 | goto out_unlock; | |
023a5355 | 849 | memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4 LT |
850 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
851 | tbuf.shm_segsz = shp->shm_segsz; | |
852 | tbuf.shm_atime = shp->shm_atim; | |
853 | tbuf.shm_dtime = shp->shm_dtim; | |
854 | tbuf.shm_ctime = shp->shm_ctim; | |
855 | tbuf.shm_cpid = shp->shm_cprid; | |
856 | tbuf.shm_lpid = shp->shm_lprid; | |
bc56bba8 | 857 | tbuf.shm_nattch = shp->shm_nattch; |
1da177e4 LT |
858 | shm_unlock(shp); |
859 | if(copy_shmid_to_user (buf, &tbuf, version)) | |
860 | err = -EFAULT; | |
861 | else | |
862 | err = result; | |
863 | goto out; | |
864 | } | |
865 | case SHM_LOCK: | |
866 | case SHM_UNLOCK: | |
867 | { | |
89e004ea LS |
868 | struct file *uninitialized_var(shm_file); |
869 | ||
870 | lru_add_drain_all(); /* drain pagevecs to lru lists */ | |
871 | ||
023a5355 ND |
872 | shp = shm_lock_check(ns, shmid); |
873 | if (IS_ERR(shp)) { | |
874 | err = PTR_ERR(shp); | |
1da177e4 LT |
875 | goto out; |
876 | } | |
1da177e4 | 877 | |
a33e6751 | 878 | audit_ipc_obj(&(shp->shm_perm)); |
073115d6 | 879 | |
b0e77598 | 880 | if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) { |
414c0708 | 881 | uid_t euid = current_euid(); |
1da177e4 | 882 | err = -EPERM; |
414c0708 DH |
883 | if (euid != shp->shm_perm.uid && |
884 | euid != shp->shm_perm.cuid) | |
1da177e4 | 885 | goto out_unlock; |
f1eb1332 | 886 | if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) |
1da177e4 LT |
887 | goto out_unlock; |
888 | } | |
889 | ||
890 | err = security_shm_shmctl(shp, cmd); | |
891 | if (err) | |
892 | goto out_unlock; | |
893 | ||
894 | if(cmd==SHM_LOCK) { | |
86a264ab | 895 | struct user_struct *user = current_user(); |
1da177e4 LT |
896 | if (!is_file_hugepages(shp->shm_file)) { |
897 | err = shmem_lock(shp->shm_file, 1, user); | |
7be77e20 | 898 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0 | 899 | shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4 LT |
900 | shp->mlock_user = user; |
901 | } | |
902 | } | |
903 | } else if (!is_file_hugepages(shp->shm_file)) { | |
904 | shmem_lock(shp->shm_file, 0, shp->mlock_user); | |
b33291c0 | 905 | shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4 LT |
906 | shp->mlock_user = NULL; |
907 | } | |
908 | shm_unlock(shp); | |
909 | goto out; | |
910 | } | |
911 | case IPC_RMID: | |
1da177e4 | 912 | case IPC_SET: |
8d4cc8b5 PP |
913 | err = shmctl_down(ns, shmid, cmd, buf, version); |
914 | return err; | |
1da177e4 | 915 | default: |
8d4cc8b5 | 916 | return -EINVAL; |
1da177e4 LT |
917 | } |
918 | ||
1da177e4 LT |
919 | out_unlock: |
920 | shm_unlock(shp); | |
921 | out: | |
922 | return err; | |
923 | } | |
924 | ||
925 | /* | |
926 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. | |
927 | * | |
928 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The | |
929 | * "raddr" thing points to kernel space, and there has to be a wrapper around | |
930 | * this. | |
931 | */ | |
932 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) | |
933 | { | |
934 | struct shmid_kernel *shp; | |
935 | unsigned long addr; | |
936 | unsigned long size; | |
937 | struct file * file; | |
938 | int err; | |
939 | unsigned long flags; | |
940 | unsigned long prot; | |
1da177e4 | 941 | int acc_mode; |
bc56bba8 | 942 | unsigned long user_addr; |
4e982311 | 943 | struct ipc_namespace *ns; |
bc56bba8 EB |
944 | struct shm_file_data *sfd; |
945 | struct path path; | |
aeb5d727 | 946 | fmode_t f_mode; |
1da177e4 | 947 | |
bc56bba8 EB |
948 | err = -EINVAL; |
949 | if (shmid < 0) | |
1da177e4 | 950 | goto out; |
bc56bba8 | 951 | else if ((addr = (ulong)shmaddr)) { |
1da177e4 LT |
952 | if (addr & (SHMLBA-1)) { |
953 | if (shmflg & SHM_RND) | |
954 | addr &= ~(SHMLBA-1); /* round down */ | |
955 | else | |
956 | #ifndef __ARCH_FORCE_SHMLBA | |
957 | if (addr & ~PAGE_MASK) | |
958 | #endif | |
bc56bba8 | 959 | goto out; |
1da177e4 LT |
960 | } |
961 | flags = MAP_SHARED | MAP_FIXED; | |
962 | } else { | |
963 | if ((shmflg & SHM_REMAP)) | |
bc56bba8 | 964 | goto out; |
1da177e4 LT |
965 | |
966 | flags = MAP_SHARED; | |
967 | } | |
968 | ||
969 | if (shmflg & SHM_RDONLY) { | |
970 | prot = PROT_READ; | |
1da177e4 | 971 | acc_mode = S_IRUGO; |
bc56bba8 | 972 | f_mode = FMODE_READ; |
1da177e4 LT |
973 | } else { |
974 | prot = PROT_READ | PROT_WRITE; | |
1da177e4 | 975 | acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8 | 976 | f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4 LT |
977 | } |
978 | if (shmflg & SHM_EXEC) { | |
979 | prot |= PROT_EXEC; | |
980 | acc_mode |= S_IXUGO; | |
981 | } | |
982 | ||
983 | /* | |
984 | * We cannot rely on the fs check since SYSV IPC does have an | |
985 | * additional creator id... | |
986 | */ | |
4e982311 | 987 | ns = current->nsproxy->ipc_ns; |
023a5355 ND |
988 | shp = shm_lock_check(ns, shmid); |
989 | if (IS_ERR(shp)) { | |
990 | err = PTR_ERR(shp); | |
1da177e4 | 991 | goto out; |
023a5355 | 992 | } |
bc56bba8 EB |
993 | |
994 | err = -EACCES; | |
b0e77598 | 995 | if (ipcperms(ns, &shp->shm_perm, acc_mode)) |
bc56bba8 | 996 | goto out_unlock; |
1da177e4 LT |
997 | |
998 | err = security_shm_shmat(shp, shmaddr, shmflg); | |
bc56bba8 EB |
999 | if (err) |
1000 | goto out_unlock; | |
1001 | ||
2c48b9c4 AV |
1002 | path = shp->shm_file->f_path; |
1003 | path_get(&path); | |
1da177e4 | 1004 | shp->shm_nattch++; |
bc56bba8 | 1005 | size = i_size_read(path.dentry->d_inode); |
1da177e4 LT |
1006 | shm_unlock(shp); |
1007 | ||
bc56bba8 EB |
1008 | err = -ENOMEM; |
1009 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); | |
1010 | if (!sfd) | |
ce8d2cdf | 1011 | goto out_put_dentry; |
bc56bba8 | 1012 | |
2c48b9c4 AV |
1013 | file = alloc_file(&path, f_mode, |
1014 | is_file_hugepages(shp->shm_file) ? | |
c4caa778 AV |
1015 | &shm_file_operations_huge : |
1016 | &shm_file_operations); | |
bc56bba8 EB |
1017 | if (!file) |
1018 | goto out_free; | |
1019 | ||
bc56bba8 | 1020 | file->private_data = sfd; |
bc56bba8 | 1021 | file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564 | 1022 | sfd->id = shp->shm_perm.id; |
bc56bba8 EB |
1023 | sfd->ns = get_ipc_ns(ns); |
1024 | sfd->file = shp->shm_file; | |
1025 | sfd->vm_ops = NULL; | |
1026 | ||
1da177e4 LT |
1027 | down_write(¤t->mm->mmap_sem); |
1028 | if (addr && !(shmflg & SHM_REMAP)) { | |
bc56bba8 | 1029 | err = -EINVAL; |
1da177e4 LT |
1030 | if (find_vma_intersection(current->mm, addr, addr + size)) |
1031 | goto invalid; | |
1032 | /* | |
1033 | * If shm segment goes below stack, make sure there is some | |
1034 | * space left for the stack to grow (at least 4 pages). | |
1035 | */ | |
1036 | if (addr < current->mm->start_stack && | |
1037 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) | |
1038 | goto invalid; | |
1039 | } | |
1040 | ||
bc56bba8 EB |
1041 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
1042 | *raddr = user_addr; | |
1043 | err = 0; | |
1044 | if (IS_ERR_VALUE(user_addr)) | |
1045 | err = (long)user_addr; | |
1da177e4 LT |
1046 | invalid: |
1047 | up_write(¤t->mm->mmap_sem); | |
1048 | ||
bc56bba8 EB |
1049 | fput(file); |
1050 | ||
1051 | out_nattch: | |
3e148c79 | 1052 | down_write(&shm_ids(ns).rw_mutex); |
00c2bf85 | 1053 | shp = shm_lock(ns, shmid); |
023a5355 | 1054 | BUG_ON(IS_ERR(shp)); |
1da177e4 | 1055 | shp->shm_nattch--; |
b34a6b1d | 1056 | if (shm_may_destroy(ns, shp)) |
4e982311 | 1057 | shm_destroy(ns, shp); |
1da177e4 LT |
1058 | else |
1059 | shm_unlock(shp); | |
3e148c79 | 1060 | up_write(&shm_ids(ns).rw_mutex); |
1da177e4 | 1061 | |
1da177e4 LT |
1062 | out: |
1063 | return err; | |
bc56bba8 EB |
1064 | |
1065 | out_unlock: | |
1066 | shm_unlock(shp); | |
1067 | goto out; | |
1068 | ||
1069 | out_free: | |
1070 | kfree(sfd); | |
ce8d2cdf | 1071 | out_put_dentry: |
2c48b9c4 | 1072 | path_put(&path); |
bc56bba8 | 1073 | goto out_nattch; |
1da177e4 LT |
1074 | } |
1075 | ||
d5460c99 | 1076 | SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
7d87e14c SR |
1077 | { |
1078 | unsigned long ret; | |
1079 | long err; | |
1080 | ||
1081 | err = do_shmat(shmid, shmaddr, shmflg, &ret); | |
1082 | if (err) | |
1083 | return err; | |
1084 | force_successful_syscall_return(); | |
1085 | return (long)ret; | |
1086 | } | |
1087 | ||
1da177e4 LT |
1088 | /* |
1089 | * detach and kill segment if marked destroyed. | |
1090 | * The work is done in shm_close. | |
1091 | */ | |
d5460c99 | 1092 | SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
1da177e4 LT |
1093 | { |
1094 | struct mm_struct *mm = current->mm; | |
586c7e6a | 1095 | struct vm_area_struct *vma; |
1da177e4 | 1096 | unsigned long addr = (unsigned long)shmaddr; |
1da177e4 | 1097 | int retval = -EINVAL; |
586c7e6a MF |
1098 | #ifdef CONFIG_MMU |
1099 | loff_t size = 0; | |
1100 | struct vm_area_struct *next; | |
1101 | #endif | |
1da177e4 | 1102 | |
df1e2fb5 HD |
1103 | if (addr & ~PAGE_MASK) |
1104 | return retval; | |
1105 | ||
1da177e4 LT |
1106 | down_write(&mm->mmap_sem); |
1107 | ||
1108 | /* | |
1109 | * This function tries to be smart and unmap shm segments that | |
1110 | * were modified by partial mlock or munmap calls: | |
1111 | * - It first determines the size of the shm segment that should be | |
1112 | * unmapped: It searches for a vma that is backed by shm and that | |
1113 | * started at address shmaddr. It records it's size and then unmaps | |
1114 | * it. | |
1115 | * - Then it unmaps all shm vmas that started at shmaddr and that | |
1116 | * are within the initially determined size. | |
1117 | * Errors from do_munmap are ignored: the function only fails if | |
1118 | * it's called with invalid parameters or if it's called to unmap | |
1119 | * a part of a vma. Both calls in this function are for full vmas, | |
1120 | * the parameters are directly copied from the vma itself and always | |
1121 | * valid - therefore do_munmap cannot fail. (famous last words?) | |
1122 | */ | |
1123 | /* | |
1124 | * If it had been mremap()'d, the starting address would not | |
1125 | * match the usual checks anyway. So assume all vma's are | |
1126 | * above the starting address given. | |
1127 | */ | |
1128 | vma = find_vma(mm, addr); | |
1129 | ||
8feae131 | 1130 | #ifdef CONFIG_MMU |
1da177e4 LT |
1131 | while (vma) { |
1132 | next = vma->vm_next; | |
1133 | ||
1134 | /* | |
1135 | * Check if the starting address would match, i.e. it's | |
1136 | * a fragment created by mprotect() and/or munmap(), or it | |
1137 | * otherwise it starts at this address with no hassles. | |
1138 | */ | |
bc56bba8 | 1139 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1140 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1141 | ||
1142 | ||
6d63079a | 1143 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4 LT |
1144 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1145 | /* | |
1146 | * We discovered the size of the shm segment, so | |
1147 | * break out of here and fall through to the next | |
1148 | * loop that uses the size information to stop | |
1149 | * searching for matching vma's. | |
1150 | */ | |
1151 | retval = 0; | |
1152 | vma = next; | |
1153 | break; | |
1154 | } | |
1155 | vma = next; | |
1156 | } | |
1157 | ||
1158 | /* | |
1159 | * We need look no further than the maximum address a fragment | |
1160 | * could possibly have landed at. Also cast things to loff_t to | |
25985edc | 1161 | * prevent overflows and make comparisons vs. equal-width types. |
1da177e4 | 1162 | */ |
8e36709d | 1163 | size = PAGE_ALIGN(size); |
1da177e4 LT |
1164 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1165 | next = vma->vm_next; | |
1166 | ||
1167 | /* finding a matching vma now does not alter retval */ | |
bc56bba8 | 1168 | if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4 LT |
1169 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1170 | ||
1171 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1172 | vma = next; | |
1173 | } | |
1174 | ||
8feae131 DH |
1175 | #else /* CONFIG_MMU */ |
1176 | /* under NOMMU conditions, the exact address to be destroyed must be | |
1177 | * given */ | |
1178 | retval = -EINVAL; | |
1179 | if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { | |
1180 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); | |
1181 | retval = 0; | |
1182 | } | |
1183 | ||
1184 | #endif | |
1185 | ||
1da177e4 LT |
1186 | up_write(&mm->mmap_sem); |
1187 | return retval; | |
1188 | } | |
1189 | ||
1190 | #ifdef CONFIG_PROC_FS | |
19b4946c | 1191 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1192 | { |
19b4946c | 1193 | struct shmid_kernel *shp = it; |
b7952180 HD |
1194 | unsigned long rss = 0, swp = 0; |
1195 | ||
1196 | shm_add_rss_swap(shp, &rss, &swp); | |
1da177e4 | 1197 | |
6c826818 PM |
1198 | #if BITS_PER_LONG <= 32 |
1199 | #define SIZE_SPEC "%10lu" | |
1200 | #else | |
1201 | #define SIZE_SPEC "%21lu" | |
1202 | #endif | |
1da177e4 | 1203 | |
6c826818 PM |
1204 | return seq_printf(s, |
1205 | "%10d %10d %4o " SIZE_SPEC " %5u %5u " | |
b7952180 HD |
1206 | "%5lu %5u %5u %5u %5u %10lu %10lu %10lu " |
1207 | SIZE_SPEC " " SIZE_SPEC "\n", | |
19b4946c | 1208 | shp->shm_perm.key, |
7ca7e564 | 1209 | shp->shm_perm.id, |
b33291c0 | 1210 | shp->shm_perm.mode, |
19b4946c MW |
1211 | shp->shm_segsz, |
1212 | shp->shm_cprid, | |
1213 | shp->shm_lprid, | |
bc56bba8 | 1214 | shp->shm_nattch, |
19b4946c MW |
1215 | shp->shm_perm.uid, |
1216 | shp->shm_perm.gid, | |
1217 | shp->shm_perm.cuid, | |
1218 | shp->shm_perm.cgid, | |
1219 | shp->shm_atim, | |
1220 | shp->shm_dtim, | |
b7952180 HD |
1221 | shp->shm_ctim, |
1222 | rss * PAGE_SIZE, | |
1223 | swp * PAGE_SIZE); | |
1da177e4 LT |
1224 | } |
1225 | #endif |