Root/
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 | * |
16 | * support for audit of ipc object properties and permission changes |
17 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> |
18 | * |
19 | * namespaces support |
20 | * OpenVZ, SWsoft Inc. |
21 | * Pavel Emelianov <xemul@openvz.org> |
22 | */ |
23 | |
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> |
31 | #include <linux/shmem_fs.h> |
32 | #include <linux/security.h> |
33 | #include <linux/syscalls.h> |
34 | #include <linux/audit.h> |
35 | #include <linux/capability.h> |
36 | #include <linux/ptrace.h> |
37 | #include <linux/seq_file.h> |
38 | #include <linux/rwsem.h> |
39 | #include <linux/nsproxy.h> |
40 | #include <linux/mount.h> |
41 | #include <linux/ipc_namespace.h> |
42 | |
43 | #include <asm/uaccess.h> |
44 | |
45 | #include "util.h" |
46 | |
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 | |
56 | static const struct file_operations shm_file_operations; |
57 | static const struct vm_operations_struct shm_vm_ops; |
58 | |
59 | #define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
60 | |
61 | #define shm_unlock(shp) \ |
62 | ipc_unlock(&(shp)->shm_perm) |
63 | |
64 | static int newseg(struct ipc_namespace *, struct ipc_params *); |
65 | static void shm_open(struct vm_area_struct *vma); |
66 | static void shm_close(struct vm_area_struct *vma); |
67 | static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); |
68 | #ifdef CONFIG_PROC_FS |
69 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
70 | #endif |
71 | |
72 | void shm_init_ns(struct ipc_namespace *ns) |
73 | { |
74 | ns->shm_ctlmax = SHMMAX; |
75 | ns->shm_ctlall = SHMALL; |
76 | ns->shm_ctlmni = SHMMNI; |
77 | ns->shm_tot = 0; |
78 | ipc_init_ids(&shm_ids(ns)); |
79 | } |
80 | |
81 | /* |
82 | * Called with shm_ids.rw_mutex (writer) and the shp structure locked. |
83 | * Only shm_ids.rw_mutex remains locked on exit. |
84 | */ |
85 | static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
86 | { |
87 | struct shmid_kernel *shp; |
88 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
89 | |
90 | if (shp->shm_nattch){ |
91 | shp->shm_perm.mode |= SHM_DEST; |
92 | /* Do not find it any more */ |
93 | shp->shm_perm.key = IPC_PRIVATE; |
94 | shm_unlock(shp); |
95 | } else |
96 | shm_destroy(ns, shp); |
97 | } |
98 | |
99 | #ifdef CONFIG_IPC_NS |
100 | void shm_exit_ns(struct ipc_namespace *ns) |
101 | { |
102 | free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
103 | idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
104 | } |
105 | #endif |
106 | |
107 | void __init shm_init (void) |
108 | { |
109 | shm_init_ns(&init_ipc_ns); |
110 | ipc_init_proc_interface("sysvipc/shm", |
111 | " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n", |
112 | IPC_SHM_IDS, sysvipc_shm_proc_show); |
113 | } |
114 | |
115 | /* |
116 | * shm_lock_(check_) routines are called in the paths where the rw_mutex |
117 | * is not necessarily held. |
118 | */ |
119 | static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
120 | { |
121 | struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id); |
122 | |
123 | if (IS_ERR(ipcp)) |
124 | return (struct shmid_kernel *)ipcp; |
125 | |
126 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
127 | } |
128 | |
129 | static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, |
130 | int id) |
131 | { |
132 | struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
133 | |
134 | if (IS_ERR(ipcp)) |
135 | return (struct shmid_kernel *)ipcp; |
136 | |
137 | return container_of(ipcp, struct shmid_kernel, shm_perm); |
138 | } |
139 | |
140 | static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
141 | { |
142 | ipc_rmid(&shm_ids(ns), &s->shm_perm); |
143 | } |
144 | |
145 | |
146 | /* This is called by fork, once for every shm attach. */ |
147 | static void shm_open(struct vm_area_struct *vma) |
148 | { |
149 | struct file *file = vma->vm_file; |
150 | struct shm_file_data *sfd = shm_file_data(file); |
151 | struct shmid_kernel *shp; |
152 | |
153 | shp = shm_lock(sfd->ns, sfd->id); |
154 | BUG_ON(IS_ERR(shp)); |
155 | shp->shm_atim = get_seconds(); |
156 | shp->shm_lprid = task_tgid_vnr(current); |
157 | shp->shm_nattch++; |
158 | shm_unlock(shp); |
159 | } |
160 | |
161 | /* |
162 | * shm_destroy - free the struct shmid_kernel |
163 | * |
164 | * @ns: namespace |
165 | * @shp: struct to free |
166 | * |
167 | * It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
168 | * but returns with shp unlocked and freed. |
169 | */ |
170 | static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
171 | { |
172 | ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
173 | shm_rmid(ns, shp); |
174 | shm_unlock(shp); |
175 | if (!is_file_hugepages(shp->shm_file)) |
176 | shmem_lock(shp->shm_file, 0, shp->mlock_user); |
177 | else if (shp->mlock_user) |
178 | user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
179 | shp->mlock_user); |
180 | fput (shp->shm_file); |
181 | security_shm_free(shp); |
182 | ipc_rcu_putref(shp); |
183 | } |
184 | |
185 | /* |
186 | * remove the attach descriptor vma. |
187 | * free memory for segment if it is marked destroyed. |
188 | * The descriptor has already been removed from the current->mm->mmap list |
189 | * and will later be kfree()d. |
190 | */ |
191 | static void shm_close(struct vm_area_struct *vma) |
192 | { |
193 | struct file * file = vma->vm_file; |
194 | struct shm_file_data *sfd = shm_file_data(file); |
195 | struct shmid_kernel *shp; |
196 | struct ipc_namespace *ns = sfd->ns; |
197 | |
198 | down_write(&shm_ids(ns).rw_mutex); |
199 | /* remove from the list of attaches of the shm segment */ |
200 | shp = shm_lock(ns, sfd->id); |
201 | BUG_ON(IS_ERR(shp)); |
202 | shp->shm_lprid = task_tgid_vnr(current); |
203 | shp->shm_dtim = get_seconds(); |
204 | shp->shm_nattch--; |
205 | if(shp->shm_nattch == 0 && |
206 | shp->shm_perm.mode & SHM_DEST) |
207 | shm_destroy(ns, shp); |
208 | else |
209 | shm_unlock(shp); |
210 | up_write(&shm_ids(ns).rw_mutex); |
211 | } |
212 | |
213 | static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
214 | { |
215 | struct file *file = vma->vm_file; |
216 | struct shm_file_data *sfd = shm_file_data(file); |
217 | |
218 | return sfd->vm_ops->fault(vma, vmf); |
219 | } |
220 | |
221 | #ifdef CONFIG_NUMA |
222 | static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
223 | { |
224 | struct file *file = vma->vm_file; |
225 | struct shm_file_data *sfd = shm_file_data(file); |
226 | int err = 0; |
227 | if (sfd->vm_ops->set_policy) |
228 | err = sfd->vm_ops->set_policy(vma, new); |
229 | return err; |
230 | } |
231 | |
232 | static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
233 | unsigned long addr) |
234 | { |
235 | struct file *file = vma->vm_file; |
236 | struct shm_file_data *sfd = shm_file_data(file); |
237 | struct mempolicy *pol = NULL; |
238 | |
239 | if (sfd->vm_ops->get_policy) |
240 | pol = sfd->vm_ops->get_policy(vma, addr); |
241 | else if (vma->vm_policy) |
242 | pol = vma->vm_policy; |
243 | |
244 | return pol; |
245 | } |
246 | #endif |
247 | |
248 | static int shm_mmap(struct file * file, struct vm_area_struct * vma) |
249 | { |
250 | struct shm_file_data *sfd = shm_file_data(file); |
251 | int ret; |
252 | |
253 | ret = sfd->file->f_op->mmap(sfd->file, vma); |
254 | if (ret != 0) |
255 | return ret; |
256 | sfd->vm_ops = vma->vm_ops; |
257 | #ifdef CONFIG_MMU |
258 | BUG_ON(!sfd->vm_ops->fault); |
259 | #endif |
260 | vma->vm_ops = &shm_vm_ops; |
261 | shm_open(vma); |
262 | |
263 | return ret; |
264 | } |
265 | |
266 | static int shm_release(struct inode *ino, struct file *file) |
267 | { |
268 | struct shm_file_data *sfd = shm_file_data(file); |
269 | |
270 | put_ipc_ns(sfd->ns); |
271 | shm_file_data(file) = NULL; |
272 | kfree(sfd); |
273 | return 0; |
274 | } |
275 | |
276 | static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) |
277 | { |
278 | int (*fsync) (struct file *, struct dentry *, int datasync); |
279 | struct shm_file_data *sfd = shm_file_data(file); |
280 | int ret = -EINVAL; |
281 | |
282 | fsync = sfd->file->f_op->fsync; |
283 | if (fsync) |
284 | ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); |
285 | return ret; |
286 | } |
287 | |
288 | static unsigned long shm_get_unmapped_area(struct file *file, |
289 | unsigned long addr, unsigned long len, unsigned long pgoff, |
290 | unsigned long flags) |
291 | { |
292 | struct shm_file_data *sfd = shm_file_data(file); |
293 | return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
294 | pgoff, flags); |
295 | } |
296 | |
297 | static const struct file_operations shm_file_operations = { |
298 | .mmap = shm_mmap, |
299 | .fsync = shm_fsync, |
300 | .release = shm_release, |
301 | #ifndef CONFIG_MMU |
302 | .get_unmapped_area = shm_get_unmapped_area, |
303 | #endif |
304 | }; |
305 | |
306 | static const struct file_operations shm_file_operations_huge = { |
307 | .mmap = shm_mmap, |
308 | .fsync = shm_fsync, |
309 | .release = shm_release, |
310 | .get_unmapped_area = shm_get_unmapped_area, |
311 | }; |
312 | |
313 | int is_file_shm_hugepages(struct file *file) |
314 | { |
315 | return file->f_op == &shm_file_operations_huge; |
316 | } |
317 | |
318 | static const struct vm_operations_struct shm_vm_ops = { |
319 | .open = shm_open, /* callback for a new vm-area open */ |
320 | .close = shm_close, /* callback for when the vm-area is released */ |
321 | .fault = shm_fault, |
322 | #if defined(CONFIG_NUMA) |
323 | .set_policy = shm_set_policy, |
324 | .get_policy = shm_get_policy, |
325 | #endif |
326 | }; |
327 | |
328 | /** |
329 | * newseg - Create a new shared memory segment |
330 | * @ns: namespace |
331 | * @params: ptr to the structure that contains key, size and shmflg |
332 | * |
333 | * Called with shm_ids.rw_mutex held as a writer. |
334 | */ |
335 | |
336 | static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
337 | { |
338 | key_t key = params->key; |
339 | int shmflg = params->flg; |
340 | size_t size = params->u.size; |
341 | int error; |
342 | struct shmid_kernel *shp; |
343 | int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; |
344 | struct file * file; |
345 | char name[13]; |
346 | int id; |
347 | int acctflag = 0; |
348 | |
349 | if (size < SHMMIN || size > ns->shm_ctlmax) |
350 | return -EINVAL; |
351 | |
352 | if (ns->shm_tot + numpages > ns->shm_ctlall) |
353 | return -ENOSPC; |
354 | |
355 | shp = ipc_rcu_alloc(sizeof(*shp)); |
356 | if (!shp) |
357 | return -ENOMEM; |
358 | |
359 | shp->shm_perm.key = key; |
360 | shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
361 | shp->mlock_user = NULL; |
362 | |
363 | shp->shm_perm.security = NULL; |
364 | error = security_shm_alloc(shp); |
365 | if (error) { |
366 | ipc_rcu_putref(shp); |
367 | return error; |
368 | } |
369 | |
370 | sprintf (name, "SYSV%08x", key); |
371 | if (shmflg & SHM_HUGETLB) { |
372 | /* hugetlb_file_setup applies strict accounting */ |
373 | if (shmflg & SHM_NORESERVE) |
374 | acctflag = VM_NORESERVE; |
375 | file = hugetlb_file_setup(name, size, acctflag, |
376 | &shp->mlock_user, HUGETLB_SHMFS_INODE); |
377 | } else { |
378 | /* |
379 | * Do not allow no accounting for OVERCOMMIT_NEVER, even |
380 | * if it's asked for. |
381 | */ |
382 | if ((shmflg & SHM_NORESERVE) && |
383 | sysctl_overcommit_memory != OVERCOMMIT_NEVER) |
384 | acctflag = VM_NORESERVE; |
385 | file = shmem_file_setup(name, size, acctflag); |
386 | } |
387 | error = PTR_ERR(file); |
388 | if (IS_ERR(file)) |
389 | goto no_file; |
390 | |
391 | id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
392 | if (id < 0) { |
393 | error = id; |
394 | goto no_id; |
395 | } |
396 | |
397 | shp->shm_cprid = task_tgid_vnr(current); |
398 | shp->shm_lprid = 0; |
399 | shp->shm_atim = shp->shm_dtim = 0; |
400 | shp->shm_ctim = get_seconds(); |
401 | shp->shm_segsz = size; |
402 | shp->shm_nattch = 0; |
403 | shp->shm_file = file; |
404 | /* |
405 | * shmid gets reported as "inode#" in /proc/pid/maps. |
406 | * proc-ps tools use this. Changing this will break them. |
407 | */ |
408 | file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
409 | |
410 | ns->shm_tot += numpages; |
411 | error = shp->shm_perm.id; |
412 | shm_unlock(shp); |
413 | return error; |
414 | |
415 | no_id: |
416 | if (is_file_hugepages(file) && shp->mlock_user) |
417 | user_shm_unlock(size, shp->mlock_user); |
418 | fput(file); |
419 | no_file: |
420 | security_shm_free(shp); |
421 | ipc_rcu_putref(shp); |
422 | return error; |
423 | } |
424 | |
425 | /* |
426 | * Called with shm_ids.rw_mutex and ipcp locked. |
427 | */ |
428 | static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
429 | { |
430 | struct shmid_kernel *shp; |
431 | |
432 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
433 | return security_shm_associate(shp, shmflg); |
434 | } |
435 | |
436 | /* |
437 | * Called with shm_ids.rw_mutex and ipcp locked. |
438 | */ |
439 | static inline int shm_more_checks(struct kern_ipc_perm *ipcp, |
440 | struct ipc_params *params) |
441 | { |
442 | struct shmid_kernel *shp; |
443 | |
444 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
445 | if (shp->shm_segsz < params->u.size) |
446 | return -EINVAL; |
447 | |
448 | return 0; |
449 | } |
450 | |
451 | SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
452 | { |
453 | struct ipc_namespace *ns; |
454 | struct ipc_ops shm_ops; |
455 | struct ipc_params shm_params; |
456 | |
457 | ns = current->nsproxy->ipc_ns; |
458 | |
459 | shm_ops.getnew = newseg; |
460 | shm_ops.associate = shm_security; |
461 | shm_ops.more_checks = shm_more_checks; |
462 | |
463 | shm_params.key = key; |
464 | shm_params.flg = shmflg; |
465 | shm_params.u.size = size; |
466 | |
467 | return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
468 | } |
469 | |
470 | static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) |
471 | { |
472 | switch(version) { |
473 | case IPC_64: |
474 | return copy_to_user(buf, in, sizeof(*in)); |
475 | case IPC_OLD: |
476 | { |
477 | struct shmid_ds out; |
478 | |
479 | ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); |
480 | out.shm_segsz = in->shm_segsz; |
481 | out.shm_atime = in->shm_atime; |
482 | out.shm_dtime = in->shm_dtime; |
483 | out.shm_ctime = in->shm_ctime; |
484 | out.shm_cpid = in->shm_cpid; |
485 | out.shm_lpid = in->shm_lpid; |
486 | out.shm_nattch = in->shm_nattch; |
487 | |
488 | return copy_to_user(buf, &out, sizeof(out)); |
489 | } |
490 | default: |
491 | return -EINVAL; |
492 | } |
493 | } |
494 | |
495 | static inline unsigned long |
496 | copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) |
497 | { |
498 | switch(version) { |
499 | case IPC_64: |
500 | if (copy_from_user(out, buf, sizeof(*out))) |
501 | return -EFAULT; |
502 | return 0; |
503 | case IPC_OLD: |
504 | { |
505 | struct shmid_ds tbuf_old; |
506 | |
507 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
508 | return -EFAULT; |
509 | |
510 | out->shm_perm.uid = tbuf_old.shm_perm.uid; |
511 | out->shm_perm.gid = tbuf_old.shm_perm.gid; |
512 | out->shm_perm.mode = tbuf_old.shm_perm.mode; |
513 | |
514 | return 0; |
515 | } |
516 | default: |
517 | return -EINVAL; |
518 | } |
519 | } |
520 | |
521 | static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) |
522 | { |
523 | switch(version) { |
524 | case IPC_64: |
525 | return copy_to_user(buf, in, sizeof(*in)); |
526 | case IPC_OLD: |
527 | { |
528 | struct shminfo out; |
529 | |
530 | if(in->shmmax > INT_MAX) |
531 | out.shmmax = INT_MAX; |
532 | else |
533 | out.shmmax = (int)in->shmmax; |
534 | |
535 | out.shmmin = in->shmmin; |
536 | out.shmmni = in->shmmni; |
537 | out.shmseg = in->shmseg; |
538 | out.shmall = in->shmall; |
539 | |
540 | return copy_to_user(buf, &out, sizeof(out)); |
541 | } |
542 | default: |
543 | return -EINVAL; |
544 | } |
545 | } |
546 | |
547 | /* |
548 | * Called with shm_ids.rw_mutex held as a reader |
549 | */ |
550 | static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
551 | unsigned long *swp) |
552 | { |
553 | int next_id; |
554 | int total, in_use; |
555 | |
556 | *rss = 0; |
557 | *swp = 0; |
558 | |
559 | in_use = shm_ids(ns).in_use; |
560 | |
561 | for (total = 0, next_id = 0; total < in_use; next_id++) { |
562 | struct kern_ipc_perm *ipc; |
563 | struct shmid_kernel *shp; |
564 | struct inode *inode; |
565 | |
566 | ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
567 | if (ipc == NULL) |
568 | continue; |
569 | shp = container_of(ipc, struct shmid_kernel, shm_perm); |
570 | |
571 | inode = shp->shm_file->f_path.dentry->d_inode; |
572 | |
573 | if (is_file_hugepages(shp->shm_file)) { |
574 | struct address_space *mapping = inode->i_mapping; |
575 | struct hstate *h = hstate_file(shp->shm_file); |
576 | *rss += pages_per_huge_page(h) * mapping->nrpages; |
577 | } else { |
578 | #ifdef CONFIG_SHMEM |
579 | struct shmem_inode_info *info = SHMEM_I(inode); |
580 | spin_lock(&info->lock); |
581 | *rss += inode->i_mapping->nrpages; |
582 | *swp += info->swapped; |
583 | spin_unlock(&info->lock); |
584 | #else |
585 | *rss += inode->i_mapping->nrpages; |
586 | #endif |
587 | } |
588 | |
589 | total++; |
590 | } |
591 | } |
592 | |
593 | /* |
594 | * This function handles some shmctl commands which require the rw_mutex |
595 | * to be held in write mode. |
596 | * NOTE: no locks must be held, the rw_mutex is taken inside this function. |
597 | */ |
598 | static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, |
599 | struct shmid_ds __user *buf, int version) |
600 | { |
601 | struct kern_ipc_perm *ipcp; |
602 | struct shmid64_ds shmid64; |
603 | struct shmid_kernel *shp; |
604 | int err; |
605 | |
606 | if (cmd == IPC_SET) { |
607 | if (copy_shmid_from_user(&shmid64, buf, version)) |
608 | return -EFAULT; |
609 | } |
610 | |
611 | ipcp = ipcctl_pre_down(&shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0); |
612 | if (IS_ERR(ipcp)) |
613 | return PTR_ERR(ipcp); |
614 | |
615 | shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
616 | |
617 | err = security_shm_shmctl(shp, cmd); |
618 | if (err) |
619 | goto out_unlock; |
620 | switch (cmd) { |
621 | case IPC_RMID: |
622 | do_shm_rmid(ns, ipcp); |
623 | goto out_up; |
624 | case IPC_SET: |
625 | ipc_update_perm(&shmid64.shm_perm, ipcp); |
626 | shp->shm_ctim = get_seconds(); |
627 | break; |
628 | default: |
629 | err = -EINVAL; |
630 | } |
631 | out_unlock: |
632 | shm_unlock(shp); |
633 | out_up: |
634 | up_write(&shm_ids(ns).rw_mutex); |
635 | return err; |
636 | } |
637 | |
638 | SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
639 | { |
640 | struct shmid_kernel *shp; |
641 | int err, version; |
642 | struct ipc_namespace *ns; |
643 | |
644 | if (cmd < 0 || shmid < 0) { |
645 | err = -EINVAL; |
646 | goto out; |
647 | } |
648 | |
649 | version = ipc_parse_version(&cmd); |
650 | ns = current->nsproxy->ipc_ns; |
651 | |
652 | switch (cmd) { /* replace with proc interface ? */ |
653 | case IPC_INFO: |
654 | { |
655 | struct shminfo64 shminfo; |
656 | |
657 | err = security_shm_shmctl(NULL, cmd); |
658 | if (err) |
659 | return err; |
660 | |
661 | memset(&shminfo, 0, sizeof(shminfo)); |
662 | shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; |
663 | shminfo.shmmax = ns->shm_ctlmax; |
664 | shminfo.shmall = ns->shm_ctlall; |
665 | |
666 | shminfo.shmmin = SHMMIN; |
667 | if(copy_shminfo_to_user (buf, &shminfo, version)) |
668 | return -EFAULT; |
669 | |
670 | down_read(&shm_ids(ns).rw_mutex); |
671 | err = ipc_get_maxid(&shm_ids(ns)); |
672 | up_read(&shm_ids(ns).rw_mutex); |
673 | |
674 | if(err<0) |
675 | err = 0; |
676 | goto out; |
677 | } |
678 | case SHM_INFO: |
679 | { |
680 | struct shm_info shm_info; |
681 | |
682 | err = security_shm_shmctl(NULL, cmd); |
683 | if (err) |
684 | return err; |
685 | |
686 | memset(&shm_info, 0, sizeof(shm_info)); |
687 | down_read(&shm_ids(ns).rw_mutex); |
688 | shm_info.used_ids = shm_ids(ns).in_use; |
689 | shm_get_stat (ns, &shm_info.shm_rss, &shm_info.shm_swp); |
690 | shm_info.shm_tot = ns->shm_tot; |
691 | shm_info.swap_attempts = 0; |
692 | shm_info.swap_successes = 0; |
693 | err = ipc_get_maxid(&shm_ids(ns)); |
694 | up_read(&shm_ids(ns).rw_mutex); |
695 | if (copy_to_user(buf, &shm_info, sizeof(shm_info))) { |
696 | err = -EFAULT; |
697 | goto out; |
698 | } |
699 | |
700 | err = err < 0 ? 0 : err; |
701 | goto out; |
702 | } |
703 | case SHM_STAT: |
704 | case IPC_STAT: |
705 | { |
706 | struct shmid64_ds tbuf; |
707 | int result; |
708 | |
709 | if (cmd == SHM_STAT) { |
710 | shp = shm_lock(ns, shmid); |
711 | if (IS_ERR(shp)) { |
712 | err = PTR_ERR(shp); |
713 | goto out; |
714 | } |
715 | result = shp->shm_perm.id; |
716 | } else { |
717 | shp = shm_lock_check(ns, shmid); |
718 | if (IS_ERR(shp)) { |
719 | err = PTR_ERR(shp); |
720 | goto out; |
721 | } |
722 | result = 0; |
723 | } |
724 | err = -EACCES; |
725 | if (ipcperms (&shp->shm_perm, S_IRUGO)) |
726 | goto out_unlock; |
727 | err = security_shm_shmctl(shp, cmd); |
728 | if (err) |
729 | goto out_unlock; |
730 | memset(&tbuf, 0, sizeof(tbuf)); |
731 | kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm); |
732 | tbuf.shm_segsz = shp->shm_segsz; |
733 | tbuf.shm_atime = shp->shm_atim; |
734 | tbuf.shm_dtime = shp->shm_dtim; |
735 | tbuf.shm_ctime = shp->shm_ctim; |
736 | tbuf.shm_cpid = shp->shm_cprid; |
737 | tbuf.shm_lpid = shp->shm_lprid; |
738 | tbuf.shm_nattch = shp->shm_nattch; |
739 | shm_unlock(shp); |
740 | if(copy_shmid_to_user (buf, &tbuf, version)) |
741 | err = -EFAULT; |
742 | else |
743 | err = result; |
744 | goto out; |
745 | } |
746 | case SHM_LOCK: |
747 | case SHM_UNLOCK: |
748 | { |
749 | struct file *uninitialized_var(shm_file); |
750 | |
751 | lru_add_drain_all(); /* drain pagevecs to lru lists */ |
752 | |
753 | shp = shm_lock_check(ns, shmid); |
754 | if (IS_ERR(shp)) { |
755 | err = PTR_ERR(shp); |
756 | goto out; |
757 | } |
758 | |
759 | audit_ipc_obj(&(shp->shm_perm)); |
760 | |
761 | if (!capable(CAP_IPC_LOCK)) { |
762 | uid_t euid = current_euid(); |
763 | err = -EPERM; |
764 | if (euid != shp->shm_perm.uid && |
765 | euid != shp->shm_perm.cuid) |
766 | goto out_unlock; |
767 | if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) |
768 | goto out_unlock; |
769 | } |
770 | |
771 | err = security_shm_shmctl(shp, cmd); |
772 | if (err) |
773 | goto out_unlock; |
774 | |
775 | if(cmd==SHM_LOCK) { |
776 | struct user_struct *user = current_user(); |
777 | if (!is_file_hugepages(shp->shm_file)) { |
778 | err = shmem_lock(shp->shm_file, 1, user); |
779 | if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
780 | shp->shm_perm.mode |= SHM_LOCKED; |
781 | shp->mlock_user = user; |
782 | } |
783 | } |
784 | } else if (!is_file_hugepages(shp->shm_file)) { |
785 | shmem_lock(shp->shm_file, 0, shp->mlock_user); |
786 | shp->shm_perm.mode &= ~SHM_LOCKED; |
787 | shp->mlock_user = NULL; |
788 | } |
789 | shm_unlock(shp); |
790 | goto out; |
791 | } |
792 | case IPC_RMID: |
793 | case IPC_SET: |
794 | err = shmctl_down(ns, shmid, cmd, buf, version); |
795 | return err; |
796 | default: |
797 | return -EINVAL; |
798 | } |
799 | |
800 | out_unlock: |
801 | shm_unlock(shp); |
802 | out: |
803 | return err; |
804 | } |
805 | |
806 | /* |
807 | * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. |
808 | * |
809 | * NOTE! Despite the name, this is NOT a direct system call entrypoint. The |
810 | * "raddr" thing points to kernel space, and there has to be a wrapper around |
811 | * this. |
812 | */ |
813 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) |
814 | { |
815 | struct shmid_kernel *shp; |
816 | unsigned long addr; |
817 | unsigned long size; |
818 | struct file * file; |
819 | int err; |
820 | unsigned long flags; |
821 | unsigned long prot; |
822 | int acc_mode; |
823 | unsigned long user_addr; |
824 | struct ipc_namespace *ns; |
825 | struct shm_file_data *sfd; |
826 | struct path path; |
827 | fmode_t f_mode; |
828 | |
829 | err = -EINVAL; |
830 | if (shmid < 0) |
831 | goto out; |
832 | else if ((addr = (ulong)shmaddr)) { |
833 | if (addr & (SHMLBA-1)) { |
834 | if (shmflg & SHM_RND) |
835 | addr &= ~(SHMLBA-1); /* round down */ |
836 | else |
837 | #ifndef __ARCH_FORCE_SHMLBA |
838 | if (addr & ~PAGE_MASK) |
839 | #endif |
840 | goto out; |
841 | } |
842 | flags = MAP_SHARED | MAP_FIXED; |
843 | } else { |
844 | if ((shmflg & SHM_REMAP)) |
845 | goto out; |
846 | |
847 | flags = MAP_SHARED; |
848 | } |
849 | |
850 | if (shmflg & SHM_RDONLY) { |
851 | prot = PROT_READ; |
852 | acc_mode = S_IRUGO; |
853 | f_mode = FMODE_READ; |
854 | } else { |
855 | prot = PROT_READ | PROT_WRITE; |
856 | acc_mode = S_IRUGO | S_IWUGO; |
857 | f_mode = FMODE_READ | FMODE_WRITE; |
858 | } |
859 | if (shmflg & SHM_EXEC) { |
860 | prot |= PROT_EXEC; |
861 | acc_mode |= S_IXUGO; |
862 | } |
863 | |
864 | /* |
865 | * We cannot rely on the fs check since SYSV IPC does have an |
866 | * additional creator id... |
867 | */ |
868 | ns = current->nsproxy->ipc_ns; |
869 | shp = shm_lock_check(ns, shmid); |
870 | if (IS_ERR(shp)) { |
871 | err = PTR_ERR(shp); |
872 | goto out; |
873 | } |
874 | |
875 | err = -EACCES; |
876 | if (ipcperms(&shp->shm_perm, acc_mode)) |
877 | goto out_unlock; |
878 | |
879 | err = security_shm_shmat(shp, shmaddr, shmflg); |
880 | if (err) |
881 | goto out_unlock; |
882 | |
883 | path = shp->shm_file->f_path; |
884 | path_get(&path); |
885 | shp->shm_nattch++; |
886 | size = i_size_read(path.dentry->d_inode); |
887 | shm_unlock(shp); |
888 | |
889 | err = -ENOMEM; |
890 | sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); |
891 | if (!sfd) |
892 | goto out_put_dentry; |
893 | |
894 | file = alloc_file(&path, f_mode, |
895 | is_file_hugepages(shp->shm_file) ? |
896 | &shm_file_operations_huge : |
897 | &shm_file_operations); |
898 | if (!file) |
899 | goto out_free; |
900 | |
901 | file->private_data = sfd; |
902 | file->f_mapping = shp->shm_file->f_mapping; |
903 | sfd->id = shp->shm_perm.id; |
904 | sfd->ns = get_ipc_ns(ns); |
905 | sfd->file = shp->shm_file; |
906 | sfd->vm_ops = NULL; |
907 | |
908 | down_write(¤t->mm->mmap_sem); |
909 | if (addr && !(shmflg & SHM_REMAP)) { |
910 | err = -EINVAL; |
911 | if (find_vma_intersection(current->mm, addr, addr + size)) |
912 | goto invalid; |
913 | /* |
914 | * If shm segment goes below stack, make sure there is some |
915 | * space left for the stack to grow (at least 4 pages). |
916 | */ |
917 | if (addr < current->mm->start_stack && |
918 | addr > current->mm->start_stack - size - PAGE_SIZE * 5) |
919 | goto invalid; |
920 | } |
921 | |
922 | user_addr = do_mmap (file, addr, size, prot, flags, 0); |
923 | *raddr = user_addr; |
924 | err = 0; |
925 | if (IS_ERR_VALUE(user_addr)) |
926 | err = (long)user_addr; |
927 | invalid: |
928 | up_write(¤t->mm->mmap_sem); |
929 | |
930 | fput(file); |
931 | |
932 | out_nattch: |
933 | down_write(&shm_ids(ns).rw_mutex); |
934 | shp = shm_lock(ns, shmid); |
935 | BUG_ON(IS_ERR(shp)); |
936 | shp->shm_nattch--; |
937 | if(shp->shm_nattch == 0 && |
938 | shp->shm_perm.mode & SHM_DEST) |
939 | shm_destroy(ns, shp); |
940 | else |
941 | shm_unlock(shp); |
942 | up_write(&shm_ids(ns).rw_mutex); |
943 | |
944 | out: |
945 | return err; |
946 | |
947 | out_unlock: |
948 | shm_unlock(shp); |
949 | goto out; |
950 | |
951 | out_free: |
952 | kfree(sfd); |
953 | out_put_dentry: |
954 | path_put(&path); |
955 | goto out_nattch; |
956 | } |
957 | |
958 | SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
959 | { |
960 | unsigned long ret; |
961 | long err; |
962 | |
963 | err = do_shmat(shmid, shmaddr, shmflg, &ret); |
964 | if (err) |
965 | return err; |
966 | force_successful_syscall_return(); |
967 | return (long)ret; |
968 | } |
969 | |
970 | /* |
971 | * detach and kill segment if marked destroyed. |
972 | * The work is done in shm_close. |
973 | */ |
974 | SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
975 | { |
976 | struct mm_struct *mm = current->mm; |
977 | struct vm_area_struct *vma; |
978 | unsigned long addr = (unsigned long)shmaddr; |
979 | int retval = -EINVAL; |
980 | #ifdef CONFIG_MMU |
981 | loff_t size = 0; |
982 | struct vm_area_struct *next; |
983 | #endif |
984 | |
985 | if (addr & ~PAGE_MASK) |
986 | return retval; |
987 | |
988 | down_write(&mm->mmap_sem); |
989 | |
990 | /* |
991 | * This function tries to be smart and unmap shm segments that |
992 | * were modified by partial mlock or munmap calls: |
993 | * - It first determines the size of the shm segment that should be |
994 | * unmapped: It searches for a vma that is backed by shm and that |
995 | * started at address shmaddr. It records it's size and then unmaps |
996 | * it. |
997 | * - Then it unmaps all shm vmas that started at shmaddr and that |
998 | * are within the initially determined size. |
999 | * Errors from do_munmap are ignored: the function only fails if |
1000 | * it's called with invalid parameters or if it's called to unmap |
1001 | * a part of a vma. Both calls in this function are for full vmas, |
1002 | * the parameters are directly copied from the vma itself and always |
1003 | * valid - therefore do_munmap cannot fail. (famous last words?) |
1004 | */ |
1005 | /* |
1006 | * If it had been mremap()'d, the starting address would not |
1007 | * match the usual checks anyway. So assume all vma's are |
1008 | * above the starting address given. |
1009 | */ |
1010 | vma = find_vma(mm, addr); |
1011 | |
1012 | #ifdef CONFIG_MMU |
1013 | while (vma) { |
1014 | next = vma->vm_next; |
1015 | |
1016 | /* |
1017 | * Check if the starting address would match, i.e. it's |
1018 | * a fragment created by mprotect() and/or munmap(), or it |
1019 | * otherwise it starts at this address with no hassles. |
1020 | */ |
1021 | if ((vma->vm_ops == &shm_vm_ops) && |
1022 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
1023 | |
1024 | |
1025 | size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1026 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1027 | /* |
1028 | * We discovered the size of the shm segment, so |
1029 | * break out of here and fall through to the next |
1030 | * loop that uses the size information to stop |
1031 | * searching for matching vma's. |
1032 | */ |
1033 | retval = 0; |
1034 | vma = next; |
1035 | break; |
1036 | } |
1037 | vma = next; |
1038 | } |
1039 | |
1040 | /* |
1041 | * We need look no further than the maximum address a fragment |
1042 | * could possibly have landed at. Also cast things to loff_t to |
1043 | * prevent overflows and make comparisions vs. equal-width types. |
1044 | */ |
1045 | size = PAGE_ALIGN(size); |
1046 | while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
1047 | next = vma->vm_next; |
1048 | |
1049 | /* finding a matching vma now does not alter retval */ |
1050 | if ((vma->vm_ops == &shm_vm_ops) && |
1051 | (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) |
1052 | |
1053 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1054 | vma = next; |
1055 | } |
1056 | |
1057 | #else /* CONFIG_MMU */ |
1058 | /* under NOMMU conditions, the exact address to be destroyed must be |
1059 | * given */ |
1060 | retval = -EINVAL; |
1061 | if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { |
1062 | do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); |
1063 | retval = 0; |
1064 | } |
1065 | |
1066 | #endif |
1067 | |
1068 | up_write(&mm->mmap_sem); |
1069 | return retval; |
1070 | } |
1071 | |
1072 | #ifdef CONFIG_PROC_FS |
1073 | static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1074 | { |
1075 | struct shmid_kernel *shp = it; |
1076 | |
1077 | #if BITS_PER_LONG <= 32 |
1078 | #define SIZE_SPEC "%10lu" |
1079 | #else |
1080 | #define SIZE_SPEC "%21lu" |
1081 | #endif |
1082 | |
1083 | return seq_printf(s, |
1084 | "%10d %10d %4o " SIZE_SPEC " %5u %5u " |
1085 | "%5lu %5u %5u %5u %5u %10lu %10lu %10lu\n", |
1086 | shp->shm_perm.key, |
1087 | shp->shm_perm.id, |
1088 | shp->shm_perm.mode, |
1089 | shp->shm_segsz, |
1090 | shp->shm_cprid, |
1091 | shp->shm_lprid, |
1092 | shp->shm_nattch, |
1093 | shp->shm_perm.uid, |
1094 | shp->shm_perm.gid, |
1095 | shp->shm_perm.cuid, |
1096 | shp->shm_perm.cgid, |
1097 | shp->shm_atim, |
1098 | shp->shm_dtim, |
1099 | shp->shm_ctim); |
1100 | } |
1101 | #endif |
1102 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9