FreeBSD/Linux Kernel Cross Reference
sys/kern/sysv_shm.c
1 /* $NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $ */
2 /*-
3 * Copyright (c) 1994 Adam Glass and Charles Hannum. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Adam Glass and Charles
16 * Hannum.
17 * 4. The names of the authors may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31 /*-
32 * Copyright (c) 2003-2005 McAfee, Inc.
33 * All rights reserved.
34 *
35 * This software was developed for the FreeBSD Project in part by McAfee
36 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
37 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
38 * program.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 */
61
62 #include <sys/cdefs.h>
63 __FBSDID("$FreeBSD: releng/10.4/sys/kern/sysv_shm.c 298835 2016-04-30 04:02:32Z jamie $");
64
65 #include "opt_compat.h"
66 #include "opt_sysvipc.h"
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/kernel.h>
71 #include <sys/limits.h>
72 #include <sys/lock.h>
73 #include <sys/sysctl.h>
74 #include <sys/shm.h>
75 #include <sys/proc.h>
76 #include <sys/malloc.h>
77 #include <sys/mman.h>
78 #include <sys/module.h>
79 #include <sys/mutex.h>
80 #include <sys/racct.h>
81 #include <sys/resourcevar.h>
82 #include <sys/rwlock.h>
83 #include <sys/stat.h>
84 #include <sys/syscall.h>
85 #include <sys/syscallsubr.h>
86 #include <sys/sysent.h>
87 #include <sys/sysproto.h>
88 #include <sys/jail.h>
89
90 #include <security/mac/mac_framework.h>
91
92 #include <vm/vm.h>
93 #include <vm/vm_param.h>
94 #include <vm/pmap.h>
95 #include <vm/vm_object.h>
96 #include <vm/vm_map.h>
97 #include <vm/vm_page.h>
98 #include <vm/vm_pager.h>
99
100 FEATURE(sysv_shm, "System V shared memory segments support");
101
102 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
103
104 static int shmget_allocate_segment(struct thread *td,
105 struct shmget_args *uap, int mode);
106 static int shmget_existing(struct thread *td, struct shmget_args *uap,
107 int mode, int segnum);
108
109 #define SHMSEG_FREE 0x0200
110 #define SHMSEG_REMOVED 0x0400
111 #define SHMSEG_ALLOCATED 0x0800
112
113 static int shm_last_free, shm_nused, shmalloced;
114 vm_size_t shm_committed;
115 static struct shmid_kernel *shmsegs;
116 static unsigned shm_prison_slot;
117
118 struct shmmap_state {
119 vm_offset_t va;
120 int shmid;
121 };
122
123 static void shm_deallocate_segment(struct shmid_kernel *);
124 static int shm_find_segment_by_key(struct prison *, key_t);
125 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool);
126 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
127 static void shmrealloc(void);
128 static int shminit(void);
129 static int sysvshm_modload(struct module *, int, void *);
130 static int shmunload(void);
131 static void shmexit_myhook(struct vmspace *vm);
132 static void shmfork_myhook(struct proc *p1, struct proc *p2);
133 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS);
134 static void shm_remove(struct shmid_kernel *, int);
135 static struct prison *shm_find_prison(struct ucred *);
136 static int shm_prison_cansee(struct prison *, struct shmid_kernel *);
137 static int shm_prison_check(void *, void *);
138 static int shm_prison_set(void *, void *);
139 static int shm_prison_get(void *, void *);
140 static int shm_prison_remove(void *, void *);
141 static void shm_prison_cleanup(struct prison *);
142
143 /*
144 * Tuneable values.
145 */
146 #ifndef SHMMAXPGS
147 #define SHMMAXPGS 131072 /* Note: sysv shared memory is swap backed. */
148 #endif
149 #ifndef SHMMAX
150 #define SHMMAX (SHMMAXPGS*PAGE_SIZE)
151 #endif
152 #ifndef SHMMIN
153 #define SHMMIN 1
154 #endif
155 #ifndef SHMMNI
156 #define SHMMNI 192
157 #endif
158 #ifndef SHMSEG
159 #define SHMSEG 128
160 #endif
161 #ifndef SHMALL
162 #define SHMALL (SHMMAXPGS)
163 #endif
164
165 struct shminfo shminfo = {
166 SHMMAX,
167 SHMMIN,
168 SHMMNI,
169 SHMSEG,
170 SHMALL
171 };
172
173 static int shm_use_phys;
174 static int shm_allow_removed;
175
176 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0,
177 "Maximum shared memory segment size");
178 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0,
179 "Minimum shared memory segment size");
180 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0,
181 "Number of shared memory identifiers");
182 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0,
183 "Number of segments per process");
184 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0,
185 "Maximum number of pages available for shared memory");
186 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW,
187 &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core");
188 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RW,
189 &shm_allow_removed, 0,
190 "Enable/Disable attachment to attached segments marked for removal");
191 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD |
192 CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "",
193 "Current number of shared memory segments allocated");
194
195 static struct sx sysvshmsx;
196 #define SYSVSHM_LOCK() sx_xlock(&sysvshmsx)
197 #define SYSVSHM_UNLOCK() sx_xunlock(&sysvshmsx)
198 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED)
199
200 static int
201 shm_find_segment_by_key(struct prison *pr, key_t key)
202 {
203 int i;
204
205 for (i = 0; i < shmalloced; i++)
206 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) &&
207 shmsegs[i].cred != NULL &&
208 shmsegs[i].cred->cr_prison == pr &&
209 shmsegs[i].u.shm_perm.key == key)
210 return (i);
211 return (-1);
212 }
213
214 /*
215 * Finds segment either by shmid if is_shmid is true, or by segnum if
216 * is_shmid is false.
217 */
218 static struct shmid_kernel *
219 shm_find_segment(struct prison *rpr, int arg, bool is_shmid)
220 {
221 struct shmid_kernel *shmseg;
222 int segnum;
223
224 segnum = is_shmid ? IPCID_TO_IX(arg) : arg;
225 if (segnum < 0 || segnum >= shmalloced)
226 return (NULL);
227 shmseg = &shmsegs[segnum];
228 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
229 (!shm_allow_removed &&
230 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) ||
231 (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) ||
232 shm_prison_cansee(rpr, shmseg) != 0)
233 return (NULL);
234 return (shmseg);
235 }
236
237 static void
238 shm_deallocate_segment(struct shmid_kernel *shmseg)
239 {
240 vm_size_t size;
241
242 SYSVSHM_ASSERT_LOCKED();
243
244 vm_object_deallocate(shmseg->object);
245 shmseg->object = NULL;
246 size = round_page(shmseg->u.shm_segsz);
247 shm_committed -= btoc(size);
248 shm_nused--;
249 shmseg->u.shm_perm.mode = SHMSEG_FREE;
250 #ifdef MAC
251 mac_sysvshm_cleanup(shmseg);
252 #endif
253 racct_sub_cred(shmseg->cred, RACCT_NSHM, 1);
254 racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size);
255 crfree(shmseg->cred);
256 shmseg->cred = NULL;
257 }
258
259 static int
260 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
261 {
262 struct shmid_kernel *shmseg;
263 int segnum, result;
264 vm_size_t size;
265
266 SYSVSHM_ASSERT_LOCKED();
267 segnum = IPCID_TO_IX(shmmap_s->shmid);
268 KASSERT(segnum >= 0 && segnum < shmalloced,
269 ("segnum %d shmalloced %d", segnum, shmalloced));
270
271 shmseg = &shmsegs[segnum];
272 size = round_page(shmseg->u.shm_segsz);
273 result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
274 if (result != KERN_SUCCESS)
275 return (EINVAL);
276 shmmap_s->shmid = -1;
277 shmseg->u.shm_dtime = time_second;
278 if ((--shmseg->u.shm_nattch <= 0) &&
279 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) {
280 shm_deallocate_segment(shmseg);
281 shm_last_free = segnum;
282 }
283 return (0);
284 }
285
286 static void
287 shm_remove(struct shmid_kernel *shmseg, int segnum)
288 {
289
290 shmseg->u.shm_perm.key = IPC_PRIVATE;
291 shmseg->u.shm_perm.mode |= SHMSEG_REMOVED;
292 if (shmseg->u.shm_nattch <= 0) {
293 shm_deallocate_segment(shmseg);
294 shm_last_free = segnum;
295 }
296 }
297
298 static struct prison *
299 shm_find_prison(struct ucred *cred)
300 {
301 struct prison *pr, *rpr;
302
303 pr = cred->cr_prison;
304 prison_lock(pr);
305 rpr = osd_jail_get(pr, shm_prison_slot);
306 prison_unlock(pr);
307 return rpr;
308 }
309
310 static int
311 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg)
312 {
313
314 if (shmseg->cred == NULL ||
315 !(rpr == shmseg->cred->cr_prison ||
316 prison_ischild(rpr, shmseg->cred->cr_prison)))
317 return (EINVAL);
318 return (0);
319 }
320
321 static int
322 kern_shmdt_locked(struct thread *td, const void *shmaddr)
323 {
324 struct proc *p = td->td_proc;
325 struct shmmap_state *shmmap_s;
326 #ifdef MAC
327 struct shmid_kernel *shmsegptr;
328 #endif
329 int error, i;
330
331 SYSVSHM_ASSERT_LOCKED();
332 if (shm_find_prison(td->td_ucred) == NULL)
333 return (ENOSYS);
334 shmmap_s = p->p_vmspace->vm_shm;
335 if (shmmap_s == NULL)
336 return (EINVAL);
337 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
338 if (shmmap_s->shmid != -1 &&
339 shmmap_s->va == (vm_offset_t)shmaddr) {
340 break;
341 }
342 }
343 if (i == shminfo.shmseg)
344 return (EINVAL);
345 #ifdef MAC
346 shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)];
347 error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr);
348 if (error != 0)
349 return (error);
350 #endif
351 error = shm_delete_mapping(p->p_vmspace, shmmap_s);
352 return (error);
353 }
354
355 #ifndef _SYS_SYSPROTO_H_
356 struct shmdt_args {
357 const void *shmaddr;
358 };
359 #endif
360 int
361 sys_shmdt(struct thread *td, struct shmdt_args *uap)
362 {
363 int error;
364
365 SYSVSHM_LOCK();
366 error = kern_shmdt_locked(td, uap->shmaddr);
367 SYSVSHM_UNLOCK();
368 return (error);
369 }
370
371 static int
372 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr,
373 int shmflg)
374 {
375 struct prison *rpr;
376 struct proc *p = td->td_proc;
377 struct shmid_kernel *shmseg;
378 struct shmmap_state *shmmap_s;
379 vm_offset_t attach_va;
380 vm_prot_t prot;
381 vm_size_t size;
382 int error, i, rv;
383
384 SYSVSHM_ASSERT_LOCKED();
385 rpr = shm_find_prison(td->td_ucred);
386 if (rpr == NULL)
387 return (ENOSYS);
388 shmmap_s = p->p_vmspace->vm_shm;
389 if (shmmap_s == NULL) {
390 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state),
391 M_SHM, M_WAITOK);
392 for (i = 0; i < shminfo.shmseg; i++)
393 shmmap_s[i].shmid = -1;
394 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced"));
395 p->p_vmspace->vm_shm = shmmap_s;
396 }
397 shmseg = shm_find_segment(rpr, shmid, true);
398 if (shmseg == NULL)
399 return (EINVAL);
400 error = ipcperm(td, &shmseg->u.shm_perm,
401 (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
402 if (error != 0)
403 return (error);
404 #ifdef MAC
405 error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg);
406 if (error != 0)
407 return (error);
408 #endif
409 for (i = 0; i < shminfo.shmseg; i++) {
410 if (shmmap_s->shmid == -1)
411 break;
412 shmmap_s++;
413 }
414 if (i >= shminfo.shmseg)
415 return (EMFILE);
416 size = round_page(shmseg->u.shm_segsz);
417 prot = VM_PROT_READ;
418 if ((shmflg & SHM_RDONLY) == 0)
419 prot |= VM_PROT_WRITE;
420 if (shmaddr != NULL) {
421 if ((shmflg & SHM_RND) != 0)
422 attach_va = (vm_offset_t)shmaddr & ~(SHMLBA-1);
423 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0)
424 attach_va = (vm_offset_t)shmaddr;
425 else
426 return (EINVAL);
427 } else {
428 /*
429 * This is just a hint to vm_map_find() about where to
430 * put it.
431 */
432 PROC_LOCK(p);
433 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr +
434 lim_max(p, RLIMIT_DATA));
435 PROC_UNLOCK(p);
436 }
437
438 vm_object_reference(shmseg->object);
439 rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object,
440 0, &attach_va, size, 0, shmaddr != NULL ? VMFS_NO_SPACE :
441 VMFS_OPTIMAL_SPACE, prot, prot, MAP_INHERIT_SHARE);
442 if (rv != KERN_SUCCESS) {
443 vm_object_deallocate(shmseg->object);
444 return (ENOMEM);
445 }
446
447 shmmap_s->va = attach_va;
448 shmmap_s->shmid = shmid;
449 shmseg->u.shm_lpid = p->p_pid;
450 shmseg->u.shm_atime = time_second;
451 shmseg->u.shm_nattch++;
452 td->td_retval[0] = attach_va;
453 return (error);
454 }
455
456 int
457 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg)
458 {
459 int error;
460
461 SYSVSHM_LOCK();
462 error = kern_shmat_locked(td, shmid, shmaddr, shmflg);
463 SYSVSHM_UNLOCK();
464 return (error);
465 }
466
467 #ifndef _SYS_SYSPROTO_H_
468 struct shmat_args {
469 int shmid;
470 const void *shmaddr;
471 int shmflg;
472 };
473 #endif
474 int
475 sys_shmat(struct thread *td, struct shmat_args *uap)
476 {
477
478 return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg));
479 }
480
481 static int
482 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf,
483 size_t *bufsz)
484 {
485 struct prison *rpr;
486 struct shmid_kernel *shmseg;
487 struct shmid_ds *shmidp;
488 struct shm_info shm_info;
489 int error;
490
491 SYSVSHM_ASSERT_LOCKED();
492
493 rpr = shm_find_prison(td->td_ucred);
494 if (rpr == NULL)
495 return (ENOSYS);
496
497 error = 0;
498 switch (cmd) {
499 /*
500 * It is possible that kern_shmctl is being called from the Linux ABI
501 * layer, in which case, we will need to implement IPC_INFO. It should
502 * be noted that other shmctl calls will be funneled through here for
503 * Linix binaries as well.
504 *
505 * NB: The Linux ABI layer will convert this data to structure(s) more
506 * consistent with the Linux ABI.
507 */
508 case IPC_INFO:
509 memcpy(buf, &shminfo, sizeof(shminfo));
510 if (bufsz)
511 *bufsz = sizeof(shminfo);
512 td->td_retval[0] = shmalloced;
513 return (0);
514 case SHM_INFO: {
515 shm_info.used_ids = shm_nused;
516 shm_info.shm_rss = 0; /*XXX where to get from ? */
517 shm_info.shm_tot = 0; /*XXX where to get from ? */
518 shm_info.shm_swp = 0; /*XXX where to get from ? */
519 shm_info.swap_attempts = 0; /*XXX where to get from ? */
520 shm_info.swap_successes = 0; /*XXX where to get from ? */
521 memcpy(buf, &shm_info, sizeof(shm_info));
522 if (bufsz != NULL)
523 *bufsz = sizeof(shm_info);
524 td->td_retval[0] = shmalloced;
525 return (0);
526 }
527 }
528 shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT);
529 if (shmseg == NULL)
530 return (EINVAL);
531 #ifdef MAC
532 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd);
533 if (error != 0)
534 return (error);
535 #endif
536 switch (cmd) {
537 case SHM_STAT:
538 case IPC_STAT:
539 shmidp = (struct shmid_ds *)buf;
540 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
541 if (error != 0)
542 return (error);
543 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds));
544 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison)
545 shmidp->shm_perm.key = IPC_PRIVATE;
546 if (bufsz != NULL)
547 *bufsz = sizeof(struct shmid_ds);
548 if (cmd == SHM_STAT) {
549 td->td_retval[0] = IXSEQ_TO_IPCID(shmid,
550 shmseg->u.shm_perm);
551 }
552 break;
553 case IPC_SET:
554 shmidp = (struct shmid_ds *)buf;
555 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
556 if (error != 0)
557 return (error);
558 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid;
559 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid;
560 shmseg->u.shm_perm.mode =
561 (shmseg->u.shm_perm.mode & ~ACCESSPERMS) |
562 (shmidp->shm_perm.mode & ACCESSPERMS);
563 shmseg->u.shm_ctime = time_second;
564 break;
565 case IPC_RMID:
566 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
567 if (error != 0)
568 return (error);
569 shm_remove(shmseg, IPCID_TO_IX(shmid));
570 break;
571 #if 0
572 case SHM_LOCK:
573 case SHM_UNLOCK:
574 #endif
575 default:
576 error = EINVAL;
577 break;
578 }
579 return (error);
580 }
581
582 int
583 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz)
584 {
585 int error;
586
587 SYSVSHM_LOCK();
588 error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz);
589 SYSVSHM_UNLOCK();
590 return (error);
591 }
592
593
594 #ifndef _SYS_SYSPROTO_H_
595 struct shmctl_args {
596 int shmid;
597 int cmd;
598 struct shmid_ds *buf;
599 };
600 #endif
601 int
602 sys_shmctl(struct thread *td, struct shmctl_args *uap)
603 {
604 int error = 0;
605 struct shmid_ds buf;
606 size_t bufsz;
607
608 /*
609 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
610 * Linux binaries. If we see the call come through the FreeBSD ABI,
611 * return an error back to the user since we do not to support this.
612 */
613 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
614 uap->cmd == SHM_STAT)
615 return (EINVAL);
616
617 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
618 if (uap->cmd == IPC_SET) {
619 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
620 goto done;
621 }
622
623 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
624 if (error)
625 goto done;
626
627 /* Cases in which we need to copyout */
628 switch (uap->cmd) {
629 case IPC_STAT:
630 error = copyout(&buf, uap->buf, bufsz);
631 break;
632 }
633
634 done:
635 if (error) {
636 /* Invalidate the return value */
637 td->td_retval[0] = -1;
638 }
639 return (error);
640 }
641
642
643 static int
644 shmget_existing(struct thread *td, struct shmget_args *uap, int mode,
645 int segnum)
646 {
647 struct shmid_kernel *shmseg;
648 #ifdef MAC
649 int error;
650 #endif
651
652 SYSVSHM_ASSERT_LOCKED();
653 KASSERT(segnum >= 0 && segnum < shmalloced,
654 ("segnum %d shmalloced %d", segnum, shmalloced));
655 shmseg = &shmsegs[segnum];
656 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
657 return (EEXIST);
658 #ifdef MAC
659 error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg);
660 if (error != 0)
661 return (error);
662 #endif
663 if (uap->size != 0 && uap->size > shmseg->u.shm_segsz)
664 return (EINVAL);
665 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
666 return (0);
667 }
668
669 static int
670 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode)
671 {
672 struct ucred *cred = td->td_ucred;
673 struct shmid_kernel *shmseg;
674 vm_object_t shm_object;
675 int i, segnum;
676 size_t size;
677
678 SYSVSHM_ASSERT_LOCKED();
679
680 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
681 return (EINVAL);
682 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
683 return (ENOSPC);
684 size = round_page(uap->size);
685 if (shm_committed + btoc(size) > shminfo.shmall)
686 return (ENOMEM);
687 if (shm_last_free < 0) {
688 shmrealloc(); /* Maybe expand the shmsegs[] array. */
689 for (i = 0; i < shmalloced; i++)
690 if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE)
691 break;
692 if (i == shmalloced)
693 return (ENOSPC);
694 segnum = i;
695 } else {
696 segnum = shm_last_free;
697 shm_last_free = -1;
698 }
699 KASSERT(segnum >= 0 && segnum < shmalloced,
700 ("segnum %d shmalloced %d", segnum, shmalloced));
701 shmseg = &shmsegs[segnum];
702 #ifdef RACCT
703 if (racct_enable) {
704 PROC_LOCK(td->td_proc);
705 if (racct_add(td->td_proc, RACCT_NSHM, 1)) {
706 PROC_UNLOCK(td->td_proc);
707 return (ENOSPC);
708 }
709 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) {
710 racct_sub(td->td_proc, RACCT_NSHM, 1);
711 PROC_UNLOCK(td->td_proc);
712 return (ENOMEM);
713 }
714 PROC_UNLOCK(td->td_proc);
715 }
716 #endif
717
718 /*
719 * We make sure that we have allocated a pager before we need
720 * to.
721 */
722 shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP,
723 0, size, VM_PROT_DEFAULT, 0, cred);
724 if (shm_object == NULL) {
725 #ifdef RACCT
726 if (racct_enable) {
727 PROC_LOCK(td->td_proc);
728 racct_sub(td->td_proc, RACCT_NSHM, 1);
729 racct_sub(td->td_proc, RACCT_SHMSIZE, size);
730 PROC_UNLOCK(td->td_proc);
731 }
732 #endif
733 return (ENOMEM);
734 }
735 shm_object->pg_color = 0;
736 VM_OBJECT_WLOCK(shm_object);
737 vm_object_clear_flag(shm_object, OBJ_ONEMAPPING);
738 vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT);
739 VM_OBJECT_WUNLOCK(shm_object);
740
741 shmseg->object = shm_object;
742 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid;
743 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid;
744 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
745 shmseg->u.shm_perm.key = uap->key;
746 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff;
747 shmseg->cred = crhold(cred);
748 shmseg->u.shm_segsz = uap->size;
749 shmseg->u.shm_cpid = td->td_proc->p_pid;
750 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0;
751 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0;
752 #ifdef MAC
753 mac_sysvshm_create(cred, shmseg);
754 #endif
755 shmseg->u.shm_ctime = time_second;
756 shm_committed += btoc(size);
757 shm_nused++;
758 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
759
760 return (0);
761 }
762
763 #ifndef _SYS_SYSPROTO_H_
764 struct shmget_args {
765 key_t key;
766 size_t size;
767 int shmflg;
768 };
769 #endif
770 int
771 sys_shmget(struct thread *td, struct shmget_args *uap)
772 {
773 int segnum, mode;
774 int error;
775
776 if (shm_find_prison(td->td_ucred) == NULL)
777 return (ENOSYS);
778 mode = uap->shmflg & ACCESSPERMS;
779 SYSVSHM_LOCK();
780 if (uap->key == IPC_PRIVATE) {
781 error = shmget_allocate_segment(td, uap, mode);
782 } else {
783 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison,
784 uap->key);
785 if (segnum >= 0)
786 error = shmget_existing(td, uap, mode, segnum);
787 else if ((uap->shmflg & IPC_CREAT) == 0)
788 error = ENOENT;
789 else
790 error = shmget_allocate_segment(td, uap, mode);
791 }
792 SYSVSHM_UNLOCK();
793 return (error);
794 }
795
796 static void
797 shmfork_myhook(struct proc *p1, struct proc *p2)
798 {
799 struct shmmap_state *shmmap_s;
800 size_t size;
801 int i;
802
803 SYSVSHM_LOCK();
804 size = shminfo.shmseg * sizeof(struct shmmap_state);
805 shmmap_s = malloc(size, M_SHM, M_WAITOK);
806 bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
807 p2->p_vmspace->vm_shm = shmmap_s;
808 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
809 if (shmmap_s->shmid != -1) {
810 KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 &&
811 IPCID_TO_IX(shmmap_s->shmid) < shmalloced,
812 ("segnum %d shmalloced %d",
813 IPCID_TO_IX(shmmap_s->shmid), shmalloced));
814 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++;
815 }
816 }
817 SYSVSHM_UNLOCK();
818 }
819
820 static void
821 shmexit_myhook(struct vmspace *vm)
822 {
823 struct shmmap_state *base, *shm;
824 int i;
825
826 base = vm->vm_shm;
827 if (base != NULL) {
828 vm->vm_shm = NULL;
829 SYSVSHM_LOCK();
830 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
831 if (shm->shmid != -1)
832 shm_delete_mapping(vm, shm);
833 }
834 SYSVSHM_UNLOCK();
835 free(base, M_SHM);
836 }
837 }
838
839 static void
840 shmrealloc(void)
841 {
842 struct shmid_kernel *newsegs;
843 int i;
844
845 SYSVSHM_ASSERT_LOCKED();
846
847 if (shmalloced >= shminfo.shmmni)
848 return;
849
850 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
851 for (i = 0; i < shmalloced; i++)
852 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
853 for (; i < shminfo.shmmni; i++) {
854 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
855 shmsegs[i].u.shm_perm.seq = 0;
856 #ifdef MAC
857 mac_sysvshm_init(&shmsegs[i]);
858 #endif
859 }
860 free(shmsegs, M_SHM);
861 shmsegs = newsegs;
862 shmalloced = shminfo.shmmni;
863 }
864
865 static struct syscall_helper_data shm_syscalls[] = {
866 SYSCALL_INIT_HELPER(shmat),
867 SYSCALL_INIT_HELPER(shmctl),
868 SYSCALL_INIT_HELPER(shmdt),
869 SYSCALL_INIT_HELPER(shmget),
870 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
871 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
872 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl),
873 #endif
874 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
875 SYSCALL_INIT_HELPER(shmsys),
876 #endif
877 SYSCALL_INIT_LAST
878 };
879
880 #ifdef COMPAT_FREEBSD32
881 #include <compat/freebsd32/freebsd32.h>
882 #include <compat/freebsd32/freebsd32_ipc.h>
883 #include <compat/freebsd32/freebsd32_proto.h>
884 #include <compat/freebsd32/freebsd32_signal.h>
885 #include <compat/freebsd32/freebsd32_syscall.h>
886 #include <compat/freebsd32/freebsd32_util.h>
887
888 static struct syscall_helper_data shm32_syscalls[] = {
889 SYSCALL32_INIT_HELPER_COMPAT(shmat),
890 SYSCALL32_INIT_HELPER_COMPAT(shmdt),
891 SYSCALL32_INIT_HELPER_COMPAT(shmget),
892 SYSCALL32_INIT_HELPER(freebsd32_shmsys),
893 SYSCALL32_INIT_HELPER(freebsd32_shmctl),
894 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
895 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
896 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
897 #endif
898 SYSCALL_INIT_LAST
899 };
900 #endif
901
902 static int
903 shminit(void)
904 {
905 struct prison *pr;
906 void *rsv;
907 int i, error;
908 osd_method_t methods[PR_MAXMETHOD] = {
909 [PR_METHOD_CHECK] = shm_prison_check,
910 [PR_METHOD_SET] = shm_prison_set,
911 [PR_METHOD_GET] = shm_prison_get,
912 [PR_METHOD_REMOVE] = shm_prison_remove,
913 };
914
915 #ifndef BURN_BRIDGES
916 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
917 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
918 #endif
919 TUNABLE_ULONG_FETCH("kern.ipc.shmall", &shminfo.shmall);
920 if (!TUNABLE_ULONG_FETCH("kern.ipc.shmmax", &shminfo.shmmax)) {
921 /* Initialize shmmax dealing with possible overflow. */
922 for (i = PAGE_SIZE; i > 0; i--) {
923 shminfo.shmmax = shminfo.shmall * i;
924 if (shminfo.shmmax >= shminfo.shmall)
925 break;
926 }
927 }
928 TUNABLE_ULONG_FETCH("kern.ipc.shmmin", &shminfo.shmmin);
929 TUNABLE_ULONG_FETCH("kern.ipc.shmmni", &shminfo.shmmni);
930 TUNABLE_ULONG_FETCH("kern.ipc.shmseg", &shminfo.shmseg);
931 TUNABLE_INT_FETCH("kern.ipc.shm_use_phys", &shm_use_phys);
932
933 shmalloced = shminfo.shmmni;
934 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
935 for (i = 0; i < shmalloced; i++) {
936 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
937 shmsegs[i].u.shm_perm.seq = 0;
938 #ifdef MAC
939 mac_sysvshm_init(&shmsegs[i]);
940 #endif
941 }
942 shm_last_free = 0;
943 shm_nused = 0;
944 shm_committed = 0;
945 sx_init(&sysvshmsx, "sysvshmsx");
946 shmexit_hook = &shmexit_myhook;
947 shmfork_hook = &shmfork_myhook;
948
949 /* Set current prisons according to their allow.sysvipc. */
950 shm_prison_slot = osd_jail_register(NULL, methods);
951 rsv = osd_reserve(shm_prison_slot);
952 prison_lock(&prison0);
953 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0);
954 prison_unlock(&prison0);
955 rsv = NULL;
956 sx_slock(&allprison_lock);
957 TAILQ_FOREACH(pr, &allprison, pr_list) {
958 if (rsv == NULL)
959 rsv = osd_reserve(shm_prison_slot);
960 prison_lock(pr);
961 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
962 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
963 &prison0);
964 rsv = NULL;
965 }
966 prison_unlock(pr);
967 }
968 if (rsv != NULL)
969 osd_free_reserved(rsv);
970 sx_sunlock(&allprison_lock);
971
972 error = syscall_helper_register(shm_syscalls);
973 if (error != 0)
974 return (error);
975 #ifdef COMPAT_FREEBSD32
976 error = syscall32_helper_register(shm32_syscalls);
977 if (error != 0)
978 return (error);
979 #endif
980 return (0);
981 }
982
983 static int
984 shmunload(void)
985 {
986 int i;
987
988 if (shm_nused > 0)
989 return (EBUSY);
990
991 #ifdef COMPAT_FREEBSD32
992 syscall32_helper_unregister(shm32_syscalls);
993 #endif
994 syscall_helper_unregister(shm_syscalls);
995 if (shm_prison_slot != 0)
996 osd_jail_deregister(shm_prison_slot);
997
998 for (i = 0; i < shmalloced; i++) {
999 #ifdef MAC
1000 mac_sysvshm_destroy(&shmsegs[i]);
1001 #endif
1002 /*
1003 * Objects might be still mapped into the processes
1004 * address spaces. Actual free would happen on the
1005 * last mapping destruction.
1006 */
1007 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
1008 vm_object_deallocate(shmsegs[i].object);
1009 }
1010 free(shmsegs, M_SHM);
1011 shmexit_hook = NULL;
1012 shmfork_hook = NULL;
1013 sx_destroy(&sysvshmsx);
1014 return (0);
1015 }
1016
1017 static int
1018 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
1019 {
1020 struct shmid_kernel tshmseg;
1021 struct prison *pr, *rpr;
1022 int error, i;
1023
1024 SYSVSHM_LOCK();
1025 pr = req->td->td_ucred->cr_prison;
1026 rpr = shm_find_prison(req->td->td_ucred);
1027 error = 0;
1028 for (i = 0; i < shmalloced; i++) {
1029 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
1030 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
1031 bzero(&tshmseg, sizeof(tshmseg));
1032 tshmseg.u.shm_perm.mode = SHMSEG_FREE;
1033 } else {
1034 tshmseg = shmsegs[i];
1035 if (tshmseg.cred->cr_prison != pr)
1036 tshmseg.u.shm_perm.key = IPC_PRIVATE;
1037 }
1038 error = SYSCTL_OUT(req, &tshmseg, sizeof(tshmseg));
1039 if (error != 0)
1040 break;
1041 }
1042 SYSVSHM_UNLOCK();
1043 return (error);
1044 }
1045
1046 static int
1047 shm_prison_check(void *obj, void *data)
1048 {
1049 struct prison *pr = obj;
1050 struct prison *prpr;
1051 struct vfsoptlist *opts = data;
1052 int error, jsys;
1053
1054 /*
1055 * sysvshm is a jailsys integer.
1056 * It must be "disable" if the parent jail is disabled.
1057 */
1058 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys));
1059 if (error != ENOENT) {
1060 if (error != 0)
1061 return (error);
1062 switch (jsys) {
1063 case JAIL_SYS_DISABLE:
1064 break;
1065 case JAIL_SYS_NEW:
1066 case JAIL_SYS_INHERIT:
1067 prison_lock(pr->pr_parent);
1068 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1069 prison_unlock(pr->pr_parent);
1070 if (prpr == NULL)
1071 return (EPERM);
1072 break;
1073 default:
1074 return (EINVAL);
1075 }
1076 }
1077
1078 return (0);
1079 }
1080
1081 static int
1082 shm_prison_set(void *obj, void *data)
1083 {
1084 struct prison *pr = obj;
1085 struct prison *tpr, *orpr, *nrpr, *trpr;
1086 struct vfsoptlist *opts = data;
1087 void *rsv;
1088 int jsys, descend;
1089
1090 /*
1091 * sysvshm controls which jail is the root of the associated segments
1092 * (this jail or same as the parent), or if the feature is available
1093 * at all.
1094 */
1095 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT)
1096 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1097 ? JAIL_SYS_INHERIT
1098 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1099 ? JAIL_SYS_DISABLE
1100 : -1;
1101 if (jsys == JAIL_SYS_DISABLE) {
1102 prison_lock(pr);
1103 orpr = osd_jail_get(pr, shm_prison_slot);
1104 if (orpr != NULL)
1105 osd_jail_del(pr, shm_prison_slot);
1106 prison_unlock(pr);
1107 if (orpr != NULL) {
1108 if (orpr == pr)
1109 shm_prison_cleanup(pr);
1110 /* Disable all child jails as well. */
1111 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1112 prison_lock(tpr);
1113 trpr = osd_jail_get(tpr, shm_prison_slot);
1114 if (trpr != NULL) {
1115 osd_jail_del(tpr, shm_prison_slot);
1116 prison_unlock(tpr);
1117 if (trpr == tpr)
1118 shm_prison_cleanup(tpr);
1119 } else {
1120 prison_unlock(tpr);
1121 descend = 0;
1122 }
1123 }
1124 }
1125 } else if (jsys != -1) {
1126 if (jsys == JAIL_SYS_NEW)
1127 nrpr = pr;
1128 else {
1129 prison_lock(pr->pr_parent);
1130 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1131 prison_unlock(pr->pr_parent);
1132 }
1133 rsv = osd_reserve(shm_prison_slot);
1134 prison_lock(pr);
1135 orpr = osd_jail_get(pr, shm_prison_slot);
1136 if (orpr != nrpr)
1137 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
1138 nrpr);
1139 else
1140 osd_free_reserved(rsv);
1141 prison_unlock(pr);
1142 if (orpr != nrpr) {
1143 if (orpr == pr)
1144 shm_prison_cleanup(pr);
1145 if (orpr != NULL) {
1146 /* Change child jails matching the old root, */
1147 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1148 prison_lock(tpr);
1149 trpr = osd_jail_get(tpr,
1150 shm_prison_slot);
1151 if (trpr == orpr) {
1152 (void)osd_jail_set(tpr,
1153 shm_prison_slot, nrpr);
1154 prison_unlock(tpr);
1155 if (trpr == tpr)
1156 shm_prison_cleanup(tpr);
1157 } else {
1158 prison_unlock(tpr);
1159 descend = 0;
1160 }
1161 }
1162 }
1163 }
1164 }
1165
1166 return (0);
1167 }
1168
1169 static int
1170 shm_prison_get(void *obj, void *data)
1171 {
1172 struct prison *pr = obj;
1173 struct prison *rpr;
1174 struct vfsoptlist *opts = data;
1175 int error, jsys;
1176
1177 /* Set sysvshm based on the jail's root prison. */
1178 prison_lock(pr);
1179 rpr = osd_jail_get(pr, shm_prison_slot);
1180 prison_unlock(pr);
1181 jsys = rpr == NULL ? JAIL_SYS_DISABLE
1182 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1183 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys));
1184 if (error == ENOENT)
1185 error = 0;
1186 return (error);
1187 }
1188
1189 static int
1190 shm_prison_remove(void *obj, void *data __unused)
1191 {
1192 struct prison *pr = obj;
1193 struct prison *rpr;
1194
1195 SYSVSHM_LOCK();
1196 prison_lock(pr);
1197 rpr = osd_jail_get(pr, shm_prison_slot);
1198 prison_unlock(pr);
1199 if (rpr == pr)
1200 shm_prison_cleanup(pr);
1201 SYSVSHM_UNLOCK();
1202 return (0);
1203 }
1204
1205 static void
1206 shm_prison_cleanup(struct prison *pr)
1207 {
1208 struct shmid_kernel *shmseg;
1209 int i;
1210
1211 /* Remove any segments that belong to this jail. */
1212 for (i = 0; i < shmalloced; i++) {
1213 shmseg = &shmsegs[i];
1214 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) &&
1215 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) {
1216 shm_remove(shmseg, i);
1217 }
1218 }
1219 }
1220
1221 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory");
1222
1223 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
1224 struct oshmid_ds {
1225 struct ipc_perm_old shm_perm; /* operation perms */
1226 int shm_segsz; /* size of segment (bytes) */
1227 u_short shm_cpid; /* pid, creator */
1228 u_short shm_lpid; /* pid, last operation */
1229 short shm_nattch; /* no. of current attaches */
1230 time_t shm_atime; /* last attach time */
1231 time_t shm_dtime; /* last detach time */
1232 time_t shm_ctime; /* last change time */
1233 void *shm_handle; /* internal handle for shm segment */
1234 };
1235
1236 struct oshmctl_args {
1237 int shmid;
1238 int cmd;
1239 struct oshmid_ds *ubuf;
1240 };
1241
1242 static int
1243 oshmctl(struct thread *td, struct oshmctl_args *uap)
1244 {
1245 #ifdef COMPAT_43
1246 int error = 0;
1247 struct prison *rpr;
1248 struct shmid_kernel *shmseg;
1249 struct oshmid_ds outbuf;
1250
1251 rpr = shm_find_prison(td->td_ucred);
1252 if (rpr == NULL)
1253 return (ENOSYS);
1254 if (uap->cmd != IPC_STAT) {
1255 return (freebsd7_shmctl(td,
1256 (struct freebsd7_shmctl_args *)uap));
1257 }
1258 SYSVSHM_LOCK();
1259 shmseg = shm_find_segment(rpr, uap->shmid, true);
1260 if (shmseg == NULL) {
1261 SYSVSHM_UNLOCK();
1262 return (EINVAL);
1263 }
1264 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
1265 if (error != 0) {
1266 SYSVSHM_UNLOCK();
1267 return (error);
1268 }
1269 #ifdef MAC
1270 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
1271 if (error != 0) {
1272 SYSVSHM_UNLOCK();
1273 return (error);
1274 }
1275 #endif
1276 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
1277 outbuf.shm_segsz = shmseg->u.shm_segsz;
1278 outbuf.shm_cpid = shmseg->u.shm_cpid;
1279 outbuf.shm_lpid = shmseg->u.shm_lpid;
1280 outbuf.shm_nattch = shmseg->u.shm_nattch;
1281 outbuf.shm_atime = shmseg->u.shm_atime;
1282 outbuf.shm_dtime = shmseg->u.shm_dtime;
1283 outbuf.shm_ctime = shmseg->u.shm_ctime;
1284 outbuf.shm_handle = shmseg->object;
1285 SYSVSHM_UNLOCK();
1286 error = copyout(&outbuf, uap->ubuf, sizeof(outbuf));
1287 return (error);
1288 #else
1289 return (EINVAL);
1290 #endif
1291 }
1292
1293 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1294 static sy_call_t *shmcalls[] = {
1295 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl,
1296 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
1297 (sy_call_t *)freebsd7_shmctl
1298 };
1299
1300 #ifndef _SYS_SYSPROTO_H_
1301 /* XXX actually varargs. */
1302 struct shmsys_args {
1303 int which;
1304 int a2;
1305 int a3;
1306 int a4;
1307 };
1308 #endif
1309 int
1310 sys_shmsys(struct thread *td, struct shmsys_args *uap)
1311 {
1312 int error;
1313
1314 if (uap->which < 0 || uap->which >= nitems(shmcalls))
1315 return (EINVAL);
1316 error = (*shmcalls[uap->which])(td, &uap->a2);
1317 return (error);
1318 }
1319
1320 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */
1321
1322 #ifdef COMPAT_FREEBSD32
1323
1324 int
1325 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
1326 {
1327
1328 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1329 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1330 switch (uap->which) {
1331 case 0: { /* shmat */
1332 struct shmat_args ap;
1333
1334 ap.shmid = uap->a2;
1335 ap.shmaddr = PTRIN(uap->a3);
1336 ap.shmflg = uap->a4;
1337 return (sysent[SYS_shmat].sy_call(td, &ap));
1338 }
1339 case 2: { /* shmdt */
1340 struct shmdt_args ap;
1341
1342 ap.shmaddr = PTRIN(uap->a2);
1343 return (sysent[SYS_shmdt].sy_call(td, &ap));
1344 }
1345 case 3: { /* shmget */
1346 struct shmget_args ap;
1347
1348 ap.key = uap->a2;
1349 ap.size = uap->a3;
1350 ap.shmflg = uap->a4;
1351 return (sysent[SYS_shmget].sy_call(td, &ap));
1352 }
1353 case 4: { /* shmctl */
1354 struct freebsd7_freebsd32_shmctl_args ap;
1355
1356 ap.shmid = uap->a2;
1357 ap.cmd = uap->a3;
1358 ap.buf = PTRIN(uap->a4);
1359 return (freebsd7_freebsd32_shmctl(td, &ap));
1360 }
1361 case 1: /* oshmctl */
1362 default:
1363 return (EINVAL);
1364 }
1365 #else
1366 return (nosys(td, NULL));
1367 #endif
1368 }
1369
1370 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1371 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1372 int
1373 freebsd7_freebsd32_shmctl(struct thread *td,
1374 struct freebsd7_freebsd32_shmctl_args *uap)
1375 {
1376 int error = 0;
1377 union {
1378 struct shmid_ds shmid_ds;
1379 struct shm_info shm_info;
1380 struct shminfo shminfo;
1381 } u;
1382 union {
1383 struct shmid_ds32_old shmid_ds32;
1384 struct shm_info32 shm_info32;
1385 struct shminfo32 shminfo32;
1386 } u32;
1387 size_t sz;
1388
1389 if (uap->cmd == IPC_SET) {
1390 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1391 sizeof(u32.shmid_ds32))))
1392 goto done;
1393 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
1394 &u.shmid_ds.shm_perm);
1395 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1396 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1397 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1398 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1399 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1400 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1401 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1402 }
1403
1404 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1405 if (error)
1406 goto done;
1407
1408 /* Cases in which we need to copyout */
1409 switch (uap->cmd) {
1410 case IPC_INFO:
1411 CP(u.shminfo, u32.shminfo32, shmmax);
1412 CP(u.shminfo, u32.shminfo32, shmmin);
1413 CP(u.shminfo, u32.shminfo32, shmmni);
1414 CP(u.shminfo, u32.shminfo32, shmseg);
1415 CP(u.shminfo, u32.shminfo32, shmall);
1416 error = copyout(&u32.shminfo32, uap->buf,
1417 sizeof(u32.shminfo32));
1418 break;
1419 case SHM_INFO:
1420 CP(u.shm_info, u32.shm_info32, used_ids);
1421 CP(u.shm_info, u32.shm_info32, shm_rss);
1422 CP(u.shm_info, u32.shm_info32, shm_tot);
1423 CP(u.shm_info, u32.shm_info32, shm_swp);
1424 CP(u.shm_info, u32.shm_info32, swap_attempts);
1425 CP(u.shm_info, u32.shm_info32, swap_successes);
1426 error = copyout(&u32.shm_info32, uap->buf,
1427 sizeof(u32.shm_info32));
1428 break;
1429 case SHM_STAT:
1430 case IPC_STAT:
1431 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
1432 &u32.shmid_ds32.shm_perm);
1433 if (u.shmid_ds.shm_segsz > INT32_MAX)
1434 u32.shmid_ds32.shm_segsz = INT32_MAX;
1435 else
1436 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1437 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1438 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1439 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1440 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1441 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1442 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1443 u32.shmid_ds32.shm_internal = 0;
1444 error = copyout(&u32.shmid_ds32, uap->buf,
1445 sizeof(u32.shmid_ds32));
1446 break;
1447 }
1448
1449 done:
1450 if (error) {
1451 /* Invalidate the return value */
1452 td->td_retval[0] = -1;
1453 }
1454 return (error);
1455 }
1456 #endif
1457
1458 int
1459 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
1460 {
1461 int error = 0;
1462 union {
1463 struct shmid_ds shmid_ds;
1464 struct shm_info shm_info;
1465 struct shminfo shminfo;
1466 } u;
1467 union {
1468 struct shmid_ds32 shmid_ds32;
1469 struct shm_info32 shm_info32;
1470 struct shminfo32 shminfo32;
1471 } u32;
1472 size_t sz;
1473
1474 if (uap->cmd == IPC_SET) {
1475 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1476 sizeof(u32.shmid_ds32))))
1477 goto done;
1478 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
1479 &u.shmid_ds.shm_perm);
1480 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1481 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1482 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1483 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1484 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1485 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1486 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1487 }
1488
1489 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1490 if (error)
1491 goto done;
1492
1493 /* Cases in which we need to copyout */
1494 switch (uap->cmd) {
1495 case IPC_INFO:
1496 CP(u.shminfo, u32.shminfo32, shmmax);
1497 CP(u.shminfo, u32.shminfo32, shmmin);
1498 CP(u.shminfo, u32.shminfo32, shmmni);
1499 CP(u.shminfo, u32.shminfo32, shmseg);
1500 CP(u.shminfo, u32.shminfo32, shmall);
1501 error = copyout(&u32.shminfo32, uap->buf,
1502 sizeof(u32.shminfo32));
1503 break;
1504 case SHM_INFO:
1505 CP(u.shm_info, u32.shm_info32, used_ids);
1506 CP(u.shm_info, u32.shm_info32, shm_rss);
1507 CP(u.shm_info, u32.shm_info32, shm_tot);
1508 CP(u.shm_info, u32.shm_info32, shm_swp);
1509 CP(u.shm_info, u32.shm_info32, swap_attempts);
1510 CP(u.shm_info, u32.shm_info32, swap_successes);
1511 error = copyout(&u32.shm_info32, uap->buf,
1512 sizeof(u32.shm_info32));
1513 break;
1514 case SHM_STAT:
1515 case IPC_STAT:
1516 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
1517 &u32.shmid_ds32.shm_perm);
1518 if (u.shmid_ds.shm_segsz > INT32_MAX)
1519 u32.shmid_ds32.shm_segsz = INT32_MAX;
1520 else
1521 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1522 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1523 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1524 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1525 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1526 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1527 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1528 error = copyout(&u32.shmid_ds32, uap->buf,
1529 sizeof(u32.shmid_ds32));
1530 break;
1531 }
1532
1533 done:
1534 if (error) {
1535 /* Invalidate the return value */
1536 td->td_retval[0] = -1;
1537 }
1538 return (error);
1539 }
1540 #endif
1541
1542 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1543 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1544
1545 #ifndef CP
1546 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0)
1547 #endif
1548
1549 #ifndef _SYS_SYSPROTO_H_
1550 struct freebsd7_shmctl_args {
1551 int shmid;
1552 int cmd;
1553 struct shmid_ds_old *buf;
1554 };
1555 #endif
1556 int
1557 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap)
1558 {
1559 int error = 0;
1560 struct shmid_ds_old old;
1561 struct shmid_ds buf;
1562 size_t bufsz;
1563
1564 /*
1565 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
1566 * Linux binaries. If we see the call come through the FreeBSD ABI,
1567 * return an error back to the user since we do not to support this.
1568 */
1569 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
1570 uap->cmd == SHM_STAT)
1571 return (EINVAL);
1572
1573 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
1574 if (uap->cmd == IPC_SET) {
1575 if ((error = copyin(uap->buf, &old, sizeof(old))))
1576 goto done;
1577 ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
1578 CP(old, buf, shm_segsz);
1579 CP(old, buf, shm_lpid);
1580 CP(old, buf, shm_cpid);
1581 CP(old, buf, shm_nattch);
1582 CP(old, buf, shm_atime);
1583 CP(old, buf, shm_dtime);
1584 CP(old, buf, shm_ctime);
1585 }
1586
1587 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
1588 if (error)
1589 goto done;
1590
1591 /* Cases in which we need to copyout */
1592 switch (uap->cmd) {
1593 case IPC_STAT:
1594 ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
1595 if (buf.shm_segsz > INT_MAX)
1596 old.shm_segsz = INT_MAX;
1597 else
1598 CP(buf, old, shm_segsz);
1599 CP(buf, old, shm_lpid);
1600 CP(buf, old, shm_cpid);
1601 if (buf.shm_nattch > SHRT_MAX)
1602 old.shm_nattch = SHRT_MAX;
1603 else
1604 CP(buf, old, shm_nattch);
1605 CP(buf, old, shm_atime);
1606 CP(buf, old, shm_dtime);
1607 CP(buf, old, shm_ctime);
1608 old.shm_internal = NULL;
1609 error = copyout(&old, uap->buf, sizeof(old));
1610 break;
1611 }
1612
1613 done:
1614 if (error) {
1615 /* Invalidate the return value */
1616 td->td_retval[0] = -1;
1617 }
1618 return (error);
1619 }
1620
1621 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1622 COMPAT_FREEBSD7 */
1623
1624 static int
1625 sysvshm_modload(struct module *module, int cmd, void *arg)
1626 {
1627 int error = 0;
1628
1629 switch (cmd) {
1630 case MOD_LOAD:
1631 error = shminit();
1632 if (error != 0)
1633 shmunload();
1634 break;
1635 case MOD_UNLOAD:
1636 error = shmunload();
1637 break;
1638 case MOD_SHUTDOWN:
1639 break;
1640 default:
1641 error = EINVAL;
1642 break;
1643 }
1644 return (error);
1645 }
1646
1647 static moduledata_t sysvshm_mod = {
1648 "sysvshm",
1649 &sysvshm_modload,
1650 NULL
1651 };
1652
1653 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1654 MODULE_VERSION(sysvshm, 1);
Cache object: d73f0c0e2c4cc867a90b953d3d4f52f8
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