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15637ed4 RG |
1 | /* |
2 | * Copyright (c) 1988 University of Utah. | |
3 | * Copyright (c) 1990 The Regents of the University of California. | |
4 | * All rights reserved. | |
5 | * | |
6 | * This code is derived from software contributed to Berkeley by | |
7 | * the Systems Programming Group of the University of Utah Computer | |
8 | * Science Department. Originally from University of Wisconsin. | |
9 | * | |
10 | * Redistribution and use in source and binary forms, with or without | |
11 | * modification, are permitted provided that the following conditions | |
12 | * are met: | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * 2. Redistributions in binary form must reproduce the above copyright | |
16 | * notice, this list of conditions and the following disclaimer in the | |
17 | * documentation and/or other materials provided with the distribution. | |
18 | * 3. All advertising materials mentioning features or use of this software | |
19 | * must display the following acknowledgement: | |
20 | * This product includes software developed by the University of | |
21 | * California, Berkeley and its contributors. | |
22 | * 4. Neither the name of the University nor the names of its contributors | |
23 | * may be used to endorse or promote products derived from this software | |
24 | * without specific prior written permission. | |
25 | * | |
26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
36 | * SUCH DAMAGE. | |
37 | * | |
38 | * from: Utah $Hdr: uipc_shm.c 1.9 89/08/14$ | |
39 | * | |
40 | * @(#)sysv_shm.c 7.15 (Berkeley) 5/13/91 | |
41 | */ | |
42 | ||
43 | /* | |
44 | * System V shared memory routines. | |
45 | * TEMPORARY, until mmap is in place; | |
46 | * needed now for HP-UX compatibility and X server (yech!). | |
47 | */ | |
48 | ||
49 | #ifdef SYSVSHM | |
50 | ||
51 | #include "param.h" | |
52 | #include "systm.h" | |
53 | #include "kernel.h" | |
54 | #include "proc.h" | |
55 | #include "shm.h" | |
56 | #include "malloc.h" | |
57 | #include "mman.h" | |
58 | #include "vm/vm.h" | |
59 | #include "vm/vm_kern.h" | |
60 | #include "vm/vm_inherit.h" | |
61 | #include "vm/vm_pager.h" | |
62 | ||
63 | #ifdef HPUXCOMPAT | |
64 | #include "hp300/hpux/hpux.h" | |
65 | #endif | |
66 | ||
67 | int shmat(), shmctl(), shmdt(), shmget(); | |
68 | int (*shmcalls[])() = { shmat, shmctl, shmdt, shmget }; | |
69 | int shmtot = 0; | |
70 | ||
71 | /* | |
72 | * Per process internal structure for managing segments. | |
73 | * Each process using shm will have an array of ``shmseg'' of these. | |
74 | */ | |
75 | struct shmdesc { | |
76 | vm_offset_t shmd_uva; | |
77 | int shmd_id; | |
78 | }; | |
79 | ||
80 | /* | |
81 | * Per segment internal structure (shm_handle). | |
82 | */ | |
83 | struct shmhandle { | |
84 | vm_offset_t shmh_kva; | |
85 | caddr_t shmh_id; | |
86 | }; | |
87 | ||
88 | vm_map_t shm_map; /* address space for shared memory segments */ | |
89 | ||
90 | shminit() | |
91 | { | |
92 | register int i; | |
93 | vm_offset_t whocares1, whocares2; | |
94 | ||
95 | shm_map = kmem_suballoc(kernel_map, &whocares1, &whocares2, | |
96 | shminfo.shmall * NBPG, FALSE); | |
97 | if (shminfo.shmmni > SHMMMNI) | |
98 | shminfo.shmmni = SHMMMNI; | |
99 | for (i = 0; i < shminfo.shmmni; i++) { | |
100 | shmsegs[i].shm_perm.mode = 0; | |
101 | shmsegs[i].shm_perm.seq = 0; | |
102 | } | |
103 | } | |
104 | ||
105 | /* | |
106 | * Entry point for all SHM calls | |
107 | */ | |
108 | shmsys(p, uap, retval) | |
109 | struct proc *p; | |
110 | struct args { | |
111 | u_int which; | |
112 | } *uap; | |
113 | int *retval; | |
114 | { | |
115 | ||
116 | if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) | |
117 | return (EINVAL); | |
118 | return ((*shmcalls[uap->which])(p, &uap[1], retval)); | |
119 | } | |
120 | ||
121 | /* | |
122 | * Get a shared memory segment | |
123 | */ | |
124 | shmget(p, uap, retval) | |
125 | struct proc *p; | |
126 | register struct args { | |
127 | key_t key; | |
128 | int size; | |
129 | int shmflg; | |
130 | } *uap; | |
131 | int *retval; | |
132 | { | |
133 | register struct shmid_ds *shp; | |
134 | register struct ucred *cred = p->p_ucred; | |
135 | register int i; | |
136 | int error, size, rval = 0; | |
137 | register struct shmhandle *shmh; | |
138 | ||
139 | /* look up the specified shm_id */ | |
140 | if (uap->key != IPC_PRIVATE) { | |
141 | for (i = 0; i < shminfo.shmmni; i++) | |
142 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) && | |
143 | shmsegs[i].shm_perm.key == uap->key) { | |
144 | rval = i; | |
145 | break; | |
146 | } | |
147 | } else | |
148 | i = shminfo.shmmni; | |
149 | ||
150 | /* create a new shared segment if necessary */ | |
151 | if (i == shminfo.shmmni) { | |
152 | if ((uap->shmflg & IPC_CREAT) == 0) | |
153 | return (ENOENT); | |
154 | if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) | |
155 | return (EINVAL); | |
156 | for (i = 0; i < shminfo.shmmni; i++) | |
157 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) { | |
158 | rval = i; | |
159 | break; | |
160 | } | |
161 | if (i == shminfo.shmmni) | |
162 | return (ENOSPC); | |
163 | size = clrnd(btoc(uap->size)); | |
164 | if (shmtot + size > shminfo.shmall) | |
165 | return (ENOMEM); | |
166 | shp = &shmsegs[rval]; | |
167 | /* | |
168 | * We need to do a couple of things to ensure consistency | |
169 | * in case we sleep in malloc(). We mark segment as | |
170 | * allocated so that other shmgets() will not allocate it. | |
171 | * We mark it as "destroyed" to insure that shmvalid() is | |
172 | * false making most operations fail (XXX). We set the key, | |
173 | * so that other shmget()s will fail. | |
174 | */ | |
175 | shp->shm_perm.mode = SHM_ALLOC | SHM_DEST; | |
176 | shp->shm_perm.key = uap->key; | |
177 | shmh = (struct shmhandle *) | |
178 | malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK); | |
179 | shmh->shmh_kva = 0; | |
180 | shmh->shmh_id = (caddr_t)(0xc0000000|rval); /* XXX */ | |
181 | error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size), | |
182 | VM_PROT_ALL, MAP_ANON, shmh->shmh_id, 0); | |
183 | if (error) { | |
184 | free((caddr_t)shmh, M_SHM); | |
185 | shp->shm_perm.mode = 0; | |
186 | return(ENOMEM); | |
187 | } | |
188 | shp->shm_handle = (void *) shmh; | |
189 | shmtot += size; | |
190 | shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid; | |
191 | shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid; | |
192 | shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777); | |
193 | shp->shm_segsz = uap->size; | |
194 | shp->shm_cpid = p->p_pid; | |
195 | shp->shm_lpid = shp->shm_nattch = 0; | |
196 | shp->shm_atime = shp->shm_dtime = 0; | |
197 | shp->shm_ctime = time.tv_sec; | |
198 | } else { | |
199 | shp = &shmsegs[rval]; | |
200 | /* XXX: probably not the right thing to do */ | |
201 | if (shp->shm_perm.mode & SHM_DEST) | |
202 | return (EBUSY); | |
203 | if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred)) | |
204 | return (error); | |
205 | if (uap->size && uap->size > shp->shm_segsz) | |
206 | return (EINVAL); | |
207 | if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL)) | |
208 | return (EEXIST); | |
209 | } | |
210 | *retval = shp->shm_perm.seq * SHMMMNI + rval; | |
211 | return (0); | |
212 | } | |
213 | ||
214 | /* | |
215 | * Shared memory control | |
216 | */ | |
217 | /* ARGSUSED */ | |
218 | shmctl(p, uap, retval) | |
219 | struct proc *p; | |
220 | register struct args { | |
221 | int shmid; | |
222 | int cmd; | |
223 | caddr_t buf; | |
224 | } *uap; | |
225 | int *retval; | |
226 | { | |
227 | register struct shmid_ds *shp; | |
228 | register struct ucred *cred = p->p_ucred; | |
229 | struct shmid_ds sbuf; | |
230 | int error; | |
231 | ||
232 | if (error = shmvalid(uap->shmid)) | |
233 | return (error); | |
234 | shp = &shmsegs[uap->shmid % SHMMMNI]; | |
235 | switch (uap->cmd) { | |
236 | case IPC_STAT: | |
237 | if (error = ipcaccess(&shp->shm_perm, IPC_R, cred)) | |
238 | return (error); | |
239 | return (copyout((caddr_t)shp, uap->buf, sizeof(*shp))); | |
240 | ||
241 | case IPC_SET: | |
242 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && | |
243 | cred->cr_uid != shp->shm_perm.cuid) | |
244 | return (EPERM); | |
245 | if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf)) | |
246 | return (error); | |
247 | shp->shm_perm.uid = sbuf.shm_perm.uid; | |
248 | shp->shm_perm.gid = sbuf.shm_perm.gid; | |
249 | shp->shm_perm.mode = (shp->shm_perm.mode & ~0777) | |
250 | | (sbuf.shm_perm.mode & 0777); | |
251 | shp->shm_ctime = time.tv_sec; | |
252 | break; | |
253 | ||
254 | case IPC_RMID: | |
255 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && | |
256 | cred->cr_uid != shp->shm_perm.cuid) | |
257 | return (EPERM); | |
258 | /* set ctime? */ | |
259 | shp->shm_perm.key = IPC_PRIVATE; | |
260 | shp->shm_perm.mode |= SHM_DEST; | |
261 | if (shp->shm_nattch <= 0) | |
262 | shmfree(shp); | |
263 | break; | |
264 | ||
265 | #ifdef HPUXCOMPAT | |
266 | case SHM_LOCK: | |
267 | case SHM_UNLOCK: | |
268 | /* don't really do anything, but make them think we did */ | |
269 | if ((p->p_flag & SHPUX) == 0) | |
270 | return (EINVAL); | |
271 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && | |
272 | cred->cr_uid != shp->shm_perm.cuid) | |
273 | return (EPERM); | |
274 | break; | |
275 | #endif | |
276 | ||
277 | default: | |
278 | return (EINVAL); | |
279 | } | |
280 | return (0); | |
281 | } | |
282 | ||
283 | /* | |
284 | * Attach to shared memory segment. | |
285 | */ | |
286 | shmat(p, uap, retval) | |
287 | struct proc *p; | |
288 | register struct args { | |
289 | int shmid; | |
290 | caddr_t shmaddr; | |
291 | int shmflg; | |
292 | } *uap; | |
293 | int *retval; | |
294 | { | |
295 | register struct shmid_ds *shp; | |
296 | register int size; | |
297 | caddr_t uva; | |
298 | int error; | |
299 | int flags; | |
300 | vm_prot_t prot; | |
301 | struct shmdesc *shmd; | |
302 | ||
303 | /* | |
304 | * Allocate descriptors now (before validity check) | |
305 | * in case malloc() blocks. | |
306 | */ | |
307 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; | |
308 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
309 | if (shmd == NULL) { | |
310 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
311 | bzero((caddr_t)shmd, size); | |
312 | p->p_vmspace->vm_shm = (caddr_t)shmd; | |
313 | } | |
314 | if (error = shmvalid(uap->shmid)) | |
315 | return (error); | |
316 | shp = &shmsegs[uap->shmid % SHMMMNI]; | |
317 | if (shp->shm_handle == NULL) | |
318 | panic("shmat NULL handle"); | |
319 | if (error = ipcaccess(&shp->shm_perm, | |
320 | (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, p->p_ucred)) | |
321 | return (error); | |
322 | uva = uap->shmaddr; | |
323 | if (uva && ((int)uva & (SHMLBA-1))) { | |
324 | if (uap->shmflg & SHM_RND) | |
325 | uva = (caddr_t) ((int)uva & ~(SHMLBA-1)); | |
326 | else | |
327 | return (EINVAL); | |
328 | } | |
329 | /* | |
330 | * Make sure user doesn't use more than their fair share | |
331 | */ | |
332 | for (size = 0; size < shminfo.shmseg; size++) { | |
333 | if (shmd->shmd_uva == 0) | |
334 | break; | |
335 | shmd++; | |
336 | } | |
337 | if (size >= shminfo.shmseg) | |
338 | return (EMFILE); | |
339 | size = ctob(clrnd(btoc(shp->shm_segsz))); | |
340 | prot = VM_PROT_READ; | |
341 | if ((uap->shmflg & SHM_RDONLY) == 0) | |
342 | prot |= VM_PROT_WRITE; | |
343 | flags = MAP_ANON|MAP_SHARED; | |
344 | if (uva) | |
345 | flags |= MAP_FIXED; | |
346 | else | |
347 | uva = (caddr_t)0x1000000; /* XXX */ | |
348 | error = vm_mmap(&p->p_vmspace->vm_map, &uva, (vm_size_t)size, prot, | |
349 | flags, ((struct shmhandle *)shp->shm_handle)->shmh_id, 0); | |
350 | if (error) | |
351 | return(error); | |
352 | shmd->shmd_uva = (vm_offset_t)uva; | |
353 | shmd->shmd_id = uap->shmid; | |
354 | /* | |
355 | * Fill in the remaining fields | |
356 | */ | |
357 | shp->shm_lpid = p->p_pid; | |
358 | shp->shm_atime = time.tv_sec; | |
359 | shp->shm_nattch++; | |
360 | *retval = (int) uva; | |
361 | return (0); | |
362 | } | |
363 | ||
364 | /* | |
365 | * Detach from shared memory segment. | |
366 | */ | |
367 | /* ARGSUSED */ | |
368 | shmdt(p, uap, retval) | |
369 | struct proc *p; | |
370 | struct args { | |
371 | caddr_t shmaddr; | |
372 | } *uap; | |
373 | int *retval; | |
374 | { | |
375 | register struct shmdesc *shmd; | |
376 | register int i; | |
377 | ||
378 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; | |
379 | for (i = 0; i < shminfo.shmseg; i++, shmd++) | |
380 | if (shmd->shmd_uva && | |
381 | shmd->shmd_uva == (vm_offset_t)uap->shmaddr) | |
382 | break; | |
383 | if (i == shminfo.shmseg) | |
384 | return(EINVAL); | |
385 | shmufree(p, shmd); | |
386 | shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid; | |
387 | } | |
388 | ||
389 | shmfork(p1, p2, isvfork) | |
390 | struct proc *p1, *p2; | |
391 | int isvfork; | |
392 | { | |
393 | register struct shmdesc *shmd; | |
394 | register int size; | |
395 | ||
396 | /* | |
397 | * Copy parents descriptive information | |
398 | */ | |
399 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
400 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
401 | bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size); | |
402 | p2->p_vmspace->vm_shm = (caddr_t)shmd; | |
403 | /* | |
404 | * Increment reference counts | |
405 | */ | |
406 | for (size = 0; size < shminfo.shmseg; size++, shmd++) | |
407 | if (shmd->shmd_uva) | |
408 | shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++; | |
409 | } | |
410 | ||
411 | shmexit(p) | |
412 | struct proc *p; | |
413 | { | |
414 | register struct shmdesc *shmd; | |
415 | register int i; | |
416 | ||
417 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; | |
418 | for (i = 0; i < shminfo.shmseg; i++, shmd++) | |
419 | if (shmd->shmd_uva) | |
420 | shmufree(p, shmd); | |
421 | free((caddr_t)p->p_vmspace->vm_shm, M_SHM); | |
422 | p->p_vmspace->vm_shm = NULL; | |
423 | } | |
424 | ||
425 | shmvalid(id) | |
426 | register int id; | |
427 | { | |
428 | register struct shmid_ds *shp; | |
429 | ||
430 | if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni) | |
431 | return(EINVAL); | |
432 | shp = &shmsegs[id % SHMMMNI]; | |
433 | if (shp->shm_perm.seq == (id / SHMMMNI) && | |
434 | (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC) | |
435 | return(0); | |
436 | return(EINVAL); | |
437 | } | |
438 | ||
439 | /* | |
440 | * Free user resources associated with a shared memory segment | |
441 | */ | |
442 | shmufree(p, shmd) | |
443 | struct proc *p; | |
444 | struct shmdesc *shmd; | |
445 | { | |
446 | register struct shmid_ds *shp; | |
447 | ||
448 | shp = &shmsegs[shmd->shmd_id % SHMMMNI]; | |
449 | (void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva, | |
450 | ctob(clrnd(btoc(shp->shm_segsz)))); | |
451 | shmd->shmd_id = 0; | |
452 | shmd->shmd_uva = 0; | |
453 | shp->shm_dtime = time.tv_sec; | |
454 | if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST)) | |
455 | shmfree(shp); | |
456 | } | |
457 | ||
458 | /* | |
459 | * Deallocate resources associated with a shared memory segment | |
460 | */ | |
461 | shmfree(shp) | |
462 | register struct shmid_ds *shp; | |
463 | { | |
464 | ||
465 | if (shp->shm_handle == NULL) | |
466 | panic("shmfree"); | |
467 | /* | |
468 | * Lose our lingering object reference by deallocating space | |
469 | * in kernel. Pager will also be deallocated as a side-effect. | |
470 | */ | |
471 | vm_deallocate(shm_map, | |
472 | ((struct shmhandle *)shp->shm_handle)->shmh_kva, | |
473 | ctob(clrnd(btoc(shp->shm_segsz)))); | |
474 | free((caddr_t)shp->shm_handle, M_SHM); | |
475 | shp->shm_handle = NULL; | |
476 | shmtot -= clrnd(btoc(shp->shm_segsz)); | |
477 | shp->shm_perm.mode = 0; | |
478 | /* | |
479 | * Increment the sequence number to ensure that outstanding | |
480 | * shmids for this segment will be invalid in the event that | |
481 | * the segment is reallocated. Note that shmids must be | |
482 | * positive as decreed by SVID. | |
483 | */ | |
484 | shp->shm_perm.seq++; | |
485 | if ((int)(shp->shm_perm.seq * SHMMMNI) < 0) | |
486 | shp->shm_perm.seq = 0; | |
487 | } | |
488 | ||
489 | /* | |
490 | * XXX This routine would be common to all sysV style IPC | |
491 | * (if the others were implemented). | |
492 | */ | |
493 | ipcaccess(ipc, mode, cred) | |
494 | register struct ipc_perm *ipc; | |
495 | int mode; | |
496 | register struct ucred *cred; | |
497 | { | |
498 | register int m; | |
499 | ||
500 | if (cred->cr_uid == 0) | |
501 | return(0); | |
502 | /* | |
503 | * Access check is based on only one of owner, group, public. | |
504 | * If not owner, then check group. | |
505 | * If not a member of the group, then check public access. | |
506 | */ | |
507 | mode &= 0700; | |
508 | m = ipc->mode; | |
509 | if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) { | |
510 | m <<= 3; | |
511 | if (!groupmember(ipc->gid, cred) && | |
512 | !groupmember(ipc->cgid, cred)) | |
513 | m <<= 3; | |
514 | } | |
515 | if ((mode&m) == mode) | |
516 | return (0); | |
517 | return (EACCES); | |
518 | } | |
519 | #endif /* SYSVSHM */ |