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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 | */ | |
3c7eb27c DG |
108 | |
109 | struct shmsys_args { | |
110 | u_int which; | |
111 | }; | |
112 | ||
15637ed4 RG |
113 | shmsys(p, uap, retval) |
114 | struct proc *p; | |
3c7eb27c | 115 | struct shmsys_args *uap; |
15637ed4 RG |
116 | int *retval; |
117 | { | |
118 | ||
119 | if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) | |
120 | return (EINVAL); | |
121 | return ((*shmcalls[uap->which])(p, &uap[1], retval)); | |
122 | } | |
123 | ||
124 | /* | |
125 | * Get a shared memory segment | |
126 | */ | |
3c7eb27c DG |
127 | |
128 | struct shmget_args { | |
129 | key_t key; | |
130 | int size; | |
131 | int shmflg; | |
132 | }; | |
133 | ||
15637ed4 RG |
134 | shmget(p, uap, retval) |
135 | struct proc *p; | |
3c7eb27c | 136 | register struct shmget_args *uap; |
15637ed4 RG |
137 | int *retval; |
138 | { | |
139 | register struct shmid_ds *shp; | |
140 | register struct ucred *cred = p->p_ucred; | |
141 | register int i; | |
142 | int error, size, rval = 0; | |
143 | register struct shmhandle *shmh; | |
144 | ||
145 | /* look up the specified shm_id */ | |
146 | if (uap->key != IPC_PRIVATE) { | |
147 | for (i = 0; i < shminfo.shmmni; i++) | |
148 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) && | |
149 | shmsegs[i].shm_perm.key == uap->key) { | |
150 | rval = i; | |
151 | break; | |
152 | } | |
153 | } else | |
154 | i = shminfo.shmmni; | |
155 | ||
156 | /* create a new shared segment if necessary */ | |
157 | if (i == shminfo.shmmni) { | |
158 | if ((uap->shmflg & IPC_CREAT) == 0) | |
159 | return (ENOENT); | |
160 | if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) | |
161 | return (EINVAL); | |
162 | for (i = 0; i < shminfo.shmmni; i++) | |
163 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) { | |
164 | rval = i; | |
165 | break; | |
166 | } | |
167 | if (i == shminfo.shmmni) | |
168 | return (ENOSPC); | |
169 | size = clrnd(btoc(uap->size)); | |
170 | if (shmtot + size > shminfo.shmall) | |
171 | return (ENOMEM); | |
172 | shp = &shmsegs[rval]; | |
173 | /* | |
174 | * We need to do a couple of things to ensure consistency | |
175 | * in case we sleep in malloc(). We mark segment as | |
176 | * allocated so that other shmgets() will not allocate it. | |
177 | * We mark it as "destroyed" to insure that shmvalid() is | |
178 | * false making most operations fail (XXX). We set the key, | |
179 | * so that other shmget()s will fail. | |
180 | */ | |
181 | shp->shm_perm.mode = SHM_ALLOC | SHM_DEST; | |
182 | shp->shm_perm.key = uap->key; | |
183 | shmh = (struct shmhandle *) | |
184 | malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK); | |
185 | shmh->shmh_kva = 0; | |
186 | shmh->shmh_id = (caddr_t)(0xc0000000|rval); /* XXX */ | |
187 | error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size), | |
188 | VM_PROT_ALL, MAP_ANON, shmh->shmh_id, 0); | |
189 | if (error) { | |
190 | free((caddr_t)shmh, M_SHM); | |
191 | shp->shm_perm.mode = 0; | |
192 | return(ENOMEM); | |
193 | } | |
194 | shp->shm_handle = (void *) shmh; | |
195 | shmtot += size; | |
196 | shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid; | |
197 | shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid; | |
198 | shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777); | |
199 | shp->shm_segsz = uap->size; | |
200 | shp->shm_cpid = p->p_pid; | |
201 | shp->shm_lpid = shp->shm_nattch = 0; | |
202 | shp->shm_atime = shp->shm_dtime = 0; | |
203 | shp->shm_ctime = time.tv_sec; | |
204 | } else { | |
205 | shp = &shmsegs[rval]; | |
206 | /* XXX: probably not the right thing to do */ | |
207 | if (shp->shm_perm.mode & SHM_DEST) | |
208 | return (EBUSY); | |
209 | if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred)) | |
210 | return (error); | |
211 | if (uap->size && uap->size > shp->shm_segsz) | |
212 | return (EINVAL); | |
213 | if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL)) | |
214 | return (EEXIST); | |
215 | } | |
216 | *retval = shp->shm_perm.seq * SHMMMNI + rval; | |
217 | return (0); | |
218 | } | |
219 | ||
220 | /* | |
221 | * Shared memory control | |
222 | */ | |
3c7eb27c DG |
223 | |
224 | struct shmctl_args { | |
225 | int shmid; | |
226 | int cmd; | |
227 | caddr_t buf; | |
228 | }; | |
229 | ||
15637ed4 RG |
230 | /* ARGSUSED */ |
231 | shmctl(p, uap, retval) | |
232 | struct proc *p; | |
3c7eb27c | 233 | register struct shmctl_args *uap; |
15637ed4 RG |
234 | int *retval; |
235 | { | |
236 | register struct shmid_ds *shp; | |
237 | register struct ucred *cred = p->p_ucred; | |
238 | struct shmid_ds sbuf; | |
239 | int error; | |
240 | ||
241 | if (error = shmvalid(uap->shmid)) | |
242 | return (error); | |
243 | shp = &shmsegs[uap->shmid % SHMMMNI]; | |
244 | switch (uap->cmd) { | |
245 | case IPC_STAT: | |
246 | if (error = ipcaccess(&shp->shm_perm, IPC_R, cred)) | |
247 | return (error); | |
248 | return (copyout((caddr_t)shp, uap->buf, sizeof(*shp))); | |
249 | ||
250 | case IPC_SET: | |
251 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && | |
252 | cred->cr_uid != shp->shm_perm.cuid) | |
253 | return (EPERM); | |
254 | if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf)) | |
255 | return (error); | |
256 | shp->shm_perm.uid = sbuf.shm_perm.uid; | |
257 | shp->shm_perm.gid = sbuf.shm_perm.gid; | |
258 | shp->shm_perm.mode = (shp->shm_perm.mode & ~0777) | |
259 | | (sbuf.shm_perm.mode & 0777); | |
260 | shp->shm_ctime = time.tv_sec; | |
261 | break; | |
262 | ||
263 | case IPC_RMID: | |
264 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && | |
265 | cred->cr_uid != shp->shm_perm.cuid) | |
266 | return (EPERM); | |
267 | /* set ctime? */ | |
268 | shp->shm_perm.key = IPC_PRIVATE; | |
269 | shp->shm_perm.mode |= SHM_DEST; | |
270 | if (shp->shm_nattch <= 0) | |
271 | shmfree(shp); | |
272 | break; | |
273 | ||
274 | #ifdef HPUXCOMPAT | |
275 | case SHM_LOCK: | |
276 | case SHM_UNLOCK: | |
277 | /* don't really do anything, but make them think we did */ | |
278 | if ((p->p_flag & SHPUX) == 0) | |
279 | return (EINVAL); | |
280 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && | |
281 | cred->cr_uid != shp->shm_perm.cuid) | |
282 | return (EPERM); | |
283 | break; | |
284 | #endif | |
285 | ||
286 | default: | |
287 | return (EINVAL); | |
288 | } | |
289 | return (0); | |
290 | } | |
291 | ||
292 | /* | |
293 | * Attach to shared memory segment. | |
294 | */ | |
3c7eb27c DG |
295 | |
296 | struct shmat_args { | |
297 | int shmid; | |
298 | caddr_t shmaddr; | |
299 | int shmflg; | |
300 | }; | |
301 | ||
15637ed4 RG |
302 | shmat(p, uap, retval) |
303 | struct proc *p; | |
3c7eb27c | 304 | register struct shmat_args *uap; |
15637ed4 RG |
305 | int *retval; |
306 | { | |
307 | register struct shmid_ds *shp; | |
308 | register int size; | |
309 | caddr_t uva; | |
310 | int error; | |
311 | int flags; | |
312 | vm_prot_t prot; | |
313 | struct shmdesc *shmd; | |
314 | ||
315 | /* | |
316 | * Allocate descriptors now (before validity check) | |
317 | * in case malloc() blocks. | |
318 | */ | |
319 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; | |
320 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
321 | if (shmd == NULL) { | |
322 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
323 | bzero((caddr_t)shmd, size); | |
324 | p->p_vmspace->vm_shm = (caddr_t)shmd; | |
325 | } | |
326 | if (error = shmvalid(uap->shmid)) | |
327 | return (error); | |
328 | shp = &shmsegs[uap->shmid % SHMMMNI]; | |
329 | if (shp->shm_handle == NULL) | |
330 | panic("shmat NULL handle"); | |
331 | if (error = ipcaccess(&shp->shm_perm, | |
332 | (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, p->p_ucred)) | |
333 | return (error); | |
334 | uva = uap->shmaddr; | |
335 | if (uva && ((int)uva & (SHMLBA-1))) { | |
336 | if (uap->shmflg & SHM_RND) | |
337 | uva = (caddr_t) ((int)uva & ~(SHMLBA-1)); | |
338 | else | |
339 | return (EINVAL); | |
340 | } | |
341 | /* | |
342 | * Make sure user doesn't use more than their fair share | |
343 | */ | |
344 | for (size = 0; size < shminfo.shmseg; size++) { | |
345 | if (shmd->shmd_uva == 0) | |
346 | break; | |
347 | shmd++; | |
348 | } | |
349 | if (size >= shminfo.shmseg) | |
350 | return (EMFILE); | |
351 | size = ctob(clrnd(btoc(shp->shm_segsz))); | |
352 | prot = VM_PROT_READ; | |
353 | if ((uap->shmflg & SHM_RDONLY) == 0) | |
354 | prot |= VM_PROT_WRITE; | |
355 | flags = MAP_ANON|MAP_SHARED; | |
356 | if (uva) | |
357 | flags |= MAP_FIXED; | |
358 | else | |
359 | uva = (caddr_t)0x1000000; /* XXX */ | |
360 | error = vm_mmap(&p->p_vmspace->vm_map, &uva, (vm_size_t)size, prot, | |
361 | flags, ((struct shmhandle *)shp->shm_handle)->shmh_id, 0); | |
362 | if (error) | |
363 | return(error); | |
364 | shmd->shmd_uva = (vm_offset_t)uva; | |
365 | shmd->shmd_id = uap->shmid; | |
366 | /* | |
367 | * Fill in the remaining fields | |
368 | */ | |
369 | shp->shm_lpid = p->p_pid; | |
370 | shp->shm_atime = time.tv_sec; | |
371 | shp->shm_nattch++; | |
372 | *retval = (int) uva; | |
373 | return (0); | |
374 | } | |
375 | ||
376 | /* | |
377 | * Detach from shared memory segment. | |
378 | */ | |
3c7eb27c DG |
379 | |
380 | struct shmdt_args { | |
381 | caddr_t shmaddr; | |
382 | }; | |
383 | ||
15637ed4 RG |
384 | /* ARGSUSED */ |
385 | shmdt(p, uap, retval) | |
386 | struct proc *p; | |
3c7eb27c | 387 | struct shmdt_args *uap; |
15637ed4 RG |
388 | int *retval; |
389 | { | |
390 | register struct shmdesc *shmd; | |
391 | register int i; | |
392 | ||
393 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; | |
394 | for (i = 0; i < shminfo.shmseg; i++, shmd++) | |
395 | if (shmd->shmd_uva && | |
396 | shmd->shmd_uva == (vm_offset_t)uap->shmaddr) | |
397 | break; | |
398 | if (i == shminfo.shmseg) | |
399 | return(EINVAL); | |
400 | shmufree(p, shmd); | |
401 | shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid; | |
402 | } | |
403 | ||
404 | shmfork(p1, p2, isvfork) | |
405 | struct proc *p1, *p2; | |
406 | int isvfork; | |
407 | { | |
408 | register struct shmdesc *shmd; | |
409 | register int size; | |
410 | ||
411 | /* | |
412 | * Copy parents descriptive information | |
413 | */ | |
414 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
415 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
416 | bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size); | |
417 | p2->p_vmspace->vm_shm = (caddr_t)shmd; | |
418 | /* | |
419 | * Increment reference counts | |
420 | */ | |
421 | for (size = 0; size < shminfo.shmseg; size++, shmd++) | |
422 | if (shmd->shmd_uva) | |
423 | shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++; | |
424 | } | |
425 | ||
426 | shmexit(p) | |
427 | struct proc *p; | |
428 | { | |
429 | register struct shmdesc *shmd; | |
430 | register int i; | |
431 | ||
432 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; | |
433 | for (i = 0; i < shminfo.shmseg; i++, shmd++) | |
434 | if (shmd->shmd_uva) | |
435 | shmufree(p, shmd); | |
436 | free((caddr_t)p->p_vmspace->vm_shm, M_SHM); | |
437 | p->p_vmspace->vm_shm = NULL; | |
438 | } | |
439 | ||
440 | shmvalid(id) | |
441 | register int id; | |
442 | { | |
443 | register struct shmid_ds *shp; | |
444 | ||
445 | if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni) | |
446 | return(EINVAL); | |
447 | shp = &shmsegs[id % SHMMMNI]; | |
448 | if (shp->shm_perm.seq == (id / SHMMMNI) && | |
449 | (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC) | |
450 | return(0); | |
451 | return(EINVAL); | |
452 | } | |
453 | ||
454 | /* | |
455 | * Free user resources associated with a shared memory segment | |
456 | */ | |
457 | shmufree(p, shmd) | |
458 | struct proc *p; | |
459 | struct shmdesc *shmd; | |
460 | { | |
461 | register struct shmid_ds *shp; | |
462 | ||
463 | shp = &shmsegs[shmd->shmd_id % SHMMMNI]; | |
464 | (void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva, | |
465 | ctob(clrnd(btoc(shp->shm_segsz)))); | |
466 | shmd->shmd_id = 0; | |
467 | shmd->shmd_uva = 0; | |
468 | shp->shm_dtime = time.tv_sec; | |
469 | if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST)) | |
470 | shmfree(shp); | |
471 | } | |
472 | ||
473 | /* | |
474 | * Deallocate resources associated with a shared memory segment | |
475 | */ | |
476 | shmfree(shp) | |
477 | register struct shmid_ds *shp; | |
478 | { | |
479 | ||
480 | if (shp->shm_handle == NULL) | |
481 | panic("shmfree"); | |
482 | /* | |
483 | * Lose our lingering object reference by deallocating space | |
484 | * in kernel. Pager will also be deallocated as a side-effect. | |
485 | */ | |
486 | vm_deallocate(shm_map, | |
487 | ((struct shmhandle *)shp->shm_handle)->shmh_kva, | |
488 | ctob(clrnd(btoc(shp->shm_segsz)))); | |
489 | free((caddr_t)shp->shm_handle, M_SHM); | |
490 | shp->shm_handle = NULL; | |
491 | shmtot -= clrnd(btoc(shp->shm_segsz)); | |
492 | shp->shm_perm.mode = 0; | |
493 | /* | |
494 | * Increment the sequence number to ensure that outstanding | |
495 | * shmids for this segment will be invalid in the event that | |
496 | * the segment is reallocated. Note that shmids must be | |
497 | * positive as decreed by SVID. | |
498 | */ | |
499 | shp->shm_perm.seq++; | |
500 | if ((int)(shp->shm_perm.seq * SHMMMNI) < 0) | |
501 | shp->shm_perm.seq = 0; | |
502 | } | |
503 | ||
504 | /* | |
505 | * XXX This routine would be common to all sysV style IPC | |
506 | * (if the others were implemented). | |
507 | */ | |
508 | ipcaccess(ipc, mode, cred) | |
509 | register struct ipc_perm *ipc; | |
510 | int mode; | |
511 | register struct ucred *cred; | |
512 | { | |
513 | register int m; | |
514 | ||
515 | if (cred->cr_uid == 0) | |
516 | return(0); | |
517 | /* | |
518 | * Access check is based on only one of owner, group, public. | |
519 | * If not owner, then check group. | |
520 | * If not a member of the group, then check public access. | |
521 | */ | |
522 | mode &= 0700; | |
523 | m = ipc->mode; | |
524 | if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) { | |
525 | m <<= 3; | |
526 | if (!groupmember(ipc->gid, cred) && | |
527 | !groupmember(ipc->cgid, cred)) | |
528 | m <<= 3; | |
529 | } | |
530 | if ((mode&m) == mode) | |
531 | return (0); | |
532 | return (EACCES); | |
533 | } | |
534 | #endif /* SYSVSHM */ |