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6f843dc9 KM |
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 | * %sccs.include.redist.c% | |
11 | * | |
3cf1b235 | 12 | * from: Utah $Hdr: uipc_shm.c 1.11 92/04/23$ |
6f843dc9 | 13 | * |
38a01dbe | 14 | * @(#)sysv_shm.c 7.20 (Berkeley) %G% |
6f843dc9 KM |
15 | */ |
16 | ||
17 | /* | |
18 | * System V shared memory routines. | |
e4f7cdf5 MK |
19 | * TEMPORARY, until mmap is in place; |
20 | * needed now for HP-UX compatibility and X server (yech!). | |
6f843dc9 KM |
21 | */ |
22 | ||
23 | #ifdef SYSVSHM | |
24 | ||
38a01dbe KB |
25 | #include <sys/param.h> |
26 | #include <sys/systm.h> | |
27 | #include <sys/kernel.h> | |
28 | #include <sys/proc.h> | |
29 | #include <sys/shm.h> | |
30 | #include <sys/malloc.h> | |
31 | #include <sys/mman.h> | |
32 | ||
33 | #include <vm/vm.h> | |
34 | #include <vm/vm_kern.h> | |
35 | #include <vm/vm_inherit.h> | |
36 | #include <vm/vm_pager.h> | |
6f843dc9 | 37 | |
6f843dc9 KM |
38 | int shmat(), shmctl(), shmdt(), shmget(); |
39 | int (*shmcalls[])() = { shmat, shmctl, shmdt, shmget }; | |
40 | int shmtot = 0; | |
41 | ||
9db58063 KM |
42 | /* |
43 | * Per process internal structure for managing segments. | |
44 | * Each process using shm will have an array of ``shmseg'' of these. | |
45 | */ | |
46 | struct shmdesc { | |
47 | vm_offset_t shmd_uva; | |
48 | int shmd_id; | |
49 | }; | |
50 | ||
51 | /* | |
52 | * Per segment internal structure (shm_handle). | |
53 | */ | |
54 | struct shmhandle { | |
55 | vm_offset_t shmh_kva; | |
56 | caddr_t shmh_id; | |
57 | }; | |
58 | ||
59 | vm_map_t shm_map; /* address space for shared memory segments */ | |
6f843dc9 KM |
60 | |
61 | shminit() | |
62 | { | |
63 | register int i; | |
9db58063 | 64 | vm_offset_t whocares1, whocares2; |
6f843dc9 | 65 | |
9db58063 KM |
66 | shm_map = kmem_suballoc(kernel_map, &whocares1, &whocares2, |
67 | shminfo.shmall * NBPG, FALSE); | |
6f843dc9 KM |
68 | if (shminfo.shmmni > SHMMMNI) |
69 | shminfo.shmmni = SHMMMNI; | |
70 | for (i = 0; i < shminfo.shmmni; i++) { | |
71 | shmsegs[i].shm_perm.mode = 0; | |
72 | shmsegs[i].shm_perm.seq = 0; | |
73 | } | |
74 | } | |
75 | ||
161c14a2 KM |
76 | /* |
77 | * Entry point for all SHM calls | |
78 | */ | |
afc12c69 CT |
79 | struct shmsys_args { |
80 | u_int which; | |
81 | }; | |
161c14a2 KM |
82 | shmsys(p, uap, retval) |
83 | struct proc *p; | |
afc12c69 | 84 | struct shmsys_args *uap; |
161c14a2 KM |
85 | int *retval; |
86 | { | |
6f843dc9 | 87 | |
161c14a2 | 88 | if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) |
d9c2f47f MK |
89 | return (EINVAL); |
90 | return ((*shmcalls[uap->which])(p, &uap[1], retval)); | |
6f843dc9 KM |
91 | } |
92 | ||
161c14a2 KM |
93 | /* |
94 | * Get a shared memory segment | |
95 | */ | |
afc12c69 CT |
96 | struct shmget_args { |
97 | key_t key; | |
98 | int size; | |
99 | int shmflg; | |
100 | }; | |
161c14a2 KM |
101 | shmget(p, uap, retval) |
102 | struct proc *p; | |
afc12c69 | 103 | register struct shmget_args *uap; |
161c14a2 KM |
104 | int *retval; |
105 | { | |
6f843dc9 | 106 | register struct shmid_ds *shp; |
8429d022 | 107 | register struct ucred *cred = p->p_ucred; |
6f843dc9 | 108 | register int i; |
161c14a2 | 109 | int error, size, rval = 0; |
9db58063 | 110 | register struct shmhandle *shmh; |
6f843dc9 KM |
111 | |
112 | /* look up the specified shm_id */ | |
113 | if (uap->key != IPC_PRIVATE) { | |
114 | for (i = 0; i < shminfo.shmmni; i++) | |
115 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) && | |
116 | shmsegs[i].shm_perm.key == uap->key) { | |
117 | rval = i; | |
118 | break; | |
119 | } | |
120 | } else | |
121 | i = shminfo.shmmni; | |
122 | ||
123 | /* create a new shared segment if necessary */ | |
124 | if (i == shminfo.shmmni) { | |
161c14a2 KM |
125 | if ((uap->shmflg & IPC_CREAT) == 0) |
126 | return (ENOENT); | |
127 | if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) | |
128 | return (EINVAL); | |
6f843dc9 KM |
129 | for (i = 0; i < shminfo.shmmni; i++) |
130 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) { | |
131 | rval = i; | |
132 | break; | |
133 | } | |
161c14a2 KM |
134 | if (i == shminfo.shmmni) |
135 | return (ENOSPC); | |
6f843dc9 | 136 | size = clrnd(btoc(uap->size)); |
161c14a2 KM |
137 | if (shmtot + size > shminfo.shmall) |
138 | return (ENOMEM); | |
6f843dc9 KM |
139 | shp = &shmsegs[rval]; |
140 | /* | |
141 | * We need to do a couple of things to ensure consistency | |
142 | * in case we sleep in malloc(). We mark segment as | |
143 | * allocated so that other shmgets() will not allocate it. | |
144 | * We mark it as "destroyed" to insure that shmvalid() is | |
145 | * false making most operations fail (XXX). We set the key, | |
146 | * so that other shmget()s will fail. | |
147 | */ | |
148 | shp->shm_perm.mode = SHM_ALLOC | SHM_DEST; | |
149 | shp->shm_perm.key = uap->key; | |
9db58063 KM |
150 | shmh = (struct shmhandle *) |
151 | malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK); | |
152 | shmh->shmh_kva = 0; | |
153 | shmh->shmh_id = (caddr_t)(0xc0000000|rval); /* XXX */ | |
154 | error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size), | |
155 | VM_PROT_ALL, MAP_ANON, shmh->shmh_id, 0); | |
156 | if (error) { | |
157 | free((caddr_t)shmh, M_SHM); | |
6f843dc9 | 158 | shp->shm_perm.mode = 0; |
9db58063 | 159 | return(ENOMEM); |
6f843dc9 | 160 | } |
9db58063 | 161 | shp->shm_handle = (void *) shmh; |
6f843dc9 | 162 | shmtot += size; |
161c14a2 KM |
163 | shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid; |
164 | shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid; | |
6f843dc9 | 165 | shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777); |
6f843dc9 | 166 | shp->shm_segsz = uap->size; |
c9714ae3 | 167 | shp->shm_cpid = p->p_pid; |
6f843dc9 KM |
168 | shp->shm_lpid = shp->shm_nattch = 0; |
169 | shp->shm_atime = shp->shm_dtime = 0; | |
170 | shp->shm_ctime = time.tv_sec; | |
171 | } else { | |
172 | shp = &shmsegs[rval]; | |
173 | /* XXX: probably not the right thing to do */ | |
161c14a2 KM |
174 | if (shp->shm_perm.mode & SHM_DEST) |
175 | return (EBUSY); | |
015c074c | 176 | if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred)) |
161c14a2 KM |
177 | return (error); |
178 | if (uap->size && uap->size > shp->shm_segsz) | |
179 | return (EINVAL); | |
180 | if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL)) | |
181 | return (EEXIST); | |
6f843dc9 | 182 | } |
161c14a2 | 183 | *retval = shp->shm_perm.seq * SHMMMNI + rval; |
015c074c | 184 | return (0); |
6f843dc9 KM |
185 | } |
186 | ||
161c14a2 KM |
187 | /* |
188 | * Shared memory control | |
189 | */ | |
afc12c69 CT |
190 | struct shmctl_args { |
191 | int shmid; | |
192 | int cmd; | |
193 | caddr_t buf; | |
194 | }; | |
161c14a2 KM |
195 | /* ARGSUSED */ |
196 | shmctl(p, uap, retval) | |
197 | struct proc *p; | |
afc12c69 | 198 | register struct shmctl_args *uap; |
161c14a2 KM |
199 | int *retval; |
200 | { | |
6f843dc9 | 201 | register struct shmid_ds *shp; |
8429d022 | 202 | register struct ucred *cred = p->p_ucred; |
6f843dc9 | 203 | struct shmid_ds sbuf; |
161c14a2 | 204 | int error; |
6f843dc9 | 205 | |
161c14a2 KM |
206 | if (error = shmvalid(uap->shmid)) |
207 | return (error); | |
6f843dc9 KM |
208 | shp = &shmsegs[uap->shmid % SHMMMNI]; |
209 | switch (uap->cmd) { | |
210 | case IPC_STAT: | |
015c074c | 211 | if (error = ipcaccess(&shp->shm_perm, IPC_R, cred)) |
161c14a2 KM |
212 | return (error); |
213 | return (copyout((caddr_t)shp, uap->buf, sizeof(*shp))); | |
6f843dc9 KM |
214 | |
215 | case IPC_SET: | |
161c14a2 KM |
216 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && |
217 | cred->cr_uid != shp->shm_perm.cuid) | |
218 | return (EPERM); | |
219 | if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf)) | |
220 | return (error); | |
221 | shp->shm_perm.uid = sbuf.shm_perm.uid; | |
222 | shp->shm_perm.gid = sbuf.shm_perm.gid; | |
223 | shp->shm_perm.mode = (shp->shm_perm.mode & ~0777) | |
224 | | (sbuf.shm_perm.mode & 0777); | |
225 | shp->shm_ctime = time.tv_sec; | |
6f843dc9 KM |
226 | break; |
227 | ||
228 | case IPC_RMID: | |
161c14a2 KM |
229 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && |
230 | cred->cr_uid != shp->shm_perm.cuid) | |
231 | return (EPERM); | |
6f843dc9 KM |
232 | /* set ctime? */ |
233 | shp->shm_perm.key = IPC_PRIVATE; | |
234 | shp->shm_perm.mode |= SHM_DEST; | |
235 | if (shp->shm_nattch <= 0) | |
236 | shmfree(shp); | |
237 | break; | |
238 | ||
6f843dc9 | 239 | default: |
161c14a2 | 240 | return (EINVAL); |
6f843dc9 | 241 | } |
161c14a2 | 242 | return (0); |
6f843dc9 KM |
243 | } |
244 | ||
161c14a2 KM |
245 | /* |
246 | * Attach to shared memory segment. | |
247 | */ | |
afc12c69 CT |
248 | struct shmat_args { |
249 | int shmid; | |
250 | caddr_t shmaddr; | |
251 | int shmflg; | |
252 | }; | |
161c14a2 KM |
253 | shmat(p, uap, retval) |
254 | struct proc *p; | |
afc12c69 | 255 | register struct shmat_args *uap; |
161c14a2 KM |
256 | int *retval; |
257 | { | |
6f843dc9 KM |
258 | register struct shmid_ds *shp; |
259 | register int size; | |
6f843dc9 | 260 | caddr_t uva; |
9db58063 KM |
261 | int error; |
262 | int flags; | |
263 | vm_prot_t prot; | |
264 | struct shmdesc *shmd; | |
6f843dc9 | 265 | |
9db58063 KM |
266 | /* |
267 | * Allocate descriptors now (before validity check) | |
268 | * in case malloc() blocks. | |
269 | */ | |
8429d022 | 270 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
271 | size = shminfo.shmseg * sizeof(struct shmdesc); |
272 | if (shmd == NULL) { | |
273 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
274 | bzero((caddr_t)shmd, size); | |
8429d022 | 275 | p->p_vmspace->vm_shm = (caddr_t)shmd; |
9db58063 | 276 | } |
161c14a2 KM |
277 | if (error = shmvalid(uap->shmid)) |
278 | return (error); | |
6f843dc9 KM |
279 | shp = &shmsegs[uap->shmid % SHMMMNI]; |
280 | if (shp->shm_handle == NULL) | |
96ea38ce | 281 | panic("shmat NULL handle"); |
015c074c | 282 | if (error = ipcaccess(&shp->shm_perm, |
8429d022 | 283 | (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, p->p_ucred)) |
161c14a2 | 284 | return (error); |
6f843dc9 KM |
285 | uva = uap->shmaddr; |
286 | if (uva && ((int)uva & (SHMLBA-1))) { | |
287 | if (uap->shmflg & SHM_RND) | |
288 | uva = (caddr_t) ((int)uva & ~(SHMLBA-1)); | |
161c14a2 KM |
289 | else |
290 | return (EINVAL); | |
6f843dc9 KM |
291 | } |
292 | /* | |
293 | * Make sure user doesn't use more than their fair share | |
294 | */ | |
9db58063 KM |
295 | for (size = 0; size < shminfo.shmseg; size++) { |
296 | if (shmd->shmd_uva == 0) | |
297 | break; | |
298 | shmd++; | |
299 | } | |
161c14a2 KM |
300 | if (size >= shminfo.shmseg) |
301 | return (EMFILE); | |
6f843dc9 | 302 | size = ctob(clrnd(btoc(shp->shm_segsz))); |
9db58063 KM |
303 | prot = VM_PROT_READ; |
304 | if ((uap->shmflg & SHM_RDONLY) == 0) | |
305 | prot |= VM_PROT_WRITE; | |
306 | flags = MAP_ANON|MAP_SHARED; | |
307 | if (uva) | |
308 | flags |= MAP_FIXED; | |
309 | else | |
310 | uva = (caddr_t)0x1000000; /* XXX */ | |
451df175 KM |
311 | error = vm_mmap(&p->p_vmspace->vm_map, (vm_offset_t *)&uva, |
312 | (vm_size_t)size, prot, flags, | |
313 | ((struct shmhandle *)shp->shm_handle)->shmh_id, 0); | |
161c14a2 | 314 | if (error) |
9db58063 KM |
315 | return(error); |
316 | shmd->shmd_uva = (vm_offset_t)uva; | |
317 | shmd->shmd_id = uap->shmid; | |
6f843dc9 KM |
318 | /* |
319 | * Fill in the remaining fields | |
320 | */ | |
c9714ae3 | 321 | shp->shm_lpid = p->p_pid; |
6f843dc9 KM |
322 | shp->shm_atime = time.tv_sec; |
323 | shp->shm_nattch++; | |
161c14a2 | 324 | *retval = (int) uva; |
015c074c | 325 | return (0); |
6f843dc9 KM |
326 | } |
327 | ||
161c14a2 KM |
328 | /* |
329 | * Detach from shared memory segment. | |
330 | */ | |
afc12c69 CT |
331 | struct shmdt_args { |
332 | caddr_t shmaddr; | |
333 | }; | |
161c14a2 KM |
334 | /* ARGSUSED */ |
335 | shmdt(p, uap, retval) | |
336 | struct proc *p; | |
afc12c69 | 337 | struct shmdt_args *uap; |
161c14a2 KM |
338 | int *retval; |
339 | { | |
9db58063 KM |
340 | register struct shmdesc *shmd; |
341 | register int i; | |
6f843dc9 | 342 | |
8429d022 | 343 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
344 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
345 | if (shmd->shmd_uva && | |
346 | shmd->shmd_uva == (vm_offset_t)uap->shmaddr) | |
6f843dc9 | 347 | break; |
9db58063 KM |
348 | if (i == shminfo.shmseg) |
349 | return(EINVAL); | |
350 | shmufree(p, shmd); | |
351 | shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid; | |
6f843dc9 KM |
352 | } |
353 | ||
8429d022 MK |
354 | shmfork(p1, p2, isvfork) |
355 | struct proc *p1, *p2; | |
9db58063 | 356 | int isvfork; |
6f843dc9 | 357 | { |
9db58063 KM |
358 | register struct shmdesc *shmd; |
359 | register int size; | |
6f843dc9 | 360 | |
9db58063 KM |
361 | /* |
362 | * Copy parents descriptive information | |
363 | */ | |
364 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
365 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
8429d022 MK |
366 | bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size); |
367 | p2->p_vmspace->vm_shm = (caddr_t)shmd; | |
9db58063 KM |
368 | /* |
369 | * Increment reference counts | |
370 | */ | |
371 | for (size = 0; size < shminfo.shmseg; size++, shmd++) | |
372 | if (shmd->shmd_uva) | |
373 | shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++; | |
6f843dc9 KM |
374 | } |
375 | ||
9db58063 KM |
376 | shmexit(p) |
377 | struct proc *p; | |
6f843dc9 | 378 | { |
9db58063 KM |
379 | register struct shmdesc *shmd; |
380 | register int i; | |
c9714ae3 | 381 | |
8429d022 | 382 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
383 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
384 | if (shmd->shmd_uva) | |
385 | shmufree(p, shmd); | |
8429d022 MK |
386 | free((caddr_t)p->p_vmspace->vm_shm, M_SHM); |
387 | p->p_vmspace->vm_shm = NULL; | |
6f843dc9 KM |
388 | } |
389 | ||
390 | shmvalid(id) | |
391 | register int id; | |
392 | { | |
393 | register struct shmid_ds *shp; | |
394 | ||
395 | if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni) | |
161c14a2 | 396 | return(EINVAL); |
6f843dc9 KM |
397 | shp = &shmsegs[id % SHMMMNI]; |
398 | if (shp->shm_perm.seq == (id / SHMMMNI) && | |
399 | (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC) | |
161c14a2 KM |
400 | return(0); |
401 | return(EINVAL); | |
6f843dc9 KM |
402 | } |
403 | ||
404 | /* | |
405 | * Free user resources associated with a shared memory segment | |
406 | */ | |
9db58063 | 407 | shmufree(p, shmd) |
c9714ae3 | 408 | struct proc *p; |
9db58063 | 409 | struct shmdesc *shmd; |
6f843dc9 KM |
410 | { |
411 | register struct shmid_ds *shp; | |
412 | ||
9db58063 | 413 | shp = &shmsegs[shmd->shmd_id % SHMMMNI]; |
aa6d6b7e | 414 | (void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva, |
9db58063 KM |
415 | ctob(clrnd(btoc(shp->shm_segsz)))); |
416 | shmd->shmd_id = 0; | |
417 | shmd->shmd_uva = 0; | |
6f843dc9 KM |
418 | shp->shm_dtime = time.tv_sec; |
419 | if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST)) | |
420 | shmfree(shp); | |
421 | } | |
422 | ||
423 | /* | |
424 | * Deallocate resources associated with a shared memory segment | |
425 | */ | |
426 | shmfree(shp) | |
427 | register struct shmid_ds *shp; | |
428 | { | |
6f843dc9 KM |
429 | |
430 | if (shp->shm_handle == NULL) | |
431 | panic("shmfree"); | |
9db58063 KM |
432 | /* |
433 | * Lose our lingering object reference by deallocating space | |
434 | * in kernel. Pager will also be deallocated as a side-effect. | |
435 | */ | |
436 | vm_deallocate(shm_map, | |
437 | ((struct shmhandle *)shp->shm_handle)->shmh_kva, | |
9d81fbb9 | 438 | ctob(clrnd(btoc(shp->shm_segsz)))); |
9db58063 | 439 | free((caddr_t)shp->shm_handle, M_SHM); |
6f843dc9 KM |
440 | shp->shm_handle = NULL; |
441 | shmtot -= clrnd(btoc(shp->shm_segsz)); | |
442 | shp->shm_perm.mode = 0; | |
443 | /* | |
444 | * Increment the sequence number to ensure that outstanding | |
445 | * shmids for this segment will be invalid in the event that | |
446 | * the segment is reallocated. Note that shmids must be | |
447 | * positive as decreed by SVID. | |
448 | */ | |
449 | shp->shm_perm.seq++; | |
450 | if ((int)(shp->shm_perm.seq * SHMMMNI) < 0) | |
451 | shp->shm_perm.seq = 0; | |
452 | } | |
453 | ||
454 | /* | |
455 | * XXX This routine would be common to all sysV style IPC | |
456 | * (if the others were implemented). | |
457 | */ | |
161c14a2 | 458 | ipcaccess(ipc, mode, cred) |
6f843dc9 | 459 | register struct ipc_perm *ipc; |
161c14a2 KM |
460 | int mode; |
461 | register struct ucred *cred; | |
6f843dc9 KM |
462 | { |
463 | register int m; | |
464 | ||
161c14a2 | 465 | if (cred->cr_uid == 0) |
6f843dc9 KM |
466 | return(0); |
467 | /* | |
468 | * Access check is based on only one of owner, group, public. | |
469 | * If not owner, then check group. | |
470 | * If not a member of the group, then check public access. | |
471 | */ | |
472 | mode &= 0700; | |
473 | m = ipc->mode; | |
161c14a2 | 474 | if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) { |
6f843dc9 | 475 | m <<= 3; |
161c14a2 KM |
476 | if (!groupmember(ipc->gid, cred) && |
477 | !groupmember(ipc->cgid, cred)) | |
6f843dc9 KM |
478 | m <<= 3; |
479 | } | |
480 | if ((mode&m) == mode) | |
161c14a2 KM |
481 | return (0); |
482 | return (EACCES); | |
6f843dc9 | 483 | } |
6f843dc9 | 484 | #endif /* SYSVSHM */ |