Commit | Line | Data |
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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 | * |
afc12c69 | 14 | * @(#)sysv_shm.c 7.19 (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 | ||
6f843dc9 KM |
25 | #include "param.h" |
26 | #include "systm.h" | |
6f843dc9 KM |
27 | #include "kernel.h" |
28 | #include "proc.h" | |
6f843dc9 | 29 | #include "shm.h" |
6f843dc9 | 30 | #include "malloc.h" |
9db58063 | 31 | #include "mman.h" |
0a464d07 MK |
32 | #include "vm/vm.h" |
33 | #include "vm/vm_kern.h" | |
34 | #include "vm/vm_inherit.h" | |
35 | #include "vm/vm_pager.h" | |
6f843dc9 | 36 | |
6f843dc9 KM |
37 | int shmat(), shmctl(), shmdt(), shmget(); |
38 | int (*shmcalls[])() = { shmat, shmctl, shmdt, shmget }; | |
39 | int shmtot = 0; | |
40 | ||
9db58063 KM |
41 | /* |
42 | * Per process internal structure for managing segments. | |
43 | * Each process using shm will have an array of ``shmseg'' of these. | |
44 | */ | |
45 | struct shmdesc { | |
46 | vm_offset_t shmd_uva; | |
47 | int shmd_id; | |
48 | }; | |
49 | ||
50 | /* | |
51 | * Per segment internal structure (shm_handle). | |
52 | */ | |
53 | struct shmhandle { | |
54 | vm_offset_t shmh_kva; | |
55 | caddr_t shmh_id; | |
56 | }; | |
57 | ||
58 | vm_map_t shm_map; /* address space for shared memory segments */ | |
6f843dc9 KM |
59 | |
60 | shminit() | |
61 | { | |
62 | register int i; | |
9db58063 | 63 | vm_offset_t whocares1, whocares2; |
6f843dc9 | 64 | |
9db58063 KM |
65 | shm_map = kmem_suballoc(kernel_map, &whocares1, &whocares2, |
66 | shminfo.shmall * NBPG, FALSE); | |
6f843dc9 KM |
67 | if (shminfo.shmmni > SHMMMNI) |
68 | shminfo.shmmni = SHMMMNI; | |
69 | for (i = 0; i < shminfo.shmmni; i++) { | |
70 | shmsegs[i].shm_perm.mode = 0; | |
71 | shmsegs[i].shm_perm.seq = 0; | |
72 | } | |
73 | } | |
74 | ||
161c14a2 KM |
75 | /* |
76 | * Entry point for all SHM calls | |
77 | */ | |
afc12c69 CT |
78 | struct shmsys_args { |
79 | u_int which; | |
80 | }; | |
161c14a2 KM |
81 | shmsys(p, uap, retval) |
82 | struct proc *p; | |
afc12c69 | 83 | struct shmsys_args *uap; |
161c14a2 KM |
84 | int *retval; |
85 | { | |
6f843dc9 | 86 | |
161c14a2 | 87 | if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) |
d9c2f47f MK |
88 | return (EINVAL); |
89 | return ((*shmcalls[uap->which])(p, &uap[1], retval)); | |
6f843dc9 KM |
90 | } |
91 | ||
161c14a2 KM |
92 | /* |
93 | * Get a shared memory segment | |
94 | */ | |
afc12c69 CT |
95 | struct shmget_args { |
96 | key_t key; | |
97 | int size; | |
98 | int shmflg; | |
99 | }; | |
161c14a2 KM |
100 | shmget(p, uap, retval) |
101 | struct proc *p; | |
afc12c69 | 102 | register struct shmget_args *uap; |
161c14a2 KM |
103 | int *retval; |
104 | { | |
6f843dc9 | 105 | register struct shmid_ds *shp; |
8429d022 | 106 | register struct ucred *cred = p->p_ucred; |
6f843dc9 | 107 | register int i; |
161c14a2 | 108 | int error, size, rval = 0; |
9db58063 | 109 | register struct shmhandle *shmh; |
6f843dc9 KM |
110 | |
111 | /* look up the specified shm_id */ | |
112 | if (uap->key != IPC_PRIVATE) { | |
113 | for (i = 0; i < shminfo.shmmni; i++) | |
114 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) && | |
115 | shmsegs[i].shm_perm.key == uap->key) { | |
116 | rval = i; | |
117 | break; | |
118 | } | |
119 | } else | |
120 | i = shminfo.shmmni; | |
121 | ||
122 | /* create a new shared segment if necessary */ | |
123 | if (i == shminfo.shmmni) { | |
161c14a2 KM |
124 | if ((uap->shmflg & IPC_CREAT) == 0) |
125 | return (ENOENT); | |
126 | if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) | |
127 | return (EINVAL); | |
6f843dc9 KM |
128 | for (i = 0; i < shminfo.shmmni; i++) |
129 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) { | |
130 | rval = i; | |
131 | break; | |
132 | } | |
161c14a2 KM |
133 | if (i == shminfo.shmmni) |
134 | return (ENOSPC); | |
6f843dc9 | 135 | size = clrnd(btoc(uap->size)); |
161c14a2 KM |
136 | if (shmtot + size > shminfo.shmall) |
137 | return (ENOMEM); | |
6f843dc9 KM |
138 | shp = &shmsegs[rval]; |
139 | /* | |
140 | * We need to do a couple of things to ensure consistency | |
141 | * in case we sleep in malloc(). We mark segment as | |
142 | * allocated so that other shmgets() will not allocate it. | |
143 | * We mark it as "destroyed" to insure that shmvalid() is | |
144 | * false making most operations fail (XXX). We set the key, | |
145 | * so that other shmget()s will fail. | |
146 | */ | |
147 | shp->shm_perm.mode = SHM_ALLOC | SHM_DEST; | |
148 | shp->shm_perm.key = uap->key; | |
9db58063 KM |
149 | shmh = (struct shmhandle *) |
150 | malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK); | |
151 | shmh->shmh_kva = 0; | |
152 | shmh->shmh_id = (caddr_t)(0xc0000000|rval); /* XXX */ | |
153 | error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size), | |
154 | VM_PROT_ALL, MAP_ANON, shmh->shmh_id, 0); | |
155 | if (error) { | |
156 | free((caddr_t)shmh, M_SHM); | |
6f843dc9 | 157 | shp->shm_perm.mode = 0; |
9db58063 | 158 | return(ENOMEM); |
6f843dc9 | 159 | } |
9db58063 | 160 | shp->shm_handle = (void *) shmh; |
6f843dc9 | 161 | shmtot += size; |
161c14a2 KM |
162 | shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid; |
163 | shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid; | |
6f843dc9 | 164 | shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777); |
6f843dc9 | 165 | shp->shm_segsz = uap->size; |
c9714ae3 | 166 | shp->shm_cpid = p->p_pid; |
6f843dc9 KM |
167 | shp->shm_lpid = shp->shm_nattch = 0; |
168 | shp->shm_atime = shp->shm_dtime = 0; | |
169 | shp->shm_ctime = time.tv_sec; | |
170 | } else { | |
171 | shp = &shmsegs[rval]; | |
172 | /* XXX: probably not the right thing to do */ | |
161c14a2 KM |
173 | if (shp->shm_perm.mode & SHM_DEST) |
174 | return (EBUSY); | |
015c074c | 175 | if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred)) |
161c14a2 KM |
176 | return (error); |
177 | if (uap->size && uap->size > shp->shm_segsz) | |
178 | return (EINVAL); | |
179 | if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL)) | |
180 | return (EEXIST); | |
6f843dc9 | 181 | } |
161c14a2 | 182 | *retval = shp->shm_perm.seq * SHMMMNI + rval; |
015c074c | 183 | return (0); |
6f843dc9 KM |
184 | } |
185 | ||
161c14a2 KM |
186 | /* |
187 | * Shared memory control | |
188 | */ | |
afc12c69 CT |
189 | struct shmctl_args { |
190 | int shmid; | |
191 | int cmd; | |
192 | caddr_t buf; | |
193 | }; | |
161c14a2 KM |
194 | /* ARGSUSED */ |
195 | shmctl(p, uap, retval) | |
196 | struct proc *p; | |
afc12c69 | 197 | register struct shmctl_args *uap; |
161c14a2 KM |
198 | int *retval; |
199 | { | |
6f843dc9 | 200 | register struct shmid_ds *shp; |
8429d022 | 201 | register struct ucred *cred = p->p_ucred; |
6f843dc9 | 202 | struct shmid_ds sbuf; |
161c14a2 | 203 | int error; |
6f843dc9 | 204 | |
161c14a2 KM |
205 | if (error = shmvalid(uap->shmid)) |
206 | return (error); | |
6f843dc9 KM |
207 | shp = &shmsegs[uap->shmid % SHMMMNI]; |
208 | switch (uap->cmd) { | |
209 | case IPC_STAT: | |
015c074c | 210 | if (error = ipcaccess(&shp->shm_perm, IPC_R, cred)) |
161c14a2 KM |
211 | return (error); |
212 | return (copyout((caddr_t)shp, uap->buf, sizeof(*shp))); | |
6f843dc9 KM |
213 | |
214 | case IPC_SET: | |
161c14a2 KM |
215 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && |
216 | cred->cr_uid != shp->shm_perm.cuid) | |
217 | return (EPERM); | |
218 | if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf)) | |
219 | return (error); | |
220 | shp->shm_perm.uid = sbuf.shm_perm.uid; | |
221 | shp->shm_perm.gid = sbuf.shm_perm.gid; | |
222 | shp->shm_perm.mode = (shp->shm_perm.mode & ~0777) | |
223 | | (sbuf.shm_perm.mode & 0777); | |
224 | shp->shm_ctime = time.tv_sec; | |
6f843dc9 KM |
225 | break; |
226 | ||
227 | case IPC_RMID: | |
161c14a2 KM |
228 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && |
229 | cred->cr_uid != shp->shm_perm.cuid) | |
230 | return (EPERM); | |
6f843dc9 KM |
231 | /* set ctime? */ |
232 | shp->shm_perm.key = IPC_PRIVATE; | |
233 | shp->shm_perm.mode |= SHM_DEST; | |
234 | if (shp->shm_nattch <= 0) | |
235 | shmfree(shp); | |
236 | break; | |
237 | ||
6f843dc9 | 238 | default: |
161c14a2 | 239 | return (EINVAL); |
6f843dc9 | 240 | } |
161c14a2 | 241 | return (0); |
6f843dc9 KM |
242 | } |
243 | ||
161c14a2 KM |
244 | /* |
245 | * Attach to shared memory segment. | |
246 | */ | |
afc12c69 CT |
247 | struct shmat_args { |
248 | int shmid; | |
249 | caddr_t shmaddr; | |
250 | int shmflg; | |
251 | }; | |
161c14a2 KM |
252 | shmat(p, uap, retval) |
253 | struct proc *p; | |
afc12c69 | 254 | register struct shmat_args *uap; |
161c14a2 KM |
255 | int *retval; |
256 | { | |
6f843dc9 KM |
257 | register struct shmid_ds *shp; |
258 | register int size; | |
6f843dc9 | 259 | caddr_t uva; |
9db58063 KM |
260 | int error; |
261 | int flags; | |
262 | vm_prot_t prot; | |
263 | struct shmdesc *shmd; | |
6f843dc9 | 264 | |
9db58063 KM |
265 | /* |
266 | * Allocate descriptors now (before validity check) | |
267 | * in case malloc() blocks. | |
268 | */ | |
8429d022 | 269 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
270 | size = shminfo.shmseg * sizeof(struct shmdesc); |
271 | if (shmd == NULL) { | |
272 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
273 | bzero((caddr_t)shmd, size); | |
8429d022 | 274 | p->p_vmspace->vm_shm = (caddr_t)shmd; |
9db58063 | 275 | } |
161c14a2 KM |
276 | if (error = shmvalid(uap->shmid)) |
277 | return (error); | |
6f843dc9 KM |
278 | shp = &shmsegs[uap->shmid % SHMMMNI]; |
279 | if (shp->shm_handle == NULL) | |
96ea38ce | 280 | panic("shmat NULL handle"); |
015c074c | 281 | if (error = ipcaccess(&shp->shm_perm, |
8429d022 | 282 | (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, p->p_ucred)) |
161c14a2 | 283 | return (error); |
6f843dc9 KM |
284 | uva = uap->shmaddr; |
285 | if (uva && ((int)uva & (SHMLBA-1))) { | |
286 | if (uap->shmflg & SHM_RND) | |
287 | uva = (caddr_t) ((int)uva & ~(SHMLBA-1)); | |
161c14a2 KM |
288 | else |
289 | return (EINVAL); | |
6f843dc9 KM |
290 | } |
291 | /* | |
292 | * Make sure user doesn't use more than their fair share | |
293 | */ | |
9db58063 KM |
294 | for (size = 0; size < shminfo.shmseg; size++) { |
295 | if (shmd->shmd_uva == 0) | |
296 | break; | |
297 | shmd++; | |
298 | } | |
161c14a2 KM |
299 | if (size >= shminfo.shmseg) |
300 | return (EMFILE); | |
6f843dc9 | 301 | size = ctob(clrnd(btoc(shp->shm_segsz))); |
9db58063 KM |
302 | prot = VM_PROT_READ; |
303 | if ((uap->shmflg & SHM_RDONLY) == 0) | |
304 | prot |= VM_PROT_WRITE; | |
305 | flags = MAP_ANON|MAP_SHARED; | |
306 | if (uva) | |
307 | flags |= MAP_FIXED; | |
308 | else | |
309 | uva = (caddr_t)0x1000000; /* XXX */ | |
451df175 KM |
310 | error = vm_mmap(&p->p_vmspace->vm_map, (vm_offset_t *)&uva, |
311 | (vm_size_t)size, prot, flags, | |
312 | ((struct shmhandle *)shp->shm_handle)->shmh_id, 0); | |
161c14a2 | 313 | if (error) |
9db58063 KM |
314 | return(error); |
315 | shmd->shmd_uva = (vm_offset_t)uva; | |
316 | shmd->shmd_id = uap->shmid; | |
6f843dc9 KM |
317 | /* |
318 | * Fill in the remaining fields | |
319 | */ | |
c9714ae3 | 320 | shp->shm_lpid = p->p_pid; |
6f843dc9 KM |
321 | shp->shm_atime = time.tv_sec; |
322 | shp->shm_nattch++; | |
161c14a2 | 323 | *retval = (int) uva; |
015c074c | 324 | return (0); |
6f843dc9 KM |
325 | } |
326 | ||
161c14a2 KM |
327 | /* |
328 | * Detach from shared memory segment. | |
329 | */ | |
afc12c69 CT |
330 | struct shmdt_args { |
331 | caddr_t shmaddr; | |
332 | }; | |
161c14a2 KM |
333 | /* ARGSUSED */ |
334 | shmdt(p, uap, retval) | |
335 | struct proc *p; | |
afc12c69 | 336 | struct shmdt_args *uap; |
161c14a2 KM |
337 | int *retval; |
338 | { | |
9db58063 KM |
339 | register struct shmdesc *shmd; |
340 | register int i; | |
6f843dc9 | 341 | |
8429d022 | 342 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
343 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
344 | if (shmd->shmd_uva && | |
345 | shmd->shmd_uva == (vm_offset_t)uap->shmaddr) | |
6f843dc9 | 346 | break; |
9db58063 KM |
347 | if (i == shminfo.shmseg) |
348 | return(EINVAL); | |
349 | shmufree(p, shmd); | |
350 | shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid; | |
6f843dc9 KM |
351 | } |
352 | ||
8429d022 MK |
353 | shmfork(p1, p2, isvfork) |
354 | struct proc *p1, *p2; | |
9db58063 | 355 | int isvfork; |
6f843dc9 | 356 | { |
9db58063 KM |
357 | register struct shmdesc *shmd; |
358 | register int size; | |
6f843dc9 | 359 | |
9db58063 KM |
360 | /* |
361 | * Copy parents descriptive information | |
362 | */ | |
363 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
364 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
8429d022 MK |
365 | bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size); |
366 | p2->p_vmspace->vm_shm = (caddr_t)shmd; | |
9db58063 KM |
367 | /* |
368 | * Increment reference counts | |
369 | */ | |
370 | for (size = 0; size < shminfo.shmseg; size++, shmd++) | |
371 | if (shmd->shmd_uva) | |
372 | shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++; | |
6f843dc9 KM |
373 | } |
374 | ||
9db58063 KM |
375 | shmexit(p) |
376 | struct proc *p; | |
6f843dc9 | 377 | { |
9db58063 KM |
378 | register struct shmdesc *shmd; |
379 | register int i; | |
c9714ae3 | 380 | |
8429d022 | 381 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
382 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
383 | if (shmd->shmd_uva) | |
384 | shmufree(p, shmd); | |
8429d022 MK |
385 | free((caddr_t)p->p_vmspace->vm_shm, M_SHM); |
386 | p->p_vmspace->vm_shm = NULL; | |
6f843dc9 KM |
387 | } |
388 | ||
389 | shmvalid(id) | |
390 | register int id; | |
391 | { | |
392 | register struct shmid_ds *shp; | |
393 | ||
394 | if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni) | |
161c14a2 | 395 | return(EINVAL); |
6f843dc9 KM |
396 | shp = &shmsegs[id % SHMMMNI]; |
397 | if (shp->shm_perm.seq == (id / SHMMMNI) && | |
398 | (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC) | |
161c14a2 KM |
399 | return(0); |
400 | return(EINVAL); | |
6f843dc9 KM |
401 | } |
402 | ||
403 | /* | |
404 | * Free user resources associated with a shared memory segment | |
405 | */ | |
9db58063 | 406 | shmufree(p, shmd) |
c9714ae3 | 407 | struct proc *p; |
9db58063 | 408 | struct shmdesc *shmd; |
6f843dc9 KM |
409 | { |
410 | register struct shmid_ds *shp; | |
411 | ||
9db58063 | 412 | shp = &shmsegs[shmd->shmd_id % SHMMMNI]; |
aa6d6b7e | 413 | (void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva, |
9db58063 KM |
414 | ctob(clrnd(btoc(shp->shm_segsz)))); |
415 | shmd->shmd_id = 0; | |
416 | shmd->shmd_uva = 0; | |
6f843dc9 KM |
417 | shp->shm_dtime = time.tv_sec; |
418 | if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST)) | |
419 | shmfree(shp); | |
420 | } | |
421 | ||
422 | /* | |
423 | * Deallocate resources associated with a shared memory segment | |
424 | */ | |
425 | shmfree(shp) | |
426 | register struct shmid_ds *shp; | |
427 | { | |
6f843dc9 KM |
428 | |
429 | if (shp->shm_handle == NULL) | |
430 | panic("shmfree"); | |
9db58063 KM |
431 | /* |
432 | * Lose our lingering object reference by deallocating space | |
433 | * in kernel. Pager will also be deallocated as a side-effect. | |
434 | */ | |
435 | vm_deallocate(shm_map, | |
436 | ((struct shmhandle *)shp->shm_handle)->shmh_kva, | |
9d81fbb9 | 437 | ctob(clrnd(btoc(shp->shm_segsz)))); |
9db58063 | 438 | free((caddr_t)shp->shm_handle, M_SHM); |
6f843dc9 KM |
439 | shp->shm_handle = NULL; |
440 | shmtot -= clrnd(btoc(shp->shm_segsz)); | |
441 | shp->shm_perm.mode = 0; | |
442 | /* | |
443 | * Increment the sequence number to ensure that outstanding | |
444 | * shmids for this segment will be invalid in the event that | |
445 | * the segment is reallocated. Note that shmids must be | |
446 | * positive as decreed by SVID. | |
447 | */ | |
448 | shp->shm_perm.seq++; | |
449 | if ((int)(shp->shm_perm.seq * SHMMMNI) < 0) | |
450 | shp->shm_perm.seq = 0; | |
451 | } | |
452 | ||
453 | /* | |
454 | * XXX This routine would be common to all sysV style IPC | |
455 | * (if the others were implemented). | |
456 | */ | |
161c14a2 | 457 | ipcaccess(ipc, mode, cred) |
6f843dc9 | 458 | register struct ipc_perm *ipc; |
161c14a2 KM |
459 | int mode; |
460 | register struct ucred *cred; | |
6f843dc9 KM |
461 | { |
462 | register int m; | |
463 | ||
161c14a2 | 464 | if (cred->cr_uid == 0) |
6f843dc9 KM |
465 | return(0); |
466 | /* | |
467 | * Access check is based on only one of owner, group, public. | |
468 | * If not owner, then check group. | |
469 | * If not a member of the group, then check public access. | |
470 | */ | |
471 | mode &= 0700; | |
472 | m = ipc->mode; | |
161c14a2 | 473 | if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) { |
6f843dc9 | 474 | m <<= 3; |
161c14a2 KM |
475 | if (!groupmember(ipc->gid, cred) && |
476 | !groupmember(ipc->cgid, cred)) | |
6f843dc9 KM |
477 | m <<= 3; |
478 | } | |
479 | if ((mode&m) == mode) | |
161c14a2 KM |
480 | return (0); |
481 | return (EACCES); | |
6f843dc9 | 482 | } |
6f843dc9 | 483 | #endif /* SYSVSHM */ |