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 | * |
3cf1b235 | 14 | * @(#)sysv_shm.c 7.18 (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 | */ | |
78 | shmsys(p, uap, retval) | |
79 | struct proc *p; | |
80 | struct args { | |
e4f7cdf5 | 81 | u_int which; |
161c14a2 KM |
82 | } *uap; |
83 | int *retval; | |
84 | { | |
6f843dc9 | 85 | |
161c14a2 | 86 | if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) |
d9c2f47f MK |
87 | return (EINVAL); |
88 | return ((*shmcalls[uap->which])(p, &uap[1], retval)); | |
6f843dc9 KM |
89 | } |
90 | ||
161c14a2 KM |
91 | /* |
92 | * Get a shared memory segment | |
93 | */ | |
94 | shmget(p, uap, retval) | |
95 | struct proc *p; | |
96 | register struct args { | |
6f843dc9 KM |
97 | key_t key; |
98 | int size; | |
99 | int shmflg; | |
161c14a2 KM |
100 | } *uap; |
101 | int *retval; | |
102 | { | |
6f843dc9 | 103 | register struct shmid_ds *shp; |
8429d022 | 104 | register struct ucred *cred = p->p_ucred; |
6f843dc9 | 105 | register int i; |
161c14a2 | 106 | int error, size, rval = 0; |
9db58063 | 107 | register struct shmhandle *shmh; |
6f843dc9 KM |
108 | |
109 | /* look up the specified shm_id */ | |
110 | if (uap->key != IPC_PRIVATE) { | |
111 | for (i = 0; i < shminfo.shmmni; i++) | |
112 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) && | |
113 | shmsegs[i].shm_perm.key == uap->key) { | |
114 | rval = i; | |
115 | break; | |
116 | } | |
117 | } else | |
118 | i = shminfo.shmmni; | |
119 | ||
120 | /* create a new shared segment if necessary */ | |
121 | if (i == shminfo.shmmni) { | |
161c14a2 KM |
122 | if ((uap->shmflg & IPC_CREAT) == 0) |
123 | return (ENOENT); | |
124 | if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) | |
125 | return (EINVAL); | |
6f843dc9 KM |
126 | for (i = 0; i < shminfo.shmmni; i++) |
127 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) { | |
128 | rval = i; | |
129 | break; | |
130 | } | |
161c14a2 KM |
131 | if (i == shminfo.shmmni) |
132 | return (ENOSPC); | |
6f843dc9 | 133 | size = clrnd(btoc(uap->size)); |
161c14a2 KM |
134 | if (shmtot + size > shminfo.shmall) |
135 | return (ENOMEM); | |
6f843dc9 KM |
136 | shp = &shmsegs[rval]; |
137 | /* | |
138 | * We need to do a couple of things to ensure consistency | |
139 | * in case we sleep in malloc(). We mark segment as | |
140 | * allocated so that other shmgets() will not allocate it. | |
141 | * We mark it as "destroyed" to insure that shmvalid() is | |
142 | * false making most operations fail (XXX). We set the key, | |
143 | * so that other shmget()s will fail. | |
144 | */ | |
145 | shp->shm_perm.mode = SHM_ALLOC | SHM_DEST; | |
146 | shp->shm_perm.key = uap->key; | |
9db58063 KM |
147 | shmh = (struct shmhandle *) |
148 | malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK); | |
149 | shmh->shmh_kva = 0; | |
150 | shmh->shmh_id = (caddr_t)(0xc0000000|rval); /* XXX */ | |
151 | error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size), | |
152 | VM_PROT_ALL, MAP_ANON, shmh->shmh_id, 0); | |
153 | if (error) { | |
154 | free((caddr_t)shmh, M_SHM); | |
6f843dc9 | 155 | shp->shm_perm.mode = 0; |
9db58063 | 156 | return(ENOMEM); |
6f843dc9 | 157 | } |
9db58063 | 158 | shp->shm_handle = (void *) shmh; |
6f843dc9 | 159 | shmtot += size; |
161c14a2 KM |
160 | shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid; |
161 | shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid; | |
6f843dc9 | 162 | shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777); |
6f843dc9 | 163 | shp->shm_segsz = uap->size; |
c9714ae3 | 164 | shp->shm_cpid = p->p_pid; |
6f843dc9 KM |
165 | shp->shm_lpid = shp->shm_nattch = 0; |
166 | shp->shm_atime = shp->shm_dtime = 0; | |
167 | shp->shm_ctime = time.tv_sec; | |
168 | } else { | |
169 | shp = &shmsegs[rval]; | |
170 | /* XXX: probably not the right thing to do */ | |
161c14a2 KM |
171 | if (shp->shm_perm.mode & SHM_DEST) |
172 | return (EBUSY); | |
015c074c | 173 | if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred)) |
161c14a2 KM |
174 | return (error); |
175 | if (uap->size && uap->size > shp->shm_segsz) | |
176 | return (EINVAL); | |
177 | if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL)) | |
178 | return (EEXIST); | |
6f843dc9 | 179 | } |
161c14a2 | 180 | *retval = shp->shm_perm.seq * SHMMMNI + rval; |
015c074c | 181 | return (0); |
6f843dc9 KM |
182 | } |
183 | ||
161c14a2 KM |
184 | /* |
185 | * Shared memory control | |
186 | */ | |
187 | /* ARGSUSED */ | |
188 | shmctl(p, uap, retval) | |
189 | struct proc *p; | |
190 | register struct args { | |
6f843dc9 KM |
191 | int shmid; |
192 | int cmd; | |
193 | caddr_t buf; | |
161c14a2 KM |
194 | } *uap; |
195 | int *retval; | |
196 | { | |
6f843dc9 | 197 | register struct shmid_ds *shp; |
8429d022 | 198 | register struct ucred *cred = p->p_ucred; |
6f843dc9 | 199 | struct shmid_ds sbuf; |
161c14a2 | 200 | int error; |
6f843dc9 | 201 | |
161c14a2 KM |
202 | if (error = shmvalid(uap->shmid)) |
203 | return (error); | |
6f843dc9 KM |
204 | shp = &shmsegs[uap->shmid % SHMMMNI]; |
205 | switch (uap->cmd) { | |
206 | case IPC_STAT: | |
015c074c | 207 | if (error = ipcaccess(&shp->shm_perm, IPC_R, cred)) |
161c14a2 KM |
208 | return (error); |
209 | return (copyout((caddr_t)shp, uap->buf, sizeof(*shp))); | |
6f843dc9 KM |
210 | |
211 | case IPC_SET: | |
161c14a2 KM |
212 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && |
213 | cred->cr_uid != shp->shm_perm.cuid) | |
214 | return (EPERM); | |
215 | if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf)) | |
216 | return (error); | |
217 | shp->shm_perm.uid = sbuf.shm_perm.uid; | |
218 | shp->shm_perm.gid = sbuf.shm_perm.gid; | |
219 | shp->shm_perm.mode = (shp->shm_perm.mode & ~0777) | |
220 | | (sbuf.shm_perm.mode & 0777); | |
221 | shp->shm_ctime = time.tv_sec; | |
6f843dc9 KM |
222 | break; |
223 | ||
224 | case IPC_RMID: | |
161c14a2 KM |
225 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && |
226 | cred->cr_uid != shp->shm_perm.cuid) | |
227 | return (EPERM); | |
6f843dc9 KM |
228 | /* set ctime? */ |
229 | shp->shm_perm.key = IPC_PRIVATE; | |
230 | shp->shm_perm.mode |= SHM_DEST; | |
231 | if (shp->shm_nattch <= 0) | |
232 | shmfree(shp); | |
233 | break; | |
234 | ||
6f843dc9 | 235 | default: |
161c14a2 | 236 | return (EINVAL); |
6f843dc9 | 237 | } |
161c14a2 | 238 | return (0); |
6f843dc9 KM |
239 | } |
240 | ||
161c14a2 KM |
241 | /* |
242 | * Attach to shared memory segment. | |
243 | */ | |
244 | shmat(p, uap, retval) | |
245 | struct proc *p; | |
246 | register struct args { | |
6f843dc9 KM |
247 | int shmid; |
248 | caddr_t shmaddr; | |
249 | int shmflg; | |
161c14a2 KM |
250 | } *uap; |
251 | int *retval; | |
252 | { | |
6f843dc9 KM |
253 | register struct shmid_ds *shp; |
254 | register int size; | |
6f843dc9 | 255 | caddr_t uva; |
9db58063 KM |
256 | int error; |
257 | int flags; | |
258 | vm_prot_t prot; | |
259 | struct shmdesc *shmd; | |
6f843dc9 | 260 | |
9db58063 KM |
261 | /* |
262 | * Allocate descriptors now (before validity check) | |
263 | * in case malloc() blocks. | |
264 | */ | |
8429d022 | 265 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
266 | size = shminfo.shmseg * sizeof(struct shmdesc); |
267 | if (shmd == NULL) { | |
268 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
269 | bzero((caddr_t)shmd, size); | |
8429d022 | 270 | p->p_vmspace->vm_shm = (caddr_t)shmd; |
9db58063 | 271 | } |
161c14a2 KM |
272 | if (error = shmvalid(uap->shmid)) |
273 | return (error); | |
6f843dc9 KM |
274 | shp = &shmsegs[uap->shmid % SHMMMNI]; |
275 | if (shp->shm_handle == NULL) | |
96ea38ce | 276 | panic("shmat NULL handle"); |
015c074c | 277 | if (error = ipcaccess(&shp->shm_perm, |
8429d022 | 278 | (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, p->p_ucred)) |
161c14a2 | 279 | return (error); |
6f843dc9 KM |
280 | uva = uap->shmaddr; |
281 | if (uva && ((int)uva & (SHMLBA-1))) { | |
282 | if (uap->shmflg & SHM_RND) | |
283 | uva = (caddr_t) ((int)uva & ~(SHMLBA-1)); | |
161c14a2 KM |
284 | else |
285 | return (EINVAL); | |
6f843dc9 KM |
286 | } |
287 | /* | |
288 | * Make sure user doesn't use more than their fair share | |
289 | */ | |
9db58063 KM |
290 | for (size = 0; size < shminfo.shmseg; size++) { |
291 | if (shmd->shmd_uva == 0) | |
292 | break; | |
293 | shmd++; | |
294 | } | |
161c14a2 KM |
295 | if (size >= shminfo.shmseg) |
296 | return (EMFILE); | |
6f843dc9 | 297 | size = ctob(clrnd(btoc(shp->shm_segsz))); |
9db58063 KM |
298 | prot = VM_PROT_READ; |
299 | if ((uap->shmflg & SHM_RDONLY) == 0) | |
300 | prot |= VM_PROT_WRITE; | |
301 | flags = MAP_ANON|MAP_SHARED; | |
302 | if (uva) | |
303 | flags |= MAP_FIXED; | |
304 | else | |
305 | uva = (caddr_t)0x1000000; /* XXX */ | |
451df175 KM |
306 | error = vm_mmap(&p->p_vmspace->vm_map, (vm_offset_t *)&uva, |
307 | (vm_size_t)size, prot, flags, | |
308 | ((struct shmhandle *)shp->shm_handle)->shmh_id, 0); | |
161c14a2 | 309 | if (error) |
9db58063 KM |
310 | return(error); |
311 | shmd->shmd_uva = (vm_offset_t)uva; | |
312 | shmd->shmd_id = uap->shmid; | |
6f843dc9 KM |
313 | /* |
314 | * Fill in the remaining fields | |
315 | */ | |
c9714ae3 | 316 | shp->shm_lpid = p->p_pid; |
6f843dc9 KM |
317 | shp->shm_atime = time.tv_sec; |
318 | shp->shm_nattch++; | |
161c14a2 | 319 | *retval = (int) uva; |
015c074c | 320 | return (0); |
6f843dc9 KM |
321 | } |
322 | ||
161c14a2 KM |
323 | /* |
324 | * Detach from shared memory segment. | |
325 | */ | |
326 | /* ARGSUSED */ | |
327 | shmdt(p, uap, retval) | |
328 | struct proc *p; | |
329 | struct args { | |
6f843dc9 | 330 | caddr_t shmaddr; |
161c14a2 KM |
331 | } *uap; |
332 | int *retval; | |
333 | { | |
9db58063 KM |
334 | register struct shmdesc *shmd; |
335 | register int i; | |
6f843dc9 | 336 | |
8429d022 | 337 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
338 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
339 | if (shmd->shmd_uva && | |
340 | shmd->shmd_uva == (vm_offset_t)uap->shmaddr) | |
6f843dc9 | 341 | break; |
9db58063 KM |
342 | if (i == shminfo.shmseg) |
343 | return(EINVAL); | |
344 | shmufree(p, shmd); | |
345 | shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid; | |
6f843dc9 KM |
346 | } |
347 | ||
8429d022 MK |
348 | shmfork(p1, p2, isvfork) |
349 | struct proc *p1, *p2; | |
9db58063 | 350 | int isvfork; |
6f843dc9 | 351 | { |
9db58063 KM |
352 | register struct shmdesc *shmd; |
353 | register int size; | |
6f843dc9 | 354 | |
9db58063 KM |
355 | /* |
356 | * Copy parents descriptive information | |
357 | */ | |
358 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
359 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
8429d022 MK |
360 | bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size); |
361 | p2->p_vmspace->vm_shm = (caddr_t)shmd; | |
9db58063 KM |
362 | /* |
363 | * Increment reference counts | |
364 | */ | |
365 | for (size = 0; size < shminfo.shmseg; size++, shmd++) | |
366 | if (shmd->shmd_uva) | |
367 | shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++; | |
6f843dc9 KM |
368 | } |
369 | ||
9db58063 KM |
370 | shmexit(p) |
371 | struct proc *p; | |
6f843dc9 | 372 | { |
9db58063 KM |
373 | register struct shmdesc *shmd; |
374 | register int i; | |
c9714ae3 | 375 | |
8429d022 | 376 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
377 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
378 | if (shmd->shmd_uva) | |
379 | shmufree(p, shmd); | |
8429d022 MK |
380 | free((caddr_t)p->p_vmspace->vm_shm, M_SHM); |
381 | p->p_vmspace->vm_shm = NULL; | |
6f843dc9 KM |
382 | } |
383 | ||
384 | shmvalid(id) | |
385 | register int id; | |
386 | { | |
387 | register struct shmid_ds *shp; | |
388 | ||
389 | if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni) | |
161c14a2 | 390 | return(EINVAL); |
6f843dc9 KM |
391 | shp = &shmsegs[id % SHMMMNI]; |
392 | if (shp->shm_perm.seq == (id / SHMMMNI) && | |
393 | (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC) | |
161c14a2 KM |
394 | return(0); |
395 | return(EINVAL); | |
6f843dc9 KM |
396 | } |
397 | ||
398 | /* | |
399 | * Free user resources associated with a shared memory segment | |
400 | */ | |
9db58063 | 401 | shmufree(p, shmd) |
c9714ae3 | 402 | struct proc *p; |
9db58063 | 403 | struct shmdesc *shmd; |
6f843dc9 KM |
404 | { |
405 | register struct shmid_ds *shp; | |
406 | ||
9db58063 | 407 | shp = &shmsegs[shmd->shmd_id % SHMMMNI]; |
aa6d6b7e | 408 | (void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva, |
9db58063 KM |
409 | ctob(clrnd(btoc(shp->shm_segsz)))); |
410 | shmd->shmd_id = 0; | |
411 | shmd->shmd_uva = 0; | |
6f843dc9 KM |
412 | shp->shm_dtime = time.tv_sec; |
413 | if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST)) | |
414 | shmfree(shp); | |
415 | } | |
416 | ||
417 | /* | |
418 | * Deallocate resources associated with a shared memory segment | |
419 | */ | |
420 | shmfree(shp) | |
421 | register struct shmid_ds *shp; | |
422 | { | |
6f843dc9 KM |
423 | |
424 | if (shp->shm_handle == NULL) | |
425 | panic("shmfree"); | |
9db58063 KM |
426 | /* |
427 | * Lose our lingering object reference by deallocating space | |
428 | * in kernel. Pager will also be deallocated as a side-effect. | |
429 | */ | |
430 | vm_deallocate(shm_map, | |
431 | ((struct shmhandle *)shp->shm_handle)->shmh_kva, | |
9d81fbb9 | 432 | ctob(clrnd(btoc(shp->shm_segsz)))); |
9db58063 | 433 | free((caddr_t)shp->shm_handle, M_SHM); |
6f843dc9 KM |
434 | shp->shm_handle = NULL; |
435 | shmtot -= clrnd(btoc(shp->shm_segsz)); | |
436 | shp->shm_perm.mode = 0; | |
437 | /* | |
438 | * Increment the sequence number to ensure that outstanding | |
439 | * shmids for this segment will be invalid in the event that | |
440 | * the segment is reallocated. Note that shmids must be | |
441 | * positive as decreed by SVID. | |
442 | */ | |
443 | shp->shm_perm.seq++; | |
444 | if ((int)(shp->shm_perm.seq * SHMMMNI) < 0) | |
445 | shp->shm_perm.seq = 0; | |
446 | } | |
447 | ||
448 | /* | |
449 | * XXX This routine would be common to all sysV style IPC | |
450 | * (if the others were implemented). | |
451 | */ | |
161c14a2 | 452 | ipcaccess(ipc, mode, cred) |
6f843dc9 | 453 | register struct ipc_perm *ipc; |
161c14a2 KM |
454 | int mode; |
455 | register struct ucred *cred; | |
6f843dc9 KM |
456 | { |
457 | register int m; | |
458 | ||
161c14a2 | 459 | if (cred->cr_uid == 0) |
6f843dc9 KM |
460 | return(0); |
461 | /* | |
462 | * Access check is based on only one of owner, group, public. | |
463 | * If not owner, then check group. | |
464 | * If not a member of the group, then check public access. | |
465 | */ | |
466 | mode &= 0700; | |
467 | m = ipc->mode; | |
161c14a2 | 468 | if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) { |
6f843dc9 | 469 | m <<= 3; |
161c14a2 KM |
470 | if (!groupmember(ipc->gid, cred) && |
471 | !groupmember(ipc->cgid, cred)) | |
6f843dc9 KM |
472 | m <<= 3; |
473 | } | |
474 | if ((mode&m) == mode) | |
161c14a2 KM |
475 | return (0); |
476 | return (EACCES); | |
6f843dc9 | 477 | } |
6f843dc9 | 478 | #endif /* SYSVSHM */ |