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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 | * | |
12 | * from: Utah $Hdr: uipc_shm.c 1.9 89/08/14$ | |
13 | * | |
294d579e | 14 | * @(#)sysv_shm.c 7.17 (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 KM |
36 | |
37 | #ifdef HPUXCOMPAT | |
294d579e | 38 | #include "hp/hpux/hpux.h" |
6f843dc9 KM |
39 | #endif |
40 | ||
41 | int shmat(), shmctl(), shmdt(), shmget(); | |
42 | int (*shmcalls[])() = { shmat, shmctl, shmdt, shmget }; | |
43 | int shmtot = 0; | |
44 | ||
9db58063 KM |
45 | /* |
46 | * Per process internal structure for managing segments. | |
47 | * Each process using shm will have an array of ``shmseg'' of these. | |
48 | */ | |
49 | struct shmdesc { | |
50 | vm_offset_t shmd_uva; | |
51 | int shmd_id; | |
52 | }; | |
53 | ||
54 | /* | |
55 | * Per segment internal structure (shm_handle). | |
56 | */ | |
57 | struct shmhandle { | |
58 | vm_offset_t shmh_kva; | |
59 | caddr_t shmh_id; | |
60 | }; | |
61 | ||
62 | vm_map_t shm_map; /* address space for shared memory segments */ | |
6f843dc9 KM |
63 | |
64 | shminit() | |
65 | { | |
66 | register int i; | |
9db58063 | 67 | vm_offset_t whocares1, whocares2; |
6f843dc9 | 68 | |
9db58063 KM |
69 | shm_map = kmem_suballoc(kernel_map, &whocares1, &whocares2, |
70 | shminfo.shmall * NBPG, FALSE); | |
6f843dc9 KM |
71 | if (shminfo.shmmni > SHMMMNI) |
72 | shminfo.shmmni = SHMMMNI; | |
73 | for (i = 0; i < shminfo.shmmni; i++) { | |
74 | shmsegs[i].shm_perm.mode = 0; | |
75 | shmsegs[i].shm_perm.seq = 0; | |
76 | } | |
77 | } | |
78 | ||
161c14a2 KM |
79 | /* |
80 | * Entry point for all SHM calls | |
81 | */ | |
82 | shmsys(p, uap, retval) | |
83 | struct proc *p; | |
84 | struct args { | |
e4f7cdf5 | 85 | u_int which; |
161c14a2 KM |
86 | } *uap; |
87 | int *retval; | |
88 | { | |
6f843dc9 | 89 | |
161c14a2 | 90 | if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) |
d9c2f47f MK |
91 | return (EINVAL); |
92 | return ((*shmcalls[uap->which])(p, &uap[1], retval)); | |
6f843dc9 KM |
93 | } |
94 | ||
161c14a2 KM |
95 | /* |
96 | * Get a shared memory segment | |
97 | */ | |
98 | shmget(p, uap, retval) | |
99 | struct proc *p; | |
100 | register struct args { | |
6f843dc9 KM |
101 | key_t key; |
102 | int size; | |
103 | int shmflg; | |
161c14a2 KM |
104 | } *uap; |
105 | int *retval; | |
106 | { | |
6f843dc9 | 107 | register struct shmid_ds *shp; |
8429d022 | 108 | register struct ucred *cred = p->p_ucred; |
6f843dc9 | 109 | register int i; |
161c14a2 | 110 | int error, size, rval = 0; |
9db58063 | 111 | register struct shmhandle *shmh; |
6f843dc9 KM |
112 | |
113 | /* look up the specified shm_id */ | |
114 | if (uap->key != IPC_PRIVATE) { | |
115 | for (i = 0; i < shminfo.shmmni; i++) | |
116 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) && | |
117 | shmsegs[i].shm_perm.key == uap->key) { | |
118 | rval = i; | |
119 | break; | |
120 | } | |
121 | } else | |
122 | i = shminfo.shmmni; | |
123 | ||
124 | /* create a new shared segment if necessary */ | |
125 | if (i == shminfo.shmmni) { | |
161c14a2 KM |
126 | if ((uap->shmflg & IPC_CREAT) == 0) |
127 | return (ENOENT); | |
128 | if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) | |
129 | return (EINVAL); | |
6f843dc9 KM |
130 | for (i = 0; i < shminfo.shmmni; i++) |
131 | if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) { | |
132 | rval = i; | |
133 | break; | |
134 | } | |
161c14a2 KM |
135 | if (i == shminfo.shmmni) |
136 | return (ENOSPC); | |
6f843dc9 | 137 | size = clrnd(btoc(uap->size)); |
161c14a2 KM |
138 | if (shmtot + size > shminfo.shmall) |
139 | return (ENOMEM); | |
6f843dc9 KM |
140 | shp = &shmsegs[rval]; |
141 | /* | |
142 | * We need to do a couple of things to ensure consistency | |
143 | * in case we sleep in malloc(). We mark segment as | |
144 | * allocated so that other shmgets() will not allocate it. | |
145 | * We mark it as "destroyed" to insure that shmvalid() is | |
146 | * false making most operations fail (XXX). We set the key, | |
147 | * so that other shmget()s will fail. | |
148 | */ | |
149 | shp->shm_perm.mode = SHM_ALLOC | SHM_DEST; | |
150 | shp->shm_perm.key = uap->key; | |
9db58063 KM |
151 | shmh = (struct shmhandle *) |
152 | malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK); | |
153 | shmh->shmh_kva = 0; | |
154 | shmh->shmh_id = (caddr_t)(0xc0000000|rval); /* XXX */ | |
155 | error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size), | |
156 | VM_PROT_ALL, MAP_ANON, shmh->shmh_id, 0); | |
157 | if (error) { | |
158 | free((caddr_t)shmh, M_SHM); | |
6f843dc9 | 159 | shp->shm_perm.mode = 0; |
9db58063 | 160 | return(ENOMEM); |
6f843dc9 | 161 | } |
9db58063 | 162 | shp->shm_handle = (void *) shmh; |
6f843dc9 | 163 | shmtot += size; |
161c14a2 KM |
164 | shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid; |
165 | shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid; | |
6f843dc9 | 166 | shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777); |
6f843dc9 | 167 | shp->shm_segsz = uap->size; |
c9714ae3 | 168 | shp->shm_cpid = p->p_pid; |
6f843dc9 KM |
169 | shp->shm_lpid = shp->shm_nattch = 0; |
170 | shp->shm_atime = shp->shm_dtime = 0; | |
171 | shp->shm_ctime = time.tv_sec; | |
172 | } else { | |
173 | shp = &shmsegs[rval]; | |
174 | /* XXX: probably not the right thing to do */ | |
161c14a2 KM |
175 | if (shp->shm_perm.mode & SHM_DEST) |
176 | return (EBUSY); | |
015c074c | 177 | if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred)) |
161c14a2 KM |
178 | return (error); |
179 | if (uap->size && uap->size > shp->shm_segsz) | |
180 | return (EINVAL); | |
181 | if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL)) | |
182 | return (EEXIST); | |
6f843dc9 | 183 | } |
161c14a2 | 184 | *retval = shp->shm_perm.seq * SHMMMNI + rval; |
015c074c | 185 | return (0); |
6f843dc9 KM |
186 | } |
187 | ||
161c14a2 KM |
188 | /* |
189 | * Shared memory control | |
190 | */ | |
191 | /* ARGSUSED */ | |
192 | shmctl(p, uap, retval) | |
193 | struct proc *p; | |
194 | register struct args { | |
6f843dc9 KM |
195 | int shmid; |
196 | int cmd; | |
197 | caddr_t buf; | |
161c14a2 KM |
198 | } *uap; |
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 | ||
239 | #ifdef HPUXCOMPAT | |
240 | case SHM_LOCK: | |
241 | case SHM_UNLOCK: | |
242 | /* don't really do anything, but make them think we did */ | |
c9714ae3 | 243 | if ((p->p_flag & SHPUX) == 0) |
161c14a2 KM |
244 | return (EINVAL); |
245 | if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid && | |
246 | cred->cr_uid != shp->shm_perm.cuid) | |
247 | return (EPERM); | |
6f843dc9 KM |
248 | break; |
249 | #endif | |
250 | ||
251 | default: | |
161c14a2 | 252 | return (EINVAL); |
6f843dc9 | 253 | } |
161c14a2 | 254 | return (0); |
6f843dc9 KM |
255 | } |
256 | ||
161c14a2 KM |
257 | /* |
258 | * Attach to shared memory segment. | |
259 | */ | |
260 | shmat(p, uap, retval) | |
261 | struct proc *p; | |
262 | register struct args { | |
6f843dc9 KM |
263 | int shmid; |
264 | caddr_t shmaddr; | |
265 | int shmflg; | |
161c14a2 KM |
266 | } *uap; |
267 | int *retval; | |
268 | { | |
6f843dc9 KM |
269 | register struct shmid_ds *shp; |
270 | register int size; | |
6f843dc9 | 271 | caddr_t uva; |
9db58063 KM |
272 | int error; |
273 | int flags; | |
274 | vm_prot_t prot; | |
275 | struct shmdesc *shmd; | |
6f843dc9 | 276 | |
9db58063 KM |
277 | /* |
278 | * Allocate descriptors now (before validity check) | |
279 | * in case malloc() blocks. | |
280 | */ | |
8429d022 | 281 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
282 | size = shminfo.shmseg * sizeof(struct shmdesc); |
283 | if (shmd == NULL) { | |
284 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
285 | bzero((caddr_t)shmd, size); | |
8429d022 | 286 | p->p_vmspace->vm_shm = (caddr_t)shmd; |
9db58063 | 287 | } |
161c14a2 KM |
288 | if (error = shmvalid(uap->shmid)) |
289 | return (error); | |
6f843dc9 KM |
290 | shp = &shmsegs[uap->shmid % SHMMMNI]; |
291 | if (shp->shm_handle == NULL) | |
96ea38ce | 292 | panic("shmat NULL handle"); |
015c074c | 293 | if (error = ipcaccess(&shp->shm_perm, |
8429d022 | 294 | (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, p->p_ucred)) |
161c14a2 | 295 | return (error); |
6f843dc9 KM |
296 | uva = uap->shmaddr; |
297 | if (uva && ((int)uva & (SHMLBA-1))) { | |
298 | if (uap->shmflg & SHM_RND) | |
299 | uva = (caddr_t) ((int)uva & ~(SHMLBA-1)); | |
161c14a2 KM |
300 | else |
301 | return (EINVAL); | |
6f843dc9 KM |
302 | } |
303 | /* | |
304 | * Make sure user doesn't use more than their fair share | |
305 | */ | |
9db58063 KM |
306 | for (size = 0; size < shminfo.shmseg; size++) { |
307 | if (shmd->shmd_uva == 0) | |
308 | break; | |
309 | shmd++; | |
310 | } | |
161c14a2 KM |
311 | if (size >= shminfo.shmseg) |
312 | return (EMFILE); | |
6f843dc9 | 313 | size = ctob(clrnd(btoc(shp->shm_segsz))); |
9db58063 KM |
314 | prot = VM_PROT_READ; |
315 | if ((uap->shmflg & SHM_RDONLY) == 0) | |
316 | prot |= VM_PROT_WRITE; | |
317 | flags = MAP_ANON|MAP_SHARED; | |
318 | if (uva) | |
319 | flags |= MAP_FIXED; | |
320 | else | |
321 | uva = (caddr_t)0x1000000; /* XXX */ | |
451df175 KM |
322 | error = vm_mmap(&p->p_vmspace->vm_map, (vm_offset_t *)&uva, |
323 | (vm_size_t)size, prot, flags, | |
324 | ((struct shmhandle *)shp->shm_handle)->shmh_id, 0); | |
161c14a2 | 325 | if (error) |
9db58063 KM |
326 | return(error); |
327 | shmd->shmd_uva = (vm_offset_t)uva; | |
328 | shmd->shmd_id = uap->shmid; | |
6f843dc9 KM |
329 | /* |
330 | * Fill in the remaining fields | |
331 | */ | |
c9714ae3 | 332 | shp->shm_lpid = p->p_pid; |
6f843dc9 KM |
333 | shp->shm_atime = time.tv_sec; |
334 | shp->shm_nattch++; | |
161c14a2 | 335 | *retval = (int) uva; |
015c074c | 336 | return (0); |
6f843dc9 KM |
337 | } |
338 | ||
161c14a2 KM |
339 | /* |
340 | * Detach from shared memory segment. | |
341 | */ | |
342 | /* ARGSUSED */ | |
343 | shmdt(p, uap, retval) | |
344 | struct proc *p; | |
345 | struct args { | |
6f843dc9 | 346 | caddr_t shmaddr; |
161c14a2 KM |
347 | } *uap; |
348 | int *retval; | |
349 | { | |
9db58063 KM |
350 | register struct shmdesc *shmd; |
351 | register int i; | |
6f843dc9 | 352 | |
8429d022 | 353 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
354 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
355 | if (shmd->shmd_uva && | |
356 | shmd->shmd_uva == (vm_offset_t)uap->shmaddr) | |
6f843dc9 | 357 | break; |
9db58063 KM |
358 | if (i == shminfo.shmseg) |
359 | return(EINVAL); | |
360 | shmufree(p, shmd); | |
361 | shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid; | |
6f843dc9 KM |
362 | } |
363 | ||
8429d022 MK |
364 | shmfork(p1, p2, isvfork) |
365 | struct proc *p1, *p2; | |
9db58063 | 366 | int isvfork; |
6f843dc9 | 367 | { |
9db58063 KM |
368 | register struct shmdesc *shmd; |
369 | register int size; | |
6f843dc9 | 370 | |
9db58063 KM |
371 | /* |
372 | * Copy parents descriptive information | |
373 | */ | |
374 | size = shminfo.shmseg * sizeof(struct shmdesc); | |
375 | shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK); | |
8429d022 MK |
376 | bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size); |
377 | p2->p_vmspace->vm_shm = (caddr_t)shmd; | |
9db58063 KM |
378 | /* |
379 | * Increment reference counts | |
380 | */ | |
381 | for (size = 0; size < shminfo.shmseg; size++, shmd++) | |
382 | if (shmd->shmd_uva) | |
383 | shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++; | |
6f843dc9 KM |
384 | } |
385 | ||
9db58063 KM |
386 | shmexit(p) |
387 | struct proc *p; | |
6f843dc9 | 388 | { |
9db58063 KM |
389 | register struct shmdesc *shmd; |
390 | register int i; | |
c9714ae3 | 391 | |
8429d022 | 392 | shmd = (struct shmdesc *)p->p_vmspace->vm_shm; |
9db58063 KM |
393 | for (i = 0; i < shminfo.shmseg; i++, shmd++) |
394 | if (shmd->shmd_uva) | |
395 | shmufree(p, shmd); | |
8429d022 MK |
396 | free((caddr_t)p->p_vmspace->vm_shm, M_SHM); |
397 | p->p_vmspace->vm_shm = NULL; | |
6f843dc9 KM |
398 | } |
399 | ||
400 | shmvalid(id) | |
401 | register int id; | |
402 | { | |
403 | register struct shmid_ds *shp; | |
404 | ||
405 | if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni) | |
161c14a2 | 406 | return(EINVAL); |
6f843dc9 KM |
407 | shp = &shmsegs[id % SHMMMNI]; |
408 | if (shp->shm_perm.seq == (id / SHMMMNI) && | |
409 | (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC) | |
161c14a2 KM |
410 | return(0); |
411 | return(EINVAL); | |
6f843dc9 KM |
412 | } |
413 | ||
414 | /* | |
415 | * Free user resources associated with a shared memory segment | |
416 | */ | |
9db58063 | 417 | shmufree(p, shmd) |
c9714ae3 | 418 | struct proc *p; |
9db58063 | 419 | struct shmdesc *shmd; |
6f843dc9 KM |
420 | { |
421 | register struct shmid_ds *shp; | |
422 | ||
9db58063 | 423 | shp = &shmsegs[shmd->shmd_id % SHMMMNI]; |
aa6d6b7e | 424 | (void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva, |
9db58063 KM |
425 | ctob(clrnd(btoc(shp->shm_segsz)))); |
426 | shmd->shmd_id = 0; | |
427 | shmd->shmd_uva = 0; | |
6f843dc9 KM |
428 | shp->shm_dtime = time.tv_sec; |
429 | if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST)) | |
430 | shmfree(shp); | |
431 | } | |
432 | ||
433 | /* | |
434 | * Deallocate resources associated with a shared memory segment | |
435 | */ | |
436 | shmfree(shp) | |
437 | register struct shmid_ds *shp; | |
438 | { | |
6f843dc9 KM |
439 | |
440 | if (shp->shm_handle == NULL) | |
441 | panic("shmfree"); | |
9db58063 KM |
442 | /* |
443 | * Lose our lingering object reference by deallocating space | |
444 | * in kernel. Pager will also be deallocated as a side-effect. | |
445 | */ | |
446 | vm_deallocate(shm_map, | |
447 | ((struct shmhandle *)shp->shm_handle)->shmh_kva, | |
9d81fbb9 | 448 | ctob(clrnd(btoc(shp->shm_segsz)))); |
9db58063 | 449 | free((caddr_t)shp->shm_handle, M_SHM); |
6f843dc9 KM |
450 | shp->shm_handle = NULL; |
451 | shmtot -= clrnd(btoc(shp->shm_segsz)); | |
452 | shp->shm_perm.mode = 0; | |
453 | /* | |
454 | * Increment the sequence number to ensure that outstanding | |
455 | * shmids for this segment will be invalid in the event that | |
456 | * the segment is reallocated. Note that shmids must be | |
457 | * positive as decreed by SVID. | |
458 | */ | |
459 | shp->shm_perm.seq++; | |
460 | if ((int)(shp->shm_perm.seq * SHMMMNI) < 0) | |
461 | shp->shm_perm.seq = 0; | |
462 | } | |
463 | ||
464 | /* | |
465 | * XXX This routine would be common to all sysV style IPC | |
466 | * (if the others were implemented). | |
467 | */ | |
161c14a2 | 468 | ipcaccess(ipc, mode, cred) |
6f843dc9 | 469 | register struct ipc_perm *ipc; |
161c14a2 KM |
470 | int mode; |
471 | register struct ucred *cred; | |
6f843dc9 KM |
472 | { |
473 | register int m; | |
474 | ||
161c14a2 | 475 | if (cred->cr_uid == 0) |
6f843dc9 KM |
476 | return(0); |
477 | /* | |
478 | * Access check is based on only one of owner, group, public. | |
479 | * If not owner, then check group. | |
480 | * If not a member of the group, then check public access. | |
481 | */ | |
482 | mode &= 0700; | |
483 | m = ipc->mode; | |
161c14a2 | 484 | if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) { |
6f843dc9 | 485 | m <<= 3; |
161c14a2 KM |
486 | if (!groupmember(ipc->gid, cred) && |
487 | !groupmember(ipc->cgid, cred)) | |
6f843dc9 KM |
488 | m <<= 3; |
489 | } | |
490 | if ((mode&m) == mode) | |
161c14a2 KM |
491 | return (0); |
492 | return (EACCES); | |
6f843dc9 | 493 | } |
6f843dc9 | 494 | #endif /* SYSVSHM */ |