| 1 | /* $NetBSD: sysv_shm.c,v 1.131 2015/11/26 13:15:34 martin Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 1999, 2007 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * This code is derived from software contributed to The NetBSD Foundation |
| 8 | * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, |
| 9 | * NASA Ames Research Center, and by Mindaugas Rasiukevicius. |
| 10 | * |
| 11 | * Redistribution and use in source and binary forms, with or without |
| 12 | * modification, are permitted provided that the following conditions |
| 13 | * are met: |
| 14 | * 1. Redistributions of source code must retain the above copyright |
| 15 | * notice, this list of conditions and the following disclaimer. |
| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer in the |
| 18 | * documentation and/or other materials provided with the distribution. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 22 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 23 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 24 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 26 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 27 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 28 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 29 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 30 | * POSSIBILITY OF SUCH DAMAGE. |
| 31 | */ |
| 32 | |
| 33 | /* |
| 34 | * Copyright (c) 1994 Adam Glass and Charles M. Hannum. All rights reserved. |
| 35 | * |
| 36 | * Redistribution and use in source and binary forms, with or without |
| 37 | * modification, are permitted provided that the following conditions |
| 38 | * are met: |
| 39 | * 1. Redistributions of source code must retain the above copyright |
| 40 | * notice, this list of conditions and the following disclaimer. |
| 41 | * 2. Redistributions in binary form must reproduce the above copyright |
| 42 | * notice, this list of conditions and the following disclaimer in the |
| 43 | * documentation and/or other materials provided with the distribution. |
| 44 | * 3. All advertising materials mentioning features or use of this software |
| 45 | * must display the following acknowledgement: |
| 46 | * This product includes software developed by Adam Glass and Charles M. |
| 47 | * Hannum. |
| 48 | * 4. The names of the authors may not be used to endorse or promote products |
| 49 | * derived from this software without specific prior written permission. |
| 50 | * |
| 51 | * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR |
| 52 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 53 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 54 | * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 55 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 56 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 57 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 58 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 59 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 60 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 61 | */ |
| 62 | |
| 63 | #include <sys/cdefs.h> |
| 64 | __KERNEL_RCSID(0, "$NetBSD: sysv_shm.c,v 1.131 2015/11/26 13:15:34 martin Exp $" ); |
| 65 | |
| 66 | #ifdef _KERNEL_OPT |
| 67 | #include "opt_sysv.h" |
| 68 | #endif |
| 69 | |
| 70 | #include <sys/param.h> |
| 71 | #include <sys/kernel.h> |
| 72 | #include <sys/kmem.h> |
| 73 | #include <sys/shm.h> |
| 74 | #include <sys/mutex.h> |
| 75 | #include <sys/mman.h> |
| 76 | #include <sys/stat.h> |
| 77 | #include <sys/sysctl.h> |
| 78 | #include <sys/mount.h> /* XXX for <sys/syscallargs.h> */ |
| 79 | #include <sys/syscallargs.h> |
| 80 | #include <sys/queue.h> |
| 81 | #include <sys/kauth.h> |
| 82 | |
| 83 | #include <uvm/uvm_extern.h> |
| 84 | #include <uvm/uvm_object.h> |
| 85 | |
| 86 | struct shmmap_entry { |
| 87 | SLIST_ENTRY(shmmap_entry) next; |
| 88 | vaddr_t va; |
| 89 | int shmid; |
| 90 | }; |
| 91 | |
| 92 | int shm_nused __cacheline_aligned; |
| 93 | struct shmid_ds * shmsegs __read_mostly; |
| 94 | |
| 95 | static kmutex_t shm_lock __cacheline_aligned; |
| 96 | static kcondvar_t * shm_cv __cacheline_aligned; |
| 97 | static int shm_last_free __cacheline_aligned; |
| 98 | static size_t shm_committed __cacheline_aligned; |
| 99 | static int shm_use_phys __read_mostly; |
| 100 | |
| 101 | static kcondvar_t shm_realloc_cv; |
| 102 | static bool shm_realloc_state; |
| 103 | static u_int shm_realloc_disable; |
| 104 | |
| 105 | struct shmmap_state { |
| 106 | unsigned int nitems; |
| 107 | unsigned int nrefs; |
| 108 | SLIST_HEAD(, shmmap_entry) entries; |
| 109 | }; |
| 110 | |
| 111 | extern int kern_has_sysvshm; |
| 112 | |
| 113 | SYSCTL_SETUP_PROTO(sysctl_ipc_shm_setup); |
| 114 | |
| 115 | #ifdef SHMDEBUG |
| 116 | #define SHMPRINTF(a) printf a |
| 117 | #else |
| 118 | #define SHMPRINTF(a) |
| 119 | #endif |
| 120 | |
| 121 | static int shmrealloc(int); |
| 122 | |
| 123 | /* |
| 124 | * Find the shared memory segment by the identifier. |
| 125 | * => must be called with shm_lock held; |
| 126 | */ |
| 127 | static struct shmid_ds * |
| 128 | shm_find_segment_by_shmid(int shmid) |
| 129 | { |
| 130 | int segnum; |
| 131 | struct shmid_ds *shmseg; |
| 132 | |
| 133 | KASSERT(mutex_owned(&shm_lock)); |
| 134 | |
| 135 | segnum = IPCID_TO_IX(shmid); |
| 136 | if (segnum < 0 || segnum >= shminfo.shmmni) |
| 137 | return NULL; |
| 138 | shmseg = &shmsegs[segnum]; |
| 139 | if ((shmseg->shm_perm.mode & SHMSEG_ALLOCATED) == 0) |
| 140 | return NULL; |
| 141 | if ((shmseg->shm_perm.mode & |
| 142 | (SHMSEG_REMOVED|SHMSEG_RMLINGER)) == SHMSEG_REMOVED) |
| 143 | return NULL; |
| 144 | if (shmseg->shm_perm._seq != IPCID_TO_SEQ(shmid)) |
| 145 | return NULL; |
| 146 | |
| 147 | return shmseg; |
| 148 | } |
| 149 | |
| 150 | /* |
| 151 | * Free memory segment. |
| 152 | * => must be called with shm_lock held; |
| 153 | */ |
| 154 | static void |
| 155 | shm_free_segment(int segnum) |
| 156 | { |
| 157 | struct shmid_ds *shmseg; |
| 158 | size_t size; |
| 159 | bool wanted; |
| 160 | |
| 161 | KASSERT(mutex_owned(&shm_lock)); |
| 162 | |
| 163 | shmseg = &shmsegs[segnum]; |
| 164 | SHMPRINTF(("shm freeing key 0x%lx seq 0x%x\n" , |
| 165 | shmseg->shm_perm._key, shmseg->shm_perm._seq)); |
| 166 | |
| 167 | size = (shmseg->shm_segsz + PGOFSET) & ~PGOFSET; |
| 168 | wanted = (shmseg->shm_perm.mode & SHMSEG_WANTED); |
| 169 | |
| 170 | shmseg->_shm_internal = NULL; |
| 171 | shm_committed -= btoc(size); |
| 172 | shm_nused--; |
| 173 | shmseg->shm_perm.mode = SHMSEG_FREE; |
| 174 | shm_last_free = segnum; |
| 175 | if (wanted == true) |
| 176 | cv_broadcast(&shm_cv[segnum]); |
| 177 | } |
| 178 | |
| 179 | /* |
| 180 | * Delete entry from the shm map. |
| 181 | * => must be called with shm_lock held; |
| 182 | */ |
| 183 | static struct uvm_object * |
| 184 | shm_delete_mapping(struct shmmap_state *shmmap_s, |
| 185 | struct shmmap_entry *shmmap_se) |
| 186 | { |
| 187 | struct uvm_object *uobj = NULL; |
| 188 | struct shmid_ds *shmseg; |
| 189 | int segnum; |
| 190 | |
| 191 | KASSERT(mutex_owned(&shm_lock)); |
| 192 | |
| 193 | segnum = IPCID_TO_IX(shmmap_se->shmid); |
| 194 | shmseg = &shmsegs[segnum]; |
| 195 | SLIST_REMOVE(&shmmap_s->entries, shmmap_se, shmmap_entry, next); |
| 196 | shmmap_s->nitems--; |
| 197 | shmseg->shm_dtime = time_second; |
| 198 | if ((--shmseg->shm_nattch <= 0) && |
| 199 | (shmseg->shm_perm.mode & SHMSEG_REMOVED)) { |
| 200 | uobj = shmseg->_shm_internal; |
| 201 | shm_free_segment(segnum); |
| 202 | } |
| 203 | |
| 204 | return uobj; |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | * Get a non-shared shm map for that vmspace. Note, that memory |
| 209 | * allocation might be performed with lock held. |
| 210 | */ |
| 211 | static struct shmmap_state * |
| 212 | shmmap_getprivate(struct proc *p) |
| 213 | { |
| 214 | struct shmmap_state *oshmmap_s, *shmmap_s; |
| 215 | struct shmmap_entry *oshmmap_se, *shmmap_se; |
| 216 | |
| 217 | KASSERT(mutex_owned(&shm_lock)); |
| 218 | |
| 219 | /* 1. A shm map with refcnt = 1, used by ourselves, thus return */ |
| 220 | oshmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; |
| 221 | if (oshmmap_s && oshmmap_s->nrefs == 1) |
| 222 | return oshmmap_s; |
| 223 | |
| 224 | /* 2. No shm map preset - create a fresh one */ |
| 225 | shmmap_s = kmem_zalloc(sizeof(struct shmmap_state), KM_SLEEP); |
| 226 | shmmap_s->nrefs = 1; |
| 227 | SLIST_INIT(&shmmap_s->entries); |
| 228 | p->p_vmspace->vm_shm = (void *)shmmap_s; |
| 229 | |
| 230 | if (oshmmap_s == NULL) |
| 231 | return shmmap_s; |
| 232 | |
| 233 | SHMPRINTF(("shmmap_getprivate: vm %p split (%d entries), was used by %d\n" , |
| 234 | p->p_vmspace, oshmmap_s->nitems, oshmmap_s->nrefs)); |
| 235 | |
| 236 | /* 3. A shared shm map, copy to a fresh one and adjust refcounts */ |
| 237 | SLIST_FOREACH(oshmmap_se, &oshmmap_s->entries, next) { |
| 238 | shmmap_se = kmem_alloc(sizeof(struct shmmap_entry), KM_SLEEP); |
| 239 | shmmap_se->va = oshmmap_se->va; |
| 240 | shmmap_se->shmid = oshmmap_se->shmid; |
| 241 | SLIST_INSERT_HEAD(&shmmap_s->entries, shmmap_se, next); |
| 242 | } |
| 243 | shmmap_s->nitems = oshmmap_s->nitems; |
| 244 | oshmmap_s->nrefs--; |
| 245 | |
| 246 | return shmmap_s; |
| 247 | } |
| 248 | |
| 249 | /* |
| 250 | * Lock/unlock the memory. |
| 251 | * => must be called with shm_lock held; |
| 252 | * => called from one place, thus, inline; |
| 253 | */ |
| 254 | static inline int |
| 255 | shm_memlock(struct lwp *l, struct shmid_ds *shmseg, int shmid, int cmd) |
| 256 | { |
| 257 | struct proc *p = l->l_proc; |
| 258 | struct shmmap_entry *shmmap_se; |
| 259 | struct shmmap_state *shmmap_s; |
| 260 | size_t size; |
| 261 | int error; |
| 262 | |
| 263 | KASSERT(mutex_owned(&shm_lock)); |
| 264 | shmmap_s = shmmap_getprivate(p); |
| 265 | |
| 266 | /* Find our shared memory address by shmid */ |
| 267 | SLIST_FOREACH(shmmap_se, &shmmap_s->entries, next) { |
| 268 | if (shmmap_se->shmid != shmid) |
| 269 | continue; |
| 270 | |
| 271 | size = (shmseg->shm_segsz + PGOFSET) & ~PGOFSET; |
| 272 | |
| 273 | if (cmd == SHM_LOCK && |
| 274 | (shmseg->shm_perm.mode & SHMSEG_WIRED) == 0) { |
| 275 | /* Wire the object and map, then tag it */ |
| 276 | error = uvm_obj_wirepages(shmseg->_shm_internal, |
| 277 | 0, size, NULL); |
| 278 | if (error) |
| 279 | return EIO; |
| 280 | error = uvm_map_pageable(&p->p_vmspace->vm_map, |
| 281 | shmmap_se->va, shmmap_se->va + size, false, 0); |
| 282 | if (error) { |
| 283 | uvm_obj_unwirepages(shmseg->_shm_internal, |
| 284 | 0, size); |
| 285 | if (error == EFAULT) |
| 286 | error = ENOMEM; |
| 287 | return error; |
| 288 | } |
| 289 | shmseg->shm_perm.mode |= SHMSEG_WIRED; |
| 290 | |
| 291 | } else if (cmd == SHM_UNLOCK && |
| 292 | (shmseg->shm_perm.mode & SHMSEG_WIRED) != 0) { |
| 293 | /* Unwire the object and map, then untag it */ |
| 294 | uvm_obj_unwirepages(shmseg->_shm_internal, 0, size); |
| 295 | error = uvm_map_pageable(&p->p_vmspace->vm_map, |
| 296 | shmmap_se->va, shmmap_se->va + size, true, 0); |
| 297 | if (error) |
| 298 | return EIO; |
| 299 | shmseg->shm_perm.mode &= ~SHMSEG_WIRED; |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | return 0; |
| 304 | } |
| 305 | |
| 306 | /* |
| 307 | * Unmap shared memory. |
| 308 | */ |
| 309 | int |
| 310 | sys_shmdt(struct lwp *l, const struct sys_shmdt_args *uap, register_t *retval) |
| 311 | { |
| 312 | /* { |
| 313 | syscallarg(const void *) shmaddr; |
| 314 | } */ |
| 315 | struct proc *p = l->l_proc; |
| 316 | struct shmmap_state *shmmap_s1, *shmmap_s; |
| 317 | struct shmmap_entry *shmmap_se; |
| 318 | struct uvm_object *uobj; |
| 319 | struct shmid_ds *shmseg; |
| 320 | size_t size; |
| 321 | |
| 322 | mutex_enter(&shm_lock); |
| 323 | /* In case of reallocation, we will wait for completion */ |
| 324 | while (__predict_false(shm_realloc_state)) |
| 325 | cv_wait(&shm_realloc_cv, &shm_lock); |
| 326 | |
| 327 | shmmap_s1 = (struct shmmap_state *)p->p_vmspace->vm_shm; |
| 328 | if (shmmap_s1 == NULL) { |
| 329 | mutex_exit(&shm_lock); |
| 330 | return EINVAL; |
| 331 | } |
| 332 | |
| 333 | /* Find the map entry */ |
| 334 | SLIST_FOREACH(shmmap_se, &shmmap_s1->entries, next) |
| 335 | if (shmmap_se->va == (vaddr_t)SCARG(uap, shmaddr)) |
| 336 | break; |
| 337 | if (shmmap_se == NULL) { |
| 338 | mutex_exit(&shm_lock); |
| 339 | return EINVAL; |
| 340 | } |
| 341 | |
| 342 | shmmap_s = shmmap_getprivate(p); |
| 343 | if (shmmap_s != shmmap_s1) { |
| 344 | /* Map has been copied, lookup entry in new map */ |
| 345 | SLIST_FOREACH(shmmap_se, &shmmap_s->entries, next) |
| 346 | if (shmmap_se->va == (vaddr_t)SCARG(uap, shmaddr)) |
| 347 | break; |
| 348 | if (shmmap_se == NULL) { |
| 349 | mutex_exit(&shm_lock); |
| 350 | return EINVAL; |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | SHMPRINTF(("shmdt: vm %p: remove %d @%lx\n" , |
| 355 | p->p_vmspace, shmmap_se->shmid, shmmap_se->va)); |
| 356 | |
| 357 | /* Delete the entry from shm map */ |
| 358 | uobj = shm_delete_mapping(shmmap_s, shmmap_se); |
| 359 | shmseg = &shmsegs[IPCID_TO_IX(shmmap_se->shmid)]; |
| 360 | size = (shmseg->shm_segsz + PGOFSET) & ~PGOFSET; |
| 361 | mutex_exit(&shm_lock); |
| 362 | |
| 363 | uvm_deallocate(&p->p_vmspace->vm_map, shmmap_se->va, size); |
| 364 | if (uobj != NULL) { |
| 365 | uao_detach(uobj); |
| 366 | } |
| 367 | kmem_free(shmmap_se, sizeof(struct shmmap_entry)); |
| 368 | |
| 369 | return 0; |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * Map shared memory. |
| 374 | */ |
| 375 | int |
| 376 | sys_shmat(struct lwp *l, const struct sys_shmat_args *uap, register_t *retval) |
| 377 | { |
| 378 | /* { |
| 379 | syscallarg(int) shmid; |
| 380 | syscallarg(const void *) shmaddr; |
| 381 | syscallarg(int) shmflg; |
| 382 | } */ |
| 383 | int error, flags = 0; |
| 384 | struct proc *p = l->l_proc; |
| 385 | kauth_cred_t cred = l->l_cred; |
| 386 | struct shmid_ds *shmseg; |
| 387 | struct shmmap_state *shmmap_s; |
| 388 | struct shmmap_entry *shmmap_se; |
| 389 | struct uvm_object *uobj; |
| 390 | struct vmspace *vm; |
| 391 | vaddr_t attach_va; |
| 392 | vm_prot_t prot; |
| 393 | vsize_t size; |
| 394 | |
| 395 | /* Allocate a new map entry and set it */ |
| 396 | shmmap_se = kmem_alloc(sizeof(struct shmmap_entry), KM_SLEEP); |
| 397 | shmmap_se->shmid = SCARG(uap, shmid); |
| 398 | |
| 399 | mutex_enter(&shm_lock); |
| 400 | /* In case of reallocation, we will wait for completion */ |
| 401 | while (__predict_false(shm_realloc_state)) |
| 402 | cv_wait(&shm_realloc_cv, &shm_lock); |
| 403 | |
| 404 | shmseg = shm_find_segment_by_shmid(SCARG(uap, shmid)); |
| 405 | if (shmseg == NULL) { |
| 406 | error = EINVAL; |
| 407 | goto err; |
| 408 | } |
| 409 | error = ipcperm(cred, &shmseg->shm_perm, |
| 410 | (SCARG(uap, shmflg) & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); |
| 411 | if (error) |
| 412 | goto err; |
| 413 | |
| 414 | vm = p->p_vmspace; |
| 415 | shmmap_s = (struct shmmap_state *)vm->vm_shm; |
| 416 | if (shmmap_s && shmmap_s->nitems >= shminfo.shmseg) { |
| 417 | error = EMFILE; |
| 418 | goto err; |
| 419 | } |
| 420 | |
| 421 | size = (shmseg->shm_segsz + PGOFSET) & ~PGOFSET; |
| 422 | prot = VM_PROT_READ; |
| 423 | if ((SCARG(uap, shmflg) & SHM_RDONLY) == 0) |
| 424 | prot |= VM_PROT_WRITE; |
| 425 | if (SCARG(uap, shmaddr)) { |
| 426 | flags |= UVM_FLAG_FIXED; |
| 427 | if (SCARG(uap, shmflg) & SHM_RND) |
| 428 | attach_va = |
| 429 | (vaddr_t)SCARG(uap, shmaddr) & ~(SHMLBA-1); |
| 430 | else if (((vaddr_t)SCARG(uap, shmaddr) & (SHMLBA-1)) == 0) |
| 431 | attach_va = (vaddr_t)SCARG(uap, shmaddr); |
| 432 | else { |
| 433 | error = EINVAL; |
| 434 | goto err; |
| 435 | } |
| 436 | } else { |
| 437 | /* This is just a hint to uvm_map() about where to put it. */ |
| 438 | attach_va = p->p_emul->e_vm_default_addr(p, |
| 439 | (vaddr_t)vm->vm_daddr, size, |
| 440 | p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN); |
| 441 | } |
| 442 | |
| 443 | /* |
| 444 | * Create a map entry, add it to the list and increase the counters. |
| 445 | * The lock will be dropped before the mapping, disable reallocation. |
| 446 | */ |
| 447 | shmmap_s = shmmap_getprivate(p); |
| 448 | SLIST_INSERT_HEAD(&shmmap_s->entries, shmmap_se, next); |
| 449 | shmmap_s->nitems++; |
| 450 | shmseg->shm_lpid = p->p_pid; |
| 451 | shmseg->shm_nattch++; |
| 452 | shm_realloc_disable++; |
| 453 | mutex_exit(&shm_lock); |
| 454 | |
| 455 | /* |
| 456 | * Add a reference to the memory object, map it to the |
| 457 | * address space, and lock the memory, if needed. |
| 458 | */ |
| 459 | uobj = shmseg->_shm_internal; |
| 460 | uao_reference(uobj); |
| 461 | error = uvm_map(&vm->vm_map, &attach_va, size, uobj, 0, 0, |
| 462 | UVM_MAPFLAG(prot, prot, UVM_INH_SHARE, UVM_ADV_RANDOM, flags)); |
| 463 | if (error) |
| 464 | goto err_detach; |
| 465 | if (shm_use_phys || (shmseg->shm_perm.mode & SHMSEG_WIRED)) { |
| 466 | error = uvm_map_pageable(&vm->vm_map, attach_va, |
| 467 | attach_va + size, false, 0); |
| 468 | if (error) { |
| 469 | if (error == EFAULT) |
| 470 | error = ENOMEM; |
| 471 | uvm_deallocate(&vm->vm_map, attach_va, size); |
| 472 | goto err_detach; |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | /* Set the new address, and update the time */ |
| 477 | mutex_enter(&shm_lock); |
| 478 | shmmap_se->va = attach_va; |
| 479 | shmseg->shm_atime = time_second; |
| 480 | shm_realloc_disable--; |
| 481 | retval[0] = attach_va; |
| 482 | SHMPRINTF(("shmat: vm %p: add %d @%lx\n" , |
| 483 | p->p_vmspace, shmmap_se->shmid, attach_va)); |
| 484 | err: |
| 485 | cv_broadcast(&shm_realloc_cv); |
| 486 | mutex_exit(&shm_lock); |
| 487 | if (error && shmmap_se) { |
| 488 | kmem_free(shmmap_se, sizeof(struct shmmap_entry)); |
| 489 | } |
| 490 | return error; |
| 491 | |
| 492 | err_detach: |
| 493 | uao_detach(uobj); |
| 494 | mutex_enter(&shm_lock); |
| 495 | uobj = shm_delete_mapping(shmmap_s, shmmap_se); |
| 496 | shm_realloc_disable--; |
| 497 | cv_broadcast(&shm_realloc_cv); |
| 498 | mutex_exit(&shm_lock); |
| 499 | if (uobj != NULL) { |
| 500 | uao_detach(uobj); |
| 501 | } |
| 502 | kmem_free(shmmap_se, sizeof(struct shmmap_entry)); |
| 503 | return error; |
| 504 | } |
| 505 | |
| 506 | /* |
| 507 | * Shared memory control operations. |
| 508 | */ |
| 509 | int |
| 510 | sys___shmctl50(struct lwp *l, const struct sys___shmctl50_args *uap, |
| 511 | register_t *retval) |
| 512 | { |
| 513 | /* { |
| 514 | syscallarg(int) shmid; |
| 515 | syscallarg(int) cmd; |
| 516 | syscallarg(struct shmid_ds *) buf; |
| 517 | } */ |
| 518 | struct shmid_ds shmbuf; |
| 519 | int cmd, error; |
| 520 | |
| 521 | cmd = SCARG(uap, cmd); |
| 522 | if (cmd == IPC_SET) { |
| 523 | error = copyin(SCARG(uap, buf), &shmbuf, sizeof(shmbuf)); |
| 524 | if (error) |
| 525 | return error; |
| 526 | } |
| 527 | |
| 528 | error = shmctl1(l, SCARG(uap, shmid), cmd, |
| 529 | (cmd == IPC_SET || cmd == IPC_STAT) ? &shmbuf : NULL); |
| 530 | |
| 531 | if (error == 0 && cmd == IPC_STAT) |
| 532 | error = copyout(&shmbuf, SCARG(uap, buf), sizeof(shmbuf)); |
| 533 | |
| 534 | return error; |
| 535 | } |
| 536 | |
| 537 | int |
| 538 | shmctl1(struct lwp *l, int shmid, int cmd, struct shmid_ds *shmbuf) |
| 539 | { |
| 540 | struct uvm_object *uobj = NULL; |
| 541 | kauth_cred_t cred = l->l_cred; |
| 542 | struct shmid_ds *shmseg; |
| 543 | int error = 0; |
| 544 | |
| 545 | mutex_enter(&shm_lock); |
| 546 | /* In case of reallocation, we will wait for completion */ |
| 547 | while (__predict_false(shm_realloc_state)) |
| 548 | cv_wait(&shm_realloc_cv, &shm_lock); |
| 549 | |
| 550 | shmseg = shm_find_segment_by_shmid(shmid); |
| 551 | if (shmseg == NULL) { |
| 552 | mutex_exit(&shm_lock); |
| 553 | return EINVAL; |
| 554 | } |
| 555 | |
| 556 | switch (cmd) { |
| 557 | case IPC_STAT: |
| 558 | if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_R)) != 0) |
| 559 | break; |
| 560 | memcpy(shmbuf, shmseg, sizeof(struct shmid_ds)); |
| 561 | break; |
| 562 | case IPC_SET: |
| 563 | if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_M)) != 0) |
| 564 | break; |
| 565 | shmseg->shm_perm.uid = shmbuf->shm_perm.uid; |
| 566 | shmseg->shm_perm.gid = shmbuf->shm_perm.gid; |
| 567 | shmseg->shm_perm.mode = |
| 568 | (shmseg->shm_perm.mode & ~ACCESSPERMS) | |
| 569 | (shmbuf->shm_perm.mode & ACCESSPERMS); |
| 570 | shmseg->shm_ctime = time_second; |
| 571 | break; |
| 572 | case IPC_RMID: |
| 573 | if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_M)) != 0) |
| 574 | break; |
| 575 | shmseg->shm_perm._key = IPC_PRIVATE; |
| 576 | shmseg->shm_perm.mode |= SHMSEG_REMOVED; |
| 577 | if (shmseg->shm_nattch <= 0) { |
| 578 | uobj = shmseg->_shm_internal; |
| 579 | shm_free_segment(IPCID_TO_IX(shmid)); |
| 580 | } |
| 581 | break; |
| 582 | case SHM_LOCK: |
| 583 | case SHM_UNLOCK: |
| 584 | if ((error = kauth_authorize_system(cred, |
| 585 | KAUTH_SYSTEM_SYSVIPC, |
| 586 | (cmd == SHM_LOCK) ? KAUTH_REQ_SYSTEM_SYSVIPC_SHM_LOCK : |
| 587 | KAUTH_REQ_SYSTEM_SYSVIPC_SHM_UNLOCK, NULL, NULL, NULL)) != 0) |
| 588 | break; |
| 589 | error = shm_memlock(l, shmseg, shmid, cmd); |
| 590 | break; |
| 591 | default: |
| 592 | error = EINVAL; |
| 593 | } |
| 594 | |
| 595 | mutex_exit(&shm_lock); |
| 596 | if (uobj != NULL) |
| 597 | uao_detach(uobj); |
| 598 | return error; |
| 599 | } |
| 600 | |
| 601 | /* |
| 602 | * Try to take an already existing segment. |
| 603 | * => must be called with shm_lock held; |
| 604 | * => called from one place, thus, inline; |
| 605 | */ |
| 606 | static inline int |
| 607 | shmget_existing(struct lwp *l, const struct sys_shmget_args *uap, int mode, |
| 608 | register_t *retval) |
| 609 | { |
| 610 | struct shmid_ds *shmseg; |
| 611 | kauth_cred_t cred = l->l_cred; |
| 612 | int segnum, error; |
| 613 | again: |
| 614 | KASSERT(mutex_owned(&shm_lock)); |
| 615 | |
| 616 | /* Find segment by key */ |
| 617 | for (segnum = 0; segnum < shminfo.shmmni; segnum++) |
| 618 | if ((shmsegs[segnum].shm_perm.mode & SHMSEG_ALLOCATED) && |
| 619 | shmsegs[segnum].shm_perm._key == SCARG(uap, key)) |
| 620 | break; |
| 621 | if (segnum == shminfo.shmmni) { |
| 622 | /* Not found */ |
| 623 | return -1; |
| 624 | } |
| 625 | |
| 626 | shmseg = &shmsegs[segnum]; |
| 627 | if (shmseg->shm_perm.mode & SHMSEG_REMOVED) { |
| 628 | /* |
| 629 | * This segment is in the process of being allocated. Wait |
| 630 | * until it's done, and look the key up again (in case the |
| 631 | * allocation failed or it was freed). |
| 632 | */ |
| 633 | shmseg->shm_perm.mode |= SHMSEG_WANTED; |
| 634 | error = cv_wait_sig(&shm_cv[segnum], &shm_lock); |
| 635 | if (error) |
| 636 | return error; |
| 637 | goto again; |
| 638 | } |
| 639 | |
| 640 | /* |
| 641 | * First check the flags, to generate a useful error when a |
| 642 | * segment already exists. |
| 643 | */ |
| 644 | if ((SCARG(uap, shmflg) & (IPC_CREAT | IPC_EXCL)) == |
| 645 | (IPC_CREAT | IPC_EXCL)) |
| 646 | return EEXIST; |
| 647 | |
| 648 | /* Check the permission and segment size. */ |
| 649 | error = ipcperm(cred, &shmseg->shm_perm, mode); |
| 650 | if (error) |
| 651 | return error; |
| 652 | if (SCARG(uap, size) && SCARG(uap, size) > shmseg->shm_segsz) |
| 653 | return EINVAL; |
| 654 | |
| 655 | *retval = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); |
| 656 | return 0; |
| 657 | } |
| 658 | |
| 659 | int |
| 660 | sys_shmget(struct lwp *l, const struct sys_shmget_args *uap, register_t *retval) |
| 661 | { |
| 662 | /* { |
| 663 | syscallarg(key_t) key; |
| 664 | syscallarg(size_t) size; |
| 665 | syscallarg(int) shmflg; |
| 666 | } */ |
| 667 | struct shmid_ds *shmseg; |
| 668 | kauth_cred_t cred = l->l_cred; |
| 669 | key_t key = SCARG(uap, key); |
| 670 | size_t size; |
| 671 | int error, mode, segnum; |
| 672 | bool lockmem; |
| 673 | |
| 674 | mode = SCARG(uap, shmflg) & ACCESSPERMS; |
| 675 | if (SCARG(uap, shmflg) & _SHM_RMLINGER) |
| 676 | mode |= SHMSEG_RMLINGER; |
| 677 | |
| 678 | SHMPRINTF(("shmget: key 0x%lx size 0x%zx shmflg 0x%x mode 0x%x\n" , |
| 679 | SCARG(uap, key), SCARG(uap, size), SCARG(uap, shmflg), mode)); |
| 680 | |
| 681 | mutex_enter(&shm_lock); |
| 682 | /* In case of reallocation, we will wait for completion */ |
| 683 | while (__predict_false(shm_realloc_state)) |
| 684 | cv_wait(&shm_realloc_cv, &shm_lock); |
| 685 | |
| 686 | if (key != IPC_PRIVATE) { |
| 687 | error = shmget_existing(l, uap, mode, retval); |
| 688 | if (error != -1) { |
| 689 | mutex_exit(&shm_lock); |
| 690 | return error; |
| 691 | } |
| 692 | if ((SCARG(uap, shmflg) & IPC_CREAT) == 0) { |
| 693 | mutex_exit(&shm_lock); |
| 694 | return ENOENT; |
| 695 | } |
| 696 | } |
| 697 | error = 0; |
| 698 | |
| 699 | /* |
| 700 | * Check the for the limits. |
| 701 | */ |
| 702 | size = SCARG(uap, size); |
| 703 | if (size < shminfo.shmmin || size > shminfo.shmmax) { |
| 704 | mutex_exit(&shm_lock); |
| 705 | return EINVAL; |
| 706 | } |
| 707 | if (shm_nused >= shminfo.shmmni) { |
| 708 | mutex_exit(&shm_lock); |
| 709 | return ENOSPC; |
| 710 | } |
| 711 | size = (size + PGOFSET) & ~PGOFSET; |
| 712 | if (shm_committed + btoc(size) > shminfo.shmall) { |
| 713 | mutex_exit(&shm_lock); |
| 714 | return ENOMEM; |
| 715 | } |
| 716 | |
| 717 | /* Find the first available segment */ |
| 718 | if (shm_last_free < 0) { |
| 719 | for (segnum = 0; segnum < shminfo.shmmni; segnum++) |
| 720 | if (shmsegs[segnum].shm_perm.mode & SHMSEG_FREE) |
| 721 | break; |
| 722 | KASSERT(segnum < shminfo.shmmni); |
| 723 | } else { |
| 724 | segnum = shm_last_free; |
| 725 | shm_last_free = -1; |
| 726 | } |
| 727 | |
| 728 | /* |
| 729 | * Initialize the segment. |
| 730 | * We will drop the lock while allocating the memory, thus mark the |
| 731 | * segment present, but removed, that no other thread could take it. |
| 732 | * Also, disable reallocation, while lock is dropped. |
| 733 | */ |
| 734 | shmseg = &shmsegs[segnum]; |
| 735 | shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED; |
| 736 | shm_committed += btoc(size); |
| 737 | shm_nused++; |
| 738 | lockmem = shm_use_phys; |
| 739 | shm_realloc_disable++; |
| 740 | mutex_exit(&shm_lock); |
| 741 | |
| 742 | /* Allocate the memory object and lock it if needed */ |
| 743 | shmseg->_shm_internal = uao_create(size, 0); |
| 744 | if (lockmem) { |
| 745 | /* Wire the pages and tag it */ |
| 746 | error = uvm_obj_wirepages(shmseg->_shm_internal, 0, size, NULL); |
| 747 | if (error) { |
| 748 | uao_detach(shmseg->_shm_internal); |
| 749 | mutex_enter(&shm_lock); |
| 750 | shm_free_segment(segnum); |
| 751 | shm_realloc_disable--; |
| 752 | mutex_exit(&shm_lock); |
| 753 | return error; |
| 754 | } |
| 755 | } |
| 756 | |
| 757 | /* |
| 758 | * Please note, while segment is marked, there are no need to hold the |
| 759 | * lock, while setting it (except shm_perm.mode). |
| 760 | */ |
| 761 | shmseg->shm_perm._key = SCARG(uap, key); |
| 762 | shmseg->shm_perm._seq = (shmseg->shm_perm._seq + 1) & 0x7fff; |
| 763 | *retval = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); |
| 764 | |
| 765 | shmseg->shm_perm.cuid = shmseg->shm_perm.uid = kauth_cred_geteuid(cred); |
| 766 | shmseg->shm_perm.cgid = shmseg->shm_perm.gid = kauth_cred_getegid(cred); |
| 767 | shmseg->shm_segsz = SCARG(uap, size); |
| 768 | shmseg->shm_cpid = l->l_proc->p_pid; |
| 769 | shmseg->shm_lpid = shmseg->shm_nattch = 0; |
| 770 | shmseg->shm_atime = shmseg->shm_dtime = 0; |
| 771 | shmseg->shm_ctime = time_second; |
| 772 | |
| 773 | /* |
| 774 | * Segment is initialized. |
| 775 | * Enter the lock, mark as allocated, and notify waiters (if any). |
| 776 | * Also, unmark the state of reallocation. |
| 777 | */ |
| 778 | mutex_enter(&shm_lock); |
| 779 | shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) | |
| 780 | (mode & (ACCESSPERMS | SHMSEG_RMLINGER)) | |
| 781 | SHMSEG_ALLOCATED | (lockmem ? SHMSEG_WIRED : 0); |
| 782 | if (shmseg->shm_perm.mode & SHMSEG_WANTED) { |
| 783 | shmseg->shm_perm.mode &= ~SHMSEG_WANTED; |
| 784 | cv_broadcast(&shm_cv[segnum]); |
| 785 | } |
| 786 | shm_realloc_disable--; |
| 787 | cv_broadcast(&shm_realloc_cv); |
| 788 | mutex_exit(&shm_lock); |
| 789 | |
| 790 | return error; |
| 791 | } |
| 792 | |
| 793 | void |
| 794 | shmfork(struct vmspace *vm1, struct vmspace *vm2) |
| 795 | { |
| 796 | struct shmmap_state *shmmap_s; |
| 797 | struct shmmap_entry *shmmap_se; |
| 798 | |
| 799 | SHMPRINTF(("shmfork %p->%p\n" , vm1, vm2)); |
| 800 | mutex_enter(&shm_lock); |
| 801 | vm2->vm_shm = vm1->vm_shm; |
| 802 | if (vm1->vm_shm) { |
| 803 | shmmap_s = (struct shmmap_state *)vm1->vm_shm; |
| 804 | SLIST_FOREACH(shmmap_se, &shmmap_s->entries, next) |
| 805 | shmsegs[IPCID_TO_IX(shmmap_se->shmid)].shm_nattch++; |
| 806 | shmmap_s->nrefs++; |
| 807 | } |
| 808 | mutex_exit(&shm_lock); |
| 809 | } |
| 810 | |
| 811 | void |
| 812 | shmexit(struct vmspace *vm) |
| 813 | { |
| 814 | struct shmmap_state *shmmap_s; |
| 815 | struct shmmap_entry *shmmap_se; |
| 816 | |
| 817 | mutex_enter(&shm_lock); |
| 818 | shmmap_s = (struct shmmap_state *)vm->vm_shm; |
| 819 | if (shmmap_s == NULL) { |
| 820 | mutex_exit(&shm_lock); |
| 821 | return; |
| 822 | } |
| 823 | vm->vm_shm = NULL; |
| 824 | |
| 825 | if (--shmmap_s->nrefs > 0) { |
| 826 | SHMPRINTF(("shmexit: vm %p drop ref (%d entries), refs = %d\n" , |
| 827 | vm, shmmap_s->nitems, shmmap_s->nrefs)); |
| 828 | SLIST_FOREACH(shmmap_se, &shmmap_s->entries, next) { |
| 829 | shmsegs[IPCID_TO_IX(shmmap_se->shmid)].shm_nattch--; |
| 830 | } |
| 831 | mutex_exit(&shm_lock); |
| 832 | return; |
| 833 | } |
| 834 | |
| 835 | SHMPRINTF(("shmexit: vm %p cleanup (%d entries)\n" , vm, shmmap_s->nitems)); |
| 836 | if (shmmap_s->nitems == 0) { |
| 837 | mutex_exit(&shm_lock); |
| 838 | kmem_free(shmmap_s, sizeof(struct shmmap_state)); |
| 839 | return; |
| 840 | } |
| 841 | |
| 842 | /* |
| 843 | * Delete the entry from shm map. |
| 844 | */ |
| 845 | for (;;) { |
| 846 | struct shmid_ds *shmseg; |
| 847 | struct uvm_object *uobj; |
| 848 | size_t sz; |
| 849 | |
| 850 | shmmap_se = SLIST_FIRST(&shmmap_s->entries); |
| 851 | KASSERT(shmmap_se != NULL); |
| 852 | |
| 853 | shmseg = &shmsegs[IPCID_TO_IX(shmmap_se->shmid)]; |
| 854 | sz = (shmseg->shm_segsz + PGOFSET) & ~PGOFSET; |
| 855 | /* shm_delete_mapping() removes from the list. */ |
| 856 | uobj = shm_delete_mapping(shmmap_s, shmmap_se); |
| 857 | mutex_exit(&shm_lock); |
| 858 | |
| 859 | uvm_deallocate(&vm->vm_map, shmmap_se->va, sz); |
| 860 | if (uobj != NULL) { |
| 861 | uao_detach(uobj); |
| 862 | } |
| 863 | kmem_free(shmmap_se, sizeof(struct shmmap_entry)); |
| 864 | |
| 865 | if (SLIST_EMPTY(&shmmap_s->entries)) { |
| 866 | break; |
| 867 | } |
| 868 | mutex_enter(&shm_lock); |
| 869 | KASSERT(!SLIST_EMPTY(&shmmap_s->entries)); |
| 870 | } |
| 871 | kmem_free(shmmap_s, sizeof(struct shmmap_state)); |
| 872 | } |
| 873 | |
| 874 | static int |
| 875 | shmrealloc(int newshmni) |
| 876 | { |
| 877 | vaddr_t v; |
| 878 | struct shmid_ds *oldshmsegs, *newshmsegs; |
| 879 | kcondvar_t *newshm_cv, *oldshm_cv; |
| 880 | size_t sz; |
| 881 | int i, lsegid, oldshmni; |
| 882 | |
| 883 | if (newshmni < 1) |
| 884 | return EINVAL; |
| 885 | |
| 886 | /* Allocate new memory area */ |
| 887 | sz = ALIGN(newshmni * sizeof(struct shmid_ds)) + |
| 888 | ALIGN(newshmni * sizeof(kcondvar_t)); |
| 889 | sz = round_page(sz); |
| 890 | v = uvm_km_alloc(kernel_map, sz, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); |
| 891 | if (v == 0) |
| 892 | return ENOMEM; |
| 893 | |
| 894 | mutex_enter(&shm_lock); |
| 895 | while (shm_realloc_state || shm_realloc_disable) |
| 896 | cv_wait(&shm_realloc_cv, &shm_lock); |
| 897 | |
| 898 | /* |
| 899 | * Get the number of last segment. Fail we are trying to |
| 900 | * reallocate less memory than we use. |
| 901 | */ |
| 902 | lsegid = 0; |
| 903 | for (i = 0; i < shminfo.shmmni; i++) |
| 904 | if ((shmsegs[i].shm_perm.mode & SHMSEG_FREE) == 0) |
| 905 | lsegid = i; |
| 906 | if (lsegid >= newshmni) { |
| 907 | mutex_exit(&shm_lock); |
| 908 | uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED); |
| 909 | return EBUSY; |
| 910 | } |
| 911 | shm_realloc_state = true; |
| 912 | |
| 913 | newshmsegs = (void *)v; |
| 914 | newshm_cv = (void *)((uintptr_t)newshmsegs + |
| 915 | ALIGN(newshmni * sizeof(struct shmid_ds))); |
| 916 | |
| 917 | /* Copy all memory to the new area */ |
| 918 | for (i = 0; i < shm_nused; i++) { |
| 919 | cv_init(&newshm_cv[i], "shmwait" ); |
| 920 | (void)memcpy(&newshmsegs[i], &shmsegs[i], |
| 921 | sizeof(newshmsegs[0])); |
| 922 | } |
| 923 | |
| 924 | /* Mark as free all new segments, if there is any */ |
| 925 | for (; i < newshmni; i++) { |
| 926 | cv_init(&newshm_cv[i], "shmwait" ); |
| 927 | newshmsegs[i].shm_perm.mode = SHMSEG_FREE; |
| 928 | newshmsegs[i].shm_perm._seq = 0; |
| 929 | } |
| 930 | |
| 931 | oldshmsegs = shmsegs; |
| 932 | oldshmni = shminfo.shmmni; |
| 933 | shminfo.shmmni = newshmni; |
| 934 | shmsegs = newshmsegs; |
| 935 | shm_cv = newshm_cv; |
| 936 | |
| 937 | /* Reallocation completed - notify all waiters, if any */ |
| 938 | shm_realloc_state = false; |
| 939 | cv_broadcast(&shm_realloc_cv); |
| 940 | mutex_exit(&shm_lock); |
| 941 | |
| 942 | /* Release now unused resources. */ |
| 943 | oldshm_cv = (void *)((uintptr_t)oldshmsegs + |
| 944 | ALIGN(oldshmni * sizeof(struct shmid_ds))); |
| 945 | for (i = 0; i < oldshmni; i++) |
| 946 | cv_destroy(&oldshm_cv[i]); |
| 947 | |
| 948 | sz = ALIGN(oldshmni * sizeof(struct shmid_ds)) + |
| 949 | ALIGN(oldshmni * sizeof(kcondvar_t)); |
| 950 | sz = round_page(sz); |
| 951 | uvm_km_free(kernel_map, (vaddr_t)oldshmsegs, sz, UVM_KMF_WIRED); |
| 952 | |
| 953 | return 0; |
| 954 | } |
| 955 | |
| 956 | void |
| 957 | shminit(struct sysctllog **clog) |
| 958 | { |
| 959 | vaddr_t v; |
| 960 | size_t sz; |
| 961 | int i; |
| 962 | |
| 963 | mutex_init(&shm_lock, MUTEX_DEFAULT, IPL_NONE); |
| 964 | cv_init(&shm_realloc_cv, "shmrealc" ); |
| 965 | |
| 966 | /* Allocate the wired memory for our structures */ |
| 967 | sz = ALIGN(shminfo.shmmni * sizeof(struct shmid_ds)) + |
| 968 | ALIGN(shminfo.shmmni * sizeof(kcondvar_t)); |
| 969 | sz = round_page(sz); |
| 970 | v = uvm_km_alloc(kernel_map, sz, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); |
| 971 | if (v == 0) |
| 972 | panic("sysv_shm: cannot allocate memory" ); |
| 973 | shmsegs = (void *)v; |
| 974 | shm_cv = (void *)((uintptr_t)shmsegs + |
| 975 | ALIGN(shminfo.shmmni * sizeof(struct shmid_ds))); |
| 976 | |
| 977 | if (shminfo.shmmax == 0) |
| 978 | shminfo.shmmax = max(physmem / 4, 1024) * PAGE_SIZE; |
| 979 | else |
| 980 | shminfo.shmmax *= PAGE_SIZE; |
| 981 | shminfo.shmall = shminfo.shmmax / PAGE_SIZE; |
| 982 | |
| 983 | for (i = 0; i < shminfo.shmmni; i++) { |
| 984 | cv_init(&shm_cv[i], "shmwait" ); |
| 985 | shmsegs[i].shm_perm.mode = SHMSEG_FREE; |
| 986 | shmsegs[i].shm_perm._seq = 0; |
| 987 | } |
| 988 | shm_last_free = 0; |
| 989 | shm_nused = 0; |
| 990 | shm_committed = 0; |
| 991 | shm_realloc_disable = 0; |
| 992 | shm_realloc_state = false; |
| 993 | |
| 994 | kern_has_sysvshm = 1; |
| 995 | |
| 996 | /* Load the callback function pointers for the uvm subsystem */ |
| 997 | uvm_shmexit = shmexit; |
| 998 | uvm_shmfork = shmfork; |
| 999 | |
| 1000 | #ifdef _MODULE |
| 1001 | if (clog) |
| 1002 | sysctl_ipc_shm_setup(clog); |
| 1003 | #endif |
| 1004 | } |
| 1005 | |
| 1006 | int |
| 1007 | shmfini(void) |
| 1008 | { |
| 1009 | size_t sz; |
| 1010 | int i; |
| 1011 | vaddr_t v = (vaddr_t)shmsegs; |
| 1012 | |
| 1013 | mutex_enter(&shm_lock); |
| 1014 | if (shm_nused) { |
| 1015 | mutex_exit(&shm_lock); |
| 1016 | return 1; |
| 1017 | } |
| 1018 | |
| 1019 | /* Clear the callback function pointers for the uvm subsystem */ |
| 1020 | uvm_shmexit = NULL; |
| 1021 | uvm_shmfork = NULL; |
| 1022 | |
| 1023 | /* Destroy all condvars */ |
| 1024 | for (i = 0; i < shminfo.shmmni; i++) |
| 1025 | cv_destroy(&shm_cv[i]); |
| 1026 | cv_destroy(&shm_realloc_cv); |
| 1027 | |
| 1028 | /* Free the allocated/wired memory */ |
| 1029 | sz = ALIGN(shminfo.shmmni * sizeof(struct shmid_ds)) + |
| 1030 | ALIGN(shminfo.shmmni * sizeof(kcondvar_t)); |
| 1031 | sz = round_page(sz); |
| 1032 | uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED); |
| 1033 | |
| 1034 | /* Release and destroy our mutex */ |
| 1035 | mutex_exit(&shm_lock); |
| 1036 | mutex_destroy(&shm_lock); |
| 1037 | |
| 1038 | kern_has_sysvshm = 0; |
| 1039 | |
| 1040 | return 0; |
| 1041 | } |
| 1042 | |
| 1043 | static int |
| 1044 | sysctl_ipc_shmmni(SYSCTLFN_ARGS) |
| 1045 | { |
| 1046 | int newsize, error; |
| 1047 | struct sysctlnode node; |
| 1048 | node = *rnode; |
| 1049 | node.sysctl_data = &newsize; |
| 1050 | |
| 1051 | newsize = shminfo.shmmni; |
| 1052 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 1053 | if (error || newp == NULL) |
| 1054 | return error; |
| 1055 | |
| 1056 | sysctl_unlock(); |
| 1057 | error = shmrealloc(newsize); |
| 1058 | sysctl_relock(); |
| 1059 | return error; |
| 1060 | } |
| 1061 | |
| 1062 | static int |
| 1063 | sysctl_ipc_shmmaxpgs(SYSCTLFN_ARGS) |
| 1064 | { |
| 1065 | uint32_t newsize; |
| 1066 | int error; |
| 1067 | struct sysctlnode node; |
| 1068 | node = *rnode; |
| 1069 | node.sysctl_data = &newsize; |
| 1070 | |
| 1071 | newsize = shminfo.shmall; |
| 1072 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 1073 | if (error || newp == NULL) |
| 1074 | return error; |
| 1075 | |
| 1076 | if (newsize < 1) |
| 1077 | return EINVAL; |
| 1078 | |
| 1079 | shminfo.shmall = newsize; |
| 1080 | shminfo.shmmax = (uint64_t)shminfo.shmall * PAGE_SIZE; |
| 1081 | |
| 1082 | return 0; |
| 1083 | } |
| 1084 | |
| 1085 | static int |
| 1086 | sysctl_ipc_shmmax(SYSCTLFN_ARGS) |
| 1087 | { |
| 1088 | uint64_t newsize; |
| 1089 | int error; |
| 1090 | struct sysctlnode node; |
| 1091 | node = *rnode; |
| 1092 | node.sysctl_data = &newsize; |
| 1093 | |
| 1094 | newsize = shminfo.shmmax; |
| 1095 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
| 1096 | if (error || newp == NULL) |
| 1097 | return error; |
| 1098 | |
| 1099 | if (newsize < PAGE_SIZE) |
| 1100 | return EINVAL; |
| 1101 | |
| 1102 | shminfo.shmmax = round_page(newsize); |
| 1103 | shminfo.shmall = shminfo.shmmax >> PAGE_SHIFT; |
| 1104 | |
| 1105 | return 0; |
| 1106 | } |
| 1107 | |
| 1108 | SYSCTL_SETUP(sysctl_ipc_shm_setup, "sysctl kern.ipc subtree setup" ) |
| 1109 | { |
| 1110 | |
| 1111 | sysctl_createv(clog, 0, NULL, NULL, |
| 1112 | CTLFLAG_PERMANENT, |
| 1113 | CTLTYPE_NODE, "ipc" , |
| 1114 | SYSCTL_DESCR("SysV IPC options" ), |
| 1115 | NULL, 0, NULL, 0, |
| 1116 | CTL_KERN, KERN_SYSVIPC, CTL_EOL); |
| 1117 | sysctl_createv(clog, 0, NULL, NULL, |
| 1118 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1119 | CTLTYPE_QUAD, "shmmax" , |
| 1120 | SYSCTL_DESCR("Max shared memory segment size in bytes" ), |
| 1121 | sysctl_ipc_shmmax, 0, &shminfo.shmmax, 0, |
| 1122 | CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_SHMMAX, CTL_EOL); |
| 1123 | sysctl_createv(clog, 0, NULL, NULL, |
| 1124 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1125 | CTLTYPE_INT, "shmmni" , |
| 1126 | SYSCTL_DESCR("Max number of shared memory identifiers" ), |
| 1127 | sysctl_ipc_shmmni, 0, &shminfo.shmmni, 0, |
| 1128 | CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_SHMMNI, CTL_EOL); |
| 1129 | sysctl_createv(clog, 0, NULL, NULL, |
| 1130 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1131 | CTLTYPE_INT, "shmseg" , |
| 1132 | SYSCTL_DESCR("Max shared memory segments per process" ), |
| 1133 | NULL, 0, &shminfo.shmseg, 0, |
| 1134 | CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_SHMSEG, CTL_EOL); |
| 1135 | sysctl_createv(clog, 0, NULL, NULL, |
| 1136 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1137 | CTLTYPE_INT, "shmmaxpgs" , |
| 1138 | SYSCTL_DESCR("Max amount of shared memory in pages" ), |
| 1139 | sysctl_ipc_shmmaxpgs, 0, &shminfo.shmall, 0, |
| 1140 | CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_SHMMAXPGS, CTL_EOL); |
| 1141 | sysctl_createv(clog, 0, NULL, NULL, |
| 1142 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
| 1143 | CTLTYPE_INT, "shm_use_phys" , |
| 1144 | SYSCTL_DESCR("Enable/disable locking of shared memory in " |
| 1145 | "physical memory" ), NULL, 0, &shm_use_phys, 0, |
| 1146 | CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_SHMUSEPHYS, CTL_EOL); |
| 1147 | } |
| 1148 | |