uipc_shm.c revision 255426
1175164Sjhb/*- 2225344Srwatson * Copyright (c) 2006, 2011 Robert N. M. Watson 3175164Sjhb * All rights reserved. 4175164Sjhb * 5175164Sjhb * Redistribution and use in source and binary forms, with or without 6175164Sjhb * modification, are permitted provided that the following conditions 7175164Sjhb * are met: 8175164Sjhb * 1. Redistributions of source code must retain the above copyright 9175164Sjhb * notice, this list of conditions and the following disclaimer. 10175164Sjhb * 2. Redistributions in binary form must reproduce the above copyright 11175164Sjhb * notice, this list of conditions and the following disclaimer in the 12175164Sjhb * documentation and/or other materials provided with the distribution. 13175164Sjhb * 14175164Sjhb * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15175164Sjhb * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16175164Sjhb * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17175164Sjhb * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18175164Sjhb * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19175164Sjhb * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20175164Sjhb * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21175164Sjhb * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22175164Sjhb * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23175164Sjhb * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24175164Sjhb * SUCH DAMAGE. 25175164Sjhb */ 26175164Sjhb 27175164Sjhb/* 28175164Sjhb * Support for shared swap-backed anonymous memory objects via 29175164Sjhb * shm_open(2) and shm_unlink(2). While most of the implementation is 30175164Sjhb * here, vm_mmap.c contains mapping logic changes. 31175164Sjhb * 32175164Sjhb * TODO: 33175164Sjhb * 34225344Srwatson * (1) Need to export data to a userland tool via a sysctl. Should ipcs(1) 35175164Sjhb * and ipcrm(1) be expanded or should new tools to manage both POSIX 36175164Sjhb * kernel semaphores and POSIX shared memory be written? 37175164Sjhb * 38225344Srwatson * (2) Add support for this file type to fstat(1). 39175164Sjhb * 40225344Srwatson * (3) Resource limits? Does this need its own resource limits or are the 41175164Sjhb * existing limits in mmap(2) sufficient? 42175164Sjhb */ 43175164Sjhb 44175164Sjhb#include <sys/cdefs.h> 45175164Sjhb__FBSDID("$FreeBSD: head/sys/kern/uipc_shm.c 255426 2013-09-09 18:11:59Z jhb $"); 46175164Sjhb 47223692Sjonathan#include "opt_capsicum.h" 48223692Sjonathan 49175164Sjhb#include <sys/param.h> 50223692Sjonathan#include <sys/capability.h> 51175164Sjhb#include <sys/fcntl.h> 52175164Sjhb#include <sys/file.h> 53175164Sjhb#include <sys/filedesc.h> 54175164Sjhb#include <sys/fnv_hash.h> 55175164Sjhb#include <sys/kernel.h> 56175164Sjhb#include <sys/lock.h> 57175164Sjhb#include <sys/malloc.h> 58175164Sjhb#include <sys/mman.h> 59175164Sjhb#include <sys/mutex.h> 60224914Skib#include <sys/priv.h> 61175164Sjhb#include <sys/proc.h> 62175164Sjhb#include <sys/refcount.h> 63175164Sjhb#include <sys/resourcevar.h> 64248084Sattilio#include <sys/rwlock.h> 65175164Sjhb#include <sys/stat.h> 66175164Sjhb#include <sys/sysctl.h> 67175164Sjhb#include <sys/sysproto.h> 68175164Sjhb#include <sys/systm.h> 69175164Sjhb#include <sys/sx.h> 70175164Sjhb#include <sys/time.h> 71175164Sjhb#include <sys/vnode.h> 72254603Skib#include <sys/unistd.h> 73175164Sjhb 74175164Sjhb#include <security/mac/mac_framework.h> 75175164Sjhb 76175164Sjhb#include <vm/vm.h> 77175164Sjhb#include <vm/vm_param.h> 78175164Sjhb#include <vm/pmap.h> 79228533Sjhb#include <vm/vm_extern.h> 80175164Sjhb#include <vm/vm_map.h> 81228509Sjhb#include <vm/vm_kern.h> 82175164Sjhb#include <vm/vm_object.h> 83175164Sjhb#include <vm/vm_page.h> 84229821Salc#include <vm/vm_pageout.h> 85175164Sjhb#include <vm/vm_pager.h> 86175164Sjhb#include <vm/swap_pager.h> 87175164Sjhb 88175164Sjhbstruct shm_mapping { 89175164Sjhb char *sm_path; 90175164Sjhb Fnv32_t sm_fnv; 91175164Sjhb struct shmfd *sm_shmfd; 92175164Sjhb LIST_ENTRY(shm_mapping) sm_link; 93175164Sjhb}; 94175164Sjhb 95175164Sjhbstatic MALLOC_DEFINE(M_SHMFD, "shmfd", "shared memory file descriptor"); 96175164Sjhbstatic LIST_HEAD(, shm_mapping) *shm_dictionary; 97175164Sjhbstatic struct sx shm_dict_lock; 98175164Sjhbstatic struct mtx shm_timestamp_lock; 99175164Sjhbstatic u_long shm_hash; 100175164Sjhb 101175164Sjhb#define SHM_HASH(fnv) (&shm_dictionary[(fnv) & shm_hash]) 102175164Sjhb 103175164Sjhbstatic int shm_access(struct shmfd *shmfd, struct ucred *ucred, int flags); 104175164Sjhbstatic struct shmfd *shm_alloc(struct ucred *ucred, mode_t mode); 105175164Sjhbstatic void shm_dict_init(void *arg); 106175164Sjhbstatic void shm_drop(struct shmfd *shmfd); 107175164Sjhbstatic struct shmfd *shm_hold(struct shmfd *shmfd); 108175164Sjhbstatic void shm_insert(char *path, Fnv32_t fnv, struct shmfd *shmfd); 109175164Sjhbstatic struct shmfd *shm_lookup(char *path, Fnv32_t fnv); 110175164Sjhbstatic int shm_remove(char *path, Fnv32_t fnv, struct ucred *ucred); 111194766Skibstatic int shm_dotruncate(struct shmfd *shmfd, off_t length); 112175164Sjhb 113175164Sjhbstatic fo_rdwr_t shm_read; 114175164Sjhbstatic fo_rdwr_t shm_write; 115175164Sjhbstatic fo_truncate_t shm_truncate; 116175164Sjhbstatic fo_ioctl_t shm_ioctl; 117175164Sjhbstatic fo_poll_t shm_poll; 118175164Sjhbstatic fo_kqfilter_t shm_kqfilter; 119175164Sjhbstatic fo_stat_t shm_stat; 120175164Sjhbstatic fo_close_t shm_close; 121224914Skibstatic fo_chmod_t shm_chmod; 122224914Skibstatic fo_chown_t shm_chown; 123254603Skibstatic fo_seek_t shm_seek; 124175164Sjhb 125175164Sjhb/* File descriptor operations. */ 126175164Sjhbstatic struct fileops shm_ops = { 127175164Sjhb .fo_read = shm_read, 128175164Sjhb .fo_write = shm_write, 129175164Sjhb .fo_truncate = shm_truncate, 130175164Sjhb .fo_ioctl = shm_ioctl, 131175164Sjhb .fo_poll = shm_poll, 132175164Sjhb .fo_kqfilter = shm_kqfilter, 133175164Sjhb .fo_stat = shm_stat, 134175164Sjhb .fo_close = shm_close, 135224914Skib .fo_chmod = shm_chmod, 136224914Skib .fo_chown = shm_chown, 137254356Sglebius .fo_sendfile = invfo_sendfile, 138254603Skib .fo_seek = shm_seek, 139254603Skib .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 140175164Sjhb}; 141175164Sjhb 142175164SjhbFEATURE(posix_shm, "POSIX shared memory"); 143175164Sjhb 144175164Sjhbstatic int 145254601Skibuiomove_object_page(vm_object_t obj, size_t len, struct uio *uio) 146254601Skib{ 147254601Skib vm_page_t m; 148254601Skib vm_pindex_t idx; 149254601Skib size_t tlen; 150254601Skib int error, offset, rv; 151254601Skib 152254601Skib idx = OFF_TO_IDX(uio->uio_offset); 153254601Skib offset = uio->uio_offset & PAGE_MASK; 154254601Skib tlen = MIN(PAGE_SIZE - offset, len); 155254601Skib 156254601Skib VM_OBJECT_WLOCK(obj); 157254601Skib 158254601Skib /* 159254601Skib * Parallel reads of the page content from disk are prevented 160254601Skib * by exclusive busy. 161254601Skib * 162254601Skib * Although the tmpfs vnode lock is held here, it is 163254601Skib * nonetheless safe to sleep waiting for a free page. The 164254601Skib * pageout daemon does not need to acquire the tmpfs vnode 165254601Skib * lock to page out tobj's pages because tobj is a OBJT_SWAP 166254601Skib * type object. 167254601Skib */ 168254649Skib m = vm_page_grab(obj, idx, VM_ALLOC_NORMAL); 169254601Skib if (m->valid != VM_PAGE_BITS_ALL) { 170254601Skib if (vm_pager_has_page(obj, idx, NULL, NULL)) { 171254601Skib rv = vm_pager_get_pages(obj, &m, 1, 0); 172254601Skib m = vm_page_lookup(obj, idx); 173254601Skib if (m == NULL) { 174254601Skib printf( 175254601Skib "uiomove_object: vm_obj %p idx %jd null lookup rv %d\n", 176254601Skib obj, idx, rv); 177254601Skib VM_OBJECT_WUNLOCK(obj); 178254601Skib return (EIO); 179254601Skib } 180254601Skib if (rv != VM_PAGER_OK) { 181254601Skib printf( 182254601Skib "uiomove_object: vm_obj %p idx %jd valid %x pager error %d\n", 183254601Skib obj, idx, m->valid, rv); 184254601Skib vm_page_lock(m); 185254601Skib vm_page_free(m); 186254601Skib vm_page_unlock(m); 187254601Skib VM_OBJECT_WUNLOCK(obj); 188254601Skib return (EIO); 189254601Skib } 190254601Skib } else 191254601Skib vm_page_zero_invalid(m, TRUE); 192254601Skib } 193254601Skib vm_page_xunbusy(m); 194254601Skib vm_page_lock(m); 195254601Skib vm_page_hold(m); 196254601Skib vm_page_unlock(m); 197254601Skib VM_OBJECT_WUNLOCK(obj); 198254601Skib error = uiomove_fromphys(&m, offset, tlen, uio); 199254601Skib if (uio->uio_rw == UIO_WRITE && error == 0) { 200254601Skib VM_OBJECT_WLOCK(obj); 201254601Skib vm_page_dirty(m); 202254601Skib VM_OBJECT_WUNLOCK(obj); 203254601Skib } 204254601Skib vm_page_lock(m); 205254601Skib vm_page_unhold(m); 206254601Skib if (m->queue == PQ_NONE) { 207254601Skib vm_page_deactivate(m); 208254601Skib } else { 209254601Skib /* Requeue to maintain LRU ordering. */ 210254601Skib vm_page_requeue(m); 211254601Skib } 212254601Skib vm_page_unlock(m); 213254601Skib 214254601Skib return (error); 215254601Skib} 216254601Skib 217254601Skibint 218254601Skibuiomove_object(vm_object_t obj, off_t obj_size, struct uio *uio) 219254601Skib{ 220254601Skib ssize_t resid; 221254601Skib size_t len; 222254601Skib int error; 223254601Skib 224254601Skib error = 0; 225254601Skib while ((resid = uio->uio_resid) > 0) { 226254601Skib if (obj_size <= uio->uio_offset) 227254601Skib break; 228254601Skib len = MIN(obj_size - uio->uio_offset, resid); 229254601Skib if (len == 0) 230254601Skib break; 231254601Skib error = uiomove_object_page(obj, len, uio); 232254601Skib if (error != 0 || resid == uio->uio_resid) 233254601Skib break; 234254601Skib } 235254601Skib return (error); 236254601Skib} 237254601Skib 238254601Skibstatic int 239254603Skibshm_seek(struct file *fp, off_t offset, int whence, struct thread *td) 240254603Skib{ 241254603Skib struct shmfd *shmfd; 242254603Skib off_t foffset; 243254603Skib int error; 244254603Skib 245254603Skib shmfd = fp->f_data; 246254603Skib foffset = foffset_lock(fp, 0); 247254603Skib error = 0; 248254603Skib switch (whence) { 249254603Skib case L_INCR: 250254603Skib if (foffset < 0 || 251254603Skib (offset > 0 && foffset > OFF_MAX - offset)) { 252254603Skib error = EOVERFLOW; 253254603Skib break; 254254603Skib } 255254603Skib offset += foffset; 256254603Skib break; 257254603Skib case L_XTND: 258254603Skib if (offset > 0 && shmfd->shm_size > OFF_MAX - offset) { 259254603Skib error = EOVERFLOW; 260254603Skib break; 261254603Skib } 262254603Skib offset += shmfd->shm_size; 263254603Skib break; 264254603Skib case L_SET: 265254603Skib break; 266254603Skib default: 267254603Skib error = EINVAL; 268254603Skib } 269254603Skib if (error == 0) { 270254603Skib if (offset < 0 || offset > shmfd->shm_size) 271254603Skib error = EINVAL; 272254603Skib else 273254603Skib *(off_t *)(td->td_retval) = offset; 274254603Skib } 275254603Skib foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 276254603Skib return (error); 277254603Skib} 278254603Skib 279254603Skibstatic int 280175164Sjhbshm_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 281175164Sjhb int flags, struct thread *td) 282175164Sjhb{ 283254603Skib struct shmfd *shmfd; 284254603Skib void *rl_cookie; 285254603Skib int error; 286175164Sjhb 287254603Skib shmfd = fp->f_data; 288254603Skib foffset_lock_uio(fp, uio, flags); 289254603Skib rl_cookie = rangelock_rlock(&shmfd->shm_rl, uio->uio_offset, 290254603Skib uio->uio_offset + uio->uio_resid, &shmfd->shm_mtx); 291254603Skib#ifdef MAC 292254603Skib error = mac_posixshm_check_read(active_cred, fp->f_cred, shmfd); 293254603Skib if (error) 294254603Skib return (error); 295254603Skib#endif 296254603Skib error = uiomove_object(shmfd->shm_object, shmfd->shm_size, uio); 297254603Skib rangelock_unlock(&shmfd->shm_rl, rl_cookie, &shmfd->shm_mtx); 298254603Skib foffset_unlock_uio(fp, uio, flags); 299254603Skib return (error); 300175164Sjhb} 301175164Sjhb 302175164Sjhbstatic int 303175164Sjhbshm_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 304175164Sjhb int flags, struct thread *td) 305175164Sjhb{ 306254603Skib struct shmfd *shmfd; 307254603Skib void *rl_cookie; 308254603Skib int error; 309175164Sjhb 310254603Skib shmfd = fp->f_data; 311254603Skib#ifdef MAC 312254603Skib error = mac_posixshm_check_write(active_cred, fp->f_cred, shmfd); 313254603Skib if (error) 314254603Skib return (error); 315254603Skib#endif 316254603Skib foffset_lock_uio(fp, uio, flags); 317254603Skib if ((flags & FOF_OFFSET) == 0) { 318254603Skib rl_cookie = rangelock_wlock(&shmfd->shm_rl, 0, OFF_MAX, 319254603Skib &shmfd->shm_mtx); 320254603Skib } else { 321254603Skib rl_cookie = rangelock_wlock(&shmfd->shm_rl, uio->uio_offset, 322254603Skib uio->uio_offset + uio->uio_resid, &shmfd->shm_mtx); 323254603Skib } 324254603Skib 325254603Skib error = uiomove_object(shmfd->shm_object, shmfd->shm_size, uio); 326254603Skib rangelock_unlock(&shmfd->shm_rl, rl_cookie, &shmfd->shm_mtx); 327254603Skib foffset_unlock_uio(fp, uio, flags); 328254603Skib return (error); 329175164Sjhb} 330175164Sjhb 331175164Sjhbstatic int 332175164Sjhbshm_truncate(struct file *fp, off_t length, struct ucred *active_cred, 333175164Sjhb struct thread *td) 334175164Sjhb{ 335175164Sjhb struct shmfd *shmfd; 336175164Sjhb#ifdef MAC 337175164Sjhb int error; 338175164Sjhb#endif 339175164Sjhb 340175164Sjhb shmfd = fp->f_data; 341175164Sjhb#ifdef MAC 342175164Sjhb error = mac_posixshm_check_truncate(active_cred, fp->f_cred, shmfd); 343175164Sjhb if (error) 344175164Sjhb return (error); 345175164Sjhb#endif 346194766Skib return (shm_dotruncate(shmfd, length)); 347175164Sjhb} 348175164Sjhb 349175164Sjhbstatic int 350175164Sjhbshm_ioctl(struct file *fp, u_long com, void *data, 351175164Sjhb struct ucred *active_cred, struct thread *td) 352175164Sjhb{ 353175164Sjhb 354175164Sjhb return (EOPNOTSUPP); 355175164Sjhb} 356175164Sjhb 357175164Sjhbstatic int 358175164Sjhbshm_poll(struct file *fp, int events, struct ucred *active_cred, 359175164Sjhb struct thread *td) 360175164Sjhb{ 361175164Sjhb 362175164Sjhb return (EOPNOTSUPP); 363175164Sjhb} 364175164Sjhb 365175164Sjhbstatic int 366175164Sjhbshm_kqfilter(struct file *fp, struct knote *kn) 367175164Sjhb{ 368175164Sjhb 369175164Sjhb return (EOPNOTSUPP); 370175164Sjhb} 371175164Sjhb 372175164Sjhbstatic int 373175164Sjhbshm_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 374175164Sjhb struct thread *td) 375175164Sjhb{ 376175164Sjhb struct shmfd *shmfd; 377175164Sjhb#ifdef MAC 378175164Sjhb int error; 379175164Sjhb#endif 380175164Sjhb 381175164Sjhb shmfd = fp->f_data; 382175164Sjhb 383175164Sjhb#ifdef MAC 384175164Sjhb error = mac_posixshm_check_stat(active_cred, fp->f_cred, shmfd); 385175164Sjhb if (error) 386175164Sjhb return (error); 387175164Sjhb#endif 388175164Sjhb 389175164Sjhb /* 390175164Sjhb * Attempt to return sanish values for fstat() on a memory file 391175164Sjhb * descriptor. 392175164Sjhb */ 393175164Sjhb bzero(sb, sizeof(*sb)); 394175164Sjhb sb->st_blksize = PAGE_SIZE; 395175164Sjhb sb->st_size = shmfd->shm_size; 396175164Sjhb sb->st_blocks = (sb->st_size + sb->st_blksize - 1) / sb->st_blksize; 397224914Skib mtx_lock(&shm_timestamp_lock); 398205792Sed sb->st_atim = shmfd->shm_atime; 399205792Sed sb->st_ctim = shmfd->shm_ctime; 400205792Sed sb->st_mtim = shmfd->shm_mtime; 401224914Skib sb->st_birthtim = shmfd->shm_birthtime; 402224914Skib sb->st_mode = S_IFREG | shmfd->shm_mode; /* XXX */ 403175164Sjhb sb->st_uid = shmfd->shm_uid; 404175164Sjhb sb->st_gid = shmfd->shm_gid; 405224914Skib mtx_unlock(&shm_timestamp_lock); 406175164Sjhb 407175164Sjhb return (0); 408175164Sjhb} 409175164Sjhb 410175164Sjhbstatic int 411175164Sjhbshm_close(struct file *fp, struct thread *td) 412175164Sjhb{ 413175164Sjhb struct shmfd *shmfd; 414175164Sjhb 415175164Sjhb shmfd = fp->f_data; 416175164Sjhb fp->f_data = NULL; 417175164Sjhb shm_drop(shmfd); 418175164Sjhb 419175164Sjhb return (0); 420175164Sjhb} 421175164Sjhb 422194766Skibstatic int 423175164Sjhbshm_dotruncate(struct shmfd *shmfd, off_t length) 424175164Sjhb{ 425175164Sjhb vm_object_t object; 426229821Salc vm_page_t m, ma[1]; 427229821Salc vm_pindex_t idx, nobjsize; 428194766Skib vm_ooffset_t delta; 429229821Salc int base, rv; 430175164Sjhb 431175164Sjhb object = shmfd->shm_object; 432248084Sattilio VM_OBJECT_WLOCK(object); 433175164Sjhb if (length == shmfd->shm_size) { 434248084Sattilio VM_OBJECT_WUNLOCK(object); 435194766Skib return (0); 436175164Sjhb } 437175164Sjhb nobjsize = OFF_TO_IDX(length + PAGE_MASK); 438175164Sjhb 439175164Sjhb /* Are we shrinking? If so, trim the end. */ 440175164Sjhb if (length < shmfd->shm_size) { 441228509Sjhb /* 442228509Sjhb * Disallow any requests to shrink the size if this 443228509Sjhb * object is mapped into the kernel. 444228509Sjhb */ 445228509Sjhb if (shmfd->shm_kmappings > 0) { 446248084Sattilio VM_OBJECT_WUNLOCK(object); 447228509Sjhb return (EBUSY); 448228509Sjhb } 449229821Salc 450229821Salc /* 451229821Salc * Zero the truncated part of the last page. 452229821Salc */ 453229821Salc base = length & PAGE_MASK; 454229821Salc if (base != 0) { 455229821Salc idx = OFF_TO_IDX(length); 456229821Salcretry: 457229821Salc m = vm_page_lookup(object, idx); 458229821Salc if (m != NULL) { 459254138Sattilio if (vm_page_sleep_if_busy(m, "shmtrc")) 460229821Salc goto retry; 461229821Salc } else if (vm_pager_has_page(object, idx, NULL, NULL)) { 462229821Salc m = vm_page_alloc(object, idx, VM_ALLOC_NORMAL); 463229821Salc if (m == NULL) { 464248084Sattilio VM_OBJECT_WUNLOCK(object); 465229821Salc VM_WAIT; 466248084Sattilio VM_OBJECT_WLOCK(object); 467229821Salc goto retry; 468229821Salc } else if (m->valid != VM_PAGE_BITS_ALL) { 469229821Salc ma[0] = m; 470229821Salc rv = vm_pager_get_pages(object, ma, 1, 471229821Salc 0); 472229821Salc m = vm_page_lookup(object, idx); 473229821Salc } else 474229821Salc /* A cached page was reactivated. */ 475229821Salc rv = VM_PAGER_OK; 476229821Salc vm_page_lock(m); 477229821Salc if (rv == VM_PAGER_OK) { 478229821Salc vm_page_deactivate(m); 479229821Salc vm_page_unlock(m); 480254138Sattilio vm_page_xunbusy(m); 481229821Salc } else { 482229821Salc vm_page_free(m); 483229821Salc vm_page_unlock(m); 484248084Sattilio VM_OBJECT_WUNLOCK(object); 485229821Salc return (EIO); 486229821Salc } 487229821Salc } 488229821Salc if (m != NULL) { 489229821Salc pmap_zero_page_area(m, base, PAGE_SIZE - base); 490229821Salc KASSERT(m->valid == VM_PAGE_BITS_ALL, 491229821Salc ("shm_dotruncate: page %p is invalid", m)); 492229821Salc vm_page_dirty(m); 493229821Salc vm_pager_page_unswapped(m); 494229821Salc } 495229821Salc } 496194766Skib delta = ptoa(object->size - nobjsize); 497194766Skib 498175164Sjhb /* Toss in memory pages. */ 499175164Sjhb if (nobjsize < object->size) 500175164Sjhb vm_object_page_remove(object, nobjsize, object->size, 501223677Salc 0); 502175164Sjhb 503175164Sjhb /* Toss pages from swap. */ 504175164Sjhb if (object->type == OBJT_SWAP) 505194766Skib swap_pager_freespace(object, nobjsize, delta); 506175164Sjhb 507194766Skib /* Free the swap accounted for shm */ 508216128Strasz swap_release_by_cred(delta, object->cred); 509194766Skib object->charge -= delta; 510194766Skib } else { 511194766Skib /* Attempt to reserve the swap */ 512194766Skib delta = ptoa(nobjsize - object->size); 513216128Strasz if (!swap_reserve_by_cred(delta, object->cred)) { 514248084Sattilio VM_OBJECT_WUNLOCK(object); 515194766Skib return (ENOMEM); 516194766Skib } 517194766Skib object->charge += delta; 518175164Sjhb } 519175164Sjhb shmfd->shm_size = length; 520175164Sjhb mtx_lock(&shm_timestamp_lock); 521175164Sjhb vfs_timestamp(&shmfd->shm_ctime); 522175164Sjhb shmfd->shm_mtime = shmfd->shm_ctime; 523175164Sjhb mtx_unlock(&shm_timestamp_lock); 524175164Sjhb object->size = nobjsize; 525248084Sattilio VM_OBJECT_WUNLOCK(object); 526194766Skib return (0); 527175164Sjhb} 528175164Sjhb 529175164Sjhb/* 530175164Sjhb * shmfd object management including creation and reference counting 531175164Sjhb * routines. 532175164Sjhb */ 533175164Sjhbstatic struct shmfd * 534175164Sjhbshm_alloc(struct ucred *ucred, mode_t mode) 535175164Sjhb{ 536175164Sjhb struct shmfd *shmfd; 537175164Sjhb 538175164Sjhb shmfd = malloc(sizeof(*shmfd), M_SHMFD, M_WAITOK | M_ZERO); 539175164Sjhb shmfd->shm_size = 0; 540175164Sjhb shmfd->shm_uid = ucred->cr_uid; 541175164Sjhb shmfd->shm_gid = ucred->cr_gid; 542175164Sjhb shmfd->shm_mode = mode; 543175164Sjhb shmfd->shm_object = vm_pager_allocate(OBJT_DEFAULT, NULL, 544194766Skib shmfd->shm_size, VM_PROT_DEFAULT, 0, ucred); 545175164Sjhb KASSERT(shmfd->shm_object != NULL, ("shm_create: vm_pager_allocate")); 546248084Sattilio VM_OBJECT_WLOCK(shmfd->shm_object); 547178181Salc vm_object_clear_flag(shmfd->shm_object, OBJ_ONEMAPPING); 548178181Salc vm_object_set_flag(shmfd->shm_object, OBJ_NOSPLIT); 549248084Sattilio VM_OBJECT_WUNLOCK(shmfd->shm_object); 550175164Sjhb vfs_timestamp(&shmfd->shm_birthtime); 551175164Sjhb shmfd->shm_atime = shmfd->shm_mtime = shmfd->shm_ctime = 552175164Sjhb shmfd->shm_birthtime; 553175164Sjhb refcount_init(&shmfd->shm_refs, 1); 554254603Skib mtx_init(&shmfd->shm_mtx, "shmrl", NULL, MTX_DEF); 555254603Skib rangelock_init(&shmfd->shm_rl); 556175164Sjhb#ifdef MAC 557175164Sjhb mac_posixshm_init(shmfd); 558175164Sjhb mac_posixshm_create(ucred, shmfd); 559175164Sjhb#endif 560175164Sjhb 561175164Sjhb return (shmfd); 562175164Sjhb} 563175164Sjhb 564175164Sjhbstatic struct shmfd * 565175164Sjhbshm_hold(struct shmfd *shmfd) 566175164Sjhb{ 567175164Sjhb 568175164Sjhb refcount_acquire(&shmfd->shm_refs); 569175164Sjhb return (shmfd); 570175164Sjhb} 571175164Sjhb 572175164Sjhbstatic void 573175164Sjhbshm_drop(struct shmfd *shmfd) 574175164Sjhb{ 575175164Sjhb 576175164Sjhb if (refcount_release(&shmfd->shm_refs)) { 577175164Sjhb#ifdef MAC 578175164Sjhb mac_posixshm_destroy(shmfd); 579175164Sjhb#endif 580254603Skib rangelock_destroy(&shmfd->shm_rl); 581254603Skib mtx_destroy(&shmfd->shm_mtx); 582175164Sjhb vm_object_deallocate(shmfd->shm_object); 583175164Sjhb free(shmfd, M_SHMFD); 584175164Sjhb } 585175164Sjhb} 586175164Sjhb 587175164Sjhb/* 588175164Sjhb * Determine if the credentials have sufficient permissions for a 589175164Sjhb * specified combination of FREAD and FWRITE. 590175164Sjhb */ 591175164Sjhbstatic int 592175164Sjhbshm_access(struct shmfd *shmfd, struct ucred *ucred, int flags) 593175164Sjhb{ 594184413Strasz accmode_t accmode; 595224914Skib int error; 596175164Sjhb 597184413Strasz accmode = 0; 598175164Sjhb if (flags & FREAD) 599184413Strasz accmode |= VREAD; 600175164Sjhb if (flags & FWRITE) 601184413Strasz accmode |= VWRITE; 602224914Skib mtx_lock(&shm_timestamp_lock); 603224914Skib error = vaccess(VREG, shmfd->shm_mode, shmfd->shm_uid, shmfd->shm_gid, 604224914Skib accmode, ucred, NULL); 605224914Skib mtx_unlock(&shm_timestamp_lock); 606224914Skib return (error); 607175164Sjhb} 608175164Sjhb 609175164Sjhb/* 610175164Sjhb * Dictionary management. We maintain an in-kernel dictionary to map 611175164Sjhb * paths to shmfd objects. We use the FNV hash on the path to store 612175164Sjhb * the mappings in a hash table. 613175164Sjhb */ 614175164Sjhbstatic void 615175164Sjhbshm_dict_init(void *arg) 616175164Sjhb{ 617175164Sjhb 618175164Sjhb mtx_init(&shm_timestamp_lock, "shm timestamps", NULL, MTX_DEF); 619175164Sjhb sx_init(&shm_dict_lock, "shm dictionary"); 620175164Sjhb shm_dictionary = hashinit(1024, M_SHMFD, &shm_hash); 621175164Sjhb} 622175164SjhbSYSINIT(shm_dict_init, SI_SUB_SYSV_SHM, SI_ORDER_ANY, shm_dict_init, NULL); 623175164Sjhb 624175164Sjhbstatic struct shmfd * 625175164Sjhbshm_lookup(char *path, Fnv32_t fnv) 626175164Sjhb{ 627175164Sjhb struct shm_mapping *map; 628175164Sjhb 629175164Sjhb LIST_FOREACH(map, SHM_HASH(fnv), sm_link) { 630175164Sjhb if (map->sm_fnv != fnv) 631175164Sjhb continue; 632175164Sjhb if (strcmp(map->sm_path, path) == 0) 633175164Sjhb return (map->sm_shmfd); 634175164Sjhb } 635175164Sjhb 636175164Sjhb return (NULL); 637175164Sjhb} 638175164Sjhb 639175164Sjhbstatic void 640175164Sjhbshm_insert(char *path, Fnv32_t fnv, struct shmfd *shmfd) 641175164Sjhb{ 642175164Sjhb struct shm_mapping *map; 643175164Sjhb 644175164Sjhb map = malloc(sizeof(struct shm_mapping), M_SHMFD, M_WAITOK); 645175164Sjhb map->sm_path = path; 646175164Sjhb map->sm_fnv = fnv; 647175164Sjhb map->sm_shmfd = shm_hold(shmfd); 648233760Sjhb shmfd->shm_path = path; 649175164Sjhb LIST_INSERT_HEAD(SHM_HASH(fnv), map, sm_link); 650175164Sjhb} 651175164Sjhb 652175164Sjhbstatic int 653175164Sjhbshm_remove(char *path, Fnv32_t fnv, struct ucred *ucred) 654175164Sjhb{ 655175164Sjhb struct shm_mapping *map; 656175164Sjhb int error; 657175164Sjhb 658175164Sjhb LIST_FOREACH(map, SHM_HASH(fnv), sm_link) { 659175164Sjhb if (map->sm_fnv != fnv) 660175164Sjhb continue; 661175164Sjhb if (strcmp(map->sm_path, path) == 0) { 662175164Sjhb#ifdef MAC 663175164Sjhb error = mac_posixshm_check_unlink(ucred, map->sm_shmfd); 664175164Sjhb if (error) 665175164Sjhb return (error); 666175164Sjhb#endif 667175164Sjhb error = shm_access(map->sm_shmfd, ucred, 668175164Sjhb FREAD | FWRITE); 669175164Sjhb if (error) 670175164Sjhb return (error); 671233760Sjhb map->sm_shmfd->shm_path = NULL; 672175164Sjhb LIST_REMOVE(map, sm_link); 673175164Sjhb shm_drop(map->sm_shmfd); 674175164Sjhb free(map->sm_path, M_SHMFD); 675175164Sjhb free(map, M_SHMFD); 676175164Sjhb return (0); 677175164Sjhb } 678175164Sjhb } 679175164Sjhb 680175164Sjhb return (ENOENT); 681175164Sjhb} 682175164Sjhb 683175164Sjhb/* System calls. */ 684175164Sjhbint 685225617Skmacysys_shm_open(struct thread *td, struct shm_open_args *uap) 686175164Sjhb{ 687175164Sjhb struct filedesc *fdp; 688175164Sjhb struct shmfd *shmfd; 689175164Sjhb struct file *fp; 690175164Sjhb char *path; 691175164Sjhb Fnv32_t fnv; 692175164Sjhb mode_t cmode; 693175164Sjhb int fd, error; 694175164Sjhb 695223692Sjonathan#ifdef CAPABILITY_MODE 696223692Sjonathan /* 697223692Sjonathan * shm_open(2) is only allowed for anonymous objects. 698223692Sjonathan */ 699223692Sjonathan if (IN_CAPABILITY_MODE(td) && (uap->path != SHM_ANON)) 700223692Sjonathan return (ECAPMODE); 701223692Sjonathan#endif 702223692Sjonathan 703175164Sjhb if ((uap->flags & O_ACCMODE) != O_RDONLY && 704175164Sjhb (uap->flags & O_ACCMODE) != O_RDWR) 705175164Sjhb return (EINVAL); 706175164Sjhb 707175164Sjhb if ((uap->flags & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC)) != 0) 708175164Sjhb return (EINVAL); 709175164Sjhb 710175164Sjhb fdp = td->td_proc->p_fd; 711175164Sjhb cmode = (uap->mode & ~fdp->fd_cmask) & ACCESSPERMS; 712175164Sjhb 713249233Sjilles error = falloc(td, &fp, &fd, O_CLOEXEC); 714175164Sjhb if (error) 715175164Sjhb return (error); 716175164Sjhb 717175164Sjhb /* A SHM_ANON path pointer creates an anonymous object. */ 718175164Sjhb if (uap->path == SHM_ANON) { 719175164Sjhb /* A read-only anonymous object is pointless. */ 720175164Sjhb if ((uap->flags & O_ACCMODE) == O_RDONLY) { 721175164Sjhb fdclose(fdp, fp, fd, td); 722175164Sjhb fdrop(fp, td); 723175164Sjhb return (EINVAL); 724175164Sjhb } 725175164Sjhb shmfd = shm_alloc(td->td_ucred, cmode); 726175164Sjhb } else { 727175164Sjhb path = malloc(MAXPATHLEN, M_SHMFD, M_WAITOK); 728175164Sjhb error = copyinstr(uap->path, path, MAXPATHLEN, NULL); 729175164Sjhb 730175164Sjhb /* Require paths to start with a '/' character. */ 731175164Sjhb if (error == 0 && path[0] != '/') 732175164Sjhb error = EINVAL; 733175164Sjhb if (error) { 734175164Sjhb fdclose(fdp, fp, fd, td); 735175164Sjhb fdrop(fp, td); 736175164Sjhb free(path, M_SHMFD); 737175164Sjhb return (error); 738175164Sjhb } 739175164Sjhb 740175164Sjhb fnv = fnv_32_str(path, FNV1_32_INIT); 741175164Sjhb sx_xlock(&shm_dict_lock); 742175164Sjhb shmfd = shm_lookup(path, fnv); 743175164Sjhb if (shmfd == NULL) { 744175164Sjhb /* Object does not yet exist, create it if requested. */ 745175164Sjhb if (uap->flags & O_CREAT) { 746225344Srwatson#ifdef MAC 747225344Srwatson error = mac_posixshm_check_create(td->td_ucred, 748225344Srwatson path); 749225344Srwatson if (error == 0) { 750225344Srwatson#endif 751225344Srwatson shmfd = shm_alloc(td->td_ucred, cmode); 752225344Srwatson shm_insert(path, fnv, shmfd); 753225344Srwatson#ifdef MAC 754225344Srwatson } 755225344Srwatson#endif 756175164Sjhb } else { 757175164Sjhb free(path, M_SHMFD); 758175164Sjhb error = ENOENT; 759175164Sjhb } 760175164Sjhb } else { 761175164Sjhb /* 762175164Sjhb * Object already exists, obtain a new 763175164Sjhb * reference if requested and permitted. 764175164Sjhb */ 765175164Sjhb free(path, M_SHMFD); 766175164Sjhb if ((uap->flags & (O_CREAT | O_EXCL)) == 767175164Sjhb (O_CREAT | O_EXCL)) 768175164Sjhb error = EEXIST; 769175164Sjhb else { 770175164Sjhb#ifdef MAC 771175164Sjhb error = mac_posixshm_check_open(td->td_ucred, 772225344Srwatson shmfd, FFLAGS(uap->flags & O_ACCMODE)); 773175164Sjhb if (error == 0) 774175164Sjhb#endif 775175164Sjhb error = shm_access(shmfd, td->td_ucred, 776175164Sjhb FFLAGS(uap->flags & O_ACCMODE)); 777175164Sjhb } 778175164Sjhb 779175164Sjhb /* 780175164Sjhb * Truncate the file back to zero length if 781175164Sjhb * O_TRUNC was specified and the object was 782175164Sjhb * opened with read/write. 783175164Sjhb */ 784175164Sjhb if (error == 0 && 785175164Sjhb (uap->flags & (O_ACCMODE | O_TRUNC)) == 786175164Sjhb (O_RDWR | O_TRUNC)) { 787175164Sjhb#ifdef MAC 788175164Sjhb error = mac_posixshm_check_truncate( 789175164Sjhb td->td_ucred, fp->f_cred, shmfd); 790175164Sjhb if (error == 0) 791175164Sjhb#endif 792175164Sjhb shm_dotruncate(shmfd, 0); 793175164Sjhb } 794175164Sjhb if (error == 0) 795175164Sjhb shm_hold(shmfd); 796175164Sjhb } 797175164Sjhb sx_xunlock(&shm_dict_lock); 798175164Sjhb 799175164Sjhb if (error) { 800175164Sjhb fdclose(fdp, fp, fd, td); 801175164Sjhb fdrop(fp, td); 802175164Sjhb return (error); 803175164Sjhb } 804175164Sjhb } 805175164Sjhb 806175164Sjhb finit(fp, FFLAGS(uap->flags & O_ACCMODE), DTYPE_SHM, shmfd, &shm_ops); 807175164Sjhb 808175164Sjhb td->td_retval[0] = fd; 809175164Sjhb fdrop(fp, td); 810175164Sjhb 811175164Sjhb return (0); 812175164Sjhb} 813175164Sjhb 814175164Sjhbint 815225617Skmacysys_shm_unlink(struct thread *td, struct shm_unlink_args *uap) 816175164Sjhb{ 817175164Sjhb char *path; 818175164Sjhb Fnv32_t fnv; 819175164Sjhb int error; 820175164Sjhb 821175164Sjhb path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 822175164Sjhb error = copyinstr(uap->path, path, MAXPATHLEN, NULL); 823175164Sjhb if (error) { 824175164Sjhb free(path, M_TEMP); 825175164Sjhb return (error); 826175164Sjhb } 827175164Sjhb 828175164Sjhb fnv = fnv_32_str(path, FNV1_32_INIT); 829175164Sjhb sx_xlock(&shm_dict_lock); 830175164Sjhb error = shm_remove(path, fnv, td->td_ucred); 831175164Sjhb sx_xunlock(&shm_dict_lock); 832175164Sjhb free(path, M_TEMP); 833175164Sjhb 834175164Sjhb return (error); 835175164Sjhb} 836175164Sjhb 837175164Sjhb/* 838175164Sjhb * mmap() helper to validate mmap() requests against shm object state 839175164Sjhb * and give mmap() the vm_object to use for the mapping. 840175164Sjhb */ 841175164Sjhbint 842175164Sjhbshm_mmap(struct shmfd *shmfd, vm_size_t objsize, vm_ooffset_t foff, 843175164Sjhb vm_object_t *obj) 844175164Sjhb{ 845175164Sjhb 846175164Sjhb /* 847175164Sjhb * XXXRW: This validation is probably insufficient, and subject to 848175164Sjhb * sign errors. It should be fixed. 849175164Sjhb */ 850185533Skan if (foff >= shmfd->shm_size || 851185533Skan foff + objsize > round_page(shmfd->shm_size)) 852175164Sjhb return (EINVAL); 853175164Sjhb 854175164Sjhb mtx_lock(&shm_timestamp_lock); 855175164Sjhb vfs_timestamp(&shmfd->shm_atime); 856175164Sjhb mtx_unlock(&shm_timestamp_lock); 857175164Sjhb vm_object_reference(shmfd->shm_object); 858175164Sjhb *obj = shmfd->shm_object; 859175164Sjhb return (0); 860175164Sjhb} 861224914Skib 862224914Skibstatic int 863224914Skibshm_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 864224914Skib struct thread *td) 865224914Skib{ 866224914Skib struct shmfd *shmfd; 867224914Skib int error; 868224914Skib 869224914Skib error = 0; 870224914Skib shmfd = fp->f_data; 871224914Skib mtx_lock(&shm_timestamp_lock); 872224914Skib /* 873224914Skib * SUSv4 says that x bits of permission need not be affected. 874224914Skib * Be consistent with our shm_open there. 875224914Skib */ 876224914Skib#ifdef MAC 877224914Skib error = mac_posixshm_check_setmode(active_cred, shmfd, mode); 878224914Skib if (error != 0) 879224914Skib goto out; 880224914Skib#endif 881224914Skib error = vaccess(VREG, shmfd->shm_mode, shmfd->shm_uid, 882224914Skib shmfd->shm_gid, VADMIN, active_cred, NULL); 883224914Skib if (error != 0) 884224914Skib goto out; 885224914Skib shmfd->shm_mode = mode & ACCESSPERMS; 886224914Skibout: 887224914Skib mtx_unlock(&shm_timestamp_lock); 888224914Skib return (error); 889224914Skib} 890224914Skib 891224914Skibstatic int 892224914Skibshm_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 893224914Skib struct thread *td) 894224914Skib{ 895224914Skib struct shmfd *shmfd; 896224914Skib int error; 897224914Skib 898224935Skib error = 0; 899224914Skib shmfd = fp->f_data; 900224914Skib mtx_lock(&shm_timestamp_lock); 901224914Skib#ifdef MAC 902224914Skib error = mac_posixshm_check_setowner(active_cred, shmfd, uid, gid); 903224914Skib if (error != 0) 904224914Skib goto out; 905224914Skib#endif 906224914Skib if (uid == (uid_t)-1) 907224914Skib uid = shmfd->shm_uid; 908224914Skib if (gid == (gid_t)-1) 909224914Skib gid = shmfd->shm_gid; 910224914Skib if (((uid != shmfd->shm_uid && uid != active_cred->cr_uid) || 911224914Skib (gid != shmfd->shm_gid && !groupmember(gid, active_cred))) && 912224914Skib (error = priv_check_cred(active_cred, PRIV_VFS_CHOWN, 0))) 913224914Skib goto out; 914224914Skib shmfd->shm_uid = uid; 915224914Skib shmfd->shm_gid = gid; 916224914Skibout: 917224914Skib mtx_unlock(&shm_timestamp_lock); 918224914Skib return (error); 919224914Skib} 920228509Sjhb 921228509Sjhb/* 922228509Sjhb * Helper routines to allow the backing object of a shared memory file 923228509Sjhb * descriptor to be mapped in the kernel. 924228509Sjhb */ 925228509Sjhbint 926228509Sjhbshm_map(struct file *fp, size_t size, off_t offset, void **memp) 927228509Sjhb{ 928228509Sjhb struct shmfd *shmfd; 929228509Sjhb vm_offset_t kva, ofs; 930228509Sjhb vm_object_t obj; 931228509Sjhb int rv; 932228509Sjhb 933228509Sjhb if (fp->f_type != DTYPE_SHM) 934228509Sjhb return (EINVAL); 935228509Sjhb shmfd = fp->f_data; 936228509Sjhb obj = shmfd->shm_object; 937248084Sattilio VM_OBJECT_WLOCK(obj); 938228509Sjhb /* 939228509Sjhb * XXXRW: This validation is probably insufficient, and subject to 940228509Sjhb * sign errors. It should be fixed. 941228509Sjhb */ 942228509Sjhb if (offset >= shmfd->shm_size || 943228509Sjhb offset + size > round_page(shmfd->shm_size)) { 944248084Sattilio VM_OBJECT_WUNLOCK(obj); 945228509Sjhb return (EINVAL); 946228509Sjhb } 947228509Sjhb 948228509Sjhb shmfd->shm_kmappings++; 949228509Sjhb vm_object_reference_locked(obj); 950248084Sattilio VM_OBJECT_WUNLOCK(obj); 951228509Sjhb 952228509Sjhb /* Map the object into the kernel_map and wire it. */ 953228509Sjhb kva = vm_map_min(kernel_map); 954228509Sjhb ofs = offset & PAGE_MASK; 955228509Sjhb offset = trunc_page(offset); 956228509Sjhb size = round_page(size + ofs); 957255426Sjhb rv = vm_map_find(kernel_map, obj, offset, &kva, size, 0, 958253620Sjhb VMFS_OPTIMAL_SPACE, VM_PROT_READ | VM_PROT_WRITE, 959228509Sjhb VM_PROT_READ | VM_PROT_WRITE, 0); 960228509Sjhb if (rv == KERN_SUCCESS) { 961228509Sjhb rv = vm_map_wire(kernel_map, kva, kva + size, 962228509Sjhb VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 963228509Sjhb if (rv == KERN_SUCCESS) { 964228509Sjhb *memp = (void *)(kva + ofs); 965228509Sjhb return (0); 966228509Sjhb } 967228509Sjhb vm_map_remove(kernel_map, kva, kva + size); 968228509Sjhb } else 969228509Sjhb vm_object_deallocate(obj); 970228509Sjhb 971228509Sjhb /* On failure, drop our mapping reference. */ 972248084Sattilio VM_OBJECT_WLOCK(obj); 973228509Sjhb shmfd->shm_kmappings--; 974248084Sattilio VM_OBJECT_WUNLOCK(obj); 975228509Sjhb 976228533Sjhb return (vm_mmap_to_errno(rv)); 977228509Sjhb} 978228509Sjhb 979228509Sjhb/* 980228509Sjhb * We require the caller to unmap the entire entry. This allows us to 981228509Sjhb * safely decrement shm_kmappings when a mapping is removed. 982228509Sjhb */ 983228509Sjhbint 984228509Sjhbshm_unmap(struct file *fp, void *mem, size_t size) 985228509Sjhb{ 986228509Sjhb struct shmfd *shmfd; 987228509Sjhb vm_map_entry_t entry; 988228509Sjhb vm_offset_t kva, ofs; 989228509Sjhb vm_object_t obj; 990228509Sjhb vm_pindex_t pindex; 991228509Sjhb vm_prot_t prot; 992228509Sjhb boolean_t wired; 993228509Sjhb vm_map_t map; 994228509Sjhb int rv; 995228509Sjhb 996228509Sjhb if (fp->f_type != DTYPE_SHM) 997228509Sjhb return (EINVAL); 998228509Sjhb shmfd = fp->f_data; 999228509Sjhb kva = (vm_offset_t)mem; 1000228509Sjhb ofs = kva & PAGE_MASK; 1001228509Sjhb kva = trunc_page(kva); 1002228509Sjhb size = round_page(size + ofs); 1003228509Sjhb map = kernel_map; 1004228509Sjhb rv = vm_map_lookup(&map, kva, VM_PROT_READ | VM_PROT_WRITE, &entry, 1005228509Sjhb &obj, &pindex, &prot, &wired); 1006228509Sjhb if (rv != KERN_SUCCESS) 1007228509Sjhb return (EINVAL); 1008228509Sjhb if (entry->start != kva || entry->end != kva + size) { 1009228509Sjhb vm_map_lookup_done(map, entry); 1010228509Sjhb return (EINVAL); 1011228509Sjhb } 1012228509Sjhb vm_map_lookup_done(map, entry); 1013228509Sjhb if (obj != shmfd->shm_object) 1014228509Sjhb return (EINVAL); 1015228509Sjhb vm_map_remove(map, kva, kva + size); 1016248084Sattilio VM_OBJECT_WLOCK(obj); 1017228509Sjhb KASSERT(shmfd->shm_kmappings > 0, ("shm_unmap: object not mapped")); 1018228509Sjhb shmfd->shm_kmappings--; 1019248084Sattilio VM_OBJECT_WUNLOCK(obj); 1020228509Sjhb return (0); 1021228509Sjhb} 1022233760Sjhb 1023233760Sjhbvoid 1024233760Sjhbshm_path(struct shmfd *shmfd, char *path, size_t size) 1025233760Sjhb{ 1026233760Sjhb 1027233760Sjhb if (shmfd->shm_path == NULL) 1028233760Sjhb return; 1029233760Sjhb sx_slock(&shm_dict_lock); 1030233760Sjhb if (shmfd->shm_path != NULL) 1031233760Sjhb strlcpy(path, shmfd->shm_path, size); 1032233760Sjhb sx_sunlock(&shm_dict_lock); 1033233760Sjhb} 1034