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("$FreeBSD$"); 46175164Sjhb 47223692Sjonathan#include "opt_capsicum.h" 48269742Srpaulo#include "opt_ktrace.h" 49223692Sjonathan 50175164Sjhb#include <sys/param.h> 51223692Sjonathan#include <sys/capability.h> 52271399Sjhb#include <sys/conf.h> 53175164Sjhb#include <sys/fcntl.h> 54175164Sjhb#include <sys/file.h> 55175164Sjhb#include <sys/filedesc.h> 56175164Sjhb#include <sys/fnv_hash.h> 57175164Sjhb#include <sys/kernel.h> 58269742Srpaulo#include <sys/uio.h> 59269742Srpaulo#include <sys/signal.h> 60269742Srpaulo#include <sys/ktrace.h> 61175164Sjhb#include <sys/lock.h> 62175164Sjhb#include <sys/malloc.h> 63175164Sjhb#include <sys/mman.h> 64175164Sjhb#include <sys/mutex.h> 65224914Skib#include <sys/priv.h> 66175164Sjhb#include <sys/proc.h> 67175164Sjhb#include <sys/refcount.h> 68175164Sjhb#include <sys/resourcevar.h> 69248084Sattilio#include <sys/rwlock.h> 70175164Sjhb#include <sys/stat.h> 71175164Sjhb#include <sys/sysctl.h> 72175164Sjhb#include <sys/sysproto.h> 73175164Sjhb#include <sys/systm.h> 74175164Sjhb#include <sys/sx.h> 75175164Sjhb#include <sys/time.h> 76175164Sjhb#include <sys/vnode.h> 77254603Skib#include <sys/unistd.h> 78175164Sjhb 79175164Sjhb#include <security/mac/mac_framework.h> 80175164Sjhb 81175164Sjhb#include <vm/vm.h> 82175164Sjhb#include <vm/vm_param.h> 83175164Sjhb#include <vm/pmap.h> 84228533Sjhb#include <vm/vm_extern.h> 85175164Sjhb#include <vm/vm_map.h> 86228509Sjhb#include <vm/vm_kern.h> 87175164Sjhb#include <vm/vm_object.h> 88175164Sjhb#include <vm/vm_page.h> 89229821Salc#include <vm/vm_pageout.h> 90175164Sjhb#include <vm/vm_pager.h> 91175164Sjhb#include <vm/swap_pager.h> 92175164Sjhb 93175164Sjhbstruct shm_mapping { 94175164Sjhb char *sm_path; 95175164Sjhb Fnv32_t sm_fnv; 96175164Sjhb struct shmfd *sm_shmfd; 97175164Sjhb LIST_ENTRY(shm_mapping) sm_link; 98175164Sjhb}; 99175164Sjhb 100175164Sjhbstatic MALLOC_DEFINE(M_SHMFD, "shmfd", "shared memory file descriptor"); 101175164Sjhbstatic LIST_HEAD(, shm_mapping) *shm_dictionary; 102175164Sjhbstatic struct sx shm_dict_lock; 103175164Sjhbstatic struct mtx shm_timestamp_lock; 104175164Sjhbstatic u_long shm_hash; 105271399Sjhbstatic struct unrhdr *shm_ino_unr; 106271399Sjhbstatic dev_t shm_dev_ino; 107175164Sjhb 108175164Sjhb#define SHM_HASH(fnv) (&shm_dictionary[(fnv) & shm_hash]) 109175164Sjhb 110175164Sjhbstatic int shm_access(struct shmfd *shmfd, struct ucred *ucred, int flags); 111175164Sjhbstatic struct shmfd *shm_alloc(struct ucred *ucred, mode_t mode); 112271399Sjhbstatic void shm_init(void *arg); 113175164Sjhbstatic void shm_drop(struct shmfd *shmfd); 114175164Sjhbstatic struct shmfd *shm_hold(struct shmfd *shmfd); 115175164Sjhbstatic void shm_insert(char *path, Fnv32_t fnv, struct shmfd *shmfd); 116175164Sjhbstatic struct shmfd *shm_lookup(char *path, Fnv32_t fnv); 117175164Sjhbstatic int shm_remove(char *path, Fnv32_t fnv, struct ucred *ucred); 118194766Skibstatic int shm_dotruncate(struct shmfd *shmfd, off_t length); 119175164Sjhb 120175164Sjhbstatic fo_rdwr_t shm_read; 121175164Sjhbstatic fo_rdwr_t shm_write; 122175164Sjhbstatic fo_truncate_t shm_truncate; 123175164Sjhbstatic fo_ioctl_t shm_ioctl; 124175164Sjhbstatic fo_poll_t shm_poll; 125175164Sjhbstatic fo_kqfilter_t shm_kqfilter; 126175164Sjhbstatic fo_stat_t shm_stat; 127175164Sjhbstatic fo_close_t shm_close; 128224914Skibstatic fo_chmod_t shm_chmod; 129224914Skibstatic fo_chown_t shm_chown; 130254603Skibstatic fo_seek_t shm_seek; 131175164Sjhb 132175164Sjhb/* File descriptor operations. */ 133175164Sjhbstatic struct fileops shm_ops = { 134175164Sjhb .fo_read = shm_read, 135175164Sjhb .fo_write = shm_write, 136175164Sjhb .fo_truncate = shm_truncate, 137175164Sjhb .fo_ioctl = shm_ioctl, 138175164Sjhb .fo_poll = shm_poll, 139175164Sjhb .fo_kqfilter = shm_kqfilter, 140175164Sjhb .fo_stat = shm_stat, 141175164Sjhb .fo_close = shm_close, 142224914Skib .fo_chmod = shm_chmod, 143224914Skib .fo_chown = shm_chown, 144255467Skib .fo_sendfile = vn_sendfile, 145254603Skib .fo_seek = shm_seek, 146254603Skib .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 147175164Sjhb}; 148175164Sjhb 149175164SjhbFEATURE(posix_shm, "POSIX shared memory"); 150175164Sjhb 151175164Sjhbstatic int 152254601Skibuiomove_object_page(vm_object_t obj, size_t len, struct uio *uio) 153254601Skib{ 154254601Skib vm_page_t m; 155254601Skib vm_pindex_t idx; 156254601Skib size_t tlen; 157254601Skib int error, offset, rv; 158254601Skib 159254601Skib idx = OFF_TO_IDX(uio->uio_offset); 160254601Skib offset = uio->uio_offset & PAGE_MASK; 161254601Skib tlen = MIN(PAGE_SIZE - offset, len); 162254601Skib 163254601Skib VM_OBJECT_WLOCK(obj); 164254601Skib 165254601Skib /* 166254601Skib * Parallel reads of the page content from disk are prevented 167254601Skib * by exclusive busy. 168254601Skib * 169254601Skib * Although the tmpfs vnode lock is held here, it is 170254601Skib * nonetheless safe to sleep waiting for a free page. The 171254601Skib * pageout daemon does not need to acquire the tmpfs vnode 172254601Skib * lock to page out tobj's pages because tobj is a OBJT_SWAP 173254601Skib * type object. 174254601Skib */ 175254649Skib m = vm_page_grab(obj, idx, VM_ALLOC_NORMAL); 176254601Skib if (m->valid != VM_PAGE_BITS_ALL) { 177254601Skib if (vm_pager_has_page(obj, idx, NULL, NULL)) { 178254601Skib rv = vm_pager_get_pages(obj, &m, 1, 0); 179254601Skib m = vm_page_lookup(obj, idx); 180254601Skib if (m == NULL) { 181254601Skib printf( 182254601Skib "uiomove_object: vm_obj %p idx %jd null lookup rv %d\n", 183254601Skib obj, idx, rv); 184254601Skib VM_OBJECT_WUNLOCK(obj); 185254601Skib return (EIO); 186254601Skib } 187254601Skib if (rv != VM_PAGER_OK) { 188254601Skib printf( 189254601Skib "uiomove_object: vm_obj %p idx %jd valid %x pager error %d\n", 190254601Skib obj, idx, m->valid, rv); 191254601Skib vm_page_lock(m); 192254601Skib vm_page_free(m); 193254601Skib vm_page_unlock(m); 194254601Skib VM_OBJECT_WUNLOCK(obj); 195254601Skib return (EIO); 196254601Skib } 197254601Skib } else 198254601Skib vm_page_zero_invalid(m, TRUE); 199254601Skib } 200254601Skib vm_page_xunbusy(m); 201254601Skib vm_page_lock(m); 202254601Skib vm_page_hold(m); 203270205Skib if (m->queue == PQ_NONE) { 204270205Skib vm_page_deactivate(m); 205270205Skib } else { 206270205Skib /* Requeue to maintain LRU ordering. */ 207270205Skib vm_page_requeue(m); 208270205Skib } 209254601Skib vm_page_unlock(m); 210254601Skib VM_OBJECT_WUNLOCK(obj); 211254601Skib error = uiomove_fromphys(&m, offset, tlen, uio); 212254601Skib if (uio->uio_rw == UIO_WRITE && error == 0) { 213254601Skib VM_OBJECT_WLOCK(obj); 214254601Skib vm_page_dirty(m); 215269495Skib vm_pager_page_unswapped(m); 216254601Skib VM_OBJECT_WUNLOCK(obj); 217254601Skib } 218254601Skib vm_page_lock(m); 219254601Skib vm_page_unhold(m); 220254601Skib vm_page_unlock(m); 221254601Skib 222254601Skib return (error); 223254601Skib} 224254601Skib 225254601Skibint 226254601Skibuiomove_object(vm_object_t obj, off_t obj_size, struct uio *uio) 227254601Skib{ 228254601Skib ssize_t resid; 229254601Skib size_t len; 230254601Skib int error; 231254601Skib 232254601Skib error = 0; 233254601Skib while ((resid = uio->uio_resid) > 0) { 234254601Skib if (obj_size <= uio->uio_offset) 235254601Skib break; 236254601Skib len = MIN(obj_size - uio->uio_offset, resid); 237254601Skib if (len == 0) 238254601Skib break; 239254601Skib error = uiomove_object_page(obj, len, uio); 240254601Skib if (error != 0 || resid == uio->uio_resid) 241254601Skib break; 242254601Skib } 243254601Skib return (error); 244254601Skib} 245254601Skib 246254601Skibstatic int 247254603Skibshm_seek(struct file *fp, off_t offset, int whence, struct thread *td) 248254603Skib{ 249254603Skib struct shmfd *shmfd; 250254603Skib off_t foffset; 251254603Skib int error; 252254603Skib 253254603Skib shmfd = fp->f_data; 254254603Skib foffset = foffset_lock(fp, 0); 255254603Skib error = 0; 256254603Skib switch (whence) { 257254603Skib case L_INCR: 258254603Skib if (foffset < 0 || 259254603Skib (offset > 0 && foffset > OFF_MAX - offset)) { 260254603Skib error = EOVERFLOW; 261254603Skib break; 262254603Skib } 263254603Skib offset += foffset; 264254603Skib break; 265254603Skib case L_XTND: 266254603Skib if (offset > 0 && shmfd->shm_size > OFF_MAX - offset) { 267254603Skib error = EOVERFLOW; 268254603Skib break; 269254603Skib } 270254603Skib offset += shmfd->shm_size; 271254603Skib break; 272254603Skib case L_SET: 273254603Skib break; 274254603Skib default: 275254603Skib error = EINVAL; 276254603Skib } 277254603Skib if (error == 0) { 278254603Skib if (offset < 0 || offset > shmfd->shm_size) 279254603Skib error = EINVAL; 280254603Skib else 281254603Skib *(off_t *)(td->td_retval) = offset; 282254603Skib } 283254603Skib foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 284254603Skib return (error); 285254603Skib} 286254603Skib 287254603Skibstatic int 288175164Sjhbshm_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 289175164Sjhb int flags, struct thread *td) 290175164Sjhb{ 291254603Skib struct shmfd *shmfd; 292254603Skib void *rl_cookie; 293254603Skib int error; 294175164Sjhb 295254603Skib shmfd = fp->f_data; 296254603Skib foffset_lock_uio(fp, uio, flags); 297254603Skib rl_cookie = rangelock_rlock(&shmfd->shm_rl, uio->uio_offset, 298254603Skib uio->uio_offset + uio->uio_resid, &shmfd->shm_mtx); 299254603Skib#ifdef MAC 300254603Skib error = mac_posixshm_check_read(active_cred, fp->f_cred, shmfd); 301254603Skib if (error) 302254603Skib return (error); 303254603Skib#endif 304254603Skib error = uiomove_object(shmfd->shm_object, shmfd->shm_size, uio); 305254603Skib rangelock_unlock(&shmfd->shm_rl, rl_cookie, &shmfd->shm_mtx); 306254603Skib foffset_unlock_uio(fp, uio, flags); 307254603Skib return (error); 308175164Sjhb} 309175164Sjhb 310175164Sjhbstatic int 311175164Sjhbshm_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 312175164Sjhb int flags, struct thread *td) 313175164Sjhb{ 314254603Skib struct shmfd *shmfd; 315254603Skib void *rl_cookie; 316254603Skib int error; 317175164Sjhb 318254603Skib shmfd = fp->f_data; 319254603Skib#ifdef MAC 320254603Skib error = mac_posixshm_check_write(active_cred, fp->f_cred, shmfd); 321254603Skib if (error) 322254603Skib return (error); 323254603Skib#endif 324254603Skib foffset_lock_uio(fp, uio, flags); 325254603Skib if ((flags & FOF_OFFSET) == 0) { 326254603Skib rl_cookie = rangelock_wlock(&shmfd->shm_rl, 0, OFF_MAX, 327254603Skib &shmfd->shm_mtx); 328254603Skib } else { 329254603Skib rl_cookie = rangelock_wlock(&shmfd->shm_rl, uio->uio_offset, 330254603Skib uio->uio_offset + uio->uio_resid, &shmfd->shm_mtx); 331254603Skib } 332254603Skib 333254603Skib error = uiomove_object(shmfd->shm_object, shmfd->shm_size, uio); 334254603Skib rangelock_unlock(&shmfd->shm_rl, rl_cookie, &shmfd->shm_mtx); 335254603Skib foffset_unlock_uio(fp, uio, flags); 336254603Skib return (error); 337175164Sjhb} 338175164Sjhb 339175164Sjhbstatic int 340175164Sjhbshm_truncate(struct file *fp, off_t length, struct ucred *active_cred, 341175164Sjhb struct thread *td) 342175164Sjhb{ 343175164Sjhb struct shmfd *shmfd; 344175164Sjhb#ifdef MAC 345175164Sjhb int error; 346175164Sjhb#endif 347175164Sjhb 348175164Sjhb shmfd = fp->f_data; 349175164Sjhb#ifdef MAC 350175164Sjhb error = mac_posixshm_check_truncate(active_cred, fp->f_cred, shmfd); 351175164Sjhb if (error) 352175164Sjhb return (error); 353175164Sjhb#endif 354194766Skib return (shm_dotruncate(shmfd, length)); 355175164Sjhb} 356175164Sjhb 357175164Sjhbstatic int 358175164Sjhbshm_ioctl(struct file *fp, u_long com, void *data, 359175164Sjhb struct ucred *active_cred, struct thread *td) 360175164Sjhb{ 361175164Sjhb 362175164Sjhb return (EOPNOTSUPP); 363175164Sjhb} 364175164Sjhb 365175164Sjhbstatic int 366175164Sjhbshm_poll(struct file *fp, int events, struct ucred *active_cred, 367175164Sjhb struct thread *td) 368175164Sjhb{ 369175164Sjhb 370175164Sjhb return (EOPNOTSUPP); 371175164Sjhb} 372175164Sjhb 373175164Sjhbstatic int 374175164Sjhbshm_kqfilter(struct file *fp, struct knote *kn) 375175164Sjhb{ 376175164Sjhb 377175164Sjhb return (EOPNOTSUPP); 378175164Sjhb} 379175164Sjhb 380175164Sjhbstatic int 381175164Sjhbshm_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 382175164Sjhb struct thread *td) 383175164Sjhb{ 384175164Sjhb struct shmfd *shmfd; 385175164Sjhb#ifdef MAC 386175164Sjhb int error; 387175164Sjhb#endif 388175164Sjhb 389175164Sjhb shmfd = fp->f_data; 390175164Sjhb 391175164Sjhb#ifdef MAC 392175164Sjhb error = mac_posixshm_check_stat(active_cred, fp->f_cred, shmfd); 393175164Sjhb if (error) 394175164Sjhb return (error); 395175164Sjhb#endif 396175164Sjhb 397175164Sjhb /* 398175164Sjhb * Attempt to return sanish values for fstat() on a memory file 399175164Sjhb * descriptor. 400175164Sjhb */ 401175164Sjhb bzero(sb, sizeof(*sb)); 402175164Sjhb sb->st_blksize = PAGE_SIZE; 403175164Sjhb sb->st_size = shmfd->shm_size; 404175164Sjhb sb->st_blocks = (sb->st_size + sb->st_blksize - 1) / sb->st_blksize; 405224914Skib mtx_lock(&shm_timestamp_lock); 406205792Sed sb->st_atim = shmfd->shm_atime; 407205792Sed sb->st_ctim = shmfd->shm_ctime; 408205792Sed sb->st_mtim = shmfd->shm_mtime; 409224914Skib sb->st_birthtim = shmfd->shm_birthtime; 410224914Skib sb->st_mode = S_IFREG | shmfd->shm_mode; /* XXX */ 411175164Sjhb sb->st_uid = shmfd->shm_uid; 412175164Sjhb sb->st_gid = shmfd->shm_gid; 413224914Skib mtx_unlock(&shm_timestamp_lock); 414271399Sjhb sb->st_dev = shm_dev_ino; 415271399Sjhb sb->st_ino = shmfd->shm_ino; 416175164Sjhb 417175164Sjhb return (0); 418175164Sjhb} 419175164Sjhb 420175164Sjhbstatic int 421175164Sjhbshm_close(struct file *fp, struct thread *td) 422175164Sjhb{ 423175164Sjhb struct shmfd *shmfd; 424175164Sjhb 425175164Sjhb shmfd = fp->f_data; 426175164Sjhb fp->f_data = NULL; 427175164Sjhb shm_drop(shmfd); 428175164Sjhb 429175164Sjhb return (0); 430175164Sjhb} 431175164Sjhb 432194766Skibstatic int 433175164Sjhbshm_dotruncate(struct shmfd *shmfd, off_t length) 434175164Sjhb{ 435175164Sjhb vm_object_t object; 436229821Salc vm_page_t m, ma[1]; 437229821Salc vm_pindex_t idx, nobjsize; 438194766Skib vm_ooffset_t delta; 439229821Salc int base, rv; 440175164Sjhb 441175164Sjhb object = shmfd->shm_object; 442248084Sattilio VM_OBJECT_WLOCK(object); 443175164Sjhb if (length == shmfd->shm_size) { 444248084Sattilio VM_OBJECT_WUNLOCK(object); 445194766Skib return (0); 446175164Sjhb } 447175164Sjhb nobjsize = OFF_TO_IDX(length + PAGE_MASK); 448175164Sjhb 449175164Sjhb /* Are we shrinking? If so, trim the end. */ 450175164Sjhb if (length < shmfd->shm_size) { 451228509Sjhb /* 452228509Sjhb * Disallow any requests to shrink the size if this 453228509Sjhb * object is mapped into the kernel. 454228509Sjhb */ 455228509Sjhb if (shmfd->shm_kmappings > 0) { 456248084Sattilio VM_OBJECT_WUNLOCK(object); 457228509Sjhb return (EBUSY); 458228509Sjhb } 459229821Salc 460229821Salc /* 461229821Salc * Zero the truncated part of the last page. 462229821Salc */ 463229821Salc base = length & PAGE_MASK; 464229821Salc if (base != 0) { 465229821Salc idx = OFF_TO_IDX(length); 466229821Salcretry: 467229821Salc m = vm_page_lookup(object, idx); 468229821Salc if (m != NULL) { 469254138Sattilio if (vm_page_sleep_if_busy(m, "shmtrc")) 470229821Salc goto retry; 471229821Salc } else if (vm_pager_has_page(object, idx, NULL, NULL)) { 472229821Salc m = vm_page_alloc(object, idx, VM_ALLOC_NORMAL); 473229821Salc if (m == NULL) { 474248084Sattilio VM_OBJECT_WUNLOCK(object); 475229821Salc VM_WAIT; 476248084Sattilio VM_OBJECT_WLOCK(object); 477229821Salc goto retry; 478229821Salc } else if (m->valid != VM_PAGE_BITS_ALL) { 479229821Salc ma[0] = m; 480229821Salc rv = vm_pager_get_pages(object, ma, 1, 481229821Salc 0); 482229821Salc m = vm_page_lookup(object, idx); 483229821Salc } else 484229821Salc /* A cached page was reactivated. */ 485229821Salc rv = VM_PAGER_OK; 486229821Salc vm_page_lock(m); 487229821Salc if (rv == VM_PAGER_OK) { 488229821Salc vm_page_deactivate(m); 489229821Salc vm_page_unlock(m); 490254138Sattilio vm_page_xunbusy(m); 491229821Salc } else { 492229821Salc vm_page_free(m); 493229821Salc vm_page_unlock(m); 494248084Sattilio VM_OBJECT_WUNLOCK(object); 495229821Salc return (EIO); 496229821Salc } 497229821Salc } 498229821Salc if (m != NULL) { 499229821Salc pmap_zero_page_area(m, base, PAGE_SIZE - base); 500229821Salc KASSERT(m->valid == VM_PAGE_BITS_ALL, 501229821Salc ("shm_dotruncate: page %p is invalid", m)); 502229821Salc vm_page_dirty(m); 503229821Salc vm_pager_page_unswapped(m); 504229821Salc } 505229821Salc } 506194766Skib delta = ptoa(object->size - nobjsize); 507194766Skib 508175164Sjhb /* Toss in memory pages. */ 509175164Sjhb if (nobjsize < object->size) 510175164Sjhb vm_object_page_remove(object, nobjsize, object->size, 511223677Salc 0); 512175164Sjhb 513175164Sjhb /* Toss pages from swap. */ 514175164Sjhb if (object->type == OBJT_SWAP) 515194766Skib swap_pager_freespace(object, nobjsize, delta); 516175164Sjhb 517194766Skib /* Free the swap accounted for shm */ 518216128Strasz swap_release_by_cred(delta, object->cred); 519194766Skib object->charge -= delta; 520194766Skib } else { 521194766Skib /* Attempt to reserve the swap */ 522194766Skib delta = ptoa(nobjsize - object->size); 523216128Strasz if (!swap_reserve_by_cred(delta, object->cred)) { 524248084Sattilio VM_OBJECT_WUNLOCK(object); 525194766Skib return (ENOMEM); 526194766Skib } 527194766Skib object->charge += delta; 528175164Sjhb } 529175164Sjhb shmfd->shm_size = length; 530175164Sjhb mtx_lock(&shm_timestamp_lock); 531175164Sjhb vfs_timestamp(&shmfd->shm_ctime); 532175164Sjhb shmfd->shm_mtime = shmfd->shm_ctime; 533175164Sjhb mtx_unlock(&shm_timestamp_lock); 534175164Sjhb object->size = nobjsize; 535248084Sattilio VM_OBJECT_WUNLOCK(object); 536194766Skib return (0); 537175164Sjhb} 538175164Sjhb 539175164Sjhb/* 540175164Sjhb * shmfd object management including creation and reference counting 541175164Sjhb * routines. 542175164Sjhb */ 543175164Sjhbstatic struct shmfd * 544175164Sjhbshm_alloc(struct ucred *ucred, mode_t mode) 545175164Sjhb{ 546175164Sjhb struct shmfd *shmfd; 547271399Sjhb int ino; 548175164Sjhb 549175164Sjhb shmfd = malloc(sizeof(*shmfd), M_SHMFD, M_WAITOK | M_ZERO); 550175164Sjhb shmfd->shm_size = 0; 551175164Sjhb shmfd->shm_uid = ucred->cr_uid; 552175164Sjhb shmfd->shm_gid = ucred->cr_gid; 553175164Sjhb shmfd->shm_mode = mode; 554175164Sjhb shmfd->shm_object = vm_pager_allocate(OBJT_DEFAULT, NULL, 555194766Skib shmfd->shm_size, VM_PROT_DEFAULT, 0, ucred); 556175164Sjhb KASSERT(shmfd->shm_object != NULL, ("shm_create: vm_pager_allocate")); 557248084Sattilio VM_OBJECT_WLOCK(shmfd->shm_object); 558178181Salc vm_object_clear_flag(shmfd->shm_object, OBJ_ONEMAPPING); 559178181Salc vm_object_set_flag(shmfd->shm_object, OBJ_NOSPLIT); 560248084Sattilio VM_OBJECT_WUNLOCK(shmfd->shm_object); 561175164Sjhb vfs_timestamp(&shmfd->shm_birthtime); 562175164Sjhb shmfd->shm_atime = shmfd->shm_mtime = shmfd->shm_ctime = 563175164Sjhb shmfd->shm_birthtime; 564271399Sjhb ino = alloc_unr(shm_ino_unr); 565271399Sjhb if (ino == -1) 566271399Sjhb shmfd->shm_ino = 0; 567271399Sjhb else 568271399Sjhb shmfd->shm_ino = ino; 569175164Sjhb refcount_init(&shmfd->shm_refs, 1); 570254603Skib mtx_init(&shmfd->shm_mtx, "shmrl", NULL, MTX_DEF); 571254603Skib rangelock_init(&shmfd->shm_rl); 572175164Sjhb#ifdef MAC 573175164Sjhb mac_posixshm_init(shmfd); 574175164Sjhb mac_posixshm_create(ucred, shmfd); 575175164Sjhb#endif 576175164Sjhb 577175164Sjhb return (shmfd); 578175164Sjhb} 579175164Sjhb 580175164Sjhbstatic struct shmfd * 581175164Sjhbshm_hold(struct shmfd *shmfd) 582175164Sjhb{ 583175164Sjhb 584175164Sjhb refcount_acquire(&shmfd->shm_refs); 585175164Sjhb return (shmfd); 586175164Sjhb} 587175164Sjhb 588175164Sjhbstatic void 589175164Sjhbshm_drop(struct shmfd *shmfd) 590175164Sjhb{ 591175164Sjhb 592175164Sjhb if (refcount_release(&shmfd->shm_refs)) { 593175164Sjhb#ifdef MAC 594175164Sjhb mac_posixshm_destroy(shmfd); 595175164Sjhb#endif 596254603Skib rangelock_destroy(&shmfd->shm_rl); 597254603Skib mtx_destroy(&shmfd->shm_mtx); 598175164Sjhb vm_object_deallocate(shmfd->shm_object); 599271399Sjhb if (shmfd->shm_ino != 0) 600271399Sjhb free_unr(shm_ino_unr, shmfd->shm_ino); 601175164Sjhb free(shmfd, M_SHMFD); 602175164Sjhb } 603175164Sjhb} 604175164Sjhb 605175164Sjhb/* 606175164Sjhb * Determine if the credentials have sufficient permissions for a 607175164Sjhb * specified combination of FREAD and FWRITE. 608175164Sjhb */ 609175164Sjhbstatic int 610175164Sjhbshm_access(struct shmfd *shmfd, struct ucred *ucred, int flags) 611175164Sjhb{ 612184413Strasz accmode_t accmode; 613224914Skib int error; 614175164Sjhb 615184413Strasz accmode = 0; 616175164Sjhb if (flags & FREAD) 617184413Strasz accmode |= VREAD; 618175164Sjhb if (flags & FWRITE) 619184413Strasz accmode |= VWRITE; 620224914Skib mtx_lock(&shm_timestamp_lock); 621224914Skib error = vaccess(VREG, shmfd->shm_mode, shmfd->shm_uid, shmfd->shm_gid, 622224914Skib accmode, ucred, NULL); 623224914Skib mtx_unlock(&shm_timestamp_lock); 624224914Skib return (error); 625175164Sjhb} 626175164Sjhb 627175164Sjhb/* 628175164Sjhb * Dictionary management. We maintain an in-kernel dictionary to map 629175164Sjhb * paths to shmfd objects. We use the FNV hash on the path to store 630175164Sjhb * the mappings in a hash table. 631175164Sjhb */ 632175164Sjhbstatic void 633271399Sjhbshm_init(void *arg) 634175164Sjhb{ 635175164Sjhb 636175164Sjhb mtx_init(&shm_timestamp_lock, "shm timestamps", NULL, MTX_DEF); 637175164Sjhb sx_init(&shm_dict_lock, "shm dictionary"); 638175164Sjhb shm_dictionary = hashinit(1024, M_SHMFD, &shm_hash); 639271399Sjhb shm_ino_unr = new_unrhdr(1, INT32_MAX, NULL); 640271399Sjhb KASSERT(shm_ino_unr != NULL, ("shm fake inodes not initialized")); 641271399Sjhb shm_dev_ino = devfs_alloc_cdp_inode(); 642271399Sjhb KASSERT(shm_dev_ino > 0, ("shm dev inode not initialized")); 643175164Sjhb} 644271399SjhbSYSINIT(shm_init, SI_SUB_SYSV_SHM, SI_ORDER_ANY, shm_init, NULL); 645175164Sjhb 646175164Sjhbstatic struct shmfd * 647175164Sjhbshm_lookup(char *path, Fnv32_t fnv) 648175164Sjhb{ 649175164Sjhb struct shm_mapping *map; 650175164Sjhb 651175164Sjhb LIST_FOREACH(map, SHM_HASH(fnv), sm_link) { 652175164Sjhb if (map->sm_fnv != fnv) 653175164Sjhb continue; 654175164Sjhb if (strcmp(map->sm_path, path) == 0) 655175164Sjhb return (map->sm_shmfd); 656175164Sjhb } 657175164Sjhb 658175164Sjhb return (NULL); 659175164Sjhb} 660175164Sjhb 661175164Sjhbstatic void 662175164Sjhbshm_insert(char *path, Fnv32_t fnv, struct shmfd *shmfd) 663175164Sjhb{ 664175164Sjhb struct shm_mapping *map; 665175164Sjhb 666175164Sjhb map = malloc(sizeof(struct shm_mapping), M_SHMFD, M_WAITOK); 667175164Sjhb map->sm_path = path; 668175164Sjhb map->sm_fnv = fnv; 669175164Sjhb map->sm_shmfd = shm_hold(shmfd); 670233760Sjhb shmfd->shm_path = path; 671175164Sjhb LIST_INSERT_HEAD(SHM_HASH(fnv), map, sm_link); 672175164Sjhb} 673175164Sjhb 674175164Sjhbstatic int 675175164Sjhbshm_remove(char *path, Fnv32_t fnv, struct ucred *ucred) 676175164Sjhb{ 677175164Sjhb struct shm_mapping *map; 678175164Sjhb int error; 679175164Sjhb 680175164Sjhb LIST_FOREACH(map, SHM_HASH(fnv), sm_link) { 681175164Sjhb if (map->sm_fnv != fnv) 682175164Sjhb continue; 683175164Sjhb if (strcmp(map->sm_path, path) == 0) { 684175164Sjhb#ifdef MAC 685175164Sjhb error = mac_posixshm_check_unlink(ucred, map->sm_shmfd); 686175164Sjhb if (error) 687175164Sjhb return (error); 688175164Sjhb#endif 689175164Sjhb error = shm_access(map->sm_shmfd, ucred, 690175164Sjhb FREAD | FWRITE); 691175164Sjhb if (error) 692175164Sjhb return (error); 693233760Sjhb map->sm_shmfd->shm_path = NULL; 694175164Sjhb LIST_REMOVE(map, sm_link); 695175164Sjhb shm_drop(map->sm_shmfd); 696175164Sjhb free(map->sm_path, M_SHMFD); 697175164Sjhb free(map, M_SHMFD); 698175164Sjhb return (0); 699175164Sjhb } 700175164Sjhb } 701175164Sjhb 702175164Sjhb return (ENOENT); 703175164Sjhb} 704175164Sjhb 705175164Sjhb/* System calls. */ 706175164Sjhbint 707225617Skmacysys_shm_open(struct thread *td, struct shm_open_args *uap) 708175164Sjhb{ 709175164Sjhb struct filedesc *fdp; 710175164Sjhb struct shmfd *shmfd; 711175164Sjhb struct file *fp; 712175164Sjhb char *path; 713175164Sjhb Fnv32_t fnv; 714175164Sjhb mode_t cmode; 715175164Sjhb int fd, error; 716175164Sjhb 717223692Sjonathan#ifdef CAPABILITY_MODE 718223692Sjonathan /* 719223692Sjonathan * shm_open(2) is only allowed for anonymous objects. 720223692Sjonathan */ 721223692Sjonathan if (IN_CAPABILITY_MODE(td) && (uap->path != SHM_ANON)) 722223692Sjonathan return (ECAPMODE); 723223692Sjonathan#endif 724223692Sjonathan 725175164Sjhb if ((uap->flags & O_ACCMODE) != O_RDONLY && 726175164Sjhb (uap->flags & O_ACCMODE) != O_RDWR) 727175164Sjhb return (EINVAL); 728175164Sjhb 729261329Srmh if ((uap->flags & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC | O_CLOEXEC)) != 0) 730175164Sjhb return (EINVAL); 731175164Sjhb 732175164Sjhb fdp = td->td_proc->p_fd; 733175164Sjhb cmode = (uap->mode & ~fdp->fd_cmask) & ACCESSPERMS; 734175164Sjhb 735249233Sjilles error = falloc(td, &fp, &fd, O_CLOEXEC); 736175164Sjhb if (error) 737175164Sjhb return (error); 738175164Sjhb 739175164Sjhb /* A SHM_ANON path pointer creates an anonymous object. */ 740175164Sjhb if (uap->path == SHM_ANON) { 741175164Sjhb /* A read-only anonymous object is pointless. */ 742175164Sjhb if ((uap->flags & O_ACCMODE) == O_RDONLY) { 743175164Sjhb fdclose(fdp, fp, fd, td); 744175164Sjhb fdrop(fp, td); 745175164Sjhb return (EINVAL); 746175164Sjhb } 747175164Sjhb shmfd = shm_alloc(td->td_ucred, cmode); 748175164Sjhb } else { 749175164Sjhb path = malloc(MAXPATHLEN, M_SHMFD, M_WAITOK); 750175164Sjhb error = copyinstr(uap->path, path, MAXPATHLEN, NULL); 751269742Srpaulo#ifdef KTRACE 752269742Srpaulo if (error == 0 && KTRPOINT(curthread, KTR_NAMEI)) 753269742Srpaulo ktrnamei(path); 754269742Srpaulo#endif 755175164Sjhb /* Require paths to start with a '/' character. */ 756175164Sjhb if (error == 0 && path[0] != '/') 757175164Sjhb error = EINVAL; 758175164Sjhb if (error) { 759175164Sjhb fdclose(fdp, fp, fd, td); 760175164Sjhb fdrop(fp, td); 761175164Sjhb free(path, M_SHMFD); 762175164Sjhb return (error); 763175164Sjhb } 764175164Sjhb 765175164Sjhb fnv = fnv_32_str(path, FNV1_32_INIT); 766175164Sjhb sx_xlock(&shm_dict_lock); 767175164Sjhb shmfd = shm_lookup(path, fnv); 768175164Sjhb if (shmfd == NULL) { 769175164Sjhb /* Object does not yet exist, create it if requested. */ 770175164Sjhb if (uap->flags & O_CREAT) { 771225344Srwatson#ifdef MAC 772225344Srwatson error = mac_posixshm_check_create(td->td_ucred, 773225344Srwatson path); 774225344Srwatson if (error == 0) { 775225344Srwatson#endif 776225344Srwatson shmfd = shm_alloc(td->td_ucred, cmode); 777225344Srwatson shm_insert(path, fnv, shmfd); 778225344Srwatson#ifdef MAC 779225344Srwatson } 780225344Srwatson#endif 781175164Sjhb } else { 782175164Sjhb free(path, M_SHMFD); 783175164Sjhb error = ENOENT; 784175164Sjhb } 785175164Sjhb } else { 786175164Sjhb /* 787175164Sjhb * Object already exists, obtain a new 788175164Sjhb * reference if requested and permitted. 789175164Sjhb */ 790175164Sjhb free(path, M_SHMFD); 791175164Sjhb if ((uap->flags & (O_CREAT | O_EXCL)) == 792175164Sjhb (O_CREAT | O_EXCL)) 793175164Sjhb error = EEXIST; 794175164Sjhb else { 795175164Sjhb#ifdef MAC 796175164Sjhb error = mac_posixshm_check_open(td->td_ucred, 797225344Srwatson shmfd, FFLAGS(uap->flags & O_ACCMODE)); 798175164Sjhb if (error == 0) 799175164Sjhb#endif 800175164Sjhb error = shm_access(shmfd, td->td_ucred, 801175164Sjhb FFLAGS(uap->flags & O_ACCMODE)); 802175164Sjhb } 803175164Sjhb 804175164Sjhb /* 805175164Sjhb * Truncate the file back to zero length if 806175164Sjhb * O_TRUNC was specified and the object was 807175164Sjhb * opened with read/write. 808175164Sjhb */ 809175164Sjhb if (error == 0 && 810175164Sjhb (uap->flags & (O_ACCMODE | O_TRUNC)) == 811175164Sjhb (O_RDWR | O_TRUNC)) { 812175164Sjhb#ifdef MAC 813175164Sjhb error = mac_posixshm_check_truncate( 814175164Sjhb td->td_ucred, fp->f_cred, shmfd); 815175164Sjhb if (error == 0) 816175164Sjhb#endif 817175164Sjhb shm_dotruncate(shmfd, 0); 818175164Sjhb } 819175164Sjhb if (error == 0) 820175164Sjhb shm_hold(shmfd); 821175164Sjhb } 822175164Sjhb sx_xunlock(&shm_dict_lock); 823175164Sjhb 824175164Sjhb if (error) { 825175164Sjhb fdclose(fdp, fp, fd, td); 826175164Sjhb fdrop(fp, td); 827175164Sjhb return (error); 828175164Sjhb } 829175164Sjhb } 830175164Sjhb 831175164Sjhb finit(fp, FFLAGS(uap->flags & O_ACCMODE), DTYPE_SHM, shmfd, &shm_ops); 832175164Sjhb 833175164Sjhb td->td_retval[0] = fd; 834175164Sjhb fdrop(fp, td); 835175164Sjhb 836175164Sjhb return (0); 837175164Sjhb} 838175164Sjhb 839175164Sjhbint 840225617Skmacysys_shm_unlink(struct thread *td, struct shm_unlink_args *uap) 841175164Sjhb{ 842175164Sjhb char *path; 843175164Sjhb Fnv32_t fnv; 844175164Sjhb int error; 845175164Sjhb 846175164Sjhb path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 847175164Sjhb error = copyinstr(uap->path, path, MAXPATHLEN, NULL); 848175164Sjhb if (error) { 849175164Sjhb free(path, M_TEMP); 850175164Sjhb return (error); 851175164Sjhb } 852269742Srpaulo#ifdef KTRACE 853269742Srpaulo if (KTRPOINT(curthread, KTR_NAMEI)) 854269742Srpaulo ktrnamei(path); 855269742Srpaulo#endif 856175164Sjhb fnv = fnv_32_str(path, FNV1_32_INIT); 857175164Sjhb sx_xlock(&shm_dict_lock); 858175164Sjhb error = shm_remove(path, fnv, td->td_ucred); 859175164Sjhb sx_xunlock(&shm_dict_lock); 860175164Sjhb free(path, M_TEMP); 861175164Sjhb 862175164Sjhb return (error); 863175164Sjhb} 864175164Sjhb 865175164Sjhb/* 866175164Sjhb * mmap() helper to validate mmap() requests against shm object state 867175164Sjhb * and give mmap() the vm_object to use for the mapping. 868175164Sjhb */ 869175164Sjhbint 870175164Sjhbshm_mmap(struct shmfd *shmfd, vm_size_t objsize, vm_ooffset_t foff, 871175164Sjhb vm_object_t *obj) 872175164Sjhb{ 873175164Sjhb 874175164Sjhb /* 875175164Sjhb * XXXRW: This validation is probably insufficient, and subject to 876175164Sjhb * sign errors. It should be fixed. 877175164Sjhb */ 878185533Skan if (foff >= shmfd->shm_size || 879185533Skan foff + objsize > round_page(shmfd->shm_size)) 880175164Sjhb return (EINVAL); 881175164Sjhb 882175164Sjhb mtx_lock(&shm_timestamp_lock); 883175164Sjhb vfs_timestamp(&shmfd->shm_atime); 884175164Sjhb mtx_unlock(&shm_timestamp_lock); 885175164Sjhb vm_object_reference(shmfd->shm_object); 886175164Sjhb *obj = shmfd->shm_object; 887175164Sjhb return (0); 888175164Sjhb} 889224914Skib 890224914Skibstatic int 891224914Skibshm_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 892224914Skib struct thread *td) 893224914Skib{ 894224914Skib struct shmfd *shmfd; 895224914Skib int error; 896224914Skib 897224914Skib error = 0; 898224914Skib shmfd = fp->f_data; 899224914Skib mtx_lock(&shm_timestamp_lock); 900224914Skib /* 901224914Skib * SUSv4 says that x bits of permission need not be affected. 902224914Skib * Be consistent with our shm_open there. 903224914Skib */ 904224914Skib#ifdef MAC 905224914Skib error = mac_posixshm_check_setmode(active_cred, shmfd, mode); 906224914Skib if (error != 0) 907224914Skib goto out; 908224914Skib#endif 909224914Skib error = vaccess(VREG, shmfd->shm_mode, shmfd->shm_uid, 910224914Skib shmfd->shm_gid, VADMIN, active_cred, NULL); 911224914Skib if (error != 0) 912224914Skib goto out; 913224914Skib shmfd->shm_mode = mode & ACCESSPERMS; 914224914Skibout: 915224914Skib mtx_unlock(&shm_timestamp_lock); 916224914Skib return (error); 917224914Skib} 918224914Skib 919224914Skibstatic int 920224914Skibshm_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 921224914Skib struct thread *td) 922224914Skib{ 923224914Skib struct shmfd *shmfd; 924224914Skib int error; 925224914Skib 926224935Skib error = 0; 927224914Skib shmfd = fp->f_data; 928224914Skib mtx_lock(&shm_timestamp_lock); 929224914Skib#ifdef MAC 930224914Skib error = mac_posixshm_check_setowner(active_cred, shmfd, uid, gid); 931224914Skib if (error != 0) 932224914Skib goto out; 933224914Skib#endif 934224914Skib if (uid == (uid_t)-1) 935224914Skib uid = shmfd->shm_uid; 936224914Skib if (gid == (gid_t)-1) 937224914Skib gid = shmfd->shm_gid; 938224914Skib if (((uid != shmfd->shm_uid && uid != active_cred->cr_uid) || 939224914Skib (gid != shmfd->shm_gid && !groupmember(gid, active_cred))) && 940224914Skib (error = priv_check_cred(active_cred, PRIV_VFS_CHOWN, 0))) 941224914Skib goto out; 942224914Skib shmfd->shm_uid = uid; 943224914Skib shmfd->shm_gid = gid; 944224914Skibout: 945224914Skib mtx_unlock(&shm_timestamp_lock); 946224914Skib return (error); 947224914Skib} 948228509Sjhb 949228509Sjhb/* 950228509Sjhb * Helper routines to allow the backing object of a shared memory file 951228509Sjhb * descriptor to be mapped in the kernel. 952228509Sjhb */ 953228509Sjhbint 954228509Sjhbshm_map(struct file *fp, size_t size, off_t offset, void **memp) 955228509Sjhb{ 956228509Sjhb struct shmfd *shmfd; 957228509Sjhb vm_offset_t kva, ofs; 958228509Sjhb vm_object_t obj; 959228509Sjhb int rv; 960228509Sjhb 961228509Sjhb if (fp->f_type != DTYPE_SHM) 962228509Sjhb return (EINVAL); 963228509Sjhb shmfd = fp->f_data; 964228509Sjhb obj = shmfd->shm_object; 965248084Sattilio VM_OBJECT_WLOCK(obj); 966228509Sjhb /* 967228509Sjhb * XXXRW: This validation is probably insufficient, and subject to 968228509Sjhb * sign errors. It should be fixed. 969228509Sjhb */ 970228509Sjhb if (offset >= shmfd->shm_size || 971228509Sjhb offset + size > round_page(shmfd->shm_size)) { 972248084Sattilio VM_OBJECT_WUNLOCK(obj); 973228509Sjhb return (EINVAL); 974228509Sjhb } 975228509Sjhb 976228509Sjhb shmfd->shm_kmappings++; 977228509Sjhb vm_object_reference_locked(obj); 978248084Sattilio VM_OBJECT_WUNLOCK(obj); 979228509Sjhb 980228509Sjhb /* Map the object into the kernel_map and wire it. */ 981228509Sjhb kva = vm_map_min(kernel_map); 982228509Sjhb ofs = offset & PAGE_MASK; 983228509Sjhb offset = trunc_page(offset); 984228509Sjhb size = round_page(size + ofs); 985255426Sjhb rv = vm_map_find(kernel_map, obj, offset, &kva, size, 0, 986253620Sjhb VMFS_OPTIMAL_SPACE, VM_PROT_READ | VM_PROT_WRITE, 987228509Sjhb VM_PROT_READ | VM_PROT_WRITE, 0); 988228509Sjhb if (rv == KERN_SUCCESS) { 989228509Sjhb rv = vm_map_wire(kernel_map, kva, kva + size, 990228509Sjhb VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 991228509Sjhb if (rv == KERN_SUCCESS) { 992228509Sjhb *memp = (void *)(kva + ofs); 993228509Sjhb return (0); 994228509Sjhb } 995228509Sjhb vm_map_remove(kernel_map, kva, kva + size); 996228509Sjhb } else 997228509Sjhb vm_object_deallocate(obj); 998228509Sjhb 999228509Sjhb /* On failure, drop our mapping reference. */ 1000248084Sattilio VM_OBJECT_WLOCK(obj); 1001228509Sjhb shmfd->shm_kmappings--; 1002248084Sattilio VM_OBJECT_WUNLOCK(obj); 1003228509Sjhb 1004228533Sjhb return (vm_mmap_to_errno(rv)); 1005228509Sjhb} 1006228509Sjhb 1007228509Sjhb/* 1008228509Sjhb * We require the caller to unmap the entire entry. This allows us to 1009228509Sjhb * safely decrement shm_kmappings when a mapping is removed. 1010228509Sjhb */ 1011228509Sjhbint 1012228509Sjhbshm_unmap(struct file *fp, void *mem, size_t size) 1013228509Sjhb{ 1014228509Sjhb struct shmfd *shmfd; 1015228509Sjhb vm_map_entry_t entry; 1016228509Sjhb vm_offset_t kva, ofs; 1017228509Sjhb vm_object_t obj; 1018228509Sjhb vm_pindex_t pindex; 1019228509Sjhb vm_prot_t prot; 1020228509Sjhb boolean_t wired; 1021228509Sjhb vm_map_t map; 1022228509Sjhb int rv; 1023228509Sjhb 1024228509Sjhb if (fp->f_type != DTYPE_SHM) 1025228509Sjhb return (EINVAL); 1026228509Sjhb shmfd = fp->f_data; 1027228509Sjhb kva = (vm_offset_t)mem; 1028228509Sjhb ofs = kva & PAGE_MASK; 1029228509Sjhb kva = trunc_page(kva); 1030228509Sjhb size = round_page(size + ofs); 1031228509Sjhb map = kernel_map; 1032228509Sjhb rv = vm_map_lookup(&map, kva, VM_PROT_READ | VM_PROT_WRITE, &entry, 1033228509Sjhb &obj, &pindex, &prot, &wired); 1034228509Sjhb if (rv != KERN_SUCCESS) 1035228509Sjhb return (EINVAL); 1036228509Sjhb if (entry->start != kva || entry->end != kva + size) { 1037228509Sjhb vm_map_lookup_done(map, entry); 1038228509Sjhb return (EINVAL); 1039228509Sjhb } 1040228509Sjhb vm_map_lookup_done(map, entry); 1041228509Sjhb if (obj != shmfd->shm_object) 1042228509Sjhb return (EINVAL); 1043228509Sjhb vm_map_remove(map, kva, kva + size); 1044248084Sattilio VM_OBJECT_WLOCK(obj); 1045228509Sjhb KASSERT(shmfd->shm_kmappings > 0, ("shm_unmap: object not mapped")); 1046228509Sjhb shmfd->shm_kmappings--; 1047248084Sattilio VM_OBJECT_WUNLOCK(obj); 1048228509Sjhb return (0); 1049228509Sjhb} 1050233760Sjhb 1051233760Sjhbvoid 1052233760Sjhbshm_path(struct shmfd *shmfd, char *path, size_t size) 1053233760Sjhb{ 1054233760Sjhb 1055233760Sjhb if (shmfd->shm_path == NULL) 1056233760Sjhb return; 1057233760Sjhb sx_slock(&shm_dict_lock); 1058233760Sjhb if (shmfd->shm_path != NULL) 1059233760Sjhb strlcpy(path, shmfd->shm_path, size); 1060233760Sjhb sx_sunlock(&shm_dict_lock); 1061233760Sjhb} 1062