uipc_shm.c revision 269742
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: stable/10/sys/kern/uipc_shm.c 269742 2014-08-08 22:08:51Z rpaulo $"); 46175164Sjhb 47223692Sjonathan#include "opt_capsicum.h" 48269742Srpaulo#include "opt_ktrace.h" 49223692Sjonathan 50175164Sjhb#include <sys/param.h> 51223692Sjonathan#include <sys/capability.h> 52175164Sjhb#include <sys/fcntl.h> 53175164Sjhb#include <sys/file.h> 54175164Sjhb#include <sys/filedesc.h> 55175164Sjhb#include <sys/fnv_hash.h> 56175164Sjhb#include <sys/kernel.h> 57269742Srpaulo#include <sys/uio.h> 58269742Srpaulo#include <sys/signal.h> 59269742Srpaulo#include <sys/ktrace.h> 60175164Sjhb#include <sys/lock.h> 61175164Sjhb#include <sys/malloc.h> 62175164Sjhb#include <sys/mman.h> 63175164Sjhb#include <sys/mutex.h> 64224914Skib#include <sys/priv.h> 65175164Sjhb#include <sys/proc.h> 66175164Sjhb#include <sys/refcount.h> 67175164Sjhb#include <sys/resourcevar.h> 68248084Sattilio#include <sys/rwlock.h> 69175164Sjhb#include <sys/stat.h> 70175164Sjhb#include <sys/sysctl.h> 71175164Sjhb#include <sys/sysproto.h> 72175164Sjhb#include <sys/systm.h> 73175164Sjhb#include <sys/sx.h> 74175164Sjhb#include <sys/time.h> 75175164Sjhb#include <sys/vnode.h> 76254603Skib#include <sys/unistd.h> 77175164Sjhb 78175164Sjhb#include <security/mac/mac_framework.h> 79175164Sjhb 80175164Sjhb#include <vm/vm.h> 81175164Sjhb#include <vm/vm_param.h> 82175164Sjhb#include <vm/pmap.h> 83228533Sjhb#include <vm/vm_extern.h> 84175164Sjhb#include <vm/vm_map.h> 85228509Sjhb#include <vm/vm_kern.h> 86175164Sjhb#include <vm/vm_object.h> 87175164Sjhb#include <vm/vm_page.h> 88229821Salc#include <vm/vm_pageout.h> 89175164Sjhb#include <vm/vm_pager.h> 90175164Sjhb#include <vm/swap_pager.h> 91175164Sjhb 92175164Sjhbstruct shm_mapping { 93175164Sjhb char *sm_path; 94175164Sjhb Fnv32_t sm_fnv; 95175164Sjhb struct shmfd *sm_shmfd; 96175164Sjhb LIST_ENTRY(shm_mapping) sm_link; 97175164Sjhb}; 98175164Sjhb 99175164Sjhbstatic MALLOC_DEFINE(M_SHMFD, "shmfd", "shared memory file descriptor"); 100175164Sjhbstatic LIST_HEAD(, shm_mapping) *shm_dictionary; 101175164Sjhbstatic struct sx shm_dict_lock; 102175164Sjhbstatic struct mtx shm_timestamp_lock; 103175164Sjhbstatic u_long shm_hash; 104175164Sjhb 105175164Sjhb#define SHM_HASH(fnv) (&shm_dictionary[(fnv) & shm_hash]) 106175164Sjhb 107175164Sjhbstatic int shm_access(struct shmfd *shmfd, struct ucred *ucred, int flags); 108175164Sjhbstatic struct shmfd *shm_alloc(struct ucred *ucred, mode_t mode); 109175164Sjhbstatic void shm_dict_init(void *arg); 110175164Sjhbstatic void shm_drop(struct shmfd *shmfd); 111175164Sjhbstatic struct shmfd *shm_hold(struct shmfd *shmfd); 112175164Sjhbstatic void shm_insert(char *path, Fnv32_t fnv, struct shmfd *shmfd); 113175164Sjhbstatic struct shmfd *shm_lookup(char *path, Fnv32_t fnv); 114175164Sjhbstatic int shm_remove(char *path, Fnv32_t fnv, struct ucred *ucred); 115194766Skibstatic int shm_dotruncate(struct shmfd *shmfd, off_t length); 116175164Sjhb 117175164Sjhbstatic fo_rdwr_t shm_read; 118175164Sjhbstatic fo_rdwr_t shm_write; 119175164Sjhbstatic fo_truncate_t shm_truncate; 120175164Sjhbstatic fo_ioctl_t shm_ioctl; 121175164Sjhbstatic fo_poll_t shm_poll; 122175164Sjhbstatic fo_kqfilter_t shm_kqfilter; 123175164Sjhbstatic fo_stat_t shm_stat; 124175164Sjhbstatic fo_close_t shm_close; 125224914Skibstatic fo_chmod_t shm_chmod; 126224914Skibstatic fo_chown_t shm_chown; 127254603Skibstatic fo_seek_t shm_seek; 128175164Sjhb 129175164Sjhb/* File descriptor operations. */ 130175164Sjhbstatic struct fileops shm_ops = { 131175164Sjhb .fo_read = shm_read, 132175164Sjhb .fo_write = shm_write, 133175164Sjhb .fo_truncate = shm_truncate, 134175164Sjhb .fo_ioctl = shm_ioctl, 135175164Sjhb .fo_poll = shm_poll, 136175164Sjhb .fo_kqfilter = shm_kqfilter, 137175164Sjhb .fo_stat = shm_stat, 138175164Sjhb .fo_close = shm_close, 139224914Skib .fo_chmod = shm_chmod, 140224914Skib .fo_chown = shm_chown, 141255467Skib .fo_sendfile = vn_sendfile, 142254603Skib .fo_seek = shm_seek, 143254603Skib .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE 144175164Sjhb}; 145175164Sjhb 146175164SjhbFEATURE(posix_shm, "POSIX shared memory"); 147175164Sjhb 148175164Sjhbstatic int 149254601Skibuiomove_object_page(vm_object_t obj, size_t len, struct uio *uio) 150254601Skib{ 151254601Skib vm_page_t m; 152254601Skib vm_pindex_t idx; 153254601Skib size_t tlen; 154254601Skib int error, offset, rv; 155254601Skib 156254601Skib idx = OFF_TO_IDX(uio->uio_offset); 157254601Skib offset = uio->uio_offset & PAGE_MASK; 158254601Skib tlen = MIN(PAGE_SIZE - offset, len); 159254601Skib 160254601Skib VM_OBJECT_WLOCK(obj); 161254601Skib 162254601Skib /* 163254601Skib * Parallel reads of the page content from disk are prevented 164254601Skib * by exclusive busy. 165254601Skib * 166254601Skib * Although the tmpfs vnode lock is held here, it is 167254601Skib * nonetheless safe to sleep waiting for a free page. The 168254601Skib * pageout daemon does not need to acquire the tmpfs vnode 169254601Skib * lock to page out tobj's pages because tobj is a OBJT_SWAP 170254601Skib * type object. 171254601Skib */ 172254649Skib m = vm_page_grab(obj, idx, VM_ALLOC_NORMAL); 173254601Skib if (m->valid != VM_PAGE_BITS_ALL) { 174254601Skib if (vm_pager_has_page(obj, idx, NULL, NULL)) { 175254601Skib rv = vm_pager_get_pages(obj, &m, 1, 0); 176254601Skib m = vm_page_lookup(obj, idx); 177254601Skib if (m == NULL) { 178254601Skib printf( 179254601Skib "uiomove_object: vm_obj %p idx %jd null lookup rv %d\n", 180254601Skib obj, idx, rv); 181254601Skib VM_OBJECT_WUNLOCK(obj); 182254601Skib return (EIO); 183254601Skib } 184254601Skib if (rv != VM_PAGER_OK) { 185254601Skib printf( 186254601Skib "uiomove_object: vm_obj %p idx %jd valid %x pager error %d\n", 187254601Skib obj, idx, m->valid, rv); 188254601Skib vm_page_lock(m); 189254601Skib vm_page_free(m); 190254601Skib vm_page_unlock(m); 191254601Skib VM_OBJECT_WUNLOCK(obj); 192254601Skib return (EIO); 193254601Skib } 194254601Skib } else 195254601Skib vm_page_zero_invalid(m, TRUE); 196254601Skib } 197254601Skib vm_page_xunbusy(m); 198254601Skib vm_page_lock(m); 199254601Skib vm_page_hold(m); 200254601Skib vm_page_unlock(m); 201254601Skib VM_OBJECT_WUNLOCK(obj); 202254601Skib error = uiomove_fromphys(&m, offset, tlen, uio); 203254601Skib if (uio->uio_rw == UIO_WRITE && error == 0) { 204254601Skib VM_OBJECT_WLOCK(obj); 205254601Skib vm_page_dirty(m); 206269495Skib vm_pager_page_unswapped(m); 207254601Skib VM_OBJECT_WUNLOCK(obj); 208254601Skib } 209254601Skib vm_page_lock(m); 210254601Skib vm_page_unhold(m); 211254601Skib if (m->queue == PQ_NONE) { 212254601Skib vm_page_deactivate(m); 213254601Skib } else { 214254601Skib /* Requeue to maintain LRU ordering. */ 215254601Skib vm_page_requeue(m); 216254601Skib } 217254601Skib vm_page_unlock(m); 218254601Skib 219254601Skib return (error); 220254601Skib} 221254601Skib 222254601Skibint 223254601Skibuiomove_object(vm_object_t obj, off_t obj_size, struct uio *uio) 224254601Skib{ 225254601Skib ssize_t resid; 226254601Skib size_t len; 227254601Skib int error; 228254601Skib 229254601Skib error = 0; 230254601Skib while ((resid = uio->uio_resid) > 0) { 231254601Skib if (obj_size <= uio->uio_offset) 232254601Skib break; 233254601Skib len = MIN(obj_size - uio->uio_offset, resid); 234254601Skib if (len == 0) 235254601Skib break; 236254601Skib error = uiomove_object_page(obj, len, uio); 237254601Skib if (error != 0 || resid == uio->uio_resid) 238254601Skib break; 239254601Skib } 240254601Skib return (error); 241254601Skib} 242254601Skib 243254601Skibstatic int 244254603Skibshm_seek(struct file *fp, off_t offset, int whence, struct thread *td) 245254603Skib{ 246254603Skib struct shmfd *shmfd; 247254603Skib off_t foffset; 248254603Skib int error; 249254603Skib 250254603Skib shmfd = fp->f_data; 251254603Skib foffset = foffset_lock(fp, 0); 252254603Skib error = 0; 253254603Skib switch (whence) { 254254603Skib case L_INCR: 255254603Skib if (foffset < 0 || 256254603Skib (offset > 0 && foffset > OFF_MAX - offset)) { 257254603Skib error = EOVERFLOW; 258254603Skib break; 259254603Skib } 260254603Skib offset += foffset; 261254603Skib break; 262254603Skib case L_XTND: 263254603Skib if (offset > 0 && shmfd->shm_size > OFF_MAX - offset) { 264254603Skib error = EOVERFLOW; 265254603Skib break; 266254603Skib } 267254603Skib offset += shmfd->shm_size; 268254603Skib break; 269254603Skib case L_SET: 270254603Skib break; 271254603Skib default: 272254603Skib error = EINVAL; 273254603Skib } 274254603Skib if (error == 0) { 275254603Skib if (offset < 0 || offset > shmfd->shm_size) 276254603Skib error = EINVAL; 277254603Skib else 278254603Skib *(off_t *)(td->td_retval) = offset; 279254603Skib } 280254603Skib foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0); 281254603Skib return (error); 282254603Skib} 283254603Skib 284254603Skibstatic int 285175164Sjhbshm_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 286175164Sjhb int flags, struct thread *td) 287175164Sjhb{ 288254603Skib struct shmfd *shmfd; 289254603Skib void *rl_cookie; 290254603Skib int error; 291175164Sjhb 292254603Skib shmfd = fp->f_data; 293254603Skib foffset_lock_uio(fp, uio, flags); 294254603Skib rl_cookie = rangelock_rlock(&shmfd->shm_rl, uio->uio_offset, 295254603Skib uio->uio_offset + uio->uio_resid, &shmfd->shm_mtx); 296254603Skib#ifdef MAC 297254603Skib error = mac_posixshm_check_read(active_cred, fp->f_cred, shmfd); 298254603Skib if (error) 299254603Skib return (error); 300254603Skib#endif 301254603Skib error = uiomove_object(shmfd->shm_object, shmfd->shm_size, uio); 302254603Skib rangelock_unlock(&shmfd->shm_rl, rl_cookie, &shmfd->shm_mtx); 303254603Skib foffset_unlock_uio(fp, uio, flags); 304254603Skib return (error); 305175164Sjhb} 306175164Sjhb 307175164Sjhbstatic int 308175164Sjhbshm_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 309175164Sjhb int flags, struct thread *td) 310175164Sjhb{ 311254603Skib struct shmfd *shmfd; 312254603Skib void *rl_cookie; 313254603Skib int error; 314175164Sjhb 315254603Skib shmfd = fp->f_data; 316254603Skib#ifdef MAC 317254603Skib error = mac_posixshm_check_write(active_cred, fp->f_cred, shmfd); 318254603Skib if (error) 319254603Skib return (error); 320254603Skib#endif 321254603Skib foffset_lock_uio(fp, uio, flags); 322254603Skib if ((flags & FOF_OFFSET) == 0) { 323254603Skib rl_cookie = rangelock_wlock(&shmfd->shm_rl, 0, OFF_MAX, 324254603Skib &shmfd->shm_mtx); 325254603Skib } else { 326254603Skib rl_cookie = rangelock_wlock(&shmfd->shm_rl, uio->uio_offset, 327254603Skib uio->uio_offset + uio->uio_resid, &shmfd->shm_mtx); 328254603Skib } 329254603Skib 330254603Skib error = uiomove_object(shmfd->shm_object, shmfd->shm_size, uio); 331254603Skib rangelock_unlock(&shmfd->shm_rl, rl_cookie, &shmfd->shm_mtx); 332254603Skib foffset_unlock_uio(fp, uio, flags); 333254603Skib return (error); 334175164Sjhb} 335175164Sjhb 336175164Sjhbstatic int 337175164Sjhbshm_truncate(struct file *fp, off_t length, struct ucred *active_cred, 338175164Sjhb struct thread *td) 339175164Sjhb{ 340175164Sjhb struct shmfd *shmfd; 341175164Sjhb#ifdef MAC 342175164Sjhb int error; 343175164Sjhb#endif 344175164Sjhb 345175164Sjhb shmfd = fp->f_data; 346175164Sjhb#ifdef MAC 347175164Sjhb error = mac_posixshm_check_truncate(active_cred, fp->f_cred, shmfd); 348175164Sjhb if (error) 349175164Sjhb return (error); 350175164Sjhb#endif 351194766Skib return (shm_dotruncate(shmfd, length)); 352175164Sjhb} 353175164Sjhb 354175164Sjhbstatic int 355175164Sjhbshm_ioctl(struct file *fp, u_long com, void *data, 356175164Sjhb struct ucred *active_cred, struct thread *td) 357175164Sjhb{ 358175164Sjhb 359175164Sjhb return (EOPNOTSUPP); 360175164Sjhb} 361175164Sjhb 362175164Sjhbstatic int 363175164Sjhbshm_poll(struct file *fp, int events, struct ucred *active_cred, 364175164Sjhb struct thread *td) 365175164Sjhb{ 366175164Sjhb 367175164Sjhb return (EOPNOTSUPP); 368175164Sjhb} 369175164Sjhb 370175164Sjhbstatic int 371175164Sjhbshm_kqfilter(struct file *fp, struct knote *kn) 372175164Sjhb{ 373175164Sjhb 374175164Sjhb return (EOPNOTSUPP); 375175164Sjhb} 376175164Sjhb 377175164Sjhbstatic int 378175164Sjhbshm_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 379175164Sjhb struct thread *td) 380175164Sjhb{ 381175164Sjhb struct shmfd *shmfd; 382175164Sjhb#ifdef MAC 383175164Sjhb int error; 384175164Sjhb#endif 385175164Sjhb 386175164Sjhb shmfd = fp->f_data; 387175164Sjhb 388175164Sjhb#ifdef MAC 389175164Sjhb error = mac_posixshm_check_stat(active_cred, fp->f_cred, shmfd); 390175164Sjhb if (error) 391175164Sjhb return (error); 392175164Sjhb#endif 393175164Sjhb 394175164Sjhb /* 395175164Sjhb * Attempt to return sanish values for fstat() on a memory file 396175164Sjhb * descriptor. 397175164Sjhb */ 398175164Sjhb bzero(sb, sizeof(*sb)); 399175164Sjhb sb->st_blksize = PAGE_SIZE; 400175164Sjhb sb->st_size = shmfd->shm_size; 401175164Sjhb sb->st_blocks = (sb->st_size + sb->st_blksize - 1) / sb->st_blksize; 402224914Skib mtx_lock(&shm_timestamp_lock); 403205792Sed sb->st_atim = shmfd->shm_atime; 404205792Sed sb->st_ctim = shmfd->shm_ctime; 405205792Sed sb->st_mtim = shmfd->shm_mtime; 406224914Skib sb->st_birthtim = shmfd->shm_birthtime; 407224914Skib sb->st_mode = S_IFREG | shmfd->shm_mode; /* XXX */ 408175164Sjhb sb->st_uid = shmfd->shm_uid; 409175164Sjhb sb->st_gid = shmfd->shm_gid; 410224914Skib mtx_unlock(&shm_timestamp_lock); 411175164Sjhb 412175164Sjhb return (0); 413175164Sjhb} 414175164Sjhb 415175164Sjhbstatic int 416175164Sjhbshm_close(struct file *fp, struct thread *td) 417175164Sjhb{ 418175164Sjhb struct shmfd *shmfd; 419175164Sjhb 420175164Sjhb shmfd = fp->f_data; 421175164Sjhb fp->f_data = NULL; 422175164Sjhb shm_drop(shmfd); 423175164Sjhb 424175164Sjhb return (0); 425175164Sjhb} 426175164Sjhb 427194766Skibstatic int 428175164Sjhbshm_dotruncate(struct shmfd *shmfd, off_t length) 429175164Sjhb{ 430175164Sjhb vm_object_t object; 431229821Salc vm_page_t m, ma[1]; 432229821Salc vm_pindex_t idx, nobjsize; 433194766Skib vm_ooffset_t delta; 434229821Salc int base, rv; 435175164Sjhb 436175164Sjhb object = shmfd->shm_object; 437248084Sattilio VM_OBJECT_WLOCK(object); 438175164Sjhb if (length == shmfd->shm_size) { 439248084Sattilio VM_OBJECT_WUNLOCK(object); 440194766Skib return (0); 441175164Sjhb } 442175164Sjhb nobjsize = OFF_TO_IDX(length + PAGE_MASK); 443175164Sjhb 444175164Sjhb /* Are we shrinking? If so, trim the end. */ 445175164Sjhb if (length < shmfd->shm_size) { 446228509Sjhb /* 447228509Sjhb * Disallow any requests to shrink the size if this 448228509Sjhb * object is mapped into the kernel. 449228509Sjhb */ 450228509Sjhb if (shmfd->shm_kmappings > 0) { 451248084Sattilio VM_OBJECT_WUNLOCK(object); 452228509Sjhb return (EBUSY); 453228509Sjhb } 454229821Salc 455229821Salc /* 456229821Salc * Zero the truncated part of the last page. 457229821Salc */ 458229821Salc base = length & PAGE_MASK; 459229821Salc if (base != 0) { 460229821Salc idx = OFF_TO_IDX(length); 461229821Salcretry: 462229821Salc m = vm_page_lookup(object, idx); 463229821Salc if (m != NULL) { 464254138Sattilio if (vm_page_sleep_if_busy(m, "shmtrc")) 465229821Salc goto retry; 466229821Salc } else if (vm_pager_has_page(object, idx, NULL, NULL)) { 467229821Salc m = vm_page_alloc(object, idx, VM_ALLOC_NORMAL); 468229821Salc if (m == NULL) { 469248084Sattilio VM_OBJECT_WUNLOCK(object); 470229821Salc VM_WAIT; 471248084Sattilio VM_OBJECT_WLOCK(object); 472229821Salc goto retry; 473229821Salc } else if (m->valid != VM_PAGE_BITS_ALL) { 474229821Salc ma[0] = m; 475229821Salc rv = vm_pager_get_pages(object, ma, 1, 476229821Salc 0); 477229821Salc m = vm_page_lookup(object, idx); 478229821Salc } else 479229821Salc /* A cached page was reactivated. */ 480229821Salc rv = VM_PAGER_OK; 481229821Salc vm_page_lock(m); 482229821Salc if (rv == VM_PAGER_OK) { 483229821Salc vm_page_deactivate(m); 484229821Salc vm_page_unlock(m); 485254138Sattilio vm_page_xunbusy(m); 486229821Salc } else { 487229821Salc vm_page_free(m); 488229821Salc vm_page_unlock(m); 489248084Sattilio VM_OBJECT_WUNLOCK(object); 490229821Salc return (EIO); 491229821Salc } 492229821Salc } 493229821Salc if (m != NULL) { 494229821Salc pmap_zero_page_area(m, base, PAGE_SIZE - base); 495229821Salc KASSERT(m->valid == VM_PAGE_BITS_ALL, 496229821Salc ("shm_dotruncate: page %p is invalid", m)); 497229821Salc vm_page_dirty(m); 498229821Salc vm_pager_page_unswapped(m); 499229821Salc } 500229821Salc } 501194766Skib delta = ptoa(object->size - nobjsize); 502194766Skib 503175164Sjhb /* Toss in memory pages. */ 504175164Sjhb if (nobjsize < object->size) 505175164Sjhb vm_object_page_remove(object, nobjsize, object->size, 506223677Salc 0); 507175164Sjhb 508175164Sjhb /* Toss pages from swap. */ 509175164Sjhb if (object->type == OBJT_SWAP) 510194766Skib swap_pager_freespace(object, nobjsize, delta); 511175164Sjhb 512194766Skib /* Free the swap accounted for shm */ 513216128Strasz swap_release_by_cred(delta, object->cred); 514194766Skib object->charge -= delta; 515194766Skib } else { 516194766Skib /* Attempt to reserve the swap */ 517194766Skib delta = ptoa(nobjsize - object->size); 518216128Strasz if (!swap_reserve_by_cred(delta, object->cred)) { 519248084Sattilio VM_OBJECT_WUNLOCK(object); 520194766Skib return (ENOMEM); 521194766Skib } 522194766Skib object->charge += delta; 523175164Sjhb } 524175164Sjhb shmfd->shm_size = length; 525175164Sjhb mtx_lock(&shm_timestamp_lock); 526175164Sjhb vfs_timestamp(&shmfd->shm_ctime); 527175164Sjhb shmfd->shm_mtime = shmfd->shm_ctime; 528175164Sjhb mtx_unlock(&shm_timestamp_lock); 529175164Sjhb object->size = nobjsize; 530248084Sattilio VM_OBJECT_WUNLOCK(object); 531194766Skib return (0); 532175164Sjhb} 533175164Sjhb 534175164Sjhb/* 535175164Sjhb * shmfd object management including creation and reference counting 536175164Sjhb * routines. 537175164Sjhb */ 538175164Sjhbstatic struct shmfd * 539175164Sjhbshm_alloc(struct ucred *ucred, mode_t mode) 540175164Sjhb{ 541175164Sjhb struct shmfd *shmfd; 542175164Sjhb 543175164Sjhb shmfd = malloc(sizeof(*shmfd), M_SHMFD, M_WAITOK | M_ZERO); 544175164Sjhb shmfd->shm_size = 0; 545175164Sjhb shmfd->shm_uid = ucred->cr_uid; 546175164Sjhb shmfd->shm_gid = ucred->cr_gid; 547175164Sjhb shmfd->shm_mode = mode; 548175164Sjhb shmfd->shm_object = vm_pager_allocate(OBJT_DEFAULT, NULL, 549194766Skib shmfd->shm_size, VM_PROT_DEFAULT, 0, ucred); 550175164Sjhb KASSERT(shmfd->shm_object != NULL, ("shm_create: vm_pager_allocate")); 551248084Sattilio VM_OBJECT_WLOCK(shmfd->shm_object); 552178181Salc vm_object_clear_flag(shmfd->shm_object, OBJ_ONEMAPPING); 553178181Salc vm_object_set_flag(shmfd->shm_object, OBJ_NOSPLIT); 554248084Sattilio VM_OBJECT_WUNLOCK(shmfd->shm_object); 555175164Sjhb vfs_timestamp(&shmfd->shm_birthtime); 556175164Sjhb shmfd->shm_atime = shmfd->shm_mtime = shmfd->shm_ctime = 557175164Sjhb shmfd->shm_birthtime; 558175164Sjhb refcount_init(&shmfd->shm_refs, 1); 559254603Skib mtx_init(&shmfd->shm_mtx, "shmrl", NULL, MTX_DEF); 560254603Skib rangelock_init(&shmfd->shm_rl); 561175164Sjhb#ifdef MAC 562175164Sjhb mac_posixshm_init(shmfd); 563175164Sjhb mac_posixshm_create(ucred, shmfd); 564175164Sjhb#endif 565175164Sjhb 566175164Sjhb return (shmfd); 567175164Sjhb} 568175164Sjhb 569175164Sjhbstatic struct shmfd * 570175164Sjhbshm_hold(struct shmfd *shmfd) 571175164Sjhb{ 572175164Sjhb 573175164Sjhb refcount_acquire(&shmfd->shm_refs); 574175164Sjhb return (shmfd); 575175164Sjhb} 576175164Sjhb 577175164Sjhbstatic void 578175164Sjhbshm_drop(struct shmfd *shmfd) 579175164Sjhb{ 580175164Sjhb 581175164Sjhb if (refcount_release(&shmfd->shm_refs)) { 582175164Sjhb#ifdef MAC 583175164Sjhb mac_posixshm_destroy(shmfd); 584175164Sjhb#endif 585254603Skib rangelock_destroy(&shmfd->shm_rl); 586254603Skib mtx_destroy(&shmfd->shm_mtx); 587175164Sjhb vm_object_deallocate(shmfd->shm_object); 588175164Sjhb free(shmfd, M_SHMFD); 589175164Sjhb } 590175164Sjhb} 591175164Sjhb 592175164Sjhb/* 593175164Sjhb * Determine if the credentials have sufficient permissions for a 594175164Sjhb * specified combination of FREAD and FWRITE. 595175164Sjhb */ 596175164Sjhbstatic int 597175164Sjhbshm_access(struct shmfd *shmfd, struct ucred *ucred, int flags) 598175164Sjhb{ 599184413Strasz accmode_t accmode; 600224914Skib int error; 601175164Sjhb 602184413Strasz accmode = 0; 603175164Sjhb if (flags & FREAD) 604184413Strasz accmode |= VREAD; 605175164Sjhb if (flags & FWRITE) 606184413Strasz accmode |= VWRITE; 607224914Skib mtx_lock(&shm_timestamp_lock); 608224914Skib error = vaccess(VREG, shmfd->shm_mode, shmfd->shm_uid, shmfd->shm_gid, 609224914Skib accmode, ucred, NULL); 610224914Skib mtx_unlock(&shm_timestamp_lock); 611224914Skib return (error); 612175164Sjhb} 613175164Sjhb 614175164Sjhb/* 615175164Sjhb * Dictionary management. We maintain an in-kernel dictionary to map 616175164Sjhb * paths to shmfd objects. We use the FNV hash on the path to store 617175164Sjhb * the mappings in a hash table. 618175164Sjhb */ 619175164Sjhbstatic void 620175164Sjhbshm_dict_init(void *arg) 621175164Sjhb{ 622175164Sjhb 623175164Sjhb mtx_init(&shm_timestamp_lock, "shm timestamps", NULL, MTX_DEF); 624175164Sjhb sx_init(&shm_dict_lock, "shm dictionary"); 625175164Sjhb shm_dictionary = hashinit(1024, M_SHMFD, &shm_hash); 626175164Sjhb} 627175164SjhbSYSINIT(shm_dict_init, SI_SUB_SYSV_SHM, SI_ORDER_ANY, shm_dict_init, NULL); 628175164Sjhb 629175164Sjhbstatic struct shmfd * 630175164Sjhbshm_lookup(char *path, Fnv32_t fnv) 631175164Sjhb{ 632175164Sjhb struct shm_mapping *map; 633175164Sjhb 634175164Sjhb LIST_FOREACH(map, SHM_HASH(fnv), sm_link) { 635175164Sjhb if (map->sm_fnv != fnv) 636175164Sjhb continue; 637175164Sjhb if (strcmp(map->sm_path, path) == 0) 638175164Sjhb return (map->sm_shmfd); 639175164Sjhb } 640175164Sjhb 641175164Sjhb return (NULL); 642175164Sjhb} 643175164Sjhb 644175164Sjhbstatic void 645175164Sjhbshm_insert(char *path, Fnv32_t fnv, struct shmfd *shmfd) 646175164Sjhb{ 647175164Sjhb struct shm_mapping *map; 648175164Sjhb 649175164Sjhb map = malloc(sizeof(struct shm_mapping), M_SHMFD, M_WAITOK); 650175164Sjhb map->sm_path = path; 651175164Sjhb map->sm_fnv = fnv; 652175164Sjhb map->sm_shmfd = shm_hold(shmfd); 653233760Sjhb shmfd->shm_path = path; 654175164Sjhb LIST_INSERT_HEAD(SHM_HASH(fnv), map, sm_link); 655175164Sjhb} 656175164Sjhb 657175164Sjhbstatic int 658175164Sjhbshm_remove(char *path, Fnv32_t fnv, struct ucred *ucred) 659175164Sjhb{ 660175164Sjhb struct shm_mapping *map; 661175164Sjhb int error; 662175164Sjhb 663175164Sjhb LIST_FOREACH(map, SHM_HASH(fnv), sm_link) { 664175164Sjhb if (map->sm_fnv != fnv) 665175164Sjhb continue; 666175164Sjhb if (strcmp(map->sm_path, path) == 0) { 667175164Sjhb#ifdef MAC 668175164Sjhb error = mac_posixshm_check_unlink(ucred, map->sm_shmfd); 669175164Sjhb if (error) 670175164Sjhb return (error); 671175164Sjhb#endif 672175164Sjhb error = shm_access(map->sm_shmfd, ucred, 673175164Sjhb FREAD | FWRITE); 674175164Sjhb if (error) 675175164Sjhb return (error); 676233760Sjhb map->sm_shmfd->shm_path = NULL; 677175164Sjhb LIST_REMOVE(map, sm_link); 678175164Sjhb shm_drop(map->sm_shmfd); 679175164Sjhb free(map->sm_path, M_SHMFD); 680175164Sjhb free(map, M_SHMFD); 681175164Sjhb return (0); 682175164Sjhb } 683175164Sjhb } 684175164Sjhb 685175164Sjhb return (ENOENT); 686175164Sjhb} 687175164Sjhb 688175164Sjhb/* System calls. */ 689175164Sjhbint 690225617Skmacysys_shm_open(struct thread *td, struct shm_open_args *uap) 691175164Sjhb{ 692175164Sjhb struct filedesc *fdp; 693175164Sjhb struct shmfd *shmfd; 694175164Sjhb struct file *fp; 695175164Sjhb char *path; 696175164Sjhb Fnv32_t fnv; 697175164Sjhb mode_t cmode; 698175164Sjhb int fd, error; 699175164Sjhb 700223692Sjonathan#ifdef CAPABILITY_MODE 701223692Sjonathan /* 702223692Sjonathan * shm_open(2) is only allowed for anonymous objects. 703223692Sjonathan */ 704223692Sjonathan if (IN_CAPABILITY_MODE(td) && (uap->path != SHM_ANON)) 705223692Sjonathan return (ECAPMODE); 706223692Sjonathan#endif 707223692Sjonathan 708175164Sjhb if ((uap->flags & O_ACCMODE) != O_RDONLY && 709175164Sjhb (uap->flags & O_ACCMODE) != O_RDWR) 710175164Sjhb return (EINVAL); 711175164Sjhb 712261329Srmh if ((uap->flags & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC | O_CLOEXEC)) != 0) 713175164Sjhb return (EINVAL); 714175164Sjhb 715175164Sjhb fdp = td->td_proc->p_fd; 716175164Sjhb cmode = (uap->mode & ~fdp->fd_cmask) & ACCESSPERMS; 717175164Sjhb 718249233Sjilles error = falloc(td, &fp, &fd, O_CLOEXEC); 719175164Sjhb if (error) 720175164Sjhb return (error); 721175164Sjhb 722175164Sjhb /* A SHM_ANON path pointer creates an anonymous object. */ 723175164Sjhb if (uap->path == SHM_ANON) { 724175164Sjhb /* A read-only anonymous object is pointless. */ 725175164Sjhb if ((uap->flags & O_ACCMODE) == O_RDONLY) { 726175164Sjhb fdclose(fdp, fp, fd, td); 727175164Sjhb fdrop(fp, td); 728175164Sjhb return (EINVAL); 729175164Sjhb } 730175164Sjhb shmfd = shm_alloc(td->td_ucred, cmode); 731175164Sjhb } else { 732175164Sjhb path = malloc(MAXPATHLEN, M_SHMFD, M_WAITOK); 733175164Sjhb error = copyinstr(uap->path, path, MAXPATHLEN, NULL); 734269742Srpaulo#ifdef KTRACE 735269742Srpaulo if (error == 0 && KTRPOINT(curthread, KTR_NAMEI)) 736269742Srpaulo ktrnamei(path); 737269742Srpaulo#endif 738175164Sjhb /* Require paths to start with a '/' character. */ 739175164Sjhb if (error == 0 && path[0] != '/') 740175164Sjhb error = EINVAL; 741175164Sjhb if (error) { 742175164Sjhb fdclose(fdp, fp, fd, td); 743175164Sjhb fdrop(fp, td); 744175164Sjhb free(path, M_SHMFD); 745175164Sjhb return (error); 746175164Sjhb } 747175164Sjhb 748175164Sjhb fnv = fnv_32_str(path, FNV1_32_INIT); 749175164Sjhb sx_xlock(&shm_dict_lock); 750175164Sjhb shmfd = shm_lookup(path, fnv); 751175164Sjhb if (shmfd == NULL) { 752175164Sjhb /* Object does not yet exist, create it if requested. */ 753175164Sjhb if (uap->flags & O_CREAT) { 754225344Srwatson#ifdef MAC 755225344Srwatson error = mac_posixshm_check_create(td->td_ucred, 756225344Srwatson path); 757225344Srwatson if (error == 0) { 758225344Srwatson#endif 759225344Srwatson shmfd = shm_alloc(td->td_ucred, cmode); 760225344Srwatson shm_insert(path, fnv, shmfd); 761225344Srwatson#ifdef MAC 762225344Srwatson } 763225344Srwatson#endif 764175164Sjhb } else { 765175164Sjhb free(path, M_SHMFD); 766175164Sjhb error = ENOENT; 767175164Sjhb } 768175164Sjhb } else { 769175164Sjhb /* 770175164Sjhb * Object already exists, obtain a new 771175164Sjhb * reference if requested and permitted. 772175164Sjhb */ 773175164Sjhb free(path, M_SHMFD); 774175164Sjhb if ((uap->flags & (O_CREAT | O_EXCL)) == 775175164Sjhb (O_CREAT | O_EXCL)) 776175164Sjhb error = EEXIST; 777175164Sjhb else { 778175164Sjhb#ifdef MAC 779175164Sjhb error = mac_posixshm_check_open(td->td_ucred, 780225344Srwatson shmfd, FFLAGS(uap->flags & O_ACCMODE)); 781175164Sjhb if (error == 0) 782175164Sjhb#endif 783175164Sjhb error = shm_access(shmfd, td->td_ucred, 784175164Sjhb FFLAGS(uap->flags & O_ACCMODE)); 785175164Sjhb } 786175164Sjhb 787175164Sjhb /* 788175164Sjhb * Truncate the file back to zero length if 789175164Sjhb * O_TRUNC was specified and the object was 790175164Sjhb * opened with read/write. 791175164Sjhb */ 792175164Sjhb if (error == 0 && 793175164Sjhb (uap->flags & (O_ACCMODE | O_TRUNC)) == 794175164Sjhb (O_RDWR | O_TRUNC)) { 795175164Sjhb#ifdef MAC 796175164Sjhb error = mac_posixshm_check_truncate( 797175164Sjhb td->td_ucred, fp->f_cred, shmfd); 798175164Sjhb if (error == 0) 799175164Sjhb#endif 800175164Sjhb shm_dotruncate(shmfd, 0); 801175164Sjhb } 802175164Sjhb if (error == 0) 803175164Sjhb shm_hold(shmfd); 804175164Sjhb } 805175164Sjhb sx_xunlock(&shm_dict_lock); 806175164Sjhb 807175164Sjhb if (error) { 808175164Sjhb fdclose(fdp, fp, fd, td); 809175164Sjhb fdrop(fp, td); 810175164Sjhb return (error); 811175164Sjhb } 812175164Sjhb } 813175164Sjhb 814175164Sjhb finit(fp, FFLAGS(uap->flags & O_ACCMODE), DTYPE_SHM, shmfd, &shm_ops); 815175164Sjhb 816175164Sjhb td->td_retval[0] = fd; 817175164Sjhb fdrop(fp, td); 818175164Sjhb 819175164Sjhb return (0); 820175164Sjhb} 821175164Sjhb 822175164Sjhbint 823225617Skmacysys_shm_unlink(struct thread *td, struct shm_unlink_args *uap) 824175164Sjhb{ 825175164Sjhb char *path; 826175164Sjhb Fnv32_t fnv; 827175164Sjhb int error; 828175164Sjhb 829175164Sjhb path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 830175164Sjhb error = copyinstr(uap->path, path, MAXPATHLEN, NULL); 831175164Sjhb if (error) { 832175164Sjhb free(path, M_TEMP); 833175164Sjhb return (error); 834175164Sjhb } 835269742Srpaulo#ifdef KTRACE 836269742Srpaulo if (KTRPOINT(curthread, KTR_NAMEI)) 837269742Srpaulo ktrnamei(path); 838269742Srpaulo#endif 839175164Sjhb fnv = fnv_32_str(path, FNV1_32_INIT); 840175164Sjhb sx_xlock(&shm_dict_lock); 841175164Sjhb error = shm_remove(path, fnv, td->td_ucred); 842175164Sjhb sx_xunlock(&shm_dict_lock); 843175164Sjhb free(path, M_TEMP); 844175164Sjhb 845175164Sjhb return (error); 846175164Sjhb} 847175164Sjhb 848175164Sjhb/* 849175164Sjhb * mmap() helper to validate mmap() requests against shm object state 850175164Sjhb * and give mmap() the vm_object to use for the mapping. 851175164Sjhb */ 852175164Sjhbint 853175164Sjhbshm_mmap(struct shmfd *shmfd, vm_size_t objsize, vm_ooffset_t foff, 854175164Sjhb vm_object_t *obj) 855175164Sjhb{ 856175164Sjhb 857175164Sjhb /* 858175164Sjhb * XXXRW: This validation is probably insufficient, and subject to 859175164Sjhb * sign errors. It should be fixed. 860175164Sjhb */ 861185533Skan if (foff >= shmfd->shm_size || 862185533Skan foff + objsize > round_page(shmfd->shm_size)) 863175164Sjhb return (EINVAL); 864175164Sjhb 865175164Sjhb mtx_lock(&shm_timestamp_lock); 866175164Sjhb vfs_timestamp(&shmfd->shm_atime); 867175164Sjhb mtx_unlock(&shm_timestamp_lock); 868175164Sjhb vm_object_reference(shmfd->shm_object); 869175164Sjhb *obj = shmfd->shm_object; 870175164Sjhb return (0); 871175164Sjhb} 872224914Skib 873224914Skibstatic int 874224914Skibshm_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, 875224914Skib struct thread *td) 876224914Skib{ 877224914Skib struct shmfd *shmfd; 878224914Skib int error; 879224914Skib 880224914Skib error = 0; 881224914Skib shmfd = fp->f_data; 882224914Skib mtx_lock(&shm_timestamp_lock); 883224914Skib /* 884224914Skib * SUSv4 says that x bits of permission need not be affected. 885224914Skib * Be consistent with our shm_open there. 886224914Skib */ 887224914Skib#ifdef MAC 888224914Skib error = mac_posixshm_check_setmode(active_cred, shmfd, mode); 889224914Skib if (error != 0) 890224914Skib goto out; 891224914Skib#endif 892224914Skib error = vaccess(VREG, shmfd->shm_mode, shmfd->shm_uid, 893224914Skib shmfd->shm_gid, VADMIN, active_cred, NULL); 894224914Skib if (error != 0) 895224914Skib goto out; 896224914Skib shmfd->shm_mode = mode & ACCESSPERMS; 897224914Skibout: 898224914Skib mtx_unlock(&shm_timestamp_lock); 899224914Skib return (error); 900224914Skib} 901224914Skib 902224914Skibstatic int 903224914Skibshm_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, 904224914Skib struct thread *td) 905224914Skib{ 906224914Skib struct shmfd *shmfd; 907224914Skib int error; 908224914Skib 909224935Skib error = 0; 910224914Skib shmfd = fp->f_data; 911224914Skib mtx_lock(&shm_timestamp_lock); 912224914Skib#ifdef MAC 913224914Skib error = mac_posixshm_check_setowner(active_cred, shmfd, uid, gid); 914224914Skib if (error != 0) 915224914Skib goto out; 916224914Skib#endif 917224914Skib if (uid == (uid_t)-1) 918224914Skib uid = shmfd->shm_uid; 919224914Skib if (gid == (gid_t)-1) 920224914Skib gid = shmfd->shm_gid; 921224914Skib if (((uid != shmfd->shm_uid && uid != active_cred->cr_uid) || 922224914Skib (gid != shmfd->shm_gid && !groupmember(gid, active_cred))) && 923224914Skib (error = priv_check_cred(active_cred, PRIV_VFS_CHOWN, 0))) 924224914Skib goto out; 925224914Skib shmfd->shm_uid = uid; 926224914Skib shmfd->shm_gid = gid; 927224914Skibout: 928224914Skib mtx_unlock(&shm_timestamp_lock); 929224914Skib return (error); 930224914Skib} 931228509Sjhb 932228509Sjhb/* 933228509Sjhb * Helper routines to allow the backing object of a shared memory file 934228509Sjhb * descriptor to be mapped in the kernel. 935228509Sjhb */ 936228509Sjhbint 937228509Sjhbshm_map(struct file *fp, size_t size, off_t offset, void **memp) 938228509Sjhb{ 939228509Sjhb struct shmfd *shmfd; 940228509Sjhb vm_offset_t kva, ofs; 941228509Sjhb vm_object_t obj; 942228509Sjhb int rv; 943228509Sjhb 944228509Sjhb if (fp->f_type != DTYPE_SHM) 945228509Sjhb return (EINVAL); 946228509Sjhb shmfd = fp->f_data; 947228509Sjhb obj = shmfd->shm_object; 948248084Sattilio VM_OBJECT_WLOCK(obj); 949228509Sjhb /* 950228509Sjhb * XXXRW: This validation is probably insufficient, and subject to 951228509Sjhb * sign errors. It should be fixed. 952228509Sjhb */ 953228509Sjhb if (offset >= shmfd->shm_size || 954228509Sjhb offset + size > round_page(shmfd->shm_size)) { 955248084Sattilio VM_OBJECT_WUNLOCK(obj); 956228509Sjhb return (EINVAL); 957228509Sjhb } 958228509Sjhb 959228509Sjhb shmfd->shm_kmappings++; 960228509Sjhb vm_object_reference_locked(obj); 961248084Sattilio VM_OBJECT_WUNLOCK(obj); 962228509Sjhb 963228509Sjhb /* Map the object into the kernel_map and wire it. */ 964228509Sjhb kva = vm_map_min(kernel_map); 965228509Sjhb ofs = offset & PAGE_MASK; 966228509Sjhb offset = trunc_page(offset); 967228509Sjhb size = round_page(size + ofs); 968255426Sjhb rv = vm_map_find(kernel_map, obj, offset, &kva, size, 0, 969253620Sjhb VMFS_OPTIMAL_SPACE, VM_PROT_READ | VM_PROT_WRITE, 970228509Sjhb VM_PROT_READ | VM_PROT_WRITE, 0); 971228509Sjhb if (rv == KERN_SUCCESS) { 972228509Sjhb rv = vm_map_wire(kernel_map, kva, kva + size, 973228509Sjhb VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES); 974228509Sjhb if (rv == KERN_SUCCESS) { 975228509Sjhb *memp = (void *)(kva + ofs); 976228509Sjhb return (0); 977228509Sjhb } 978228509Sjhb vm_map_remove(kernel_map, kva, kva + size); 979228509Sjhb } else 980228509Sjhb vm_object_deallocate(obj); 981228509Sjhb 982228509Sjhb /* On failure, drop our mapping reference. */ 983248084Sattilio VM_OBJECT_WLOCK(obj); 984228509Sjhb shmfd->shm_kmappings--; 985248084Sattilio VM_OBJECT_WUNLOCK(obj); 986228509Sjhb 987228533Sjhb return (vm_mmap_to_errno(rv)); 988228509Sjhb} 989228509Sjhb 990228509Sjhb/* 991228509Sjhb * We require the caller to unmap the entire entry. This allows us to 992228509Sjhb * safely decrement shm_kmappings when a mapping is removed. 993228509Sjhb */ 994228509Sjhbint 995228509Sjhbshm_unmap(struct file *fp, void *mem, size_t size) 996228509Sjhb{ 997228509Sjhb struct shmfd *shmfd; 998228509Sjhb vm_map_entry_t entry; 999228509Sjhb vm_offset_t kva, ofs; 1000228509Sjhb vm_object_t obj; 1001228509Sjhb vm_pindex_t pindex; 1002228509Sjhb vm_prot_t prot; 1003228509Sjhb boolean_t wired; 1004228509Sjhb vm_map_t map; 1005228509Sjhb int rv; 1006228509Sjhb 1007228509Sjhb if (fp->f_type != DTYPE_SHM) 1008228509Sjhb return (EINVAL); 1009228509Sjhb shmfd = fp->f_data; 1010228509Sjhb kva = (vm_offset_t)mem; 1011228509Sjhb ofs = kva & PAGE_MASK; 1012228509Sjhb kva = trunc_page(kva); 1013228509Sjhb size = round_page(size + ofs); 1014228509Sjhb map = kernel_map; 1015228509Sjhb rv = vm_map_lookup(&map, kva, VM_PROT_READ | VM_PROT_WRITE, &entry, 1016228509Sjhb &obj, &pindex, &prot, &wired); 1017228509Sjhb if (rv != KERN_SUCCESS) 1018228509Sjhb return (EINVAL); 1019228509Sjhb if (entry->start != kva || entry->end != kva + size) { 1020228509Sjhb vm_map_lookup_done(map, entry); 1021228509Sjhb return (EINVAL); 1022228509Sjhb } 1023228509Sjhb vm_map_lookup_done(map, entry); 1024228509Sjhb if (obj != shmfd->shm_object) 1025228509Sjhb return (EINVAL); 1026228509Sjhb vm_map_remove(map, kva, kva + size); 1027248084Sattilio VM_OBJECT_WLOCK(obj); 1028228509Sjhb KASSERT(shmfd->shm_kmappings > 0, ("shm_unmap: object not mapped")); 1029228509Sjhb shmfd->shm_kmappings--; 1030248084Sattilio VM_OBJECT_WUNLOCK(obj); 1031228509Sjhb return (0); 1032228509Sjhb} 1033233760Sjhb 1034233760Sjhbvoid 1035233760Sjhbshm_path(struct shmfd *shmfd, char *path, size_t size) 1036233760Sjhb{ 1037233760Sjhb 1038233760Sjhb if (shmfd->shm_path == NULL) 1039233760Sjhb return; 1040233760Sjhb sx_slock(&shm_dict_lock); 1041233760Sjhb if (shmfd->shm_path != NULL) 1042233760Sjhb strlcpy(path, shmfd->shm_path, size); 1043233760Sjhb sx_sunlock(&shm_dict_lock); 1044233760Sjhb} 1045