1 /*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department, and code derived from software contributed to 9 * Berkeley by William Jolitz. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 36 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 37 * $FreeBSD: src/sys/i386/i386/mem.c,v 1.79.2.9 2003/01/04 22:58:01 njl Exp $ 38 */ 39 40 /* 41 * Memory special file 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/buf.h> 47 #include <sys/conf.h> 48 #include <sys/fcntl.h> 49 #include <sys/filio.h> 50 #include <sys/kernel.h> 51 #include <sys/malloc.h> 52 #include <sys/memrange.h> 53 #include <sys/proc.h> 54 #include <sys/priv.h> 55 #include <sys/random.h> 56 #include <sys/signalvar.h> 57 #include <sys/uio.h> 58 #include <sys/vnode.h> 59 #include <sys/sysctl.h> 60 61 #include <sys/signal2.h> 62 #include <sys/mplock2.h> 63 64 #include <vm/vm.h> 65 #include <vm/pmap.h> 66 #include <vm/vm_extern.h> 67 68 69 static d_open_t mmopen; 70 static d_close_t mmclose; 71 static d_read_t mmread; 72 static d_write_t mmwrite; 73 static d_ioctl_t mmioctl; 74 #if 0 75 static d_mmap_t memmmap; 76 #endif 77 static d_kqfilter_t mmkqfilter; 78 static int memuksmap(cdev_t dev, vm_page_t fake); 79 80 #define CDEV_MAJOR 2 81 static struct dev_ops mem_ops = { 82 { "mem", 0, D_MPSAFE }, 83 .d_open = mmopen, 84 .d_close = mmclose, 85 .d_read = mmread, 86 .d_write = mmwrite, 87 .d_ioctl = mmioctl, 88 .d_kqfilter = mmkqfilter, 89 #if 0 90 .d_mmap = memmmap, 91 #endif 92 .d_uksmap = memuksmap 93 }; 94 95 static int rand_bolt; 96 static caddr_t zbuf; 97 static cdev_t zerodev = NULL; 98 99 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 100 static int mem_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *); 101 static int random_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *); 102 103 struct mem_range_softc mem_range_softc; 104 105 static int seedenable; 106 SYSCTL_INT(_kern, OID_AUTO, seedenable, CTLFLAG_RW, &seedenable, 0, ""); 107 108 static int 109 mmopen(struct dev_open_args *ap) 110 { 111 cdev_t dev = ap->a_head.a_dev; 112 int error; 113 114 switch (minor(dev)) { 115 case 0: 116 case 1: 117 /* 118 * /dev/mem and /dev/kmem 119 */ 120 if (ap->a_oflags & FWRITE) { 121 if (securelevel > 0 || kernel_mem_readonly) 122 return (EPERM); 123 } 124 error = 0; 125 break; 126 case 6: 127 /* 128 * /dev/kpmap can only be opened for reading. 129 */ 130 if (ap->a_oflags & FWRITE) 131 return (EPERM); 132 error = 0; 133 break; 134 case 14: 135 error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0); 136 if (error != 0) 137 break; 138 if (securelevel > 0 || kernel_mem_readonly) { 139 error = EPERM; 140 break; 141 } 142 error = cpu_set_iopl(); 143 break; 144 default: 145 error = 0; 146 break; 147 } 148 return (error); 149 } 150 151 static int 152 mmclose(struct dev_close_args *ap) 153 { 154 cdev_t dev = ap->a_head.a_dev; 155 int error; 156 157 switch (minor(dev)) { 158 case 14: 159 error = cpu_clr_iopl(); 160 break; 161 default: 162 error = 0; 163 break; 164 } 165 return (error); 166 } 167 168 169 static int 170 mmrw(cdev_t dev, struct uio *uio, int flags) 171 { 172 int o; 173 u_int c; 174 u_int poolsize; 175 u_long v; 176 struct iovec *iov; 177 int error = 0; 178 caddr_t buf = NULL; 179 180 while (uio->uio_resid > 0 && error == 0) { 181 iov = uio->uio_iov; 182 if (iov->iov_len == 0) { 183 uio->uio_iov++; 184 uio->uio_iovcnt--; 185 if (uio->uio_iovcnt < 0) 186 panic("mmrw"); 187 continue; 188 } 189 switch (minor(dev)) { 190 case 0: 191 /* 192 * minor device 0 is physical memory, /dev/mem 193 */ 194 v = uio->uio_offset; 195 v &= ~(long)PAGE_MASK; 196 pmap_kenter((vm_offset_t)ptvmmap, v); 197 o = (int)uio->uio_offset & PAGE_MASK; 198 c = (u_int)(PAGE_SIZE - ((uintptr_t)iov->iov_base & PAGE_MASK)); 199 c = min(c, (u_int)(PAGE_SIZE - o)); 200 c = min(c, (u_int)iov->iov_len); 201 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); 202 pmap_kremove((vm_offset_t)ptvmmap); 203 continue; 204 205 case 1: { 206 /* 207 * minor device 1 is kernel memory, /dev/kmem 208 */ 209 vm_offset_t saddr, eaddr; 210 int prot; 211 212 c = iov->iov_len; 213 214 /* 215 * Make sure that all of the pages are currently 216 * resident so that we don't create any zero-fill 217 * pages. 218 */ 219 saddr = trunc_page(uio->uio_offset); 220 eaddr = round_page(uio->uio_offset + c); 221 if (saddr > eaddr) 222 return EFAULT; 223 224 /* 225 * Make sure the kernel addresses are mapped. 226 * platform_direct_mapped() can be used to bypass 227 * default mapping via the page table (virtual kernels 228 * contain a lot of out-of-band data). 229 */ 230 prot = VM_PROT_READ; 231 if (uio->uio_rw != UIO_READ) 232 prot |= VM_PROT_WRITE; 233 error = kvm_access_check(saddr, eaddr, prot); 234 if (error) 235 return (error); 236 error = uiomove((caddr_t)(vm_offset_t)uio->uio_offset, 237 (int)c, uio); 238 continue; 239 } 240 case 2: 241 /* 242 * minor device 2 (/dev/null) is EOF/RATHOLE 243 */ 244 if (uio->uio_rw == UIO_READ) 245 return (0); 246 c = iov->iov_len; 247 break; 248 case 3: 249 /* 250 * minor device 3 (/dev/random) is source of filth 251 * on read, seeder on write 252 */ 253 if (buf == NULL) 254 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK); 255 c = min(iov->iov_len, PAGE_SIZE); 256 if (uio->uio_rw == UIO_WRITE) { 257 error = uiomove(buf, (int)c, uio); 258 if (error == 0 && 259 seedenable && 260 securelevel <= 0) { 261 error = add_buffer_randomness_src(buf, c, RAND_SRC_SEEDING); 262 } else if (error == 0) { 263 error = EPERM; 264 } 265 } else { 266 poolsize = read_random(buf, c); 267 if (poolsize == 0) { 268 if (buf) 269 kfree(buf, M_TEMP); 270 if ((flags & IO_NDELAY) != 0) 271 return (EWOULDBLOCK); 272 return (0); 273 } 274 c = min(c, poolsize); 275 error = uiomove(buf, (int)c, uio); 276 } 277 continue; 278 case 4: 279 /* 280 * minor device 4 (/dev/urandom) is source of muck 281 * on read, writes are disallowed. 282 */ 283 c = min(iov->iov_len, PAGE_SIZE); 284 if (uio->uio_rw == UIO_WRITE) { 285 error = EPERM; 286 break; 287 } 288 if (CURSIG(curthread->td_lwp) != 0) { 289 /* 290 * Use tsleep() to get the error code right. 291 * It should return immediately. 292 */ 293 error = tsleep(&rand_bolt, PCATCH, "urand", 1); 294 if (error != 0 && error != EWOULDBLOCK) 295 continue; 296 } 297 if (buf == NULL) 298 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK); 299 poolsize = read_random_unlimited(buf, c); 300 c = min(c, poolsize); 301 error = uiomove(buf, (int)c, uio); 302 continue; 303 /* case 5: read/write not supported, mmap only */ 304 /* case 6: read/write not supported, mmap only */ 305 case 12: 306 /* 307 * minor device 12 (/dev/zero) is source of nulls 308 * on read, write are disallowed. 309 */ 310 if (uio->uio_rw == UIO_WRITE) { 311 c = iov->iov_len; 312 break; 313 } 314 if (zbuf == NULL) { 315 zbuf = (caddr_t)kmalloc(PAGE_SIZE, M_TEMP, 316 M_WAITOK | M_ZERO); 317 } 318 c = min(iov->iov_len, PAGE_SIZE); 319 error = uiomove(zbuf, (int)c, uio); 320 continue; 321 default: 322 return (ENODEV); 323 } 324 if (error) 325 break; 326 iov->iov_base = (char *)iov->iov_base + c; 327 iov->iov_len -= c; 328 uio->uio_offset += c; 329 uio->uio_resid -= c; 330 } 331 if (buf) 332 kfree(buf, M_TEMP); 333 return (error); 334 } 335 336 static int 337 mmread(struct dev_read_args *ap) 338 { 339 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag)); 340 } 341 342 static int 343 mmwrite(struct dev_write_args *ap) 344 { 345 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag)); 346 } 347 348 /*******************************************************\ 349 * allow user processes to MMAP some memory sections * 350 * instead of going through read/write * 351 \*******************************************************/ 352 353 static int user_kernel_mapping(int num, vm_ooffset_t offset, 354 vm_ooffset_t *resultp); 355 356 #if 0 357 358 static int 359 memmmap(struct dev_mmap_args *ap) 360 { 361 cdev_t dev = ap->a_head.a_dev; 362 vm_ooffset_t result; 363 int error; 364 365 switch (minor(dev)) { 366 case 0: 367 /* 368 * minor device 0 is physical memory 369 */ 370 ap->a_result = atop(ap->a_offset); 371 error = 0; 372 break; 373 case 1: 374 /* 375 * minor device 1 is kernel memory 376 */ 377 ap->a_result = atop(vtophys(ap->a_offset)); 378 error = 0; 379 break; 380 case 5: 381 case 6: 382 /* 383 * minor device 5 is /dev/upmap (see sys/upmap.h) 384 * minor device 6 is /dev/kpmap (see sys/upmap.h) 385 */ 386 result = 0; 387 error = user_kernel_mapping(minor(dev), ap->a_offset, &result); 388 ap->a_result = atop(result); 389 break; 390 default: 391 error = EINVAL; 392 break; 393 } 394 return error; 395 } 396 397 #endif 398 399 static int 400 memuksmap(cdev_t dev, vm_page_t fake) 401 { 402 vm_ooffset_t result; 403 int error; 404 405 switch (minor(dev)) { 406 case 0: 407 /* 408 * minor device 0 is physical memory 409 */ 410 fake->phys_addr = ptoa(fake->pindex); 411 error = 0; 412 break; 413 case 1: 414 /* 415 * minor device 1 is kernel memory 416 */ 417 fake->phys_addr = vtophys(ptoa(fake->pindex)); 418 error = 0; 419 break; 420 case 5: 421 case 6: 422 /* 423 * minor device 5 is /dev/upmap (see sys/upmap.h) 424 * minor device 6 is /dev/kpmap (see sys/upmap.h) 425 */ 426 result = 0; 427 error = user_kernel_mapping(minor(dev), 428 ptoa(fake->pindex), &result); 429 fake->phys_addr = result; 430 break; 431 default: 432 error = EINVAL; 433 break; 434 } 435 return error; 436 } 437 438 static int 439 mmioctl(struct dev_ioctl_args *ap) 440 { 441 cdev_t dev = ap->a_head.a_dev; 442 int error; 443 444 get_mplock(); 445 446 switch (minor(dev)) { 447 case 0: 448 error = mem_ioctl(dev, ap->a_cmd, ap->a_data, 449 ap->a_fflag, ap->a_cred); 450 break; 451 case 3: 452 case 4: 453 error = random_ioctl(dev, ap->a_cmd, ap->a_data, 454 ap->a_fflag, ap->a_cred); 455 break; 456 default: 457 error = ENODEV; 458 break; 459 } 460 461 rel_mplock(); 462 return (error); 463 } 464 465 /* 466 * Operations for changing memory attributes. 467 * 468 * This is basically just an ioctl shim for mem_range_attr_get 469 * and mem_range_attr_set. 470 */ 471 static int 472 mem_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred) 473 { 474 int nd, error = 0; 475 struct mem_range_op *mo = (struct mem_range_op *)data; 476 struct mem_range_desc *md; 477 478 /* is this for us? */ 479 if ((cmd != MEMRANGE_GET) && 480 (cmd != MEMRANGE_SET)) 481 return (ENOTTY); 482 483 /* any chance we can handle this? */ 484 if (mem_range_softc.mr_op == NULL) 485 return (EOPNOTSUPP); 486 487 /* do we have any descriptors? */ 488 if (mem_range_softc.mr_ndesc == 0) 489 return (ENXIO); 490 491 switch (cmd) { 492 case MEMRANGE_GET: 493 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 494 if (nd > 0) { 495 md = (struct mem_range_desc *) 496 kmalloc(nd * sizeof(struct mem_range_desc), 497 M_MEMDESC, M_WAITOK); 498 error = mem_range_attr_get(md, &nd); 499 if (!error) 500 error = copyout(md, mo->mo_desc, 501 nd * sizeof(struct mem_range_desc)); 502 kfree(md, M_MEMDESC); 503 } else { 504 nd = mem_range_softc.mr_ndesc; 505 } 506 mo->mo_arg[0] = nd; 507 break; 508 509 case MEMRANGE_SET: 510 md = (struct mem_range_desc *)kmalloc(sizeof(struct mem_range_desc), 511 M_MEMDESC, M_WAITOK); 512 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 513 /* clamp description string */ 514 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 515 if (error == 0) 516 error = mem_range_attr_set(md, &mo->mo_arg[0]); 517 kfree(md, M_MEMDESC); 518 break; 519 } 520 return (error); 521 } 522 523 /* 524 * Implementation-neutral, kernel-callable functions for manipulating 525 * memory range attributes. 526 */ 527 int 528 mem_range_attr_get(struct mem_range_desc *mrd, int *arg) 529 { 530 /* can we handle this? */ 531 if (mem_range_softc.mr_op == NULL) 532 return (EOPNOTSUPP); 533 534 if (*arg == 0) { 535 *arg = mem_range_softc.mr_ndesc; 536 } else { 537 bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc)); 538 } 539 return (0); 540 } 541 542 int 543 mem_range_attr_set(struct mem_range_desc *mrd, int *arg) 544 { 545 /* can we handle this? */ 546 if (mem_range_softc.mr_op == NULL) 547 return (EOPNOTSUPP); 548 549 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); 550 } 551 552 void 553 mem_range_AP_init(void) 554 { 555 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP) 556 mem_range_softc.mr_op->initAP(&mem_range_softc); 557 } 558 559 static int 560 random_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred) 561 { 562 int error; 563 int intr; 564 565 /* 566 * Even inspecting the state is privileged, since it gives a hint 567 * about how easily the randomness might be guessed. 568 */ 569 error = 0; 570 571 switch (cmd) { 572 /* Really handled in upper layer */ 573 case FIOASYNC: 574 break; 575 case MEM_SETIRQ: 576 intr = *(int16_t *)data; 577 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0) 578 break; 579 if (intr < 0 || intr >= MAX_INTS) 580 return (EINVAL); 581 register_randintr(intr); 582 break; 583 case MEM_CLEARIRQ: 584 intr = *(int16_t *)data; 585 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0) 586 break; 587 if (intr < 0 || intr >= MAX_INTS) 588 return (EINVAL); 589 unregister_randintr(intr); 590 break; 591 case MEM_RETURNIRQ: 592 error = ENOTSUP; 593 break; 594 case MEM_FINDIRQ: 595 intr = *(int16_t *)data; 596 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0) 597 break; 598 if (intr < 0 || intr >= MAX_INTS) 599 return (EINVAL); 600 intr = next_registered_randintr(intr); 601 if (intr == MAX_INTS) 602 return (ENOENT); 603 *(u_int16_t *)data = intr; 604 break; 605 default: 606 error = ENOTSUP; 607 break; 608 } 609 return (error); 610 } 611 612 static int 613 mm_filter_read(struct knote *kn, long hint) 614 { 615 return (1); 616 } 617 618 static int 619 mm_filter_write(struct knote *kn, long hint) 620 { 621 return (1); 622 } 623 624 static void 625 dummy_filter_detach(struct knote *kn) {} 626 627 /* Implemented in kern_nrandom.c */ 628 static struct filterops random_read_filtops = 629 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, random_filter_read }; 630 631 static struct filterops mm_read_filtops = 632 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, mm_filter_read }; 633 634 static struct filterops mm_write_filtops = 635 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, mm_filter_write }; 636 637 static int 638 mmkqfilter(struct dev_kqfilter_args *ap) 639 { 640 struct knote *kn = ap->a_kn; 641 cdev_t dev = ap->a_head.a_dev; 642 643 ap->a_result = 0; 644 switch (kn->kn_filter) { 645 case EVFILT_READ: 646 switch (minor(dev)) { 647 case 3: 648 kn->kn_fop = &random_read_filtops; 649 break; 650 default: 651 kn->kn_fop = &mm_read_filtops; 652 break; 653 } 654 break; 655 case EVFILT_WRITE: 656 kn->kn_fop = &mm_write_filtops; 657 break; 658 default: 659 ap->a_result = EOPNOTSUPP; 660 return (0); 661 } 662 663 return (0); 664 } 665 666 int 667 iszerodev(cdev_t dev) 668 { 669 return (zerodev == dev); 670 } 671 672 /* 673 * /dev/upmap and /dev/kpmap. 674 */ 675 static int 676 user_kernel_mapping(int num, vm_ooffset_t offset, vm_ooffset_t *resultp) 677 { 678 struct proc *p; 679 int error; 680 int invfork; 681 682 if ((p = curproc) == NULL) 683 return (EINVAL); 684 685 /* 686 * If this is a child currently in vfork the pmap is shared with 687 * the parent! We need to actually set-up the parent's p_upmap, 688 * not the child's, and we need to set the invfork flag. Userland 689 * will probably adjust its static state so it must be consistent 690 * with the parent or userland will be really badly confused. 691 * 692 * (this situation can happen when user code in vfork() calls 693 * libc's getpid() or some other function which then decides 694 * it wants the upmap). 695 */ 696 if (p->p_flags & P_PPWAIT) { 697 p = p->p_pptr; 698 if (p == NULL) 699 return (EINVAL); 700 invfork = 1; 701 } else { 702 invfork = 0; 703 } 704 705 error = EINVAL; 706 707 switch(num) { 708 case 5: 709 /* 710 * /dev/upmap - maps RW per-process shared user-kernel area. 711 */ 712 if (p->p_upmap == NULL) 713 proc_usermap(p, invfork); 714 else if (invfork) 715 p->p_upmap->invfork = invfork; 716 717 if (p->p_upmap && 718 offset < roundup2(sizeof(*p->p_upmap), PAGE_SIZE)) { 719 /* only good for current process */ 720 *resultp = pmap_kextract((vm_offset_t)p->p_upmap + 721 offset); 722 error = 0; 723 } 724 break; 725 case 6: 726 /* 727 * /dev/kpmap - maps RO shared kernel global page 728 */ 729 if (kpmap && 730 offset < roundup2(sizeof(*kpmap), PAGE_SIZE)) { 731 *resultp = pmap_kextract((vm_offset_t)kpmap + 732 offset); 733 error = 0; 734 } 735 break; 736 default: 737 break; 738 } 739 return error; 740 } 741 742 static void 743 mem_drvinit(void *unused) 744 { 745 746 /* Initialise memory range handling */ 747 if (mem_range_softc.mr_op != NULL) 748 mem_range_softc.mr_op->init(&mem_range_softc); 749 750 make_dev(&mem_ops, 0, UID_ROOT, GID_KMEM, 0640, "mem"); 751 make_dev(&mem_ops, 1, UID_ROOT, GID_KMEM, 0640, "kmem"); 752 make_dev(&mem_ops, 2, UID_ROOT, GID_WHEEL, 0666, "null"); 753 make_dev(&mem_ops, 3, UID_ROOT, GID_WHEEL, 0644, "random"); 754 make_dev(&mem_ops, 4, UID_ROOT, GID_WHEEL, 0644, "urandom"); 755 make_dev(&mem_ops, 5, UID_ROOT, GID_WHEEL, 0666, "upmap"); 756 make_dev(&mem_ops, 6, UID_ROOT, GID_WHEEL, 0444, "kpmap"); 757 zerodev = make_dev(&mem_ops, 12, UID_ROOT, GID_WHEEL, 0666, "zero"); 758 make_dev(&mem_ops, 14, UID_ROOT, GID_WHEEL, 0600, "io"); 759 } 760 761 SYSINIT(memdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR, mem_drvinit, 762 NULL); 763 764