Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/mem.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
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. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 40 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 41 * $FreeBSD$ 42 */ 43 44 /* 45 * Memory special file 46 */ 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/buf.h> 51 #include <sys/conf.h> 52 #include <sys/fcntl.h> 53 #include <sys/filio.h> 54 #include <sys/ioccom.h> 55 #include <sys/kernel.h> 56 #include <sys/malloc.h> 57 #include <sys/memrange.h> 58 #include <sys/proc.h> 59 #include <sys/random.h> 60 #include <sys/signalvar.h> 61 #include <sys/uio.h> 62 #include <sys/vnode.h> 63 64 #include <machine/frame.h> 65 #include <machine/psl.h> 66 #include <machine/specialreg.h> 67 #include <i386/isa/intr_machdep.h> 68 69 #include <vm/vm.h> 70 #include <vm/pmap.h> 71 #include <vm/vm_extern.h> 72 73 74 static d_open_t mmopen; 75 static d_close_t mmclose; 76 static d_read_t mmrw; 77 static d_ioctl_t mmioctl; 78 static d_mmap_t memmmap; 79 static d_poll_t mmpoll; 80 81 #define CDEV_MAJOR 2 82 static struct cdevsw mem_cdevsw = { 83 /* open */ mmopen, 84 /* close */ mmclose, 85 /* read */ mmrw, 86 /* write */ mmrw, 87 /* ioctl */ mmioctl, 88 /* poll */ mmpoll, 89 /* mmap */ memmmap, 90 /* strategy */ nostrategy, 91 /* name */ "mem", 92 /* maj */ CDEV_MAJOR, 93 /* dump */ nodump, 94 /* psize */ nopsize, 95 /* flags */ D_MEM, 96 /* bmaj */ -1 97 }; 98 99 static struct random_softc random_softc[16]; 100 static caddr_t zbuf; 101 102 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 103 static int mem_ioctl __P((dev_t, u_long, caddr_t, int, struct proc *)); 104 static int random_ioctl __P((dev_t, u_long, caddr_t, int, struct proc *)); 105 106 struct mem_range_softc mem_range_softc; 107 108 109 static int 110 mmclose(dev, flags, fmt, p) 111 dev_t dev; 112 int flags; 113 int fmt; 114 struct proc *p; 115 { 116 switch (minor(dev)) { 117 case 14: 118 p->p_md.md_regs->tf_eflags &= ~PSL_IOPL; 119 break; 120 default: 121 break; 122 } 123 return (0); 124 } 125 126 static int 127 mmopen(dev, flags, fmt, p) 128 dev_t dev; 129 int flags; 130 int fmt; 131 struct proc *p; 132 { 133 int error; 134 135 switch (minor(dev)) { 136 case 0: 137 case 1: 138 if ((flags & FWRITE) && securelevel > 0) 139 return (EPERM); 140 break; 141 case 14: 142 error = suser(p); 143 if (error != 0) 144 return (error); 145 if (securelevel > 0) 146 return (EPERM); 147 p->p_md.md_regs->tf_eflags |= PSL_IOPL; 148 break; 149 default: 150 break; 151 } 152 return (0); 153 } 154 155 static int 156 mmrw(dev, uio, flags) 157 dev_t dev; 158 struct uio *uio; 159 int flags; 160 { 161 register int o; 162 register u_int c; 163 u_int poolsize; 164 register struct iovec *iov; 165 int error = 0; 166 caddr_t buf = NULL; 167 168 while (uio->uio_resid > 0 && error == 0) { 169 iov = uio->uio_iov; 170 if (iov->iov_len == 0) { 171 uio->uio_iov++; 172 uio->uio_iovcnt--; 173 if (uio->uio_iovcnt < 0) 174 panic("mmrw"); 175 continue; 176 } 177 switch (minor(dev)) { 178 179 /* minor device 0 is physical memory */ 180 case 0: 181 pmap_kenter((vm_offset_t)ptvmmap, 182 uio->uio_offset & ~PAGE_MASK); 183 o = (int)uio->uio_offset & PAGE_MASK; 184 c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK)); 185 c = min(c, (u_int)(PAGE_SIZE - o)); 186 c = min(c, (u_int)iov->iov_len); 187 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); 188 pmap_kremove((vm_offset_t)ptvmmap); 189 continue; 190 191 /* minor device 1 is kernel memory */ 192 case 1: { 193 vm_offset_t addr, eaddr; 194 c = iov->iov_len; 195 196 /* 197 * Make sure that all of the pages are currently resident so 198 * that we don't create any zero-fill pages. 199 */ 200 addr = trunc_page(uio->uio_offset); 201 eaddr = round_page(uio->uio_offset + c); 202 203 if (addr < (vm_offset_t)VADDR(PTDPTDI, 0)) 204 return EFAULT; 205 for (; addr < eaddr; addr += PAGE_SIZE) 206 if (pmap_extract(kernel_pmap, addr) == 0) 207 return EFAULT; 208 209 if (!kernacc((caddr_t)(int)uio->uio_offset, c, 210 uio->uio_rw == UIO_READ ? 211 VM_PROT_READ : VM_PROT_WRITE)) 212 return (EFAULT); 213 error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio); 214 continue; 215 } 216 217 /* minor device 2 is EOF/RATHOLE */ 218 case 2: 219 if (uio->uio_rw == UIO_READ) 220 return (0); 221 c = iov->iov_len; 222 break; 223 224 /* minor device 3 (/dev/random) is source of filth on read, rathole on write */ 225 case 3: 226 if (uio->uio_rw == UIO_WRITE) { 227 c = iov->iov_len; 228 break; 229 } 230 if (buf == NULL) 231 buf = (caddr_t) 232 malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 233 c = min(iov->iov_len, PAGE_SIZE); 234 poolsize = read_random(buf, c); 235 if (poolsize == 0) { 236 if (buf) 237 free(buf, M_TEMP); 238 if ((flags & IO_NDELAY) != 0) 239 return (EWOULDBLOCK); 240 return (0); 241 } 242 c = min(c, poolsize); 243 error = uiomove(buf, (int)c, uio); 244 continue; 245 246 /* minor device 4 (/dev/urandom) is source of muck on read, rathole on write */ 247 case 4: 248 if (uio->uio_rw == UIO_WRITE) { 249 c = iov->iov_len; 250 break; 251 } 252 if (CURSIG(curproc) != 0) { 253 /* 254 * Use tsleep() to get the error code right. 255 * It should return immediately. 256 */ 257 error = tsleep(&random_softc[0], 258 PZERO | PCATCH, "urand", 1); 259 if (error != 0 && error != EWOULDBLOCK) 260 continue; 261 } 262 if (buf == NULL) 263 buf = (caddr_t) 264 malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 265 c = min(iov->iov_len, PAGE_SIZE); 266 poolsize = read_random_unlimited(buf, c); 267 c = min(c, poolsize); 268 error = uiomove(buf, (int)c, uio); 269 continue; 270 271 /* minor device 12 (/dev/zero) is source of nulls on read, rathole on write */ 272 case 12: 273 if (uio->uio_rw == UIO_WRITE) { 274 c = iov->iov_len; 275 break; 276 } 277 if (zbuf == NULL) { 278 zbuf = (caddr_t) 279 malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 280 bzero(zbuf, PAGE_SIZE); 281 } 282 c = min(iov->iov_len, PAGE_SIZE); 283 error = uiomove(zbuf, (int)c, uio); 284 continue; 285 286 default: 287 return (ENODEV); 288 } 289 if (error) 290 break; 291 iov->iov_base += c; 292 iov->iov_len -= c; 293 uio->uio_offset += c; 294 uio->uio_resid -= c; 295 } 296 if (buf) 297 free(buf, M_TEMP); 298 return (error); 299 } 300 301 302 303 304 /*******************************************************\ 305 * allow user processes to MMAP some memory sections * 306 * instead of going through read/write * 307 \*******************************************************/ 308 static int 309 memmmap(dev_t dev, vm_offset_t offset, int nprot) 310 { 311 switch (minor(dev)) 312 { 313 314 /* minor device 0 is physical memory */ 315 case 0: 316 return i386_btop(offset); 317 318 /* minor device 1 is kernel memory */ 319 case 1: 320 return i386_btop(vtophys(offset)); 321 322 default: 323 return -1; 324 } 325 } 326 327 static int 328 mmioctl(dev, cmd, data, flags, p) 329 dev_t dev; 330 u_long cmd; 331 caddr_t data; 332 int flags; 333 struct proc *p; 334 { 335 336 switch (minor(dev)) { 337 case 0: 338 return mem_ioctl(dev, cmd, data, flags, p); 339 case 3: 340 case 4: 341 return random_ioctl(dev, cmd, data, flags, p); 342 } 343 return (ENODEV); 344 } 345 346 /* 347 * Operations for changing memory attributes. 348 * 349 * This is basically just an ioctl shim for mem_range_attr_get 350 * and mem_range_attr_set. 351 */ 352 static int 353 mem_ioctl(dev, cmd, data, flags, p) 354 dev_t dev; 355 u_long cmd; 356 caddr_t data; 357 int flags; 358 struct proc *p; 359 { 360 int nd, error = 0; 361 struct mem_range_op *mo = (struct mem_range_op *)data; 362 struct mem_range_desc *md; 363 364 /* is this for us? */ 365 if ((cmd != MEMRANGE_GET) && 366 (cmd != MEMRANGE_SET)) 367 return (ENOTTY); 368 369 /* any chance we can handle this? */ 370 if (mem_range_softc.mr_op == NULL) 371 return (EOPNOTSUPP); 372 373 /* do we have any descriptors? */ 374 if (mem_range_softc.mr_ndesc == 0) 375 return (ENXIO); 376 377 switch (cmd) { 378 case MEMRANGE_GET: 379 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 380 if (nd > 0) { 381 md = (struct mem_range_desc *) 382 malloc(nd * sizeof(struct mem_range_desc), 383 M_MEMDESC, M_WAITOK); 384 error = mem_range_attr_get(md, &nd); 385 if (!error) 386 error = copyout(md, mo->mo_desc, 387 nd * sizeof(struct mem_range_desc)); 388 free(md, M_MEMDESC); 389 } else { 390 nd = mem_range_softc.mr_ndesc; 391 } 392 mo->mo_arg[0] = nd; 393 break; 394 395 case MEMRANGE_SET: 396 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 397 M_MEMDESC, M_WAITOK); 398 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 399 /* clamp description string */ 400 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 401 if (error == 0) 402 error = mem_range_attr_set(md, &mo->mo_arg[0]); 403 free(md, M_MEMDESC); 404 break; 405 } 406 return (error); 407 } 408 409 /* 410 * Implementation-neutral, kernel-callable functions for manipulating 411 * memory range attributes. 412 */ 413 int 414 mem_range_attr_get(mrd, arg) 415 struct mem_range_desc *mrd; 416 int *arg; 417 { 418 /* can we handle this? */ 419 if (mem_range_softc.mr_op == NULL) 420 return (EOPNOTSUPP); 421 422 if (*arg == 0) { 423 *arg = mem_range_softc.mr_ndesc; 424 } else { 425 bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc)); 426 } 427 return (0); 428 } 429 430 int 431 mem_range_attr_set(mrd, arg) 432 struct mem_range_desc *mrd; 433 int *arg; 434 { 435 /* can we handle this? */ 436 if (mem_range_softc.mr_op == NULL) 437 return (EOPNOTSUPP); 438 439 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg)); 440 } 441 442 #ifdef SMP 443 void 444 mem_range_AP_init(void) 445 { 446 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP) 447 return (mem_range_softc.mr_op->initAP(&mem_range_softc)); 448 } 449 #endif 450 451 static int 452 random_ioctl(dev, cmd, data, flags, p) 453 dev_t dev; 454 u_long cmd; 455 caddr_t data; 456 int flags; 457 struct proc *p; 458 { 459 static intrmask_t interrupt_allowed; 460 intrmask_t interrupt_mask; 461 int error, intr; 462 struct random_softc *sc; 463 464 /* 465 * We're the random or urandom device. The only ioctls are for 466 * selecting and inspecting which interrupts are used in the muck 467 * gathering business and the fcntl() stuff. 468 */ 469 if (cmd != MEM_SETIRQ && cmd != MEM_CLEARIRQ && cmd != MEM_RETURNIRQ 470 && cmd != FIONBIO && cmd != FIOASYNC) 471 return (ENOTTY); 472 473 /* 474 * XXX the data is 16-bit due to a historical botch, so we use 475 * magic 16's instead of ICU_LEN and can't support 24 interrupts 476 * under SMP. 477 * Even inspecting the state is privileged, since it gives a hint 478 * about how easily the randomness might be guessed. 479 */ 480 intr = *(int16_t *)data; 481 interrupt_mask = 1 << intr; 482 sc = &random_softc[intr]; 483 switch (cmd) { 484 /* Really handled in upper layer */ 485 case FIOASYNC: 486 case FIONBIO: 487 break; 488 case MEM_SETIRQ: 489 error = suser(p); 490 if (error != 0) 491 return (error); 492 if (intr < 0 || intr >= 16) 493 return (EINVAL); 494 if (interrupt_allowed & interrupt_mask) 495 break; 496 interrupt_allowed |= interrupt_mask; 497 sc->sc_intr = intr; 498 disable_intr(); 499 sc->sc_handler = intr_handler[intr]; 500 intr_handler[intr] = add_interrupt_randomness; 501 sc->sc_arg = intr_unit[intr]; 502 intr_unit[intr] = sc; 503 enable_intr(); 504 break; 505 case MEM_CLEARIRQ: 506 error = suser(p); 507 if (error != 0) 508 return (error); 509 if (intr < 0 || intr >= 16) 510 return (EINVAL); 511 if (!(interrupt_allowed & interrupt_mask)) 512 break; 513 interrupt_allowed &= ~interrupt_mask; 514 disable_intr(); 515 intr_handler[intr] = sc->sc_handler; 516 intr_unit[intr] = sc->sc_arg; 517 enable_intr(); 518 break; 519 case MEM_RETURNIRQ: 520 error = suser(p); 521 if (error != 0) 522 return (error); 523 *(u_int16_t *)data = interrupt_allowed; 524 break; 525 } 526 return (0); 527 } 528 529 int 530 mmpoll(dev, events, p) 531 dev_t dev; 532 int events; 533 struct proc *p; 534 { 535 switch (minor(dev)) { 536 case 3: /* /dev/random */ 537 return random_poll(dev, events, p); 538 case 4: /* /dev/urandom */ 539 default: 540 return seltrue(dev, events, p); 541 } 542 } 543 544 int 545 iszerodev(dev) 546 dev_t dev; 547 { 548 return ((major(dev) == mem_cdevsw.d_maj) 549 && minor(dev) == 12); 550 } 551 552 static void 553 mem_drvinit(void *unused) 554 { 555 556 /* Initialise memory range handling */ 557 if (mem_range_softc.mr_op != NULL) 558 mem_range_softc.mr_op->init(&mem_range_softc); 559 560 make_dev(&mem_cdevsw, 0, UID_ROOT, GID_KMEM, 0640, "mem"); 561 make_dev(&mem_cdevsw, 1, UID_ROOT, GID_KMEM, 0640, "kmem"); 562 make_dev(&mem_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "null"); 563 make_dev(&mem_cdevsw, 3, UID_ROOT, GID_WHEEL, 0644, "random"); 564 make_dev(&mem_cdevsw, 4, UID_ROOT, GID_WHEEL, 0644, "urandom"); 565 make_dev(&mem_cdevsw, 12, UID_ROOT, GID_WHEEL, 0666, "zero"); 566 make_dev(&mem_cdevsw, 14, UID_ROOT, GID_WHEEL, 0600, "io"); 567 } 568 569 SYSINIT(memdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,mem_drvinit,NULL) 570
Cache object: c4a60d56a7c2d714f72c9f40a0a32532
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]