1 /*- 2 * Copyright (c) 1982, 1986, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Copyright (c) 2014 The FreeBSD Foundation 11 * 12 * Portions of this software were developed by Konstantin Belousov 13 * under sponsorship from the FreeBSD Foundation. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 3. 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 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 40 */ 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/limits.h> 49 #include <sys/lock.h> 50 #include <sys/mman.h> 51 #include <sys/proc.h> 52 #include <sys/resourcevar.h> 53 #include <sys/rwlock.h> 54 #include <sys/sched.h> 55 #include <sys/sysctl.h> 56 #include <sys/vnode.h> 57 58 #include <vm/vm.h> 59 #include <vm/vm_param.h> 60 #include <vm/vm_extern.h> 61 #include <vm/vm_page.h> 62 #include <vm/vm_pageout.h> 63 #include <vm/vm_map.h> 64 65 #include <machine/bus.h> 66 67 SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, UIO_MAXIOV, 68 "Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)"); 69 70 static int uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault); 71 72 int 73 copyin_nofault(const void *udaddr, void *kaddr, size_t len) 74 { 75 int error, save; 76 77 save = vm_fault_disable_pagefaults(); 78 error = copyin(udaddr, kaddr, len); 79 vm_fault_enable_pagefaults(save); 80 return (error); 81 } 82 83 int 84 copyout_nofault(const void *kaddr, void *udaddr, size_t len) 85 { 86 int error, save; 87 88 save = vm_fault_disable_pagefaults(); 89 error = copyout(kaddr, udaddr, len); 90 vm_fault_enable_pagefaults(save); 91 return (error); 92 } 93 94 #define PHYS_PAGE_COUNT(len) (howmany(len, PAGE_SIZE) + 1) 95 96 int 97 physcopyin(void *src, vm_paddr_t dst, size_t len) 98 { 99 vm_page_t m[PHYS_PAGE_COUNT(len)]; 100 struct iovec iov[1]; 101 struct uio uio; 102 int i; 103 104 iov[0].iov_base = src; 105 iov[0].iov_len = len; 106 uio.uio_iov = iov; 107 uio.uio_iovcnt = 1; 108 uio.uio_offset = 0; 109 uio.uio_resid = len; 110 uio.uio_segflg = UIO_SYSSPACE; 111 uio.uio_rw = UIO_WRITE; 112 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, dst += PAGE_SIZE) 113 m[i] = PHYS_TO_VM_PAGE(dst); 114 return (uiomove_fromphys(m, dst & PAGE_MASK, len, &uio)); 115 } 116 117 int 118 physcopyout(vm_paddr_t src, void *dst, size_t len) 119 { 120 vm_page_t m[PHYS_PAGE_COUNT(len)]; 121 struct iovec iov[1]; 122 struct uio uio; 123 int i; 124 125 iov[0].iov_base = dst; 126 iov[0].iov_len = len; 127 uio.uio_iov = iov; 128 uio.uio_iovcnt = 1; 129 uio.uio_offset = 0; 130 uio.uio_resid = len; 131 uio.uio_segflg = UIO_SYSSPACE; 132 uio.uio_rw = UIO_READ; 133 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, src += PAGE_SIZE) 134 m[i] = PHYS_TO_VM_PAGE(src); 135 return (uiomove_fromphys(m, src & PAGE_MASK, len, &uio)); 136 } 137 138 #undef PHYS_PAGE_COUNT 139 140 int 141 physcopyin_vlist(bus_dma_segment_t *src, off_t offset, vm_paddr_t dst, 142 size_t len) 143 { 144 size_t seg_len; 145 int error; 146 147 error = 0; 148 while (offset >= src->ds_len) { 149 offset -= src->ds_len; 150 src++; 151 } 152 153 while (len > 0 && error == 0) { 154 seg_len = MIN(src->ds_len - offset, len); 155 error = physcopyin((void *)(uintptr_t)(src->ds_addr + offset), 156 dst, seg_len); 157 offset = 0; 158 src++; 159 len -= seg_len; 160 dst += seg_len; 161 } 162 163 return (error); 164 } 165 166 int 167 physcopyout_vlist(vm_paddr_t src, bus_dma_segment_t *dst, off_t offset, 168 size_t len) 169 { 170 size_t seg_len; 171 int error; 172 173 error = 0; 174 while (offset >= dst->ds_len) { 175 offset -= dst->ds_len; 176 dst++; 177 } 178 179 while (len > 0 && error == 0) { 180 seg_len = MIN(dst->ds_len - offset, len); 181 error = physcopyout(src, (void *)(uintptr_t)(dst->ds_addr + 182 offset), seg_len); 183 offset = 0; 184 dst++; 185 len -= seg_len; 186 src += seg_len; 187 } 188 189 return (error); 190 } 191 192 int 193 uiomove(void *cp, int n, struct uio *uio) 194 { 195 196 return (uiomove_faultflag(cp, n, uio, 0)); 197 } 198 199 int 200 uiomove_nofault(void *cp, int n, struct uio *uio) 201 { 202 203 return (uiomove_faultflag(cp, n, uio, 1)); 204 } 205 206 static int 207 uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault) 208 { 209 struct iovec *iov; 210 size_t cnt; 211 int error, newflags, save; 212 213 error = 0; 214 215 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 216 ("uiomove: mode")); 217 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 218 ("uiomove proc")); 219 220 if (uio->uio_segflg == UIO_USERSPACE) { 221 newflags = TDP_DEADLKTREAT; 222 if (nofault) { 223 /* 224 * Fail if a non-spurious page fault occurs. 225 */ 226 newflags |= TDP_NOFAULTING | TDP_RESETSPUR; 227 } else { 228 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 229 "Calling uiomove()"); 230 } 231 save = curthread_pflags_set(newflags); 232 } else { 233 KASSERT(nofault == 0, ("uiomove: nofault")); 234 } 235 236 while (n > 0 && uio->uio_resid) { 237 iov = uio->uio_iov; 238 cnt = iov->iov_len; 239 if (cnt == 0) { 240 uio->uio_iov++; 241 uio->uio_iovcnt--; 242 continue; 243 } 244 if (cnt > n) 245 cnt = n; 246 247 switch (uio->uio_segflg) { 248 249 case UIO_USERSPACE: 250 maybe_yield(); 251 if (uio->uio_rw == UIO_READ) 252 error = copyout(cp, iov->iov_base, cnt); 253 else 254 error = copyin(iov->iov_base, cp, cnt); 255 if (error) 256 goto out; 257 break; 258 259 case UIO_SYSSPACE: 260 if (uio->uio_rw == UIO_READ) 261 bcopy(cp, iov->iov_base, cnt); 262 else 263 bcopy(iov->iov_base, cp, cnt); 264 break; 265 case UIO_NOCOPY: 266 break; 267 } 268 iov->iov_base = (char *)iov->iov_base + cnt; 269 iov->iov_len -= cnt; 270 uio->uio_resid -= cnt; 271 uio->uio_offset += cnt; 272 cp = (char *)cp + cnt; 273 n -= cnt; 274 } 275 out: 276 if (uio->uio_segflg == UIO_USERSPACE) 277 curthread_pflags_restore(save); 278 return (error); 279 } 280 281 /* 282 * Wrapper for uiomove() that validates the arguments against a known-good 283 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which 284 * is almost definitely a bad thing, so we catch that here as well. We 285 * return a runtime failure, but it might be desirable to generate a runtime 286 * assertion failure instead. 287 */ 288 int 289 uiomove_frombuf(void *buf, int buflen, struct uio *uio) 290 { 291 size_t offset, n; 292 293 if (uio->uio_offset < 0 || uio->uio_resid < 0 || 294 (offset = uio->uio_offset) != uio->uio_offset) 295 return (EINVAL); 296 if (buflen <= 0 || offset >= buflen) 297 return (0); 298 if ((n = buflen - offset) > IOSIZE_MAX) 299 return (EINVAL); 300 return (uiomove((char *)buf + offset, n, uio)); 301 } 302 303 /* 304 * Give next character to user as result of read. 305 */ 306 int 307 ureadc(int c, struct uio *uio) 308 { 309 struct iovec *iov; 310 char *iov_base; 311 312 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 313 "Calling ureadc()"); 314 315 again: 316 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0) 317 panic("ureadc"); 318 iov = uio->uio_iov; 319 if (iov->iov_len == 0) { 320 uio->uio_iovcnt--; 321 uio->uio_iov++; 322 goto again; 323 } 324 switch (uio->uio_segflg) { 325 326 case UIO_USERSPACE: 327 if (subyte(iov->iov_base, c) < 0) 328 return (EFAULT); 329 break; 330 331 case UIO_SYSSPACE: 332 iov_base = iov->iov_base; 333 *iov_base = c; 334 break; 335 336 case UIO_NOCOPY: 337 break; 338 } 339 iov->iov_base = (char *)iov->iov_base + 1; 340 iov->iov_len--; 341 uio->uio_resid--; 342 uio->uio_offset++; 343 return (0); 344 } 345 346 int 347 copyinfrom(const void * __restrict src, void * __restrict dst, size_t len, 348 int seg) 349 { 350 int error = 0; 351 352 switch (seg) { 353 case UIO_USERSPACE: 354 error = copyin(src, dst, len); 355 break; 356 case UIO_SYSSPACE: 357 bcopy(src, dst, len); 358 break; 359 default: 360 panic("copyinfrom: bad seg %d\n", seg); 361 } 362 return (error); 363 } 364 365 int 366 copyinstrfrom(const void * __restrict src, void * __restrict dst, size_t len, 367 size_t * __restrict copied, int seg) 368 { 369 int error = 0; 370 371 switch (seg) { 372 case UIO_USERSPACE: 373 error = copyinstr(src, dst, len, copied); 374 break; 375 case UIO_SYSSPACE: 376 error = copystr(src, dst, len, copied); 377 break; 378 default: 379 panic("copyinstrfrom: bad seg %d\n", seg); 380 } 381 return (error); 382 } 383 384 int 385 copyiniov(const struct iovec *iovp, u_int iovcnt, struct iovec **iov, int error) 386 { 387 u_int iovlen; 388 389 *iov = NULL; 390 if (iovcnt > UIO_MAXIOV) 391 return (error); 392 iovlen = iovcnt * sizeof (struct iovec); 393 *iov = malloc(iovlen, M_IOV, M_WAITOK); 394 error = copyin(iovp, *iov, iovlen); 395 if (error) { 396 free(*iov, M_IOV); 397 *iov = NULL; 398 } 399 return (error); 400 } 401 402 int 403 copyinuio(const struct iovec *iovp, u_int iovcnt, struct uio **uiop) 404 { 405 struct iovec *iov; 406 struct uio *uio; 407 u_int iovlen; 408 int error, i; 409 410 *uiop = NULL; 411 if (iovcnt > UIO_MAXIOV) 412 return (EINVAL); 413 iovlen = iovcnt * sizeof (struct iovec); 414 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 415 iov = (struct iovec *)(uio + 1); 416 error = copyin(iovp, iov, iovlen); 417 if (error) { 418 free(uio, M_IOV); 419 return (error); 420 } 421 uio->uio_iov = iov; 422 uio->uio_iovcnt = iovcnt; 423 uio->uio_segflg = UIO_USERSPACE; 424 uio->uio_offset = -1; 425 uio->uio_resid = 0; 426 for (i = 0; i < iovcnt; i++) { 427 if (iov->iov_len > IOSIZE_MAX - uio->uio_resid) { 428 free(uio, M_IOV); 429 return (EINVAL); 430 } 431 uio->uio_resid += iov->iov_len; 432 iov++; 433 } 434 *uiop = uio; 435 return (0); 436 } 437 438 struct uio * 439 cloneuio(struct uio *uiop) 440 { 441 struct uio *uio; 442 int iovlen; 443 444 iovlen = uiop->uio_iovcnt * sizeof (struct iovec); 445 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 446 *uio = *uiop; 447 uio->uio_iov = (struct iovec *)(uio + 1); 448 bcopy(uiop->uio_iov, uio->uio_iov, iovlen); 449 return (uio); 450 } 451 452 /* 453 * Map some anonymous memory in user space of size sz, rounded up to the page 454 * boundary. 455 */ 456 int 457 copyout_map(struct thread *td, vm_offset_t *addr, size_t sz) 458 { 459 struct vmspace *vms; 460 int error; 461 vm_size_t size; 462 463 vms = td->td_proc->p_vmspace; 464 465 /* 466 * Map somewhere after heap in process memory. 467 */ 468 *addr = round_page((vm_offset_t)vms->vm_daddr + 469 lim_max(td, RLIMIT_DATA)); 470 471 /* round size up to page boundary */ 472 size = (vm_size_t)round_page(sz); 473 if (size == 0) 474 return (EINVAL); 475 error = vm_mmap_object(&vms->vm_map, addr, size, VM_PROT_READ | 476 VM_PROT_WRITE, VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, NULL, 0, 477 FALSE, td); 478 return (error); 479 } 480 481 /* 482 * Unmap memory in user space. 483 */ 484 int 485 copyout_unmap(struct thread *td, vm_offset_t addr, size_t sz) 486 { 487 vm_map_t map; 488 vm_size_t size; 489 490 if (sz == 0) 491 return (0); 492 493 map = &td->td_proc->p_vmspace->vm_map; 494 size = (vm_size_t)round_page(sz); 495 496 if (vm_map_remove(map, addr, addr + size) != KERN_SUCCESS) 497 return (EINVAL); 498 499 return (0); 500 } 501 502 #ifdef NO_FUEWORD 503 /* 504 * XXXKIB The temporal implementation of fue*() functions which do not 505 * handle usermode -1 properly, mixing it with the fault code. Keep 506 * this until MD code is written. Currently sparc64 and mips do not 507 * have proper implementation. 508 */ 509 510 int 511 fueword(volatile const void *base, long *val) 512 { 513 long res; 514 515 res = fuword(base); 516 if (res == -1) 517 return (-1); 518 *val = res; 519 return (0); 520 } 521 522 int 523 fueword32(volatile const void *base, int32_t *val) 524 { 525 int32_t res; 526 527 res = fuword32(base); 528 if (res == -1) 529 return (-1); 530 *val = res; 531 return (0); 532 } 533 534 #ifdef _LP64 535 int 536 fueword64(volatile const void *base, int64_t *val) 537 { 538 int64_t res; 539 540 res = fuword64(base); 541 if (res == -1) 542 return (-1); 543 *val = res; 544 return (0); 545 } 546 #endif 547 548 int 549 casueword32(volatile uint32_t *base, uint32_t oldval, uint32_t *oldvalp, 550 uint32_t newval) 551 { 552 int32_t ov; 553 554 ov = casuword32(base, oldval, newval); 555 if (ov == -1) 556 return (-1); 557 *oldvalp = ov; 558 return (0); 559 } 560 561 int 562 casueword(volatile u_long *p, u_long oldval, u_long *oldvalp, u_long newval) 563 { 564 u_long ov; 565 566 ov = casuword(p, oldval, newval); 567 if (ov == -1) 568 return (-1); 569 *oldvalp = ov; 570 return (0); 571 } 572 #else /* NO_FUEWORD */ 573 int32_t 574 fuword32(volatile const void *addr) 575 { 576 int rv; 577 int32_t val; 578 579 rv = fueword32(addr, &val); 580 return (rv == -1 ? -1 : val); 581 } 582 583 #ifdef _LP64 584 int64_t 585 fuword64(volatile const void *addr) 586 { 587 int rv; 588 int64_t val; 589 590 rv = fueword64(addr, &val); 591 return (rv == -1 ? -1 : val); 592 } 593 #endif /* _LP64 */ 594 595 long 596 fuword(volatile const void *addr) 597 { 598 long val; 599 int rv; 600 601 rv = fueword(addr, &val); 602 return (rv == -1 ? -1 : val); 603 } 604 605 uint32_t 606 casuword32(volatile uint32_t *addr, uint32_t old, uint32_t new) 607 { 608 int rv; 609 uint32_t val; 610 611 rv = casueword32(addr, old, &val, new); 612 return (rv == -1 ? -1 : val); 613 } 614 615 u_long 616 casuword(volatile u_long *addr, u_long old, u_long new) 617 { 618 int rv; 619 u_long val; 620 621 rv = casueword(addr, old, &val, new); 622 return (rv == -1 ? -1 : val); 623 } 624 625 #endif /* NO_FUEWORD */ 626