1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Copyright (c) 2014 The FreeBSD Foundation 13 * 14 * Portions of this software were developed by Konstantin Belousov 15 * under sponsorship from the FreeBSD Foundation. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 3. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/limits.h> 46 #include <sys/lock.h> 47 #include <sys/mman.h> 48 #include <sys/proc.h> 49 #include <sys/resourcevar.h> 50 #include <sys/rwlock.h> 51 #include <sys/sched.h> 52 #include <sys/sysctl.h> 53 #include <sys/vnode.h> 54 55 #include <vm/vm.h> 56 #include <vm/vm_param.h> 57 #include <vm/vm_extern.h> 58 #include <vm/vm_page.h> 59 #include <vm/vm_pageout.h> 60 #include <vm/vm_map.h> 61 62 #include <machine/bus.h> 63 64 SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, UIO_MAXIOV, 65 "Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)"); 66 67 static int uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault); 68 69 int 70 copyin_nofault(const void *udaddr, void *kaddr, size_t len) 71 { 72 int error, save; 73 74 save = vm_fault_disable_pagefaults(); 75 error = copyin(udaddr, kaddr, len); 76 vm_fault_enable_pagefaults(save); 77 return (error); 78 } 79 80 int 81 copyout_nofault(const void *kaddr, void *udaddr, size_t len) 82 { 83 int error, save; 84 85 save = vm_fault_disable_pagefaults(); 86 error = copyout(kaddr, udaddr, len); 87 vm_fault_enable_pagefaults(save); 88 return (error); 89 } 90 91 #define PHYS_PAGE_COUNT(len) (howmany(len, PAGE_SIZE) + 1) 92 93 int 94 physcopyin(void *src, vm_paddr_t dst, size_t len) 95 { 96 vm_page_t m[PHYS_PAGE_COUNT(len)]; 97 struct iovec iov[1]; 98 struct uio uio; 99 int i; 100 101 iov[0].iov_base = src; 102 iov[0].iov_len = len; 103 uio.uio_iov = iov; 104 uio.uio_iovcnt = 1; 105 uio.uio_offset = 0; 106 uio.uio_resid = len; 107 uio.uio_segflg = UIO_SYSSPACE; 108 uio.uio_rw = UIO_WRITE; 109 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, dst += PAGE_SIZE) 110 m[i] = PHYS_TO_VM_PAGE(dst); 111 return (uiomove_fromphys(m, dst & PAGE_MASK, len, &uio)); 112 } 113 114 int 115 physcopyout(vm_paddr_t src, void *dst, size_t len) 116 { 117 vm_page_t m[PHYS_PAGE_COUNT(len)]; 118 struct iovec iov[1]; 119 struct uio uio; 120 int i; 121 122 iov[0].iov_base = dst; 123 iov[0].iov_len = len; 124 uio.uio_iov = iov; 125 uio.uio_iovcnt = 1; 126 uio.uio_offset = 0; 127 uio.uio_resid = len; 128 uio.uio_segflg = UIO_SYSSPACE; 129 uio.uio_rw = UIO_READ; 130 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, src += PAGE_SIZE) 131 m[i] = PHYS_TO_VM_PAGE(src); 132 return (uiomove_fromphys(m, src & PAGE_MASK, len, &uio)); 133 } 134 135 #undef PHYS_PAGE_COUNT 136 137 int 138 physcopyin_vlist(bus_dma_segment_t *src, off_t offset, vm_paddr_t dst, 139 size_t len) 140 { 141 size_t seg_len; 142 int error; 143 144 error = 0; 145 while (offset >= src->ds_len) { 146 offset -= src->ds_len; 147 src++; 148 } 149 150 while (len > 0 && error == 0) { 151 seg_len = MIN(src->ds_len - offset, len); 152 error = physcopyin((void *)(uintptr_t)(src->ds_addr + offset), 153 dst, seg_len); 154 offset = 0; 155 src++; 156 len -= seg_len; 157 dst += seg_len; 158 } 159 160 return (error); 161 } 162 163 int 164 physcopyout_vlist(vm_paddr_t src, bus_dma_segment_t *dst, off_t offset, 165 size_t len) 166 { 167 size_t seg_len; 168 int error; 169 170 error = 0; 171 while (offset >= dst->ds_len) { 172 offset -= dst->ds_len; 173 dst++; 174 } 175 176 while (len > 0 && error == 0) { 177 seg_len = MIN(dst->ds_len - offset, len); 178 error = physcopyout(src, (void *)(uintptr_t)(dst->ds_addr + 179 offset), seg_len); 180 offset = 0; 181 dst++; 182 len -= seg_len; 183 src += seg_len; 184 } 185 186 return (error); 187 } 188 189 int 190 uiomove(void *cp, int n, struct uio *uio) 191 { 192 193 return (uiomove_faultflag(cp, n, uio, 0)); 194 } 195 196 int 197 uiomove_nofault(void *cp, int n, struct uio *uio) 198 { 199 200 return (uiomove_faultflag(cp, n, uio, 1)); 201 } 202 203 static int 204 uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault) 205 { 206 struct iovec *iov; 207 size_t cnt; 208 int error, newflags, save; 209 210 save = error = 0; 211 212 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 213 ("uiomove: mode")); 214 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 215 ("uiomove proc")); 216 KASSERT(uio->uio_resid >= 0, 217 ("%s: uio %p resid underflow", __func__, uio)); 218 219 if (uio->uio_segflg == UIO_USERSPACE) { 220 newflags = TDP_DEADLKTREAT; 221 if (nofault) { 222 /* 223 * Fail if a non-spurious page fault occurs. 224 */ 225 newflags |= TDP_NOFAULTING | TDP_RESETSPUR; 226 } else { 227 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 228 "Calling uiomove()"); 229 } 230 save = curthread_pflags_set(newflags); 231 } else { 232 KASSERT(nofault == 0, ("uiomove: nofault")); 233 } 234 235 while (n > 0 && uio->uio_resid) { 236 KASSERT(uio->uio_iovcnt > 0, 237 ("%s: uio %p iovcnt underflow", __func__, uio)); 238 239 iov = uio->uio_iov; 240 cnt = iov->iov_len; 241 if (cnt == 0) { 242 uio->uio_iov++; 243 uio->uio_iovcnt--; 244 continue; 245 } 246 if (cnt > n) 247 cnt = n; 248 249 switch (uio->uio_segflg) { 250 case UIO_USERSPACE: 251 maybe_yield(); 252 switch (uio->uio_rw) { 253 case UIO_READ: 254 error = copyout(cp, iov->iov_base, cnt); 255 break; 256 case UIO_WRITE: 257 error = copyin(iov->iov_base, cp, cnt); 258 break; 259 } 260 if (error) 261 goto out; 262 break; 263 264 case UIO_SYSSPACE: 265 switch (uio->uio_rw) { 266 case UIO_READ: 267 bcopy(cp, iov->iov_base, cnt); 268 break; 269 case UIO_WRITE: 270 bcopy(iov->iov_base, cp, cnt); 271 break; 272 } 273 break; 274 case UIO_NOCOPY: 275 break; 276 } 277 iov->iov_base = (char *)iov->iov_base + cnt; 278 iov->iov_len -= cnt; 279 uio->uio_resid -= cnt; 280 uio->uio_offset += cnt; 281 cp = (char *)cp + cnt; 282 n -= cnt; 283 } 284 out: 285 if (save) 286 curthread_pflags_restore(save); 287 return (error); 288 } 289 290 /* 291 * Wrapper for uiomove() that validates the arguments against a known-good 292 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which 293 * is almost definitely a bad thing, so we catch that here as well. We 294 * return a runtime failure, but it might be desirable to generate a runtime 295 * assertion failure instead. 296 */ 297 int 298 uiomove_frombuf(void *buf, int buflen, struct uio *uio) 299 { 300 size_t offset, n; 301 302 if (uio->uio_offset < 0 || uio->uio_resid < 0 || 303 (offset = uio->uio_offset) != uio->uio_offset) 304 return (EINVAL); 305 if (buflen <= 0 || offset >= buflen) 306 return (0); 307 if ((n = buflen - offset) > IOSIZE_MAX) 308 return (EINVAL); 309 return (uiomove((char *)buf + offset, n, uio)); 310 } 311 312 /* 313 * Give next character to user as result of read. 314 */ 315 int 316 ureadc(int c, struct uio *uio) 317 { 318 struct iovec *iov; 319 char *iov_base; 320 321 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 322 "Calling ureadc()"); 323 324 again: 325 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0) 326 panic("ureadc"); 327 iov = uio->uio_iov; 328 if (iov->iov_len == 0) { 329 uio->uio_iovcnt--; 330 uio->uio_iov++; 331 goto again; 332 } 333 switch (uio->uio_segflg) { 334 case UIO_USERSPACE: 335 if (subyte(iov->iov_base, c) < 0) 336 return (EFAULT); 337 break; 338 339 case UIO_SYSSPACE: 340 iov_base = iov->iov_base; 341 *iov_base = c; 342 break; 343 344 case UIO_NOCOPY: 345 break; 346 } 347 iov->iov_base = (char *)iov->iov_base + 1; 348 iov->iov_len--; 349 uio->uio_resid--; 350 uio->uio_offset++; 351 return (0); 352 } 353 354 int 355 copyiniov(const struct iovec *iovp, u_int iovcnt, struct iovec **iov, int error) 356 { 357 u_int iovlen; 358 359 *iov = NULL; 360 if (iovcnt > UIO_MAXIOV) 361 return (error); 362 iovlen = iovcnt * sizeof(struct iovec); 363 *iov = malloc(iovlen, M_IOV, M_WAITOK); 364 error = copyin(iovp, *iov, iovlen); 365 if (error) { 366 free(*iov, M_IOV); 367 *iov = NULL; 368 } 369 return (error); 370 } 371 372 int 373 copyinuio(const struct iovec *iovp, u_int iovcnt, struct uio **uiop) 374 { 375 struct iovec *iov; 376 struct uio *uio; 377 u_int iovlen; 378 int error, i; 379 380 *uiop = NULL; 381 if (iovcnt > UIO_MAXIOV) 382 return (EINVAL); 383 iovlen = iovcnt * sizeof(struct iovec); 384 uio = allocuio(iovcnt); 385 iov = uio->uio_iov; 386 error = copyin(iovp, iov, iovlen); 387 if (error != 0) { 388 freeuio(uio); 389 return (error); 390 } 391 uio->uio_iovcnt = iovcnt; 392 uio->uio_segflg = UIO_USERSPACE; 393 uio->uio_offset = -1; 394 uio->uio_resid = 0; 395 for (i = 0; i < iovcnt; i++) { 396 if (iov->iov_len > IOSIZE_MAX - uio->uio_resid) { 397 freeuio(uio); 398 return (EINVAL); 399 } 400 uio->uio_resid += iov->iov_len; 401 iov++; 402 } 403 *uiop = uio; 404 return (0); 405 } 406 407 struct uio * 408 allocuio(u_int iovcnt) 409 { 410 struct uio *uio; 411 int iovlen; 412 413 KASSERT(iovcnt <= UIO_MAXIOV, 414 ("Requested %u iovecs exceed UIO_MAXIOV", iovcnt)); 415 iovlen = iovcnt * sizeof(struct iovec); 416 uio = malloc(iovlen + sizeof(*uio), M_IOV, M_WAITOK); 417 uio->uio_iov = (struct iovec *)(uio + 1); 418 419 return (uio); 420 } 421 422 void 423 freeuio(struct uio *uio) 424 { 425 free(uio, M_IOV); 426 } 427 428 struct uio * 429 cloneuio(struct uio *uiop) 430 { 431 struct iovec *iov; 432 struct uio *uio; 433 int iovlen; 434 435 iovlen = uiop->uio_iovcnt * sizeof(struct iovec); 436 uio = allocuio(uiop->uio_iovcnt); 437 iov = uio->uio_iov; 438 *uio = *uiop; 439 uio->uio_iov = iov; 440 bcopy(uiop->uio_iov, uio->uio_iov, iovlen); 441 return (uio); 442 } 443 444 /* 445 * Map some anonymous memory in user space of size sz, rounded up to the page 446 * boundary. 447 */ 448 int 449 copyout_map(struct thread *td, vm_offset_t *addr, size_t sz) 450 { 451 struct vmspace *vms; 452 int error; 453 vm_size_t size; 454 455 vms = td->td_proc->p_vmspace; 456 457 /* 458 * Map somewhere after heap in process memory. 459 */ 460 *addr = round_page((vm_offset_t)vms->vm_daddr + 461 lim_max(td, RLIMIT_DATA)); 462 463 /* round size up to page boundary */ 464 size = (vm_size_t)round_page(sz); 465 if (size == 0) 466 return (EINVAL); 467 error = vm_mmap_object(&vms->vm_map, addr, size, VM_PROT_READ | 468 VM_PROT_WRITE, VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, NULL, 0, 469 FALSE, td); 470 return (error); 471 } 472 473 /* 474 * Unmap memory in user space. 475 */ 476 int 477 copyout_unmap(struct thread *td, vm_offset_t addr, size_t sz) 478 { 479 vm_map_t map; 480 vm_size_t size; 481 482 if (sz == 0) 483 return (0); 484 485 map = &td->td_proc->p_vmspace->vm_map; 486 size = (vm_size_t)round_page(sz); 487 488 if (vm_map_remove(map, addr, addr + size) != KERN_SUCCESS) 489 return (EINVAL); 490 491 return (0); 492 } 493 494 int32_t 495 fuword32(volatile const void *addr) 496 { 497 int rv; 498 int32_t val; 499 500 rv = fueword32(addr, &val); 501 return (rv == -1 ? -1 : val); 502 } 503 504 #ifdef _LP64 505 int64_t 506 fuword64(volatile const void *addr) 507 { 508 int rv; 509 int64_t val; 510 511 rv = fueword64(addr, &val); 512 return (rv == -1 ? -1 : val); 513 } 514 #endif /* _LP64 */ 515 516 long 517 fuword(volatile const void *addr) 518 { 519 long val; 520 int rv; 521 522 rv = fueword(addr, &val); 523 return (rv == -1 ? -1 : val); 524 } 525 526 uint32_t 527 casuword32(volatile uint32_t *addr, uint32_t old, uint32_t new) 528 { 529 int rv; 530 uint32_t val; 531 532 rv = casueword32(addr, old, &val, new); 533 return (rv == -1 ? -1 : val); 534 } 535 536 u_long 537 casuword(volatile u_long *addr, u_long old, u_long new) 538 { 539 int rv; 540 u_long val; 541 542 rv = casueword(addr, old, &val, new); 543 return (rv == -1 ? -1 : val); 544 } 545