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 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 42 */ 43 44 #include <sys/cdefs.h> 45 __FBSDID("$FreeBSD$"); 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/limits.h> 51 #include <sys/lock.h> 52 #include <sys/mman.h> 53 #include <sys/proc.h> 54 #include <sys/resourcevar.h> 55 #include <sys/rwlock.h> 56 #include <sys/sched.h> 57 #include <sys/sysctl.h> 58 #include <sys/vnode.h> 59 60 #include <vm/vm.h> 61 #include <vm/vm_param.h> 62 #include <vm/vm_extern.h> 63 #include <vm/vm_page.h> 64 #include <vm/vm_pageout.h> 65 #include <vm/vm_map.h> 66 67 #include <machine/bus.h> 68 69 SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, UIO_MAXIOV, 70 "Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)"); 71 72 static int uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault); 73 74 int 75 copyin_nofault(const void *udaddr, void *kaddr, size_t len) 76 { 77 int error, save; 78 79 save = vm_fault_disable_pagefaults(); 80 error = copyin(udaddr, kaddr, len); 81 vm_fault_enable_pagefaults(save); 82 return (error); 83 } 84 85 int 86 copyout_nofault(const void *kaddr, void *udaddr, size_t len) 87 { 88 int error, save; 89 90 save = vm_fault_disable_pagefaults(); 91 error = copyout(kaddr, udaddr, len); 92 vm_fault_enable_pagefaults(save); 93 return (error); 94 } 95 96 #define PHYS_PAGE_COUNT(len) (howmany(len, PAGE_SIZE) + 1) 97 98 int 99 physcopyin(void *src, vm_paddr_t dst, size_t len) 100 { 101 vm_page_t m[PHYS_PAGE_COUNT(len)]; 102 struct iovec iov[1]; 103 struct uio uio; 104 int i; 105 106 iov[0].iov_base = src; 107 iov[0].iov_len = len; 108 uio.uio_iov = iov; 109 uio.uio_iovcnt = 1; 110 uio.uio_offset = 0; 111 uio.uio_resid = len; 112 uio.uio_segflg = UIO_SYSSPACE; 113 uio.uio_rw = UIO_WRITE; 114 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, dst += PAGE_SIZE) 115 m[i] = PHYS_TO_VM_PAGE(dst); 116 return (uiomove_fromphys(m, dst & PAGE_MASK, len, &uio)); 117 } 118 119 int 120 physcopyout(vm_paddr_t src, void *dst, size_t len) 121 { 122 vm_page_t m[PHYS_PAGE_COUNT(len)]; 123 struct iovec iov[1]; 124 struct uio uio; 125 int i; 126 127 iov[0].iov_base = dst; 128 iov[0].iov_len = len; 129 uio.uio_iov = iov; 130 uio.uio_iovcnt = 1; 131 uio.uio_offset = 0; 132 uio.uio_resid = len; 133 uio.uio_segflg = UIO_SYSSPACE; 134 uio.uio_rw = UIO_READ; 135 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, src += PAGE_SIZE) 136 m[i] = PHYS_TO_VM_PAGE(src); 137 return (uiomove_fromphys(m, src & PAGE_MASK, len, &uio)); 138 } 139 140 #undef PHYS_PAGE_COUNT 141 142 int 143 physcopyin_vlist(bus_dma_segment_t *src, off_t offset, vm_paddr_t dst, 144 size_t len) 145 { 146 size_t seg_len; 147 int error; 148 149 error = 0; 150 while (offset >= src->ds_len) { 151 offset -= src->ds_len; 152 src++; 153 } 154 155 while (len > 0 && error == 0) { 156 seg_len = MIN(src->ds_len - offset, len); 157 error = physcopyin((void *)(uintptr_t)(src->ds_addr + offset), 158 dst, seg_len); 159 offset = 0; 160 src++; 161 len -= seg_len; 162 dst += seg_len; 163 } 164 165 return (error); 166 } 167 168 int 169 physcopyout_vlist(vm_paddr_t src, bus_dma_segment_t *dst, off_t offset, 170 size_t len) 171 { 172 size_t seg_len; 173 int error; 174 175 error = 0; 176 while (offset >= dst->ds_len) { 177 offset -= dst->ds_len; 178 dst++; 179 } 180 181 while (len > 0 && error == 0) { 182 seg_len = MIN(dst->ds_len - offset, len); 183 error = physcopyout(src, (void *)(uintptr_t)(dst->ds_addr + 184 offset), seg_len); 185 offset = 0; 186 dst++; 187 len -= seg_len; 188 src += seg_len; 189 } 190 191 return (error); 192 } 193 194 int 195 uiomove(void *cp, int n, struct uio *uio) 196 { 197 198 return (uiomove_faultflag(cp, n, uio, 0)); 199 } 200 201 int 202 uiomove_nofault(void *cp, int n, struct uio *uio) 203 { 204 205 return (uiomove_faultflag(cp, n, uio, 1)); 206 } 207 208 static int 209 uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault) 210 { 211 struct iovec *iov; 212 size_t cnt; 213 int error, newflags, save; 214 215 save = error = 0; 216 217 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 218 ("uiomove: mode")); 219 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 220 ("uiomove proc")); 221 222 if (uio->uio_segflg == UIO_USERSPACE) { 223 newflags = TDP_DEADLKTREAT; 224 if (nofault) { 225 /* 226 * Fail if a non-spurious page fault occurs. 227 */ 228 newflags |= TDP_NOFAULTING | TDP_RESETSPUR; 229 } else { 230 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 231 "Calling uiomove()"); 232 } 233 save = curthread_pflags_set(newflags); 234 } else { 235 KASSERT(nofault == 0, ("uiomove: nofault")); 236 } 237 238 while (n > 0 && uio->uio_resid) { 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) { 250 251 case UIO_USERSPACE: 252 maybe_yield(); 253 if (uio->uio_rw == UIO_READ) 254 error = copyout(cp, iov->iov_base, cnt); 255 else 256 error = copyin(iov->iov_base, cp, cnt); 257 if (error) 258 goto out; 259 break; 260 261 case UIO_SYSSPACE: 262 if (uio->uio_rw == UIO_READ) 263 bcopy(cp, iov->iov_base, cnt); 264 else 265 bcopy(iov->iov_base, cp, cnt); 266 break; 267 case UIO_NOCOPY: 268 break; 269 } 270 iov->iov_base = (char *)iov->iov_base + cnt; 271 iov->iov_len -= cnt; 272 uio->uio_resid -= cnt; 273 uio->uio_offset += cnt; 274 cp = (char *)cp + cnt; 275 n -= cnt; 276 } 277 out: 278 if (save) 279 curthread_pflags_restore(save); 280 return (error); 281 } 282 283 /* 284 * Wrapper for uiomove() that validates the arguments against a known-good 285 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which 286 * is almost definitely a bad thing, so we catch that here as well. We 287 * return a runtime failure, but it might be desirable to generate a runtime 288 * assertion failure instead. 289 */ 290 int 291 uiomove_frombuf(void *buf, int buflen, struct uio *uio) 292 { 293 size_t offset, n; 294 295 if (uio->uio_offset < 0 || uio->uio_resid < 0 || 296 (offset = uio->uio_offset) != uio->uio_offset) 297 return (EINVAL); 298 if (buflen <= 0 || offset >= buflen) 299 return (0); 300 if ((n = buflen - offset) > IOSIZE_MAX) 301 return (EINVAL); 302 return (uiomove((char *)buf + offset, n, uio)); 303 } 304 305 /* 306 * Give next character to user as result of read. 307 */ 308 int 309 ureadc(int c, struct uio *uio) 310 { 311 struct iovec *iov; 312 char *iov_base; 313 314 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 315 "Calling ureadc()"); 316 317 again: 318 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0) 319 panic("ureadc"); 320 iov = uio->uio_iov; 321 if (iov->iov_len == 0) { 322 uio->uio_iovcnt--; 323 uio->uio_iov++; 324 goto again; 325 } 326 switch (uio->uio_segflg) { 327 328 case UIO_USERSPACE: 329 if (subyte(iov->iov_base, c) < 0) 330 return (EFAULT); 331 break; 332 333 case UIO_SYSSPACE: 334 iov_base = iov->iov_base; 335 *iov_base = c; 336 break; 337 338 case UIO_NOCOPY: 339 break; 340 } 341 iov->iov_base = (char *)iov->iov_base + 1; 342 iov->iov_len--; 343 uio->uio_resid--; 344 uio->uio_offset++; 345 return (0); 346 } 347 348 int 349 copyinfrom(const void * __restrict src, void * __restrict dst, size_t len, 350 int seg) 351 { 352 int error = 0; 353 354 switch (seg) { 355 case UIO_USERSPACE: 356 error = copyin(src, dst, len); 357 break; 358 case UIO_SYSSPACE: 359 bcopy(src, dst, len); 360 break; 361 default: 362 panic("copyinfrom: bad seg %d\n", seg); 363 } 364 return (error); 365 } 366 367 int 368 copyinstrfrom(const void * __restrict src, void * __restrict dst, size_t len, 369 size_t * __restrict copied, int seg) 370 { 371 int error = 0; 372 373 switch (seg) { 374 case UIO_USERSPACE: 375 error = copyinstr(src, dst, len, copied); 376 break; 377 case UIO_SYSSPACE: 378 error = copystr(src, dst, len, copied); 379 break; 380 default: 381 panic("copyinstrfrom: bad seg %d\n", seg); 382 } 383 return (error); 384 } 385 386 int 387 copyiniov(const struct iovec *iovp, u_int iovcnt, struct iovec **iov, int error) 388 { 389 u_int iovlen; 390 391 *iov = NULL; 392 if (iovcnt > UIO_MAXIOV) 393 return (error); 394 iovlen = iovcnt * sizeof (struct iovec); 395 *iov = malloc(iovlen, M_IOV, M_WAITOK); 396 error = copyin(iovp, *iov, iovlen); 397 if (error) { 398 free(*iov, M_IOV); 399 *iov = NULL; 400 } 401 return (error); 402 } 403 404 int 405 copyinuio(const struct iovec *iovp, u_int iovcnt, struct uio **uiop) 406 { 407 struct iovec *iov; 408 struct uio *uio; 409 u_int iovlen; 410 int error, i; 411 412 *uiop = NULL; 413 if (iovcnt > UIO_MAXIOV) 414 return (EINVAL); 415 iovlen = iovcnt * sizeof (struct iovec); 416 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 417 iov = (struct iovec *)(uio + 1); 418 error = copyin(iovp, iov, iovlen); 419 if (error) { 420 free(uio, M_IOV); 421 return (error); 422 } 423 uio->uio_iov = iov; 424 uio->uio_iovcnt = iovcnt; 425 uio->uio_segflg = UIO_USERSPACE; 426 uio->uio_offset = -1; 427 uio->uio_resid = 0; 428 for (i = 0; i < iovcnt; i++) { 429 if (iov->iov_len > IOSIZE_MAX - uio->uio_resid) { 430 free(uio, M_IOV); 431 return (EINVAL); 432 } 433 uio->uio_resid += iov->iov_len; 434 iov++; 435 } 436 *uiop = uio; 437 return (0); 438 } 439 440 struct uio * 441 cloneuio(struct uio *uiop) 442 { 443 struct uio *uio; 444 int iovlen; 445 446 iovlen = uiop->uio_iovcnt * sizeof (struct iovec); 447 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 448 *uio = *uiop; 449 uio->uio_iov = (struct iovec *)(uio + 1); 450 bcopy(uiop->uio_iov, uio->uio_iov, iovlen); 451 return (uio); 452 } 453 454 /* 455 * Map some anonymous memory in user space of size sz, rounded up to the page 456 * boundary. 457 */ 458 int 459 copyout_map(struct thread *td, vm_offset_t *addr, size_t sz) 460 { 461 struct vmspace *vms; 462 int error; 463 vm_size_t size; 464 465 vms = td->td_proc->p_vmspace; 466 467 /* 468 * Map somewhere after heap in process memory. 469 */ 470 *addr = round_page((vm_offset_t)vms->vm_daddr + 471 lim_max(td, RLIMIT_DATA)); 472 473 /* round size up to page boundary */ 474 size = (vm_size_t)round_page(sz); 475 if (size == 0) 476 return (EINVAL); 477 error = vm_mmap_object(&vms->vm_map, addr, size, VM_PROT_READ | 478 VM_PROT_WRITE, VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, NULL, 0, 479 FALSE, td); 480 return (error); 481 } 482 483 /* 484 * Unmap memory in user space. 485 */ 486 int 487 copyout_unmap(struct thread *td, vm_offset_t addr, size_t sz) 488 { 489 vm_map_t map; 490 vm_size_t size; 491 492 if (sz == 0) 493 return (0); 494 495 map = &td->td_proc->p_vmspace->vm_map; 496 size = (vm_size_t)round_page(sz); 497 498 if (vm_map_remove(map, addr, addr + size) != KERN_SUCCESS) 499 return (EINVAL); 500 501 return (0); 502 } 503 504 int32_t 505 fuword32(volatile const void *addr) 506 { 507 int rv; 508 int32_t val; 509 510 rv = fueword32(addr, &val); 511 return (rv == -1 ? -1 : val); 512 } 513 514 #ifdef _LP64 515 int64_t 516 fuword64(volatile const void *addr) 517 { 518 int rv; 519 int64_t val; 520 521 rv = fueword64(addr, &val); 522 return (rv == -1 ? -1 : val); 523 } 524 #endif /* _LP64 */ 525 526 long 527 fuword(volatile const void *addr) 528 { 529 long val; 530 int rv; 531 532 rv = fueword(addr, &val); 533 return (rv == -1 ? -1 : val); 534 } 535 536 uint32_t 537 casuword32(volatile uint32_t *addr, uint32_t old, uint32_t new) 538 { 539 int rv; 540 uint32_t val; 541 542 rv = casueword32(addr, old, &val, new); 543 return (rv == -1 ? -1 : val); 544 } 545 546 u_long 547 casuword(volatile u_long *addr, u_long old, u_long new) 548 { 549 int rv; 550 u_long val; 551 552 rv = casueword(addr, old, &val, new); 553 return (rv == -1 ? -1 : val); 554 } 555