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 * 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 * @(#)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 SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, UIO_MAXIOV, 66 "Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)"); 67 68 static int uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault); 69 70 int 71 copyin_nofault(const void *udaddr, void *kaddr, size_t len) 72 { 73 int error, save; 74 75 save = vm_fault_disable_pagefaults(); 76 error = copyin(udaddr, kaddr, len); 77 vm_fault_enable_pagefaults(save); 78 return (error); 79 } 80 81 int 82 copyout_nofault(const void *kaddr, void *udaddr, size_t len) 83 { 84 int error, save; 85 86 save = vm_fault_disable_pagefaults(); 87 error = copyout(kaddr, udaddr, len); 88 vm_fault_enable_pagefaults(save); 89 return (error); 90 } 91 92 #define PHYS_PAGE_COUNT(len) (howmany(len, PAGE_SIZE) + 1) 93 94 int 95 physcopyin(void *src, vm_paddr_t dst, size_t len) 96 { 97 vm_page_t m[PHYS_PAGE_COUNT(len)]; 98 struct iovec iov[1]; 99 struct uio uio; 100 int i; 101 102 iov[0].iov_base = src; 103 iov[0].iov_len = len; 104 uio.uio_iov = iov; 105 uio.uio_iovcnt = 1; 106 uio.uio_offset = 0; 107 uio.uio_resid = len; 108 uio.uio_segflg = UIO_SYSSPACE; 109 uio.uio_rw = UIO_WRITE; 110 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, dst += PAGE_SIZE) 111 m[i] = PHYS_TO_VM_PAGE(dst); 112 return (uiomove_fromphys(m, dst & PAGE_MASK, len, &uio)); 113 } 114 115 int 116 physcopyout(vm_paddr_t src, void *dst, size_t len) 117 { 118 vm_page_t m[PHYS_PAGE_COUNT(len)]; 119 struct iovec iov[1]; 120 struct uio uio; 121 int i; 122 123 iov[0].iov_base = dst; 124 iov[0].iov_len = len; 125 uio.uio_iov = iov; 126 uio.uio_iovcnt = 1; 127 uio.uio_offset = 0; 128 uio.uio_resid = len; 129 uio.uio_segflg = UIO_SYSSPACE; 130 uio.uio_rw = UIO_READ; 131 for (i = 0; i < PHYS_PAGE_COUNT(len); i++, src += PAGE_SIZE) 132 m[i] = PHYS_TO_VM_PAGE(src); 133 return (uiomove_fromphys(m, src & PAGE_MASK, len, &uio)); 134 } 135 136 #undef PHYS_PAGE_COUNT 137 138 int 139 uiomove(void *cp, int n, struct uio *uio) 140 { 141 142 return (uiomove_faultflag(cp, n, uio, 0)); 143 } 144 145 int 146 uiomove_nofault(void *cp, int n, struct uio *uio) 147 { 148 149 return (uiomove_faultflag(cp, n, uio, 1)); 150 } 151 152 static int 153 uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault) 154 { 155 struct thread *td; 156 struct iovec *iov; 157 size_t cnt; 158 int error, newflags, save; 159 160 td = curthread; 161 error = 0; 162 163 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 164 ("uiomove: mode")); 165 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == td, 166 ("uiomove proc")); 167 if (!nofault) 168 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 169 "Calling uiomove()"); 170 171 /* XXX does it make a sense to set TDP_DEADLKTREAT for UIO_SYSSPACE ? */ 172 newflags = TDP_DEADLKTREAT; 173 if (uio->uio_segflg == UIO_USERSPACE && nofault) { 174 /* 175 * Fail if a non-spurious page fault occurs. 176 */ 177 newflags |= TDP_NOFAULTING | TDP_RESETSPUR; 178 } 179 save = curthread_pflags_set(newflags); 180 181 while (n > 0 && uio->uio_resid) { 182 iov = uio->uio_iov; 183 cnt = iov->iov_len; 184 if (cnt == 0) { 185 uio->uio_iov++; 186 uio->uio_iovcnt--; 187 continue; 188 } 189 if (cnt > n) 190 cnt = n; 191 192 switch (uio->uio_segflg) { 193 194 case UIO_USERSPACE: 195 maybe_yield(); 196 if (uio->uio_rw == UIO_READ) 197 error = copyout(cp, iov->iov_base, cnt); 198 else 199 error = copyin(iov->iov_base, cp, cnt); 200 if (error) 201 goto out; 202 break; 203 204 case UIO_SYSSPACE: 205 if (uio->uio_rw == UIO_READ) 206 bcopy(cp, iov->iov_base, cnt); 207 else 208 bcopy(iov->iov_base, cp, cnt); 209 break; 210 case UIO_NOCOPY: 211 break; 212 } 213 iov->iov_base = (char *)iov->iov_base + cnt; 214 iov->iov_len -= cnt; 215 uio->uio_resid -= cnt; 216 uio->uio_offset += cnt; 217 cp = (char *)cp + cnt; 218 n -= cnt; 219 } 220 out: 221 curthread_pflags_restore(save); 222 return (error); 223 } 224 225 /* 226 * Wrapper for uiomove() that validates the arguments against a known-good 227 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which 228 * is almost definitely a bad thing, so we catch that here as well. We 229 * return a runtime failure, but it might be desirable to generate a runtime 230 * assertion failure instead. 231 */ 232 int 233 uiomove_frombuf(void *buf, int buflen, struct uio *uio) 234 { 235 size_t offset, n; 236 237 if (uio->uio_offset < 0 || uio->uio_resid < 0 || 238 (offset = uio->uio_offset) != uio->uio_offset) 239 return (EINVAL); 240 if (buflen <= 0 || offset >= buflen) 241 return (0); 242 if ((n = buflen - offset) > IOSIZE_MAX) 243 return (EINVAL); 244 return (uiomove((char *)buf + offset, n, uio)); 245 } 246 247 /* 248 * Give next character to user as result of read. 249 */ 250 int 251 ureadc(int c, struct uio *uio) 252 { 253 struct iovec *iov; 254 char *iov_base; 255 256 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 257 "Calling ureadc()"); 258 259 again: 260 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0) 261 panic("ureadc"); 262 iov = uio->uio_iov; 263 if (iov->iov_len == 0) { 264 uio->uio_iovcnt--; 265 uio->uio_iov++; 266 goto again; 267 } 268 switch (uio->uio_segflg) { 269 270 case UIO_USERSPACE: 271 if (subyte(iov->iov_base, c) < 0) 272 return (EFAULT); 273 break; 274 275 case UIO_SYSSPACE: 276 iov_base = iov->iov_base; 277 *iov_base = c; 278 break; 279 280 case UIO_NOCOPY: 281 break; 282 } 283 iov->iov_base = (char *)iov->iov_base + 1; 284 iov->iov_len--; 285 uio->uio_resid--; 286 uio->uio_offset++; 287 return (0); 288 } 289 290 int 291 copyinfrom(const void * __restrict src, void * __restrict dst, size_t len, 292 int seg) 293 { 294 int error = 0; 295 296 switch (seg) { 297 case UIO_USERSPACE: 298 error = copyin(src, dst, len); 299 break; 300 case UIO_SYSSPACE: 301 bcopy(src, dst, len); 302 break; 303 default: 304 panic("copyinfrom: bad seg %d\n", seg); 305 } 306 return (error); 307 } 308 309 int 310 copyinstrfrom(const void * __restrict src, void * __restrict dst, size_t len, 311 size_t * __restrict copied, int seg) 312 { 313 int error = 0; 314 315 switch (seg) { 316 case UIO_USERSPACE: 317 error = copyinstr(src, dst, len, copied); 318 break; 319 case UIO_SYSSPACE: 320 error = copystr(src, dst, len, copied); 321 break; 322 default: 323 panic("copyinstrfrom: bad seg %d\n", seg); 324 } 325 return (error); 326 } 327 328 int 329 copyiniov(const struct iovec *iovp, u_int iovcnt, struct iovec **iov, int error) 330 { 331 u_int iovlen; 332 333 *iov = NULL; 334 if (iovcnt > UIO_MAXIOV) 335 return (error); 336 iovlen = iovcnt * sizeof (struct iovec); 337 *iov = malloc(iovlen, M_IOV, M_WAITOK); 338 error = copyin(iovp, *iov, iovlen); 339 if (error) { 340 free(*iov, M_IOV); 341 *iov = NULL; 342 } 343 return (error); 344 } 345 346 int 347 copyinuio(const struct iovec *iovp, u_int iovcnt, struct uio **uiop) 348 { 349 struct iovec *iov; 350 struct uio *uio; 351 u_int iovlen; 352 int error, i; 353 354 *uiop = NULL; 355 if (iovcnt > UIO_MAXIOV) 356 return (EINVAL); 357 iovlen = iovcnt * sizeof (struct iovec); 358 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 359 iov = (struct iovec *)(uio + 1); 360 error = copyin(iovp, iov, iovlen); 361 if (error) { 362 free(uio, M_IOV); 363 return (error); 364 } 365 uio->uio_iov = iov; 366 uio->uio_iovcnt = iovcnt; 367 uio->uio_segflg = UIO_USERSPACE; 368 uio->uio_offset = -1; 369 uio->uio_resid = 0; 370 for (i = 0; i < iovcnt; i++) { 371 if (iov->iov_len > IOSIZE_MAX - uio->uio_resid) { 372 free(uio, M_IOV); 373 return (EINVAL); 374 } 375 uio->uio_resid += iov->iov_len; 376 iov++; 377 } 378 *uiop = uio; 379 return (0); 380 } 381 382 struct uio * 383 cloneuio(struct uio *uiop) 384 { 385 struct uio *uio; 386 int iovlen; 387 388 iovlen = uiop->uio_iovcnt * sizeof (struct iovec); 389 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 390 *uio = *uiop; 391 uio->uio_iov = (struct iovec *)(uio + 1); 392 bcopy(uiop->uio_iov, uio->uio_iov, iovlen); 393 return (uio); 394 } 395 396 /* 397 * Map some anonymous memory in user space of size sz, rounded up to the page 398 * boundary. 399 */ 400 int 401 copyout_map(struct thread *td, vm_offset_t *addr, size_t sz) 402 { 403 struct vmspace *vms; 404 int error; 405 vm_size_t size; 406 407 vms = td->td_proc->p_vmspace; 408 409 /* 410 * Map somewhere after heap in process memory. 411 */ 412 PROC_LOCK(td->td_proc); 413 *addr = round_page((vm_offset_t)vms->vm_daddr + 414 lim_max(td->td_proc, RLIMIT_DATA)); 415 PROC_UNLOCK(td->td_proc); 416 417 /* round size up to page boundry */ 418 size = (vm_size_t)round_page(sz); 419 420 error = vm_mmap(&vms->vm_map, addr, size, PROT_READ | PROT_WRITE, 421 VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, OBJT_DEFAULT, NULL, 0); 422 423 return (error); 424 } 425 426 /* 427 * Unmap memory in user space. 428 */ 429 int 430 copyout_unmap(struct thread *td, vm_offset_t addr, size_t sz) 431 { 432 vm_map_t map; 433 vm_size_t size; 434 435 if (sz == 0) 436 return (0); 437 438 map = &td->td_proc->p_vmspace->vm_map; 439 size = (vm_size_t)round_page(sz); 440 441 if (vm_map_remove(map, addr, addr + size) != KERN_SUCCESS) 442 return (EINVAL); 443 444 return (0); 445 } 446 447 #ifdef NO_FUEWORD 448 /* 449 * XXXKIB The temporal implementation of fue*() functions which do not 450 * handle usermode -1 properly, mixing it with the fault code. Keep 451 * this until MD code is written. Currently sparc64, mips and arm do 452 * not have proper implementation. 453 */ 454 455 int 456 fueword(volatile const void *base, long *val) 457 { 458 long res; 459 460 res = fuword(base); 461 if (res == -1) 462 return (-1); 463 *val = res; 464 return (0); 465 } 466 467 int 468 fueword32(volatile const void *base, int32_t *val) 469 { 470 int32_t res; 471 472 res = fuword32(base); 473 if (res == -1) 474 return (-1); 475 *val = res; 476 return (0); 477 } 478 479 #ifdef _LP64 480 int 481 fueword64(volatile const void *base, int64_t *val) 482 { 483 int32_t res; 484 485 res = fuword64(base); 486 if (res == -1) 487 return (-1); 488 *val = res; 489 return (0); 490 } 491 #endif 492 493 int 494 casueword32(volatile uint32_t *base, uint32_t oldval, uint32_t *oldvalp, 495 uint32_t newval) 496 { 497 int32_t ov; 498 499 ov = casuword32(base, oldval, newval); 500 if (ov == -1) 501 return (-1); 502 *oldvalp = ov; 503 return (0); 504 } 505 506 int 507 casueword(volatile u_long *p, u_long oldval, u_long *oldvalp, u_long newval) 508 { 509 u_long ov; 510 511 ov = casuword(p, oldval, newval); 512 if (ov == -1) 513 return (-1); 514 *oldvalp = ov; 515 return (0); 516 } 517 #else /* NO_FUEWORD */ 518 int32_t 519 fuword32(volatile const void *addr) 520 { 521 int rv; 522 int32_t val; 523 524 rv = fueword32(addr, &val); 525 return (rv == -1 ? -1 : val); 526 } 527 528 #ifdef _LP64 529 int64_t 530 fuword64(volatile const void *addr) 531 { 532 int rv; 533 int64_t val; 534 535 rv = fueword64(addr, &val); 536 return (rv == -1 ? -1 : val); 537 } 538 #endif /* _LP64 */ 539 540 long 541 fuword(volatile const void *addr) 542 { 543 long val; 544 int rv; 545 546 rv = fueword(addr, &val); 547 return (rv == -1 ? -1 : val); 548 } 549 550 uint32_t 551 casuword32(volatile uint32_t *addr, uint32_t old, uint32_t new) 552 { 553 int rv; 554 uint32_t val; 555 556 rv = casueword32(addr, old, &val, new); 557 return (rv == -1 ? -1 : val); 558 } 559 560 u_long 561 casuword(volatile u_long *addr, u_long old, u_long new) 562 { 563 int rv; 564 u_long val; 565 566 rv = casueword(addr, old, &val, new); 567 return (rv == -1 ? -1 : val); 568 } 569 570 #endif /* NO_FUEWORD */ 571