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 #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 thread *td; 210 struct iovec *iov; 211 size_t cnt; 212 int error, newflags, save; 213 214 td = curthread; 215 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 == td, 220 ("uiomove proc")); 221 if (!nofault) 222 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 223 "Calling uiomove()"); 224 225 /* XXX does it make a sense to set TDP_DEADLKTREAT for UIO_SYSSPACE ? */ 226 newflags = TDP_DEADLKTREAT; 227 if (uio->uio_segflg == UIO_USERSPACE && nofault) { 228 /* 229 * Fail if a non-spurious page fault occurs. 230 */ 231 newflags |= TDP_NOFAULTING | TDP_RESETSPUR; 232 } 233 save = curthread_pflags_set(newflags); 234 235 while (n > 0 && uio->uio_resid) { 236 iov = uio->uio_iov; 237 cnt = iov->iov_len; 238 if (cnt == 0) { 239 uio->uio_iov++; 240 uio->uio_iovcnt--; 241 continue; 242 } 243 if (cnt > n) 244 cnt = n; 245 246 switch (uio->uio_segflg) { 247 248 case UIO_USERSPACE: 249 maybe_yield(); 250 if (uio->uio_rw == UIO_READ) 251 error = copyout(cp, iov->iov_base, cnt); 252 else 253 error = copyin(iov->iov_base, cp, cnt); 254 if (error) 255 goto out; 256 break; 257 258 case UIO_SYSSPACE: 259 if (uio->uio_rw == UIO_READ) 260 bcopy(cp, iov->iov_base, cnt); 261 else 262 bcopy(iov->iov_base, cp, cnt); 263 break; 264 case UIO_NOCOPY: 265 break; 266 } 267 iov->iov_base = (char *)iov->iov_base + cnt; 268 iov->iov_len -= cnt; 269 uio->uio_resid -= cnt; 270 uio->uio_offset += cnt; 271 cp = (char *)cp + cnt; 272 n -= cnt; 273 } 274 out: 275 curthread_pflags_restore(save); 276 return (error); 277 } 278 279 /* 280 * Wrapper for uiomove() that validates the arguments against a known-good 281 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which 282 * is almost definitely a bad thing, so we catch that here as well. We 283 * return a runtime failure, but it might be desirable to generate a runtime 284 * assertion failure instead. 285 */ 286 int 287 uiomove_frombuf(void *buf, int buflen, struct uio *uio) 288 { 289 size_t offset, n; 290 291 if (uio->uio_offset < 0 || uio->uio_resid < 0 || 292 (offset = uio->uio_offset) != uio->uio_offset) 293 return (EINVAL); 294 if (buflen <= 0 || offset >= buflen) 295 return (0); 296 if ((n = buflen - offset) > IOSIZE_MAX) 297 return (EINVAL); 298 return (uiomove((char *)buf + offset, n, uio)); 299 } 300 301 /* 302 * Give next character to user as result of read. 303 */ 304 int 305 ureadc(int c, struct uio *uio) 306 { 307 struct iovec *iov; 308 char *iov_base; 309 310 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, 311 "Calling ureadc()"); 312 313 again: 314 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0) 315 panic("ureadc"); 316 iov = uio->uio_iov; 317 if (iov->iov_len == 0) { 318 uio->uio_iovcnt--; 319 uio->uio_iov++; 320 goto again; 321 } 322 switch (uio->uio_segflg) { 323 324 case UIO_USERSPACE: 325 if (subyte(iov->iov_base, c) < 0) 326 return (EFAULT); 327 break; 328 329 case UIO_SYSSPACE: 330 iov_base = iov->iov_base; 331 *iov_base = c; 332 break; 333 334 case UIO_NOCOPY: 335 break; 336 } 337 iov->iov_base = (char *)iov->iov_base + 1; 338 iov->iov_len--; 339 uio->uio_resid--; 340 uio->uio_offset++; 341 return (0); 342 } 343 344 int 345 copyinfrom(const void * __restrict src, void * __restrict dst, size_t len, 346 int seg) 347 { 348 int error = 0; 349 350 switch (seg) { 351 case UIO_USERSPACE: 352 error = copyin(src, dst, len); 353 break; 354 case UIO_SYSSPACE: 355 bcopy(src, dst, len); 356 break; 357 default: 358 panic("copyinfrom: bad seg %d\n", seg); 359 } 360 return (error); 361 } 362 363 int 364 copyinstrfrom(const void * __restrict src, void * __restrict dst, size_t len, 365 size_t * __restrict copied, int seg) 366 { 367 int error = 0; 368 369 switch (seg) { 370 case UIO_USERSPACE: 371 error = copyinstr(src, dst, len, copied); 372 break; 373 case UIO_SYSSPACE: 374 error = copystr(src, dst, len, copied); 375 break; 376 default: 377 panic("copyinstrfrom: bad seg %d\n", seg); 378 } 379 return (error); 380 } 381 382 int 383 copyiniov(const struct iovec *iovp, u_int iovcnt, struct iovec **iov, int error) 384 { 385 u_int iovlen; 386 387 *iov = NULL; 388 if (iovcnt > UIO_MAXIOV) 389 return (error); 390 iovlen = iovcnt * sizeof (struct iovec); 391 *iov = malloc(iovlen, M_IOV, M_WAITOK); 392 error = copyin(iovp, *iov, iovlen); 393 if (error) { 394 free(*iov, M_IOV); 395 *iov = NULL; 396 } 397 return (error); 398 } 399 400 int 401 copyinuio(const struct iovec *iovp, u_int iovcnt, struct uio **uiop) 402 { 403 struct iovec *iov; 404 struct uio *uio; 405 u_int iovlen; 406 int error, i; 407 408 *uiop = NULL; 409 if (iovcnt > UIO_MAXIOV) 410 return (EINVAL); 411 iovlen = iovcnt * sizeof (struct iovec); 412 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 413 iov = (struct iovec *)(uio + 1); 414 error = copyin(iovp, iov, iovlen); 415 if (error) { 416 free(uio, M_IOV); 417 return (error); 418 } 419 uio->uio_iov = iov; 420 uio->uio_iovcnt = iovcnt; 421 uio->uio_segflg = UIO_USERSPACE; 422 uio->uio_offset = -1; 423 uio->uio_resid = 0; 424 for (i = 0; i < iovcnt; i++) { 425 if (iov->iov_len > IOSIZE_MAX - uio->uio_resid) { 426 free(uio, M_IOV); 427 return (EINVAL); 428 } 429 uio->uio_resid += iov->iov_len; 430 iov++; 431 } 432 *uiop = uio; 433 return (0); 434 } 435 436 struct uio * 437 cloneuio(struct uio *uiop) 438 { 439 struct uio *uio; 440 int iovlen; 441 442 iovlen = uiop->uio_iovcnt * sizeof (struct iovec); 443 uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK); 444 *uio = *uiop; 445 uio->uio_iov = (struct iovec *)(uio + 1); 446 bcopy(uiop->uio_iov, uio->uio_iov, iovlen); 447 return (uio); 448 } 449 450 /* 451 * Map some anonymous memory in user space of size sz, rounded up to the page 452 * boundary. 453 */ 454 int 455 copyout_map(struct thread *td, vm_offset_t *addr, size_t sz) 456 { 457 struct vmspace *vms; 458 int error; 459 vm_size_t size; 460 461 vms = td->td_proc->p_vmspace; 462 463 /* 464 * Map somewhere after heap in process memory. 465 */ 466 *addr = round_page((vm_offset_t)vms->vm_daddr + 467 lim_max(td, RLIMIT_DATA)); 468 469 /* round size up to page boundary */ 470 size = (vm_size_t)round_page(sz); 471 472 error = vm_mmap(&vms->vm_map, addr, size, VM_PROT_READ | VM_PROT_WRITE, 473 VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, OBJT_DEFAULT, NULL, 0); 474 475 return (error); 476 } 477 478 /* 479 * Unmap memory in user space. 480 */ 481 int 482 copyout_unmap(struct thread *td, vm_offset_t addr, size_t sz) 483 { 484 vm_map_t map; 485 vm_size_t size; 486 487 if (sz == 0) 488 return (0); 489 490 map = &td->td_proc->p_vmspace->vm_map; 491 size = (vm_size_t)round_page(sz); 492 493 if (vm_map_remove(map, addr, addr + size) != KERN_SUCCESS) 494 return (EINVAL); 495 496 return (0); 497 } 498 499 #ifdef NO_FUEWORD 500 /* 501 * XXXKIB The temporal implementation of fue*() functions which do not 502 * handle usermode -1 properly, mixing it with the fault code. Keep 503 * this until MD code is written. Currently sparc64 and mips do not 504 * have proper implementation. 505 */ 506 507 int 508 fueword(volatile const void *base, long *val) 509 { 510 long res; 511 512 res = fuword(base); 513 if (res == -1) 514 return (-1); 515 *val = res; 516 return (0); 517 } 518 519 int 520 fueword32(volatile const void *base, int32_t *val) 521 { 522 int32_t res; 523 524 res = fuword32(base); 525 if (res == -1) 526 return (-1); 527 *val = res; 528 return (0); 529 } 530 531 #ifdef _LP64 532 int 533 fueword64(volatile const void *base, int64_t *val) 534 { 535 int32_t res; 536 537 res = fuword64(base); 538 if (res == -1) 539 return (-1); 540 *val = res; 541 return (0); 542 } 543 #endif 544 545 int 546 casueword32(volatile uint32_t *base, uint32_t oldval, uint32_t *oldvalp, 547 uint32_t newval) 548 { 549 int32_t ov; 550 551 ov = casuword32(base, oldval, newval); 552 if (ov == -1) 553 return (-1); 554 *oldvalp = ov; 555 return (0); 556 } 557 558 int 559 casueword(volatile u_long *p, u_long oldval, u_long *oldvalp, u_long newval) 560 { 561 u_long ov; 562 563 ov = casuword(p, oldval, newval); 564 if (ov == -1) 565 return (-1); 566 *oldvalp = ov; 567 return (0); 568 } 569 #else /* NO_FUEWORD */ 570 int32_t 571 fuword32(volatile const void *addr) 572 { 573 int rv; 574 int32_t val; 575 576 rv = fueword32(addr, &val); 577 return (rv == -1 ? -1 : val); 578 } 579 580 #ifdef _LP64 581 int64_t 582 fuword64(volatile const void *addr) 583 { 584 int rv; 585 int64_t val; 586 587 rv = fueword64(addr, &val); 588 return (rv == -1 ? -1 : val); 589 } 590 #endif /* _LP64 */ 591 592 long 593 fuword(volatile const void *addr) 594 { 595 long val; 596 int rv; 597 598 rv = fueword(addr, &val); 599 return (rv == -1 ? -1 : val); 600 } 601 602 uint32_t 603 casuword32(volatile uint32_t *addr, uint32_t old, uint32_t new) 604 { 605 int rv; 606 uint32_t val; 607 608 rv = casueword32(addr, old, &val, new); 609 return (rv == -1 ? -1 : val); 610 } 611 612 u_long 613 casuword(volatile u_long *addr, u_long old, u_long new) 614 { 615 int rv; 616 u_long val; 617 618 rv = casueword(addr, old, &val, new); 619 return (rv == -1 ? -1 : val); 620 } 621 622 #endif /* NO_FUEWORD */ 623