1 /* 2 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. 3 * Copyright (C) 2007 The Regents of the University of California. 4 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). 5 * Written by Brian Behlendorf <behlendorf1@llnl.gov>. 6 * UCRL-CODE-235197 7 * 8 * This file is part of the SPL, Solaris Porting Layer. 9 * 10 * The SPL is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the 12 * Free Software Foundation; either version 2 of the License, or (at your 13 * option) any later version. 14 * 15 * The SPL is distributed in the hope that it will be useful, but WITHOUT 16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 18 * for more details. 19 * 20 * You should have received a copy of the GNU General Public License along 21 * with the SPL. If not, see <http://www.gnu.org/licenses/>. 22 * 23 * Solaris Porting Layer (SPL) Generic Implementation. 24 */ 25 26 #include <sys/sysmacros.h> 27 #include <sys/systeminfo.h> 28 #include <sys/vmsystm.h> 29 #include <sys/kmem.h> 30 #include <sys/kmem_cache.h> 31 #include <sys/vmem.h> 32 #include <sys/mutex.h> 33 #include <sys/rwlock.h> 34 #include <sys/taskq.h> 35 #include <sys/tsd.h> 36 #include <sys/zmod.h> 37 #include <sys/debug.h> 38 #include <sys/proc.h> 39 #include <sys/kstat.h> 40 #include <sys/file.h> 41 #include <sys/sunddi.h> 42 #include <linux/ctype.h> 43 #include <sys/disp.h> 44 #include <sys/random.h> 45 #include <sys/strings.h> 46 #include <linux/kmod.h> 47 #include "zfs_gitrev.h" 48 #include <linux/mod_compat.h> 49 #include <sys/cred.h> 50 #include <sys/vnode.h> 51 52 char spl_gitrev[64] = ZFS_META_GITREV; 53 54 /* BEGIN CSTYLED */ 55 unsigned long spl_hostid = 0; 56 EXPORT_SYMBOL(spl_hostid); 57 /* BEGIN CSTYLED */ 58 module_param(spl_hostid, ulong, 0644); 59 MODULE_PARM_DESC(spl_hostid, "The system hostid."); 60 /* END CSTYLED */ 61 62 proc_t p0; 63 EXPORT_SYMBOL(p0); 64 65 /* 66 * Xorshift Pseudo Random Number Generator based on work by Sebastiano Vigna 67 * 68 * "Further scramblings of Marsaglia's xorshift generators" 69 * http://vigna.di.unimi.it/ftp/papers/xorshiftplus.pdf 70 * 71 * random_get_pseudo_bytes() is an API function on Illumos whose sole purpose 72 * is to provide bytes containing random numbers. It is mapped to /dev/urandom 73 * on Illumos, which uses a "FIPS 186-2 algorithm". No user of the SPL's 74 * random_get_pseudo_bytes() needs bytes that are of cryptographic quality, so 75 * we can implement it using a fast PRNG that we seed using Linux' actual 76 * equivalent to random_get_pseudo_bytes(). We do this by providing each CPU 77 * with an independent seed so that all calls to random_get_pseudo_bytes() are 78 * free of atomic instructions. 79 * 80 * A consequence of using a fast PRNG is that using random_get_pseudo_bytes() 81 * to generate words larger than 128 bits will paradoxically be limited to 82 * `2^128 - 1` possibilities. This is because we have a sequence of `2^128 - 1` 83 * 128-bit words and selecting the first will implicitly select the second. If 84 * a caller finds this behavior undesirable, random_get_bytes() should be used 85 * instead. 86 * 87 * XXX: Linux interrupt handlers that trigger within the critical section 88 * formed by `s[1] = xp[1];` and `xp[0] = s[0];` and call this function will 89 * see the same numbers. Nothing in the code currently calls this in an 90 * interrupt handler, so this is considered to be okay. If that becomes a 91 * problem, we could create a set of per-cpu variables for interrupt handlers 92 * and use them when in_interrupt() from linux/preempt_mask.h evaluates to 93 * true. 94 */ 95 void __percpu *spl_pseudo_entropy; 96 97 /* 98 * spl_rand_next()/spl_rand_jump() are copied from the following CC-0 licensed 99 * file: 100 * 101 * http://xorshift.di.unimi.it/xorshift128plus.c 102 */ 103 104 static inline uint64_t 105 spl_rand_next(uint64_t *s) 106 { 107 uint64_t s1 = s[0]; 108 const uint64_t s0 = s[1]; 109 s[0] = s0; 110 s1 ^= s1 << 23; // a 111 s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5); // b, c 112 return (s[1] + s0); 113 } 114 115 static inline void 116 spl_rand_jump(uint64_t *s) 117 { 118 static const uint64_t JUMP[] = 119 { 0x8a5cd789635d2dff, 0x121fd2155c472f96 }; 120 121 uint64_t s0 = 0; 122 uint64_t s1 = 0; 123 int i, b; 124 for (i = 0; i < sizeof (JUMP) / sizeof (*JUMP); i++) 125 for (b = 0; b < 64; b++) { 126 if (JUMP[i] & 1ULL << b) { 127 s0 ^= s[0]; 128 s1 ^= s[1]; 129 } 130 (void) spl_rand_next(s); 131 } 132 133 s[0] = s0; 134 s[1] = s1; 135 } 136 137 int 138 random_get_pseudo_bytes(uint8_t *ptr, size_t len) 139 { 140 uint64_t *xp, s[2]; 141 142 ASSERT(ptr); 143 144 xp = get_cpu_ptr(spl_pseudo_entropy); 145 146 s[0] = xp[0]; 147 s[1] = xp[1]; 148 149 while (len) { 150 union { 151 uint64_t ui64; 152 uint8_t byte[sizeof (uint64_t)]; 153 }entropy; 154 int i = MIN(len, sizeof (uint64_t)); 155 156 len -= i; 157 entropy.ui64 = spl_rand_next(s); 158 159 while (i--) 160 *ptr++ = entropy.byte[i]; 161 } 162 163 xp[0] = s[0]; 164 xp[1] = s[1]; 165 166 put_cpu_ptr(spl_pseudo_entropy); 167 168 return (0); 169 } 170 171 172 EXPORT_SYMBOL(random_get_pseudo_bytes); 173 174 #if BITS_PER_LONG == 32 175 176 /* 177 * Support 64/64 => 64 division on a 32-bit platform. While the kernel 178 * provides a div64_u64() function for this we do not use it because the 179 * implementation is flawed. There are cases which return incorrect 180 * results as late as linux-2.6.35. Until this is fixed upstream the 181 * spl must provide its own implementation. 182 * 183 * This implementation is a slightly modified version of the algorithm 184 * proposed by the book 'Hacker's Delight'. The original source can be 185 * found here and is available for use without restriction. 186 * 187 * http://www.hackersdelight.org/HDcode/newCode/divDouble.c 188 */ 189 190 /* 191 * Calculate number of leading of zeros for a 64-bit value. 192 */ 193 static int 194 nlz64(uint64_t x) 195 { 196 register int n = 0; 197 198 if (x == 0) 199 return (64); 200 201 if (x <= 0x00000000FFFFFFFFULL) { n = n + 32; x = x << 32; } 202 if (x <= 0x0000FFFFFFFFFFFFULL) { n = n + 16; x = x << 16; } 203 if (x <= 0x00FFFFFFFFFFFFFFULL) { n = n + 8; x = x << 8; } 204 if (x <= 0x0FFFFFFFFFFFFFFFULL) { n = n + 4; x = x << 4; } 205 if (x <= 0x3FFFFFFFFFFFFFFFULL) { n = n + 2; x = x << 2; } 206 if (x <= 0x7FFFFFFFFFFFFFFFULL) { n = n + 1; } 207 208 return (n); 209 } 210 211 /* 212 * Newer kernels have a div_u64() function but we define our own 213 * to simplify portability between kernel versions. 214 */ 215 static inline uint64_t 216 __div_u64(uint64_t u, uint32_t v) 217 { 218 (void) do_div(u, v); 219 return (u); 220 } 221 222 /* 223 * Turn off missing prototypes warning for these functions. They are 224 * replacements for libgcc-provided functions and will never be called 225 * directly. 226 */ 227 #pragma GCC diagnostic push 228 #pragma GCC diagnostic ignored "-Wmissing-prototypes" 229 230 /* 231 * Implementation of 64-bit unsigned division for 32-bit machines. 232 * 233 * First the procedure takes care of the case in which the divisor is a 234 * 32-bit quantity. There are two subcases: (1) If the left half of the 235 * dividend is less than the divisor, one execution of do_div() is all that 236 * is required (overflow is not possible). (2) Otherwise it does two 237 * divisions, using the grade school method. 238 */ 239 uint64_t 240 __udivdi3(uint64_t u, uint64_t v) 241 { 242 uint64_t u0, u1, v1, q0, q1, k; 243 int n; 244 245 if (v >> 32 == 0) { // If v < 2**32: 246 if (u >> 32 < v) { // If u/v cannot overflow, 247 return (__div_u64(u, v)); // just do one division. 248 } else { // If u/v would overflow: 249 u1 = u >> 32; // Break u into two halves. 250 u0 = u & 0xFFFFFFFF; 251 q1 = __div_u64(u1, v); // First quotient digit. 252 k = u1 - q1 * v; // First remainder, < v. 253 u0 += (k << 32); 254 q0 = __div_u64(u0, v); // Seconds quotient digit. 255 return ((q1 << 32) + q0); 256 } 257 } else { // If v >= 2**32: 258 n = nlz64(v); // 0 <= n <= 31. 259 v1 = (v << n) >> 32; // Normalize divisor, MSB is 1. 260 u1 = u >> 1; // To ensure no overflow. 261 q1 = __div_u64(u1, v1); // Get quotient from 262 q0 = (q1 << n) >> 31; // Undo normalization and 263 // division of u by 2. 264 if (q0 != 0) // Make q0 correct or 265 q0 = q0 - 1; // too small by 1. 266 if ((u - q0 * v) >= v) 267 q0 = q0 + 1; // Now q0 is correct. 268 269 return (q0); 270 } 271 } 272 EXPORT_SYMBOL(__udivdi3); 273 274 /* BEGIN CSTYLED */ 275 #ifndef abs64 276 #define abs64(x) ({ uint64_t t = (x) >> 63; ((x) ^ t) - t; }) 277 #endif 278 /* END CSTYLED */ 279 280 /* 281 * Implementation of 64-bit signed division for 32-bit machines. 282 */ 283 int64_t 284 __divdi3(int64_t u, int64_t v) 285 { 286 int64_t q, t; 287 // cppcheck-suppress shiftTooManyBitsSigned 288 q = __udivdi3(abs64(u), abs64(v)); 289 // cppcheck-suppress shiftTooManyBitsSigned 290 t = (u ^ v) >> 63; // If u, v have different 291 return ((q ^ t) - t); // signs, negate q. 292 } 293 EXPORT_SYMBOL(__divdi3); 294 295 /* 296 * Implementation of 64-bit unsigned modulo for 32-bit machines. 297 */ 298 uint64_t 299 __umoddi3(uint64_t dividend, uint64_t divisor) 300 { 301 return (dividend - (divisor * __udivdi3(dividend, divisor))); 302 } 303 EXPORT_SYMBOL(__umoddi3); 304 305 /* 64-bit signed modulo for 32-bit machines. */ 306 int64_t 307 __moddi3(int64_t n, int64_t d) 308 { 309 int64_t q; 310 boolean_t nn = B_FALSE; 311 312 if (n < 0) { 313 nn = B_TRUE; 314 n = -n; 315 } 316 if (d < 0) 317 d = -d; 318 319 q = __umoddi3(n, d); 320 321 return (nn ? -q : q); 322 } 323 EXPORT_SYMBOL(__moddi3); 324 325 /* 326 * Implementation of 64-bit unsigned division/modulo for 32-bit machines. 327 */ 328 uint64_t 329 __udivmoddi4(uint64_t n, uint64_t d, uint64_t *r) 330 { 331 uint64_t q = __udivdi3(n, d); 332 if (r) 333 *r = n - d * q; 334 return (q); 335 } 336 EXPORT_SYMBOL(__udivmoddi4); 337 338 /* 339 * Implementation of 64-bit signed division/modulo for 32-bit machines. 340 */ 341 int64_t 342 __divmoddi4(int64_t n, int64_t d, int64_t *r) 343 { 344 int64_t q, rr; 345 boolean_t nn = B_FALSE; 346 boolean_t nd = B_FALSE; 347 if (n < 0) { 348 nn = B_TRUE; 349 n = -n; 350 } 351 if (d < 0) { 352 nd = B_TRUE; 353 d = -d; 354 } 355 356 q = __udivmoddi4(n, d, (uint64_t *)&rr); 357 358 if (nn != nd) 359 q = -q; 360 if (nn) 361 rr = -rr; 362 if (r) 363 *r = rr; 364 return (q); 365 } 366 EXPORT_SYMBOL(__divmoddi4); 367 368 #if defined(__arm) || defined(__arm__) 369 /* 370 * Implementation of 64-bit (un)signed division for 32-bit arm machines. 371 * 372 * Run-time ABI for the ARM Architecture (page 20). A pair of (unsigned) 373 * long longs is returned in {{r0, r1}, {r2,r3}}, the quotient in {r0, r1}, 374 * and the remainder in {r2, r3}. The return type is specifically left 375 * set to 'void' to ensure the compiler does not overwrite these registers 376 * during the return. All results are in registers as per ABI 377 */ 378 void 379 __aeabi_uldivmod(uint64_t u, uint64_t v) 380 { 381 uint64_t res; 382 uint64_t mod; 383 384 res = __udivdi3(u, v); 385 mod = __umoddi3(u, v); 386 { 387 register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); 388 register uint32_t r1 asm("r1") = (res >> 32); 389 register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); 390 register uint32_t r3 asm("r3") = (mod >> 32); 391 392 /* BEGIN CSTYLED */ 393 asm volatile("" 394 : "+r"(r0), "+r"(r1), "+r"(r2),"+r"(r3) /* output */ 395 : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ 396 /* END CSTYLED */ 397 398 return; /* r0; */ 399 } 400 } 401 EXPORT_SYMBOL(__aeabi_uldivmod); 402 403 void 404 __aeabi_ldivmod(int64_t u, int64_t v) 405 { 406 int64_t res; 407 uint64_t mod; 408 409 res = __divdi3(u, v); 410 mod = __umoddi3(u, v); 411 { 412 register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); 413 register uint32_t r1 asm("r1") = (res >> 32); 414 register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); 415 register uint32_t r3 asm("r3") = (mod >> 32); 416 417 /* BEGIN CSTYLED */ 418 asm volatile("" 419 : "+r"(r0), "+r"(r1), "+r"(r2),"+r"(r3) /* output */ 420 : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ 421 /* END CSTYLED */ 422 423 return; /* r0; */ 424 } 425 } 426 EXPORT_SYMBOL(__aeabi_ldivmod); 427 #endif /* __arm || __arm__ */ 428 429 #pragma GCC diagnostic pop 430 431 #endif /* BITS_PER_LONG */ 432 433 /* 434 * NOTE: The strtoxx behavior is solely based on my reading of the Solaris 435 * ddi_strtol(9F) man page. I have not verified the behavior of these 436 * functions against their Solaris counterparts. It is possible that I 437 * may have misinterpreted the man page or the man page is incorrect. 438 */ 439 int ddi_strtoul(const char *, char **, int, unsigned long *); 440 int ddi_strtol(const char *, char **, int, long *); 441 int ddi_strtoull(const char *, char **, int, unsigned long long *); 442 int ddi_strtoll(const char *, char **, int, long long *); 443 444 #define define_ddi_strtoux(type, valtype) \ 445 int ddi_strtou##type(const char *str, char **endptr, \ 446 int base, valtype *result) \ 447 { \ 448 valtype last_value, value = 0; \ 449 char *ptr = (char *)str; \ 450 int flag = 1, digit; \ 451 \ 452 if (strlen(ptr) == 0) \ 453 return (EINVAL); \ 454 \ 455 /* Auto-detect base based on prefix */ \ 456 if (!base) { \ 457 if (str[0] == '0') { \ 458 if (tolower(str[1]) == 'x' && isxdigit(str[2])) { \ 459 base = 16; /* hex */ \ 460 ptr += 2; \ 461 } else if (str[1] >= '0' && str[1] < 8) { \ 462 base = 8; /* octal */ \ 463 ptr += 1; \ 464 } else { \ 465 return (EINVAL); \ 466 } \ 467 } else { \ 468 base = 10; /* decimal */ \ 469 } \ 470 } \ 471 \ 472 while (1) { \ 473 if (isdigit(*ptr)) \ 474 digit = *ptr - '0'; \ 475 else if (isalpha(*ptr)) \ 476 digit = tolower(*ptr) - 'a' + 10; \ 477 else \ 478 break; \ 479 \ 480 if (digit >= base) \ 481 break; \ 482 \ 483 last_value = value; \ 484 value = value * base + digit; \ 485 if (last_value > value) /* Overflow */ \ 486 return (ERANGE); \ 487 \ 488 flag = 1; \ 489 ptr++; \ 490 } \ 491 \ 492 if (flag) \ 493 *result = value; \ 494 \ 495 if (endptr) \ 496 *endptr = (char *)(flag ? ptr : str); \ 497 \ 498 return (0); \ 499 } \ 500 501 #define define_ddi_strtox(type, valtype) \ 502 int ddi_strto##type(const char *str, char **endptr, \ 503 int base, valtype *result) \ 504 { \ 505 int rc; \ 506 \ 507 if (*str == '-') { \ 508 rc = ddi_strtou##type(str + 1, endptr, base, result); \ 509 if (!rc) { \ 510 if (*endptr == str + 1) \ 511 *endptr = (char *)str; \ 512 else \ 513 *result = -*result; \ 514 } \ 515 } else { \ 516 rc = ddi_strtou##type(str, endptr, base, result); \ 517 } \ 518 \ 519 return (rc); \ 520 } 521 522 define_ddi_strtoux(l, unsigned long) 523 define_ddi_strtox(l, long) 524 define_ddi_strtoux(ll, unsigned long long) 525 define_ddi_strtox(ll, long long) 526 527 EXPORT_SYMBOL(ddi_strtoul); 528 EXPORT_SYMBOL(ddi_strtol); 529 EXPORT_SYMBOL(ddi_strtoll); 530 EXPORT_SYMBOL(ddi_strtoull); 531 532 int 533 ddi_copyin(const void *from, void *to, size_t len, int flags) 534 { 535 /* Fake ioctl() issued by kernel, 'from' is a kernel address */ 536 if (flags & FKIOCTL) { 537 memcpy(to, from, len); 538 return (0); 539 } 540 541 return (copyin(from, to, len)); 542 } 543 EXPORT_SYMBOL(ddi_copyin); 544 545 int 546 ddi_copyout(const void *from, void *to, size_t len, int flags) 547 { 548 /* Fake ioctl() issued by kernel, 'from' is a kernel address */ 549 if (flags & FKIOCTL) { 550 memcpy(to, from, len); 551 return (0); 552 } 553 554 return (copyout(from, to, len)); 555 } 556 EXPORT_SYMBOL(ddi_copyout); 557 558 static ssize_t 559 spl_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) 560 { 561 #if defined(HAVE_KERNEL_READ_PPOS) 562 return (kernel_read(file, buf, count, pos)); 563 #else 564 mm_segment_t saved_fs; 565 ssize_t ret; 566 567 saved_fs = get_fs(); 568 set_fs(KERNEL_DS); 569 570 ret = vfs_read(file, (void __user *)buf, count, pos); 571 572 set_fs(saved_fs); 573 574 return (ret); 575 #endif 576 } 577 578 static int 579 spl_getattr(struct file *filp, struct kstat *stat) 580 { 581 int rc; 582 583 ASSERT(filp); 584 ASSERT(stat); 585 586 #if defined(HAVE_4ARGS_VFS_GETATTR) 587 rc = vfs_getattr(&filp->f_path, stat, STATX_BASIC_STATS, 588 AT_STATX_SYNC_AS_STAT); 589 #elif defined(HAVE_2ARGS_VFS_GETATTR) 590 rc = vfs_getattr(&filp->f_path, stat); 591 #else 592 rc = vfs_getattr(filp->f_path.mnt, filp->f_dentry, stat); 593 #endif 594 if (rc) 595 return (-rc); 596 597 return (0); 598 } 599 600 /* 601 * Read the unique system identifier from the /etc/hostid file. 602 * 603 * The behavior of /usr/bin/hostid on Linux systems with the 604 * regular eglibc and coreutils is: 605 * 606 * 1. Generate the value if the /etc/hostid file does not exist 607 * or if the /etc/hostid file is less than four bytes in size. 608 * 609 * 2. If the /etc/hostid file is at least 4 bytes, then return 610 * the first four bytes [0..3] in native endian order. 611 * 612 * 3. Always ignore bytes [4..] if they exist in the file. 613 * 614 * Only the first four bytes are significant, even on systems that 615 * have a 64-bit word size. 616 * 617 * See: 618 * 619 * eglibc: sysdeps/unix/sysv/linux/gethostid.c 620 * coreutils: src/hostid.c 621 * 622 * Notes: 623 * 624 * The /etc/hostid file on Solaris is a text file that often reads: 625 * 626 * # DO NOT EDIT 627 * "0123456789" 628 * 629 * Directly copying this file to Linux results in a constant 630 * hostid of 4f442023 because the default comment constitutes 631 * the first four bytes of the file. 632 * 633 */ 634 635 char *spl_hostid_path = HW_HOSTID_PATH; 636 module_param(spl_hostid_path, charp, 0444); 637 MODULE_PARM_DESC(spl_hostid_path, "The system hostid file (/etc/hostid)"); 638 639 static int 640 hostid_read(uint32_t *hostid) 641 { 642 uint64_t size; 643 uint32_t value = 0; 644 int error; 645 loff_t off; 646 struct file *filp; 647 struct kstat stat; 648 649 filp = filp_open(spl_hostid_path, 0, 0); 650 651 if (IS_ERR(filp)) 652 return (ENOENT); 653 654 error = spl_getattr(filp, &stat); 655 if (error) { 656 filp_close(filp, 0); 657 return (error); 658 } 659 size = stat.size; 660 if (size < sizeof (HW_HOSTID_MASK)) { 661 filp_close(filp, 0); 662 return (EINVAL); 663 } 664 665 off = 0; 666 /* 667 * Read directly into the variable like eglibc does. 668 * Short reads are okay; native behavior is preserved. 669 */ 670 error = spl_kernel_read(filp, &value, sizeof (value), &off); 671 if (error < 0) { 672 filp_close(filp, 0); 673 return (EIO); 674 } 675 676 /* Mask down to 32 bits like coreutils does. */ 677 *hostid = (value & HW_HOSTID_MASK); 678 filp_close(filp, 0); 679 680 return (0); 681 } 682 683 /* 684 * Return the system hostid. Preferentially use the spl_hostid module option 685 * when set, otherwise use the value in the /etc/hostid file. 686 */ 687 uint32_t 688 zone_get_hostid(void *zone) 689 { 690 uint32_t hostid; 691 692 ASSERT3P(zone, ==, NULL); 693 694 if (spl_hostid != 0) 695 return ((uint32_t)(spl_hostid & HW_HOSTID_MASK)); 696 697 if (hostid_read(&hostid) == 0) 698 return (hostid); 699 700 return (0); 701 } 702 EXPORT_SYMBOL(zone_get_hostid); 703 704 static int 705 spl_kvmem_init(void) 706 { 707 int rc = 0; 708 709 rc = spl_kmem_init(); 710 if (rc) 711 return (rc); 712 713 rc = spl_vmem_init(); 714 if (rc) { 715 spl_kmem_fini(); 716 return (rc); 717 } 718 719 return (rc); 720 } 721 722 /* 723 * We initialize the random number generator with 128 bits of entropy from the 724 * system random number generator. In the improbable case that we have a zero 725 * seed, we fallback to the system jiffies, unless it is also zero, in which 726 * situation we use a preprogrammed seed. We step forward by 2^64 iterations to 727 * initialize each of the per-cpu seeds so that the sequences generated on each 728 * CPU are guaranteed to never overlap in practice. 729 */ 730 static void __init 731 spl_random_init(void) 732 { 733 uint64_t s[2]; 734 int i = 0; 735 736 spl_pseudo_entropy = __alloc_percpu(2 * sizeof (uint64_t), 737 sizeof (uint64_t)); 738 739 get_random_bytes(s, sizeof (s)); 740 741 if (s[0] == 0 && s[1] == 0) { 742 if (jiffies != 0) { 743 s[0] = jiffies; 744 s[1] = ~0 - jiffies; 745 } else { 746 (void) memcpy(s, "improbable seed", sizeof (s)); 747 } 748 printk("SPL: get_random_bytes() returned 0 " 749 "when generating random seed. Setting initial seed to " 750 "0x%016llx%016llx.\n", cpu_to_be64(s[0]), 751 cpu_to_be64(s[1])); 752 } 753 754 for_each_possible_cpu(i) { 755 uint64_t *wordp = per_cpu_ptr(spl_pseudo_entropy, i); 756 757 spl_rand_jump(s); 758 759 wordp[0] = s[0]; 760 wordp[1] = s[1]; 761 } 762 } 763 764 static void 765 spl_random_fini(void) 766 { 767 free_percpu(spl_pseudo_entropy); 768 } 769 770 static void 771 spl_kvmem_fini(void) 772 { 773 spl_vmem_fini(); 774 spl_kmem_fini(); 775 } 776 777 static int __init 778 spl_init(void) 779 { 780 int rc = 0; 781 782 bzero(&p0, sizeof (proc_t)); 783 spl_random_init(); 784 785 if ((rc = spl_kvmem_init())) 786 goto out1; 787 788 if ((rc = spl_tsd_init())) 789 goto out2; 790 791 if ((rc = spl_taskq_init())) 792 goto out3; 793 794 if ((rc = spl_kmem_cache_init())) 795 goto out4; 796 797 if ((rc = spl_proc_init())) 798 goto out5; 799 800 if ((rc = spl_kstat_init())) 801 goto out6; 802 803 if ((rc = spl_zlib_init())) 804 goto out7; 805 806 return (rc); 807 808 out7: 809 spl_kstat_fini(); 810 out6: 811 spl_proc_fini(); 812 out5: 813 spl_kmem_cache_fini(); 814 out4: 815 spl_taskq_fini(); 816 out3: 817 spl_tsd_fini(); 818 out2: 819 spl_kvmem_fini(); 820 out1: 821 return (rc); 822 } 823 824 static void __exit 825 spl_fini(void) 826 { 827 spl_zlib_fini(); 828 spl_kstat_fini(); 829 spl_proc_fini(); 830 spl_kmem_cache_fini(); 831 spl_taskq_fini(); 832 spl_tsd_fini(); 833 spl_kvmem_fini(); 834 spl_random_fini(); 835 } 836 837 module_init(spl_init); 838 module_exit(spl_fini); 839 840 ZFS_MODULE_DESCRIPTION("Solaris Porting Layer"); 841 ZFS_MODULE_AUTHOR(ZFS_META_AUTHOR); 842 ZFS_MODULE_LICENSE("GPL"); 843 ZFS_MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE); 844