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 q = __udivdi3(abs64(u), abs64(v)); 288 t = (u ^ v) >> 63; // If u, v have different 289 return ((q ^ t) - t); // signs, negate q. 290 } 291 EXPORT_SYMBOL(__divdi3); 292 293 /* 294 * Implementation of 64-bit unsigned modulo for 32-bit machines. 295 */ 296 uint64_t 297 __umoddi3(uint64_t dividend, uint64_t divisor) 298 { 299 return (dividend - (divisor * __udivdi3(dividend, divisor))); 300 } 301 EXPORT_SYMBOL(__umoddi3); 302 303 /* 64-bit signed modulo for 32-bit machines. */ 304 int64_t 305 __moddi3(int64_t n, int64_t d) 306 { 307 int64_t q; 308 boolean_t nn = B_FALSE; 309 310 if (n < 0) { 311 nn = B_TRUE; 312 n = -n; 313 } 314 if (d < 0) 315 d = -d; 316 317 q = __umoddi3(n, d); 318 319 return (nn ? -q : q); 320 } 321 EXPORT_SYMBOL(__moddi3); 322 323 /* 324 * Implementation of 64-bit unsigned division/modulo for 32-bit machines. 325 */ 326 uint64_t 327 __udivmoddi4(uint64_t n, uint64_t d, uint64_t *r) 328 { 329 uint64_t q = __udivdi3(n, d); 330 if (r) 331 *r = n - d * q; 332 return (q); 333 } 334 EXPORT_SYMBOL(__udivmoddi4); 335 336 /* 337 * Implementation of 64-bit signed division/modulo for 32-bit machines. 338 */ 339 int64_t 340 __divmoddi4(int64_t n, int64_t d, int64_t *r) 341 { 342 int64_t q, rr; 343 boolean_t nn = B_FALSE; 344 boolean_t nd = B_FALSE; 345 if (n < 0) { 346 nn = B_TRUE; 347 n = -n; 348 } 349 if (d < 0) { 350 nd = B_TRUE; 351 d = -d; 352 } 353 354 q = __udivmoddi4(n, d, (uint64_t *)&rr); 355 356 if (nn != nd) 357 q = -q; 358 if (nn) 359 rr = -rr; 360 if (r) 361 *r = rr; 362 return (q); 363 } 364 EXPORT_SYMBOL(__divmoddi4); 365 366 #if defined(__arm) || defined(__arm__) 367 /* 368 * Implementation of 64-bit (un)signed division for 32-bit arm machines. 369 * 370 * Run-time ABI for the ARM Architecture (page 20). A pair of (unsigned) 371 * long longs is returned in {{r0, r1}, {r2,r3}}, the quotient in {r0, r1}, 372 * and the remainder in {r2, r3}. The return type is specifically left 373 * set to 'void' to ensure the compiler does not overwrite these registers 374 * during the return. All results are in registers as per ABI 375 */ 376 void 377 __aeabi_uldivmod(uint64_t u, uint64_t v) 378 { 379 uint64_t res; 380 uint64_t mod; 381 382 res = __udivdi3(u, v); 383 mod = __umoddi3(u, v); 384 { 385 register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); 386 register uint32_t r1 asm("r1") = (res >> 32); 387 register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); 388 register uint32_t r3 asm("r3") = (mod >> 32); 389 390 /* BEGIN CSTYLED */ 391 asm volatile("" 392 : "+r"(r0), "+r"(r1), "+r"(r2),"+r"(r3) /* output */ 393 : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ 394 /* END CSTYLED */ 395 396 return; /* r0; */ 397 } 398 } 399 EXPORT_SYMBOL(__aeabi_uldivmod); 400 401 void 402 __aeabi_ldivmod(int64_t u, int64_t v) 403 { 404 int64_t res; 405 uint64_t mod; 406 407 res = __divdi3(u, v); 408 mod = __umoddi3(u, v); 409 { 410 register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); 411 register uint32_t r1 asm("r1") = (res >> 32); 412 register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); 413 register uint32_t r3 asm("r3") = (mod >> 32); 414 415 /* BEGIN CSTYLED */ 416 asm volatile("" 417 : "+r"(r0), "+r"(r1), "+r"(r2),"+r"(r3) /* output */ 418 : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ 419 /* END CSTYLED */ 420 421 return; /* r0; */ 422 } 423 } 424 EXPORT_SYMBOL(__aeabi_ldivmod); 425 #endif /* __arm || __arm__ */ 426 427 #pragma GCC diagnostic pop 428 429 #endif /* BITS_PER_LONG */ 430 431 /* 432 * NOTE: The strtoxx behavior is solely based on my reading of the Solaris 433 * ddi_strtol(9F) man page. I have not verified the behavior of these 434 * functions against their Solaris counterparts. It is possible that I 435 * may have misinterpreted the man page or the man page is incorrect. 436 */ 437 int ddi_strtoul(const char *, char **, int, unsigned long *); 438 int ddi_strtol(const char *, char **, int, long *); 439 int ddi_strtoull(const char *, char **, int, unsigned long long *); 440 int ddi_strtoll(const char *, char **, int, long long *); 441 442 #define define_ddi_strtoux(type, valtype) \ 443 int ddi_strtou##type(const char *str, char **endptr, \ 444 int base, valtype *result) \ 445 { \ 446 valtype last_value, value = 0; \ 447 char *ptr = (char *)str; \ 448 int flag = 1, digit; \ 449 \ 450 if (strlen(ptr) == 0) \ 451 return (EINVAL); \ 452 \ 453 /* Auto-detect base based on prefix */ \ 454 if (!base) { \ 455 if (str[0] == '0') { \ 456 if (tolower(str[1]) == 'x' && isxdigit(str[2])) { \ 457 base = 16; /* hex */ \ 458 ptr += 2; \ 459 } else if (str[1] >= '0' && str[1] < 8) { \ 460 base = 8; /* octal */ \ 461 ptr += 1; \ 462 } else { \ 463 return (EINVAL); \ 464 } \ 465 } else { \ 466 base = 10; /* decimal */ \ 467 } \ 468 } \ 469 \ 470 while (1) { \ 471 if (isdigit(*ptr)) \ 472 digit = *ptr - '0'; \ 473 else if (isalpha(*ptr)) \ 474 digit = tolower(*ptr) - 'a' + 10; \ 475 else \ 476 break; \ 477 \ 478 if (digit >= base) \ 479 break; \ 480 \ 481 last_value = value; \ 482 value = value * base + digit; \ 483 if (last_value > value) /* Overflow */ \ 484 return (ERANGE); \ 485 \ 486 flag = 1; \ 487 ptr++; \ 488 } \ 489 \ 490 if (flag) \ 491 *result = value; \ 492 \ 493 if (endptr) \ 494 *endptr = (char *)(flag ? ptr : str); \ 495 \ 496 return (0); \ 497 } \ 498 499 #define define_ddi_strtox(type, valtype) \ 500 int ddi_strto##type(const char *str, char **endptr, \ 501 int base, valtype *result) \ 502 { \ 503 int rc; \ 504 \ 505 if (*str == '-') { \ 506 rc = ddi_strtou##type(str + 1, endptr, base, result); \ 507 if (!rc) { \ 508 if (*endptr == str + 1) \ 509 *endptr = (char *)str; \ 510 else \ 511 *result = -*result; \ 512 } \ 513 } else { \ 514 rc = ddi_strtou##type(str, endptr, base, result); \ 515 } \ 516 \ 517 return (rc); \ 518 } 519 520 define_ddi_strtoux(l, unsigned long) 521 define_ddi_strtox(l, long) 522 define_ddi_strtoux(ll, unsigned long long) 523 define_ddi_strtox(ll, long long) 524 525 EXPORT_SYMBOL(ddi_strtoul); 526 EXPORT_SYMBOL(ddi_strtol); 527 EXPORT_SYMBOL(ddi_strtoll); 528 EXPORT_SYMBOL(ddi_strtoull); 529 530 int 531 ddi_copyin(const void *from, void *to, size_t len, int flags) 532 { 533 /* Fake ioctl() issued by kernel, 'from' is a kernel address */ 534 if (flags & FKIOCTL) { 535 memcpy(to, from, len); 536 return (0); 537 } 538 539 return (copyin(from, to, len)); 540 } 541 EXPORT_SYMBOL(ddi_copyin); 542 543 int 544 ddi_copyout(const void *from, void *to, size_t len, int flags) 545 { 546 /* Fake ioctl() issued by kernel, 'from' is a kernel address */ 547 if (flags & FKIOCTL) { 548 memcpy(to, from, len); 549 return (0); 550 } 551 552 return (copyout(from, to, len)); 553 } 554 EXPORT_SYMBOL(ddi_copyout); 555 556 static ssize_t 557 spl_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) 558 { 559 #if defined(HAVE_KERNEL_READ_PPOS) 560 return (kernel_read(file, buf, count, pos)); 561 #else 562 mm_segment_t saved_fs; 563 ssize_t ret; 564 565 saved_fs = get_fs(); 566 set_fs(KERNEL_DS); 567 568 ret = vfs_read(file, (void __user *)buf, count, pos); 569 570 set_fs(saved_fs); 571 572 return (ret); 573 #endif 574 } 575 576 static int 577 spl_getattr(struct file *filp, struct kstat *stat) 578 { 579 int rc; 580 581 ASSERT(filp); 582 ASSERT(stat); 583 584 #if defined(HAVE_4ARGS_VFS_GETATTR) 585 rc = vfs_getattr(&filp->f_path, stat, STATX_BASIC_STATS, 586 AT_STATX_SYNC_AS_STAT); 587 #elif defined(HAVE_2ARGS_VFS_GETATTR) 588 rc = vfs_getattr(&filp->f_path, stat); 589 #elif defined(HAVE_3ARGS_VFS_GETATTR) 590 rc = vfs_getattr(filp->f_path.mnt, filp->f_dentry, stat); 591 #else 592 #error "No available vfs_getattr()" 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 // cppcheck-suppress sizeofwithnumericparameter 661 if (size < sizeof (HW_HOSTID_MASK)) { 662 filp_close(filp, 0); 663 return (EINVAL); 664 } 665 666 off = 0; 667 /* 668 * Read directly into the variable like eglibc does. 669 * Short reads are okay; native behavior is preserved. 670 */ 671 error = spl_kernel_read(filp, &value, sizeof (value), &off); 672 if (error < 0) { 673 filp_close(filp, 0); 674 return (EIO); 675 } 676 677 /* Mask down to 32 bits like coreutils does. */ 678 *hostid = (value & HW_HOSTID_MASK); 679 filp_close(filp, 0); 680 681 return (0); 682 } 683 684 /* 685 * Return the system hostid. Preferentially use the spl_hostid module option 686 * when set, otherwise use the value in the /etc/hostid file. 687 */ 688 uint32_t 689 zone_get_hostid(void *zone) 690 { 691 uint32_t hostid; 692 693 ASSERT3P(zone, ==, NULL); 694 695 if (spl_hostid != 0) 696 return ((uint32_t)(spl_hostid & HW_HOSTID_MASK)); 697 698 if (hostid_read(&hostid) == 0) 699 return (hostid); 700 701 return (0); 702 } 703 EXPORT_SYMBOL(zone_get_hostid); 704 705 static int 706 spl_kvmem_init(void) 707 { 708 int rc = 0; 709 710 rc = spl_kmem_init(); 711 if (rc) 712 return (rc); 713 714 rc = spl_vmem_init(); 715 if (rc) { 716 spl_kmem_fini(); 717 return (rc); 718 } 719 720 return (rc); 721 } 722 723 /* 724 * We initialize the random number generator with 128 bits of entropy from the 725 * system random number generator. In the improbable case that we have a zero 726 * seed, we fallback to the system jiffies, unless it is also zero, in which 727 * situation we use a preprogrammed seed. We step forward by 2^64 iterations to 728 * initialize each of the per-cpu seeds so that the sequences generated on each 729 * CPU are guaranteed to never overlap in practice. 730 */ 731 static void __init 732 spl_random_init(void) 733 { 734 uint64_t s[2]; 735 int i = 0; 736 737 spl_pseudo_entropy = __alloc_percpu(2 * sizeof (uint64_t), 738 sizeof (uint64_t)); 739 740 get_random_bytes(s, sizeof (s)); 741 742 if (s[0] == 0 && s[1] == 0) { 743 if (jiffies != 0) { 744 s[0] = jiffies; 745 s[1] = ~0 - jiffies; 746 } else { 747 (void) memcpy(s, "improbable seed", sizeof (s)); 748 } 749 printk("SPL: get_random_bytes() returned 0 " 750 "when generating random seed. Setting initial seed to " 751 "0x%016llx%016llx.\n", cpu_to_be64(s[0]), 752 cpu_to_be64(s[1])); 753 } 754 755 for_each_possible_cpu(i) { 756 uint64_t *wordp = per_cpu_ptr(spl_pseudo_entropy, i); 757 758 spl_rand_jump(s); 759 760 wordp[0] = s[0]; 761 wordp[1] = s[1]; 762 } 763 } 764 765 static void 766 spl_random_fini(void) 767 { 768 free_percpu(spl_pseudo_entropy); 769 } 770 771 static void 772 spl_kvmem_fini(void) 773 { 774 spl_vmem_fini(); 775 spl_kmem_fini(); 776 } 777 778 static int __init 779 spl_init(void) 780 { 781 int rc = 0; 782 783 bzero(&p0, sizeof (proc_t)); 784 spl_random_init(); 785 786 if ((rc = spl_kvmem_init())) 787 goto out1; 788 789 if ((rc = spl_tsd_init())) 790 goto out2; 791 792 if ((rc = spl_taskq_init())) 793 goto out3; 794 795 if ((rc = spl_kmem_cache_init())) 796 goto out4; 797 798 if ((rc = spl_proc_init())) 799 goto out5; 800 801 if ((rc = spl_kstat_init())) 802 goto out6; 803 804 if ((rc = spl_zlib_init())) 805 goto out7; 806 807 return (rc); 808 809 out7: 810 spl_kstat_fini(); 811 out6: 812 spl_proc_fini(); 813 out5: 814 spl_kmem_cache_fini(); 815 out4: 816 spl_taskq_fini(); 817 out3: 818 spl_tsd_fini(); 819 out2: 820 spl_kvmem_fini(); 821 out1: 822 return (rc); 823 } 824 825 static void __exit 826 spl_fini(void) 827 { 828 spl_zlib_fini(); 829 spl_kstat_fini(); 830 spl_proc_fini(); 831 spl_kmem_cache_fini(); 832 spl_taskq_fini(); 833 spl_tsd_fini(); 834 spl_kvmem_fini(); 835 spl_random_fini(); 836 } 837 838 module_init(spl_init); 839 module_exit(spl_fini); 840 841 ZFS_MODULE_DESCRIPTION("Solaris Porting Layer"); 842 ZFS_MODULE_AUTHOR(ZFS_META_AUTHOR); 843 ZFS_MODULE_LICENSE("GPL"); 844 ZFS_MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE); 845