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/isa_defs.h> 27 #include <sys/sysmacros.h> 28 #include <sys/systeminfo.h> 29 #include <sys/vmsystm.h> 30 #include <sys/kmem.h> 31 #include <sys/kmem_cache.h> 32 #include <sys/vmem.h> 33 #include <sys/mutex.h> 34 #include <sys/rwlock.h> 35 #include <sys/taskq.h> 36 #include <sys/tsd.h> 37 #include <sys/zmod.h> 38 #include <sys/debug.h> 39 #include <sys/proc.h> 40 #include <sys/kstat.h> 41 #include <sys/file.h> 42 #include <sys/sunddi.h> 43 #include <linux/ctype.h> 44 #include <sys/disp.h> 45 #include <sys/random.h> 46 #include <sys/string.h> 47 #include <linux/kmod.h> 48 #include <linux/mod_compat.h> 49 #include <sys/cred.h> 50 #include <sys/vnode.h> 51 #include <sys/misc.h> 52 #include <linux/mod_compat.h> 53 54 unsigned long spl_hostid = 0; 55 EXPORT_SYMBOL(spl_hostid); 56 57 /* CSTYLED */ 58 module_param(spl_hostid, ulong, 0644); 59 MODULE_PARM_DESC(spl_hostid, "The system hostid."); 60 61 proc_t p0; 62 EXPORT_SYMBOL(p0); 63 64 /* 65 * xoshiro256++ 1.0 PRNG by David Blackman and Sebastiano Vigna 66 * 67 * "Scrambled Linear Pseudorandom Number Generators∗" 68 * https://vigna.di.unimi.it/ftp/papers/ScrambledLinear.pdf 69 * 70 * random_get_pseudo_bytes() is an API function on Illumos whose sole purpose 71 * is to provide bytes containing random numbers. It is mapped to /dev/urandom 72 * on Illumos, which uses a "FIPS 186-2 algorithm". No user of the SPL's 73 * random_get_pseudo_bytes() needs bytes that are of cryptographic quality, so 74 * we can implement it using a fast PRNG that we seed using Linux' actual 75 * equivalent to random_get_pseudo_bytes(). We do this by providing each CPU 76 * with an independent seed so that all calls to random_get_pseudo_bytes() are 77 * free of atomic instructions. 78 * 79 * A consequence of using a fast PRNG is that using random_get_pseudo_bytes() 80 * to generate words larger than 256 bits will paradoxically be limited to 81 * `2^256 - 1` possibilities. This is because we have a sequence of `2^256 - 1` 82 * 256-bit words and selecting the first will implicitly select the second. If 83 * a caller finds this behavior undesirable, random_get_bytes() should be used 84 * instead. 85 * 86 * XXX: Linux interrupt handlers that trigger within the critical section 87 * formed by `s[3] = xp[3];` and `xp[0] = s[0];` and call this function will 88 * see the same numbers. Nothing in the code currently calls this in an 89 * interrupt handler, so this is considered to be okay. If that becomes a 90 * problem, we could create a set of per-cpu variables for interrupt handlers 91 * and use them when in_interrupt() from linux/preempt_mask.h evaluates to 92 * true. 93 */ 94 static void __percpu *spl_pseudo_entropy; 95 96 /* 97 * rotl()/spl_rand_next()/spl_rand_jump() are copied from the following CC-0 98 * licensed file: 99 * 100 * https://prng.di.unimi.it/xoshiro256plusplus.c 101 */ 102 103 static inline uint64_t rotl(const uint64_t x, int k) 104 { 105 return ((x << k) | (x >> (64 - k))); 106 } 107 108 static inline uint64_t 109 spl_rand_next(uint64_t *s) 110 { 111 const uint64_t result = rotl(s[0] + s[3], 23) + s[0]; 112 113 const uint64_t t = s[1] << 17; 114 115 s[2] ^= s[0]; 116 s[3] ^= s[1]; 117 s[1] ^= s[2]; 118 s[0] ^= s[3]; 119 120 s[2] ^= t; 121 122 s[3] = rotl(s[3], 45); 123 124 return (result); 125 } 126 127 static inline void 128 spl_rand_jump(uint64_t *s) 129 { 130 static const uint64_t JUMP[] = { 0x180ec6d33cfd0aba, 131 0xd5a61266f0c9392c, 0xa9582618e03fc9aa, 0x39abdc4529b1661c }; 132 133 uint64_t s0 = 0; 134 uint64_t s1 = 0; 135 uint64_t s2 = 0; 136 uint64_t s3 = 0; 137 int i, b; 138 for (i = 0; i < sizeof (JUMP) / sizeof (*JUMP); i++) 139 for (b = 0; b < 64; b++) { 140 if (JUMP[i] & 1ULL << b) { 141 s0 ^= s[0]; 142 s1 ^= s[1]; 143 s2 ^= s[2]; 144 s3 ^= s[3]; 145 } 146 (void) spl_rand_next(s); 147 } 148 149 s[0] = s0; 150 s[1] = s1; 151 s[2] = s2; 152 s[3] = s3; 153 } 154 155 int 156 random_get_pseudo_bytes(uint8_t *ptr, size_t len) 157 { 158 uint64_t *xp, s[4]; 159 160 ASSERT(ptr); 161 162 xp = get_cpu_ptr(spl_pseudo_entropy); 163 164 s[0] = xp[0]; 165 s[1] = xp[1]; 166 s[2] = xp[2]; 167 s[3] = xp[3]; 168 169 while (len) { 170 union { 171 uint64_t ui64; 172 uint8_t byte[sizeof (uint64_t)]; 173 }entropy; 174 int i = MIN(len, sizeof (uint64_t)); 175 176 len -= i; 177 entropy.ui64 = spl_rand_next(s); 178 179 /* 180 * xoshiro256++ has low entropy lower bytes, so we copy the 181 * higher order bytes first. 182 */ 183 while (i--) 184 #ifdef _ZFS_BIG_ENDIAN 185 *ptr++ = entropy.byte[i]; 186 #else 187 *ptr++ = entropy.byte[7 - i]; 188 #endif 189 } 190 191 xp[0] = s[0]; 192 xp[1] = s[1]; 193 xp[2] = s[2]; 194 xp[3] = s[3]; 195 196 put_cpu_ptr(spl_pseudo_entropy); 197 198 return (0); 199 } 200 201 202 EXPORT_SYMBOL(random_get_pseudo_bytes); 203 204 #if BITS_PER_LONG == 32 205 206 /* 207 * Support 64/64 => 64 division on a 32-bit platform. While the kernel 208 * provides a div64_u64() function for this we do not use it because the 209 * implementation is flawed. There are cases which return incorrect 210 * results as late as linux-2.6.35. Until this is fixed upstream the 211 * spl must provide its own implementation. 212 * 213 * This implementation is a slightly modified version of the algorithm 214 * proposed by the book 'Hacker's Delight'. The original source can be 215 * found here and is available for use without restriction. 216 * 217 * http://www.hackersdelight.org/HDcode/newCode/divDouble.c 218 */ 219 220 /* 221 * Calculate number of leading of zeros for a 64-bit value. 222 */ 223 static int 224 nlz64(uint64_t x) 225 { 226 register int n = 0; 227 228 if (x == 0) 229 return (64); 230 231 if (x <= 0x00000000FFFFFFFFULL) { n = n + 32; x = x << 32; } 232 if (x <= 0x0000FFFFFFFFFFFFULL) { n = n + 16; x = x << 16; } 233 if (x <= 0x00FFFFFFFFFFFFFFULL) { n = n + 8; x = x << 8; } 234 if (x <= 0x0FFFFFFFFFFFFFFFULL) { n = n + 4; x = x << 4; } 235 if (x <= 0x3FFFFFFFFFFFFFFFULL) { n = n + 2; x = x << 2; } 236 if (x <= 0x7FFFFFFFFFFFFFFFULL) { n = n + 1; } 237 238 return (n); 239 } 240 241 /* 242 * Newer kernels have a div_u64() function but we define our own 243 * to simplify portability between kernel versions. 244 */ 245 static inline uint64_t 246 __div_u64(uint64_t u, uint32_t v) 247 { 248 (void) do_div(u, v); 249 return (u); 250 } 251 252 /* 253 * Turn off missing prototypes warning for these functions. They are 254 * replacements for libgcc-provided functions and will never be called 255 * directly. 256 */ 257 #if defined(__GNUC__) && !defined(__clang__) 258 #pragma GCC diagnostic push 259 #pragma GCC diagnostic ignored "-Wmissing-prototypes" 260 #endif 261 262 /* 263 * Implementation of 64-bit unsigned division for 32-bit machines. 264 * 265 * First the procedure takes care of the case in which the divisor is a 266 * 32-bit quantity. There are two subcases: (1) If the left half of the 267 * dividend is less than the divisor, one execution of do_div() is all that 268 * is required (overflow is not possible). (2) Otherwise it does two 269 * divisions, using the grade school method. 270 */ 271 uint64_t 272 __udivdi3(uint64_t u, uint64_t v) 273 { 274 uint64_t u0, u1, v1, q0, q1, k; 275 int n; 276 277 if (v >> 32 == 0) { // If v < 2**32: 278 if (u >> 32 < v) { // If u/v cannot overflow, 279 return (__div_u64(u, v)); // just do one division. 280 } else { // If u/v would overflow: 281 u1 = u >> 32; // Break u into two halves. 282 u0 = u & 0xFFFFFFFF; 283 q1 = __div_u64(u1, v); // First quotient digit. 284 k = u1 - q1 * v; // First remainder, < v. 285 u0 += (k << 32); 286 q0 = __div_u64(u0, v); // Seconds quotient digit. 287 return ((q1 << 32) + q0); 288 } 289 } else { // If v >= 2**32: 290 n = nlz64(v); // 0 <= n <= 31. 291 v1 = (v << n) >> 32; // Normalize divisor, MSB is 1. 292 u1 = u >> 1; // To ensure no overflow. 293 q1 = __div_u64(u1, v1); // Get quotient from 294 q0 = (q1 << n) >> 31; // Undo normalization and 295 // division of u by 2. 296 if (q0 != 0) // Make q0 correct or 297 q0 = q0 - 1; // too small by 1. 298 if ((u - q0 * v) >= v) 299 q0 = q0 + 1; // Now q0 is correct. 300 301 return (q0); 302 } 303 } 304 EXPORT_SYMBOL(__udivdi3); 305 306 #ifndef abs64 307 /* CSTYLED */ 308 #define abs64(x) ({ uint64_t t = (x) >> 63; ((x) ^ t) - t; }) 309 #endif 310 311 /* 312 * Implementation of 64-bit signed division for 32-bit machines. 313 */ 314 int64_t 315 __divdi3(int64_t u, int64_t v) 316 { 317 int64_t q, t; 318 q = __udivdi3(abs64(u), abs64(v)); 319 t = (u ^ v) >> 63; // If u, v have different 320 return ((q ^ t) - t); // signs, negate q. 321 } 322 EXPORT_SYMBOL(__divdi3); 323 324 /* 325 * Implementation of 64-bit unsigned modulo for 32-bit machines. 326 */ 327 uint64_t 328 __umoddi3(uint64_t dividend, uint64_t divisor) 329 { 330 return (dividend - (divisor * __udivdi3(dividend, divisor))); 331 } 332 EXPORT_SYMBOL(__umoddi3); 333 334 /* 64-bit signed modulo for 32-bit machines. */ 335 int64_t 336 __moddi3(int64_t n, int64_t d) 337 { 338 int64_t q; 339 boolean_t nn = B_FALSE; 340 341 if (n < 0) { 342 nn = B_TRUE; 343 n = -n; 344 } 345 if (d < 0) 346 d = -d; 347 348 q = __umoddi3(n, d); 349 350 return (nn ? -q : q); 351 } 352 EXPORT_SYMBOL(__moddi3); 353 354 /* 355 * Implementation of 64-bit unsigned division/modulo for 32-bit machines. 356 */ 357 uint64_t 358 __udivmoddi4(uint64_t n, uint64_t d, uint64_t *r) 359 { 360 uint64_t q = __udivdi3(n, d); 361 if (r) 362 *r = n - d * q; 363 return (q); 364 } 365 EXPORT_SYMBOL(__udivmoddi4); 366 367 /* 368 * Implementation of 64-bit signed division/modulo for 32-bit machines. 369 */ 370 int64_t 371 __divmoddi4(int64_t n, int64_t d, int64_t *r) 372 { 373 int64_t q, rr; 374 boolean_t nn = B_FALSE; 375 boolean_t nd = B_FALSE; 376 if (n < 0) { 377 nn = B_TRUE; 378 n = -n; 379 } 380 if (d < 0) { 381 nd = B_TRUE; 382 d = -d; 383 } 384 385 q = __udivmoddi4(n, d, (uint64_t *)&rr); 386 387 if (nn != nd) 388 q = -q; 389 if (nn) 390 rr = -rr; 391 if (r) 392 *r = rr; 393 return (q); 394 } 395 EXPORT_SYMBOL(__divmoddi4); 396 397 #if defined(__arm) || defined(__arm__) 398 /* 399 * Implementation of 64-bit (un)signed division for 32-bit arm machines. 400 * 401 * Run-time ABI for the ARM Architecture (page 20). A pair of (unsigned) 402 * long longs is returned in {{r0, r1}, {r2,r3}}, the quotient in {r0, r1}, 403 * and the remainder in {r2, r3}. The return type is specifically left 404 * set to 'void' to ensure the compiler does not overwrite these registers 405 * during the return. All results are in registers as per ABI 406 */ 407 void 408 __aeabi_uldivmod(uint64_t u, uint64_t v) 409 { 410 uint64_t res; 411 uint64_t mod; 412 413 res = __udivdi3(u, v); 414 mod = __umoddi3(u, v); 415 { 416 register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); 417 register uint32_t r1 asm("r1") = (res >> 32); 418 register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); 419 register uint32_t r3 asm("r3") = (mod >> 32); 420 421 asm volatile("" 422 : "+r"(r0), "+r"(r1), "+r"(r2), "+r"(r3) /* output */ 423 : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ 424 425 return; /* r0; */ 426 } 427 } 428 EXPORT_SYMBOL(__aeabi_uldivmod); 429 430 void 431 __aeabi_ldivmod(int64_t u, int64_t v) 432 { 433 int64_t res; 434 uint64_t mod; 435 436 res = __divdi3(u, v); 437 mod = __umoddi3(u, v); 438 { 439 register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); 440 register uint32_t r1 asm("r1") = (res >> 32); 441 register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); 442 register uint32_t r3 asm("r3") = (mod >> 32); 443 444 asm volatile("" 445 : "+r"(r0), "+r"(r1), "+r"(r2), "+r"(r3) /* output */ 446 : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ 447 448 return; /* r0; */ 449 } 450 } 451 EXPORT_SYMBOL(__aeabi_ldivmod); 452 #endif /* __arm || __arm__ */ 453 454 #if defined(__GNUC__) && !defined(__clang__) 455 #pragma GCC diagnostic pop 456 #endif 457 458 #endif /* BITS_PER_LONG */ 459 460 /* 461 * NOTE: The strtoxx behavior is solely based on my reading of the Solaris 462 * ddi_strtol(9F) man page. I have not verified the behavior of these 463 * functions against their Solaris counterparts. It is possible that I 464 * may have misinterpreted the man page or the man page is incorrect. 465 */ 466 int ddi_strtol(const char *, char **, int, long *); 467 int ddi_strtoull(const char *, char **, int, unsigned long long *); 468 int ddi_strtoll(const char *, char **, int, long long *); 469 470 #define define_ddi_strtox(type, valtype) \ 471 int ddi_strto##type(const char *str, char **endptr, \ 472 int base, valtype *result) \ 473 { \ 474 valtype last_value, value = 0; \ 475 char *ptr = (char *)str; \ 476 int digit, minus = 0; \ 477 \ 478 while (strchr(" \t\n\r\f", *ptr)) \ 479 ++ptr; \ 480 \ 481 if (strlen(ptr) == 0) \ 482 return (EINVAL); \ 483 \ 484 switch (*ptr) { \ 485 case '-': \ 486 minus = 1; \ 487 zfs_fallthrough; \ 488 case '+': \ 489 ++ptr; \ 490 break; \ 491 } \ 492 \ 493 /* Auto-detect base based on prefix */ \ 494 if (!base) { \ 495 if (str[0] == '0') { \ 496 if (tolower(str[1]) == 'x' && isxdigit(str[2])) { \ 497 base = 16; /* hex */ \ 498 ptr += 2; \ 499 } else if (str[1] >= '0' && str[1] < '8') { \ 500 base = 8; /* octal */ \ 501 ptr += 1; \ 502 } else { \ 503 return (EINVAL); \ 504 } \ 505 } else { \ 506 base = 10; /* decimal */ \ 507 } \ 508 } \ 509 \ 510 while (1) { \ 511 if (isdigit(*ptr)) \ 512 digit = *ptr - '0'; \ 513 else if (isalpha(*ptr)) \ 514 digit = tolower(*ptr) - 'a' + 10; \ 515 else \ 516 break; \ 517 \ 518 if (digit >= base) \ 519 break; \ 520 \ 521 last_value = value; \ 522 value = value * base + digit; \ 523 if (last_value > value) /* Overflow */ \ 524 return (ERANGE); \ 525 \ 526 ptr++; \ 527 } \ 528 \ 529 *result = minus ? -value : value; \ 530 \ 531 if (endptr) \ 532 *endptr = ptr; \ 533 \ 534 return (0); \ 535 } \ 536 537 define_ddi_strtox(l, long) 538 define_ddi_strtox(ull, unsigned long long) 539 define_ddi_strtox(ll, long long) 540 541 EXPORT_SYMBOL(ddi_strtol); 542 EXPORT_SYMBOL(ddi_strtoll); 543 EXPORT_SYMBOL(ddi_strtoull); 544 545 int 546 ddi_copyin(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 (copyin(from, to, len)); 555 } 556 EXPORT_SYMBOL(ddi_copyin); 557 558 #define define_spl_param(type, fmt) \ 559 int \ 560 spl_param_get_##type(char *buf, zfs_kernel_param_t *kp) \ 561 { \ 562 return (scnprintf(buf, PAGE_SIZE, fmt "\n", \ 563 *(type *)kp->arg)); \ 564 } \ 565 int \ 566 spl_param_set_##type(const char *buf, zfs_kernel_param_t *kp) \ 567 { \ 568 return (kstrto##type(buf, 0, (type *)kp->arg)); \ 569 } \ 570 const struct kernel_param_ops spl_param_ops_##type = { \ 571 .set = spl_param_set_##type, \ 572 .get = spl_param_get_##type, \ 573 }; \ 574 EXPORT_SYMBOL(spl_param_get_##type); \ 575 EXPORT_SYMBOL(spl_param_set_##type); \ 576 EXPORT_SYMBOL(spl_param_ops_##type); 577 578 define_spl_param(s64, "%lld") 579 define_spl_param(u64, "%llu") 580 581 /* 582 * Post a uevent to userspace whenever a new vdev adds to the pool. It is 583 * necessary to sync blkid information with udev, which zed daemon uses 584 * during device hotplug to identify the vdev. 585 */ 586 void 587 spl_signal_kobj_evt(struct block_device *bdev) 588 { 589 #if defined(HAVE_BDEV_KOBJ) || defined(HAVE_PART_TO_DEV) 590 #ifdef HAVE_BDEV_KOBJ 591 struct kobject *disk_kobj = bdev_kobj(bdev); 592 #else 593 struct kobject *disk_kobj = &part_to_dev(bdev->bd_part)->kobj; 594 #endif 595 if (disk_kobj) { 596 int ret = kobject_uevent(disk_kobj, KOBJ_CHANGE); 597 if (ret) { 598 pr_warn("ZFS: Sending event '%d' to kobject: '%s'" 599 " (%p): failed(ret:%d)\n", KOBJ_CHANGE, 600 kobject_name(disk_kobj), disk_kobj, ret); 601 } 602 } 603 #else 604 /* 605 * This is encountered if neither bdev_kobj() nor part_to_dev() is available 606 * in the kernel - likely due to an API change that needs to be chased down. 607 */ 608 #error "Unsupported kernel: unable to get struct kobj from bdev" 609 #endif 610 } 611 EXPORT_SYMBOL(spl_signal_kobj_evt); 612 613 int 614 ddi_copyout(const void *from, void *to, size_t len, int flags) 615 { 616 /* Fake ioctl() issued by kernel, 'from' is a kernel address */ 617 if (flags & FKIOCTL) { 618 memcpy(to, from, len); 619 return (0); 620 } 621 622 return (copyout(from, to, len)); 623 } 624 EXPORT_SYMBOL(ddi_copyout); 625 626 static ssize_t 627 spl_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) 628 { 629 #if defined(HAVE_KERNEL_READ_PPOS) 630 return (kernel_read(file, buf, count, pos)); 631 #else 632 mm_segment_t saved_fs; 633 ssize_t ret; 634 635 saved_fs = get_fs(); 636 set_fs(KERNEL_DS); 637 638 ret = vfs_read(file, (void __user *)buf, count, pos); 639 640 set_fs(saved_fs); 641 642 return (ret); 643 #endif 644 } 645 646 static int 647 spl_getattr(struct file *filp, struct kstat *stat) 648 { 649 int rc; 650 651 ASSERT(filp); 652 ASSERT(stat); 653 654 #if defined(HAVE_4ARGS_VFS_GETATTR) 655 rc = vfs_getattr(&filp->f_path, stat, STATX_BASIC_STATS, 656 AT_STATX_SYNC_AS_STAT); 657 #elif defined(HAVE_2ARGS_VFS_GETATTR) 658 rc = vfs_getattr(&filp->f_path, stat); 659 #elif defined(HAVE_3ARGS_VFS_GETATTR) 660 rc = vfs_getattr(filp->f_path.mnt, filp->f_dentry, stat); 661 #else 662 #error "No available vfs_getattr()" 663 #endif 664 if (rc) 665 return (-rc); 666 667 return (0); 668 } 669 670 /* 671 * Read the unique system identifier from the /etc/hostid file. 672 * 673 * The behavior of /usr/bin/hostid on Linux systems with the 674 * regular eglibc and coreutils is: 675 * 676 * 1. Generate the value if the /etc/hostid file does not exist 677 * or if the /etc/hostid file is less than four bytes in size. 678 * 679 * 2. If the /etc/hostid file is at least 4 bytes, then return 680 * the first four bytes [0..3] in native endian order. 681 * 682 * 3. Always ignore bytes [4..] if they exist in the file. 683 * 684 * Only the first four bytes are significant, even on systems that 685 * have a 64-bit word size. 686 * 687 * See: 688 * 689 * eglibc: sysdeps/unix/sysv/linux/gethostid.c 690 * coreutils: src/hostid.c 691 * 692 * Notes: 693 * 694 * The /etc/hostid file on Solaris is a text file that often reads: 695 * 696 * # DO NOT EDIT 697 * "0123456789" 698 * 699 * Directly copying this file to Linux results in a constant 700 * hostid of 4f442023 because the default comment constitutes 701 * the first four bytes of the file. 702 * 703 */ 704 705 static char *spl_hostid_path = HW_HOSTID_PATH; 706 module_param(spl_hostid_path, charp, 0444); 707 MODULE_PARM_DESC(spl_hostid_path, "The system hostid file (/etc/hostid)"); 708 709 static int 710 hostid_read(uint32_t *hostid) 711 { 712 uint64_t size; 713 uint32_t value = 0; 714 int error; 715 loff_t off; 716 struct file *filp; 717 struct kstat stat; 718 719 filp = filp_open(spl_hostid_path, 0, 0); 720 721 if (IS_ERR(filp)) 722 return (ENOENT); 723 724 error = spl_getattr(filp, &stat); 725 if (error) { 726 filp_close(filp, 0); 727 return (error); 728 } 729 size = stat.size; 730 // cppcheck-suppress sizeofwithnumericparameter 731 if (size < sizeof (HW_HOSTID_MASK)) { 732 filp_close(filp, 0); 733 return (EINVAL); 734 } 735 736 off = 0; 737 /* 738 * Read directly into the variable like eglibc does. 739 * Short reads are okay; native behavior is preserved. 740 */ 741 error = spl_kernel_read(filp, &value, sizeof (value), &off); 742 if (error < 0) { 743 filp_close(filp, 0); 744 return (EIO); 745 } 746 747 /* Mask down to 32 bits like coreutils does. */ 748 *hostid = (value & HW_HOSTID_MASK); 749 filp_close(filp, 0); 750 751 return (0); 752 } 753 754 /* 755 * Return the system hostid. Preferentially use the spl_hostid module option 756 * when set, otherwise use the value in the /etc/hostid file. 757 */ 758 uint32_t 759 zone_get_hostid(void *zone) 760 { 761 uint32_t hostid; 762 763 ASSERT3P(zone, ==, NULL); 764 765 if (spl_hostid != 0) 766 return ((uint32_t)(spl_hostid & HW_HOSTID_MASK)); 767 768 if (hostid_read(&hostid) == 0) 769 return (hostid); 770 771 return (0); 772 } 773 EXPORT_SYMBOL(zone_get_hostid); 774 775 static int 776 spl_kvmem_init(void) 777 { 778 int rc = 0; 779 780 rc = spl_kmem_init(); 781 if (rc) 782 return (rc); 783 784 rc = spl_vmem_init(); 785 if (rc) { 786 spl_kmem_fini(); 787 return (rc); 788 } 789 790 return (rc); 791 } 792 793 /* 794 * We initialize the random number generator with 128 bits of entropy from the 795 * system random number generator. In the improbable case that we have a zero 796 * seed, we fallback to the system jiffies, unless it is also zero, in which 797 * situation we use a preprogrammed seed. We step forward by 2^64 iterations to 798 * initialize each of the per-cpu seeds so that the sequences generated on each 799 * CPU are guaranteed to never overlap in practice. 800 */ 801 static int __init 802 spl_random_init(void) 803 { 804 uint64_t s[4]; 805 int i = 0; 806 807 spl_pseudo_entropy = __alloc_percpu(4 * sizeof (uint64_t), 808 sizeof (uint64_t)); 809 810 if (!spl_pseudo_entropy) 811 return (-ENOMEM); 812 813 get_random_bytes(s, sizeof (s)); 814 815 if (s[0] == 0 && s[1] == 0 && s[2] == 0 && s[3] == 0) { 816 if (jiffies != 0) { 817 s[0] = jiffies; 818 s[1] = ~0 - jiffies; 819 s[2] = ~jiffies; 820 s[3] = jiffies - ~0; 821 } else { 822 (void) memcpy(s, "improbable seed", 16); 823 } 824 printk("SPL: get_random_bytes() returned 0 " 825 "when generating random seed. Setting initial seed to " 826 "0x%016llx%016llx%016llx%016llx.\n", cpu_to_be64(s[0]), 827 cpu_to_be64(s[1]), cpu_to_be64(s[2]), cpu_to_be64(s[3])); 828 } 829 830 for_each_possible_cpu(i) { 831 uint64_t *wordp = per_cpu_ptr(spl_pseudo_entropy, i); 832 833 spl_rand_jump(s); 834 835 wordp[0] = s[0]; 836 wordp[1] = s[1]; 837 wordp[2] = s[2]; 838 wordp[3] = s[3]; 839 } 840 841 return (0); 842 } 843 844 static void 845 spl_random_fini(void) 846 { 847 free_percpu(spl_pseudo_entropy); 848 } 849 850 static void 851 spl_kvmem_fini(void) 852 { 853 spl_vmem_fini(); 854 spl_kmem_fini(); 855 } 856 857 static int __init 858 spl_init(void) 859 { 860 int rc = 0; 861 862 if ((rc = spl_random_init())) 863 goto out0; 864 865 if ((rc = spl_kvmem_init())) 866 goto out1; 867 868 if ((rc = spl_tsd_init())) 869 goto out2; 870 871 if ((rc = spl_taskq_init())) 872 goto out3; 873 874 if ((rc = spl_kmem_cache_init())) 875 goto out4; 876 877 if ((rc = spl_proc_init())) 878 goto out5; 879 880 if ((rc = spl_kstat_init())) 881 goto out6; 882 883 if ((rc = spl_zlib_init())) 884 goto out7; 885 886 if ((rc = spl_zone_init())) 887 goto out8; 888 889 return (rc); 890 891 out8: 892 spl_zlib_fini(); 893 out7: 894 spl_kstat_fini(); 895 out6: 896 spl_proc_fini(); 897 out5: 898 spl_kmem_cache_fini(); 899 out4: 900 spl_taskq_fini(); 901 out3: 902 spl_tsd_fini(); 903 out2: 904 spl_kvmem_fini(); 905 out1: 906 spl_random_fini(); 907 out0: 908 return (rc); 909 } 910 911 static void __exit 912 spl_fini(void) 913 { 914 spl_zone_fini(); 915 spl_zlib_fini(); 916 spl_kstat_fini(); 917 spl_proc_fini(); 918 spl_kmem_cache_fini(); 919 spl_taskq_fini(); 920 spl_tsd_fini(); 921 spl_kvmem_fini(); 922 spl_random_fini(); 923 } 924 925 module_init(spl_init); 926 module_exit(spl_fini); 927 928 MODULE_DESCRIPTION("Solaris Porting Layer"); 929 MODULE_AUTHOR(ZFS_META_AUTHOR); 930 MODULE_LICENSE("GPL"); 931 MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE); 932