1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
4 * Copyright (C) 2007 The Regents of the University of California.
5 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
6 * Written by Brian Behlendorf <behlendorf1@llnl.gov>.
7 * UCRL-CODE-235197
8 *
9 * This file is part of the SPL, Solaris Porting Layer.
10 *
11 * The SPL is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
15 *
16 * The SPL is distributed in the hope that it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 * for more details.
20 *
21 * You should have received a copy of the GNU General Public License along
22 * with the SPL. If not, see <http://www.gnu.org/licenses/>.
23 *
24 * Solaris Porting Layer (SPL) Generic Implementation.
25 */
26
27 #include <sys/isa_defs.h>
28 #include <sys/sysmacros.h>
29 #include <sys/systeminfo.h>
30 #include <sys/vmsystm.h>
31 #include <sys/kmem.h>
32 #include <sys/kmem_cache.h>
33 #include <sys/vmem.h>
34 #include <sys/mutex.h>
35 #include <sys/rwlock.h>
36 #include <sys/taskq.h>
37 #include <sys/tsd.h>
38 #include <sys/zmod.h>
39 #include <sys/debug.h>
40 #include <sys/proc.h>
41 #include <sys/kstat.h>
42 #include <sys/file.h>
43 #include <sys/sunddi.h>
44 #include <linux/ctype.h>
45 #include <sys/disp.h>
46 #include <sys/random.h>
47 #include <sys/string.h>
48 #include <linux/kmod.h>
49 #include <linux/mod_compat.h>
50 #include <sys/cred.h>
51 #include <sys/vnode.h>
52 #include <sys/misc.h>
53 #include <linux/mod_compat.h>
54
55 unsigned long spl_hostid = 0;
56 EXPORT_SYMBOL(spl_hostid);
57
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
rotl(const uint64_t x,int k)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
spl_rand_next(uint64_t * s)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
spl_rand_jump(uint64_t * s)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
random_get_pseudo_bytes(uint8_t * ptr,size_t len)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
nlz64(uint64_t x)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
__div_u64(uint64_t u,uint32_t v)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
__udivdi3(uint64_t u,uint64_t v)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
__divdi3(int64_t u,int64_t v)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
__umoddi3(uint64_t dividend,uint64_t divisor)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
__moddi3(int64_t n,int64_t d)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
__udivmoddi4(uint64_t n,uint64_t d,uint64_t * r)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
__divmoddi4(int64_t n,int64_t d,int64_t * r)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
__aeabi_uldivmod(uint64_t u,uint64_t v)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
__aeabi_ldivmod(int64_t u,int64_t v)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
ddi_copyin(const void * from,void * to,size_t len,int flags)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
spl_signal_kobj_evt(struct block_device * bdev)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
ddi_copyout(const void * from,void * to,size_t len,int flags)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 int
spl_getattr(struct file * filp,struct kstat * stat)627 spl_getattr(struct file *filp, struct kstat *stat)
628 {
629 int rc;
630
631 ASSERT(filp);
632 ASSERT(stat);
633
634 rc = vfs_getattr(&filp->f_path, stat, STATX_BASIC_STATS,
635 AT_STATX_SYNC_AS_STAT);
636 if (rc)
637 return (-rc);
638
639 return (0);
640 }
641
642 /*
643 * Read the unique system identifier from the /etc/hostid file.
644 *
645 * The behavior of /usr/bin/hostid on Linux systems with the
646 * regular eglibc and coreutils is:
647 *
648 * 1. Generate the value if the /etc/hostid file does not exist
649 * or if the /etc/hostid file is less than four bytes in size.
650 *
651 * 2. If the /etc/hostid file is at least 4 bytes, then return
652 * the first four bytes [0..3] in native endian order.
653 *
654 * 3. Always ignore bytes [4..] if they exist in the file.
655 *
656 * Only the first four bytes are significant, even on systems that
657 * have a 64-bit word size.
658 *
659 * See:
660 *
661 * eglibc: sysdeps/unix/sysv/linux/gethostid.c
662 * coreutils: src/hostid.c
663 *
664 * Notes:
665 *
666 * The /etc/hostid file on Solaris is a text file that often reads:
667 *
668 * # DO NOT EDIT
669 * "0123456789"
670 *
671 * Directly copying this file to Linux results in a constant
672 * hostid of 4f442023 because the default comment constitutes
673 * the first four bytes of the file.
674 *
675 */
676
677 static char *spl_hostid_path = HW_HOSTID_PATH;
678 module_param(spl_hostid_path, charp, 0444);
679 MODULE_PARM_DESC(spl_hostid_path, "The system hostid file (/etc/hostid)");
680
681 static int
hostid_read(uint32_t * hostid)682 hostid_read(uint32_t *hostid)
683 {
684 uint64_t size;
685 uint32_t value = 0;
686 int error;
687 loff_t off;
688 struct file *filp;
689 struct kstat stat;
690
691 filp = filp_open(spl_hostid_path, 0, 0);
692
693 if (IS_ERR(filp))
694 return (ENOENT);
695
696 error = spl_getattr(filp, &stat);
697 if (error) {
698 filp_close(filp, 0);
699 return (error);
700 }
701 size = stat.size;
702 // cppcheck-suppress sizeofwithnumericparameter
703 if (size < sizeof (HW_HOSTID_MASK)) {
704 filp_close(filp, 0);
705 return (EINVAL);
706 }
707
708 off = 0;
709 /*
710 * Read directly into the variable like eglibc does.
711 * Short reads are okay; native behavior is preserved.
712 */
713 error = kernel_read(filp, &value, sizeof (value), &off);
714 if (error < 0) {
715 filp_close(filp, 0);
716 return (EIO);
717 }
718
719 /* Mask down to 32 bits like coreutils does. */
720 *hostid = (value & HW_HOSTID_MASK);
721 filp_close(filp, 0);
722
723 return (0);
724 }
725
726 /*
727 * Return the system hostid. Preferentially use the spl_hostid module option
728 * when set, otherwise use the value in the /etc/hostid file.
729 */
730 uint32_t
zone_get_hostid(void * zone)731 zone_get_hostid(void *zone)
732 {
733 uint32_t hostid;
734
735 ASSERT3P(zone, ==, NULL);
736
737 if (spl_hostid != 0)
738 return ((uint32_t)(spl_hostid & HW_HOSTID_MASK));
739
740 if (hostid_read(&hostid) == 0)
741 return (hostid);
742
743 return (0);
744 }
745 EXPORT_SYMBOL(zone_get_hostid);
746
747 static int
spl_kvmem_init(void)748 spl_kvmem_init(void)
749 {
750 int rc = 0;
751
752 rc = spl_kmem_init();
753 if (rc)
754 return (rc);
755
756 rc = spl_vmem_init();
757 if (rc) {
758 spl_kmem_fini();
759 return (rc);
760 }
761
762 return (rc);
763 }
764
765 /*
766 * We initialize the random number generator with 128 bits of entropy from the
767 * system random number generator. In the improbable case that we have a zero
768 * seed, we fallback to the system jiffies, unless it is also zero, in which
769 * situation we use a preprogrammed seed. We step forward by 2^64 iterations to
770 * initialize each of the per-cpu seeds so that the sequences generated on each
771 * CPU are guaranteed to never overlap in practice.
772 */
773 static int __init
spl_random_init(void)774 spl_random_init(void)
775 {
776 uint64_t s[4];
777 int i = 0;
778
779 spl_pseudo_entropy = __alloc_percpu(4 * sizeof (uint64_t),
780 sizeof (uint64_t));
781
782 if (!spl_pseudo_entropy)
783 return (-ENOMEM);
784
785 get_random_bytes(s, sizeof (s));
786
787 if (s[0] == 0 && s[1] == 0 && s[2] == 0 && s[3] == 0) {
788 if (jiffies != 0) {
789 s[0] = jiffies;
790 s[1] = ~0 - jiffies;
791 s[2] = ~jiffies;
792 s[3] = jiffies - ~0;
793 } else {
794 (void) memcpy(s, "improbable seed", 16);
795 }
796 printk("SPL: get_random_bytes() returned 0 "
797 "when generating random seed. Setting initial seed to "
798 "0x%016llx%016llx%016llx%016llx.\n", cpu_to_be64(s[0]),
799 cpu_to_be64(s[1]), cpu_to_be64(s[2]), cpu_to_be64(s[3]));
800 }
801
802 for_each_possible_cpu(i) {
803 uint64_t *wordp = per_cpu_ptr(spl_pseudo_entropy, i);
804
805 spl_rand_jump(s);
806
807 wordp[0] = s[0];
808 wordp[1] = s[1];
809 wordp[2] = s[2];
810 wordp[3] = s[3];
811 }
812
813 return (0);
814 }
815
816 static void
spl_random_fini(void)817 spl_random_fini(void)
818 {
819 free_percpu(spl_pseudo_entropy);
820 }
821
822 static void
spl_kvmem_fini(void)823 spl_kvmem_fini(void)
824 {
825 spl_vmem_fini();
826 spl_kmem_fini();
827 }
828
829 static int __init
spl_init(void)830 spl_init(void)
831 {
832 int rc = 0;
833
834 if ((rc = spl_random_init()))
835 goto out0;
836
837 if ((rc = spl_kvmem_init()))
838 goto out1;
839
840 if ((rc = spl_tsd_init()))
841 goto out2;
842
843 if ((rc = spl_proc_init()))
844 goto out3;
845
846 if ((rc = spl_kstat_init()))
847 goto out4;
848
849 if ((rc = spl_taskq_init()))
850 goto out5;
851
852 if ((rc = spl_kmem_cache_init()))
853 goto out6;
854
855 if ((rc = spl_zlib_init()))
856 goto out7;
857
858 if ((rc = spl_zone_init()))
859 goto out8;
860
861 return (rc);
862
863 out8:
864 spl_zlib_fini();
865 out7:
866 spl_kmem_cache_fini();
867 out6:
868 spl_taskq_fini();
869 out5:
870 spl_kstat_fini();
871 out4:
872 spl_proc_fini();
873 out3:
874 spl_tsd_fini();
875 out2:
876 spl_kvmem_fini();
877 out1:
878 spl_random_fini();
879 out0:
880 return (rc);
881 }
882
883 static void __exit
spl_fini(void)884 spl_fini(void)
885 {
886 spl_zone_fini();
887 spl_zlib_fini();
888 spl_kmem_cache_fini();
889 spl_taskq_fini();
890 spl_kstat_fini();
891 spl_proc_fini();
892 spl_tsd_fini();
893 spl_kvmem_fini();
894 spl_random_fini();
895 }
896
897 module_init(spl_init);
898 module_exit(spl_fini);
899
900 MODULE_DESCRIPTION("Solaris Porting Layer");
901 MODULE_AUTHOR(ZFS_META_AUTHOR);
902 MODULE_LICENSE("GPL");
903 MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);
904