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
54unsigned long spl_hostid = 0;
55EXPORT_SYMBOL(spl_hostid);
56
57/* CSTYLED */
58module_param(spl_hostid, ulong, 0644);
59MODULE_PARM_DESC(spl_hostid, "The system hostid.");
60
61proc_t p0;
62EXPORT_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 */
94static 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
103static inline uint64_t rotl(const uint64_t x, int k)
104{
105	return ((x << k) | (x >> (64 - k)));
106}
107
108static inline uint64_t
109spl_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
127static inline void
128spl_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
155int
156random_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
202EXPORT_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 */
223static int
224nlz64(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 */
245static 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 */
271uint64_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}
304EXPORT_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 */
314int64_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}
322EXPORT_SYMBOL(__divdi3);
323
324/*
325 * Implementation of 64-bit unsigned modulo for 32-bit machines.
326 */
327uint64_t
328__umoddi3(uint64_t dividend, uint64_t divisor)
329{
330	return (dividend - (divisor * __udivdi3(dividend, divisor)));
331}
332EXPORT_SYMBOL(__umoddi3);
333
334/* 64-bit signed modulo for 32-bit machines. */
335int64_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}
352EXPORT_SYMBOL(__moddi3);
353
354/*
355 * Implementation of 64-bit unsigned division/modulo for 32-bit machines.
356 */
357uint64_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}
365EXPORT_SYMBOL(__udivmoddi4);
366
367/*
368 * Implementation of 64-bit signed division/modulo for 32-bit machines.
369 */
370int64_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}
395EXPORT_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 */
407void
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}
428EXPORT_SYMBOL(__aeabi_uldivmod);
429
430void
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}
451EXPORT_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 */
466int ddi_strtol(const char *, char **, int, long *);
467int ddi_strtoull(const char *, char **, int, unsigned long long *);
468int ddi_strtoll(const char *, char **, int, long long *);
469
470#define	define_ddi_strtox(type, valtype)				\
471int 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
537define_ddi_strtox(l, long)
538define_ddi_strtox(ull, unsigned long long)
539define_ddi_strtox(ll, long long)
540
541EXPORT_SYMBOL(ddi_strtol);
542EXPORT_SYMBOL(ddi_strtoll);
543EXPORT_SYMBOL(ddi_strtoull);
544
545int
546ddi_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}
556EXPORT_SYMBOL(ddi_copyin);
557
558#define	define_spl_param(type, fmt)					\
559int									\
560spl_param_get_##type(char *buf, zfs_kernel_param_t *kp)			\
561{									\
562	return (scnprintf(buf, PAGE_SIZE, fmt "\n",			\
563	    *(type *)kp->arg));						\
564}									\
565int									\
566spl_param_set_##type(const char *buf, zfs_kernel_param_t *kp)		\
567{									\
568	return (kstrto##type(buf, 0, (type *)kp->arg));			\
569}									\
570const struct kernel_param_ops spl_param_ops_##type = {			\
571	.set = spl_param_set_##type,					\
572	.get = spl_param_get_##type,					\
573};									\
574EXPORT_SYMBOL(spl_param_get_##type);					\
575EXPORT_SYMBOL(spl_param_set_##type);					\
576EXPORT_SYMBOL(spl_param_ops_##type);
577
578define_spl_param(s64, "%lld")
579define_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 */
586void
587spl_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}
611EXPORT_SYMBOL(spl_signal_kobj_evt);
612
613int
614ddi_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}
624EXPORT_SYMBOL(ddi_copyout);
625
626static ssize_t
627spl_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
646static int
647spl_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
705static char *spl_hostid_path = HW_HOSTID_PATH;
706module_param(spl_hostid_path, charp, 0444);
707MODULE_PARM_DESC(spl_hostid_path, "The system hostid file (/etc/hostid)");
708
709static int
710hostid_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 */
758uint32_t
759zone_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}
773EXPORT_SYMBOL(zone_get_hostid);
774
775static int
776spl_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 */
801static int __init
802spl_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
844static void
845spl_random_fini(void)
846{
847	free_percpu(spl_pseudo_entropy);
848}
849
850static void
851spl_kvmem_fini(void)
852{
853	spl_vmem_fini();
854	spl_kmem_fini();
855}
856
857static int __init
858spl_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
891out8:
892	spl_zlib_fini();
893out7:
894	spl_kstat_fini();
895out6:
896	spl_proc_fini();
897out5:
898	spl_kmem_cache_fini();
899out4:
900	spl_taskq_fini();
901out3:
902	spl_tsd_fini();
903out2:
904	spl_kvmem_fini();
905out1:
906	spl_random_fini();
907out0:
908	return (rc);
909}
910
911static void __exit
912spl_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
925module_init(spl_init);
926module_exit(spl_fini);
927
928MODULE_DESCRIPTION("Solaris Porting Layer");
929MODULE_AUTHOR(ZFS_META_AUTHOR);
930MODULE_LICENSE("GPL");
931MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);
932