/* * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. * Copyright (C) 2007 The Regents of the University of California. * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). * Written by Brian Behlendorf . * UCRL-CODE-235197 * * This file is part of the SPL, Solaris Porting Layer. * * The SPL is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * * The SPL is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with the SPL. If not, see . * * Solaris Porting Layer (SPL) Generic Implementation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include unsigned long spl_hostid = 0; EXPORT_SYMBOL(spl_hostid); /* CSTYLED */ module_param(spl_hostid, ulong, 0644); MODULE_PARM_DESC(spl_hostid, "The system hostid."); proc_t p0; EXPORT_SYMBOL(p0); /* * Xorshift Pseudo Random Number Generator based on work by Sebastiano Vigna * * "Further scramblings of Marsaglia's xorshift generators" * http://vigna.di.unimi.it/ftp/papers/xorshiftplus.pdf * * random_get_pseudo_bytes() is an API function on Illumos whose sole purpose * is to provide bytes containing random numbers. It is mapped to /dev/urandom * on Illumos, which uses a "FIPS 186-2 algorithm". No user of the SPL's * random_get_pseudo_bytes() needs bytes that are of cryptographic quality, so * we can implement it using a fast PRNG that we seed using Linux' actual * equivalent to random_get_pseudo_bytes(). We do this by providing each CPU * with an independent seed so that all calls to random_get_pseudo_bytes() are * free of atomic instructions. * * A consequence of using a fast PRNG is that using random_get_pseudo_bytes() * to generate words larger than 128 bits will paradoxically be limited to * `2^128 - 1` possibilities. This is because we have a sequence of `2^128 - 1` * 128-bit words and selecting the first will implicitly select the second. If * a caller finds this behavior undesirable, random_get_bytes() should be used * instead. * * XXX: Linux interrupt handlers that trigger within the critical section * formed by `s[1] = xp[1];` and `xp[0] = s[0];` and call this function will * see the same numbers. Nothing in the code currently calls this in an * interrupt handler, so this is considered to be okay. If that becomes a * problem, we could create a set of per-cpu variables for interrupt handlers * and use them when in_interrupt() from linux/preempt_mask.h evaluates to * true. */ void __percpu *spl_pseudo_entropy; /* * spl_rand_next()/spl_rand_jump() are copied from the following CC-0 licensed * file: * * http://xorshift.di.unimi.it/xorshift128plus.c */ static inline uint64_t spl_rand_next(uint64_t *s) { uint64_t s1 = s[0]; const uint64_t s0 = s[1]; s[0] = s0; s1 ^= s1 << 23; // a s[1] = s1 ^ s0 ^ (s1 >> 18) ^ (s0 >> 5); // b, c return (s[1] + s0); } static inline void spl_rand_jump(uint64_t *s) { static const uint64_t JUMP[] = { 0x8a5cd789635d2dff, 0x121fd2155c472f96 }; uint64_t s0 = 0; uint64_t s1 = 0; int i, b; for (i = 0; i < sizeof (JUMP) / sizeof (*JUMP); i++) for (b = 0; b < 64; b++) { if (JUMP[i] & 1ULL << b) { s0 ^= s[0]; s1 ^= s[1]; } (void) spl_rand_next(s); } s[0] = s0; s[1] = s1; } int random_get_pseudo_bytes(uint8_t *ptr, size_t len) { uint64_t *xp, s[2]; ASSERT(ptr); xp = get_cpu_ptr(spl_pseudo_entropy); s[0] = xp[0]; s[1] = xp[1]; while (len) { union { uint64_t ui64; uint8_t byte[sizeof (uint64_t)]; }entropy; int i = MIN(len, sizeof (uint64_t)); len -= i; entropy.ui64 = spl_rand_next(s); while (i--) *ptr++ = entropy.byte[i]; } xp[0] = s[0]; xp[1] = s[1]; put_cpu_ptr(spl_pseudo_entropy); return (0); } EXPORT_SYMBOL(random_get_pseudo_bytes); #if BITS_PER_LONG == 32 /* * Support 64/64 => 64 division on a 32-bit platform. While the kernel * provides a div64_u64() function for this we do not use it because the * implementation is flawed. There are cases which return incorrect * results as late as linux-2.6.35. Until this is fixed upstream the * spl must provide its own implementation. * * This implementation is a slightly modified version of the algorithm * proposed by the book 'Hacker's Delight'. The original source can be * found here and is available for use without restriction. * * http://www.hackersdelight.org/HDcode/newCode/divDouble.c */ /* * Calculate number of leading of zeros for a 64-bit value. */ static int nlz64(uint64_t x) { register int n = 0; if (x == 0) return (64); if (x <= 0x00000000FFFFFFFFULL) { n = n + 32; x = x << 32; } if (x <= 0x0000FFFFFFFFFFFFULL) { n = n + 16; x = x << 16; } if (x <= 0x00FFFFFFFFFFFFFFULL) { n = n + 8; x = x << 8; } if (x <= 0x0FFFFFFFFFFFFFFFULL) { n = n + 4; x = x << 4; } if (x <= 0x3FFFFFFFFFFFFFFFULL) { n = n + 2; x = x << 2; } if (x <= 0x7FFFFFFFFFFFFFFFULL) { n = n + 1; } return (n); } /* * Newer kernels have a div_u64() function but we define our own * to simplify portability between kernel versions. */ static inline uint64_t __div_u64(uint64_t u, uint32_t v) { (void) do_div(u, v); return (u); } /* * Turn off missing prototypes warning for these functions. They are * replacements for libgcc-provided functions and will never be called * directly. */ #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wmissing-prototypes" /* * Implementation of 64-bit unsigned division for 32-bit machines. * * First the procedure takes care of the case in which the divisor is a * 32-bit quantity. There are two subcases: (1) If the left half of the * dividend is less than the divisor, one execution of do_div() is all that * is required (overflow is not possible). (2) Otherwise it does two * divisions, using the grade school method. */ uint64_t __udivdi3(uint64_t u, uint64_t v) { uint64_t u0, u1, v1, q0, q1, k; int n; if (v >> 32 == 0) { // If v < 2**32: if (u >> 32 < v) { // If u/v cannot overflow, return (__div_u64(u, v)); // just do one division. } else { // If u/v would overflow: u1 = u >> 32; // Break u into two halves. u0 = u & 0xFFFFFFFF; q1 = __div_u64(u1, v); // First quotient digit. k = u1 - q1 * v; // First remainder, < v. u0 += (k << 32); q0 = __div_u64(u0, v); // Seconds quotient digit. return ((q1 << 32) + q0); } } else { // If v >= 2**32: n = nlz64(v); // 0 <= n <= 31. v1 = (v << n) >> 32; // Normalize divisor, MSB is 1. u1 = u >> 1; // To ensure no overflow. q1 = __div_u64(u1, v1); // Get quotient from q0 = (q1 << n) >> 31; // Undo normalization and // division of u by 2. if (q0 != 0) // Make q0 correct or q0 = q0 - 1; // too small by 1. if ((u - q0 * v) >= v) q0 = q0 + 1; // Now q0 is correct. return (q0); } } EXPORT_SYMBOL(__udivdi3); #ifndef abs64 /* CSTYLED */ #define abs64(x) ({ uint64_t t = (x) >> 63; ((x) ^ t) - t; }) #endif /* * Implementation of 64-bit signed division for 32-bit machines. */ int64_t __divdi3(int64_t u, int64_t v) { int64_t q, t; q = __udivdi3(abs64(u), abs64(v)); t = (u ^ v) >> 63; // If u, v have different return ((q ^ t) - t); // signs, negate q. } EXPORT_SYMBOL(__divdi3); /* * Implementation of 64-bit unsigned modulo for 32-bit machines. */ uint64_t __umoddi3(uint64_t dividend, uint64_t divisor) { return (dividend - (divisor * __udivdi3(dividend, divisor))); } EXPORT_SYMBOL(__umoddi3); /* 64-bit signed modulo for 32-bit machines. */ int64_t __moddi3(int64_t n, int64_t d) { int64_t q; boolean_t nn = B_FALSE; if (n < 0) { nn = B_TRUE; n = -n; } if (d < 0) d = -d; q = __umoddi3(n, d); return (nn ? -q : q); } EXPORT_SYMBOL(__moddi3); /* * Implementation of 64-bit unsigned division/modulo for 32-bit machines. */ uint64_t __udivmoddi4(uint64_t n, uint64_t d, uint64_t *r) { uint64_t q = __udivdi3(n, d); if (r) *r = n - d * q; return (q); } EXPORT_SYMBOL(__udivmoddi4); /* * Implementation of 64-bit signed division/modulo for 32-bit machines. */ int64_t __divmoddi4(int64_t n, int64_t d, int64_t *r) { int64_t q, rr; boolean_t nn = B_FALSE; boolean_t nd = B_FALSE; if (n < 0) { nn = B_TRUE; n = -n; } if (d < 0) { nd = B_TRUE; d = -d; } q = __udivmoddi4(n, d, (uint64_t *)&rr); if (nn != nd) q = -q; if (nn) rr = -rr; if (r) *r = rr; return (q); } EXPORT_SYMBOL(__divmoddi4); #if defined(__arm) || defined(__arm__) /* * Implementation of 64-bit (un)signed division for 32-bit arm machines. * * Run-time ABI for the ARM Architecture (page 20). A pair of (unsigned) * long longs is returned in {{r0, r1}, {r2,r3}}, the quotient in {r0, r1}, * and the remainder in {r2, r3}. The return type is specifically left * set to 'void' to ensure the compiler does not overwrite these registers * during the return. All results are in registers as per ABI */ void __aeabi_uldivmod(uint64_t u, uint64_t v) { uint64_t res; uint64_t mod; res = __udivdi3(u, v); mod = __umoddi3(u, v); { register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); register uint32_t r1 asm("r1") = (res >> 32); register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); register uint32_t r3 asm("r3") = (mod >> 32); asm volatile("" : "+r"(r0), "+r"(r1), "+r"(r2), "+r"(r3) /* output */ : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ return; /* r0; */ } } EXPORT_SYMBOL(__aeabi_uldivmod); void __aeabi_ldivmod(int64_t u, int64_t v) { int64_t res; uint64_t mod; res = __divdi3(u, v); mod = __umoddi3(u, v); { register uint32_t r0 asm("r0") = (res & 0xFFFFFFFF); register uint32_t r1 asm("r1") = (res >> 32); register uint32_t r2 asm("r2") = (mod & 0xFFFFFFFF); register uint32_t r3 asm("r3") = (mod >> 32); asm volatile("" : "+r"(r0), "+r"(r1), "+r"(r2), "+r"(r3) /* output */ : "r"(r0), "r"(r1), "r"(r2), "r"(r3)); /* input */ return; /* r0; */ } } EXPORT_SYMBOL(__aeabi_ldivmod); #endif /* __arm || __arm__ */ #pragma GCC diagnostic pop #endif /* BITS_PER_LONG */ /* * NOTE: The strtoxx behavior is solely based on my reading of the Solaris * ddi_strtol(9F) man page. I have not verified the behavior of these * functions against their Solaris counterparts. It is possible that I * may have misinterpreted the man page or the man page is incorrect. */ int ddi_strtol(const char *, char **, int, long *); int ddi_strtoull(const char *, char **, int, unsigned long long *); int ddi_strtoll(const char *, char **, int, long long *); #define define_ddi_strtox(type, valtype) \ int ddi_strto##type(const char *str, char **endptr, \ int base, valtype *result) \ { \ valtype last_value, value = 0; \ char *ptr = (char *)str; \ int digit, minus = 0; \ \ while (strchr(" \t\n\r\f", *ptr)) \ ++ptr; \ \ if (strlen(ptr) == 0) \ return (EINVAL); \ \ switch (*ptr) { \ case '-': \ minus = 1; \ zfs_fallthrough; \ case '+': \ ++ptr; \ break; \ } \ \ /* Auto-detect base based on prefix */ \ if (!base) { \ if (str[0] == '0') { \ if (tolower(str[1]) == 'x' && isxdigit(str[2])) { \ base = 16; /* hex */ \ ptr += 2; \ } else if (str[1] >= '0' && str[1] < 8) { \ base = 8; /* octal */ \ ptr += 1; \ } else { \ return (EINVAL); \ } \ } else { \ base = 10; /* decimal */ \ } \ } \ \ while (1) { \ if (isdigit(*ptr)) \ digit = *ptr - '0'; \ else if (isalpha(*ptr)) \ digit = tolower(*ptr) - 'a' + 10; \ else \ break; \ \ if (digit >= base) \ break; \ \ last_value = value; \ value = value * base + digit; \ if (last_value > value) /* Overflow */ \ return (ERANGE); \ \ ptr++; \ } \ \ *result = minus ? -value : value; \ \ if (endptr) \ *endptr = ptr; \ \ return (0); \ } \ define_ddi_strtox(l, long) define_ddi_strtox(ull, unsigned long long) define_ddi_strtox(ll, long long) EXPORT_SYMBOL(ddi_strtol); EXPORT_SYMBOL(ddi_strtoll); EXPORT_SYMBOL(ddi_strtoull); int ddi_copyin(const void *from, void *to, size_t len, int flags) { /* Fake ioctl() issued by kernel, 'from' is a kernel address */ if (flags & FKIOCTL) { memcpy(to, from, len); return (0); } return (copyin(from, to, len)); } EXPORT_SYMBOL(ddi_copyin); int ddi_copyout(const void *from, void *to, size_t len, int flags) { /* Fake ioctl() issued by kernel, 'from' is a kernel address */ if (flags & FKIOCTL) { memcpy(to, from, len); return (0); } return (copyout(from, to, len)); } EXPORT_SYMBOL(ddi_copyout); static ssize_t spl_kernel_read(struct file *file, void *buf, size_t count, loff_t *pos) { #if defined(HAVE_KERNEL_READ_PPOS) return (kernel_read(file, buf, count, pos)); #else mm_segment_t saved_fs; ssize_t ret; saved_fs = get_fs(); set_fs(KERNEL_DS); ret = vfs_read(file, (void __user *)buf, count, pos); set_fs(saved_fs); return (ret); #endif } static int spl_getattr(struct file *filp, struct kstat *stat) { int rc; ASSERT(filp); ASSERT(stat); #if defined(HAVE_4ARGS_VFS_GETATTR) rc = vfs_getattr(&filp->f_path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); #elif defined(HAVE_2ARGS_VFS_GETATTR) rc = vfs_getattr(&filp->f_path, stat); #elif defined(HAVE_3ARGS_VFS_GETATTR) rc = vfs_getattr(filp->f_path.mnt, filp->f_dentry, stat); #else #error "No available vfs_getattr()" #endif if (rc) return (-rc); return (0); } /* * Read the unique system identifier from the /etc/hostid file. * * The behavior of /usr/bin/hostid on Linux systems with the * regular eglibc and coreutils is: * * 1. Generate the value if the /etc/hostid file does not exist * or if the /etc/hostid file is less than four bytes in size. * * 2. If the /etc/hostid file is at least 4 bytes, then return * the first four bytes [0..3] in native endian order. * * 3. Always ignore bytes [4..] if they exist in the file. * * Only the first four bytes are significant, even on systems that * have a 64-bit word size. * * See: * * eglibc: sysdeps/unix/sysv/linux/gethostid.c * coreutils: src/hostid.c * * Notes: * * The /etc/hostid file on Solaris is a text file that often reads: * * # DO NOT EDIT * "0123456789" * * Directly copying this file to Linux results in a constant * hostid of 4f442023 because the default comment constitutes * the first four bytes of the file. * */ static char *spl_hostid_path = HW_HOSTID_PATH; module_param(spl_hostid_path, charp, 0444); MODULE_PARM_DESC(spl_hostid_path, "The system hostid file (/etc/hostid)"); static int hostid_read(uint32_t *hostid) { uint64_t size; uint32_t value = 0; int error; loff_t off; struct file *filp; struct kstat stat; filp = filp_open(spl_hostid_path, 0, 0); if (IS_ERR(filp)) return (ENOENT); error = spl_getattr(filp, &stat); if (error) { filp_close(filp, 0); return (error); } size = stat.size; // cppcheck-suppress sizeofwithnumericparameter if (size < sizeof (HW_HOSTID_MASK)) { filp_close(filp, 0); return (EINVAL); } off = 0; /* * Read directly into the variable like eglibc does. * Short reads are okay; native behavior is preserved. */ error = spl_kernel_read(filp, &value, sizeof (value), &off); if (error < 0) { filp_close(filp, 0); return (EIO); } /* Mask down to 32 bits like coreutils does. */ *hostid = (value & HW_HOSTID_MASK); filp_close(filp, 0); return (0); } /* * Return the system hostid. Preferentially use the spl_hostid module option * when set, otherwise use the value in the /etc/hostid file. */ uint32_t zone_get_hostid(void *zone) { uint32_t hostid; ASSERT3P(zone, ==, NULL); if (spl_hostid != 0) return ((uint32_t)(spl_hostid & HW_HOSTID_MASK)); if (hostid_read(&hostid) == 0) return (hostid); return (0); } EXPORT_SYMBOL(zone_get_hostid); static int spl_kvmem_init(void) { int rc = 0; rc = spl_kmem_init(); if (rc) return (rc); rc = spl_vmem_init(); if (rc) { spl_kmem_fini(); return (rc); } return (rc); } /* * We initialize the random number generator with 128 bits of entropy from the * system random number generator. In the improbable case that we have a zero * seed, we fallback to the system jiffies, unless it is also zero, in which * situation we use a preprogrammed seed. We step forward by 2^64 iterations to * initialize each of the per-cpu seeds so that the sequences generated on each * CPU are guaranteed to never overlap in practice. */ static void __init spl_random_init(void) { uint64_t s[2]; int i = 0; spl_pseudo_entropy = __alloc_percpu(2 * sizeof (uint64_t), sizeof (uint64_t)); get_random_bytes(s, sizeof (s)); if (s[0] == 0 && s[1] == 0) { if (jiffies != 0) { s[0] = jiffies; s[1] = ~0 - jiffies; } else { (void) memcpy(s, "improbable seed", sizeof (s)); } printk("SPL: get_random_bytes() returned 0 " "when generating random seed. Setting initial seed to " "0x%016llx%016llx.\n", cpu_to_be64(s[0]), cpu_to_be64(s[1])); } for_each_possible_cpu(i) { uint64_t *wordp = per_cpu_ptr(spl_pseudo_entropy, i); spl_rand_jump(s); wordp[0] = s[0]; wordp[1] = s[1]; } } static void spl_random_fini(void) { free_percpu(spl_pseudo_entropy); } static void spl_kvmem_fini(void) { spl_vmem_fini(); spl_kmem_fini(); } static int __init spl_init(void) { int rc = 0; spl_random_init(); if ((rc = spl_kvmem_init())) goto out1; if ((rc = spl_tsd_init())) goto out2; if ((rc = spl_taskq_init())) goto out3; if ((rc = spl_kmem_cache_init())) goto out4; if ((rc = spl_proc_init())) goto out5; if ((rc = spl_kstat_init())) goto out6; if ((rc = spl_zlib_init())) goto out7; if ((rc = spl_zone_init())) goto out8; return (rc); out8: spl_zlib_fini(); out7: spl_kstat_fini(); out6: spl_proc_fini(); out5: spl_kmem_cache_fini(); out4: spl_taskq_fini(); out3: spl_tsd_fini(); out2: spl_kvmem_fini(); out1: return (rc); } static void __exit spl_fini(void) { spl_zone_fini(); spl_zlib_fini(); spl_kstat_fini(); spl_proc_fini(); spl_kmem_cache_fini(); spl_taskq_fini(); spl_tsd_fini(); spl_kvmem_fini(); spl_random_fini(); } module_init(spl_init); module_exit(spl_fini); MODULE_DESCRIPTION("Solaris Porting Layer"); MODULE_AUTHOR(ZFS_META_AUTHOR); MODULE_LICENSE("GPL"); MODULE_VERSION(ZFS_META_VERSION "-" ZFS_META_RELEASE);