module/spl/spl-generic.c

   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  *  For details, see <http://github.com/behlendorf/spl/>.
  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/sysmacros.h>
  28 #include <sys/systeminfo.h>
  29 #include <sys/vmsystm.h>
  30 #include <sys/vnode.h>
  31 #include <sys/kmem.h>
  32 #include <sys/mutex.h>
  33 #include <sys/rwlock.h>
  34 #include <sys/taskq.h>
  35 #include <sys/tsd.h>
  36 #include <sys/debug.h>
  37 #include <sys/proc.h>
  38 #include <sys/kstat.h>
  39 #include <sys/utsname.h>
  40 #include <sys/file.h>
  41 #include <linux/kmod.h>
  42 #include <linux/proc_compat.h>
  43 #include <spl-debug.h>
  44
  45 #ifdef SS_DEBUG_SUBSYS
  46 #undef SS_DEBUG_SUBSYS
  47 #endif
  48
  49 #define SS_DEBUG_SUBSYS SS_GENERIC
  50
  51 char spl_version[16] = "SPL v" SPL_META_VERSION;
  52 EXPORT_SYMBOL(spl_version);
  53
  54 long spl_hostid = 0;
  55 EXPORT_SYMBOL(spl_hostid);
  56
  57 char hw_serial[HW_HOSTID_LEN] = "<none>";
  58 EXPORT_SYMBOL(hw_serial);
  59
  60 proc_t p0 = { 0 };
  61 EXPORT_SYMBOL(p0);
  62
  63 #ifndef HAVE_KALLSYMS_LOOKUP_NAME
  64 kallsyms_lookup_name_t spl_kallsyms_lookup_name_fn = SYMBOL_POISON;
  65 #endif
  66
  67 int
  68 highbit(unsigned long i)
  69 {
  70         register int h = 1;
  71         SENTRY;
  72
  73         if (i == 0)
  74                 SRETURN(0);
  75 #if BITS_PER_LONG == 64
  76         if (i & 0xffffffff00000000ul) {
  77                 h += 32; i >>= 32;
  78         }
  79 #endif
  80         if (i & 0xffff0000) {
  81                 h += 16; i >>= 16;
  82         }
  83         if (i & 0xff00) {
  84                 h += 8; i >>= 8;
  85         }
  86         if (i & 0xf0) {
  87                 h += 4; i >>= 4;
  88         }
  89         if (i & 0xc) {
  90                 h += 2; i >>= 2;
  91         }
  92         if (i & 0x2) {
  93                 h += 1;
  94         }
  95         SRETURN(h);
  96 }
  97 EXPORT_SYMBOL(highbit);
  98
  99 #if BITS_PER_LONG == 32
 100 /*
 101  * Support 64/64 => 64 division on a 32-bit platform.  While the kernel
 102  * provides a div64_u64() function for this we do not use it because the
 103  * implementation is flawed.  There are cases which return incorrect
 104  * results as late as linux-2.6.35.  Until this is fixed upstream the
 105  * spl must provide its own implementation.
 106  *
 107  * This implementation is a slightly modified version of the algorithm
 108  * proposed by the book 'Hacker's Delight'.  The original source can be
 109  * found here and is available for use without restriction.
 110  *
 111  * http://www.hackersdelight.org/HDcode/newCode/divDouble.c
 112  */
 113
 114 /*
 115  * Calculate number of leading of zeros for a 64-bit value.
 116  */
 117 static int
 118 nlz64(uint64_t x) {
 119         register int n = 0;
 120
 121         if (x == 0)
 122                 return 64;
 123
 124         if (x <= 0x00000000FFFFFFFFULL) {n = n + 32; x = x << 32;}
 125         if (x <= 0x0000FFFFFFFFFFFFULL) {n = n + 16; x = x << 16;}
 126         if (x <= 0x00FFFFFFFFFFFFFFULL) {n = n +  8; x = x <<  8;}
 127         if (x <= 0x0FFFFFFFFFFFFFFFULL) {n = n +  4; x = x <<  4;}
 128         if (x <= 0x3FFFFFFFFFFFFFFFULL) {n = n +  2; x = x <<  2;}
 129         if (x <= 0x7FFFFFFFFFFFFFFFULL) {n = n +  1;}
 130
 131         return n;
 132 }
 133
 134 /*
 135  * Newer kernels have a div_u64() function but we define our own
 136  * to simplify portibility between kernel versions.
 137  */
 138 static inline uint64_t
 139 __div_u64(uint64_t u, uint32_t v)
 140 {
 141         (void) do_div(u, v);
 142         return u;
 143 }
 144
 145 /*
 146  * Implementation of 64-bit unsigned division for 32-bit machines.
 147  *
 148  * First the procedure takes care of the case in which the divisor is a
 149  * 32-bit quantity. There are two subcases: (1) If the left half of the
 150  * dividend is less than the divisor, one execution of do_div() is all that
 151  * is required (overflow is not possible). (2) Otherwise it does two
 152  * divisions, using the grade school method.
 153  */
 154 uint64_t
 155 __udivdi3(uint64_t u, uint64_t v)
 156 {
 157         uint64_t u0, u1, v1, q0, q1, k;
 158         int n;
 159
 160         if (v >> 32 == 0) {                     // If v < 2**32:
 161                 if (u >> 32 < v) {              // If u/v cannot overflow,
 162                         return __div_u64(u, v); // just do one division.
 163                 } else {                        // If u/v would overflow:
 164                         u1 = u >> 32;           // Break u into two halves.
 165                         u0 = u & 0xFFFFFFFF;
 166                         q1 = __div_u64(u1, v);  // First quotient digit.
 167                         k  = u1 - q1 * v;       // First remainder, < v.
 168                         u0 += (k << 32);
 169                         q0 = __div_u64(u0, v);  // Seconds quotient digit.
 170                         return (q1 << 32) + q0;
 171                 }
 172         } else {                                // If v >= 2**32:
 173                 n = nlz64(v);                   // 0 <= n <= 31.
 174                 v1 = (v << n) >> 32;            // Normalize divisor, MSB is 1.
 175                 u1 = u >> 1;                    // To ensure no overflow.
 176                 q1 = __div_u64(u1, v1);         // Get quotient from
 177                 q0 = (q1 << n) >> 31;           // Undo normalization and
 178                                                 // division of u by 2.
 179                 if (q0 != 0)                    // Make q0 correct or
 180                         q0 = q0 - 1;            // too small by 1.
 181                 if ((u - q0 * v) >= v)
 182                         q0 = q0 + 1;            // Now q0 is correct.
 183
 184                 return q0;
 185         }
 186 }
 187 EXPORT_SYMBOL(__udivdi3);
 188
 189 /*
 190  * Implementation of 64-bit signed division for 32-bit machines.
 191  */
 192 int64_t
 193 __divdi3(int64_t u, int64_t v)
 194 {
 195         int64_t q, t;
 196         q = __udivdi3(abs64(u), abs64(v));
 197         t = (u ^ v) >> 63;      // If u, v have different
 198         return (q ^ t) - t;     // signs, negate q.
 199 }
 200 EXPORT_SYMBOL(__divdi3);
 201
 202 /*
 203  * Implementation of 64-bit unsigned modulo for 32-bit machines.
 204  */
 205 uint64_t
 206 __umoddi3(uint64_t dividend, uint64_t divisor)
 207 {
 208         return (dividend - (divisor * __udivdi3(dividend, divisor)));
 209 }
 210 EXPORT_SYMBOL(__umoddi3);
 211
 212 #endif /* BITS_PER_LONG */
 213
 214 /* NOTE: The strtoxx behavior is solely based on my reading of the Solaris
 215  * ddi_strtol(9F) man page.  I have not verified the behavior of these
 216  * functions against their Solaris counterparts.  It is possible that I
 217  * may have misinterpreted the man page or the man page is incorrect.
 218  */
 219 int ddi_strtoul(const char *, char **, int, unsigned long *);
 220 int ddi_strtol(const char *, char **, int, long *);
 221 int ddi_strtoull(const char *, char **, int, unsigned long long *);
 222 int ddi_strtoll(const char *, char **, int, long long *);
 223
 224 #define define_ddi_strtoux(type, valtype)                               \
 225 int ddi_strtou##type(const char *str, char **endptr,                    \
 226                      int base, valtype *result)                         \
 227 {                                                                       \
 228         valtype last_value, value = 0;                                  \
 229         char *ptr = (char *)str;                                        \
 230         int flag = 1, digit;                                            \
 231                                                                         \
 232         if (strlen(ptr) == 0)                                           \
 233                 return EINVAL;                                          \
 234                                                                         \
 235         /* Auto-detect base based on prefix */                          \
 236         if (!base) {                                                    \
 237                 if (str[0] == '0') {                                    \
 238                         if (tolower(str[1])=='x' && isxdigit(str[2])) { \
 239                                 base = 16; /* hex */                    \
 240                                 ptr += 2;                               \
 241                         } else if (str[1] >= '0' && str[1] < 8) {       \
 242                                 base = 8; /* octal */                   \
 243                                 ptr += 1;                               \
 244                         } else {                                        \
 245                                 return EINVAL;                          \
 246                         }                                               \
 247                 } else {                                                \
 248                         base = 10; /* decimal */                        \
 249                 }                                                       \
 250         }                                                               \
 251                                                                         \
 252         while (1) {                                                     \
 253                 if (isdigit(*ptr))                                      \
 254                         digit = *ptr - '0';                             \
 255                 else if (isalpha(*ptr))                                 \
 256                         digit = tolower(*ptr) - 'a' + 10;               \
 257                 else                                                    \
 258                         break;                                          \
 259                                                                         \
 260                 if (digit >= base)                                      \
 261                         break;                                          \
 262                                                                         \
 263                 last_value = value;                                     \
 264                 value = value * base + digit;                           \
 265                 if (last_value > value) /* Overflow */                  \
 266                         return ERANGE;                                  \
 267                                                                         \
 268                 flag = 1;                                               \
 269                 ptr++;                                                  \
 270         }                                                               \
 271                                                                         \
 272         if (flag)                                                       \
 273                 *result = value;                                        \
 274                                                                         \
 275         if (endptr)                                                     \
 276                 *endptr = (char *)(flag ? ptr : str);                   \
 277                                                                         \
 278         return 0;                                                       \
 279 }                                                                       \
 280
 281 #define define_ddi_strtox(type, valtype)                                \
 282 int ddi_strto##type(const char *str, char **endptr,                     \
 283                        int base, valtype *result)                       \
 284 {                                                                       \
 285         int rc;                                                         \
 286                                                                         \
 287         if (*str == '-') {                                              \
 288                 rc = ddi_strtou##type(str + 1, endptr, base, result);   \
 289                 if (!rc) {                                              \
 290                         if (*endptr == str + 1)                         \
 291                                 *endptr = (char *)str;                  \
 292                         else                                            \
 293                                 *result = -*result;                     \
 294                 }                                                       \
 295         } else {                                                        \
 296                 rc = ddi_strtou##type(str, endptr, base, result);       \
 297         }                                                               \
 298                                                                         \
 299         return rc;                                                      \
 300 }
 301
 302 define_ddi_strtoux(l, unsigned long)
 303 define_ddi_strtox(l, long)
 304 define_ddi_strtoux(ll, unsigned long long)
 305 define_ddi_strtox(ll, long long)
 306
 307 EXPORT_SYMBOL(ddi_strtoul);
 308 EXPORT_SYMBOL(ddi_strtol);
 309 EXPORT_SYMBOL(ddi_strtoll);
 310 EXPORT_SYMBOL(ddi_strtoull);
 311
 312 int
 313 ddi_copyin(const void *from, void *to, size_t len, int flags)
 314 {
 315         /* Fake ioctl() issued by kernel, 'from' is a kernel address */
 316         if (flags & FKIOCTL) {
 317                 memcpy(to, from, len);
 318                 return 0;
 319         }
 320
 321         return copyin(from, to, len);
 322 }
 323 EXPORT_SYMBOL(ddi_copyin);
 324
 325 int
 326 ddi_copyout(const void *from, void *to, size_t len, int flags)
 327 {
 328         /* Fake ioctl() issued by kernel, 'from' is a kernel address */
 329         if (flags & FKIOCTL) {
 330                 memcpy(to, from, len);
 331                 return 0;
 332         }
 333
 334         return copyout(from, to, len);
 335 }
 336 EXPORT_SYMBOL(ddi_copyout);
 337
 338 #ifndef HAVE_PUT_TASK_STRUCT
 339 /*
 340  * This is only a stub function which should never be used.  The SPL should
 341  * never be putting away the last reference on a task structure so this will
 342  * not be called.  However, we still need to define it so the module does not
 343  * have undefined symbol at load time.  That all said if this impossible
 344  * thing does somehow happen PANIC immediately so we know about it.
 345  */
 346 void
 347 __put_task_struct(struct task_struct *t)
 348 {
 349         PANIC("Unexpectly put last reference on task %d\n", (int)t->pid);
 350 }
 351 EXPORT_SYMBOL(__put_task_struct);
 352 #endif /* HAVE_PUT_TASK_STRUCT */
 353
 354 struct new_utsname *__utsname(void)
 355 {
 356 #ifdef HAVE_INIT_UTSNAME
 357         return init_utsname();
 358 #else
 359         return &system_utsname;
 360 #endif
 361 }
 362 EXPORT_SYMBOL(__utsname);
 363
 364 static int
 365 set_hostid(void)
 366 {
 367         char sh_path[] = "/bin/sh";
 368         char *argv[] = { sh_path,
 369                          "-c",
 370                          "/usr/bin/hostid >/proc/sys/kernel/spl/hostid",
 371                          NULL };
 372         char *envp[] = { "HOME=/",
 373                          "TERM=linux",
 374                          "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 375                          NULL };
 376         int rc;
 377
 378         /* Doing address resolution in the kernel is tricky and just
 379          * not a good idea in general.  So to set the proper 'hw_serial'
 380          * use the usermodehelper support to ask '/bin/sh' to run
 381          * '/usr/bin/hostid' and redirect the result to /proc/sys/spl/hostid
 382          * for us to use.  It's a horrific solution but it will do for now.
 383          */
 384         rc = call_usermodehelper(sh_path, argv, envp, 1);
 385         if (rc)
 386                 printk("SPL: Failed user helper '%s %s %s', rc = %d\n",
 387                        argv[0], argv[1], argv[2], rc);
 388
 389         return rc;
 390 }
 391
 392 uint32_t
 393 zone_get_hostid(void *zone)
 394 {
 395         unsigned long hostid;
 396
 397         /* Only the global zone is supported */
 398         ASSERT(zone == NULL);
 399
 400         if (ddi_strtoul(hw_serial, NULL, HW_HOSTID_LEN-1, &hostid) != 0)
 401                 return HW_INVALID_HOSTID;
 402
 403         return (uint32_t)hostid;
 404 }
 405 EXPORT_SYMBOL(zone_get_hostid);
 406
 407 #ifndef HAVE_KALLSYMS_LOOKUP_NAME
 408 /*
 409  * Because kallsyms_lookup_name() is no longer exported in the
 410  * mainline kernel we are forced to resort to somewhat drastic
 411  * measures.  This function replaces the functionality by performing
 412  * an upcall to user space where /proc/kallsyms is consulted for
 413  * the requested address.
 414  */
 415 #define GET_KALLSYMS_ADDR_CMD                                           \
 416         "gawk '{ if ( $3 == \"kallsyms_lookup_name\") { print $1 } }' " \
 417         "/proc/kallsyms >/proc/sys/kernel/spl/kallsyms_lookup_name"
 418
 419 static int
 420 set_kallsyms_lookup_name(void)
 421 {
 422         char sh_path[] = "/bin/sh";
 423         char *argv[] = { sh_path,
 424                          "-c",
 425                          GET_KALLSYMS_ADDR_CMD,
 426                          NULL };
 427         char *envp[] = { "HOME=/",
 428                          "TERM=linux",
 429                          "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 430                          NULL };
 431         int rc;
 432
 433         rc = call_usermodehelper(sh_path, argv, envp, 1);
 434         if (rc)
 435                 printk("SPL: Failed user helper '%s %s %s', rc = %d\n",
 436                        argv[0], argv[1], argv[2], rc);
 437
 438         return rc;
 439 }
 440 #endif
 441
 442 static int
 443 __init spl_init(void)
 444 {
 445         int rc = 0;
 446
 447         if ((rc = debug_init()))
 448                 return rc;
 449
 450         if ((rc = spl_kmem_init()))
 451                 SGOTO(out1, rc);
 452
 453         if ((rc = spl_mutex_init()))
 454                 SGOTO(out2, rc);
 455
 456         if ((rc = spl_rw_init()))
 457                 SGOTO(out3, rc);
 458
 459         if ((rc = spl_taskq_init()))
 460                 SGOTO(out4, rc);
 461
 462         if ((rc = vn_init()))
 463                 SGOTO(out5, rc);
 464
 465         if ((rc = proc_init()))
 466                 SGOTO(out6, rc);
 467
 468         if ((rc = kstat_init()))
 469                 SGOTO(out7, rc);
 470
 471         if ((rc = tsd_init()))
 472                 SGOTO(out8, rc);
 473
 474         if ((rc = set_hostid()))
 475                 SGOTO(out9, rc = -EADDRNOTAVAIL);
 476
 477 #ifndef HAVE_KALLSYMS_LOOKUP_NAME
 478         if ((rc = set_kallsyms_lookup_name()))
 479                 SGOTO(out9, rc = -EADDRNOTAVAIL);
 480 #endif /* HAVE_KALLSYMS_LOOKUP_NAME */
 481
 482         if ((rc = spl_kmem_init_kallsyms_lookup()))
 483                 SGOTO(out9, rc);
 484
 485         printk(KERN_NOTICE "SPL: Loaded Solaris Porting Layer v%s%s\n",
 486                SPL_META_VERSION, SPL_DEBUG_STR);
 487         SRETURN(rc);
 488 out9:
 489         tsd_fini();
 490 out8:
 491         kstat_fini();
 492 out7:
 493         proc_fini();
 494 out6:
 495         vn_fini();
 496 out5:
 497         spl_taskq_fini();
 498 out4:
 499         spl_rw_fini();
 500 out3:
 501         spl_mutex_fini();
 502 out2:
 503         spl_kmem_fini();
 504 out1:
 505         debug_fini();
 506
 507         printk(KERN_NOTICE "SPL: Failed to Load Solaris Porting Layer v%s%s"
 508                ", rc = %d\n", SPL_META_VERSION, SPL_DEBUG_STR, rc);
 509         return rc;
 510 }
 511
 512 static void
 513 spl_fini(void)
 514 {
 515         SENTRY;
 516
 517         printk(KERN_NOTICE "SPL: Unloaded Solaris Porting Layer v%s%s\n",
 518                SPL_META_VERSION, SPL_DEBUG_STR);
 519         tsd_fini();
 520         kstat_fini();
 521         proc_fini();
 522         vn_fini();
 523         spl_taskq_fini();
 524         spl_rw_fini();
 525         spl_mutex_fini();
 526         spl_kmem_fini();
 527         debug_fini();
 528 }
 529
 530 /* Called when a dependent module is loaded */
 531 void
 532 spl_setup(void)
 533 {
 534         int rc;
 535
 536         /*
 537          * At module load time the pwd is set to '/' on a Solaris system.
 538          * On a Linux system will be set to whatever directory the caller
 539          * was in when executing insmod/modprobe.
 540          */
 541         rc = vn_set_pwd("/");
 542         if (rc)
 543                 printk("SPL: Warning unable to set pwd to '/': %d\n", rc);
 544 }
 545 EXPORT_SYMBOL(spl_setup);
 546
 547 /* Called when a dependent module is unloaded */
 548 void
 549 spl_cleanup(void)
 550 {
 551 }
 552 EXPORT_SYMBOL(spl_cleanup);
 553
 554 module_init(spl_init);
 555 module_exit(spl_fini);
 556
 557 MODULE_AUTHOR("Lawrence Livermore National Labs");
 558 MODULE_DESCRIPTION("Solaris Porting Layer");
 559 MODULE_LICENSE("GPL");