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/zmod.h>
  37 #include <sys/debug.h>
  38 #include <sys/proc.h>
  39 #include <sys/kstat.h>
  40 #include <sys/utsname.h>
  41 #include <sys/file.h>
  42 #include <linux/kmod.h>
  43 #include <linux/proc_compat.h>
  44 #include <spl-debug.h>
  45
  46 #ifdef SS_DEBUG_SUBSYS
  47 #undef SS_DEBUG_SUBSYS
  48 #endif
  49
  50 #define SS_DEBUG_SUBSYS SS_GENERIC
  51
  52 char spl_version[16] = "SPL v" SPL_META_VERSION;
  53 EXPORT_SYMBOL(spl_version);
  54
  55 unsigned long spl_hostid = 0;
  56 EXPORT_SYMBOL(spl_hostid);
  57 module_param(spl_hostid, ulong, 0644);
  58 MODULE_PARM_DESC(spl_hostid, "The system hostid.");
  59
  60 char hw_serial[HW_HOSTID_LEN] = "<none>";
  61 EXPORT_SYMBOL(hw_serial);
  62
  63 proc_t p0 = { 0 };
  64 EXPORT_SYMBOL(p0);
  65
  66 #ifndef HAVE_KALLSYMS_LOOKUP_NAME
  67 kallsyms_lookup_name_t spl_kallsyms_lookup_name_fn = SYMBOL_POISON;
  68 #endif
  69
  70 int
  71 highbit(unsigned long i)
  72 {
  73         register int h = 1;
  74         SENTRY;
  75
  76         if (i == 0)
  77                 SRETURN(0);
  78 #if BITS_PER_LONG == 64
  79         if (i & 0xffffffff00000000ul) {
  80                 h += 32; i >>= 32;
  81         }
  82 #endif
  83         if (i & 0xffff0000) {
  84                 h += 16; i >>= 16;
  85         }
  86         if (i & 0xff00) {
  87                 h += 8; i >>= 8;
  88         }
  89         if (i & 0xf0) {
  90                 h += 4; i >>= 4;
  91         }
  92         if (i & 0xc) {
  93                 h += 2; i >>= 2;
  94         }
  95         if (i & 0x2) {
  96                 h += 1;
  97         }
  98         SRETURN(h);
  99 }
 100 EXPORT_SYMBOL(highbit);
 101
 102 #if BITS_PER_LONG == 32
 103 /*
 104  * Support 64/64 => 64 division on a 32-bit platform.  While the kernel
 105  * provides a div64_u64() function for this we do not use it because the
 106  * implementation is flawed.  There are cases which return incorrect
 107  * results as late as linux-2.6.35.  Until this is fixed upstream the
 108  * spl must provide its own implementation.
 109  *
 110  * This implementation is a slightly modified version of the algorithm
 111  * proposed by the book 'Hacker's Delight'.  The original source can be
 112  * found here and is available for use without restriction.
 113  *
 114  * http://www.hackersdelight.org/HDcode/newCode/divDouble.c
 115  */
 116
 117 /*
 118  * Calculate number of leading of zeros for a 64-bit value.
 119  */
 120 static int
 121 nlz64(uint64_t x) {
 122         register int n = 0;
 123
 124         if (x == 0)
 125                 return 64;
 126
 127         if (x <= 0x00000000FFFFFFFFULL) {n = n + 32; x = x << 32;}
 128         if (x <= 0x0000FFFFFFFFFFFFULL) {n = n + 16; x = x << 16;}
 129         if (x <= 0x00FFFFFFFFFFFFFFULL) {n = n +  8; x = x <<  8;}
 130         if (x <= 0x0FFFFFFFFFFFFFFFULL) {n = n +  4; x = x <<  4;}
 131         if (x <= 0x3FFFFFFFFFFFFFFFULL) {n = n +  2; x = x <<  2;}
 132         if (x <= 0x7FFFFFFFFFFFFFFFULL) {n = n +  1;}
 133
 134         return n;
 135 }
 136
 137 /*
 138  * Newer kernels have a div_u64() function but we define our own
 139  * to simplify portibility between kernel versions.
 140  */
 141 static inline uint64_t
 142 __div_u64(uint64_t u, uint32_t v)
 143 {
 144         (void) do_div(u, v);
 145         return u;
 146 }
 147
 148 /*
 149  * Implementation of 64-bit unsigned division for 32-bit machines.
 150  *
 151  * First the procedure takes care of the case in which the divisor is a
 152  * 32-bit quantity. There are two subcases: (1) If the left half of the
 153  * dividend is less than the divisor, one execution of do_div() is all that
 154  * is required (overflow is not possible). (2) Otherwise it does two
 155  * divisions, using the grade school method.
 156  */
 157 uint64_t
 158 __udivdi3(uint64_t u, uint64_t v)
 159 {
 160         uint64_t u0, u1, v1, q0, q1, k;
 161         int n;
 162
 163         if (v >> 32 == 0) {                     // If v < 2**32:
 164                 if (u >> 32 < v) {              // If u/v cannot overflow,
 165                         return __div_u64(u, v); // just do one division.
 166                 } else {                        // If u/v would overflow:
 167                         u1 = u >> 32;           // Break u into two halves.
 168                         u0 = u & 0xFFFFFFFF;
 169                         q1 = __div_u64(u1, v);  // First quotient digit.
 170                         k  = u1 - q1 * v;       // First remainder, < v.
 171                         u0 += (k << 32);
 172                         q0 = __div_u64(u0, v);  // Seconds quotient digit.
 173                         return (q1 << 32) + q0;
 174                 }
 175         } else {                                // If v >= 2**32:
 176                 n = nlz64(v);                   // 0 <= n <= 31.
 177                 v1 = (v << n) >> 32;            // Normalize divisor, MSB is 1.
 178                 u1 = u >> 1;                    // To ensure no overflow.
 179                 q1 = __div_u64(u1, v1);         // Get quotient from
 180                 q0 = (q1 << n) >> 31;           // Undo normalization and
 181                                                 // division of u by 2.
 182                 if (q0 != 0)                    // Make q0 correct or
 183                         q0 = q0 - 1;            // too small by 1.
 184                 if ((u - q0 * v) >= v)
 185                         q0 = q0 + 1;            // Now q0 is correct.
 186
 187                 return q0;
 188         }
 189 }
 190 EXPORT_SYMBOL(__udivdi3);
 191
 192 /*
 193  * Implementation of 64-bit signed division for 32-bit machines.
 194  */
 195 int64_t
 196 __divdi3(int64_t u, int64_t v)
 197 {
 198         int64_t q, t;
 199         q = __udivdi3(abs64(u), abs64(v));
 200         t = (u ^ v) >> 63;      // If u, v have different
 201         return (q ^ t) - t;     // signs, negate q.
 202 }
 203 EXPORT_SYMBOL(__divdi3);
 204
 205 /*
 206  * Implementation of 64-bit unsigned modulo for 32-bit machines.
 207  */
 208 uint64_t
 209 __umoddi3(uint64_t dividend, uint64_t divisor)
 210 {
 211         return (dividend - (divisor * __udivdi3(dividend, divisor)));
 212 }
 213 EXPORT_SYMBOL(__umoddi3);
 214
 215 #endif /* BITS_PER_LONG */
 216
 217 /* NOTE: The strtoxx behavior is solely based on my reading of the Solaris
 218  * ddi_strtol(9F) man page.  I have not verified the behavior of these
 219  * functions against their Solaris counterparts.  It is possible that I
 220  * may have misinterpreted the man page or the man page is incorrect.
 221  */
 222 int ddi_strtoul(const char *, char **, int, unsigned long *);
 223 int ddi_strtol(const char *, char **, int, long *);
 224 int ddi_strtoull(const char *, char **, int, unsigned long long *);
 225 int ddi_strtoll(const char *, char **, int, long long *);
 226
 227 #define define_ddi_strtoux(type, valtype)                               \
 228 int ddi_strtou##type(const char *str, char **endptr,                    \
 229                      int base, valtype *result)                         \
 230 {                                                                       \
 231         valtype last_value, value = 0;                                  \
 232         char *ptr = (char *)str;                                        \
 233         int flag = 1, digit;                                            \
 234                                                                         \
 235         if (strlen(ptr) == 0)                                           \
 236                 return EINVAL;                                          \
 237                                                                         \
 238         /* Auto-detect base based on prefix */                          \
 239         if (!base) {                                                    \
 240                 if (str[0] == '0') {                                    \
 241                         if (tolower(str[1])=='x' && isxdigit(str[2])) { \
 242                                 base = 16; /* hex */                    \
 243                                 ptr += 2;                               \
 244                         } else if (str[1] >= '0' && str[1] < 8) {       \
 245                                 base = 8; /* octal */                   \
 246                                 ptr += 1;                               \
 247                         } else {                                        \
 248                                 return EINVAL;                          \
 249                         }                                               \
 250                 } else {                                                \
 251                         base = 10; /* decimal */                        \
 252                 }                                                       \
 253         }                                                               \
 254                                                                         \
 255         while (1) {                                                     \
 256                 if (isdigit(*ptr))                                      \
 257                         digit = *ptr - '0';                             \
 258                 else if (isalpha(*ptr))                                 \
 259                         digit = tolower(*ptr) - 'a' + 10;               \
 260                 else                                                    \
 261                         break;                                          \
 262                                                                         \
 263                 if (digit >= base)                                      \
 264                         break;                                          \
 265                                                                         \
 266                 last_value = value;                                     \
 267                 value = value * base + digit;                           \
 268                 if (last_value > value) /* Overflow */                  \
 269                         return ERANGE;                                  \
 270                                                                         \
 271                 flag = 1;                                               \
 272                 ptr++;                                                  \
 273         }                                                               \
 274                                                                         \
 275         if (flag)                                                       \
 276                 *result = value;                                        \
 277                                                                         \
 278         if (endptr)                                                     \
 279                 *endptr = (char *)(flag ? ptr : str);                   \
 280                                                                         \
 281         return 0;                                                       \
 282 }                                                                       \
 283
 284 #define define_ddi_strtox(type, valtype)                                \
 285 int ddi_strto##type(const char *str, char **endptr,                     \
 286                        int base, valtype *result)                       \
 287 {                                                                       \
 288         int rc;                                                         \
 289                                                                         \
 290         if (*str == '-') {                                              \
 291                 rc = ddi_strtou##type(str + 1, endptr, base, result);   \
 292                 if (!rc) {                                              \
 293                         if (*endptr == str + 1)                         \
 294                                 *endptr = (char *)str;                  \
 295                         else                                            \
 296                                 *result = -*result;                     \
 297                 }                                                       \
 298         } else {                                                        \
 299                 rc = ddi_strtou##type(str, endptr, base, result);       \
 300         }                                                               \
 301                                                                         \
 302         return rc;                                                      \
 303 }
 304
 305 define_ddi_strtoux(l, unsigned long)
 306 define_ddi_strtox(l, long)
 307 define_ddi_strtoux(ll, unsigned long long)
 308 define_ddi_strtox(ll, long long)
 309
 310 EXPORT_SYMBOL(ddi_strtoul);
 311 EXPORT_SYMBOL(ddi_strtol);
 312 EXPORT_SYMBOL(ddi_strtoll);
 313 EXPORT_SYMBOL(ddi_strtoull);
 314
 315 int
 316 ddi_copyin(const void *from, void *to, size_t len, int flags)
 317 {
 318         /* Fake ioctl() issued by kernel, 'from' is a kernel address */
 319         if (flags & FKIOCTL) {
 320                 memcpy(to, from, len);
 321                 return 0;
 322         }
 323
 324         return copyin(from, to, len);
 325 }
 326 EXPORT_SYMBOL(ddi_copyin);
 327
 328 int
 329 ddi_copyout(const void *from, void *to, size_t len, int flags)
 330 {
 331         /* Fake ioctl() issued by kernel, 'from' is a kernel address */
 332         if (flags & FKIOCTL) {
 333                 memcpy(to, from, len);
 334                 return 0;
 335         }
 336
 337         return copyout(from, to, len);
 338 }
 339 EXPORT_SYMBOL(ddi_copyout);
 340
 341 #ifndef HAVE_PUT_TASK_STRUCT
 342 /*
 343  * This is only a stub function which should never be used.  The SPL should
 344  * never be putting away the last reference on a task structure so this will
 345  * not be called.  However, we still need to define it so the module does not
 346  * have undefined symbol at load time.  That all said if this impossible
 347  * thing does somehow happen PANIC immediately so we know about it.
 348  */
 349 void
 350 __put_task_struct(struct task_struct *t)
 351 {
 352         PANIC("Unexpectly put last reference on task %d\n", (int)t->pid);
 353 }
 354 EXPORT_SYMBOL(__put_task_struct);
 355 #endif /* HAVE_PUT_TASK_STRUCT */
 356
 357 struct new_utsname *__utsname(void)
 358 {
 359 #ifdef HAVE_INIT_UTSNAME
 360         return init_utsname();
 361 #else
 362         return &system_utsname;
 363 #endif
 364 }
 365 EXPORT_SYMBOL(__utsname);
 366
 367 #define GET_HOSTID_CMD \
 368         "exec 0</dev/null " \
 369         "     1>/proc/sys/kernel/spl/hostid " \
 370         "     2>/dev/null; " \
 371         "hostid"
 372
 373 static int
 374 set_hostid(void)
 375 {
 376         char *argv[] = { "/bin/sh",
 377                          "-c",
 378                          GET_HOSTID_CMD,
 379                          NULL };
 380         char *envp[] = { "HOME=/",
 381                          "TERM=linux",
 382                          "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 383                          NULL };
 384         int rc;
 385
 386         /* Doing address resolution in the kernel is tricky and just
 387          * not a good idea in general.  So to set the proper 'hw_serial'
 388          * use the usermodehelper support to ask '/bin/sh' to run
 389          * '/usr/bin/hostid' and redirect the result to /proc/sys/spl/hostid
 390          * for us to use.  It's a horrific solution but it will do for now.
 391          */
 392         rc = call_usermodehelper(argv[0], argv, envp, 1);
 393         if (rc)
 394                 printk("SPL: Failed user helper '%s %s %s', rc = %d\n",
 395                        argv[0], argv[1], argv[2], rc);
 396
 397         return rc;
 398 }
 399
 400 uint32_t
 401 zone_get_hostid(void *zone)
 402 {
 403         unsigned long hostid;
 404
 405         /* Only the global zone is supported */
 406         ASSERT(zone == NULL);
 407
 408         if (ddi_strtoul(hw_serial, NULL, HW_HOSTID_LEN-1, &hostid) != 0)
 409                 return HW_INVALID_HOSTID;
 410
 411         return (uint32_t)hostid;
 412 }
 413 EXPORT_SYMBOL(zone_get_hostid);
 414
 415 #ifndef HAVE_KALLSYMS_LOOKUP_NAME
 416 /*
 417  * The kallsyms_lookup_name() kernel function is not an exported symbol in
 418  * Linux 2.6.19 through 2.6.32 inclusive.
 419  *
 420  * This function replaces the functionality by performing an upcall to user
 421  * space where /proc/kallsyms is consulted for the requested address.
 422  *
 423  */
 424
 425 #define GET_KALLSYMS_ADDR_CMD \
 426         "exec 0</dev/null " \
 427         "     1>/proc/sys/kernel/spl/kallsyms_lookup_name " \
 428         "     2>/dev/null; " \
 429         "awk  '{ if ( $3 == \"kallsyms_lookup_name\" ) { print $1 } }' " \
 430         "     /proc/kallsyms "
 431
 432 static int
 433 set_kallsyms_lookup_name(void)
 434 {
 435         char *argv[] = { "/bin/sh",
 436                          "-c",
 437                          GET_KALLSYMS_ADDR_CMD,
 438                          NULL };
 439         char *envp[] = { "HOME=/",
 440                          "TERM=linux",
 441                          "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 442                          NULL };
 443         int rc;
 444
 445         rc = call_usermodehelper(argv[0], argv, envp, 1);
 446         if (rc)
 447                 printk("SPL: Failed user helper '%s %s %s', rc = %d\n",
 448                        argv[0], argv[1], argv[2], rc);
 449
 450         return rc;
 451 }
 452 #endif
 453
 454 static int
 455 __init spl_init(void)
 456 {
 457         int rc = 0;
 458
 459         if ((rc = debug_init()))
 460                 return rc;
 461
 462         if ((rc = spl_kmem_init()))
 463                 SGOTO(out1, rc);
 464
 465         if ((rc = spl_mutex_init()))
 466                 SGOTO(out2, rc);
 467
 468         if ((rc = spl_rw_init()))
 469                 SGOTO(out3, rc);
 470
 471         if ((rc = spl_taskq_init()))
 472                 SGOTO(out4, rc);
 473
 474         if ((rc = vn_init()))
 475                 SGOTO(out5, rc);
 476
 477         if ((rc = proc_init()))
 478                 SGOTO(out6, rc);
 479
 480         if ((rc = kstat_init()))
 481                 SGOTO(out7, rc);
 482
 483         if ((rc = tsd_init()))
 484                 SGOTO(out8, rc);
 485
 486         if ((rc = zlib_init()))
 487                 SGOTO(out9, rc);
 488
 489         /* Get the hostid if it was not passed as a module parameter. */
 490         if (spl_hostid == 0 && (rc = set_hostid()))
 491                 SGOTO(out10, rc = -EADDRNOTAVAIL);
 492
 493 #ifndef HAVE_KALLSYMS_LOOKUP_NAME
 494         if ((rc = set_kallsyms_lookup_name()))
 495                 SGOTO(out10, rc = -EADDRNOTAVAIL);
 496 #endif /* HAVE_KALLSYMS_LOOKUP_NAME */
 497
 498         if ((rc = spl_kmem_init_kallsyms_lookup()))
 499                 SGOTO(out10, rc);
 500
 501         printk(KERN_NOTICE "SPL: Loaded module v%s%s, using hostid 0x%08x\n",
 502                SPL_META_VERSION, SPL_DEBUG_STR, (unsigned int) spl_hostid);
 503         SRETURN(rc);
 504 out10:
 505         zlib_fini();
 506 out9:
 507         tsd_fini();
 508 out8:
 509         kstat_fini();
 510 out7:
 511         proc_fini();
 512 out6:
 513         vn_fini();
 514 out5:
 515         spl_taskq_fini();
 516 out4:
 517         spl_rw_fini();
 518 out3:
 519         spl_mutex_fini();
 520 out2:
 521         spl_kmem_fini();
 522 out1:
 523         debug_fini();
 524
 525         printk(KERN_NOTICE "SPL: Failed to Load Solaris Porting Layer v%s%s"
 526                ", rc = %d\n", SPL_META_VERSION, SPL_DEBUG_STR, rc);
 527         return rc;
 528 }
 529
 530 static void
 531 spl_fini(void)
 532 {
 533         SENTRY;
 534
 535         printk(KERN_NOTICE "SPL: Unloaded module v%s%s\n",
 536                SPL_META_VERSION, SPL_DEBUG_STR);
 537         zlib_fini();
 538         tsd_fini();
 539         kstat_fini();
 540         proc_fini();
 541         vn_fini();
 542         spl_taskq_fini();
 543         spl_rw_fini();
 544         spl_mutex_fini();
 545         spl_kmem_fini();
 546         debug_fini();
 547 }
 548
 549 /* Called when a dependent module is loaded */
 550 void
 551 spl_setup(void)
 552 {
 553         int rc;
 554
 555         /*
 556          * At module load time the pwd is set to '/' on a Solaris system.
 557          * On a Linux system will be set to whatever directory the caller
 558          * was in when executing insmod/modprobe.
 559          */
 560         rc = vn_set_pwd("/");
 561         if (rc)
 562                 printk("SPL: Warning unable to set pwd to '/': %d\n", rc);
 563 }
 564 EXPORT_SYMBOL(spl_setup);
 565
 566 /* Called when a dependent module is unloaded */
 567 void
 568 spl_cleanup(void)
 569 {
 570 }
 571 EXPORT_SYMBOL(spl_cleanup);
 572
 573 module_init(spl_init);
 574 module_exit(spl_fini);
 575
 576 MODULE_AUTHOR("Lawrence Livermore National Labs");
 577 MODULE_DESCRIPTION("Solaris Porting Layer");
 578 MODULE_LICENSE("GPL");