kernel/debug/kdb/kdb_main.c

   1 /*
   2  * Kernel Debugger Architecture Independent Main Code
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 1999-2004 Silicon Graphics, Inc.  All Rights Reserved.
   9  * Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
  10  * Xscale (R) modifications copyright (C) 2003 Intel Corporation.
  11  * Copyright (c) 2009 Wind River Systems, Inc.  All Rights Reserved.
  12  */
  13
  14 #include <linux/ctype.h>
  15 #include <linux/types.h>
  16 #include <linux/string.h>
  17 #include <linux/kernel.h>
  18 #include <linux/kmsg_dump.h>
  19 #include <linux/reboot.h>
  20 #include <linux/sched.h>
  21 #include <linux/sched/loadavg.h>
  22 #include <linux/sched/stat.h>
  23 #include <linux/sched/debug.h>
  24 #include <linux/sysrq.h>
  25 #include <linux/smp.h>
  26 #include <linux/utsname.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/atomic.h>
  29 #include <linux/module.h>
  30 #include <linux/moduleparam.h>
  31 #include <linux/mm.h>
  32 #include <linux/init.h>
  33 #include <linux/kallsyms.h>
  34 #include <linux/kgdb.h>
  35 #include <linux/kdb.h>
  36 #include <linux/notifier.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/delay.h>
  39 #include <linux/nmi.h>
  40 #include <linux/time.h>
  41 #include <linux/ptrace.h>
  42 #include <linux/sysctl.h>
  43 #include <linux/cpu.h>
  44 #include <linux/kdebug.h>
  45 #include <linux/proc_fs.h>
  46 #include <linux/uaccess.h>
  47 #include <linux/slab.h>
  48 #include "kdb_private.h"
  49
  50 #undef  MODULE_PARAM_PREFIX
  51 #define MODULE_PARAM_PREFIX "kdb."
  52
  53 static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;
  54 module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);
  55
  56 char kdb_grep_string[KDB_GREP_STRLEN];
  57 int kdb_grepping_flag;
  58 EXPORT_SYMBOL(kdb_grepping_flag);
  59 int kdb_grep_leading;
  60 int kdb_grep_trailing;
  61
  62 /*
  63  * Kernel debugger state flags
  64  */
  65 int kdb_flags;
  66
  67 /*
  68  * kdb_lock protects updates to kdb_initial_cpu.  Used to
  69  * single thread processors through the kernel debugger.
  70  */
  71 int kdb_initial_cpu = -1;       /* cpu number that owns kdb */
  72 int kdb_nextline = 1;
  73 int kdb_state;                  /* General KDB state */
  74
  75 struct task_struct *kdb_current_task;
  76 EXPORT_SYMBOL(kdb_current_task);
  77 struct pt_regs *kdb_current_regs;
  78
  79 const char *kdb_diemsg;
  80 static int kdb_go_count;
  81 #ifdef CONFIG_KDB_CONTINUE_CATASTROPHIC
  82 static unsigned int kdb_continue_catastrophic =
  83         CONFIG_KDB_CONTINUE_CATASTROPHIC;
  84 #else
  85 static unsigned int kdb_continue_catastrophic;
  86 #endif
  87
  88 /* kdb_commands describes the available commands. */
  89 static kdbtab_t *kdb_commands;
  90 #define KDB_BASE_CMD_MAX 50
  91 static int kdb_max_commands = KDB_BASE_CMD_MAX;
  92 static kdbtab_t kdb_base_commands[KDB_BASE_CMD_MAX];
  93 #define for_each_kdbcmd(cmd, num)                                       \
  94         for ((cmd) = kdb_base_commands, (num) = 0;                      \
  95              num < kdb_max_commands;                                    \
  96              num++, num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++)
  97
  98 typedef struct _kdbmsg {
  99         int     km_diag;        /* kdb diagnostic */
 100         char    *km_msg;        /* Corresponding message text */
 101 } kdbmsg_t;
 102
 103 #define KDBMSG(msgnum, text) \
 104         { KDB_##msgnum, text }
 105
 106 static kdbmsg_t kdbmsgs[] = {
 107         KDBMSG(NOTFOUND, "Command Not Found"),
 108         KDBMSG(ARGCOUNT, "Improper argument count, see usage."),
 109         KDBMSG(BADWIDTH, "Illegal value for BYTESPERWORD use 1, 2, 4 or 8, "
 110                "8 is only allowed on 64 bit systems"),
 111         KDBMSG(BADRADIX, "Illegal value for RADIX use 8, 10 or 16"),
 112         KDBMSG(NOTENV, "Cannot find environment variable"),
 113         KDBMSG(NOENVVALUE, "Environment variable should have value"),
 114         KDBMSG(NOTIMP, "Command not implemented"),
 115         KDBMSG(ENVFULL, "Environment full"),
 116         KDBMSG(ENVBUFFULL, "Environment buffer full"),
 117         KDBMSG(TOOMANYBPT, "Too many breakpoints defined"),
 118 #ifdef CONFIG_CPU_XSCALE
 119         KDBMSG(TOOMANYDBREGS, "More breakpoints than ibcr registers defined"),
 120 #else
 121         KDBMSG(TOOMANYDBREGS, "More breakpoints than db registers defined"),
 122 #endif
 123         KDBMSG(DUPBPT, "Duplicate breakpoint address"),
 124         KDBMSG(BPTNOTFOUND, "Breakpoint not found"),
 125         KDBMSG(BADMODE, "Invalid IDMODE"),
 126         KDBMSG(BADINT, "Illegal numeric value"),
 127         KDBMSG(INVADDRFMT, "Invalid symbolic address format"),
 128         KDBMSG(BADREG, "Invalid register name"),
 129         KDBMSG(BADCPUNUM, "Invalid cpu number"),
 130         KDBMSG(BADLENGTH, "Invalid length field"),
 131         KDBMSG(NOBP, "No Breakpoint exists"),
 132         KDBMSG(BADADDR, "Invalid address"),
 133         KDBMSG(NOPERM, "Permission denied"),
 134 };
 135 #undef KDBMSG
 136
 137 static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
 138
 139
 140 /*
 141  * Initial environment.   This is all kept static and local to
 142  * this file.   We don't want to rely on the memory allocation
 143  * mechanisms in the kernel, so we use a very limited allocate-only
 144  * heap for new and altered environment variables.  The entire
 145  * environment is limited to a fixed number of entries (add more
 146  * to __env[] if required) and a fixed amount of heap (add more to
 147  * KDB_ENVBUFSIZE if required).
 148  */
 149
 150 static char *__env[] = {
 151 #if defined(CONFIG_SMP)
 152  "PROMPT=[%d]kdb> ",
 153 #else
 154  "PROMPT=kdb> ",
 155 #endif
 156  "MOREPROMPT=more> ",
 157  "RADIX=16",
 158  "MDCOUNT=8",                   /* lines of md output */
 159  KDB_PLATFORM_ENV,
 160  "DTABCOUNT=30",
 161  "NOSECT=1",
 162  (char *)0,
 163  (char *)0,
 164  (char *)0,
 165  (char *)0,
 166  (char *)0,
 167  (char *)0,
 168  (char *)0,
 169  (char *)0,
 170  (char *)0,
 171  (char *)0,
 172  (char *)0,
 173  (char *)0,
 174  (char *)0,
 175  (char *)0,
 176  (char *)0,
 177  (char *)0,
 178  (char *)0,
 179  (char *)0,
 180  (char *)0,
 181  (char *)0,
 182  (char *)0,
 183  (char *)0,
 184  (char *)0,
 185  (char *)0,
 186 };
 187
 188 static const int __nenv = ARRAY_SIZE(__env);
 189
 190 struct task_struct *kdb_curr_task(int cpu)
 191 {
 192         struct task_struct *p = curr_task(cpu);
 193 #ifdef  _TIF_MCA_INIT
 194         if ((task_thread_info(p)->flags & _TIF_MCA_INIT) && KDB_TSK(cpu))
 195                 p = krp->p;
 196 #endif
 197         return p;
 198 }
 199
 200 /*
 201  * Check whether the flags of the current command and the permissions
 202  * of the kdb console has allow a command to be run.
 203  */
 204 static inline bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
 205                                    bool no_args)
 206 {
 207         /* permissions comes from userspace so needs massaging slightly */
 208         permissions &= KDB_ENABLE_MASK;
 209         permissions |= KDB_ENABLE_ALWAYS_SAFE;
 210
 211         /* some commands change group when launched with no arguments */
 212         if (no_args)
 213                 permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
 214
 215         flags |= KDB_ENABLE_ALL;
 216
 217         return permissions & flags;
 218 }
 219
 220 /*
 221  * kdbgetenv - This function will return the character string value of
 222  *      an environment variable.
 223  * Parameters:
 224  *      match   A character string representing an environment variable.
 225  * Returns:
 226  *      NULL    No environment variable matches 'match'
 227  *      char*   Pointer to string value of environment variable.
 228  */
 229 char *kdbgetenv(const char *match)
 230 {
 231         char **ep = __env;
 232         int matchlen = strlen(match);
 233         int i;
 234
 235         for (i = 0; i < __nenv; i++) {
 236                 char *e = *ep++;
 237
 238                 if (!e)
 239                         continue;
 240
 241                 if ((strncmp(match, e, matchlen) == 0)
 242                  && ((e[matchlen] == '\0')
 243                    || (e[matchlen] == '='))) {
 244                         char *cp = strchr(e, '=');
 245                         return cp ? ++cp : "";
 246                 }
 247         }
 248         return NULL;
 249 }
 250
 251 /*
 252  * kdballocenv - This function is used to allocate bytes for
 253  *      environment entries.
 254  * Parameters:
 255  *      match   A character string representing a numeric value
 256  * Outputs:
 257  *      *value  the unsigned long representation of the env variable 'match'
 258  * Returns:
 259  *      Zero on success, a kdb diagnostic on failure.
 260  * Remarks:
 261  *      We use a static environment buffer (envbuffer) to hold the values
 262  *      of dynamically generated environment variables (see kdb_set).  Buffer
 263  *      space once allocated is never free'd, so over time, the amount of space
 264  *      (currently 512 bytes) will be exhausted if env variables are changed
 265  *      frequently.
 266  */
 267 static char *kdballocenv(size_t bytes)
 268 {
 269 #define KDB_ENVBUFSIZE  512
 270         static char envbuffer[KDB_ENVBUFSIZE];
 271         static int envbufsize;
 272         char *ep = NULL;
 273
 274         if ((KDB_ENVBUFSIZE - envbufsize) >= bytes) {
 275                 ep = &envbuffer[envbufsize];
 276                 envbufsize += bytes;
 277         }
 278         return ep;
 279 }
 280
 281 /*
 282  * kdbgetulenv - This function will return the value of an unsigned
 283  *      long-valued environment variable.
 284  * Parameters:
 285  *      match   A character string representing a numeric value
 286  * Outputs:
 287  *      *value  the unsigned long represntation of the env variable 'match'
 288  * Returns:
 289  *      Zero on success, a kdb diagnostic on failure.
 290  */
 291 static int kdbgetulenv(const char *match, unsigned long *value)
 292 {
 293         char *ep;
 294
 295         ep = kdbgetenv(match);
 296         if (!ep)
 297                 return KDB_NOTENV;
 298         if (strlen(ep) == 0)
 299                 return KDB_NOENVVALUE;
 300
 301         *value = simple_strtoul(ep, NULL, 0);
 302
 303         return 0;
 304 }
 305
 306 /*
 307  * kdbgetintenv - This function will return the value of an
 308  *      integer-valued environment variable.
 309  * Parameters:
 310  *      match   A character string representing an integer-valued env variable
 311  * Outputs:
 312  *      *value  the integer representation of the environment variable 'match'
 313  * Returns:
 314  *      Zero on success, a kdb diagnostic on failure.
 315  */
 316 int kdbgetintenv(const char *match, int *value)
 317 {
 318         unsigned long val;
 319         int diag;
 320
 321         diag = kdbgetulenv(match, &val);
 322         if (!diag)
 323                 *value = (int) val;
 324         return diag;
 325 }
 326
 327 /*
 328  * kdbgetularg - This function will convert a numeric string into an
 329  *      unsigned long value.
 330  * Parameters:
 331  *      arg     A character string representing a numeric value
 332  * Outputs:
 333  *      *value  the unsigned long represntation of arg.
 334  * Returns:
 335  *      Zero on success, a kdb diagnostic on failure.
 336  */
 337 int kdbgetularg(const char *arg, unsigned long *value)
 338 {
 339         char *endp;
 340         unsigned long val;
 341
 342         val = simple_strtoul(arg, &endp, 0);
 343
 344         if (endp == arg) {
 345                 /*
 346                  * Also try base 16, for us folks too lazy to type the
 347                  * leading 0x...
 348                  */
 349                 val = simple_strtoul(arg, &endp, 16);
 350                 if (endp == arg)
 351                         return KDB_BADINT;
 352         }
 353
 354         *value = val;
 355
 356         return 0;
 357 }
 358
 359 int kdbgetu64arg(const char *arg, u64 *value)
 360 {
 361         char *endp;
 362         u64 val;
 363
 364         val = simple_strtoull(arg, &endp, 0);
 365
 366         if (endp == arg) {
 367
 368                 val = simple_strtoull(arg, &endp, 16);
 369                 if (endp == arg)
 370                         return KDB_BADINT;
 371         }
 372
 373         *value = val;
 374
 375         return 0;
 376 }
 377
 378 /*
 379  * kdb_set - This function implements the 'set' command.  Alter an
 380  *      existing environment variable or create a new one.
 381  */
 382 int kdb_set(int argc, const char **argv)
 383 {
 384         int i;
 385         char *ep;
 386         size_t varlen, vallen;
 387
 388         /*
 389          * we can be invoked two ways:
 390          *   set var=value    argv[1]="var", argv[2]="value"
 391          *   set var = value  argv[1]="var", argv[2]="=", argv[3]="value"
 392          * - if the latter, shift 'em down.
 393          */
 394         if (argc == 3) {
 395                 argv[2] = argv[3];
 396                 argc--;
 397         }
 398
 399         if (argc != 2)
 400                 return KDB_ARGCOUNT;
 401
 402         /*
 403          * Check for internal variables
 404          */
 405         if (strcmp(argv[1], "KDBDEBUG") == 0) {
 406                 unsigned int debugflags;
 407                 char *cp;
 408
 409                 debugflags = simple_strtoul(argv[2], &cp, 0);
 410                 if (cp == argv[2] || debugflags & ~KDB_DEBUG_FLAG_MASK) {
 411                         kdb_printf("kdb: illegal debug flags '%s'\n",
 412                                     argv[2]);
 413                         return 0;
 414                 }
 415                 kdb_flags = (kdb_flags &
 416                              ~(KDB_DEBUG_FLAG_MASK << KDB_DEBUG_FLAG_SHIFT))
 417                         | (debugflags << KDB_DEBUG_FLAG_SHIFT);
 418
 419                 return 0;
 420         }
 421
 422         /*
 423          * Tokenizer squashed the '=' sign.  argv[1] is variable
 424          * name, argv[2] = value.
 425          */
 426         varlen = strlen(argv[1]);
 427         vallen = strlen(argv[2]);
 428         ep = kdballocenv(varlen + vallen + 2);
 429         if (ep == (char *)0)
 430                 return KDB_ENVBUFFULL;
 431
 432         sprintf(ep, "%s=%s", argv[1], argv[2]);
 433
 434         ep[varlen+vallen+1] = '\0';
 435
 436         for (i = 0; i < __nenv; i++) {
 437                 if (__env[i]
 438                  && ((strncmp(__env[i], argv[1], varlen) == 0)
 439                    && ((__env[i][varlen] == '\0')
 440                     || (__env[i][varlen] == '=')))) {
 441                         __env[i] = ep;
 442                         return 0;
 443                 }
 444         }
 445
 446         /*
 447          * Wasn't existing variable.  Fit into slot.
 448          */
 449         for (i = 0; i < __nenv-1; i++) {
 450                 if (__env[i] == (char *)0) {
 451                         __env[i] = ep;
 452                         return 0;
 453                 }
 454         }
 455
 456         return KDB_ENVFULL;
 457 }
 458
 459 static int kdb_check_regs(void)
 460 {
 461         if (!kdb_current_regs) {
 462                 kdb_printf("No current kdb registers."
 463                            "  You may need to select another task\n");
 464                 return KDB_BADREG;
 465         }
 466         return 0;
 467 }
 468
 469 /*
 470  * kdbgetaddrarg - This function is responsible for parsing an
 471  *      address-expression and returning the value of the expression,
 472  *      symbol name, and offset to the caller.
 473  *
 474  *      The argument may consist of a numeric value (decimal or
 475  *      hexidecimal), a symbol name, a register name (preceded by the
 476  *      percent sign), an environment variable with a numeric value
 477  *      (preceded by a dollar sign) or a simple arithmetic expression
 478  *      consisting of a symbol name, +/-, and a numeric constant value
 479  *      (offset).
 480  * Parameters:
 481  *      argc    - count of arguments in argv
 482  *      argv    - argument vector
 483  *      *nextarg - index to next unparsed argument in argv[]
 484  *      regs    - Register state at time of KDB entry
 485  * Outputs:
 486  *      *value  - receives the value of the address-expression
 487  *      *offset - receives the offset specified, if any
 488  *      *name   - receives the symbol name, if any
 489  *      *nextarg - index to next unparsed argument in argv[]
 490  * Returns:
 491  *      zero is returned on success, a kdb diagnostic code is
 492  *      returned on error.
 493  */
 494 int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
 495                   unsigned long *value,  long *offset,
 496                   char **name)
 497 {
 498         unsigned long addr;
 499         unsigned long off = 0;
 500         int positive;
 501         int diag;
 502         int found = 0;
 503         char *symname;
 504         char symbol = '\0';
 505         char *cp;
 506         kdb_symtab_t symtab;
 507
 508         /*
 509          * If the enable flags prohibit both arbitrary memory access
 510          * and flow control then there are no reasonable grounds to
 511          * provide symbol lookup.
 512          */
 513         if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
 514                              kdb_cmd_enabled, false))
 515                 return KDB_NOPERM;
 516
 517         /*
 518          * Process arguments which follow the following syntax:
 519          *
 520          *  symbol | numeric-address [+/- numeric-offset]
 521          *  %register
 522          *  $environment-variable
 523          */
 524
 525         if (*nextarg > argc)
 526                 return KDB_ARGCOUNT;
 527
 528         symname = (char *)argv[*nextarg];
 529
 530         /*
 531          * If there is no whitespace between the symbol
 532          * or address and the '+' or '-' symbols, we
 533          * remember the character and replace it with a
 534          * null so the symbol/value can be properly parsed
 535          */
 536         cp = strpbrk(symname, "+-");
 537         if (cp != NULL) {
 538                 symbol = *cp;
 539                 *cp++ = '\0';
 540         }
 541
 542         if (symname[0] == '$') {
 543                 diag = kdbgetulenv(&symname[1], &addr);
 544                 if (diag)
 545                         return diag;
 546         } else if (symname[0] == '%') {
 547                 diag = kdb_check_regs();
 548                 if (diag)
 549                         return diag;
 550                 /* Implement register values with % at a later time as it is
 551                  * arch optional.
 552                  */
 553                 return KDB_NOTIMP;
 554         } else {
 555                 found = kdbgetsymval(symname, &symtab);
 556                 if (found) {
 557                         addr = symtab.sym_start;
 558                 } else {
 559                         diag = kdbgetularg(argv[*nextarg], &addr);
 560                         if (diag)
 561                                 return diag;
 562                 }
 563         }
 564
 565         if (!found)
 566                 found = kdbnearsym(addr, &symtab);
 567
 568         (*nextarg)++;
 569
 570         if (name)
 571                 *name = symname;
 572         if (value)
 573                 *value = addr;
 574         if (offset && name && *name)
 575                 *offset = addr - symtab.sym_start;
 576
 577         if ((*nextarg > argc)
 578          && (symbol == '\0'))
 579                 return 0;
 580
 581         /*
 582          * check for +/- and offset
 583          */
 584
 585         if (symbol == '\0') {
 586                 if ((argv[*nextarg][0] != '+')
 587                  && (argv[*nextarg][0] != '-')) {
 588                         /*
 589                          * Not our argument.  Return.
 590                          */
 591                         return 0;
 592                 } else {
 593                         positive = (argv[*nextarg][0] == '+');
 594                         (*nextarg)++;
 595                 }
 596         } else
 597                 positive = (symbol == '+');
 598
 599         /*
 600          * Now there must be an offset!
 601          */
 602         if ((*nextarg > argc)
 603          && (symbol == '\0')) {
 604                 return KDB_INVADDRFMT;
 605         }
 606
 607         if (!symbol) {
 608                 cp = (char *)argv[*nextarg];
 609                 (*nextarg)++;
 610         }
 611
 612         diag = kdbgetularg(cp, &off);
 613         if (diag)
 614                 return diag;
 615
 616         if (!positive)
 617                 off = -off;
 618
 619         if (offset)
 620                 *offset += off;
 621
 622         if (value)
 623                 *value += off;
 624
 625         return 0;
 626 }
 627
 628 static void kdb_cmderror(int diag)
 629 {
 630         int i;
 631
 632         if (diag >= 0) {
 633                 kdb_printf("no error detected (diagnostic is %d)\n", diag);
 634                 return;
 635         }
 636
 637         for (i = 0; i < __nkdb_err; i++) {
 638                 if (kdbmsgs[i].km_diag == diag) {
 639                         kdb_printf("diag: %d: %s\n", diag, kdbmsgs[i].km_msg);
 640                         return;
 641                 }
 642         }
 643
 644         kdb_printf("Unknown diag %d\n", -diag);
 645 }
 646
 647 /*
 648  * kdb_defcmd, kdb_defcmd2 - This function implements the 'defcmd'
 649  *      command which defines one command as a set of other commands,
 650  *      terminated by endefcmd.  kdb_defcmd processes the initial
 651  *      'defcmd' command, kdb_defcmd2 is invoked from kdb_parse for
 652  *      the following commands until 'endefcmd'.
 653  * Inputs:
 654  *      argc    argument count
 655  *      argv    argument vector
 656  * Returns:
 657  *      zero for success, a kdb diagnostic if error
 658  */
 659 struct defcmd_set {
 660         int count;
 661         int usable;
 662         char *name;
 663         char *usage;
 664         char *help;
 665         char **command;
 666 };
 667 static struct defcmd_set *defcmd_set;
 668 static int defcmd_set_count;
 669 static int defcmd_in_progress;
 670
 671 /* Forward references */
 672 static int kdb_exec_defcmd(int argc, const char **argv);
 673
 674 static int kdb_defcmd2(const char *cmdstr, const char *argv0)
 675 {
 676         struct defcmd_set *s = defcmd_set + defcmd_set_count - 1;
 677         char **save_command = s->command;
 678         if (strcmp(argv0, "endefcmd") == 0) {
 679                 defcmd_in_progress = 0;
 680                 if (!s->count)
 681                         s->usable = 0;
 682                 if (s->usable)
 683                         /* macros are always safe because when executed each
 684                          * internal command re-enters kdb_parse() and is
 685                          * safety checked individually.
 686                          */
 687                         kdb_register_flags(s->name, kdb_exec_defcmd, s->usage,
 688                                            s->help, 0,
 689                                            KDB_ENABLE_ALWAYS_SAFE);
 690                 return 0;
 691         }
 692         if (!s->usable)
 693                 return KDB_NOTIMP;
 694         s->command = kzalloc((s->count + 1) * sizeof(*(s->command)), GFP_KDB);
 695         if (!s->command) {
 696                 kdb_printf("Could not allocate new kdb_defcmd table for %s\n",
 697                            cmdstr);
 698                 s->usable = 0;
 699                 return KDB_NOTIMP;
 700         }
 701         memcpy(s->command, save_command, s->count * sizeof(*(s->command)));
 702         s->command[s->count++] = kdb_strdup(cmdstr, GFP_KDB);
 703         kfree(save_command);
 704         return 0;
 705 }
 706
 707 static int kdb_defcmd(int argc, const char **argv)
 708 {
 709         struct defcmd_set *save_defcmd_set = defcmd_set, *s;
 710         if (defcmd_in_progress) {
 711                 kdb_printf("kdb: nested defcmd detected, assuming missing "
 712                            "endefcmd\n");
 713                 kdb_defcmd2("endefcmd", "endefcmd");
 714         }
 715         if (argc == 0) {
 716                 int i;
 717                 for (s = defcmd_set; s < defcmd_set + defcmd_set_count; ++s) {
 718                         kdb_printf("defcmd %s \"%s\" \"%s\"\n", s->name,
 719                                    s->usage, s->help);
 720                         for (i = 0; i < s->count; ++i)
 721                                 kdb_printf("%s", s->command[i]);
 722                         kdb_printf("endefcmd\n");
 723                 }
 724                 return 0;
 725         }
 726         if (argc != 3)
 727                 return KDB_ARGCOUNT;
 728         if (in_dbg_master()) {
 729                 kdb_printf("Command only available during kdb_init()\n");
 730                 return KDB_NOTIMP;
 731         }
 732         defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
 733                              GFP_KDB);
 734         if (!defcmd_set)
 735                 goto fail_defcmd;
 736         memcpy(defcmd_set, save_defcmd_set,
 737                defcmd_set_count * sizeof(*defcmd_set));
 738         s = defcmd_set + defcmd_set_count;
 739         memset(s, 0, sizeof(*s));
 740         s->usable = 1;
 741         s->name = kdb_strdup(argv[1], GFP_KDB);
 742         if (!s->name)
 743                 goto fail_name;
 744         s->usage = kdb_strdup(argv[2], GFP_KDB);
 745         if (!s->usage)
 746                 goto fail_usage;
 747         s->help = kdb_strdup(argv[3], GFP_KDB);
 748         if (!s->help)
 749                 goto fail_help;
 750         if (s->usage[0] == '"') {
 751                 strcpy(s->usage, argv[2]+1);
 752                 s->usage[strlen(s->usage)-1] = '\0';
 753         }
 754         if (s->help[0] == '"') {
 755                 strcpy(s->help, argv[3]+1);
 756                 s->help[strlen(s->help)-1] = '\0';
 757         }
 758         ++defcmd_set_count;
 759         defcmd_in_progress = 1;
 760         kfree(save_defcmd_set);
 761         return 0;
 762 fail_help:
 763         kfree(s->usage);
 764 fail_usage:
 765         kfree(s->name);
 766 fail_name:
 767         kfree(defcmd_set);
 768 fail_defcmd:
 769         kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]);
 770         defcmd_set = save_defcmd_set;
 771         return KDB_NOTIMP;
 772 }
 773
 774 /*
 775  * kdb_exec_defcmd - Execute the set of commands associated with this
 776  *      defcmd name.
 777  * Inputs:
 778  *      argc    argument count
 779  *      argv    argument vector
 780  * Returns:
 781  *      zero for success, a kdb diagnostic if error
 782  */
 783 static int kdb_exec_defcmd(int argc, const char **argv)
 784 {
 785         int i, ret;
 786         struct defcmd_set *s;
 787         if (argc != 0)
 788                 return KDB_ARGCOUNT;
 789         for (s = defcmd_set, i = 0; i < defcmd_set_count; ++i, ++s) {
 790                 if (strcmp(s->name, argv[0]) == 0)
 791                         break;
 792         }
 793         if (i == defcmd_set_count) {
 794                 kdb_printf("kdb_exec_defcmd: could not find commands for %s\n",
 795                            argv[0]);
 796                 return KDB_NOTIMP;
 797         }
 798         for (i = 0; i < s->count; ++i) {
 799                 /* Recursive use of kdb_parse, do not use argv after
 800                  * this point */
 801                 argv = NULL;
 802                 kdb_printf("[%s]kdb> %s\n", s->name, s->command[i]);
 803                 ret = kdb_parse(s->command[i]);
 804                 if (ret)
 805                         return ret;
 806         }
 807         return 0;
 808 }
 809
 810 /* Command history */
 811 #define KDB_CMD_HISTORY_COUNT   32
 812 #define CMD_BUFLEN              200     /* kdb_printf: max printline
 813                                          * size == 256 */
 814 static unsigned int cmd_head, cmd_tail;
 815 static unsigned int cmdptr;
 816 static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN];
 817 static char cmd_cur[CMD_BUFLEN];
 818
 819 /*
 820  * The "str" argument may point to something like  | grep xyz
 821  */
 822 static void parse_grep(const char *str)
 823 {
 824         int     len;
 825         char    *cp = (char *)str, *cp2;
 826
 827         /* sanity check: we should have been called with the \ first */
 828         if (*cp != '|')
 829                 return;
 830         cp++;
 831         while (isspace(*cp))
 832                 cp++;
 833         if (strncmp(cp, "grep ", 5)) {
 834                 kdb_printf("invalid 'pipe', see grephelp\n");
 835                 return;
 836         }
 837         cp += 5;
 838         while (isspace(*cp))
 839                 cp++;
 840         cp2 = strchr(cp, '\n');
 841         if (cp2)
 842                 *cp2 = '\0'; /* remove the trailing newline */
 843         len = strlen(cp);
 844         if (len == 0) {
 845                 kdb_printf("invalid 'pipe', see grephelp\n");
 846                 return;
 847         }
 848         /* now cp points to a nonzero length search string */
 849         if (*cp == '"') {
 850                 /* allow it be "x y z" by removing the "'s - there must
 851                    be two of them */
 852                 cp++;
 853                 cp2 = strchr(cp, '"');
 854                 if (!cp2) {
 855                         kdb_printf("invalid quoted string, see grephelp\n");
 856                         return;
 857                 }
 858                 *cp2 = '\0'; /* end the string where the 2nd " was */
 859         }
 860         kdb_grep_leading = 0;
 861         if (*cp == '^') {
 862                 kdb_grep_leading = 1;
 863                 cp++;
 864         }
 865         len = strlen(cp);
 866         kdb_grep_trailing = 0;
 867         if (*(cp+len-1) == '$') {
 868                 kdb_grep_trailing = 1;
 869                 *(cp+len-1) = '\0';
 870         }
 871         len = strlen(cp);
 872         if (!len)
 873                 return;
 874         if (len >= KDB_GREP_STRLEN) {
 875                 kdb_printf("search string too long\n");
 876                 return;
 877         }
 878         strcpy(kdb_grep_string, cp);
 879         kdb_grepping_flag++;
 880         return;
 881 }
 882
 883 /*
 884  * kdb_parse - Parse the command line, search the command table for a
 885  *      matching command and invoke the command function.  This
 886  *      function may be called recursively, if it is, the second call
 887  *      will overwrite argv and cbuf.  It is the caller's
 888  *      responsibility to save their argv if they recursively call
 889  *      kdb_parse().
 890  * Parameters:
 891  *      cmdstr  The input command line to be parsed.
 892  *      regs    The registers at the time kdb was entered.
 893  * Returns:
 894  *      Zero for success, a kdb diagnostic if failure.
 895  * Remarks:
 896  *      Limited to 20 tokens.
 897  *
 898  *      Real rudimentary tokenization. Basically only whitespace
 899  *      is considered a token delimeter (but special consideration
 900  *      is taken of the '=' sign as used by the 'set' command).
 901  *
 902  *      The algorithm used to tokenize the input string relies on
 903  *      there being at least one whitespace (or otherwise useless)
 904  *      character between tokens as the character immediately following
 905  *      the token is altered in-place to a null-byte to terminate the
 906  *      token string.
 907  */
 908
 909 #define MAXARGC 20
 910
 911 int kdb_parse(const char *cmdstr)
 912 {
 913         static char *argv[MAXARGC];
 914         static int argc;
 915         static char cbuf[CMD_BUFLEN+2];
 916         char *cp;
 917         char *cpp, quoted;
 918         kdbtab_t *tp;
 919         int i, escaped, ignore_errors = 0, check_grep = 0;
 920
 921         /*
 922          * First tokenize the command string.
 923          */
 924         cp = (char *)cmdstr;
 925
 926         if (KDB_FLAG(CMD_INTERRUPT)) {
 927                 /* Previous command was interrupted, newline must not
 928                  * repeat the command */
 929                 KDB_FLAG_CLEAR(CMD_INTERRUPT);
 930                 KDB_STATE_SET(PAGER);
 931                 argc = 0;       /* no repeat */
 932         }
 933
 934         if (*cp != '\n' && *cp != '\0') {
 935                 argc = 0;
 936                 cpp = cbuf;
 937                 while (*cp) {
 938                         /* skip whitespace */
 939                         while (isspace(*cp))
 940                                 cp++;
 941                         if ((*cp == '\0') || (*cp == '\n') ||
 942                             (*cp == '#' && !defcmd_in_progress))
 943                                 break;
 944                         /* special case: check for | grep pattern */
 945                         if (*cp == '|') {
 946                                 check_grep++;
 947                                 break;
 948                         }
 949                         if (cpp >= cbuf + CMD_BUFLEN) {
 950                                 kdb_printf("kdb_parse: command buffer "
 951                                            "overflow, command ignored\n%s\n",
 952                                            cmdstr);
 953                                 return KDB_NOTFOUND;
 954                         }
 955                         if (argc >= MAXARGC - 1) {
 956                                 kdb_printf("kdb_parse: too many arguments, "
 957                                            "command ignored\n%s\n", cmdstr);
 958                                 return KDB_NOTFOUND;
 959                         }
 960                         argv[argc++] = cpp;
 961                         escaped = 0;
 962                         quoted = '\0';
 963                         /* Copy to next unquoted and unescaped
 964                          * whitespace or '=' */
 965                         while (*cp && *cp != '\n' &&
 966                                (escaped || quoted || !isspace(*cp))) {
 967                                 if (cpp >= cbuf + CMD_BUFLEN)
 968                                         break;
 969                                 if (escaped) {
 970                                         escaped = 0;
 971                                         *cpp++ = *cp++;
 972                                         continue;
 973                                 }
 974                                 if (*cp == '\\') {
 975                                         escaped = 1;
 976                                         ++cp;
 977                                         continue;
 978                                 }
 979                                 if (*cp == quoted)
 980                                         quoted = '\0';
 981                                 else if (*cp == '\'' || *cp == '"')
 982                                         quoted = *cp;
 983                                 *cpp = *cp++;
 984                                 if (*cpp == '=' && !quoted)
 985                                         break;
 986                                 ++cpp;
 987                         }
 988                         *cpp++ = '\0';  /* Squash a ws or '=' character */
 989                 }
 990         }
 991         if (!argc)
 992                 return 0;
 993         if (check_grep)
 994                 parse_grep(cp);
 995         if (defcmd_in_progress) {
 996                 int result = kdb_defcmd2(cmdstr, argv[0]);
 997                 if (!defcmd_in_progress) {
 998                         argc = 0;       /* avoid repeat on endefcmd */
 999                         *(argv[0]) = '\0';
1000                 }
1001                 return result;
1002         }
1003         if (argv[0][0] == '-' && argv[0][1] &&
1004             (argv[0][1] < '0' || argv[0][1] > '9')) {
1005                 ignore_errors = 1;
1006                 ++argv[0];
1007         }
1008
1009         for_each_kdbcmd(tp, i) {
1010                 if (tp->cmd_name) {
1011                         /*
1012                          * If this command is allowed to be abbreviated,
1013                          * check to see if this is it.
1014                          */
1015
1016                         if (tp->cmd_minlen
1017                          && (strlen(argv[0]) <= tp->cmd_minlen)) {
1018                                 if (strncmp(argv[0],
1019                                             tp->cmd_name,
1020                                             tp->cmd_minlen) == 0) {
1021                                         break;
1022                                 }
1023                         }
1024
1025                         if (strcmp(argv[0], tp->cmd_name) == 0)
1026                                 break;
1027                 }
1028         }
1029
1030         /*
1031          * If we don't find a command by this name, see if the first
1032          * few characters of this match any of the known commands.
1033          * e.g., md1c20 should match md.
1034          */
1035         if (i == kdb_max_commands) {
1036                 for_each_kdbcmd(tp, i) {
1037                         if (tp->cmd_name) {
1038                                 if (strncmp(argv[0],
1039                                             tp->cmd_name,
1040                                             strlen(tp->cmd_name)) == 0) {
1041                                         break;
1042                                 }
1043                         }
1044                 }
1045         }
1046
1047         if (i < kdb_max_commands) {
1048                 int result;
1049
1050                 if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1))
1051                         return KDB_NOPERM;
1052
1053                 KDB_STATE_SET(CMD);
1054                 result = (*tp->cmd_func)(argc-1, (const char **)argv);
1055                 if (result && ignore_errors && result > KDB_CMD_GO)
1056                         result = 0;
1057                 KDB_STATE_CLEAR(CMD);
1058
1059                 if (tp->cmd_flags & KDB_REPEAT_WITH_ARGS)
1060                         return result;
1061
1062                 argc = tp->cmd_flags & KDB_REPEAT_NO_ARGS ? 1 : 0;
1063                 if (argv[argc])
1064                         *(argv[argc]) = '\0';
1065                 return result;
1066         }
1067
1068         /*
1069          * If the input with which we were presented does not
1070          * map to an existing command, attempt to parse it as an
1071          * address argument and display the result.   Useful for
1072          * obtaining the address of a variable, or the nearest symbol
1073          * to an address contained in a register.
1074          */
1075         {
1076                 unsigned long value;
1077                 char *name = NULL;
1078                 long offset;
1079                 int nextarg = 0;
1080
1081                 if (kdbgetaddrarg(0, (const char **)argv, &nextarg,
1082                                   &value, &offset, &name)) {
1083                         return KDB_NOTFOUND;
1084                 }
1085
1086                 kdb_printf("%s = ", argv[0]);
1087                 kdb_symbol_print(value, NULL, KDB_SP_DEFAULT);
1088                 kdb_printf("\n");
1089                 return 0;
1090         }
1091 }
1092
1093
1094 static int handle_ctrl_cmd(char *cmd)
1095 {
1096 #define CTRL_P  16
1097 #define CTRL_N  14
1098
1099         /* initial situation */
1100         if (cmd_head == cmd_tail)
1101                 return 0;
1102         switch (*cmd) {
1103         case CTRL_P:
1104                 if (cmdptr != cmd_tail)
1105                         cmdptr = (cmdptr-1) % KDB_CMD_HISTORY_COUNT;
1106                 strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1107                 return 1;
1108         case CTRL_N:
1109                 if (cmdptr != cmd_head)
1110                         cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT;
1111                 strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1112                 return 1;
1113         }
1114         return 0;
1115 }
1116
1117 /*
1118  * kdb_reboot - This function implements the 'reboot' command.  Reboot
1119  *      the system immediately, or loop for ever on failure.
1120  */
1121 static int kdb_reboot(int argc, const char **argv)
1122 {
1123         emergency_restart();
1124         kdb_printf("Hmm, kdb_reboot did not reboot, spinning here\n");
1125         while (1)
1126                 cpu_relax();
1127         /* NOTREACHED */
1128         return 0;
1129 }
1130
1131 static void kdb_dumpregs(struct pt_regs *regs)
1132 {
1133         int old_lvl = console_loglevel;
1134         console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
1135         kdb_trap_printk++;
1136         show_regs(regs);
1137         kdb_trap_printk--;
1138         kdb_printf("\n");
1139         console_loglevel = old_lvl;
1140 }
1141
1142 void kdb_set_current_task(struct task_struct *p)
1143 {
1144         kdb_current_task = p;
1145
1146         if (kdb_task_has_cpu(p)) {
1147                 kdb_current_regs = KDB_TSKREGS(kdb_process_cpu(p));
1148                 return;
1149         }
1150         kdb_current_regs = NULL;
1151 }
1152
1153 /*
1154  * kdb_local - The main code for kdb.  This routine is invoked on a
1155  *      specific processor, it is not global.  The main kdb() routine
1156  *      ensures that only one processor at a time is in this routine.
1157  *      This code is called with the real reason code on the first
1158  *      entry to a kdb session, thereafter it is called with reason
1159  *      SWITCH, even if the user goes back to the original cpu.
1160  * Inputs:
1161  *      reason          The reason KDB was invoked
1162  *      error           The hardware-defined error code
1163  *      regs            The exception frame at time of fault/breakpoint.
1164  *      db_result       Result code from the break or debug point.
1165  * Returns:
1166  *      0       KDB was invoked for an event which it wasn't responsible
1167  *      1       KDB handled the event for which it was invoked.
1168  *      KDB_CMD_GO      User typed 'go'.
1169  *      KDB_CMD_CPU     User switched to another cpu.
1170  *      KDB_CMD_SS      Single step.
1171  */
1172 static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
1173                      kdb_dbtrap_t db_result)
1174 {
1175         char *cmdbuf;
1176         int diag;
1177         struct task_struct *kdb_current =
1178                 kdb_curr_task(raw_smp_processor_id());
1179
1180         KDB_DEBUG_STATE("kdb_local 1", reason);
1181         kdb_go_count = 0;
1182         if (reason == KDB_REASON_DEBUG) {
1183                 /* special case below */
1184         } else {
1185                 kdb_printf("\nEntering kdb (current=0x%p, pid %d) ",
1186                            kdb_current, kdb_current ? kdb_current->pid : 0);
1187 #if defined(CONFIG_SMP)
1188                 kdb_printf("on processor %d ", raw_smp_processor_id());
1189 #endif
1190         }
1191
1192         switch (reason) {
1193         case KDB_REASON_DEBUG:
1194         {
1195                 /*
1196                  * If re-entering kdb after a single step
1197                  * command, don't print the message.
1198                  */
1199                 switch (db_result) {
1200                 case KDB_DB_BPT:
1201                         kdb_printf("\nEntering kdb (0x%p, pid %d) ",
1202                                    kdb_current, kdb_current->pid);
1203 #if defined(CONFIG_SMP)
1204                         kdb_printf("on processor %d ", raw_smp_processor_id());
1205 #endif
1206                         kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
1207                                    instruction_pointer(regs));
1208                         break;
1209                 case KDB_DB_SS:
1210                         break;
1211                 case KDB_DB_SSBPT:
1212                         KDB_DEBUG_STATE("kdb_local 4", reason);
1213                         return 1;       /* kdba_db_trap did the work */
1214                 default:
1215                         kdb_printf("kdb: Bad result from kdba_db_trap: %d\n",
1216                                    db_result);
1217                         break;
1218                 }
1219
1220         }
1221                 break;
1222         case KDB_REASON_ENTER:
1223                 if (KDB_STATE(KEYBOARD))
1224                         kdb_printf("due to Keyboard Entry\n");
1225                 else
1226                         kdb_printf("due to KDB_ENTER()\n");
1227                 break;
1228         case KDB_REASON_KEYBOARD:
1229                 KDB_STATE_SET(KEYBOARD);
1230                 kdb_printf("due to Keyboard Entry\n");
1231                 break;
1232         case KDB_REASON_ENTER_SLAVE:
1233                 /* drop through, slaves only get released via cpu switch */
1234         case KDB_REASON_SWITCH:
1235                 kdb_printf("due to cpu switch\n");
1236                 break;
1237         case KDB_REASON_OOPS:
1238                 kdb_printf("Oops: %s\n", kdb_diemsg);
1239                 kdb_printf("due to oops @ " kdb_machreg_fmt "\n",
1240                            instruction_pointer(regs));
1241                 kdb_dumpregs(regs);
1242                 break;
1243         case KDB_REASON_SYSTEM_NMI:
1244                 kdb_printf("due to System NonMaskable Interrupt\n");
1245                 break;
1246         case KDB_REASON_NMI:
1247                 kdb_printf("due to NonMaskable Interrupt @ "
1248                            kdb_machreg_fmt "\n",
1249                            instruction_pointer(regs));
1250                 break;
1251         case KDB_REASON_SSTEP:
1252         case KDB_REASON_BREAK:
1253                 kdb_printf("due to %s @ " kdb_machreg_fmt "\n",
1254                            reason == KDB_REASON_BREAK ?
1255                            "Breakpoint" : "SS trap", instruction_pointer(regs));
1256                 /*
1257                  * Determine if this breakpoint is one that we
1258                  * are interested in.
1259                  */
1260                 if (db_result != KDB_DB_BPT) {
1261                         kdb_printf("kdb: error return from kdba_bp_trap: %d\n",
1262                                    db_result);
1263                         KDB_DEBUG_STATE("kdb_local 6", reason);
1264                         return 0;       /* Not for us, dismiss it */
1265                 }
1266                 break;
1267         case KDB_REASON_RECURSE:
1268                 kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n",
1269                            instruction_pointer(regs));
1270                 break;
1271         default:
1272                 kdb_printf("kdb: unexpected reason code: %d\n", reason);
1273                 KDB_DEBUG_STATE("kdb_local 8", reason);
1274                 return 0;       /* Not for us, dismiss it */
1275         }
1276
1277         while (1) {
1278                 /*
1279                  * Initialize pager context.
1280                  */
1281                 kdb_nextline = 1;
1282                 KDB_STATE_CLEAR(SUPPRESS);
1283                 kdb_grepping_flag = 0;
1284                 /* ensure the old search does not leak into '/' commands */
1285                 kdb_grep_string[0] = '\0';
1286
1287                 cmdbuf = cmd_cur;
1288                 *cmdbuf = '\0';
1289                 *(cmd_hist[cmd_head]) = '\0';
1290
1291 do_full_getstr:
1292 #if defined(CONFIG_SMP)
1293                 snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
1294                          raw_smp_processor_id());
1295 #else
1296                 snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"));
1297 #endif
1298                 if (defcmd_in_progress)
1299                         strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
1300
1301                 /*
1302                  * Fetch command from keyboard
1303                  */
1304                 cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str);
1305                 if (*cmdbuf != '\n') {
1306                         if (*cmdbuf < 32) {
1307                                 if (cmdptr == cmd_head) {
1308                                         strncpy(cmd_hist[cmd_head], cmd_cur,
1309                                                 CMD_BUFLEN);
1310                                         *(cmd_hist[cmd_head] +
1311                                           strlen(cmd_hist[cmd_head])-1) = '\0';
1312                                 }
1313                                 if (!handle_ctrl_cmd(cmdbuf))
1314                                         *(cmd_cur+strlen(cmd_cur)-1) = '\0';
1315                                 cmdbuf = cmd_cur;
1316                                 goto do_full_getstr;
1317                         } else {
1318                                 strncpy(cmd_hist[cmd_head], cmd_cur,
1319                                         CMD_BUFLEN);
1320                         }
1321
1322                         cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT;
1323                         if (cmd_head == cmd_tail)
1324                                 cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT;
1325                 }
1326
1327                 cmdptr = cmd_head;
1328                 diag = kdb_parse(cmdbuf);
1329                 if (diag == KDB_NOTFOUND) {
1330                         kdb_printf("Unknown kdb command: '%s'\n", cmdbuf);
1331                         diag = 0;
1332                 }
1333                 if (diag == KDB_CMD_GO
1334                  || diag == KDB_CMD_CPU
1335                  || diag == KDB_CMD_SS
1336                  || diag == KDB_CMD_KGDB)
1337                         break;
1338
1339                 if (diag)
1340                         kdb_cmderror(diag);
1341         }
1342         KDB_DEBUG_STATE("kdb_local 9", diag);
1343         return diag;
1344 }
1345
1346
1347 /*
1348  * kdb_print_state - Print the state data for the current processor
1349  *      for debugging.
1350  * Inputs:
1351  *      text            Identifies the debug point
1352  *      value           Any integer value to be printed, e.g. reason code.
1353  */
1354 void kdb_print_state(const char *text, int value)
1355 {
1356         kdb_printf("state: %s cpu %d value %d initial %d state %x\n",
1357                    text, raw_smp_processor_id(), value, kdb_initial_cpu,
1358                    kdb_state);
1359 }
1360
1361 /*
1362  * kdb_main_loop - After initial setup and assignment of the
1363  *      controlling cpu, all cpus are in this loop.  One cpu is in
1364  *      control and will issue the kdb prompt, the others will spin
1365  *      until 'go' or cpu switch.
1366  *
1367  *      To get a consistent view of the kernel stacks for all
1368  *      processes, this routine is invoked from the main kdb code via
1369  *      an architecture specific routine.  kdba_main_loop is
1370  *      responsible for making the kernel stacks consistent for all
1371  *      processes, there should be no difference between a blocked
1372  *      process and a running process as far as kdb is concerned.
1373  * Inputs:
1374  *      reason          The reason KDB was invoked
1375  *      error           The hardware-defined error code
1376  *      reason2         kdb's current reason code.
1377  *                      Initially error but can change
1378  *                      according to kdb state.
1379  *      db_result       Result code from break or debug point.
1380  *      regs            The exception frame at time of fault/breakpoint.
1381  *                      should always be valid.
1382  * Returns:
1383  *      0       KDB was invoked for an event which it wasn't responsible
1384  *      1       KDB handled the event for which it was invoked.
1385  */
1386 int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
1387               kdb_dbtrap_t db_result, struct pt_regs *regs)
1388 {
1389         int result = 1;
1390         /* Stay in kdb() until 'go', 'ss[b]' or an error */
1391         while (1) {
1392                 /*
1393                  * All processors except the one that is in control
1394                  * will spin here.
1395                  */
1396                 KDB_DEBUG_STATE("kdb_main_loop 1", reason);
1397                 while (KDB_STATE(HOLD_CPU)) {
1398                         /* state KDB is turned off by kdb_cpu to see if the
1399                          * other cpus are still live, each cpu in this loop
1400                          * turns it back on.
1401                          */
1402                         if (!KDB_STATE(KDB))
1403                                 KDB_STATE_SET(KDB);
1404                 }
1405
1406                 KDB_STATE_CLEAR(SUPPRESS);
1407                 KDB_DEBUG_STATE("kdb_main_loop 2", reason);
1408                 if (KDB_STATE(LEAVING))
1409                         break;  /* Another cpu said 'go' */
1410                 /* Still using kdb, this processor is in control */
1411                 result = kdb_local(reason2, error, regs, db_result);
1412                 KDB_DEBUG_STATE("kdb_main_loop 3", result);
1413
1414                 if (result == KDB_CMD_CPU)
1415                         break;
1416
1417                 if (result == KDB_CMD_SS) {
1418                         KDB_STATE_SET(DOING_SS);
1419                         break;
1420                 }
1421
1422                 if (result == KDB_CMD_KGDB) {
1423                         if (!KDB_STATE(DOING_KGDB))
1424                                 kdb_printf("Entering please attach debugger "
1425                                            "or use $D#44+ or $3#33\n");
1426                         break;
1427                 }
1428                 if (result && result != 1 && result != KDB_CMD_GO)
1429                         kdb_printf("\nUnexpected kdb_local return code %d\n",
1430                                    result);
1431                 KDB_DEBUG_STATE("kdb_main_loop 4", reason);
1432                 break;
1433         }
1434         if (KDB_STATE(DOING_SS))
1435                 KDB_STATE_CLEAR(SSBPT);
1436
1437         /* Clean up any keyboard devices before leaving */
1438         kdb_kbd_cleanup_state();
1439
1440         return result;
1441 }
1442
1443 /*
1444  * kdb_mdr - This function implements the guts of the 'mdr', memory
1445  * read command.
1446  *      mdr  <addr arg>,<byte count>
1447  * Inputs:
1448  *      addr    Start address
1449  *      count   Number of bytes
1450  * Returns:
1451  *      Always 0.  Any errors are detected and printed by kdb_getarea.
1452  */
1453 static int kdb_mdr(unsigned long addr, unsigned int count)
1454 {
1455         unsigned char c;
1456         while (count--) {
1457                 if (kdb_getarea(c, addr))
1458                         return 0;
1459                 kdb_printf("%02x", c);
1460                 addr++;
1461         }
1462         kdb_printf("\n");
1463         return 0;
1464 }
1465
1466 /*
1467  * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4',
1468  *      'md8' 'mdr' and 'mds' commands.
1469  *
1470  *      md|mds  [<addr arg> [<line count> [<radix>]]]
1471  *      mdWcN   [<addr arg> [<line count> [<radix>]]]
1472  *              where W = is the width (1, 2, 4 or 8) and N is the count.
1473  *              for eg., md1c20 reads 20 bytes, 1 at a time.
1474  *      mdr  <addr arg>,<byte count>
1475  */
1476 static void kdb_md_line(const char *fmtstr, unsigned long addr,
1477                         int symbolic, int nosect, int bytesperword,
1478                         int num, int repeat, int phys)
1479 {
1480         /* print just one line of data */
1481         kdb_symtab_t symtab;
1482         char cbuf[32];
1483         char *c = cbuf;
1484         int i;
1485         unsigned long word;
1486
1487         memset(cbuf, '\0', sizeof(cbuf));
1488         if (phys)
1489                 kdb_printf("phys " kdb_machreg_fmt0 " ", addr);
1490         else
1491                 kdb_printf(kdb_machreg_fmt0 " ", addr);
1492
1493         for (i = 0; i < num && repeat--; i++) {
1494                 if (phys) {
1495                         if (kdb_getphysword(&word, addr, bytesperword))
1496                                 break;
1497                 } else if (kdb_getword(&word, addr, bytesperword))
1498                         break;
1499                 kdb_printf(fmtstr, word);
1500                 if (symbolic)
1501                         kdbnearsym(word, &symtab);
1502                 else
1503                         memset(&symtab, 0, sizeof(symtab));
1504                 if (symtab.sym_name) {
1505                         kdb_symbol_print(word, &symtab, 0);
1506                         if (!nosect) {
1507                                 kdb_printf("\n");
1508                                 kdb_printf("                       %s %s "
1509                                            kdb_machreg_fmt " "
1510                                            kdb_machreg_fmt " "
1511                                            kdb_machreg_fmt, symtab.mod_name,
1512                                            symtab.sec_name, symtab.sec_start,
1513                                            symtab.sym_start, symtab.sym_end);
1514                         }
1515                         addr += bytesperword;
1516                 } else {
1517                         union {
1518                                 u64 word;
1519                                 unsigned char c[8];
1520                         } wc;
1521                         unsigned char *cp;
1522 #ifdef  __BIG_ENDIAN
1523                         cp = wc.c + 8 - bytesperword;
1524 #else
1525                         cp = wc.c;
1526 #endif
1527                         wc.word = word;
1528 #define printable_char(c) \
1529         ({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; })
1530                         switch (bytesperword) {
1531                         case 8:
1532                                 *c++ = printable_char(*cp++);
1533                                 *c++ = printable_char(*cp++);
1534                                 *c++ = printable_char(*cp++);
1535                                 *c++ = printable_char(*cp++);
1536                                 addr += 4;
1537                         case 4:
1538                                 *c++ = printable_char(*cp++);
1539                                 *c++ = printable_char(*cp++);
1540                                 addr += 2;
1541                         case 2:
1542                                 *c++ = printable_char(*cp++);
1543                                 addr++;
1544                         case 1:
1545                                 *c++ = printable_char(*cp++);
1546                                 addr++;
1547                                 break;
1548                         }
1549 #undef printable_char
1550                 }
1551         }
1552         kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1),
1553                    " ", cbuf);
1554 }
1555
1556 static int kdb_md(int argc, const char **argv)
1557 {
1558         static unsigned long last_addr;
1559         static int last_radix, last_bytesperword, last_repeat;
1560         int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
1561         int nosect = 0;
1562         char fmtchar, fmtstr[64];
1563         unsigned long addr;
1564         unsigned long word;
1565         long offset = 0;
1566         int symbolic = 0;
1567         int valid = 0;
1568         int phys = 0;
1569
1570         kdbgetintenv("MDCOUNT", &mdcount);
1571         kdbgetintenv("RADIX", &radix);
1572         kdbgetintenv("BYTESPERWORD", &bytesperword);
1573
1574         /* Assume 'md <addr>' and start with environment values */
1575         repeat = mdcount * 16 / bytesperword;
1576
1577         if (strcmp(argv[0], "mdr") == 0) {
1578                 if (argc != 2)
1579                         return KDB_ARGCOUNT;
1580                 valid = 1;
1581         } else if (isdigit(argv[0][2])) {
1582                 bytesperword = (int)(argv[0][2] - '0');
1583                 if (bytesperword == 0) {
1584                         bytesperword = last_bytesperword;
1585                         if (bytesperword == 0)
1586                                 bytesperword = 4;
1587                 }
1588                 last_bytesperword = bytesperword;
1589                 repeat = mdcount * 16 / bytesperword;
1590                 if (!argv[0][3])
1591                         valid = 1;
1592                 else if (argv[0][3] == 'c' && argv[0][4]) {
1593                         char *p;
1594                         repeat = simple_strtoul(argv[0] + 4, &p, 10);
1595                         mdcount = ((repeat * bytesperword) + 15) / 16;
1596                         valid = !*p;
1597                 }
1598                 last_repeat = repeat;
1599         } else if (strcmp(argv[0], "md") == 0)
1600                 valid = 1;
1601         else if (strcmp(argv[0], "mds") == 0)
1602                 valid = 1;
1603         else if (strcmp(argv[0], "mdp") == 0) {
1604                 phys = valid = 1;
1605         }
1606         if (!valid)
1607                 return KDB_NOTFOUND;
1608
1609         if (argc == 0) {
1610                 if (last_addr == 0)
1611                         return KDB_ARGCOUNT;
1612                 addr = last_addr;
1613                 radix = last_radix;
1614                 bytesperword = last_bytesperword;
1615                 repeat = last_repeat;
1616                 mdcount = ((repeat * bytesperword) + 15) / 16;
1617         }
1618
1619         if (argc) {
1620                 unsigned long val;
1621                 int diag, nextarg = 1;
1622                 diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
1623                                      &offset, NULL);
1624                 if (diag)
1625                         return diag;
1626                 if (argc > nextarg+2)
1627                         return KDB_ARGCOUNT;
1628
1629                 if (argc >= nextarg) {
1630                         diag = kdbgetularg(argv[nextarg], &val);
1631                         if (!diag) {
1632                                 mdcount = (int) val;
1633                                 repeat = mdcount * 16 / bytesperword;
1634                         }
1635                 }
1636                 if (argc >= nextarg+1) {
1637                         diag = kdbgetularg(argv[nextarg+1], &val);
1638                         if (!diag)
1639                                 radix = (int) val;
1640                 }
1641         }
1642
1643         if (strcmp(argv[0], "mdr") == 0)
1644                 return kdb_mdr(addr, mdcount);
1645
1646         switch (radix) {
1647         case 10:
1648                 fmtchar = 'd';
1649                 break;
1650         case 16:
1651                 fmtchar = 'x';
1652                 break;
1653         case 8:
1654                 fmtchar = 'o';
1655                 break;
1656         default:
1657                 return KDB_BADRADIX;
1658         }
1659
1660         last_radix = radix;
1661
1662         if (bytesperword > KDB_WORD_SIZE)
1663                 return KDB_BADWIDTH;
1664
1665         switch (bytesperword) {
1666         case 8:
1667                 sprintf(fmtstr, "%%16.16l%c ", fmtchar);
1668                 break;
1669         case 4:
1670                 sprintf(fmtstr, "%%8.8l%c ", fmtchar);
1671                 break;
1672         case 2:
1673                 sprintf(fmtstr, "%%4.4l%c ", fmtchar);
1674                 break;
1675         case 1:
1676                 sprintf(fmtstr, "%%2.2l%c ", fmtchar);
1677                 break;
1678         default:
1679                 return KDB_BADWIDTH;
1680         }
1681
1682         last_repeat = repeat;
1683         last_bytesperword = bytesperword;
1684
1685         if (strcmp(argv[0], "mds") == 0) {
1686                 symbolic = 1;
1687                 /* Do not save these changes as last_*, they are temporary mds
1688                  * overrides.
1689                  */
1690                 bytesperword = KDB_WORD_SIZE;
1691                 repeat = mdcount;
1692                 kdbgetintenv("NOSECT", &nosect);
1693         }
1694
1695         /* Round address down modulo BYTESPERWORD */
1696
1697         addr &= ~(bytesperword-1);
1698
1699         while (repeat > 0) {
1700                 unsigned long a;
1701                 int n, z, num = (symbolic ? 1 : (16 / bytesperword));
1702
1703                 if (KDB_FLAG(CMD_INTERRUPT))
1704                         return 0;
1705                 for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) {
1706                         if (phys) {
1707                                 if (kdb_getphysword(&word, a, bytesperword)
1708                                                 || word)
1709                                         break;
1710                         } else if (kdb_getword(&word, a, bytesperword) || word)
1711                                 break;
1712                 }
1713                 n = min(num, repeat);
1714                 kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword,
1715                             num, repeat, phys);
1716                 addr += bytesperword * n;
1717                 repeat -= n;
1718                 z = (z + num - 1) / num;
1719                 if (z > 2) {
1720                         int s = num * (z-2);
1721                         kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0
1722                                    " zero suppressed\n",
1723                                 addr, addr + bytesperword * s - 1);
1724                         addr += bytesperword * s;
1725                         repeat -= s;
1726                 }
1727         }
1728         last_addr = addr;
1729
1730         return 0;
1731 }
1732
1733 /*
1734  * kdb_mm - This function implements the 'mm' command.
1735  *      mm address-expression new-value
1736  * Remarks:
1737  *      mm works on machine words, mmW works on bytes.
1738  */
1739 static int kdb_mm(int argc, const char **argv)
1740 {
1741         int diag;
1742         unsigned long addr;
1743         long offset = 0;
1744         unsigned long contents;
1745         int nextarg;
1746         int width;
1747
1748         if (argv[0][2] && !isdigit(argv[0][2]))
1749                 return KDB_NOTFOUND;
1750
1751         if (argc < 2)
1752                 return KDB_ARGCOUNT;
1753
1754         nextarg = 1;
1755         diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1756         if (diag)
1757                 return diag;
1758
1759         if (nextarg > argc)
1760                 return KDB_ARGCOUNT;
1761         diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL);
1762         if (diag)
1763                 return diag;
1764
1765         if (nextarg != argc + 1)
1766                 return KDB_ARGCOUNT;
1767
1768         width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE);
1769         diag = kdb_putword(addr, contents, width);
1770         if (diag)
1771                 return diag;
1772
1773         kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents);
1774
1775         return 0;
1776 }
1777
1778 /*
1779  * kdb_go - This function implements the 'go' command.
1780  *      go [address-expression]
1781  */
1782 static int kdb_go(int argc, const char **argv)
1783 {
1784         unsigned long addr;
1785         int diag;
1786         int nextarg;
1787         long offset;
1788
1789         if (raw_smp_processor_id() != kdb_initial_cpu) {
1790                 kdb_printf("go must execute on the entry cpu, "
1791                            "please use \"cpu %d\" and then execute go\n",
1792                            kdb_initial_cpu);
1793                 return KDB_BADCPUNUM;
1794         }
1795         if (argc == 1) {
1796                 nextarg = 1;
1797                 diag = kdbgetaddrarg(argc, argv, &nextarg,
1798                                      &addr, &offset, NULL);
1799                 if (diag)
1800                         return diag;
1801         } else if (argc) {
1802                 return KDB_ARGCOUNT;
1803         }
1804
1805         diag = KDB_CMD_GO;
1806         if (KDB_FLAG(CATASTROPHIC)) {
1807                 kdb_printf("Catastrophic error detected\n");
1808                 kdb_printf("kdb_continue_catastrophic=%d, ",
1809                         kdb_continue_catastrophic);
1810                 if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) {
1811                         kdb_printf("type go a second time if you really want "
1812                                    "to continue\n");
1813                         return 0;
1814                 }
1815                 if (kdb_continue_catastrophic == 2) {
1816                         kdb_printf("forcing reboot\n");
1817                         kdb_reboot(0, NULL);
1818                 }
1819                 kdb_printf("attempting to continue\n");
1820         }
1821         return diag;
1822 }
1823
1824 /*
1825  * kdb_rd - This function implements the 'rd' command.
1826  */
1827 static int kdb_rd(int argc, const char **argv)
1828 {
1829         int len = kdb_check_regs();
1830 #if DBG_MAX_REG_NUM > 0
1831         int i;
1832         char *rname;
1833         int rsize;
1834         u64 reg64;
1835         u32 reg32;
1836         u16 reg16;
1837         u8 reg8;
1838
1839         if (len)
1840                 return len;
1841
1842         for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1843                 rsize = dbg_reg_def[i].size * 2;
1844                 if (rsize > 16)
1845                         rsize = 2;
1846                 if (len + strlen(dbg_reg_def[i].name) + 4 + rsize > 80) {
1847                         len = 0;
1848                         kdb_printf("\n");
1849                 }
1850                 if (len)
1851                         len += kdb_printf("  ");
1852                 switch(dbg_reg_def[i].size * 8) {
1853                 case 8:
1854                         rname = dbg_get_reg(i, &reg8, kdb_current_regs);
1855                         if (!rname)
1856                                 break;
1857                         len += kdb_printf("%s: %02x", rname, reg8);
1858                         break;
1859                 case 16:
1860                         rname = dbg_get_reg(i, &reg16, kdb_current_regs);
1861                         if (!rname)
1862                                 break;
1863                         len += kdb_printf("%s: %04x", rname, reg16);
1864                         break;
1865                 case 32:
1866                         rname = dbg_get_reg(i, &reg32, kdb_current_regs);
1867                         if (!rname)
1868                                 break;
1869                         len += kdb_printf("%s: %08x", rname, reg32);
1870                         break;
1871                 case 64:
1872                         rname = dbg_get_reg(i, &reg64, kdb_current_regs);
1873                         if (!rname)
1874                                 break;
1875                         len += kdb_printf("%s: %016llx", rname, reg64);
1876                         break;
1877                 default:
1878                         len += kdb_printf("%s: ??", dbg_reg_def[i].name);
1879                 }
1880         }
1881         kdb_printf("\n");
1882 #else
1883         if (len)
1884                 return len;
1885
1886         kdb_dumpregs(kdb_current_regs);
1887 #endif
1888         return 0;
1889 }
1890
1891 /*
1892  * kdb_rm - This function implements the 'rm' (register modify)  command.
1893  *      rm register-name new-contents
1894  * Remarks:
1895  *      Allows register modification with the same restrictions as gdb
1896  */
1897 static int kdb_rm(int argc, const char **argv)
1898 {
1899 #if DBG_MAX_REG_NUM > 0
1900         int diag;
1901         const char *rname;
1902         int i;
1903         u64 reg64;
1904         u32 reg32;
1905         u16 reg16;
1906         u8 reg8;
1907
1908         if (argc != 2)
1909                 return KDB_ARGCOUNT;
1910         /*
1911          * Allow presence or absence of leading '%' symbol.
1912          */
1913         rname = argv[1];
1914         if (*rname == '%')
1915                 rname++;
1916
1917         diag = kdbgetu64arg(argv[2], &reg64);
1918         if (diag)
1919                 return diag;
1920
1921         diag = kdb_check_regs();
1922         if (diag)
1923                 return diag;
1924
1925         diag = KDB_BADREG;
1926         for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1927                 if (strcmp(rname, dbg_reg_def[i].name) == 0) {
1928                         diag = 0;
1929                         break;
1930                 }
1931         }
1932         if (!diag) {
1933                 switch(dbg_reg_def[i].size * 8) {
1934                 case 8:
1935                         reg8 = reg64;
1936                         dbg_set_reg(i, &reg8, kdb_current_regs);
1937                         break;
1938                 case 16:
1939                         reg16 = reg64;
1940                         dbg_set_reg(i, &reg16, kdb_current_regs);
1941                         break;
1942                 case 32:
1943                         reg32 = reg64;
1944                         dbg_set_reg(i, &reg32, kdb_current_regs);
1945                         break;
1946                 case 64:
1947                         dbg_set_reg(i, &reg64, kdb_current_regs);
1948                         break;
1949                 }
1950         }
1951         return diag;
1952 #else
1953         kdb_printf("ERROR: Register set currently not implemented\n");
1954     return 0;
1955 #endif
1956 }
1957
1958 #if defined(CONFIG_MAGIC_SYSRQ)
1959 /*
1960  * kdb_sr - This function implements the 'sr' (SYSRQ key) command
1961  *      which interfaces to the soi-disant MAGIC SYSRQ functionality.
1962  *              sr <magic-sysrq-code>
1963  */
1964 static int kdb_sr(int argc, const char **argv)
1965 {
1966         bool check_mask =
1967             !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
1968
1969         if (argc != 1)
1970                 return KDB_ARGCOUNT;
1971
1972         kdb_trap_printk++;
1973         __handle_sysrq(*argv[1], check_mask);
1974         kdb_trap_printk--;
1975
1976         return 0;
1977 }
1978 #endif  /* CONFIG_MAGIC_SYSRQ */
1979
1980 /*
1981  * kdb_ef - This function implements the 'regs' (display exception
1982  *      frame) command.  This command takes an address and expects to
1983  *      find an exception frame at that address, formats and prints
1984  *      it.
1985  *              regs address-expression
1986  * Remarks:
1987  *      Not done yet.
1988  */
1989 static int kdb_ef(int argc, const char **argv)
1990 {
1991         int diag;
1992         unsigned long addr;
1993         long offset;
1994         int nextarg;
1995
1996         if (argc != 1)
1997                 return KDB_ARGCOUNT;
1998
1999         nextarg = 1;
2000         diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
2001         if (diag)
2002                 return diag;
2003         show_regs((struct pt_regs *)addr);
2004         return 0;
2005 }
2006
2007 #if defined(CONFIG_MODULES)
2008 /*
2009  * kdb_lsmod - This function implements the 'lsmod' command.  Lists
2010  *      currently loaded kernel modules.
2011  *      Mostly taken from userland lsmod.
2012  */
2013 static int kdb_lsmod(int argc, const char **argv)
2014 {
2015         struct module *mod;
2016
2017         if (argc != 0)
2018                 return KDB_ARGCOUNT;
2019
2020         kdb_printf("Module                  Size  modstruct     Used by\n");
2021         list_for_each_entry(mod, kdb_modules, list) {
2022                 if (mod->state == MODULE_STATE_UNFORMED)
2023                         continue;
2024
2025                 kdb_printf("%-20s%8u  0x%p ", mod->name,
2026                            mod->core_layout.size, (void *)mod);
2027 #ifdef CONFIG_MODULE_UNLOAD
2028                 kdb_printf("%4d ", module_refcount(mod));
2029 #endif
2030                 if (mod->state == MODULE_STATE_GOING)
2031                         kdb_printf(" (Unloading)");
2032                 else if (mod->state == MODULE_STATE_COMING)
2033                         kdb_printf(" (Loading)");
2034                 else
2035                         kdb_printf(" (Live)");
2036                 kdb_printf(" 0x%p", mod->core_layout.base);
2037
2038 #ifdef CONFIG_MODULE_UNLOAD
2039                 {
2040                         struct module_use *use;
2041                         kdb_printf(" [ ");
2042                         list_for_each_entry(use, &mod->source_list,
2043                                             source_list)
2044                                 kdb_printf("%s ", use->target->name);
2045                         kdb_printf("]\n");
2046                 }
2047 #endif
2048         }
2049
2050         return 0;
2051 }
2052
2053 #endif  /* CONFIG_MODULES */
2054
2055 /*
2056  * kdb_env - This function implements the 'env' command.  Display the
2057  *      current environment variables.
2058  */
2059
2060 static int kdb_env(int argc, const char **argv)
2061 {
2062         int i;
2063
2064         for (i = 0; i < __nenv; i++) {
2065                 if (__env[i])
2066                         kdb_printf("%s\n", __env[i]);
2067         }
2068
2069         if (KDB_DEBUG(MASK))
2070                 kdb_printf("KDBFLAGS=0x%x\n", kdb_flags);
2071
2072         return 0;
2073 }
2074
2075 #ifdef CONFIG_PRINTK
2076 /*
2077  * kdb_dmesg - This function implements the 'dmesg' command to display
2078  *      the contents of the syslog buffer.
2079  *              dmesg [lines] [adjust]
2080  */
2081 static int kdb_dmesg(int argc, const char **argv)
2082 {
2083         int diag;
2084         int logging;
2085         int lines = 0;
2086         int adjust = 0;
2087         int n = 0;
2088         int skip = 0;
2089         struct kmsg_dumper dumper = { .active = 1 };
2090         size_t len;
2091         char buf[201];
2092
2093         if (argc > 2)
2094                 return KDB_ARGCOUNT;
2095         if (argc) {
2096                 char *cp;
2097                 lines = simple_strtol(argv[1], &cp, 0);
2098                 if (*cp)
2099                         lines = 0;
2100                 if (argc > 1) {
2101                         adjust = simple_strtoul(argv[2], &cp, 0);
2102                         if (*cp || adjust < 0)
2103                                 adjust = 0;
2104                 }
2105         }
2106
2107         /* disable LOGGING if set */
2108         diag = kdbgetintenv("LOGGING", &logging);
2109         if (!diag && logging) {
2110                 const char *setargs[] = { "set", "LOGGING", "0" };
2111                 kdb_set(2, setargs);
2112         }
2113
2114         kmsg_dump_rewind_nolock(&dumper);
2115         while (kmsg_dump_get_line_nolock(&dumper, 1, NULL, 0, NULL))
2116                 n++;
2117
2118         if (lines < 0) {
2119                 if (adjust >= n)
2120                         kdb_printf("buffer only contains %d lines, nothing "
2121                                    "printed\n", n);
2122                 else if (adjust - lines >= n)
2123                         kdb_printf("buffer only contains %d lines, last %d "
2124                                    "lines printed\n", n, n - adjust);
2125                 skip = adjust;
2126                 lines = abs(lines);
2127         } else if (lines > 0) {
2128                 skip = n - lines - adjust;
2129                 lines = abs(lines);
2130                 if (adjust >= n) {
2131                         kdb_printf("buffer only contains %d lines, "
2132                                    "nothing printed\n", n);
2133                         skip = n;
2134                 } else if (skip < 0) {
2135                         lines += skip;
2136                         skip = 0;
2137                         kdb_printf("buffer only contains %d lines, first "
2138                                    "%d lines printed\n", n, lines);
2139                 }
2140         } else {
2141                 lines = n;
2142         }
2143
2144         if (skip >= n || skip < 0)
2145                 return 0;
2146
2147         kmsg_dump_rewind_nolock(&dumper);
2148         while (kmsg_dump_get_line_nolock(&dumper, 1, buf, sizeof(buf), &len)) {
2149                 if (skip) {
2150                         skip--;
2151                         continue;
2152                 }
2153                 if (!lines--)
2154                         break;
2155                 if (KDB_FLAG(CMD_INTERRUPT))
2156                         return 0;
2157
2158                 kdb_printf("%.*s\n", (int)len - 1, buf);
2159         }
2160
2161         return 0;
2162 }
2163 #endif /* CONFIG_PRINTK */
2164
2165 /* Make sure we balance enable/disable calls, must disable first. */
2166 static atomic_t kdb_nmi_disabled;
2167
2168 static int kdb_disable_nmi(int argc, const char *argv[])
2169 {
2170         if (atomic_read(&kdb_nmi_disabled))
2171                 return 0;
2172         atomic_set(&kdb_nmi_disabled, 1);
2173         arch_kgdb_ops.enable_nmi(0);
2174         return 0;
2175 }
2176
2177 static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
2178 {
2179         if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
2180                 return -EINVAL;
2181         arch_kgdb_ops.enable_nmi(1);
2182         return 0;
2183 }
2184
2185 static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
2186         .set = kdb_param_enable_nmi,
2187 };
2188 module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
2189
2190 /*
2191  * kdb_cpu - This function implements the 'cpu' command.
2192  *      cpu     [<cpunum>]
2193  * Returns:
2194  *      KDB_CMD_CPU for success, a kdb diagnostic if error
2195  */
2196 static void kdb_cpu_status(void)
2197 {
2198         int i, start_cpu, first_print = 1;
2199         char state, prev_state = '?';
2200
2201         kdb_printf("Currently on cpu %d\n", raw_smp_processor_id());
2202         kdb_printf("Available cpus: ");
2203         for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
2204                 if (!cpu_online(i)) {
2205                         state = 'F';    /* cpu is offline */
2206                 } else if (!kgdb_info[i].enter_kgdb) {
2207                         state = 'D';    /* cpu is online but unresponsive */
2208                 } else {
2209                         state = ' ';    /* cpu is responding to kdb */
2210                         if (kdb_task_state_char(KDB_TSK(i)) == 'I')
2211                                 state = 'I';    /* idle task */
2212                 }
2213                 if (state != prev_state) {
2214                         if (prev_state != '?') {
2215                                 if (!first_print)
2216                                         kdb_printf(", ");
2217                                 first_print = 0;
2218                                 kdb_printf("%d", start_cpu);
2219                                 if (start_cpu < i-1)
2220                                         kdb_printf("-%d", i-1);
2221                                 if (prev_state != ' ')
2222                                         kdb_printf("(%c)", prev_state);
2223                         }
2224                         prev_state = state;
2225                         start_cpu = i;
2226                 }
2227         }
2228         /* print the trailing cpus, ignoring them if they are all offline */
2229         if (prev_state != 'F') {
2230                 if (!first_print)
2231                         kdb_printf(", ");
2232                 kdb_printf("%d", start_cpu);
2233                 if (start_cpu < i-1)
2234                         kdb_printf("-%d", i-1);
2235                 if (prev_state != ' ')
2236                         kdb_printf("(%c)", prev_state);
2237         }
2238         kdb_printf("\n");
2239 }
2240
2241 static int kdb_cpu(int argc, const char **argv)
2242 {
2243         unsigned long cpunum;
2244         int diag;
2245
2246         if (argc == 0) {
2247                 kdb_cpu_status();
2248                 return 0;
2249         }
2250
2251         if (argc != 1)
2252                 return KDB_ARGCOUNT;
2253
2254         diag = kdbgetularg(argv[1], &cpunum);
2255         if (diag)
2256                 return diag;
2257
2258         /*
2259          * Validate cpunum
2260          */
2261         if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
2262                 return KDB_BADCPUNUM;
2263
2264         dbg_switch_cpu = cpunum;
2265
2266         /*
2267          * Switch to other cpu
2268          */
2269         return KDB_CMD_CPU;
2270 }
2271
2272 /* The user may not realize that ps/bta with no parameters does not print idle
2273  * or sleeping system daemon processes, so tell them how many were suppressed.
2274  */
2275 void kdb_ps_suppressed(void)
2276 {
2277         int idle = 0, daemon = 0;
2278         unsigned long mask_I = kdb_task_state_string("I"),
2279                       mask_M = kdb_task_state_string("M");
2280         unsigned long cpu;
2281         const struct task_struct *p, *g;
2282         for_each_online_cpu(cpu) {
2283                 p = kdb_curr_task(cpu);
2284                 if (kdb_task_state(p, mask_I))
2285                         ++idle;
2286         }
2287         kdb_do_each_thread(g, p) {
2288                 if (kdb_task_state(p, mask_M))
2289                         ++daemon;
2290         } kdb_while_each_thread(g, p);
2291         if (idle || daemon) {
2292                 if (idle)
2293                         kdb_printf("%d idle process%s (state I)%s\n",
2294                                    idle, idle == 1 ? "" : "es",
2295                                    daemon ? " and " : "");
2296                 if (daemon)
2297                         kdb_printf("%d sleeping system daemon (state M) "
2298                                    "process%s", daemon,
2299                                    daemon == 1 ? "" : "es");
2300                 kdb_printf(" suppressed,\nuse 'ps A' to see all.\n");
2301         }
2302 }
2303
2304 /*
2305  * kdb_ps - This function implements the 'ps' command which shows a
2306  *      list of the active processes.
2307  *              ps [DRSTCZEUIMA]   All processes, optionally filtered by state
2308  */
2309 void kdb_ps1(const struct task_struct *p)
2310 {
2311         int cpu;
2312         unsigned long tmp;
2313
2314         if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
2315                 return;
2316
2317         cpu = kdb_process_cpu(p);
2318         kdb_printf("0x%p %8d %8d  %d %4d   %c  0x%p %c%s\n",
2319                    (void *)p, p->pid, p->parent->pid,
2320                    kdb_task_has_cpu(p), kdb_process_cpu(p),
2321                    kdb_task_state_char(p),
2322                    (void *)(&p->thread),
2323                    p == kdb_curr_task(raw_smp_processor_id()) ? '*' : ' ',
2324                    p->comm);
2325         if (kdb_task_has_cpu(p)) {
2326                 if (!KDB_TSK(cpu)) {
2327                         kdb_printf("  Error: no saved data for this cpu\n");
2328                 } else {
2329                         if (KDB_TSK(cpu) != p)
2330                                 kdb_printf("  Error: does not match running "
2331                                    "process table (0x%p)\n", KDB_TSK(cpu));
2332                 }
2333         }
2334 }
2335
2336 static int kdb_ps(int argc, const char **argv)
2337 {
2338         struct task_struct *g, *p;
2339         unsigned long mask, cpu;
2340
2341         if (argc == 0)
2342                 kdb_ps_suppressed();
2343         kdb_printf("%-*s      Pid   Parent [*] cpu State %-*s Command\n",
2344                 (int)(2*sizeof(void *))+2, "Task Addr",
2345                 (int)(2*sizeof(void *))+2, "Thread");
2346         mask = kdb_task_state_string(argc ? argv[1] : NULL);
2347         /* Run the active tasks first */
2348         for_each_online_cpu(cpu) {
2349                 if (KDB_FLAG(CMD_INTERRUPT))
2350                         return 0;
2351                 p = kdb_curr_task(cpu);
2352                 if (kdb_task_state(p, mask))
2353                         kdb_ps1(p);
2354         }
2355         kdb_printf("\n");
2356         /* Now the real tasks */
2357         kdb_do_each_thread(g, p) {
2358                 if (KDB_FLAG(CMD_INTERRUPT))
2359                         return 0;
2360                 if (kdb_task_state(p, mask))
2361                         kdb_ps1(p);
2362         } kdb_while_each_thread(g, p);
2363
2364         return 0;
2365 }
2366
2367 /*
2368  * kdb_pid - This function implements the 'pid' command which switches
2369  *      the currently active process.
2370  *              pid [<pid> | R]
2371  */
2372 static int kdb_pid(int argc, const char **argv)
2373 {
2374         struct task_struct *p;
2375         unsigned long val;
2376         int diag;
2377
2378         if (argc > 1)
2379                 return KDB_ARGCOUNT;
2380
2381         if (argc) {
2382                 if (strcmp(argv[1], "R") == 0) {
2383                         p = KDB_TSK(kdb_initial_cpu);
2384                 } else {
2385                         diag = kdbgetularg(argv[1], &val);
2386                         if (diag)
2387                                 return KDB_BADINT;
2388
2389                         p = find_task_by_pid_ns((pid_t)val,     &init_pid_ns);
2390                         if (!p) {
2391                                 kdb_printf("No task with pid=%d\n", (pid_t)val);
2392                                 return 0;
2393                         }
2394                 }
2395                 kdb_set_current_task(p);
2396         }
2397         kdb_printf("KDB current process is %s(pid=%d)\n",
2398                    kdb_current_task->comm,
2399                    kdb_current_task->pid);
2400
2401         return 0;
2402 }
2403
2404 static int kdb_kgdb(int argc, const char **argv)
2405 {
2406         return KDB_CMD_KGDB;
2407 }
2408
2409 /*
2410  * kdb_help - This function implements the 'help' and '?' commands.
2411  */
2412 static int kdb_help(int argc, const char **argv)
2413 {
2414         kdbtab_t *kt;
2415         int i;
2416
2417         kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
2418         kdb_printf("-----------------------------"
2419                    "-----------------------------\n");
2420         for_each_kdbcmd(kt, i) {
2421                 char *space = "";
2422                 if (KDB_FLAG(CMD_INTERRUPT))
2423                         return 0;
2424                 if (!kt->cmd_name)
2425                         continue;
2426                 if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
2427                         continue;
2428                 if (strlen(kt->cmd_usage) > 20)
2429                         space = "\n                                    ";
2430                 kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
2431                            kt->cmd_usage, space, kt->cmd_help);
2432         }
2433         return 0;
2434 }
2435
2436 /*
2437  * kdb_kill - This function implements the 'kill' commands.
2438  */
2439 static int kdb_kill(int argc, const char **argv)
2440 {
2441         long sig, pid;
2442         char *endp;
2443         struct task_struct *p;
2444
2445         if (argc != 2)
2446                 return KDB_ARGCOUNT;
2447
2448         sig = simple_strtol(argv[1], &endp, 0);
2449         if (*endp)
2450                 return KDB_BADINT;
2451         if ((sig >= 0) || !valid_signal(-sig)) {
2452                 kdb_printf("Invalid signal parameter.<-signal>\n");
2453                 return 0;
2454         }
2455         sig = -sig;
2456
2457         pid = simple_strtol(argv[2], &endp, 0);
2458         if (*endp)
2459                 return KDB_BADINT;
2460         if (pid <= 0) {
2461                 kdb_printf("Process ID must be large than 0.\n");
2462                 return 0;
2463         }
2464
2465         /* Find the process. */
2466         p = find_task_by_pid_ns(pid, &init_pid_ns);
2467         if (!p) {
2468                 kdb_printf("The specified process isn't found.\n");
2469                 return 0;
2470         }
2471         p = p->group_leader;
2472         kdb_send_sig(p, sig);
2473         return 0;
2474 }
2475
2476 struct kdb_tm {
2477         int tm_sec;     /* seconds */
2478         int tm_min;     /* minutes */
2479         int tm_hour;    /* hours */
2480         int tm_mday;    /* day of the month */
2481         int tm_mon;     /* month */
2482         int tm_year;    /* year */
2483 };
2484
2485 static void kdb_gmtime(struct timespec *tv, struct kdb_tm *tm)
2486 {
2487         /* This will work from 1970-2099, 2100 is not a leap year */
2488         static int mon_day[] = { 31, 29, 31, 30, 31, 30, 31,
2489                                  31, 30, 31, 30, 31 };
2490         memset(tm, 0, sizeof(*tm));
2491         tm->tm_sec  = tv->tv_sec % (24 * 60 * 60);
2492         tm->tm_mday = tv->tv_sec / (24 * 60 * 60) +
2493                 (2 * 365 + 1); /* shift base from 1970 to 1968 */
2494         tm->tm_min =  tm->tm_sec / 60 % 60;
2495         tm->tm_hour = tm->tm_sec / 60 / 60;
2496         tm->tm_sec =  tm->tm_sec % 60;
2497         tm->tm_year = 68 + 4*(tm->tm_mday / (4*365+1));
2498         tm->tm_mday %= (4*365+1);
2499         mon_day[1] = 29;
2500         while (tm->tm_mday >= mon_day[tm->tm_mon]) {
2501                 tm->tm_mday -= mon_day[tm->tm_mon];
2502                 if (++tm->tm_mon == 12) {
2503                         tm->tm_mon = 0;
2504                         ++tm->tm_year;
2505                         mon_day[1] = 28;
2506                 }
2507         }
2508         ++tm->tm_mday;
2509 }
2510
2511 /*
2512  * Most of this code has been lifted from kernel/timer.c::sys_sysinfo().
2513  * I cannot call that code directly from kdb, it has an unconditional
2514  * cli()/sti() and calls routines that take locks which can stop the debugger.
2515  */
2516 static void kdb_sysinfo(struct sysinfo *val)
2517 {
2518         struct timespec uptime;
2519         ktime_get_ts(&uptime);
2520         memset(val, 0, sizeof(*val));
2521         val->uptime = uptime.tv_sec;
2522         val->loads[0] = avenrun[0];
2523         val->loads[1] = avenrun[1];
2524         val->loads[2] = avenrun[2];
2525         val->procs = nr_threads-1;
2526         si_meminfo(val);
2527
2528         return;
2529 }
2530
2531 /*
2532  * kdb_summary - This function implements the 'summary' command.
2533  */
2534 static int kdb_summary(int argc, const char **argv)
2535 {
2536         struct timespec now;
2537         struct kdb_tm tm;
2538         struct sysinfo val;
2539
2540         if (argc)
2541                 return KDB_ARGCOUNT;
2542
2543         kdb_printf("sysname    %s\n", init_uts_ns.name.sysname);
2544         kdb_printf("release    %s\n", init_uts_ns.name.release);
2545         kdb_printf("version    %s\n", init_uts_ns.name.version);
2546         kdb_printf("machine    %s\n", init_uts_ns.name.machine);
2547         kdb_printf("nodename   %s\n", init_uts_ns.name.nodename);
2548         kdb_printf("domainname %s\n", init_uts_ns.name.domainname);
2549         kdb_printf("ccversion  %s\n", __stringify(CCVERSION));
2550
2551         now = __current_kernel_time();
2552         kdb_gmtime(&now, &tm);
2553         kdb_printf("date       %04d-%02d-%02d %02d:%02d:%02d "
2554                    "tz_minuteswest %d\n",
2555                 1900+tm.tm_year, tm.tm_mon+1, tm.tm_mday,
2556                 tm.tm_hour, tm.tm_min, tm.tm_sec,
2557                 sys_tz.tz_minuteswest);
2558
2559         kdb_sysinfo(&val);
2560         kdb_printf("uptime     ");
2561         if (val.uptime > (24*60*60)) {
2562                 int days = val.uptime / (24*60*60);
2563                 val.uptime %= (24*60*60);
2564                 kdb_printf("%d day%s ", days, days == 1 ? "" : "s");
2565         }
2566         kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
2567
2568         /* lifted from fs/proc/proc_misc.c::loadavg_read_proc() */
2569
2570 #define LOAD_INT(x) ((x) >> FSHIFT)
2571 #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
2572         kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
2573                 LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
2574                 LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
2575                 LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
2576 #undef LOAD_INT
2577 #undef LOAD_FRAC
2578         /* Display in kilobytes */
2579 #define K(x) ((x) << (PAGE_SHIFT - 10))
2580         kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
2581                    "Buffers:        %8lu kB\n",
2582                    K(val.totalram), K(val.freeram), K(val.bufferram));
2583         return 0;
2584 }
2585
2586 /*
2587  * kdb_per_cpu - This function implements the 'per_cpu' command.
2588  */
2589 static int kdb_per_cpu(int argc, const char **argv)
2590 {
2591         char fmtstr[64];
2592         int cpu, diag, nextarg = 1;
2593         unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL;
2594
2595         if (argc < 1 || argc > 3)
2596                 return KDB_ARGCOUNT;
2597
2598         diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL);
2599         if (diag)
2600                 return diag;
2601
2602         if (argc >= 2) {
2603                 diag = kdbgetularg(argv[2], &bytesperword);
2604                 if (diag)
2605                         return diag;
2606         }
2607         if (!bytesperword)
2608                 bytesperword = KDB_WORD_SIZE;
2609         else if (bytesperword > KDB_WORD_SIZE)
2610                 return KDB_BADWIDTH;
2611         sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword));
2612         if (argc >= 3) {
2613                 diag = kdbgetularg(argv[3], &whichcpu);
2614                 if (diag)
2615                         return diag;
2616                 if (!cpu_online(whichcpu)) {
2617                         kdb_printf("cpu %ld is not online\n", whichcpu);
2618                         return KDB_BADCPUNUM;
2619                 }
2620         }
2621
2622         /* Most architectures use __per_cpu_offset[cpu], some use
2623          * __per_cpu_offset(cpu), smp has no __per_cpu_offset.
2624          */
2625 #ifdef  __per_cpu_offset
2626 #define KDB_PCU(cpu) __per_cpu_offset(cpu)
2627 #else
2628 #ifdef  CONFIG_SMP
2629 #define KDB_PCU(cpu) __per_cpu_offset[cpu]
2630 #else
2631 #define KDB_PCU(cpu) 0
2632 #endif
2633 #endif
2634         for_each_online_cpu(cpu) {
2635                 if (KDB_FLAG(CMD_INTERRUPT))
2636                         return 0;
2637
2638                 if (whichcpu != ~0UL && whichcpu != cpu)
2639                         continue;
2640                 addr = symaddr + KDB_PCU(cpu);
2641                 diag = kdb_getword(&val, addr, bytesperword);
2642                 if (diag) {
2643                         kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to "
2644                                    "read, diag=%d\n", cpu, addr, diag);
2645                         continue;
2646                 }
2647                 kdb_printf("%5d ", cpu);
2648                 kdb_md_line(fmtstr, addr,
2649                         bytesperword == KDB_WORD_SIZE,
2650                         1, bytesperword, 1, 1, 0);
2651         }
2652 #undef KDB_PCU
2653         return 0;
2654 }
2655
2656 /*
2657  * display help for the use of cmd | grep pattern
2658  */
2659 static int kdb_grep_help(int argc, const char **argv)
2660 {
2661         kdb_printf("Usage of  cmd args | grep pattern:\n");
2662         kdb_printf("  Any command's output may be filtered through an ");
2663         kdb_printf("emulated 'pipe'.\n");
2664         kdb_printf("  'grep' is just a key word.\n");
2665         kdb_printf("  The pattern may include a very limited set of "
2666                    "metacharacters:\n");
2667         kdb_printf("   pattern or ^pattern or pattern$ or ^pattern$\n");
2668         kdb_printf("  And if there are spaces in the pattern, you may "
2669                    "quote it:\n");
2670         kdb_printf("   \"pat tern\" or \"^pat tern\" or \"pat tern$\""
2671                    " or \"^pat tern$\"\n");
2672         return 0;
2673 }
2674
2675 /*
2676  * kdb_register_flags - This function is used to register a kernel
2677  *      debugger command.
2678  * Inputs:
2679  *      cmd     Command name
2680  *      func    Function to execute the command
2681  *      usage   A simple usage string showing arguments
2682  *      help    A simple help string describing command
2683  *      repeat  Does the command auto repeat on enter?
2684  * Returns:
2685  *      zero for success, one if a duplicate command.
2686  */
2687 #define kdb_command_extend 50   /* arbitrary */
2688 int kdb_register_flags(char *cmd,
2689                        kdb_func_t func,
2690                        char *usage,
2691                        char *help,
2692                        short minlen,
2693                        kdb_cmdflags_t flags)
2694 {
2695         int i;
2696         kdbtab_t *kp;
2697
2698         /*
2699          *  Brute force method to determine duplicates
2700          */
2701         for_each_kdbcmd(kp, i) {
2702                 if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2703                         kdb_printf("Duplicate kdb command registered: "
2704                                 "%s, func %p help %s\n", cmd, func, help);
2705                         return 1;
2706                 }
2707         }
2708
2709         /*
2710          * Insert command into first available location in table
2711          */
2712         for_each_kdbcmd(kp, i) {
2713                 if (kp->cmd_name == NULL)
2714                         break;
2715         }
2716
2717         if (i >= kdb_max_commands) {
2718                 kdbtab_t *new = kmalloc((kdb_max_commands - KDB_BASE_CMD_MAX +
2719                          kdb_command_extend) * sizeof(*new), GFP_KDB);
2720                 if (!new) {
2721                         kdb_printf("Could not allocate new kdb_command "
2722                                    "table\n");
2723                         return 1;
2724                 }
2725                 if (kdb_commands) {
2726                         memcpy(new, kdb_commands,
2727                           (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
2728                         kfree(kdb_commands);
2729                 }
2730                 memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
2731                        kdb_command_extend * sizeof(*new));
2732                 kdb_commands = new;
2733                 kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
2734                 kdb_max_commands += kdb_command_extend;
2735         }
2736
2737         kp->cmd_name   = cmd;
2738         kp->cmd_func   = func;
2739         kp->cmd_usage  = usage;
2740         kp->cmd_help   = help;
2741         kp->cmd_minlen = minlen;
2742         kp->cmd_flags  = flags;
2743
2744         return 0;
2745 }
2746 EXPORT_SYMBOL_GPL(kdb_register_flags);
2747
2748
2749 /*
2750  * kdb_register - Compatibility register function for commands that do
2751  *      not need to specify a repeat state.  Equivalent to
2752  *      kdb_register_flags with flags set to 0.
2753  * Inputs:
2754  *      cmd     Command name
2755  *      func    Function to execute the command
2756  *      usage   A simple usage string showing arguments
2757  *      help    A simple help string describing command
2758  * Returns:
2759  *      zero for success, one if a duplicate command.
2760  */
2761 int kdb_register(char *cmd,
2762              kdb_func_t func,
2763              char *usage,
2764              char *help,
2765              short minlen)
2766 {
2767         return kdb_register_flags(cmd, func, usage, help, minlen, 0);
2768 }
2769 EXPORT_SYMBOL_GPL(kdb_register);
2770
2771 /*
2772  * kdb_unregister - This function is used to unregister a kernel
2773  *      debugger command.  It is generally called when a module which
2774  *      implements kdb commands is unloaded.
2775  * Inputs:
2776  *      cmd     Command name
2777  * Returns:
2778  *      zero for success, one command not registered.
2779  */
2780 int kdb_unregister(char *cmd)
2781 {
2782         int i;
2783         kdbtab_t *kp;
2784
2785         /*
2786          *  find the command.
2787          */
2788         for_each_kdbcmd(kp, i) {
2789                 if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2790                         kp->cmd_name = NULL;
2791                         return 0;
2792                 }
2793         }
2794
2795         /* Couldn't find it.  */
2796         return 1;
2797 }
2798 EXPORT_SYMBOL_GPL(kdb_unregister);
2799
2800 /* Initialize the kdb command table. */
2801 static void __init kdb_inittab(void)
2802 {
2803         int i;
2804         kdbtab_t *kp;
2805
2806         for_each_kdbcmd(kp, i)
2807                 kp->cmd_name = NULL;
2808
2809         kdb_register_flags("md", kdb_md, "<vaddr>",
2810           "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
2811           KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2812         kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
2813           "Display Raw Memory", 0,
2814           KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2815         kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
2816           "Display Physical Memory", 0,
2817           KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2818         kdb_register_flags("mds", kdb_md, "<vaddr>",
2819           "Display Memory Symbolically", 0,
2820           KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2821         kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
2822           "Modify Memory Contents", 0,
2823           KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
2824         kdb_register_flags("go", kdb_go, "[<vaddr>]",
2825           "Continue Execution", 1,
2826           KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2827         kdb_register_flags("rd", kdb_rd, "",
2828           "Display Registers", 0,
2829           KDB_ENABLE_REG_READ);
2830         kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
2831           "Modify Registers", 0,
2832           KDB_ENABLE_REG_WRITE);
2833         kdb_register_flags("ef", kdb_ef, "<vaddr>",
2834           "Display exception frame", 0,
2835           KDB_ENABLE_MEM_READ);
2836         kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
2837           "Stack traceback", 1,
2838           KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2839         kdb_register_flags("btp", kdb_bt, "<pid>",
2840           "Display stack for process <pid>", 0,
2841           KDB_ENABLE_INSPECT);
2842         kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
2843           "Backtrace all processes matching state flag", 0,
2844           KDB_ENABLE_INSPECT);
2845         kdb_register_flags("btc", kdb_bt, "",
2846           "Backtrace current process on each cpu", 0,
2847           KDB_ENABLE_INSPECT);
2848         kdb_register_flags("btt", kdb_bt, "<vaddr>",
2849           "Backtrace process given its struct task address", 0,
2850           KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2851         kdb_register_flags("env", kdb_env, "",
2852           "Show environment variables", 0,
2853           KDB_ENABLE_ALWAYS_SAFE);
2854         kdb_register_flags("set", kdb_set, "",
2855           "Set environment variables", 0,
2856           KDB_ENABLE_ALWAYS_SAFE);
2857         kdb_register_flags("help", kdb_help, "",
2858           "Display Help Message", 1,
2859           KDB_ENABLE_ALWAYS_SAFE);
2860         kdb_register_flags("?", kdb_help, "",
2861           "Display Help Message", 0,
2862           KDB_ENABLE_ALWAYS_SAFE);
2863         kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
2864           "Switch to new cpu", 0,
2865           KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2866         kdb_register_flags("kgdb", kdb_kgdb, "",
2867           "Enter kgdb mode", 0, 0);
2868         kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
2869           "Display active task list", 0,
2870           KDB_ENABLE_INSPECT);
2871         kdb_register_flags("pid", kdb_pid, "<pidnum>",
2872           "Switch to another task", 0,
2873           KDB_ENABLE_INSPECT);
2874         kdb_register_flags("reboot", kdb_reboot, "",
2875           "Reboot the machine immediately", 0,
2876           KDB_ENABLE_REBOOT);
2877 #if defined(CONFIG_MODULES)
2878         kdb_register_flags("lsmod", kdb_lsmod, "",
2879           "List loaded kernel modules", 0,
2880           KDB_ENABLE_INSPECT);
2881 #endif
2882 #if defined(CONFIG_MAGIC_SYSRQ)
2883         kdb_register_flags("sr", kdb_sr, "<key>",
2884           "Magic SysRq key", 0,
2885           KDB_ENABLE_ALWAYS_SAFE);
2886 #endif
2887 #if defined(CONFIG_PRINTK)
2888         kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
2889           "Display syslog buffer", 0,
2890           KDB_ENABLE_ALWAYS_SAFE);
2891 #endif
2892         if (arch_kgdb_ops.enable_nmi) {
2893                 kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
2894                   "Disable NMI entry to KDB", 0,
2895                   KDB_ENABLE_ALWAYS_SAFE);
2896         }
2897         kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
2898           "Define a set of commands, down to endefcmd", 0,
2899           KDB_ENABLE_ALWAYS_SAFE);
2900         kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
2901           "Send a signal to a process", 0,
2902           KDB_ENABLE_SIGNAL);
2903         kdb_register_flags("summary", kdb_summary, "",
2904           "Summarize the system", 4,
2905           KDB_ENABLE_ALWAYS_SAFE);
2906         kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
2907           "Display per_cpu variables", 3,
2908           KDB_ENABLE_MEM_READ);
2909         kdb_register_flags("grephelp", kdb_grep_help, "",
2910           "Display help on | grep", 0,
2911           KDB_ENABLE_ALWAYS_SAFE);
2912 }
2913
2914 /* Execute any commands defined in kdb_cmds.  */
2915 static void __init kdb_cmd_init(void)
2916 {
2917         int i, diag;
2918         for (i = 0; kdb_cmds[i]; ++i) {
2919                 diag = kdb_parse(kdb_cmds[i]);
2920                 if (diag)
2921                         kdb_printf("kdb command %s failed, kdb diag %d\n",
2922                                 kdb_cmds[i], diag);
2923         }
2924         if (defcmd_in_progress) {
2925                 kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n");
2926                 kdb_parse("endefcmd");
2927         }
2928 }
2929
2930 /* Initialize kdb_printf, breakpoint tables and kdb state */
2931 void __init kdb_init(int lvl)
2932 {
2933         static int kdb_init_lvl = KDB_NOT_INITIALIZED;
2934         int i;
2935
2936         if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl)
2937                 return;
2938         for (i = kdb_init_lvl; i < lvl; i++) {
2939                 switch (i) {
2940                 case KDB_NOT_INITIALIZED:
2941                         kdb_inittab();          /* Initialize Command Table */
2942                         kdb_initbptab();        /* Initialize Breakpoints */
2943                         break;
2944                 case KDB_INIT_EARLY:
2945                         kdb_cmd_init();         /* Build kdb_cmds tables */
2946                         break;
2947                 }
2948         }
2949         kdb_init_lvl = lvl;
2950 }