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v5.4
   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
  53static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;
  54module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);
  55
  56char kdb_grep_string[KDB_GREP_STRLEN];
  57int kdb_grepping_flag;
  58EXPORT_SYMBOL(kdb_grepping_flag);
  59int kdb_grep_leading;
  60int kdb_grep_trailing;
  61
  62/*
  63 * Kernel debugger state flags
  64 */
  65int kdb_flags;
  66
  67/*
  68 * kdb_lock protects updates to kdb_initial_cpu.  Used to
  69 * single thread processors through the kernel debugger.
  70 */
  71int kdb_initial_cpu = -1;	/* cpu number that owns kdb */
  72int kdb_nextline = 1;
  73int kdb_state;			/* General KDB state */
  74
  75struct task_struct *kdb_current_task;
  76EXPORT_SYMBOL(kdb_current_task);
  77struct pt_regs *kdb_current_regs;
  78
  79const char *kdb_diemsg;
  80static int kdb_go_count;
  81#ifdef CONFIG_KDB_CONTINUE_CATASTROPHIC
  82static unsigned int kdb_continue_catastrophic =
  83	CONFIG_KDB_CONTINUE_CATASTROPHIC;
  84#else
  85static unsigned int kdb_continue_catastrophic;
  86#endif
  87
  88/* kdb_commands describes the available commands. */
  89static kdbtab_t *kdb_commands;
  90#define KDB_BASE_CMD_MAX 50
  91static int kdb_max_commands = KDB_BASE_CMD_MAX;
  92static 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
  98typedef 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
 106static 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
 137static 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
 150static 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
 188static const int __nenv = ARRAY_SIZE(__env);
 189
 190struct 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 */
 204static 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 */
 229char *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 */
 267static 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 */
 291static 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 */
 316int 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 */
 337int 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
 359int 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 */
 382int 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
 459static 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 */
 494int 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
 628static 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 */
 659struct defcmd_set {
 660	int count;
 661	bool usable;
 662	char *name;
 663	char *usage;
 664	char *help;
 665	char **command;
 666};
 667static struct defcmd_set *defcmd_set;
 668static int defcmd_set_count;
 669static bool defcmd_in_progress;
 670
 671/* Forward references */
 672static int kdb_exec_defcmd(int argc, const char **argv);
 673
 674static 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 = false;
 680		if (!s->count)
 681			s->usable = false;
 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 = kcalloc(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 = false;
 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
 707static 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_array(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 = true;
 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 = true;
 760	kfree(save_defcmd_set);
 761	return 0;
 762fail_help:
 763	kfree(s->usage);
 764fail_usage:
 765	kfree(s->name);
 766fail_name:
 767	kfree(defcmd_set);
 768fail_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 */
 783static 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 */
 814static unsigned int cmd_head, cmd_tail;
 815static unsigned int cmdptr;
 816static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN];
 817static char cmd_cur[CMD_BUFLEN];
 818
 819/*
 820 * The "str" argument may point to something like  | grep xyz
 821 */
 822static 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 (!str_has_prefix(cp, "grep ")) {
 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
 911int 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
1094static 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 */
1121static 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
1131static 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
1142void 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
1153static void drop_newline(char *buf)
1154{
1155	size_t len = strlen(buf);
1156
1157	if (len == 0)
1158		return;
1159	if (*(buf + len - 1) == '\n')
1160		*(buf + len - 1) = '\0';
1161}
1162
1163/*
1164 * kdb_local - The main code for kdb.  This routine is invoked on a
1165 *	specific processor, it is not global.  The main kdb() routine
1166 *	ensures that only one processor at a time is in this routine.
1167 *	This code is called with the real reason code on the first
1168 *	entry to a kdb session, thereafter it is called with reason
1169 *	SWITCH, even if the user goes back to the original cpu.
1170 * Inputs:
1171 *	reason		The reason KDB was invoked
1172 *	error		The hardware-defined error code
1173 *	regs		The exception frame at time of fault/breakpoint.
1174 *	db_result	Result code from the break or debug point.
1175 * Returns:
1176 *	0	KDB was invoked for an event which it wasn't responsible
1177 *	1	KDB handled the event for which it was invoked.
1178 *	KDB_CMD_GO	User typed 'go'.
1179 *	KDB_CMD_CPU	User switched to another cpu.
1180 *	KDB_CMD_SS	Single step.
1181 */
1182static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
1183		     kdb_dbtrap_t db_result)
1184{
1185	char *cmdbuf;
1186	int diag;
1187	struct task_struct *kdb_current =
1188		kdb_curr_task(raw_smp_processor_id());
1189
1190	KDB_DEBUG_STATE("kdb_local 1", reason);
1191	kdb_go_count = 0;
1192	if (reason == KDB_REASON_DEBUG) {
1193		/* special case below */
1194	} else {
1195		kdb_printf("\nEntering kdb (current=0x%px, pid %d) ",
1196			   kdb_current, kdb_current ? kdb_current->pid : 0);
1197#if defined(CONFIG_SMP)
1198		kdb_printf("on processor %d ", raw_smp_processor_id());
1199#endif
1200	}
1201
1202	switch (reason) {
1203	case KDB_REASON_DEBUG:
1204	{
1205		/*
1206		 * If re-entering kdb after a single step
1207		 * command, don't print the message.
1208		 */
1209		switch (db_result) {
1210		case KDB_DB_BPT:
1211			kdb_printf("\nEntering kdb (0x%px, pid %d) ",
1212				   kdb_current, kdb_current->pid);
1213#if defined(CONFIG_SMP)
1214			kdb_printf("on processor %d ", raw_smp_processor_id());
1215#endif
1216			kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
1217				   instruction_pointer(regs));
1218			break;
1219		case KDB_DB_SS:
1220			break;
1221		case KDB_DB_SSBPT:
1222			KDB_DEBUG_STATE("kdb_local 4", reason);
1223			return 1;	/* kdba_db_trap did the work */
1224		default:
1225			kdb_printf("kdb: Bad result from kdba_db_trap: %d\n",
1226				   db_result);
1227			break;
1228		}
1229
1230	}
1231		break;
1232	case KDB_REASON_ENTER:
1233		if (KDB_STATE(KEYBOARD))
1234			kdb_printf("due to Keyboard Entry\n");
1235		else
1236			kdb_printf("due to KDB_ENTER()\n");
1237		break;
1238	case KDB_REASON_KEYBOARD:
1239		KDB_STATE_SET(KEYBOARD);
1240		kdb_printf("due to Keyboard Entry\n");
1241		break;
1242	case KDB_REASON_ENTER_SLAVE:
1243		/* drop through, slaves only get released via cpu switch */
1244	case KDB_REASON_SWITCH:
1245		kdb_printf("due to cpu switch\n");
1246		break;
1247	case KDB_REASON_OOPS:
1248		kdb_printf("Oops: %s\n", kdb_diemsg);
1249		kdb_printf("due to oops @ " kdb_machreg_fmt "\n",
1250			   instruction_pointer(regs));
1251		kdb_dumpregs(regs);
1252		break;
1253	case KDB_REASON_SYSTEM_NMI:
1254		kdb_printf("due to System NonMaskable Interrupt\n");
1255		break;
1256	case KDB_REASON_NMI:
1257		kdb_printf("due to NonMaskable Interrupt @ "
1258			   kdb_machreg_fmt "\n",
1259			   instruction_pointer(regs));
1260		break;
1261	case KDB_REASON_SSTEP:
1262	case KDB_REASON_BREAK:
1263		kdb_printf("due to %s @ " kdb_machreg_fmt "\n",
1264			   reason == KDB_REASON_BREAK ?
1265			   "Breakpoint" : "SS trap", instruction_pointer(regs));
1266		/*
1267		 * Determine if this breakpoint is one that we
1268		 * are interested in.
1269		 */
1270		if (db_result != KDB_DB_BPT) {
1271			kdb_printf("kdb: error return from kdba_bp_trap: %d\n",
1272				   db_result);
1273			KDB_DEBUG_STATE("kdb_local 6", reason);
1274			return 0;	/* Not for us, dismiss it */
1275		}
1276		break;
1277	case KDB_REASON_RECURSE:
1278		kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n",
1279			   instruction_pointer(regs));
1280		break;
1281	default:
1282		kdb_printf("kdb: unexpected reason code: %d\n", reason);
1283		KDB_DEBUG_STATE("kdb_local 8", reason);
1284		return 0;	/* Not for us, dismiss it */
1285	}
1286
1287	while (1) {
1288		/*
1289		 * Initialize pager context.
1290		 */
1291		kdb_nextline = 1;
1292		KDB_STATE_CLEAR(SUPPRESS);
1293		kdb_grepping_flag = 0;
1294		/* ensure the old search does not leak into '/' commands */
1295		kdb_grep_string[0] = '\0';
1296
1297		cmdbuf = cmd_cur;
1298		*cmdbuf = '\0';
1299		*(cmd_hist[cmd_head]) = '\0';
1300
1301do_full_getstr:
1302#if defined(CONFIG_SMP)
1303		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
1304			 raw_smp_processor_id());
1305#else
1306		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"));
1307#endif
1308		if (defcmd_in_progress)
1309			strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
1310
1311		/*
1312		 * Fetch command from keyboard
1313		 */
1314		cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str);
1315		if (*cmdbuf != '\n') {
1316			if (*cmdbuf < 32) {
1317				if (cmdptr == cmd_head) {
1318					strncpy(cmd_hist[cmd_head], cmd_cur,
1319						CMD_BUFLEN);
1320					*(cmd_hist[cmd_head] +
1321					  strlen(cmd_hist[cmd_head])-1) = '\0';
1322				}
1323				if (!handle_ctrl_cmd(cmdbuf))
1324					*(cmd_cur+strlen(cmd_cur)-1) = '\0';
1325				cmdbuf = cmd_cur;
1326				goto do_full_getstr;
1327			} else {
1328				strncpy(cmd_hist[cmd_head], cmd_cur,
1329					CMD_BUFLEN);
1330			}
1331
1332			cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT;
1333			if (cmd_head == cmd_tail)
1334				cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT;
1335		}
1336
1337		cmdptr = cmd_head;
1338		diag = kdb_parse(cmdbuf);
1339		if (diag == KDB_NOTFOUND) {
1340			drop_newline(cmdbuf);
1341			kdb_printf("Unknown kdb command: '%s'\n", cmdbuf);
1342			diag = 0;
1343		}
1344		if (diag == KDB_CMD_GO
1345		 || diag == KDB_CMD_CPU
1346		 || diag == KDB_CMD_SS
1347		 || diag == KDB_CMD_KGDB)
1348			break;
1349
1350		if (diag)
1351			kdb_cmderror(diag);
1352	}
1353	KDB_DEBUG_STATE("kdb_local 9", diag);
1354	return diag;
1355}
1356
1357
1358/*
1359 * kdb_print_state - Print the state data for the current processor
1360 *	for debugging.
1361 * Inputs:
1362 *	text		Identifies the debug point
1363 *	value		Any integer value to be printed, e.g. reason code.
1364 */
1365void kdb_print_state(const char *text, int value)
1366{
1367	kdb_printf("state: %s cpu %d value %d initial %d state %x\n",
1368		   text, raw_smp_processor_id(), value, kdb_initial_cpu,
1369		   kdb_state);
1370}
1371
1372/*
1373 * kdb_main_loop - After initial setup and assignment of the
1374 *	controlling cpu, all cpus are in this loop.  One cpu is in
1375 *	control and will issue the kdb prompt, the others will spin
1376 *	until 'go' or cpu switch.
1377 *
1378 *	To get a consistent view of the kernel stacks for all
1379 *	processes, this routine is invoked from the main kdb code via
1380 *	an architecture specific routine.  kdba_main_loop is
1381 *	responsible for making the kernel stacks consistent for all
1382 *	processes, there should be no difference between a blocked
1383 *	process and a running process as far as kdb is concerned.
1384 * Inputs:
1385 *	reason		The reason KDB was invoked
1386 *	error		The hardware-defined error code
1387 *	reason2		kdb's current reason code.
1388 *			Initially error but can change
1389 *			according to kdb state.
1390 *	db_result	Result code from break or debug point.
1391 *	regs		The exception frame at time of fault/breakpoint.
1392 *			should always be valid.
1393 * Returns:
1394 *	0	KDB was invoked for an event which it wasn't responsible
1395 *	1	KDB handled the event for which it was invoked.
1396 */
1397int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
1398	      kdb_dbtrap_t db_result, struct pt_regs *regs)
1399{
1400	int result = 1;
1401	/* Stay in kdb() until 'go', 'ss[b]' or an error */
1402	while (1) {
1403		/*
1404		 * All processors except the one that is in control
1405		 * will spin here.
1406		 */
1407		KDB_DEBUG_STATE("kdb_main_loop 1", reason);
1408		while (KDB_STATE(HOLD_CPU)) {
1409			/* state KDB is turned off by kdb_cpu to see if the
1410			 * other cpus are still live, each cpu in this loop
1411			 * turns it back on.
1412			 */
1413			if (!KDB_STATE(KDB))
1414				KDB_STATE_SET(KDB);
1415		}
1416
1417		KDB_STATE_CLEAR(SUPPRESS);
1418		KDB_DEBUG_STATE("kdb_main_loop 2", reason);
1419		if (KDB_STATE(LEAVING))
1420			break;	/* Another cpu said 'go' */
1421		/* Still using kdb, this processor is in control */
1422		result = kdb_local(reason2, error, regs, db_result);
1423		KDB_DEBUG_STATE("kdb_main_loop 3", result);
1424
1425		if (result == KDB_CMD_CPU)
1426			break;
1427
1428		if (result == KDB_CMD_SS) {
1429			KDB_STATE_SET(DOING_SS);
1430			break;
1431		}
1432
1433		if (result == KDB_CMD_KGDB) {
1434			if (!KDB_STATE(DOING_KGDB))
1435				kdb_printf("Entering please attach debugger "
1436					   "or use $D#44+ or $3#33\n");
1437			break;
1438		}
1439		if (result && result != 1 && result != KDB_CMD_GO)
1440			kdb_printf("\nUnexpected kdb_local return code %d\n",
1441				   result);
1442		KDB_DEBUG_STATE("kdb_main_loop 4", reason);
1443		break;
1444	}
1445	if (KDB_STATE(DOING_SS))
1446		KDB_STATE_CLEAR(SSBPT);
1447
1448	/* Clean up any keyboard devices before leaving */
1449	kdb_kbd_cleanup_state();
1450
1451	return result;
1452}
1453
1454/*
1455 * kdb_mdr - This function implements the guts of the 'mdr', memory
1456 * read command.
1457 *	mdr  <addr arg>,<byte count>
1458 * Inputs:
1459 *	addr	Start address
1460 *	count	Number of bytes
1461 * Returns:
1462 *	Always 0.  Any errors are detected and printed by kdb_getarea.
1463 */
1464static int kdb_mdr(unsigned long addr, unsigned int count)
1465{
1466	unsigned char c;
1467	while (count--) {
1468		if (kdb_getarea(c, addr))
1469			return 0;
1470		kdb_printf("%02x", c);
1471		addr++;
1472	}
1473	kdb_printf("\n");
1474	return 0;
1475}
1476
1477/*
1478 * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4',
1479 *	'md8' 'mdr' and 'mds' commands.
1480 *
1481 *	md|mds  [<addr arg> [<line count> [<radix>]]]
1482 *	mdWcN	[<addr arg> [<line count> [<radix>]]]
1483 *		where W = is the width (1, 2, 4 or 8) and N is the count.
1484 *		for eg., md1c20 reads 20 bytes, 1 at a time.
1485 *	mdr  <addr arg>,<byte count>
1486 */
1487static void kdb_md_line(const char *fmtstr, unsigned long addr,
1488			int symbolic, int nosect, int bytesperword,
1489			int num, int repeat, int phys)
1490{
1491	/* print just one line of data */
1492	kdb_symtab_t symtab;
1493	char cbuf[32];
1494	char *c = cbuf;
1495	int i;
1496	int j;
1497	unsigned long word;
1498
1499	memset(cbuf, '\0', sizeof(cbuf));
1500	if (phys)
1501		kdb_printf("phys " kdb_machreg_fmt0 " ", addr);
1502	else
1503		kdb_printf(kdb_machreg_fmt0 " ", addr);
1504
1505	for (i = 0; i < num && repeat--; i++) {
1506		if (phys) {
1507			if (kdb_getphysword(&word, addr, bytesperword))
1508				break;
1509		} else if (kdb_getword(&word, addr, bytesperword))
1510			break;
1511		kdb_printf(fmtstr, word);
1512		if (symbolic)
1513			kdbnearsym(word, &symtab);
1514		else
1515			memset(&symtab, 0, sizeof(symtab));
1516		if (symtab.sym_name) {
1517			kdb_symbol_print(word, &symtab, 0);
1518			if (!nosect) {
1519				kdb_printf("\n");
1520				kdb_printf("                       %s %s "
1521					   kdb_machreg_fmt " "
1522					   kdb_machreg_fmt " "
1523					   kdb_machreg_fmt, symtab.mod_name,
1524					   symtab.sec_name, symtab.sec_start,
1525					   symtab.sym_start, symtab.sym_end);
1526			}
1527			addr += bytesperword;
1528		} else {
1529			union {
1530				u64 word;
1531				unsigned char c[8];
1532			} wc;
1533			unsigned char *cp;
1534#ifdef	__BIG_ENDIAN
1535			cp = wc.c + 8 - bytesperword;
1536#else
1537			cp = wc.c;
1538#endif
1539			wc.word = word;
1540#define printable_char(c) \
1541	({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; })
1542			for (j = 0; j < bytesperword; j++)
1543				*c++ = printable_char(*cp++);
1544			addr += bytesperword;
1545#undef printable_char
1546		}
1547	}
1548	kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1),
1549		   " ", cbuf);
1550}
1551
1552static int kdb_md(int argc, const char **argv)
1553{
1554	static unsigned long last_addr;
1555	static int last_radix, last_bytesperword, last_repeat;
1556	int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
1557	int nosect = 0;
1558	char fmtchar, fmtstr[64];
1559	unsigned long addr;
1560	unsigned long word;
1561	long offset = 0;
1562	int symbolic = 0;
1563	int valid = 0;
1564	int phys = 0;
1565	int raw = 0;
1566
1567	kdbgetintenv("MDCOUNT", &mdcount);
1568	kdbgetintenv("RADIX", &radix);
1569	kdbgetintenv("BYTESPERWORD", &bytesperword);
1570
1571	/* Assume 'md <addr>' and start with environment values */
1572	repeat = mdcount * 16 / bytesperword;
1573
1574	if (strcmp(argv[0], "mdr") == 0) {
1575		if (argc == 2 || (argc == 0 && last_addr != 0))
1576			valid = raw = 1;
1577		else
1578			return KDB_ARGCOUNT;
1579	} else if (isdigit(argv[0][2])) {
1580		bytesperword = (int)(argv[0][2] - '0');
1581		if (bytesperword == 0) {
1582			bytesperword = last_bytesperword;
1583			if (bytesperword == 0)
1584				bytesperword = 4;
1585		}
1586		last_bytesperword = bytesperword;
1587		repeat = mdcount * 16 / bytesperword;
1588		if (!argv[0][3])
1589			valid = 1;
1590		else if (argv[0][3] == 'c' && argv[0][4]) {
1591			char *p;
1592			repeat = simple_strtoul(argv[0] + 4, &p, 10);
1593			mdcount = ((repeat * bytesperword) + 15) / 16;
1594			valid = !*p;
1595		}
1596		last_repeat = repeat;
1597	} else if (strcmp(argv[0], "md") == 0)
1598		valid = 1;
1599	else if (strcmp(argv[0], "mds") == 0)
1600		valid = 1;
1601	else if (strcmp(argv[0], "mdp") == 0) {
1602		phys = valid = 1;
1603	}
1604	if (!valid)
1605		return KDB_NOTFOUND;
1606
1607	if (argc == 0) {
1608		if (last_addr == 0)
1609			return KDB_ARGCOUNT;
1610		addr = last_addr;
1611		radix = last_radix;
1612		bytesperword = last_bytesperword;
1613		repeat = last_repeat;
1614		if (raw)
1615			mdcount = repeat;
1616		else
1617			mdcount = ((repeat * bytesperword) + 15) / 16;
1618	}
1619
1620	if (argc) {
1621		unsigned long val;
1622		int diag, nextarg = 1;
1623		diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
1624				     &offset, NULL);
1625		if (diag)
1626			return diag;
1627		if (argc > nextarg+2)
1628			return KDB_ARGCOUNT;
1629
1630		if (argc >= nextarg) {
1631			diag = kdbgetularg(argv[nextarg], &val);
1632			if (!diag) {
1633				mdcount = (int) val;
1634				if (raw)
1635					repeat = mdcount;
1636				else
1637					repeat = mdcount * 16 / bytesperword;
1638			}
1639		}
1640		if (argc >= nextarg+1) {
1641			diag = kdbgetularg(argv[nextarg+1], &val);
1642			if (!diag)
1643				radix = (int) val;
1644		}
1645	}
1646
1647	if (strcmp(argv[0], "mdr") == 0) {
1648		int ret;
1649		last_addr = addr;
1650		ret = kdb_mdr(addr, mdcount);
1651		last_addr += mdcount;
1652		last_repeat = mdcount;
1653		last_bytesperword = bytesperword; // to make REPEAT happy
1654		return ret;
1655	}
1656
1657	switch (radix) {
1658	case 10:
1659		fmtchar = 'd';
1660		break;
1661	case 16:
1662		fmtchar = 'x';
1663		break;
1664	case 8:
1665		fmtchar = 'o';
1666		break;
1667	default:
1668		return KDB_BADRADIX;
1669	}
1670
1671	last_radix = radix;
1672
1673	if (bytesperword > KDB_WORD_SIZE)
1674		return KDB_BADWIDTH;
1675
1676	switch (bytesperword) {
1677	case 8:
1678		sprintf(fmtstr, "%%16.16l%c ", fmtchar);
1679		break;
1680	case 4:
1681		sprintf(fmtstr, "%%8.8l%c ", fmtchar);
1682		break;
1683	case 2:
1684		sprintf(fmtstr, "%%4.4l%c ", fmtchar);
1685		break;
1686	case 1:
1687		sprintf(fmtstr, "%%2.2l%c ", fmtchar);
1688		break;
1689	default:
1690		return KDB_BADWIDTH;
1691	}
1692
1693	last_repeat = repeat;
1694	last_bytesperword = bytesperword;
1695
1696	if (strcmp(argv[0], "mds") == 0) {
1697		symbolic = 1;
1698		/* Do not save these changes as last_*, they are temporary mds
1699		 * overrides.
1700		 */
1701		bytesperword = KDB_WORD_SIZE;
1702		repeat = mdcount;
1703		kdbgetintenv("NOSECT", &nosect);
1704	}
1705
1706	/* Round address down modulo BYTESPERWORD */
1707
1708	addr &= ~(bytesperword-1);
1709
1710	while (repeat > 0) {
1711		unsigned long a;
1712		int n, z, num = (symbolic ? 1 : (16 / bytesperword));
1713
1714		if (KDB_FLAG(CMD_INTERRUPT))
1715			return 0;
1716		for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) {
1717			if (phys) {
1718				if (kdb_getphysword(&word, a, bytesperword)
1719						|| word)
1720					break;
1721			} else if (kdb_getword(&word, a, bytesperword) || word)
1722				break;
1723		}
1724		n = min(num, repeat);
1725		kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword,
1726			    num, repeat, phys);
1727		addr += bytesperword * n;
1728		repeat -= n;
1729		z = (z + num - 1) / num;
1730		if (z > 2) {
1731			int s = num * (z-2);
1732			kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0
1733				   " zero suppressed\n",
1734				addr, addr + bytesperword * s - 1);
1735			addr += bytesperword * s;
1736			repeat -= s;
1737		}
1738	}
1739	last_addr = addr;
1740
1741	return 0;
1742}
1743
1744/*
1745 * kdb_mm - This function implements the 'mm' command.
1746 *	mm address-expression new-value
1747 * Remarks:
1748 *	mm works on machine words, mmW works on bytes.
1749 */
1750static int kdb_mm(int argc, const char **argv)
1751{
1752	int diag;
1753	unsigned long addr;
1754	long offset = 0;
1755	unsigned long contents;
1756	int nextarg;
1757	int width;
1758
1759	if (argv[0][2] && !isdigit(argv[0][2]))
1760		return KDB_NOTFOUND;
1761
1762	if (argc < 2)
1763		return KDB_ARGCOUNT;
1764
1765	nextarg = 1;
1766	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1767	if (diag)
1768		return diag;
1769
1770	if (nextarg > argc)
1771		return KDB_ARGCOUNT;
1772	diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL);
1773	if (diag)
1774		return diag;
1775
1776	if (nextarg != argc + 1)
1777		return KDB_ARGCOUNT;
1778
1779	width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE);
1780	diag = kdb_putword(addr, contents, width);
1781	if (diag)
1782		return diag;
1783
1784	kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents);
1785
1786	return 0;
1787}
1788
1789/*
1790 * kdb_go - This function implements the 'go' command.
1791 *	go [address-expression]
1792 */
1793static int kdb_go(int argc, const char **argv)
1794{
1795	unsigned long addr;
1796	int diag;
1797	int nextarg;
1798	long offset;
1799
1800	if (raw_smp_processor_id() != kdb_initial_cpu) {
1801		kdb_printf("go must execute on the entry cpu, "
1802			   "please use \"cpu %d\" and then execute go\n",
1803			   kdb_initial_cpu);
1804		return KDB_BADCPUNUM;
1805	}
1806	if (argc == 1) {
1807		nextarg = 1;
1808		diag = kdbgetaddrarg(argc, argv, &nextarg,
1809				     &addr, &offset, NULL);
1810		if (diag)
1811			return diag;
1812	} else if (argc) {
1813		return KDB_ARGCOUNT;
1814	}
1815
1816	diag = KDB_CMD_GO;
1817	if (KDB_FLAG(CATASTROPHIC)) {
1818		kdb_printf("Catastrophic error detected\n");
1819		kdb_printf("kdb_continue_catastrophic=%d, ",
1820			kdb_continue_catastrophic);
1821		if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) {
1822			kdb_printf("type go a second time if you really want "
1823				   "to continue\n");
1824			return 0;
1825		}
1826		if (kdb_continue_catastrophic == 2) {
1827			kdb_printf("forcing reboot\n");
1828			kdb_reboot(0, NULL);
1829		}
1830		kdb_printf("attempting to continue\n");
1831	}
1832	return diag;
1833}
1834
1835/*
1836 * kdb_rd - This function implements the 'rd' command.
1837 */
1838static int kdb_rd(int argc, const char **argv)
1839{
1840	int len = kdb_check_regs();
1841#if DBG_MAX_REG_NUM > 0
1842	int i;
1843	char *rname;
1844	int rsize;
1845	u64 reg64;
1846	u32 reg32;
1847	u16 reg16;
1848	u8 reg8;
1849
1850	if (len)
1851		return len;
1852
1853	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1854		rsize = dbg_reg_def[i].size * 2;
1855		if (rsize > 16)
1856			rsize = 2;
1857		if (len + strlen(dbg_reg_def[i].name) + 4 + rsize > 80) {
1858			len = 0;
1859			kdb_printf("\n");
1860		}
1861		if (len)
1862			len += kdb_printf("  ");
1863		switch(dbg_reg_def[i].size * 8) {
1864		case 8:
1865			rname = dbg_get_reg(i, &reg8, kdb_current_regs);
1866			if (!rname)
1867				break;
1868			len += kdb_printf("%s: %02x", rname, reg8);
1869			break;
1870		case 16:
1871			rname = dbg_get_reg(i, &reg16, kdb_current_regs);
1872			if (!rname)
1873				break;
1874			len += kdb_printf("%s: %04x", rname, reg16);
1875			break;
1876		case 32:
1877			rname = dbg_get_reg(i, &reg32, kdb_current_regs);
1878			if (!rname)
1879				break;
1880			len += kdb_printf("%s: %08x", rname, reg32);
1881			break;
1882		case 64:
1883			rname = dbg_get_reg(i, &reg64, kdb_current_regs);
1884			if (!rname)
1885				break;
1886			len += kdb_printf("%s: %016llx", rname, reg64);
1887			break;
1888		default:
1889			len += kdb_printf("%s: ??", dbg_reg_def[i].name);
1890		}
1891	}
1892	kdb_printf("\n");
1893#else
1894	if (len)
1895		return len;
1896
1897	kdb_dumpregs(kdb_current_regs);
1898#endif
1899	return 0;
1900}
1901
1902/*
1903 * kdb_rm - This function implements the 'rm' (register modify)  command.
1904 *	rm register-name new-contents
1905 * Remarks:
1906 *	Allows register modification with the same restrictions as gdb
1907 */
1908static int kdb_rm(int argc, const char **argv)
1909{
1910#if DBG_MAX_REG_NUM > 0
1911	int diag;
1912	const char *rname;
1913	int i;
1914	u64 reg64;
1915	u32 reg32;
1916	u16 reg16;
1917	u8 reg8;
1918
1919	if (argc != 2)
1920		return KDB_ARGCOUNT;
1921	/*
1922	 * Allow presence or absence of leading '%' symbol.
1923	 */
1924	rname = argv[1];
1925	if (*rname == '%')
1926		rname++;
1927
1928	diag = kdbgetu64arg(argv[2], &reg64);
1929	if (diag)
1930		return diag;
1931
1932	diag = kdb_check_regs();
1933	if (diag)
1934		return diag;
1935
1936	diag = KDB_BADREG;
1937	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1938		if (strcmp(rname, dbg_reg_def[i].name) == 0) {
1939			diag = 0;
1940			break;
1941		}
1942	}
1943	if (!diag) {
1944		switch(dbg_reg_def[i].size * 8) {
1945		case 8:
1946			reg8 = reg64;
1947			dbg_set_reg(i, &reg8, kdb_current_regs);
1948			break;
1949		case 16:
1950			reg16 = reg64;
1951			dbg_set_reg(i, &reg16, kdb_current_regs);
1952			break;
1953		case 32:
1954			reg32 = reg64;
1955			dbg_set_reg(i, &reg32, kdb_current_regs);
1956			break;
1957		case 64:
1958			dbg_set_reg(i, &reg64, kdb_current_regs);
1959			break;
1960		}
1961	}
1962	return diag;
1963#else
1964	kdb_printf("ERROR: Register set currently not implemented\n");
1965    return 0;
1966#endif
1967}
1968
1969#if defined(CONFIG_MAGIC_SYSRQ)
1970/*
1971 * kdb_sr - This function implements the 'sr' (SYSRQ key) command
1972 *	which interfaces to the soi-disant MAGIC SYSRQ functionality.
1973 *		sr <magic-sysrq-code>
1974 */
1975static int kdb_sr(int argc, const char **argv)
1976{
1977	bool check_mask =
1978	    !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
1979
1980	if (argc != 1)
1981		return KDB_ARGCOUNT;
1982
1983	kdb_trap_printk++;
1984	__handle_sysrq(*argv[1], check_mask);
1985	kdb_trap_printk--;
1986
1987	return 0;
1988}
1989#endif	/* CONFIG_MAGIC_SYSRQ */
1990
1991/*
1992 * kdb_ef - This function implements the 'regs' (display exception
1993 *	frame) command.  This command takes an address and expects to
1994 *	find an exception frame at that address, formats and prints
1995 *	it.
1996 *		regs address-expression
1997 * Remarks:
1998 *	Not done yet.
1999 */
2000static int kdb_ef(int argc, const char **argv)
2001{
2002	int diag;
2003	unsigned long addr;
2004	long offset;
2005	int nextarg;
2006
2007	if (argc != 1)
2008		return KDB_ARGCOUNT;
2009
2010	nextarg = 1;
2011	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
2012	if (diag)
2013		return diag;
2014	show_regs((struct pt_regs *)addr);
2015	return 0;
2016}
2017
2018#if defined(CONFIG_MODULES)
2019/*
2020 * kdb_lsmod - This function implements the 'lsmod' command.  Lists
2021 *	currently loaded kernel modules.
2022 *	Mostly taken from userland lsmod.
2023 */
2024static int kdb_lsmod(int argc, const char **argv)
2025{
2026	struct module *mod;
2027
2028	if (argc != 0)
2029		return KDB_ARGCOUNT;
2030
2031	kdb_printf("Module                  Size  modstruct     Used by\n");
2032	list_for_each_entry(mod, kdb_modules, list) {
2033		if (mod->state == MODULE_STATE_UNFORMED)
2034			continue;
2035
2036		kdb_printf("%-20s%8u  0x%px ", mod->name,
2037			   mod->core_layout.size, (void *)mod);
2038#ifdef CONFIG_MODULE_UNLOAD
2039		kdb_printf("%4d ", module_refcount(mod));
2040#endif
2041		if (mod->state == MODULE_STATE_GOING)
2042			kdb_printf(" (Unloading)");
2043		else if (mod->state == MODULE_STATE_COMING)
2044			kdb_printf(" (Loading)");
2045		else
2046			kdb_printf(" (Live)");
2047		kdb_printf(" 0x%px", mod->core_layout.base);
2048
2049#ifdef CONFIG_MODULE_UNLOAD
2050		{
2051			struct module_use *use;
2052			kdb_printf(" [ ");
2053			list_for_each_entry(use, &mod->source_list,
2054					    source_list)
2055				kdb_printf("%s ", use->target->name);
2056			kdb_printf("]\n");
2057		}
2058#endif
2059	}
2060
2061	return 0;
2062}
2063
2064#endif	/* CONFIG_MODULES */
2065
2066/*
2067 * kdb_env - This function implements the 'env' command.  Display the
2068 *	current environment variables.
2069 */
2070
2071static int kdb_env(int argc, const char **argv)
2072{
2073	int i;
2074
2075	for (i = 0; i < __nenv; i++) {
2076		if (__env[i])
2077			kdb_printf("%s\n", __env[i]);
2078	}
2079
2080	if (KDB_DEBUG(MASK))
2081		kdb_printf("KDBFLAGS=0x%x\n", kdb_flags);
 
2082
2083	return 0;
2084}
2085
2086#ifdef CONFIG_PRINTK
2087/*
2088 * kdb_dmesg - This function implements the 'dmesg' command to display
2089 *	the contents of the syslog buffer.
2090 *		dmesg [lines] [adjust]
2091 */
2092static int kdb_dmesg(int argc, const char **argv)
2093{
2094	int diag;
2095	int logging;
2096	int lines = 0;
2097	int adjust = 0;
2098	int n = 0;
2099	int skip = 0;
2100	struct kmsg_dumper dumper = { .active = 1 };
2101	size_t len;
2102	char buf[201];
2103
2104	if (argc > 2)
2105		return KDB_ARGCOUNT;
2106	if (argc) {
2107		char *cp;
2108		lines = simple_strtol(argv[1], &cp, 0);
2109		if (*cp)
2110			lines = 0;
2111		if (argc > 1) {
2112			adjust = simple_strtoul(argv[2], &cp, 0);
2113			if (*cp || adjust < 0)
2114				adjust = 0;
2115		}
2116	}
2117
2118	/* disable LOGGING if set */
2119	diag = kdbgetintenv("LOGGING", &logging);
2120	if (!diag && logging) {
2121		const char *setargs[] = { "set", "LOGGING", "0" };
2122		kdb_set(2, setargs);
2123	}
2124
2125	kmsg_dump_rewind_nolock(&dumper);
2126	while (kmsg_dump_get_line_nolock(&dumper, 1, NULL, 0, NULL))
2127		n++;
2128
2129	if (lines < 0) {
2130		if (adjust >= n)
2131			kdb_printf("buffer only contains %d lines, nothing "
2132				   "printed\n", n);
2133		else if (adjust - lines >= n)
2134			kdb_printf("buffer only contains %d lines, last %d "
2135				   "lines printed\n", n, n - adjust);
2136		skip = adjust;
2137		lines = abs(lines);
2138	} else if (lines > 0) {
2139		skip = n - lines - adjust;
2140		lines = abs(lines);
2141		if (adjust >= n) {
2142			kdb_printf("buffer only contains %d lines, "
2143				   "nothing printed\n", n);
2144			skip = n;
2145		} else if (skip < 0) {
2146			lines += skip;
2147			skip = 0;
2148			kdb_printf("buffer only contains %d lines, first "
2149				   "%d lines printed\n", n, lines);
2150		}
2151	} else {
2152		lines = n;
2153	}
2154
2155	if (skip >= n || skip < 0)
2156		return 0;
2157
2158	kmsg_dump_rewind_nolock(&dumper);
2159	while (kmsg_dump_get_line_nolock(&dumper, 1, buf, sizeof(buf), &len)) {
2160		if (skip) {
2161			skip--;
2162			continue;
2163		}
2164		if (!lines--)
2165			break;
2166		if (KDB_FLAG(CMD_INTERRUPT))
2167			return 0;
2168
2169		kdb_printf("%.*s\n", (int)len - 1, buf);
2170	}
2171
2172	return 0;
2173}
2174#endif /* CONFIG_PRINTK */
2175
2176/* Make sure we balance enable/disable calls, must disable first. */
2177static atomic_t kdb_nmi_disabled;
2178
2179static int kdb_disable_nmi(int argc, const char *argv[])
2180{
2181	if (atomic_read(&kdb_nmi_disabled))
2182		return 0;
2183	atomic_set(&kdb_nmi_disabled, 1);
2184	arch_kgdb_ops.enable_nmi(0);
2185	return 0;
2186}
2187
2188static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
2189{
2190	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
2191		return -EINVAL;
2192	arch_kgdb_ops.enable_nmi(1);
2193	return 0;
2194}
2195
2196static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
2197	.set = kdb_param_enable_nmi,
2198};
2199module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
2200
2201/*
2202 * kdb_cpu - This function implements the 'cpu' command.
2203 *	cpu	[<cpunum>]
2204 * Returns:
2205 *	KDB_CMD_CPU for success, a kdb diagnostic if error
2206 */
2207static void kdb_cpu_status(void)
2208{
2209	int i, start_cpu, first_print = 1;
2210	char state, prev_state = '?';
2211
2212	kdb_printf("Currently on cpu %d\n", raw_smp_processor_id());
2213	kdb_printf("Available cpus: ");
2214	for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
2215		if (!cpu_online(i)) {
2216			state = 'F';	/* cpu is offline */
2217		} else if (!kgdb_info[i].enter_kgdb) {
2218			state = 'D';	/* cpu is online but unresponsive */
2219		} else {
2220			state = ' ';	/* cpu is responding to kdb */
2221			if (kdb_task_state_char(KDB_TSK(i)) == 'I')
2222				state = 'I';	/* idle task */
2223		}
2224		if (state != prev_state) {
2225			if (prev_state != '?') {
2226				if (!first_print)
2227					kdb_printf(", ");
2228				first_print = 0;
2229				kdb_printf("%d", start_cpu);
2230				if (start_cpu < i-1)
2231					kdb_printf("-%d", i-1);
2232				if (prev_state != ' ')
2233					kdb_printf("(%c)", prev_state);
2234			}
2235			prev_state = state;
2236			start_cpu = i;
2237		}
2238	}
2239	/* print the trailing cpus, ignoring them if they are all offline */
2240	if (prev_state != 'F') {
2241		if (!first_print)
2242			kdb_printf(", ");
2243		kdb_printf("%d", start_cpu);
2244		if (start_cpu < i-1)
2245			kdb_printf("-%d", i-1);
2246		if (prev_state != ' ')
2247			kdb_printf("(%c)", prev_state);
2248	}
2249	kdb_printf("\n");
2250}
2251
2252static int kdb_cpu(int argc, const char **argv)
2253{
2254	unsigned long cpunum;
2255	int diag;
2256
2257	if (argc == 0) {
2258		kdb_cpu_status();
2259		return 0;
2260	}
2261
2262	if (argc != 1)
2263		return KDB_ARGCOUNT;
2264
2265	diag = kdbgetularg(argv[1], &cpunum);
2266	if (diag)
2267		return diag;
2268
2269	/*
2270	 * Validate cpunum
2271	 */
2272	if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
2273		return KDB_BADCPUNUM;
2274
2275	dbg_switch_cpu = cpunum;
2276
2277	/*
2278	 * Switch to other cpu
2279	 */
2280	return KDB_CMD_CPU;
2281}
2282
2283/* The user may not realize that ps/bta with no parameters does not print idle
2284 * or sleeping system daemon processes, so tell them how many were suppressed.
2285 */
2286void kdb_ps_suppressed(void)
2287{
2288	int idle = 0, daemon = 0;
2289	unsigned long mask_I = kdb_task_state_string("I"),
2290		      mask_M = kdb_task_state_string("M");
2291	unsigned long cpu;
2292	const struct task_struct *p, *g;
2293	for_each_online_cpu(cpu) {
2294		p = kdb_curr_task(cpu);
2295		if (kdb_task_state(p, mask_I))
2296			++idle;
2297	}
2298	kdb_do_each_thread(g, p) {
2299		if (kdb_task_state(p, mask_M))
2300			++daemon;
2301	} kdb_while_each_thread(g, p);
2302	if (idle || daemon) {
2303		if (idle)
2304			kdb_printf("%d idle process%s (state I)%s\n",
2305				   idle, idle == 1 ? "" : "es",
2306				   daemon ? " and " : "");
2307		if (daemon)
2308			kdb_printf("%d sleeping system daemon (state M) "
2309				   "process%s", daemon,
2310				   daemon == 1 ? "" : "es");
2311		kdb_printf(" suppressed,\nuse 'ps A' to see all.\n");
2312	}
2313}
2314
2315/*
2316 * kdb_ps - This function implements the 'ps' command which shows a
2317 *	list of the active processes.
2318 *		ps [DRSTCZEUIMA]   All processes, optionally filtered by state
2319 */
2320void kdb_ps1(const struct task_struct *p)
2321{
2322	int cpu;
2323	unsigned long tmp;
2324
2325	if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
 
2326		return;
2327
2328	cpu = kdb_process_cpu(p);
2329	kdb_printf("0x%px %8d %8d  %d %4d   %c  0x%px %c%s\n",
2330		   (void *)p, p->pid, p->parent->pid,
2331		   kdb_task_has_cpu(p), kdb_process_cpu(p),
2332		   kdb_task_state_char(p),
2333		   (void *)(&p->thread),
2334		   p == kdb_curr_task(raw_smp_processor_id()) ? '*' : ' ',
2335		   p->comm);
2336	if (kdb_task_has_cpu(p)) {
2337		if (!KDB_TSK(cpu)) {
2338			kdb_printf("  Error: no saved data for this cpu\n");
2339		} else {
2340			if (KDB_TSK(cpu) != p)
2341				kdb_printf("  Error: does not match running "
2342				   "process table (0x%px)\n", KDB_TSK(cpu));
2343		}
2344	}
2345}
2346
2347static int kdb_ps(int argc, const char **argv)
2348{
2349	struct task_struct *g, *p;
2350	unsigned long mask, cpu;
2351
2352	if (argc == 0)
2353		kdb_ps_suppressed();
2354	kdb_printf("%-*s      Pid   Parent [*] cpu State %-*s Command\n",
2355		(int)(2*sizeof(void *))+2, "Task Addr",
2356		(int)(2*sizeof(void *))+2, "Thread");
2357	mask = kdb_task_state_string(argc ? argv[1] : NULL);
2358	/* Run the active tasks first */
2359	for_each_online_cpu(cpu) {
2360		if (KDB_FLAG(CMD_INTERRUPT))
2361			return 0;
2362		p = kdb_curr_task(cpu);
2363		if (kdb_task_state(p, mask))
2364			kdb_ps1(p);
2365	}
2366	kdb_printf("\n");
2367	/* Now the real tasks */
2368	kdb_do_each_thread(g, p) {
2369		if (KDB_FLAG(CMD_INTERRUPT))
2370			return 0;
2371		if (kdb_task_state(p, mask))
2372			kdb_ps1(p);
2373	} kdb_while_each_thread(g, p);
2374
2375	return 0;
2376}
2377
2378/*
2379 * kdb_pid - This function implements the 'pid' command which switches
2380 *	the currently active process.
2381 *		pid [<pid> | R]
2382 */
2383static int kdb_pid(int argc, const char **argv)
2384{
2385	struct task_struct *p;
2386	unsigned long val;
2387	int diag;
2388
2389	if (argc > 1)
2390		return KDB_ARGCOUNT;
2391
2392	if (argc) {
2393		if (strcmp(argv[1], "R") == 0) {
2394			p = KDB_TSK(kdb_initial_cpu);
2395		} else {
2396			diag = kdbgetularg(argv[1], &val);
2397			if (diag)
2398				return KDB_BADINT;
2399
2400			p = find_task_by_pid_ns((pid_t)val,	&init_pid_ns);
2401			if (!p) {
2402				kdb_printf("No task with pid=%d\n", (pid_t)val);
2403				return 0;
2404			}
2405		}
2406		kdb_set_current_task(p);
2407	}
2408	kdb_printf("KDB current process is %s(pid=%d)\n",
2409		   kdb_current_task->comm,
2410		   kdb_current_task->pid);
2411
2412	return 0;
2413}
2414
2415static int kdb_kgdb(int argc, const char **argv)
2416{
2417	return KDB_CMD_KGDB;
2418}
2419
2420/*
2421 * kdb_help - This function implements the 'help' and '?' commands.
2422 */
2423static int kdb_help(int argc, const char **argv)
2424{
2425	kdbtab_t *kt;
2426	int i;
2427
2428	kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
2429	kdb_printf("-----------------------------"
2430		   "-----------------------------\n");
2431	for_each_kdbcmd(kt, i) {
2432		char *space = "";
2433		if (KDB_FLAG(CMD_INTERRUPT))
2434			return 0;
2435		if (!kt->cmd_name)
2436			continue;
2437		if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
2438			continue;
2439		if (strlen(kt->cmd_usage) > 20)
2440			space = "\n                                    ";
2441		kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
2442			   kt->cmd_usage, space, kt->cmd_help);
2443	}
2444	return 0;
2445}
2446
2447/*
2448 * kdb_kill - This function implements the 'kill' commands.
2449 */
2450static int kdb_kill(int argc, const char **argv)
2451{
2452	long sig, pid;
2453	char *endp;
2454	struct task_struct *p;
2455
2456	if (argc != 2)
2457		return KDB_ARGCOUNT;
2458
2459	sig = simple_strtol(argv[1], &endp, 0);
2460	if (*endp)
2461		return KDB_BADINT;
2462	if ((sig >= 0) || !valid_signal(-sig)) {
2463		kdb_printf("Invalid signal parameter.<-signal>\n");
2464		return 0;
2465	}
2466	sig = -sig;
2467
2468	pid = simple_strtol(argv[2], &endp, 0);
2469	if (*endp)
2470		return KDB_BADINT;
2471	if (pid <= 0) {
2472		kdb_printf("Process ID must be large than 0.\n");
2473		return 0;
2474	}
2475
2476	/* Find the process. */
2477	p = find_task_by_pid_ns(pid, &init_pid_ns);
2478	if (!p) {
2479		kdb_printf("The specified process isn't found.\n");
2480		return 0;
2481	}
2482	p = p->group_leader;
2483	kdb_send_sig(p, sig);
2484	return 0;
2485}
2486
2487/*
2488 * Most of this code has been lifted from kernel/timer.c::sys_sysinfo().
2489 * I cannot call that code directly from kdb, it has an unconditional
2490 * cli()/sti() and calls routines that take locks which can stop the debugger.
2491 */
2492static void kdb_sysinfo(struct sysinfo *val)
2493{
2494	u64 uptime = ktime_get_mono_fast_ns();
2495
2496	memset(val, 0, sizeof(*val));
2497	val->uptime = div_u64(uptime, NSEC_PER_SEC);
2498	val->loads[0] = avenrun[0];
2499	val->loads[1] = avenrun[1];
2500	val->loads[2] = avenrun[2];
2501	val->procs = nr_threads-1;
2502	si_meminfo(val);
2503
2504	return;
2505}
2506
2507/*
2508 * kdb_summary - This function implements the 'summary' command.
2509 */
2510static int kdb_summary(int argc, const char **argv)
2511{
2512	time64_t now;
2513	struct tm tm;
2514	struct sysinfo val;
2515
2516	if (argc)
2517		return KDB_ARGCOUNT;
2518
2519	kdb_printf("sysname    %s\n", init_uts_ns.name.sysname);
2520	kdb_printf("release    %s\n", init_uts_ns.name.release);
2521	kdb_printf("version    %s\n", init_uts_ns.name.version);
2522	kdb_printf("machine    %s\n", init_uts_ns.name.machine);
2523	kdb_printf("nodename   %s\n", init_uts_ns.name.nodename);
2524	kdb_printf("domainname %s\n", init_uts_ns.name.domainname);
2525
2526	now = __ktime_get_real_seconds();
2527	time64_to_tm(now, 0, &tm);
2528	kdb_printf("date       %04ld-%02d-%02d %02d:%02d:%02d "
2529		   "tz_minuteswest %d\n",
2530		1900+tm.tm_year, tm.tm_mon+1, tm.tm_mday,
2531		tm.tm_hour, tm.tm_min, tm.tm_sec,
2532		sys_tz.tz_minuteswest);
2533
2534	kdb_sysinfo(&val);
2535	kdb_printf("uptime     ");
2536	if (val.uptime > (24*60*60)) {
2537		int days = val.uptime / (24*60*60);
2538		val.uptime %= (24*60*60);
2539		kdb_printf("%d day%s ", days, days == 1 ? "" : "s");
2540	}
2541	kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
2542
2543	kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
2544		LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
2545		LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
2546		LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
2547
2548	/* Display in kilobytes */
2549#define K(x) ((x) << (PAGE_SHIFT - 10))
2550	kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
2551		   "Buffers:        %8lu kB\n",
2552		   K(val.totalram), K(val.freeram), K(val.bufferram));
2553	return 0;
2554}
2555
2556/*
2557 * kdb_per_cpu - This function implements the 'per_cpu' command.
2558 */
2559static int kdb_per_cpu(int argc, const char **argv)
2560{
2561	char fmtstr[64];
2562	int cpu, diag, nextarg = 1;
2563	unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL;
2564
2565	if (argc < 1 || argc > 3)
2566		return KDB_ARGCOUNT;
2567
2568	diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL);
2569	if (diag)
2570		return diag;
2571
2572	if (argc >= 2) {
2573		diag = kdbgetularg(argv[2], &bytesperword);
2574		if (diag)
2575			return diag;
2576	}
2577	if (!bytesperword)
2578		bytesperword = KDB_WORD_SIZE;
2579	else if (bytesperword > KDB_WORD_SIZE)
2580		return KDB_BADWIDTH;
2581	sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword));
2582	if (argc >= 3) {
2583		diag = kdbgetularg(argv[3], &whichcpu);
2584		if (diag)
2585			return diag;
2586		if (whichcpu >= nr_cpu_ids || !cpu_online(whichcpu)) {
2587			kdb_printf("cpu %ld is not online\n", whichcpu);
2588			return KDB_BADCPUNUM;
2589		}
2590	}
2591
2592	/* Most architectures use __per_cpu_offset[cpu], some use
2593	 * __per_cpu_offset(cpu), smp has no __per_cpu_offset.
2594	 */
2595#ifdef	__per_cpu_offset
2596#define KDB_PCU(cpu) __per_cpu_offset(cpu)
2597#else
2598#ifdef	CONFIG_SMP
2599#define KDB_PCU(cpu) __per_cpu_offset[cpu]
2600#else
2601#define KDB_PCU(cpu) 0
2602#endif
2603#endif
2604	for_each_online_cpu(cpu) {
2605		if (KDB_FLAG(CMD_INTERRUPT))
2606			return 0;
2607
2608		if (whichcpu != ~0UL && whichcpu != cpu)
2609			continue;
2610		addr = symaddr + KDB_PCU(cpu);
2611		diag = kdb_getword(&val, addr, bytesperword);
2612		if (diag) {
2613			kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to "
2614				   "read, diag=%d\n", cpu, addr, diag);
2615			continue;
2616		}
2617		kdb_printf("%5d ", cpu);
2618		kdb_md_line(fmtstr, addr,
2619			bytesperword == KDB_WORD_SIZE,
2620			1, bytesperword, 1, 1, 0);
2621	}
2622#undef KDB_PCU
2623	return 0;
2624}
2625
2626/*
2627 * display help for the use of cmd | grep pattern
2628 */
2629static int kdb_grep_help(int argc, const char **argv)
2630{
2631	kdb_printf("Usage of  cmd args | grep pattern:\n");
2632	kdb_printf("  Any command's output may be filtered through an ");
2633	kdb_printf("emulated 'pipe'.\n");
2634	kdb_printf("  'grep' is just a key word.\n");
2635	kdb_printf("  The pattern may include a very limited set of "
2636		   "metacharacters:\n");
2637	kdb_printf("   pattern or ^pattern or pattern$ or ^pattern$\n");
2638	kdb_printf("  And if there are spaces in the pattern, you may "
2639		   "quote it:\n");
2640	kdb_printf("   \"pat tern\" or \"^pat tern\" or \"pat tern$\""
2641		   " or \"^pat tern$\"\n");
2642	return 0;
2643}
2644
2645/*
2646 * kdb_register_flags - This function is used to register a kernel
2647 * 	debugger command.
2648 * Inputs:
2649 *	cmd	Command name
2650 *	func	Function to execute the command
2651 *	usage	A simple usage string showing arguments
2652 *	help	A simple help string describing command
2653 *	repeat	Does the command auto repeat on enter?
2654 * Returns:
2655 *	zero for success, one if a duplicate command.
2656 */
2657#define kdb_command_extend 50	/* arbitrary */
2658int kdb_register_flags(char *cmd,
2659		       kdb_func_t func,
2660		       char *usage,
2661		       char *help,
2662		       short minlen,
2663		       kdb_cmdflags_t flags)
2664{
2665	int i;
2666	kdbtab_t *kp;
2667
2668	/*
2669	 *  Brute force method to determine duplicates
2670	 */
2671	for_each_kdbcmd(kp, i) {
2672		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2673			kdb_printf("Duplicate kdb command registered: "
2674				"%s, func %px help %s\n", cmd, func, help);
2675			return 1;
2676		}
2677	}
2678
2679	/*
2680	 * Insert command into first available location in table
2681	 */
2682	for_each_kdbcmd(kp, i) {
2683		if (kp->cmd_name == NULL)
2684			break;
2685	}
2686
2687	if (i >= kdb_max_commands) {
2688		kdbtab_t *new = kmalloc_array(kdb_max_commands -
2689						KDB_BASE_CMD_MAX +
2690						kdb_command_extend,
2691					      sizeof(*new),
2692					      GFP_KDB);
2693		if (!new) {
2694			kdb_printf("Could not allocate new kdb_command "
2695				   "table\n");
2696			return 1;
2697		}
2698		if (kdb_commands) {
2699			memcpy(new, kdb_commands,
2700			  (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
2701			kfree(kdb_commands);
2702		}
2703		memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
2704		       kdb_command_extend * sizeof(*new));
2705		kdb_commands = new;
2706		kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
2707		kdb_max_commands += kdb_command_extend;
2708	}
2709
2710	kp->cmd_name   = cmd;
2711	kp->cmd_func   = func;
2712	kp->cmd_usage  = usage;
2713	kp->cmd_help   = help;
2714	kp->cmd_minlen = minlen;
2715	kp->cmd_flags  = flags;
2716
2717	return 0;
2718}
2719EXPORT_SYMBOL_GPL(kdb_register_flags);
2720
2721
2722/*
2723 * kdb_register - Compatibility register function for commands that do
2724 *	not need to specify a repeat state.  Equivalent to
2725 *	kdb_register_flags with flags set to 0.
2726 * Inputs:
2727 *	cmd	Command name
2728 *	func	Function to execute the command
2729 *	usage	A simple usage string showing arguments
2730 *	help	A simple help string describing command
2731 * Returns:
2732 *	zero for success, one if a duplicate command.
2733 */
2734int kdb_register(char *cmd,
2735	     kdb_func_t func,
2736	     char *usage,
2737	     char *help,
2738	     short minlen)
2739{
2740	return kdb_register_flags(cmd, func, usage, help, minlen, 0);
2741}
2742EXPORT_SYMBOL_GPL(kdb_register);
2743
2744/*
2745 * kdb_unregister - This function is used to unregister a kernel
2746 *	debugger command.  It is generally called when a module which
2747 *	implements kdb commands is unloaded.
2748 * Inputs:
2749 *	cmd	Command name
2750 * Returns:
2751 *	zero for success, one command not registered.
2752 */
2753int kdb_unregister(char *cmd)
2754{
2755	int i;
2756	kdbtab_t *kp;
2757
2758	/*
2759	 *  find the command.
2760	 */
2761	for_each_kdbcmd(kp, i) {
2762		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2763			kp->cmd_name = NULL;
2764			return 0;
2765		}
2766	}
2767
2768	/* Couldn't find it.  */
2769	return 1;
2770}
2771EXPORT_SYMBOL_GPL(kdb_unregister);
2772
2773/* Initialize the kdb command table. */
2774static void __init kdb_inittab(void)
2775{
2776	int i;
2777	kdbtab_t *kp;
2778
2779	for_each_kdbcmd(kp, i)
2780		kp->cmd_name = NULL;
2781
2782	kdb_register_flags("md", kdb_md, "<vaddr>",
2783	  "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
2784	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2785	kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
2786	  "Display Raw Memory", 0,
2787	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2788	kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
2789	  "Display Physical Memory", 0,
2790	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2791	kdb_register_flags("mds", kdb_md, "<vaddr>",
2792	  "Display Memory Symbolically", 0,
2793	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2794	kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
2795	  "Modify Memory Contents", 0,
2796	  KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
2797	kdb_register_flags("go", kdb_go, "[<vaddr>]",
2798	  "Continue Execution", 1,
2799	  KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2800	kdb_register_flags("rd", kdb_rd, "",
2801	  "Display Registers", 0,
2802	  KDB_ENABLE_REG_READ);
2803	kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
2804	  "Modify Registers", 0,
2805	  KDB_ENABLE_REG_WRITE);
2806	kdb_register_flags("ef", kdb_ef, "<vaddr>",
2807	  "Display exception frame", 0,
2808	  KDB_ENABLE_MEM_READ);
2809	kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
2810	  "Stack traceback", 1,
2811	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2812	kdb_register_flags("btp", kdb_bt, "<pid>",
2813	  "Display stack for process <pid>", 0,
2814	  KDB_ENABLE_INSPECT);
2815	kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
2816	  "Backtrace all processes matching state flag", 0,
2817	  KDB_ENABLE_INSPECT);
2818	kdb_register_flags("btc", kdb_bt, "",
2819	  "Backtrace current process on each cpu", 0,
2820	  KDB_ENABLE_INSPECT);
2821	kdb_register_flags("btt", kdb_bt, "<vaddr>",
2822	  "Backtrace process given its struct task address", 0,
2823	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2824	kdb_register_flags("env", kdb_env, "",
2825	  "Show environment variables", 0,
2826	  KDB_ENABLE_ALWAYS_SAFE);
2827	kdb_register_flags("set", kdb_set, "",
2828	  "Set environment variables", 0,
2829	  KDB_ENABLE_ALWAYS_SAFE);
2830	kdb_register_flags("help", kdb_help, "",
2831	  "Display Help Message", 1,
2832	  KDB_ENABLE_ALWAYS_SAFE);
2833	kdb_register_flags("?", kdb_help, "",
2834	  "Display Help Message", 0,
2835	  KDB_ENABLE_ALWAYS_SAFE);
2836	kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
2837	  "Switch to new cpu", 0,
2838	  KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2839	kdb_register_flags("kgdb", kdb_kgdb, "",
2840	  "Enter kgdb mode", 0, 0);
2841	kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
2842	  "Display active task list", 0,
2843	  KDB_ENABLE_INSPECT);
2844	kdb_register_flags("pid", kdb_pid, "<pidnum>",
2845	  "Switch to another task", 0,
2846	  KDB_ENABLE_INSPECT);
2847	kdb_register_flags("reboot", kdb_reboot, "",
2848	  "Reboot the machine immediately", 0,
2849	  KDB_ENABLE_REBOOT);
2850#if defined(CONFIG_MODULES)
2851	kdb_register_flags("lsmod", kdb_lsmod, "",
2852	  "List loaded kernel modules", 0,
2853	  KDB_ENABLE_INSPECT);
2854#endif
2855#if defined(CONFIG_MAGIC_SYSRQ)
2856	kdb_register_flags("sr", kdb_sr, "<key>",
2857	  "Magic SysRq key", 0,
2858	  KDB_ENABLE_ALWAYS_SAFE);
2859#endif
2860#if defined(CONFIG_PRINTK)
2861	kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
2862	  "Display syslog buffer", 0,
2863	  KDB_ENABLE_ALWAYS_SAFE);
2864#endif
2865	if (arch_kgdb_ops.enable_nmi) {
2866		kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
2867		  "Disable NMI entry to KDB", 0,
2868		  KDB_ENABLE_ALWAYS_SAFE);
2869	}
2870	kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
2871	  "Define a set of commands, down to endefcmd", 0,
2872	  KDB_ENABLE_ALWAYS_SAFE);
2873	kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
2874	  "Send a signal to a process", 0,
2875	  KDB_ENABLE_SIGNAL);
2876	kdb_register_flags("summary", kdb_summary, "",
2877	  "Summarize the system", 4,
2878	  KDB_ENABLE_ALWAYS_SAFE);
2879	kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
2880	  "Display per_cpu variables", 3,
2881	  KDB_ENABLE_MEM_READ);
2882	kdb_register_flags("grephelp", kdb_grep_help, "",
2883	  "Display help on | grep", 0,
2884	  KDB_ENABLE_ALWAYS_SAFE);
2885}
2886
2887/* Execute any commands defined in kdb_cmds.  */
2888static void __init kdb_cmd_init(void)
2889{
2890	int i, diag;
2891	for (i = 0; kdb_cmds[i]; ++i) {
2892		diag = kdb_parse(kdb_cmds[i]);
2893		if (diag)
2894			kdb_printf("kdb command %s failed, kdb diag %d\n",
2895				kdb_cmds[i], diag);
2896	}
2897	if (defcmd_in_progress) {
2898		kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n");
2899		kdb_parse("endefcmd");
2900	}
2901}
2902
2903/* Initialize kdb_printf, breakpoint tables and kdb state */
2904void __init kdb_init(int lvl)
2905{
2906	static int kdb_init_lvl = KDB_NOT_INITIALIZED;
2907	int i;
2908
2909	if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl)
2910		return;
2911	for (i = kdb_init_lvl; i < lvl; i++) {
2912		switch (i) {
2913		case KDB_NOT_INITIALIZED:
2914			kdb_inittab();		/* Initialize Command Table */
2915			kdb_initbptab();	/* Initialize Breakpoints */
2916			break;
2917		case KDB_INIT_EARLY:
2918			kdb_cmd_init();		/* Build kdb_cmds tables */
2919			break;
2920		}
2921	}
2922	kdb_init_lvl = lvl;
2923}
v5.9
   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
  53static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;
  54module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);
  55
  56char kdb_grep_string[KDB_GREP_STRLEN];
  57int kdb_grepping_flag;
  58EXPORT_SYMBOL(kdb_grepping_flag);
  59int kdb_grep_leading;
  60int kdb_grep_trailing;
  61
  62/*
  63 * Kernel debugger state flags
  64 */
  65unsigned 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 */
  71int kdb_initial_cpu = -1;	/* cpu number that owns kdb */
  72int kdb_nextline = 1;
  73int kdb_state;			/* General KDB state */
  74
  75struct task_struct *kdb_current_task;
 
  76struct pt_regs *kdb_current_regs;
  77
  78const char *kdb_diemsg;
  79static int kdb_go_count;
  80#ifdef CONFIG_KDB_CONTINUE_CATASTROPHIC
  81static unsigned int kdb_continue_catastrophic =
  82	CONFIG_KDB_CONTINUE_CATASTROPHIC;
  83#else
  84static unsigned int kdb_continue_catastrophic;
  85#endif
  86
  87/* kdb_commands describes the available commands. */
  88static kdbtab_t *kdb_commands;
  89#define KDB_BASE_CMD_MAX 50
  90static int kdb_max_commands = KDB_BASE_CMD_MAX;
  91static kdbtab_t kdb_base_commands[KDB_BASE_CMD_MAX];
  92#define for_each_kdbcmd(cmd, num)					\
  93	for ((cmd) = kdb_base_commands, (num) = 0;			\
  94	     num < kdb_max_commands;					\
  95	     num++, num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++)
  96
  97typedef struct _kdbmsg {
  98	int	km_diag;	/* kdb diagnostic */
  99	char	*km_msg;	/* Corresponding message text */
 100} kdbmsg_t;
 101
 102#define KDBMSG(msgnum, text) \
 103	{ KDB_##msgnum, text }
 104
 105static kdbmsg_t kdbmsgs[] = {
 106	KDBMSG(NOTFOUND, "Command Not Found"),
 107	KDBMSG(ARGCOUNT, "Improper argument count, see usage."),
 108	KDBMSG(BADWIDTH, "Illegal value for BYTESPERWORD use 1, 2, 4 or 8, "
 109	       "8 is only allowed on 64 bit systems"),
 110	KDBMSG(BADRADIX, "Illegal value for RADIX use 8, 10 or 16"),
 111	KDBMSG(NOTENV, "Cannot find environment variable"),
 112	KDBMSG(NOENVVALUE, "Environment variable should have value"),
 113	KDBMSG(NOTIMP, "Command not implemented"),
 114	KDBMSG(ENVFULL, "Environment full"),
 115	KDBMSG(ENVBUFFULL, "Environment buffer full"),
 116	KDBMSG(TOOMANYBPT, "Too many breakpoints defined"),
 117#ifdef CONFIG_CPU_XSCALE
 118	KDBMSG(TOOMANYDBREGS, "More breakpoints than ibcr registers defined"),
 119#else
 120	KDBMSG(TOOMANYDBREGS, "More breakpoints than db registers defined"),
 121#endif
 122	KDBMSG(DUPBPT, "Duplicate breakpoint address"),
 123	KDBMSG(BPTNOTFOUND, "Breakpoint not found"),
 124	KDBMSG(BADMODE, "Invalid IDMODE"),
 125	KDBMSG(BADINT, "Illegal numeric value"),
 126	KDBMSG(INVADDRFMT, "Invalid symbolic address format"),
 127	KDBMSG(BADREG, "Invalid register name"),
 128	KDBMSG(BADCPUNUM, "Invalid cpu number"),
 129	KDBMSG(BADLENGTH, "Invalid length field"),
 130	KDBMSG(NOBP, "No Breakpoint exists"),
 131	KDBMSG(BADADDR, "Invalid address"),
 132	KDBMSG(NOPERM, "Permission denied"),
 133};
 134#undef KDBMSG
 135
 136static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
 137
 138
 139/*
 140 * Initial environment.   This is all kept static and local to
 141 * this file.   We don't want to rely on the memory allocation
 142 * mechanisms in the kernel, so we use a very limited allocate-only
 143 * heap for new and altered environment variables.  The entire
 144 * environment is limited to a fixed number of entries (add more
 145 * to __env[] if required) and a fixed amount of heap (add more to
 146 * KDB_ENVBUFSIZE if required).
 147 */
 148
 149static char *__env[] = {
 150#if defined(CONFIG_SMP)
 151 "PROMPT=[%d]kdb> ",
 152#else
 153 "PROMPT=kdb> ",
 154#endif
 155 "MOREPROMPT=more> ",
 156 "RADIX=16",
 157 "MDCOUNT=8",			/* lines of md output */
 158 KDB_PLATFORM_ENV,
 159 "DTABCOUNT=30",
 160 "NOSECT=1",
 161 (char *)0,
 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};
 186
 187static const int __nenv = ARRAY_SIZE(__env);
 188
 189struct task_struct *kdb_curr_task(int cpu)
 190{
 191	struct task_struct *p = curr_task(cpu);
 192#ifdef	_TIF_MCA_INIT
 193	if ((task_thread_info(p)->flags & _TIF_MCA_INIT) && KDB_TSK(cpu))
 194		p = krp->p;
 195#endif
 196	return p;
 197}
 198
 199/*
 200 * Check whether the flags of the current command and the permissions
 201 * of the kdb console has allow a command to be run.
 202 */
 203static inline bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
 204				   bool no_args)
 205{
 206	/* permissions comes from userspace so needs massaging slightly */
 207	permissions &= KDB_ENABLE_MASK;
 208	permissions |= KDB_ENABLE_ALWAYS_SAFE;
 209
 210	/* some commands change group when launched with no arguments */
 211	if (no_args)
 212		permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
 213
 214	flags |= KDB_ENABLE_ALL;
 215
 216	return permissions & flags;
 217}
 218
 219/*
 220 * kdbgetenv - This function will return the character string value of
 221 *	an environment variable.
 222 * Parameters:
 223 *	match	A character string representing an environment variable.
 224 * Returns:
 225 *	NULL	No environment variable matches 'match'
 226 *	char*	Pointer to string value of environment variable.
 227 */
 228char *kdbgetenv(const char *match)
 229{
 230	char **ep = __env;
 231	int matchlen = strlen(match);
 232	int i;
 233
 234	for (i = 0; i < __nenv; i++) {
 235		char *e = *ep++;
 236
 237		if (!e)
 238			continue;
 239
 240		if ((strncmp(match, e, matchlen) == 0)
 241		 && ((e[matchlen] == '\0')
 242		   || (e[matchlen] == '='))) {
 243			char *cp = strchr(e, '=');
 244			return cp ? ++cp : "";
 245		}
 246	}
 247	return NULL;
 248}
 249
 250/*
 251 * kdballocenv - This function is used to allocate bytes for
 252 *	environment entries.
 253 * Parameters:
 254 *	match	A character string representing a numeric value
 255 * Outputs:
 256 *	*value  the unsigned long representation of the env variable 'match'
 257 * Returns:
 258 *	Zero on success, a kdb diagnostic on failure.
 259 * Remarks:
 260 *	We use a static environment buffer (envbuffer) to hold the values
 261 *	of dynamically generated environment variables (see kdb_set).  Buffer
 262 *	space once allocated is never free'd, so over time, the amount of space
 263 *	(currently 512 bytes) will be exhausted if env variables are changed
 264 *	frequently.
 265 */
 266static char *kdballocenv(size_t bytes)
 267{
 268#define	KDB_ENVBUFSIZE	512
 269	static char envbuffer[KDB_ENVBUFSIZE];
 270	static int envbufsize;
 271	char *ep = NULL;
 272
 273	if ((KDB_ENVBUFSIZE - envbufsize) >= bytes) {
 274		ep = &envbuffer[envbufsize];
 275		envbufsize += bytes;
 276	}
 277	return ep;
 278}
 279
 280/*
 281 * kdbgetulenv - This function will return the value of an unsigned
 282 *	long-valued environment variable.
 283 * Parameters:
 284 *	match	A character string representing a numeric value
 285 * Outputs:
 286 *	*value  the unsigned long represntation of the env variable 'match'
 287 * Returns:
 288 *	Zero on success, a kdb diagnostic on failure.
 289 */
 290static int kdbgetulenv(const char *match, unsigned long *value)
 291{
 292	char *ep;
 293
 294	ep = kdbgetenv(match);
 295	if (!ep)
 296		return KDB_NOTENV;
 297	if (strlen(ep) == 0)
 298		return KDB_NOENVVALUE;
 299
 300	*value = simple_strtoul(ep, NULL, 0);
 301
 302	return 0;
 303}
 304
 305/*
 306 * kdbgetintenv - This function will return the value of an
 307 *	integer-valued environment variable.
 308 * Parameters:
 309 *	match	A character string representing an integer-valued env variable
 310 * Outputs:
 311 *	*value  the integer representation of the environment variable 'match'
 312 * Returns:
 313 *	Zero on success, a kdb diagnostic on failure.
 314 */
 315int kdbgetintenv(const char *match, int *value)
 316{
 317	unsigned long val;
 318	int diag;
 319
 320	diag = kdbgetulenv(match, &val);
 321	if (!diag)
 322		*value = (int) val;
 323	return diag;
 324}
 325
 326/*
 327 * kdbgetularg - This function will convert a numeric string into an
 328 *	unsigned long value.
 329 * Parameters:
 330 *	arg	A character string representing a numeric value
 331 * Outputs:
 332 *	*value  the unsigned long represntation of arg.
 333 * Returns:
 334 *	Zero on success, a kdb diagnostic on failure.
 335 */
 336int kdbgetularg(const char *arg, unsigned long *value)
 337{
 338	char *endp;
 339	unsigned long val;
 340
 341	val = simple_strtoul(arg, &endp, 0);
 342
 343	if (endp == arg) {
 344		/*
 345		 * Also try base 16, for us folks too lazy to type the
 346		 * leading 0x...
 347		 */
 348		val = simple_strtoul(arg, &endp, 16);
 349		if (endp == arg)
 350			return KDB_BADINT;
 351	}
 352
 353	*value = val;
 354
 355	return 0;
 356}
 357
 358int kdbgetu64arg(const char *arg, u64 *value)
 359{
 360	char *endp;
 361	u64 val;
 362
 363	val = simple_strtoull(arg, &endp, 0);
 364
 365	if (endp == arg) {
 366
 367		val = simple_strtoull(arg, &endp, 16);
 368		if (endp == arg)
 369			return KDB_BADINT;
 370	}
 371
 372	*value = val;
 373
 374	return 0;
 375}
 376
 377/*
 378 * kdb_set - This function implements the 'set' command.  Alter an
 379 *	existing environment variable or create a new one.
 380 */
 381int kdb_set(int argc, const char **argv)
 382{
 383	int i;
 384	char *ep;
 385	size_t varlen, vallen;
 386
 387	/*
 388	 * we can be invoked two ways:
 389	 *   set var=value    argv[1]="var", argv[2]="value"
 390	 *   set var = value  argv[1]="var", argv[2]="=", argv[3]="value"
 391	 * - if the latter, shift 'em down.
 392	 */
 393	if (argc == 3) {
 394		argv[2] = argv[3];
 395		argc--;
 396	}
 397
 398	if (argc != 2)
 399		return KDB_ARGCOUNT;
 400
 401	/*
 402	 * Censor sensitive variables
 403	 */
 404	if (strcmp(argv[1], "PROMPT") == 0 &&
 405	    !kdb_check_flags(KDB_ENABLE_MEM_READ, kdb_cmd_enabled, false))
 406		return KDB_NOPERM;
 407
 408	/*
 409	 * Check for internal variables
 410	 */
 411	if (strcmp(argv[1], "KDBDEBUG") == 0) {
 412		unsigned int debugflags;
 413		char *cp;
 414
 415		debugflags = simple_strtoul(argv[2], &cp, 0);
 416		if (cp == argv[2] || debugflags & ~KDB_DEBUG_FLAG_MASK) {
 417			kdb_printf("kdb: illegal debug flags '%s'\n",
 418				    argv[2]);
 419			return 0;
 420		}
 421		kdb_flags = (kdb_flags & ~KDB_DEBUG(MASK))
 
 422			| (debugflags << KDB_DEBUG_FLAG_SHIFT);
 423
 424		return 0;
 425	}
 426
 427	/*
 428	 * Tokenizer squashed the '=' sign.  argv[1] is variable
 429	 * name, argv[2] = value.
 430	 */
 431	varlen = strlen(argv[1]);
 432	vallen = strlen(argv[2]);
 433	ep = kdballocenv(varlen + vallen + 2);
 434	if (ep == (char *)0)
 435		return KDB_ENVBUFFULL;
 436
 437	sprintf(ep, "%s=%s", argv[1], argv[2]);
 438
 439	ep[varlen+vallen+1] = '\0';
 440
 441	for (i = 0; i < __nenv; i++) {
 442		if (__env[i]
 443		 && ((strncmp(__env[i], argv[1], varlen) == 0)
 444		   && ((__env[i][varlen] == '\0')
 445		    || (__env[i][varlen] == '=')))) {
 446			__env[i] = ep;
 447			return 0;
 448		}
 449	}
 450
 451	/*
 452	 * Wasn't existing variable.  Fit into slot.
 453	 */
 454	for (i = 0; i < __nenv-1; i++) {
 455		if (__env[i] == (char *)0) {
 456			__env[i] = ep;
 457			return 0;
 458		}
 459	}
 460
 461	return KDB_ENVFULL;
 462}
 463
 464static int kdb_check_regs(void)
 465{
 466	if (!kdb_current_regs) {
 467		kdb_printf("No current kdb registers."
 468			   "  You may need to select another task\n");
 469		return KDB_BADREG;
 470	}
 471	return 0;
 472}
 473
 474/*
 475 * kdbgetaddrarg - This function is responsible for parsing an
 476 *	address-expression and returning the value of the expression,
 477 *	symbol name, and offset to the caller.
 478 *
 479 *	The argument may consist of a numeric value (decimal or
 480 *	hexidecimal), a symbol name, a register name (preceded by the
 481 *	percent sign), an environment variable with a numeric value
 482 *	(preceded by a dollar sign) or a simple arithmetic expression
 483 *	consisting of a symbol name, +/-, and a numeric constant value
 484 *	(offset).
 485 * Parameters:
 486 *	argc	- count of arguments in argv
 487 *	argv	- argument vector
 488 *	*nextarg - index to next unparsed argument in argv[]
 489 *	regs	- Register state at time of KDB entry
 490 * Outputs:
 491 *	*value	- receives the value of the address-expression
 492 *	*offset - receives the offset specified, if any
 493 *	*name   - receives the symbol name, if any
 494 *	*nextarg - index to next unparsed argument in argv[]
 495 * Returns:
 496 *	zero is returned on success, a kdb diagnostic code is
 497 *      returned on error.
 498 */
 499int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
 500		  unsigned long *value,  long *offset,
 501		  char **name)
 502{
 503	unsigned long addr;
 504	unsigned long off = 0;
 505	int positive;
 506	int diag;
 507	int found = 0;
 508	char *symname;
 509	char symbol = '\0';
 510	char *cp;
 511	kdb_symtab_t symtab;
 512
 513	/*
 514	 * If the enable flags prohibit both arbitrary memory access
 515	 * and flow control then there are no reasonable grounds to
 516	 * provide symbol lookup.
 517	 */
 518	if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
 519			     kdb_cmd_enabled, false))
 520		return KDB_NOPERM;
 521
 522	/*
 523	 * Process arguments which follow the following syntax:
 524	 *
 525	 *  symbol | numeric-address [+/- numeric-offset]
 526	 *  %register
 527	 *  $environment-variable
 528	 */
 529
 530	if (*nextarg > argc)
 531		return KDB_ARGCOUNT;
 532
 533	symname = (char *)argv[*nextarg];
 534
 535	/*
 536	 * If there is no whitespace between the symbol
 537	 * or address and the '+' or '-' symbols, we
 538	 * remember the character and replace it with a
 539	 * null so the symbol/value can be properly parsed
 540	 */
 541	cp = strpbrk(symname, "+-");
 542	if (cp != NULL) {
 543		symbol = *cp;
 544		*cp++ = '\0';
 545	}
 546
 547	if (symname[0] == '$') {
 548		diag = kdbgetulenv(&symname[1], &addr);
 549		if (diag)
 550			return diag;
 551	} else if (symname[0] == '%') {
 552		diag = kdb_check_regs();
 553		if (diag)
 554			return diag;
 555		/* Implement register values with % at a later time as it is
 556		 * arch optional.
 557		 */
 558		return KDB_NOTIMP;
 559	} else {
 560		found = kdbgetsymval(symname, &symtab);
 561		if (found) {
 562			addr = symtab.sym_start;
 563		} else {
 564			diag = kdbgetularg(argv[*nextarg], &addr);
 565			if (diag)
 566				return diag;
 567		}
 568	}
 569
 570	if (!found)
 571		found = kdbnearsym(addr, &symtab);
 572
 573	(*nextarg)++;
 574
 575	if (name)
 576		*name = symname;
 577	if (value)
 578		*value = addr;
 579	if (offset && name && *name)
 580		*offset = addr - symtab.sym_start;
 581
 582	if ((*nextarg > argc)
 583	 && (symbol == '\0'))
 584		return 0;
 585
 586	/*
 587	 * check for +/- and offset
 588	 */
 589
 590	if (symbol == '\0') {
 591		if ((argv[*nextarg][0] != '+')
 592		 && (argv[*nextarg][0] != '-')) {
 593			/*
 594			 * Not our argument.  Return.
 595			 */
 596			return 0;
 597		} else {
 598			positive = (argv[*nextarg][0] == '+');
 599			(*nextarg)++;
 600		}
 601	} else
 602		positive = (symbol == '+');
 603
 604	/*
 605	 * Now there must be an offset!
 606	 */
 607	if ((*nextarg > argc)
 608	 && (symbol == '\0')) {
 609		return KDB_INVADDRFMT;
 610	}
 611
 612	if (!symbol) {
 613		cp = (char *)argv[*nextarg];
 614		(*nextarg)++;
 615	}
 616
 617	diag = kdbgetularg(cp, &off);
 618	if (diag)
 619		return diag;
 620
 621	if (!positive)
 622		off = -off;
 623
 624	if (offset)
 625		*offset += off;
 626
 627	if (value)
 628		*value += off;
 629
 630	return 0;
 631}
 632
 633static void kdb_cmderror(int diag)
 634{
 635	int i;
 636
 637	if (diag >= 0) {
 638		kdb_printf("no error detected (diagnostic is %d)\n", diag);
 639		return;
 640	}
 641
 642	for (i = 0; i < __nkdb_err; i++) {
 643		if (kdbmsgs[i].km_diag == diag) {
 644			kdb_printf("diag: %d: %s\n", diag, kdbmsgs[i].km_msg);
 645			return;
 646		}
 647	}
 648
 649	kdb_printf("Unknown diag %d\n", -diag);
 650}
 651
 652/*
 653 * kdb_defcmd, kdb_defcmd2 - This function implements the 'defcmd'
 654 *	command which defines one command as a set of other commands,
 655 *	terminated by endefcmd.  kdb_defcmd processes the initial
 656 *	'defcmd' command, kdb_defcmd2 is invoked from kdb_parse for
 657 *	the following commands until 'endefcmd'.
 658 * Inputs:
 659 *	argc	argument count
 660 *	argv	argument vector
 661 * Returns:
 662 *	zero for success, a kdb diagnostic if error
 663 */
 664struct defcmd_set {
 665	int count;
 666	bool usable;
 667	char *name;
 668	char *usage;
 669	char *help;
 670	char **command;
 671};
 672static struct defcmd_set *defcmd_set;
 673static int defcmd_set_count;
 674static bool defcmd_in_progress;
 675
 676/* Forward references */
 677static int kdb_exec_defcmd(int argc, const char **argv);
 678
 679static int kdb_defcmd2(const char *cmdstr, const char *argv0)
 680{
 681	struct defcmd_set *s = defcmd_set + defcmd_set_count - 1;
 682	char **save_command = s->command;
 683	if (strcmp(argv0, "endefcmd") == 0) {
 684		defcmd_in_progress = false;
 685		if (!s->count)
 686			s->usable = false;
 687		if (s->usable)
 688			/* macros are always safe because when executed each
 689			 * internal command re-enters kdb_parse() and is
 690			 * safety checked individually.
 691			 */
 692			kdb_register_flags(s->name, kdb_exec_defcmd, s->usage,
 693					   s->help, 0,
 694					   KDB_ENABLE_ALWAYS_SAFE);
 695		return 0;
 696	}
 697	if (!s->usable)
 698		return KDB_NOTIMP;
 699	s->command = kcalloc(s->count + 1, sizeof(*(s->command)), GFP_KDB);
 700	if (!s->command) {
 701		kdb_printf("Could not allocate new kdb_defcmd table for %s\n",
 702			   cmdstr);
 703		s->usable = false;
 704		return KDB_NOTIMP;
 705	}
 706	memcpy(s->command, save_command, s->count * sizeof(*(s->command)));
 707	s->command[s->count++] = kdb_strdup(cmdstr, GFP_KDB);
 708	kfree(save_command);
 709	return 0;
 710}
 711
 712static int kdb_defcmd(int argc, const char **argv)
 713{
 714	struct defcmd_set *save_defcmd_set = defcmd_set, *s;
 715	if (defcmd_in_progress) {
 716		kdb_printf("kdb: nested defcmd detected, assuming missing "
 717			   "endefcmd\n");
 718		kdb_defcmd2("endefcmd", "endefcmd");
 719	}
 720	if (argc == 0) {
 721		int i;
 722		for (s = defcmd_set; s < defcmd_set + defcmd_set_count; ++s) {
 723			kdb_printf("defcmd %s \"%s\" \"%s\"\n", s->name,
 724				   s->usage, s->help);
 725			for (i = 0; i < s->count; ++i)
 726				kdb_printf("%s", s->command[i]);
 727			kdb_printf("endefcmd\n");
 728		}
 729		return 0;
 730	}
 731	if (argc != 3)
 732		return KDB_ARGCOUNT;
 733	if (in_dbg_master()) {
 734		kdb_printf("Command only available during kdb_init()\n");
 735		return KDB_NOTIMP;
 736	}
 737	defcmd_set = kmalloc_array(defcmd_set_count + 1, sizeof(*defcmd_set),
 738				   GFP_KDB);
 739	if (!defcmd_set)
 740		goto fail_defcmd;
 741	memcpy(defcmd_set, save_defcmd_set,
 742	       defcmd_set_count * sizeof(*defcmd_set));
 743	s = defcmd_set + defcmd_set_count;
 744	memset(s, 0, sizeof(*s));
 745	s->usable = true;
 746	s->name = kdb_strdup(argv[1], GFP_KDB);
 747	if (!s->name)
 748		goto fail_name;
 749	s->usage = kdb_strdup(argv[2], GFP_KDB);
 750	if (!s->usage)
 751		goto fail_usage;
 752	s->help = kdb_strdup(argv[3], GFP_KDB);
 753	if (!s->help)
 754		goto fail_help;
 755	if (s->usage[0] == '"') {
 756		strcpy(s->usage, argv[2]+1);
 757		s->usage[strlen(s->usage)-1] = '\0';
 758	}
 759	if (s->help[0] == '"') {
 760		strcpy(s->help, argv[3]+1);
 761		s->help[strlen(s->help)-1] = '\0';
 762	}
 763	++defcmd_set_count;
 764	defcmd_in_progress = true;
 765	kfree(save_defcmd_set);
 766	return 0;
 767fail_help:
 768	kfree(s->usage);
 769fail_usage:
 770	kfree(s->name);
 771fail_name:
 772	kfree(defcmd_set);
 773fail_defcmd:
 774	kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]);
 775	defcmd_set = save_defcmd_set;
 776	return KDB_NOTIMP;
 777}
 778
 779/*
 780 * kdb_exec_defcmd - Execute the set of commands associated with this
 781 *	defcmd name.
 782 * Inputs:
 783 *	argc	argument count
 784 *	argv	argument vector
 785 * Returns:
 786 *	zero for success, a kdb diagnostic if error
 787 */
 788static int kdb_exec_defcmd(int argc, const char **argv)
 789{
 790	int i, ret;
 791	struct defcmd_set *s;
 792	if (argc != 0)
 793		return KDB_ARGCOUNT;
 794	for (s = defcmd_set, i = 0; i < defcmd_set_count; ++i, ++s) {
 795		if (strcmp(s->name, argv[0]) == 0)
 796			break;
 797	}
 798	if (i == defcmd_set_count) {
 799		kdb_printf("kdb_exec_defcmd: could not find commands for %s\n",
 800			   argv[0]);
 801		return KDB_NOTIMP;
 802	}
 803	for (i = 0; i < s->count; ++i) {
 804		/* Recursive use of kdb_parse, do not use argv after
 805		 * this point */
 806		argv = NULL;
 807		kdb_printf("[%s]kdb> %s\n", s->name, s->command[i]);
 808		ret = kdb_parse(s->command[i]);
 809		if (ret)
 810			return ret;
 811	}
 812	return 0;
 813}
 814
 815/* Command history */
 816#define KDB_CMD_HISTORY_COUNT	32
 817#define CMD_BUFLEN		200	/* kdb_printf: max printline
 818					 * size == 256 */
 819static unsigned int cmd_head, cmd_tail;
 820static unsigned int cmdptr;
 821static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN];
 822static char cmd_cur[CMD_BUFLEN];
 823
 824/*
 825 * The "str" argument may point to something like  | grep xyz
 826 */
 827static void parse_grep(const char *str)
 828{
 829	int	len;
 830	char	*cp = (char *)str, *cp2;
 831
 832	/* sanity check: we should have been called with the \ first */
 833	if (*cp != '|')
 834		return;
 835	cp++;
 836	while (isspace(*cp))
 837		cp++;
 838	if (!str_has_prefix(cp, "grep ")) {
 839		kdb_printf("invalid 'pipe', see grephelp\n");
 840		return;
 841	}
 842	cp += 5;
 843	while (isspace(*cp))
 844		cp++;
 845	cp2 = strchr(cp, '\n');
 846	if (cp2)
 847		*cp2 = '\0'; /* remove the trailing newline */
 848	len = strlen(cp);
 849	if (len == 0) {
 850		kdb_printf("invalid 'pipe', see grephelp\n");
 851		return;
 852	}
 853	/* now cp points to a nonzero length search string */
 854	if (*cp == '"') {
 855		/* allow it be "x y z" by removing the "'s - there must
 856		   be two of them */
 857		cp++;
 858		cp2 = strchr(cp, '"');
 859		if (!cp2) {
 860			kdb_printf("invalid quoted string, see grephelp\n");
 861			return;
 862		}
 863		*cp2 = '\0'; /* end the string where the 2nd " was */
 864	}
 865	kdb_grep_leading = 0;
 866	if (*cp == '^') {
 867		kdb_grep_leading = 1;
 868		cp++;
 869	}
 870	len = strlen(cp);
 871	kdb_grep_trailing = 0;
 872	if (*(cp+len-1) == '$') {
 873		kdb_grep_trailing = 1;
 874		*(cp+len-1) = '\0';
 875	}
 876	len = strlen(cp);
 877	if (!len)
 878		return;
 879	if (len >= KDB_GREP_STRLEN) {
 880		kdb_printf("search string too long\n");
 881		return;
 882	}
 883	strcpy(kdb_grep_string, cp);
 884	kdb_grepping_flag++;
 885	return;
 886}
 887
 888/*
 889 * kdb_parse - Parse the command line, search the command table for a
 890 *	matching command and invoke the command function.  This
 891 *	function may be called recursively, if it is, the second call
 892 *	will overwrite argv and cbuf.  It is the caller's
 893 *	responsibility to save their argv if they recursively call
 894 *	kdb_parse().
 895 * Parameters:
 896 *      cmdstr	The input command line to be parsed.
 897 *	regs	The registers at the time kdb was entered.
 898 * Returns:
 899 *	Zero for success, a kdb diagnostic if failure.
 900 * Remarks:
 901 *	Limited to 20 tokens.
 902 *
 903 *	Real rudimentary tokenization. Basically only whitespace
 904 *	is considered a token delimeter (but special consideration
 905 *	is taken of the '=' sign as used by the 'set' command).
 906 *
 907 *	The algorithm used to tokenize the input string relies on
 908 *	there being at least one whitespace (or otherwise useless)
 909 *	character between tokens as the character immediately following
 910 *	the token is altered in-place to a null-byte to terminate the
 911 *	token string.
 912 */
 913
 914#define MAXARGC	20
 915
 916int kdb_parse(const char *cmdstr)
 917{
 918	static char *argv[MAXARGC];
 919	static int argc;
 920	static char cbuf[CMD_BUFLEN+2];
 921	char *cp;
 922	char *cpp, quoted;
 923	kdbtab_t *tp;
 924	int i, escaped, ignore_errors = 0, check_grep = 0;
 925
 926	/*
 927	 * First tokenize the command string.
 928	 */
 929	cp = (char *)cmdstr;
 930
 931	if (KDB_FLAG(CMD_INTERRUPT)) {
 932		/* Previous command was interrupted, newline must not
 933		 * repeat the command */
 934		KDB_FLAG_CLEAR(CMD_INTERRUPT);
 935		KDB_STATE_SET(PAGER);
 936		argc = 0;	/* no repeat */
 937	}
 938
 939	if (*cp != '\n' && *cp != '\0') {
 940		argc = 0;
 941		cpp = cbuf;
 942		while (*cp) {
 943			/* skip whitespace */
 944			while (isspace(*cp))
 945				cp++;
 946			if ((*cp == '\0') || (*cp == '\n') ||
 947			    (*cp == '#' && !defcmd_in_progress))
 948				break;
 949			/* special case: check for | grep pattern */
 950			if (*cp == '|') {
 951				check_grep++;
 952				break;
 953			}
 954			if (cpp >= cbuf + CMD_BUFLEN) {
 955				kdb_printf("kdb_parse: command buffer "
 956					   "overflow, command ignored\n%s\n",
 957					   cmdstr);
 958				return KDB_NOTFOUND;
 959			}
 960			if (argc >= MAXARGC - 1) {
 961				kdb_printf("kdb_parse: too many arguments, "
 962					   "command ignored\n%s\n", cmdstr);
 963				return KDB_NOTFOUND;
 964			}
 965			argv[argc++] = cpp;
 966			escaped = 0;
 967			quoted = '\0';
 968			/* Copy to next unquoted and unescaped
 969			 * whitespace or '=' */
 970			while (*cp && *cp != '\n' &&
 971			       (escaped || quoted || !isspace(*cp))) {
 972				if (cpp >= cbuf + CMD_BUFLEN)
 973					break;
 974				if (escaped) {
 975					escaped = 0;
 976					*cpp++ = *cp++;
 977					continue;
 978				}
 979				if (*cp == '\\') {
 980					escaped = 1;
 981					++cp;
 982					continue;
 983				}
 984				if (*cp == quoted)
 985					quoted = '\0';
 986				else if (*cp == '\'' || *cp == '"')
 987					quoted = *cp;
 988				*cpp = *cp++;
 989				if (*cpp == '=' && !quoted)
 990					break;
 991				++cpp;
 992			}
 993			*cpp++ = '\0';	/* Squash a ws or '=' character */
 994		}
 995	}
 996	if (!argc)
 997		return 0;
 998	if (check_grep)
 999		parse_grep(cp);
1000	if (defcmd_in_progress) {
1001		int result = kdb_defcmd2(cmdstr, argv[0]);
1002		if (!defcmd_in_progress) {
1003			argc = 0;	/* avoid repeat on endefcmd */
1004			*(argv[0]) = '\0';
1005		}
1006		return result;
1007	}
1008	if (argv[0][0] == '-' && argv[0][1] &&
1009	    (argv[0][1] < '0' || argv[0][1] > '9')) {
1010		ignore_errors = 1;
1011		++argv[0];
1012	}
1013
1014	for_each_kdbcmd(tp, i) {
1015		if (tp->cmd_name) {
1016			/*
1017			 * If this command is allowed to be abbreviated,
1018			 * check to see if this is it.
1019			 */
1020
1021			if (tp->cmd_minlen
1022			 && (strlen(argv[0]) <= tp->cmd_minlen)) {
1023				if (strncmp(argv[0],
1024					    tp->cmd_name,
1025					    tp->cmd_minlen) == 0) {
1026					break;
1027				}
1028			}
1029
1030			if (strcmp(argv[0], tp->cmd_name) == 0)
1031				break;
1032		}
1033	}
1034
1035	/*
1036	 * If we don't find a command by this name, see if the first
1037	 * few characters of this match any of the known commands.
1038	 * e.g., md1c20 should match md.
1039	 */
1040	if (i == kdb_max_commands) {
1041		for_each_kdbcmd(tp, i) {
1042			if (tp->cmd_name) {
1043				if (strncmp(argv[0],
1044					    tp->cmd_name,
1045					    strlen(tp->cmd_name)) == 0) {
1046					break;
1047				}
1048			}
1049		}
1050	}
1051
1052	if (i < kdb_max_commands) {
1053		int result;
1054
1055		if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1))
1056			return KDB_NOPERM;
1057
1058		KDB_STATE_SET(CMD);
1059		result = (*tp->cmd_func)(argc-1, (const char **)argv);
1060		if (result && ignore_errors && result > KDB_CMD_GO)
1061			result = 0;
1062		KDB_STATE_CLEAR(CMD);
1063
1064		if (tp->cmd_flags & KDB_REPEAT_WITH_ARGS)
1065			return result;
1066
1067		argc = tp->cmd_flags & KDB_REPEAT_NO_ARGS ? 1 : 0;
1068		if (argv[argc])
1069			*(argv[argc]) = '\0';
1070		return result;
1071	}
1072
1073	/*
1074	 * If the input with which we were presented does not
1075	 * map to an existing command, attempt to parse it as an
1076	 * address argument and display the result.   Useful for
1077	 * obtaining the address of a variable, or the nearest symbol
1078	 * to an address contained in a register.
1079	 */
1080	{
1081		unsigned long value;
1082		char *name = NULL;
1083		long offset;
1084		int nextarg = 0;
1085
1086		if (kdbgetaddrarg(0, (const char **)argv, &nextarg,
1087				  &value, &offset, &name)) {
1088			return KDB_NOTFOUND;
1089		}
1090
1091		kdb_printf("%s = ", argv[0]);
1092		kdb_symbol_print(value, NULL, KDB_SP_DEFAULT);
1093		kdb_printf("\n");
1094		return 0;
1095	}
1096}
1097
1098
1099static int handle_ctrl_cmd(char *cmd)
1100{
1101#define CTRL_P	16
1102#define CTRL_N	14
1103
1104	/* initial situation */
1105	if (cmd_head == cmd_tail)
1106		return 0;
1107	switch (*cmd) {
1108	case CTRL_P:
1109		if (cmdptr != cmd_tail)
1110			cmdptr = (cmdptr + KDB_CMD_HISTORY_COUNT - 1) %
1111				 KDB_CMD_HISTORY_COUNT;
1112		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1113		return 1;
1114	case CTRL_N:
1115		if (cmdptr != cmd_head)
1116			cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT;
1117		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1118		return 1;
1119	}
1120	return 0;
1121}
1122
1123/*
1124 * kdb_reboot - This function implements the 'reboot' command.  Reboot
1125 *	the system immediately, or loop for ever on failure.
1126 */
1127static int kdb_reboot(int argc, const char **argv)
1128{
1129	emergency_restart();
1130	kdb_printf("Hmm, kdb_reboot did not reboot, spinning here\n");
1131	while (1)
1132		cpu_relax();
1133	/* NOTREACHED */
1134	return 0;
1135}
1136
1137static void kdb_dumpregs(struct pt_regs *regs)
1138{
1139	int old_lvl = console_loglevel;
1140	console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
1141	kdb_trap_printk++;
1142	show_regs(regs);
1143	kdb_trap_printk--;
1144	kdb_printf("\n");
1145	console_loglevel = old_lvl;
1146}
1147
1148static void kdb_set_current_task(struct task_struct *p)
1149{
1150	kdb_current_task = p;
1151
1152	if (kdb_task_has_cpu(p)) {
1153		kdb_current_regs = KDB_TSKREGS(kdb_process_cpu(p));
1154		return;
1155	}
1156	kdb_current_regs = NULL;
1157}
1158
1159static void drop_newline(char *buf)
1160{
1161	size_t len = strlen(buf);
1162
1163	if (len == 0)
1164		return;
1165	if (*(buf + len - 1) == '\n')
1166		*(buf + len - 1) = '\0';
1167}
1168
1169/*
1170 * kdb_local - The main code for kdb.  This routine is invoked on a
1171 *	specific processor, it is not global.  The main kdb() routine
1172 *	ensures that only one processor at a time is in this routine.
1173 *	This code is called with the real reason code on the first
1174 *	entry to a kdb session, thereafter it is called with reason
1175 *	SWITCH, even if the user goes back to the original cpu.
1176 * Inputs:
1177 *	reason		The reason KDB was invoked
1178 *	error		The hardware-defined error code
1179 *	regs		The exception frame at time of fault/breakpoint.
1180 *	db_result	Result code from the break or debug point.
1181 * Returns:
1182 *	0	KDB was invoked for an event which it wasn't responsible
1183 *	1	KDB handled the event for which it was invoked.
1184 *	KDB_CMD_GO	User typed 'go'.
1185 *	KDB_CMD_CPU	User switched to another cpu.
1186 *	KDB_CMD_SS	Single step.
1187 */
1188static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
1189		     kdb_dbtrap_t db_result)
1190{
1191	char *cmdbuf;
1192	int diag;
1193	struct task_struct *kdb_current =
1194		kdb_curr_task(raw_smp_processor_id());
1195
1196	KDB_DEBUG_STATE("kdb_local 1", reason);
1197	kdb_go_count = 0;
1198	if (reason == KDB_REASON_DEBUG) {
1199		/* special case below */
1200	} else {
1201		kdb_printf("\nEntering kdb (current=0x%px, pid %d) ",
1202			   kdb_current, kdb_current ? kdb_current->pid : 0);
1203#if defined(CONFIG_SMP)
1204		kdb_printf("on processor %d ", raw_smp_processor_id());
1205#endif
1206	}
1207
1208	switch (reason) {
1209	case KDB_REASON_DEBUG:
1210	{
1211		/*
1212		 * If re-entering kdb after a single step
1213		 * command, don't print the message.
1214		 */
1215		switch (db_result) {
1216		case KDB_DB_BPT:
1217			kdb_printf("\nEntering kdb (0x%px, pid %d) ",
1218				   kdb_current, kdb_current->pid);
1219#if defined(CONFIG_SMP)
1220			kdb_printf("on processor %d ", raw_smp_processor_id());
1221#endif
1222			kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
1223				   instruction_pointer(regs));
1224			break;
1225		case KDB_DB_SS:
1226			break;
1227		case KDB_DB_SSBPT:
1228			KDB_DEBUG_STATE("kdb_local 4", reason);
1229			return 1;	/* kdba_db_trap did the work */
1230		default:
1231			kdb_printf("kdb: Bad result from kdba_db_trap: %d\n",
1232				   db_result);
1233			break;
1234		}
1235
1236	}
1237		break;
1238	case KDB_REASON_ENTER:
1239		if (KDB_STATE(KEYBOARD))
1240			kdb_printf("due to Keyboard Entry\n");
1241		else
1242			kdb_printf("due to KDB_ENTER()\n");
1243		break;
1244	case KDB_REASON_KEYBOARD:
1245		KDB_STATE_SET(KEYBOARD);
1246		kdb_printf("due to Keyboard Entry\n");
1247		break;
1248	case KDB_REASON_ENTER_SLAVE:
1249		/* drop through, slaves only get released via cpu switch */
1250	case KDB_REASON_SWITCH:
1251		kdb_printf("due to cpu switch\n");
1252		break;
1253	case KDB_REASON_OOPS:
1254		kdb_printf("Oops: %s\n", kdb_diemsg);
1255		kdb_printf("due to oops @ " kdb_machreg_fmt "\n",
1256			   instruction_pointer(regs));
1257		kdb_dumpregs(regs);
1258		break;
1259	case KDB_REASON_SYSTEM_NMI:
1260		kdb_printf("due to System NonMaskable Interrupt\n");
1261		break;
1262	case KDB_REASON_NMI:
1263		kdb_printf("due to NonMaskable Interrupt @ "
1264			   kdb_machreg_fmt "\n",
1265			   instruction_pointer(regs));
1266		break;
1267	case KDB_REASON_SSTEP:
1268	case KDB_REASON_BREAK:
1269		kdb_printf("due to %s @ " kdb_machreg_fmt "\n",
1270			   reason == KDB_REASON_BREAK ?
1271			   "Breakpoint" : "SS trap", instruction_pointer(regs));
1272		/*
1273		 * Determine if this breakpoint is one that we
1274		 * are interested in.
1275		 */
1276		if (db_result != KDB_DB_BPT) {
1277			kdb_printf("kdb: error return from kdba_bp_trap: %d\n",
1278				   db_result);
1279			KDB_DEBUG_STATE("kdb_local 6", reason);
1280			return 0;	/* Not for us, dismiss it */
1281		}
1282		break;
1283	case KDB_REASON_RECURSE:
1284		kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n",
1285			   instruction_pointer(regs));
1286		break;
1287	default:
1288		kdb_printf("kdb: unexpected reason code: %d\n", reason);
1289		KDB_DEBUG_STATE("kdb_local 8", reason);
1290		return 0;	/* Not for us, dismiss it */
1291	}
1292
1293	while (1) {
1294		/*
1295		 * Initialize pager context.
1296		 */
1297		kdb_nextline = 1;
1298		KDB_STATE_CLEAR(SUPPRESS);
1299		kdb_grepping_flag = 0;
1300		/* ensure the old search does not leak into '/' commands */
1301		kdb_grep_string[0] = '\0';
1302
1303		cmdbuf = cmd_cur;
1304		*cmdbuf = '\0';
1305		*(cmd_hist[cmd_head]) = '\0';
1306
1307do_full_getstr:
1308		/* PROMPT can only be set if we have MEM_READ permission. */
1309		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
1310			 raw_smp_processor_id());
 
 
 
1311		if (defcmd_in_progress)
1312			strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
1313
1314		/*
1315		 * Fetch command from keyboard
1316		 */
1317		cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str);
1318		if (*cmdbuf != '\n') {
1319			if (*cmdbuf < 32) {
1320				if (cmdptr == cmd_head) {
1321					strscpy(cmd_hist[cmd_head], cmd_cur,
1322						CMD_BUFLEN);
1323					*(cmd_hist[cmd_head] +
1324					  strlen(cmd_hist[cmd_head])-1) = '\0';
1325				}
1326				if (!handle_ctrl_cmd(cmdbuf))
1327					*(cmd_cur+strlen(cmd_cur)-1) = '\0';
1328				cmdbuf = cmd_cur;
1329				goto do_full_getstr;
1330			} else {
1331				strscpy(cmd_hist[cmd_head], cmd_cur,
1332					CMD_BUFLEN);
1333			}
1334
1335			cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT;
1336			if (cmd_head == cmd_tail)
1337				cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT;
1338		}
1339
1340		cmdptr = cmd_head;
1341		diag = kdb_parse(cmdbuf);
1342		if (diag == KDB_NOTFOUND) {
1343			drop_newline(cmdbuf);
1344			kdb_printf("Unknown kdb command: '%s'\n", cmdbuf);
1345			diag = 0;
1346		}
1347		if (diag == KDB_CMD_GO
1348		 || diag == KDB_CMD_CPU
1349		 || diag == KDB_CMD_SS
1350		 || diag == KDB_CMD_KGDB)
1351			break;
1352
1353		if (diag)
1354			kdb_cmderror(diag);
1355	}
1356	KDB_DEBUG_STATE("kdb_local 9", diag);
1357	return diag;
1358}
1359
1360
1361/*
1362 * kdb_print_state - Print the state data for the current processor
1363 *	for debugging.
1364 * Inputs:
1365 *	text		Identifies the debug point
1366 *	value		Any integer value to be printed, e.g. reason code.
1367 */
1368void kdb_print_state(const char *text, int value)
1369{
1370	kdb_printf("state: %s cpu %d value %d initial %d state %x\n",
1371		   text, raw_smp_processor_id(), value, kdb_initial_cpu,
1372		   kdb_state);
1373}
1374
1375/*
1376 * kdb_main_loop - After initial setup and assignment of the
1377 *	controlling cpu, all cpus are in this loop.  One cpu is in
1378 *	control and will issue the kdb prompt, the others will spin
1379 *	until 'go' or cpu switch.
1380 *
1381 *	To get a consistent view of the kernel stacks for all
1382 *	processes, this routine is invoked from the main kdb code via
1383 *	an architecture specific routine.  kdba_main_loop is
1384 *	responsible for making the kernel stacks consistent for all
1385 *	processes, there should be no difference between a blocked
1386 *	process and a running process as far as kdb is concerned.
1387 * Inputs:
1388 *	reason		The reason KDB was invoked
1389 *	error		The hardware-defined error code
1390 *	reason2		kdb's current reason code.
1391 *			Initially error but can change
1392 *			according to kdb state.
1393 *	db_result	Result code from break or debug point.
1394 *	regs		The exception frame at time of fault/breakpoint.
1395 *			should always be valid.
1396 * Returns:
1397 *	0	KDB was invoked for an event which it wasn't responsible
1398 *	1	KDB handled the event for which it was invoked.
1399 */
1400int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
1401	      kdb_dbtrap_t db_result, struct pt_regs *regs)
1402{
1403	int result = 1;
1404	/* Stay in kdb() until 'go', 'ss[b]' or an error */
1405	while (1) {
1406		/*
1407		 * All processors except the one that is in control
1408		 * will spin here.
1409		 */
1410		KDB_DEBUG_STATE("kdb_main_loop 1", reason);
1411		while (KDB_STATE(HOLD_CPU)) {
1412			/* state KDB is turned off by kdb_cpu to see if the
1413			 * other cpus are still live, each cpu in this loop
1414			 * turns it back on.
1415			 */
1416			if (!KDB_STATE(KDB))
1417				KDB_STATE_SET(KDB);
1418		}
1419
1420		KDB_STATE_CLEAR(SUPPRESS);
1421		KDB_DEBUG_STATE("kdb_main_loop 2", reason);
1422		if (KDB_STATE(LEAVING))
1423			break;	/* Another cpu said 'go' */
1424		/* Still using kdb, this processor is in control */
1425		result = kdb_local(reason2, error, regs, db_result);
1426		KDB_DEBUG_STATE("kdb_main_loop 3", result);
1427
1428		if (result == KDB_CMD_CPU)
1429			break;
1430
1431		if (result == KDB_CMD_SS) {
1432			KDB_STATE_SET(DOING_SS);
1433			break;
1434		}
1435
1436		if (result == KDB_CMD_KGDB) {
1437			if (!KDB_STATE(DOING_KGDB))
1438				kdb_printf("Entering please attach debugger "
1439					   "or use $D#44+ or $3#33\n");
1440			break;
1441		}
1442		if (result && result != 1 && result != KDB_CMD_GO)
1443			kdb_printf("\nUnexpected kdb_local return code %d\n",
1444				   result);
1445		KDB_DEBUG_STATE("kdb_main_loop 4", reason);
1446		break;
1447	}
1448	if (KDB_STATE(DOING_SS))
1449		KDB_STATE_CLEAR(SSBPT);
1450
1451	/* Clean up any keyboard devices before leaving */
1452	kdb_kbd_cleanup_state();
1453
1454	return result;
1455}
1456
1457/*
1458 * kdb_mdr - This function implements the guts of the 'mdr', memory
1459 * read command.
1460 *	mdr  <addr arg>,<byte count>
1461 * Inputs:
1462 *	addr	Start address
1463 *	count	Number of bytes
1464 * Returns:
1465 *	Always 0.  Any errors are detected and printed by kdb_getarea.
1466 */
1467static int kdb_mdr(unsigned long addr, unsigned int count)
1468{
1469	unsigned char c;
1470	while (count--) {
1471		if (kdb_getarea(c, addr))
1472			return 0;
1473		kdb_printf("%02x", c);
1474		addr++;
1475	}
1476	kdb_printf("\n");
1477	return 0;
1478}
1479
1480/*
1481 * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4',
1482 *	'md8' 'mdr' and 'mds' commands.
1483 *
1484 *	md|mds  [<addr arg> [<line count> [<radix>]]]
1485 *	mdWcN	[<addr arg> [<line count> [<radix>]]]
1486 *		where W = is the width (1, 2, 4 or 8) and N is the count.
1487 *		for eg., md1c20 reads 20 bytes, 1 at a time.
1488 *	mdr  <addr arg>,<byte count>
1489 */
1490static void kdb_md_line(const char *fmtstr, unsigned long addr,
1491			int symbolic, int nosect, int bytesperword,
1492			int num, int repeat, int phys)
1493{
1494	/* print just one line of data */
1495	kdb_symtab_t symtab;
1496	char cbuf[32];
1497	char *c = cbuf;
1498	int i;
1499	int j;
1500	unsigned long word;
1501
1502	memset(cbuf, '\0', sizeof(cbuf));
1503	if (phys)
1504		kdb_printf("phys " kdb_machreg_fmt0 " ", addr);
1505	else
1506		kdb_printf(kdb_machreg_fmt0 " ", addr);
1507
1508	for (i = 0; i < num && repeat--; i++) {
1509		if (phys) {
1510			if (kdb_getphysword(&word, addr, bytesperword))
1511				break;
1512		} else if (kdb_getword(&word, addr, bytesperword))
1513			break;
1514		kdb_printf(fmtstr, word);
1515		if (symbolic)
1516			kdbnearsym(word, &symtab);
1517		else
1518			memset(&symtab, 0, sizeof(symtab));
1519		if (symtab.sym_name) {
1520			kdb_symbol_print(word, &symtab, 0);
1521			if (!nosect) {
1522				kdb_printf("\n");
1523				kdb_printf("                       %s %s "
1524					   kdb_machreg_fmt " "
1525					   kdb_machreg_fmt " "
1526					   kdb_machreg_fmt, symtab.mod_name,
1527					   symtab.sec_name, symtab.sec_start,
1528					   symtab.sym_start, symtab.sym_end);
1529			}
1530			addr += bytesperword;
1531		} else {
1532			union {
1533				u64 word;
1534				unsigned char c[8];
1535			} wc;
1536			unsigned char *cp;
1537#ifdef	__BIG_ENDIAN
1538			cp = wc.c + 8 - bytesperword;
1539#else
1540			cp = wc.c;
1541#endif
1542			wc.word = word;
1543#define printable_char(c) \
1544	({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; })
1545			for (j = 0; j < bytesperword; j++)
1546				*c++ = printable_char(*cp++);
1547			addr += bytesperword;
1548#undef printable_char
1549		}
1550	}
1551	kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1),
1552		   " ", cbuf);
1553}
1554
1555static int kdb_md(int argc, const char **argv)
1556{
1557	static unsigned long last_addr;
1558	static int last_radix, last_bytesperword, last_repeat;
1559	int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
1560	int nosect = 0;
1561	char fmtchar, fmtstr[64];
1562	unsigned long addr;
1563	unsigned long word;
1564	long offset = 0;
1565	int symbolic = 0;
1566	int valid = 0;
1567	int phys = 0;
1568	int raw = 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 || (argc == 0 && last_addr != 0))
1579			valid = raw = 1;
1580		else
1581			return KDB_ARGCOUNT;
1582	} else if (isdigit(argv[0][2])) {
1583		bytesperword = (int)(argv[0][2] - '0');
1584		if (bytesperword == 0) {
1585			bytesperword = last_bytesperword;
1586			if (bytesperword == 0)
1587				bytesperword = 4;
1588		}
1589		last_bytesperword = bytesperword;
1590		repeat = mdcount * 16 / bytesperword;
1591		if (!argv[0][3])
1592			valid = 1;
1593		else if (argv[0][3] == 'c' && argv[0][4]) {
1594			char *p;
1595			repeat = simple_strtoul(argv[0] + 4, &p, 10);
1596			mdcount = ((repeat * bytesperword) + 15) / 16;
1597			valid = !*p;
1598		}
1599		last_repeat = repeat;
1600	} else if (strcmp(argv[0], "md") == 0)
1601		valid = 1;
1602	else if (strcmp(argv[0], "mds") == 0)
1603		valid = 1;
1604	else if (strcmp(argv[0], "mdp") == 0) {
1605		phys = valid = 1;
1606	}
1607	if (!valid)
1608		return KDB_NOTFOUND;
1609
1610	if (argc == 0) {
1611		if (last_addr == 0)
1612			return KDB_ARGCOUNT;
1613		addr = last_addr;
1614		radix = last_radix;
1615		bytesperword = last_bytesperword;
1616		repeat = last_repeat;
1617		if (raw)
1618			mdcount = repeat;
1619		else
1620			mdcount = ((repeat * bytesperword) + 15) / 16;
1621	}
1622
1623	if (argc) {
1624		unsigned long val;
1625		int diag, nextarg = 1;
1626		diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
1627				     &offset, NULL);
1628		if (diag)
1629			return diag;
1630		if (argc > nextarg+2)
1631			return KDB_ARGCOUNT;
1632
1633		if (argc >= nextarg) {
1634			diag = kdbgetularg(argv[nextarg], &val);
1635			if (!diag) {
1636				mdcount = (int) val;
1637				if (raw)
1638					repeat = mdcount;
1639				else
1640					repeat = mdcount * 16 / bytesperword;
1641			}
1642		}
1643		if (argc >= nextarg+1) {
1644			diag = kdbgetularg(argv[nextarg+1], &val);
1645			if (!diag)
1646				radix = (int) val;
1647		}
1648	}
1649
1650	if (strcmp(argv[0], "mdr") == 0) {
1651		int ret;
1652		last_addr = addr;
1653		ret = kdb_mdr(addr, mdcount);
1654		last_addr += mdcount;
1655		last_repeat = mdcount;
1656		last_bytesperword = bytesperword; // to make REPEAT happy
1657		return ret;
1658	}
1659
1660	switch (radix) {
1661	case 10:
1662		fmtchar = 'd';
1663		break;
1664	case 16:
1665		fmtchar = 'x';
1666		break;
1667	case 8:
1668		fmtchar = 'o';
1669		break;
1670	default:
1671		return KDB_BADRADIX;
1672	}
1673
1674	last_radix = radix;
1675
1676	if (bytesperword > KDB_WORD_SIZE)
1677		return KDB_BADWIDTH;
1678
1679	switch (bytesperword) {
1680	case 8:
1681		sprintf(fmtstr, "%%16.16l%c ", fmtchar);
1682		break;
1683	case 4:
1684		sprintf(fmtstr, "%%8.8l%c ", fmtchar);
1685		break;
1686	case 2:
1687		sprintf(fmtstr, "%%4.4l%c ", fmtchar);
1688		break;
1689	case 1:
1690		sprintf(fmtstr, "%%2.2l%c ", fmtchar);
1691		break;
1692	default:
1693		return KDB_BADWIDTH;
1694	}
1695
1696	last_repeat = repeat;
1697	last_bytesperword = bytesperword;
1698
1699	if (strcmp(argv[0], "mds") == 0) {
1700		symbolic = 1;
1701		/* Do not save these changes as last_*, they are temporary mds
1702		 * overrides.
1703		 */
1704		bytesperword = KDB_WORD_SIZE;
1705		repeat = mdcount;
1706		kdbgetintenv("NOSECT", &nosect);
1707	}
1708
1709	/* Round address down modulo BYTESPERWORD */
1710
1711	addr &= ~(bytesperword-1);
1712
1713	while (repeat > 0) {
1714		unsigned long a;
1715		int n, z, num = (symbolic ? 1 : (16 / bytesperword));
1716
1717		if (KDB_FLAG(CMD_INTERRUPT))
1718			return 0;
1719		for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) {
1720			if (phys) {
1721				if (kdb_getphysword(&word, a, bytesperword)
1722						|| word)
1723					break;
1724			} else if (kdb_getword(&word, a, bytesperword) || word)
1725				break;
1726		}
1727		n = min(num, repeat);
1728		kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword,
1729			    num, repeat, phys);
1730		addr += bytesperword * n;
1731		repeat -= n;
1732		z = (z + num - 1) / num;
1733		if (z > 2) {
1734			int s = num * (z-2);
1735			kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0
1736				   " zero suppressed\n",
1737				addr, addr + bytesperword * s - 1);
1738			addr += bytesperword * s;
1739			repeat -= s;
1740		}
1741	}
1742	last_addr = addr;
1743
1744	return 0;
1745}
1746
1747/*
1748 * kdb_mm - This function implements the 'mm' command.
1749 *	mm address-expression new-value
1750 * Remarks:
1751 *	mm works on machine words, mmW works on bytes.
1752 */
1753static int kdb_mm(int argc, const char **argv)
1754{
1755	int diag;
1756	unsigned long addr;
1757	long offset = 0;
1758	unsigned long contents;
1759	int nextarg;
1760	int width;
1761
1762	if (argv[0][2] && !isdigit(argv[0][2]))
1763		return KDB_NOTFOUND;
1764
1765	if (argc < 2)
1766		return KDB_ARGCOUNT;
1767
1768	nextarg = 1;
1769	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1770	if (diag)
1771		return diag;
1772
1773	if (nextarg > argc)
1774		return KDB_ARGCOUNT;
1775	diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL);
1776	if (diag)
1777		return diag;
1778
1779	if (nextarg != argc + 1)
1780		return KDB_ARGCOUNT;
1781
1782	width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE);
1783	diag = kdb_putword(addr, contents, width);
1784	if (diag)
1785		return diag;
1786
1787	kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents);
1788
1789	return 0;
1790}
1791
1792/*
1793 * kdb_go - This function implements the 'go' command.
1794 *	go [address-expression]
1795 */
1796static int kdb_go(int argc, const char **argv)
1797{
1798	unsigned long addr;
1799	int diag;
1800	int nextarg;
1801	long offset;
1802
1803	if (raw_smp_processor_id() != kdb_initial_cpu) {
1804		kdb_printf("go must execute on the entry cpu, "
1805			   "please use \"cpu %d\" and then execute go\n",
1806			   kdb_initial_cpu);
1807		return KDB_BADCPUNUM;
1808	}
1809	if (argc == 1) {
1810		nextarg = 1;
1811		diag = kdbgetaddrarg(argc, argv, &nextarg,
1812				     &addr, &offset, NULL);
1813		if (diag)
1814			return diag;
1815	} else if (argc) {
1816		return KDB_ARGCOUNT;
1817	}
1818
1819	diag = KDB_CMD_GO;
1820	if (KDB_FLAG(CATASTROPHIC)) {
1821		kdb_printf("Catastrophic error detected\n");
1822		kdb_printf("kdb_continue_catastrophic=%d, ",
1823			kdb_continue_catastrophic);
1824		if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) {
1825			kdb_printf("type go a second time if you really want "
1826				   "to continue\n");
1827			return 0;
1828		}
1829		if (kdb_continue_catastrophic == 2) {
1830			kdb_printf("forcing reboot\n");
1831			kdb_reboot(0, NULL);
1832		}
1833		kdb_printf("attempting to continue\n");
1834	}
1835	return diag;
1836}
1837
1838/*
1839 * kdb_rd - This function implements the 'rd' command.
1840 */
1841static int kdb_rd(int argc, const char **argv)
1842{
1843	int len = kdb_check_regs();
1844#if DBG_MAX_REG_NUM > 0
1845	int i;
1846	char *rname;
1847	int rsize;
1848	u64 reg64;
1849	u32 reg32;
1850	u16 reg16;
1851	u8 reg8;
1852
1853	if (len)
1854		return len;
1855
1856	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1857		rsize = dbg_reg_def[i].size * 2;
1858		if (rsize > 16)
1859			rsize = 2;
1860		if (len + strlen(dbg_reg_def[i].name) + 4 + rsize > 80) {
1861			len = 0;
1862			kdb_printf("\n");
1863		}
1864		if (len)
1865			len += kdb_printf("  ");
1866		switch(dbg_reg_def[i].size * 8) {
1867		case 8:
1868			rname = dbg_get_reg(i, &reg8, kdb_current_regs);
1869			if (!rname)
1870				break;
1871			len += kdb_printf("%s: %02x", rname, reg8);
1872			break;
1873		case 16:
1874			rname = dbg_get_reg(i, &reg16, kdb_current_regs);
1875			if (!rname)
1876				break;
1877			len += kdb_printf("%s: %04x", rname, reg16);
1878			break;
1879		case 32:
1880			rname = dbg_get_reg(i, &reg32, kdb_current_regs);
1881			if (!rname)
1882				break;
1883			len += kdb_printf("%s: %08x", rname, reg32);
1884			break;
1885		case 64:
1886			rname = dbg_get_reg(i, &reg64, kdb_current_regs);
1887			if (!rname)
1888				break;
1889			len += kdb_printf("%s: %016llx", rname, reg64);
1890			break;
1891		default:
1892			len += kdb_printf("%s: ??", dbg_reg_def[i].name);
1893		}
1894	}
1895	kdb_printf("\n");
1896#else
1897	if (len)
1898		return len;
1899
1900	kdb_dumpregs(kdb_current_regs);
1901#endif
1902	return 0;
1903}
1904
1905/*
1906 * kdb_rm - This function implements the 'rm' (register modify)  command.
1907 *	rm register-name new-contents
1908 * Remarks:
1909 *	Allows register modification with the same restrictions as gdb
1910 */
1911static int kdb_rm(int argc, const char **argv)
1912{
1913#if DBG_MAX_REG_NUM > 0
1914	int diag;
1915	const char *rname;
1916	int i;
1917	u64 reg64;
1918	u32 reg32;
1919	u16 reg16;
1920	u8 reg8;
1921
1922	if (argc != 2)
1923		return KDB_ARGCOUNT;
1924	/*
1925	 * Allow presence or absence of leading '%' symbol.
1926	 */
1927	rname = argv[1];
1928	if (*rname == '%')
1929		rname++;
1930
1931	diag = kdbgetu64arg(argv[2], &reg64);
1932	if (diag)
1933		return diag;
1934
1935	diag = kdb_check_regs();
1936	if (diag)
1937		return diag;
1938
1939	diag = KDB_BADREG;
1940	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1941		if (strcmp(rname, dbg_reg_def[i].name) == 0) {
1942			diag = 0;
1943			break;
1944		}
1945	}
1946	if (!diag) {
1947		switch(dbg_reg_def[i].size * 8) {
1948		case 8:
1949			reg8 = reg64;
1950			dbg_set_reg(i, &reg8, kdb_current_regs);
1951			break;
1952		case 16:
1953			reg16 = reg64;
1954			dbg_set_reg(i, &reg16, kdb_current_regs);
1955			break;
1956		case 32:
1957			reg32 = reg64;
1958			dbg_set_reg(i, &reg32, kdb_current_regs);
1959			break;
1960		case 64:
1961			dbg_set_reg(i, &reg64, kdb_current_regs);
1962			break;
1963		}
1964	}
1965	return diag;
1966#else
1967	kdb_printf("ERROR: Register set currently not implemented\n");
1968    return 0;
1969#endif
1970}
1971
1972#if defined(CONFIG_MAGIC_SYSRQ)
1973/*
1974 * kdb_sr - This function implements the 'sr' (SYSRQ key) command
1975 *	which interfaces to the soi-disant MAGIC SYSRQ functionality.
1976 *		sr <magic-sysrq-code>
1977 */
1978static int kdb_sr(int argc, const char **argv)
1979{
1980	bool check_mask =
1981	    !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
1982
1983	if (argc != 1)
1984		return KDB_ARGCOUNT;
1985
1986	kdb_trap_printk++;
1987	__handle_sysrq(*argv[1], check_mask);
1988	kdb_trap_printk--;
1989
1990	return 0;
1991}
1992#endif	/* CONFIG_MAGIC_SYSRQ */
1993
1994/*
1995 * kdb_ef - This function implements the 'regs' (display exception
1996 *	frame) command.  This command takes an address and expects to
1997 *	find an exception frame at that address, formats and prints
1998 *	it.
1999 *		regs address-expression
2000 * Remarks:
2001 *	Not done yet.
2002 */
2003static int kdb_ef(int argc, const char **argv)
2004{
2005	int diag;
2006	unsigned long addr;
2007	long offset;
2008	int nextarg;
2009
2010	if (argc != 1)
2011		return KDB_ARGCOUNT;
2012
2013	nextarg = 1;
2014	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
2015	if (diag)
2016		return diag;
2017	show_regs((struct pt_regs *)addr);
2018	return 0;
2019}
2020
2021#if defined(CONFIG_MODULES)
2022/*
2023 * kdb_lsmod - This function implements the 'lsmod' command.  Lists
2024 *	currently loaded kernel modules.
2025 *	Mostly taken from userland lsmod.
2026 */
2027static int kdb_lsmod(int argc, const char **argv)
2028{
2029	struct module *mod;
2030
2031	if (argc != 0)
2032		return KDB_ARGCOUNT;
2033
2034	kdb_printf("Module                  Size  modstruct     Used by\n");
2035	list_for_each_entry(mod, kdb_modules, list) {
2036		if (mod->state == MODULE_STATE_UNFORMED)
2037			continue;
2038
2039		kdb_printf("%-20s%8u  0x%px ", mod->name,
2040			   mod->core_layout.size, (void *)mod);
2041#ifdef CONFIG_MODULE_UNLOAD
2042		kdb_printf("%4d ", module_refcount(mod));
2043#endif
2044		if (mod->state == MODULE_STATE_GOING)
2045			kdb_printf(" (Unloading)");
2046		else if (mod->state == MODULE_STATE_COMING)
2047			kdb_printf(" (Loading)");
2048		else
2049			kdb_printf(" (Live)");
2050		kdb_printf(" 0x%px", mod->core_layout.base);
2051
2052#ifdef CONFIG_MODULE_UNLOAD
2053		{
2054			struct module_use *use;
2055			kdb_printf(" [ ");
2056			list_for_each_entry(use, &mod->source_list,
2057					    source_list)
2058				kdb_printf("%s ", use->target->name);
2059			kdb_printf("]\n");
2060		}
2061#endif
2062	}
2063
2064	return 0;
2065}
2066
2067#endif	/* CONFIG_MODULES */
2068
2069/*
2070 * kdb_env - This function implements the 'env' command.  Display the
2071 *	current environment variables.
2072 */
2073
2074static int kdb_env(int argc, const char **argv)
2075{
2076	int i;
2077
2078	for (i = 0; i < __nenv; i++) {
2079		if (__env[i])
2080			kdb_printf("%s\n", __env[i]);
2081	}
2082
2083	if (KDB_DEBUG(MASK))
2084		kdb_printf("KDBDEBUG=0x%x\n",
2085			(kdb_flags & KDB_DEBUG(MASK)) >> KDB_DEBUG_FLAG_SHIFT);
2086
2087	return 0;
2088}
2089
2090#ifdef CONFIG_PRINTK
2091/*
2092 * kdb_dmesg - This function implements the 'dmesg' command to display
2093 *	the contents of the syslog buffer.
2094 *		dmesg [lines] [adjust]
2095 */
2096static int kdb_dmesg(int argc, const char **argv)
2097{
2098	int diag;
2099	int logging;
2100	int lines = 0;
2101	int adjust = 0;
2102	int n = 0;
2103	int skip = 0;
2104	struct kmsg_dumper dumper = { .active = 1 };
2105	size_t len;
2106	char buf[201];
2107
2108	if (argc > 2)
2109		return KDB_ARGCOUNT;
2110	if (argc) {
2111		char *cp;
2112		lines = simple_strtol(argv[1], &cp, 0);
2113		if (*cp)
2114			lines = 0;
2115		if (argc > 1) {
2116			adjust = simple_strtoul(argv[2], &cp, 0);
2117			if (*cp || adjust < 0)
2118				adjust = 0;
2119		}
2120	}
2121
2122	/* disable LOGGING if set */
2123	diag = kdbgetintenv("LOGGING", &logging);
2124	if (!diag && logging) {
2125		const char *setargs[] = { "set", "LOGGING", "0" };
2126		kdb_set(2, setargs);
2127	}
2128
2129	kmsg_dump_rewind_nolock(&dumper);
2130	while (kmsg_dump_get_line_nolock(&dumper, 1, NULL, 0, NULL))
2131		n++;
2132
2133	if (lines < 0) {
2134		if (adjust >= n)
2135			kdb_printf("buffer only contains %d lines, nothing "
2136				   "printed\n", n);
2137		else if (adjust - lines >= n)
2138			kdb_printf("buffer only contains %d lines, last %d "
2139				   "lines printed\n", n, n - adjust);
2140		skip = adjust;
2141		lines = abs(lines);
2142	} else if (lines > 0) {
2143		skip = n - lines - adjust;
2144		lines = abs(lines);
2145		if (adjust >= n) {
2146			kdb_printf("buffer only contains %d lines, "
2147				   "nothing printed\n", n);
2148			skip = n;
2149		} else if (skip < 0) {
2150			lines += skip;
2151			skip = 0;
2152			kdb_printf("buffer only contains %d lines, first "
2153				   "%d lines printed\n", n, lines);
2154		}
2155	} else {
2156		lines = n;
2157	}
2158
2159	if (skip >= n || skip < 0)
2160		return 0;
2161
2162	kmsg_dump_rewind_nolock(&dumper);
2163	while (kmsg_dump_get_line_nolock(&dumper, 1, buf, sizeof(buf), &len)) {
2164		if (skip) {
2165			skip--;
2166			continue;
2167		}
2168		if (!lines--)
2169			break;
2170		if (KDB_FLAG(CMD_INTERRUPT))
2171			return 0;
2172
2173		kdb_printf("%.*s\n", (int)len - 1, buf);
2174	}
2175
2176	return 0;
2177}
2178#endif /* CONFIG_PRINTK */
2179
2180/* Make sure we balance enable/disable calls, must disable first. */
2181static atomic_t kdb_nmi_disabled;
2182
2183static int kdb_disable_nmi(int argc, const char *argv[])
2184{
2185	if (atomic_read(&kdb_nmi_disabled))
2186		return 0;
2187	atomic_set(&kdb_nmi_disabled, 1);
2188	arch_kgdb_ops.enable_nmi(0);
2189	return 0;
2190}
2191
2192static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
2193{
2194	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
2195		return -EINVAL;
2196	arch_kgdb_ops.enable_nmi(1);
2197	return 0;
2198}
2199
2200static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
2201	.set = kdb_param_enable_nmi,
2202};
2203module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
2204
2205/*
2206 * kdb_cpu - This function implements the 'cpu' command.
2207 *	cpu	[<cpunum>]
2208 * Returns:
2209 *	KDB_CMD_CPU for success, a kdb diagnostic if error
2210 */
2211static void kdb_cpu_status(void)
2212{
2213	int i, start_cpu, first_print = 1;
2214	char state, prev_state = '?';
2215
2216	kdb_printf("Currently on cpu %d\n", raw_smp_processor_id());
2217	kdb_printf("Available cpus: ");
2218	for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
2219		if (!cpu_online(i)) {
2220			state = 'F';	/* cpu is offline */
2221		} else if (!kgdb_info[i].enter_kgdb) {
2222			state = 'D';	/* cpu is online but unresponsive */
2223		} else {
2224			state = ' ';	/* cpu is responding to kdb */
2225			if (kdb_task_state_char(KDB_TSK(i)) == 'I')
2226				state = 'I';	/* idle task */
2227		}
2228		if (state != prev_state) {
2229			if (prev_state != '?') {
2230				if (!first_print)
2231					kdb_printf(", ");
2232				first_print = 0;
2233				kdb_printf("%d", start_cpu);
2234				if (start_cpu < i-1)
2235					kdb_printf("-%d", i-1);
2236				if (prev_state != ' ')
2237					kdb_printf("(%c)", prev_state);
2238			}
2239			prev_state = state;
2240			start_cpu = i;
2241		}
2242	}
2243	/* print the trailing cpus, ignoring them if they are all offline */
2244	if (prev_state != 'F') {
2245		if (!first_print)
2246			kdb_printf(", ");
2247		kdb_printf("%d", start_cpu);
2248		if (start_cpu < i-1)
2249			kdb_printf("-%d", i-1);
2250		if (prev_state != ' ')
2251			kdb_printf("(%c)", prev_state);
2252	}
2253	kdb_printf("\n");
2254}
2255
2256static int kdb_cpu(int argc, const char **argv)
2257{
2258	unsigned long cpunum;
2259	int diag;
2260
2261	if (argc == 0) {
2262		kdb_cpu_status();
2263		return 0;
2264	}
2265
2266	if (argc != 1)
2267		return KDB_ARGCOUNT;
2268
2269	diag = kdbgetularg(argv[1], &cpunum);
2270	if (diag)
2271		return diag;
2272
2273	/*
2274	 * Validate cpunum
2275	 */
2276	if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
2277		return KDB_BADCPUNUM;
2278
2279	dbg_switch_cpu = cpunum;
2280
2281	/*
2282	 * Switch to other cpu
2283	 */
2284	return KDB_CMD_CPU;
2285}
2286
2287/* The user may not realize that ps/bta with no parameters does not print idle
2288 * or sleeping system daemon processes, so tell them how many were suppressed.
2289 */
2290void kdb_ps_suppressed(void)
2291{
2292	int idle = 0, daemon = 0;
2293	unsigned long mask_I = kdb_task_state_string("I"),
2294		      mask_M = kdb_task_state_string("M");
2295	unsigned long cpu;
2296	const struct task_struct *p, *g;
2297	for_each_online_cpu(cpu) {
2298		p = kdb_curr_task(cpu);
2299		if (kdb_task_state(p, mask_I))
2300			++idle;
2301	}
2302	kdb_do_each_thread(g, p) {
2303		if (kdb_task_state(p, mask_M))
2304			++daemon;
2305	} kdb_while_each_thread(g, p);
2306	if (idle || daemon) {
2307		if (idle)
2308			kdb_printf("%d idle process%s (state I)%s\n",
2309				   idle, idle == 1 ? "" : "es",
2310				   daemon ? " and " : "");
2311		if (daemon)
2312			kdb_printf("%d sleeping system daemon (state M) "
2313				   "process%s", daemon,
2314				   daemon == 1 ? "" : "es");
2315		kdb_printf(" suppressed,\nuse 'ps A' to see all.\n");
2316	}
2317}
2318
2319/*
2320 * kdb_ps - This function implements the 'ps' command which shows a
2321 *	list of the active processes.
2322 *		ps [DRSTCZEUIMA]   All processes, optionally filtered by state
2323 */
2324void kdb_ps1(const struct task_struct *p)
2325{
2326	int cpu;
2327	unsigned long tmp;
2328
2329	if (!p ||
2330	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
2331		return;
2332
2333	cpu = kdb_process_cpu(p);
2334	kdb_printf("0x%px %8d %8d  %d %4d   %c  0x%px %c%s\n",
2335		   (void *)p, p->pid, p->parent->pid,
2336		   kdb_task_has_cpu(p), kdb_process_cpu(p),
2337		   kdb_task_state_char(p),
2338		   (void *)(&p->thread),
2339		   p == kdb_curr_task(raw_smp_processor_id()) ? '*' : ' ',
2340		   p->comm);
2341	if (kdb_task_has_cpu(p)) {
2342		if (!KDB_TSK(cpu)) {
2343			kdb_printf("  Error: no saved data for this cpu\n");
2344		} else {
2345			if (KDB_TSK(cpu) != p)
2346				kdb_printf("  Error: does not match running "
2347				   "process table (0x%px)\n", KDB_TSK(cpu));
2348		}
2349	}
2350}
2351
2352static int kdb_ps(int argc, const char **argv)
2353{
2354	struct task_struct *g, *p;
2355	unsigned long mask, cpu;
2356
2357	if (argc == 0)
2358		kdb_ps_suppressed();
2359	kdb_printf("%-*s      Pid   Parent [*] cpu State %-*s Command\n",
2360		(int)(2*sizeof(void *))+2, "Task Addr",
2361		(int)(2*sizeof(void *))+2, "Thread");
2362	mask = kdb_task_state_string(argc ? argv[1] : NULL);
2363	/* Run the active tasks first */
2364	for_each_online_cpu(cpu) {
2365		if (KDB_FLAG(CMD_INTERRUPT))
2366			return 0;
2367		p = kdb_curr_task(cpu);
2368		if (kdb_task_state(p, mask))
2369			kdb_ps1(p);
2370	}
2371	kdb_printf("\n");
2372	/* Now the real tasks */
2373	kdb_do_each_thread(g, p) {
2374		if (KDB_FLAG(CMD_INTERRUPT))
2375			return 0;
2376		if (kdb_task_state(p, mask))
2377			kdb_ps1(p);
2378	} kdb_while_each_thread(g, p);
2379
2380	return 0;
2381}
2382
2383/*
2384 * kdb_pid - This function implements the 'pid' command which switches
2385 *	the currently active process.
2386 *		pid [<pid> | R]
2387 */
2388static int kdb_pid(int argc, const char **argv)
2389{
2390	struct task_struct *p;
2391	unsigned long val;
2392	int diag;
2393
2394	if (argc > 1)
2395		return KDB_ARGCOUNT;
2396
2397	if (argc) {
2398		if (strcmp(argv[1], "R") == 0) {
2399			p = KDB_TSK(kdb_initial_cpu);
2400		} else {
2401			diag = kdbgetularg(argv[1], &val);
2402			if (diag)
2403				return KDB_BADINT;
2404
2405			p = find_task_by_pid_ns((pid_t)val,	&init_pid_ns);
2406			if (!p) {
2407				kdb_printf("No task with pid=%d\n", (pid_t)val);
2408				return 0;
2409			}
2410		}
2411		kdb_set_current_task(p);
2412	}
2413	kdb_printf("KDB current process is %s(pid=%d)\n",
2414		   kdb_current_task->comm,
2415		   kdb_current_task->pid);
2416
2417	return 0;
2418}
2419
2420static int kdb_kgdb(int argc, const char **argv)
2421{
2422	return KDB_CMD_KGDB;
2423}
2424
2425/*
2426 * kdb_help - This function implements the 'help' and '?' commands.
2427 */
2428static int kdb_help(int argc, const char **argv)
2429{
2430	kdbtab_t *kt;
2431	int i;
2432
2433	kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
2434	kdb_printf("-----------------------------"
2435		   "-----------------------------\n");
2436	for_each_kdbcmd(kt, i) {
2437		char *space = "";
2438		if (KDB_FLAG(CMD_INTERRUPT))
2439			return 0;
2440		if (!kt->cmd_name)
2441			continue;
2442		if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
2443			continue;
2444		if (strlen(kt->cmd_usage) > 20)
2445			space = "\n                                    ";
2446		kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
2447			   kt->cmd_usage, space, kt->cmd_help);
2448	}
2449	return 0;
2450}
2451
2452/*
2453 * kdb_kill - This function implements the 'kill' commands.
2454 */
2455static int kdb_kill(int argc, const char **argv)
2456{
2457	long sig, pid;
2458	char *endp;
2459	struct task_struct *p;
2460
2461	if (argc != 2)
2462		return KDB_ARGCOUNT;
2463
2464	sig = simple_strtol(argv[1], &endp, 0);
2465	if (*endp)
2466		return KDB_BADINT;
2467	if ((sig >= 0) || !valid_signal(-sig)) {
2468		kdb_printf("Invalid signal parameter.<-signal>\n");
2469		return 0;
2470	}
2471	sig = -sig;
2472
2473	pid = simple_strtol(argv[2], &endp, 0);
2474	if (*endp)
2475		return KDB_BADINT;
2476	if (pid <= 0) {
2477		kdb_printf("Process ID must be large than 0.\n");
2478		return 0;
2479	}
2480
2481	/* Find the process. */
2482	p = find_task_by_pid_ns(pid, &init_pid_ns);
2483	if (!p) {
2484		kdb_printf("The specified process isn't found.\n");
2485		return 0;
2486	}
2487	p = p->group_leader;
2488	kdb_send_sig(p, sig);
2489	return 0;
2490}
2491
2492/*
2493 * Most of this code has been lifted from kernel/timer.c::sys_sysinfo().
2494 * I cannot call that code directly from kdb, it has an unconditional
2495 * cli()/sti() and calls routines that take locks which can stop the debugger.
2496 */
2497static void kdb_sysinfo(struct sysinfo *val)
2498{
2499	u64 uptime = ktime_get_mono_fast_ns();
2500
2501	memset(val, 0, sizeof(*val));
2502	val->uptime = div_u64(uptime, NSEC_PER_SEC);
2503	val->loads[0] = avenrun[0];
2504	val->loads[1] = avenrun[1];
2505	val->loads[2] = avenrun[2];
2506	val->procs = nr_threads-1;
2507	si_meminfo(val);
2508
2509	return;
2510}
2511
2512/*
2513 * kdb_summary - This function implements the 'summary' command.
2514 */
2515static int kdb_summary(int argc, const char **argv)
2516{
2517	time64_t now;
2518	struct tm tm;
2519	struct sysinfo val;
2520
2521	if (argc)
2522		return KDB_ARGCOUNT;
2523
2524	kdb_printf("sysname    %s\n", init_uts_ns.name.sysname);
2525	kdb_printf("release    %s\n", init_uts_ns.name.release);
2526	kdb_printf("version    %s\n", init_uts_ns.name.version);
2527	kdb_printf("machine    %s\n", init_uts_ns.name.machine);
2528	kdb_printf("nodename   %s\n", init_uts_ns.name.nodename);
2529	kdb_printf("domainname %s\n", init_uts_ns.name.domainname);
2530
2531	now = __ktime_get_real_seconds();
2532	time64_to_tm(now, 0, &tm);
2533	kdb_printf("date       %04ld-%02d-%02d %02d:%02d:%02d "
2534		   "tz_minuteswest %d\n",
2535		1900+tm.tm_year, tm.tm_mon+1, tm.tm_mday,
2536		tm.tm_hour, tm.tm_min, tm.tm_sec,
2537		sys_tz.tz_minuteswest);
2538
2539	kdb_sysinfo(&val);
2540	kdb_printf("uptime     ");
2541	if (val.uptime > (24*60*60)) {
2542		int days = val.uptime / (24*60*60);
2543		val.uptime %= (24*60*60);
2544		kdb_printf("%d day%s ", days, days == 1 ? "" : "s");
2545	}
2546	kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
2547
2548	kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
2549		LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
2550		LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
2551		LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
2552
2553	/* Display in kilobytes */
2554#define K(x) ((x) << (PAGE_SHIFT - 10))
2555	kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
2556		   "Buffers:        %8lu kB\n",
2557		   K(val.totalram), K(val.freeram), K(val.bufferram));
2558	return 0;
2559}
2560
2561/*
2562 * kdb_per_cpu - This function implements the 'per_cpu' command.
2563 */
2564static int kdb_per_cpu(int argc, const char **argv)
2565{
2566	char fmtstr[64];
2567	int cpu, diag, nextarg = 1;
2568	unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL;
2569
2570	if (argc < 1 || argc > 3)
2571		return KDB_ARGCOUNT;
2572
2573	diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL);
2574	if (diag)
2575		return diag;
2576
2577	if (argc >= 2) {
2578		diag = kdbgetularg(argv[2], &bytesperword);
2579		if (diag)
2580			return diag;
2581	}
2582	if (!bytesperword)
2583		bytesperword = KDB_WORD_SIZE;
2584	else if (bytesperword > KDB_WORD_SIZE)
2585		return KDB_BADWIDTH;
2586	sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword));
2587	if (argc >= 3) {
2588		diag = kdbgetularg(argv[3], &whichcpu);
2589		if (diag)
2590			return diag;
2591		if (whichcpu >= nr_cpu_ids || !cpu_online(whichcpu)) {
2592			kdb_printf("cpu %ld is not online\n", whichcpu);
2593			return KDB_BADCPUNUM;
2594		}
2595	}
2596
2597	/* Most architectures use __per_cpu_offset[cpu], some use
2598	 * __per_cpu_offset(cpu), smp has no __per_cpu_offset.
2599	 */
2600#ifdef	__per_cpu_offset
2601#define KDB_PCU(cpu) __per_cpu_offset(cpu)
2602#else
2603#ifdef	CONFIG_SMP
2604#define KDB_PCU(cpu) __per_cpu_offset[cpu]
2605#else
2606#define KDB_PCU(cpu) 0
2607#endif
2608#endif
2609	for_each_online_cpu(cpu) {
2610		if (KDB_FLAG(CMD_INTERRUPT))
2611			return 0;
2612
2613		if (whichcpu != ~0UL && whichcpu != cpu)
2614			continue;
2615		addr = symaddr + KDB_PCU(cpu);
2616		diag = kdb_getword(&val, addr, bytesperword);
2617		if (diag) {
2618			kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to "
2619				   "read, diag=%d\n", cpu, addr, diag);
2620			continue;
2621		}
2622		kdb_printf("%5d ", cpu);
2623		kdb_md_line(fmtstr, addr,
2624			bytesperword == KDB_WORD_SIZE,
2625			1, bytesperword, 1, 1, 0);
2626	}
2627#undef KDB_PCU
2628	return 0;
2629}
2630
2631/*
2632 * display help for the use of cmd | grep pattern
2633 */
2634static int kdb_grep_help(int argc, const char **argv)
2635{
2636	kdb_printf("Usage of  cmd args | grep pattern:\n");
2637	kdb_printf("  Any command's output may be filtered through an ");
2638	kdb_printf("emulated 'pipe'.\n");
2639	kdb_printf("  'grep' is just a key word.\n");
2640	kdb_printf("  The pattern may include a very limited set of "
2641		   "metacharacters:\n");
2642	kdb_printf("   pattern or ^pattern or pattern$ or ^pattern$\n");
2643	kdb_printf("  And if there are spaces in the pattern, you may "
2644		   "quote it:\n");
2645	kdb_printf("   \"pat tern\" or \"^pat tern\" or \"pat tern$\""
2646		   " or \"^pat tern$\"\n");
2647	return 0;
2648}
2649
2650/*
2651 * kdb_register_flags - This function is used to register a kernel
2652 * 	debugger command.
2653 * Inputs:
2654 *	cmd	Command name
2655 *	func	Function to execute the command
2656 *	usage	A simple usage string showing arguments
2657 *	help	A simple help string describing command
2658 *	repeat	Does the command auto repeat on enter?
2659 * Returns:
2660 *	zero for success, one if a duplicate command.
2661 */
2662#define kdb_command_extend 50	/* arbitrary */
2663int kdb_register_flags(char *cmd,
2664		       kdb_func_t func,
2665		       char *usage,
2666		       char *help,
2667		       short minlen,
2668		       kdb_cmdflags_t flags)
2669{
2670	int i;
2671	kdbtab_t *kp;
2672
2673	/*
2674	 *  Brute force method to determine duplicates
2675	 */
2676	for_each_kdbcmd(kp, i) {
2677		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2678			kdb_printf("Duplicate kdb command registered: "
2679				"%s, func %px help %s\n", cmd, func, help);
2680			return 1;
2681		}
2682	}
2683
2684	/*
2685	 * Insert command into first available location in table
2686	 */
2687	for_each_kdbcmd(kp, i) {
2688		if (kp->cmd_name == NULL)
2689			break;
2690	}
2691
2692	if (i >= kdb_max_commands) {
2693		kdbtab_t *new = kmalloc_array(kdb_max_commands -
2694						KDB_BASE_CMD_MAX +
2695						kdb_command_extend,
2696					      sizeof(*new),
2697					      GFP_KDB);
2698		if (!new) {
2699			kdb_printf("Could not allocate new kdb_command "
2700				   "table\n");
2701			return 1;
2702		}
2703		if (kdb_commands) {
2704			memcpy(new, kdb_commands,
2705			  (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
2706			kfree(kdb_commands);
2707		}
2708		memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
2709		       kdb_command_extend * sizeof(*new));
2710		kdb_commands = new;
2711		kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
2712		kdb_max_commands += kdb_command_extend;
2713	}
2714
2715	kp->cmd_name   = cmd;
2716	kp->cmd_func   = func;
2717	kp->cmd_usage  = usage;
2718	kp->cmd_help   = help;
2719	kp->cmd_minlen = minlen;
2720	kp->cmd_flags  = flags;
2721
2722	return 0;
2723}
2724EXPORT_SYMBOL_GPL(kdb_register_flags);
2725
2726
2727/*
2728 * kdb_register - Compatibility register function for commands that do
2729 *	not need to specify a repeat state.  Equivalent to
2730 *	kdb_register_flags with flags set to 0.
2731 * Inputs:
2732 *	cmd	Command name
2733 *	func	Function to execute the command
2734 *	usage	A simple usage string showing arguments
2735 *	help	A simple help string describing command
2736 * Returns:
2737 *	zero for success, one if a duplicate command.
2738 */
2739int kdb_register(char *cmd,
2740	     kdb_func_t func,
2741	     char *usage,
2742	     char *help,
2743	     short minlen)
2744{
2745	return kdb_register_flags(cmd, func, usage, help, minlen, 0);
2746}
2747EXPORT_SYMBOL_GPL(kdb_register);
2748
2749/*
2750 * kdb_unregister - This function is used to unregister a kernel
2751 *	debugger command.  It is generally called when a module which
2752 *	implements kdb commands is unloaded.
2753 * Inputs:
2754 *	cmd	Command name
2755 * Returns:
2756 *	zero for success, one command not registered.
2757 */
2758int kdb_unregister(char *cmd)
2759{
2760	int i;
2761	kdbtab_t *kp;
2762
2763	/*
2764	 *  find the command.
2765	 */
2766	for_each_kdbcmd(kp, i) {
2767		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2768			kp->cmd_name = NULL;
2769			return 0;
2770		}
2771	}
2772
2773	/* Couldn't find it.  */
2774	return 1;
2775}
2776EXPORT_SYMBOL_GPL(kdb_unregister);
2777
2778/* Initialize the kdb command table. */
2779static void __init kdb_inittab(void)
2780{
2781	int i;
2782	kdbtab_t *kp;
2783
2784	for_each_kdbcmd(kp, i)
2785		kp->cmd_name = NULL;
2786
2787	kdb_register_flags("md", kdb_md, "<vaddr>",
2788	  "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
2789	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2790	kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
2791	  "Display Raw Memory", 0,
2792	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2793	kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
2794	  "Display Physical Memory", 0,
2795	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2796	kdb_register_flags("mds", kdb_md, "<vaddr>",
2797	  "Display Memory Symbolically", 0,
2798	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2799	kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
2800	  "Modify Memory Contents", 0,
2801	  KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
2802	kdb_register_flags("go", kdb_go, "[<vaddr>]",
2803	  "Continue Execution", 1,
2804	  KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2805	kdb_register_flags("rd", kdb_rd, "",
2806	  "Display Registers", 0,
2807	  KDB_ENABLE_REG_READ);
2808	kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
2809	  "Modify Registers", 0,
2810	  KDB_ENABLE_REG_WRITE);
2811	kdb_register_flags("ef", kdb_ef, "<vaddr>",
2812	  "Display exception frame", 0,
2813	  KDB_ENABLE_MEM_READ);
2814	kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
2815	  "Stack traceback", 1,
2816	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2817	kdb_register_flags("btp", kdb_bt, "<pid>",
2818	  "Display stack for process <pid>", 0,
2819	  KDB_ENABLE_INSPECT);
2820	kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
2821	  "Backtrace all processes matching state flag", 0,
2822	  KDB_ENABLE_INSPECT);
2823	kdb_register_flags("btc", kdb_bt, "",
2824	  "Backtrace current process on each cpu", 0,
2825	  KDB_ENABLE_INSPECT);
2826	kdb_register_flags("btt", kdb_bt, "<vaddr>",
2827	  "Backtrace process given its struct task address", 0,
2828	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2829	kdb_register_flags("env", kdb_env, "",
2830	  "Show environment variables", 0,
2831	  KDB_ENABLE_ALWAYS_SAFE);
2832	kdb_register_flags("set", kdb_set, "",
2833	  "Set environment variables", 0,
2834	  KDB_ENABLE_ALWAYS_SAFE);
2835	kdb_register_flags("help", kdb_help, "",
2836	  "Display Help Message", 1,
2837	  KDB_ENABLE_ALWAYS_SAFE);
2838	kdb_register_flags("?", kdb_help, "",
2839	  "Display Help Message", 0,
2840	  KDB_ENABLE_ALWAYS_SAFE);
2841	kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
2842	  "Switch to new cpu", 0,
2843	  KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2844	kdb_register_flags("kgdb", kdb_kgdb, "",
2845	  "Enter kgdb mode", 0, 0);
2846	kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
2847	  "Display active task list", 0,
2848	  KDB_ENABLE_INSPECT);
2849	kdb_register_flags("pid", kdb_pid, "<pidnum>",
2850	  "Switch to another task", 0,
2851	  KDB_ENABLE_INSPECT);
2852	kdb_register_flags("reboot", kdb_reboot, "",
2853	  "Reboot the machine immediately", 0,
2854	  KDB_ENABLE_REBOOT);
2855#if defined(CONFIG_MODULES)
2856	kdb_register_flags("lsmod", kdb_lsmod, "",
2857	  "List loaded kernel modules", 0,
2858	  KDB_ENABLE_INSPECT);
2859#endif
2860#if defined(CONFIG_MAGIC_SYSRQ)
2861	kdb_register_flags("sr", kdb_sr, "<key>",
2862	  "Magic SysRq key", 0,
2863	  KDB_ENABLE_ALWAYS_SAFE);
2864#endif
2865#if defined(CONFIG_PRINTK)
2866	kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
2867	  "Display syslog buffer", 0,
2868	  KDB_ENABLE_ALWAYS_SAFE);
2869#endif
2870	if (arch_kgdb_ops.enable_nmi) {
2871		kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
2872		  "Disable NMI entry to KDB", 0,
2873		  KDB_ENABLE_ALWAYS_SAFE);
2874	}
2875	kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
2876	  "Define a set of commands, down to endefcmd", 0,
2877	  KDB_ENABLE_ALWAYS_SAFE);
2878	kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
2879	  "Send a signal to a process", 0,
2880	  KDB_ENABLE_SIGNAL);
2881	kdb_register_flags("summary", kdb_summary, "",
2882	  "Summarize the system", 4,
2883	  KDB_ENABLE_ALWAYS_SAFE);
2884	kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
2885	  "Display per_cpu variables", 3,
2886	  KDB_ENABLE_MEM_READ);
2887	kdb_register_flags("grephelp", kdb_grep_help, "",
2888	  "Display help on | grep", 0,
2889	  KDB_ENABLE_ALWAYS_SAFE);
2890}
2891
2892/* Execute any commands defined in kdb_cmds.  */
2893static void __init kdb_cmd_init(void)
2894{
2895	int i, diag;
2896	for (i = 0; kdb_cmds[i]; ++i) {
2897		diag = kdb_parse(kdb_cmds[i]);
2898		if (diag)
2899			kdb_printf("kdb command %s failed, kdb diag %d\n",
2900				kdb_cmds[i], diag);
2901	}
2902	if (defcmd_in_progress) {
2903		kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n");
2904		kdb_parse("endefcmd");
2905	}
2906}
2907
2908/* Initialize kdb_printf, breakpoint tables and kdb state */
2909void __init kdb_init(int lvl)
2910{
2911	static int kdb_init_lvl = KDB_NOT_INITIALIZED;
2912	int i;
2913
2914	if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl)
2915		return;
2916	for (i = kdb_init_lvl; i < lvl; i++) {
2917		switch (i) {
2918		case KDB_NOT_INITIALIZED:
2919			kdb_inittab();		/* Initialize Command Table */
2920			kdb_initbptab();	/* Initialize Breakpoints */
2921			break;
2922		case KDB_INIT_EARLY:
2923			kdb_cmd_init();		/* Build kdb_cmds tables */
2924			break;
2925		}
2926	}
2927	kdb_init_lvl = lvl;
2928}