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v6.2
   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/moduleparam.h>
  30#include <linux/mm.h>
  31#include <linux/init.h>
  32#include <linux/kallsyms.h>
  33#include <linux/kgdb.h>
  34#include <linux/kdb.h>
  35#include <linux/notifier.h>
  36#include <linux/interrupt.h>
  37#include <linux/delay.h>
  38#include <linux/nmi.h>
  39#include <linux/time.h>
  40#include <linux/ptrace.h>
  41#include <linux/sysctl.h>
  42#include <linux/cpu.h>
  43#include <linux/kdebug.h>
  44#include <linux/proc_fs.h>
  45#include <linux/uaccess.h>
  46#include <linux/slab.h>
  47#include <linux/security.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_cmds_head describes the available commands. */
  88static LIST_HEAD(kdb_cmds_head);
  89
  90typedef struct _kdbmsg {
  91	int	km_diag;	/* kdb diagnostic */
  92	char	*km_msg;	/* Corresponding message text */
  93} kdbmsg_t;
  94
  95#define KDBMSG(msgnum, text) \
  96	{ KDB_##msgnum, text }
  97
  98static kdbmsg_t kdbmsgs[] = {
  99	KDBMSG(NOTFOUND, "Command Not Found"),
 100	KDBMSG(ARGCOUNT, "Improper argument count, see usage."),
 101	KDBMSG(BADWIDTH, "Illegal value for BYTESPERWORD use 1, 2, 4 or 8, "
 102	       "8 is only allowed on 64 bit systems"),
 103	KDBMSG(BADRADIX, "Illegal value for RADIX use 8, 10 or 16"),
 104	KDBMSG(NOTENV, "Cannot find environment variable"),
 105	KDBMSG(NOENVVALUE, "Environment variable should have value"),
 106	KDBMSG(NOTIMP, "Command not implemented"),
 107	KDBMSG(ENVFULL, "Environment full"),
 108	KDBMSG(ENVBUFFULL, "Environment buffer full"),
 109	KDBMSG(TOOMANYBPT, "Too many breakpoints defined"),
 110#ifdef CONFIG_CPU_XSCALE
 111	KDBMSG(TOOMANYDBREGS, "More breakpoints than ibcr registers defined"),
 112#else
 113	KDBMSG(TOOMANYDBREGS, "More breakpoints than db registers defined"),
 114#endif
 115	KDBMSG(DUPBPT, "Duplicate breakpoint address"),
 116	KDBMSG(BPTNOTFOUND, "Breakpoint not found"),
 117	KDBMSG(BADMODE, "Invalid IDMODE"),
 118	KDBMSG(BADINT, "Illegal numeric value"),
 119	KDBMSG(INVADDRFMT, "Invalid symbolic address format"),
 120	KDBMSG(BADREG, "Invalid register name"),
 121	KDBMSG(BADCPUNUM, "Invalid cpu number"),
 122	KDBMSG(BADLENGTH, "Invalid length field"),
 123	KDBMSG(NOBP, "No Breakpoint exists"),
 124	KDBMSG(BADADDR, "Invalid address"),
 125	KDBMSG(NOPERM, "Permission denied"),
 126};
 127#undef KDBMSG
 128
 129static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
 130
 131
 132/*
 133 * Initial environment.   This is all kept static and local to
 134 * this file.   We don't want to rely on the memory allocation
 135 * mechanisms in the kernel, so we use a very limited allocate-only
 136 * heap for new and altered environment variables.  The entire
 137 * environment is limited to a fixed number of entries (add more
 138 * to __env[] if required) and a fixed amount of heap (add more to
 139 * KDB_ENVBUFSIZE if required).
 140 */
 141
 142static char *__env[31] = {
 143#if defined(CONFIG_SMP)
 144	"PROMPT=[%d]kdb> ",
 145#else
 146	"PROMPT=kdb> ",
 147#endif
 148	"MOREPROMPT=more> ",
 149	"RADIX=16",
 150	"MDCOUNT=8",		/* lines of md output */
 151	KDB_PLATFORM_ENV,
 152	"DTABCOUNT=30",
 153	"NOSECT=1",
 154};
 155
 156static const int __nenv = ARRAY_SIZE(__env);
 157
 158struct task_struct *kdb_curr_task(int cpu)
 159{
 160	struct task_struct *p = curr_task(cpu);
 161#ifdef	_TIF_MCA_INIT
 162	if ((task_thread_info(p)->flags & _TIF_MCA_INIT) && KDB_TSK(cpu))
 163		p = krp->p;
 164#endif
 165	return p;
 166}
 167
 168/*
 169 * Update the permissions flags (kdb_cmd_enabled) to match the
 170 * current lockdown state.
 171 *
 172 * Within this function the calls to security_locked_down() are "lazy". We
 173 * avoid calling them if the current value of kdb_cmd_enabled already excludes
 174 * flags that might be subject to lockdown. Additionally we deliberately check
 175 * the lockdown flags independently (even though read lockdown implies write
 176 * lockdown) since that results in both simpler code and clearer messages to
 177 * the user on first-time debugger entry.
 178 *
 179 * The permission masks during a read+write lockdown permits the following
 180 * flags: INSPECT, SIGNAL, REBOOT (and ALWAYS_SAFE).
 181 *
 182 * The INSPECT commands are not blocked during lockdown because they are
 183 * not arbitrary memory reads. INSPECT covers the backtrace family (sometimes
 184 * forcing them to have no arguments) and lsmod. These commands do expose
 185 * some kernel state but do not allow the developer seated at the console to
 186 * choose what state is reported. SIGNAL and REBOOT should not be controversial,
 187 * given these are allowed for root during lockdown already.
 188 */
 189static void kdb_check_for_lockdown(void)
 190{
 191	const int write_flags = KDB_ENABLE_MEM_WRITE |
 192				KDB_ENABLE_REG_WRITE |
 193				KDB_ENABLE_FLOW_CTRL;
 194	const int read_flags = KDB_ENABLE_MEM_READ |
 195			       KDB_ENABLE_REG_READ;
 196
 197	bool need_to_lockdown_write = false;
 198	bool need_to_lockdown_read = false;
 199
 200	if (kdb_cmd_enabled & (KDB_ENABLE_ALL | write_flags))
 201		need_to_lockdown_write =
 202			security_locked_down(LOCKDOWN_DBG_WRITE_KERNEL);
 203
 204	if (kdb_cmd_enabled & (KDB_ENABLE_ALL | read_flags))
 205		need_to_lockdown_read =
 206			security_locked_down(LOCKDOWN_DBG_READ_KERNEL);
 207
 208	/* De-compose KDB_ENABLE_ALL if required */
 209	if (need_to_lockdown_write || need_to_lockdown_read)
 210		if (kdb_cmd_enabled & KDB_ENABLE_ALL)
 211			kdb_cmd_enabled = KDB_ENABLE_MASK & ~KDB_ENABLE_ALL;
 212
 213	if (need_to_lockdown_write)
 214		kdb_cmd_enabled &= ~write_flags;
 215
 216	if (need_to_lockdown_read)
 217		kdb_cmd_enabled &= ~read_flags;
 218}
 219
 220/*
 221 * Check whether the flags of the current command, the permissions of the kdb
 222 * console and the lockdown state allow a command to be run.
 223 */
 224static bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
 225				   bool no_args)
 226{
 227	/* permissions comes from userspace so needs massaging slightly */
 228	permissions &= KDB_ENABLE_MASK;
 229	permissions |= KDB_ENABLE_ALWAYS_SAFE;
 230
 231	/* some commands change group when launched with no arguments */
 232	if (no_args)
 233		permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
 234
 235	flags |= KDB_ENABLE_ALL;
 236
 237	return permissions & flags;
 238}
 239
 240/*
 241 * kdbgetenv - This function will return the character string value of
 242 *	an environment variable.
 243 * Parameters:
 244 *	match	A character string representing an environment variable.
 245 * Returns:
 246 *	NULL	No environment variable matches 'match'
 247 *	char*	Pointer to string value of environment variable.
 248 */
 249char *kdbgetenv(const char *match)
 250{
 251	char **ep = __env;
 252	int matchlen = strlen(match);
 253	int i;
 254
 255	for (i = 0; i < __nenv; i++) {
 256		char *e = *ep++;
 257
 258		if (!e)
 259			continue;
 260
 261		if ((strncmp(match, e, matchlen) == 0)
 262		 && ((e[matchlen] == '\0')
 263		   || (e[matchlen] == '='))) {
 264			char *cp = strchr(e, '=');
 265			return cp ? ++cp : "";
 266		}
 267	}
 268	return NULL;
 269}
 270
 271/*
 272 * kdballocenv - This function is used to allocate bytes for
 273 *	environment entries.
 274 * Parameters:
 275 *	match	A character string representing a numeric value
 276 * Outputs:
 277 *	*value  the unsigned long representation of the env variable 'match'
 278 * Returns:
 279 *	Zero on success, a kdb diagnostic on failure.
 
 280 * Remarks:
 281 *	We use a static environment buffer (envbuffer) to hold the values
 282 *	of dynamically generated environment variables (see kdb_set).  Buffer
 283 *	space once allocated is never free'd, so over time, the amount of space
 284 *	(currently 512 bytes) will be exhausted if env variables are changed
 285 *	frequently.
 286 */
 287static char *kdballocenv(size_t bytes)
 288{
 289#define	KDB_ENVBUFSIZE	512
 290	static char envbuffer[KDB_ENVBUFSIZE];
 291	static int envbufsize;
 292	char *ep = NULL;
 293
 294	if ((KDB_ENVBUFSIZE - envbufsize) >= bytes) {
 295		ep = &envbuffer[envbufsize];
 296		envbufsize += bytes;
 297	}
 298	return ep;
 299}
 300
 301/*
 302 * kdbgetulenv - This function will return the value of an unsigned
 303 *	long-valued environment variable.
 304 * Parameters:
 305 *	match	A character string representing a numeric value
 306 * Outputs:
 307 *	*value  the unsigned long representation of the env variable 'match'
 308 * Returns:
 309 *	Zero on success, a kdb diagnostic on failure.
 310 */
 311static int kdbgetulenv(const char *match, unsigned long *value)
 312{
 313	char *ep;
 314
 315	ep = kdbgetenv(match);
 316	if (!ep)
 317		return KDB_NOTENV;
 318	if (strlen(ep) == 0)
 319		return KDB_NOENVVALUE;
 320
 321	*value = simple_strtoul(ep, NULL, 0);
 322
 323	return 0;
 324}
 325
 326/*
 327 * kdbgetintenv - This function will return the value of an
 328 *	integer-valued environment variable.
 329 * Parameters:
 330 *	match	A character string representing an integer-valued env variable
 331 * Outputs:
 332 *	*value  the integer representation of the environment variable 'match'
 333 * Returns:
 334 *	Zero on success, a kdb diagnostic on failure.
 335 */
 336int kdbgetintenv(const char *match, int *value)
 337{
 338	unsigned long val;
 339	int diag;
 340
 341	diag = kdbgetulenv(match, &val);
 342	if (!diag)
 343		*value = (int) val;
 344	return diag;
 345}
 346
 347/*
 348 * kdb_setenv() - Alter an existing environment variable or create a new one.
 349 * @var: Name of the variable
 350 * @val: Value of the variable
 351 *
 352 * Return: Zero on success, a kdb diagnostic on failure.
 353 */
 354static int kdb_setenv(const char *var, const char *val)
 355{
 356	int i;
 357	char *ep;
 358	size_t varlen, vallen;
 359
 360	varlen = strlen(var);
 361	vallen = strlen(val);
 362	ep = kdballocenv(varlen + vallen + 2);
 363	if (ep == (char *)0)
 364		return KDB_ENVBUFFULL;
 365
 366	sprintf(ep, "%s=%s", var, val);
 367
 368	for (i = 0; i < __nenv; i++) {
 369		if (__env[i]
 370		 && ((strncmp(__env[i], var, varlen) == 0)
 371		   && ((__env[i][varlen] == '\0')
 372		    || (__env[i][varlen] == '=')))) {
 373			__env[i] = ep;
 374			return 0;
 375		}
 376	}
 377
 378	/*
 379	 * Wasn't existing variable.  Fit into slot.
 380	 */
 381	for (i = 0; i < __nenv-1; i++) {
 382		if (__env[i] == (char *)0) {
 383			__env[i] = ep;
 384			return 0;
 385		}
 386	}
 387
 388	return KDB_ENVFULL;
 389}
 390
 391/*
 392 * kdb_printenv() - Display the current environment variables.
 393 */
 394static void kdb_printenv(void)
 395{
 396	int i;
 397
 398	for (i = 0; i < __nenv; i++) {
 399		if (__env[i])
 400			kdb_printf("%s\n", __env[i]);
 401	}
 402}
 403
 404/*
 405 * kdbgetularg - This function will convert a numeric string into an
 406 *	unsigned long value.
 407 * Parameters:
 408 *	arg	A character string representing a numeric value
 409 * Outputs:
 410 *	*value  the unsigned long representation of arg.
 411 * Returns:
 412 *	Zero on success, a kdb diagnostic on failure.
 413 */
 414int kdbgetularg(const char *arg, unsigned long *value)
 415{
 416	char *endp;
 417	unsigned long val;
 418
 419	val = simple_strtoul(arg, &endp, 0);
 420
 421	if (endp == arg) {
 422		/*
 423		 * Also try base 16, for us folks too lazy to type the
 424		 * leading 0x...
 425		 */
 426		val = simple_strtoul(arg, &endp, 16);
 427		if (endp == arg)
 428			return KDB_BADINT;
 429	}
 430
 431	*value = val;
 432
 433	return 0;
 434}
 435
 436int kdbgetu64arg(const char *arg, u64 *value)
 437{
 438	char *endp;
 439	u64 val;
 440
 441	val = simple_strtoull(arg, &endp, 0);
 442
 443	if (endp == arg) {
 444
 445		val = simple_strtoull(arg, &endp, 16);
 446		if (endp == arg)
 447			return KDB_BADINT;
 448	}
 449
 450	*value = val;
 451
 452	return 0;
 453}
 454
 455/*
 456 * kdb_set - This function implements the 'set' command.  Alter an
 457 *	existing environment variable or create a new one.
 458 */
 459int kdb_set(int argc, const char **argv)
 460{
 461	/*
 462	 * we can be invoked two ways:
 463	 *   set var=value    argv[1]="var", argv[2]="value"
 464	 *   set var = value  argv[1]="var", argv[2]="=", argv[3]="value"
 465	 * - if the latter, shift 'em down.
 466	 */
 467	if (argc == 3) {
 468		argv[2] = argv[3];
 469		argc--;
 470	}
 471
 472	if (argc != 2)
 473		return KDB_ARGCOUNT;
 474
 475	/*
 476	 * Censor sensitive variables
 477	 */
 478	if (strcmp(argv[1], "PROMPT") == 0 &&
 479	    !kdb_check_flags(KDB_ENABLE_MEM_READ, kdb_cmd_enabled, false))
 480		return KDB_NOPERM;
 481
 482	/*
 483	 * Check for internal variables
 484	 */
 485	if (strcmp(argv[1], "KDBDEBUG") == 0) {
 486		unsigned int debugflags;
 487		char *cp;
 488
 489		debugflags = simple_strtoul(argv[2], &cp, 0);
 490		if (cp == argv[2] || debugflags & ~KDB_DEBUG_FLAG_MASK) {
 491			kdb_printf("kdb: illegal debug flags '%s'\n",
 492				    argv[2]);
 493			return 0;
 494		}
 495		kdb_flags = (kdb_flags & ~KDB_DEBUG(MASK))
 496			| (debugflags << KDB_DEBUG_FLAG_SHIFT);
 497
 498		return 0;
 499	}
 500
 501	/*
 502	 * Tokenizer squashed the '=' sign.  argv[1] is variable
 503	 * name, argv[2] = value.
 504	 */
 505	return kdb_setenv(argv[1], argv[2]);
 506}
 507
 508static int kdb_check_regs(void)
 509{
 510	if (!kdb_current_regs) {
 511		kdb_printf("No current kdb registers."
 512			   "  You may need to select another task\n");
 513		return KDB_BADREG;
 514	}
 515	return 0;
 516}
 517
 518/*
 519 * kdbgetaddrarg - This function is responsible for parsing an
 520 *	address-expression and returning the value of the expression,
 521 *	symbol name, and offset to the caller.
 522 *
 523 *	The argument may consist of a numeric value (decimal or
 524 *	hexadecimal), a symbol name, a register name (preceded by the
 525 *	percent sign), an environment variable with a numeric value
 526 *	(preceded by a dollar sign) or a simple arithmetic expression
 527 *	consisting of a symbol name, +/-, and a numeric constant value
 528 *	(offset).
 529 * Parameters:
 530 *	argc	- count of arguments in argv
 531 *	argv	- argument vector
 532 *	*nextarg - index to next unparsed argument in argv[]
 533 *	regs	- Register state at time of KDB entry
 534 * Outputs:
 535 *	*value	- receives the value of the address-expression
 536 *	*offset - receives the offset specified, if any
 537 *	*name   - receives the symbol name, if any
 538 *	*nextarg - index to next unparsed argument in argv[]
 539 * Returns:
 540 *	zero is returned on success, a kdb diagnostic code is
 541 *      returned on error.
 542 */
 543int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
 544		  unsigned long *value,  long *offset,
 545		  char **name)
 546{
 547	unsigned long addr;
 548	unsigned long off = 0;
 549	int positive;
 550	int diag;
 551	int found = 0;
 552	char *symname;
 553	char symbol = '\0';
 554	char *cp;
 555	kdb_symtab_t symtab;
 556
 557	/*
 558	 * If the enable flags prohibit both arbitrary memory access
 559	 * and flow control then there are no reasonable grounds to
 560	 * provide symbol lookup.
 561	 */
 562	if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
 563			     kdb_cmd_enabled, false))
 564		return KDB_NOPERM;
 565
 566	/*
 567	 * Process arguments which follow the following syntax:
 568	 *
 569	 *  symbol | numeric-address [+/- numeric-offset]
 570	 *  %register
 571	 *  $environment-variable
 572	 */
 573
 574	if (*nextarg > argc)
 575		return KDB_ARGCOUNT;
 576
 577	symname = (char *)argv[*nextarg];
 578
 579	/*
 580	 * If there is no whitespace between the symbol
 581	 * or address and the '+' or '-' symbols, we
 582	 * remember the character and replace it with a
 583	 * null so the symbol/value can be properly parsed
 584	 */
 585	cp = strpbrk(symname, "+-");
 586	if (cp != NULL) {
 587		symbol = *cp;
 588		*cp++ = '\0';
 589	}
 590
 591	if (symname[0] == '$') {
 592		diag = kdbgetulenv(&symname[1], &addr);
 593		if (diag)
 594			return diag;
 595	} else if (symname[0] == '%') {
 596		diag = kdb_check_regs();
 597		if (diag)
 598			return diag;
 599		/* Implement register values with % at a later time as it is
 600		 * arch optional.
 601		 */
 602		return KDB_NOTIMP;
 603	} else {
 604		found = kdbgetsymval(symname, &symtab);
 605		if (found) {
 606			addr = symtab.sym_start;
 607		} else {
 608			diag = kdbgetularg(argv[*nextarg], &addr);
 609			if (diag)
 610				return diag;
 611		}
 612	}
 613
 614	if (!found)
 615		found = kdbnearsym(addr, &symtab);
 616
 617	(*nextarg)++;
 618
 619	if (name)
 620		*name = symname;
 621	if (value)
 622		*value = addr;
 623	if (offset && name && *name)
 624		*offset = addr - symtab.sym_start;
 625
 626	if ((*nextarg > argc)
 627	 && (symbol == '\0'))
 628		return 0;
 629
 630	/*
 631	 * check for +/- and offset
 632	 */
 633
 634	if (symbol == '\0') {
 635		if ((argv[*nextarg][0] != '+')
 636		 && (argv[*nextarg][0] != '-')) {
 637			/*
 638			 * Not our argument.  Return.
 639			 */
 640			return 0;
 641		} else {
 642			positive = (argv[*nextarg][0] == '+');
 643			(*nextarg)++;
 644		}
 645	} else
 646		positive = (symbol == '+');
 647
 648	/*
 649	 * Now there must be an offset!
 650	 */
 651	if ((*nextarg > argc)
 652	 && (symbol == '\0')) {
 653		return KDB_INVADDRFMT;
 654	}
 655
 656	if (!symbol) {
 657		cp = (char *)argv[*nextarg];
 658		(*nextarg)++;
 659	}
 660
 661	diag = kdbgetularg(cp, &off);
 662	if (diag)
 663		return diag;
 664
 665	if (!positive)
 666		off = -off;
 667
 668	if (offset)
 669		*offset += off;
 670
 671	if (value)
 672		*value += off;
 673
 674	return 0;
 675}
 676
 677static void kdb_cmderror(int diag)
 678{
 679	int i;
 680
 681	if (diag >= 0) {
 682		kdb_printf("no error detected (diagnostic is %d)\n", diag);
 683		return;
 684	}
 685
 686	for (i = 0; i < __nkdb_err; i++) {
 687		if (kdbmsgs[i].km_diag == diag) {
 688			kdb_printf("diag: %d: %s\n", diag, kdbmsgs[i].km_msg);
 689			return;
 690		}
 691	}
 692
 693	kdb_printf("Unknown diag %d\n", -diag);
 694}
 695
 696/*
 697 * kdb_defcmd, kdb_defcmd2 - This function implements the 'defcmd'
 698 *	command which defines one command as a set of other commands,
 699 *	terminated by endefcmd.  kdb_defcmd processes the initial
 700 *	'defcmd' command, kdb_defcmd2 is invoked from kdb_parse for
 701 *	the following commands until 'endefcmd'.
 702 * Inputs:
 703 *	argc	argument count
 704 *	argv	argument vector
 705 * Returns:
 706 *	zero for success, a kdb diagnostic if error
 707 */
 708struct kdb_macro {
 709	kdbtab_t cmd;			/* Macro command */
 710	struct list_head statements;	/* Associated statement list */
 711};
 712
 713struct kdb_macro_statement {
 714	char *statement;		/* Statement text */
 715	struct list_head list_node;	/* Statement list node */
 716};
 717
 718static struct kdb_macro *kdb_macro;
 719static bool defcmd_in_progress;
 720
 721/* Forward references */
 722static int kdb_exec_defcmd(int argc, const char **argv);
 723
 724static int kdb_defcmd2(const char *cmdstr, const char *argv0)
 725{
 726	struct kdb_macro_statement *kms;
 727
 728	if (!kdb_macro)
 729		return KDB_NOTIMP;
 730
 731	if (strcmp(argv0, "endefcmd") == 0) {
 732		defcmd_in_progress = false;
 733		if (!list_empty(&kdb_macro->statements))
 734			kdb_register(&kdb_macro->cmd);
 735		return 0;
 736	}
 737
 738	kms = kmalloc(sizeof(*kms), GFP_KDB);
 739	if (!kms) {
 740		kdb_printf("Could not allocate new kdb macro command: %s\n",
 741			   cmdstr);
 742		return KDB_NOTIMP;
 743	}
 744
 745	kms->statement = kdb_strdup(cmdstr, GFP_KDB);
 746	list_add_tail(&kms->list_node, &kdb_macro->statements);
 747
 748	return 0;
 749}
 750
 751static int kdb_defcmd(int argc, const char **argv)
 752{
 753	kdbtab_t *mp;
 754
 755	if (defcmd_in_progress) {
 756		kdb_printf("kdb: nested defcmd detected, assuming missing "
 757			   "endefcmd\n");
 758		kdb_defcmd2("endefcmd", "endefcmd");
 759	}
 760	if (argc == 0) {
 761		kdbtab_t *kp;
 762		struct kdb_macro *kmp;
 763		struct kdb_macro_statement *kms;
 764
 765		list_for_each_entry(kp, &kdb_cmds_head, list_node) {
 766			if (kp->func == kdb_exec_defcmd) {
 767				kdb_printf("defcmd %s \"%s\" \"%s\"\n",
 768					   kp->name, kp->usage, kp->help);
 769				kmp = container_of(kp, struct kdb_macro, cmd);
 770				list_for_each_entry(kms, &kmp->statements,
 771						    list_node)
 772					kdb_printf("%s", kms->statement);
 773				kdb_printf("endefcmd\n");
 774			}
 775		}
 776		return 0;
 777	}
 778	if (argc != 3)
 779		return KDB_ARGCOUNT;
 780	if (in_dbg_master()) {
 781		kdb_printf("Command only available during kdb_init()\n");
 782		return KDB_NOTIMP;
 783	}
 784	kdb_macro = kzalloc(sizeof(*kdb_macro), GFP_KDB);
 785	if (!kdb_macro)
 786		goto fail_defcmd;
 787
 788	mp = &kdb_macro->cmd;
 789	mp->func = kdb_exec_defcmd;
 790	mp->minlen = 0;
 791	mp->flags = KDB_ENABLE_ALWAYS_SAFE;
 792	mp->name = kdb_strdup(argv[1], GFP_KDB);
 793	if (!mp->name)
 794		goto fail_name;
 795	mp->usage = kdb_strdup(argv[2], GFP_KDB);
 796	if (!mp->usage)
 797		goto fail_usage;
 798	mp->help = kdb_strdup(argv[3], GFP_KDB);
 799	if (!mp->help)
 800		goto fail_help;
 801	if (mp->usage[0] == '"') {
 802		strcpy(mp->usage, argv[2]+1);
 803		mp->usage[strlen(mp->usage)-1] = '\0';
 804	}
 805	if (mp->help[0] == '"') {
 806		strcpy(mp->help, argv[3]+1);
 807		mp->help[strlen(mp->help)-1] = '\0';
 808	}
 809
 810	INIT_LIST_HEAD(&kdb_macro->statements);
 811	defcmd_in_progress = true;
 812	return 0;
 813fail_help:
 814	kfree(mp->usage);
 815fail_usage:
 816	kfree(mp->name);
 817fail_name:
 818	kfree(kdb_macro);
 819fail_defcmd:
 820	kdb_printf("Could not allocate new kdb_macro entry for %s\n", argv[1]);
 821	return KDB_NOTIMP;
 822}
 823
 824/*
 825 * kdb_exec_defcmd - Execute the set of commands associated with this
 826 *	defcmd name.
 827 * Inputs:
 828 *	argc	argument count
 829 *	argv	argument vector
 830 * Returns:
 831 *	zero for success, a kdb diagnostic if error
 832 */
 833static int kdb_exec_defcmd(int argc, const char **argv)
 834{
 835	int ret;
 836	kdbtab_t *kp;
 837	struct kdb_macro *kmp;
 838	struct kdb_macro_statement *kms;
 839
 840	if (argc != 0)
 841		return KDB_ARGCOUNT;
 842
 843	list_for_each_entry(kp, &kdb_cmds_head, list_node) {
 844		if (strcmp(kp->name, argv[0]) == 0)
 845			break;
 846	}
 847	if (list_entry_is_head(kp, &kdb_cmds_head, list_node)) {
 848		kdb_printf("kdb_exec_defcmd: could not find commands for %s\n",
 849			   argv[0]);
 850		return KDB_NOTIMP;
 851	}
 852	kmp = container_of(kp, struct kdb_macro, cmd);
 853	list_for_each_entry(kms, &kmp->statements, list_node) {
 854		/*
 855		 * Recursive use of kdb_parse, do not use argv after this point.
 856		 */
 857		argv = NULL;
 858		kdb_printf("[%s]kdb> %s\n", kmp->cmd.name, kms->statement);
 859		ret = kdb_parse(kms->statement);
 860		if (ret)
 861			return ret;
 862	}
 863	return 0;
 864}
 865
 866/* Command history */
 867#define KDB_CMD_HISTORY_COUNT	32
 868#define CMD_BUFLEN		200	/* kdb_printf: max printline
 869					 * size == 256 */
 870static unsigned int cmd_head, cmd_tail;
 871static unsigned int cmdptr;
 872static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN];
 873static char cmd_cur[CMD_BUFLEN];
 874
 875/*
 876 * The "str" argument may point to something like  | grep xyz
 877 */
 878static void parse_grep(const char *str)
 879{
 880	int	len;
 881	char	*cp = (char *)str, *cp2;
 882
 883	/* sanity check: we should have been called with the \ first */
 884	if (*cp != '|')
 885		return;
 886	cp++;
 887	while (isspace(*cp))
 888		cp++;
 889	if (!str_has_prefix(cp, "grep ")) {
 890		kdb_printf("invalid 'pipe', see grephelp\n");
 891		return;
 892	}
 893	cp += 5;
 894	while (isspace(*cp))
 895		cp++;
 896	cp2 = strchr(cp, '\n');
 897	if (cp2)
 898		*cp2 = '\0'; /* remove the trailing newline */
 899	len = strlen(cp);
 900	if (len == 0) {
 901		kdb_printf("invalid 'pipe', see grephelp\n");
 902		return;
 903	}
 904	/* now cp points to a nonzero length search string */
 905	if (*cp == '"') {
 906		/* allow it be "x y z" by removing the "'s - there must
 907		   be two of them */
 908		cp++;
 909		cp2 = strchr(cp, '"');
 910		if (!cp2) {
 911			kdb_printf("invalid quoted string, see grephelp\n");
 912			return;
 913		}
 914		*cp2 = '\0'; /* end the string where the 2nd " was */
 915	}
 916	kdb_grep_leading = 0;
 917	if (*cp == '^') {
 918		kdb_grep_leading = 1;
 919		cp++;
 920	}
 921	len = strlen(cp);
 922	kdb_grep_trailing = 0;
 923	if (*(cp+len-1) == '$') {
 924		kdb_grep_trailing = 1;
 925		*(cp+len-1) = '\0';
 926	}
 927	len = strlen(cp);
 928	if (!len)
 929		return;
 930	if (len >= KDB_GREP_STRLEN) {
 931		kdb_printf("search string too long\n");
 932		return;
 933	}
 934	strcpy(kdb_grep_string, cp);
 935	kdb_grepping_flag++;
 936	return;
 937}
 938
 939/*
 940 * kdb_parse - Parse the command line, search the command table for a
 941 *	matching command and invoke the command function.  This
 942 *	function may be called recursively, if it is, the second call
 943 *	will overwrite argv and cbuf.  It is the caller's
 944 *	responsibility to save their argv if they recursively call
 945 *	kdb_parse().
 946 * Parameters:
 947 *      cmdstr	The input command line to be parsed.
 948 *	regs	The registers at the time kdb was entered.
 949 * Returns:
 950 *	Zero for success, a kdb diagnostic if failure.
 951 * Remarks:
 952 *	Limited to 20 tokens.
 953 *
 954 *	Real rudimentary tokenization. Basically only whitespace
 955 *	is considered a token delimiter (but special consideration
 956 *	is taken of the '=' sign as used by the 'set' command).
 957 *
 958 *	The algorithm used to tokenize the input string relies on
 959 *	there being at least one whitespace (or otherwise useless)
 960 *	character between tokens as the character immediately following
 961 *	the token is altered in-place to a null-byte to terminate the
 962 *	token string.
 963 */
 964
 965#define MAXARGC	20
 966
 967int kdb_parse(const char *cmdstr)
 968{
 969	static char *argv[MAXARGC];
 970	static int argc;
 971	static char cbuf[CMD_BUFLEN+2];
 972	char *cp;
 973	char *cpp, quoted;
 974	kdbtab_t *tp;
 975	int escaped, ignore_errors = 0, check_grep = 0;
 976
 977	/*
 978	 * First tokenize the command string.
 979	 */
 980	cp = (char *)cmdstr;
 981
 982	if (KDB_FLAG(CMD_INTERRUPT)) {
 983		/* Previous command was interrupted, newline must not
 984		 * repeat the command */
 985		KDB_FLAG_CLEAR(CMD_INTERRUPT);
 986		KDB_STATE_SET(PAGER);
 987		argc = 0;	/* no repeat */
 988	}
 989
 990	if (*cp != '\n' && *cp != '\0') {
 991		argc = 0;
 992		cpp = cbuf;
 993		while (*cp) {
 994			/* skip whitespace */
 995			while (isspace(*cp))
 996				cp++;
 997			if ((*cp == '\0') || (*cp == '\n') ||
 998			    (*cp == '#' && !defcmd_in_progress))
 999				break;
1000			/* special case: check for | grep pattern */
1001			if (*cp == '|') {
1002				check_grep++;
1003				break;
1004			}
1005			if (cpp >= cbuf + CMD_BUFLEN) {
1006				kdb_printf("kdb_parse: command buffer "
1007					   "overflow, command ignored\n%s\n",
1008					   cmdstr);
1009				return KDB_NOTFOUND;
1010			}
1011			if (argc >= MAXARGC - 1) {
1012				kdb_printf("kdb_parse: too many arguments, "
1013					   "command ignored\n%s\n", cmdstr);
1014				return KDB_NOTFOUND;
1015			}
1016			argv[argc++] = cpp;
1017			escaped = 0;
1018			quoted = '\0';
1019			/* Copy to next unquoted and unescaped
1020			 * whitespace or '=' */
1021			while (*cp && *cp != '\n' &&
1022			       (escaped || quoted || !isspace(*cp))) {
1023				if (cpp >= cbuf + CMD_BUFLEN)
1024					break;
1025				if (escaped) {
1026					escaped = 0;
1027					*cpp++ = *cp++;
1028					continue;
1029				}
1030				if (*cp == '\\') {
1031					escaped = 1;
1032					++cp;
1033					continue;
1034				}
1035				if (*cp == quoted)
1036					quoted = '\0';
1037				else if (*cp == '\'' || *cp == '"')
1038					quoted = *cp;
1039				*cpp = *cp++;
1040				if (*cpp == '=' && !quoted)
1041					break;
1042				++cpp;
1043			}
1044			*cpp++ = '\0';	/* Squash a ws or '=' character */
1045		}
1046	}
1047	if (!argc)
1048		return 0;
1049	if (check_grep)
1050		parse_grep(cp);
1051	if (defcmd_in_progress) {
1052		int result = kdb_defcmd2(cmdstr, argv[0]);
1053		if (!defcmd_in_progress) {
1054			argc = 0;	/* avoid repeat on endefcmd */
1055			*(argv[0]) = '\0';
1056		}
1057		return result;
1058	}
1059	if (argv[0][0] == '-' && argv[0][1] &&
1060	    (argv[0][1] < '0' || argv[0][1] > '9')) {
1061		ignore_errors = 1;
1062		++argv[0];
1063	}
1064
1065	list_for_each_entry(tp, &kdb_cmds_head, list_node) {
1066		/*
1067		 * If this command is allowed to be abbreviated,
1068		 * check to see if this is it.
1069		 */
1070		if (tp->minlen && (strlen(argv[0]) <= tp->minlen) &&
1071		    (strncmp(argv[0], tp->name, tp->minlen) == 0))
1072			break;
1073
1074		if (strcmp(argv[0], tp->name) == 0)
1075			break;
1076	}
1077
1078	/*
1079	 * If we don't find a command by this name, see if the first
1080	 * few characters of this match any of the known commands.
1081	 * e.g., md1c20 should match md.
1082	 */
1083	if (list_entry_is_head(tp, &kdb_cmds_head, list_node)) {
1084		list_for_each_entry(tp, &kdb_cmds_head, list_node) {
1085			if (strncmp(argv[0], tp->name, strlen(tp->name)) == 0)
1086				break;
1087		}
1088	}
1089
1090	if (!list_entry_is_head(tp, &kdb_cmds_head, list_node)) {
1091		int result;
1092
1093		if (!kdb_check_flags(tp->flags, kdb_cmd_enabled, argc <= 1))
1094			return KDB_NOPERM;
1095
1096		KDB_STATE_SET(CMD);
1097		result = (*tp->func)(argc-1, (const char **)argv);
1098		if (result && ignore_errors && result > KDB_CMD_GO)
1099			result = 0;
1100		KDB_STATE_CLEAR(CMD);
1101
1102		if (tp->flags & KDB_REPEAT_WITH_ARGS)
1103			return result;
1104
1105		argc = tp->flags & KDB_REPEAT_NO_ARGS ? 1 : 0;
1106		if (argv[argc])
1107			*(argv[argc]) = '\0';
1108		return result;
1109	}
1110
1111	/*
1112	 * If the input with which we were presented does not
1113	 * map to an existing command, attempt to parse it as an
1114	 * address argument and display the result.   Useful for
1115	 * obtaining the address of a variable, or the nearest symbol
1116	 * to an address contained in a register.
1117	 */
1118	{
1119		unsigned long value;
1120		char *name = NULL;
1121		long offset;
1122		int nextarg = 0;
1123
1124		if (kdbgetaddrarg(0, (const char **)argv, &nextarg,
1125				  &value, &offset, &name)) {
1126			return KDB_NOTFOUND;
1127		}
1128
1129		kdb_printf("%s = ", argv[0]);
1130		kdb_symbol_print(value, NULL, KDB_SP_DEFAULT);
1131		kdb_printf("\n");
1132		return 0;
1133	}
1134}
1135
1136
1137static int handle_ctrl_cmd(char *cmd)
1138{
1139#define CTRL_P	16
1140#define CTRL_N	14
1141
1142	/* initial situation */
1143	if (cmd_head == cmd_tail)
1144		return 0;
1145	switch (*cmd) {
1146	case CTRL_P:
1147		if (cmdptr != cmd_tail)
1148			cmdptr = (cmdptr + KDB_CMD_HISTORY_COUNT - 1) %
1149				 KDB_CMD_HISTORY_COUNT;
1150		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1151		return 1;
1152	case CTRL_N:
1153		if (cmdptr != cmd_head)
1154			cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT;
1155		strscpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1156		return 1;
1157	}
1158	return 0;
1159}
1160
1161/*
1162 * kdb_reboot - This function implements the 'reboot' command.  Reboot
1163 *	the system immediately, or loop for ever on failure.
1164 */
1165static int kdb_reboot(int argc, const char **argv)
1166{
1167	emergency_restart();
1168	kdb_printf("Hmm, kdb_reboot did not reboot, spinning here\n");
1169	while (1)
1170		cpu_relax();
1171	/* NOTREACHED */
1172	return 0;
1173}
1174
1175static void kdb_dumpregs(struct pt_regs *regs)
1176{
1177	int old_lvl = console_loglevel;
1178	console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
1179	kdb_trap_printk++;
1180	show_regs(regs);
1181	kdb_trap_printk--;
1182	kdb_printf("\n");
1183	console_loglevel = old_lvl;
1184}
1185
1186static void kdb_set_current_task(struct task_struct *p)
1187{
1188	kdb_current_task = p;
1189
1190	if (kdb_task_has_cpu(p)) {
1191		kdb_current_regs = KDB_TSKREGS(kdb_process_cpu(p));
1192		return;
1193	}
1194	kdb_current_regs = NULL;
1195}
1196
1197static void drop_newline(char *buf)
1198{
1199	size_t len = strlen(buf);
1200
1201	if (len == 0)
1202		return;
1203	if (*(buf + len - 1) == '\n')
1204		*(buf + len - 1) = '\0';
1205}
1206
1207/*
1208 * kdb_local - The main code for kdb.  This routine is invoked on a
1209 *	specific processor, it is not global.  The main kdb() routine
1210 *	ensures that only one processor at a time is in this routine.
1211 *	This code is called with the real reason code on the first
1212 *	entry to a kdb session, thereafter it is called with reason
1213 *	SWITCH, even if the user goes back to the original cpu.
1214 * Inputs:
1215 *	reason		The reason KDB was invoked
1216 *	error		The hardware-defined error code
1217 *	regs		The exception frame at time of fault/breakpoint.
1218 *	db_result	Result code from the break or debug point.
1219 * Returns:
1220 *	0	KDB was invoked for an event which it wasn't responsible
1221 *	1	KDB handled the event for which it was invoked.
1222 *	KDB_CMD_GO	User typed 'go'.
1223 *	KDB_CMD_CPU	User switched to another cpu.
1224 *	KDB_CMD_SS	Single step.
1225 */
1226static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
1227		     kdb_dbtrap_t db_result)
1228{
1229	char *cmdbuf;
1230	int diag;
1231	struct task_struct *kdb_current =
1232		kdb_curr_task(raw_smp_processor_id());
1233
1234	KDB_DEBUG_STATE("kdb_local 1", reason);
1235
1236	kdb_check_for_lockdown();
1237
1238	kdb_go_count = 0;
1239	if (reason == KDB_REASON_DEBUG) {
1240		/* special case below */
1241	} else {
1242		kdb_printf("\nEntering kdb (current=0x%px, pid %d) ",
1243			   kdb_current, kdb_current ? kdb_current->pid : 0);
1244#if defined(CONFIG_SMP)
1245		kdb_printf("on processor %d ", raw_smp_processor_id());
1246#endif
1247	}
1248
1249	switch (reason) {
1250	case KDB_REASON_DEBUG:
1251	{
1252		/*
1253		 * If re-entering kdb after a single step
1254		 * command, don't print the message.
1255		 */
1256		switch (db_result) {
1257		case KDB_DB_BPT:
1258			kdb_printf("\nEntering kdb (0x%px, pid %d) ",
1259				   kdb_current, kdb_current->pid);
1260#if defined(CONFIG_SMP)
1261			kdb_printf("on processor %d ", raw_smp_processor_id());
1262#endif
1263			kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
1264				   instruction_pointer(regs));
1265			break;
1266		case KDB_DB_SS:
1267			break;
1268		case KDB_DB_SSBPT:
1269			KDB_DEBUG_STATE("kdb_local 4", reason);
1270			return 1;	/* kdba_db_trap did the work */
1271		default:
1272			kdb_printf("kdb: Bad result from kdba_db_trap: %d\n",
1273				   db_result);
1274			break;
1275		}
1276
1277	}
1278		break;
1279	case KDB_REASON_ENTER:
1280		if (KDB_STATE(KEYBOARD))
1281			kdb_printf("due to Keyboard Entry\n");
1282		else
1283			kdb_printf("due to KDB_ENTER()\n");
1284		break;
1285	case KDB_REASON_KEYBOARD:
1286		KDB_STATE_SET(KEYBOARD);
1287		kdb_printf("due to Keyboard Entry\n");
1288		break;
1289	case KDB_REASON_ENTER_SLAVE:
1290		/* drop through, slaves only get released via cpu switch */
1291	case KDB_REASON_SWITCH:
1292		kdb_printf("due to cpu switch\n");
1293		break;
1294	case KDB_REASON_OOPS:
1295		kdb_printf("Oops: %s\n", kdb_diemsg);
1296		kdb_printf("due to oops @ " kdb_machreg_fmt "\n",
1297			   instruction_pointer(regs));
1298		kdb_dumpregs(regs);
1299		break;
1300	case KDB_REASON_SYSTEM_NMI:
1301		kdb_printf("due to System NonMaskable Interrupt\n");
1302		break;
1303	case KDB_REASON_NMI:
1304		kdb_printf("due to NonMaskable Interrupt @ "
1305			   kdb_machreg_fmt "\n",
1306			   instruction_pointer(regs));
1307		break;
1308	case KDB_REASON_SSTEP:
1309	case KDB_REASON_BREAK:
1310		kdb_printf("due to %s @ " kdb_machreg_fmt "\n",
1311			   reason == KDB_REASON_BREAK ?
1312			   "Breakpoint" : "SS trap", instruction_pointer(regs));
1313		/*
1314		 * Determine if this breakpoint is one that we
1315		 * are interested in.
1316		 */
1317		if (db_result != KDB_DB_BPT) {
1318			kdb_printf("kdb: error return from kdba_bp_trap: %d\n",
1319				   db_result);
1320			KDB_DEBUG_STATE("kdb_local 6", reason);
1321			return 0;	/* Not for us, dismiss it */
1322		}
1323		break;
1324	case KDB_REASON_RECURSE:
1325		kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n",
1326			   instruction_pointer(regs));
1327		break;
1328	default:
1329		kdb_printf("kdb: unexpected reason code: %d\n", reason);
1330		KDB_DEBUG_STATE("kdb_local 8", reason);
1331		return 0;	/* Not for us, dismiss it */
1332	}
1333
1334	while (1) {
1335		/*
1336		 * Initialize pager context.
1337		 */
1338		kdb_nextline = 1;
1339		KDB_STATE_CLEAR(SUPPRESS);
1340		kdb_grepping_flag = 0;
1341		/* ensure the old search does not leak into '/' commands */
1342		kdb_grep_string[0] = '\0';
1343
1344		cmdbuf = cmd_cur;
1345		*cmdbuf = '\0';
1346		*(cmd_hist[cmd_head]) = '\0';
1347
1348do_full_getstr:
1349		/* PROMPT can only be set if we have MEM_READ permission. */
1350		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
1351			 raw_smp_processor_id());
1352		if (defcmd_in_progress)
1353			strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
1354
1355		/*
1356		 * Fetch command from keyboard
1357		 */
1358		cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str);
1359		if (*cmdbuf != '\n') {
1360			if (*cmdbuf < 32) {
1361				if (cmdptr == cmd_head) {
1362					strscpy(cmd_hist[cmd_head], cmd_cur,
1363						CMD_BUFLEN);
1364					*(cmd_hist[cmd_head] +
1365					  strlen(cmd_hist[cmd_head])-1) = '\0';
1366				}
1367				if (!handle_ctrl_cmd(cmdbuf))
1368					*(cmd_cur+strlen(cmd_cur)-1) = '\0';
1369				cmdbuf = cmd_cur;
1370				goto do_full_getstr;
1371			} else {
1372				strscpy(cmd_hist[cmd_head], cmd_cur,
1373					CMD_BUFLEN);
1374			}
1375
1376			cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT;
1377			if (cmd_head == cmd_tail)
1378				cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT;
1379		}
1380
1381		cmdptr = cmd_head;
1382		diag = kdb_parse(cmdbuf);
1383		if (diag == KDB_NOTFOUND) {
1384			drop_newline(cmdbuf);
1385			kdb_printf("Unknown kdb command: '%s'\n", cmdbuf);
1386			diag = 0;
1387		}
1388		if (diag == KDB_CMD_GO
1389		 || diag == KDB_CMD_CPU
1390		 || diag == KDB_CMD_SS
1391		 || diag == KDB_CMD_KGDB)
1392			break;
1393
1394		if (diag)
1395			kdb_cmderror(diag);
1396	}
1397	KDB_DEBUG_STATE("kdb_local 9", diag);
1398	return diag;
1399}
1400
1401
1402/*
1403 * kdb_print_state - Print the state data for the current processor
1404 *	for debugging.
1405 * Inputs:
1406 *	text		Identifies the debug point
1407 *	value		Any integer value to be printed, e.g. reason code.
1408 */
1409void kdb_print_state(const char *text, int value)
1410{
1411	kdb_printf("state: %s cpu %d value %d initial %d state %x\n",
1412		   text, raw_smp_processor_id(), value, kdb_initial_cpu,
1413		   kdb_state);
1414}
1415
1416/*
1417 * kdb_main_loop - After initial setup and assignment of the
1418 *	controlling cpu, all cpus are in this loop.  One cpu is in
1419 *	control and will issue the kdb prompt, the others will spin
1420 *	until 'go' or cpu switch.
1421 *
1422 *	To get a consistent view of the kernel stacks for all
1423 *	processes, this routine is invoked from the main kdb code via
1424 *	an architecture specific routine.  kdba_main_loop is
1425 *	responsible for making the kernel stacks consistent for all
1426 *	processes, there should be no difference between a blocked
1427 *	process and a running process as far as kdb is concerned.
1428 * Inputs:
1429 *	reason		The reason KDB was invoked
1430 *	error		The hardware-defined error code
1431 *	reason2		kdb's current reason code.
1432 *			Initially error but can change
1433 *			according to kdb state.
1434 *	db_result	Result code from break or debug point.
1435 *	regs		The exception frame at time of fault/breakpoint.
1436 *			should always be valid.
1437 * Returns:
1438 *	0	KDB was invoked for an event which it wasn't responsible
1439 *	1	KDB handled the event for which it was invoked.
1440 */
1441int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
1442	      kdb_dbtrap_t db_result, struct pt_regs *regs)
1443{
1444	int result = 1;
1445	/* Stay in kdb() until 'go', 'ss[b]' or an error */
1446	while (1) {
1447		/*
1448		 * All processors except the one that is in control
1449		 * will spin here.
1450		 */
1451		KDB_DEBUG_STATE("kdb_main_loop 1", reason);
1452		while (KDB_STATE(HOLD_CPU)) {
1453			/* state KDB is turned off by kdb_cpu to see if the
1454			 * other cpus are still live, each cpu in this loop
1455			 * turns it back on.
1456			 */
1457			if (!KDB_STATE(KDB))
1458				KDB_STATE_SET(KDB);
1459		}
1460
1461		KDB_STATE_CLEAR(SUPPRESS);
1462		KDB_DEBUG_STATE("kdb_main_loop 2", reason);
1463		if (KDB_STATE(LEAVING))
1464			break;	/* Another cpu said 'go' */
1465		/* Still using kdb, this processor is in control */
1466		result = kdb_local(reason2, error, regs, db_result);
1467		KDB_DEBUG_STATE("kdb_main_loop 3", result);
1468
1469		if (result == KDB_CMD_CPU)
1470			break;
1471
1472		if (result == KDB_CMD_SS) {
1473			KDB_STATE_SET(DOING_SS);
1474			break;
1475		}
1476
1477		if (result == KDB_CMD_KGDB) {
1478			if (!KDB_STATE(DOING_KGDB))
1479				kdb_printf("Entering please attach debugger "
1480					   "or use $D#44+ or $3#33\n");
1481			break;
1482		}
1483		if (result && result != 1 && result != KDB_CMD_GO)
1484			kdb_printf("\nUnexpected kdb_local return code %d\n",
1485				   result);
1486		KDB_DEBUG_STATE("kdb_main_loop 4", reason);
1487		break;
1488	}
1489	if (KDB_STATE(DOING_SS))
1490		KDB_STATE_CLEAR(SSBPT);
1491
1492	/* Clean up any keyboard devices before leaving */
1493	kdb_kbd_cleanup_state();
1494
1495	return result;
1496}
1497
1498/*
1499 * kdb_mdr - This function implements the guts of the 'mdr', memory
1500 * read command.
1501 *	mdr  <addr arg>,<byte count>
1502 * Inputs:
1503 *	addr	Start address
1504 *	count	Number of bytes
1505 * Returns:
1506 *	Always 0.  Any errors are detected and printed by kdb_getarea.
1507 */
1508static int kdb_mdr(unsigned long addr, unsigned int count)
1509{
1510	unsigned char c;
1511	while (count--) {
1512		if (kdb_getarea(c, addr))
1513			return 0;
1514		kdb_printf("%02x", c);
1515		addr++;
1516	}
1517	kdb_printf("\n");
1518	return 0;
1519}
1520
1521/*
1522 * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4',
1523 *	'md8' 'mdr' and 'mds' commands.
1524 *
1525 *	md|mds  [<addr arg> [<line count> [<radix>]]]
1526 *	mdWcN	[<addr arg> [<line count> [<radix>]]]
1527 *		where W = is the width (1, 2, 4 or 8) and N is the count.
1528 *		for eg., md1c20 reads 20 bytes, 1 at a time.
1529 *	mdr  <addr arg>,<byte count>
1530 */
1531static void kdb_md_line(const char *fmtstr, unsigned long addr,
1532			int symbolic, int nosect, int bytesperword,
1533			int num, int repeat, int phys)
1534{
1535	/* print just one line of data */
1536	kdb_symtab_t symtab;
1537	char cbuf[32];
1538	char *c = cbuf;
1539	int i;
1540	int j;
1541	unsigned long word;
1542
1543	memset(cbuf, '\0', sizeof(cbuf));
1544	if (phys)
1545		kdb_printf("phys " kdb_machreg_fmt0 " ", addr);
1546	else
1547		kdb_printf(kdb_machreg_fmt0 " ", addr);
1548
1549	for (i = 0; i < num && repeat--; i++) {
1550		if (phys) {
1551			if (kdb_getphysword(&word, addr, bytesperword))
1552				break;
1553		} else if (kdb_getword(&word, addr, bytesperword))
1554			break;
1555		kdb_printf(fmtstr, word);
1556		if (symbolic)
1557			kdbnearsym(word, &symtab);
1558		else
1559			memset(&symtab, 0, sizeof(symtab));
1560		if (symtab.sym_name) {
1561			kdb_symbol_print(word, &symtab, 0);
1562			if (!nosect) {
1563				kdb_printf("\n");
1564				kdb_printf("                       %s %s "
1565					   kdb_machreg_fmt " "
1566					   kdb_machreg_fmt " "
1567					   kdb_machreg_fmt, symtab.mod_name,
1568					   symtab.sec_name, symtab.sec_start,
1569					   symtab.sym_start, symtab.sym_end);
1570			}
1571			addr += bytesperword;
1572		} else {
1573			union {
1574				u64 word;
1575				unsigned char c[8];
1576			} wc;
1577			unsigned char *cp;
1578#ifdef	__BIG_ENDIAN
1579			cp = wc.c + 8 - bytesperword;
1580#else
1581			cp = wc.c;
1582#endif
1583			wc.word = word;
1584#define printable_char(c) \
1585	({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; })
1586			for (j = 0; j < bytesperword; j++)
1587				*c++ = printable_char(*cp++);
1588			addr += bytesperword;
1589#undef printable_char
1590		}
1591	}
1592	kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1),
1593		   " ", cbuf);
1594}
1595
1596static int kdb_md(int argc, const char **argv)
1597{
1598	static unsigned long last_addr;
1599	static int last_radix, last_bytesperword, last_repeat;
1600	int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
1601	int nosect = 0;
1602	char fmtchar, fmtstr[64];
1603	unsigned long addr;
1604	unsigned long word;
1605	long offset = 0;
1606	int symbolic = 0;
1607	int valid = 0;
1608	int phys = 0;
1609	int raw = 0;
1610
1611	kdbgetintenv("MDCOUNT", &mdcount);
1612	kdbgetintenv("RADIX", &radix);
1613	kdbgetintenv("BYTESPERWORD", &bytesperword);
1614
1615	/* Assume 'md <addr>' and start with environment values */
1616	repeat = mdcount * 16 / bytesperword;
1617
1618	if (strcmp(argv[0], "mdr") == 0) {
1619		if (argc == 2 || (argc == 0 && last_addr != 0))
1620			valid = raw = 1;
1621		else
1622			return KDB_ARGCOUNT;
1623	} else if (isdigit(argv[0][2])) {
1624		bytesperword = (int)(argv[0][2] - '0');
1625		if (bytesperword == 0) {
1626			bytesperword = last_bytesperword;
1627			if (bytesperword == 0)
1628				bytesperword = 4;
1629		}
1630		last_bytesperword = bytesperword;
1631		repeat = mdcount * 16 / bytesperword;
1632		if (!argv[0][3])
1633			valid = 1;
1634		else if (argv[0][3] == 'c' && argv[0][4]) {
1635			char *p;
1636			repeat = simple_strtoul(argv[0] + 4, &p, 10);
1637			mdcount = ((repeat * bytesperword) + 15) / 16;
1638			valid = !*p;
1639		}
1640		last_repeat = repeat;
1641	} else if (strcmp(argv[0], "md") == 0)
1642		valid = 1;
1643	else if (strcmp(argv[0], "mds") == 0)
1644		valid = 1;
1645	else if (strcmp(argv[0], "mdp") == 0) {
1646		phys = valid = 1;
1647	}
1648	if (!valid)
1649		return KDB_NOTFOUND;
1650
1651	if (argc == 0) {
1652		if (last_addr == 0)
1653			return KDB_ARGCOUNT;
1654		addr = last_addr;
1655		radix = last_radix;
1656		bytesperword = last_bytesperword;
1657		repeat = last_repeat;
1658		if (raw)
1659			mdcount = repeat;
1660		else
1661			mdcount = ((repeat * bytesperword) + 15) / 16;
1662	}
1663
1664	if (argc) {
1665		unsigned long val;
1666		int diag, nextarg = 1;
1667		diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
1668				     &offset, NULL);
1669		if (diag)
1670			return diag;
1671		if (argc > nextarg+2)
1672			return KDB_ARGCOUNT;
1673
1674		if (argc >= nextarg) {
1675			diag = kdbgetularg(argv[nextarg], &val);
1676			if (!diag) {
1677				mdcount = (int) val;
1678				if (raw)
1679					repeat = mdcount;
1680				else
1681					repeat = mdcount * 16 / bytesperword;
1682			}
1683		}
1684		if (argc >= nextarg+1) {
1685			diag = kdbgetularg(argv[nextarg+1], &val);
1686			if (!diag)
1687				radix = (int) val;
1688		}
1689	}
1690
1691	if (strcmp(argv[0], "mdr") == 0) {
1692		int ret;
1693		last_addr = addr;
1694		ret = kdb_mdr(addr, mdcount);
1695		last_addr += mdcount;
1696		last_repeat = mdcount;
1697		last_bytesperword = bytesperword; // to make REPEAT happy
1698		return ret;
1699	}
1700
1701	switch (radix) {
1702	case 10:
1703		fmtchar = 'd';
1704		break;
1705	case 16:
1706		fmtchar = 'x';
1707		break;
1708	case 8:
1709		fmtchar = 'o';
1710		break;
1711	default:
1712		return KDB_BADRADIX;
1713	}
1714
1715	last_radix = radix;
1716
1717	if (bytesperword > KDB_WORD_SIZE)
1718		return KDB_BADWIDTH;
1719
1720	switch (bytesperword) {
1721	case 8:
1722		sprintf(fmtstr, "%%16.16l%c ", fmtchar);
1723		break;
1724	case 4:
1725		sprintf(fmtstr, "%%8.8l%c ", fmtchar);
1726		break;
1727	case 2:
1728		sprintf(fmtstr, "%%4.4l%c ", fmtchar);
1729		break;
1730	case 1:
1731		sprintf(fmtstr, "%%2.2l%c ", fmtchar);
1732		break;
1733	default:
1734		return KDB_BADWIDTH;
1735	}
1736
1737	last_repeat = repeat;
1738	last_bytesperword = bytesperword;
1739
1740	if (strcmp(argv[0], "mds") == 0) {
1741		symbolic = 1;
1742		/* Do not save these changes as last_*, they are temporary mds
1743		 * overrides.
1744		 */
1745		bytesperword = KDB_WORD_SIZE;
1746		repeat = mdcount;
1747		kdbgetintenv("NOSECT", &nosect);
1748	}
1749
1750	/* Round address down modulo BYTESPERWORD */
1751
1752	addr &= ~(bytesperword-1);
1753
1754	while (repeat > 0) {
1755		unsigned long a;
1756		int n, z, num = (symbolic ? 1 : (16 / bytesperword));
1757
1758		if (KDB_FLAG(CMD_INTERRUPT))
1759			return 0;
1760		for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) {
1761			if (phys) {
1762				if (kdb_getphysword(&word, a, bytesperword)
1763						|| word)
1764					break;
1765			} else if (kdb_getword(&word, a, bytesperword) || word)
1766				break;
1767		}
1768		n = min(num, repeat);
1769		kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword,
1770			    num, repeat, phys);
1771		addr += bytesperword * n;
1772		repeat -= n;
1773		z = (z + num - 1) / num;
1774		if (z > 2) {
1775			int s = num * (z-2);
1776			kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0
1777				   " zero suppressed\n",
1778				addr, addr + bytesperword * s - 1);
1779			addr += bytesperword * s;
1780			repeat -= s;
1781		}
1782	}
1783	last_addr = addr;
1784
1785	return 0;
1786}
1787
1788/*
1789 * kdb_mm - This function implements the 'mm' command.
1790 *	mm address-expression new-value
1791 * Remarks:
1792 *	mm works on machine words, mmW works on bytes.
1793 */
1794static int kdb_mm(int argc, const char **argv)
1795{
1796	int diag;
1797	unsigned long addr;
1798	long offset = 0;
1799	unsigned long contents;
1800	int nextarg;
1801	int width;
1802
1803	if (argv[0][2] && !isdigit(argv[0][2]))
1804		return KDB_NOTFOUND;
1805
1806	if (argc < 2)
1807		return KDB_ARGCOUNT;
1808
1809	nextarg = 1;
1810	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1811	if (diag)
1812		return diag;
1813
1814	if (nextarg > argc)
1815		return KDB_ARGCOUNT;
1816	diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL);
1817	if (diag)
1818		return diag;
1819
1820	if (nextarg != argc + 1)
1821		return KDB_ARGCOUNT;
1822
1823	width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE);
1824	diag = kdb_putword(addr, contents, width);
1825	if (diag)
1826		return diag;
1827
1828	kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents);
1829
1830	return 0;
1831}
1832
1833/*
1834 * kdb_go - This function implements the 'go' command.
1835 *	go [address-expression]
1836 */
1837static int kdb_go(int argc, const char **argv)
1838{
1839	unsigned long addr;
1840	int diag;
1841	int nextarg;
1842	long offset;
1843
1844	if (raw_smp_processor_id() != kdb_initial_cpu) {
1845		kdb_printf("go must execute on the entry cpu, "
1846			   "please use \"cpu %d\" and then execute go\n",
1847			   kdb_initial_cpu);
1848		return KDB_BADCPUNUM;
1849	}
1850	if (argc == 1) {
1851		nextarg = 1;
1852		diag = kdbgetaddrarg(argc, argv, &nextarg,
1853				     &addr, &offset, NULL);
1854		if (diag)
1855			return diag;
1856	} else if (argc) {
1857		return KDB_ARGCOUNT;
1858	}
1859
1860	diag = KDB_CMD_GO;
1861	if (KDB_FLAG(CATASTROPHIC)) {
1862		kdb_printf("Catastrophic error detected\n");
1863		kdb_printf("kdb_continue_catastrophic=%d, ",
1864			kdb_continue_catastrophic);
1865		if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) {
1866			kdb_printf("type go a second time if you really want "
1867				   "to continue\n");
1868			return 0;
1869		}
1870		if (kdb_continue_catastrophic == 2) {
1871			kdb_printf("forcing reboot\n");
1872			kdb_reboot(0, NULL);
1873		}
1874		kdb_printf("attempting to continue\n");
1875	}
1876	return diag;
1877}
1878
1879/*
1880 * kdb_rd - This function implements the 'rd' command.
1881 */
1882static int kdb_rd(int argc, const char **argv)
1883{
1884	int len = kdb_check_regs();
1885#if DBG_MAX_REG_NUM > 0
1886	int i;
1887	char *rname;
1888	int rsize;
1889	u64 reg64;
1890	u32 reg32;
1891	u16 reg16;
1892	u8 reg8;
1893
1894	if (len)
1895		return len;
1896
1897	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1898		rsize = dbg_reg_def[i].size * 2;
1899		if (rsize > 16)
1900			rsize = 2;
1901		if (len + strlen(dbg_reg_def[i].name) + 4 + rsize > 80) {
1902			len = 0;
1903			kdb_printf("\n");
1904		}
1905		if (len)
1906			len += kdb_printf("  ");
1907		switch(dbg_reg_def[i].size * 8) {
1908		case 8:
1909			rname = dbg_get_reg(i, &reg8, kdb_current_regs);
1910			if (!rname)
1911				break;
1912			len += kdb_printf("%s: %02x", rname, reg8);
1913			break;
1914		case 16:
1915			rname = dbg_get_reg(i, &reg16, kdb_current_regs);
1916			if (!rname)
1917				break;
1918			len += kdb_printf("%s: %04x", rname, reg16);
1919			break;
1920		case 32:
1921			rname = dbg_get_reg(i, &reg32, kdb_current_regs);
1922			if (!rname)
1923				break;
1924			len += kdb_printf("%s: %08x", rname, reg32);
1925			break;
1926		case 64:
1927			rname = dbg_get_reg(i, &reg64, kdb_current_regs);
1928			if (!rname)
1929				break;
1930			len += kdb_printf("%s: %016llx", rname, reg64);
1931			break;
1932		default:
1933			len += kdb_printf("%s: ??", dbg_reg_def[i].name);
1934		}
1935	}
1936	kdb_printf("\n");
1937#else
1938	if (len)
1939		return len;
1940
1941	kdb_dumpregs(kdb_current_regs);
1942#endif
1943	return 0;
1944}
1945
1946/*
1947 * kdb_rm - This function implements the 'rm' (register modify)  command.
1948 *	rm register-name new-contents
1949 * Remarks:
1950 *	Allows register modification with the same restrictions as gdb
1951 */
1952static int kdb_rm(int argc, const char **argv)
1953{
1954#if DBG_MAX_REG_NUM > 0
1955	int diag;
1956	const char *rname;
1957	int i;
1958	u64 reg64;
1959	u32 reg32;
1960	u16 reg16;
1961	u8 reg8;
1962
1963	if (argc != 2)
1964		return KDB_ARGCOUNT;
1965	/*
1966	 * Allow presence or absence of leading '%' symbol.
1967	 */
1968	rname = argv[1];
1969	if (*rname == '%')
1970		rname++;
1971
1972	diag = kdbgetu64arg(argv[2], &reg64);
1973	if (diag)
1974		return diag;
1975
1976	diag = kdb_check_regs();
1977	if (diag)
1978		return diag;
1979
1980	diag = KDB_BADREG;
1981	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1982		if (strcmp(rname, dbg_reg_def[i].name) == 0) {
1983			diag = 0;
1984			break;
1985		}
1986	}
1987	if (!diag) {
1988		switch(dbg_reg_def[i].size * 8) {
1989		case 8:
1990			reg8 = reg64;
1991			dbg_set_reg(i, &reg8, kdb_current_regs);
1992			break;
1993		case 16:
1994			reg16 = reg64;
1995			dbg_set_reg(i, &reg16, kdb_current_regs);
1996			break;
1997		case 32:
1998			reg32 = reg64;
1999			dbg_set_reg(i, &reg32, kdb_current_regs);
2000			break;
2001		case 64:
2002			dbg_set_reg(i, &reg64, kdb_current_regs);
2003			break;
2004		}
2005	}
2006	return diag;
2007#else
2008	kdb_printf("ERROR: Register set currently not implemented\n");
2009    return 0;
2010#endif
2011}
2012
2013#if defined(CONFIG_MAGIC_SYSRQ)
2014/*
2015 * kdb_sr - This function implements the 'sr' (SYSRQ key) command
2016 *	which interfaces to the soi-disant MAGIC SYSRQ functionality.
2017 *		sr <magic-sysrq-code>
2018 */
2019static int kdb_sr(int argc, const char **argv)
2020{
2021	bool check_mask =
2022	    !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
2023
2024	if (argc != 1)
2025		return KDB_ARGCOUNT;
2026
2027	kdb_trap_printk++;
2028	__handle_sysrq(*argv[1], check_mask);
2029	kdb_trap_printk--;
2030
2031	return 0;
2032}
2033#endif	/* CONFIG_MAGIC_SYSRQ */
2034
2035/*
2036 * kdb_ef - This function implements the 'regs' (display exception
2037 *	frame) command.  This command takes an address and expects to
2038 *	find an exception frame at that address, formats and prints
2039 *	it.
2040 *		regs address-expression
2041 * Remarks:
2042 *	Not done yet.
2043 */
2044static int kdb_ef(int argc, const char **argv)
2045{
2046	int diag;
2047	unsigned long addr;
2048	long offset;
2049	int nextarg;
2050
2051	if (argc != 1)
2052		return KDB_ARGCOUNT;
2053
2054	nextarg = 1;
2055	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
2056	if (diag)
2057		return diag;
2058	show_regs((struct pt_regs *)addr);
2059	return 0;
2060}
2061
2062/*
2063 * kdb_env - This function implements the 'env' command.  Display the
2064 *	current environment variables.
2065 */
2066
2067static int kdb_env(int argc, const char **argv)
2068{
2069	kdb_printenv();
2070
2071	if (KDB_DEBUG(MASK))
2072		kdb_printf("KDBDEBUG=0x%x\n",
2073			(kdb_flags & KDB_DEBUG(MASK)) >> KDB_DEBUG_FLAG_SHIFT);
2074
2075	return 0;
2076}
2077
2078#ifdef CONFIG_PRINTK
2079/*
2080 * kdb_dmesg - This function implements the 'dmesg' command to display
2081 *	the contents of the syslog buffer.
2082 *		dmesg [lines] [adjust]
2083 */
2084static int kdb_dmesg(int argc, const char **argv)
2085{
2086	int diag;
2087	int logging;
2088	int lines = 0;
2089	int adjust = 0;
2090	int n = 0;
2091	int skip = 0;
2092	struct kmsg_dump_iter iter;
2093	size_t len;
2094	char buf[201];
2095
2096	if (argc > 2)
2097		return KDB_ARGCOUNT;
2098	if (argc) {
2099		char *cp;
2100		lines = simple_strtol(argv[1], &cp, 0);
2101		if (*cp)
2102			lines = 0;
2103		if (argc > 1) {
2104			adjust = simple_strtoul(argv[2], &cp, 0);
2105			if (*cp || adjust < 0)
2106				adjust = 0;
2107		}
2108	}
2109
2110	/* disable LOGGING if set */
2111	diag = kdbgetintenv("LOGGING", &logging);
2112	if (!diag && logging) {
2113		const char *setargs[] = { "set", "LOGGING", "0" };
2114		kdb_set(2, setargs);
2115	}
2116
2117	kmsg_dump_rewind(&iter);
2118	while (kmsg_dump_get_line(&iter, 1, NULL, 0, NULL))
2119		n++;
2120
2121	if (lines < 0) {
2122		if (adjust >= n)
2123			kdb_printf("buffer only contains %d lines, nothing "
2124				   "printed\n", n);
2125		else if (adjust - lines >= n)
2126			kdb_printf("buffer only contains %d lines, last %d "
2127				   "lines printed\n", n, n - adjust);
2128		skip = adjust;
2129		lines = abs(lines);
2130	} else if (lines > 0) {
2131		skip = n - lines - adjust;
2132		lines = abs(lines);
2133		if (adjust >= n) {
2134			kdb_printf("buffer only contains %d lines, "
2135				   "nothing printed\n", n);
2136			skip = n;
2137		} else if (skip < 0) {
2138			lines += skip;
2139			skip = 0;
2140			kdb_printf("buffer only contains %d lines, first "
2141				   "%d lines printed\n", n, lines);
2142		}
2143	} else {
2144		lines = n;
2145	}
2146
2147	if (skip >= n || skip < 0)
2148		return 0;
2149
2150	kmsg_dump_rewind(&iter);
2151	while (kmsg_dump_get_line(&iter, 1, buf, sizeof(buf), &len)) {
2152		if (skip) {
2153			skip--;
2154			continue;
2155		}
2156		if (!lines--)
2157			break;
2158		if (KDB_FLAG(CMD_INTERRUPT))
2159			return 0;
2160
2161		kdb_printf("%.*s\n", (int)len - 1, buf);
2162	}
2163
2164	return 0;
2165}
2166#endif /* CONFIG_PRINTK */
2167
2168/* Make sure we balance enable/disable calls, must disable first. */
2169static atomic_t kdb_nmi_disabled;
2170
2171static int kdb_disable_nmi(int argc, const char *argv[])
2172{
2173	if (atomic_read(&kdb_nmi_disabled))
2174		return 0;
2175	atomic_set(&kdb_nmi_disabled, 1);
2176	arch_kgdb_ops.enable_nmi(0);
2177	return 0;
2178}
2179
2180static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
2181{
2182	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
2183		return -EINVAL;
2184	arch_kgdb_ops.enable_nmi(1);
2185	return 0;
2186}
2187
2188static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
2189	.set = kdb_param_enable_nmi,
2190};
2191module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
2192
2193/*
2194 * kdb_cpu - This function implements the 'cpu' command.
2195 *	cpu	[<cpunum>]
2196 * Returns:
2197 *	KDB_CMD_CPU for success, a kdb diagnostic if error
2198 */
2199static void kdb_cpu_status(void)
2200{
2201	int i, start_cpu, first_print = 1;
2202	char state, prev_state = '?';
2203
2204	kdb_printf("Currently on cpu %d\n", raw_smp_processor_id());
2205	kdb_printf("Available cpus: ");
2206	for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
2207		if (!cpu_online(i)) {
2208			state = 'F';	/* cpu is offline */
2209		} else if (!kgdb_info[i].enter_kgdb) {
2210			state = 'D';	/* cpu is online but unresponsive */
2211		} else {
2212			state = ' ';	/* cpu is responding to kdb */
2213			if (kdb_task_state_char(KDB_TSK(i)) == '-')
2214				state = '-';	/* idle task */
2215		}
2216		if (state != prev_state) {
2217			if (prev_state != '?') {
2218				if (!first_print)
2219					kdb_printf(", ");
2220				first_print = 0;
2221				kdb_printf("%d", start_cpu);
2222				if (start_cpu < i-1)
2223					kdb_printf("-%d", i-1);
2224				if (prev_state != ' ')
2225					kdb_printf("(%c)", prev_state);
2226			}
2227			prev_state = state;
2228			start_cpu = i;
2229		}
2230	}
2231	/* print the trailing cpus, ignoring them if they are all offline */
2232	if (prev_state != 'F') {
2233		if (!first_print)
2234			kdb_printf(", ");
2235		kdb_printf("%d", start_cpu);
2236		if (start_cpu < i-1)
2237			kdb_printf("-%d", i-1);
2238		if (prev_state != ' ')
2239			kdb_printf("(%c)", prev_state);
2240	}
2241	kdb_printf("\n");
2242}
2243
2244static int kdb_cpu(int argc, const char **argv)
2245{
2246	unsigned long cpunum;
2247	int diag;
2248
2249	if (argc == 0) {
2250		kdb_cpu_status();
2251		return 0;
2252	}
2253
2254	if (argc != 1)
2255		return KDB_ARGCOUNT;
2256
2257	diag = kdbgetularg(argv[1], &cpunum);
2258	if (diag)
2259		return diag;
2260
2261	/*
2262	 * Validate cpunum
2263	 */
2264	if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
2265		return KDB_BADCPUNUM;
2266
2267	dbg_switch_cpu = cpunum;
2268
2269	/*
2270	 * Switch to other cpu
2271	 */
2272	return KDB_CMD_CPU;
2273}
2274
2275/* The user may not realize that ps/bta with no parameters does not print idle
2276 * or sleeping system daemon processes, so tell them how many were suppressed.
2277 */
2278void kdb_ps_suppressed(void)
2279{
2280	int idle = 0, daemon = 0;
2281	unsigned long cpu;
2282	const struct task_struct *p, *g;
2283	for_each_online_cpu(cpu) {
2284		p = kdb_curr_task(cpu);
2285		if (kdb_task_state(p, "-"))
2286			++idle;
2287	}
2288	for_each_process_thread(g, p) {
2289		if (kdb_task_state(p, "ims"))
2290			++daemon;
2291	}
2292	if (idle || daemon) {
2293		if (idle)
2294			kdb_printf("%d idle process%s (state -)%s\n",
2295				   idle, idle == 1 ? "" : "es",
2296				   daemon ? " and " : "");
2297		if (daemon)
2298			kdb_printf("%d sleeping system daemon (state [ims]) "
2299				   "process%s", daemon,
2300				   daemon == 1 ? "" : "es");
2301		kdb_printf(" suppressed,\nuse 'ps A' to see all.\n");
2302	}
2303}
2304
2305void kdb_ps1(const struct task_struct *p)
2306{
2307	int cpu;
2308	unsigned long tmp;
2309
2310	if (!p ||
2311	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
2312		return;
2313
2314	cpu = kdb_process_cpu(p);
2315	kdb_printf("0x%px %8d %8d  %d %4d   %c  0x%px %c%s\n",
2316		   (void *)p, p->pid, p->parent->pid,
2317		   kdb_task_has_cpu(p), kdb_process_cpu(p),
2318		   kdb_task_state_char(p),
2319		   (void *)(&p->thread),
2320		   p == kdb_curr_task(raw_smp_processor_id()) ? '*' : ' ',
2321		   p->comm);
2322	if (kdb_task_has_cpu(p)) {
2323		if (!KDB_TSK(cpu)) {
2324			kdb_printf("  Error: no saved data for this cpu\n");
2325		} else {
2326			if (KDB_TSK(cpu) != p)
2327				kdb_printf("  Error: does not match running "
2328				   "process table (0x%px)\n", KDB_TSK(cpu));
2329		}
2330	}
2331}
2332
2333/*
2334 * kdb_ps - This function implements the 'ps' command which shows a
2335 *	    list of the active processes.
2336 *
2337 * ps [<state_chars>]   Show processes, optionally selecting only those whose
2338 *                      state character is found in <state_chars>.
2339 */
2340static int kdb_ps(int argc, const char **argv)
2341{
2342	struct task_struct *g, *p;
2343	const char *mask;
2344	unsigned long cpu;
2345
2346	if (argc == 0)
2347		kdb_ps_suppressed();
2348	kdb_printf("%-*s      Pid   Parent [*] cpu State %-*s Command\n",
2349		(int)(2*sizeof(void *))+2, "Task Addr",
2350		(int)(2*sizeof(void *))+2, "Thread");
2351	mask = argc ? argv[1] : kdbgetenv("PS");
2352	/* Run the active tasks first */
2353	for_each_online_cpu(cpu) {
2354		if (KDB_FLAG(CMD_INTERRUPT))
2355			return 0;
2356		p = kdb_curr_task(cpu);
2357		if (kdb_task_state(p, mask))
2358			kdb_ps1(p);
2359	}
2360	kdb_printf("\n");
2361	/* Now the real tasks */
2362	for_each_process_thread(g, p) {
2363		if (KDB_FLAG(CMD_INTERRUPT))
2364			return 0;
2365		if (kdb_task_state(p, mask))
2366			kdb_ps1(p);
2367	}
2368
2369	return 0;
2370}
2371
2372/*
2373 * kdb_pid - This function implements the 'pid' command which switches
2374 *	the currently active process.
2375 *		pid [<pid> | R]
2376 */
2377static int kdb_pid(int argc, const char **argv)
2378{
2379	struct task_struct *p;
2380	unsigned long val;
2381	int diag;
2382
2383	if (argc > 1)
2384		return KDB_ARGCOUNT;
2385
2386	if (argc) {
2387		if (strcmp(argv[1], "R") == 0) {
2388			p = KDB_TSK(kdb_initial_cpu);
2389		} else {
2390			diag = kdbgetularg(argv[1], &val);
2391			if (diag)
2392				return KDB_BADINT;
2393
2394			p = find_task_by_pid_ns((pid_t)val,	&init_pid_ns);
2395			if (!p) {
2396				kdb_printf("No task with pid=%d\n", (pid_t)val);
2397				return 0;
2398			}
2399		}
2400		kdb_set_current_task(p);
2401	}
2402	kdb_printf("KDB current process is %s(pid=%d)\n",
2403		   kdb_current_task->comm,
2404		   kdb_current_task->pid);
2405
2406	return 0;
2407}
2408
2409static int kdb_kgdb(int argc, const char **argv)
2410{
2411	return KDB_CMD_KGDB;
2412}
2413
2414/*
2415 * kdb_help - This function implements the 'help' and '?' commands.
2416 */
2417static int kdb_help(int argc, const char **argv)
2418{
2419	kdbtab_t *kt;
2420
2421	kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
2422	kdb_printf("-----------------------------"
2423		   "-----------------------------\n");
2424	list_for_each_entry(kt, &kdb_cmds_head, list_node) {
2425		char *space = "";
2426		if (KDB_FLAG(CMD_INTERRUPT))
2427			return 0;
2428		if (!kdb_check_flags(kt->flags, kdb_cmd_enabled, true))
2429			continue;
2430		if (strlen(kt->usage) > 20)
2431			space = "\n                                    ";
2432		kdb_printf("%-15.15s %-20s%s%s\n", kt->name,
2433			   kt->usage, space, kt->help);
2434	}
2435	return 0;
2436}
2437
2438/*
2439 * kdb_kill - This function implements the 'kill' commands.
2440 */
2441static int kdb_kill(int argc, const char **argv)
2442{
2443	long sig, pid;
2444	char *endp;
2445	struct task_struct *p;
2446
2447	if (argc != 2)
2448		return KDB_ARGCOUNT;
2449
2450	sig = simple_strtol(argv[1], &endp, 0);
2451	if (*endp)
2452		return KDB_BADINT;
2453	if ((sig >= 0) || !valid_signal(-sig)) {
2454		kdb_printf("Invalid signal parameter.<-signal>\n");
2455		return 0;
2456	}
2457	sig = -sig;
2458
2459	pid = simple_strtol(argv[2], &endp, 0);
2460	if (*endp)
2461		return KDB_BADINT;
2462	if (pid <= 0) {
2463		kdb_printf("Process ID must be large than 0.\n");
2464		return 0;
2465	}
2466
2467	/* Find the process. */
2468	p = find_task_by_pid_ns(pid, &init_pid_ns);
2469	if (!p) {
2470		kdb_printf("The specified process isn't found.\n");
2471		return 0;
2472	}
2473	p = p->group_leader;
2474	kdb_send_sig(p, sig);
2475	return 0;
2476}
2477
2478/*
2479 * Most of this code has been lifted from kernel/timer.c::sys_sysinfo().
2480 * I cannot call that code directly from kdb, it has an unconditional
2481 * cli()/sti() and calls routines that take locks which can stop the debugger.
2482 */
2483static void kdb_sysinfo(struct sysinfo *val)
2484{
2485	u64 uptime = ktime_get_mono_fast_ns();
2486
2487	memset(val, 0, sizeof(*val));
2488	val->uptime = div_u64(uptime, NSEC_PER_SEC);
2489	val->loads[0] = avenrun[0];
2490	val->loads[1] = avenrun[1];
2491	val->loads[2] = avenrun[2];
2492	val->procs = nr_threads-1;
2493	si_meminfo(val);
2494
2495	return;
2496}
2497
2498/*
2499 * kdb_summary - This function implements the 'summary' command.
2500 */
2501static int kdb_summary(int argc, const char **argv)
2502{
2503	time64_t now;
2504	struct sysinfo val;
2505
2506	if (argc)
2507		return KDB_ARGCOUNT;
2508
2509	kdb_printf("sysname    %s\n", init_uts_ns.name.sysname);
2510	kdb_printf("release    %s\n", init_uts_ns.name.release);
2511	kdb_printf("version    %s\n", init_uts_ns.name.version);
2512	kdb_printf("machine    %s\n", init_uts_ns.name.machine);
2513	kdb_printf("nodename   %s\n", init_uts_ns.name.nodename);
2514	kdb_printf("domainname %s\n", init_uts_ns.name.domainname);
2515
2516	now = __ktime_get_real_seconds();
2517	kdb_printf("date       %ptTs tz_minuteswest %d\n", &now, sys_tz.tz_minuteswest);
2518	kdb_sysinfo(&val);
2519	kdb_printf("uptime     ");
2520	if (val.uptime > (24*60*60)) {
2521		int days = val.uptime / (24*60*60);
2522		val.uptime %= (24*60*60);
2523		kdb_printf("%d day%s ", days, days == 1 ? "" : "s");
2524	}
2525	kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
2526
2527	kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
2528		LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
2529		LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
2530		LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
2531
2532	/* Display in kilobytes */
2533#define K(x) ((x) << (PAGE_SHIFT - 10))
2534	kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
2535		   "Buffers:        %8lu kB\n",
2536		   K(val.totalram), K(val.freeram), K(val.bufferram));
2537	return 0;
2538}
2539
2540/*
2541 * kdb_per_cpu - This function implements the 'per_cpu' command.
2542 */
2543static int kdb_per_cpu(int argc, const char **argv)
2544{
2545	char fmtstr[64];
2546	int cpu, diag, nextarg = 1;
2547	unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL;
2548
2549	if (argc < 1 || argc > 3)
2550		return KDB_ARGCOUNT;
2551
2552	diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL);
2553	if (diag)
2554		return diag;
2555
2556	if (argc >= 2) {
2557		diag = kdbgetularg(argv[2], &bytesperword);
2558		if (diag)
2559			return diag;
2560	}
2561	if (!bytesperword)
2562		bytesperword = KDB_WORD_SIZE;
2563	else if (bytesperword > KDB_WORD_SIZE)
2564		return KDB_BADWIDTH;
2565	sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword));
2566	if (argc >= 3) {
2567		diag = kdbgetularg(argv[3], &whichcpu);
2568		if (diag)
2569			return diag;
2570		if (whichcpu >= nr_cpu_ids || !cpu_online(whichcpu)) {
2571			kdb_printf("cpu %ld is not online\n", whichcpu);
2572			return KDB_BADCPUNUM;
2573		}
2574	}
2575
2576	/* Most architectures use __per_cpu_offset[cpu], some use
2577	 * __per_cpu_offset(cpu), smp has no __per_cpu_offset.
2578	 */
2579#ifdef	__per_cpu_offset
2580#define KDB_PCU(cpu) __per_cpu_offset(cpu)
2581#else
2582#ifdef	CONFIG_SMP
2583#define KDB_PCU(cpu) __per_cpu_offset[cpu]
2584#else
2585#define KDB_PCU(cpu) 0
2586#endif
2587#endif
2588	for_each_online_cpu(cpu) {
2589		if (KDB_FLAG(CMD_INTERRUPT))
2590			return 0;
2591
2592		if (whichcpu != ~0UL && whichcpu != cpu)
2593			continue;
2594		addr = symaddr + KDB_PCU(cpu);
2595		diag = kdb_getword(&val, addr, bytesperword);
2596		if (diag) {
2597			kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to "
2598				   "read, diag=%d\n", cpu, addr, diag);
2599			continue;
2600		}
2601		kdb_printf("%5d ", cpu);
2602		kdb_md_line(fmtstr, addr,
2603			bytesperword == KDB_WORD_SIZE,
2604			1, bytesperword, 1, 1, 0);
2605	}
2606#undef KDB_PCU
2607	return 0;
2608}
2609
2610/*
2611 * display help for the use of cmd | grep pattern
2612 */
2613static int kdb_grep_help(int argc, const char **argv)
2614{
2615	kdb_printf("Usage of  cmd args | grep pattern:\n");
2616	kdb_printf("  Any command's output may be filtered through an ");
2617	kdb_printf("emulated 'pipe'.\n");
2618	kdb_printf("  'grep' is just a key word.\n");
2619	kdb_printf("  The pattern may include a very limited set of "
2620		   "metacharacters:\n");
2621	kdb_printf("   pattern or ^pattern or pattern$ or ^pattern$\n");
2622	kdb_printf("  And if there are spaces in the pattern, you may "
2623		   "quote it:\n");
2624	kdb_printf("   \"pat tern\" or \"^pat tern\" or \"pat tern$\""
2625		   " or \"^pat tern$\"\n");
2626	return 0;
2627}
2628
2629/**
2630 * kdb_register() - This function is used to register a kernel debugger
2631 *                  command.
2632 * @cmd: pointer to kdb command
2633 *
2634 * Note that it's the job of the caller to keep the memory for the cmd
2635 * allocated until unregister is called.
2636 */
2637int kdb_register(kdbtab_t *cmd)
2638{
2639	kdbtab_t *kp;
2640
2641	list_for_each_entry(kp, &kdb_cmds_head, list_node) {
2642		if (strcmp(kp->name, cmd->name) == 0) {
2643			kdb_printf("Duplicate kdb cmd: %s, func %p help %s\n",
2644				   cmd->name, cmd->func, cmd->help);
2645			return 1;
2646		}
2647	}
2648
2649	list_add_tail(&cmd->list_node, &kdb_cmds_head);
2650	return 0;
2651}
2652EXPORT_SYMBOL_GPL(kdb_register);
2653
2654/**
2655 * kdb_register_table() - This function is used to register a kdb command
2656 *                        table.
2657 * @kp: pointer to kdb command table
2658 * @len: length of kdb command table
2659 */
2660void kdb_register_table(kdbtab_t *kp, size_t len)
2661{
2662	while (len--) {
2663		list_add_tail(&kp->list_node, &kdb_cmds_head);
2664		kp++;
2665	}
2666}
2667
2668/**
2669 * kdb_unregister() - This function is used to unregister a kernel debugger
2670 *                    command. It is generally called when a module which
2671 *                    implements kdb command is unloaded.
2672 * @cmd: pointer to kdb command
2673 */
2674void kdb_unregister(kdbtab_t *cmd)
2675{
2676	list_del(&cmd->list_node);
2677}
2678EXPORT_SYMBOL_GPL(kdb_unregister);
2679
2680static kdbtab_t maintab[] = {
2681	{	.name = "md",
2682		.func = kdb_md,
2683		.usage = "<vaddr>",
2684		.help = "Display Memory Contents, also mdWcN, e.g. md8c1",
2685		.minlen = 1,
2686		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2687	},
2688	{	.name = "mdr",
2689		.func = kdb_md,
2690		.usage = "<vaddr> <bytes>",
2691		.help = "Display Raw Memory",
2692		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2693	},
2694	{	.name = "mdp",
2695		.func = kdb_md,
2696		.usage = "<paddr> <bytes>",
2697		.help = "Display Physical Memory",
2698		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2699	},
2700	{	.name = "mds",
2701		.func = kdb_md,
2702		.usage = "<vaddr>",
2703		.help = "Display Memory Symbolically",
2704		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2705	},
2706	{	.name = "mm",
2707		.func = kdb_mm,
2708		.usage = "<vaddr> <contents>",
2709		.help = "Modify Memory Contents",
2710		.flags = KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS,
2711	},
2712	{	.name = "go",
2713		.func = kdb_go,
2714		.usage = "[<vaddr>]",
2715		.help = "Continue Execution",
2716		.minlen = 1,
2717		.flags = KDB_ENABLE_REG_WRITE |
2718			     KDB_ENABLE_ALWAYS_SAFE_NO_ARGS,
2719	},
2720	{	.name = "rd",
2721		.func = kdb_rd,
2722		.usage = "",
2723		.help = "Display Registers",
2724		.flags = KDB_ENABLE_REG_READ,
2725	},
2726	{	.name = "rm",
2727		.func = kdb_rm,
2728		.usage = "<reg> <contents>",
2729		.help = "Modify Registers",
2730		.flags = KDB_ENABLE_REG_WRITE,
2731	},
2732	{	.name = "ef",
2733		.func = kdb_ef,
2734		.usage = "<vaddr>",
2735		.help = "Display exception frame",
2736		.flags = KDB_ENABLE_MEM_READ,
2737	},
2738	{	.name = "bt",
2739		.func = kdb_bt,
2740		.usage = "[<vaddr>]",
2741		.help = "Stack traceback",
2742		.minlen = 1,
2743		.flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS,
2744	},
2745	{	.name = "btp",
2746		.func = kdb_bt,
2747		.usage = "<pid>",
2748		.help = "Display stack for process <pid>",
2749		.flags = KDB_ENABLE_INSPECT,
2750	},
2751	{	.name = "bta",
2752		.func = kdb_bt,
2753		.usage = "[<state_chars>|A]",
2754		.help = "Backtrace all processes whose state matches",
2755		.flags = KDB_ENABLE_INSPECT,
2756	},
2757	{	.name = "btc",
2758		.func = kdb_bt,
2759		.usage = "",
2760		.help = "Backtrace current process on each cpu",
2761		.flags = KDB_ENABLE_INSPECT,
2762	},
2763	{	.name = "btt",
2764		.func = kdb_bt,
2765		.usage = "<vaddr>",
2766		.help = "Backtrace process given its struct task address",
2767		.flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS,
2768	},
2769	{	.name = "env",
2770		.func = kdb_env,
2771		.usage = "",
2772		.help = "Show environment variables",
2773		.flags = KDB_ENABLE_ALWAYS_SAFE,
2774	},
2775	{	.name = "set",
2776		.func = kdb_set,
2777		.usage = "",
2778		.help = "Set environment variables",
2779		.flags = KDB_ENABLE_ALWAYS_SAFE,
2780	},
2781	{	.name = "help",
2782		.func = kdb_help,
2783		.usage = "",
2784		.help = "Display Help Message",
2785		.minlen = 1,
2786		.flags = KDB_ENABLE_ALWAYS_SAFE,
2787	},
2788	{	.name = "?",
2789		.func = kdb_help,
2790		.usage = "",
2791		.help = "Display Help Message",
2792		.flags = KDB_ENABLE_ALWAYS_SAFE,
2793	},
2794	{	.name = "cpu",
2795		.func = kdb_cpu,
2796		.usage = "<cpunum>",
2797		.help = "Switch to new cpu",
2798		.flags = KDB_ENABLE_ALWAYS_SAFE_NO_ARGS,
2799	},
2800	{	.name = "kgdb",
2801		.func = kdb_kgdb,
2802		.usage = "",
2803		.help = "Enter kgdb mode",
2804		.flags = 0,
2805	},
2806	{	.name = "ps",
2807		.func = kdb_ps,
2808		.usage = "[<state_chars>|A]",
2809		.help = "Display active task list",
2810		.flags = KDB_ENABLE_INSPECT,
2811	},
2812	{	.name = "pid",
2813		.func = kdb_pid,
2814		.usage = "<pidnum>",
2815		.help = "Switch to another task",
2816		.flags = KDB_ENABLE_INSPECT,
2817	},
2818	{	.name = "reboot",
2819		.func = kdb_reboot,
2820		.usage = "",
2821		.help = "Reboot the machine immediately",
2822		.flags = KDB_ENABLE_REBOOT,
2823	},
2824#if defined(CONFIG_MODULES)
2825	{	.name = "lsmod",
2826		.func = kdb_lsmod,
2827		.usage = "",
2828		.help = "List loaded kernel modules",
2829		.flags = KDB_ENABLE_INSPECT,
2830	},
2831#endif
2832#if defined(CONFIG_MAGIC_SYSRQ)
2833	{	.name = "sr",
2834		.func = kdb_sr,
2835		.usage = "<key>",
2836		.help = "Magic SysRq key",
2837		.flags = KDB_ENABLE_ALWAYS_SAFE,
2838	},
2839#endif
2840#if defined(CONFIG_PRINTK)
2841	{	.name = "dmesg",
2842		.func = kdb_dmesg,
2843		.usage = "[lines]",
2844		.help = "Display syslog buffer",
2845		.flags = KDB_ENABLE_ALWAYS_SAFE,
2846	},
2847#endif
2848	{	.name = "defcmd",
2849		.func = kdb_defcmd,
2850		.usage = "name \"usage\" \"help\"",
2851		.help = "Define a set of commands, down to endefcmd",
2852		/*
2853		 * Macros are always safe because when executed each
2854		 * internal command re-enters kdb_parse() and is safety
2855		 * checked individually.
2856		 */
2857		.flags = KDB_ENABLE_ALWAYS_SAFE,
2858	},
2859	{	.name = "kill",
2860		.func = kdb_kill,
2861		.usage = "<-signal> <pid>",
2862		.help = "Send a signal to a process",
2863		.flags = KDB_ENABLE_SIGNAL,
2864	},
2865	{	.name = "summary",
2866		.func = kdb_summary,
2867		.usage = "",
2868		.help = "Summarize the system",
2869		.minlen = 4,
2870		.flags = KDB_ENABLE_ALWAYS_SAFE,
2871	},
2872	{	.name = "per_cpu",
2873		.func = kdb_per_cpu,
2874		.usage = "<sym> [<bytes>] [<cpu>]",
2875		.help = "Display per_cpu variables",
2876		.minlen = 3,
2877		.flags = KDB_ENABLE_MEM_READ,
2878	},
2879	{	.name = "grephelp",
2880		.func = kdb_grep_help,
2881		.usage = "",
2882		.help = "Display help on | grep",
2883		.flags = KDB_ENABLE_ALWAYS_SAFE,
2884	},
2885};
2886
2887static kdbtab_t nmicmd = {
2888	.name = "disable_nmi",
2889	.func = kdb_disable_nmi,
2890	.usage = "",
2891	.help = "Disable NMI entry to KDB",
2892	.flags = KDB_ENABLE_ALWAYS_SAFE,
2893};
2894
2895/* Initialize the kdb command table. */
2896static void __init kdb_inittab(void)
2897{
2898	kdb_register_table(maintab, ARRAY_SIZE(maintab));
2899	if (arch_kgdb_ops.enable_nmi)
2900		kdb_register_table(&nmicmd, 1);
2901}
2902
2903/* Execute any commands defined in kdb_cmds.  */
2904static void __init kdb_cmd_init(void)
2905{
2906	int i, diag;
2907	for (i = 0; kdb_cmds[i]; ++i) {
2908		diag = kdb_parse(kdb_cmds[i]);
2909		if (diag)
2910			kdb_printf("kdb command %s failed, kdb diag %d\n",
2911				kdb_cmds[i], diag);
2912	}
2913	if (defcmd_in_progress) {
2914		kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n");
2915		kdb_parse("endefcmd");
2916	}
2917}
2918
2919/* Initialize kdb_printf, breakpoint tables and kdb state */
2920void __init kdb_init(int lvl)
2921{
2922	static int kdb_init_lvl = KDB_NOT_INITIALIZED;
2923	int i;
2924
2925	if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl)
2926		return;
2927	for (i = kdb_init_lvl; i < lvl; i++) {
2928		switch (i) {
2929		case KDB_NOT_INITIALIZED:
2930			kdb_inittab();		/* Initialize Command Table */
2931			kdb_initbptab();	/* Initialize Breakpoints */
2932			break;
2933		case KDB_INIT_EARLY:
2934			kdb_cmd_init();		/* Build kdb_cmds tables */
2935			break;
2936		}
2937	}
2938	kdb_init_lvl = lvl;
2939}
v6.13.7
   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/moduleparam.h>
  30#include <linux/mm.h>
  31#include <linux/init.h>
  32#include <linux/kallsyms.h>
  33#include <linux/kgdb.h>
  34#include <linux/kdb.h>
  35#include <linux/notifier.h>
  36#include <linux/interrupt.h>
  37#include <linux/delay.h>
  38#include <linux/nmi.h>
  39#include <linux/time.h>
  40#include <linux/ptrace.h>
  41#include <linux/sysctl.h>
  42#include <linux/cpu.h>
  43#include <linux/kdebug.h>
  44#include <linux/proc_fs.h>
  45#include <linux/uaccess.h>
  46#include <linux/slab.h>
  47#include <linux/security.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_cmds_head describes the available commands. */
  88static LIST_HEAD(kdb_cmds_head);
  89
  90typedef struct _kdbmsg {
  91	int	km_diag;	/* kdb diagnostic */
  92	char	*km_msg;	/* Corresponding message text */
  93} kdbmsg_t;
  94
  95#define KDBMSG(msgnum, text) \
  96	{ KDB_##msgnum, text }
  97
  98static kdbmsg_t kdbmsgs[] = {
  99	KDBMSG(NOTFOUND, "Command Not Found"),
 100	KDBMSG(ARGCOUNT, "Improper argument count, see usage."),
 101	KDBMSG(BADWIDTH, "Illegal value for BYTESPERWORD use 1, 2, 4 or 8, "
 102	       "8 is only allowed on 64 bit systems"),
 103	KDBMSG(BADRADIX, "Illegal value for RADIX use 8, 10 or 16"),
 104	KDBMSG(NOTENV, "Cannot find environment variable"),
 105	KDBMSG(NOENVVALUE, "Environment variable should have value"),
 106	KDBMSG(NOTIMP, "Command not implemented"),
 107	KDBMSG(ENVFULL, "Environment full"),
 108	KDBMSG(ENVBUFFULL, "Environment buffer full"),
 109	KDBMSG(TOOMANYBPT, "Too many breakpoints defined"),
 110#ifdef CONFIG_CPU_XSCALE
 111	KDBMSG(TOOMANYDBREGS, "More breakpoints than ibcr registers defined"),
 112#else
 113	KDBMSG(TOOMANYDBREGS, "More breakpoints than db registers defined"),
 114#endif
 115	KDBMSG(DUPBPT, "Duplicate breakpoint address"),
 116	KDBMSG(BPTNOTFOUND, "Breakpoint not found"),
 117	KDBMSG(BADMODE, "Invalid IDMODE"),
 118	KDBMSG(BADINT, "Illegal numeric value"),
 119	KDBMSG(INVADDRFMT, "Invalid symbolic address format"),
 120	KDBMSG(BADREG, "Invalid register name"),
 121	KDBMSG(BADCPUNUM, "Invalid cpu number"),
 122	KDBMSG(BADLENGTH, "Invalid length field"),
 123	KDBMSG(NOBP, "No Breakpoint exists"),
 124	KDBMSG(BADADDR, "Invalid address"),
 125	KDBMSG(NOPERM, "Permission denied"),
 126};
 127#undef KDBMSG
 128
 129static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
 130
 131
 132/*
 133 * Initial environment.   This is all kept static and local to
 134 * this file.   We don't want to rely on the memory allocation
 135 * mechanisms in the kernel, so we use a very limited allocate-only
 136 * heap for new and altered environment variables.  The entire
 137 * environment is limited to a fixed number of entries (add more
 138 * to __env[] if required) and a fixed amount of heap (add more to
 139 * KDB_ENVBUFSIZE if required).
 140 */
 141
 142static char *__env[31] = {
 143#if defined(CONFIG_SMP)
 144	"PROMPT=[%d]kdb> ",
 145#else
 146	"PROMPT=kdb> ",
 147#endif
 148	"MOREPROMPT=more> ",
 149	"RADIX=16",
 150	"MDCOUNT=8",		/* lines of md output */
 151	KDB_PLATFORM_ENV,
 152	"DTABCOUNT=30",
 153	"NOSECT=1",
 154};
 155
 156static const int __nenv = ARRAY_SIZE(__env);
 157
 
 
 
 
 
 
 
 
 
 
 158/*
 159 * Update the permissions flags (kdb_cmd_enabled) to match the
 160 * current lockdown state.
 161 *
 162 * Within this function the calls to security_locked_down() are "lazy". We
 163 * avoid calling them if the current value of kdb_cmd_enabled already excludes
 164 * flags that might be subject to lockdown. Additionally we deliberately check
 165 * the lockdown flags independently (even though read lockdown implies write
 166 * lockdown) since that results in both simpler code and clearer messages to
 167 * the user on first-time debugger entry.
 168 *
 169 * The permission masks during a read+write lockdown permits the following
 170 * flags: INSPECT, SIGNAL, REBOOT (and ALWAYS_SAFE).
 171 *
 172 * The INSPECT commands are not blocked during lockdown because they are
 173 * not arbitrary memory reads. INSPECT covers the backtrace family (sometimes
 174 * forcing them to have no arguments) and lsmod. These commands do expose
 175 * some kernel state but do not allow the developer seated at the console to
 176 * choose what state is reported. SIGNAL and REBOOT should not be controversial,
 177 * given these are allowed for root during lockdown already.
 178 */
 179static void kdb_check_for_lockdown(void)
 180{
 181	const int write_flags = KDB_ENABLE_MEM_WRITE |
 182				KDB_ENABLE_REG_WRITE |
 183				KDB_ENABLE_FLOW_CTRL;
 184	const int read_flags = KDB_ENABLE_MEM_READ |
 185			       KDB_ENABLE_REG_READ;
 186
 187	bool need_to_lockdown_write = false;
 188	bool need_to_lockdown_read = false;
 189
 190	if (kdb_cmd_enabled & (KDB_ENABLE_ALL | write_flags))
 191		need_to_lockdown_write =
 192			security_locked_down(LOCKDOWN_DBG_WRITE_KERNEL);
 193
 194	if (kdb_cmd_enabled & (KDB_ENABLE_ALL | read_flags))
 195		need_to_lockdown_read =
 196			security_locked_down(LOCKDOWN_DBG_READ_KERNEL);
 197
 198	/* De-compose KDB_ENABLE_ALL if required */
 199	if (need_to_lockdown_write || need_to_lockdown_read)
 200		if (kdb_cmd_enabled & KDB_ENABLE_ALL)
 201			kdb_cmd_enabled = KDB_ENABLE_MASK & ~KDB_ENABLE_ALL;
 202
 203	if (need_to_lockdown_write)
 204		kdb_cmd_enabled &= ~write_flags;
 205
 206	if (need_to_lockdown_read)
 207		kdb_cmd_enabled &= ~read_flags;
 208}
 209
 210/*
 211 * Check whether the flags of the current command, the permissions of the kdb
 212 * console and the lockdown state allow a command to be run.
 213 */
 214static bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
 215				   bool no_args)
 216{
 217	/* permissions comes from userspace so needs massaging slightly */
 218	permissions &= KDB_ENABLE_MASK;
 219	permissions |= KDB_ENABLE_ALWAYS_SAFE;
 220
 221	/* some commands change group when launched with no arguments */
 222	if (no_args)
 223		permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
 224
 225	flags |= KDB_ENABLE_ALL;
 226
 227	return permissions & flags;
 228}
 229
 230/*
 231 * kdbgetenv - This function will return the character string value of
 232 *	an environment variable.
 233 * Parameters:
 234 *	match	A character string representing an environment variable.
 235 * Returns:
 236 *	NULL	No environment variable matches 'match'
 237 *	char*	Pointer to string value of environment variable.
 238 */
 239char *kdbgetenv(const char *match)
 240{
 241	char **ep = __env;
 242	int matchlen = strlen(match);
 243	int i;
 244
 245	for (i = 0; i < __nenv; i++) {
 246		char *e = *ep++;
 247
 248		if (!e)
 249			continue;
 250
 251		if ((strncmp(match, e, matchlen) == 0)
 252		 && ((e[matchlen] == '\0')
 253		   || (e[matchlen] == '='))) {
 254			char *cp = strchr(e, '=');
 255			return cp ? ++cp : "";
 256		}
 257	}
 258	return NULL;
 259}
 260
 261/*
 262 * kdballocenv - This function is used to allocate bytes for
 263 *	environment entries.
 264 * Parameters:
 265 *	bytes	The number of bytes to allocate in the static buffer.
 
 
 266 * Returns:
 267 *	A pointer to the allocated space in the buffer on success.
 268 *	NULL if bytes > size available in the envbuffer.
 269 * Remarks:
 270 *	We use a static environment buffer (envbuffer) to hold the values
 271 *	of dynamically generated environment variables (see kdb_set).  Buffer
 272 *	space once allocated is never free'd, so over time, the amount of space
 273 *	(currently 512 bytes) will be exhausted if env variables are changed
 274 *	frequently.
 275 */
 276static char *kdballocenv(size_t bytes)
 277{
 278#define	KDB_ENVBUFSIZE	512
 279	static char envbuffer[KDB_ENVBUFSIZE];
 280	static int envbufsize;
 281	char *ep = NULL;
 282
 283	if ((KDB_ENVBUFSIZE - envbufsize) >= bytes) {
 284		ep = &envbuffer[envbufsize];
 285		envbufsize += bytes;
 286	}
 287	return ep;
 288}
 289
 290/*
 291 * kdbgetulenv - This function will return the value of an unsigned
 292 *	long-valued environment variable.
 293 * Parameters:
 294 *	match	A character string representing a numeric value
 295 * Outputs:
 296 *	*value  the unsigned long representation of the env variable 'match'
 297 * Returns:
 298 *	Zero on success, a kdb diagnostic on failure.
 299 */
 300static int kdbgetulenv(const char *match, unsigned long *value)
 301{
 302	char *ep;
 303
 304	ep = kdbgetenv(match);
 305	if (!ep)
 306		return KDB_NOTENV;
 307	if (strlen(ep) == 0)
 308		return KDB_NOENVVALUE;
 309	if (kstrtoul(ep, 0, value))
 310		return KDB_BADINT;
 311
 312	return 0;
 313}
 314
 315/*
 316 * kdbgetintenv - This function will return the value of an
 317 *	integer-valued environment variable.
 318 * Parameters:
 319 *	match	A character string representing an integer-valued env variable
 320 * Outputs:
 321 *	*value  the integer representation of the environment variable 'match'
 322 * Returns:
 323 *	Zero on success, a kdb diagnostic on failure.
 324 */
 325int kdbgetintenv(const char *match, int *value)
 326{
 327	unsigned long val;
 328	int diag;
 329
 330	diag = kdbgetulenv(match, &val);
 331	if (!diag)
 332		*value = (int) val;
 333	return diag;
 334}
 335
 336/*
 337 * kdb_setenv() - Alter an existing environment variable or create a new one.
 338 * @var: Name of the variable
 339 * @val: Value of the variable
 340 *
 341 * Return: Zero on success, a kdb diagnostic on failure.
 342 */
 343static int kdb_setenv(const char *var, const char *val)
 344{
 345	int i;
 346	char *ep;
 347	size_t varlen, vallen;
 348
 349	varlen = strlen(var);
 350	vallen = strlen(val);
 351	ep = kdballocenv(varlen + vallen + 2);
 352	if (ep == (char *)0)
 353		return KDB_ENVBUFFULL;
 354
 355	sprintf(ep, "%s=%s", var, val);
 356
 357	for (i = 0; i < __nenv; i++) {
 358		if (__env[i]
 359		 && ((strncmp(__env[i], var, varlen) == 0)
 360		   && ((__env[i][varlen] == '\0')
 361		    || (__env[i][varlen] == '=')))) {
 362			__env[i] = ep;
 363			return 0;
 364		}
 365	}
 366
 367	/*
 368	 * Wasn't existing variable.  Fit into slot.
 369	 */
 370	for (i = 0; i < __nenv-1; i++) {
 371		if (__env[i] == (char *)0) {
 372			__env[i] = ep;
 373			return 0;
 374		}
 375	}
 376
 377	return KDB_ENVFULL;
 378}
 379
 380/*
 381 * kdb_printenv() - Display the current environment variables.
 382 */
 383static void kdb_printenv(void)
 384{
 385	int i;
 386
 387	for (i = 0; i < __nenv; i++) {
 388		if (__env[i])
 389			kdb_printf("%s\n", __env[i]);
 390	}
 391}
 392
 393/*
 394 * kdbgetularg - This function will convert a numeric string into an
 395 *	unsigned long value.
 396 * Parameters:
 397 *	arg	A character string representing a numeric value
 398 * Outputs:
 399 *	*value  the unsigned long representation of arg.
 400 * Returns:
 401 *	Zero on success, a kdb diagnostic on failure.
 402 */
 403int kdbgetularg(const char *arg, unsigned long *value)
 404{
 405	if (kstrtoul(arg, 0, value))
 406		return KDB_BADINT;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 407	return 0;
 408}
 409
 410int kdbgetu64arg(const char *arg, u64 *value)
 411{
 412	if (kstrtou64(arg, 0, value))
 413		return KDB_BADINT;
 
 
 
 
 
 
 
 
 
 
 
 
 414	return 0;
 415}
 416
 417/*
 418 * kdb_set - This function implements the 'set' command.  Alter an
 419 *	existing environment variable or create a new one.
 420 */
 421int kdb_set(int argc, const char **argv)
 422{
 423	/*
 424	 * we can be invoked two ways:
 425	 *   set var=value    argv[1]="var", argv[2]="value"
 426	 *   set var = value  argv[1]="var", argv[2]="=", argv[3]="value"
 427	 * - if the latter, shift 'em down.
 428	 */
 429	if (argc == 3) {
 430		argv[2] = argv[3];
 431		argc--;
 432	}
 433
 434	if (argc != 2)
 435		return KDB_ARGCOUNT;
 436
 437	/*
 438	 * Censor sensitive variables
 439	 */
 440	if (strcmp(argv[1], "PROMPT") == 0 &&
 441	    !kdb_check_flags(KDB_ENABLE_MEM_READ, kdb_cmd_enabled, false))
 442		return KDB_NOPERM;
 443
 444	/*
 445	 * Check for internal variables
 446	 */
 447	if (strcmp(argv[1], "KDBDEBUG") == 0) {
 448		unsigned int debugflags;
 449		int ret;
 450
 451		ret = kstrtouint(argv[2], 0, &debugflags);
 452		if (ret || debugflags & ~KDB_DEBUG_FLAG_MASK) {
 453			kdb_printf("kdb: illegal debug flags '%s'\n",
 454				    argv[2]);
 455			return 0;
 456		}
 457		kdb_flags = (kdb_flags & ~KDB_DEBUG(MASK))
 458			| (debugflags << KDB_DEBUG_FLAG_SHIFT);
 459
 460		return 0;
 461	}
 462
 463	/*
 464	 * Tokenizer squashed the '=' sign.  argv[1] is variable
 465	 * name, argv[2] = value.
 466	 */
 467	return kdb_setenv(argv[1], argv[2]);
 468}
 469
 470static int kdb_check_regs(void)
 471{
 472	if (!kdb_current_regs) {
 473		kdb_printf("No current kdb registers."
 474			   "  You may need to select another task\n");
 475		return KDB_BADREG;
 476	}
 477	return 0;
 478}
 479
 480/*
 481 * kdbgetaddrarg - This function is responsible for parsing an
 482 *	address-expression and returning the value of the expression,
 483 *	symbol name, and offset to the caller.
 484 *
 485 *	The argument may consist of a numeric value (decimal or
 486 *	hexadecimal), a symbol name, a register name (preceded by the
 487 *	percent sign), an environment variable with a numeric value
 488 *	(preceded by a dollar sign) or a simple arithmetic expression
 489 *	consisting of a symbol name, +/-, and a numeric constant value
 490 *	(offset).
 491 * Parameters:
 492 *	argc	- count of arguments in argv
 493 *	argv	- argument vector
 494 *	*nextarg - index to next unparsed argument in argv[]
 495 *	regs	- Register state at time of KDB entry
 496 * Outputs:
 497 *	*value	- receives the value of the address-expression
 498 *	*offset - receives the offset specified, if any
 499 *	*name   - receives the symbol name, if any
 500 *	*nextarg - index to next unparsed argument in argv[]
 501 * Returns:
 502 *	zero is returned on success, a kdb diagnostic code is
 503 *      returned on error.
 504 */
 505int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
 506		  unsigned long *value,  long *offset,
 507		  char **name)
 508{
 509	unsigned long addr;
 510	unsigned long off = 0;
 511	int positive;
 512	int diag;
 513	int found = 0;
 514	char *symname;
 515	char symbol = '\0';
 516	char *cp;
 517	kdb_symtab_t symtab;
 518
 519	/*
 520	 * If the enable flags prohibit both arbitrary memory access
 521	 * and flow control then there are no reasonable grounds to
 522	 * provide symbol lookup.
 523	 */
 524	if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
 525			     kdb_cmd_enabled, false))
 526		return KDB_NOPERM;
 527
 528	/*
 529	 * Process arguments which follow the following syntax:
 530	 *
 531	 *  symbol | numeric-address [+/- numeric-offset]
 532	 *  %register
 533	 *  $environment-variable
 534	 */
 535
 536	if (*nextarg > argc)
 537		return KDB_ARGCOUNT;
 538
 539	symname = (char *)argv[*nextarg];
 540
 541	/*
 542	 * If there is no whitespace between the symbol
 543	 * or address and the '+' or '-' symbols, we
 544	 * remember the character and replace it with a
 545	 * null so the symbol/value can be properly parsed
 546	 */
 547	cp = strpbrk(symname, "+-");
 548	if (cp != NULL) {
 549		symbol = *cp;
 550		*cp++ = '\0';
 551	}
 552
 553	if (symname[0] == '$') {
 554		diag = kdbgetulenv(&symname[1], &addr);
 555		if (diag)
 556			return diag;
 557	} else if (symname[0] == '%') {
 558		diag = kdb_check_regs();
 559		if (diag)
 560			return diag;
 561		/* Implement register values with % at a later time as it is
 562		 * arch optional.
 563		 */
 564		return KDB_NOTIMP;
 565	} else {
 566		found = kdbgetsymval(symname, &symtab);
 567		if (found) {
 568			addr = symtab.sym_start;
 569		} else {
 570			diag = kdbgetularg(argv[*nextarg], &addr);
 571			if (diag)
 572				return diag;
 573		}
 574	}
 575
 576	if (!found)
 577		found = kdbnearsym(addr, &symtab);
 578
 579	(*nextarg)++;
 580
 581	if (name)
 582		*name = symname;
 583	if (value)
 584		*value = addr;
 585	if (offset && name && *name)
 586		*offset = addr - symtab.sym_start;
 587
 588	if ((*nextarg > argc)
 589	 && (symbol == '\0'))
 590		return 0;
 591
 592	/*
 593	 * check for +/- and offset
 594	 */
 595
 596	if (symbol == '\0') {
 597		if ((argv[*nextarg][0] != '+')
 598		 && (argv[*nextarg][0] != '-')) {
 599			/*
 600			 * Not our argument.  Return.
 601			 */
 602			return 0;
 603		} else {
 604			positive = (argv[*nextarg][0] == '+');
 605			(*nextarg)++;
 606		}
 607	} else
 608		positive = (symbol == '+');
 609
 610	/*
 611	 * Now there must be an offset!
 612	 */
 613	if ((*nextarg > argc)
 614	 && (symbol == '\0')) {
 615		return KDB_INVADDRFMT;
 616	}
 617
 618	if (!symbol) {
 619		cp = (char *)argv[*nextarg];
 620		(*nextarg)++;
 621	}
 622
 623	diag = kdbgetularg(cp, &off);
 624	if (diag)
 625		return diag;
 626
 627	if (!positive)
 628		off = -off;
 629
 630	if (offset)
 631		*offset += off;
 632
 633	if (value)
 634		*value += off;
 635
 636	return 0;
 637}
 638
 639static void kdb_cmderror(int diag)
 640{
 641	int i;
 642
 643	if (diag >= 0) {
 644		kdb_printf("no error detected (diagnostic is %d)\n", diag);
 645		return;
 646	}
 647
 648	for (i = 0; i < __nkdb_err; i++) {
 649		if (kdbmsgs[i].km_diag == diag) {
 650			kdb_printf("diag: %d: %s\n", diag, kdbmsgs[i].km_msg);
 651			return;
 652		}
 653	}
 654
 655	kdb_printf("Unknown diag %d\n", -diag);
 656}
 657
 658/*
 659 * kdb_defcmd, kdb_defcmd2 - This function implements the 'defcmd'
 660 *	command which defines one command as a set of other commands,
 661 *	terminated by endefcmd.  kdb_defcmd processes the initial
 662 *	'defcmd' command, kdb_defcmd2 is invoked from kdb_parse for
 663 *	the following commands until 'endefcmd'.
 664 * Inputs:
 665 *	argc	argument count
 666 *	argv	argument vector
 667 * Returns:
 668 *	zero for success, a kdb diagnostic if error
 669 */
 670struct kdb_macro {
 671	kdbtab_t cmd;			/* Macro command */
 672	struct list_head statements;	/* Associated statement list */
 673};
 674
 675struct kdb_macro_statement {
 676	char *statement;		/* Statement text */
 677	struct list_head list_node;	/* Statement list node */
 678};
 679
 680static struct kdb_macro *kdb_macro;
 681static bool defcmd_in_progress;
 682
 683/* Forward references */
 684static int kdb_exec_defcmd(int argc, const char **argv);
 685
 686static int kdb_defcmd2(const char *cmdstr, const char *argv0)
 687{
 688	struct kdb_macro_statement *kms;
 689
 690	if (!kdb_macro)
 691		return KDB_NOTIMP;
 692
 693	if (strcmp(argv0, "endefcmd") == 0) {
 694		defcmd_in_progress = false;
 695		if (!list_empty(&kdb_macro->statements))
 696			kdb_register(&kdb_macro->cmd);
 697		return 0;
 698	}
 699
 700	kms = kmalloc(sizeof(*kms), GFP_KDB);
 701	if (!kms) {
 702		kdb_printf("Could not allocate new kdb macro command: %s\n",
 703			   cmdstr);
 704		return KDB_NOTIMP;
 705	}
 706
 707	kms->statement = kdb_strdup(cmdstr, GFP_KDB);
 708	list_add_tail(&kms->list_node, &kdb_macro->statements);
 709
 710	return 0;
 711}
 712
 713static int kdb_defcmd(int argc, const char **argv)
 714{
 715	kdbtab_t *mp;
 716
 717	if (defcmd_in_progress) {
 718		kdb_printf("kdb: nested defcmd detected, assuming missing "
 719			   "endefcmd\n");
 720		kdb_defcmd2("endefcmd", "endefcmd");
 721	}
 722	if (argc == 0) {
 723		kdbtab_t *kp;
 724		struct kdb_macro *kmp;
 725		struct kdb_macro_statement *kms;
 726
 727		list_for_each_entry(kp, &kdb_cmds_head, list_node) {
 728			if (kp->func == kdb_exec_defcmd) {
 729				kdb_printf("defcmd %s \"%s\" \"%s\"\n",
 730					   kp->name, kp->usage, kp->help);
 731				kmp = container_of(kp, struct kdb_macro, cmd);
 732				list_for_each_entry(kms, &kmp->statements,
 733						    list_node)
 734					kdb_printf("%s", kms->statement);
 735				kdb_printf("endefcmd\n");
 736			}
 737		}
 738		return 0;
 739	}
 740	if (argc != 3)
 741		return KDB_ARGCOUNT;
 742	if (in_dbg_master()) {
 743		kdb_printf("Command only available during kdb_init()\n");
 744		return KDB_NOTIMP;
 745	}
 746	kdb_macro = kzalloc(sizeof(*kdb_macro), GFP_KDB);
 747	if (!kdb_macro)
 748		goto fail_defcmd;
 749
 750	mp = &kdb_macro->cmd;
 751	mp->func = kdb_exec_defcmd;
 752	mp->minlen = 0;
 753	mp->flags = KDB_ENABLE_ALWAYS_SAFE;
 754	mp->name = kdb_strdup(argv[1], GFP_KDB);
 755	if (!mp->name)
 756		goto fail_name;
 757	mp->usage = kdb_strdup(argv[2], GFP_KDB);
 758	if (!mp->usage)
 759		goto fail_usage;
 760	mp->help = kdb_strdup(argv[3], GFP_KDB);
 761	if (!mp->help)
 762		goto fail_help;
 763	if (mp->usage[0] == '"') {
 764		strcpy(mp->usage, argv[2]+1);
 765		mp->usage[strlen(mp->usage)-1] = '\0';
 766	}
 767	if (mp->help[0] == '"') {
 768		strcpy(mp->help, argv[3]+1);
 769		mp->help[strlen(mp->help)-1] = '\0';
 770	}
 771
 772	INIT_LIST_HEAD(&kdb_macro->statements);
 773	defcmd_in_progress = true;
 774	return 0;
 775fail_help:
 776	kfree(mp->usage);
 777fail_usage:
 778	kfree(mp->name);
 779fail_name:
 780	kfree(kdb_macro);
 781fail_defcmd:
 782	kdb_printf("Could not allocate new kdb_macro entry for %s\n", argv[1]);
 783	return KDB_NOTIMP;
 784}
 785
 786/*
 787 * kdb_exec_defcmd - Execute the set of commands associated with this
 788 *	defcmd name.
 789 * Inputs:
 790 *	argc	argument count
 791 *	argv	argument vector
 792 * Returns:
 793 *	zero for success, a kdb diagnostic if error
 794 */
 795static int kdb_exec_defcmd(int argc, const char **argv)
 796{
 797	int ret;
 798	kdbtab_t *kp;
 799	struct kdb_macro *kmp;
 800	struct kdb_macro_statement *kms;
 801
 802	if (argc != 0)
 803		return KDB_ARGCOUNT;
 804
 805	list_for_each_entry(kp, &kdb_cmds_head, list_node) {
 806		if (strcmp(kp->name, argv[0]) == 0)
 807			break;
 808	}
 809	if (list_entry_is_head(kp, &kdb_cmds_head, list_node)) {
 810		kdb_printf("kdb_exec_defcmd: could not find commands for %s\n",
 811			   argv[0]);
 812		return KDB_NOTIMP;
 813	}
 814	kmp = container_of(kp, struct kdb_macro, cmd);
 815	list_for_each_entry(kms, &kmp->statements, list_node) {
 816		/*
 817		 * Recursive use of kdb_parse, do not use argv after this point.
 818		 */
 819		argv = NULL;
 820		kdb_printf("[%s]kdb> %s\n", kmp->cmd.name, kms->statement);
 821		ret = kdb_parse(kms->statement);
 822		if (ret)
 823			return ret;
 824	}
 825	return 0;
 826}
 827
 828/* Command history */
 829#define KDB_CMD_HISTORY_COUNT	32
 830#define CMD_BUFLEN		200	/* kdb_printf: max printline
 831					 * size == 256 */
 832static unsigned int cmd_head, cmd_tail;
 833static unsigned int cmdptr;
 834static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN];
 835static char cmd_cur[CMD_BUFLEN];
 836
 837/*
 838 * The "str" argument may point to something like  | grep xyz
 839 */
 840static void parse_grep(const char *str)
 841{
 842	int	len;
 843	char	*cp = (char *)str, *cp2;
 844
 845	/* sanity check: we should have been called with the \ first */
 846	if (*cp != '|')
 847		return;
 848	cp++;
 849	while (isspace(*cp))
 850		cp++;
 851	if (!str_has_prefix(cp, "grep ")) {
 852		kdb_printf("invalid 'pipe', see grephelp\n");
 853		return;
 854	}
 855	cp += 5;
 856	while (isspace(*cp))
 857		cp++;
 858	cp2 = strchr(cp, '\n');
 859	if (cp2)
 860		*cp2 = '\0'; /* remove the trailing newline */
 861	len = strlen(cp);
 862	if (len == 0) {
 863		kdb_printf("invalid 'pipe', see grephelp\n");
 864		return;
 865	}
 866	/* now cp points to a nonzero length search string */
 867	if (*cp == '"') {
 868		/* allow it be "x y z" by removing the "'s - there must
 869		   be two of them */
 870		cp++;
 871		cp2 = strchr(cp, '"');
 872		if (!cp2) {
 873			kdb_printf("invalid quoted string, see grephelp\n");
 874			return;
 875		}
 876		*cp2 = '\0'; /* end the string where the 2nd " was */
 877	}
 878	kdb_grep_leading = 0;
 879	if (*cp == '^') {
 880		kdb_grep_leading = 1;
 881		cp++;
 882	}
 883	len = strlen(cp);
 884	kdb_grep_trailing = 0;
 885	if (*(cp+len-1) == '$') {
 886		kdb_grep_trailing = 1;
 887		*(cp+len-1) = '\0';
 888	}
 889	len = strlen(cp);
 890	if (!len)
 891		return;
 892	if (len >= KDB_GREP_STRLEN) {
 893		kdb_printf("search string too long\n");
 894		return;
 895	}
 896	strcpy(kdb_grep_string, cp);
 897	kdb_grepping_flag++;
 898	return;
 899}
 900
 901/*
 902 * kdb_parse - Parse the command line, search the command table for a
 903 *	matching command and invoke the command function.  This
 904 *	function may be called recursively, if it is, the second call
 905 *	will overwrite argv and cbuf.  It is the caller's
 906 *	responsibility to save their argv if they recursively call
 907 *	kdb_parse().
 908 * Parameters:
 909 *      cmdstr	The input command line to be parsed.
 910 *	regs	The registers at the time kdb was entered.
 911 * Returns:
 912 *	Zero for success, a kdb diagnostic if failure.
 913 * Remarks:
 914 *	Limited to 20 tokens.
 915 *
 916 *	Real rudimentary tokenization. Basically only whitespace
 917 *	is considered a token delimiter (but special consideration
 918 *	is taken of the '=' sign as used by the 'set' command).
 919 *
 920 *	The algorithm used to tokenize the input string relies on
 921 *	there being at least one whitespace (or otherwise useless)
 922 *	character between tokens as the character immediately following
 923 *	the token is altered in-place to a null-byte to terminate the
 924 *	token string.
 925 */
 926
 927#define MAXARGC	20
 928
 929int kdb_parse(const char *cmdstr)
 930{
 931	static char *argv[MAXARGC];
 932	static int argc;
 933	static char cbuf[CMD_BUFLEN+2];
 934	char *cp;
 935	char *cpp, quoted;
 936	kdbtab_t *tp;
 937	int escaped, ignore_errors = 0, check_grep = 0;
 938
 939	/*
 940	 * First tokenize the command string.
 941	 */
 942	cp = (char *)cmdstr;
 943
 944	if (KDB_FLAG(CMD_INTERRUPT)) {
 945		/* Previous command was interrupted, newline must not
 946		 * repeat the command */
 947		KDB_FLAG_CLEAR(CMD_INTERRUPT);
 948		KDB_STATE_SET(PAGER);
 949		argc = 0;	/* no repeat */
 950	}
 951
 952	if (*cp != '\n' && *cp != '\0') {
 953		argc = 0;
 954		cpp = cbuf;
 955		while (*cp) {
 956			/* skip whitespace */
 957			while (isspace(*cp))
 958				cp++;
 959			if ((*cp == '\0') || (*cp == '\n') ||
 960			    (*cp == '#' && !defcmd_in_progress))
 961				break;
 962			/* special case: check for | grep pattern */
 963			if (*cp == '|') {
 964				check_grep++;
 965				break;
 966			}
 967			if (cpp >= cbuf + CMD_BUFLEN) {
 968				kdb_printf("kdb_parse: command buffer "
 969					   "overflow, command ignored\n%s\n",
 970					   cmdstr);
 971				return KDB_NOTFOUND;
 972			}
 973			if (argc >= MAXARGC - 1) {
 974				kdb_printf("kdb_parse: too many arguments, "
 975					   "command ignored\n%s\n", cmdstr);
 976				return KDB_NOTFOUND;
 977			}
 978			argv[argc++] = cpp;
 979			escaped = 0;
 980			quoted = '\0';
 981			/* Copy to next unquoted and unescaped
 982			 * whitespace or '=' */
 983			while (*cp && *cp != '\n' &&
 984			       (escaped || quoted || !isspace(*cp))) {
 985				if (cpp >= cbuf + CMD_BUFLEN)
 986					break;
 987				if (escaped) {
 988					escaped = 0;
 989					*cpp++ = *cp++;
 990					continue;
 991				}
 992				if (*cp == '\\') {
 993					escaped = 1;
 994					++cp;
 995					continue;
 996				}
 997				if (*cp == quoted)
 998					quoted = '\0';
 999				else if (*cp == '\'' || *cp == '"')
1000					quoted = *cp;
1001				*cpp = *cp++;
1002				if (*cpp == '=' && !quoted)
1003					break;
1004				++cpp;
1005			}
1006			*cpp++ = '\0';	/* Squash a ws or '=' character */
1007		}
1008	}
1009	if (!argc)
1010		return 0;
1011	if (check_grep)
1012		parse_grep(cp);
1013	if (defcmd_in_progress) {
1014		int result = kdb_defcmd2(cmdstr, argv[0]);
1015		if (!defcmd_in_progress) {
1016			argc = 0;	/* avoid repeat on endefcmd */
1017			*(argv[0]) = '\0';
1018		}
1019		return result;
1020	}
1021	if (argv[0][0] == '-' && argv[0][1] &&
1022	    (argv[0][1] < '0' || argv[0][1] > '9')) {
1023		ignore_errors = 1;
1024		++argv[0];
1025	}
1026
1027	list_for_each_entry(tp, &kdb_cmds_head, list_node) {
1028		/*
1029		 * If this command is allowed to be abbreviated,
1030		 * check to see if this is it.
1031		 */
1032		if (tp->minlen && (strlen(argv[0]) <= tp->minlen) &&
1033		    (strncmp(argv[0], tp->name, tp->minlen) == 0))
1034			break;
1035
1036		if (strcmp(argv[0], tp->name) == 0)
1037			break;
1038	}
1039
1040	/*
1041	 * If we don't find a command by this name, see if the first
1042	 * few characters of this match any of the known commands.
1043	 * e.g., md1c20 should match md.
1044	 */
1045	if (list_entry_is_head(tp, &kdb_cmds_head, list_node)) {
1046		list_for_each_entry(tp, &kdb_cmds_head, list_node) {
1047			if (strncmp(argv[0], tp->name, strlen(tp->name)) == 0)
1048				break;
1049		}
1050	}
1051
1052	if (!list_entry_is_head(tp, &kdb_cmds_head, list_node)) {
1053		int result;
1054
1055		if (!kdb_check_flags(tp->flags, kdb_cmd_enabled, argc <= 1))
1056			return KDB_NOPERM;
1057
1058		KDB_STATE_SET(CMD);
1059		result = (*tp->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->flags & KDB_REPEAT_WITH_ARGS)
1065			return result;
1066
1067		argc = tp->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		curr_task(raw_smp_processor_id());
1195
1196	KDB_DEBUG_STATE("kdb_local 1", reason);
1197
1198	kdb_check_for_lockdown();
1199
1200	kdb_go_count = 0;
1201	if (reason == KDB_REASON_DEBUG) {
1202		/* special case below */
1203	} else {
1204		kdb_printf("\nEntering kdb (current=0x%px, pid %d) ",
1205			   kdb_current, kdb_current ? kdb_current->pid : 0);
1206#if defined(CONFIG_SMP)
1207		kdb_printf("on processor %d ", raw_smp_processor_id());
1208#endif
1209	}
1210
1211	switch (reason) {
1212	case KDB_REASON_DEBUG:
1213	{
1214		/*
1215		 * If re-entering kdb after a single step
1216		 * command, don't print the message.
1217		 */
1218		switch (db_result) {
1219		case KDB_DB_BPT:
1220			kdb_printf("\nEntering kdb (0x%px, pid %d) ",
1221				   kdb_current, kdb_current->pid);
1222#if defined(CONFIG_SMP)
1223			kdb_printf("on processor %d ", raw_smp_processor_id());
1224#endif
1225			kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
1226				   instruction_pointer(regs));
1227			break;
1228		case KDB_DB_SS:
1229			break;
1230		case KDB_DB_SSBPT:
1231			KDB_DEBUG_STATE("kdb_local 4", reason);
1232			return 1;	/* kdba_db_trap did the work */
1233		default:
1234			kdb_printf("kdb: Bad result from kdba_db_trap: %d\n",
1235				   db_result);
1236			break;
1237		}
1238
1239	}
1240		break;
1241	case KDB_REASON_ENTER:
1242		if (KDB_STATE(KEYBOARD))
1243			kdb_printf("due to Keyboard Entry\n");
1244		else
1245			kdb_printf("due to KDB_ENTER()\n");
1246		break;
1247	case KDB_REASON_KEYBOARD:
1248		KDB_STATE_SET(KEYBOARD);
1249		kdb_printf("due to Keyboard Entry\n");
1250		break;
1251	case KDB_REASON_ENTER_SLAVE:
1252		/* drop through, slaves only get released via cpu switch */
1253	case KDB_REASON_SWITCH:
1254		kdb_printf("due to cpu switch\n");
1255		break;
1256	case KDB_REASON_OOPS:
1257		kdb_printf("Oops: %s\n", kdb_diemsg);
1258		kdb_printf("due to oops @ " kdb_machreg_fmt "\n",
1259			   instruction_pointer(regs));
1260		kdb_dumpregs(regs);
1261		break;
1262	case KDB_REASON_SYSTEM_NMI:
1263		kdb_printf("due to System NonMaskable Interrupt\n");
1264		break;
1265	case KDB_REASON_NMI:
1266		kdb_printf("due to NonMaskable Interrupt @ "
1267			   kdb_machreg_fmt "\n",
1268			   instruction_pointer(regs));
1269		break;
1270	case KDB_REASON_SSTEP:
1271	case KDB_REASON_BREAK:
1272		kdb_printf("due to %s @ " kdb_machreg_fmt "\n",
1273			   reason == KDB_REASON_BREAK ?
1274			   "Breakpoint" : "SS trap", instruction_pointer(regs));
1275		/*
1276		 * Determine if this breakpoint is one that we
1277		 * are interested in.
1278		 */
1279		if (db_result != KDB_DB_BPT) {
1280			kdb_printf("kdb: error return from kdba_bp_trap: %d\n",
1281				   db_result);
1282			KDB_DEBUG_STATE("kdb_local 6", reason);
1283			return 0;	/* Not for us, dismiss it */
1284		}
1285		break;
1286	case KDB_REASON_RECURSE:
1287		kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n",
1288			   instruction_pointer(regs));
1289		break;
1290	default:
1291		kdb_printf("kdb: unexpected reason code: %d\n", reason);
1292		KDB_DEBUG_STATE("kdb_local 8", reason);
1293		return 0;	/* Not for us, dismiss it */
1294	}
1295
1296	while (1) {
1297		/*
1298		 * Initialize pager context.
1299		 */
1300		kdb_nextline = 1;
1301		KDB_STATE_CLEAR(SUPPRESS);
1302		kdb_grepping_flag = 0;
1303		/* ensure the old search does not leak into '/' commands */
1304		kdb_grep_string[0] = '\0';
1305
1306		cmdbuf = cmd_cur;
1307		*cmdbuf = '\0';
1308		*(cmd_hist[cmd_head]) = '\0';
1309
1310do_full_getstr:
1311		/* PROMPT can only be set if we have MEM_READ permission. */
1312		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
1313			 raw_smp_processor_id());
 
 
1314
1315		/*
1316		 * Fetch command from keyboard
1317		 */
1318		cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str);
1319		if (*cmdbuf != '\n') {
1320			if (*cmdbuf < 32) {
1321				if (cmdptr == cmd_head) {
1322					strscpy(cmd_hist[cmd_head], cmd_cur,
1323						CMD_BUFLEN);
1324					*(cmd_hist[cmd_head] +
1325					  strlen(cmd_hist[cmd_head])-1) = '\0';
1326				}
1327				if (!handle_ctrl_cmd(cmdbuf))
1328					*(cmd_cur+strlen(cmd_cur)-1) = '\0';
1329				cmdbuf = cmd_cur;
1330				goto do_full_getstr;
1331			} else {
1332				strscpy(cmd_hist[cmd_head], cmd_cur,
1333					CMD_BUFLEN);
1334			}
1335
1336			cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT;
1337			if (cmd_head == cmd_tail)
1338				cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT;
1339		}
1340
1341		cmdptr = cmd_head;
1342		diag = kdb_parse(cmdbuf);
1343		if (diag == KDB_NOTFOUND) {
1344			drop_newline(cmdbuf);
1345			kdb_printf("Unknown kdb command: '%s'\n", cmdbuf);
1346			diag = 0;
1347		}
1348		if (diag == KDB_CMD_GO
1349		 || diag == KDB_CMD_CPU
1350		 || diag == KDB_CMD_SS
1351		 || diag == KDB_CMD_KGDB)
1352			break;
1353
1354		if (diag)
1355			kdb_cmderror(diag);
1356	}
1357	KDB_DEBUG_STATE("kdb_local 9", diag);
1358	return diag;
1359}
1360
1361
1362/*
1363 * kdb_print_state - Print the state data for the current processor
1364 *	for debugging.
1365 * Inputs:
1366 *	text		Identifies the debug point
1367 *	value		Any integer value to be printed, e.g. reason code.
1368 */
1369void kdb_print_state(const char *text, int value)
1370{
1371	kdb_printf("state: %s cpu %d value %d initial %d state %x\n",
1372		   text, raw_smp_processor_id(), value, kdb_initial_cpu,
1373		   kdb_state);
1374}
1375
1376/*
1377 * kdb_main_loop - After initial setup and assignment of the
1378 *	controlling cpu, all cpus are in this loop.  One cpu is in
1379 *	control and will issue the kdb prompt, the others will spin
1380 *	until 'go' or cpu switch.
1381 *
1382 *	To get a consistent view of the kernel stacks for all
1383 *	processes, this routine is invoked from the main kdb code via
1384 *	an architecture specific routine.  kdba_main_loop is
1385 *	responsible for making the kernel stacks consistent for all
1386 *	processes, there should be no difference between a blocked
1387 *	process and a running process as far as kdb is concerned.
1388 * Inputs:
1389 *	reason		The reason KDB was invoked
1390 *	error		The hardware-defined error code
1391 *	reason2		kdb's current reason code.
1392 *			Initially error but can change
1393 *			according to kdb state.
1394 *	db_result	Result code from break or debug point.
1395 *	regs		The exception frame at time of fault/breakpoint.
1396 *			should always be valid.
1397 * Returns:
1398 *	0	KDB was invoked for an event which it wasn't responsible
1399 *	1	KDB handled the event for which it was invoked.
1400 */
1401int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
1402	      kdb_dbtrap_t db_result, struct pt_regs *regs)
1403{
1404	int result = 1;
1405	/* Stay in kdb() until 'go', 'ss[b]' or an error */
1406	while (1) {
1407		/*
1408		 * All processors except the one that is in control
1409		 * will spin here.
1410		 */
1411		KDB_DEBUG_STATE("kdb_main_loop 1", reason);
1412		while (KDB_STATE(HOLD_CPU)) {
1413			/* state KDB is turned off by kdb_cpu to see if the
1414			 * other cpus are still live, each cpu in this loop
1415			 * turns it back on.
1416			 */
1417			if (!KDB_STATE(KDB))
1418				KDB_STATE_SET(KDB);
1419		}
1420
1421		KDB_STATE_CLEAR(SUPPRESS);
1422		KDB_DEBUG_STATE("kdb_main_loop 2", reason);
1423		if (KDB_STATE(LEAVING))
1424			break;	/* Another cpu said 'go' */
1425		/* Still using kdb, this processor is in control */
1426		result = kdb_local(reason2, error, regs, db_result);
1427		KDB_DEBUG_STATE("kdb_main_loop 3", result);
1428
1429		if (result == KDB_CMD_CPU)
1430			break;
1431
1432		if (result == KDB_CMD_SS) {
1433			KDB_STATE_SET(DOING_SS);
1434			break;
1435		}
1436
1437		if (result == KDB_CMD_KGDB) {
1438			if (!KDB_STATE(DOING_KGDB))
1439				kdb_printf("Entering please attach debugger "
1440					   "or use $D#44+ or $3#33\n");
1441			break;
1442		}
1443		if (result && result != 1 && result != KDB_CMD_GO)
1444			kdb_printf("\nUnexpected kdb_local return code %d\n",
1445				   result);
1446		KDB_DEBUG_STATE("kdb_main_loop 4", reason);
1447		break;
1448	}
1449	if (KDB_STATE(DOING_SS))
1450		KDB_STATE_CLEAR(SSBPT);
1451
1452	/* Clean up any keyboard devices before leaving */
1453	kdb_kbd_cleanup_state();
1454
1455	return result;
1456}
1457
1458/*
1459 * kdb_mdr - This function implements the guts of the 'mdr', memory
1460 * read command.
1461 *	mdr  <addr arg>,<byte count>
1462 * Inputs:
1463 *	addr	Start address
1464 *	count	Number of bytes
1465 * Returns:
1466 *	Always 0.  Any errors are detected and printed by kdb_getarea.
1467 */
1468static int kdb_mdr(unsigned long addr, unsigned int count)
1469{
1470	unsigned char c;
1471	while (count--) {
1472		if (kdb_getarea(c, addr))
1473			return 0;
1474		kdb_printf("%02x", c);
1475		addr++;
1476	}
1477	kdb_printf("\n");
1478	return 0;
1479}
1480
1481/*
1482 * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4',
1483 *	'md8' 'mdr' and 'mds' commands.
1484 *
1485 *	md|mds  [<addr arg> [<line count> [<radix>]]]
1486 *	mdWcN	[<addr arg> [<line count> [<radix>]]]
1487 *		where W = is the width (1, 2, 4 or 8) and N is the count.
1488 *		for eg., md1c20 reads 20 bytes, 1 at a time.
1489 *	mdr  <addr arg>,<byte count>
1490 */
1491static void kdb_md_line(const char *fmtstr, unsigned long addr,
1492			int symbolic, int nosect, int bytesperword,
1493			int num, int repeat, int phys)
1494{
1495	/* print just one line of data */
1496	kdb_symtab_t symtab;
1497	char cbuf[32];
1498	char *c = cbuf;
1499	int i;
1500	int j;
1501	unsigned long word;
1502
1503	memset(cbuf, '\0', sizeof(cbuf));
1504	if (phys)
1505		kdb_printf("phys " kdb_machreg_fmt0 " ", addr);
1506	else
1507		kdb_printf(kdb_machreg_fmt0 " ", addr);
1508
1509	for (i = 0; i < num && repeat--; i++) {
1510		if (phys) {
1511			if (kdb_getphysword(&word, addr, bytesperword))
1512				break;
1513		} else if (kdb_getword(&word, addr, bytesperword))
1514			break;
1515		kdb_printf(fmtstr, word);
1516		if (symbolic)
1517			kdbnearsym(word, &symtab);
1518		else
1519			memset(&symtab, 0, sizeof(symtab));
1520		if (symtab.sym_name) {
1521			kdb_symbol_print(word, &symtab, 0);
1522			if (!nosect) {
1523				kdb_printf("\n");
1524				kdb_printf("                       %s %s "
1525					   kdb_machreg_fmt " "
1526					   kdb_machreg_fmt " "
1527					   kdb_machreg_fmt, symtab.mod_name,
1528					   symtab.sec_name, symtab.sec_start,
1529					   symtab.sym_start, symtab.sym_end);
1530			}
1531			addr += bytesperword;
1532		} else {
1533			union {
1534				u64 word;
1535				unsigned char c[8];
1536			} wc;
1537			unsigned char *cp;
1538#ifdef	__BIG_ENDIAN
1539			cp = wc.c + 8 - bytesperword;
1540#else
1541			cp = wc.c;
1542#endif
1543			wc.word = word;
1544#define printable_char(c) \
1545	({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; })
1546			for (j = 0; j < bytesperword; j++)
1547				*c++ = printable_char(*cp++);
1548			addr += bytesperword;
1549#undef printable_char
1550		}
1551	}
1552	kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1),
1553		   " ", cbuf);
1554}
1555
1556static int kdb_md(int argc, const char **argv)
1557{
1558	static unsigned long last_addr;
1559	static int last_radix, last_bytesperword, last_repeat;
1560	int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
1561	int nosect = 0;
1562	char fmtchar, fmtstr[64];
1563	unsigned long addr;
1564	unsigned long word;
1565	long offset = 0;
1566	int symbolic = 0;
1567	int valid = 0;
1568	int phys = 0;
1569	int raw = 0;
1570
1571	kdbgetintenv("MDCOUNT", &mdcount);
1572	kdbgetintenv("RADIX", &radix);
1573	kdbgetintenv("BYTESPERWORD", &bytesperword);
1574
1575	/* Assume 'md <addr>' and start with environment values */
1576	repeat = mdcount * 16 / bytesperword;
1577
1578	if (strcmp(argv[0], "mdr") == 0) {
1579		if (argc == 2 || (argc == 0 && last_addr != 0))
1580			valid = raw = 1;
1581		else
1582			return KDB_ARGCOUNT;
1583	} else if (isdigit(argv[0][2])) {
1584		bytesperword = (int)(argv[0][2] - '0');
1585		if (bytesperword == 0) {
1586			bytesperword = last_bytesperword;
1587			if (bytesperword == 0)
1588				bytesperword = 4;
1589		}
1590		last_bytesperword = bytesperword;
1591		repeat = mdcount * 16 / bytesperword;
1592		if (!argv[0][3])
1593			valid = 1;
1594		else if (argv[0][3] == 'c' && argv[0][4]) {
1595			if (kstrtouint(argv[0] + 4, 10, &repeat))
1596				return KDB_BADINT;
1597			mdcount = ((repeat * bytesperword) + 15) / 16;
1598			valid = 1;
1599		}
1600		last_repeat = repeat;
1601	} else if (strcmp(argv[0], "md") == 0)
1602		valid = 1;
1603	else if (strcmp(argv[0], "mds") == 0)
1604		valid = 1;
1605	else if (strcmp(argv[0], "mdp") == 0) {
1606		phys = valid = 1;
1607	}
1608	if (!valid)
1609		return KDB_NOTFOUND;
1610
1611	if (argc == 0) {
1612		if (last_addr == 0)
1613			return KDB_ARGCOUNT;
1614		addr = last_addr;
1615		radix = last_radix;
1616		bytesperword = last_bytesperword;
1617		repeat = last_repeat;
1618		if (raw)
1619			mdcount = repeat;
1620		else
1621			mdcount = ((repeat * bytesperword) + 15) / 16;
1622	}
1623
1624	if (argc) {
1625		unsigned long val;
1626		int diag, nextarg = 1;
1627		diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
1628				     &offset, NULL);
1629		if (diag)
1630			return diag;
1631		if (argc > nextarg+2)
1632			return KDB_ARGCOUNT;
1633
1634		if (argc >= nextarg) {
1635			diag = kdbgetularg(argv[nextarg], &val);
1636			if (!diag) {
1637				mdcount = (int) val;
1638				if (raw)
1639					repeat = mdcount;
1640				else
1641					repeat = mdcount * 16 / bytesperword;
1642			}
1643		}
1644		if (argc >= nextarg+1) {
1645			diag = kdbgetularg(argv[nextarg+1], &val);
1646			if (!diag)
1647				radix = (int) val;
1648		}
1649	}
1650
1651	if (strcmp(argv[0], "mdr") == 0) {
1652		int ret;
1653		last_addr = addr;
1654		ret = kdb_mdr(addr, mdcount);
1655		last_addr += mdcount;
1656		last_repeat = mdcount;
1657		last_bytesperword = bytesperword; // to make REPEAT happy
1658		return ret;
1659	}
1660
1661	switch (radix) {
1662	case 10:
1663		fmtchar = 'd';
1664		break;
1665	case 16:
1666		fmtchar = 'x';
1667		break;
1668	case 8:
1669		fmtchar = 'o';
1670		break;
1671	default:
1672		return KDB_BADRADIX;
1673	}
1674
1675	last_radix = radix;
1676
1677	if (bytesperword > KDB_WORD_SIZE)
1678		return KDB_BADWIDTH;
1679
1680	switch (bytesperword) {
1681	case 8:
1682		sprintf(fmtstr, "%%16.16l%c ", fmtchar);
1683		break;
1684	case 4:
1685		sprintf(fmtstr, "%%8.8l%c ", fmtchar);
1686		break;
1687	case 2:
1688		sprintf(fmtstr, "%%4.4l%c ", fmtchar);
1689		break;
1690	case 1:
1691		sprintf(fmtstr, "%%2.2l%c ", fmtchar);
1692		break;
1693	default:
1694		return KDB_BADWIDTH;
1695	}
1696
1697	last_repeat = repeat;
1698	last_bytesperword = bytesperword;
1699
1700	if (strcmp(argv[0], "mds") == 0) {
1701		symbolic = 1;
1702		/* Do not save these changes as last_*, they are temporary mds
1703		 * overrides.
1704		 */
1705		bytesperword = KDB_WORD_SIZE;
1706		repeat = mdcount;
1707		kdbgetintenv("NOSECT", &nosect);
1708	}
1709
1710	/* Round address down modulo BYTESPERWORD */
1711
1712	addr &= ~(bytesperword-1);
1713
1714	while (repeat > 0) {
1715		unsigned long a;
1716		int n, z, num = (symbolic ? 1 : (16 / bytesperword));
1717
1718		if (KDB_FLAG(CMD_INTERRUPT))
1719			return 0;
1720		for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) {
1721			if (phys) {
1722				if (kdb_getphysword(&word, a, bytesperword)
1723						|| word)
1724					break;
1725			} else if (kdb_getword(&word, a, bytesperword) || word)
1726				break;
1727		}
1728		n = min(num, repeat);
1729		kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword,
1730			    num, repeat, phys);
1731		addr += bytesperword * n;
1732		repeat -= n;
1733		z = (z + num - 1) / num;
1734		if (z > 2) {
1735			int s = num * (z-2);
1736			kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0
1737				   " zero suppressed\n",
1738				addr, addr + bytesperword * s - 1);
1739			addr += bytesperword * s;
1740			repeat -= s;
1741		}
1742	}
1743	last_addr = addr;
1744
1745	return 0;
1746}
1747
1748/*
1749 * kdb_mm - This function implements the 'mm' command.
1750 *	mm address-expression new-value
1751 * Remarks:
1752 *	mm works on machine words, mmW works on bytes.
1753 */
1754static int kdb_mm(int argc, const char **argv)
1755{
1756	int diag;
1757	unsigned long addr;
1758	long offset = 0;
1759	unsigned long contents;
1760	int nextarg;
1761	int width;
1762
1763	if (argv[0][2] && !isdigit(argv[0][2]))
1764		return KDB_NOTFOUND;
1765
1766	if (argc < 2)
1767		return KDB_ARGCOUNT;
1768
1769	nextarg = 1;
1770	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1771	if (diag)
1772		return diag;
1773
1774	if (nextarg > argc)
1775		return KDB_ARGCOUNT;
1776	diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL);
1777	if (diag)
1778		return diag;
1779
1780	if (nextarg != argc + 1)
1781		return KDB_ARGCOUNT;
1782
1783	width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE);
1784	diag = kdb_putword(addr, contents, width);
1785	if (diag)
1786		return diag;
1787
1788	kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents);
1789
1790	return 0;
1791}
1792
1793/*
1794 * kdb_go - This function implements the 'go' command.
1795 *	go [address-expression]
1796 */
1797static int kdb_go(int argc, const char **argv)
1798{
1799	unsigned long addr;
1800	int diag;
1801	int nextarg;
1802	long offset;
1803
1804	if (raw_smp_processor_id() != kdb_initial_cpu) {
1805		kdb_printf("go must execute on the entry cpu, "
1806			   "please use \"cpu %d\" and then execute go\n",
1807			   kdb_initial_cpu);
1808		return KDB_BADCPUNUM;
1809	}
1810	if (argc == 1) {
1811		nextarg = 1;
1812		diag = kdbgetaddrarg(argc, argv, &nextarg,
1813				     &addr, &offset, NULL);
1814		if (diag)
1815			return diag;
1816	} else if (argc) {
1817		return KDB_ARGCOUNT;
1818	}
1819
1820	diag = KDB_CMD_GO;
1821	if (KDB_FLAG(CATASTROPHIC)) {
1822		kdb_printf("Catastrophic error detected\n");
1823		kdb_printf("kdb_continue_catastrophic=%d, ",
1824			kdb_continue_catastrophic);
1825		if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) {
1826			kdb_printf("type go a second time if you really want "
1827				   "to continue\n");
1828			return 0;
1829		}
1830		if (kdb_continue_catastrophic == 2) {
1831			kdb_printf("forcing reboot\n");
1832			kdb_reboot(0, NULL);
1833		}
1834		kdb_printf("attempting to continue\n");
1835	}
1836	return diag;
1837}
1838
1839/*
1840 * kdb_rd - This function implements the 'rd' command.
1841 */
1842static int kdb_rd(int argc, const char **argv)
1843{
1844	int len = kdb_check_regs();
1845#if DBG_MAX_REG_NUM > 0
1846	int i;
1847	char *rname;
1848	int rsize;
1849	u64 reg64;
1850	u32 reg32;
1851	u16 reg16;
1852	u8 reg8;
1853
1854	if (len)
1855		return len;
1856
1857	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1858		rsize = dbg_reg_def[i].size * 2;
1859		if (rsize > 16)
1860			rsize = 2;
1861		if (len + strlen(dbg_reg_def[i].name) + 4 + rsize > 80) {
1862			len = 0;
1863			kdb_printf("\n");
1864		}
1865		if (len)
1866			len += kdb_printf("  ");
1867		switch(dbg_reg_def[i].size * 8) {
1868		case 8:
1869			rname = dbg_get_reg(i, &reg8, kdb_current_regs);
1870			if (!rname)
1871				break;
1872			len += kdb_printf("%s: %02x", rname, reg8);
1873			break;
1874		case 16:
1875			rname = dbg_get_reg(i, &reg16, kdb_current_regs);
1876			if (!rname)
1877				break;
1878			len += kdb_printf("%s: %04x", rname, reg16);
1879			break;
1880		case 32:
1881			rname = dbg_get_reg(i, &reg32, kdb_current_regs);
1882			if (!rname)
1883				break;
1884			len += kdb_printf("%s: %08x", rname, reg32);
1885			break;
1886		case 64:
1887			rname = dbg_get_reg(i, &reg64, kdb_current_regs);
1888			if (!rname)
1889				break;
1890			len += kdb_printf("%s: %016llx", rname, reg64);
1891			break;
1892		default:
1893			len += kdb_printf("%s: ??", dbg_reg_def[i].name);
1894		}
1895	}
1896	kdb_printf("\n");
1897#else
1898	if (len)
1899		return len;
1900
1901	kdb_dumpregs(kdb_current_regs);
1902#endif
1903	return 0;
1904}
1905
1906/*
1907 * kdb_rm - This function implements the 'rm' (register modify)  command.
1908 *	rm register-name new-contents
1909 * Remarks:
1910 *	Allows register modification with the same restrictions as gdb
1911 */
1912static int kdb_rm(int argc, const char **argv)
1913{
1914#if DBG_MAX_REG_NUM > 0
1915	int diag;
1916	const char *rname;
1917	int i;
1918	u64 reg64;
1919	u32 reg32;
1920	u16 reg16;
1921	u8 reg8;
1922
1923	if (argc != 2)
1924		return KDB_ARGCOUNT;
1925	/*
1926	 * Allow presence or absence of leading '%' symbol.
1927	 */
1928	rname = argv[1];
1929	if (*rname == '%')
1930		rname++;
1931
1932	diag = kdbgetu64arg(argv[2], &reg64);
1933	if (diag)
1934		return diag;
1935
1936	diag = kdb_check_regs();
1937	if (diag)
1938		return diag;
1939
1940	diag = KDB_BADREG;
1941	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1942		if (strcmp(rname, dbg_reg_def[i].name) == 0) {
1943			diag = 0;
1944			break;
1945		}
1946	}
1947	if (!diag) {
1948		switch(dbg_reg_def[i].size * 8) {
1949		case 8:
1950			reg8 = reg64;
1951			dbg_set_reg(i, &reg8, kdb_current_regs);
1952			break;
1953		case 16:
1954			reg16 = reg64;
1955			dbg_set_reg(i, &reg16, kdb_current_regs);
1956			break;
1957		case 32:
1958			reg32 = reg64;
1959			dbg_set_reg(i, &reg32, kdb_current_regs);
1960			break;
1961		case 64:
1962			dbg_set_reg(i, &reg64, kdb_current_regs);
1963			break;
1964		}
1965	}
1966	return diag;
1967#else
1968	kdb_printf("ERROR: Register set currently not implemented\n");
1969    return 0;
1970#endif
1971}
1972
1973#if defined(CONFIG_MAGIC_SYSRQ)
1974/*
1975 * kdb_sr - This function implements the 'sr' (SYSRQ key) command
1976 *	which interfaces to the soi-disant MAGIC SYSRQ functionality.
1977 *		sr <magic-sysrq-code>
1978 */
1979static int kdb_sr(int argc, const char **argv)
1980{
1981	bool check_mask =
1982	    !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
1983
1984	if (argc != 1)
1985		return KDB_ARGCOUNT;
1986
1987	kdb_trap_printk++;
1988	__handle_sysrq(*argv[1], check_mask);
1989	kdb_trap_printk--;
1990
1991	return 0;
1992}
1993#endif	/* CONFIG_MAGIC_SYSRQ */
1994
1995/*
1996 * kdb_ef - This function implements the 'regs' (display exception
1997 *	frame) command.  This command takes an address and expects to
1998 *	find an exception frame at that address, formats and prints
1999 *	it.
2000 *		regs address-expression
2001 * Remarks:
2002 *	Not done yet.
2003 */
2004static int kdb_ef(int argc, const char **argv)
2005{
2006	int diag;
2007	unsigned long addr;
2008	long offset;
2009	int nextarg;
2010
2011	if (argc != 1)
2012		return KDB_ARGCOUNT;
2013
2014	nextarg = 1;
2015	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
2016	if (diag)
2017		return diag;
2018	show_regs((struct pt_regs *)addr);
2019	return 0;
2020}
2021
2022/*
2023 * kdb_env - This function implements the 'env' command.  Display the
2024 *	current environment variables.
2025 */
2026
2027static int kdb_env(int argc, const char **argv)
2028{
2029	kdb_printenv();
2030
2031	if (KDB_DEBUG(MASK))
2032		kdb_printf("KDBDEBUG=0x%x\n",
2033			(kdb_flags & KDB_DEBUG(MASK)) >> KDB_DEBUG_FLAG_SHIFT);
2034
2035	return 0;
2036}
2037
2038#ifdef CONFIG_PRINTK
2039/*
2040 * kdb_dmesg - This function implements the 'dmesg' command to display
2041 *	the contents of the syslog buffer.
2042 *		dmesg [lines] [adjust]
2043 */
2044static int kdb_dmesg(int argc, const char **argv)
2045{
2046	int diag;
2047	int logging;
2048	int lines = 0;
2049	int adjust = 0;
2050	int n = 0;
2051	int skip = 0;
2052	struct kmsg_dump_iter iter;
2053	size_t len;
2054	char buf[201];
2055
2056	if (argc > 2)
2057		return KDB_ARGCOUNT;
2058	if (argc) {
2059		if (kstrtoint(argv[1], 0, &lines))
 
 
2060			lines = 0;
2061		if (argc > 1 && (kstrtoint(argv[2], 0, &adjust) || adjust < 0))
2062			adjust = 0;
 
 
 
2063	}
2064
2065	/* disable LOGGING if set */
2066	diag = kdbgetintenv("LOGGING", &logging);
2067	if (!diag && logging) {
2068		const char *setargs[] = { "set", "LOGGING", "0" };
2069		kdb_set(2, setargs);
2070	}
2071
2072	kmsg_dump_rewind(&iter);
2073	while (kmsg_dump_get_line(&iter, 1, NULL, 0, NULL))
2074		n++;
2075
2076	if (lines < 0) {
2077		if (adjust >= n)
2078			kdb_printf("buffer only contains %d lines, nothing "
2079				   "printed\n", n);
2080		else if (adjust - lines >= n)
2081			kdb_printf("buffer only contains %d lines, last %d "
2082				   "lines printed\n", n, n - adjust);
2083		skip = adjust;
2084		lines = abs(lines);
2085	} else if (lines > 0) {
2086		skip = n - lines - adjust;
2087		lines = abs(lines);
2088		if (adjust >= n) {
2089			kdb_printf("buffer only contains %d lines, "
2090				   "nothing printed\n", n);
2091			skip = n;
2092		} else if (skip < 0) {
2093			lines += skip;
2094			skip = 0;
2095			kdb_printf("buffer only contains %d lines, first "
2096				   "%d lines printed\n", n, lines);
2097		}
2098	} else {
2099		lines = n;
2100	}
2101
2102	if (skip >= n || skip < 0)
2103		return 0;
2104
2105	kmsg_dump_rewind(&iter);
2106	while (kmsg_dump_get_line(&iter, 1, buf, sizeof(buf), &len)) {
2107		if (skip) {
2108			skip--;
2109			continue;
2110		}
2111		if (!lines--)
2112			break;
2113		if (KDB_FLAG(CMD_INTERRUPT))
2114			return 0;
2115
2116		kdb_printf("%.*s\n", (int)len - 1, buf);
2117	}
2118
2119	return 0;
2120}
2121#endif /* CONFIG_PRINTK */
2122
2123/* Make sure we balance enable/disable calls, must disable first. */
2124static atomic_t kdb_nmi_disabled;
2125
2126static int kdb_disable_nmi(int argc, const char *argv[])
2127{
2128	if (atomic_read(&kdb_nmi_disabled))
2129		return 0;
2130	atomic_set(&kdb_nmi_disabled, 1);
2131	arch_kgdb_ops.enable_nmi(0);
2132	return 0;
2133}
2134
2135static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
2136{
2137	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
2138		return -EINVAL;
2139	arch_kgdb_ops.enable_nmi(1);
2140	return 0;
2141}
2142
2143static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
2144	.set = kdb_param_enable_nmi,
2145};
2146module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
2147
2148/*
2149 * kdb_cpu - This function implements the 'cpu' command.
2150 *	cpu	[<cpunum>]
2151 * Returns:
2152 *	KDB_CMD_CPU for success, a kdb diagnostic if error
2153 */
2154static void kdb_cpu_status(void)
2155{
2156	int i, start_cpu, first_print = 1;
2157	char state, prev_state = '?';
2158
2159	kdb_printf("Currently on cpu %d\n", raw_smp_processor_id());
2160	kdb_printf("Available cpus: ");
2161	for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
2162		if (!cpu_online(i)) {
2163			state = 'F';	/* cpu is offline */
2164		} else if (!kgdb_info[i].enter_kgdb) {
2165			state = 'D';	/* cpu is online but unresponsive */
2166		} else {
2167			state = ' ';	/* cpu is responding to kdb */
2168			if (kdb_task_state_char(KDB_TSK(i)) == '-')
2169				state = '-';	/* idle task */
2170		}
2171		if (state != prev_state) {
2172			if (prev_state != '?') {
2173				if (!first_print)
2174					kdb_printf(", ");
2175				first_print = 0;
2176				kdb_printf("%d", start_cpu);
2177				if (start_cpu < i-1)
2178					kdb_printf("-%d", i-1);
2179				if (prev_state != ' ')
2180					kdb_printf("(%c)", prev_state);
2181			}
2182			prev_state = state;
2183			start_cpu = i;
2184		}
2185	}
2186	/* print the trailing cpus, ignoring them if they are all offline */
2187	if (prev_state != 'F') {
2188		if (!first_print)
2189			kdb_printf(", ");
2190		kdb_printf("%d", start_cpu);
2191		if (start_cpu < i-1)
2192			kdb_printf("-%d", i-1);
2193		if (prev_state != ' ')
2194			kdb_printf("(%c)", prev_state);
2195	}
2196	kdb_printf("\n");
2197}
2198
2199static int kdb_cpu(int argc, const char **argv)
2200{
2201	unsigned long cpunum;
2202	int diag;
2203
2204	if (argc == 0) {
2205		kdb_cpu_status();
2206		return 0;
2207	}
2208
2209	if (argc != 1)
2210		return KDB_ARGCOUNT;
2211
2212	diag = kdbgetularg(argv[1], &cpunum);
2213	if (diag)
2214		return diag;
2215
2216	/*
2217	 * Validate cpunum
2218	 */
2219	if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
2220		return KDB_BADCPUNUM;
2221
2222	dbg_switch_cpu = cpunum;
2223
2224	/*
2225	 * Switch to other cpu
2226	 */
2227	return KDB_CMD_CPU;
2228}
2229
2230/* The user may not realize that ps/bta with no parameters does not print idle
2231 * or sleeping system daemon processes, so tell them how many were suppressed.
2232 */
2233void kdb_ps_suppressed(void)
2234{
2235	int idle = 0, daemon = 0;
2236	unsigned long cpu;
2237	const struct task_struct *p, *g;
2238	for_each_online_cpu(cpu) {
2239		p = curr_task(cpu);
2240		if (kdb_task_state(p, "-"))
2241			++idle;
2242	}
2243	for_each_process_thread(g, p) {
2244		if (kdb_task_state(p, "ims"))
2245			++daemon;
2246	}
2247	if (idle || daemon) {
2248		if (idle)
2249			kdb_printf("%d idle process%s (state -)%s\n",
2250				   idle, idle == 1 ? "" : "es",
2251				   daemon ? " and " : "");
2252		if (daemon)
2253			kdb_printf("%d sleeping system daemon (state [ims]) "
2254				   "process%s", daemon,
2255				   daemon == 1 ? "" : "es");
2256		kdb_printf(" suppressed,\nuse 'ps A' to see all.\n");
2257	}
2258}
2259
2260void kdb_ps1(const struct task_struct *p)
2261{
2262	int cpu;
2263	unsigned long tmp;
2264
2265	if (!p ||
2266	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
2267		return;
2268
2269	cpu = kdb_process_cpu(p);
2270	kdb_printf("0x%px %8d %8d  %d %4d   %c  0x%px %c%s\n",
2271		   (void *)p, p->pid, p->parent->pid,
2272		   kdb_task_has_cpu(p), kdb_process_cpu(p),
2273		   kdb_task_state_char(p),
2274		   (void *)(&p->thread),
2275		   p == curr_task(raw_smp_processor_id()) ? '*' : ' ',
2276		   p->comm);
2277	if (kdb_task_has_cpu(p)) {
2278		if (!KDB_TSK(cpu)) {
2279			kdb_printf("  Error: no saved data for this cpu\n");
2280		} else {
2281			if (KDB_TSK(cpu) != p)
2282				kdb_printf("  Error: does not match running "
2283				   "process table (0x%px)\n", KDB_TSK(cpu));
2284		}
2285	}
2286}
2287
2288/*
2289 * kdb_ps - This function implements the 'ps' command which shows a
2290 *	    list of the active processes.
2291 *
2292 * ps [<state_chars>]   Show processes, optionally selecting only those whose
2293 *                      state character is found in <state_chars>.
2294 */
2295static int kdb_ps(int argc, const char **argv)
2296{
2297	struct task_struct *g, *p;
2298	const char *mask;
2299	unsigned long cpu;
2300
2301	if (argc == 0)
2302		kdb_ps_suppressed();
2303	kdb_printf("%-*s      Pid   Parent [*] cpu State %-*s Command\n",
2304		(int)(2*sizeof(void *))+2, "Task Addr",
2305		(int)(2*sizeof(void *))+2, "Thread");
2306	mask = argc ? argv[1] : kdbgetenv("PS");
2307	/* Run the active tasks first */
2308	for_each_online_cpu(cpu) {
2309		if (KDB_FLAG(CMD_INTERRUPT))
2310			return 0;
2311		p = curr_task(cpu);
2312		if (kdb_task_state(p, mask))
2313			kdb_ps1(p);
2314	}
2315	kdb_printf("\n");
2316	/* Now the real tasks */
2317	for_each_process_thread(g, p) {
2318		if (KDB_FLAG(CMD_INTERRUPT))
2319			return 0;
2320		if (kdb_task_state(p, mask))
2321			kdb_ps1(p);
2322	}
2323
2324	return 0;
2325}
2326
2327/*
2328 * kdb_pid - This function implements the 'pid' command which switches
2329 *	the currently active process.
2330 *		pid [<pid> | R]
2331 */
2332static int kdb_pid(int argc, const char **argv)
2333{
2334	struct task_struct *p;
2335	unsigned long val;
2336	int diag;
2337
2338	if (argc > 1)
2339		return KDB_ARGCOUNT;
2340
2341	if (argc) {
2342		if (strcmp(argv[1], "R") == 0) {
2343			p = KDB_TSK(kdb_initial_cpu);
2344		} else {
2345			diag = kdbgetularg(argv[1], &val);
2346			if (diag)
2347				return KDB_BADINT;
2348
2349			p = find_task_by_pid_ns((pid_t)val,	&init_pid_ns);
2350			if (!p) {
2351				kdb_printf("No task with pid=%d\n", (pid_t)val);
2352				return 0;
2353			}
2354		}
2355		kdb_set_current_task(p);
2356	}
2357	kdb_printf("KDB current process is %s(pid=%d)\n",
2358		   kdb_current_task->comm,
2359		   kdb_current_task->pid);
2360
2361	return 0;
2362}
2363
2364static int kdb_kgdb(int argc, const char **argv)
2365{
2366	return KDB_CMD_KGDB;
2367}
2368
2369/*
2370 * kdb_help - This function implements the 'help' and '?' commands.
2371 */
2372static int kdb_help(int argc, const char **argv)
2373{
2374	kdbtab_t *kt;
2375
2376	kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
2377	kdb_printf("-----------------------------"
2378		   "-----------------------------\n");
2379	list_for_each_entry(kt, &kdb_cmds_head, list_node) {
2380		char *space = "";
2381		if (KDB_FLAG(CMD_INTERRUPT))
2382			return 0;
2383		if (!kdb_check_flags(kt->flags, kdb_cmd_enabled, true))
2384			continue;
2385		if (strlen(kt->usage) > 20)
2386			space = "\n                                    ";
2387		kdb_printf("%-15.15s %-20s%s%s\n", kt->name,
2388			   kt->usage, space, kt->help);
2389	}
2390	return 0;
2391}
2392
2393/*
2394 * kdb_kill - This function implements the 'kill' commands.
2395 */
2396static int kdb_kill(int argc, const char **argv)
2397{
2398	long sig, pid;
 
2399	struct task_struct *p;
2400
2401	if (argc != 2)
2402		return KDB_ARGCOUNT;
2403
2404	if (kstrtol(argv[1], 0, &sig))
 
2405		return KDB_BADINT;
2406	if ((sig >= 0) || !valid_signal(-sig)) {
2407		kdb_printf("Invalid signal parameter.<-signal>\n");
2408		return 0;
2409	}
2410	sig = -sig;
2411
2412	if (kstrtol(argv[2], 0, &pid))
 
2413		return KDB_BADINT;
2414	if (pid <= 0) {
2415		kdb_printf("Process ID must be large than 0.\n");
2416		return 0;
2417	}
2418
2419	/* Find the process. */
2420	p = find_task_by_pid_ns(pid, &init_pid_ns);
2421	if (!p) {
2422		kdb_printf("The specified process isn't found.\n");
2423		return 0;
2424	}
2425	p = p->group_leader;
2426	kdb_send_sig(p, sig);
2427	return 0;
2428}
2429
2430/*
2431 * Most of this code has been lifted from kernel/timer.c::sys_sysinfo().
2432 * I cannot call that code directly from kdb, it has an unconditional
2433 * cli()/sti() and calls routines that take locks which can stop the debugger.
2434 */
2435static void kdb_sysinfo(struct sysinfo *val)
2436{
2437	u64 uptime = ktime_get_mono_fast_ns();
2438
2439	memset(val, 0, sizeof(*val));
2440	val->uptime = div_u64(uptime, NSEC_PER_SEC);
2441	val->loads[0] = avenrun[0];
2442	val->loads[1] = avenrun[1];
2443	val->loads[2] = avenrun[2];
2444	val->procs = nr_threads-1;
2445	si_meminfo(val);
2446
2447	return;
2448}
2449
2450/*
2451 * kdb_summary - This function implements the 'summary' command.
2452 */
2453static int kdb_summary(int argc, const char **argv)
2454{
2455	time64_t now;
2456	struct sysinfo val;
2457
2458	if (argc)
2459		return KDB_ARGCOUNT;
2460
2461	kdb_printf("sysname    %s\n", init_uts_ns.name.sysname);
2462	kdb_printf("release    %s\n", init_uts_ns.name.release);
2463	kdb_printf("version    %s\n", init_uts_ns.name.version);
2464	kdb_printf("machine    %s\n", init_uts_ns.name.machine);
2465	kdb_printf("nodename   %s\n", init_uts_ns.name.nodename);
2466	kdb_printf("domainname %s\n", init_uts_ns.name.domainname);
2467
2468	now = __ktime_get_real_seconds();
2469	kdb_printf("date       %ptTs tz_minuteswest %d\n", &now, sys_tz.tz_minuteswest);
2470	kdb_sysinfo(&val);
2471	kdb_printf("uptime     ");
2472	if (val.uptime > (24*60*60)) {
2473		int days = val.uptime / (24*60*60);
2474		val.uptime %= (24*60*60);
2475		kdb_printf("%d day%s ", days, str_plural(days));
2476	}
2477	kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
2478
2479	kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
2480		LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
2481		LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
2482		LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
2483
2484	/* Display in kilobytes */
2485#define K(x) ((x) << (PAGE_SHIFT - 10))
2486	kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
2487		   "Buffers:        %8lu kB\n",
2488		   K(val.totalram), K(val.freeram), K(val.bufferram));
2489	return 0;
2490}
2491
2492/*
2493 * kdb_per_cpu - This function implements the 'per_cpu' command.
2494 */
2495static int kdb_per_cpu(int argc, const char **argv)
2496{
2497	char fmtstr[64];
2498	int cpu, diag, nextarg = 1;
2499	unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL;
2500
2501	if (argc < 1 || argc > 3)
2502		return KDB_ARGCOUNT;
2503
2504	diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL);
2505	if (diag)
2506		return diag;
2507
2508	if (argc >= 2) {
2509		diag = kdbgetularg(argv[2], &bytesperword);
2510		if (diag)
2511			return diag;
2512	}
2513	if (!bytesperword)
2514		bytesperword = KDB_WORD_SIZE;
2515	else if (bytesperword > KDB_WORD_SIZE)
2516		return KDB_BADWIDTH;
2517	sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword));
2518	if (argc >= 3) {
2519		diag = kdbgetularg(argv[3], &whichcpu);
2520		if (diag)
2521			return diag;
2522		if (whichcpu >= nr_cpu_ids || !cpu_online(whichcpu)) {
2523			kdb_printf("cpu %ld is not online\n", whichcpu);
2524			return KDB_BADCPUNUM;
2525		}
2526	}
2527
2528	/* Most architectures use __per_cpu_offset[cpu], some use
2529	 * __per_cpu_offset(cpu), smp has no __per_cpu_offset.
2530	 */
2531#ifdef	__per_cpu_offset
2532#define KDB_PCU(cpu) __per_cpu_offset(cpu)
2533#else
2534#ifdef	CONFIG_SMP
2535#define KDB_PCU(cpu) __per_cpu_offset[cpu]
2536#else
2537#define KDB_PCU(cpu) 0
2538#endif
2539#endif
2540	for_each_online_cpu(cpu) {
2541		if (KDB_FLAG(CMD_INTERRUPT))
2542			return 0;
2543
2544		if (whichcpu != ~0UL && whichcpu != cpu)
2545			continue;
2546		addr = symaddr + KDB_PCU(cpu);
2547		diag = kdb_getword(&val, addr, bytesperword);
2548		if (diag) {
2549			kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to "
2550				   "read, diag=%d\n", cpu, addr, diag);
2551			continue;
2552		}
2553		kdb_printf("%5d ", cpu);
2554		kdb_md_line(fmtstr, addr,
2555			bytesperword == KDB_WORD_SIZE,
2556			1, bytesperword, 1, 1, 0);
2557	}
2558#undef KDB_PCU
2559	return 0;
2560}
2561
2562/*
2563 * display help for the use of cmd | grep pattern
2564 */
2565static int kdb_grep_help(int argc, const char **argv)
2566{
2567	kdb_printf("Usage of  cmd args | grep pattern:\n");
2568	kdb_printf("  Any command's output may be filtered through an ");
2569	kdb_printf("emulated 'pipe'.\n");
2570	kdb_printf("  'grep' is just a key word.\n");
2571	kdb_printf("  The pattern may include a very limited set of "
2572		   "metacharacters:\n");
2573	kdb_printf("   pattern or ^pattern or pattern$ or ^pattern$\n");
2574	kdb_printf("  And if there are spaces in the pattern, you may "
2575		   "quote it:\n");
2576	kdb_printf("   \"pat tern\" or \"^pat tern\" or \"pat tern$\""
2577		   " or \"^pat tern$\"\n");
2578	return 0;
2579}
2580
2581/**
2582 * kdb_register() - This function is used to register a kernel debugger
2583 *                  command.
2584 * @cmd: pointer to kdb command
2585 *
2586 * Note that it's the job of the caller to keep the memory for the cmd
2587 * allocated until unregister is called.
2588 */
2589int kdb_register(kdbtab_t *cmd)
2590{
2591	kdbtab_t *kp;
2592
2593	list_for_each_entry(kp, &kdb_cmds_head, list_node) {
2594		if (strcmp(kp->name, cmd->name) == 0) {
2595			kdb_printf("Duplicate kdb cmd: %s, func %p help %s\n",
2596				   cmd->name, cmd->func, cmd->help);
2597			return 1;
2598		}
2599	}
2600
2601	list_add_tail(&cmd->list_node, &kdb_cmds_head);
2602	return 0;
2603}
2604EXPORT_SYMBOL_GPL(kdb_register);
2605
2606/**
2607 * kdb_register_table() - This function is used to register a kdb command
2608 *                        table.
2609 * @kp: pointer to kdb command table
2610 * @len: length of kdb command table
2611 */
2612void kdb_register_table(kdbtab_t *kp, size_t len)
2613{
2614	while (len--) {
2615		list_add_tail(&kp->list_node, &kdb_cmds_head);
2616		kp++;
2617	}
2618}
2619
2620/**
2621 * kdb_unregister() - This function is used to unregister a kernel debugger
2622 *                    command. It is generally called when a module which
2623 *                    implements kdb command is unloaded.
2624 * @cmd: pointer to kdb command
2625 */
2626void kdb_unregister(kdbtab_t *cmd)
2627{
2628	list_del(&cmd->list_node);
2629}
2630EXPORT_SYMBOL_GPL(kdb_unregister);
2631
2632static kdbtab_t maintab[] = {
2633	{	.name = "md",
2634		.func = kdb_md,
2635		.usage = "<vaddr>",
2636		.help = "Display Memory Contents, also mdWcN, e.g. md8c1",
2637		.minlen = 1,
2638		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2639	},
2640	{	.name = "mdr",
2641		.func = kdb_md,
2642		.usage = "<vaddr> <bytes>",
2643		.help = "Display Raw Memory",
2644		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2645	},
2646	{	.name = "mdp",
2647		.func = kdb_md,
2648		.usage = "<paddr> <bytes>",
2649		.help = "Display Physical Memory",
2650		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2651	},
2652	{	.name = "mds",
2653		.func = kdb_md,
2654		.usage = "<vaddr>",
2655		.help = "Display Memory Symbolically",
2656		.flags = KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS,
2657	},
2658	{	.name = "mm",
2659		.func = kdb_mm,
2660		.usage = "<vaddr> <contents>",
2661		.help = "Modify Memory Contents",
2662		.flags = KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS,
2663	},
2664	{	.name = "go",
2665		.func = kdb_go,
2666		.usage = "[<vaddr>]",
2667		.help = "Continue Execution",
2668		.minlen = 1,
2669		.flags = KDB_ENABLE_REG_WRITE |
2670			     KDB_ENABLE_ALWAYS_SAFE_NO_ARGS,
2671	},
2672	{	.name = "rd",
2673		.func = kdb_rd,
2674		.usage = "",
2675		.help = "Display Registers",
2676		.flags = KDB_ENABLE_REG_READ,
2677	},
2678	{	.name = "rm",
2679		.func = kdb_rm,
2680		.usage = "<reg> <contents>",
2681		.help = "Modify Registers",
2682		.flags = KDB_ENABLE_REG_WRITE,
2683	},
2684	{	.name = "ef",
2685		.func = kdb_ef,
2686		.usage = "<vaddr>",
2687		.help = "Display exception frame",
2688		.flags = KDB_ENABLE_MEM_READ,
2689	},
2690	{	.name = "bt",
2691		.func = kdb_bt,
2692		.usage = "[<vaddr>]",
2693		.help = "Stack traceback",
2694		.minlen = 1,
2695		.flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS,
2696	},
2697	{	.name = "btp",
2698		.func = kdb_bt,
2699		.usage = "<pid>",
2700		.help = "Display stack for process <pid>",
2701		.flags = KDB_ENABLE_INSPECT,
2702	},
2703	{	.name = "bta",
2704		.func = kdb_bt,
2705		.usage = "[<state_chars>|A]",
2706		.help = "Backtrace all processes whose state matches",
2707		.flags = KDB_ENABLE_INSPECT,
2708	},
2709	{	.name = "btc",
2710		.func = kdb_bt,
2711		.usage = "",
2712		.help = "Backtrace current process on each cpu",
2713		.flags = KDB_ENABLE_INSPECT,
2714	},
2715	{	.name = "btt",
2716		.func = kdb_bt,
2717		.usage = "<vaddr>",
2718		.help = "Backtrace process given its struct task address",
2719		.flags = KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS,
2720	},
2721	{	.name = "env",
2722		.func = kdb_env,
2723		.usage = "",
2724		.help = "Show environment variables",
2725		.flags = KDB_ENABLE_ALWAYS_SAFE,
2726	},
2727	{	.name = "set",
2728		.func = kdb_set,
2729		.usage = "",
2730		.help = "Set environment variables",
2731		.flags = KDB_ENABLE_ALWAYS_SAFE,
2732	},
2733	{	.name = "help",
2734		.func = kdb_help,
2735		.usage = "",
2736		.help = "Display Help Message",
2737		.minlen = 1,
2738		.flags = KDB_ENABLE_ALWAYS_SAFE,
2739	},
2740	{	.name = "?",
2741		.func = kdb_help,
2742		.usage = "",
2743		.help = "Display Help Message",
2744		.flags = KDB_ENABLE_ALWAYS_SAFE,
2745	},
2746	{	.name = "cpu",
2747		.func = kdb_cpu,
2748		.usage = "<cpunum>",
2749		.help = "Switch to new cpu",
2750		.flags = KDB_ENABLE_ALWAYS_SAFE_NO_ARGS,
2751	},
2752	{	.name = "kgdb",
2753		.func = kdb_kgdb,
2754		.usage = "",
2755		.help = "Enter kgdb mode",
2756		.flags = 0,
2757	},
2758	{	.name = "ps",
2759		.func = kdb_ps,
2760		.usage = "[<state_chars>|A]",
2761		.help = "Display active task list",
2762		.flags = KDB_ENABLE_INSPECT,
2763	},
2764	{	.name = "pid",
2765		.func = kdb_pid,
2766		.usage = "<pidnum>",
2767		.help = "Switch to another task",
2768		.flags = KDB_ENABLE_INSPECT,
2769	},
2770	{	.name = "reboot",
2771		.func = kdb_reboot,
2772		.usage = "",
2773		.help = "Reboot the machine immediately",
2774		.flags = KDB_ENABLE_REBOOT,
2775	},
2776#if defined(CONFIG_MODULES)
2777	{	.name = "lsmod",
2778		.func = kdb_lsmod,
2779		.usage = "",
2780		.help = "List loaded kernel modules",
2781		.flags = KDB_ENABLE_INSPECT,
2782	},
2783#endif
2784#if defined(CONFIG_MAGIC_SYSRQ)
2785	{	.name = "sr",
2786		.func = kdb_sr,
2787		.usage = "<key>",
2788		.help = "Magic SysRq key",
2789		.flags = KDB_ENABLE_ALWAYS_SAFE,
2790	},
2791#endif
2792#if defined(CONFIG_PRINTK)
2793	{	.name = "dmesg",
2794		.func = kdb_dmesg,
2795		.usage = "[lines]",
2796		.help = "Display syslog buffer",
2797		.flags = KDB_ENABLE_ALWAYS_SAFE,
2798	},
2799#endif
2800	{	.name = "defcmd",
2801		.func = kdb_defcmd,
2802		.usage = "name \"usage\" \"help\"",
2803		.help = "Define a set of commands, down to endefcmd",
2804		/*
2805		 * Macros are always safe because when executed each
2806		 * internal command re-enters kdb_parse() and is safety
2807		 * checked individually.
2808		 */
2809		.flags = KDB_ENABLE_ALWAYS_SAFE,
2810	},
2811	{	.name = "kill",
2812		.func = kdb_kill,
2813		.usage = "<-signal> <pid>",
2814		.help = "Send a signal to a process",
2815		.flags = KDB_ENABLE_SIGNAL,
2816	},
2817	{	.name = "summary",
2818		.func = kdb_summary,
2819		.usage = "",
2820		.help = "Summarize the system",
2821		.minlen = 4,
2822		.flags = KDB_ENABLE_ALWAYS_SAFE,
2823	},
2824	{	.name = "per_cpu",
2825		.func = kdb_per_cpu,
2826		.usage = "<sym> [<bytes>] [<cpu>]",
2827		.help = "Display per_cpu variables",
2828		.minlen = 3,
2829		.flags = KDB_ENABLE_MEM_READ,
2830	},
2831	{	.name = "grephelp",
2832		.func = kdb_grep_help,
2833		.usage = "",
2834		.help = "Display help on | grep",
2835		.flags = KDB_ENABLE_ALWAYS_SAFE,
2836	},
2837};
2838
2839static kdbtab_t nmicmd = {
2840	.name = "disable_nmi",
2841	.func = kdb_disable_nmi,
2842	.usage = "",
2843	.help = "Disable NMI entry to KDB",
2844	.flags = KDB_ENABLE_ALWAYS_SAFE,
2845};
2846
2847/* Initialize the kdb command table. */
2848static void __init kdb_inittab(void)
2849{
2850	kdb_register_table(maintab, ARRAY_SIZE(maintab));
2851	if (arch_kgdb_ops.enable_nmi)
2852		kdb_register_table(&nmicmd, 1);
2853}
2854
2855/* Execute any commands defined in kdb_cmds.  */
2856static void __init kdb_cmd_init(void)
2857{
2858	int i, diag;
2859	for (i = 0; kdb_cmds[i]; ++i) {
2860		diag = kdb_parse(kdb_cmds[i]);
2861		if (diag)
2862			kdb_printf("kdb command %s failed, kdb diag %d\n",
2863				kdb_cmds[i], diag);
2864	}
2865	if (defcmd_in_progress) {
2866		kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n");
2867		kdb_parse("endefcmd");
2868	}
2869}
2870
2871/* Initialize kdb_printf, breakpoint tables and kdb state */
2872void __init kdb_init(int lvl)
2873{
2874	static int kdb_init_lvl = KDB_NOT_INITIALIZED;
2875	int i;
2876
2877	if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl)
2878		return;
2879	for (i = kdb_init_lvl; i < lvl; i++) {
2880		switch (i) {
2881		case KDB_NOT_INITIALIZED:
2882			kdb_inittab();		/* Initialize Command Table */
2883			kdb_initbptab();	/* Initialize Breakpoints */
2884			break;
2885		case KDB_INIT_EARLY:
2886			kdb_cmd_init();		/* Build kdb_cmds tables */
2887			break;
2888		}
2889	}
2890	kdb_init_lvl = lvl;
2891}