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