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v4.10.11
   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/sysrq.h>
  22#include <linux/smp.h>
  23#include <linux/utsname.h>
  24#include <linux/vmalloc.h>
  25#include <linux/atomic.h>
  26#include <linux/module.h>
  27#include <linux/moduleparam.h>
  28#include <linux/mm.h>
  29#include <linux/init.h>
  30#include <linux/kallsyms.h>
  31#include <linux/kgdb.h>
  32#include <linux/kdb.h>
  33#include <linux/notifier.h>
  34#include <linux/interrupt.h>
  35#include <linux/delay.h>
  36#include <linux/nmi.h>
  37#include <linux/time.h>
  38#include <linux/ptrace.h>
  39#include <linux/sysctl.h>
  40#include <linux/cpu.h>
  41#include <linux/kdebug.h>
  42#include <linux/proc_fs.h>
  43#include <linux/uaccess.h>
  44#include <linux/slab.h>
  45#include "kdb_private.h"
  46
  47#undef	MODULE_PARAM_PREFIX
  48#define	MODULE_PARAM_PREFIX "kdb."
  49
  50static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;
  51module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);
  52
  53char kdb_grep_string[KDB_GREP_STRLEN];
  54int kdb_grepping_flag;
  55EXPORT_SYMBOL(kdb_grepping_flag);
  56int kdb_grep_leading;
  57int kdb_grep_trailing;
  58
  59/*
  60 * Kernel debugger state flags
  61 */
  62int kdb_flags;
  63
  64/*
  65 * kdb_lock protects updates to kdb_initial_cpu.  Used to
  66 * single thread processors through the kernel debugger.
  67 */
  68int kdb_initial_cpu = -1;	/* cpu number that owns kdb */
  69int kdb_nextline = 1;
  70int kdb_state;			/* General KDB state */
  71
  72struct task_struct *kdb_current_task;
  73EXPORT_SYMBOL(kdb_current_task);
  74struct pt_regs *kdb_current_regs;
  75
  76const char *kdb_diemsg;
  77static int kdb_go_count;
  78#ifdef CONFIG_KDB_CONTINUE_CATASTROPHIC
  79static unsigned int kdb_continue_catastrophic =
  80	CONFIG_KDB_CONTINUE_CATASTROPHIC;
  81#else
  82static unsigned int kdb_continue_catastrophic;
  83#endif
  84
  85/* kdb_commands describes the available commands. */
  86static kdbtab_t *kdb_commands;
  87#define KDB_BASE_CMD_MAX 50
  88static int kdb_max_commands = KDB_BASE_CMD_MAX;
  89static kdbtab_t kdb_base_commands[KDB_BASE_CMD_MAX];
  90#define for_each_kdbcmd(cmd, num)					\
  91	for ((cmd) = kdb_base_commands, (num) = 0;			\
  92	     num < kdb_max_commands;					\
  93	     num++, num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++)
  94
  95typedef struct _kdbmsg {
  96	int	km_diag;	/* kdb diagnostic */
  97	char	*km_msg;	/* Corresponding message text */
  98} kdbmsg_t;
  99
 100#define KDBMSG(msgnum, text) \
 101	{ KDB_##msgnum, text }
 102
 103static kdbmsg_t kdbmsgs[] = {
 104	KDBMSG(NOTFOUND, "Command Not Found"),
 105	KDBMSG(ARGCOUNT, "Improper argument count, see usage."),
 106	KDBMSG(BADWIDTH, "Illegal value for BYTESPERWORD use 1, 2, 4 or 8, "
 107	       "8 is only allowed on 64 bit systems"),
 108	KDBMSG(BADRADIX, "Illegal value for RADIX use 8, 10 or 16"),
 109	KDBMSG(NOTENV, "Cannot find environment variable"),
 110	KDBMSG(NOENVVALUE, "Environment variable should have value"),
 111	KDBMSG(NOTIMP, "Command not implemented"),
 112	KDBMSG(ENVFULL, "Environment full"),
 113	KDBMSG(ENVBUFFULL, "Environment buffer full"),
 114	KDBMSG(TOOMANYBPT, "Too many breakpoints defined"),
 115#ifdef CONFIG_CPU_XSCALE
 116	KDBMSG(TOOMANYDBREGS, "More breakpoints than ibcr registers defined"),
 117#else
 118	KDBMSG(TOOMANYDBREGS, "More breakpoints than db registers defined"),
 119#endif
 120	KDBMSG(DUPBPT, "Duplicate breakpoint address"),
 121	KDBMSG(BPTNOTFOUND, "Breakpoint not found"),
 122	KDBMSG(BADMODE, "Invalid IDMODE"),
 123	KDBMSG(BADINT, "Illegal numeric value"),
 124	KDBMSG(INVADDRFMT, "Invalid symbolic address format"),
 125	KDBMSG(BADREG, "Invalid register name"),
 126	KDBMSG(BADCPUNUM, "Invalid cpu number"),
 127	KDBMSG(BADLENGTH, "Invalid length field"),
 128	KDBMSG(NOBP, "No Breakpoint exists"),
 129	KDBMSG(BADADDR, "Invalid address"),
 130	KDBMSG(NOPERM, "Permission denied"),
 131};
 132#undef KDBMSG
 133
 134static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
 135
 136
 137/*
 138 * Initial environment.   This is all kept static and local to
 139 * this file.   We don't want to rely on the memory allocation
 140 * mechanisms in the kernel, so we use a very limited allocate-only
 141 * heap for new and altered environment variables.  The entire
 142 * environment is limited to a fixed number of entries (add more
 143 * to __env[] if required) and a fixed amount of heap (add more to
 144 * KDB_ENVBUFSIZE if required).
 145 */
 146
 147static char *__env[] = {
 148#if defined(CONFIG_SMP)
 149 "PROMPT=[%d]kdb> ",
 150#else
 151 "PROMPT=kdb> ",
 152#endif
 153 "MOREPROMPT=more> ",
 154 "RADIX=16",
 155 "MDCOUNT=8",			/* lines of md output */
 156 KDB_PLATFORM_ENV,
 157 "DTABCOUNT=30",
 158 "NOSECT=1",
 159 (char *)0,
 160 (char *)0,
 161 (char *)0,
 162 (char *)0,
 163 (char *)0,
 164 (char *)0,
 165 (char *)0,
 166 (char *)0,
 167 (char *)0,
 168 (char *)0,
 169 (char *)0,
 170 (char *)0,
 171 (char *)0,
 172 (char *)0,
 173 (char *)0,
 174 (char *)0,
 175 (char *)0,
 176 (char *)0,
 177 (char *)0,
 178 (char *)0,
 179 (char *)0,
 180 (char *)0,
 181 (char *)0,
 182 (char *)0,
 183};
 184
 185static const int __nenv = ARRAY_SIZE(__env);
 186
 187struct task_struct *kdb_curr_task(int cpu)
 188{
 189	struct task_struct *p = curr_task(cpu);
 190#ifdef	_TIF_MCA_INIT
 191	if ((task_thread_info(p)->flags & _TIF_MCA_INIT) && KDB_TSK(cpu))
 192		p = krp->p;
 193#endif
 194	return p;
 195}
 196
 197/*
 198 * Check whether the flags of the current command and the permissions
 199 * of the kdb console has allow a command to be run.
 200 */
 201static inline bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
 202				   bool no_args)
 203{
 204	/* permissions comes from userspace so needs massaging slightly */
 205	permissions &= KDB_ENABLE_MASK;
 206	permissions |= KDB_ENABLE_ALWAYS_SAFE;
 207
 208	/* some commands change group when launched with no arguments */
 209	if (no_args)
 210		permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
 211
 212	flags |= KDB_ENABLE_ALL;
 213
 214	return permissions & flags;
 215}
 216
 217/*
 218 * kdbgetenv - This function will return the character string value of
 219 *	an environment variable.
 220 * Parameters:
 221 *	match	A character string representing an environment variable.
 222 * Returns:
 223 *	NULL	No environment variable matches 'match'
 224 *	char*	Pointer to string value of environment variable.
 225 */
 226char *kdbgetenv(const char *match)
 227{
 228	char **ep = __env;
 229	int matchlen = strlen(match);
 230	int i;
 231
 232	for (i = 0; i < __nenv; i++) {
 233		char *e = *ep++;
 234
 235		if (!e)
 236			continue;
 237
 238		if ((strncmp(match, e, matchlen) == 0)
 239		 && ((e[matchlen] == '\0')
 240		   || (e[matchlen] == '='))) {
 241			char *cp = strchr(e, '=');
 242			return cp ? ++cp : "";
 243		}
 244	}
 245	return NULL;
 246}
 247
 248/*
 249 * kdballocenv - This function is used to allocate bytes for
 250 *	environment entries.
 251 * Parameters:
 252 *	match	A character string representing a numeric value
 253 * Outputs:
 254 *	*value  the unsigned long representation of the env variable 'match'
 255 * Returns:
 256 *	Zero on success, a kdb diagnostic on failure.
 257 * Remarks:
 258 *	We use a static environment buffer (envbuffer) to hold the values
 259 *	of dynamically generated environment variables (see kdb_set).  Buffer
 260 *	space once allocated is never free'd, so over time, the amount of space
 261 *	(currently 512 bytes) will be exhausted if env variables are changed
 262 *	frequently.
 263 */
 264static char *kdballocenv(size_t bytes)
 265{
 266#define	KDB_ENVBUFSIZE	512
 267	static char envbuffer[KDB_ENVBUFSIZE];
 268	static int envbufsize;
 269	char *ep = NULL;
 270
 271	if ((KDB_ENVBUFSIZE - envbufsize) >= bytes) {
 272		ep = &envbuffer[envbufsize];
 273		envbufsize += bytes;
 274	}
 275	return ep;
 276}
 277
 278/*
 279 * kdbgetulenv - This function will return the value of an unsigned
 280 *	long-valued environment variable.
 281 * Parameters:
 282 *	match	A character string representing a numeric value
 283 * Outputs:
 284 *	*value  the unsigned long represntation of the env variable 'match'
 285 * Returns:
 286 *	Zero on success, a kdb diagnostic on failure.
 287 */
 288static int kdbgetulenv(const char *match, unsigned long *value)
 289{
 290	char *ep;
 291
 292	ep = kdbgetenv(match);
 293	if (!ep)
 294		return KDB_NOTENV;
 295	if (strlen(ep) == 0)
 296		return KDB_NOENVVALUE;
 297
 298	*value = simple_strtoul(ep, NULL, 0);
 299
 300	return 0;
 301}
 302
 303/*
 304 * kdbgetintenv - This function will return the value of an
 305 *	integer-valued environment variable.
 306 * Parameters:
 307 *	match	A character string representing an integer-valued env variable
 308 * Outputs:
 309 *	*value  the integer representation of the environment variable 'match'
 310 * Returns:
 311 *	Zero on success, a kdb diagnostic on failure.
 312 */
 313int kdbgetintenv(const char *match, int *value)
 314{
 315	unsigned long val;
 316	int diag;
 317
 318	diag = kdbgetulenv(match, &val);
 319	if (!diag)
 320		*value = (int) val;
 321	return diag;
 322}
 323
 324/*
 325 * kdbgetularg - This function will convert a numeric string into an
 326 *	unsigned long value.
 327 * Parameters:
 328 *	arg	A character string representing a numeric value
 329 * Outputs:
 330 *	*value  the unsigned long represntation of arg.
 331 * Returns:
 332 *	Zero on success, a kdb diagnostic on failure.
 333 */
 334int kdbgetularg(const char *arg, unsigned long *value)
 335{
 336	char *endp;
 337	unsigned long val;
 338
 339	val = simple_strtoul(arg, &endp, 0);
 340
 341	if (endp == arg) {
 342		/*
 343		 * Also try base 16, for us folks too lazy to type the
 344		 * leading 0x...
 345		 */
 346		val = simple_strtoul(arg, &endp, 16);
 347		if (endp == arg)
 348			return KDB_BADINT;
 349	}
 350
 351	*value = val;
 352
 353	return 0;
 354}
 355
 356int kdbgetu64arg(const char *arg, u64 *value)
 357{
 358	char *endp;
 359	u64 val;
 360
 361	val = simple_strtoull(arg, &endp, 0);
 362
 363	if (endp == arg) {
 364
 365		val = simple_strtoull(arg, &endp, 16);
 366		if (endp == arg)
 367			return KDB_BADINT;
 368	}
 369
 370	*value = val;
 371
 372	return 0;
 373}
 374
 375/*
 376 * kdb_set - This function implements the 'set' command.  Alter an
 377 *	existing environment variable or create a new one.
 378 */
 379int kdb_set(int argc, const char **argv)
 380{
 381	int i;
 382	char *ep;
 383	size_t varlen, vallen;
 384
 385	/*
 386	 * we can be invoked two ways:
 387	 *   set var=value    argv[1]="var", argv[2]="value"
 388	 *   set var = value  argv[1]="var", argv[2]="=", argv[3]="value"
 389	 * - if the latter, shift 'em down.
 390	 */
 391	if (argc == 3) {
 392		argv[2] = argv[3];
 393		argc--;
 394	}
 395
 396	if (argc != 2)
 397		return KDB_ARGCOUNT;
 398
 399	/*
 400	 * Check for internal variables
 401	 */
 402	if (strcmp(argv[1], "KDBDEBUG") == 0) {
 403		unsigned int debugflags;
 404		char *cp;
 405
 406		debugflags = simple_strtoul(argv[2], &cp, 0);
 407		if (cp == argv[2] || debugflags & ~KDB_DEBUG_FLAG_MASK) {
 408			kdb_printf("kdb: illegal debug flags '%s'\n",
 409				    argv[2]);
 410			return 0;
 411		}
 412		kdb_flags = (kdb_flags &
 413			     ~(KDB_DEBUG_FLAG_MASK << KDB_DEBUG_FLAG_SHIFT))
 414			| (debugflags << KDB_DEBUG_FLAG_SHIFT);
 415
 416		return 0;
 417	}
 418
 419	/*
 420	 * Tokenizer squashed the '=' sign.  argv[1] is variable
 421	 * name, argv[2] = value.
 422	 */
 423	varlen = strlen(argv[1]);
 424	vallen = strlen(argv[2]);
 425	ep = kdballocenv(varlen + vallen + 2);
 426	if (ep == (char *)0)
 427		return KDB_ENVBUFFULL;
 428
 429	sprintf(ep, "%s=%s", argv[1], argv[2]);
 430
 431	ep[varlen+vallen+1] = '\0';
 432
 433	for (i = 0; i < __nenv; i++) {
 434		if (__env[i]
 435		 && ((strncmp(__env[i], argv[1], varlen) == 0)
 436		   && ((__env[i][varlen] == '\0')
 437		    || (__env[i][varlen] == '=')))) {
 438			__env[i] = ep;
 439			return 0;
 440		}
 441	}
 442
 443	/*
 444	 * Wasn't existing variable.  Fit into slot.
 445	 */
 446	for (i = 0; i < __nenv-1; i++) {
 447		if (__env[i] == (char *)0) {
 448			__env[i] = ep;
 449			return 0;
 450		}
 451	}
 452
 453	return KDB_ENVFULL;
 454}
 455
 456static int kdb_check_regs(void)
 457{
 458	if (!kdb_current_regs) {
 459		kdb_printf("No current kdb registers."
 460			   "  You may need to select another task\n");
 461		return KDB_BADREG;
 462	}
 463	return 0;
 464}
 465
 466/*
 467 * kdbgetaddrarg - This function is responsible for parsing an
 468 *	address-expression and returning the value of the expression,
 469 *	symbol name, and offset to the caller.
 470 *
 471 *	The argument may consist of a numeric value (decimal or
 472 *	hexidecimal), a symbol name, a register name (preceded by the
 473 *	percent sign), an environment variable with a numeric value
 474 *	(preceded by a dollar sign) or a simple arithmetic expression
 475 *	consisting of a symbol name, +/-, and a numeric constant value
 476 *	(offset).
 477 * Parameters:
 478 *	argc	- count of arguments in argv
 479 *	argv	- argument vector
 480 *	*nextarg - index to next unparsed argument in argv[]
 481 *	regs	- Register state at time of KDB entry
 482 * Outputs:
 483 *	*value	- receives the value of the address-expression
 484 *	*offset - receives the offset specified, if any
 485 *	*name   - receives the symbol name, if any
 486 *	*nextarg - index to next unparsed argument in argv[]
 487 * Returns:
 488 *	zero is returned on success, a kdb diagnostic code is
 489 *      returned on error.
 490 */
 491int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
 492		  unsigned long *value,  long *offset,
 493		  char **name)
 494{
 495	unsigned long addr;
 496	unsigned long off = 0;
 497	int positive;
 498	int diag;
 499	int found = 0;
 500	char *symname;
 501	char symbol = '\0';
 502	char *cp;
 503	kdb_symtab_t symtab;
 504
 505	/*
 506	 * If the enable flags prohibit both arbitrary memory access
 507	 * and flow control then there are no reasonable grounds to
 508	 * provide symbol lookup.
 509	 */
 510	if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
 511			     kdb_cmd_enabled, false))
 512		return KDB_NOPERM;
 513
 514	/*
 515	 * Process arguments which follow the following syntax:
 516	 *
 517	 *  symbol | numeric-address [+/- numeric-offset]
 518	 *  %register
 519	 *  $environment-variable
 520	 */
 521
 522	if (*nextarg > argc)
 523		return KDB_ARGCOUNT;
 524
 525	symname = (char *)argv[*nextarg];
 526
 527	/*
 528	 * If there is no whitespace between the symbol
 529	 * or address and the '+' or '-' symbols, we
 530	 * remember the character and replace it with a
 531	 * null so the symbol/value can be properly parsed
 532	 */
 533	cp = strpbrk(symname, "+-");
 534	if (cp != NULL) {
 535		symbol = *cp;
 536		*cp++ = '\0';
 537	}
 538
 539	if (symname[0] == '$') {
 540		diag = kdbgetulenv(&symname[1], &addr);
 541		if (diag)
 542			return diag;
 543	} else if (symname[0] == '%') {
 544		diag = kdb_check_regs();
 545		if (diag)
 546			return diag;
 547		/* Implement register values with % at a later time as it is
 548		 * arch optional.
 549		 */
 550		return KDB_NOTIMP;
 551	} else {
 552		found = kdbgetsymval(symname, &symtab);
 553		if (found) {
 554			addr = symtab.sym_start;
 555		} else {
 556			diag = kdbgetularg(argv[*nextarg], &addr);
 557			if (diag)
 558				return diag;
 559		}
 560	}
 561
 562	if (!found)
 563		found = kdbnearsym(addr, &symtab);
 564
 565	(*nextarg)++;
 566
 567	if (name)
 568		*name = symname;
 569	if (value)
 570		*value = addr;
 571	if (offset && name && *name)
 572		*offset = addr - symtab.sym_start;
 573
 574	if ((*nextarg > argc)
 575	 && (symbol == '\0'))
 576		return 0;
 577
 578	/*
 579	 * check for +/- and offset
 580	 */
 581
 582	if (symbol == '\0') {
 583		if ((argv[*nextarg][0] != '+')
 584		 && (argv[*nextarg][0] != '-')) {
 585			/*
 586			 * Not our argument.  Return.
 587			 */
 588			return 0;
 589		} else {
 590			positive = (argv[*nextarg][0] == '+');
 591			(*nextarg)++;
 592		}
 593	} else
 594		positive = (symbol == '+');
 595
 596	/*
 597	 * Now there must be an offset!
 598	 */
 599	if ((*nextarg > argc)
 600	 && (symbol == '\0')) {
 601		return KDB_INVADDRFMT;
 602	}
 603
 604	if (!symbol) {
 605		cp = (char *)argv[*nextarg];
 606		(*nextarg)++;
 607	}
 608
 609	diag = kdbgetularg(cp, &off);
 610	if (diag)
 611		return diag;
 612
 613	if (!positive)
 614		off = -off;
 615
 616	if (offset)
 617		*offset += off;
 618
 619	if (value)
 620		*value += off;
 621
 622	return 0;
 623}
 624
 625static void kdb_cmderror(int diag)
 626{
 627	int i;
 628
 629	if (diag >= 0) {
 630		kdb_printf("no error detected (diagnostic is %d)\n", diag);
 631		return;
 632	}
 633
 634	for (i = 0; i < __nkdb_err; i++) {
 635		if (kdbmsgs[i].km_diag == diag) {
 636			kdb_printf("diag: %d: %s\n", diag, kdbmsgs[i].km_msg);
 637			return;
 638		}
 639	}
 640
 641	kdb_printf("Unknown diag %d\n", -diag);
 642}
 643
 644/*
 645 * kdb_defcmd, kdb_defcmd2 - This function implements the 'defcmd'
 646 *	command which defines one command as a set of other commands,
 647 *	terminated by endefcmd.  kdb_defcmd processes the initial
 648 *	'defcmd' command, kdb_defcmd2 is invoked from kdb_parse for
 649 *	the following commands until 'endefcmd'.
 650 * Inputs:
 651 *	argc	argument count
 652 *	argv	argument vector
 653 * Returns:
 654 *	zero for success, a kdb diagnostic if error
 655 */
 656struct defcmd_set {
 657	int count;
 658	int usable;
 659	char *name;
 660	char *usage;
 661	char *help;
 662	char **command;
 663};
 664static struct defcmd_set *defcmd_set;
 665static int defcmd_set_count;
 666static int defcmd_in_progress;
 667
 668/* Forward references */
 669static int kdb_exec_defcmd(int argc, const char **argv);
 670
 671static int kdb_defcmd2(const char *cmdstr, const char *argv0)
 672{
 673	struct defcmd_set *s = defcmd_set + defcmd_set_count - 1;
 674	char **save_command = s->command;
 675	if (strcmp(argv0, "endefcmd") == 0) {
 676		defcmd_in_progress = 0;
 677		if (!s->count)
 678			s->usable = 0;
 679		if (s->usable)
 680			/* macros are always safe because when executed each
 681			 * internal command re-enters kdb_parse() and is
 682			 * safety checked individually.
 683			 */
 684			kdb_register_flags(s->name, kdb_exec_defcmd, s->usage,
 685					   s->help, 0,
 686					   KDB_ENABLE_ALWAYS_SAFE);
 687		return 0;
 688	}
 689	if (!s->usable)
 690		return KDB_NOTIMP;
 691	s->command = kzalloc((s->count + 1) * sizeof(*(s->command)), GFP_KDB);
 692	if (!s->command) {
 693		kdb_printf("Could not allocate new kdb_defcmd table for %s\n",
 694			   cmdstr);
 695		s->usable = 0;
 696		return KDB_NOTIMP;
 697	}
 698	memcpy(s->command, save_command, s->count * sizeof(*(s->command)));
 699	s->command[s->count++] = kdb_strdup(cmdstr, GFP_KDB);
 700	kfree(save_command);
 701	return 0;
 702}
 703
 704static int kdb_defcmd(int argc, const char **argv)
 705{
 706	struct defcmd_set *save_defcmd_set = defcmd_set, *s;
 707	if (defcmd_in_progress) {
 708		kdb_printf("kdb: nested defcmd detected, assuming missing "
 709			   "endefcmd\n");
 710		kdb_defcmd2("endefcmd", "endefcmd");
 711	}
 712	if (argc == 0) {
 713		int i;
 714		for (s = defcmd_set; s < defcmd_set + defcmd_set_count; ++s) {
 715			kdb_printf("defcmd %s \"%s\" \"%s\"\n", s->name,
 716				   s->usage, s->help);
 717			for (i = 0; i < s->count; ++i)
 718				kdb_printf("%s", s->command[i]);
 719			kdb_printf("endefcmd\n");
 720		}
 721		return 0;
 722	}
 723	if (argc != 3)
 724		return KDB_ARGCOUNT;
 725	if (in_dbg_master()) {
 726		kdb_printf("Command only available during kdb_init()\n");
 727		return KDB_NOTIMP;
 728	}
 729	defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
 730			     GFP_KDB);
 731	if (!defcmd_set)
 732		goto fail_defcmd;
 733	memcpy(defcmd_set, save_defcmd_set,
 734	       defcmd_set_count * sizeof(*defcmd_set));
 735	s = defcmd_set + defcmd_set_count;
 736	memset(s, 0, sizeof(*s));
 737	s->usable = 1;
 738	s->name = kdb_strdup(argv[1], GFP_KDB);
 739	if (!s->name)
 740		goto fail_name;
 741	s->usage = kdb_strdup(argv[2], GFP_KDB);
 742	if (!s->usage)
 743		goto fail_usage;
 744	s->help = kdb_strdup(argv[3], GFP_KDB);
 745	if (!s->help)
 746		goto fail_help;
 747	if (s->usage[0] == '"') {
 748		strcpy(s->usage, argv[2]+1);
 749		s->usage[strlen(s->usage)-1] = '\0';
 750	}
 751	if (s->help[0] == '"') {
 752		strcpy(s->help, argv[3]+1);
 753		s->help[strlen(s->help)-1] = '\0';
 754	}
 755	++defcmd_set_count;
 756	defcmd_in_progress = 1;
 757	kfree(save_defcmd_set);
 758	return 0;
 759fail_help:
 760	kfree(s->usage);
 761fail_usage:
 762	kfree(s->name);
 763fail_name:
 764	kfree(defcmd_set);
 765fail_defcmd:
 766	kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]);
 767	defcmd_set = save_defcmd_set;
 768	return KDB_NOTIMP;
 769}
 770
 771/*
 772 * kdb_exec_defcmd - Execute the set of commands associated with this
 773 *	defcmd name.
 774 * Inputs:
 775 *	argc	argument count
 776 *	argv	argument vector
 777 * Returns:
 778 *	zero for success, a kdb diagnostic if error
 779 */
 780static int kdb_exec_defcmd(int argc, const char **argv)
 781{
 782	int i, ret;
 783	struct defcmd_set *s;
 784	if (argc != 0)
 785		return KDB_ARGCOUNT;
 786	for (s = defcmd_set, i = 0; i < defcmd_set_count; ++i, ++s) {
 787		if (strcmp(s->name, argv[0]) == 0)
 788			break;
 789	}
 790	if (i == defcmd_set_count) {
 791		kdb_printf("kdb_exec_defcmd: could not find commands for %s\n",
 792			   argv[0]);
 793		return KDB_NOTIMP;
 794	}
 795	for (i = 0; i < s->count; ++i) {
 796		/* Recursive use of kdb_parse, do not use argv after
 797		 * this point */
 798		argv = NULL;
 799		kdb_printf("[%s]kdb> %s\n", s->name, s->command[i]);
 800		ret = kdb_parse(s->command[i]);
 801		if (ret)
 802			return ret;
 803	}
 804	return 0;
 805}
 806
 807/* Command history */
 808#define KDB_CMD_HISTORY_COUNT	32
 809#define CMD_BUFLEN		200	/* kdb_printf: max printline
 810					 * size == 256 */
 811static unsigned int cmd_head, cmd_tail;
 812static unsigned int cmdptr;
 813static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN];
 814static char cmd_cur[CMD_BUFLEN];
 815
 816/*
 817 * The "str" argument may point to something like  | grep xyz
 818 */
 819static void parse_grep(const char *str)
 820{
 821	int	len;
 822	char	*cp = (char *)str, *cp2;
 823
 824	/* sanity check: we should have been called with the \ first */
 825	if (*cp != '|')
 826		return;
 827	cp++;
 828	while (isspace(*cp))
 829		cp++;
 830	if (strncmp(cp, "grep ", 5)) {
 831		kdb_printf("invalid 'pipe', see grephelp\n");
 832		return;
 833	}
 834	cp += 5;
 835	while (isspace(*cp))
 836		cp++;
 837	cp2 = strchr(cp, '\n');
 838	if (cp2)
 839		*cp2 = '\0'; /* remove the trailing newline */
 840	len = strlen(cp);
 841	if (len == 0) {
 842		kdb_printf("invalid 'pipe', see grephelp\n");
 843		return;
 844	}
 845	/* now cp points to a nonzero length search string */
 846	if (*cp == '"') {
 847		/* allow it be "x y z" by removing the "'s - there must
 848		   be two of them */
 849		cp++;
 850		cp2 = strchr(cp, '"');
 851		if (!cp2) {
 852			kdb_printf("invalid quoted string, see grephelp\n");
 853			return;
 854		}
 855		*cp2 = '\0'; /* end the string where the 2nd " was */
 856	}
 857	kdb_grep_leading = 0;
 858	if (*cp == '^') {
 859		kdb_grep_leading = 1;
 860		cp++;
 861	}
 862	len = strlen(cp);
 863	kdb_grep_trailing = 0;
 864	if (*(cp+len-1) == '$') {
 865		kdb_grep_trailing = 1;
 866		*(cp+len-1) = '\0';
 867	}
 868	len = strlen(cp);
 869	if (!len)
 870		return;
 871	if (len >= KDB_GREP_STRLEN) {
 872		kdb_printf("search string too long\n");
 873		return;
 874	}
 875	strcpy(kdb_grep_string, cp);
 876	kdb_grepping_flag++;
 877	return;
 878}
 879
 880/*
 881 * kdb_parse - Parse the command line, search the command table for a
 882 *	matching command and invoke the command function.  This
 883 *	function may be called recursively, if it is, the second call
 884 *	will overwrite argv and cbuf.  It is the caller's
 885 *	responsibility to save their argv if they recursively call
 886 *	kdb_parse().
 887 * Parameters:
 888 *      cmdstr	The input command line to be parsed.
 889 *	regs	The registers at the time kdb was entered.
 890 * Returns:
 891 *	Zero for success, a kdb diagnostic if failure.
 892 * Remarks:
 893 *	Limited to 20 tokens.
 894 *
 895 *	Real rudimentary tokenization. Basically only whitespace
 896 *	is considered a token delimeter (but special consideration
 897 *	is taken of the '=' sign as used by the 'set' command).
 898 *
 899 *	The algorithm used to tokenize the input string relies on
 900 *	there being at least one whitespace (or otherwise useless)
 901 *	character between tokens as the character immediately following
 902 *	the token is altered in-place to a null-byte to terminate the
 903 *	token string.
 904 */
 905
 906#define MAXARGC	20
 907
 908int kdb_parse(const char *cmdstr)
 909{
 910	static char *argv[MAXARGC];
 911	static int argc;
 912	static char cbuf[CMD_BUFLEN+2];
 913	char *cp;
 914	char *cpp, quoted;
 915	kdbtab_t *tp;
 916	int i, escaped, ignore_errors = 0, check_grep = 0;
 917
 918	/*
 919	 * First tokenize the command string.
 920	 */
 921	cp = (char *)cmdstr;
 922
 923	if (KDB_FLAG(CMD_INTERRUPT)) {
 924		/* Previous command was interrupted, newline must not
 925		 * repeat the command */
 926		KDB_FLAG_CLEAR(CMD_INTERRUPT);
 927		KDB_STATE_SET(PAGER);
 928		argc = 0;	/* no repeat */
 929	}
 930
 931	if (*cp != '\n' && *cp != '\0') {
 932		argc = 0;
 933		cpp = cbuf;
 934		while (*cp) {
 935			/* skip whitespace */
 936			while (isspace(*cp))
 937				cp++;
 938			if ((*cp == '\0') || (*cp == '\n') ||
 939			    (*cp == '#' && !defcmd_in_progress))
 940				break;
 941			/* special case: check for | grep pattern */
 942			if (*cp == '|') {
 943				check_grep++;
 944				break;
 945			}
 946			if (cpp >= cbuf + CMD_BUFLEN) {
 947				kdb_printf("kdb_parse: command buffer "
 948					   "overflow, command ignored\n%s\n",
 949					   cmdstr);
 950				return KDB_NOTFOUND;
 951			}
 952			if (argc >= MAXARGC - 1) {
 953				kdb_printf("kdb_parse: too many arguments, "
 954					   "command ignored\n%s\n", cmdstr);
 955				return KDB_NOTFOUND;
 956			}
 957			argv[argc++] = cpp;
 958			escaped = 0;
 959			quoted = '\0';
 960			/* Copy to next unquoted and unescaped
 961			 * whitespace or '=' */
 962			while (*cp && *cp != '\n' &&
 963			       (escaped || quoted || !isspace(*cp))) {
 964				if (cpp >= cbuf + CMD_BUFLEN)
 965					break;
 966				if (escaped) {
 967					escaped = 0;
 968					*cpp++ = *cp++;
 969					continue;
 970				}
 971				if (*cp == '\\') {
 972					escaped = 1;
 973					++cp;
 974					continue;
 975				}
 976				if (*cp == quoted)
 977					quoted = '\0';
 978				else if (*cp == '\'' || *cp == '"')
 979					quoted = *cp;
 980				*cpp = *cp++;
 981				if (*cpp == '=' && !quoted)
 982					break;
 983				++cpp;
 984			}
 985			*cpp++ = '\0';	/* Squash a ws or '=' character */
 986		}
 987	}
 988	if (!argc)
 989		return 0;
 990	if (check_grep)
 991		parse_grep(cp);
 992	if (defcmd_in_progress) {
 993		int result = kdb_defcmd2(cmdstr, argv[0]);
 994		if (!defcmd_in_progress) {
 995			argc = 0;	/* avoid repeat on endefcmd */
 996			*(argv[0]) = '\0';
 997		}
 998		return result;
 999	}
1000	if (argv[0][0] == '-' && argv[0][1] &&
1001	    (argv[0][1] < '0' || argv[0][1] > '9')) {
1002		ignore_errors = 1;
1003		++argv[0];
1004	}
1005
1006	for_each_kdbcmd(tp, i) {
1007		if (tp->cmd_name) {
1008			/*
1009			 * If this command is allowed to be abbreviated,
1010			 * check to see if this is it.
1011			 */
1012
1013			if (tp->cmd_minlen
1014			 && (strlen(argv[0]) <= tp->cmd_minlen)) {
1015				if (strncmp(argv[0],
1016					    tp->cmd_name,
1017					    tp->cmd_minlen) == 0) {
1018					break;
1019				}
1020			}
1021
1022			if (strcmp(argv[0], tp->cmd_name) == 0)
1023				break;
1024		}
1025	}
1026
1027	/*
1028	 * If we don't find a command by this name, see if the first
1029	 * few characters of this match any of the known commands.
1030	 * e.g., md1c20 should match md.
1031	 */
1032	if (i == kdb_max_commands) {
1033		for_each_kdbcmd(tp, i) {
1034			if (tp->cmd_name) {
1035				if (strncmp(argv[0],
1036					    tp->cmd_name,
1037					    strlen(tp->cmd_name)) == 0) {
1038					break;
1039				}
1040			}
1041		}
1042	}
1043
1044	if (i < kdb_max_commands) {
1045		int result;
1046
1047		if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1))
1048			return KDB_NOPERM;
1049
1050		KDB_STATE_SET(CMD);
1051		result = (*tp->cmd_func)(argc-1, (const char **)argv);
1052		if (result && ignore_errors && result > KDB_CMD_GO)
1053			result = 0;
1054		KDB_STATE_CLEAR(CMD);
1055
1056		if (tp->cmd_flags & KDB_REPEAT_WITH_ARGS)
1057			return result;
1058
1059		argc = tp->cmd_flags & KDB_REPEAT_NO_ARGS ? 1 : 0;
1060		if (argv[argc])
1061			*(argv[argc]) = '\0';
1062		return result;
1063	}
1064
1065	/*
1066	 * If the input with which we were presented does not
1067	 * map to an existing command, attempt to parse it as an
1068	 * address argument and display the result.   Useful for
1069	 * obtaining the address of a variable, or the nearest symbol
1070	 * to an address contained in a register.
1071	 */
1072	{
1073		unsigned long value;
1074		char *name = NULL;
1075		long offset;
1076		int nextarg = 0;
1077
1078		if (kdbgetaddrarg(0, (const char **)argv, &nextarg,
1079				  &value, &offset, &name)) {
1080			return KDB_NOTFOUND;
1081		}
1082
1083		kdb_printf("%s = ", argv[0]);
1084		kdb_symbol_print(value, NULL, KDB_SP_DEFAULT);
1085		kdb_printf("\n");
1086		return 0;
1087	}
1088}
1089
1090
1091static int handle_ctrl_cmd(char *cmd)
1092{
1093#define CTRL_P	16
1094#define CTRL_N	14
1095
1096	/* initial situation */
1097	if (cmd_head == cmd_tail)
1098		return 0;
1099	switch (*cmd) {
1100	case CTRL_P:
1101		if (cmdptr != cmd_tail)
1102			cmdptr = (cmdptr-1) % KDB_CMD_HISTORY_COUNT;
1103		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1104		return 1;
1105	case CTRL_N:
1106		if (cmdptr != cmd_head)
1107			cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT;
1108		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1109		return 1;
1110	}
1111	return 0;
1112}
1113
1114/*
1115 * kdb_reboot - This function implements the 'reboot' command.  Reboot
1116 *	the system immediately, or loop for ever on failure.
1117 */
1118static int kdb_reboot(int argc, const char **argv)
1119{
1120	emergency_restart();
1121	kdb_printf("Hmm, kdb_reboot did not reboot, spinning here\n");
1122	while (1)
1123		cpu_relax();
1124	/* NOTREACHED */
1125	return 0;
1126}
1127
1128static void kdb_dumpregs(struct pt_regs *regs)
1129{
1130	int old_lvl = console_loglevel;
1131	console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
1132	kdb_trap_printk++;
1133	show_regs(regs);
1134	kdb_trap_printk--;
1135	kdb_printf("\n");
1136	console_loglevel = old_lvl;
1137}
1138
1139void kdb_set_current_task(struct task_struct *p)
1140{
1141	kdb_current_task = p;
1142
1143	if (kdb_task_has_cpu(p)) {
1144		kdb_current_regs = KDB_TSKREGS(kdb_process_cpu(p));
1145		return;
1146	}
1147	kdb_current_regs = NULL;
1148}
1149
 
 
 
 
 
 
 
 
 
 
1150/*
1151 * kdb_local - The main code for kdb.  This routine is invoked on a
1152 *	specific processor, it is not global.  The main kdb() routine
1153 *	ensures that only one processor at a time is in this routine.
1154 *	This code is called with the real reason code on the first
1155 *	entry to a kdb session, thereafter it is called with reason
1156 *	SWITCH, even if the user goes back to the original cpu.
1157 * Inputs:
1158 *	reason		The reason KDB was invoked
1159 *	error		The hardware-defined error code
1160 *	regs		The exception frame at time of fault/breakpoint.
1161 *	db_result	Result code from the break or debug point.
1162 * Returns:
1163 *	0	KDB was invoked for an event which it wasn't responsible
1164 *	1	KDB handled the event for which it was invoked.
1165 *	KDB_CMD_GO	User typed 'go'.
1166 *	KDB_CMD_CPU	User switched to another cpu.
1167 *	KDB_CMD_SS	Single step.
1168 */
1169static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
1170		     kdb_dbtrap_t db_result)
1171{
1172	char *cmdbuf;
1173	int diag;
1174	struct task_struct *kdb_current =
1175		kdb_curr_task(raw_smp_processor_id());
1176
1177	KDB_DEBUG_STATE("kdb_local 1", reason);
1178	kdb_go_count = 0;
1179	if (reason == KDB_REASON_DEBUG) {
1180		/* special case below */
1181	} else {
1182		kdb_printf("\nEntering kdb (current=0x%p, pid %d) ",
1183			   kdb_current, kdb_current ? kdb_current->pid : 0);
1184#if defined(CONFIG_SMP)
1185		kdb_printf("on processor %d ", raw_smp_processor_id());
1186#endif
1187	}
1188
1189	switch (reason) {
1190	case KDB_REASON_DEBUG:
1191	{
1192		/*
1193		 * If re-entering kdb after a single step
1194		 * command, don't print the message.
1195		 */
1196		switch (db_result) {
1197		case KDB_DB_BPT:
1198			kdb_printf("\nEntering kdb (0x%p, pid %d) ",
1199				   kdb_current, kdb_current->pid);
1200#if defined(CONFIG_SMP)
1201			kdb_printf("on processor %d ", raw_smp_processor_id());
1202#endif
1203			kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
1204				   instruction_pointer(regs));
1205			break;
1206		case KDB_DB_SS:
1207			break;
1208		case KDB_DB_SSBPT:
1209			KDB_DEBUG_STATE("kdb_local 4", reason);
1210			return 1;	/* kdba_db_trap did the work */
1211		default:
1212			kdb_printf("kdb: Bad result from kdba_db_trap: %d\n",
1213				   db_result);
1214			break;
1215		}
1216
1217	}
1218		break;
1219	case KDB_REASON_ENTER:
1220		if (KDB_STATE(KEYBOARD))
1221			kdb_printf("due to Keyboard Entry\n");
1222		else
1223			kdb_printf("due to KDB_ENTER()\n");
1224		break;
1225	case KDB_REASON_KEYBOARD:
1226		KDB_STATE_SET(KEYBOARD);
1227		kdb_printf("due to Keyboard Entry\n");
1228		break;
1229	case KDB_REASON_ENTER_SLAVE:
1230		/* drop through, slaves only get released via cpu switch */
1231	case KDB_REASON_SWITCH:
1232		kdb_printf("due to cpu switch\n");
1233		break;
1234	case KDB_REASON_OOPS:
1235		kdb_printf("Oops: %s\n", kdb_diemsg);
1236		kdb_printf("due to oops @ " kdb_machreg_fmt "\n",
1237			   instruction_pointer(regs));
1238		kdb_dumpregs(regs);
1239		break;
1240	case KDB_REASON_SYSTEM_NMI:
1241		kdb_printf("due to System NonMaskable Interrupt\n");
1242		break;
1243	case KDB_REASON_NMI:
1244		kdb_printf("due to NonMaskable Interrupt @ "
1245			   kdb_machreg_fmt "\n",
1246			   instruction_pointer(regs));
1247		break;
1248	case KDB_REASON_SSTEP:
1249	case KDB_REASON_BREAK:
1250		kdb_printf("due to %s @ " kdb_machreg_fmt "\n",
1251			   reason == KDB_REASON_BREAK ?
1252			   "Breakpoint" : "SS trap", instruction_pointer(regs));
1253		/*
1254		 * Determine if this breakpoint is one that we
1255		 * are interested in.
1256		 */
1257		if (db_result != KDB_DB_BPT) {
1258			kdb_printf("kdb: error return from kdba_bp_trap: %d\n",
1259				   db_result);
1260			KDB_DEBUG_STATE("kdb_local 6", reason);
1261			return 0;	/* Not for us, dismiss it */
1262		}
1263		break;
1264	case KDB_REASON_RECURSE:
1265		kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n",
1266			   instruction_pointer(regs));
1267		break;
1268	default:
1269		kdb_printf("kdb: unexpected reason code: %d\n", reason);
1270		KDB_DEBUG_STATE("kdb_local 8", reason);
1271		return 0;	/* Not for us, dismiss it */
1272	}
1273
1274	while (1) {
1275		/*
1276		 * Initialize pager context.
1277		 */
1278		kdb_nextline = 1;
1279		KDB_STATE_CLEAR(SUPPRESS);
1280		kdb_grepping_flag = 0;
1281		/* ensure the old search does not leak into '/' commands */
1282		kdb_grep_string[0] = '\0';
1283
1284		cmdbuf = cmd_cur;
1285		*cmdbuf = '\0';
1286		*(cmd_hist[cmd_head]) = '\0';
1287
1288do_full_getstr:
1289#if defined(CONFIG_SMP)
1290		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
1291			 raw_smp_processor_id());
1292#else
1293		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"));
1294#endif
1295		if (defcmd_in_progress)
1296			strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
1297
1298		/*
1299		 * Fetch command from keyboard
1300		 */
1301		cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str);
1302		if (*cmdbuf != '\n') {
1303			if (*cmdbuf < 32) {
1304				if (cmdptr == cmd_head) {
1305					strncpy(cmd_hist[cmd_head], cmd_cur,
1306						CMD_BUFLEN);
1307					*(cmd_hist[cmd_head] +
1308					  strlen(cmd_hist[cmd_head])-1) = '\0';
1309				}
1310				if (!handle_ctrl_cmd(cmdbuf))
1311					*(cmd_cur+strlen(cmd_cur)-1) = '\0';
1312				cmdbuf = cmd_cur;
1313				goto do_full_getstr;
1314			} else {
1315				strncpy(cmd_hist[cmd_head], cmd_cur,
1316					CMD_BUFLEN);
1317			}
1318
1319			cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT;
1320			if (cmd_head == cmd_tail)
1321				cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT;
1322		}
1323
1324		cmdptr = cmd_head;
1325		diag = kdb_parse(cmdbuf);
1326		if (diag == KDB_NOTFOUND) {
 
1327			kdb_printf("Unknown kdb command: '%s'\n", cmdbuf);
1328			diag = 0;
1329		}
1330		if (diag == KDB_CMD_GO
1331		 || diag == KDB_CMD_CPU
1332		 || diag == KDB_CMD_SS
1333		 || diag == KDB_CMD_KGDB)
1334			break;
1335
1336		if (diag)
1337			kdb_cmderror(diag);
1338	}
1339	KDB_DEBUG_STATE("kdb_local 9", diag);
1340	return diag;
1341}
1342
1343
1344/*
1345 * kdb_print_state - Print the state data for the current processor
1346 *	for debugging.
1347 * Inputs:
1348 *	text		Identifies the debug point
1349 *	value		Any integer value to be printed, e.g. reason code.
1350 */
1351void kdb_print_state(const char *text, int value)
1352{
1353	kdb_printf("state: %s cpu %d value %d initial %d state %x\n",
1354		   text, raw_smp_processor_id(), value, kdb_initial_cpu,
1355		   kdb_state);
1356}
1357
1358/*
1359 * kdb_main_loop - After initial setup and assignment of the
1360 *	controlling cpu, all cpus are in this loop.  One cpu is in
1361 *	control and will issue the kdb prompt, the others will spin
1362 *	until 'go' or cpu switch.
1363 *
1364 *	To get a consistent view of the kernel stacks for all
1365 *	processes, this routine is invoked from the main kdb code via
1366 *	an architecture specific routine.  kdba_main_loop is
1367 *	responsible for making the kernel stacks consistent for all
1368 *	processes, there should be no difference between a blocked
1369 *	process and a running process as far as kdb is concerned.
1370 * Inputs:
1371 *	reason		The reason KDB was invoked
1372 *	error		The hardware-defined error code
1373 *	reason2		kdb's current reason code.
1374 *			Initially error but can change
1375 *			according to kdb state.
1376 *	db_result	Result code from break or debug point.
1377 *	regs		The exception frame at time of fault/breakpoint.
1378 *			should always be valid.
1379 * Returns:
1380 *	0	KDB was invoked for an event which it wasn't responsible
1381 *	1	KDB handled the event for which it was invoked.
1382 */
1383int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
1384	      kdb_dbtrap_t db_result, struct pt_regs *regs)
1385{
1386	int result = 1;
1387	/* Stay in kdb() until 'go', 'ss[b]' or an error */
1388	while (1) {
1389		/*
1390		 * All processors except the one that is in control
1391		 * will spin here.
1392		 */
1393		KDB_DEBUG_STATE("kdb_main_loop 1", reason);
1394		while (KDB_STATE(HOLD_CPU)) {
1395			/* state KDB is turned off by kdb_cpu to see if the
1396			 * other cpus are still live, each cpu in this loop
1397			 * turns it back on.
1398			 */
1399			if (!KDB_STATE(KDB))
1400				KDB_STATE_SET(KDB);
1401		}
1402
1403		KDB_STATE_CLEAR(SUPPRESS);
1404		KDB_DEBUG_STATE("kdb_main_loop 2", reason);
1405		if (KDB_STATE(LEAVING))
1406			break;	/* Another cpu said 'go' */
1407		/* Still using kdb, this processor is in control */
1408		result = kdb_local(reason2, error, regs, db_result);
1409		KDB_DEBUG_STATE("kdb_main_loop 3", result);
1410
1411		if (result == KDB_CMD_CPU)
1412			break;
1413
1414		if (result == KDB_CMD_SS) {
1415			KDB_STATE_SET(DOING_SS);
1416			break;
1417		}
1418
1419		if (result == KDB_CMD_KGDB) {
1420			if (!KDB_STATE(DOING_KGDB))
1421				kdb_printf("Entering please attach debugger "
1422					   "or use $D#44+ or $3#33\n");
1423			break;
1424		}
1425		if (result && result != 1 && result != KDB_CMD_GO)
1426			kdb_printf("\nUnexpected kdb_local return code %d\n",
1427				   result);
1428		KDB_DEBUG_STATE("kdb_main_loop 4", reason);
1429		break;
1430	}
1431	if (KDB_STATE(DOING_SS))
1432		KDB_STATE_CLEAR(SSBPT);
1433
1434	/* Clean up any keyboard devices before leaving */
1435	kdb_kbd_cleanup_state();
1436
1437	return result;
1438}
1439
1440/*
1441 * kdb_mdr - This function implements the guts of the 'mdr', memory
1442 * read command.
1443 *	mdr  <addr arg>,<byte count>
1444 * Inputs:
1445 *	addr	Start address
1446 *	count	Number of bytes
1447 * Returns:
1448 *	Always 0.  Any errors are detected and printed by kdb_getarea.
1449 */
1450static int kdb_mdr(unsigned long addr, unsigned int count)
1451{
1452	unsigned char c;
1453	while (count--) {
1454		if (kdb_getarea(c, addr))
1455			return 0;
1456		kdb_printf("%02x", c);
1457		addr++;
1458	}
1459	kdb_printf("\n");
1460	return 0;
1461}
1462
1463/*
1464 * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4',
1465 *	'md8' 'mdr' and 'mds' commands.
1466 *
1467 *	md|mds  [<addr arg> [<line count> [<radix>]]]
1468 *	mdWcN	[<addr arg> [<line count> [<radix>]]]
1469 *		where W = is the width (1, 2, 4 or 8) and N is the count.
1470 *		for eg., md1c20 reads 20 bytes, 1 at a time.
1471 *	mdr  <addr arg>,<byte count>
1472 */
1473static void kdb_md_line(const char *fmtstr, unsigned long addr,
1474			int symbolic, int nosect, int bytesperword,
1475			int num, int repeat, int phys)
1476{
1477	/* print just one line of data */
1478	kdb_symtab_t symtab;
1479	char cbuf[32];
1480	char *c = cbuf;
1481	int i;
1482	unsigned long word;
1483
1484	memset(cbuf, '\0', sizeof(cbuf));
1485	if (phys)
1486		kdb_printf("phys " kdb_machreg_fmt0 " ", addr);
1487	else
1488		kdb_printf(kdb_machreg_fmt0 " ", addr);
1489
1490	for (i = 0; i < num && repeat--; i++) {
1491		if (phys) {
1492			if (kdb_getphysword(&word, addr, bytesperword))
1493				break;
1494		} else if (kdb_getword(&word, addr, bytesperword))
1495			break;
1496		kdb_printf(fmtstr, word);
1497		if (symbolic)
1498			kdbnearsym(word, &symtab);
1499		else
1500			memset(&symtab, 0, sizeof(symtab));
1501		if (symtab.sym_name) {
1502			kdb_symbol_print(word, &symtab, 0);
1503			if (!nosect) {
1504				kdb_printf("\n");
1505				kdb_printf("                       %s %s "
1506					   kdb_machreg_fmt " "
1507					   kdb_machreg_fmt " "
1508					   kdb_machreg_fmt, symtab.mod_name,
1509					   symtab.sec_name, symtab.sec_start,
1510					   symtab.sym_start, symtab.sym_end);
1511			}
1512			addr += bytesperword;
1513		} else {
1514			union {
1515				u64 word;
1516				unsigned char c[8];
1517			} wc;
1518			unsigned char *cp;
1519#ifdef	__BIG_ENDIAN
1520			cp = wc.c + 8 - bytesperword;
1521#else
1522			cp = wc.c;
1523#endif
1524			wc.word = word;
1525#define printable_char(c) \
1526	({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; })
1527			switch (bytesperword) {
1528			case 8:
1529				*c++ = printable_char(*cp++);
1530				*c++ = printable_char(*cp++);
1531				*c++ = printable_char(*cp++);
1532				*c++ = printable_char(*cp++);
1533				addr += 4;
1534			case 4:
1535				*c++ = printable_char(*cp++);
1536				*c++ = printable_char(*cp++);
1537				addr += 2;
1538			case 2:
1539				*c++ = printable_char(*cp++);
1540				addr++;
1541			case 1:
1542				*c++ = printable_char(*cp++);
1543				addr++;
1544				break;
1545			}
1546#undef printable_char
1547		}
1548	}
1549	kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1),
1550		   " ", cbuf);
1551}
1552
1553static int kdb_md(int argc, const char **argv)
1554{
1555	static unsigned long last_addr;
1556	static int last_radix, last_bytesperword, last_repeat;
1557	int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
1558	int nosect = 0;
1559	char fmtchar, fmtstr[64];
1560	unsigned long addr;
1561	unsigned long word;
1562	long offset = 0;
1563	int symbolic = 0;
1564	int valid = 0;
1565	int phys = 0;
 
1566
1567	kdbgetintenv("MDCOUNT", &mdcount);
1568	kdbgetintenv("RADIX", &radix);
1569	kdbgetintenv("BYTESPERWORD", &bytesperword);
1570
1571	/* Assume 'md <addr>' and start with environment values */
1572	repeat = mdcount * 16 / bytesperword;
1573
1574	if (strcmp(argv[0], "mdr") == 0) {
1575		if (argc != 2)
 
 
1576			return KDB_ARGCOUNT;
1577		valid = 1;
1578	} else if (isdigit(argv[0][2])) {
1579		bytesperword = (int)(argv[0][2] - '0');
1580		if (bytesperword == 0) {
1581			bytesperword = last_bytesperword;
1582			if (bytesperword == 0)
1583				bytesperword = 4;
1584		}
1585		last_bytesperword = bytesperword;
1586		repeat = mdcount * 16 / bytesperword;
1587		if (!argv[0][3])
1588			valid = 1;
1589		else if (argv[0][3] == 'c' && argv[0][4]) {
1590			char *p;
1591			repeat = simple_strtoul(argv[0] + 4, &p, 10);
1592			mdcount = ((repeat * bytesperword) + 15) / 16;
1593			valid = !*p;
1594		}
1595		last_repeat = repeat;
1596	} else if (strcmp(argv[0], "md") == 0)
1597		valid = 1;
1598	else if (strcmp(argv[0], "mds") == 0)
1599		valid = 1;
1600	else if (strcmp(argv[0], "mdp") == 0) {
1601		phys = valid = 1;
1602	}
1603	if (!valid)
1604		return KDB_NOTFOUND;
1605
1606	if (argc == 0) {
1607		if (last_addr == 0)
1608			return KDB_ARGCOUNT;
1609		addr = last_addr;
1610		radix = last_radix;
1611		bytesperword = last_bytesperword;
1612		repeat = last_repeat;
1613		mdcount = ((repeat * bytesperword) + 15) / 16;
 
 
 
1614	}
1615
1616	if (argc) {
1617		unsigned long val;
1618		int diag, nextarg = 1;
1619		diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
1620				     &offset, NULL);
1621		if (diag)
1622			return diag;
1623		if (argc > nextarg+2)
1624			return KDB_ARGCOUNT;
1625
1626		if (argc >= nextarg) {
1627			diag = kdbgetularg(argv[nextarg], &val);
1628			if (!diag) {
1629				mdcount = (int) val;
1630				repeat = mdcount * 16 / bytesperword;
 
 
 
1631			}
1632		}
1633		if (argc >= nextarg+1) {
1634			diag = kdbgetularg(argv[nextarg+1], &val);
1635			if (!diag)
1636				radix = (int) val;
1637		}
1638	}
1639
1640	if (strcmp(argv[0], "mdr") == 0)
1641		return kdb_mdr(addr, mdcount);
 
 
 
 
 
 
 
1642
1643	switch (radix) {
1644	case 10:
1645		fmtchar = 'd';
1646		break;
1647	case 16:
1648		fmtchar = 'x';
1649		break;
1650	case 8:
1651		fmtchar = 'o';
1652		break;
1653	default:
1654		return KDB_BADRADIX;
1655	}
1656
1657	last_radix = radix;
1658
1659	if (bytesperword > KDB_WORD_SIZE)
1660		return KDB_BADWIDTH;
1661
1662	switch (bytesperword) {
1663	case 8:
1664		sprintf(fmtstr, "%%16.16l%c ", fmtchar);
1665		break;
1666	case 4:
1667		sprintf(fmtstr, "%%8.8l%c ", fmtchar);
1668		break;
1669	case 2:
1670		sprintf(fmtstr, "%%4.4l%c ", fmtchar);
1671		break;
1672	case 1:
1673		sprintf(fmtstr, "%%2.2l%c ", fmtchar);
1674		break;
1675	default:
1676		return KDB_BADWIDTH;
1677	}
1678
1679	last_repeat = repeat;
1680	last_bytesperword = bytesperword;
1681
1682	if (strcmp(argv[0], "mds") == 0) {
1683		symbolic = 1;
1684		/* Do not save these changes as last_*, they are temporary mds
1685		 * overrides.
1686		 */
1687		bytesperword = KDB_WORD_SIZE;
1688		repeat = mdcount;
1689		kdbgetintenv("NOSECT", &nosect);
1690	}
1691
1692	/* Round address down modulo BYTESPERWORD */
1693
1694	addr &= ~(bytesperword-1);
1695
1696	while (repeat > 0) {
1697		unsigned long a;
1698		int n, z, num = (symbolic ? 1 : (16 / bytesperword));
1699
1700		if (KDB_FLAG(CMD_INTERRUPT))
1701			return 0;
1702		for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) {
1703			if (phys) {
1704				if (kdb_getphysword(&word, a, bytesperword)
1705						|| word)
1706					break;
1707			} else if (kdb_getword(&word, a, bytesperword) || word)
1708				break;
1709		}
1710		n = min(num, repeat);
1711		kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword,
1712			    num, repeat, phys);
1713		addr += bytesperword * n;
1714		repeat -= n;
1715		z = (z + num - 1) / num;
1716		if (z > 2) {
1717			int s = num * (z-2);
1718			kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0
1719				   " zero suppressed\n",
1720				addr, addr + bytesperword * s - 1);
1721			addr += bytesperword * s;
1722			repeat -= s;
1723		}
1724	}
1725	last_addr = addr;
1726
1727	return 0;
1728}
1729
1730/*
1731 * kdb_mm - This function implements the 'mm' command.
1732 *	mm address-expression new-value
1733 * Remarks:
1734 *	mm works on machine words, mmW works on bytes.
1735 */
1736static int kdb_mm(int argc, const char **argv)
1737{
1738	int diag;
1739	unsigned long addr;
1740	long offset = 0;
1741	unsigned long contents;
1742	int nextarg;
1743	int width;
1744
1745	if (argv[0][2] && !isdigit(argv[0][2]))
1746		return KDB_NOTFOUND;
1747
1748	if (argc < 2)
1749		return KDB_ARGCOUNT;
1750
1751	nextarg = 1;
1752	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1753	if (diag)
1754		return diag;
1755
1756	if (nextarg > argc)
1757		return KDB_ARGCOUNT;
1758	diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL);
1759	if (diag)
1760		return diag;
1761
1762	if (nextarg != argc + 1)
1763		return KDB_ARGCOUNT;
1764
1765	width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE);
1766	diag = kdb_putword(addr, contents, width);
1767	if (diag)
1768		return diag;
1769
1770	kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents);
1771
1772	return 0;
1773}
1774
1775/*
1776 * kdb_go - This function implements the 'go' command.
1777 *	go [address-expression]
1778 */
1779static int kdb_go(int argc, const char **argv)
1780{
1781	unsigned long addr;
1782	int diag;
1783	int nextarg;
1784	long offset;
1785
1786	if (raw_smp_processor_id() != kdb_initial_cpu) {
1787		kdb_printf("go must execute on the entry cpu, "
1788			   "please use \"cpu %d\" and then execute go\n",
1789			   kdb_initial_cpu);
1790		return KDB_BADCPUNUM;
1791	}
1792	if (argc == 1) {
1793		nextarg = 1;
1794		diag = kdbgetaddrarg(argc, argv, &nextarg,
1795				     &addr, &offset, NULL);
1796		if (diag)
1797			return diag;
1798	} else if (argc) {
1799		return KDB_ARGCOUNT;
1800	}
1801
1802	diag = KDB_CMD_GO;
1803	if (KDB_FLAG(CATASTROPHIC)) {
1804		kdb_printf("Catastrophic error detected\n");
1805		kdb_printf("kdb_continue_catastrophic=%d, ",
1806			kdb_continue_catastrophic);
1807		if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) {
1808			kdb_printf("type go a second time if you really want "
1809				   "to continue\n");
1810			return 0;
1811		}
1812		if (kdb_continue_catastrophic == 2) {
1813			kdb_printf("forcing reboot\n");
1814			kdb_reboot(0, NULL);
1815		}
1816		kdb_printf("attempting to continue\n");
1817	}
1818	return diag;
1819}
1820
1821/*
1822 * kdb_rd - This function implements the 'rd' command.
1823 */
1824static int kdb_rd(int argc, const char **argv)
1825{
1826	int len = kdb_check_regs();
1827#if DBG_MAX_REG_NUM > 0
1828	int i;
1829	char *rname;
1830	int rsize;
1831	u64 reg64;
1832	u32 reg32;
1833	u16 reg16;
1834	u8 reg8;
1835
1836	if (len)
1837		return len;
1838
1839	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1840		rsize = dbg_reg_def[i].size * 2;
1841		if (rsize > 16)
1842			rsize = 2;
1843		if (len + strlen(dbg_reg_def[i].name) + 4 + rsize > 80) {
1844			len = 0;
1845			kdb_printf("\n");
1846		}
1847		if (len)
1848			len += kdb_printf("  ");
1849		switch(dbg_reg_def[i].size * 8) {
1850		case 8:
1851			rname = dbg_get_reg(i, &reg8, kdb_current_regs);
1852			if (!rname)
1853				break;
1854			len += kdb_printf("%s: %02x", rname, reg8);
1855			break;
1856		case 16:
1857			rname = dbg_get_reg(i, &reg16, kdb_current_regs);
1858			if (!rname)
1859				break;
1860			len += kdb_printf("%s: %04x", rname, reg16);
1861			break;
1862		case 32:
1863			rname = dbg_get_reg(i, &reg32, kdb_current_regs);
1864			if (!rname)
1865				break;
1866			len += kdb_printf("%s: %08x", rname, reg32);
1867			break;
1868		case 64:
1869			rname = dbg_get_reg(i, &reg64, kdb_current_regs);
1870			if (!rname)
1871				break;
1872			len += kdb_printf("%s: %016llx", rname, reg64);
1873			break;
1874		default:
1875			len += kdb_printf("%s: ??", dbg_reg_def[i].name);
1876		}
1877	}
1878	kdb_printf("\n");
1879#else
1880	if (len)
1881		return len;
1882
1883	kdb_dumpregs(kdb_current_regs);
1884#endif
1885	return 0;
1886}
1887
1888/*
1889 * kdb_rm - This function implements the 'rm' (register modify)  command.
1890 *	rm register-name new-contents
1891 * Remarks:
1892 *	Allows register modification with the same restrictions as gdb
1893 */
1894static int kdb_rm(int argc, const char **argv)
1895{
1896#if DBG_MAX_REG_NUM > 0
1897	int diag;
1898	const char *rname;
1899	int i;
1900	u64 reg64;
1901	u32 reg32;
1902	u16 reg16;
1903	u8 reg8;
1904
1905	if (argc != 2)
1906		return KDB_ARGCOUNT;
1907	/*
1908	 * Allow presence or absence of leading '%' symbol.
1909	 */
1910	rname = argv[1];
1911	if (*rname == '%')
1912		rname++;
1913
1914	diag = kdbgetu64arg(argv[2], &reg64);
1915	if (diag)
1916		return diag;
1917
1918	diag = kdb_check_regs();
1919	if (diag)
1920		return diag;
1921
1922	diag = KDB_BADREG;
1923	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1924		if (strcmp(rname, dbg_reg_def[i].name) == 0) {
1925			diag = 0;
1926			break;
1927		}
1928	}
1929	if (!diag) {
1930		switch(dbg_reg_def[i].size * 8) {
1931		case 8:
1932			reg8 = reg64;
1933			dbg_set_reg(i, &reg8, kdb_current_regs);
1934			break;
1935		case 16:
1936			reg16 = reg64;
1937			dbg_set_reg(i, &reg16, kdb_current_regs);
1938			break;
1939		case 32:
1940			reg32 = reg64;
1941			dbg_set_reg(i, &reg32, kdb_current_regs);
1942			break;
1943		case 64:
1944			dbg_set_reg(i, &reg64, kdb_current_regs);
1945			break;
1946		}
1947	}
1948	return diag;
1949#else
1950	kdb_printf("ERROR: Register set currently not implemented\n");
1951    return 0;
1952#endif
1953}
1954
1955#if defined(CONFIG_MAGIC_SYSRQ)
1956/*
1957 * kdb_sr - This function implements the 'sr' (SYSRQ key) command
1958 *	which interfaces to the soi-disant MAGIC SYSRQ functionality.
1959 *		sr <magic-sysrq-code>
1960 */
1961static int kdb_sr(int argc, const char **argv)
1962{
1963	bool check_mask =
1964	    !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
1965
1966	if (argc != 1)
1967		return KDB_ARGCOUNT;
1968
1969	kdb_trap_printk++;
1970	__handle_sysrq(*argv[1], check_mask);
1971	kdb_trap_printk--;
1972
1973	return 0;
1974}
1975#endif	/* CONFIG_MAGIC_SYSRQ */
1976
1977/*
1978 * kdb_ef - This function implements the 'regs' (display exception
1979 *	frame) command.  This command takes an address and expects to
1980 *	find an exception frame at that address, formats and prints
1981 *	it.
1982 *		regs address-expression
1983 * Remarks:
1984 *	Not done yet.
1985 */
1986static int kdb_ef(int argc, const char **argv)
1987{
1988	int diag;
1989	unsigned long addr;
1990	long offset;
1991	int nextarg;
1992
1993	if (argc != 1)
1994		return KDB_ARGCOUNT;
1995
1996	nextarg = 1;
1997	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1998	if (diag)
1999		return diag;
2000	show_regs((struct pt_regs *)addr);
2001	return 0;
2002}
2003
2004#if defined(CONFIG_MODULES)
2005/*
2006 * kdb_lsmod - This function implements the 'lsmod' command.  Lists
2007 *	currently loaded kernel modules.
2008 *	Mostly taken from userland lsmod.
2009 */
2010static int kdb_lsmod(int argc, const char **argv)
2011{
2012	struct module *mod;
2013
2014	if (argc != 0)
2015		return KDB_ARGCOUNT;
2016
2017	kdb_printf("Module                  Size  modstruct     Used by\n");
2018	list_for_each_entry(mod, kdb_modules, list) {
2019		if (mod->state == MODULE_STATE_UNFORMED)
2020			continue;
2021
2022		kdb_printf("%-20s%8u  0x%p ", mod->name,
2023			   mod->core_layout.size, (void *)mod);
2024#ifdef CONFIG_MODULE_UNLOAD
2025		kdb_printf("%4d ", module_refcount(mod));
2026#endif
2027		if (mod->state == MODULE_STATE_GOING)
2028			kdb_printf(" (Unloading)");
2029		else if (mod->state == MODULE_STATE_COMING)
2030			kdb_printf(" (Loading)");
2031		else
2032			kdb_printf(" (Live)");
2033		kdb_printf(" 0x%p", mod->core_layout.base);
2034
2035#ifdef CONFIG_MODULE_UNLOAD
2036		{
2037			struct module_use *use;
2038			kdb_printf(" [ ");
2039			list_for_each_entry(use, &mod->source_list,
2040					    source_list)
2041				kdb_printf("%s ", use->target->name);
2042			kdb_printf("]\n");
2043		}
2044#endif
2045	}
2046
2047	return 0;
2048}
2049
2050#endif	/* CONFIG_MODULES */
2051
2052/*
2053 * kdb_env - This function implements the 'env' command.  Display the
2054 *	current environment variables.
2055 */
2056
2057static int kdb_env(int argc, const char **argv)
2058{
2059	int i;
2060
2061	for (i = 0; i < __nenv; i++) {
2062		if (__env[i])
2063			kdb_printf("%s\n", __env[i]);
2064	}
2065
2066	if (KDB_DEBUG(MASK))
2067		kdb_printf("KDBFLAGS=0x%x\n", kdb_flags);
2068
2069	return 0;
2070}
2071
2072#ifdef CONFIG_PRINTK
2073/*
2074 * kdb_dmesg - This function implements the 'dmesg' command to display
2075 *	the contents of the syslog buffer.
2076 *		dmesg [lines] [adjust]
2077 */
2078static int kdb_dmesg(int argc, const char **argv)
2079{
2080	int diag;
2081	int logging;
2082	int lines = 0;
2083	int adjust = 0;
2084	int n = 0;
2085	int skip = 0;
2086	struct kmsg_dumper dumper = { .active = 1 };
2087	size_t len;
2088	char buf[201];
2089
2090	if (argc > 2)
2091		return KDB_ARGCOUNT;
2092	if (argc) {
2093		char *cp;
2094		lines = simple_strtol(argv[1], &cp, 0);
2095		if (*cp)
2096			lines = 0;
2097		if (argc > 1) {
2098			adjust = simple_strtoul(argv[2], &cp, 0);
2099			if (*cp || adjust < 0)
2100				adjust = 0;
2101		}
2102	}
2103
2104	/* disable LOGGING if set */
2105	diag = kdbgetintenv("LOGGING", &logging);
2106	if (!diag && logging) {
2107		const char *setargs[] = { "set", "LOGGING", "0" };
2108		kdb_set(2, setargs);
2109	}
2110
2111	kmsg_dump_rewind_nolock(&dumper);
2112	while (kmsg_dump_get_line_nolock(&dumper, 1, NULL, 0, NULL))
2113		n++;
2114
2115	if (lines < 0) {
2116		if (adjust >= n)
2117			kdb_printf("buffer only contains %d lines, nothing "
2118				   "printed\n", n);
2119		else if (adjust - lines >= n)
2120			kdb_printf("buffer only contains %d lines, last %d "
2121				   "lines printed\n", n, n - adjust);
2122		skip = adjust;
2123		lines = abs(lines);
2124	} else if (lines > 0) {
2125		skip = n - lines - adjust;
2126		lines = abs(lines);
2127		if (adjust >= n) {
2128			kdb_printf("buffer only contains %d lines, "
2129				   "nothing printed\n", n);
2130			skip = n;
2131		} else if (skip < 0) {
2132			lines += skip;
2133			skip = 0;
2134			kdb_printf("buffer only contains %d lines, first "
2135				   "%d lines printed\n", n, lines);
2136		}
2137	} else {
2138		lines = n;
2139	}
2140
2141	if (skip >= n || skip < 0)
2142		return 0;
2143
2144	kmsg_dump_rewind_nolock(&dumper);
2145	while (kmsg_dump_get_line_nolock(&dumper, 1, buf, sizeof(buf), &len)) {
2146		if (skip) {
2147			skip--;
2148			continue;
2149		}
2150		if (!lines--)
2151			break;
2152		if (KDB_FLAG(CMD_INTERRUPT))
2153			return 0;
2154
2155		kdb_printf("%.*s\n", (int)len - 1, buf);
2156	}
2157
2158	return 0;
2159}
2160#endif /* CONFIG_PRINTK */
2161
2162/* Make sure we balance enable/disable calls, must disable first. */
2163static atomic_t kdb_nmi_disabled;
2164
2165static int kdb_disable_nmi(int argc, const char *argv[])
2166{
2167	if (atomic_read(&kdb_nmi_disabled))
2168		return 0;
2169	atomic_set(&kdb_nmi_disabled, 1);
2170	arch_kgdb_ops.enable_nmi(0);
2171	return 0;
2172}
2173
2174static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
2175{
2176	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
2177		return -EINVAL;
2178	arch_kgdb_ops.enable_nmi(1);
2179	return 0;
2180}
2181
2182static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
2183	.set = kdb_param_enable_nmi,
2184};
2185module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
2186
2187/*
2188 * kdb_cpu - This function implements the 'cpu' command.
2189 *	cpu	[<cpunum>]
2190 * Returns:
2191 *	KDB_CMD_CPU for success, a kdb diagnostic if error
2192 */
2193static void kdb_cpu_status(void)
2194{
2195	int i, start_cpu, first_print = 1;
2196	char state, prev_state = '?';
2197
2198	kdb_printf("Currently on cpu %d\n", raw_smp_processor_id());
2199	kdb_printf("Available cpus: ");
2200	for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
2201		if (!cpu_online(i)) {
2202			state = 'F';	/* cpu is offline */
2203		} else if (!kgdb_info[i].enter_kgdb) {
2204			state = 'D';	/* cpu is online but unresponsive */
2205		} else {
2206			state = ' ';	/* cpu is responding to kdb */
2207			if (kdb_task_state_char(KDB_TSK(i)) == 'I')
2208				state = 'I';	/* idle task */
2209		}
2210		if (state != prev_state) {
2211			if (prev_state != '?') {
2212				if (!first_print)
2213					kdb_printf(", ");
2214				first_print = 0;
2215				kdb_printf("%d", start_cpu);
2216				if (start_cpu < i-1)
2217					kdb_printf("-%d", i-1);
2218				if (prev_state != ' ')
2219					kdb_printf("(%c)", prev_state);
2220			}
2221			prev_state = state;
2222			start_cpu = i;
2223		}
2224	}
2225	/* print the trailing cpus, ignoring them if they are all offline */
2226	if (prev_state != 'F') {
2227		if (!first_print)
2228			kdb_printf(", ");
2229		kdb_printf("%d", start_cpu);
2230		if (start_cpu < i-1)
2231			kdb_printf("-%d", i-1);
2232		if (prev_state != ' ')
2233			kdb_printf("(%c)", prev_state);
2234	}
2235	kdb_printf("\n");
2236}
2237
2238static int kdb_cpu(int argc, const char **argv)
2239{
2240	unsigned long cpunum;
2241	int diag;
2242
2243	if (argc == 0) {
2244		kdb_cpu_status();
2245		return 0;
2246	}
2247
2248	if (argc != 1)
2249		return KDB_ARGCOUNT;
2250
2251	diag = kdbgetularg(argv[1], &cpunum);
2252	if (diag)
2253		return diag;
2254
2255	/*
2256	 * Validate cpunum
2257	 */
2258	if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
2259		return KDB_BADCPUNUM;
2260
2261	dbg_switch_cpu = cpunum;
2262
2263	/*
2264	 * Switch to other cpu
2265	 */
2266	return KDB_CMD_CPU;
2267}
2268
2269/* The user may not realize that ps/bta with no parameters does not print idle
2270 * or sleeping system daemon processes, so tell them how many were suppressed.
2271 */
2272void kdb_ps_suppressed(void)
2273{
2274	int idle = 0, daemon = 0;
2275	unsigned long mask_I = kdb_task_state_string("I"),
2276		      mask_M = kdb_task_state_string("M");
2277	unsigned long cpu;
2278	const struct task_struct *p, *g;
2279	for_each_online_cpu(cpu) {
2280		p = kdb_curr_task(cpu);
2281		if (kdb_task_state(p, mask_I))
2282			++idle;
2283	}
2284	kdb_do_each_thread(g, p) {
2285		if (kdb_task_state(p, mask_M))
2286			++daemon;
2287	} kdb_while_each_thread(g, p);
2288	if (idle || daemon) {
2289		if (idle)
2290			kdb_printf("%d idle process%s (state I)%s\n",
2291				   idle, idle == 1 ? "" : "es",
2292				   daemon ? " and " : "");
2293		if (daemon)
2294			kdb_printf("%d sleeping system daemon (state M) "
2295				   "process%s", daemon,
2296				   daemon == 1 ? "" : "es");
2297		kdb_printf(" suppressed,\nuse 'ps A' to see all.\n");
2298	}
2299}
2300
2301/*
2302 * kdb_ps - This function implements the 'ps' command which shows a
2303 *	list of the active processes.
2304 *		ps [DRSTCZEUIMA]   All processes, optionally filtered by state
2305 */
2306void kdb_ps1(const struct task_struct *p)
2307{
2308	int cpu;
2309	unsigned long tmp;
2310
2311	if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
2312		return;
2313
2314	cpu = kdb_process_cpu(p);
2315	kdb_printf("0x%p %8d %8d  %d %4d   %c  0x%p %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%p)\n", KDB_TSK(cpu));
2329		}
2330	}
2331}
2332
2333static int kdb_ps(int argc, const char **argv)
2334{
2335	struct task_struct *g, *p;
2336	unsigned long mask, cpu;
2337
2338	if (argc == 0)
2339		kdb_ps_suppressed();
2340	kdb_printf("%-*s      Pid   Parent [*] cpu State %-*s Command\n",
2341		(int)(2*sizeof(void *))+2, "Task Addr",
2342		(int)(2*sizeof(void *))+2, "Thread");
2343	mask = kdb_task_state_string(argc ? argv[1] : NULL);
2344	/* Run the active tasks first */
2345	for_each_online_cpu(cpu) {
2346		if (KDB_FLAG(CMD_INTERRUPT))
2347			return 0;
2348		p = kdb_curr_task(cpu);
2349		if (kdb_task_state(p, mask))
2350			kdb_ps1(p);
2351	}
2352	kdb_printf("\n");
2353	/* Now the real tasks */
2354	kdb_do_each_thread(g, p) {
2355		if (KDB_FLAG(CMD_INTERRUPT))
2356			return 0;
2357		if (kdb_task_state(p, mask))
2358			kdb_ps1(p);
2359	} kdb_while_each_thread(g, p);
2360
2361	return 0;
2362}
2363
2364/*
2365 * kdb_pid - This function implements the 'pid' command which switches
2366 *	the currently active process.
2367 *		pid [<pid> | R]
2368 */
2369static int kdb_pid(int argc, const char **argv)
2370{
2371	struct task_struct *p;
2372	unsigned long val;
2373	int diag;
2374
2375	if (argc > 1)
2376		return KDB_ARGCOUNT;
2377
2378	if (argc) {
2379		if (strcmp(argv[1], "R") == 0) {
2380			p = KDB_TSK(kdb_initial_cpu);
2381		} else {
2382			diag = kdbgetularg(argv[1], &val);
2383			if (diag)
2384				return KDB_BADINT;
2385
2386			p = find_task_by_pid_ns((pid_t)val,	&init_pid_ns);
2387			if (!p) {
2388				kdb_printf("No task with pid=%d\n", (pid_t)val);
2389				return 0;
2390			}
2391		}
2392		kdb_set_current_task(p);
2393	}
2394	kdb_printf("KDB current process is %s(pid=%d)\n",
2395		   kdb_current_task->comm,
2396		   kdb_current_task->pid);
2397
2398	return 0;
2399}
2400
2401static int kdb_kgdb(int argc, const char **argv)
2402{
2403	return KDB_CMD_KGDB;
2404}
2405
2406/*
2407 * kdb_help - This function implements the 'help' and '?' commands.
2408 */
2409static int kdb_help(int argc, const char **argv)
2410{
2411	kdbtab_t *kt;
2412	int i;
2413
2414	kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
2415	kdb_printf("-----------------------------"
2416		   "-----------------------------\n");
2417	for_each_kdbcmd(kt, i) {
2418		char *space = "";
2419		if (KDB_FLAG(CMD_INTERRUPT))
2420			return 0;
2421		if (!kt->cmd_name)
2422			continue;
2423		if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
2424			continue;
2425		if (strlen(kt->cmd_usage) > 20)
2426			space = "\n                                    ";
2427		kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
2428			   kt->cmd_usage, space, kt->cmd_help);
2429	}
2430	return 0;
2431}
2432
2433/*
2434 * kdb_kill - This function implements the 'kill' commands.
2435 */
2436static int kdb_kill(int argc, const char **argv)
2437{
2438	long sig, pid;
2439	char *endp;
2440	struct task_struct *p;
2441	struct siginfo info;
2442
2443	if (argc != 2)
2444		return KDB_ARGCOUNT;
2445
2446	sig = simple_strtol(argv[1], &endp, 0);
2447	if (*endp)
2448		return KDB_BADINT;
2449	if (sig >= 0) {
2450		kdb_printf("Invalid signal parameter.<-signal>\n");
2451		return 0;
2452	}
2453	sig = -sig;
2454
2455	pid = simple_strtol(argv[2], &endp, 0);
2456	if (*endp)
2457		return KDB_BADINT;
2458	if (pid <= 0) {
2459		kdb_printf("Process ID must be large than 0.\n");
2460		return 0;
2461	}
2462
2463	/* Find the process. */
2464	p = find_task_by_pid_ns(pid, &init_pid_ns);
2465	if (!p) {
2466		kdb_printf("The specified process isn't found.\n");
2467		return 0;
2468	}
2469	p = p->group_leader;
2470	info.si_signo = sig;
2471	info.si_errno = 0;
2472	info.si_code = SI_USER;
2473	info.si_pid = pid;  /* same capabilities as process being signalled */
2474	info.si_uid = 0;    /* kdb has root authority */
2475	kdb_send_sig_info(p, &info);
2476	return 0;
2477}
2478
2479struct kdb_tm {
2480	int tm_sec;	/* seconds */
2481	int tm_min;	/* minutes */
2482	int tm_hour;	/* hours */
2483	int tm_mday;	/* day of the month */
2484	int tm_mon;	/* month */
2485	int tm_year;	/* year */
2486};
2487
2488static void kdb_gmtime(struct timespec *tv, struct kdb_tm *tm)
2489{
2490	/* This will work from 1970-2099, 2100 is not a leap year */
2491	static int mon_day[] = { 31, 29, 31, 30, 31, 30, 31,
2492				 31, 30, 31, 30, 31 };
2493	memset(tm, 0, sizeof(*tm));
2494	tm->tm_sec  = tv->tv_sec % (24 * 60 * 60);
2495	tm->tm_mday = tv->tv_sec / (24 * 60 * 60) +
2496		(2 * 365 + 1); /* shift base from 1970 to 1968 */
2497	tm->tm_min =  tm->tm_sec / 60 % 60;
2498	tm->tm_hour = tm->tm_sec / 60 / 60;
2499	tm->tm_sec =  tm->tm_sec % 60;
2500	tm->tm_year = 68 + 4*(tm->tm_mday / (4*365+1));
2501	tm->tm_mday %= (4*365+1);
2502	mon_day[1] = 29;
2503	while (tm->tm_mday >= mon_day[tm->tm_mon]) {
2504		tm->tm_mday -= mon_day[tm->tm_mon];
2505		if (++tm->tm_mon == 12) {
2506			tm->tm_mon = 0;
2507			++tm->tm_year;
2508			mon_day[1] = 28;
2509		}
2510	}
2511	++tm->tm_mday;
2512}
2513
2514/*
2515 * Most of this code has been lifted from kernel/timer.c::sys_sysinfo().
2516 * I cannot call that code directly from kdb, it has an unconditional
2517 * cli()/sti() and calls routines that take locks which can stop the debugger.
2518 */
2519static void kdb_sysinfo(struct sysinfo *val)
2520{
2521	struct timespec uptime;
2522	ktime_get_ts(&uptime);
2523	memset(val, 0, sizeof(*val));
2524	val->uptime = uptime.tv_sec;
2525	val->loads[0] = avenrun[0];
2526	val->loads[1] = avenrun[1];
2527	val->loads[2] = avenrun[2];
2528	val->procs = nr_threads-1;
2529	si_meminfo(val);
2530
2531	return;
2532}
2533
2534/*
2535 * kdb_summary - This function implements the 'summary' command.
2536 */
2537static int kdb_summary(int argc, const char **argv)
2538{
2539	struct timespec now;
2540	struct kdb_tm tm;
2541	struct sysinfo val;
2542
2543	if (argc)
2544		return KDB_ARGCOUNT;
2545
2546	kdb_printf("sysname    %s\n", init_uts_ns.name.sysname);
2547	kdb_printf("release    %s\n", init_uts_ns.name.release);
2548	kdb_printf("version    %s\n", init_uts_ns.name.version);
2549	kdb_printf("machine    %s\n", init_uts_ns.name.machine);
2550	kdb_printf("nodename   %s\n", init_uts_ns.name.nodename);
2551	kdb_printf("domainname %s\n", init_uts_ns.name.domainname);
2552	kdb_printf("ccversion  %s\n", __stringify(CCVERSION));
2553
2554	now = __current_kernel_time();
2555	kdb_gmtime(&now, &tm);
2556	kdb_printf("date       %04d-%02d-%02d %02d:%02d:%02d "
2557		   "tz_minuteswest %d\n",
2558		1900+tm.tm_year, tm.tm_mon+1, tm.tm_mday,
2559		tm.tm_hour, tm.tm_min, tm.tm_sec,
2560		sys_tz.tz_minuteswest);
2561
2562	kdb_sysinfo(&val);
2563	kdb_printf("uptime     ");
2564	if (val.uptime > (24*60*60)) {
2565		int days = val.uptime / (24*60*60);
2566		val.uptime %= (24*60*60);
2567		kdb_printf("%d day%s ", days, days == 1 ? "" : "s");
2568	}
2569	kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
2570
2571	/* lifted from fs/proc/proc_misc.c::loadavg_read_proc() */
2572
2573#define LOAD_INT(x) ((x) >> FSHIFT)
2574#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
2575	kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
2576		LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
2577		LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
2578		LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
2579#undef LOAD_INT
2580#undef LOAD_FRAC
2581	/* Display in kilobytes */
2582#define K(x) ((x) << (PAGE_SHIFT - 10))
2583	kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
2584		   "Buffers:        %8lu kB\n",
2585		   K(val.totalram), K(val.freeram), K(val.bufferram));
2586	return 0;
2587}
2588
2589/*
2590 * kdb_per_cpu - This function implements the 'per_cpu' command.
2591 */
2592static int kdb_per_cpu(int argc, const char **argv)
2593{
2594	char fmtstr[64];
2595	int cpu, diag, nextarg = 1;
2596	unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL;
2597
2598	if (argc < 1 || argc > 3)
2599		return KDB_ARGCOUNT;
2600
2601	diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL);
2602	if (diag)
2603		return diag;
2604
2605	if (argc >= 2) {
2606		diag = kdbgetularg(argv[2], &bytesperword);
2607		if (diag)
2608			return diag;
2609	}
2610	if (!bytesperword)
2611		bytesperword = KDB_WORD_SIZE;
2612	else if (bytesperword > KDB_WORD_SIZE)
2613		return KDB_BADWIDTH;
2614	sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword));
2615	if (argc >= 3) {
2616		diag = kdbgetularg(argv[3], &whichcpu);
2617		if (diag)
2618			return diag;
2619		if (!cpu_online(whichcpu)) {
2620			kdb_printf("cpu %ld is not online\n", whichcpu);
2621			return KDB_BADCPUNUM;
2622		}
2623	}
2624
2625	/* Most architectures use __per_cpu_offset[cpu], some use
2626	 * __per_cpu_offset(cpu), smp has no __per_cpu_offset.
2627	 */
2628#ifdef	__per_cpu_offset
2629#define KDB_PCU(cpu) __per_cpu_offset(cpu)
2630#else
2631#ifdef	CONFIG_SMP
2632#define KDB_PCU(cpu) __per_cpu_offset[cpu]
2633#else
2634#define KDB_PCU(cpu) 0
2635#endif
2636#endif
2637	for_each_online_cpu(cpu) {
2638		if (KDB_FLAG(CMD_INTERRUPT))
2639			return 0;
2640
2641		if (whichcpu != ~0UL && whichcpu != cpu)
2642			continue;
2643		addr = symaddr + KDB_PCU(cpu);
2644		diag = kdb_getword(&val, addr, bytesperword);
2645		if (diag) {
2646			kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to "
2647				   "read, diag=%d\n", cpu, addr, diag);
2648			continue;
2649		}
2650		kdb_printf("%5d ", cpu);
2651		kdb_md_line(fmtstr, addr,
2652			bytesperword == KDB_WORD_SIZE,
2653			1, bytesperword, 1, 1, 0);
2654	}
2655#undef KDB_PCU
2656	return 0;
2657}
2658
2659/*
2660 * display help for the use of cmd | grep pattern
2661 */
2662static int kdb_grep_help(int argc, const char **argv)
2663{
2664	kdb_printf("Usage of  cmd args | grep pattern:\n");
2665	kdb_printf("  Any command's output may be filtered through an ");
2666	kdb_printf("emulated 'pipe'.\n");
2667	kdb_printf("  'grep' is just a key word.\n");
2668	kdb_printf("  The pattern may include a very limited set of "
2669		   "metacharacters:\n");
2670	kdb_printf("   pattern or ^pattern or pattern$ or ^pattern$\n");
2671	kdb_printf("  And if there are spaces in the pattern, you may "
2672		   "quote it:\n");
2673	kdb_printf("   \"pat tern\" or \"^pat tern\" or \"pat tern$\""
2674		   " or \"^pat tern$\"\n");
2675	return 0;
2676}
2677
2678/*
2679 * kdb_register_flags - This function is used to register a kernel
2680 * 	debugger command.
2681 * Inputs:
2682 *	cmd	Command name
2683 *	func	Function to execute the command
2684 *	usage	A simple usage string showing arguments
2685 *	help	A simple help string describing command
2686 *	repeat	Does the command auto repeat on enter?
2687 * Returns:
2688 *	zero for success, one if a duplicate command.
2689 */
2690#define kdb_command_extend 50	/* arbitrary */
2691int kdb_register_flags(char *cmd,
2692		       kdb_func_t func,
2693		       char *usage,
2694		       char *help,
2695		       short minlen,
2696		       kdb_cmdflags_t flags)
2697{
2698	int i;
2699	kdbtab_t *kp;
2700
2701	/*
2702	 *  Brute force method to determine duplicates
2703	 */
2704	for_each_kdbcmd(kp, i) {
2705		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2706			kdb_printf("Duplicate kdb command registered: "
2707				"%s, func %p help %s\n", cmd, func, help);
2708			return 1;
2709		}
2710	}
2711
2712	/*
2713	 * Insert command into first available location in table
2714	 */
2715	for_each_kdbcmd(kp, i) {
2716		if (kp->cmd_name == NULL)
2717			break;
2718	}
2719
2720	if (i >= kdb_max_commands) {
2721		kdbtab_t *new = kmalloc((kdb_max_commands - KDB_BASE_CMD_MAX +
2722			 kdb_command_extend) * sizeof(*new), GFP_KDB);
2723		if (!new) {
2724			kdb_printf("Could not allocate new kdb_command "
2725				   "table\n");
2726			return 1;
2727		}
2728		if (kdb_commands) {
2729			memcpy(new, kdb_commands,
2730			  (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
2731			kfree(kdb_commands);
2732		}
2733		memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
2734		       kdb_command_extend * sizeof(*new));
2735		kdb_commands = new;
2736		kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
2737		kdb_max_commands += kdb_command_extend;
2738	}
2739
2740	kp->cmd_name   = cmd;
2741	kp->cmd_func   = func;
2742	kp->cmd_usage  = usage;
2743	kp->cmd_help   = help;
2744	kp->cmd_minlen = minlen;
2745	kp->cmd_flags  = flags;
2746
2747	return 0;
2748}
2749EXPORT_SYMBOL_GPL(kdb_register_flags);
2750
2751
2752/*
2753 * kdb_register - Compatibility register function for commands that do
2754 *	not need to specify a repeat state.  Equivalent to
2755 *	kdb_register_flags with flags set to 0.
2756 * Inputs:
2757 *	cmd	Command name
2758 *	func	Function to execute the command
2759 *	usage	A simple usage string showing arguments
2760 *	help	A simple help string describing command
2761 * Returns:
2762 *	zero for success, one if a duplicate command.
2763 */
2764int kdb_register(char *cmd,
2765	     kdb_func_t func,
2766	     char *usage,
2767	     char *help,
2768	     short minlen)
2769{
2770	return kdb_register_flags(cmd, func, usage, help, minlen, 0);
2771}
2772EXPORT_SYMBOL_GPL(kdb_register);
2773
2774/*
2775 * kdb_unregister - This function is used to unregister a kernel
2776 *	debugger command.  It is generally called when a module which
2777 *	implements kdb commands is unloaded.
2778 * Inputs:
2779 *	cmd	Command name
2780 * Returns:
2781 *	zero for success, one command not registered.
2782 */
2783int kdb_unregister(char *cmd)
2784{
2785	int i;
2786	kdbtab_t *kp;
2787
2788	/*
2789	 *  find the command.
2790	 */
2791	for_each_kdbcmd(kp, i) {
2792		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2793			kp->cmd_name = NULL;
2794			return 0;
2795		}
2796	}
2797
2798	/* Couldn't find it.  */
2799	return 1;
2800}
2801EXPORT_SYMBOL_GPL(kdb_unregister);
2802
2803/* Initialize the kdb command table. */
2804static void __init kdb_inittab(void)
2805{
2806	int i;
2807	kdbtab_t *kp;
2808
2809	for_each_kdbcmd(kp, i)
2810		kp->cmd_name = NULL;
2811
2812	kdb_register_flags("md", kdb_md, "<vaddr>",
2813	  "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
2814	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2815	kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
2816	  "Display Raw Memory", 0,
2817	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2818	kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
2819	  "Display Physical Memory", 0,
2820	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2821	kdb_register_flags("mds", kdb_md, "<vaddr>",
2822	  "Display Memory Symbolically", 0,
2823	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2824	kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
2825	  "Modify Memory Contents", 0,
2826	  KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
2827	kdb_register_flags("go", kdb_go, "[<vaddr>]",
2828	  "Continue Execution", 1,
2829	  KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2830	kdb_register_flags("rd", kdb_rd, "",
2831	  "Display Registers", 0,
2832	  KDB_ENABLE_REG_READ);
2833	kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
2834	  "Modify Registers", 0,
2835	  KDB_ENABLE_REG_WRITE);
2836	kdb_register_flags("ef", kdb_ef, "<vaddr>",
2837	  "Display exception frame", 0,
2838	  KDB_ENABLE_MEM_READ);
2839	kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
2840	  "Stack traceback", 1,
2841	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2842	kdb_register_flags("btp", kdb_bt, "<pid>",
2843	  "Display stack for process <pid>", 0,
2844	  KDB_ENABLE_INSPECT);
2845	kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
2846	  "Backtrace all processes matching state flag", 0,
2847	  KDB_ENABLE_INSPECT);
2848	kdb_register_flags("btc", kdb_bt, "",
2849	  "Backtrace current process on each cpu", 0,
2850	  KDB_ENABLE_INSPECT);
2851	kdb_register_flags("btt", kdb_bt, "<vaddr>",
2852	  "Backtrace process given its struct task address", 0,
2853	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2854	kdb_register_flags("env", kdb_env, "",
2855	  "Show environment variables", 0,
2856	  KDB_ENABLE_ALWAYS_SAFE);
2857	kdb_register_flags("set", kdb_set, "",
2858	  "Set environment variables", 0,
2859	  KDB_ENABLE_ALWAYS_SAFE);
2860	kdb_register_flags("help", kdb_help, "",
2861	  "Display Help Message", 1,
2862	  KDB_ENABLE_ALWAYS_SAFE);
2863	kdb_register_flags("?", kdb_help, "",
2864	  "Display Help Message", 0,
2865	  KDB_ENABLE_ALWAYS_SAFE);
2866	kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
2867	  "Switch to new cpu", 0,
2868	  KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2869	kdb_register_flags("kgdb", kdb_kgdb, "",
2870	  "Enter kgdb mode", 0, 0);
2871	kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
2872	  "Display active task list", 0,
2873	  KDB_ENABLE_INSPECT);
2874	kdb_register_flags("pid", kdb_pid, "<pidnum>",
2875	  "Switch to another task", 0,
2876	  KDB_ENABLE_INSPECT);
2877	kdb_register_flags("reboot", kdb_reboot, "",
2878	  "Reboot the machine immediately", 0,
2879	  KDB_ENABLE_REBOOT);
2880#if defined(CONFIG_MODULES)
2881	kdb_register_flags("lsmod", kdb_lsmod, "",
2882	  "List loaded kernel modules", 0,
2883	  KDB_ENABLE_INSPECT);
2884#endif
2885#if defined(CONFIG_MAGIC_SYSRQ)
2886	kdb_register_flags("sr", kdb_sr, "<key>",
2887	  "Magic SysRq key", 0,
2888	  KDB_ENABLE_ALWAYS_SAFE);
2889#endif
2890#if defined(CONFIG_PRINTK)
2891	kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
2892	  "Display syslog buffer", 0,
2893	  KDB_ENABLE_ALWAYS_SAFE);
2894#endif
2895	if (arch_kgdb_ops.enable_nmi) {
2896		kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
2897		  "Disable NMI entry to KDB", 0,
2898		  KDB_ENABLE_ALWAYS_SAFE);
2899	}
2900	kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
2901	  "Define a set of commands, down to endefcmd", 0,
2902	  KDB_ENABLE_ALWAYS_SAFE);
2903	kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
2904	  "Send a signal to a process", 0,
2905	  KDB_ENABLE_SIGNAL);
2906	kdb_register_flags("summary", kdb_summary, "",
2907	  "Summarize the system", 4,
2908	  KDB_ENABLE_ALWAYS_SAFE);
2909	kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
2910	  "Display per_cpu variables", 3,
2911	  KDB_ENABLE_MEM_READ);
2912	kdb_register_flags("grephelp", kdb_grep_help, "",
2913	  "Display help on | grep", 0,
2914	  KDB_ENABLE_ALWAYS_SAFE);
2915}
2916
2917/* Execute any commands defined in kdb_cmds.  */
2918static void __init kdb_cmd_init(void)
2919{
2920	int i, diag;
2921	for (i = 0; kdb_cmds[i]; ++i) {
2922		diag = kdb_parse(kdb_cmds[i]);
2923		if (diag)
2924			kdb_printf("kdb command %s failed, kdb diag %d\n",
2925				kdb_cmds[i], diag);
2926	}
2927	if (defcmd_in_progress) {
2928		kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n");
2929		kdb_parse("endefcmd");
2930	}
2931}
2932
2933/* Initialize kdb_printf, breakpoint tables and kdb state */
2934void __init kdb_init(int lvl)
2935{
2936	static int kdb_init_lvl = KDB_NOT_INITIALIZED;
2937	int i;
2938
2939	if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl)
2940		return;
2941	for (i = kdb_init_lvl; i < lvl; i++) {
2942		switch (i) {
2943		case KDB_NOT_INITIALIZED:
2944			kdb_inittab();		/* Initialize Command Table */
2945			kdb_initbptab();	/* Initialize Breakpoints */
2946			break;
2947		case KDB_INIT_EARLY:
2948			kdb_cmd_init();		/* Build kdb_cmds tables */
2949			break;
2950		}
2951	}
2952	kdb_init_lvl = lvl;
2953}
v4.17
   1/*
   2 * Kernel Debugger Architecture Independent Main Code
   3 *
   4 * This file is subject to the terms and conditions of the GNU General Public
   5 * License.  See the file "COPYING" in the main directory of this archive
   6 * for more details.
   7 *
   8 * Copyright (C) 1999-2004 Silicon Graphics, Inc.  All Rights Reserved.
   9 * Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
  10 * Xscale (R) modifications copyright (C) 2003 Intel Corporation.
  11 * Copyright (c) 2009 Wind River Systems, Inc.  All Rights Reserved.
  12 */
  13
  14#include <linux/ctype.h>
  15#include <linux/types.h>
  16#include <linux/string.h>
  17#include <linux/kernel.h>
  18#include <linux/kmsg_dump.h>
  19#include <linux/reboot.h>
  20#include <linux/sched.h>
  21#include <linux/sched/loadavg.h>
  22#include <linux/sched/stat.h>
  23#include <linux/sched/debug.h>
  24#include <linux/sysrq.h>
  25#include <linux/smp.h>
  26#include <linux/utsname.h>
  27#include <linux/vmalloc.h>
  28#include <linux/atomic.h>
  29#include <linux/module.h>
  30#include <linux/moduleparam.h>
  31#include <linux/mm.h>
  32#include <linux/init.h>
  33#include <linux/kallsyms.h>
  34#include <linux/kgdb.h>
  35#include <linux/kdb.h>
  36#include <linux/notifier.h>
  37#include <linux/interrupt.h>
  38#include <linux/delay.h>
  39#include <linux/nmi.h>
  40#include <linux/time.h>
  41#include <linux/ptrace.h>
  42#include <linux/sysctl.h>
  43#include <linux/cpu.h>
  44#include <linux/kdebug.h>
  45#include <linux/proc_fs.h>
  46#include <linux/uaccess.h>
  47#include <linux/slab.h>
  48#include "kdb_private.h"
  49
  50#undef	MODULE_PARAM_PREFIX
  51#define	MODULE_PARAM_PREFIX "kdb."
  52
  53static int kdb_cmd_enabled = CONFIG_KDB_DEFAULT_ENABLE;
  54module_param_named(cmd_enable, kdb_cmd_enabled, int, 0600);
  55
  56char kdb_grep_string[KDB_GREP_STRLEN];
  57int kdb_grepping_flag;
  58EXPORT_SYMBOL(kdb_grepping_flag);
  59int kdb_grep_leading;
  60int kdb_grep_trailing;
  61
  62/*
  63 * Kernel debugger state flags
  64 */
  65int kdb_flags;
  66
  67/*
  68 * kdb_lock protects updates to kdb_initial_cpu.  Used to
  69 * single thread processors through the kernel debugger.
  70 */
  71int kdb_initial_cpu = -1;	/* cpu number that owns kdb */
  72int kdb_nextline = 1;
  73int kdb_state;			/* General KDB state */
  74
  75struct task_struct *kdb_current_task;
  76EXPORT_SYMBOL(kdb_current_task);
  77struct pt_regs *kdb_current_regs;
  78
  79const char *kdb_diemsg;
  80static int kdb_go_count;
  81#ifdef CONFIG_KDB_CONTINUE_CATASTROPHIC
  82static unsigned int kdb_continue_catastrophic =
  83	CONFIG_KDB_CONTINUE_CATASTROPHIC;
  84#else
  85static unsigned int kdb_continue_catastrophic;
  86#endif
  87
  88/* kdb_commands describes the available commands. */
  89static kdbtab_t *kdb_commands;
  90#define KDB_BASE_CMD_MAX 50
  91static int kdb_max_commands = KDB_BASE_CMD_MAX;
  92static kdbtab_t kdb_base_commands[KDB_BASE_CMD_MAX];
  93#define for_each_kdbcmd(cmd, num)					\
  94	for ((cmd) = kdb_base_commands, (num) = 0;			\
  95	     num < kdb_max_commands;					\
  96	     num++, num == KDB_BASE_CMD_MAX ? cmd = kdb_commands : cmd++)
  97
  98typedef struct _kdbmsg {
  99	int	km_diag;	/* kdb diagnostic */
 100	char	*km_msg;	/* Corresponding message text */
 101} kdbmsg_t;
 102
 103#define KDBMSG(msgnum, text) \
 104	{ KDB_##msgnum, text }
 105
 106static kdbmsg_t kdbmsgs[] = {
 107	KDBMSG(NOTFOUND, "Command Not Found"),
 108	KDBMSG(ARGCOUNT, "Improper argument count, see usage."),
 109	KDBMSG(BADWIDTH, "Illegal value for BYTESPERWORD use 1, 2, 4 or 8, "
 110	       "8 is only allowed on 64 bit systems"),
 111	KDBMSG(BADRADIX, "Illegal value for RADIX use 8, 10 or 16"),
 112	KDBMSG(NOTENV, "Cannot find environment variable"),
 113	KDBMSG(NOENVVALUE, "Environment variable should have value"),
 114	KDBMSG(NOTIMP, "Command not implemented"),
 115	KDBMSG(ENVFULL, "Environment full"),
 116	KDBMSG(ENVBUFFULL, "Environment buffer full"),
 117	KDBMSG(TOOMANYBPT, "Too many breakpoints defined"),
 118#ifdef CONFIG_CPU_XSCALE
 119	KDBMSG(TOOMANYDBREGS, "More breakpoints than ibcr registers defined"),
 120#else
 121	KDBMSG(TOOMANYDBREGS, "More breakpoints than db registers defined"),
 122#endif
 123	KDBMSG(DUPBPT, "Duplicate breakpoint address"),
 124	KDBMSG(BPTNOTFOUND, "Breakpoint not found"),
 125	KDBMSG(BADMODE, "Invalid IDMODE"),
 126	KDBMSG(BADINT, "Illegal numeric value"),
 127	KDBMSG(INVADDRFMT, "Invalid symbolic address format"),
 128	KDBMSG(BADREG, "Invalid register name"),
 129	KDBMSG(BADCPUNUM, "Invalid cpu number"),
 130	KDBMSG(BADLENGTH, "Invalid length field"),
 131	KDBMSG(NOBP, "No Breakpoint exists"),
 132	KDBMSG(BADADDR, "Invalid address"),
 133	KDBMSG(NOPERM, "Permission denied"),
 134};
 135#undef KDBMSG
 136
 137static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
 138
 139
 140/*
 141 * Initial environment.   This is all kept static and local to
 142 * this file.   We don't want to rely on the memory allocation
 143 * mechanisms in the kernel, so we use a very limited allocate-only
 144 * heap for new and altered environment variables.  The entire
 145 * environment is limited to a fixed number of entries (add more
 146 * to __env[] if required) and a fixed amount of heap (add more to
 147 * KDB_ENVBUFSIZE if required).
 148 */
 149
 150static char *__env[] = {
 151#if defined(CONFIG_SMP)
 152 "PROMPT=[%d]kdb> ",
 153#else
 154 "PROMPT=kdb> ",
 155#endif
 156 "MOREPROMPT=more> ",
 157 "RADIX=16",
 158 "MDCOUNT=8",			/* lines of md output */
 159 KDB_PLATFORM_ENV,
 160 "DTABCOUNT=30",
 161 "NOSECT=1",
 162 (char *)0,
 163 (char *)0,
 164 (char *)0,
 165 (char *)0,
 166 (char *)0,
 167 (char *)0,
 168 (char *)0,
 169 (char *)0,
 170 (char *)0,
 171 (char *)0,
 172 (char *)0,
 173 (char *)0,
 174 (char *)0,
 175 (char *)0,
 176 (char *)0,
 177 (char *)0,
 178 (char *)0,
 179 (char *)0,
 180 (char *)0,
 181 (char *)0,
 182 (char *)0,
 183 (char *)0,
 184 (char *)0,
 185 (char *)0,
 186};
 187
 188static const int __nenv = ARRAY_SIZE(__env);
 189
 190struct task_struct *kdb_curr_task(int cpu)
 191{
 192	struct task_struct *p = curr_task(cpu);
 193#ifdef	_TIF_MCA_INIT
 194	if ((task_thread_info(p)->flags & _TIF_MCA_INIT) && KDB_TSK(cpu))
 195		p = krp->p;
 196#endif
 197	return p;
 198}
 199
 200/*
 201 * Check whether the flags of the current command and the permissions
 202 * of the kdb console has allow a command to be run.
 203 */
 204static inline bool kdb_check_flags(kdb_cmdflags_t flags, int permissions,
 205				   bool no_args)
 206{
 207	/* permissions comes from userspace so needs massaging slightly */
 208	permissions &= KDB_ENABLE_MASK;
 209	permissions |= KDB_ENABLE_ALWAYS_SAFE;
 210
 211	/* some commands change group when launched with no arguments */
 212	if (no_args)
 213		permissions |= permissions << KDB_ENABLE_NO_ARGS_SHIFT;
 214
 215	flags |= KDB_ENABLE_ALL;
 216
 217	return permissions & flags;
 218}
 219
 220/*
 221 * kdbgetenv - This function will return the character string value of
 222 *	an environment variable.
 223 * Parameters:
 224 *	match	A character string representing an environment variable.
 225 * Returns:
 226 *	NULL	No environment variable matches 'match'
 227 *	char*	Pointer to string value of environment variable.
 228 */
 229char *kdbgetenv(const char *match)
 230{
 231	char **ep = __env;
 232	int matchlen = strlen(match);
 233	int i;
 234
 235	for (i = 0; i < __nenv; i++) {
 236		char *e = *ep++;
 237
 238		if (!e)
 239			continue;
 240
 241		if ((strncmp(match, e, matchlen) == 0)
 242		 && ((e[matchlen] == '\0')
 243		   || (e[matchlen] == '='))) {
 244			char *cp = strchr(e, '=');
 245			return cp ? ++cp : "";
 246		}
 247	}
 248	return NULL;
 249}
 250
 251/*
 252 * kdballocenv - This function is used to allocate bytes for
 253 *	environment entries.
 254 * Parameters:
 255 *	match	A character string representing a numeric value
 256 * Outputs:
 257 *	*value  the unsigned long representation of the env variable 'match'
 258 * Returns:
 259 *	Zero on success, a kdb diagnostic on failure.
 260 * Remarks:
 261 *	We use a static environment buffer (envbuffer) to hold the values
 262 *	of dynamically generated environment variables (see kdb_set).  Buffer
 263 *	space once allocated is never free'd, so over time, the amount of space
 264 *	(currently 512 bytes) will be exhausted if env variables are changed
 265 *	frequently.
 266 */
 267static char *kdballocenv(size_t bytes)
 268{
 269#define	KDB_ENVBUFSIZE	512
 270	static char envbuffer[KDB_ENVBUFSIZE];
 271	static int envbufsize;
 272	char *ep = NULL;
 273
 274	if ((KDB_ENVBUFSIZE - envbufsize) >= bytes) {
 275		ep = &envbuffer[envbufsize];
 276		envbufsize += bytes;
 277	}
 278	return ep;
 279}
 280
 281/*
 282 * kdbgetulenv - This function will return the value of an unsigned
 283 *	long-valued environment variable.
 284 * Parameters:
 285 *	match	A character string representing a numeric value
 286 * Outputs:
 287 *	*value  the unsigned long represntation of the env variable 'match'
 288 * Returns:
 289 *	Zero on success, a kdb diagnostic on failure.
 290 */
 291static int kdbgetulenv(const char *match, unsigned long *value)
 292{
 293	char *ep;
 294
 295	ep = kdbgetenv(match);
 296	if (!ep)
 297		return KDB_NOTENV;
 298	if (strlen(ep) == 0)
 299		return KDB_NOENVVALUE;
 300
 301	*value = simple_strtoul(ep, NULL, 0);
 302
 303	return 0;
 304}
 305
 306/*
 307 * kdbgetintenv - This function will return the value of an
 308 *	integer-valued environment variable.
 309 * Parameters:
 310 *	match	A character string representing an integer-valued env variable
 311 * Outputs:
 312 *	*value  the integer representation of the environment variable 'match'
 313 * Returns:
 314 *	Zero on success, a kdb diagnostic on failure.
 315 */
 316int kdbgetintenv(const char *match, int *value)
 317{
 318	unsigned long val;
 319	int diag;
 320
 321	diag = kdbgetulenv(match, &val);
 322	if (!diag)
 323		*value = (int) val;
 324	return diag;
 325}
 326
 327/*
 328 * kdbgetularg - This function will convert a numeric string into an
 329 *	unsigned long value.
 330 * Parameters:
 331 *	arg	A character string representing a numeric value
 332 * Outputs:
 333 *	*value  the unsigned long represntation of arg.
 334 * Returns:
 335 *	Zero on success, a kdb diagnostic on failure.
 336 */
 337int kdbgetularg(const char *arg, unsigned long *value)
 338{
 339	char *endp;
 340	unsigned long val;
 341
 342	val = simple_strtoul(arg, &endp, 0);
 343
 344	if (endp == arg) {
 345		/*
 346		 * Also try base 16, for us folks too lazy to type the
 347		 * leading 0x...
 348		 */
 349		val = simple_strtoul(arg, &endp, 16);
 350		if (endp == arg)
 351			return KDB_BADINT;
 352	}
 353
 354	*value = val;
 355
 356	return 0;
 357}
 358
 359int kdbgetu64arg(const char *arg, u64 *value)
 360{
 361	char *endp;
 362	u64 val;
 363
 364	val = simple_strtoull(arg, &endp, 0);
 365
 366	if (endp == arg) {
 367
 368		val = simple_strtoull(arg, &endp, 16);
 369		if (endp == arg)
 370			return KDB_BADINT;
 371	}
 372
 373	*value = val;
 374
 375	return 0;
 376}
 377
 378/*
 379 * kdb_set - This function implements the 'set' command.  Alter an
 380 *	existing environment variable or create a new one.
 381 */
 382int kdb_set(int argc, const char **argv)
 383{
 384	int i;
 385	char *ep;
 386	size_t varlen, vallen;
 387
 388	/*
 389	 * we can be invoked two ways:
 390	 *   set var=value    argv[1]="var", argv[2]="value"
 391	 *   set var = value  argv[1]="var", argv[2]="=", argv[3]="value"
 392	 * - if the latter, shift 'em down.
 393	 */
 394	if (argc == 3) {
 395		argv[2] = argv[3];
 396		argc--;
 397	}
 398
 399	if (argc != 2)
 400		return KDB_ARGCOUNT;
 401
 402	/*
 403	 * Check for internal variables
 404	 */
 405	if (strcmp(argv[1], "KDBDEBUG") == 0) {
 406		unsigned int debugflags;
 407		char *cp;
 408
 409		debugflags = simple_strtoul(argv[2], &cp, 0);
 410		if (cp == argv[2] || debugflags & ~KDB_DEBUG_FLAG_MASK) {
 411			kdb_printf("kdb: illegal debug flags '%s'\n",
 412				    argv[2]);
 413			return 0;
 414		}
 415		kdb_flags = (kdb_flags &
 416			     ~(KDB_DEBUG_FLAG_MASK << KDB_DEBUG_FLAG_SHIFT))
 417			| (debugflags << KDB_DEBUG_FLAG_SHIFT);
 418
 419		return 0;
 420	}
 421
 422	/*
 423	 * Tokenizer squashed the '=' sign.  argv[1] is variable
 424	 * name, argv[2] = value.
 425	 */
 426	varlen = strlen(argv[1]);
 427	vallen = strlen(argv[2]);
 428	ep = kdballocenv(varlen + vallen + 2);
 429	if (ep == (char *)0)
 430		return KDB_ENVBUFFULL;
 431
 432	sprintf(ep, "%s=%s", argv[1], argv[2]);
 433
 434	ep[varlen+vallen+1] = '\0';
 435
 436	for (i = 0; i < __nenv; i++) {
 437		if (__env[i]
 438		 && ((strncmp(__env[i], argv[1], varlen) == 0)
 439		   && ((__env[i][varlen] == '\0')
 440		    || (__env[i][varlen] == '=')))) {
 441			__env[i] = ep;
 442			return 0;
 443		}
 444	}
 445
 446	/*
 447	 * Wasn't existing variable.  Fit into slot.
 448	 */
 449	for (i = 0; i < __nenv-1; i++) {
 450		if (__env[i] == (char *)0) {
 451			__env[i] = ep;
 452			return 0;
 453		}
 454	}
 455
 456	return KDB_ENVFULL;
 457}
 458
 459static int kdb_check_regs(void)
 460{
 461	if (!kdb_current_regs) {
 462		kdb_printf("No current kdb registers."
 463			   "  You may need to select another task\n");
 464		return KDB_BADREG;
 465	}
 466	return 0;
 467}
 468
 469/*
 470 * kdbgetaddrarg - This function is responsible for parsing an
 471 *	address-expression and returning the value of the expression,
 472 *	symbol name, and offset to the caller.
 473 *
 474 *	The argument may consist of a numeric value (decimal or
 475 *	hexidecimal), a symbol name, a register name (preceded by the
 476 *	percent sign), an environment variable with a numeric value
 477 *	(preceded by a dollar sign) or a simple arithmetic expression
 478 *	consisting of a symbol name, +/-, and a numeric constant value
 479 *	(offset).
 480 * Parameters:
 481 *	argc	- count of arguments in argv
 482 *	argv	- argument vector
 483 *	*nextarg - index to next unparsed argument in argv[]
 484 *	regs	- Register state at time of KDB entry
 485 * Outputs:
 486 *	*value	- receives the value of the address-expression
 487 *	*offset - receives the offset specified, if any
 488 *	*name   - receives the symbol name, if any
 489 *	*nextarg - index to next unparsed argument in argv[]
 490 * Returns:
 491 *	zero is returned on success, a kdb diagnostic code is
 492 *      returned on error.
 493 */
 494int kdbgetaddrarg(int argc, const char **argv, int *nextarg,
 495		  unsigned long *value,  long *offset,
 496		  char **name)
 497{
 498	unsigned long addr;
 499	unsigned long off = 0;
 500	int positive;
 501	int diag;
 502	int found = 0;
 503	char *symname;
 504	char symbol = '\0';
 505	char *cp;
 506	kdb_symtab_t symtab;
 507
 508	/*
 509	 * If the enable flags prohibit both arbitrary memory access
 510	 * and flow control then there are no reasonable grounds to
 511	 * provide symbol lookup.
 512	 */
 513	if (!kdb_check_flags(KDB_ENABLE_MEM_READ | KDB_ENABLE_FLOW_CTRL,
 514			     kdb_cmd_enabled, false))
 515		return KDB_NOPERM;
 516
 517	/*
 518	 * Process arguments which follow the following syntax:
 519	 *
 520	 *  symbol | numeric-address [+/- numeric-offset]
 521	 *  %register
 522	 *  $environment-variable
 523	 */
 524
 525	if (*nextarg > argc)
 526		return KDB_ARGCOUNT;
 527
 528	symname = (char *)argv[*nextarg];
 529
 530	/*
 531	 * If there is no whitespace between the symbol
 532	 * or address and the '+' or '-' symbols, we
 533	 * remember the character and replace it with a
 534	 * null so the symbol/value can be properly parsed
 535	 */
 536	cp = strpbrk(symname, "+-");
 537	if (cp != NULL) {
 538		symbol = *cp;
 539		*cp++ = '\0';
 540	}
 541
 542	if (symname[0] == '$') {
 543		diag = kdbgetulenv(&symname[1], &addr);
 544		if (diag)
 545			return diag;
 546	} else if (symname[0] == '%') {
 547		diag = kdb_check_regs();
 548		if (diag)
 549			return diag;
 550		/* Implement register values with % at a later time as it is
 551		 * arch optional.
 552		 */
 553		return KDB_NOTIMP;
 554	} else {
 555		found = kdbgetsymval(symname, &symtab);
 556		if (found) {
 557			addr = symtab.sym_start;
 558		} else {
 559			diag = kdbgetularg(argv[*nextarg], &addr);
 560			if (diag)
 561				return diag;
 562		}
 563	}
 564
 565	if (!found)
 566		found = kdbnearsym(addr, &symtab);
 567
 568	(*nextarg)++;
 569
 570	if (name)
 571		*name = symname;
 572	if (value)
 573		*value = addr;
 574	if (offset && name && *name)
 575		*offset = addr - symtab.sym_start;
 576
 577	if ((*nextarg > argc)
 578	 && (symbol == '\0'))
 579		return 0;
 580
 581	/*
 582	 * check for +/- and offset
 583	 */
 584
 585	if (symbol == '\0') {
 586		if ((argv[*nextarg][0] != '+')
 587		 && (argv[*nextarg][0] != '-')) {
 588			/*
 589			 * Not our argument.  Return.
 590			 */
 591			return 0;
 592		} else {
 593			positive = (argv[*nextarg][0] == '+');
 594			(*nextarg)++;
 595		}
 596	} else
 597		positive = (symbol == '+');
 598
 599	/*
 600	 * Now there must be an offset!
 601	 */
 602	if ((*nextarg > argc)
 603	 && (symbol == '\0')) {
 604		return KDB_INVADDRFMT;
 605	}
 606
 607	if (!symbol) {
 608		cp = (char *)argv[*nextarg];
 609		(*nextarg)++;
 610	}
 611
 612	diag = kdbgetularg(cp, &off);
 613	if (diag)
 614		return diag;
 615
 616	if (!positive)
 617		off = -off;
 618
 619	if (offset)
 620		*offset += off;
 621
 622	if (value)
 623		*value += off;
 624
 625	return 0;
 626}
 627
 628static void kdb_cmderror(int diag)
 629{
 630	int i;
 631
 632	if (diag >= 0) {
 633		kdb_printf("no error detected (diagnostic is %d)\n", diag);
 634		return;
 635	}
 636
 637	for (i = 0; i < __nkdb_err; i++) {
 638		if (kdbmsgs[i].km_diag == diag) {
 639			kdb_printf("diag: %d: %s\n", diag, kdbmsgs[i].km_msg);
 640			return;
 641		}
 642	}
 643
 644	kdb_printf("Unknown diag %d\n", -diag);
 645}
 646
 647/*
 648 * kdb_defcmd, kdb_defcmd2 - This function implements the 'defcmd'
 649 *	command which defines one command as a set of other commands,
 650 *	terminated by endefcmd.  kdb_defcmd processes the initial
 651 *	'defcmd' command, kdb_defcmd2 is invoked from kdb_parse for
 652 *	the following commands until 'endefcmd'.
 653 * Inputs:
 654 *	argc	argument count
 655 *	argv	argument vector
 656 * Returns:
 657 *	zero for success, a kdb diagnostic if error
 658 */
 659struct defcmd_set {
 660	int count;
 661	int usable;
 662	char *name;
 663	char *usage;
 664	char *help;
 665	char **command;
 666};
 667static struct defcmd_set *defcmd_set;
 668static int defcmd_set_count;
 669static int defcmd_in_progress;
 670
 671/* Forward references */
 672static int kdb_exec_defcmd(int argc, const char **argv);
 673
 674static int kdb_defcmd2(const char *cmdstr, const char *argv0)
 675{
 676	struct defcmd_set *s = defcmd_set + defcmd_set_count - 1;
 677	char **save_command = s->command;
 678	if (strcmp(argv0, "endefcmd") == 0) {
 679		defcmd_in_progress = 0;
 680		if (!s->count)
 681			s->usable = 0;
 682		if (s->usable)
 683			/* macros are always safe because when executed each
 684			 * internal command re-enters kdb_parse() and is
 685			 * safety checked individually.
 686			 */
 687			kdb_register_flags(s->name, kdb_exec_defcmd, s->usage,
 688					   s->help, 0,
 689					   KDB_ENABLE_ALWAYS_SAFE);
 690		return 0;
 691	}
 692	if (!s->usable)
 693		return KDB_NOTIMP;
 694	s->command = kzalloc((s->count + 1) * sizeof(*(s->command)), GFP_KDB);
 695	if (!s->command) {
 696		kdb_printf("Could not allocate new kdb_defcmd table for %s\n",
 697			   cmdstr);
 698		s->usable = 0;
 699		return KDB_NOTIMP;
 700	}
 701	memcpy(s->command, save_command, s->count * sizeof(*(s->command)));
 702	s->command[s->count++] = kdb_strdup(cmdstr, GFP_KDB);
 703	kfree(save_command);
 704	return 0;
 705}
 706
 707static int kdb_defcmd(int argc, const char **argv)
 708{
 709	struct defcmd_set *save_defcmd_set = defcmd_set, *s;
 710	if (defcmd_in_progress) {
 711		kdb_printf("kdb: nested defcmd detected, assuming missing "
 712			   "endefcmd\n");
 713		kdb_defcmd2("endefcmd", "endefcmd");
 714	}
 715	if (argc == 0) {
 716		int i;
 717		for (s = defcmd_set; s < defcmd_set + defcmd_set_count; ++s) {
 718			kdb_printf("defcmd %s \"%s\" \"%s\"\n", s->name,
 719				   s->usage, s->help);
 720			for (i = 0; i < s->count; ++i)
 721				kdb_printf("%s", s->command[i]);
 722			kdb_printf("endefcmd\n");
 723		}
 724		return 0;
 725	}
 726	if (argc != 3)
 727		return KDB_ARGCOUNT;
 728	if (in_dbg_master()) {
 729		kdb_printf("Command only available during kdb_init()\n");
 730		return KDB_NOTIMP;
 731	}
 732	defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
 733			     GFP_KDB);
 734	if (!defcmd_set)
 735		goto fail_defcmd;
 736	memcpy(defcmd_set, save_defcmd_set,
 737	       defcmd_set_count * sizeof(*defcmd_set));
 738	s = defcmd_set + defcmd_set_count;
 739	memset(s, 0, sizeof(*s));
 740	s->usable = 1;
 741	s->name = kdb_strdup(argv[1], GFP_KDB);
 742	if (!s->name)
 743		goto fail_name;
 744	s->usage = kdb_strdup(argv[2], GFP_KDB);
 745	if (!s->usage)
 746		goto fail_usage;
 747	s->help = kdb_strdup(argv[3], GFP_KDB);
 748	if (!s->help)
 749		goto fail_help;
 750	if (s->usage[0] == '"') {
 751		strcpy(s->usage, argv[2]+1);
 752		s->usage[strlen(s->usage)-1] = '\0';
 753	}
 754	if (s->help[0] == '"') {
 755		strcpy(s->help, argv[3]+1);
 756		s->help[strlen(s->help)-1] = '\0';
 757	}
 758	++defcmd_set_count;
 759	defcmd_in_progress = 1;
 760	kfree(save_defcmd_set);
 761	return 0;
 762fail_help:
 763	kfree(s->usage);
 764fail_usage:
 765	kfree(s->name);
 766fail_name:
 767	kfree(defcmd_set);
 768fail_defcmd:
 769	kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]);
 770	defcmd_set = save_defcmd_set;
 771	return KDB_NOTIMP;
 772}
 773
 774/*
 775 * kdb_exec_defcmd - Execute the set of commands associated with this
 776 *	defcmd name.
 777 * Inputs:
 778 *	argc	argument count
 779 *	argv	argument vector
 780 * Returns:
 781 *	zero for success, a kdb diagnostic if error
 782 */
 783static int kdb_exec_defcmd(int argc, const char **argv)
 784{
 785	int i, ret;
 786	struct defcmd_set *s;
 787	if (argc != 0)
 788		return KDB_ARGCOUNT;
 789	for (s = defcmd_set, i = 0; i < defcmd_set_count; ++i, ++s) {
 790		if (strcmp(s->name, argv[0]) == 0)
 791			break;
 792	}
 793	if (i == defcmd_set_count) {
 794		kdb_printf("kdb_exec_defcmd: could not find commands for %s\n",
 795			   argv[0]);
 796		return KDB_NOTIMP;
 797	}
 798	for (i = 0; i < s->count; ++i) {
 799		/* Recursive use of kdb_parse, do not use argv after
 800		 * this point */
 801		argv = NULL;
 802		kdb_printf("[%s]kdb> %s\n", s->name, s->command[i]);
 803		ret = kdb_parse(s->command[i]);
 804		if (ret)
 805			return ret;
 806	}
 807	return 0;
 808}
 809
 810/* Command history */
 811#define KDB_CMD_HISTORY_COUNT	32
 812#define CMD_BUFLEN		200	/* kdb_printf: max printline
 813					 * size == 256 */
 814static unsigned int cmd_head, cmd_tail;
 815static unsigned int cmdptr;
 816static char cmd_hist[KDB_CMD_HISTORY_COUNT][CMD_BUFLEN];
 817static char cmd_cur[CMD_BUFLEN];
 818
 819/*
 820 * The "str" argument may point to something like  | grep xyz
 821 */
 822static void parse_grep(const char *str)
 823{
 824	int	len;
 825	char	*cp = (char *)str, *cp2;
 826
 827	/* sanity check: we should have been called with the \ first */
 828	if (*cp != '|')
 829		return;
 830	cp++;
 831	while (isspace(*cp))
 832		cp++;
 833	if (strncmp(cp, "grep ", 5)) {
 834		kdb_printf("invalid 'pipe', see grephelp\n");
 835		return;
 836	}
 837	cp += 5;
 838	while (isspace(*cp))
 839		cp++;
 840	cp2 = strchr(cp, '\n');
 841	if (cp2)
 842		*cp2 = '\0'; /* remove the trailing newline */
 843	len = strlen(cp);
 844	if (len == 0) {
 845		kdb_printf("invalid 'pipe', see grephelp\n");
 846		return;
 847	}
 848	/* now cp points to a nonzero length search string */
 849	if (*cp == '"') {
 850		/* allow it be "x y z" by removing the "'s - there must
 851		   be two of them */
 852		cp++;
 853		cp2 = strchr(cp, '"');
 854		if (!cp2) {
 855			kdb_printf("invalid quoted string, see grephelp\n");
 856			return;
 857		}
 858		*cp2 = '\0'; /* end the string where the 2nd " was */
 859	}
 860	kdb_grep_leading = 0;
 861	if (*cp == '^') {
 862		kdb_grep_leading = 1;
 863		cp++;
 864	}
 865	len = strlen(cp);
 866	kdb_grep_trailing = 0;
 867	if (*(cp+len-1) == '$') {
 868		kdb_grep_trailing = 1;
 869		*(cp+len-1) = '\0';
 870	}
 871	len = strlen(cp);
 872	if (!len)
 873		return;
 874	if (len >= KDB_GREP_STRLEN) {
 875		kdb_printf("search string too long\n");
 876		return;
 877	}
 878	strcpy(kdb_grep_string, cp);
 879	kdb_grepping_flag++;
 880	return;
 881}
 882
 883/*
 884 * kdb_parse - Parse the command line, search the command table for a
 885 *	matching command and invoke the command function.  This
 886 *	function may be called recursively, if it is, the second call
 887 *	will overwrite argv and cbuf.  It is the caller's
 888 *	responsibility to save their argv if they recursively call
 889 *	kdb_parse().
 890 * Parameters:
 891 *      cmdstr	The input command line to be parsed.
 892 *	regs	The registers at the time kdb was entered.
 893 * Returns:
 894 *	Zero for success, a kdb diagnostic if failure.
 895 * Remarks:
 896 *	Limited to 20 tokens.
 897 *
 898 *	Real rudimentary tokenization. Basically only whitespace
 899 *	is considered a token delimeter (but special consideration
 900 *	is taken of the '=' sign as used by the 'set' command).
 901 *
 902 *	The algorithm used to tokenize the input string relies on
 903 *	there being at least one whitespace (or otherwise useless)
 904 *	character between tokens as the character immediately following
 905 *	the token is altered in-place to a null-byte to terminate the
 906 *	token string.
 907 */
 908
 909#define MAXARGC	20
 910
 911int kdb_parse(const char *cmdstr)
 912{
 913	static char *argv[MAXARGC];
 914	static int argc;
 915	static char cbuf[CMD_BUFLEN+2];
 916	char *cp;
 917	char *cpp, quoted;
 918	kdbtab_t *tp;
 919	int i, escaped, ignore_errors = 0, check_grep = 0;
 920
 921	/*
 922	 * First tokenize the command string.
 923	 */
 924	cp = (char *)cmdstr;
 925
 926	if (KDB_FLAG(CMD_INTERRUPT)) {
 927		/* Previous command was interrupted, newline must not
 928		 * repeat the command */
 929		KDB_FLAG_CLEAR(CMD_INTERRUPT);
 930		KDB_STATE_SET(PAGER);
 931		argc = 0;	/* no repeat */
 932	}
 933
 934	if (*cp != '\n' && *cp != '\0') {
 935		argc = 0;
 936		cpp = cbuf;
 937		while (*cp) {
 938			/* skip whitespace */
 939			while (isspace(*cp))
 940				cp++;
 941			if ((*cp == '\0') || (*cp == '\n') ||
 942			    (*cp == '#' && !defcmd_in_progress))
 943				break;
 944			/* special case: check for | grep pattern */
 945			if (*cp == '|') {
 946				check_grep++;
 947				break;
 948			}
 949			if (cpp >= cbuf + CMD_BUFLEN) {
 950				kdb_printf("kdb_parse: command buffer "
 951					   "overflow, command ignored\n%s\n",
 952					   cmdstr);
 953				return KDB_NOTFOUND;
 954			}
 955			if (argc >= MAXARGC - 1) {
 956				kdb_printf("kdb_parse: too many arguments, "
 957					   "command ignored\n%s\n", cmdstr);
 958				return KDB_NOTFOUND;
 959			}
 960			argv[argc++] = cpp;
 961			escaped = 0;
 962			quoted = '\0';
 963			/* Copy to next unquoted and unescaped
 964			 * whitespace or '=' */
 965			while (*cp && *cp != '\n' &&
 966			       (escaped || quoted || !isspace(*cp))) {
 967				if (cpp >= cbuf + CMD_BUFLEN)
 968					break;
 969				if (escaped) {
 970					escaped = 0;
 971					*cpp++ = *cp++;
 972					continue;
 973				}
 974				if (*cp == '\\') {
 975					escaped = 1;
 976					++cp;
 977					continue;
 978				}
 979				if (*cp == quoted)
 980					quoted = '\0';
 981				else if (*cp == '\'' || *cp == '"')
 982					quoted = *cp;
 983				*cpp = *cp++;
 984				if (*cpp == '=' && !quoted)
 985					break;
 986				++cpp;
 987			}
 988			*cpp++ = '\0';	/* Squash a ws or '=' character */
 989		}
 990	}
 991	if (!argc)
 992		return 0;
 993	if (check_grep)
 994		parse_grep(cp);
 995	if (defcmd_in_progress) {
 996		int result = kdb_defcmd2(cmdstr, argv[0]);
 997		if (!defcmd_in_progress) {
 998			argc = 0;	/* avoid repeat on endefcmd */
 999			*(argv[0]) = '\0';
1000		}
1001		return result;
1002	}
1003	if (argv[0][0] == '-' && argv[0][1] &&
1004	    (argv[0][1] < '0' || argv[0][1] > '9')) {
1005		ignore_errors = 1;
1006		++argv[0];
1007	}
1008
1009	for_each_kdbcmd(tp, i) {
1010		if (tp->cmd_name) {
1011			/*
1012			 * If this command is allowed to be abbreviated,
1013			 * check to see if this is it.
1014			 */
1015
1016			if (tp->cmd_minlen
1017			 && (strlen(argv[0]) <= tp->cmd_minlen)) {
1018				if (strncmp(argv[0],
1019					    tp->cmd_name,
1020					    tp->cmd_minlen) == 0) {
1021					break;
1022				}
1023			}
1024
1025			if (strcmp(argv[0], tp->cmd_name) == 0)
1026				break;
1027		}
1028	}
1029
1030	/*
1031	 * If we don't find a command by this name, see if the first
1032	 * few characters of this match any of the known commands.
1033	 * e.g., md1c20 should match md.
1034	 */
1035	if (i == kdb_max_commands) {
1036		for_each_kdbcmd(tp, i) {
1037			if (tp->cmd_name) {
1038				if (strncmp(argv[0],
1039					    tp->cmd_name,
1040					    strlen(tp->cmd_name)) == 0) {
1041					break;
1042				}
1043			}
1044		}
1045	}
1046
1047	if (i < kdb_max_commands) {
1048		int result;
1049
1050		if (!kdb_check_flags(tp->cmd_flags, kdb_cmd_enabled, argc <= 1))
1051			return KDB_NOPERM;
1052
1053		KDB_STATE_SET(CMD);
1054		result = (*tp->cmd_func)(argc-1, (const char **)argv);
1055		if (result && ignore_errors && result > KDB_CMD_GO)
1056			result = 0;
1057		KDB_STATE_CLEAR(CMD);
1058
1059		if (tp->cmd_flags & KDB_REPEAT_WITH_ARGS)
1060			return result;
1061
1062		argc = tp->cmd_flags & KDB_REPEAT_NO_ARGS ? 1 : 0;
1063		if (argv[argc])
1064			*(argv[argc]) = '\0';
1065		return result;
1066	}
1067
1068	/*
1069	 * If the input with which we were presented does not
1070	 * map to an existing command, attempt to parse it as an
1071	 * address argument and display the result.   Useful for
1072	 * obtaining the address of a variable, or the nearest symbol
1073	 * to an address contained in a register.
1074	 */
1075	{
1076		unsigned long value;
1077		char *name = NULL;
1078		long offset;
1079		int nextarg = 0;
1080
1081		if (kdbgetaddrarg(0, (const char **)argv, &nextarg,
1082				  &value, &offset, &name)) {
1083			return KDB_NOTFOUND;
1084		}
1085
1086		kdb_printf("%s = ", argv[0]);
1087		kdb_symbol_print(value, NULL, KDB_SP_DEFAULT);
1088		kdb_printf("\n");
1089		return 0;
1090	}
1091}
1092
1093
1094static int handle_ctrl_cmd(char *cmd)
1095{
1096#define CTRL_P	16
1097#define CTRL_N	14
1098
1099	/* initial situation */
1100	if (cmd_head == cmd_tail)
1101		return 0;
1102	switch (*cmd) {
1103	case CTRL_P:
1104		if (cmdptr != cmd_tail)
1105			cmdptr = (cmdptr-1) % KDB_CMD_HISTORY_COUNT;
1106		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1107		return 1;
1108	case CTRL_N:
1109		if (cmdptr != cmd_head)
1110			cmdptr = (cmdptr+1) % KDB_CMD_HISTORY_COUNT;
1111		strncpy(cmd_cur, cmd_hist[cmdptr], CMD_BUFLEN);
1112		return 1;
1113	}
1114	return 0;
1115}
1116
1117/*
1118 * kdb_reboot - This function implements the 'reboot' command.  Reboot
1119 *	the system immediately, or loop for ever on failure.
1120 */
1121static int kdb_reboot(int argc, const char **argv)
1122{
1123	emergency_restart();
1124	kdb_printf("Hmm, kdb_reboot did not reboot, spinning here\n");
1125	while (1)
1126		cpu_relax();
1127	/* NOTREACHED */
1128	return 0;
1129}
1130
1131static void kdb_dumpregs(struct pt_regs *regs)
1132{
1133	int old_lvl = console_loglevel;
1134	console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH;
1135	kdb_trap_printk++;
1136	show_regs(regs);
1137	kdb_trap_printk--;
1138	kdb_printf("\n");
1139	console_loglevel = old_lvl;
1140}
1141
1142void kdb_set_current_task(struct task_struct *p)
1143{
1144	kdb_current_task = p;
1145
1146	if (kdb_task_has_cpu(p)) {
1147		kdb_current_regs = KDB_TSKREGS(kdb_process_cpu(p));
1148		return;
1149	}
1150	kdb_current_regs = NULL;
1151}
1152
1153static void drop_newline(char *buf)
1154{
1155	size_t len = strlen(buf);
1156
1157	if (len == 0)
1158		return;
1159	if (*(buf + len - 1) == '\n')
1160		*(buf + len - 1) = '\0';
1161}
1162
1163/*
1164 * kdb_local - The main code for kdb.  This routine is invoked on a
1165 *	specific processor, it is not global.  The main kdb() routine
1166 *	ensures that only one processor at a time is in this routine.
1167 *	This code is called with the real reason code on the first
1168 *	entry to a kdb session, thereafter it is called with reason
1169 *	SWITCH, even if the user goes back to the original cpu.
1170 * Inputs:
1171 *	reason		The reason KDB was invoked
1172 *	error		The hardware-defined error code
1173 *	regs		The exception frame at time of fault/breakpoint.
1174 *	db_result	Result code from the break or debug point.
1175 * Returns:
1176 *	0	KDB was invoked for an event which it wasn't responsible
1177 *	1	KDB handled the event for which it was invoked.
1178 *	KDB_CMD_GO	User typed 'go'.
1179 *	KDB_CMD_CPU	User switched to another cpu.
1180 *	KDB_CMD_SS	Single step.
1181 */
1182static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
1183		     kdb_dbtrap_t db_result)
1184{
1185	char *cmdbuf;
1186	int diag;
1187	struct task_struct *kdb_current =
1188		kdb_curr_task(raw_smp_processor_id());
1189
1190	KDB_DEBUG_STATE("kdb_local 1", reason);
1191	kdb_go_count = 0;
1192	if (reason == KDB_REASON_DEBUG) {
1193		/* special case below */
1194	} else {
1195		kdb_printf("\nEntering kdb (current=0x%p, pid %d) ",
1196			   kdb_current, kdb_current ? kdb_current->pid : 0);
1197#if defined(CONFIG_SMP)
1198		kdb_printf("on processor %d ", raw_smp_processor_id());
1199#endif
1200	}
1201
1202	switch (reason) {
1203	case KDB_REASON_DEBUG:
1204	{
1205		/*
1206		 * If re-entering kdb after a single step
1207		 * command, don't print the message.
1208		 */
1209		switch (db_result) {
1210		case KDB_DB_BPT:
1211			kdb_printf("\nEntering kdb (0x%p, pid %d) ",
1212				   kdb_current, kdb_current->pid);
1213#if defined(CONFIG_SMP)
1214			kdb_printf("on processor %d ", raw_smp_processor_id());
1215#endif
1216			kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
1217				   instruction_pointer(regs));
1218			break;
1219		case KDB_DB_SS:
1220			break;
1221		case KDB_DB_SSBPT:
1222			KDB_DEBUG_STATE("kdb_local 4", reason);
1223			return 1;	/* kdba_db_trap did the work */
1224		default:
1225			kdb_printf("kdb: Bad result from kdba_db_trap: %d\n",
1226				   db_result);
1227			break;
1228		}
1229
1230	}
1231		break;
1232	case KDB_REASON_ENTER:
1233		if (KDB_STATE(KEYBOARD))
1234			kdb_printf("due to Keyboard Entry\n");
1235		else
1236			kdb_printf("due to KDB_ENTER()\n");
1237		break;
1238	case KDB_REASON_KEYBOARD:
1239		KDB_STATE_SET(KEYBOARD);
1240		kdb_printf("due to Keyboard Entry\n");
1241		break;
1242	case KDB_REASON_ENTER_SLAVE:
1243		/* drop through, slaves only get released via cpu switch */
1244	case KDB_REASON_SWITCH:
1245		kdb_printf("due to cpu switch\n");
1246		break;
1247	case KDB_REASON_OOPS:
1248		kdb_printf("Oops: %s\n", kdb_diemsg);
1249		kdb_printf("due to oops @ " kdb_machreg_fmt "\n",
1250			   instruction_pointer(regs));
1251		kdb_dumpregs(regs);
1252		break;
1253	case KDB_REASON_SYSTEM_NMI:
1254		kdb_printf("due to System NonMaskable Interrupt\n");
1255		break;
1256	case KDB_REASON_NMI:
1257		kdb_printf("due to NonMaskable Interrupt @ "
1258			   kdb_machreg_fmt "\n",
1259			   instruction_pointer(regs));
1260		break;
1261	case KDB_REASON_SSTEP:
1262	case KDB_REASON_BREAK:
1263		kdb_printf("due to %s @ " kdb_machreg_fmt "\n",
1264			   reason == KDB_REASON_BREAK ?
1265			   "Breakpoint" : "SS trap", instruction_pointer(regs));
1266		/*
1267		 * Determine if this breakpoint is one that we
1268		 * are interested in.
1269		 */
1270		if (db_result != KDB_DB_BPT) {
1271			kdb_printf("kdb: error return from kdba_bp_trap: %d\n",
1272				   db_result);
1273			KDB_DEBUG_STATE("kdb_local 6", reason);
1274			return 0;	/* Not for us, dismiss it */
1275		}
1276		break;
1277	case KDB_REASON_RECURSE:
1278		kdb_printf("due to Recursion @ " kdb_machreg_fmt "\n",
1279			   instruction_pointer(regs));
1280		break;
1281	default:
1282		kdb_printf("kdb: unexpected reason code: %d\n", reason);
1283		KDB_DEBUG_STATE("kdb_local 8", reason);
1284		return 0;	/* Not for us, dismiss it */
1285	}
1286
1287	while (1) {
1288		/*
1289		 * Initialize pager context.
1290		 */
1291		kdb_nextline = 1;
1292		KDB_STATE_CLEAR(SUPPRESS);
1293		kdb_grepping_flag = 0;
1294		/* ensure the old search does not leak into '/' commands */
1295		kdb_grep_string[0] = '\0';
1296
1297		cmdbuf = cmd_cur;
1298		*cmdbuf = '\0';
1299		*(cmd_hist[cmd_head]) = '\0';
1300
1301do_full_getstr:
1302#if defined(CONFIG_SMP)
1303		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
1304			 raw_smp_processor_id());
1305#else
1306		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"));
1307#endif
1308		if (defcmd_in_progress)
1309			strncat(kdb_prompt_str, "[defcmd]", CMD_BUFLEN);
1310
1311		/*
1312		 * Fetch command from keyboard
1313		 */
1314		cmdbuf = kdb_getstr(cmdbuf, CMD_BUFLEN, kdb_prompt_str);
1315		if (*cmdbuf != '\n') {
1316			if (*cmdbuf < 32) {
1317				if (cmdptr == cmd_head) {
1318					strncpy(cmd_hist[cmd_head], cmd_cur,
1319						CMD_BUFLEN);
1320					*(cmd_hist[cmd_head] +
1321					  strlen(cmd_hist[cmd_head])-1) = '\0';
1322				}
1323				if (!handle_ctrl_cmd(cmdbuf))
1324					*(cmd_cur+strlen(cmd_cur)-1) = '\0';
1325				cmdbuf = cmd_cur;
1326				goto do_full_getstr;
1327			} else {
1328				strncpy(cmd_hist[cmd_head], cmd_cur,
1329					CMD_BUFLEN);
1330			}
1331
1332			cmd_head = (cmd_head+1) % KDB_CMD_HISTORY_COUNT;
1333			if (cmd_head == cmd_tail)
1334				cmd_tail = (cmd_tail+1) % KDB_CMD_HISTORY_COUNT;
1335		}
1336
1337		cmdptr = cmd_head;
1338		diag = kdb_parse(cmdbuf);
1339		if (diag == KDB_NOTFOUND) {
1340			drop_newline(cmdbuf);
1341			kdb_printf("Unknown kdb command: '%s'\n", cmdbuf);
1342			diag = 0;
1343		}
1344		if (diag == KDB_CMD_GO
1345		 || diag == KDB_CMD_CPU
1346		 || diag == KDB_CMD_SS
1347		 || diag == KDB_CMD_KGDB)
1348			break;
1349
1350		if (diag)
1351			kdb_cmderror(diag);
1352	}
1353	KDB_DEBUG_STATE("kdb_local 9", diag);
1354	return diag;
1355}
1356
1357
1358/*
1359 * kdb_print_state - Print the state data for the current processor
1360 *	for debugging.
1361 * Inputs:
1362 *	text		Identifies the debug point
1363 *	value		Any integer value to be printed, e.g. reason code.
1364 */
1365void kdb_print_state(const char *text, int value)
1366{
1367	kdb_printf("state: %s cpu %d value %d initial %d state %x\n",
1368		   text, raw_smp_processor_id(), value, kdb_initial_cpu,
1369		   kdb_state);
1370}
1371
1372/*
1373 * kdb_main_loop - After initial setup and assignment of the
1374 *	controlling cpu, all cpus are in this loop.  One cpu is in
1375 *	control and will issue the kdb prompt, the others will spin
1376 *	until 'go' or cpu switch.
1377 *
1378 *	To get a consistent view of the kernel stacks for all
1379 *	processes, this routine is invoked from the main kdb code via
1380 *	an architecture specific routine.  kdba_main_loop is
1381 *	responsible for making the kernel stacks consistent for all
1382 *	processes, there should be no difference between a blocked
1383 *	process and a running process as far as kdb is concerned.
1384 * Inputs:
1385 *	reason		The reason KDB was invoked
1386 *	error		The hardware-defined error code
1387 *	reason2		kdb's current reason code.
1388 *			Initially error but can change
1389 *			according to kdb state.
1390 *	db_result	Result code from break or debug point.
1391 *	regs		The exception frame at time of fault/breakpoint.
1392 *			should always be valid.
1393 * Returns:
1394 *	0	KDB was invoked for an event which it wasn't responsible
1395 *	1	KDB handled the event for which it was invoked.
1396 */
1397int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
1398	      kdb_dbtrap_t db_result, struct pt_regs *regs)
1399{
1400	int result = 1;
1401	/* Stay in kdb() until 'go', 'ss[b]' or an error */
1402	while (1) {
1403		/*
1404		 * All processors except the one that is in control
1405		 * will spin here.
1406		 */
1407		KDB_DEBUG_STATE("kdb_main_loop 1", reason);
1408		while (KDB_STATE(HOLD_CPU)) {
1409			/* state KDB is turned off by kdb_cpu to see if the
1410			 * other cpus are still live, each cpu in this loop
1411			 * turns it back on.
1412			 */
1413			if (!KDB_STATE(KDB))
1414				KDB_STATE_SET(KDB);
1415		}
1416
1417		KDB_STATE_CLEAR(SUPPRESS);
1418		KDB_DEBUG_STATE("kdb_main_loop 2", reason);
1419		if (KDB_STATE(LEAVING))
1420			break;	/* Another cpu said 'go' */
1421		/* Still using kdb, this processor is in control */
1422		result = kdb_local(reason2, error, regs, db_result);
1423		KDB_DEBUG_STATE("kdb_main_loop 3", result);
1424
1425		if (result == KDB_CMD_CPU)
1426			break;
1427
1428		if (result == KDB_CMD_SS) {
1429			KDB_STATE_SET(DOING_SS);
1430			break;
1431		}
1432
1433		if (result == KDB_CMD_KGDB) {
1434			if (!KDB_STATE(DOING_KGDB))
1435				kdb_printf("Entering please attach debugger "
1436					   "or use $D#44+ or $3#33\n");
1437			break;
1438		}
1439		if (result && result != 1 && result != KDB_CMD_GO)
1440			kdb_printf("\nUnexpected kdb_local return code %d\n",
1441				   result);
1442		KDB_DEBUG_STATE("kdb_main_loop 4", reason);
1443		break;
1444	}
1445	if (KDB_STATE(DOING_SS))
1446		KDB_STATE_CLEAR(SSBPT);
1447
1448	/* Clean up any keyboard devices before leaving */
1449	kdb_kbd_cleanup_state();
1450
1451	return result;
1452}
1453
1454/*
1455 * kdb_mdr - This function implements the guts of the 'mdr', memory
1456 * read command.
1457 *	mdr  <addr arg>,<byte count>
1458 * Inputs:
1459 *	addr	Start address
1460 *	count	Number of bytes
1461 * Returns:
1462 *	Always 0.  Any errors are detected and printed by kdb_getarea.
1463 */
1464static int kdb_mdr(unsigned long addr, unsigned int count)
1465{
1466	unsigned char c;
1467	while (count--) {
1468		if (kdb_getarea(c, addr))
1469			return 0;
1470		kdb_printf("%02x", c);
1471		addr++;
1472	}
1473	kdb_printf("\n");
1474	return 0;
1475}
1476
1477/*
1478 * kdb_md - This function implements the 'md', 'md1', 'md2', 'md4',
1479 *	'md8' 'mdr' and 'mds' commands.
1480 *
1481 *	md|mds  [<addr arg> [<line count> [<radix>]]]
1482 *	mdWcN	[<addr arg> [<line count> [<radix>]]]
1483 *		where W = is the width (1, 2, 4 or 8) and N is the count.
1484 *		for eg., md1c20 reads 20 bytes, 1 at a time.
1485 *	mdr  <addr arg>,<byte count>
1486 */
1487static void kdb_md_line(const char *fmtstr, unsigned long addr,
1488			int symbolic, int nosect, int bytesperword,
1489			int num, int repeat, int phys)
1490{
1491	/* print just one line of data */
1492	kdb_symtab_t symtab;
1493	char cbuf[32];
1494	char *c = cbuf;
1495	int i;
1496	unsigned long word;
1497
1498	memset(cbuf, '\0', sizeof(cbuf));
1499	if (phys)
1500		kdb_printf("phys " kdb_machreg_fmt0 " ", addr);
1501	else
1502		kdb_printf(kdb_machreg_fmt0 " ", addr);
1503
1504	for (i = 0; i < num && repeat--; i++) {
1505		if (phys) {
1506			if (kdb_getphysword(&word, addr, bytesperword))
1507				break;
1508		} else if (kdb_getword(&word, addr, bytesperword))
1509			break;
1510		kdb_printf(fmtstr, word);
1511		if (symbolic)
1512			kdbnearsym(word, &symtab);
1513		else
1514			memset(&symtab, 0, sizeof(symtab));
1515		if (symtab.sym_name) {
1516			kdb_symbol_print(word, &symtab, 0);
1517			if (!nosect) {
1518				kdb_printf("\n");
1519				kdb_printf("                       %s %s "
1520					   kdb_machreg_fmt " "
1521					   kdb_machreg_fmt " "
1522					   kdb_machreg_fmt, symtab.mod_name,
1523					   symtab.sec_name, symtab.sec_start,
1524					   symtab.sym_start, symtab.sym_end);
1525			}
1526			addr += bytesperword;
1527		} else {
1528			union {
1529				u64 word;
1530				unsigned char c[8];
1531			} wc;
1532			unsigned char *cp;
1533#ifdef	__BIG_ENDIAN
1534			cp = wc.c + 8 - bytesperword;
1535#else
1536			cp = wc.c;
1537#endif
1538			wc.word = word;
1539#define printable_char(c) \
1540	({unsigned char __c = c; isascii(__c) && isprint(__c) ? __c : '.'; })
1541			switch (bytesperword) {
1542			case 8:
1543				*c++ = printable_char(*cp++);
1544				*c++ = printable_char(*cp++);
1545				*c++ = printable_char(*cp++);
1546				*c++ = printable_char(*cp++);
1547				addr += 4;
1548			case 4:
1549				*c++ = printable_char(*cp++);
1550				*c++ = printable_char(*cp++);
1551				addr += 2;
1552			case 2:
1553				*c++ = printable_char(*cp++);
1554				addr++;
1555			case 1:
1556				*c++ = printable_char(*cp++);
1557				addr++;
1558				break;
1559			}
1560#undef printable_char
1561		}
1562	}
1563	kdb_printf("%*s %s\n", (int)((num-i)*(2*bytesperword + 1)+1),
1564		   " ", cbuf);
1565}
1566
1567static int kdb_md(int argc, const char **argv)
1568{
1569	static unsigned long last_addr;
1570	static int last_radix, last_bytesperword, last_repeat;
1571	int radix = 16, mdcount = 8, bytesperword = KDB_WORD_SIZE, repeat;
1572	int nosect = 0;
1573	char fmtchar, fmtstr[64];
1574	unsigned long addr;
1575	unsigned long word;
1576	long offset = 0;
1577	int symbolic = 0;
1578	int valid = 0;
1579	int phys = 0;
1580	int raw = 0;
1581
1582	kdbgetintenv("MDCOUNT", &mdcount);
1583	kdbgetintenv("RADIX", &radix);
1584	kdbgetintenv("BYTESPERWORD", &bytesperword);
1585
1586	/* Assume 'md <addr>' and start with environment values */
1587	repeat = mdcount * 16 / bytesperword;
1588
1589	if (strcmp(argv[0], "mdr") == 0) {
1590		if (argc == 2 || (argc == 0 && last_addr != 0))
1591			valid = raw = 1;
1592		else
1593			return KDB_ARGCOUNT;
 
1594	} else if (isdigit(argv[0][2])) {
1595		bytesperword = (int)(argv[0][2] - '0');
1596		if (bytesperword == 0) {
1597			bytesperword = last_bytesperword;
1598			if (bytesperword == 0)
1599				bytesperword = 4;
1600		}
1601		last_bytesperword = bytesperword;
1602		repeat = mdcount * 16 / bytesperword;
1603		if (!argv[0][3])
1604			valid = 1;
1605		else if (argv[0][3] == 'c' && argv[0][4]) {
1606			char *p;
1607			repeat = simple_strtoul(argv[0] + 4, &p, 10);
1608			mdcount = ((repeat * bytesperword) + 15) / 16;
1609			valid = !*p;
1610		}
1611		last_repeat = repeat;
1612	} else if (strcmp(argv[0], "md") == 0)
1613		valid = 1;
1614	else if (strcmp(argv[0], "mds") == 0)
1615		valid = 1;
1616	else if (strcmp(argv[0], "mdp") == 0) {
1617		phys = valid = 1;
1618	}
1619	if (!valid)
1620		return KDB_NOTFOUND;
1621
1622	if (argc == 0) {
1623		if (last_addr == 0)
1624			return KDB_ARGCOUNT;
1625		addr = last_addr;
1626		radix = last_radix;
1627		bytesperword = last_bytesperword;
1628		repeat = last_repeat;
1629		if (raw)
1630			mdcount = repeat;
1631		else
1632			mdcount = ((repeat * bytesperword) + 15) / 16;
1633	}
1634
1635	if (argc) {
1636		unsigned long val;
1637		int diag, nextarg = 1;
1638		diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
1639				     &offset, NULL);
1640		if (diag)
1641			return diag;
1642		if (argc > nextarg+2)
1643			return KDB_ARGCOUNT;
1644
1645		if (argc >= nextarg) {
1646			diag = kdbgetularg(argv[nextarg], &val);
1647			if (!diag) {
1648				mdcount = (int) val;
1649				if (raw)
1650					repeat = mdcount;
1651				else
1652					repeat = mdcount * 16 / bytesperword;
1653			}
1654		}
1655		if (argc >= nextarg+1) {
1656			diag = kdbgetularg(argv[nextarg+1], &val);
1657			if (!diag)
1658				radix = (int) val;
1659		}
1660	}
1661
1662	if (strcmp(argv[0], "mdr") == 0) {
1663		int ret;
1664		last_addr = addr;
1665		ret = kdb_mdr(addr, mdcount);
1666		last_addr += mdcount;
1667		last_repeat = mdcount;
1668		last_bytesperword = bytesperword; // to make REPEAT happy
1669		return ret;
1670	}
1671
1672	switch (radix) {
1673	case 10:
1674		fmtchar = 'd';
1675		break;
1676	case 16:
1677		fmtchar = 'x';
1678		break;
1679	case 8:
1680		fmtchar = 'o';
1681		break;
1682	default:
1683		return KDB_BADRADIX;
1684	}
1685
1686	last_radix = radix;
1687
1688	if (bytesperword > KDB_WORD_SIZE)
1689		return KDB_BADWIDTH;
1690
1691	switch (bytesperword) {
1692	case 8:
1693		sprintf(fmtstr, "%%16.16l%c ", fmtchar);
1694		break;
1695	case 4:
1696		sprintf(fmtstr, "%%8.8l%c ", fmtchar);
1697		break;
1698	case 2:
1699		sprintf(fmtstr, "%%4.4l%c ", fmtchar);
1700		break;
1701	case 1:
1702		sprintf(fmtstr, "%%2.2l%c ", fmtchar);
1703		break;
1704	default:
1705		return KDB_BADWIDTH;
1706	}
1707
1708	last_repeat = repeat;
1709	last_bytesperword = bytesperword;
1710
1711	if (strcmp(argv[0], "mds") == 0) {
1712		symbolic = 1;
1713		/* Do not save these changes as last_*, they are temporary mds
1714		 * overrides.
1715		 */
1716		bytesperword = KDB_WORD_SIZE;
1717		repeat = mdcount;
1718		kdbgetintenv("NOSECT", &nosect);
1719	}
1720
1721	/* Round address down modulo BYTESPERWORD */
1722
1723	addr &= ~(bytesperword-1);
1724
1725	while (repeat > 0) {
1726		unsigned long a;
1727		int n, z, num = (symbolic ? 1 : (16 / bytesperword));
1728
1729		if (KDB_FLAG(CMD_INTERRUPT))
1730			return 0;
1731		for (a = addr, z = 0; z < repeat; a += bytesperword, ++z) {
1732			if (phys) {
1733				if (kdb_getphysword(&word, a, bytesperword)
1734						|| word)
1735					break;
1736			} else if (kdb_getword(&word, a, bytesperword) || word)
1737				break;
1738		}
1739		n = min(num, repeat);
1740		kdb_md_line(fmtstr, addr, symbolic, nosect, bytesperword,
1741			    num, repeat, phys);
1742		addr += bytesperword * n;
1743		repeat -= n;
1744		z = (z + num - 1) / num;
1745		if (z > 2) {
1746			int s = num * (z-2);
1747			kdb_printf(kdb_machreg_fmt0 "-" kdb_machreg_fmt0
1748				   " zero suppressed\n",
1749				addr, addr + bytesperword * s - 1);
1750			addr += bytesperword * s;
1751			repeat -= s;
1752		}
1753	}
1754	last_addr = addr;
1755
1756	return 0;
1757}
1758
1759/*
1760 * kdb_mm - This function implements the 'mm' command.
1761 *	mm address-expression new-value
1762 * Remarks:
1763 *	mm works on machine words, mmW works on bytes.
1764 */
1765static int kdb_mm(int argc, const char **argv)
1766{
1767	int diag;
1768	unsigned long addr;
1769	long offset = 0;
1770	unsigned long contents;
1771	int nextarg;
1772	int width;
1773
1774	if (argv[0][2] && !isdigit(argv[0][2]))
1775		return KDB_NOTFOUND;
1776
1777	if (argc < 2)
1778		return KDB_ARGCOUNT;
1779
1780	nextarg = 1;
1781	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
1782	if (diag)
1783		return diag;
1784
1785	if (nextarg > argc)
1786		return KDB_ARGCOUNT;
1787	diag = kdbgetaddrarg(argc, argv, &nextarg, &contents, NULL, NULL);
1788	if (diag)
1789		return diag;
1790
1791	if (nextarg != argc + 1)
1792		return KDB_ARGCOUNT;
1793
1794	width = argv[0][2] ? (argv[0][2] - '0') : (KDB_WORD_SIZE);
1795	diag = kdb_putword(addr, contents, width);
1796	if (diag)
1797		return diag;
1798
1799	kdb_printf(kdb_machreg_fmt " = " kdb_machreg_fmt "\n", addr, contents);
1800
1801	return 0;
1802}
1803
1804/*
1805 * kdb_go - This function implements the 'go' command.
1806 *	go [address-expression]
1807 */
1808static int kdb_go(int argc, const char **argv)
1809{
1810	unsigned long addr;
1811	int diag;
1812	int nextarg;
1813	long offset;
1814
1815	if (raw_smp_processor_id() != kdb_initial_cpu) {
1816		kdb_printf("go must execute on the entry cpu, "
1817			   "please use \"cpu %d\" and then execute go\n",
1818			   kdb_initial_cpu);
1819		return KDB_BADCPUNUM;
1820	}
1821	if (argc == 1) {
1822		nextarg = 1;
1823		diag = kdbgetaddrarg(argc, argv, &nextarg,
1824				     &addr, &offset, NULL);
1825		if (diag)
1826			return diag;
1827	} else if (argc) {
1828		return KDB_ARGCOUNT;
1829	}
1830
1831	diag = KDB_CMD_GO;
1832	if (KDB_FLAG(CATASTROPHIC)) {
1833		kdb_printf("Catastrophic error detected\n");
1834		kdb_printf("kdb_continue_catastrophic=%d, ",
1835			kdb_continue_catastrophic);
1836		if (kdb_continue_catastrophic == 0 && kdb_go_count++ == 0) {
1837			kdb_printf("type go a second time if you really want "
1838				   "to continue\n");
1839			return 0;
1840		}
1841		if (kdb_continue_catastrophic == 2) {
1842			kdb_printf("forcing reboot\n");
1843			kdb_reboot(0, NULL);
1844		}
1845		kdb_printf("attempting to continue\n");
1846	}
1847	return diag;
1848}
1849
1850/*
1851 * kdb_rd - This function implements the 'rd' command.
1852 */
1853static int kdb_rd(int argc, const char **argv)
1854{
1855	int len = kdb_check_regs();
1856#if DBG_MAX_REG_NUM > 0
1857	int i;
1858	char *rname;
1859	int rsize;
1860	u64 reg64;
1861	u32 reg32;
1862	u16 reg16;
1863	u8 reg8;
1864
1865	if (len)
1866		return len;
1867
1868	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1869		rsize = dbg_reg_def[i].size * 2;
1870		if (rsize > 16)
1871			rsize = 2;
1872		if (len + strlen(dbg_reg_def[i].name) + 4 + rsize > 80) {
1873			len = 0;
1874			kdb_printf("\n");
1875		}
1876		if (len)
1877			len += kdb_printf("  ");
1878		switch(dbg_reg_def[i].size * 8) {
1879		case 8:
1880			rname = dbg_get_reg(i, &reg8, kdb_current_regs);
1881			if (!rname)
1882				break;
1883			len += kdb_printf("%s: %02x", rname, reg8);
1884			break;
1885		case 16:
1886			rname = dbg_get_reg(i, &reg16, kdb_current_regs);
1887			if (!rname)
1888				break;
1889			len += kdb_printf("%s: %04x", rname, reg16);
1890			break;
1891		case 32:
1892			rname = dbg_get_reg(i, &reg32, kdb_current_regs);
1893			if (!rname)
1894				break;
1895			len += kdb_printf("%s: %08x", rname, reg32);
1896			break;
1897		case 64:
1898			rname = dbg_get_reg(i, &reg64, kdb_current_regs);
1899			if (!rname)
1900				break;
1901			len += kdb_printf("%s: %016llx", rname, reg64);
1902			break;
1903		default:
1904			len += kdb_printf("%s: ??", dbg_reg_def[i].name);
1905		}
1906	}
1907	kdb_printf("\n");
1908#else
1909	if (len)
1910		return len;
1911
1912	kdb_dumpregs(kdb_current_regs);
1913#endif
1914	return 0;
1915}
1916
1917/*
1918 * kdb_rm - This function implements the 'rm' (register modify)  command.
1919 *	rm register-name new-contents
1920 * Remarks:
1921 *	Allows register modification with the same restrictions as gdb
1922 */
1923static int kdb_rm(int argc, const char **argv)
1924{
1925#if DBG_MAX_REG_NUM > 0
1926	int diag;
1927	const char *rname;
1928	int i;
1929	u64 reg64;
1930	u32 reg32;
1931	u16 reg16;
1932	u8 reg8;
1933
1934	if (argc != 2)
1935		return KDB_ARGCOUNT;
1936	/*
1937	 * Allow presence or absence of leading '%' symbol.
1938	 */
1939	rname = argv[1];
1940	if (*rname == '%')
1941		rname++;
1942
1943	diag = kdbgetu64arg(argv[2], &reg64);
1944	if (diag)
1945		return diag;
1946
1947	diag = kdb_check_regs();
1948	if (diag)
1949		return diag;
1950
1951	diag = KDB_BADREG;
1952	for (i = 0; i < DBG_MAX_REG_NUM; i++) {
1953		if (strcmp(rname, dbg_reg_def[i].name) == 0) {
1954			diag = 0;
1955			break;
1956		}
1957	}
1958	if (!diag) {
1959		switch(dbg_reg_def[i].size * 8) {
1960		case 8:
1961			reg8 = reg64;
1962			dbg_set_reg(i, &reg8, kdb_current_regs);
1963			break;
1964		case 16:
1965			reg16 = reg64;
1966			dbg_set_reg(i, &reg16, kdb_current_regs);
1967			break;
1968		case 32:
1969			reg32 = reg64;
1970			dbg_set_reg(i, &reg32, kdb_current_regs);
1971			break;
1972		case 64:
1973			dbg_set_reg(i, &reg64, kdb_current_regs);
1974			break;
1975		}
1976	}
1977	return diag;
1978#else
1979	kdb_printf("ERROR: Register set currently not implemented\n");
1980    return 0;
1981#endif
1982}
1983
1984#if defined(CONFIG_MAGIC_SYSRQ)
1985/*
1986 * kdb_sr - This function implements the 'sr' (SYSRQ key) command
1987 *	which interfaces to the soi-disant MAGIC SYSRQ functionality.
1988 *		sr <magic-sysrq-code>
1989 */
1990static int kdb_sr(int argc, const char **argv)
1991{
1992	bool check_mask =
1993	    !kdb_check_flags(KDB_ENABLE_ALL, kdb_cmd_enabled, false);
1994
1995	if (argc != 1)
1996		return KDB_ARGCOUNT;
1997
1998	kdb_trap_printk++;
1999	__handle_sysrq(*argv[1], check_mask);
2000	kdb_trap_printk--;
2001
2002	return 0;
2003}
2004#endif	/* CONFIG_MAGIC_SYSRQ */
2005
2006/*
2007 * kdb_ef - This function implements the 'regs' (display exception
2008 *	frame) command.  This command takes an address and expects to
2009 *	find an exception frame at that address, formats and prints
2010 *	it.
2011 *		regs address-expression
2012 * Remarks:
2013 *	Not done yet.
2014 */
2015static int kdb_ef(int argc, const char **argv)
2016{
2017	int diag;
2018	unsigned long addr;
2019	long offset;
2020	int nextarg;
2021
2022	if (argc != 1)
2023		return KDB_ARGCOUNT;
2024
2025	nextarg = 1;
2026	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
2027	if (diag)
2028		return diag;
2029	show_regs((struct pt_regs *)addr);
2030	return 0;
2031}
2032
2033#if defined(CONFIG_MODULES)
2034/*
2035 * kdb_lsmod - This function implements the 'lsmod' command.  Lists
2036 *	currently loaded kernel modules.
2037 *	Mostly taken from userland lsmod.
2038 */
2039static int kdb_lsmod(int argc, const char **argv)
2040{
2041	struct module *mod;
2042
2043	if (argc != 0)
2044		return KDB_ARGCOUNT;
2045
2046	kdb_printf("Module                  Size  modstruct     Used by\n");
2047	list_for_each_entry(mod, kdb_modules, list) {
2048		if (mod->state == MODULE_STATE_UNFORMED)
2049			continue;
2050
2051		kdb_printf("%-20s%8u  0x%p ", mod->name,
2052			   mod->core_layout.size, (void *)mod);
2053#ifdef CONFIG_MODULE_UNLOAD
2054		kdb_printf("%4d ", module_refcount(mod));
2055#endif
2056		if (mod->state == MODULE_STATE_GOING)
2057			kdb_printf(" (Unloading)");
2058		else if (mod->state == MODULE_STATE_COMING)
2059			kdb_printf(" (Loading)");
2060		else
2061			kdb_printf(" (Live)");
2062		kdb_printf(" 0x%p", mod->core_layout.base);
2063
2064#ifdef CONFIG_MODULE_UNLOAD
2065		{
2066			struct module_use *use;
2067			kdb_printf(" [ ");
2068			list_for_each_entry(use, &mod->source_list,
2069					    source_list)
2070				kdb_printf("%s ", use->target->name);
2071			kdb_printf("]\n");
2072		}
2073#endif
2074	}
2075
2076	return 0;
2077}
2078
2079#endif	/* CONFIG_MODULES */
2080
2081/*
2082 * kdb_env - This function implements the 'env' command.  Display the
2083 *	current environment variables.
2084 */
2085
2086static int kdb_env(int argc, const char **argv)
2087{
2088	int i;
2089
2090	for (i = 0; i < __nenv; i++) {
2091		if (__env[i])
2092			kdb_printf("%s\n", __env[i]);
2093	}
2094
2095	if (KDB_DEBUG(MASK))
2096		kdb_printf("KDBFLAGS=0x%x\n", kdb_flags);
2097
2098	return 0;
2099}
2100
2101#ifdef CONFIG_PRINTK
2102/*
2103 * kdb_dmesg - This function implements the 'dmesg' command to display
2104 *	the contents of the syslog buffer.
2105 *		dmesg [lines] [adjust]
2106 */
2107static int kdb_dmesg(int argc, const char **argv)
2108{
2109	int diag;
2110	int logging;
2111	int lines = 0;
2112	int adjust = 0;
2113	int n = 0;
2114	int skip = 0;
2115	struct kmsg_dumper dumper = { .active = 1 };
2116	size_t len;
2117	char buf[201];
2118
2119	if (argc > 2)
2120		return KDB_ARGCOUNT;
2121	if (argc) {
2122		char *cp;
2123		lines = simple_strtol(argv[1], &cp, 0);
2124		if (*cp)
2125			lines = 0;
2126		if (argc > 1) {
2127			adjust = simple_strtoul(argv[2], &cp, 0);
2128			if (*cp || adjust < 0)
2129				adjust = 0;
2130		}
2131	}
2132
2133	/* disable LOGGING if set */
2134	diag = kdbgetintenv("LOGGING", &logging);
2135	if (!diag && logging) {
2136		const char *setargs[] = { "set", "LOGGING", "0" };
2137		kdb_set(2, setargs);
2138	}
2139
2140	kmsg_dump_rewind_nolock(&dumper);
2141	while (kmsg_dump_get_line_nolock(&dumper, 1, NULL, 0, NULL))
2142		n++;
2143
2144	if (lines < 0) {
2145		if (adjust >= n)
2146			kdb_printf("buffer only contains %d lines, nothing "
2147				   "printed\n", n);
2148		else if (adjust - lines >= n)
2149			kdb_printf("buffer only contains %d lines, last %d "
2150				   "lines printed\n", n, n - adjust);
2151		skip = adjust;
2152		lines = abs(lines);
2153	} else if (lines > 0) {
2154		skip = n - lines - adjust;
2155		lines = abs(lines);
2156		if (adjust >= n) {
2157			kdb_printf("buffer only contains %d lines, "
2158				   "nothing printed\n", n);
2159			skip = n;
2160		} else if (skip < 0) {
2161			lines += skip;
2162			skip = 0;
2163			kdb_printf("buffer only contains %d lines, first "
2164				   "%d lines printed\n", n, lines);
2165		}
2166	} else {
2167		lines = n;
2168	}
2169
2170	if (skip >= n || skip < 0)
2171		return 0;
2172
2173	kmsg_dump_rewind_nolock(&dumper);
2174	while (kmsg_dump_get_line_nolock(&dumper, 1, buf, sizeof(buf), &len)) {
2175		if (skip) {
2176			skip--;
2177			continue;
2178		}
2179		if (!lines--)
2180			break;
2181		if (KDB_FLAG(CMD_INTERRUPT))
2182			return 0;
2183
2184		kdb_printf("%.*s\n", (int)len - 1, buf);
2185	}
2186
2187	return 0;
2188}
2189#endif /* CONFIG_PRINTK */
2190
2191/* Make sure we balance enable/disable calls, must disable first. */
2192static atomic_t kdb_nmi_disabled;
2193
2194static int kdb_disable_nmi(int argc, const char *argv[])
2195{
2196	if (atomic_read(&kdb_nmi_disabled))
2197		return 0;
2198	atomic_set(&kdb_nmi_disabled, 1);
2199	arch_kgdb_ops.enable_nmi(0);
2200	return 0;
2201}
2202
2203static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
2204{
2205	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
2206		return -EINVAL;
2207	arch_kgdb_ops.enable_nmi(1);
2208	return 0;
2209}
2210
2211static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
2212	.set = kdb_param_enable_nmi,
2213};
2214module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
2215
2216/*
2217 * kdb_cpu - This function implements the 'cpu' command.
2218 *	cpu	[<cpunum>]
2219 * Returns:
2220 *	KDB_CMD_CPU for success, a kdb diagnostic if error
2221 */
2222static void kdb_cpu_status(void)
2223{
2224	int i, start_cpu, first_print = 1;
2225	char state, prev_state = '?';
2226
2227	kdb_printf("Currently on cpu %d\n", raw_smp_processor_id());
2228	kdb_printf("Available cpus: ");
2229	for (start_cpu = -1, i = 0; i < NR_CPUS; i++) {
2230		if (!cpu_online(i)) {
2231			state = 'F';	/* cpu is offline */
2232		} else if (!kgdb_info[i].enter_kgdb) {
2233			state = 'D';	/* cpu is online but unresponsive */
2234		} else {
2235			state = ' ';	/* cpu is responding to kdb */
2236			if (kdb_task_state_char(KDB_TSK(i)) == 'I')
2237				state = 'I';	/* idle task */
2238		}
2239		if (state != prev_state) {
2240			if (prev_state != '?') {
2241				if (!first_print)
2242					kdb_printf(", ");
2243				first_print = 0;
2244				kdb_printf("%d", start_cpu);
2245				if (start_cpu < i-1)
2246					kdb_printf("-%d", i-1);
2247				if (prev_state != ' ')
2248					kdb_printf("(%c)", prev_state);
2249			}
2250			prev_state = state;
2251			start_cpu = i;
2252		}
2253	}
2254	/* print the trailing cpus, ignoring them if they are all offline */
2255	if (prev_state != 'F') {
2256		if (!first_print)
2257			kdb_printf(", ");
2258		kdb_printf("%d", start_cpu);
2259		if (start_cpu < i-1)
2260			kdb_printf("-%d", i-1);
2261		if (prev_state != ' ')
2262			kdb_printf("(%c)", prev_state);
2263	}
2264	kdb_printf("\n");
2265}
2266
2267static int kdb_cpu(int argc, const char **argv)
2268{
2269	unsigned long cpunum;
2270	int diag;
2271
2272	if (argc == 0) {
2273		kdb_cpu_status();
2274		return 0;
2275	}
2276
2277	if (argc != 1)
2278		return KDB_ARGCOUNT;
2279
2280	diag = kdbgetularg(argv[1], &cpunum);
2281	if (diag)
2282		return diag;
2283
2284	/*
2285	 * Validate cpunum
2286	 */
2287	if ((cpunum >= CONFIG_NR_CPUS) || !kgdb_info[cpunum].enter_kgdb)
2288		return KDB_BADCPUNUM;
2289
2290	dbg_switch_cpu = cpunum;
2291
2292	/*
2293	 * Switch to other cpu
2294	 */
2295	return KDB_CMD_CPU;
2296}
2297
2298/* The user may not realize that ps/bta with no parameters does not print idle
2299 * or sleeping system daemon processes, so tell them how many were suppressed.
2300 */
2301void kdb_ps_suppressed(void)
2302{
2303	int idle = 0, daemon = 0;
2304	unsigned long mask_I = kdb_task_state_string("I"),
2305		      mask_M = kdb_task_state_string("M");
2306	unsigned long cpu;
2307	const struct task_struct *p, *g;
2308	for_each_online_cpu(cpu) {
2309		p = kdb_curr_task(cpu);
2310		if (kdb_task_state(p, mask_I))
2311			++idle;
2312	}
2313	kdb_do_each_thread(g, p) {
2314		if (kdb_task_state(p, mask_M))
2315			++daemon;
2316	} kdb_while_each_thread(g, p);
2317	if (idle || daemon) {
2318		if (idle)
2319			kdb_printf("%d idle process%s (state I)%s\n",
2320				   idle, idle == 1 ? "" : "es",
2321				   daemon ? " and " : "");
2322		if (daemon)
2323			kdb_printf("%d sleeping system daemon (state M) "
2324				   "process%s", daemon,
2325				   daemon == 1 ? "" : "es");
2326		kdb_printf(" suppressed,\nuse 'ps A' to see all.\n");
2327	}
2328}
2329
2330/*
2331 * kdb_ps - This function implements the 'ps' command which shows a
2332 *	list of the active processes.
2333 *		ps [DRSTCZEUIMA]   All processes, optionally filtered by state
2334 */
2335void kdb_ps1(const struct task_struct *p)
2336{
2337	int cpu;
2338	unsigned long tmp;
2339
2340	if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
2341		return;
2342
2343	cpu = kdb_process_cpu(p);
2344	kdb_printf("0x%p %8d %8d  %d %4d   %c  0x%p %c%s\n",
2345		   (void *)p, p->pid, p->parent->pid,
2346		   kdb_task_has_cpu(p), kdb_process_cpu(p),
2347		   kdb_task_state_char(p),
2348		   (void *)(&p->thread),
2349		   p == kdb_curr_task(raw_smp_processor_id()) ? '*' : ' ',
2350		   p->comm);
2351	if (kdb_task_has_cpu(p)) {
2352		if (!KDB_TSK(cpu)) {
2353			kdb_printf("  Error: no saved data for this cpu\n");
2354		} else {
2355			if (KDB_TSK(cpu) != p)
2356				kdb_printf("  Error: does not match running "
2357				   "process table (0x%p)\n", KDB_TSK(cpu));
2358		}
2359	}
2360}
2361
2362static int kdb_ps(int argc, const char **argv)
2363{
2364	struct task_struct *g, *p;
2365	unsigned long mask, cpu;
2366
2367	if (argc == 0)
2368		kdb_ps_suppressed();
2369	kdb_printf("%-*s      Pid   Parent [*] cpu State %-*s Command\n",
2370		(int)(2*sizeof(void *))+2, "Task Addr",
2371		(int)(2*sizeof(void *))+2, "Thread");
2372	mask = kdb_task_state_string(argc ? argv[1] : NULL);
2373	/* Run the active tasks first */
2374	for_each_online_cpu(cpu) {
2375		if (KDB_FLAG(CMD_INTERRUPT))
2376			return 0;
2377		p = kdb_curr_task(cpu);
2378		if (kdb_task_state(p, mask))
2379			kdb_ps1(p);
2380	}
2381	kdb_printf("\n");
2382	/* Now the real tasks */
2383	kdb_do_each_thread(g, p) {
2384		if (KDB_FLAG(CMD_INTERRUPT))
2385			return 0;
2386		if (kdb_task_state(p, mask))
2387			kdb_ps1(p);
2388	} kdb_while_each_thread(g, p);
2389
2390	return 0;
2391}
2392
2393/*
2394 * kdb_pid - This function implements the 'pid' command which switches
2395 *	the currently active process.
2396 *		pid [<pid> | R]
2397 */
2398static int kdb_pid(int argc, const char **argv)
2399{
2400	struct task_struct *p;
2401	unsigned long val;
2402	int diag;
2403
2404	if (argc > 1)
2405		return KDB_ARGCOUNT;
2406
2407	if (argc) {
2408		if (strcmp(argv[1], "R") == 0) {
2409			p = KDB_TSK(kdb_initial_cpu);
2410		} else {
2411			diag = kdbgetularg(argv[1], &val);
2412			if (diag)
2413				return KDB_BADINT;
2414
2415			p = find_task_by_pid_ns((pid_t)val,	&init_pid_ns);
2416			if (!p) {
2417				kdb_printf("No task with pid=%d\n", (pid_t)val);
2418				return 0;
2419			}
2420		}
2421		kdb_set_current_task(p);
2422	}
2423	kdb_printf("KDB current process is %s(pid=%d)\n",
2424		   kdb_current_task->comm,
2425		   kdb_current_task->pid);
2426
2427	return 0;
2428}
2429
2430static int kdb_kgdb(int argc, const char **argv)
2431{
2432	return KDB_CMD_KGDB;
2433}
2434
2435/*
2436 * kdb_help - This function implements the 'help' and '?' commands.
2437 */
2438static int kdb_help(int argc, const char **argv)
2439{
2440	kdbtab_t *kt;
2441	int i;
2442
2443	kdb_printf("%-15.15s %-20.20s %s\n", "Command", "Usage", "Description");
2444	kdb_printf("-----------------------------"
2445		   "-----------------------------\n");
2446	for_each_kdbcmd(kt, i) {
2447		char *space = "";
2448		if (KDB_FLAG(CMD_INTERRUPT))
2449			return 0;
2450		if (!kt->cmd_name)
2451			continue;
2452		if (!kdb_check_flags(kt->cmd_flags, kdb_cmd_enabled, true))
2453			continue;
2454		if (strlen(kt->cmd_usage) > 20)
2455			space = "\n                                    ";
2456		kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
2457			   kt->cmd_usage, space, kt->cmd_help);
2458	}
2459	return 0;
2460}
2461
2462/*
2463 * kdb_kill - This function implements the 'kill' commands.
2464 */
2465static int kdb_kill(int argc, const char **argv)
2466{
2467	long sig, pid;
2468	char *endp;
2469	struct task_struct *p;
 
2470
2471	if (argc != 2)
2472		return KDB_ARGCOUNT;
2473
2474	sig = simple_strtol(argv[1], &endp, 0);
2475	if (*endp)
2476		return KDB_BADINT;
2477	if ((sig >= 0) || !valid_signal(-sig)) {
2478		kdb_printf("Invalid signal parameter.<-signal>\n");
2479		return 0;
2480	}
2481	sig = -sig;
2482
2483	pid = simple_strtol(argv[2], &endp, 0);
2484	if (*endp)
2485		return KDB_BADINT;
2486	if (pid <= 0) {
2487		kdb_printf("Process ID must be large than 0.\n");
2488		return 0;
2489	}
2490
2491	/* Find the process. */
2492	p = find_task_by_pid_ns(pid, &init_pid_ns);
2493	if (!p) {
2494		kdb_printf("The specified process isn't found.\n");
2495		return 0;
2496	}
2497	p = p->group_leader;
2498	kdb_send_sig(p, sig);
 
 
 
 
 
2499	return 0;
2500}
2501
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2502/*
2503 * Most of this code has been lifted from kernel/timer.c::sys_sysinfo().
2504 * I cannot call that code directly from kdb, it has an unconditional
2505 * cli()/sti() and calls routines that take locks which can stop the debugger.
2506 */
2507static void kdb_sysinfo(struct sysinfo *val)
2508{
2509	u64 uptime = ktime_get_mono_fast_ns();
2510
2511	memset(val, 0, sizeof(*val));
2512	val->uptime = div_u64(uptime, NSEC_PER_SEC);
2513	val->loads[0] = avenrun[0];
2514	val->loads[1] = avenrun[1];
2515	val->loads[2] = avenrun[2];
2516	val->procs = nr_threads-1;
2517	si_meminfo(val);
2518
2519	return;
2520}
2521
2522/*
2523 * kdb_summary - This function implements the 'summary' command.
2524 */
2525static int kdb_summary(int argc, const char **argv)
2526{
2527	time64_t now;
2528	struct tm tm;
2529	struct sysinfo val;
2530
2531	if (argc)
2532		return KDB_ARGCOUNT;
2533
2534	kdb_printf("sysname    %s\n", init_uts_ns.name.sysname);
2535	kdb_printf("release    %s\n", init_uts_ns.name.release);
2536	kdb_printf("version    %s\n", init_uts_ns.name.version);
2537	kdb_printf("machine    %s\n", init_uts_ns.name.machine);
2538	kdb_printf("nodename   %s\n", init_uts_ns.name.nodename);
2539	kdb_printf("domainname %s\n", init_uts_ns.name.domainname);
2540	kdb_printf("ccversion  %s\n", __stringify(CCVERSION));
2541
2542	now = __ktime_get_real_seconds();
2543	time64_to_tm(now, 0, &tm);
2544	kdb_printf("date       %04ld-%02d-%02d %02d:%02d:%02d "
2545		   "tz_minuteswest %d\n",
2546		1900+tm.tm_year, tm.tm_mon+1, tm.tm_mday,
2547		tm.tm_hour, tm.tm_min, tm.tm_sec,
2548		sys_tz.tz_minuteswest);
2549
2550	kdb_sysinfo(&val);
2551	kdb_printf("uptime     ");
2552	if (val.uptime > (24*60*60)) {
2553		int days = val.uptime / (24*60*60);
2554		val.uptime %= (24*60*60);
2555		kdb_printf("%d day%s ", days, days == 1 ? "" : "s");
2556	}
2557	kdb_printf("%02ld:%02ld\n", val.uptime/(60*60), (val.uptime/60)%60);
2558
2559	/* lifted from fs/proc/proc_misc.c::loadavg_read_proc() */
2560
2561#define LOAD_INT(x) ((x) >> FSHIFT)
2562#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
2563	kdb_printf("load avg   %ld.%02ld %ld.%02ld %ld.%02ld\n",
2564		LOAD_INT(val.loads[0]), LOAD_FRAC(val.loads[0]),
2565		LOAD_INT(val.loads[1]), LOAD_FRAC(val.loads[1]),
2566		LOAD_INT(val.loads[2]), LOAD_FRAC(val.loads[2]));
2567#undef LOAD_INT
2568#undef LOAD_FRAC
2569	/* Display in kilobytes */
2570#define K(x) ((x) << (PAGE_SHIFT - 10))
2571	kdb_printf("\nMemTotal:       %8lu kB\nMemFree:        %8lu kB\n"
2572		   "Buffers:        %8lu kB\n",
2573		   K(val.totalram), K(val.freeram), K(val.bufferram));
2574	return 0;
2575}
2576
2577/*
2578 * kdb_per_cpu - This function implements the 'per_cpu' command.
2579 */
2580static int kdb_per_cpu(int argc, const char **argv)
2581{
2582	char fmtstr[64];
2583	int cpu, diag, nextarg = 1;
2584	unsigned long addr, symaddr, val, bytesperword = 0, whichcpu = ~0UL;
2585
2586	if (argc < 1 || argc > 3)
2587		return KDB_ARGCOUNT;
2588
2589	diag = kdbgetaddrarg(argc, argv, &nextarg, &symaddr, NULL, NULL);
2590	if (diag)
2591		return diag;
2592
2593	if (argc >= 2) {
2594		diag = kdbgetularg(argv[2], &bytesperword);
2595		if (diag)
2596			return diag;
2597	}
2598	if (!bytesperword)
2599		bytesperword = KDB_WORD_SIZE;
2600	else if (bytesperword > KDB_WORD_SIZE)
2601		return KDB_BADWIDTH;
2602	sprintf(fmtstr, "%%0%dlx ", (int)(2*bytesperword));
2603	if (argc >= 3) {
2604		diag = kdbgetularg(argv[3], &whichcpu);
2605		if (diag)
2606			return diag;
2607		if (!cpu_online(whichcpu)) {
2608			kdb_printf("cpu %ld is not online\n", whichcpu);
2609			return KDB_BADCPUNUM;
2610		}
2611	}
2612
2613	/* Most architectures use __per_cpu_offset[cpu], some use
2614	 * __per_cpu_offset(cpu), smp has no __per_cpu_offset.
2615	 */
2616#ifdef	__per_cpu_offset
2617#define KDB_PCU(cpu) __per_cpu_offset(cpu)
2618#else
2619#ifdef	CONFIG_SMP
2620#define KDB_PCU(cpu) __per_cpu_offset[cpu]
2621#else
2622#define KDB_PCU(cpu) 0
2623#endif
2624#endif
2625	for_each_online_cpu(cpu) {
2626		if (KDB_FLAG(CMD_INTERRUPT))
2627			return 0;
2628
2629		if (whichcpu != ~0UL && whichcpu != cpu)
2630			continue;
2631		addr = symaddr + KDB_PCU(cpu);
2632		diag = kdb_getword(&val, addr, bytesperword);
2633		if (diag) {
2634			kdb_printf("%5d " kdb_bfd_vma_fmt0 " - unable to "
2635				   "read, diag=%d\n", cpu, addr, diag);
2636			continue;
2637		}
2638		kdb_printf("%5d ", cpu);
2639		kdb_md_line(fmtstr, addr,
2640			bytesperword == KDB_WORD_SIZE,
2641			1, bytesperword, 1, 1, 0);
2642	}
2643#undef KDB_PCU
2644	return 0;
2645}
2646
2647/*
2648 * display help for the use of cmd | grep pattern
2649 */
2650static int kdb_grep_help(int argc, const char **argv)
2651{
2652	kdb_printf("Usage of  cmd args | grep pattern:\n");
2653	kdb_printf("  Any command's output may be filtered through an ");
2654	kdb_printf("emulated 'pipe'.\n");
2655	kdb_printf("  'grep' is just a key word.\n");
2656	kdb_printf("  The pattern may include a very limited set of "
2657		   "metacharacters:\n");
2658	kdb_printf("   pattern or ^pattern or pattern$ or ^pattern$\n");
2659	kdb_printf("  And if there are spaces in the pattern, you may "
2660		   "quote it:\n");
2661	kdb_printf("   \"pat tern\" or \"^pat tern\" or \"pat tern$\""
2662		   " or \"^pat tern$\"\n");
2663	return 0;
2664}
2665
2666/*
2667 * kdb_register_flags - This function is used to register a kernel
2668 * 	debugger command.
2669 * Inputs:
2670 *	cmd	Command name
2671 *	func	Function to execute the command
2672 *	usage	A simple usage string showing arguments
2673 *	help	A simple help string describing command
2674 *	repeat	Does the command auto repeat on enter?
2675 * Returns:
2676 *	zero for success, one if a duplicate command.
2677 */
2678#define kdb_command_extend 50	/* arbitrary */
2679int kdb_register_flags(char *cmd,
2680		       kdb_func_t func,
2681		       char *usage,
2682		       char *help,
2683		       short minlen,
2684		       kdb_cmdflags_t flags)
2685{
2686	int i;
2687	kdbtab_t *kp;
2688
2689	/*
2690	 *  Brute force method to determine duplicates
2691	 */
2692	for_each_kdbcmd(kp, i) {
2693		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2694			kdb_printf("Duplicate kdb command registered: "
2695				"%s, func %p help %s\n", cmd, func, help);
2696			return 1;
2697		}
2698	}
2699
2700	/*
2701	 * Insert command into first available location in table
2702	 */
2703	for_each_kdbcmd(kp, i) {
2704		if (kp->cmd_name == NULL)
2705			break;
2706	}
2707
2708	if (i >= kdb_max_commands) {
2709		kdbtab_t *new = kmalloc((kdb_max_commands - KDB_BASE_CMD_MAX +
2710			 kdb_command_extend) * sizeof(*new), GFP_KDB);
2711		if (!new) {
2712			kdb_printf("Could not allocate new kdb_command "
2713				   "table\n");
2714			return 1;
2715		}
2716		if (kdb_commands) {
2717			memcpy(new, kdb_commands,
2718			  (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
2719			kfree(kdb_commands);
2720		}
2721		memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
2722		       kdb_command_extend * sizeof(*new));
2723		kdb_commands = new;
2724		kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
2725		kdb_max_commands += kdb_command_extend;
2726	}
2727
2728	kp->cmd_name   = cmd;
2729	kp->cmd_func   = func;
2730	kp->cmd_usage  = usage;
2731	kp->cmd_help   = help;
2732	kp->cmd_minlen = minlen;
2733	kp->cmd_flags  = flags;
2734
2735	return 0;
2736}
2737EXPORT_SYMBOL_GPL(kdb_register_flags);
2738
2739
2740/*
2741 * kdb_register - Compatibility register function for commands that do
2742 *	not need to specify a repeat state.  Equivalent to
2743 *	kdb_register_flags with flags set to 0.
2744 * Inputs:
2745 *	cmd	Command name
2746 *	func	Function to execute the command
2747 *	usage	A simple usage string showing arguments
2748 *	help	A simple help string describing command
2749 * Returns:
2750 *	zero for success, one if a duplicate command.
2751 */
2752int kdb_register(char *cmd,
2753	     kdb_func_t func,
2754	     char *usage,
2755	     char *help,
2756	     short minlen)
2757{
2758	return kdb_register_flags(cmd, func, usage, help, minlen, 0);
2759}
2760EXPORT_SYMBOL_GPL(kdb_register);
2761
2762/*
2763 * kdb_unregister - This function is used to unregister a kernel
2764 *	debugger command.  It is generally called when a module which
2765 *	implements kdb commands is unloaded.
2766 * Inputs:
2767 *	cmd	Command name
2768 * Returns:
2769 *	zero for success, one command not registered.
2770 */
2771int kdb_unregister(char *cmd)
2772{
2773	int i;
2774	kdbtab_t *kp;
2775
2776	/*
2777	 *  find the command.
2778	 */
2779	for_each_kdbcmd(kp, i) {
2780		if (kp->cmd_name && (strcmp(kp->cmd_name, cmd) == 0)) {
2781			kp->cmd_name = NULL;
2782			return 0;
2783		}
2784	}
2785
2786	/* Couldn't find it.  */
2787	return 1;
2788}
2789EXPORT_SYMBOL_GPL(kdb_unregister);
2790
2791/* Initialize the kdb command table. */
2792static void __init kdb_inittab(void)
2793{
2794	int i;
2795	kdbtab_t *kp;
2796
2797	for_each_kdbcmd(kp, i)
2798		kp->cmd_name = NULL;
2799
2800	kdb_register_flags("md", kdb_md, "<vaddr>",
2801	  "Display Memory Contents, also mdWcN, e.g. md8c1", 1,
2802	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2803	kdb_register_flags("mdr", kdb_md, "<vaddr> <bytes>",
2804	  "Display Raw Memory", 0,
2805	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2806	kdb_register_flags("mdp", kdb_md, "<paddr> <bytes>",
2807	  "Display Physical Memory", 0,
2808	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2809	kdb_register_flags("mds", kdb_md, "<vaddr>",
2810	  "Display Memory Symbolically", 0,
2811	  KDB_ENABLE_MEM_READ | KDB_REPEAT_NO_ARGS);
2812	kdb_register_flags("mm", kdb_mm, "<vaddr> <contents>",
2813	  "Modify Memory Contents", 0,
2814	  KDB_ENABLE_MEM_WRITE | KDB_REPEAT_NO_ARGS);
2815	kdb_register_flags("go", kdb_go, "[<vaddr>]",
2816	  "Continue Execution", 1,
2817	  KDB_ENABLE_REG_WRITE | KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2818	kdb_register_flags("rd", kdb_rd, "",
2819	  "Display Registers", 0,
2820	  KDB_ENABLE_REG_READ);
2821	kdb_register_flags("rm", kdb_rm, "<reg> <contents>",
2822	  "Modify Registers", 0,
2823	  KDB_ENABLE_REG_WRITE);
2824	kdb_register_flags("ef", kdb_ef, "<vaddr>",
2825	  "Display exception frame", 0,
2826	  KDB_ENABLE_MEM_READ);
2827	kdb_register_flags("bt", kdb_bt, "[<vaddr>]",
2828	  "Stack traceback", 1,
2829	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2830	kdb_register_flags("btp", kdb_bt, "<pid>",
2831	  "Display stack for process <pid>", 0,
2832	  KDB_ENABLE_INSPECT);
2833	kdb_register_flags("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
2834	  "Backtrace all processes matching state flag", 0,
2835	  KDB_ENABLE_INSPECT);
2836	kdb_register_flags("btc", kdb_bt, "",
2837	  "Backtrace current process on each cpu", 0,
2838	  KDB_ENABLE_INSPECT);
2839	kdb_register_flags("btt", kdb_bt, "<vaddr>",
2840	  "Backtrace process given its struct task address", 0,
2841	  KDB_ENABLE_MEM_READ | KDB_ENABLE_INSPECT_NO_ARGS);
2842	kdb_register_flags("env", kdb_env, "",
2843	  "Show environment variables", 0,
2844	  KDB_ENABLE_ALWAYS_SAFE);
2845	kdb_register_flags("set", kdb_set, "",
2846	  "Set environment variables", 0,
2847	  KDB_ENABLE_ALWAYS_SAFE);
2848	kdb_register_flags("help", kdb_help, "",
2849	  "Display Help Message", 1,
2850	  KDB_ENABLE_ALWAYS_SAFE);
2851	kdb_register_flags("?", kdb_help, "",
2852	  "Display Help Message", 0,
2853	  KDB_ENABLE_ALWAYS_SAFE);
2854	kdb_register_flags("cpu", kdb_cpu, "<cpunum>",
2855	  "Switch to new cpu", 0,
2856	  KDB_ENABLE_ALWAYS_SAFE_NO_ARGS);
2857	kdb_register_flags("kgdb", kdb_kgdb, "",
2858	  "Enter kgdb mode", 0, 0);
2859	kdb_register_flags("ps", kdb_ps, "[<flags>|A]",
2860	  "Display active task list", 0,
2861	  KDB_ENABLE_INSPECT);
2862	kdb_register_flags("pid", kdb_pid, "<pidnum>",
2863	  "Switch to another task", 0,
2864	  KDB_ENABLE_INSPECT);
2865	kdb_register_flags("reboot", kdb_reboot, "",
2866	  "Reboot the machine immediately", 0,
2867	  KDB_ENABLE_REBOOT);
2868#if defined(CONFIG_MODULES)
2869	kdb_register_flags("lsmod", kdb_lsmod, "",
2870	  "List loaded kernel modules", 0,
2871	  KDB_ENABLE_INSPECT);
2872#endif
2873#if defined(CONFIG_MAGIC_SYSRQ)
2874	kdb_register_flags("sr", kdb_sr, "<key>",
2875	  "Magic SysRq key", 0,
2876	  KDB_ENABLE_ALWAYS_SAFE);
2877#endif
2878#if defined(CONFIG_PRINTK)
2879	kdb_register_flags("dmesg", kdb_dmesg, "[lines]",
2880	  "Display syslog buffer", 0,
2881	  KDB_ENABLE_ALWAYS_SAFE);
2882#endif
2883	if (arch_kgdb_ops.enable_nmi) {
2884		kdb_register_flags("disable_nmi", kdb_disable_nmi, "",
2885		  "Disable NMI entry to KDB", 0,
2886		  KDB_ENABLE_ALWAYS_SAFE);
2887	}
2888	kdb_register_flags("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
2889	  "Define a set of commands, down to endefcmd", 0,
2890	  KDB_ENABLE_ALWAYS_SAFE);
2891	kdb_register_flags("kill", kdb_kill, "<-signal> <pid>",
2892	  "Send a signal to a process", 0,
2893	  KDB_ENABLE_SIGNAL);
2894	kdb_register_flags("summary", kdb_summary, "",
2895	  "Summarize the system", 4,
2896	  KDB_ENABLE_ALWAYS_SAFE);
2897	kdb_register_flags("per_cpu", kdb_per_cpu, "<sym> [<bytes>] [<cpu>]",
2898	  "Display per_cpu variables", 3,
2899	  KDB_ENABLE_MEM_READ);
2900	kdb_register_flags("grephelp", kdb_grep_help, "",
2901	  "Display help on | grep", 0,
2902	  KDB_ENABLE_ALWAYS_SAFE);
2903}
2904
2905/* Execute any commands defined in kdb_cmds.  */
2906static void __init kdb_cmd_init(void)
2907{
2908	int i, diag;
2909	for (i = 0; kdb_cmds[i]; ++i) {
2910		diag = kdb_parse(kdb_cmds[i]);
2911		if (diag)
2912			kdb_printf("kdb command %s failed, kdb diag %d\n",
2913				kdb_cmds[i], diag);
2914	}
2915	if (defcmd_in_progress) {
2916		kdb_printf("Incomplete 'defcmd' set, forcing endefcmd\n");
2917		kdb_parse("endefcmd");
2918	}
2919}
2920
2921/* Initialize kdb_printf, breakpoint tables and kdb state */
2922void __init kdb_init(int lvl)
2923{
2924	static int kdb_init_lvl = KDB_NOT_INITIALIZED;
2925	int i;
2926
2927	if (kdb_init_lvl == KDB_INIT_FULL || lvl <= kdb_init_lvl)
2928		return;
2929	for (i = kdb_init_lvl; i < lvl; i++) {
2930		switch (i) {
2931		case KDB_NOT_INITIALIZED:
2932			kdb_inittab();		/* Initialize Command Table */
2933			kdb_initbptab();	/* Initialize Breakpoints */
2934			break;
2935		case KDB_INIT_EARLY:
2936			kdb_cmd_init();		/* Build kdb_cmds tables */
2937			break;
2938		}
2939	}
2940	kdb_init_lvl = lvl;
2941}