linux/kernel/debug/kdb/kdb_bt.c

/*
 * Kernel Debugger Architecture Independent Stack Traceback
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 1999-2004 Silicon Graphics, Inc.  All Rights Reserved.
 * Copyright (c) 2009 Wind River Systems, Inc.  All Rights Reserved.
 */

#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/kdb.h>
#include <linux/nmi.h>
#include "kdb_private.h"


static void kdb_show_stack(struct task_struct *p, void *addr)
{ … }

/*
 * kdb_bt
 *
 *	This function implements the 'bt' command.  Print a stack
 *	traceback.
 *
 *	bt [<address-expression>]	(addr-exp is for alternate stacks)
 *	btp <pid>			Kernel stack for <pid>
 *	btt <address-expression>	Kernel stack for task structure at
 *					<address-expression>
 *	bta [state_chars>|A]		All useful processes, optionally
 *					filtered by state
 *	btc [<cpu>]			The current process on one cpu,
 *					default is all cpus
 *
 *	bt <address-expression> refers to a address on the stack, that location
 *	is assumed to contain a return address.
 *
 *	btt <address-expression> refers to the address of a struct task.
 *
 * Inputs:
 *	argc	argument count
 *	argv	argument vector
 * Outputs:
 *	None.
 * Returns:
 *	zero for success, a kdb diagnostic if error
 * Locking:
 *	none.
 * Remarks:
 *	Backtrack works best when the code uses frame pointers.  But even
 *	without frame pointers we should get a reasonable trace.
 *
 *	mds comes in handy when examining the stack to do a manual traceback or
 *	to get a starting point for bt <address-expression>.
 */

static int
kdb_bt1(struct task_struct *p, const char *mask, bool btaprompt)
{ … }

static void
kdb_bt_cpu(unsigned long cpu)
{ … }

int
kdb_bt(int argc, const char **argv)
{ … }