db_break.c

/*	$NetBSD: db_break.c,v 1.26 2007/02/22 06:41:00 thorpej Exp $	*/

/*
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 *
 *	Author: David B. Golub, Carnegie Mellon University
 *	Date:	7/90
 */

/*
 * Breakpoints.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: db_break.c,v 1.26 2007/02/22 06:41:00 thorpej Exp $");

#include <sys/param.h>
#include <sys/proc.h>

#include <machine/db_machdep.h>		/* type definitions */

#include <ddb/db_lex.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>
#include <ddb/db_break.h>
#include <ddb/db_output.h>

#define	NBREAKPOINTS	100
static struct db_breakpoint	db_break_table[NBREAKPOINTS];
static db_breakpoint_t		db_next_free_breakpoint = &db_break_table[0];
static db_breakpoint_t		db_free_breakpoints = 0;
static db_breakpoint_t		db_breakpoint_list = 0;

static db_breakpoint_t	db_breakpoint_alloc(void);
static void		db_breakpoint_free(db_breakpoint_t);
static void		db_delete_breakpoint(struct vm_map *, db_addr_t);
static db_breakpoint_t	db_find_breakpoint(struct vm_map *, db_addr_t);
static void		db_list_breakpoints(void);
static void		db_set_breakpoint(struct vm_map *, db_addr_t, int);

static db_breakpoint_t
db_breakpoint_alloc(void)
{
	db_breakpoint_t	bkpt;

	if ((bkpt = db_free_breakpoints) != 0) {
		db_free_breakpoints = bkpt->link;
		return (bkpt);
	}
	if (db_next_free_breakpoint == &db_break_table[NBREAKPOINTS]) {
		db_printf("All breakpoints used.\n");
		return (0);
	}
	bkpt = db_next_free_breakpoint;
	db_next_free_breakpoint++;

	return (bkpt);
}

static void
db_breakpoint_free(db_breakpoint_t bkpt)
{
	bkpt->link = db_free_breakpoints;
	db_free_breakpoints = bkpt;
}

void
db_set_breakpoint(struct vm_map *map, db_addr_t addr, int count)
{
	db_breakpoint_t	bkpt;

	if (db_find_breakpoint(map, addr)) {
		db_printf("Already set.\n");
		return;
	}

	bkpt = db_breakpoint_alloc();
	if (bkpt == 0) {
		db_printf("Too many breakpoints.\n");
		return;
	}

	bkpt->map = map;
	bkpt->address = BKPT_ADDR(addr);
	bkpt->flags = 0;
	bkpt->init_count = count;
	bkpt->count = count;

	bkpt->link = db_breakpoint_list;
	db_breakpoint_list = bkpt;
}

static void
db_delete_breakpoint(struct vm_map *map, db_addr_t addr)
{
	db_breakpoint_t	bkpt;
	db_breakpoint_t	*prev;

	for (prev = &db_breakpoint_list;
	     (bkpt = *prev) != 0;
	     prev = &bkpt->link) {
		if (db_map_equal(bkpt->map, map) &&
		    (bkpt->address == BKPT_ADDR(addr))) {
			*prev = bkpt->link;
			break;
		}
	}
	if (bkpt == 0) {
		db_printf("Not set.\n");
		return;
	}

	db_breakpoint_free(bkpt);
}

db_breakpoint_t
db_find_breakpoint(struct vm_map *map, db_addr_t addr)
{
	db_breakpoint_t	bkpt;

	for (bkpt = db_breakpoint_list;
	     bkpt != 0;
	     bkpt = bkpt->link)
		if (db_map_equal(bkpt->map, map) &&
		    (bkpt->address == BKPT_ADDR(addr)))
			return (bkpt);

	return (0);
}

db_breakpoint_t
db_find_breakpoint_here(db_addr_t addr)
{
	return db_find_breakpoint(db_map_addr(addr), addr);
}

static bool db_breakpoints_inserted = true;

void
db_set_breakpoints(void)
{
	db_breakpoint_t	bkpt;

	if (!db_breakpoints_inserted) {

		for (bkpt = db_breakpoint_list;
		     bkpt != 0;
		     bkpt = bkpt->link)
			if (db_map_current(bkpt->map)) {
				bkpt->bkpt_inst = db_get_value(bkpt->address,
				    BKPT_SIZE, false);
				db_put_value(bkpt->address,
				    BKPT_SIZE,
				    BKPT_SET(bkpt->bkpt_inst, bkpt->address));
			}
		db_breakpoints_inserted = true;
	}
}

void
db_clear_breakpoints(void)
{
	db_breakpoint_t	bkpt;

	if (db_breakpoints_inserted) {

		for (bkpt = db_breakpoint_list;
		     bkpt != 0;
		     bkpt = bkpt->link)
			if (db_map_current(bkpt->map))
			    db_put_value(bkpt->address, BKPT_SIZE,
				bkpt->bkpt_inst);
		db_breakpoints_inserted = false;
	}
}

/*
 * List breakpoints.
 */
void
db_list_breakpoints(void)
{
	db_breakpoint_t	bkpt;

	if (db_breakpoint_list == 0) {
		db_printf("No breakpoints set\n");
		return;
	}

	db_printf(" Map      Count    Address\n");
	for (bkpt = db_breakpoint_list;
	     bkpt != 0;
	     bkpt = bkpt->link) {
		db_printf("%s%p %5d    ",
		    db_map_current(bkpt->map) ? "*" : " ",
		    bkpt->map, bkpt->init_count);
		db_printsym(bkpt->address, DB_STGY_PROC, db_printf);
		db_printf("\n");
	}
}

/* Delete breakpoint */
/*ARGSUSED*/
void
db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
    const char *modif)
{

	db_delete_breakpoint(db_map_addr(addr), (db_addr_t)addr);
}

/* Set breakpoint with skip count */
/*ARGSUSED*/
void
db_breakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
    const char *modif)
{

	if (count == -1)
		count = 1;

	db_set_breakpoint(db_map_addr(addr), (db_addr_t)addr, count);
}

/* list breakpoints */
/*ARGSUSED*/
void
db_listbreak_cmd(db_expr_t addr, bool have_addr,
    db_expr_t count, const char *modif)
{

	db_list_breakpoints();
}

#include <uvm/uvm_extern.h>

/*
 *	We want ddb to be usable before most of the kernel has been
 *	initialized.  In particular, current_thread() or kernel_map
 *	(or both) may be null.
 */

bool
db_map_equal(struct vm_map *map1, struct vm_map *map2)
{

	return ((map1 == map2) ||
		((map1 == NULL) && (map2 == kernel_map)) ||
		((map1 == kernel_map) && (map2 == NULL)));
}

bool
db_map_current(struct vm_map *map)
{
#if 0
	thread_t	thread;

	return ((map == NULL) ||
		(map == kernel_map) ||
		(((thread = current_thread()) != NULL) &&
		 (map == thread->task->map)));
#else

	return (1);
#endif
}

struct vm_map *
db_map_addr(vaddr_t addr)
{
#if 0
	thread_t	thread;

	/*
	 *	We want to return kernel_map for all
	 *	non-user addresses, even when debugging
	 *	kernel tasks with their own maps.
	 */

	if ((VM_MIN_ADDRESS <= addr) && (addr < VM_MAX_ADDRESS) &&
	    ((thread = current_thread()) != NULL))
		return thread->task->map;
	else
#endif
		return kernel_map;
}