HardenedBSD/sys/ddb/db_break.c
Andrew Turner 076b64e83a sys/ddb: Add hardware breakpoint support to ddb
As with hardware watchpoints add support for hardware breakpoints. The
command is only enabled on architectures that report support for them.
Currently no architectures do, however arm64 will add support in a
future change.

Reviewed by:	jhb (earlier version)
Sponsored by:	Arm Ltd
Sponsored by:	Innovate UK
Differential Revision:	https://reviews.freebsd.org/D22191
2024-04-12 09:32:41 +00:00

406 lines
9.0 KiB
C

/*-
* SPDX-License-Identifier: MIT-CMU
*
* 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
* 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/param.h>
#include <sys/systm.h>
#include <sys/kdb.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <machine/kdb.h>
#include <ddb/ddb.h>
#include <ddb/db_break.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>
struct db_breakpoint_type {
db_breakpoint_t db_next_free_breakpoint;
db_breakpoint_t db_breakpoint_limit;
db_breakpoint_t db_free_breakpoints;
db_breakpoint_t db_breakpoint_list;
};
#define NBREAKPOINTS 100
static struct db_breakpoint db_break_table[NBREAKPOINTS];
static struct db_breakpoint_type db_breakpoint = {
.db_next_free_breakpoint = &db_break_table[0],
.db_breakpoint_limit = &db_break_table[NBREAKPOINTS],
.db_free_breakpoints = NULL,
.db_breakpoint_list = NULL,
};
#ifdef HAS_HW_BREAKPOINT
static struct db_breakpoint db_hbreak_table[NHBREAKPOINTS];
static struct db_breakpoint_type db_hbreakpoint = {
.db_next_free_breakpoint = &db_hbreak_table[0],
.db_breakpoint_limit = &db_hbreak_table[NHBREAKPOINTS],
.db_free_breakpoints = NULL,
.db_breakpoint_list = NULL,
};
#endif
static db_breakpoint_t db_breakpoint_alloc(
struct db_breakpoint_type *bkpt_type);
static void db_breakpoint_free(struct db_breakpoint_type *bkpt_typ,
db_breakpoint_t bkpt);
static void db_delete_breakpoint(struct db_breakpoint_type *bkpt_type,
vm_map_t map, db_addr_t addr);
static db_breakpoint_t db_find_breakpoint(struct db_breakpoint_type *bkpt_type,
vm_map_t map, db_addr_t addr);
static void db_list_breakpoints(void);
static bool db_set_breakpoint(struct db_breakpoint_type *bkpt_type,
vm_map_t map, db_addr_t addr, int count);
static db_breakpoint_t
db_breakpoint_alloc(struct db_breakpoint_type *bkpt_type)
{
register db_breakpoint_t bkpt;
if ((bkpt = bkpt_type->db_free_breakpoints) != 0) {
bkpt_type->db_free_breakpoints = bkpt->link;
return (bkpt);
}
if (bkpt_type->db_next_free_breakpoint ==
bkpt_type->db_breakpoint_limit) {
db_printf("All breakpoints used.\n");
return (0);
}
bkpt = bkpt_type->db_next_free_breakpoint;
bkpt_type->db_next_free_breakpoint++;
return (bkpt);
}
static void
db_breakpoint_free(struct db_breakpoint_type *bkpt_type, db_breakpoint_t bkpt)
{
bkpt->link = bkpt_type->db_free_breakpoints;
bkpt_type->db_free_breakpoints = bkpt;
}
static bool
db_set_breakpoint(struct db_breakpoint_type *bkpt_type, vm_map_t map,
db_addr_t addr, int count)
{
register db_breakpoint_t bkpt;
if (db_find_breakpoint(bkpt_type, map, addr)) {
db_printf("Already set.\n");
return (false);
}
bkpt = db_breakpoint_alloc(bkpt_type);
if (bkpt == 0) {
db_printf("Too many breakpoints.\n");
return (false);
}
bkpt->map = map;
bkpt->address = addr;
bkpt->flags = 0;
bkpt->init_count = count;
bkpt->count = count;
bkpt->link = bkpt_type->db_breakpoint_list;
bkpt_type->db_breakpoint_list = bkpt;
return (true);
}
static void
db_delete_breakpoint(struct db_breakpoint_type *bkpt_type, vm_map_t map,
db_addr_t addr)
{
register db_breakpoint_t bkpt;
register db_breakpoint_t *prev;
for (prev = &bkpt_type->db_breakpoint_list;
(bkpt = *prev) != 0;
prev = &bkpt->link) {
if (db_map_equal(bkpt->map, map) &&
(bkpt->address == addr)) {
*prev = bkpt->link;
break;
}
}
if (bkpt == 0) {
db_printf("Not set.\n");
return;
}
db_breakpoint_free(bkpt_type, bkpt);
}
static db_breakpoint_t
db_find_breakpoint(struct db_breakpoint_type *bkpt_type, vm_map_t map,
db_addr_t addr)
{
register db_breakpoint_t bkpt;
for (bkpt = bkpt_type->db_breakpoint_list;
bkpt != 0;
bkpt = bkpt->link)
{
if (db_map_equal(bkpt->map, map) &&
(bkpt->address == addr))
return (bkpt);
}
return (0);
}
db_breakpoint_t
db_find_breakpoint_here(db_addr_t addr)
{
db_breakpoint_t bkpt;
bkpt = db_find_breakpoint(&db_breakpoint, db_map_addr(addr), addr);
#ifdef HAS_HW_BREAKPOINT
if (bkpt == NULL)
bkpt = db_find_breakpoint(&db_hbreakpoint, db_map_addr(addr),
addr);
#endif
return (bkpt);
}
static bool db_breakpoints_inserted = true;
#ifndef BKPT_WRITE
#define BKPT_WRITE(addr, storage) \
do { \
*storage = db_get_value(addr, BKPT_SIZE, false); \
db_put_value(addr, BKPT_SIZE, BKPT_SET(*storage)); \
} while (0)
#endif
#ifndef BKPT_CLEAR
#define BKPT_CLEAR(addr, storage) \
db_put_value(addr, BKPT_SIZE, *storage)
#endif
/*
* Set software breakpoints.
*/
void
db_set_breakpoints(void)
{
register db_breakpoint_t bkpt;
if (!db_breakpoints_inserted) {
for (bkpt = db_breakpoint.db_breakpoint_list;
bkpt != 0;
bkpt = bkpt->link)
if (db_map_current(bkpt->map)) {
BKPT_WRITE(bkpt->address, &bkpt->bkpt_inst);
}
db_breakpoints_inserted = true;
}
}
/*
* Clean software breakpoints.
*/
void
db_clear_breakpoints(void)
{
register db_breakpoint_t bkpt;
if (db_breakpoints_inserted) {
for (bkpt = db_breakpoint.db_breakpoint_list;
bkpt != 0;
bkpt = bkpt->link)
if (db_map_current(bkpt->map)) {
BKPT_CLEAR(bkpt->address, &bkpt->bkpt_inst);
}
db_breakpoints_inserted = false;
}
}
/*
* List software breakpoints.
*/
static void
db_list_breakpoints(void)
{
register db_breakpoint_t bkpt;
if (db_breakpoint.db_breakpoint_list == 0) {
db_printf("No breakpoints set\n");
return;
}
db_printf(" Map Count Address\n");
for (bkpt = db_breakpoint.db_breakpoint_list;
bkpt != 0;
bkpt = bkpt->link) {
db_printf("%s%8p %5d ",
db_map_current(bkpt->map) ? "*" : " ",
(void *)bkpt->map, bkpt->init_count);
db_printsym(bkpt->address, DB_STGY_PROC);
db_printf("\n");
}
}
/*
* Delete software breakpoint
*/
/*ARGSUSED*/
void
db_delete_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
{
db_delete_breakpoint(&db_breakpoint, db_map_addr(addr),
(db_addr_t)addr);
}
/*
* Set software breakpoint with skip count
*/
/*ARGSUSED*/
void
db_breakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
{
if (count == -1)
count = 1;
db_set_breakpoint(&db_breakpoint, db_map_addr(addr), (db_addr_t)addr,
count);
}
#ifdef HAS_HW_BREAKPOINT
/*
* Delete hardware breakpoint
*/
void
db_deletehbreak_cmd(db_expr_t addr, bool have_addr, db_expr_t count,
char *modif)
{
if (count == -1)
count = 1;
if (kdb_cpu_clr_breakpoint(addr) != 0) {
db_printf("hardware breakpoint could not be delete\n");
return;
}
db_delete_breakpoint(&db_hbreakpoint, db_map_addr(addr),
(db_addr_t)addr);
}
/*
* Set hardware breakpoint
*/
void
db_hbreakpoint_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
{
if (count == -1)
count = 1;
if (!db_set_breakpoint(&db_hbreakpoint, db_map_addr(addr),
(db_addr_t)addr, count))
return;
if (kdb_cpu_set_breakpoint(addr) != 0) {
db_printf("hardware breakpoint could not be set\n");
db_delete_breakpoint(&db_hbreakpoint, db_map_addr(addr),
(db_addr_t)addr);
}
}
#endif
/* list breakpoints */
void
db_listbreak_cmd(db_expr_t dummy1, bool dummy2, db_expr_t dummy3, char *dummy4)
{
db_list_breakpoints();
#ifdef HAS_HW_BREAKPOINT
db_md_list_breakpoints();
#endif
}
/*
* 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(vm_map_t map1, vm_map_t map2)
{
return ((map1 == map2) ||
((map1 == NULL) && (map2 == kernel_map)) ||
((map1 == kernel_map) && (map2 == NULL)));
}
bool
db_map_current(vm_map_t map)
{
#if 0
thread_t thread;
return ((map == NULL) ||
(map == kernel_map) ||
(((thread = current_thread()) != NULL) &&
(map == thread->task->map)));
#else
return (true);
#endif
}
vm_map_t
db_map_addr(vm_offset_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;
}