freebsd-skq/sys/ddb/db_watch.c
Brian S. Dean 17bbfb5897 Add 'hwatch' and 'dhwatch' ddb commands analogous to 'watch' and
'dwatch'.  The new commands install hardware watchpoints if supported
by the architecture and if there are enough registers to cover the
desired memory area.

No objection by: audit@, hackers@

MFC after: 2 weeks
2001-07-11 03:15:25 +00:00

330 lines
7.0 KiB
C

/*
* 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.
*
* $FreeBSD$
*/
/*
* Author: Richard P. Draves, Carnegie Mellon University
* Date: 10/90
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <ddb/ddb.h>
#include <ddb/db_watch.h>
/*
* Watchpoints.
*/
static boolean_t db_watchpoints_inserted = TRUE;
#define NWATCHPOINTS 100
static struct db_watchpoint db_watch_table[NWATCHPOINTS];
static db_watchpoint_t db_next_free_watchpoint = &db_watch_table[0];
static db_watchpoint_t db_free_watchpoints = 0;
static db_watchpoint_t db_watchpoint_list = 0;
static db_watchpoint_t db_watchpoint_alloc __P((void));
static void db_watchpoint_free __P((db_watchpoint_t watch));
static void db_delete_watchpoint __P((vm_map_t map,
db_addr_t addr));
#ifdef notused
static boolean_t db_find_watchpoint __P((vm_map_t map, db_addr_t addr,
db_regs_t *regs));
#endif
static void db_list_watchpoints __P((void));
static void db_set_watchpoint __P((vm_map_t map, db_addr_t addr,
vm_size_t size));
int db_md_set_watchpoint __P((db_expr_t addr, db_expr_t size));
int db_md_clr_watchpoint __P((db_expr_t addr, db_expr_t size));
void db_md_list_watchpoints __P((void));
db_watchpoint_t
db_watchpoint_alloc()
{
register db_watchpoint_t watch;
if ((watch = db_free_watchpoints) != 0) {
db_free_watchpoints = watch->link;
return (watch);
}
if (db_next_free_watchpoint == &db_watch_table[NWATCHPOINTS]) {
db_printf("All watchpoints used.\n");
return (0);
}
watch = db_next_free_watchpoint;
db_next_free_watchpoint++;
return (watch);
}
void
db_watchpoint_free(watch)
register db_watchpoint_t watch;
{
watch->link = db_free_watchpoints;
db_free_watchpoints = watch;
}
static void
db_set_watchpoint(map, addr, size)
vm_map_t map;
db_addr_t addr;
vm_size_t size;
{
register db_watchpoint_t watch;
if (map == NULL) {
db_printf("No map.\n");
return;
}
/*
* Should we do anything fancy with overlapping regions?
*/
for (watch = db_watchpoint_list;
watch != 0;
watch = watch->link)
if (db_map_equal(watch->map, map) &&
(watch->loaddr == addr) &&
(watch->hiaddr == addr+size)) {
db_printf("Already set.\n");
return;
}
watch = db_watchpoint_alloc();
if (watch == 0) {
db_printf("Too many watchpoints.\n");
return;
}
watch->map = map;
watch->loaddr = addr;
watch->hiaddr = addr+size;
watch->link = db_watchpoint_list;
db_watchpoint_list = watch;
db_watchpoints_inserted = FALSE;
}
static void
db_delete_watchpoint(map, addr)
vm_map_t map;
db_addr_t addr;
{
register db_watchpoint_t watch;
register db_watchpoint_t *prev;
for (prev = &db_watchpoint_list;
(watch = *prev) != 0;
prev = &watch->link)
if (db_map_equal(watch->map, map) &&
(watch->loaddr <= addr) &&
(addr < watch->hiaddr)) {
*prev = watch->link;
db_watchpoint_free(watch);
return;
}
db_printf("Not set.\n");
}
static void
db_list_watchpoints()
{
register db_watchpoint_t watch;
if (db_watchpoint_list == 0) {
db_printf("No watchpoints set\n");
return;
}
db_printf(" Map Address Size\n");
for (watch = db_watchpoint_list;
watch != 0;
watch = watch->link)
db_printf("%s%8p %8lx %lx\n",
db_map_current(watch->map) ? "*" : " ",
(void *)watch->map, (long)watch->loaddr,
(long)watch->hiaddr - (long)watch->loaddr);
}
/* Delete watchpoint */
/*ARGSUSED*/
void
db_deletewatch_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
db_delete_watchpoint(db_map_addr(addr), addr);
}
/* Set watchpoint */
/*ARGSUSED*/
void
db_watchpoint_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
vm_size_t size;
db_expr_t value;
if (db_expression(&value))
size = (vm_size_t) value;
else
size = 4;
db_skip_to_eol();
db_set_watchpoint(db_map_addr(addr), addr, size);
}
/*
* At least one non-optional show-command must be implemented using
* DB_SHOW_COMMAND() so that db_show_cmd_set gets created. Here is one.
*/
DB_SHOW_COMMAND(watches, db_listwatch_cmd)
{
db_list_watchpoints();
db_md_list_watchpoints();
}
void
db_set_watchpoints()
{
register db_watchpoint_t watch;
if (!db_watchpoints_inserted) {
for (watch = db_watchpoint_list;
watch != 0;
watch = watch->link)
pmap_protect(watch->map->pmap,
trunc_page(watch->loaddr),
round_page(watch->hiaddr),
VM_PROT_READ);
db_watchpoints_inserted = TRUE;
}
}
void
db_clear_watchpoints()
{
db_watchpoints_inserted = FALSE;
}
#ifdef notused
static boolean_t
db_find_watchpoint(map, addr, regs)
vm_map_t map;
db_addr_t addr;
db_regs_t *regs;
{
register db_watchpoint_t watch;
db_watchpoint_t found = 0;
for (watch = db_watchpoint_list;
watch != 0;
watch = watch->link)
if (db_map_equal(watch->map, map)) {
if ((watch->loaddr <= addr) &&
(addr < watch->hiaddr))
return (TRUE);
else if ((trunc_page(watch->loaddr) <= addr) &&
(addr < round_page(watch->hiaddr)))
found = watch;
}
/*
* We didn't hit exactly on a watchpoint, but we are
* in a protected region. We want to single-step
* and then re-protect.
*/
if (found) {
db_watchpoints_inserted = FALSE;
db_single_step(regs);
}
return (FALSE);
}
#endif
/* Delete hardware watchpoint */
/*ARGSUSED*/
void
db_deletehwatch_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
int rc;
if (count < 0)
count = 4;
rc = db_md_clr_watchpoint(addr, count);
if (rc < 0)
db_printf("hardware watchpoint could not be deleted\n");
}
/* Set hardware watchpoint */
/*ARGSUSED*/
void
db_hwatchpoint_cmd(addr, have_addr, count, modif)
db_expr_t addr;
boolean_t have_addr;
db_expr_t count;
char * modif;
{
int rc;
if (count < 0)
count = 4;
rc = db_md_set_watchpoint(addr, count);
if (rc < 0)
db_printf("hardware watchpoint could not be set\n");
}