Wed Jun 1 11:08:52 1994 Stan Shebs (shebs@andros.cygnus.com)

Hardware watchpoints for Linux, from Rick Sladkey
	(jrs@world.std.com).
	* infrun.c (wait_for_inferior) [HAVE_CONTINUABLE_WATCHPOINT]: Add
	new hardware breakpoint recovery method.
	* i386v-nat.c (i386_insert_watchpoint,
	i386_insert_nonaligned_watchpoint, i386_remove_watchpoint,
	i386_stopped_by_watchpoint) [TARGET_CAN_USE_HARWARE_WATCHPOINT]:
	New functions to support the 386 hardware debugging registers.
	* config/i386/nm-linux.h (TARGET_CAN_USE_HARDWARE_WATCHPOINT,
	HAVE_CONTINUABLE_WATCHPOINT, STOPPED_BY_WATCHPOINT,
	target_insert_watchpoint, target_remove_watchpoint): Define these
	macros to use the hardware debugging functions in i386v-nat.c.
This commit is contained in:
Stan Shebs 1994-06-01 18:26:16 +00:00
parent 0221ddf71a
commit 6d40175db0
3 changed files with 194 additions and 1 deletions

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@ -1,3 +1,18 @@
Wed Jun 1 11:08:52 1994 Stan Shebs (shebs@andros.cygnus.com)
Hardware watchpoints for Linux, from Rick Sladkey
(jrs@world.std.com).
* infrun.c (wait_for_inferior) [HAVE_CONTINUABLE_WATCHPOINT]: Add
new hardware breakpoint recovery method.
* i386v-nat.c (i386_insert_watchpoint,
i386_insert_nonaligned_watchpoint, i386_remove_watchpoint,
i386_stopped_by_watchpoint) [TARGET_CAN_USE_HARWARE_WATCHPOINT]:
New functions to support the 386 hardware debugging registers.
* config/i386/nm-linux.h (TARGET_CAN_USE_HARDWARE_WATCHPOINT,
HAVE_CONTINUABLE_WATCHPOINT, STOPPED_BY_WATCHPOINT,
target_insert_watchpoint, target_remove_watchpoint): Define these
macros to use the hardware debugging functions in i386v-nat.c.
Wed May 25 17:06:15 1994 Jim Kingdon (kingdon@lioth.cygnus.com)
* Makefile.in: Replace libgdb.a with libgdb-files. Make "all"

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@ -1,5 +1,5 @@
/* Intel 386 native support for SYSV systems (pre-SVR4).
Copyright (C) 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
Copyright (C) 1988, 1989, 1991, 1992, 1994 Free Software Foundation, Inc.
This file is part of GDB.
@ -34,6 +34,10 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <sys/ioctl.h>
#include <fcntl.h>
#ifdef TARGET_CAN_USE_HARDWARE_WATCHPOINT
#include <sys/debugreg.h>
#endif
#include <sys/file.h>
#include <sys/stat.h>
@ -83,6 +87,175 @@ i386_register_u_addr (blockend, regnum)
return (blockend + 4 * regmap[regnum]);
}
#ifdef TARGET_CAN_USE_HARDWARE_WATCHPOINT
#if !defined (offsetof)
#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
#endif
/* Record the value of the debug control register. */
static int debug_control_mirror;
/* Record which address associates with which register. */
static CORE_ADDR address_lookup[DR_LASTADDR - DR_FIRSTADDR + 1];
static int
i386_insert_nonaligned_watchpoint PARAMS ((int, CORE_ADDR, int, int));
/* Insert a watchpoint. */
int
i386_insert_watchpoint (pid, addr, len, rw)
int pid;
CORE_ADDR addr;
int len;
int rw;
{
int i;
int read_write_bits, len_bits;
int free_debug_register;
int register_number;
/* Look for a free debug register. */
for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
{
if (address_lookup[i - DR_FIRSTADDR] == 0)
break;
}
/* No more debug registers! */
if (i > DR_LASTADDR)
return -1;
read_write_bits = ((rw & 1) ? DR_RW_READ : 0) | ((rw & 2) ? DR_RW_WRITE : 0);
if (len == 1)
len_bits = DR_LEN_1;
else if (len == 2)
{
if (addr % 2)
return i386_insert_nonaligned_watchpoint (pid, addr, len, rw);
len_bits = DR_LEN_2;
}
else if (len == 4)
{
if (addr % 4)
return i386_insert_nonaligned_watchpoint (pid, addr, len, rw);
len_bits = DR_LEN_4;
}
else
return i386_insert_nonaligned_watchpoint (pid, addr, len, rw);
free_debug_register = i;
register_number = free_debug_register - DR_FIRSTADDR;
debug_control_mirror |=
((read_write_bits | len_bits)
<< (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * register_number));
debug_control_mirror |=
(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number));
debug_control_mirror |= DR_LOCAL_SLOWDOWN;
debug_control_mirror &= ~DR_CONTROL_RESERVED;
ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]),
debug_control_mirror);
ptrace (6, pid, offsetof (struct user, u_debugreg[free_debug_register]),
addr);
/* Record where we came from. */
address_lookup[register_number] = addr;
return 0;
}
static int
i386_insert_nonaligned_watchpoint (pid, addr, len, rw)
int pid;
CORE_ADDR addr;
int len;
int rw;
{
int align;
int size;
int rv;
static int size_try_array[16] = {
1, 1, 1, 1, /* trying size one */
2, 1, 2, 1, /* trying size two */
2, 1, 2, 1, /* trying size three */
4, 1, 2, 1 /* trying size four */
};
rv = 0;
while (len > 0)
{
align = addr % 4;
/* Four is the maximum length for 386. */
size = (len > 4) ? 3 : len - 1;
size = size_try_array[size * 4 + align];
rv = i386_insert_watchpoint (pid, addr, size, rw);
if (rv)
{
i386_remove_watchpoint (pid, addr, size);
return rv;
}
addr += size;
len -= size;
}
return rv;
}
/* Remove a watchpoint. */
int
i386_remove_watchpoint (pid, addr, len)
int pid;
CORE_ADDR addr;
int len;
{
int i;
int register_number;
for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
{
register_number = i - DR_FIRSTADDR;
if (address_lookup[register_number] == addr)
{
debug_control_mirror &=
~(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number));
address_lookup[register_number] = 0;
}
}
ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]),
debug_control_mirror);
ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
return 0;
}
/* Check if stopped by a watchpoint. */
CORE_ADDR
i386_stopped_by_watchpoint (pid)
int pid;
{
int i;
int status;
status = ptrace (3, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
{
if (status & (1 << (i - DR_FIRSTADDR)))
return address_lookup[i - DR_FIRSTADDR];
}
return 0;
}
#endif /* TARGET_CAN_USE_HARDWARE_WATCHPOINT */
#if 0
/* using FLOAT_INFO as is would be a problem. FLOAT_INFO is called

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@ -680,6 +680,11 @@ switch_thread:
}
#endif
#ifdef HAVE_CONTINUABLE_WATCHPOINT
/* It may be possible to simply continue after a watchpoint. */
STOPPED_BY_WATCHPOINT (w);
#endif
stop_frame_address = FRAME_FP (get_current_frame ());
stop_sp = read_sp ();
stop_func_start = 0;