binutils-gdb/gdb/i386v-nat.c
1999-04-16 01:35:26 +00:00

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/* Intel 386 native support for SYSV systems (pre-SVR4).
Copyright (C) 1988, 89, 91, 92, 94, 96, 1998 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
#ifdef HAVE_PTRACE_H
# include <ptrace.h>
#else
# ifdef HAVE_SYS_PTRACE_H
# include <sys/ptrace.h>
# endif
#endif
#include "frame.h"
#include "inferior.h"
#include "language.h"
#include "gdbcore.h"
#ifdef USG
#include <sys/types.h>
#endif
#include <sys/param.h>
#include <sys/dir.h>
#include <signal.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include <fcntl.h>
/* FIXME: The following used to be just "#include <sys/debugreg.h>", but
* the the Linux 2.1.x kernel and glibc 2.0.x are not in sync; including
* <sys/debugreg.h> will result in an error. With luck, these losers
* will get their act together and we can trash this hack in the near future.
* --jsm 1998-10-21
*/
#ifdef TARGET_HAS_HARDWARE_WATCHPOINTS
# ifdef HAVE_ASM_DEBUGREG_H
# include <asm/debugreg.h>
# else
# include <sys/debugreg.h>
# endif
#endif
#include <sys/file.h>
#include "gdb_stat.h"
#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif
#include "floatformat.h"
#include "target.h"
/* this table must line up with REGISTER_NAMES in tm-i386v.h */
/* symbols like 'EAX' come from <sys/reg.h> */
static int regmap[] =
{
EAX, ECX, EDX, EBX,
UESP, EBP, ESI, EDI,
EIP, EFL, CS, SS,
DS, ES, FS, GS,
};
/* blockend is the value of u.u_ar0, and points to the
* place where GS is stored
*/
int
i386_register_u_addr (blockend, regnum)
int blockend;
int regnum;
{
struct user u;
int fpstate;
int ubase;
ubase = blockend;
/* FIXME: Should have better way to test floating point range */
if (regnum >= FP0_REGNUM && regnum <= (FP0_REGNUM + 7))
{
#ifdef KSTKSZ /* SCO, and others? */
ubase += 4 * (SS + 1) - KSTKSZ;
fpstate = ubase + ((char *)&u.u_fps.u_fpstate - (char *)&u);
return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
#else
fpstate = ubase + ((char *)&u.i387.st_space - (char *)&u);
return (fpstate + 10 * (regnum - FP0_REGNUM));
#endif
}
else
{
return (ubase + 4 * regmap[regnum]);
}
}
int
kernel_u_size ()
{
return (sizeof (struct user));
}
#ifdef TARGET_HAS_HARDWARE_WATCHPOINTS
#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_aligned_watchpoint PARAMS ((int, CORE_ADDR, CORE_ADDR, int,
int));
static int
i386_insert_nonaligned_watchpoint PARAMS ((int, CORE_ADDR, CORE_ADDR, int,
int));
/* Insert a watchpoint. */
int
i386_insert_watchpoint (pid, addr, len, rw)
int pid;
CORE_ADDR addr;
int len;
int rw;
{
return i386_insert_aligned_watchpoint (pid, addr, addr, len, rw);
}
static int
i386_insert_aligned_watchpoint (pid, waddr, addr, len, rw)
int pid;
CORE_ADDR waddr;
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 : DR_RW_WRITE;
if (len == 1)
len_bits = DR_LEN_1;
else if (len == 2)
{
if (addr % 2)
return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
len_bits = DR_LEN_2;
}
else if (len == 4)
{
if (addr % 4)
return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
len_bits = DR_LEN_4;
}
else
return i386_insert_nonaligned_watchpoint (pid, waddr, 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, waddr, addr, len, rw)
int pid;
CORE_ADDR waddr;
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_aligned_watchpoint (pid, waddr, addr, size, rw);
if (rv)
{
i386_remove_watchpoint (pid, waddr, 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_HAS_HARDWARE_WATCHPOINTS */
#if 0
/* using FLOAT_INFO as is would be a problem. FLOAT_INFO is called
via a command xxx and eventually calls ptrace without ever having
traversed the target vector. This would be terribly impolite
behaviour for a sun4 hosted remote gdb.
A fix might be to move this code into the "info registers" command.
rich@cygnus.com 15 Sept 92. */
i386_float_info ()
{
struct user u; /* just for address computations */
int i;
/* fpstate defined in <sys/user.h> */
struct fpstate *fpstatep;
char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
unsigned int uaddr;
char fpvalid = 0;
unsigned int rounded_addr;
unsigned int rounded_size;
extern int corechan;
int skip;
uaddr = (char *)&u.u_fpvalid - (char *)&u;
if (target_has_execution)
{
unsigned int data;
unsigned int mask;
rounded_addr = uaddr & -sizeof (int);
data = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
mask = 0xff << ((uaddr - rounded_addr) * 8);
fpvalid = ((data & mask) != 0);
}
#if 0
else
{
if (lseek (corechan, uaddr, 0) < 0)
perror ("seek on core file");
if (myread (corechan, &fpvalid, 1) < 0)
perror ("read on core file");
}
#endif /* no core support yet */
if (fpvalid == 0)
{
printf_unfiltered ("no floating point status saved\n");
return;
}
uaddr = (char *)&U_FPSTATE(u) - (char *)&u;
if (target_has_execution)
{
int *ip;
rounded_addr = uaddr & -sizeof (int);
rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
sizeof (int) - 1) / sizeof (int);
skip = uaddr - rounded_addr;
ip = (int *)buf;
for (i = 0; i < rounded_size; i++)
{
*ip++ = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
rounded_addr += sizeof (int);
}
}
#if 0
else
{
if (lseek (corechan, uaddr, 0) < 0)
perror_with_name ("seek on core file");
if (myread (corechan, buf, sizeof (struct fpstate)) < 0)
perror_with_name ("read from core file");
skip = 0;
}
#endif /* 0 */
fpstatep = (struct fpstate *)(buf + skip);
print_387_status (fpstatep->status, (struct env387 *)fpstatep->state);
}
#endif /* never */