binutils-gdb/gdb/i386v-nat.c

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/* Intel 386 native support for System V systems (pre-SVR4).
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Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1998,
1999, 2000, 2002 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"
#include <sys/param.h>
#include <sys/dir.h>
#include <signal.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#ifdef TARGET_HAS_HARDWARE_WATCHPOINTS
#include <sys/debugreg.h>
#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"
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#include "i386-tdep.h"
/* Mapping between the general-purpose registers in `struct user'
format and GDB's register array layout. */
static int regmap[] =
{
EAX, ECX, EDX, EBX,
UESP, EBP, ESI, EDI,
EIP, EFL, CS, SS,
DS, ES, FS, GS,
};
/* Support for the user struct. */
/* Return the address of register REGNUM. BLOCKEND is the value of
u.u_ar0, and points to the place where GS is stored. */
CORE_ADDR
register_u_addr (CORE_ADDR blockend, int regnum)
{
struct user u;
CORE_ADDR fpstate;
if (i386_fp_regnum_p (regnum))
{
#ifdef KSTKSZ /* SCO, and others? */
blockend += 4 * (SS + 1) - KSTKSZ;
fpstate = blockend + ((char *) &u.u_fps.u_fpstate - (char *) &u);
return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
#else
fpstate = blockend + ((char *) &u.i387.st_space - (char *) &u);
return (fpstate + 10 * (regnum - FP0_REGNUM));
#endif
}
return (blockend + 4 * regmap[regnum]);
}
/* Return the size of the user struct. */
int
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kernel_u_size (void)
{
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 (int, CORE_ADDR, CORE_ADDR, int,
int);
static int i386_insert_nonaligned_watchpoint (int, CORE_ADDR, CORE_ADDR, int,
int);
/* Insert a watchpoint. */
int
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i386_insert_watchpoint (int pid, CORE_ADDR addr, int len, int rw)
{
return i386_insert_aligned_watchpoint (pid, addr, addr, len, rw);
}
static int
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i386_insert_aligned_watchpoint (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
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i386_insert_nonaligned_watchpoint (int pid, CORE_ADDR waddr, CORE_ADDR addr,
int len, int rw)
{
int align;
int size;
int rv;
static int size_try_array[4][4] =
{
{ 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 = size_try_array[len > 4 ? 3 : len - 1][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
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i386_remove_watchpoint (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
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i386_stopped_by_watchpoint (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 */