[deliverable/binutils-gdb.git] / gdb / i386v-nat.c

/* Intel 386 native support for SYSV systems (pre-SVR4).
   Copyright (C) 1988, 1989, 1991, 1992, 1994 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#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>

#ifdef TARGET_CAN_USE_HARDWARE_WATCHPOINT
#include <sys/debugreg.h>
#endif

#include <sys/file.h>
#include <sys/stat.h>

#ifndef NO_SYS_REG_H
#include <sys/reg.h>
#endif

#include "floatformat.h"

#include "target.h"

\f
/* 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;
{
#if 0
  /* this will be needed if fp registers are reinstated */
  /* for now, you can look at them with 'info float'
   * sys5 wont let you change them with ptrace anyway
   */
  if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM) 
    {
      int ubase, fpstate;
      struct user u;
      ubase = blockend + 4 * (SS + 1) - KSTKSZ;
      fpstate = ubase + ((char *)&u.u_fpstate - (char *)&u);
      return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
    } 
  else
#endif
    return (blockend + 4 * regmap[regnum]);
  
}
\f
#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, CORE_ADDR, int,
					   int));

static int
i386_insert_aligned_watchpoint PARAMS ((pid, addr, len, rw));

/* 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 : 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, 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_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_CAN_USE_HARDWARE_WATCHPOINT */

#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 */
Commit	Line	Data
ebd99d54	1	/* Intel 386 native support for SYSV systems (pre-SVR4).
6d40175d	2	Copyright (C) 1988, 1989, 1991, 1992, 1994 Free Software Foundation, Inc.
c7c94073 RP	3
	4	This file is part of GDB.
	5
	6	This program is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2 of the License, or
	9	(at your option) any later version.
	10
	11	This program is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
	15
	16	You should have received a copy of the GNU General Public License
	17	along with this program; if not, write to the Free Software
	18	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
	19
	20	#include "defs.h"
	21	#include "frame.h"
	22	#include "inferior.h"
	23	#include "language.h"
	24	#include "gdbcore.h"
	25
	26	#ifdef USG
	27	#include <sys/types.h>
	28	#endif
	29
	30	#include <sys/param.h>
	31	#include <sys/dir.h>
	32	#include <signal.h>
	33	#include <sys/user.h>
	34	#include <sys/ioctl.h>
	35	#include <fcntl.h>
	36
6d40175d SS	37	#ifdef TARGET_CAN_USE_HARDWARE_WATCHPOINT
	38	#include <sys/debugreg.h>
	39	#endif
	40
c7c94073 RP	41	#include <sys/file.h>
	42	#include <sys/stat.h>
	43
ebd99d54	44	#ifndef NO_SYS_REG_H
c7c94073	45	#include <sys/reg.h>
ebd99d54 FF	46	#endif
ebd99d54 FF	47
eae3f093	48	#include "floatformat.h"
c7c94073 RP	49
	50	#include "target.h"
	51
c7c94073 RP	52	\f
	53	/* this table must line up with REGISTER_NAMES in tm-i386v.h */
	54	/* symbols like 'EAX' come from <sys/reg.h> */
	55	static int regmap[] =
	56	{
	57	EAX, ECX, EDX, EBX,
	58	UESP, EBP, ESI, EDI,
	59	EIP, EFL, CS, SS,
	60	DS, ES, FS, GS,
	61	};
	62
	63	/* blockend is the value of u.u_ar0, and points to the
	64	* place where GS is stored
	65	*/
	66
	67	int
	68	i386_register_u_addr (blockend, regnum)
	69	int blockend;
	70	int regnum;
	71	{
	72	#if 0
	73	/* this will be needed if fp registers are reinstated */
	74	/* for now, you can look at them with 'info float'
	75	* sys5 wont let you change them with ptrace anyway
	76	*/
	77	if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM)
	78	{
	79	int ubase, fpstate;
	80	struct user u;
	81	ubase = blockend + 4 * (SS + 1) - KSTKSZ;
	82	fpstate = ubase + ((char )&u.u_fpstate - (char )&u);
	83	return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
	84	}
	85	else
	86	#endif
	87	return (blockend + 4 * regmap[regnum]);
	88
	89	}
6d40175d SS	90	\f
	91	#ifdef TARGET_CAN_USE_HARDWARE_WATCHPOINT
	92
	93	#if !defined (offsetof)
	94	#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
	95	#endif
	96
	97	/* Record the value of the debug control register. */
	98	static int debug_control_mirror;
	99
	100	/* Record which address associates with which register. */
	101	static CORE_ADDR address_lookup[DR_LASTADDR - DR_FIRSTADDR + 1];
	102
	103	static int
04dd69e1 FF	104	i386_insert_nonaligned_watchpoint PARAMS ((int, CORE_ADDR, CORE_ADDR, int,
	105	int));
	106
	107	static int
	108	i386_insert_aligned_watchpoint PARAMS ((pid, addr, len, rw));
6d40175d SS	109
	110	/* Insert a watchpoint. */
	111
	112	int
	113	i386_insert_watchpoint (pid, addr, len, rw)
	114	int pid;
	115	CORE_ADDR addr;
	116	int len;
	117	int rw;
04dd69e1 FF	118	{
	119	return i386_insert_aligned_watchpoint (pid, addr, addr, len, rw);
	120	}
	121
	122	static int
	123	i386_insert_aligned_watchpoint (pid, waddr, addr, len, rw)
	124	int pid;
	125	CORE_ADDR waddr;
	126	CORE_ADDR addr;
	127	int len;
	128	int rw;
6d40175d SS	129	{
	130	int i;
	131	int read_write_bits, len_bits;
	132	int free_debug_register;
	133	int register_number;
	134
	135	/* Look for a free debug register. */
	136	for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
	137	{
	138	if (address_lookup[i - DR_FIRSTADDR] == 0)
	139	break;
	140	}
	141
	142	/* No more debug registers! */
	143	if (i > DR_LASTADDR)
	144	return -1;
	145
	146	read_write_bits = ((rw & 1) ? DR_RW_READ : 0) \| ((rw & 2) ? DR_RW_WRITE : 0);
	147
	148	if (len == 1)
	149	len_bits = DR_LEN_1;
	150	else if (len == 2)
	151	{
	152	if (addr % 2)
04dd69e1	153	return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
6d40175d SS	154	len_bits = DR_LEN_2;
	155	}
	156
	157	else if (len == 4)
	158	{
	159	if (addr % 4)
04dd69e1	160	return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
6d40175d SS	161	len_bits = DR_LEN_4;
	162	}
	163	else
04dd69e1	164	return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
6d40175d SS	165
	166	free_debug_register = i;
	167	register_number = free_debug_register - DR_FIRSTADDR;
	168	debug_control_mirror \|=
	169	((read_write_bits \| len_bits)
	170	<< (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * register_number));
	171	debug_control_mirror \|=
	172	(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number));
	173	debug_control_mirror \|= DR_LOCAL_SLOWDOWN;
	174	debug_control_mirror &= ~DR_CONTROL_RESERVED;
	175
	176	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]),
	177	debug_control_mirror);
	178	ptrace (6, pid, offsetof (struct user, u_debugreg[free_debug_register]),
	179	addr);
	180
	181	/* Record where we came from. */
	182	address_lookup[register_number] = addr;
	183	return 0;
	184	}
	185
	186	static int
04dd69e1 FF	187	i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw)
	188	int pid;
	189	CORE_ADDR waddr;
	190	CORE_ADDR addr;
	191	int len;
	192	int rw;
6d40175d SS	193	{
	194	int align;
	195	int size;
	196	int rv;
	197
	198	static int size_try_array[16] = {
	199	1, 1, 1, 1, /* trying size one */
	200	2, 1, 2, 1, /* trying size two */
	201	2, 1, 2, 1, /* trying size three */
	202	4, 1, 2, 1 /* trying size four */
	203	};
	204
	205	rv = 0;
	206	while (len > 0)
	207	{
	208	align = addr % 4;
	209	/* Four is the maximum length for 386. */
	210	size = (len > 4) ? 3 : len - 1;
	211	size = size_try_array[size * 4 + align];
	212
04dd69e1	213	rv = i386_insert_watchpoint (pid, waddr, addr, size, rw);
6d40175d SS	214	if (rv)
6d40175d SS	215	{
04dd69e1	216	i386_remove_watchpoint (pid, waddr, size);
6d40175d SS	217	return rv;
	218	}
	219	addr += size;
	220	len -= size;
	221	}
	222	return rv;
	223	}
	224
	225	/* Remove a watchpoint. */
	226
	227	int
	228	i386_remove_watchpoint (pid, addr, len)
	229	int pid;
	230	CORE_ADDR addr;
	231	int len;
	232	{
	233	int i;
	234	int register_number;
	235
	236	for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
	237	{
	238	register_number = i - DR_FIRSTADDR;
	239	if (address_lookup[register_number] == addr)
	240	{
	241	debug_control_mirror &=
	242	~(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number));
	243	address_lookup[register_number] = 0;
	244	}
	245	}
	246	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]),
	247	debug_control_mirror);
	248	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
	249
	250	return 0;
	251	}
	252
	253	/* Check if stopped by a watchpoint. */
	254
	255	CORE_ADDR
	256	i386_stopped_by_watchpoint (pid)
	257	int pid;
	258	{
	259	int i;
	260	int status;
	261
	262	status = ptrace (3, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
	263	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
	264
	265	for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
	266	{
	267	if (status & (1 << (i - DR_FIRSTADDR)))
	268	return address_lookup[i - DR_FIRSTADDR];
	269	}
	270
	271	return 0;
	272	}
	273
	274	#endif /* TARGET_CAN_USE_HARDWARE_WATCHPOINT */
c7c94073 RP	275
	276	#if 0
	277	/* using FLOAT_INFO as is would be a problem. FLOAT_INFO is called
	278	via a command xxx and eventually calls ptrace without ever having
	279	traversed the target vector. This would be terribly impolite
	280	behaviour for a sun4 hosted remote gdb.
	281
	282	A fix might be to move this code into the "info registers" command.
	283	rich@cygnus.com 15 Sept 92. */
	284	i386_float_info ()
	285	{
	286	struct user u; /* just for address computations */
	287	int i;
	288	/* fpstate defined in <sys/user.h> */
	289	struct fpstate *fpstatep;
	290	char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
	291	unsigned int uaddr;
	292	char fpvalid = 0;
	293	unsigned int rounded_addr;
	294	unsigned int rounded_size;
	295	extern int corechan;
	296	int skip;
	297
	298	uaddr = (char )&u.u_fpvalid - (char )&u;
	299	if (target_has_execution)
	300	{
	301	unsigned int data;
	302	unsigned int mask;
	303
	304	rounded_addr = uaddr & -sizeof (int);
	305	data = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
	306	mask = 0xff << ((uaddr - rounded_addr) * 8);
	307
	308	fpvalid = ((data & mask) != 0);
	309	}
	310	#if 0
	311	else
	312	{
	313	if (lseek (corechan, uaddr, 0) < 0)
	314	perror ("seek on core file");
	315	if (myread (corechan, &fpvalid, 1) < 0)
	316	perror ("read on core file");
	317
	318	}
	319	#endif /* no core support yet */
	320
	321	if (fpvalid == 0)
	322	{
199b2450	323	printf_unfiltered ("no floating point status saved\n");
c7c94073 RP	324	return;
	325	}
	326
	327	uaddr = (char )&U_FPSTATE(u) - (char )&u;
	328	if (target_has_execution)
	329	{
	330	int *ip;
	331
	332	rounded_addr = uaddr & -sizeof (int);
	333	rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
	334	sizeof (int) - 1) / sizeof (int);
	335	skip = uaddr - rounded_addr;
	336
	337	ip = (int *)buf;
	338	for (i = 0; i < rounded_size; i++)
	339	{
	340	*ip++ = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
	341	rounded_addr += sizeof (int);
	342	}
	343	}
	344	#if 0
	345	else
	346	{
	347	if (lseek (corechan, uaddr, 0) < 0)
	348	perror_with_name ("seek on core file");
	349	if (myread (corechan, buf, sizeof (struct fpstate)) < 0)
	350	perror_with_name ("read from core file");
	351	skip = 0;
	352	}
3496b745	353	#endif /* 0 */
c7c94073 RP	354
	355	fpstatep = (struct fpstate *)(buf + skip);
	356	print_387_status (fpstatep->status, (struct env387 *)fpstatep->state);
	357	}
	358
	359	#endif /* never */