[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_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 : 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_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_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
95618211	104	i386_insert_aligned_watchpoint PARAMS ((int, CORE_ADDR, CORE_ADDR, int,
04dd69e1 FF	105	int));
	106
	107	static int
95618211 SS	108	i386_insert_nonaligned_watchpoint PARAMS ((int, CORE_ADDR, CORE_ADDR, int,
95618211 SS	109	int));
6d40175d SS	110
	111	/* Insert a watchpoint. */
	112
	113	int
	114	i386_insert_watchpoint (pid, addr, len, rw)
	115	int pid;
	116	CORE_ADDR addr;
	117	int len;
	118	int rw;
04dd69e1 FF	119	{
	120	return i386_insert_aligned_watchpoint (pid, addr, addr, len, rw);
	121	}
	122
	123	static int
	124	i386_insert_aligned_watchpoint (pid, waddr, addr, len, rw)
	125	int pid;
	126	CORE_ADDR waddr;
	127	CORE_ADDR addr;
	128	int len;
	129	int rw;
6d40175d SS	130	{
	131	int i;
	132	int read_write_bits, len_bits;
	133	int free_debug_register;
	134	int register_number;
	135
	136	/* Look for a free debug register. */
	137	for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
	138	{
	139	if (address_lookup[i - DR_FIRSTADDR] == 0)
	140	break;
	141	}
	142
	143	/* No more debug registers! */
	144	if (i > DR_LASTADDR)
	145	return -1;
	146
	147	read_write_bits = ((rw & 1) ? DR_RW_READ : 0) \| ((rw & 2) ? DR_RW_WRITE : 0);
	148
	149	if (len == 1)
	150	len_bits = DR_LEN_1;
	151	else if (len == 2)
	152	{
	153	if (addr % 2)
04dd69e1	154	return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
6d40175d SS	155	len_bits = DR_LEN_2;
	156	}
	157
	158	else if (len == 4)
	159	{
	160	if (addr % 4)
04dd69e1	161	return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
6d40175d SS	162	len_bits = DR_LEN_4;
	163	}
	164	else
04dd69e1	165	return i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw);
6d40175d SS	166
	167	free_debug_register = i;
	168	register_number = free_debug_register - DR_FIRSTADDR;
	169	debug_control_mirror \|=
	170	((read_write_bits \| len_bits)
	171	<< (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * register_number));
	172	debug_control_mirror \|=
	173	(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number));
	174	debug_control_mirror \|= DR_LOCAL_SLOWDOWN;
	175	debug_control_mirror &= ~DR_CONTROL_RESERVED;
	176
	177	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]),
	178	debug_control_mirror);
	179	ptrace (6, pid, offsetof (struct user, u_debugreg[free_debug_register]),
	180	addr);
	181
	182	/* Record where we came from. */
	183	address_lookup[register_number] = addr;
	184	return 0;
	185	}
	186
	187	static int
04dd69e1 FF	188	i386_insert_nonaligned_watchpoint (pid, waddr, addr, len, rw)
	189	int pid;
	190	CORE_ADDR waddr;
	191	CORE_ADDR addr;
	192	int len;
	193	int rw;
6d40175d SS	194	{
	195	int align;
	196	int size;
	197	int rv;
	198
	199	static int size_try_array[16] = {
	200	1, 1, 1, 1, /* trying size one */
	201	2, 1, 2, 1, /* trying size two */
	202	2, 1, 2, 1, /* trying size three */
	203	4, 1, 2, 1 /* trying size four */
	204	};
	205
	206	rv = 0;
	207	while (len > 0)
	208	{
	209	align = addr % 4;
	210	/* Four is the maximum length for 386. */
	211	size = (len > 4) ? 3 : len - 1;
	212	size = size_try_array[size * 4 + align];
	213
95618211	214	rv = i386_insert_aligned_watchpoint (pid, waddr, addr, size, rw);
6d40175d SS	215	if (rv)
6d40175d SS	216	{
04dd69e1	217	i386_remove_watchpoint (pid, waddr, size);
6d40175d SS	218	return rv;
	219	}
	220	addr += size;
	221	len -= size;
	222	}
	223	return rv;
	224	}
	225
	226	/* Remove a watchpoint. */
	227
	228	int
	229	i386_remove_watchpoint (pid, addr, len)
	230	int pid;
	231	CORE_ADDR addr;
	232	int len;
	233	{
	234	int i;
	235	int register_number;
	236
	237	for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
	238	{
	239	register_number = i - DR_FIRSTADDR;
	240	if (address_lookup[register_number] == addr)
	241	{
	242	debug_control_mirror &=
	243	~(1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * register_number));
	244	address_lookup[register_number] = 0;
	245	}
	246	}
	247	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_CONTROL]),
	248	debug_control_mirror);
	249	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
	250
	251	return 0;
	252	}
	253
	254	/* Check if stopped by a watchpoint. */
	255
	256	CORE_ADDR
	257	i386_stopped_by_watchpoint (pid)
	258	int pid;
	259	{
	260	int i;
	261	int status;
	262
	263	status = ptrace (3, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
	264	ptrace (6, pid, offsetof (struct user, u_debugreg[DR_STATUS]), 0);
	265
	266	for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
	267	{
	268	if (status & (1 << (i - DR_FIRSTADDR)))
	269	return address_lookup[i - DR_FIRSTADDR];
	270	}
	271
	272	return 0;
	273	}
	274
	275	#endif /* TARGET_CAN_USE_HARDWARE_WATCHPOINT */
c7c94073 RP	276
	277	#if 0
	278	/* using FLOAT_INFO as is would be a problem. FLOAT_INFO is called
	279	via a command xxx and eventually calls ptrace without ever having
	280	traversed the target vector. This would be terribly impolite
	281	behaviour for a sun4 hosted remote gdb.
	282
	283	A fix might be to move this code into the "info registers" command.
	284	rich@cygnus.com 15 Sept 92. */
	285	i386_float_info ()
	286	{
	287	struct user u; /* just for address computations */
	288	int i;
	289	/* fpstate defined in <sys/user.h> */
	290	struct fpstate *fpstatep;
	291	char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
	292	unsigned int uaddr;
	293	char fpvalid = 0;
	294	unsigned int rounded_addr;
	295	unsigned int rounded_size;
	296	extern int corechan;
	297	int skip;
	298
	299	uaddr = (char )&u.u_fpvalid - (char )&u;
	300	if (target_has_execution)
	301	{
	302	unsigned int data;
	303	unsigned int mask;
	304
	305	rounded_addr = uaddr & -sizeof (int);
	306	data = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
	307	mask = 0xff << ((uaddr - rounded_addr) * 8);
	308
	309	fpvalid = ((data & mask) != 0);
	310	}
	311	#if 0
	312	else
	313	{
	314	if (lseek (corechan, uaddr, 0) < 0)
	315	perror ("seek on core file");
	316	if (myread (corechan, &fpvalid, 1) < 0)
	317	perror ("read on core file");
	318
	319	}
	320	#endif /* no core support yet */
	321
	322	if (fpvalid == 0)
	323	{
199b2450	324	printf_unfiltered ("no floating point status saved\n");
c7c94073 RP	325	return;
	326	}
	327
	328	uaddr = (char )&U_FPSTATE(u) - (char )&u;
	329	if (target_has_execution)
	330	{
	331	int *ip;
	332
	333	rounded_addr = uaddr & -sizeof (int);
	334	rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
	335	sizeof (int) - 1) / sizeof (int);
	336	skip = uaddr - rounded_addr;
	337
	338	ip = (int *)buf;
	339	for (i = 0; i < rounded_size; i++)
	340	{
	341	*ip++ = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
	342	rounded_addr += sizeof (int);
	343	}
	344	}
	345	#if 0
	346	else
	347	{
	348	if (lseek (corechan, uaddr, 0) < 0)
	349	perror_with_name ("seek on core file");
	350	if (myread (corechan, buf, sizeof (struct fpstate)) < 0)
	351	perror_with_name ("read from core file");
	352	skip = 0;
	353	}
3496b745	354	#endif /* 0 */
c7c94073 RP	355
	356	fpstatep = (struct fpstate *)(buf + skip);
	357	print_387_status (fpstatep->status, (struct env387 *)fpstatep->state);
	358	}
	359
	360	#endif /* never */