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

/* Machine-dependent hooks for the unix child process stratum.  This
   code is for the HP PA-RISC cpu.

   Copyright 1986, 1987, 1989, 1990, 1991, 1992 Free Software Foundation, Inc.

   Contributed by the Center for Software Science at the
   University of Utah (pa-gdb-bugs@cs.utah.edu).

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 "inferior.h"

#ifndef PT_ATTACH
#define PT_ATTACH PTRACE_ATTACH
#endif
#ifndef PT_DETACH
#define PT_DETACH PTRACE_DETACH
#endif

/* This function simply calls ptrace with the given arguments.  
   It exists so that all calls to ptrace are isolated in this 
   machine-dependent file. */
#ifdef WANT_NATIVE_TARGET
int
call_ptrace (request, pid, addr, data)
     int request, pid;
     PTRACE_ARG3_TYPE addr;
     int data;
{
  return ptrace (request, pid, addr, data, 0);
}
#endif /* WANT_NATIVE_TARGET */

#ifdef DEBUG_PTRACE
/* For the rest of the file, use an extra level of indirection */
/* This lets us breakpoint usefully on call_ptrace. */
#define ptrace call_ptrace
#endif

void
kill_inferior ()
{
  if (inferior_pid == 0)
    return;
  ptrace (PT_EXIT, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0, 0); /* PT_EXIT = PT_KILL ? */
  wait ((int *)0);
  target_mourn_inferior ();
}

#ifdef ATTACH_DETACH
/* Nonzero if we are debugging an attached process rather than
   an inferior.  */
extern int attach_flag;

/* Start debugging the process whose number is PID.  */
int
attach (pid)
     int pid;
{
  errno = 0;
  ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0, 0);
  if (errno)
    perror_with_name ("ptrace");
  attach_flag = 1;
  return pid;
}

/* Stop debugging the process whose number is PID
   and continue it with signal number SIGNAL.
   SIGNAL = 0 means just continue it.  */

void
detach (signal)
     int signal;
{
  errno = 0;
  ptrace (PT_DETACH, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal, 0);
  if (errno)
    perror_with_name ("ptrace");
  attach_flag = 0;
}
#endif /* ATTACH_DETACH */

/* Fetch all registers, or just one, from the child process.  */

void
fetch_inferior_registers (regno)
     int regno;
{
  if (regno == -1)
    for (regno = 0; regno < NUM_REGS; regno++)
      fetch_register (regno);
  else
    fetch_register (regno);
}

/* Registers we shouldn't try to store.  */
#if !defined (CANNOT_STORE_REGISTER)
#define CANNOT_STORE_REGISTER(regno) 0
#endif

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[80];
  extern char registers[];
  register int i;

  unsigned int offset = U_REGS_OFFSET;

  if (regno >= 0)
    {
      regaddr = register_addr (regno, offset);
      for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int))
	{
	  errno = 0;
	  ptrace (PT_WUAREA, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
		  *(int *) &registers[REGISTER_BYTE (regno) + i], 0);
	  if (errno != 0)
	    {
	      sprintf (buf, "writing register number %d(%d)", regno, i);
	      perror_with_name (buf);
	    }
	  regaddr += sizeof(int);
	}
    }
  else
    {
      for (regno = 0; regno < NUM_REGS; regno++)
	{
	  if (CANNOT_STORE_REGISTER (regno))
	    continue;
	  regaddr = register_addr (regno, offset);
	  for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int))
	    {
	      errno = 0;
	      ptrace (PT_WUAREA, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
		      *(int *) &registers[REGISTER_BYTE (regno) + i], 0);
	      if (errno != 0)
		{
		  sprintf (buf, "writing register number %d(%d)", regno, i);
		  perror_with_name (buf);
		}
	      regaddr += sizeof(int);
	    }
	}
    }
  return;
}

/* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
   to get the offset in the core file of the register values.  */
#if defined (KERNEL_U_ADDR_BSD)
/* Get kernel_u_addr using BSD-style nlist().  */
CORE_ADDR kernel_u_addr;

#include <a.out.gnu.h>		/* For struct nlist */

void
_initialize_kernel_u_addr ()
{
  struct nlist names[2];

  names[0].n_un.n_name = "_u";
  names[1].n_un.n_name = NULL;
  if (nlist ("/vmunix", names) == 0)
    kernel_u_addr = names[0].n_value;
  else
    fatal ("Unable to get kernel u area address.");
}
#endif /* KERNEL_U_ADDR_BSD.  */

#if defined (KERNEL_U_ADDR_HPUX)
/* Get kernel_u_addr using HPUX-style nlist().  */
CORE_ADDR kernel_u_addr;

struct hpnlist {      
        char *          n_name;
        long            n_value;  
        unsigned char   n_type;   
        unsigned char   n_length;  
        short           n_almod;   
        short           n_unused;
};
static struct hpnlist nl[] = {{ "_u", -1, }, { (char *) 0, }};

/* read the value of the u area from the hp-ux kernel */
void _initialize_kernel_u_addr ()
{
    struct user u;
    nlist ("/hp-ux", &nl);
    kernel_u_addr = nl[0].n_value;
}
#endif /* KERNEL_U_ADDR_HPUX.  */

#if !defined (offsetof)
#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
#endif

/* U_REGS_OFFSET is the offset of the registers within the u area.  */
#if !defined (U_REGS_OFFSET)
#define U_REGS_OFFSET \
  ptrace (PT_READ_U, inferior_pid, \
          (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0, 0) \
    - KERNEL_U_ADDR
#endif

/* Registers we shouldn't try to fetch.  */
#if !defined (CANNOT_FETCH_REGISTER)
#define CANNOT_FETCH_REGISTER(regno) 0
#endif

/* Fetch one register.  */

static void
fetch_register (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[MAX_REGISTER_RAW_SIZE];
  char mess[128];				/* For messages */
  register int i;

  /* Offset of registers within the u area.  */
  unsigned int offset;

  if (CANNOT_FETCH_REGISTER (regno))
    {
      bzero (buf, REGISTER_RAW_SIZE (regno));	/* Supply zeroes */
      supply_register (regno, buf);
      return;
    }

  offset = U_REGS_OFFSET;

  regaddr = register_addr (regno, offset);
  for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
    {
      errno = 0;
      *(int *) &buf[i] = ptrace (PT_RUREGS, inferior_pid,
				 (PTRACE_ARG3_TYPE) regaddr, 0, 0);
      regaddr += sizeof (int);
      if (errno != 0)
	{
	  sprintf (mess, "reading register %s (#%d)", reg_names[regno], regno);
	  perror_with_name (mess);
	}
    }
  supply_register (regno, buf);
}


/* Resume execution of the inferior process.
   If STEP is nonzero, single-step it.
   If SIGNAL is nonzero, give it that signal.  */

void
child_resume (step, signal)
     int step;
     int signal;
{
  errno = 0;

  /* An address of (PTRACE_ARG3_TYPE) 1 tells ptrace to continue from where
     it was. (If GDB wanted it to start some other way, we have already
     written a new PC value to the child.)  */

  if (step)
    ptrace (PT_SINGLE, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal, 0);
  else
    ptrace (PT_CONTIN, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal, 0);

  if (errno)
    perror_with_name ("ptrace");
}

/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
   in the NEW_SUN_PTRACE case.
   It ought to be straightforward.  But it appears that writing did
   not write the data that I specified.  I cannot understand where
   it got the data that it actually did write.  */

/* Copy LEN bytes to or from inferior's memory starting at MEMADDR
   to debugger memory starting at MYADDR.   Copy to inferior if
   WRITE is nonzero.
  
   Returns the length copied, which is either the LEN argument or zero.
   This xfer function does not do partial moves, since child_ops
   doesn't allow memory operations to cross below us in the target stack
   anyway.  */

int
child_xfer_memory (memaddr, myaddr, len, write, target)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
     int write;
     struct target_ops *target;		/* ignored */
{
  register int i;
  /* Round starting address down to longword boundary.  */
  register CORE_ADDR addr = memaddr & - sizeof (int);
  /* Round ending address up; get number of longwords that makes.  */
  register int count
    = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
  /* Allocate buffer of that many longwords.  */
  register int *buffer = (int *) alloca (count * sizeof (int));

  if (write)
    {
      /* Fill start and end extra bytes of buffer with existing memory data.  */

      if (addr != memaddr || len < (int)sizeof (int)) {
	/* Need part of initial word -- fetch it.  */
        buffer[0] = ptrace (PT_RIUSER, inferior_pid,
			    (PTRACE_ARG3_TYPE) addr, 0, 0);
      }

      if (count > 1)		/* FIXME, avoid if even boundary */
	{
	  buffer[count - 1]
	    = ptrace (PT_RIUSER, inferior_pid,
		      (PTRACE_ARG3_TYPE) (addr + (count - 1) * sizeof (int)),
		      0, 0);
	}

      /* Copy data to be written over corresponding part of buffer */

      bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);

      /* Write the entire buffer.  */

      for (i = 0; i < count; i++, addr += sizeof (int))
	{
#if 0
/* The HP-UX kernel crashes if you use PT_WDUSER to write into the text
   segment.  FIXME -- does it work to write into the data segment using
   WIUSER, or do these idiots really expect us to figure out which segment
   the address is in, so we can use a separate system call for it??!  */
	  errno = 0;
	  ptrace (PT_WDUSER, inferior_pid, (PTRACE_ARG3_TYPE) addr,
		  buffer[i], 0);
	  if (errno)
#endif
	    {
	      /* Using the appropriate one (I or D) is necessary for
		 Gould NP1, at least.  */
	      errno = 0;
	      ptrace (PT_WIUSER, inferior_pid, (PTRACE_ARG3_TYPE) addr,
		      buffer[i], 0);
	    }
	  if (errno)
	    return 0;
	}
    }
  else
    {
      /* Read all the longwords */
      for (i = 0; i < count; i++, addr += sizeof (int))
	{
	  errno = 0;
	  buffer[i] = ptrace (PT_RIUSER, inferior_pid,
			      (PTRACE_ARG3_TYPE) addr, 0, 0);
	  if (errno)
	    return 0;
	  QUIT;
	}

      /* Copy appropriate bytes out of the buffer.  */
      bcopy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
    }
  return len;
}
Commit	Line	Data
ca048722 RP	1	/* Machine-dependent hooks for the unix child process stratum. This
	2	code is for the HP PA-RISC cpu.
	3
	4	Copyright 1986, 1987, 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
	5
	6	Contributed by the Center for Software Science at the
	7	University of Utah (pa-gdb-bugs@cs.utah.edu).
	8
	9	This file is part of GDB.
	10
	11	This program is free software; you can redistribute it and/or modify
	12	it under the terms of the GNU General Public License as published by
	13	the Free Software Foundation; either version 2 of the License, or
	14	(at your option) any later version.
	15
	16	This program is distributed in the hope that it will be useful,
	17	but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	19	GNU General Public License for more details.
	20
	21	You should have received a copy of the GNU General Public License
	22	along with this program; if not, write to the Free Software
	23	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
	24
	25
	26	#include "defs.h"
	27	#include "inferior.h"
	28
	29	#ifndef PT_ATTACH
	30	#define PT_ATTACH PTRACE_ATTACH
	31	#endif
	32	#ifndef PT_DETACH
	33	#define PT_DETACH PTRACE_DETACH
	34	#endif
	35
	36	/* This function simply calls ptrace with the given arguments.
	37	It exists so that all calls to ptrace are isolated in this
	38	machine-dependent file. */
	39	#ifdef WANT_NATIVE_TARGET
	40	int
	41	call_ptrace (request, pid, addr, data)
	42	int request, pid;
	43	PTRACE_ARG3_TYPE addr;
	44	int data;
	45	{
	46	return ptrace (request, pid, addr, data, 0);
	47	}
	48	#endif /* WANT_NATIVE_TARGET */
	49
	50	#ifdef DEBUG_PTRACE
	51	/* For the rest of the file, use an extra level of indirection */
	52	/* This lets us breakpoint usefully on call_ptrace. */
	53	#define ptrace call_ptrace
	54	#endif
	55
	56	void
	57	kill_inferior ()
	58	{
	59	if (inferior_pid == 0)
	60	return;
	61	ptrace (PT_EXIT, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0, 0); /* PT_EXIT = PT_KILL ? */
	62	wait ((int *)0);
	63	target_mourn_inferior ();
	64	}
65
66	#ifdef ATTACH_DETACH
67	/* Nonzero if we are debugging an attached process rather than
68	an inferior. */
69	extern int attach_flag;
70
71	/* Start debugging the process whose number is PID. */
72	int
73	attach (pid)
74	int pid;
75	{
76	errno = 0;
77	ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0, 0);
78	if (errno)
79	perror_with_name ("ptrace");
80	attach_flag = 1;
81	return pid;
82	}
83
84	/* Stop debugging the process whose number is PID
85	and continue it with signal number SIGNAL.
86	SIGNAL = 0 means just continue it. */
87
88	void
89	detach (signal)
90	int signal;
91	{
92	errno = 0;
93	ptrace (PT_DETACH, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal, 0);
94	if (errno)
95	perror_with_name ("ptrace");
96	attach_flag = 0;
97	}
98	#endif /* ATTACH_DETACH */
99
100	/* Fetch all registers, or just one, from the child process. */
101
102	void
103	fetch_inferior_registers (regno)
104	int regno;
105	{
106	if (regno == -1)
107	for (regno = 0; regno < NUM_REGS; regno++)
108	fetch_register (regno);
109	else
110	fetch_register (regno);
111	}
112
113	/* Registers we shouldn't try to store. */
114	#if !defined (CANNOT_STORE_REGISTER)
115	#define CANNOT_STORE_REGISTER(regno) 0
116	#endif
117
118	/* Store our register values back into the inferior.
119	If REGNO is -1, do this for all registers.
120	Otherwise, REGNO specifies which register (so we can save time). */
121
122	void
123	store_inferior_registers (regno)
124	int regno;
125	{
126	register unsigned int regaddr;
127	char buf[80];
128	extern char registers[];
129	register int i;
130
131	unsigned int offset = U_REGS_OFFSET;
132
133	if (regno >= 0)
134	{
135	regaddr = register_addr (regno, offset);
136	for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int))
137	{
138	errno = 0;
139	ptrace (PT_WUAREA, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
140	(int ) &registers[REGISTER_BYTE (regno) + i], 0);
141	if (errno != 0)
142	{
143	sprintf (buf, "writing register number %d(%d)", regno, i);
144	perror_with_name (buf);
145	}
146	regaddr += sizeof(int);
147	}
148	}
149	else
150	{
151	for (regno = 0; regno < NUM_REGS; regno++)
152	{
153	if (CANNOT_STORE_REGISTER (regno))
154	continue;
155	regaddr = register_addr (regno, offset);
156	for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(int))
157	{
158	errno = 0;
159	ptrace (PT_WUAREA, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
160	(int ) &registers[REGISTER_BYTE (regno) + i], 0);
161	if (errno != 0)
162	{
163	sprintf (buf, "writing register number %d(%d)", regno, i);
164	perror_with_name (buf);
165	}
166	regaddr += sizeof(int);
167	}
168	}
169	}
170	return;
171	}
172
173	/* KERNEL_U_ADDR is the amount to subtract from u.u_ar0
174	to get the offset in the core file of the register values. */
175	#if defined (KERNEL_U_ADDR_BSD)
176	/* Get kernel_u_addr using BSD-style nlist(). */
177	CORE_ADDR kernel_u_addr;
178
179	#include <a.out.gnu.h> /* For struct nlist */
180
181	void
182	_initialize_kernel_u_addr ()
183	{
184	struct nlist names[2];
185
186	names[0].n_un.n_name = "_u";
187	names[1].n_un.n_name = NULL;
188	if (nlist ("/vmunix", names) == 0)
189	kernel_u_addr = names[0].n_value;
190	else
191	fatal ("Unable to get kernel u area address.");
192	}
193	#endif /* KERNEL_U_ADDR_BSD. */
194
195	#if defined (KERNEL_U_ADDR_HPUX)
196	/* Get kernel_u_addr using HPUX-style nlist(). */
197	CORE_ADDR kernel_u_addr;
198
199	struct hpnlist {
200	char * n_name;
201	long n_value;
202	unsigned char n_type;
203	unsigned char n_length;
204	short n_almod;
205	short n_unused;
206	};
207	static struct hpnlist nl[] = {{ "_u", -1, }, { (char *) 0, }};
208
209	/* read the value of the u area from the hp-ux kernel */
210	void _initialize_kernel_u_addr ()
211	{
212	struct user u;
213	nlist ("/hp-ux", &nl);
214	kernel_u_addr = nl[0].n_value;
215	}
216	#endif /* KERNEL_U_ADDR_HPUX. */
217
218	#if !defined (offsetof)
219	#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
220	#endif
221
222	/* U_REGS_OFFSET is the offset of the registers within the u area. */
223	#if !defined (U_REGS_OFFSET)
224	#define U_REGS_OFFSET \
225	ptrace (PT_READ_U, inferior_pid, \
226	(PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0, 0) \
227	- KERNEL_U_ADDR
228	#endif
229
230	/* Registers we shouldn't try to fetch. */
231	#if !defined (CANNOT_FETCH_REGISTER)
232	#define CANNOT_FETCH_REGISTER(regno) 0
233	#endif
234
235	/* Fetch one register. */
236
237	static void
238	fetch_register (regno)
239	int regno;
240	{
241	register unsigned int regaddr;
242	char buf[MAX_REGISTER_RAW_SIZE];
243	char mess[128]; /* For messages */
244	register int i;
245
246	/* Offset of registers within the u area. */
247	unsigned int offset;
248
249	if (CANNOT_FETCH_REGISTER (regno))
250	{
251	bzero (buf, REGISTER_RAW_SIZE (regno)); /* Supply zeroes */
252	supply_register (regno, buf);
253	return;
254	}
255
256	offset = U_REGS_OFFSET;
257
258	regaddr = register_addr (regno, offset);
259	for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
260	{
261	errno = 0;
262	(int ) &buf[i] = ptrace (PT_RUREGS, inferior_pid,
263	(PTRACE_ARG3_TYPE) regaddr, 0, 0);
264	regaddr += sizeof (int);
265	if (errno != 0)
266	{
267	sprintf (mess, "reading register %s (#%d)", reg_names[regno], regno);
268	perror_with_name (mess);
269	}
270	}
271	supply_register (regno, buf);
272	}
273
274
275
276	/* Resume execution of the inferior process.
277	If STEP is nonzero, single-step it.
278	If SIGNAL is nonzero, give it that signal. */
279
280	void
281	child_resume (step, signal)
282	int step;
283	int signal;
284	{
285	errno = 0;
286
287	/* An address of (PTRACE_ARG3_TYPE) 1 tells ptrace to continue from where
288	it was. (If GDB wanted it to start some other way, we have already
289	written a new PC value to the child.) */
290
291	if (step)
292	ptrace (PT_SINGLE, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal, 0);
293	else
294	ptrace (PT_CONTIN, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal, 0);
295
296	if (errno)
297	perror_with_name ("ptrace");
298	}
299
300	/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
301	in the NEW_SUN_PTRACE case.
302	It ought to be straightforward. But it appears that writing did
303	not write the data that I specified. I cannot understand where
304	it got the data that it actually did write. */
305
306	/* Copy LEN bytes to or from inferior's memory starting at MEMADDR
307	to debugger memory starting at MYADDR. Copy to inferior if
308	WRITE is nonzero.
309
310	Returns the length copied, which is either the LEN argument or zero.
311	This xfer function does not do partial moves, since child_ops
312	doesn't allow memory operations to cross below us in the target stack
313	anyway. */
314
315	int
316	child_xfer_memory (memaddr, myaddr, len, write, target)
317	CORE_ADDR memaddr;
318	char *myaddr;
319	int len;
320	int write;
321	struct target_ops target; / ignored */
322	{
323	register int i;
324	/* Round starting address down to longword boundary. */
325	register CORE_ADDR addr = memaddr & - sizeof (int);
326	/* Round ending address up; get number of longwords that makes. */
327	register int count
328	= (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
329	/* Allocate buffer of that many longwords. */
330	register int buffer = (int ) alloca (count * sizeof (int));
331
332	if (write)
333	{
334	/* Fill start and end extra bytes of buffer with existing memory data. */
335
336	if (addr != memaddr \|\| len < (int)sizeof (int)) {
337	/* Need part of initial word -- fetch it. */
338	buffer[0] = ptrace (PT_RIUSER, inferior_pid,
339	(PTRACE_ARG3_TYPE) addr, 0, 0);
340	}
341
342	if (count > 1) /* FIXME, avoid if even boundary */
343	{
344	buffer[count - 1]
345	= ptrace (PT_RIUSER, inferior_pid,
346	(PTRACE_ARG3_TYPE) (addr + (count - 1) * sizeof (int)),
347	0, 0);
348	}
349
350	/* Copy data to be written over corresponding part of buffer */
351
352	bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);
353
354	/* Write the entire buffer. */
355
356	for (i = 0; i < count; i++, addr += sizeof (int))
357	{
358	#if 0
359	/* The HP-UX kernel crashes if you use PT_WDUSER to write into the text
360	segment. FIXME -- does it work to write into the data segment using
361	WIUSER, or do these idiots really expect us to figure out which segment
362	the address is in, so we can use a separate system call for it??! */
363	errno = 0;
364	ptrace (PT_WDUSER, inferior_pid, (PTRACE_ARG3_TYPE) addr,
365	buffer[i], 0);
366	if (errno)
367	#endif
368	{
369	/* Using the appropriate one (I or D) is necessary for
370	Gould NP1, at least. */
371	errno = 0;
372	ptrace (PT_WIUSER, inferior_pid, (PTRACE_ARG3_TYPE) addr,
373	buffer[i], 0);
374	}
375	if (errno)
376	return 0;
377	}
378	}
379	else
380	{
381	/* Read all the longwords */
382	for (i = 0; i < count; i++, addr += sizeof (int))
383	{
384	errno = 0;
385	buffer[i] = ptrace (PT_RIUSER, inferior_pid,
386	(PTRACE_ARG3_TYPE) addr, 0, 0);
387	if (errno)
388	return 0;
389	QUIT;
390	}
391
392	/* Copy appropriate bytes out of the buffer. */
393	bcopy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
394	}
395	return len;
396	}
397