aboutsummaryrefslogtreecommitdiff
path: root/gdb/m68klinux-nat.c
blob: 5e30ad20c78b0fc58612e95d48f58d0d9dd58bfe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
/* Motorola m68k native support for GNU/Linux.

   Copyright (C) 1996-2013 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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "frame.h"
#include "inferior.h"
#include "language.h"
#include "gdbcore.h"
#include "gdb_string.h"
#include "regcache.h"
#include "target.h"
#include "linux-nat.h"

#include "m68k-tdep.h"

#include <sys/dir.h>
#include <signal.h>
#include <sys/ptrace.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <sys/procfs.h>

#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif

#include <sys/file.h>
#include "gdb_stat.h"

#include "floatformat.h"

#include "target.h"

/* Prototypes for supply_gregset etc.  */
#include "gregset.h"

/* Defines ps_err_e, struct ps_prochandle.  */
#include "gdb_proc_service.h"

#ifndef PTRACE_GET_THREAD_AREA
#define PTRACE_GET_THREAD_AREA 25
#endif

/* This table must line up with gdbarch_register_name in "m68k-tdep.c".  */
static const int regmap[] =
{
  PT_D0, PT_D1, PT_D2, PT_D3, PT_D4, PT_D5, PT_D6, PT_D7,
  PT_A0, PT_A1, PT_A2, PT_A3, PT_A4, PT_A5, PT_A6, PT_USP,
  PT_SR, PT_PC,
  /* PT_FP0, ..., PT_FP7 */
  21, 24, 27, 30, 33, 36, 39, 42,
  /* PT_FPCR, PT_FPSR, PT_FPIAR */
  45, 46, 47
};

/* Which ptrace request retrieves which registers?
   These apply to the corresponding SET requests as well.  */
#define NUM_GREGS (18)
#define MAX_NUM_REGS (NUM_GREGS + 11)

static int
getregs_supplies (int regno)
{
  return 0 <= regno && regno < NUM_GREGS;
}

static int
getfpregs_supplies (int regno)
{
  return M68K_FP0_REGNUM <= regno && regno <= M68K_FPI_REGNUM;
}

/* Does the current host support the GETREGS request?  */
static int have_ptrace_getregs =
#ifdef HAVE_PTRACE_GETREGS
  1
#else
  0
#endif
;



/* Fetching registers directly from the U area, one at a time.  */

/* Fetch one register.  */

static void
fetch_register (struct regcache *regcache, int regno)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  long regaddr, val;
  int i;
  gdb_byte buf[MAX_REGISTER_SIZE];
  int tid;

  /* Overload thread id onto process id.  */
  tid = TIDGET (inferior_ptid);
  if (tid == 0)
    tid = PIDGET (inferior_ptid);	/* no thread id, just use
					   process id.  */

  regaddr = 4 * regmap[regno];
  for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long))
    {
      errno = 0;
      val = ptrace (PTRACE_PEEKUSER, tid, regaddr, 0);
      memcpy (&buf[i], &val, sizeof (long));
      regaddr += sizeof (long);
      if (errno != 0)
	error (_("Couldn't read register %s (#%d): %s."), 
	       gdbarch_register_name (gdbarch, regno),
	       regno, safe_strerror (errno));
    }
  regcache_raw_supply (regcache, regno, buf);
}

/* Fetch register values from the inferior.
   If REGNO is negative, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

static void
old_fetch_inferior_registers (struct regcache *regcache, int regno)
{
  if (regno >= 0)
    {
      fetch_register (regcache, regno);
    }
  else
    {
      for (regno = 0;
	   regno < gdbarch_num_regs (get_regcache_arch (regcache));
	   regno++)
	{
	  fetch_register (regcache, regno);
	}
    }
}

/* Store one register.  */

static void
store_register (const struct regcache *regcache, int regno)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  long regaddr, val;
  int i;
  int tid;
  gdb_byte buf[MAX_REGISTER_SIZE];

  /* Overload thread id onto process id.  */
  tid = TIDGET (inferior_ptid);
  if (tid == 0)
    tid = PIDGET (inferior_ptid);	/* no thread id, just use
					   process id.  */

  regaddr = 4 * regmap[regno];

  /* Put the contents of regno into a local buffer.  */
  regcache_raw_collect (regcache, regno, buf);

  /* Store the local buffer into the inferior a chunk at the time.  */
  for (i = 0; i < register_size (gdbarch, regno); i += sizeof (long))
    {
      errno = 0;
      memcpy (&val, &buf[i], sizeof (long));
      ptrace (PTRACE_POKEUSER, tid, regaddr, val);
      regaddr += sizeof (long);
      if (errno != 0)
	error (_("Couldn't write register %s (#%d): %s."),
	       gdbarch_register_name (gdbarch, regno),
	       regno, safe_strerror (errno));
    }
}

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

static void
old_store_inferior_registers (const struct regcache *regcache, int regno)
{
  if (regno >= 0)
    {
      store_register (regcache, regno);
    }
  else
    {
      for (regno = 0;
	   regno < gdbarch_num_regs (get_regcache_arch (regcache));
	   regno++)
	{
	  store_register (regcache, regno);
	}
    }
}

/*  Given a pointer to a general register set in /proc format
   (elf_gregset_t *), unpack the register contents and supply
   them as gdb's idea of the current register values.  */

void
supply_gregset (struct regcache *regcache, const elf_gregset_t *gregsetp)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
  int regi;

  for (regi = M68K_D0_REGNUM;
       regi <= gdbarch_sp_regnum (gdbarch);
       regi++)
    regcache_raw_supply (regcache, regi, &regp[regmap[regi]]);
  regcache_raw_supply (regcache, gdbarch_ps_regnum (gdbarch),
		       &regp[PT_SR]);
  regcache_raw_supply (regcache,
		       gdbarch_pc_regnum (gdbarch), &regp[PT_PC]);
}

/* Fill register REGNO (if it is a general-purpose register) in
   *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
   do this for all registers.  */
void
fill_gregset (const struct regcache *regcache,
	      elf_gregset_t *gregsetp, int regno)
{
  elf_greg_t *regp = (elf_greg_t *) gregsetp;
  int i;

  for (i = 0; i < NUM_GREGS; i++)
    if (regno == -1 || regno == i)
      regcache_raw_collect (regcache, i, regp + regmap[i]);
}

#ifdef HAVE_PTRACE_GETREGS

/* Fetch all general-purpose registers from process/thread TID and
   store their values in GDB's register array.  */

static void
fetch_regs (struct regcache *regcache, int tid)
{
  elf_gregset_t regs;

  if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
    {
      if (errno == EIO)
	{
	  /* The kernel we're running on doesn't support the GETREGS
             request.  Reset `have_ptrace_getregs'.  */
	  have_ptrace_getregs = 0;
	  return;
	}

      perror_with_name (_("Couldn't get registers"));
    }

  supply_gregset (regcache, (const elf_gregset_t *) &regs);
}

/* Store all valid general-purpose registers in GDB's register array
   into the process/thread specified by TID.  */

static void
store_regs (const struct regcache *regcache, int tid, int regno)
{
  elf_gregset_t regs;

  if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
    perror_with_name (_("Couldn't get registers"));

  fill_gregset (regcache, &regs, regno);

  if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
    perror_with_name (_("Couldn't write registers"));
}

#else

static void fetch_regs (struct regcache *regcache, int tid)
{
}

static void store_regs (const struct regcache *regcache, int tid, int regno)
{
}

#endif


/* Transfering floating-point registers between GDB, inferiors and cores.  */

/* What is the address of fpN within the floating-point register set F?  */
#define FPREG_ADDR(f, n) (&(f)->fpregs[(n) * 3])

/* Fill GDB's register array with the floating-point register values in
   *FPREGSETP.  */

void
supply_fpregset (struct regcache *regcache, const elf_fpregset_t *fpregsetp)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  int regi;

  for (regi = gdbarch_fp0_regnum (gdbarch);
       regi < gdbarch_fp0_regnum (gdbarch) + 8; regi++)
    regcache_raw_supply (regcache, regi,
			 FPREG_ADDR (fpregsetp,
				     regi - gdbarch_fp0_regnum (gdbarch)));
  regcache_raw_supply (regcache, M68K_FPC_REGNUM, &fpregsetp->fpcntl[0]);
  regcache_raw_supply (regcache, M68K_FPS_REGNUM, &fpregsetp->fpcntl[1]);
  regcache_raw_supply (regcache, M68K_FPI_REGNUM, &fpregsetp->fpcntl[2]);
}

/* Fill register REGNO (if it is a floating-point register) in
   *FPREGSETP with the value in GDB's register array.  If REGNO is -1,
   do this for all registers.  */

void
fill_fpregset (const struct regcache *regcache,
	       elf_fpregset_t *fpregsetp, int regno)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  int i;

  /* Fill in the floating-point registers.  */
  for (i = gdbarch_fp0_regnum (gdbarch);
       i < gdbarch_fp0_regnum (gdbarch) + 8; i++)
    if (regno == -1 || regno == i)
      regcache_raw_collect (regcache, i,
			    FPREG_ADDR (fpregsetp,
				        i - gdbarch_fp0_regnum (gdbarch)));

  /* Fill in the floating-point control registers.  */
  for (i = M68K_FPC_REGNUM; i <= M68K_FPI_REGNUM; i++)
    if (regno == -1 || regno == i)
      regcache_raw_collect (regcache, i,
			    &fpregsetp->fpcntl[i - M68K_FPC_REGNUM]);
}

#ifdef HAVE_PTRACE_GETREGS

/* Fetch all floating-point registers from process/thread TID and store
   thier values in GDB's register array.  */

static void
fetch_fpregs (struct regcache *regcache, int tid)
{
  elf_fpregset_t fpregs;

  if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
    perror_with_name (_("Couldn't get floating point status"));

  supply_fpregset (regcache, (const elf_fpregset_t *) &fpregs);
}

/* Store all valid floating-point registers in GDB's register array
   into the process/thread specified by TID.  */

static void
store_fpregs (const struct regcache *regcache, int tid, int regno)
{
  elf_fpregset_t fpregs;

  if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
    perror_with_name (_("Couldn't get floating point status"));

  fill_fpregset (regcache, &fpregs, regno);

  if (ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs) < 0)
    perror_with_name (_("Couldn't write floating point status"));
}

#else

static void fetch_fpregs (struct regcache *regcache, int tid)
{
}

static void store_fpregs (const struct regcache *regcache, int tid, int regno)
{
}

#endif

/* Transferring arbitrary registers between GDB and inferior.  */

/* Fetch register REGNO from the child process.  If REGNO is -1, do
   this for all registers (including the floating point and SSE
   registers).  */

static void
m68k_linux_fetch_inferior_registers (struct target_ops *ops,
				     struct regcache *regcache, int regno)
{
  int tid;

  /* Use the old method of peeking around in `struct user' if the
     GETREGS request isn't available.  */
  if (! have_ptrace_getregs)
    {
      old_fetch_inferior_registers (regcache, regno);
      return;
    }

  /* GNU/Linux LWP ID's are process ID's.  */
  tid = TIDGET (inferior_ptid);
  if (tid == 0)
    tid = PIDGET (inferior_ptid);	/* Not a threaded program.  */

  /* Use the PTRACE_GETFPXREGS request whenever possible, since it
     transfers more registers in one system call, and we'll cache the
     results.  But remember that fetch_fpxregs can fail, and return
     zero.  */
  if (regno == -1)
    {
      fetch_regs (regcache, tid);

      /* The call above might reset `have_ptrace_getregs'.  */
      if (! have_ptrace_getregs)
	{
	  old_fetch_inferior_registers (regcache, -1);
	  return;
	}

      fetch_fpregs (regcache, tid);
      return;
    }

  if (getregs_supplies (regno))
    {
      fetch_regs (regcache, tid);
      return;
    }

  if (getfpregs_supplies (regno))
    {
      fetch_fpregs (regcache, tid);
      return;
    }

  internal_error (__FILE__, __LINE__,
		  _("Got request for bad register number %d."), regno);
}

/* Store register REGNO back into the child process.  If REGNO is -1,
   do this for all registers (including the floating point and SSE
   registers).  */
static void
m68k_linux_store_inferior_registers (struct target_ops *ops,
				     struct regcache *regcache, int regno)
{
  int tid;

  /* Use the old method of poking around in `struct user' if the
     SETREGS request isn't available.  */
  if (! have_ptrace_getregs)
    {
      old_store_inferior_registers (regcache, regno);
      return;
    }

  /* GNU/Linux LWP ID's are process ID's.  */
  tid = TIDGET (inferior_ptid);
  if (tid == 0)
    tid = PIDGET (inferior_ptid);	/* Not a threaded program.  */

  /* Use the PTRACE_SETFPREGS requests whenever possible, since it
     transfers more registers in one system call.  But remember that
     store_fpregs can fail, and return zero.  */
  if (regno == -1)
    {
      store_regs (regcache, tid, regno);
      store_fpregs (regcache, tid, regno);
      return;
    }

  if (getregs_supplies (regno))
    {
      store_regs (regcache, tid, regno);
      return;
    }

  if (getfpregs_supplies (regno))
    {
      store_fpregs (regcache, tid, regno);
      return;
    }

  internal_error (__FILE__, __LINE__,
		  _("Got request to store bad register number %d."), regno);
}

/* Interpreting register set info found in core files.  */

/* Provide registers to GDB from a core file.

   (We can't use the generic version of this function in
   core-regset.c, because we need to use elf_gregset_t instead of
   gregset_t.)

   CORE_REG_SECT points to an array of bytes, which are the contents
   of a `note' from a core file which BFD thinks might contain
   register contents.  CORE_REG_SIZE is its size.

   WHICH says which register set corelow suspects this is:
     0 --- the general-purpose register set, in elf_gregset_t format
     2 --- the floating-point register set, in elf_fpregset_t format

   REG_ADDR isn't used on GNU/Linux.  */

static void
fetch_core_registers (struct regcache *regcache,
		      char *core_reg_sect, unsigned core_reg_size,
		      int which, CORE_ADDR reg_addr)
{
  elf_gregset_t gregset;
  elf_fpregset_t fpregset;

  switch (which)
    {
    case 0:
      if (core_reg_size != sizeof (gregset))
	warning (_("Wrong size gregset in core file."));
      else
	{
	  memcpy (&gregset, core_reg_sect, sizeof (gregset));
	  supply_gregset (regcache, (const elf_gregset_t *) &gregset);
	}
      break;

    case 2:
      if (core_reg_size != sizeof (fpregset))
	warning (_("Wrong size fpregset in core file."));
      else
	{
	  memcpy (&fpregset, core_reg_sect, sizeof (fpregset));
	  supply_fpregset (regcache, (const elf_fpregset_t *) &fpregset);
	}
      break;

    default:
      /* We've covered all the kinds of registers we know about here,
         so this must be something we wouldn't know what to do with
         anyway.  Just ignore it.  */
      break;
    }
}


/* Fetch the thread-local storage pointer for libthread_db.  */

ps_err_e
ps_get_thread_area (const struct ps_prochandle *ph, 
		    lwpid_t lwpid, int idx, void **base)
{
  if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) < 0)
    return PS_ERR;

  /* IDX is the bias from the thread pointer to the beginning of the
     thread descriptor.  It has to be subtracted due to implementation
     quirks in libthread_db.  */
  *base = (char *) *base - idx;

  return PS_OK;
}


/* Register that we are able to handle GNU/Linux ELF core file
   formats.  */

static struct core_fns linux_elf_core_fns =
{
  bfd_target_elf_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_core_registers,			/* core_read_registers */
  NULL					/* next */
};

void _initialize_m68k_linux_nat (void);

void
_initialize_m68k_linux_nat (void)
{
  struct target_ops *t;

  /* Fill in the generic GNU/Linux methods.  */
  t = linux_target ();

  /* Add our register access methods.  */
  t->to_fetch_registers = m68k_linux_fetch_inferior_registers;
  t->to_store_registers = m68k_linux_store_inferior_registers;

  /* Register the target.  */
  linux_nat_add_target (t);

  deprecated_add_core_fns (&linux_elf_core_fns);
}