summaryrefslogtreecommitdiff
path: root/gdb/gdbserver/spu-low.c
blob: f3a564587ed79e8d5a5523318921e03c41cf0a40 (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
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
/* Low level interface to SPUs, for the remote server for GDB.
   Copyright (C) 2006-2012 Free Software Foundation, Inc.

   Contributed by Ulrich Weigand <uweigand@de.ibm.com>.

   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 "server.h"

#include <sys/wait.h>
#include <stdio.h>
#include <sys/ptrace.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/syscall.h>

/* Some older glibc versions do not define this.  */
#ifndef __WNOTHREAD
#define __WNOTHREAD     0x20000000      /* Don't wait on children of other
					   threads in this group */
#endif

#define PTRACE_TYPE_RET long
#define PTRACE_TYPE_ARG3 long

/* Number of registers.  */
#define SPU_NUM_REGS         130
#define SPU_NUM_CORE_REGS    128

/* Special registers.  */
#define SPU_ID_REGNUM        128
#define SPU_PC_REGNUM        129

/* PPU side system calls.  */
#define INSTR_SC	0x44000002
#define NR_spu_run	0x0116

/* Get current thread ID (Linux task ID).  */
#define current_ptid ((struct inferior_list_entry *)current_inferior)->id

/* These are used in remote-utils.c.  */
int using_threads = 0;

/* Defined in auto-generated file reg-spu.c.  */
void init_registers_spu (void);


/* Fetch PPU register REGNO.  */
static CORE_ADDR
fetch_ppc_register (int regno)
{
  PTRACE_TYPE_RET res;

  int tid = ptid_get_lwp (current_ptid);

#ifndef __powerpc64__
  /* If running as a 32-bit process on a 64-bit system, we attempt
     to get the full 64-bit register content of the target process.
     If the PPC special ptrace call fails, we're on a 32-bit system;
     just fall through to the regular ptrace call in that case.  */
  {
    char buf[8];

    errno = 0;
    ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
	    (PTRACE_TYPE_ARG3) (regno * 8), buf);
    if (errno == 0)
      ptrace (PPC_PTRACE_PEEKUSR_3264, tid,
	      (PTRACE_TYPE_ARG3) (regno * 8 + 4), buf + 4);
    if (errno == 0)
      return (CORE_ADDR) *(unsigned long long *)buf;
  }
#endif

  errno = 0;
  res = ptrace (PT_READ_U, tid,
		(PTRACE_TYPE_ARG3) (regno * sizeof (PTRACE_TYPE_RET)), 0);
  if (errno != 0)
    {
      char mess[128];
      sprintf (mess, "reading PPC register #%d", regno);
      perror_with_name (mess);
    }

  return (CORE_ADDR) (unsigned long) res;
}

/* Fetch WORD from PPU memory at (aligned) MEMADDR in thread TID.  */
static int
fetch_ppc_memory_1 (int tid, CORE_ADDR memaddr, PTRACE_TYPE_RET *word)
{
  errno = 0;

#ifndef __powerpc64__
  if (memaddr >> 32)
    {
      unsigned long long addr_8 = (unsigned long long) memaddr;
      ptrace (PPC_PTRACE_PEEKTEXT_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
    }
  else
#endif
    *word = ptrace (PT_READ_I, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, 0);

  return errno;
}

/* Store WORD into PPU memory at (aligned) MEMADDR in thread TID.  */
static int
store_ppc_memory_1 (int tid, CORE_ADDR memaddr, PTRACE_TYPE_RET word)
{
  errno = 0;

#ifndef __powerpc64__
  if (memaddr >> 32)
    {
      unsigned long long addr_8 = (unsigned long long) memaddr;
      ptrace (PPC_PTRACE_POKEDATA_3264, tid, (PTRACE_TYPE_ARG3) &addr_8, word);
    }
  else
#endif
    ptrace (PT_WRITE_D, tid, (PTRACE_TYPE_ARG3) (size_t) memaddr, word);

  return errno;
}

/* Fetch LEN bytes of PPU memory at MEMADDR to MYADDR.  */
static int
fetch_ppc_memory (CORE_ADDR memaddr, char *myaddr, int len)
{
  int i, ret;

  CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET);
  int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
	       / sizeof (PTRACE_TYPE_RET));
  PTRACE_TYPE_RET *buffer;

  int tid = ptid_get_lwp (current_ptid);

  buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));
  for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
    if ((ret = fetch_ppc_memory_1 (tid, addr, &buffer[i])) != 0)
      return ret;

  memcpy (myaddr,
	  (char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
	  len);

  return 0;
}

/* Store LEN bytes from MYADDR to PPU memory at MEMADDR.  */
static int
store_ppc_memory (CORE_ADDR memaddr, char *myaddr, int len)
{
  int i, ret;

  CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_TYPE_RET);
  int count = ((((memaddr + len) - addr) + sizeof (PTRACE_TYPE_RET) - 1)
	       / sizeof (PTRACE_TYPE_RET));
  PTRACE_TYPE_RET *buffer;

  int tid = ptid_get_lwp (current_ptid);

  buffer = (PTRACE_TYPE_RET *) alloca (count * sizeof (PTRACE_TYPE_RET));

  if (addr != memaddr || len < (int) sizeof (PTRACE_TYPE_RET))
    if ((ret = fetch_ppc_memory_1 (tid, addr, &buffer[0])) != 0)
      return ret;

  if (count > 1)
    if ((ret = fetch_ppc_memory_1 (tid, addr + (count - 1)
					       * sizeof (PTRACE_TYPE_RET),
				   &buffer[count - 1])) != 0)
      return ret;

  memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_TYPE_RET) - 1)),
	  myaddr, len);

  for (i = 0; i < count; i++, addr += sizeof (PTRACE_TYPE_RET))
    if ((ret = store_ppc_memory_1 (tid, addr, buffer[i])) != 0)
      return ret;

  return 0;
}


/* If the PPU thread is currently stopped on a spu_run system call,
   return to FD and ADDR the file handle and NPC parameter address
   used with the system call.  Return non-zero if successful.  */
static int
parse_spufs_run (int *fd, CORE_ADDR *addr)
{
  unsigned int insn;
  CORE_ADDR pc = fetch_ppc_register (32);  /* nip */

  /* Fetch instruction preceding current NIP.  */
  if (fetch_ppc_memory (pc-4, (char *) &insn, 4) != 0)
    return 0;
  /* It should be a "sc" instruction.  */
  if (insn != INSTR_SC)
    return 0;
  /* System call number should be NR_spu_run.  */
  if (fetch_ppc_register (0) != NR_spu_run)
    return 0;

  /* Register 3 contains fd, register 4 the NPC param pointer.  */
  *fd = fetch_ppc_register (34);  /* orig_gpr3 */
  *addr = fetch_ppc_register (4);
  return 1;
}


/* Copy LEN bytes at OFFSET in spufs file ANNEX into/from READBUF or WRITEBUF,
   using the /proc file system.  */
static int
spu_proc_xfer_spu (const char *annex, unsigned char *readbuf,
		   const unsigned char *writebuf,
		   CORE_ADDR offset, int len)
{
  char buf[128];
  int fd = 0;
  int ret = -1;

  if (!annex)
    return 0;

  sprintf (buf, "/proc/%ld/fd/%s", ptid_get_lwp (current_ptid), annex);
  fd = open (buf, writebuf? O_WRONLY : O_RDONLY);
  if (fd <= 0)
    return -1;

  if (offset != 0
      && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
    {
      close (fd);
      return 0;
    }

  if (writebuf)
    ret = write (fd, writebuf, (size_t) len);
  else if (readbuf)
    ret = read (fd, readbuf, (size_t) len);

  close (fd);
  return ret;
}


/* Start an inferior process and returns its pid.
   ALLARGS is a vector of program-name and args. */
static int
spu_create_inferior (char *program, char **allargs)
{
  int pid;
  ptid_t ptid;

  pid = fork ();
  if (pid < 0)
    perror_with_name ("fork");

  if (pid == 0)
    {
      ptrace (PTRACE_TRACEME, 0, 0, 0);

      setpgid (0, 0);

      execv (program, allargs);
      if (errno == ENOENT)
	execvp (program, allargs);

      fprintf (stderr, "Cannot exec %s: %s.\n", program,
	       strerror (errno));
      fflush (stderr);
      _exit (0177);
    }

  add_process (pid, 0);

  ptid = ptid_build (pid, pid, 0);
  add_thread (ptid, NULL);
  return pid;
}

/* Attach to an inferior process.  */
int
spu_attach (unsigned long  pid)
{
  ptid_t ptid;

  if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
    {
      fprintf (stderr, "Cannot attach to process %ld: %s (%d)\n", pid,
	       strerror (errno), errno);
      fflush (stderr);
      _exit (0177);
    }

  add_process (pid, 1);
  ptid = ptid_build (pid, pid, 0);
  add_thread (ptid, NULL);
  return 0;
}

/* Kill the inferior process.  */
static int
spu_kill (int pid)
{
  int status, ret;
  struct process_info *process = find_process_pid (pid);
  if (process == NULL)
    return -1;

  ptrace (PTRACE_KILL, pid, 0, 0);

  do {
    ret = waitpid (pid, &status, 0);
    if (WIFEXITED (status) || WIFSIGNALED (status))
      break;
  } while (ret != -1 || errno != ECHILD);

  clear_inferiors ();
  remove_process (process);
  return 0;
}

/* Detach from inferior process.  */
static int
spu_detach (int pid)
{
  struct process_info *process = find_process_pid (pid);
  if (process == NULL)
    return -1;

  ptrace (PTRACE_DETACH, pid, 0, 0);

  clear_inferiors ();
  remove_process (process);
  return 0;
}

static void
spu_mourn (struct process_info *process)
{
  remove_process (process);
}

static void
spu_join (int pid)
{
  int status, ret;

  do {
    ret = waitpid (pid, &status, 0);
    if (WIFEXITED (status) || WIFSIGNALED (status))
      break;
  } while (ret != -1 || errno != ECHILD);
}

/* Return nonzero if the given thread is still alive.  */
static int
spu_thread_alive (ptid_t ptid)
{
  return ptid_equal (ptid, current_ptid);
}

/* Resume process.  */
static void
spu_resume (struct thread_resume *resume_info, size_t n)
{
  size_t i;

  for (i = 0; i < n; i++)
    if (ptid_equal (resume_info[i].thread, minus_one_ptid)
	|| ptid_equal (resume_info[i].thread, current_ptid))
      break;

  if (i == n)
    return;

  /* We don't support hardware single-stepping right now, assume
     GDB knows to use software single-stepping.  */
  if (resume_info[i].kind == resume_step)
    fprintf (stderr, "Hardware single-step not supported.\n");

  regcache_invalidate ();

  errno = 0;
  ptrace (PTRACE_CONT, ptid_get_lwp (current_ptid), 0, resume_info[i].sig);
  if (errno)
    perror_with_name ("ptrace");
}

/* Wait for process, returns status.  */
static ptid_t
spu_wait (ptid_t ptid, struct target_waitstatus *ourstatus, int options)
{
  int pid = ptid_get_pid (ptid);
  int w;
  int ret;

  while (1)
    {
      ret = waitpid (pid, &w, WNOHANG | __WALL | __WNOTHREAD);

      if (ret == -1)
	{
	  if (errno != ECHILD)
	    perror_with_name ("waitpid");
	}
      else if (ret > 0)
	break;

      usleep (1000);
    }

  /* On the first wait, continue running the inferior until we are
     blocked inside an spu_run system call.  */
  if (!server_waiting)
    {
      int fd;
      CORE_ADDR addr;

      while (!parse_spufs_run (&fd, &addr))
	{
	  ptrace (PT_SYSCALL, pid, (PTRACE_TYPE_ARG3) 0, 0);
	  waitpid (pid, NULL, __WALL | __WNOTHREAD);
	}
    }

  if (WIFEXITED (w))
    {
      fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
      ourstatus->kind =  TARGET_WAITKIND_EXITED;
      ourstatus->value.integer = WEXITSTATUS (w);
      clear_inferiors ();
      return pid_to_ptid (ret);
    }
  else if (!WIFSTOPPED (w))
    {
      fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
      ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
      ourstatus->value.sig = gdb_signal_from_host (WTERMSIG (w));
      clear_inferiors ();
      return pid_to_ptid (ret);
    }

  /* After attach, we may have received a SIGSTOP.  Do not return this
     as signal to GDB, or else it will try to continue with SIGSTOP ...  */
  if (!server_waiting)
    {
      ourstatus->kind = TARGET_WAITKIND_STOPPED;
      ourstatus->value.sig = TARGET_SIGNAL_0;
      return ptid_build (ret, ret, 0);
    }

  ourstatus->kind = TARGET_WAITKIND_STOPPED;
  ourstatus->value.sig = gdb_signal_from_host (WSTOPSIG (w));
  return ptid_build (ret, ret, 0);
}

/* Fetch inferior registers.  */
static void
spu_fetch_registers (struct regcache *regcache, int regno)
{
  int fd;
  CORE_ADDR addr;

  /* We must be stopped on a spu_run system call.  */
  if (!parse_spufs_run (&fd, &addr))
    return;

  /* The ID register holds the spufs file handle.  */
  if (regno == -1 || regno == SPU_ID_REGNUM)
    supply_register (regcache, SPU_ID_REGNUM, (char *)&fd);

  /* The NPC register is found at ADDR.  */
  if (regno == -1 || regno == SPU_PC_REGNUM)
    {
      char buf[4];
      if (fetch_ppc_memory (addr, buf, 4) == 0)
	supply_register (regcache, SPU_PC_REGNUM, buf);
    }

  /* The GPRs are found in the "regs" spufs file.  */
  if (regno == -1 || (regno >= 0 && regno < SPU_NUM_CORE_REGS))
    {
      unsigned char buf[16*SPU_NUM_CORE_REGS];
      char annex[32];
      int i;

      sprintf (annex, "%d/regs", fd);
      if (spu_proc_xfer_spu (annex, buf, NULL, 0, sizeof buf) == sizeof buf)
	for (i = 0; i < SPU_NUM_CORE_REGS; i++)
	  supply_register (regcache, i, buf + i*16);
    }
}

/* Store inferior registers.  */
static void
spu_store_registers (struct regcache *regcache, int regno)
{
  int fd;
  CORE_ADDR addr;

  /* ??? Some callers use 0 to mean all registers.  */
  if (regno == 0)
    regno = -1;

  /* We must be stopped on a spu_run system call.  */
  if (!parse_spufs_run (&fd, &addr))
    return;

  /* The NPC register is found at ADDR.  */
  if (regno == -1 || regno == SPU_PC_REGNUM)
    {
      char buf[4];
      collect_register (regcache, SPU_PC_REGNUM, buf);
      store_ppc_memory (addr, buf, 4);
    }

  /* The GPRs are found in the "regs" spufs file.  */
  if (regno == -1 || (regno >= 0 && regno < SPU_NUM_CORE_REGS))
    {
      unsigned char buf[16*SPU_NUM_CORE_REGS];
      char annex[32];
      int i;

      for (i = 0; i < SPU_NUM_CORE_REGS; i++)
	collect_register (regcache, i, buf + i*16);

      sprintf (annex, "%d/regs", fd);
      spu_proc_xfer_spu (annex, NULL, buf, 0, sizeof buf);
    }
}

/* Copy LEN bytes from inferior's memory starting at MEMADDR
   to debugger memory starting at MYADDR.  */
static int
spu_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
{
  int fd, ret;
  CORE_ADDR addr;
  char annex[32], lslr_annex[32], buf[32];
  CORE_ADDR lslr;

  /* We must be stopped on a spu_run system call.  */
  if (!parse_spufs_run (&fd, &addr))
    return 0;

  /* Use the "mem" spufs file to access SPU local store.  */
  sprintf (annex, "%d/mem", fd);
  ret = spu_proc_xfer_spu (annex, myaddr, NULL, memaddr, len);
  if (ret > 0)
    return ret == len ? 0 : EIO;

  /* SPU local store access wraps the address around at the
     local store limit.  We emulate this here.  To avoid needing
     an extra access to retrieve the LSLR, we only do that after
     trying the original address first, and getting end-of-file.  */
  sprintf (lslr_annex, "%d/lslr", fd);
  memset (buf, 0, sizeof buf);
  if (spu_proc_xfer_spu (lslr_annex, (unsigned char *)buf, NULL,
			 0, sizeof buf) <= 0)
    return ret;

  lslr = strtoul (buf, NULL, 16);
  ret = spu_proc_xfer_spu (annex, myaddr, NULL, memaddr & lslr, len);

  return ret == len ? 0 : EIO;
}

/* Copy LEN bytes of data from debugger memory at MYADDR
   to inferior's memory at MEMADDR.
   On failure (cannot write the inferior)
   returns the value of errno.  */
static int
spu_write_memory (CORE_ADDR memaddr, const unsigned char *myaddr, int len)
{
  int fd, ret;
  CORE_ADDR addr;
  char annex[32], lslr_annex[32], buf[32];
  CORE_ADDR lslr;

  /* We must be stopped on a spu_run system call.  */
  if (!parse_spufs_run (&fd, &addr))
    return 0;

  /* Use the "mem" spufs file to access SPU local store.  */
  sprintf (annex, "%d/mem", fd);
  ret = spu_proc_xfer_spu (annex, NULL, myaddr, memaddr, len);
  if (ret > 0)
    return ret == len ? 0 : EIO;

  /* SPU local store access wraps the address around at the
     local store limit.  We emulate this here.  To avoid needing
     an extra access to retrieve the LSLR, we only do that after
     trying the original address first, and getting end-of-file.  */
  sprintf (lslr_annex, "%d/lslr", fd);
  memset (buf, 0, sizeof buf);
  if (spu_proc_xfer_spu (lslr_annex, (unsigned char *)buf, NULL,
			 0, sizeof buf) <= 0)
    return ret;

  lslr = strtoul (buf, NULL, 16);
  ret = spu_proc_xfer_spu (annex, NULL, myaddr, memaddr & lslr, len);

  return ret == len ? 0 : EIO;
}

/* Look up special symbols -- unneded here.  */
static void
spu_look_up_symbols (void)
{
}

/* Send signal to inferior.  */
static void
spu_request_interrupt (void)
{
  syscall (SYS_tkill, ptid_get_lwp (current_ptid), SIGINT);
}

static struct target_ops spu_target_ops = {
  spu_create_inferior,
  spu_attach,
  spu_kill,
  spu_detach,
  spu_mourn,
  spu_join,
  spu_thread_alive,
  spu_resume,
  spu_wait,
  spu_fetch_registers,
  spu_store_registers,
  NULL, /* prepare_to_access_memory */
  NULL, /* done_accessing_memory */
  spu_read_memory,
  spu_write_memory,
  spu_look_up_symbols,
  spu_request_interrupt,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  spu_proc_xfer_spu,
  hostio_last_error_from_errno,
};

void
initialize_low (void)
{
  static const unsigned char breakpoint[] = { 0x00, 0x00, 0x3f, 0xff };

  set_target_ops (&spu_target_ops);
  set_breakpoint_data (breakpoint, sizeof breakpoint);
  init_registers_spu ();
}