aboutsummaryrefslogtreecommitdiff
path: root/gdb/tracefile.c
blob: e208fc6d2b900e2f81c1c0358c9bf1e61963804e (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
/* Trace file support in GDB.

   Copyright (C) 1997-2017 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 "tracefile.h"
#include "ctf.h"
#include "exec.h"
#include "regcache.h"

/* Helper macros.  */

#define TRACE_WRITE_R_BLOCK(writer, buf, size)	\
  writer->ops->frame_ops->write_r_block ((writer), (buf), (size))
#define TRACE_WRITE_M_BLOCK_HEADER(writer, addr, size)		  \
  writer->ops->frame_ops->write_m_block_header ((writer), (addr), \
						(size))
#define TRACE_WRITE_M_BLOCK_MEMORY(writer, buf, size)	  \
  writer->ops->frame_ops->write_m_block_memory ((writer), (buf), \
						(size))
#define TRACE_WRITE_V_BLOCK(writer, num, val)	\
  writer->ops->frame_ops->write_v_block ((writer), (num), (val))

/* Free trace file writer.  */

static void
trace_file_writer_xfree (void *arg)
{
  struct trace_file_writer *writer = (struct trace_file_writer *) arg;

  writer->ops->dtor (writer);
  xfree (writer);
}

/* Save tracepoint data to file named FILENAME through WRITER.  WRITER
   determines the trace file format.  If TARGET_DOES_SAVE is non-zero,
   the save is performed on the target, otherwise GDB obtains all trace
   data and saves it locally.  */

static void
trace_save (const char *filename, struct trace_file_writer *writer,
	    int target_does_save)
{
  struct trace_status *ts = current_trace_status ();
  struct uploaded_tp *uploaded_tps = NULL, *utp;
  struct uploaded_tsv *uploaded_tsvs = NULL, *utsv;

  ULONGEST offset = 0;
#define MAX_TRACE_UPLOAD 2000
  gdb_byte buf[MAX_TRACE_UPLOAD];
  enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());

  /* If the target is to save the data to a file on its own, then just
     send the command and be done with it.  */
  if (target_does_save)
    {
      if (!writer->ops->target_save (writer, filename))
	error (_("Target failed to save trace data to '%s'."),
	       filename);
      return;
    }

  /* Get the trace status first before opening the file, so if the
     target is losing, we can get out without touching files.  Since
     we're just calling this for side effects, we ignore the
     result.  */
  target_get_trace_status (ts);

  writer->ops->start (writer, filename);

  writer->ops->write_header (writer);

  /* Write descriptive info.  */

  /* Write out the size of a register block.  */
  writer->ops->write_regblock_type (writer, trace_regblock_size);

  /* Write out the target description info.  */
  writer->ops->write_tdesc (writer);

  /* Write out status of the tracing run (aka "tstatus" info).  */
  writer->ops->write_status (writer, ts);

  /* Note that we want to upload tracepoints and save those, rather
     than simply writing out the local ones, because the user may have
     changed tracepoints in GDB in preparation for a future tracing
     run, or maybe just mass-deleted all types of breakpoints as part
     of cleaning up.  So as not to contaminate the session, leave the
     data in its uploaded form, don't make into real tracepoints.  */

  /* Get trace state variables first, they may be checked when parsing
     uploaded commands.  */

  target_upload_trace_state_variables (&uploaded_tsvs);

  for (utsv = uploaded_tsvs; utsv; utsv = utsv->next)
    writer->ops->write_uploaded_tsv (writer, utsv);

  free_uploaded_tsvs (&uploaded_tsvs);

  target_upload_tracepoints (&uploaded_tps);

  for (utp = uploaded_tps; utp; utp = utp->next)
    target_get_tracepoint_status (NULL, utp);

  for (utp = uploaded_tps; utp; utp = utp->next)
    writer->ops->write_uploaded_tp (writer, utp);

  free_uploaded_tps (&uploaded_tps);

  /* Mark the end of the definition section.  */
  writer->ops->write_definition_end (writer);

  /* Get and write the trace data proper.  */
  while (1)
    {
      LONGEST gotten = 0;

      /* The writer supports writing the contents of trace buffer
	  directly to trace file.  Don't parse the contents of trace
	  buffer.  */
      if (writer->ops->write_trace_buffer != NULL)
	{
	  /* We ask for big blocks, in the hopes of efficiency, but
	     will take less if the target has packet size limitations
	     or some such.  */
	  gotten = target_get_raw_trace_data (buf, offset,
					      MAX_TRACE_UPLOAD);
	  if (gotten < 0)
	    error (_("Failure to get requested trace buffer data"));
	  /* No more data is forthcoming, we're done.  */
	  if (gotten == 0)
	    break;

	  writer->ops->write_trace_buffer (writer, buf, gotten);

	  offset += gotten;
	}
      else
	{
	  uint16_t tp_num;
	  uint32_t tf_size;
	  /* Parse the trace buffers according to how data are stored
	     in trace buffer in GDBserver.  */

	  gotten = target_get_raw_trace_data (buf, offset, 6);

	  if (gotten == 0)
	    break;

	  /* Read the first six bytes in, which is the tracepoint
	     number and trace frame size.  */
	  tp_num = (uint16_t)
	    extract_unsigned_integer (&buf[0], 2, byte_order);

	  tf_size = (uint32_t)
	    extract_unsigned_integer (&buf[2], 4, byte_order);

	  writer->ops->frame_ops->start (writer, tp_num);
	  gotten = 6;

	  if (tf_size > 0)
	    {
	      unsigned int block;

	      offset += 6;

	      for (block = 0; block < tf_size; )
		{
		  gdb_byte block_type;

		  /* We'll fetch one block each time, in order to
		     handle the extremely large 'M' block.  We first
		     fetch one byte to get the type of the block.  */
		  gotten = target_get_raw_trace_data (buf, offset, 1);
		  if (gotten < 1)
		    error (_("Failure to get requested trace buffer data"));

		  gotten = 1;
		  block += 1;
		  offset += 1;

		  block_type = buf[0];
		  switch (block_type)
		    {
		    case 'R':
		      gotten
			= target_get_raw_trace_data (buf, offset,
						     trace_regblock_size);
		      if (gotten < trace_regblock_size)
			error (_("Failure to get requested trace"
				 " buffer data"));

		      TRACE_WRITE_R_BLOCK (writer, buf,
					   trace_regblock_size);
		      break;
		    case 'M':
		      {
			unsigned short mlen;
			ULONGEST addr;
			LONGEST t;
			int j;

			t = target_get_raw_trace_data (buf,offset, 10);
			if (t < 10)
			  error (_("Failure to get requested trace"
				   " buffer data"));

			offset += 10;
			block += 10;

			gotten = 0;
			addr = (ULONGEST)
			  extract_unsigned_integer (buf, 8,
						    byte_order);
			mlen = (unsigned short)
			  extract_unsigned_integer (&buf[8], 2,
						    byte_order);

			TRACE_WRITE_M_BLOCK_HEADER (writer, addr,
						    mlen);

			/* The memory contents in 'M' block may be
			   very large.  Fetch the data from the target
			   and write them into file one by one.  */
			for (j = 0; j < mlen; )
			  {
			    unsigned int read_length;

			    if (mlen - j > MAX_TRACE_UPLOAD)
			      read_length = MAX_TRACE_UPLOAD;
			    else
			      read_length = mlen - j;

			    t = target_get_raw_trace_data (buf,
							   offset + j,
							   read_length);
			    if (t < read_length)
			      error (_("Failure to get requested"
				       " trace buffer data"));

			    TRACE_WRITE_M_BLOCK_MEMORY (writer, buf,
							read_length);

			    j += read_length;
			    gotten += read_length;
			  }

			break;
		      }
		    case 'V':
		      {
			int vnum;
			LONGEST val;

			gotten
			  = target_get_raw_trace_data (buf, offset,
						       12);
			if (gotten < 12)
			  error (_("Failure to get requested"
				   " trace buffer data"));

			vnum  = (int) extract_signed_integer (buf,
							      4,
							      byte_order);
			val
			  = extract_signed_integer (&buf[4], 8,
						    byte_order);

			TRACE_WRITE_V_BLOCK (writer, vnum, val);
		      }
		      break;
		    default:
		      error (_("Unknown block type '%c' (0x%x) in"
			       " trace frame"),
			     block_type, block_type);
		    }

		  block += gotten;
		  offset += gotten;
		}
	    }
	  else
	    offset += gotten;

	  writer->ops->frame_ops->end (writer);
	}
    }

  writer->ops->end (writer);
}

static void
tsave_command (char *args, int from_tty)
{
  int target_does_save = 0;
  char **argv;
  char *filename = NULL;
  struct cleanup *back_to;
  int generate_ctf = 0;
  struct trace_file_writer *writer = NULL;

  if (args == NULL)
    error_no_arg (_("file in which to save trace data"));

  argv = gdb_buildargv (args);
  back_to = make_cleanup_freeargv (argv);

  for (; *argv; ++argv)
    {
      if (strcmp (*argv, "-r") == 0)
	target_does_save = 1;
      else if (strcmp (*argv, "-ctf") == 0)
	generate_ctf = 1;
      else if (**argv == '-')
	error (_("unknown option `%s'"), *argv);
      else
	filename = *argv;
    }

  if (!filename)
    error_no_arg (_("file in which to save trace data"));

  if (generate_ctf)
    writer = ctf_trace_file_writer_new ();
  else
    writer = tfile_trace_file_writer_new ();

  make_cleanup (trace_file_writer_xfree, writer);

  trace_save (filename, writer, target_does_save);

  if (from_tty)
    printf_filtered (_("Trace data saved to %s '%s'.\n"),
		     generate_ctf ? "directory" : "file", filename);

  do_cleanups (back_to);
}

/* Save the trace data to file FILENAME of tfile format.  */

void
trace_save_tfile (const char *filename, int target_does_save)
{
  struct trace_file_writer *writer;
  struct cleanup *back_to;

  writer = tfile_trace_file_writer_new ();
  back_to = make_cleanup (trace_file_writer_xfree, writer);
  trace_save (filename, writer, target_does_save);
  do_cleanups (back_to);
}

/* Save the trace data to dir DIRNAME of ctf format.  */

void
trace_save_ctf (const char *dirname, int target_does_save)
{
  struct trace_file_writer *writer;
  struct cleanup *back_to;

  writer = ctf_trace_file_writer_new ();
  back_to = make_cleanup (trace_file_writer_xfree, writer);

  trace_save (dirname, writer, target_does_save);
  do_cleanups (back_to);
}

/* Fetch register data from tracefile, shared for both tfile and
   ctf.  */

void
tracefile_fetch_registers (struct regcache *regcache, int regno)
{
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
  struct tracepoint *tp = get_tracepoint (get_tracepoint_number ());
  int regn;

  /* We get here if no register data has been found.  Mark registers
     as unavailable.  */
  for (regn = 0; regn < gdbarch_num_regs (gdbarch); regn++)
    regcache_raw_supply (regcache, regn, NULL);

  /* We can often usefully guess that the PC is going to be the same
     as the address of the tracepoint.  */
  if (tp == NULL || tp->loc == NULL)
    return;

  /* But don't try to guess if tracepoint is multi-location...  */
  if (tp->loc->next)
    {
      warning (_("Tracepoint %d has multiple "
		 "locations, cannot infer $pc"),
	       tp->number);
      return;
    }
  /* ... or does while-stepping.  */
  else if (tp->step_count > 0)
    {
      warning (_("Tracepoint %d does while-stepping, "
		 "cannot infer $pc"),
	       tp->number);
      return;
    }

  /* Guess what we can from the tracepoint location.  */
  gdbarch_guess_tracepoint_registers (gdbarch, regcache,
				      tp->loc->address);
}

/* This is the implementation of target_ops method to_has_all_memory.  */

static int
tracefile_has_all_memory (struct target_ops *ops)
{
  return 1;
}

/* This is the implementation of target_ops method to_has_memory.  */

static int
tracefile_has_memory (struct target_ops *ops)
{
  return 1;
}

/* This is the implementation of target_ops method to_has_stack.
   The target has a stack when GDB has already selected one trace
   frame.  */

static int
tracefile_has_stack (struct target_ops *ops)
{
  return get_traceframe_number () != -1;
}

/* This is the implementation of target_ops method to_has_registers.
   The target has registers when GDB has already selected one trace
   frame.  */

static int
tracefile_has_registers (struct target_ops *ops)
{
  return get_traceframe_number () != -1;
}

/* This is the implementation of target_ops method to_thread_alive.
   tracefile has one thread faked by GDB.  */

static int
tracefile_thread_alive (struct target_ops *ops, ptid_t ptid)
{
  return 1;
}

/* This is the implementation of target_ops method to_get_trace_status.
   The trace status for a file is that tracing can never be run.  */

static int
tracefile_get_trace_status (struct target_ops *self, struct trace_status *ts)
{
  /* Other bits of trace status were collected as part of opening the
     trace files, so nothing to do here.  */

  return -1;
}

/* Initialize OPS for tracefile related targets.  */

void
init_tracefile_ops (struct target_ops *ops)
{
  ops->to_stratum = process_stratum;
  ops->to_get_trace_status = tracefile_get_trace_status;
  ops->to_has_all_memory = tracefile_has_all_memory;
  ops->to_has_memory = tracefile_has_memory;
  ops->to_has_stack = tracefile_has_stack;
  ops->to_has_registers = tracefile_has_registers;
  ops->to_thread_alive = tracefile_thread_alive;
  ops->to_magic = OPS_MAGIC;
}

extern initialize_file_ftype _initialize_tracefile;

void
_initialize_tracefile (void)
{
  add_com ("tsave", class_trace, tsave_command, _("\
Save the trace data to a file.\n\
Use the '-ctf' option to save the data to CTF format.\n\
Use the '-r' option to direct the target to save directly to the file,\n\
using its own filesystem."));
}