| 1 | /* Trace file support in GDB. |
| 2 | |
| 3 | Copyright (C) 1997-2019 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "tracefile.h" |
| 22 | #include "tracectf.h" |
| 23 | #include "exec.h" |
| 24 | #include "regcache.h" |
| 25 | #include "gdbsupport/byte-vector.h" |
| 26 | #include "gdbarch.h" |
| 27 | |
| 28 | /* Helper macros. */ |
| 29 | |
| 30 | #define TRACE_WRITE_R_BLOCK(writer, buf, size) \ |
| 31 | writer->ops->frame_ops->write_r_block ((writer), (buf), (size)) |
| 32 | #define TRACE_WRITE_M_BLOCK_HEADER(writer, addr, size) \ |
| 33 | writer->ops->frame_ops->write_m_block_header ((writer), (addr), \ |
| 34 | (size)) |
| 35 | #define TRACE_WRITE_M_BLOCK_MEMORY(writer, buf, size) \ |
| 36 | writer->ops->frame_ops->write_m_block_memory ((writer), (buf), \ |
| 37 | (size)) |
| 38 | #define TRACE_WRITE_V_BLOCK(writer, num, val) \ |
| 39 | writer->ops->frame_ops->write_v_block ((writer), (num), (val)) |
| 40 | |
| 41 | /* A unique pointer policy class for trace_file_writer. */ |
| 42 | |
| 43 | struct trace_file_writer_deleter |
| 44 | { |
| 45 | void operator() (struct trace_file_writer *writer) |
| 46 | { |
| 47 | writer->ops->dtor (writer); |
| 48 | xfree (writer); |
| 49 | } |
| 50 | }; |
| 51 | |
| 52 | /* A unique_ptr specialization for trace_file_writer. */ |
| 53 | |
| 54 | typedef std::unique_ptr<trace_file_writer, trace_file_writer_deleter> |
| 55 | trace_file_writer_up; |
| 56 | |
| 57 | /* Save tracepoint data to file named FILENAME through WRITER. WRITER |
| 58 | determines the trace file format. If TARGET_DOES_SAVE is non-zero, |
| 59 | the save is performed on the target, otherwise GDB obtains all trace |
| 60 | data and saves it locally. */ |
| 61 | |
| 62 | static void |
| 63 | trace_save (const char *filename, struct trace_file_writer *writer, |
| 64 | int target_does_save) |
| 65 | { |
| 66 | struct trace_status *ts = current_trace_status (); |
| 67 | struct uploaded_tp *uploaded_tps = NULL, *utp; |
| 68 | struct uploaded_tsv *uploaded_tsvs = NULL, *utsv; |
| 69 | |
| 70 | ULONGEST offset = 0; |
| 71 | #define MAX_TRACE_UPLOAD 2000 |
| 72 | gdb::byte_vector buf (std::max (MAX_TRACE_UPLOAD, trace_regblock_size)); |
| 73 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| 74 | |
| 75 | /* If the target is to save the data to a file on its own, then just |
| 76 | send the command and be done with it. */ |
| 77 | if (target_does_save) |
| 78 | { |
| 79 | if (!writer->ops->target_save (writer, filename)) |
| 80 | error (_("Target failed to save trace data to '%s'."), |
| 81 | filename); |
| 82 | return; |
| 83 | } |
| 84 | |
| 85 | /* Get the trace status first before opening the file, so if the |
| 86 | target is losing, we can get out without touching files. Since |
| 87 | we're just calling this for side effects, we ignore the |
| 88 | result. */ |
| 89 | target_get_trace_status (ts); |
| 90 | |
| 91 | writer->ops->start (writer, filename); |
| 92 | |
| 93 | writer->ops->write_header (writer); |
| 94 | |
| 95 | /* Write descriptive info. */ |
| 96 | |
| 97 | /* Write out the size of a register block. */ |
| 98 | writer->ops->write_regblock_type (writer, trace_regblock_size); |
| 99 | |
| 100 | /* Write out the target description info. */ |
| 101 | writer->ops->write_tdesc (writer); |
| 102 | |
| 103 | /* Write out status of the tracing run (aka "tstatus" info). */ |
| 104 | writer->ops->write_status (writer, ts); |
| 105 | |
| 106 | /* Note that we want to upload tracepoints and save those, rather |
| 107 | than simply writing out the local ones, because the user may have |
| 108 | changed tracepoints in GDB in preparation for a future tracing |
| 109 | run, or maybe just mass-deleted all types of breakpoints as part |
| 110 | of cleaning up. So as not to contaminate the session, leave the |
| 111 | data in its uploaded form, don't make into real tracepoints. */ |
| 112 | |
| 113 | /* Get trace state variables first, they may be checked when parsing |
| 114 | uploaded commands. */ |
| 115 | |
| 116 | target_upload_trace_state_variables (&uploaded_tsvs); |
| 117 | |
| 118 | for (utsv = uploaded_tsvs; utsv; utsv = utsv->next) |
| 119 | writer->ops->write_uploaded_tsv (writer, utsv); |
| 120 | |
| 121 | free_uploaded_tsvs (&uploaded_tsvs); |
| 122 | |
| 123 | target_upload_tracepoints (&uploaded_tps); |
| 124 | |
| 125 | for (utp = uploaded_tps; utp; utp = utp->next) |
| 126 | target_get_tracepoint_status (NULL, utp); |
| 127 | |
| 128 | for (utp = uploaded_tps; utp; utp = utp->next) |
| 129 | writer->ops->write_uploaded_tp (writer, utp); |
| 130 | |
| 131 | free_uploaded_tps (&uploaded_tps); |
| 132 | |
| 133 | /* Mark the end of the definition section. */ |
| 134 | writer->ops->write_definition_end (writer); |
| 135 | |
| 136 | /* Get and write the trace data proper. */ |
| 137 | while (1) |
| 138 | { |
| 139 | LONGEST gotten = 0; |
| 140 | |
| 141 | /* The writer supports writing the contents of trace buffer |
| 142 | directly to trace file. Don't parse the contents of trace |
| 143 | buffer. */ |
| 144 | if (writer->ops->write_trace_buffer != NULL) |
| 145 | { |
| 146 | /* We ask for big blocks, in the hopes of efficiency, but |
| 147 | will take less if the target has packet size limitations |
| 148 | or some such. */ |
| 149 | gotten = target_get_raw_trace_data (buf.data (), offset, |
| 150 | MAX_TRACE_UPLOAD); |
| 151 | if (gotten < 0) |
| 152 | error (_("Failure to get requested trace buffer data")); |
| 153 | /* No more data is forthcoming, we're done. */ |
| 154 | if (gotten == 0) |
| 155 | break; |
| 156 | |
| 157 | writer->ops->write_trace_buffer (writer, buf.data (), gotten); |
| 158 | |
| 159 | offset += gotten; |
| 160 | } |
| 161 | else |
| 162 | { |
| 163 | uint16_t tp_num; |
| 164 | uint32_t tf_size; |
| 165 | /* Parse the trace buffers according to how data are stored |
| 166 | in trace buffer in GDBserver. */ |
| 167 | |
| 168 | gotten = target_get_raw_trace_data (buf.data (), offset, 6); |
| 169 | |
| 170 | if (gotten == 0) |
| 171 | break; |
| 172 | |
| 173 | /* Read the first six bytes in, which is the tracepoint |
| 174 | number and trace frame size. */ |
| 175 | tp_num = (uint16_t) |
| 176 | extract_unsigned_integer (&((buf.data ())[0]), 2, byte_order); |
| 177 | |
| 178 | tf_size = (uint32_t) |
| 179 | extract_unsigned_integer (&((buf.data ())[2]), 4, byte_order); |
| 180 | |
| 181 | writer->ops->frame_ops->start (writer, tp_num); |
| 182 | gotten = 6; |
| 183 | |
| 184 | if (tf_size > 0) |
| 185 | { |
| 186 | unsigned int block; |
| 187 | |
| 188 | offset += 6; |
| 189 | |
| 190 | for (block = 0; block < tf_size; ) |
| 191 | { |
| 192 | gdb_byte block_type; |
| 193 | |
| 194 | /* We'll fetch one block each time, in order to |
| 195 | handle the extremely large 'M' block. We first |
| 196 | fetch one byte to get the type of the block. */ |
| 197 | gotten = target_get_raw_trace_data (buf.data (), |
| 198 | offset, 1); |
| 199 | if (gotten < 1) |
| 200 | error (_("Failure to get requested trace buffer data")); |
| 201 | |
| 202 | gotten = 1; |
| 203 | block += 1; |
| 204 | offset += 1; |
| 205 | |
| 206 | block_type = buf[0]; |
| 207 | switch (block_type) |
| 208 | { |
| 209 | case 'R': |
| 210 | gotten |
| 211 | = target_get_raw_trace_data (buf.data (), offset, |
| 212 | trace_regblock_size); |
| 213 | if (gotten < trace_regblock_size) |
| 214 | error (_("Failure to get requested trace" |
| 215 | " buffer data")); |
| 216 | |
| 217 | TRACE_WRITE_R_BLOCK (writer, buf.data (), |
| 218 | trace_regblock_size); |
| 219 | break; |
| 220 | case 'M': |
| 221 | { |
| 222 | unsigned short mlen; |
| 223 | ULONGEST addr; |
| 224 | LONGEST t; |
| 225 | int j; |
| 226 | |
| 227 | t = target_get_raw_trace_data (buf.data (), |
| 228 | offset, 10); |
| 229 | if (t < 10) |
| 230 | error (_("Failure to get requested trace" |
| 231 | " buffer data")); |
| 232 | |
| 233 | offset += 10; |
| 234 | block += 10; |
| 235 | |
| 236 | gotten = 0; |
| 237 | addr = (ULONGEST) |
| 238 | extract_unsigned_integer (buf.data (), 8, |
| 239 | byte_order); |
| 240 | mlen = (unsigned short) |
| 241 | extract_unsigned_integer (&((buf.data ())[8]), 2, |
| 242 | byte_order); |
| 243 | |
| 244 | TRACE_WRITE_M_BLOCK_HEADER (writer, addr, |
| 245 | mlen); |
| 246 | |
| 247 | /* The memory contents in 'M' block may be |
| 248 | very large. Fetch the data from the target |
| 249 | and write them into file one by one. */ |
| 250 | for (j = 0; j < mlen; ) |
| 251 | { |
| 252 | unsigned int read_length; |
| 253 | |
| 254 | if (mlen - j > MAX_TRACE_UPLOAD) |
| 255 | read_length = MAX_TRACE_UPLOAD; |
| 256 | else |
| 257 | read_length = mlen - j; |
| 258 | |
| 259 | t = target_get_raw_trace_data (buf.data (), |
| 260 | offset + j, |
| 261 | read_length); |
| 262 | if (t < read_length) |
| 263 | error (_("Failure to get requested" |
| 264 | " trace buffer data")); |
| 265 | |
| 266 | TRACE_WRITE_M_BLOCK_MEMORY (writer, |
| 267 | buf.data (), |
| 268 | read_length); |
| 269 | |
| 270 | j += read_length; |
| 271 | gotten += read_length; |
| 272 | } |
| 273 | |
| 274 | break; |
| 275 | } |
| 276 | case 'V': |
| 277 | { |
| 278 | int vnum; |
| 279 | LONGEST val; |
| 280 | |
| 281 | gotten |
| 282 | = target_get_raw_trace_data (buf.data (), |
| 283 | offset, 12); |
| 284 | if (gotten < 12) |
| 285 | error (_("Failure to get requested" |
| 286 | " trace buffer data")); |
| 287 | |
| 288 | vnum = (int) extract_signed_integer (buf.data (), |
| 289 | 4, |
| 290 | byte_order); |
| 291 | val |
| 292 | = extract_signed_integer (&((buf.data ())[4]), |
| 293 | 8, byte_order); |
| 294 | |
| 295 | TRACE_WRITE_V_BLOCK (writer, vnum, val); |
| 296 | } |
| 297 | break; |
| 298 | default: |
| 299 | error (_("Unknown block type '%c' (0x%x) in" |
| 300 | " trace frame"), |
| 301 | block_type, block_type); |
| 302 | } |
| 303 | |
| 304 | block += gotten; |
| 305 | offset += gotten; |
| 306 | } |
| 307 | } |
| 308 | else |
| 309 | offset += gotten; |
| 310 | |
| 311 | writer->ops->frame_ops->end (writer); |
| 312 | } |
| 313 | } |
| 314 | |
| 315 | writer->ops->end (writer); |
| 316 | } |
| 317 | |
| 318 | static void |
| 319 | tsave_command (const char *args, int from_tty) |
| 320 | { |
| 321 | int target_does_save = 0; |
| 322 | char **argv; |
| 323 | char *filename = NULL; |
| 324 | int generate_ctf = 0; |
| 325 | |
| 326 | if (args == NULL) |
| 327 | error_no_arg (_("file in which to save trace data")); |
| 328 | |
| 329 | gdb_argv built_argv (args); |
| 330 | argv = built_argv.get (); |
| 331 | |
| 332 | for (; *argv; ++argv) |
| 333 | { |
| 334 | if (strcmp (*argv, "-r") == 0) |
| 335 | target_does_save = 1; |
| 336 | else if (strcmp (*argv, "-ctf") == 0) |
| 337 | generate_ctf = 1; |
| 338 | else if (**argv == '-') |
| 339 | error (_("unknown option `%s'"), *argv); |
| 340 | else |
| 341 | filename = *argv; |
| 342 | } |
| 343 | |
| 344 | if (!filename) |
| 345 | error_no_arg (_("file in which to save trace data")); |
| 346 | |
| 347 | if (generate_ctf) |
| 348 | trace_save_ctf (filename, target_does_save); |
| 349 | else |
| 350 | trace_save_tfile (filename, target_does_save); |
| 351 | |
| 352 | if (from_tty) |
| 353 | printf_filtered (_("Trace data saved to %s '%s'.\n"), |
| 354 | generate_ctf ? "directory" : "file", filename); |
| 355 | } |
| 356 | |
| 357 | /* Save the trace data to file FILENAME of tfile format. */ |
| 358 | |
| 359 | void |
| 360 | trace_save_tfile (const char *filename, int target_does_save) |
| 361 | { |
| 362 | trace_file_writer_up writer (tfile_trace_file_writer_new ()); |
| 363 | trace_save (filename, writer.get (), target_does_save); |
| 364 | } |
| 365 | |
| 366 | /* Save the trace data to dir DIRNAME of ctf format. */ |
| 367 | |
| 368 | void |
| 369 | trace_save_ctf (const char *dirname, int target_does_save) |
| 370 | { |
| 371 | trace_file_writer_up writer (ctf_trace_file_writer_new ()); |
| 372 | trace_save (dirname, writer.get (), target_does_save); |
| 373 | } |
| 374 | |
| 375 | /* Fetch register data from tracefile, shared for both tfile and |
| 376 | ctf. */ |
| 377 | |
| 378 | void |
| 379 | tracefile_fetch_registers (struct regcache *regcache, int regno) |
| 380 | { |
| 381 | struct gdbarch *gdbarch = regcache->arch (); |
| 382 | struct tracepoint *tp = get_tracepoint (get_tracepoint_number ()); |
| 383 | int regn; |
| 384 | |
| 385 | /* We get here if no register data has been found. Mark registers |
| 386 | as unavailable. */ |
| 387 | for (regn = 0; regn < gdbarch_num_regs (gdbarch); regn++) |
| 388 | regcache->raw_supply (regn, NULL); |
| 389 | |
| 390 | /* We can often usefully guess that the PC is going to be the same |
| 391 | as the address of the tracepoint. */ |
| 392 | if (tp == NULL || tp->loc == NULL) |
| 393 | return; |
| 394 | |
| 395 | /* But don't try to guess if tracepoint is multi-location... */ |
| 396 | if (tp->loc->next) |
| 397 | { |
| 398 | warning (_("Tracepoint %d has multiple " |
| 399 | "locations, cannot infer $pc"), |
| 400 | tp->number); |
| 401 | return; |
| 402 | } |
| 403 | /* ... or does while-stepping. */ |
| 404 | else if (tp->step_count > 0) |
| 405 | { |
| 406 | warning (_("Tracepoint %d does while-stepping, " |
| 407 | "cannot infer $pc"), |
| 408 | tp->number); |
| 409 | return; |
| 410 | } |
| 411 | |
| 412 | /* Guess what we can from the tracepoint location. */ |
| 413 | gdbarch_guess_tracepoint_registers (gdbarch, regcache, |
| 414 | tp->loc->address); |
| 415 | } |
| 416 | |
| 417 | /* This is the implementation of target_ops method to_has_all_memory. */ |
| 418 | |
| 419 | bool |
| 420 | tracefile_target::has_all_memory () |
| 421 | { |
| 422 | return 1; |
| 423 | } |
| 424 | |
| 425 | /* This is the implementation of target_ops method to_has_memory. */ |
| 426 | |
| 427 | bool |
| 428 | tracefile_target::has_memory () |
| 429 | { |
| 430 | return 1; |
| 431 | } |
| 432 | |
| 433 | /* This is the implementation of target_ops method to_has_stack. |
| 434 | The target has a stack when GDB has already selected one trace |
| 435 | frame. */ |
| 436 | |
| 437 | bool |
| 438 | tracefile_target::has_stack () |
| 439 | { |
| 440 | return get_traceframe_number () != -1; |
| 441 | } |
| 442 | |
| 443 | /* This is the implementation of target_ops method to_has_registers. |
| 444 | The target has registers when GDB has already selected one trace |
| 445 | frame. */ |
| 446 | |
| 447 | bool |
| 448 | tracefile_target::has_registers () |
| 449 | { |
| 450 | return get_traceframe_number () != -1; |
| 451 | } |
| 452 | |
| 453 | /* This is the implementation of target_ops method to_thread_alive. |
| 454 | tracefile has one thread faked by GDB. */ |
| 455 | |
| 456 | bool |
| 457 | tracefile_target::thread_alive (ptid_t ptid) |
| 458 | { |
| 459 | return 1; |
| 460 | } |
| 461 | |
| 462 | /* This is the implementation of target_ops method to_get_trace_status. |
| 463 | The trace status for a file is that tracing can never be run. */ |
| 464 | |
| 465 | int |
| 466 | tracefile_target::get_trace_status (struct trace_status *ts) |
| 467 | { |
| 468 | /* Other bits of trace status were collected as part of opening the |
| 469 | trace files, so nothing to do here. */ |
| 470 | |
| 471 | return -1; |
| 472 | } |
| 473 | |
| 474 | void |
| 475 | _initialize_tracefile (void) |
| 476 | { |
| 477 | add_com ("tsave", class_trace, tsave_command, _("\ |
| 478 | Save the trace data to a file.\n\ |
| 479 | Use the '-ctf' option to save the data to CTF format.\n\ |
| 480 | Use the '-r' option to direct the target to save directly to the file,\n\ |
| 481 | using its own filesystem.")); |
| 482 | } |