| 1 | /* Low-level child interface to ptrace. |
| 2 | |
| 3 | Copyright (C) 1988-2014 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 "command.h" |
| 22 | #include "inferior.h" |
| 23 | #include "inflow.h" |
| 24 | #include "terminal.h" |
| 25 | #include "gdbcore.h" |
| 26 | #include "regcache.h" |
| 27 | |
| 28 | #include "gdb_assert.h" |
| 29 | #include <string.h> |
| 30 | #include "gdb_ptrace.h" |
| 31 | #include "gdb_wait.h" |
| 32 | #include <signal.h> |
| 33 | |
| 34 | #include "inf-ptrace.h" |
| 35 | #include "inf-child.h" |
| 36 | #include "gdbthread.h" |
| 37 | |
| 38 | \f |
| 39 | |
| 40 | #ifdef PT_GET_PROCESS_STATE |
| 41 | |
| 42 | static int |
| 43 | inf_ptrace_follow_fork (struct target_ops *ops, int follow_child, |
| 44 | int detach_fork) |
| 45 | { |
| 46 | pid_t pid, fpid; |
| 47 | ptrace_state_t pe; |
| 48 | |
| 49 | pid = ptid_get_pid (inferior_ptid); |
| 50 | |
| 51 | if (ptrace (PT_GET_PROCESS_STATE, pid, |
| 52 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) |
| 53 | perror_with_name (("ptrace")); |
| 54 | |
| 55 | gdb_assert (pe.pe_report_event == PTRACE_FORK); |
| 56 | fpid = pe.pe_other_pid; |
| 57 | |
| 58 | if (follow_child) |
| 59 | { |
| 60 | struct inferior *parent_inf, *child_inf; |
| 61 | struct thread_info *tp; |
| 62 | |
| 63 | parent_inf = find_inferior_pid (pid); |
| 64 | |
| 65 | /* Add the child. */ |
| 66 | child_inf = add_inferior (fpid); |
| 67 | child_inf->attach_flag = parent_inf->attach_flag; |
| 68 | copy_terminal_info (child_inf, parent_inf); |
| 69 | child_inf->pspace = parent_inf->pspace; |
| 70 | child_inf->aspace = parent_inf->aspace; |
| 71 | |
| 72 | /* Before detaching from the parent, remove all breakpoints from |
| 73 | it. */ |
| 74 | remove_breakpoints (); |
| 75 | |
| 76 | if (ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, 0) == -1) |
| 77 | perror_with_name (("ptrace")); |
| 78 | |
| 79 | /* Switch inferior_ptid out of the parent's way. */ |
| 80 | inferior_ptid = pid_to_ptid (fpid); |
| 81 | |
| 82 | /* Delete the parent. */ |
| 83 | detach_inferior (pid); |
| 84 | |
| 85 | add_thread_silent (inferior_ptid); |
| 86 | } |
| 87 | else |
| 88 | { |
| 89 | /* Breakpoints have already been detached from the child by |
| 90 | infrun.c. */ |
| 91 | |
| 92 | if (ptrace (PT_DETACH, fpid, (PTRACE_TYPE_ARG3)1, 0) == -1) |
| 93 | perror_with_name (("ptrace")); |
| 94 | } |
| 95 | |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | #endif /* PT_GET_PROCESS_STATE */ |
| 100 | \f |
| 101 | |
| 102 | /* Prepare to be traced. */ |
| 103 | |
| 104 | static void |
| 105 | inf_ptrace_me (void) |
| 106 | { |
| 107 | /* "Trace me, Dr. Memory!" */ |
| 108 | ptrace (PT_TRACE_ME, 0, (PTRACE_TYPE_ARG3)0, 0); |
| 109 | } |
| 110 | |
| 111 | /* Start a new inferior Unix child process. EXEC_FILE is the file to |
| 112 | run, ALLARGS is a string containing the arguments to the program. |
| 113 | ENV is the environment vector to pass. If FROM_TTY is non-zero, be |
| 114 | chatty about it. */ |
| 115 | |
| 116 | static void |
| 117 | inf_ptrace_create_inferior (struct target_ops *ops, |
| 118 | char *exec_file, char *allargs, char **env, |
| 119 | int from_tty) |
| 120 | { |
| 121 | int pid; |
| 122 | |
| 123 | /* Do not change either targets above or the same target if already present. |
| 124 | The reason is the target stack is shared across multiple inferiors. */ |
| 125 | int ops_already_pushed = target_is_pushed (ops); |
| 126 | struct cleanup *back_to = make_cleanup (null_cleanup, NULL); |
| 127 | |
| 128 | if (! ops_already_pushed) |
| 129 | { |
| 130 | /* Clear possible core file with its process_stratum. */ |
| 131 | push_target (ops); |
| 132 | make_cleanup_unpush_target (ops); |
| 133 | } |
| 134 | |
| 135 | pid = fork_inferior (exec_file, allargs, env, inf_ptrace_me, NULL, |
| 136 | NULL, NULL, NULL); |
| 137 | |
| 138 | discard_cleanups (back_to); |
| 139 | |
| 140 | startup_inferior (START_INFERIOR_TRAPS_EXPECTED); |
| 141 | |
| 142 | /* On some targets, there must be some explicit actions taken after |
| 143 | the inferior has been started up. */ |
| 144 | target_post_startup_inferior (pid_to_ptid (pid)); |
| 145 | } |
| 146 | |
| 147 | #ifdef PT_GET_PROCESS_STATE |
| 148 | |
| 149 | static void |
| 150 | inf_ptrace_post_startup_inferior (ptid_t pid) |
| 151 | { |
| 152 | ptrace_event_t pe; |
| 153 | |
| 154 | /* Set the initial event mask. */ |
| 155 | memset (&pe, 0, sizeof pe); |
| 156 | pe.pe_set_event |= PTRACE_FORK; |
| 157 | if (ptrace (PT_SET_EVENT_MASK, ptid_get_pid (pid), |
| 158 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) |
| 159 | perror_with_name (("ptrace")); |
| 160 | } |
| 161 | |
| 162 | #endif |
| 163 | |
| 164 | /* Clean up a rotting corpse of an inferior after it died. */ |
| 165 | |
| 166 | static void |
| 167 | inf_ptrace_mourn_inferior (struct target_ops *ops) |
| 168 | { |
| 169 | int status; |
| 170 | |
| 171 | /* Wait just one more time to collect the inferior's exit status. |
| 172 | Do not check whether this succeeds though, since we may be |
| 173 | dealing with a process that we attached to. Such a process will |
| 174 | only report its exit status to its original parent. */ |
| 175 | waitpid (ptid_get_pid (inferior_ptid), &status, 0); |
| 176 | |
| 177 | generic_mourn_inferior (); |
| 178 | |
| 179 | if (!have_inferiors ()) |
| 180 | unpush_target (ops); |
| 181 | } |
| 182 | |
| 183 | /* Attach to the process specified by ARGS. If FROM_TTY is non-zero, |
| 184 | be chatty about it. */ |
| 185 | |
| 186 | static void |
| 187 | inf_ptrace_attach (struct target_ops *ops, char *args, int from_tty) |
| 188 | { |
| 189 | char *exec_file; |
| 190 | pid_t pid; |
| 191 | struct inferior *inf; |
| 192 | |
| 193 | /* Do not change either targets above or the same target if already present. |
| 194 | The reason is the target stack is shared across multiple inferiors. */ |
| 195 | int ops_already_pushed = target_is_pushed (ops); |
| 196 | struct cleanup *back_to = make_cleanup (null_cleanup, NULL); |
| 197 | |
| 198 | pid = parse_pid_to_attach (args); |
| 199 | |
| 200 | if (pid == getpid ()) /* Trying to masturbate? */ |
| 201 | error (_("I refuse to debug myself!")); |
| 202 | |
| 203 | if (! ops_already_pushed) |
| 204 | { |
| 205 | /* target_pid_to_str already uses the target. Also clear possible core |
| 206 | file with its process_stratum. */ |
| 207 | push_target (ops); |
| 208 | make_cleanup_unpush_target (ops); |
| 209 | } |
| 210 | |
| 211 | if (from_tty) |
| 212 | { |
| 213 | exec_file = get_exec_file (0); |
| 214 | |
| 215 | if (exec_file) |
| 216 | printf_unfiltered (_("Attaching to program: %s, %s\n"), exec_file, |
| 217 | target_pid_to_str (pid_to_ptid (pid))); |
| 218 | else |
| 219 | printf_unfiltered (_("Attaching to %s\n"), |
| 220 | target_pid_to_str (pid_to_ptid (pid))); |
| 221 | |
| 222 | gdb_flush (gdb_stdout); |
| 223 | } |
| 224 | |
| 225 | #ifdef PT_ATTACH |
| 226 | errno = 0; |
| 227 | ptrace (PT_ATTACH, pid, (PTRACE_TYPE_ARG3)0, 0); |
| 228 | if (errno != 0) |
| 229 | perror_with_name (("ptrace")); |
| 230 | #else |
| 231 | error (_("This system does not support attaching to a process")); |
| 232 | #endif |
| 233 | |
| 234 | inf = current_inferior (); |
| 235 | inferior_appeared (inf, pid); |
| 236 | inf->attach_flag = 1; |
| 237 | inferior_ptid = pid_to_ptid (pid); |
| 238 | |
| 239 | /* Always add a main thread. If some target extends the ptrace |
| 240 | target, it should decorate the ptid later with more info. */ |
| 241 | add_thread_silent (inferior_ptid); |
| 242 | |
| 243 | discard_cleanups (back_to); |
| 244 | } |
| 245 | |
| 246 | #ifdef PT_GET_PROCESS_STATE |
| 247 | |
| 248 | static void |
| 249 | inf_ptrace_post_attach (struct target_ops *self, int pid) |
| 250 | { |
| 251 | ptrace_event_t pe; |
| 252 | |
| 253 | /* Set the initial event mask. */ |
| 254 | memset (&pe, 0, sizeof pe); |
| 255 | pe.pe_set_event |= PTRACE_FORK; |
| 256 | if (ptrace (PT_SET_EVENT_MASK, pid, |
| 257 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) |
| 258 | perror_with_name (("ptrace")); |
| 259 | } |
| 260 | |
| 261 | #endif |
| 262 | |
| 263 | /* Detach from the inferior, optionally passing it the signal |
| 264 | specified by ARGS. If FROM_TTY is non-zero, be chatty about it. */ |
| 265 | |
| 266 | static void |
| 267 | inf_ptrace_detach (struct target_ops *ops, const char *args, int from_tty) |
| 268 | { |
| 269 | pid_t pid = ptid_get_pid (inferior_ptid); |
| 270 | int sig = 0; |
| 271 | |
| 272 | if (from_tty) |
| 273 | { |
| 274 | char *exec_file = get_exec_file (0); |
| 275 | if (exec_file == 0) |
| 276 | exec_file = ""; |
| 277 | printf_unfiltered (_("Detaching from program: %s, %s\n"), exec_file, |
| 278 | target_pid_to_str (pid_to_ptid (pid))); |
| 279 | gdb_flush (gdb_stdout); |
| 280 | } |
| 281 | if (args) |
| 282 | sig = atoi (args); |
| 283 | |
| 284 | #ifdef PT_DETACH |
| 285 | /* We'd better not have left any breakpoints in the program or it'll |
| 286 | die when it hits one. Also note that this may only work if we |
| 287 | previously attached to the inferior. It *might* work if we |
| 288 | started the process ourselves. */ |
| 289 | errno = 0; |
| 290 | ptrace (PT_DETACH, pid, (PTRACE_TYPE_ARG3)1, sig); |
| 291 | if (errno != 0) |
| 292 | perror_with_name (("ptrace")); |
| 293 | #else |
| 294 | error (_("This system does not support detaching from a process")); |
| 295 | #endif |
| 296 | |
| 297 | inferior_ptid = null_ptid; |
| 298 | detach_inferior (pid); |
| 299 | |
| 300 | if (!have_inferiors ()) |
| 301 | unpush_target (ops); |
| 302 | } |
| 303 | |
| 304 | /* Kill the inferior. */ |
| 305 | |
| 306 | static void |
| 307 | inf_ptrace_kill (struct target_ops *ops) |
| 308 | { |
| 309 | pid_t pid = ptid_get_pid (inferior_ptid); |
| 310 | int status; |
| 311 | |
| 312 | if (pid == 0) |
| 313 | return; |
| 314 | |
| 315 | ptrace (PT_KILL, pid, (PTRACE_TYPE_ARG3)0, 0); |
| 316 | waitpid (pid, &status, 0); |
| 317 | |
| 318 | target_mourn_inferior (); |
| 319 | } |
| 320 | |
| 321 | /* Stop the inferior. */ |
| 322 | |
| 323 | static void |
| 324 | inf_ptrace_stop (ptid_t ptid) |
| 325 | { |
| 326 | /* Send a SIGINT to the process group. This acts just like the user |
| 327 | typed a ^C on the controlling terminal. Note that using a |
| 328 | negative process number in kill() is a System V-ism. The proper |
| 329 | BSD interface is killpg(). However, all modern BSDs support the |
| 330 | System V interface too. */ |
| 331 | kill (-inferior_process_group (), SIGINT); |
| 332 | } |
| 333 | |
| 334 | /* Resume execution of thread PTID, or all threads if PTID is -1. If |
| 335 | STEP is nonzero, single-step it. If SIGNAL is nonzero, give it |
| 336 | that signal. */ |
| 337 | |
| 338 | static void |
| 339 | inf_ptrace_resume (struct target_ops *ops, |
| 340 | ptid_t ptid, int step, enum gdb_signal signal) |
| 341 | { |
| 342 | pid_t pid = ptid_get_pid (ptid); |
| 343 | int request; |
| 344 | |
| 345 | if (pid == -1) |
| 346 | /* Resume all threads. Traditionally ptrace() only supports |
| 347 | single-threaded processes, so simply resume the inferior. */ |
| 348 | pid = ptid_get_pid (inferior_ptid); |
| 349 | |
| 350 | if (catch_syscall_enabled () > 0) |
| 351 | request = PT_SYSCALL; |
| 352 | else |
| 353 | request = PT_CONTINUE; |
| 354 | |
| 355 | if (step) |
| 356 | { |
| 357 | /* If this system does not support PT_STEP, a higher level |
| 358 | function will have called single_step() to transmute the step |
| 359 | request into a continue request (by setting breakpoints on |
| 360 | all possible successor instructions), so we don't have to |
| 361 | worry about that here. */ |
| 362 | request = PT_STEP; |
| 363 | } |
| 364 | |
| 365 | /* An address of (PTRACE_TYPE_ARG3)1 tells ptrace to continue from |
| 366 | where it was. If GDB wanted it to start some other way, we have |
| 367 | already written a new program counter value to the child. */ |
| 368 | errno = 0; |
| 369 | ptrace (request, pid, (PTRACE_TYPE_ARG3)1, gdb_signal_to_host (signal)); |
| 370 | if (errno != 0) |
| 371 | perror_with_name (("ptrace")); |
| 372 | } |
| 373 | |
| 374 | /* Wait for the child specified by PTID to do something. Return the |
| 375 | process ID of the child, or MINUS_ONE_PTID in case of error; store |
| 376 | the status in *OURSTATUS. */ |
| 377 | |
| 378 | static ptid_t |
| 379 | inf_ptrace_wait (struct target_ops *ops, |
| 380 | ptid_t ptid, struct target_waitstatus *ourstatus, int options) |
| 381 | { |
| 382 | pid_t pid; |
| 383 | int status, save_errno; |
| 384 | |
| 385 | do |
| 386 | { |
| 387 | set_sigint_trap (); |
| 388 | |
| 389 | do |
| 390 | { |
| 391 | pid = waitpid (ptid_get_pid (ptid), &status, 0); |
| 392 | save_errno = errno; |
| 393 | } |
| 394 | while (pid == -1 && errno == EINTR); |
| 395 | |
| 396 | clear_sigint_trap (); |
| 397 | |
| 398 | if (pid == -1) |
| 399 | { |
| 400 | fprintf_unfiltered (gdb_stderr, |
| 401 | _("Child process unexpectedly missing: %s.\n"), |
| 402 | safe_strerror (save_errno)); |
| 403 | |
| 404 | /* Claim it exited with unknown signal. */ |
| 405 | ourstatus->kind = TARGET_WAITKIND_SIGNALLED; |
| 406 | ourstatus->value.sig = GDB_SIGNAL_UNKNOWN; |
| 407 | return inferior_ptid; |
| 408 | } |
| 409 | |
| 410 | /* Ignore terminated detached child processes. */ |
| 411 | if (!WIFSTOPPED (status) && pid != ptid_get_pid (inferior_ptid)) |
| 412 | pid = -1; |
| 413 | } |
| 414 | while (pid == -1); |
| 415 | |
| 416 | #ifdef PT_GET_PROCESS_STATE |
| 417 | if (WIFSTOPPED (status)) |
| 418 | { |
| 419 | ptrace_state_t pe; |
| 420 | pid_t fpid; |
| 421 | |
| 422 | if (ptrace (PT_GET_PROCESS_STATE, pid, |
| 423 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) |
| 424 | perror_with_name (("ptrace")); |
| 425 | |
| 426 | switch (pe.pe_report_event) |
| 427 | { |
| 428 | case PTRACE_FORK: |
| 429 | ourstatus->kind = TARGET_WAITKIND_FORKED; |
| 430 | ourstatus->value.related_pid = pid_to_ptid (pe.pe_other_pid); |
| 431 | |
| 432 | /* Make sure the other end of the fork is stopped too. */ |
| 433 | fpid = waitpid (pe.pe_other_pid, &status, 0); |
| 434 | if (fpid == -1) |
| 435 | perror_with_name (("waitpid")); |
| 436 | |
| 437 | if (ptrace (PT_GET_PROCESS_STATE, fpid, |
| 438 | (PTRACE_TYPE_ARG3)&pe, sizeof pe) == -1) |
| 439 | perror_with_name (("ptrace")); |
| 440 | |
| 441 | gdb_assert (pe.pe_report_event == PTRACE_FORK); |
| 442 | gdb_assert (pe.pe_other_pid == pid); |
| 443 | if (fpid == ptid_get_pid (inferior_ptid)) |
| 444 | { |
| 445 | ourstatus->value.related_pid = pid_to_ptid (pe.pe_other_pid); |
| 446 | return pid_to_ptid (fpid); |
| 447 | } |
| 448 | |
| 449 | return pid_to_ptid (pid); |
| 450 | } |
| 451 | } |
| 452 | #endif |
| 453 | |
| 454 | store_waitstatus (ourstatus, status); |
| 455 | return pid_to_ptid (pid); |
| 456 | } |
| 457 | |
| 458 | /* Implement the to_xfer_partial target_ops method. */ |
| 459 | |
| 460 | static enum target_xfer_status |
| 461 | inf_ptrace_xfer_partial (struct target_ops *ops, enum target_object object, |
| 462 | const char *annex, gdb_byte *readbuf, |
| 463 | const gdb_byte *writebuf, |
| 464 | ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) |
| 465 | { |
| 466 | pid_t pid = ptid_get_pid (inferior_ptid); |
| 467 | |
| 468 | switch (object) |
| 469 | { |
| 470 | case TARGET_OBJECT_MEMORY: |
| 471 | #ifdef PT_IO |
| 472 | /* OpenBSD 3.1, NetBSD 1.6 and FreeBSD 5.0 have a new PT_IO |
| 473 | request that promises to be much more efficient in reading |
| 474 | and writing data in the traced process's address space. */ |
| 475 | { |
| 476 | struct ptrace_io_desc piod; |
| 477 | |
| 478 | /* NOTE: We assume that there are no distinct address spaces |
| 479 | for instruction and data. However, on OpenBSD 3.9 and |
| 480 | later, PIOD_WRITE_D doesn't allow changing memory that's |
| 481 | mapped read-only. Since most code segments will be |
| 482 | read-only, using PIOD_WRITE_D will prevent us from |
| 483 | inserting breakpoints, so we use PIOD_WRITE_I instead. */ |
| 484 | piod.piod_op = writebuf ? PIOD_WRITE_I : PIOD_READ_D; |
| 485 | piod.piod_addr = writebuf ? (void *) writebuf : readbuf; |
| 486 | piod.piod_offs = (void *) (long) offset; |
| 487 | piod.piod_len = len; |
| 488 | |
| 489 | errno = 0; |
| 490 | if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0) |
| 491 | { |
| 492 | /* Return the actual number of bytes read or written. */ |
| 493 | *xfered_len = piod.piod_len; |
| 494 | return (piod.piod_len == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK; |
| 495 | } |
| 496 | /* If the PT_IO request is somehow not supported, fallback on |
| 497 | using PT_WRITE_D/PT_READ_D. Otherwise we will return zero |
| 498 | to indicate failure. */ |
| 499 | if (errno != EINVAL) |
| 500 | return TARGET_XFER_EOF; |
| 501 | } |
| 502 | #endif |
| 503 | { |
| 504 | union |
| 505 | { |
| 506 | PTRACE_TYPE_RET word; |
| 507 | gdb_byte byte[sizeof (PTRACE_TYPE_RET)]; |
| 508 | } buffer; |
| 509 | ULONGEST rounded_offset; |
| 510 | ULONGEST partial_len; |
| 511 | |
| 512 | /* Round the start offset down to the next long word |
| 513 | boundary. */ |
| 514 | rounded_offset = offset & -(ULONGEST) sizeof (PTRACE_TYPE_RET); |
| 515 | |
| 516 | /* Since ptrace will transfer a single word starting at that |
| 517 | rounded_offset the partial_len needs to be adjusted down to |
| 518 | that (remember this function only does a single transfer). |
| 519 | Should the required length be even less, adjust it down |
| 520 | again. */ |
| 521 | partial_len = (rounded_offset + sizeof (PTRACE_TYPE_RET)) - offset; |
| 522 | if (partial_len > len) |
| 523 | partial_len = len; |
| 524 | |
| 525 | if (writebuf) |
| 526 | { |
| 527 | /* If OFFSET:PARTIAL_LEN is smaller than |
| 528 | ROUNDED_OFFSET:WORDSIZE then a read/modify write will |
| 529 | be needed. Read in the entire word. */ |
| 530 | if (rounded_offset < offset |
| 531 | || (offset + partial_len |
| 532 | < rounded_offset + sizeof (PTRACE_TYPE_RET))) |
| 533 | /* Need part of initial word -- fetch it. */ |
| 534 | buffer.word = ptrace (PT_READ_I, pid, |
| 535 | (PTRACE_TYPE_ARG3)(uintptr_t) |
| 536 | rounded_offset, 0); |
| 537 | |
| 538 | /* Copy data to be written over corresponding part of |
| 539 | buffer. */ |
| 540 | memcpy (buffer.byte + (offset - rounded_offset), |
| 541 | writebuf, partial_len); |
| 542 | |
| 543 | errno = 0; |
| 544 | ptrace (PT_WRITE_D, pid, |
| 545 | (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, |
| 546 | buffer.word); |
| 547 | if (errno) |
| 548 | { |
| 549 | /* Using the appropriate one (I or D) is necessary for |
| 550 | Gould NP1, at least. */ |
| 551 | errno = 0; |
| 552 | ptrace (PT_WRITE_I, pid, |
| 553 | (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, |
| 554 | buffer.word); |
| 555 | if (errno) |
| 556 | return TARGET_XFER_EOF; |
| 557 | } |
| 558 | } |
| 559 | |
| 560 | if (readbuf) |
| 561 | { |
| 562 | errno = 0; |
| 563 | buffer.word = ptrace (PT_READ_I, pid, |
| 564 | (PTRACE_TYPE_ARG3)(uintptr_t)rounded_offset, |
| 565 | 0); |
| 566 | if (errno) |
| 567 | return TARGET_XFER_EOF; |
| 568 | /* Copy appropriate bytes out of the buffer. */ |
| 569 | memcpy (readbuf, buffer.byte + (offset - rounded_offset), |
| 570 | partial_len); |
| 571 | } |
| 572 | |
| 573 | *xfered_len = partial_len; |
| 574 | return TARGET_XFER_OK; |
| 575 | } |
| 576 | |
| 577 | case TARGET_OBJECT_UNWIND_TABLE: |
| 578 | return TARGET_XFER_E_IO; |
| 579 | |
| 580 | case TARGET_OBJECT_AUXV: |
| 581 | #if defined (PT_IO) && defined (PIOD_READ_AUXV) |
| 582 | /* OpenBSD 4.5 has a new PIOD_READ_AUXV operation for the PT_IO |
| 583 | request that allows us to read the auxilliary vector. Other |
| 584 | BSD's may follow if they feel the need to support PIE. */ |
| 585 | { |
| 586 | struct ptrace_io_desc piod; |
| 587 | |
| 588 | if (writebuf) |
| 589 | return TARGET_XFER_E_IO; |
| 590 | piod.piod_op = PIOD_READ_AUXV; |
| 591 | piod.piod_addr = readbuf; |
| 592 | piod.piod_offs = (void *) (long) offset; |
| 593 | piod.piod_len = len; |
| 594 | |
| 595 | errno = 0; |
| 596 | if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0) |
| 597 | { |
| 598 | /* Return the actual number of bytes read or written. */ |
| 599 | *xfered_len = piod.piod_len; |
| 600 | return (piod.piod_len == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK; |
| 601 | } |
| 602 | } |
| 603 | #endif |
| 604 | return TARGET_XFER_E_IO; |
| 605 | |
| 606 | case TARGET_OBJECT_WCOOKIE: |
| 607 | return TARGET_XFER_E_IO; |
| 608 | |
| 609 | default: |
| 610 | return TARGET_XFER_E_IO; |
| 611 | } |
| 612 | } |
| 613 | |
| 614 | /* Return non-zero if the thread specified by PTID is alive. */ |
| 615 | |
| 616 | static int |
| 617 | inf_ptrace_thread_alive (struct target_ops *ops, ptid_t ptid) |
| 618 | { |
| 619 | /* ??? Is kill the right way to do this? */ |
| 620 | return (kill (ptid_get_pid (ptid), 0) != -1); |
| 621 | } |
| 622 | |
| 623 | /* Print status information about what we're accessing. */ |
| 624 | |
| 625 | static void |
| 626 | inf_ptrace_files_info (struct target_ops *ignore) |
| 627 | { |
| 628 | struct inferior *inf = current_inferior (); |
| 629 | |
| 630 | printf_filtered (_("\tUsing the running image of %s %s.\n"), |
| 631 | inf->attach_flag ? "attached" : "child", |
| 632 | target_pid_to_str (inferior_ptid)); |
| 633 | } |
| 634 | |
| 635 | static char * |
| 636 | inf_ptrace_pid_to_str (struct target_ops *ops, ptid_t ptid) |
| 637 | { |
| 638 | return normal_pid_to_str (ptid); |
| 639 | } |
| 640 | |
| 641 | #if defined (PT_IO) && defined (PIOD_READ_AUXV) |
| 642 | |
| 643 | /* Read one auxv entry from *READPTR, not reading locations >= ENDPTR. |
| 644 | Return 0 if *READPTR is already at the end of the buffer. |
| 645 | Return -1 if there is insufficient buffer for a whole entry. |
| 646 | Return 1 if an entry was read into *TYPEP and *VALP. */ |
| 647 | |
| 648 | static int |
| 649 | inf_ptrace_auxv_parse (struct target_ops *ops, gdb_byte **readptr, |
| 650 | gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp) |
| 651 | { |
| 652 | struct type *int_type = builtin_type (target_gdbarch ())->builtin_int; |
| 653 | struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr; |
| 654 | const int sizeof_auxv_type = TYPE_LENGTH (int_type); |
| 655 | const int sizeof_auxv_val = TYPE_LENGTH (ptr_type); |
| 656 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
| 657 | gdb_byte *ptr = *readptr; |
| 658 | |
| 659 | if (endptr == ptr) |
| 660 | return 0; |
| 661 | |
| 662 | if (endptr - ptr < 2 * sizeof_auxv_val) |
| 663 | return -1; |
| 664 | |
| 665 | *typep = extract_unsigned_integer (ptr, sizeof_auxv_type, byte_order); |
| 666 | ptr += sizeof_auxv_val; /* Alignment. */ |
| 667 | *valp = extract_unsigned_integer (ptr, sizeof_auxv_val, byte_order); |
| 668 | ptr += sizeof_auxv_val; |
| 669 | |
| 670 | *readptr = ptr; |
| 671 | return 1; |
| 672 | } |
| 673 | |
| 674 | #endif |
| 675 | |
| 676 | /* Create a prototype ptrace target. The client can override it with |
| 677 | local methods. */ |
| 678 | |
| 679 | struct target_ops * |
| 680 | inf_ptrace_target (void) |
| 681 | { |
| 682 | struct target_ops *t = inf_child_target (); |
| 683 | |
| 684 | t->to_attach = inf_ptrace_attach; |
| 685 | t->to_detach = inf_ptrace_detach; |
| 686 | t->to_resume = inf_ptrace_resume; |
| 687 | t->to_wait = inf_ptrace_wait; |
| 688 | t->to_files_info = inf_ptrace_files_info; |
| 689 | t->to_kill = inf_ptrace_kill; |
| 690 | t->to_create_inferior = inf_ptrace_create_inferior; |
| 691 | #ifdef PT_GET_PROCESS_STATE |
| 692 | t->to_follow_fork = inf_ptrace_follow_fork; |
| 693 | t->to_post_startup_inferior = inf_ptrace_post_startup_inferior; |
| 694 | t->to_post_attach = inf_ptrace_post_attach; |
| 695 | #endif |
| 696 | t->to_mourn_inferior = inf_ptrace_mourn_inferior; |
| 697 | t->to_thread_alive = inf_ptrace_thread_alive; |
| 698 | t->to_pid_to_str = inf_ptrace_pid_to_str; |
| 699 | t->to_stop = inf_ptrace_stop; |
| 700 | t->to_xfer_partial = inf_ptrace_xfer_partial; |
| 701 | #if defined (PT_IO) && defined (PIOD_READ_AUXV) |
| 702 | t->to_auxv_parse = inf_ptrace_auxv_parse; |
| 703 | #endif |
| 704 | |
| 705 | return t; |
| 706 | } |
| 707 | \f |
| 708 | |
| 709 | /* Pointer to a function that returns the offset within the user area |
| 710 | where a particular register is stored. */ |
| 711 | static CORE_ADDR (*inf_ptrace_register_u_offset)(struct gdbarch *, int, int); |
| 712 | |
| 713 | /* Fetch register REGNUM from the inferior. */ |
| 714 | |
| 715 | static void |
| 716 | inf_ptrace_fetch_register (struct regcache *regcache, int regnum) |
| 717 | { |
| 718 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 719 | CORE_ADDR addr; |
| 720 | size_t size; |
| 721 | PTRACE_TYPE_RET *buf; |
| 722 | int pid, i; |
| 723 | |
| 724 | /* This isn't really an address, but ptrace thinks of it as one. */ |
| 725 | addr = inf_ptrace_register_u_offset (gdbarch, regnum, 0); |
| 726 | if (addr == (CORE_ADDR)-1 |
| 727 | || gdbarch_cannot_fetch_register (gdbarch, regnum)) |
| 728 | { |
| 729 | regcache_raw_supply (regcache, regnum, NULL); |
| 730 | return; |
| 731 | } |
| 732 | |
| 733 | /* Cater for systems like GNU/Linux, that implement threads as |
| 734 | separate processes. */ |
| 735 | pid = ptid_get_lwp (inferior_ptid); |
| 736 | if (pid == 0) |
| 737 | pid = ptid_get_pid (inferior_ptid); |
| 738 | |
| 739 | size = register_size (gdbarch, regnum); |
| 740 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); |
| 741 | buf = alloca (size); |
| 742 | |
| 743 | /* Read the register contents from the inferior a chunk at a time. */ |
| 744 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) |
| 745 | { |
| 746 | errno = 0; |
| 747 | buf[i] = ptrace (PT_READ_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, 0); |
| 748 | if (errno != 0) |
| 749 | error (_("Couldn't read register %s (#%d): %s."), |
| 750 | gdbarch_register_name (gdbarch, regnum), |
| 751 | regnum, safe_strerror (errno)); |
| 752 | |
| 753 | addr += sizeof (PTRACE_TYPE_RET); |
| 754 | } |
| 755 | regcache_raw_supply (regcache, regnum, buf); |
| 756 | } |
| 757 | |
| 758 | /* Fetch register REGNUM from the inferior. If REGNUM is -1, do this |
| 759 | for all registers. */ |
| 760 | |
| 761 | static void |
| 762 | inf_ptrace_fetch_registers (struct target_ops *ops, |
| 763 | struct regcache *regcache, int regnum) |
| 764 | { |
| 765 | if (regnum == -1) |
| 766 | for (regnum = 0; |
| 767 | regnum < gdbarch_num_regs (get_regcache_arch (regcache)); |
| 768 | regnum++) |
| 769 | inf_ptrace_fetch_register (regcache, regnum); |
| 770 | else |
| 771 | inf_ptrace_fetch_register (regcache, regnum); |
| 772 | } |
| 773 | |
| 774 | /* Store register REGNUM into the inferior. */ |
| 775 | |
| 776 | static void |
| 777 | inf_ptrace_store_register (const struct regcache *regcache, int regnum) |
| 778 | { |
| 779 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 780 | CORE_ADDR addr; |
| 781 | size_t size; |
| 782 | PTRACE_TYPE_RET *buf; |
| 783 | int pid, i; |
| 784 | |
| 785 | /* This isn't really an address, but ptrace thinks of it as one. */ |
| 786 | addr = inf_ptrace_register_u_offset (gdbarch, regnum, 1); |
| 787 | if (addr == (CORE_ADDR)-1 |
| 788 | || gdbarch_cannot_store_register (gdbarch, regnum)) |
| 789 | return; |
| 790 | |
| 791 | /* Cater for systems like GNU/Linux, that implement threads as |
| 792 | separate processes. */ |
| 793 | pid = ptid_get_lwp (inferior_ptid); |
| 794 | if (pid == 0) |
| 795 | pid = ptid_get_pid (inferior_ptid); |
| 796 | |
| 797 | size = register_size (gdbarch, regnum); |
| 798 | gdb_assert ((size % sizeof (PTRACE_TYPE_RET)) == 0); |
| 799 | buf = alloca (size); |
| 800 | |
| 801 | /* Write the register contents into the inferior a chunk at a time. */ |
| 802 | regcache_raw_collect (regcache, regnum, buf); |
| 803 | for (i = 0; i < size / sizeof (PTRACE_TYPE_RET); i++) |
| 804 | { |
| 805 | errno = 0; |
| 806 | ptrace (PT_WRITE_U, pid, (PTRACE_TYPE_ARG3)(uintptr_t)addr, buf[i]); |
| 807 | if (errno != 0) |
| 808 | error (_("Couldn't write register %s (#%d): %s."), |
| 809 | gdbarch_register_name (gdbarch, regnum), |
| 810 | regnum, safe_strerror (errno)); |
| 811 | |
| 812 | addr += sizeof (PTRACE_TYPE_RET); |
| 813 | } |
| 814 | } |
| 815 | |
| 816 | /* Store register REGNUM back into the inferior. If REGNUM is -1, do |
| 817 | this for all registers. */ |
| 818 | |
| 819 | static void |
| 820 | inf_ptrace_store_registers (struct target_ops *ops, |
| 821 | struct regcache *regcache, int regnum) |
| 822 | { |
| 823 | if (regnum == -1) |
| 824 | for (regnum = 0; |
| 825 | regnum < gdbarch_num_regs (get_regcache_arch (regcache)); |
| 826 | regnum++) |
| 827 | inf_ptrace_store_register (regcache, regnum); |
| 828 | else |
| 829 | inf_ptrace_store_register (regcache, regnum); |
| 830 | } |
| 831 | |
| 832 | /* Create a "traditional" ptrace target. REGISTER_U_OFFSET should be |
| 833 | a function returning the offset within the user area where a |
| 834 | particular register is stored. */ |
| 835 | |
| 836 | struct target_ops * |
| 837 | inf_ptrace_trad_target (CORE_ADDR (*register_u_offset) |
| 838 | (struct gdbarch *, int, int)) |
| 839 | { |
| 840 | struct target_ops *t = inf_ptrace_target(); |
| 841 | |
| 842 | gdb_assert (register_u_offset); |
| 843 | inf_ptrace_register_u_offset = register_u_offset; |
| 844 | t->to_fetch_registers = inf_ptrace_fetch_registers; |
| 845 | t->to_store_registers = inf_ptrace_store_registers; |
| 846 | |
| 847 | return t; |
| 848 | } |