| 1 | /* Low level interface to ptrace, for GDB when running under Unix. |
| 2 | Copyright (C) 1986-2019 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include "defs.h" |
| 20 | #include "frame.h" |
| 21 | #include "inferior.h" |
| 22 | #include "command.h" |
| 23 | #include "serial.h" |
| 24 | #include "terminal.h" |
| 25 | #include "target.h" |
| 26 | #include "gdbthread.h" |
| 27 | #include "observable.h" |
| 28 | #include <signal.h> |
| 29 | #include <fcntl.h> |
| 30 | #include "gdb_select.h" |
| 31 | |
| 32 | #include "inflow.h" |
| 33 | #include "gdbcmd.h" |
| 34 | #ifdef HAVE_TERMIOS_H |
| 35 | #include <termios.h> |
| 36 | #endif |
| 37 | #include "common/job-control.h" |
| 38 | |
| 39 | #ifdef HAVE_SYS_IOCTL_H |
| 40 | #include <sys/ioctl.h> |
| 41 | #endif |
| 42 | |
| 43 | #ifndef O_NOCTTY |
| 44 | #define O_NOCTTY 0 |
| 45 | #endif |
| 46 | |
| 47 | static void pass_signal (int); |
| 48 | |
| 49 | static void child_terminal_ours_1 (target_terminal_state); |
| 50 | \f |
| 51 | /* Record terminal status separately for debugger and inferior. */ |
| 52 | |
| 53 | static struct serial *stdin_serial; |
| 54 | |
| 55 | /* Terminal related info we need to keep track of. Each inferior |
| 56 | holds an instance of this structure --- we save it whenever the |
| 57 | corresponding inferior stops, and restore it to the terminal when |
| 58 | the inferior is resumed in the foreground. */ |
| 59 | struct terminal_info |
| 60 | { |
| 61 | /* The name of the tty (from the `tty' command) that we gave to the |
| 62 | inferior when it was started. */ |
| 63 | char *run_terminal; |
| 64 | |
| 65 | /* TTY state. We save it whenever the inferior stops, and restore |
| 66 | it when it resumes in the foreground. */ |
| 67 | serial_ttystate ttystate; |
| 68 | |
| 69 | #ifdef HAVE_TERMIOS_H |
| 70 | /* The terminal's foreground process group. Saved whenever the |
| 71 | inferior stops. This is the pgrp displayed by "info terminal". |
| 72 | Note that this may be not the inferior's actual process group, |
| 73 | since each inferior that we spawn has its own process group, and |
| 74 | only one can be in the foreground at a time. When the inferior |
| 75 | resumes, if we can determine the inferior's actual pgrp, then we |
| 76 | make that the foreground pgrp instead of what was saved here. |
| 77 | While it's a bit arbitrary which inferior's pgrp ends up in the |
| 78 | foreground when we resume several inferiors, this at least makes |
| 79 | 'resume inf1+inf2' + 'stop all' + 'resume inf2' end up with |
| 80 | inf2's pgrp in the foreground instead of inf1's (which would be |
| 81 | problematic since it would be left stopped: Ctrl-C wouldn't work, |
| 82 | for example). */ |
| 83 | pid_t process_group; |
| 84 | #endif |
| 85 | |
| 86 | /* fcntl flags. Saved and restored just like ttystate. */ |
| 87 | int tflags; |
| 88 | }; |
| 89 | |
| 90 | /* Our own tty state, which we restore every time we need to deal with |
| 91 | the terminal. This is set once, when GDB first starts, and then |
| 92 | whenever we enter/leave TUI mode (gdb_save_tty_state). The |
| 93 | settings of flags which readline saves and restores are |
| 94 | unimportant. */ |
| 95 | static struct terminal_info our_terminal_info; |
| 96 | |
| 97 | /* Snapshot of the initial tty state taken during initialization of |
| 98 | GDB, before readline/ncurses have had a chance to change it. This |
| 99 | is used as the initial tty state given to each new spawned |
| 100 | inferior. Unlike our_terminal_info, this is only ever set |
| 101 | once. */ |
| 102 | static serial_ttystate initial_gdb_ttystate; |
| 103 | |
| 104 | static struct terminal_info *get_inflow_inferior_data (struct inferior *); |
| 105 | |
| 106 | /* RAII class used to ignore SIGTTOU in a scope. */ |
| 107 | |
| 108 | class scoped_ignore_sigttou |
| 109 | { |
| 110 | public: |
| 111 | scoped_ignore_sigttou () |
| 112 | { |
| 113 | #ifdef SIGTTOU |
| 114 | if (job_control) |
| 115 | m_osigttou = signal (SIGTTOU, SIG_IGN); |
| 116 | #endif |
| 117 | } |
| 118 | |
| 119 | ~scoped_ignore_sigttou () |
| 120 | { |
| 121 | #ifdef SIGTTOU |
| 122 | if (job_control) |
| 123 | signal (SIGTTOU, m_osigttou); |
| 124 | #endif |
| 125 | } |
| 126 | |
| 127 | DISABLE_COPY_AND_ASSIGN (scoped_ignore_sigttou); |
| 128 | |
| 129 | private: |
| 130 | #ifdef SIGTTOU |
| 131 | sighandler_t m_osigttou = NULL; |
| 132 | #endif |
| 133 | }; |
| 134 | |
| 135 | /* While the inferior is running, we want SIGINT and SIGQUIT to go to the |
| 136 | inferior only. If we have job control, that takes care of it. If not, |
| 137 | we save our handlers in these two variables and set SIGINT and SIGQUIT |
| 138 | to SIG_IGN. */ |
| 139 | |
| 140 | static sighandler_t sigint_ours; |
| 141 | #ifdef SIGQUIT |
| 142 | static sighandler_t sigquit_ours; |
| 143 | #endif |
| 144 | |
| 145 | /* The name of the tty (from the `tty' command) that we're giving to |
| 146 | the inferior when starting it up. This is only (and should only |
| 147 | be) used as a transient global by new_tty_prefork, |
| 148 | create_tty_session, new_tty and new_tty_postfork, all called from |
| 149 | fork_inferior, while forking a new child. */ |
| 150 | static const char *inferior_thisrun_terminal; |
| 151 | |
| 152 | /* Track who owns GDB's terminal (is it GDB or some inferior?). While |
| 153 | target_terminal::is_ours() etc. tracks the core's intention and is |
| 154 | independent of the target backend, this tracks the actual state of |
| 155 | GDB's own tty. So for example, |
| 156 | |
| 157 | (target_terminal::is_inferior () && gdb_tty_state == terminal_is_ours) |
| 158 | |
| 159 | is true when the (native) inferior is not sharing a terminal with |
| 160 | GDB (e.g., because we attached to an inferior that is running on a |
| 161 | different terminal). */ |
| 162 | static target_terminal_state gdb_tty_state = target_terminal_state::is_ours; |
| 163 | |
| 164 | /* See terminal.h. */ |
| 165 | |
| 166 | void |
| 167 | set_initial_gdb_ttystate (void) |
| 168 | { |
| 169 | /* Note we can't do any of this in _initialize_inflow because at |
| 170 | that point stdin_serial has not been created yet. */ |
| 171 | |
| 172 | initial_gdb_ttystate = serial_get_tty_state (stdin_serial); |
| 173 | |
| 174 | if (initial_gdb_ttystate != NULL) |
| 175 | { |
| 176 | our_terminal_info.ttystate |
| 177 | = serial_copy_tty_state (stdin_serial, initial_gdb_ttystate); |
| 178 | #ifdef F_GETFL |
| 179 | our_terminal_info.tflags = fcntl (0, F_GETFL, 0); |
| 180 | #endif |
| 181 | #ifdef HAVE_TERMIOS_H |
| 182 | our_terminal_info.process_group = tcgetpgrp (0); |
| 183 | #endif |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | /* Does GDB have a terminal (on stdin)? */ |
| 188 | |
| 189 | static int |
| 190 | gdb_has_a_terminal (void) |
| 191 | { |
| 192 | return initial_gdb_ttystate != NULL; |
| 193 | } |
| 194 | |
| 195 | /* Macro for printing errors from ioctl operations */ |
| 196 | |
| 197 | #define OOPSY(what) \ |
| 198 | if (result == -1) \ |
| 199 | fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \ |
| 200 | what, safe_strerror (errno)) |
| 201 | |
| 202 | /* Initialize the terminal settings we record for the inferior, |
| 203 | before we actually run the inferior. */ |
| 204 | |
| 205 | void |
| 206 | child_terminal_init (struct target_ops *self) |
| 207 | { |
| 208 | if (!gdb_has_a_terminal ()) |
| 209 | return; |
| 210 | |
| 211 | inferior *inf = current_inferior (); |
| 212 | terminal_info *tinfo = get_inflow_inferior_data (inf); |
| 213 | |
| 214 | #ifdef HAVE_TERMIOS_H |
| 215 | /* A child we spawn should be a process group leader (PGID==PID) at |
| 216 | this point, though that may not be true if we're attaching to an |
| 217 | existing process. */ |
| 218 | tinfo->process_group = inf->pid; |
| 219 | #endif |
| 220 | |
| 221 | xfree (tinfo->ttystate); |
| 222 | tinfo->ttystate = serial_copy_tty_state (stdin_serial, initial_gdb_ttystate); |
| 223 | } |
| 224 | |
| 225 | /* Save the terminal settings again. This is necessary for the TUI |
| 226 | when it switches to TUI or non-TUI mode; curses changes the terminal |
| 227 | and gdb must be able to restore it correctly. */ |
| 228 | |
| 229 | void |
| 230 | gdb_save_tty_state (void) |
| 231 | { |
| 232 | if (gdb_has_a_terminal ()) |
| 233 | { |
| 234 | xfree (our_terminal_info.ttystate); |
| 235 | our_terminal_info.ttystate = serial_get_tty_state (stdin_serial); |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | /* Try to determine whether TTY is GDB's input terminal. Returns |
| 240 | TRIBOOL_UNKNOWN if we can't tell. */ |
| 241 | |
| 242 | static tribool |
| 243 | is_gdb_terminal (const char *tty) |
| 244 | { |
| 245 | struct stat gdb_tty; |
| 246 | struct stat other_tty; |
| 247 | int res; |
| 248 | |
| 249 | res = stat (tty, &other_tty); |
| 250 | if (res == -1) |
| 251 | return TRIBOOL_UNKNOWN; |
| 252 | |
| 253 | res = fstat (STDIN_FILENO, &gdb_tty); |
| 254 | if (res == -1) |
| 255 | return TRIBOOL_UNKNOWN; |
| 256 | |
| 257 | return ((gdb_tty.st_dev == other_tty.st_dev |
| 258 | && gdb_tty.st_ino == other_tty.st_ino) |
| 259 | ? TRIBOOL_TRUE |
| 260 | : TRIBOOL_FALSE); |
| 261 | } |
| 262 | |
| 263 | /* Helper for sharing_input_terminal. Try to determine whether |
| 264 | inferior INF is using the same TTY for input as GDB is. Returns |
| 265 | TRIBOOL_UNKNOWN if we can't tell. */ |
| 266 | |
| 267 | static tribool |
| 268 | sharing_input_terminal_1 (inferior *inf) |
| 269 | { |
| 270 | /* Using host-dependent code here is fine, because the |
| 271 | child_terminal_foo functions are meant to be used by child/native |
| 272 | targets. */ |
| 273 | #if defined (__linux__) || defined (__sun__) |
| 274 | char buf[100]; |
| 275 | |
| 276 | xsnprintf (buf, sizeof (buf), "/proc/%d/fd/0", inf->pid); |
| 277 | return is_gdb_terminal (buf); |
| 278 | #else |
| 279 | return TRIBOOL_UNKNOWN; |
| 280 | #endif |
| 281 | } |
| 282 | |
| 283 | /* Return true if the inferior is using the same TTY for input as GDB |
| 284 | is. If this is true, then we save/restore terminal flags/state. |
| 285 | |
| 286 | This is necessary because if inf->attach_flag is set, we don't |
| 287 | offhand know whether we are sharing a terminal with the inferior or |
| 288 | not. Attaching a process without a terminal is one case where we |
| 289 | do not; attaching a process which we ran from the same shell as GDB |
| 290 | via `&' is one case where we do. |
| 291 | |
| 292 | If we can't determine, we assume the TTY is being shared. This |
| 293 | works OK if you're only debugging one inferior. However, if you're |
| 294 | debugging more than one inferior, and e.g., one is spawned by GDB |
| 295 | with "run" (sharing terminal with GDB), and another is attached to |
| 296 | (and running on a different terminal, as is most common), then it |
| 297 | matters, because we can only restore the terminal settings of one |
| 298 | of the inferiors, and in that scenario, we want to restore the |
| 299 | settings of the "run"'ed inferior. |
| 300 | |
| 301 | Note, this is not the same as determining whether GDB and the |
| 302 | inferior are in the same session / connected to the same |
| 303 | controlling tty. An inferior (fork child) may call setsid, |
| 304 | disconnecting itself from the ctty, while still leaving |
| 305 | stdin/stdout/stderr associated with the original terminal. If |
| 306 | we're debugging that process, we should also save/restore terminal |
| 307 | settings. */ |
| 308 | |
| 309 | static bool |
| 310 | sharing_input_terminal (inferior *inf) |
| 311 | { |
| 312 | terminal_info *tinfo = get_inflow_inferior_data (inf); |
| 313 | |
| 314 | tribool res = sharing_input_terminal_1 (inf); |
| 315 | |
| 316 | if (res == TRIBOOL_UNKNOWN) |
| 317 | { |
| 318 | /* As fallback, if we can't determine by stat'ing the inferior's |
| 319 | tty directly (because it's not supported on this host) and |
| 320 | the child was spawned, check whether run_terminal is our tty. |
| 321 | This isn't ideal, since this is checking the child's |
| 322 | controlling terminal, not the input terminal (which may have |
| 323 | been redirected), but is still better than nothing. A false |
| 324 | positive ("set inferior-tty" points to our terminal, but I/O |
| 325 | was redirected) is much more likely than a false negative |
| 326 | ("set inferior-tty" points to some other terminal, and then |
| 327 | output was redirected to our terminal), and with a false |
| 328 | positive we just end up trying to save/restore terminal |
| 329 | settings when we didn't need to or we actually can't. */ |
| 330 | if (tinfo->run_terminal != NULL) |
| 331 | res = is_gdb_terminal (tinfo->run_terminal); |
| 332 | |
| 333 | /* If we still can't determine, assume yes. */ |
| 334 | if (res == TRIBOOL_UNKNOWN) |
| 335 | return true; |
| 336 | } |
| 337 | |
| 338 | return res == TRIBOOL_TRUE; |
| 339 | } |
| 340 | |
| 341 | /* Put the inferior's terminal settings into effect. This is |
| 342 | preparation for starting or resuming the inferior. */ |
| 343 | |
| 344 | void |
| 345 | child_terminal_inferior (struct target_ops *self) |
| 346 | { |
| 347 | /* If we resume more than one inferior in the foreground on GDB's |
| 348 | terminal, then the first inferior's terminal settings "win". |
| 349 | Note that every child process is put in its own process group, so |
| 350 | the first process that ends up resumed ends up determining which |
| 351 | process group the kernel forwards Ctrl-C/Ctrl-Z (SIGINT/SIGTTOU) |
| 352 | to. */ |
| 353 | if (gdb_tty_state == target_terminal_state::is_inferior) |
| 354 | return; |
| 355 | |
| 356 | inferior *inf = current_inferior (); |
| 357 | terminal_info *tinfo = get_inflow_inferior_data (inf); |
| 358 | |
| 359 | if (gdb_has_a_terminal () |
| 360 | && tinfo->ttystate != NULL |
| 361 | && sharing_input_terminal (inf)) |
| 362 | { |
| 363 | int result; |
| 364 | |
| 365 | /* Ignore SIGTTOU since it will happen when we try to set the |
| 366 | terminal's state (if gdb_tty_state is currently |
| 367 | ours_for_output). */ |
| 368 | scoped_ignore_sigttou ignore_sigttou; |
| 369 | |
| 370 | #ifdef F_GETFL |
| 371 | result = fcntl (0, F_SETFL, tinfo->tflags); |
| 372 | OOPSY ("fcntl F_SETFL"); |
| 373 | #endif |
| 374 | |
| 375 | result = serial_set_tty_state (stdin_serial, tinfo->ttystate); |
| 376 | OOPSY ("setting tty state"); |
| 377 | |
| 378 | if (!job_control) |
| 379 | { |
| 380 | sigint_ours = signal (SIGINT, SIG_IGN); |
| 381 | #ifdef SIGQUIT |
| 382 | sigquit_ours = signal (SIGQUIT, SIG_IGN); |
| 383 | #endif |
| 384 | } |
| 385 | |
| 386 | if (job_control) |
| 387 | { |
| 388 | #ifdef HAVE_TERMIOS_H |
| 389 | /* If we can't tell the inferior's actual process group, |
| 390 | then restore whatever was the foreground pgrp the last |
| 391 | time the inferior was running. See also comments |
| 392 | describing terminal_state::process_group. */ |
| 393 | #ifdef HAVE_GETPGID |
| 394 | result = tcsetpgrp (0, getpgid (inf->pid)); |
| 395 | #else |
| 396 | result = tcsetpgrp (0, tinfo->process_group); |
| 397 | #endif |
| 398 | if (result == -1) |
| 399 | { |
| 400 | #if 0 |
| 401 | /* This fails if either GDB has no controlling terminal, |
| 402 | e.g., running under 'setsid(1)', or if the inferior |
| 403 | is not attached to GDB's controlling terminal. E.g., |
| 404 | if it called setsid to create a new session or used |
| 405 | the TIOCNOTTY ioctl, or simply if we've attached to a |
| 406 | process running on another terminal and we couldn't |
| 407 | tell whether it was sharing GDB's terminal (and so |
| 408 | assumed yes). */ |
| 409 | fprintf_unfiltered |
| 410 | (gdb_stderr, |
| 411 | "[tcsetpgrp failed in child_terminal_inferior: %s]\n", |
| 412 | safe_strerror (errno)); |
| 413 | #endif |
| 414 | } |
| 415 | #endif |
| 416 | } |
| 417 | |
| 418 | gdb_tty_state = target_terminal_state::is_inferior; |
| 419 | } |
| 420 | } |
| 421 | |
| 422 | /* Put some of our terminal settings into effect, |
| 423 | enough to get proper results from our output, |
| 424 | but do not change into or out of RAW mode |
| 425 | so that no input is discarded. |
| 426 | |
| 427 | After doing this, either terminal_ours or terminal_inferior |
| 428 | should be called to get back to a normal state of affairs. |
| 429 | |
| 430 | N.B. The implementation is (currently) no different than |
| 431 | child_terminal_ours. See child_terminal_ours_1. */ |
| 432 | |
| 433 | void |
| 434 | child_terminal_ours_for_output (struct target_ops *self) |
| 435 | { |
| 436 | child_terminal_ours_1 (target_terminal_state::is_ours_for_output); |
| 437 | } |
| 438 | |
| 439 | /* Put our terminal settings into effect. |
| 440 | First record the inferior's terminal settings |
| 441 | so they can be restored properly later. |
| 442 | |
| 443 | N.B. Targets that want to use this with async support must build that |
| 444 | support on top of this (e.g., the caller still needs to add stdin to the |
| 445 | event loop). E.g., see linux_nat_terminal_ours. */ |
| 446 | |
| 447 | void |
| 448 | child_terminal_ours (struct target_ops *self) |
| 449 | { |
| 450 | child_terminal_ours_1 (target_terminal_state::is_ours); |
| 451 | } |
| 452 | |
| 453 | /* Save the current terminal settings in the inferior's terminal_info |
| 454 | cache. */ |
| 455 | |
| 456 | void |
| 457 | child_terminal_save_inferior (struct target_ops *self) |
| 458 | { |
| 459 | /* Avoid attempting all the ioctl's when running in batch. */ |
| 460 | if (!gdb_has_a_terminal ()) |
| 461 | return; |
| 462 | |
| 463 | inferior *inf = current_inferior (); |
| 464 | terminal_info *tinfo = get_inflow_inferior_data (inf); |
| 465 | |
| 466 | /* No need to save/restore if the inferior is not sharing GDB's |
| 467 | tty. */ |
| 468 | if (!sharing_input_terminal (inf)) |
| 469 | return; |
| 470 | |
| 471 | xfree (tinfo->ttystate); |
| 472 | tinfo->ttystate = serial_get_tty_state (stdin_serial); |
| 473 | |
| 474 | #ifdef HAVE_TERMIOS_H |
| 475 | tinfo->process_group = tcgetpgrp (0); |
| 476 | #endif |
| 477 | |
| 478 | #ifdef F_GETFL |
| 479 | tinfo->tflags = fcntl (0, F_GETFL, 0); |
| 480 | #endif |
| 481 | } |
| 482 | |
| 483 | /* Switch terminal state to DESIRED_STATE, either is_ours, or |
| 484 | is_ours_for_output. */ |
| 485 | |
| 486 | static void |
| 487 | child_terminal_ours_1 (target_terminal_state desired_state) |
| 488 | { |
| 489 | gdb_assert (desired_state != target_terminal_state::is_inferior); |
| 490 | |
| 491 | /* Avoid attempting all the ioctl's when running in batch. */ |
| 492 | if (!gdb_has_a_terminal ()) |
| 493 | return; |
| 494 | |
| 495 | if (gdb_tty_state != desired_state) |
| 496 | { |
| 497 | int result ATTRIBUTE_UNUSED; |
| 498 | |
| 499 | /* Ignore SIGTTOU since it will happen when we try to set the |
| 500 | terminal's pgrp. */ |
| 501 | scoped_ignore_sigttou ignore_sigttou; |
| 502 | |
| 503 | /* Set tty state to our_ttystate. */ |
| 504 | serial_set_tty_state (stdin_serial, our_terminal_info.ttystate); |
| 505 | |
| 506 | /* If we only want output, then leave the inferior's pgrp in the |
| 507 | foreground, so that Ctrl-C/Ctrl-Z reach the inferior |
| 508 | directly. */ |
| 509 | if (job_control && desired_state == target_terminal_state::is_ours) |
| 510 | { |
| 511 | #ifdef HAVE_TERMIOS_H |
| 512 | result = tcsetpgrp (0, our_terminal_info.process_group); |
| 513 | #if 0 |
| 514 | /* This fails on Ultrix with EINVAL if you run the testsuite |
| 515 | in the background with nohup, and then log out. GDB never |
| 516 | used to check for an error here, so perhaps there are other |
| 517 | such situations as well. */ |
| 518 | if (result == -1) |
| 519 | fprintf_unfiltered (gdb_stderr, |
| 520 | "[tcsetpgrp failed in child_terminal_ours: %s]\n", |
| 521 | safe_strerror (errno)); |
| 522 | #endif |
| 523 | #endif /* termios */ |
| 524 | } |
| 525 | |
| 526 | if (!job_control && desired_state == target_terminal_state::is_ours) |
| 527 | { |
| 528 | signal (SIGINT, sigint_ours); |
| 529 | #ifdef SIGQUIT |
| 530 | signal (SIGQUIT, sigquit_ours); |
| 531 | #endif |
| 532 | } |
| 533 | |
| 534 | #ifdef F_GETFL |
| 535 | result = fcntl (0, F_SETFL, our_terminal_info.tflags); |
| 536 | #endif |
| 537 | |
| 538 | gdb_tty_state = desired_state; |
| 539 | } |
| 540 | } |
| 541 | |
| 542 | /* Interrupt the inferior. Implementation of target_interrupt for |
| 543 | child/native targets. */ |
| 544 | |
| 545 | void |
| 546 | child_interrupt (struct target_ops *self) |
| 547 | { |
| 548 | /* Interrupt the first inferior that has a resumed thread. */ |
| 549 | thread_info *resumed = NULL; |
| 550 | for (thread_info *thr : all_non_exited_threads ()) |
| 551 | { |
| 552 | if (thr->executing) |
| 553 | { |
| 554 | resumed = thr; |
| 555 | break; |
| 556 | } |
| 557 | if (thr->suspend.waitstatus_pending_p) |
| 558 | resumed = thr; |
| 559 | } |
| 560 | |
| 561 | if (resumed != NULL) |
| 562 | { |
| 563 | /* Note that unlike pressing Ctrl-C on the controlling terminal, |
| 564 | here we only interrupt one process, not the whole process |
| 565 | group. This is because interrupting a process group (with |
| 566 | either Ctrl-C or with kill(3) with negative PID) sends a |
| 567 | SIGINT to each process in the process group, and we may not |
| 568 | be debugging all processes in the process group. */ |
| 569 | #ifndef _WIN32 |
| 570 | kill (resumed->inf->pid, SIGINT); |
| 571 | #endif |
| 572 | } |
| 573 | } |
| 574 | |
| 575 | /* Pass a Ctrl-C to the inferior as-if a Ctrl-C was pressed while the |
| 576 | inferior was in the foreground. Implementation of |
| 577 | target_pass_ctrlc for child/native targets. */ |
| 578 | |
| 579 | void |
| 580 | child_pass_ctrlc (struct target_ops *self) |
| 581 | { |
| 582 | gdb_assert (!target_terminal::is_ours ()); |
| 583 | |
| 584 | #ifdef HAVE_TERMIOS_H |
| 585 | if (job_control) |
| 586 | { |
| 587 | pid_t term_pgrp = tcgetpgrp (0); |
| 588 | |
| 589 | /* If there's any inferior sharing our terminal, pass the SIGINT |
| 590 | to the terminal's foreground process group. This acts just |
| 591 | like the user typed a ^C on the terminal while the inferior |
| 592 | was in the foreground. Note that using a negative process |
| 593 | number in kill() is a System V-ism. The proper BSD interface |
| 594 | is killpg(). However, all modern BSDs support the System V |
| 595 | interface too. */ |
| 596 | |
| 597 | if (term_pgrp != -1 && term_pgrp != our_terminal_info.process_group) |
| 598 | { |
| 599 | kill (-term_pgrp, SIGINT); |
| 600 | return; |
| 601 | } |
| 602 | } |
| 603 | #endif |
| 604 | |
| 605 | /* Otherwise, pass the Ctrl-C to the first inferior that was resumed |
| 606 | in the foreground. */ |
| 607 | for (inferior *inf : all_inferiors ()) |
| 608 | { |
| 609 | if (inf->terminal_state != target_terminal_state::is_ours) |
| 610 | { |
| 611 | gdb_assert (inf->pid != 0); |
| 612 | |
| 613 | #ifndef _WIN32 |
| 614 | kill (inf->pid, SIGINT); |
| 615 | #endif |
| 616 | return; |
| 617 | } |
| 618 | } |
| 619 | |
| 620 | /* If no inferior was resumed in the foreground, then how did the |
| 621 | !is_ours assert above pass? */ |
| 622 | gdb_assert_not_reached ("no inferior resumed in the fg found"); |
| 623 | } |
| 624 | |
| 625 | /* Per-inferior data key. */ |
| 626 | static const struct inferior_data *inflow_inferior_data; |
| 627 | |
| 628 | static void |
| 629 | inflow_inferior_data_cleanup (struct inferior *inf, void *arg) |
| 630 | { |
| 631 | struct terminal_info *info = (struct terminal_info *) arg; |
| 632 | |
| 633 | xfree (info->run_terminal); |
| 634 | xfree (info->ttystate); |
| 635 | xfree (info); |
| 636 | } |
| 637 | |
| 638 | /* Get the current svr4 data. If none is found yet, add it now. This |
| 639 | function always returns a valid object. */ |
| 640 | |
| 641 | static struct terminal_info * |
| 642 | get_inflow_inferior_data (struct inferior *inf) |
| 643 | { |
| 644 | struct terminal_info *info; |
| 645 | |
| 646 | info = (struct terminal_info *) inferior_data (inf, inflow_inferior_data); |
| 647 | if (info == NULL) |
| 648 | { |
| 649 | info = XCNEW (struct terminal_info); |
| 650 | set_inferior_data (inf, inflow_inferior_data, info); |
| 651 | } |
| 652 | |
| 653 | return info; |
| 654 | } |
| 655 | |
| 656 | /* This is a "inferior_exit" observer. Releases the TERMINAL_INFO member |
| 657 | of the inferior structure. This field is private to inflow.c, and |
| 658 | its type is opaque to the rest of GDB. PID is the target pid of |
| 659 | the inferior that is about to be removed from the inferior |
| 660 | list. */ |
| 661 | |
| 662 | static void |
| 663 | inflow_inferior_exit (struct inferior *inf) |
| 664 | { |
| 665 | struct terminal_info *info; |
| 666 | |
| 667 | inf->terminal_state = target_terminal_state::is_ours; |
| 668 | |
| 669 | info = (struct terminal_info *) inferior_data (inf, inflow_inferior_data); |
| 670 | if (info != NULL) |
| 671 | { |
| 672 | xfree (info->run_terminal); |
| 673 | xfree (info->ttystate); |
| 674 | xfree (info); |
| 675 | set_inferior_data (inf, inflow_inferior_data, NULL); |
| 676 | } |
| 677 | } |
| 678 | |
| 679 | void |
| 680 | copy_terminal_info (struct inferior *to, struct inferior *from) |
| 681 | { |
| 682 | struct terminal_info *tinfo_to, *tinfo_from; |
| 683 | |
| 684 | tinfo_to = get_inflow_inferior_data (to); |
| 685 | tinfo_from = get_inflow_inferior_data (from); |
| 686 | |
| 687 | xfree (tinfo_to->run_terminal); |
| 688 | xfree (tinfo_to->ttystate); |
| 689 | |
| 690 | *tinfo_to = *tinfo_from; |
| 691 | |
| 692 | if (tinfo_from->run_terminal) |
| 693 | tinfo_to->run_terminal |
| 694 | = xstrdup (tinfo_from->run_terminal); |
| 695 | |
| 696 | if (tinfo_from->ttystate) |
| 697 | tinfo_to->ttystate |
| 698 | = serial_copy_tty_state (stdin_serial, tinfo_from->ttystate); |
| 699 | |
| 700 | to->terminal_state = from->terminal_state; |
| 701 | } |
| 702 | |
| 703 | /* See terminal.h. */ |
| 704 | |
| 705 | void |
| 706 | swap_terminal_info (inferior *a, inferior *b) |
| 707 | { |
| 708 | terminal_info *info_a |
| 709 | = (terminal_info *) inferior_data (a, inflow_inferior_data); |
| 710 | terminal_info *info_b |
| 711 | = (terminal_info *) inferior_data (a, inflow_inferior_data); |
| 712 | |
| 713 | set_inferior_data (a, inflow_inferior_data, info_b); |
| 714 | set_inferior_data (b, inflow_inferior_data, info_a); |
| 715 | |
| 716 | std::swap (a->terminal_state, b->terminal_state); |
| 717 | } |
| 718 | |
| 719 | void |
| 720 | info_terminal_command (const char *arg, int from_tty) |
| 721 | { |
| 722 | target_terminal::info (arg, from_tty); |
| 723 | } |
| 724 | |
| 725 | void |
| 726 | child_terminal_info (struct target_ops *self, const char *args, int from_tty) |
| 727 | { |
| 728 | struct inferior *inf; |
| 729 | struct terminal_info *tinfo; |
| 730 | |
| 731 | if (!gdb_has_a_terminal ()) |
| 732 | { |
| 733 | printf_filtered (_("This GDB does not control a terminal.\n")); |
| 734 | return; |
| 735 | } |
| 736 | |
| 737 | if (inferior_ptid == null_ptid) |
| 738 | return; |
| 739 | |
| 740 | inf = current_inferior (); |
| 741 | tinfo = get_inflow_inferior_data (inf); |
| 742 | |
| 743 | printf_filtered (_("Inferior's terminal status " |
| 744 | "(currently saved by GDB):\n")); |
| 745 | |
| 746 | /* First the fcntl flags. */ |
| 747 | { |
| 748 | int flags; |
| 749 | |
| 750 | flags = tinfo->tflags; |
| 751 | |
| 752 | printf_filtered ("File descriptor flags = "); |
| 753 | |
| 754 | #ifndef O_ACCMODE |
| 755 | #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR) |
| 756 | #endif |
| 757 | /* (O_ACCMODE) parens are to avoid Ultrix header file bug. */ |
| 758 | switch (flags & (O_ACCMODE)) |
| 759 | { |
| 760 | case O_RDONLY: |
| 761 | printf_filtered ("O_RDONLY"); |
| 762 | break; |
| 763 | case O_WRONLY: |
| 764 | printf_filtered ("O_WRONLY"); |
| 765 | break; |
| 766 | case O_RDWR: |
| 767 | printf_filtered ("O_RDWR"); |
| 768 | break; |
| 769 | } |
| 770 | flags &= ~(O_ACCMODE); |
| 771 | |
| 772 | #ifdef O_NONBLOCK |
| 773 | if (flags & O_NONBLOCK) |
| 774 | printf_filtered (" | O_NONBLOCK"); |
| 775 | flags &= ~O_NONBLOCK; |
| 776 | #endif |
| 777 | |
| 778 | #if defined (O_NDELAY) |
| 779 | /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will |
| 780 | print it as O_NONBLOCK, which is good cause that is what POSIX |
| 781 | has, and the flag will already be cleared by the time we get here. */ |
| 782 | if (flags & O_NDELAY) |
| 783 | printf_filtered (" | O_NDELAY"); |
| 784 | flags &= ~O_NDELAY; |
| 785 | #endif |
| 786 | |
| 787 | if (flags & O_APPEND) |
| 788 | printf_filtered (" | O_APPEND"); |
| 789 | flags &= ~O_APPEND; |
| 790 | |
| 791 | #if defined (O_BINARY) |
| 792 | if (flags & O_BINARY) |
| 793 | printf_filtered (" | O_BINARY"); |
| 794 | flags &= ~O_BINARY; |
| 795 | #endif |
| 796 | |
| 797 | if (flags) |
| 798 | printf_filtered (" | 0x%x", flags); |
| 799 | printf_filtered ("\n"); |
| 800 | } |
| 801 | |
| 802 | #ifdef HAVE_TERMIOS_H |
| 803 | printf_filtered ("Process group = %d\n", (int) tinfo->process_group); |
| 804 | #endif |
| 805 | |
| 806 | serial_print_tty_state (stdin_serial, tinfo->ttystate, gdb_stdout); |
| 807 | } |
| 808 | \f |
| 809 | /* NEW_TTY_PREFORK is called before forking a new child process, |
| 810 | so we can record the state of ttys in the child to be formed. |
| 811 | TTYNAME is null if we are to share the terminal with gdb; |
| 812 | or points to a string containing the name of the desired tty. |
| 813 | |
| 814 | NEW_TTY is called in new child processes under Unix, which will |
| 815 | become debugger target processes. This actually switches to |
| 816 | the terminal specified in the NEW_TTY_PREFORK call. */ |
| 817 | |
| 818 | void |
| 819 | new_tty_prefork (const char *ttyname) |
| 820 | { |
| 821 | /* Save the name for later, for determining whether we and the child |
| 822 | are sharing a tty. */ |
| 823 | inferior_thisrun_terminal = ttyname; |
| 824 | } |
| 825 | |
| 826 | #if !defined(__GO32__) && !defined(_WIN32) |
| 827 | /* If RESULT, assumed to be the return value from a system call, is |
| 828 | negative, print the error message indicated by errno and exit. |
| 829 | MSG should identify the operation that failed. */ |
| 830 | static void |
| 831 | check_syscall (const char *msg, int result) |
| 832 | { |
| 833 | if (result < 0) |
| 834 | { |
| 835 | print_sys_errmsg (msg, errno); |
| 836 | _exit (1); |
| 837 | } |
| 838 | } |
| 839 | #endif |
| 840 | |
| 841 | void |
| 842 | new_tty (void) |
| 843 | { |
| 844 | if (inferior_thisrun_terminal == 0) |
| 845 | return; |
| 846 | #if !defined(__GO32__) && !defined(_WIN32) |
| 847 | int tty; |
| 848 | |
| 849 | #ifdef TIOCNOTTY |
| 850 | /* Disconnect the child process from our controlling terminal. On some |
| 851 | systems (SVR4 for example), this may cause a SIGTTOU, so temporarily |
| 852 | ignore SIGTTOU. */ |
| 853 | tty = open ("/dev/tty", O_RDWR); |
| 854 | if (tty > 0) |
| 855 | { |
| 856 | scoped_ignore_sigttou ignore_sigttou; |
| 857 | |
| 858 | ioctl (tty, TIOCNOTTY, 0); |
| 859 | close (tty); |
| 860 | } |
| 861 | #endif |
| 862 | |
| 863 | /* Now open the specified new terminal. */ |
| 864 | tty = open (inferior_thisrun_terminal, O_RDWR | O_NOCTTY); |
| 865 | check_syscall (inferior_thisrun_terminal, tty); |
| 866 | |
| 867 | /* Avoid use of dup2; doesn't exist on all systems. */ |
| 868 | if (tty != 0) |
| 869 | { |
| 870 | close (0); |
| 871 | check_syscall ("dup'ing tty into fd 0", dup (tty)); |
| 872 | } |
| 873 | if (tty != 1) |
| 874 | { |
| 875 | close (1); |
| 876 | check_syscall ("dup'ing tty into fd 1", dup (tty)); |
| 877 | } |
| 878 | if (tty != 2) |
| 879 | { |
| 880 | close (2); |
| 881 | check_syscall ("dup'ing tty into fd 2", dup (tty)); |
| 882 | } |
| 883 | |
| 884 | #ifdef TIOCSCTTY |
| 885 | /* Make tty our new controlling terminal. */ |
| 886 | if (ioctl (tty, TIOCSCTTY, 0) == -1) |
| 887 | /* Mention GDB in warning because it will appear in the inferior's |
| 888 | terminal instead of GDB's. */ |
| 889 | warning (_("GDB: Failed to set controlling terminal: %s"), |
| 890 | safe_strerror (errno)); |
| 891 | #endif |
| 892 | |
| 893 | if (tty > 2) |
| 894 | close (tty); |
| 895 | #endif /* !go32 && !win32 */ |
| 896 | } |
| 897 | |
| 898 | /* NEW_TTY_POSTFORK is called after forking a new child process, and |
| 899 | adding it to the inferior table, to store the TTYNAME being used by |
| 900 | the child, or null if it sharing the terminal with gdb. */ |
| 901 | |
| 902 | void |
| 903 | new_tty_postfork (void) |
| 904 | { |
| 905 | /* Save the name for later, for determining whether we and the child |
| 906 | are sharing a tty. */ |
| 907 | |
| 908 | if (inferior_thisrun_terminal) |
| 909 | { |
| 910 | struct inferior *inf = current_inferior (); |
| 911 | struct terminal_info *tinfo = get_inflow_inferior_data (inf); |
| 912 | |
| 913 | tinfo->run_terminal = xstrdup (inferior_thisrun_terminal); |
| 914 | } |
| 915 | |
| 916 | inferior_thisrun_terminal = NULL; |
| 917 | } |
| 918 | |
| 919 | \f |
| 920 | /* Call set_sigint_trap when you need to pass a signal on to an attached |
| 921 | process when handling SIGINT. */ |
| 922 | |
| 923 | static void |
| 924 | pass_signal (int signo) |
| 925 | { |
| 926 | #ifndef _WIN32 |
| 927 | kill (inferior_ptid.pid (), SIGINT); |
| 928 | #endif |
| 929 | } |
| 930 | |
| 931 | static sighandler_t osig; |
| 932 | static int osig_set; |
| 933 | |
| 934 | void |
| 935 | set_sigint_trap (void) |
| 936 | { |
| 937 | struct inferior *inf = current_inferior (); |
| 938 | struct terminal_info *tinfo = get_inflow_inferior_data (inf); |
| 939 | |
| 940 | if (inf->attach_flag || tinfo->run_terminal) |
| 941 | { |
| 942 | osig = signal (SIGINT, pass_signal); |
| 943 | osig_set = 1; |
| 944 | } |
| 945 | else |
| 946 | osig_set = 0; |
| 947 | } |
| 948 | |
| 949 | void |
| 950 | clear_sigint_trap (void) |
| 951 | { |
| 952 | if (osig_set) |
| 953 | { |
| 954 | signal (SIGINT, osig); |
| 955 | osig_set = 0; |
| 956 | } |
| 957 | } |
| 958 | \f |
| 959 | |
| 960 | /* Create a new session if the inferior will run in a different tty. |
| 961 | A session is UNIX's way of grouping processes that share a controlling |
| 962 | terminal, so a new one is needed if the inferior terminal will be |
| 963 | different from GDB's. |
| 964 | |
| 965 | Returns the session id of the new session, 0 if no session was created |
| 966 | or -1 if an error occurred. */ |
| 967 | pid_t |
| 968 | create_tty_session (void) |
| 969 | { |
| 970 | #ifdef HAVE_SETSID |
| 971 | pid_t ret; |
| 972 | |
| 973 | if (!job_control || inferior_thisrun_terminal == 0) |
| 974 | return 0; |
| 975 | |
| 976 | ret = setsid (); |
| 977 | if (ret == -1) |
| 978 | warning (_("Failed to create new terminal session: setsid: %s"), |
| 979 | safe_strerror (errno)); |
| 980 | |
| 981 | return ret; |
| 982 | #else |
| 983 | return 0; |
| 984 | #endif /* HAVE_SETSID */ |
| 985 | } |
| 986 | |
| 987 | /* Get all the current tty settings (including whether we have a |
| 988 | tty at all!). We can't do this in _initialize_inflow because |
| 989 | serial_fdopen() won't work until the serial_ops_list is |
| 990 | initialized, but we don't want to do it lazily either, so |
| 991 | that we can guarantee stdin_serial is opened if there is |
| 992 | a terminal. */ |
| 993 | void |
| 994 | initialize_stdin_serial (void) |
| 995 | { |
| 996 | stdin_serial = serial_fdopen (0); |
| 997 | } |
| 998 | |
| 999 | void |
| 1000 | _initialize_inflow (void) |
| 1001 | { |
| 1002 | add_info ("terminal", info_terminal_command, |
| 1003 | _("Print inferior's saved terminal status.")); |
| 1004 | |
| 1005 | /* OK, figure out whether we have job control. */ |
| 1006 | have_job_control (); |
| 1007 | |
| 1008 | gdb::observers::inferior_exit.attach (inflow_inferior_exit); |
| 1009 | |
| 1010 | inflow_inferior_data |
| 1011 | = register_inferior_data_with_cleanup (NULL, inflow_inferior_data_cleanup); |
| 1012 | } |