1 /* Low level interface to ptrace, for GDB when running under Unix.
2 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
3 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
28 #include "gdbthread.h"
30 #include "gdb_string.h"
33 #include "gdb_select.h"
37 #ifdef HAVE_SYS_IOCTL_H
38 #include <sys/ioctl.h>
45 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
46 static void handle_sigio (int);
49 extern void _initialize_inflow (void);
51 static void pass_signal (int);
53 static void kill_command (char *, int);
55 static void terminal_ours_1 (int);
57 /* Record terminal status separately for debugger and inferior. */
59 static struct serial
*stdin_serial
;
61 /* TTY state for the inferior. We save it whenever the inferior stops, and
62 restore it when it resumes. */
63 static serial_ttystate inferior_ttystate
;
65 /* Our own tty state, which we restore every time we need to deal with the
66 terminal. We only set it once, when GDB first starts. The settings of
67 flags which readline saves and restores and unimportant. */
68 static serial_ttystate our_ttystate
;
70 /* fcntl flags for us and the inferior. Saved and restored just like
71 {our,inferior}_ttystate. */
72 static int tflags_inferior
;
73 static int tflags_ours
;
75 #ifdef PROCESS_GROUP_TYPE
76 /* Process group for us and the inferior. Saved and restored just like
77 {our,inferior}_ttystate. */
78 PROCESS_GROUP_TYPE our_process_group
;
79 PROCESS_GROUP_TYPE inferior_process_group
;
82 /* While the inferior is running, we want SIGINT and SIGQUIT to go to the
83 inferior only. If we have job control, that takes care of it. If not,
84 we save our handlers in these two variables and set SIGINT and SIGQUIT
87 static void (*sigint_ours
) ();
88 static void (*sigquit_ours
) ();
90 /* The name of the tty (from the `tty' command) that we gave to the inferior
91 when it was last started. */
93 static const char *inferior_thisrun_terminal
;
95 /* Nonzero if our terminal settings are in effect. Zero if the
96 inferior's settings are in effect. Ignored if !gdb_has_a_terminal
101 #ifdef PROCESS_GROUP_TYPE
102 static PROCESS_GROUP_TYPE
105 int process_group
= -1;
107 process_group
= tcgetpgrp (0);
110 process_group
= getpgrp ();
113 ioctl (0, TIOCGPGRP
, &process_group
);
115 return process_group
;
121 yes
, no
, have_not_checked
123 gdb_has_a_terminal_flag
= have_not_checked
;
125 /* Does GDB have a terminal (on stdin)? */
127 gdb_has_a_terminal (void)
129 switch (gdb_has_a_terminal_flag
)
135 case have_not_checked
:
136 /* Get all the current tty settings (including whether we have a
137 tty at all!). Can't do this in _initialize_inflow because
138 serial_fdopen() won't work until the serial_ops_list is
142 tflags_ours
= fcntl (0, F_GETFL
, 0);
145 gdb_has_a_terminal_flag
= no
;
146 if (stdin_serial
!= NULL
)
148 our_ttystate
= serial_get_tty_state (stdin_serial
);
150 if (our_ttystate
!= NULL
)
152 gdb_has_a_terminal_flag
= yes
;
153 our_process_group
= gdb_getpgrp ();
157 return gdb_has_a_terminal_flag
== yes
;
159 /* "Can't happen". */
164 /* Macro for printing errors from ioctl operations */
166 #define OOPSY(what) \
168 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
169 what, safe_strerror (errno))
171 static void terminal_ours_1 (int);
173 /* Initialize the terminal settings we record for the inferior,
174 before we actually run the inferior. */
177 terminal_init_inferior_with_pgrp (int pgrp
)
179 if (gdb_has_a_terminal ())
181 /* We could just as well copy our_ttystate (if we felt like
182 adding a new function serial_copy_tty_state()). */
183 if (inferior_ttystate
)
184 xfree (inferior_ttystate
);
185 inferior_ttystate
= serial_get_tty_state (stdin_serial
);
187 #ifdef PROCESS_GROUP_TYPE
188 inferior_process_group
= pgrp
;
191 /* Make sure that next time we call terminal_inferior (which will be
192 before the program runs, as it needs to be), we install the new
194 terminal_is_ours
= 1;
198 /* Save the terminal settings again. This is necessary for the TUI
199 when it switches to TUI or non-TUI mode; curses changes the terminal
200 and gdb must be able to restore it correctly. */
203 terminal_save_ours (void)
205 if (gdb_has_a_terminal ())
207 /* We could just as well copy our_ttystate (if we felt like adding
208 a new function serial_copy_tty_state). */
210 xfree (our_ttystate
);
211 our_ttystate
= serial_get_tty_state (stdin_serial
);
216 terminal_init_inferior (void)
218 #ifdef PROCESS_GROUP_TYPE
219 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
220 debugging target with a version of target_terminal_init_inferior which
221 passes in the process group to a generic routine which does all the work
222 (and the non-threaded child_terminal_init_inferior can just pass in
223 inferior_ptid to the same routine). */
224 /* We assume INFERIOR_PID is also the child's process group. */
225 terminal_init_inferior_with_pgrp (PIDGET (inferior_ptid
));
226 #endif /* PROCESS_GROUP_TYPE */
229 /* Put the inferior's terminal settings into effect.
230 This is preparation for starting or resuming the inferior. */
233 terminal_inferior (void)
235 if (gdb_has_a_terminal () && terminal_is_ours
236 && inferior_ttystate
!= NULL
237 && inferior_thisrun_terminal
== 0)
242 /* Is there a reason this is being done twice? It happens both
243 places we use F_SETFL, so I'm inclined to think perhaps there
244 is some reason, however perverse. Perhaps not though... */
245 result
= fcntl (0, F_SETFL
, tflags_inferior
);
246 result
= fcntl (0, F_SETFL
, tflags_inferior
);
247 OOPSY ("fcntl F_SETFL");
250 /* Because we were careful to not change in or out of raw mode in
251 terminal_ours, we will not change in our out of raw mode with
252 this call, so we don't flush any input. */
253 result
= serial_set_tty_state (stdin_serial
, inferior_ttystate
);
254 OOPSY ("setting tty state");
258 sigint_ours
= (void (*)()) signal (SIGINT
, SIG_IGN
);
260 sigquit_ours
= (void (*)()) signal (SIGQUIT
, SIG_IGN
);
264 /* If attach_flag is set, we don't know whether we are sharing a
265 terminal with the inferior or not. (attaching a process
266 without a terminal is one case where we do not; attaching a
267 process which we ran from the same shell as GDB via `&' is
268 one case where we do, I think (but perhaps this is not
269 `sharing' in the sense that we need to save and restore tty
270 state)). I don't know if there is any way to tell whether we
271 are sharing a terminal. So what we do is to go through all
272 the saving and restoring of the tty state, but ignore errors
273 setting the process group, which will happen if we are not
274 sharing a terminal). */
279 result
= tcsetpgrp (0, inferior_process_group
);
285 result
= ioctl (0, TIOCSPGRP
, &inferior_process_group
);
292 terminal_is_ours
= 0;
295 /* Put some of our terminal settings into effect,
296 enough to get proper results from our output,
297 but do not change into or out of RAW mode
298 so that no input is discarded.
300 After doing this, either terminal_ours or terminal_inferior
301 should be called to get back to a normal state of affairs. */
304 terminal_ours_for_output (void)
309 /* Put our terminal settings into effect.
310 First record the inferior's terminal settings
311 so they can be restored properly later. */
319 /* output_only is not used, and should not be used unless we introduce
320 separate terminal_is_ours and terminal_is_ours_for_output
324 terminal_ours_1 (int output_only
)
326 /* Checking inferior_thisrun_terminal is necessary so that
327 if GDB is running in the background, it won't block trying
328 to do the ioctl()'s below. Checking gdb_has_a_terminal
329 avoids attempting all the ioctl's when running in batch. */
330 if (inferior_thisrun_terminal
!= 0 || gdb_has_a_terminal () == 0)
333 if (!terminal_is_ours
)
336 /* Ignore this signal since it will happen when we try to set the
338 void (*osigttou
) () = NULL
;
342 terminal_is_ours
= 1;
346 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
349 if (inferior_ttystate
)
350 xfree (inferior_ttystate
);
351 inferior_ttystate
= serial_get_tty_state (stdin_serial
);
354 /* If setpgrp failed in terminal_inferior, this would give us
355 our process group instead of the inferior's. See
356 terminal_inferior for details. */
357 inferior_process_group
= gdb_getpgrp ();
359 /* Here we used to set ICANON in our ttystate, but I believe this
360 was an artifact from before when we used readline. Readline sets
361 the tty state when it needs to.
362 FIXME-maybe: However, query() expects non-raw mode and doesn't
363 use readline. Maybe query should use readline (on the other hand,
364 this only matters for HAVE_SGTTY, not termio or termios, I think). */
366 /* Set tty state to our_ttystate. We don't change in our out of raw
367 mode, to avoid flushing input. We need to do the same thing
368 regardless of output_only, because we don't have separate
369 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
370 though, since readline will deal with raw mode when/if it needs to.
373 serial_noflush_set_tty_state (stdin_serial
, our_ttystate
,
379 result
= tcsetpgrp (0, our_process_group
);
381 /* This fails on Ultrix with EINVAL if you run the testsuite
382 in the background with nohup, and then log out. GDB never
383 used to check for an error here, so perhaps there are other
384 such situations as well. */
386 fprintf_unfiltered (gdb_stderr
, "[tcsetpgrp failed in terminal_ours: %s]\n",
387 safe_strerror (errno
));
392 result
= ioctl (0, TIOCSPGRP
, &our_process_group
);
398 signal (SIGTTOU
, osigttou
);
403 signal (SIGINT
, sigint_ours
);
405 signal (SIGQUIT
, sigquit_ours
);
410 tflags_inferior
= fcntl (0, F_GETFL
, 0);
412 /* Is there a reason this is being done twice? It happens both
413 places we use F_SETFL, so I'm inclined to think perhaps there
414 is some reason, however perverse. Perhaps not though... */
415 result
= fcntl (0, F_SETFL
, tflags_ours
);
416 result
= fcntl (0, F_SETFL
, tflags_ours
);
422 term_info (char *arg
, int from_tty
)
424 target_terminal_info (arg
, from_tty
);
428 child_terminal_info (char *args
, int from_tty
)
430 if (!gdb_has_a_terminal ())
432 printf_filtered (_("This GDB does not control a terminal.\n"));
436 printf_filtered (_("Inferior's terminal status (currently saved by GDB):\n"));
438 /* First the fcntl flags. */
442 flags
= tflags_inferior
;
444 printf_filtered ("File descriptor flags = ");
447 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
449 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
450 switch (flags
& (O_ACCMODE
))
453 printf_filtered ("O_RDONLY");
456 printf_filtered ("O_WRONLY");
459 printf_filtered ("O_RDWR");
462 flags
&= ~(O_ACCMODE
);
465 if (flags
& O_NONBLOCK
)
466 printf_filtered (" | O_NONBLOCK");
467 flags
&= ~O_NONBLOCK
;
470 #if defined (O_NDELAY)
471 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
472 print it as O_NONBLOCK, which is good cause that is what POSIX
473 has, and the flag will already be cleared by the time we get here. */
474 if (flags
& O_NDELAY
)
475 printf_filtered (" | O_NDELAY");
479 if (flags
& O_APPEND
)
480 printf_filtered (" | O_APPEND");
483 #if defined (O_BINARY)
484 if (flags
& O_BINARY
)
485 printf_filtered (" | O_BINARY");
490 printf_filtered (" | 0x%x", flags
);
491 printf_filtered ("\n");
494 #ifdef PROCESS_GROUP_TYPE
495 printf_filtered ("Process group = %d\n",
496 (int) inferior_process_group
);
499 serial_print_tty_state (stdin_serial
, inferior_ttystate
, gdb_stdout
);
502 /* NEW_TTY_PREFORK is called before forking a new child process,
503 so we can record the state of ttys in the child to be formed.
504 TTYNAME is null if we are to share the terminal with gdb;
505 or points to a string containing the name of the desired tty.
507 NEW_TTY is called in new child processes under Unix, which will
508 become debugger target processes. This actually switches to
509 the terminal specified in the NEW_TTY_PREFORK call. */
512 new_tty_prefork (const char *ttyname
)
514 /* Save the name for later, for determining whether we and the child
515 are sharing a tty. */
516 inferior_thisrun_terminal
= ttyname
;
524 if (inferior_thisrun_terminal
== 0)
526 #if !defined(__GO32__) && !defined(_WIN32)
528 /* Disconnect the child process from our controlling terminal. On some
529 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
531 tty
= open ("/dev/tty", O_RDWR
);
536 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
537 ioctl (tty
, TIOCNOTTY
, 0);
539 signal (SIGTTOU
, osigttou
);
543 /* Now open the specified new terminal. */
544 tty
= open (inferior_thisrun_terminal
, O_RDWR
| O_NOCTTY
);
547 print_sys_errmsg (inferior_thisrun_terminal
, errno
);
551 /* Avoid use of dup2; doesn't exist on all systems. */
569 /* Make tty our new controlling terminal. */
570 if (ioctl (tty
, TIOCSCTTY
, 0) == -1)
571 /* Mention GDB in warning because it will appear in the inferior's
572 terminal instead of GDB's. */
573 warning ("GDB: Failed to set controlling terminal: %s",
574 safe_strerror (errno
));
579 #endif /* !go32 && !win32 */
582 /* Kill the inferior process. Make us have no inferior. */
585 kill_command (char *arg
, int from_tty
)
587 /* FIXME: This should not really be inferior_ptid (or target_has_execution).
588 It should be a distinct flag that indicates that a target is active, cuz
589 some targets don't have processes! */
591 if (ptid_equal (inferior_ptid
, null_ptid
))
592 error (_("The program is not being run."));
593 if (!query ("Kill the program being debugged? "))
594 error (_("Not confirmed."));
597 init_thread_list (); /* Destroy thread info */
599 /* Killing off the inferior can leave us with a core file. If so,
600 print the state we are left in. */
601 if (target_has_stack
)
603 printf_filtered (_("In %s,\n"), target_longname
);
604 print_stack_frame (get_selected_frame (NULL
), 1, SRC_AND_LOC
);
606 bfd_cache_close_all ();
609 /* Call set_sigint_trap when you need to pass a signal on to an attached
610 process when handling SIGINT */
613 pass_signal (int signo
)
616 kill (PIDGET (inferior_ptid
), SIGINT
);
620 static void (*osig
) ();
623 set_sigint_trap (void)
625 if (attach_flag
|| inferior_thisrun_terminal
)
627 osig
= (void (*)()) signal (SIGINT
, pass_signal
);
632 clear_sigint_trap (void)
634 if (attach_flag
|| inferior_thisrun_terminal
)
636 signal (SIGINT
, osig
);
640 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
641 static void (*old_sigio
) ();
644 handle_sigio (int signo
)
649 signal (SIGIO
, handle_sigio
);
652 FD_SET (target_activity_fd
, &readfds
);
653 numfds
= gdb_select (target_activity_fd
+ 1, &readfds
, NULL
, NULL
, NULL
);
654 if (numfds
>= 0 && FD_ISSET (target_activity_fd
, &readfds
))
657 if ((*target_activity_function
) ())
658 kill (PIDGET (inferior_ptid
), SIGINT
);
663 static int old_fcntl_flags
;
666 set_sigio_trap (void)
668 if (target_activity_function
)
670 old_sigio
= (void (*)()) signal (SIGIO
, handle_sigio
);
671 fcntl (target_activity_fd
, F_SETOWN
, getpid ());
672 old_fcntl_flags
= fcntl (target_activity_fd
, F_GETFL
, 0);
673 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
| FASYNC
);
678 clear_sigio_trap (void)
680 if (target_activity_function
)
682 signal (SIGIO
, old_sigio
);
683 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
);
686 #else /* No SIGIO. */
688 set_sigio_trap (void)
690 if (target_activity_function
)
691 internal_error (__FILE__
, __LINE__
, _("failed internal consistency check"));
695 clear_sigio_trap (void)
697 if (target_activity_function
)
698 internal_error (__FILE__
, __LINE__
, _("failed internal consistency check"));
700 #endif /* No SIGIO. */
703 /* Create a new session if the inferior will run in a different tty.
704 A session is UNIX's way of grouping processes that share a controlling
705 terminal, so a new one is needed if the inferior terminal will be
706 different from GDB's.
708 Returns the session id of the new session, 0 if no session was created
709 or -1 if an error occurred. */
711 create_tty_session (void)
716 if (!job_control
|| inferior_thisrun_terminal
== 0)
721 warning ("Failed to create new terminal session: setsid: %s",
722 safe_strerror (errno
));
727 #endif /* HAVE_SETSID */
730 /* This is here because this is where we figure out whether we (probably)
731 have job control. Just using job_control only does part of it because
732 setpgid or setpgrp might not exist on a system without job control.
733 It might be considered misplaced (on the other hand, process groups and
734 job control are closely related to ttys).
736 For a more clean implementation, in libiberty, put a setpgid which merely
737 calls setpgrp and a setpgrp which does nothing (any system with job control
738 will have one or the other). */
746 #if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
748 /* The call setpgid (0, 0) is supposed to work and mean the same
749 thing as this, but on Ultrix 4.2A it fails with EPERM (and
750 setpgid (getpid (), getpid ()) succeeds). */
751 retval
= setpgid (getpid (), getpid ());
757 retval
= setpgrp (getpid (), getpid ());
759 #endif /* HAVE_SETPGRP */
760 #endif /* HAVE_SETPGID */
761 #endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
767 /* Get all the current tty settings (including whether we have a
768 tty at all!). We can't do this in _initialize_inflow because
769 serial_fdopen() won't work until the serial_ops_list is
770 initialized, but we don't want to do it lazily either, so
771 that we can guarantee stdin_serial is opened if there is
774 initialize_stdin_serial (void)
776 stdin_serial
= serial_fdopen (0);
780 _initialize_inflow (void)
782 add_info ("terminal", term_info
,
783 _("Print inferior's saved terminal status."));
785 add_com ("kill", class_run
, kill_command
,
786 _("Kill execution of program being debugged."));
788 inferior_ptid
= null_ptid
;
790 terminal_is_ours
= 1;
792 /* OK, figure out whether we have job control. If neither termios nor
793 sgtty (i.e. termio or go32), leave job_control 0. */
795 #if defined (HAVE_TERMIOS)
796 /* Do all systems with termios have the POSIX way of identifying job
797 control? I hope so. */
798 #ifdef _POSIX_JOB_CONTROL
801 #ifdef _SC_JOB_CONTROL
802 job_control
= sysconf (_SC_JOB_CONTROL
);
804 job_control
= 0; /* have to assume the worst */
805 #endif /* _SC_JOB_CONTROL */
806 #endif /* _POSIX_JOB_CONTROL */
807 #endif /* HAVE_TERMIOS */
814 #endif /* TIOCGPGRP */