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
103 yes
, no
, have_not_checked
105 gdb_has_a_terminal_flag
= have_not_checked
;
107 /* Does GDB have a terminal (on stdin)? */
109 gdb_has_a_terminal (void)
111 switch (gdb_has_a_terminal_flag
)
117 case have_not_checked
:
118 /* Get all the current tty settings (including whether we have a
119 tty at all!). Can't do this in _initialize_inflow because
120 serial_fdopen() won't work until the serial_ops_list is
124 tflags_ours
= fcntl (0, F_GETFL
, 0);
127 gdb_has_a_terminal_flag
= no
;
128 if (stdin_serial
!= NULL
)
130 our_ttystate
= serial_get_tty_state (stdin_serial
);
132 if (our_ttystate
!= NULL
)
134 gdb_has_a_terminal_flag
= yes
;
136 our_process_group
= tcgetpgrp (0);
139 our_process_group
= getpgrp ();
142 ioctl (0, TIOCGPGRP
, &our_process_group
);
147 return gdb_has_a_terminal_flag
== yes
;
149 /* "Can't happen". */
154 /* Macro for printing errors from ioctl operations */
156 #define OOPSY(what) \
158 fprintf_unfiltered(gdb_stderr, "[%s failed in terminal_inferior: %s]\n", \
159 what, safe_strerror (errno))
161 static void terminal_ours_1 (int);
163 /* Initialize the terminal settings we record for the inferior,
164 before we actually run the inferior. */
167 terminal_init_inferior_with_pgrp (int pgrp
)
169 if (gdb_has_a_terminal ())
171 /* We could just as well copy our_ttystate (if we felt like
172 adding a new function serial_copy_tty_state()). */
173 if (inferior_ttystate
)
174 xfree (inferior_ttystate
);
175 inferior_ttystate
= serial_get_tty_state (stdin_serial
);
177 #ifdef PROCESS_GROUP_TYPE
178 inferior_process_group
= pgrp
;
181 /* Make sure that next time we call terminal_inferior (which will be
182 before the program runs, as it needs to be), we install the new
184 terminal_is_ours
= 1;
188 /* Save the terminal settings again. This is necessary for the TUI
189 when it switches to TUI or non-TUI mode; curses changes the terminal
190 and gdb must be able to restore it correctly. */
193 terminal_save_ours (void)
195 if (gdb_has_a_terminal ())
197 /* We could just as well copy our_ttystate (if we felt like adding
198 a new function serial_copy_tty_state). */
200 xfree (our_ttystate
);
201 our_ttystate
= serial_get_tty_state (stdin_serial
);
206 terminal_init_inferior (void)
208 #ifdef PROCESS_GROUP_TYPE
209 /* This is for Lynx, and should be cleaned up by having Lynx be a separate
210 debugging target with a version of target_terminal_init_inferior which
211 passes in the process group to a generic routine which does all the work
212 (and the non-threaded child_terminal_init_inferior can just pass in
213 inferior_ptid to the same routine). */
214 /* We assume INFERIOR_PID is also the child's process group. */
215 terminal_init_inferior_with_pgrp (PIDGET (inferior_ptid
));
216 #endif /* PROCESS_GROUP_TYPE */
219 /* Put the inferior's terminal settings into effect.
220 This is preparation for starting or resuming the inferior. */
223 terminal_inferior (void)
225 if (gdb_has_a_terminal () && terminal_is_ours
226 && inferior_ttystate
!= NULL
227 && inferior_thisrun_terminal
== 0)
232 /* Is there a reason this is being done twice? It happens both
233 places we use F_SETFL, so I'm inclined to think perhaps there
234 is some reason, however perverse. Perhaps not though... */
235 result
= fcntl (0, F_SETFL
, tflags_inferior
);
236 result
= fcntl (0, F_SETFL
, tflags_inferior
);
237 OOPSY ("fcntl F_SETFL");
240 /* Because we were careful to not change in or out of raw mode in
241 terminal_ours, we will not change in our out of raw mode with
242 this call, so we don't flush any input. */
243 result
= serial_set_tty_state (stdin_serial
, inferior_ttystate
);
244 OOPSY ("setting tty state");
248 sigint_ours
= (void (*)()) signal (SIGINT
, SIG_IGN
);
250 sigquit_ours
= (void (*)()) signal (SIGQUIT
, SIG_IGN
);
254 /* If attach_flag is set, we don't know whether we are sharing a
255 terminal with the inferior or not. (attaching a process
256 without a terminal is one case where we do not; attaching a
257 process which we ran from the same shell as GDB via `&' is
258 one case where we do, I think (but perhaps this is not
259 `sharing' in the sense that we need to save and restore tty
260 state)). I don't know if there is any way to tell whether we
261 are sharing a terminal. So what we do is to go through all
262 the saving and restoring of the tty state, but ignore errors
263 setting the process group, which will happen if we are not
264 sharing a terminal). */
269 result
= tcsetpgrp (0, inferior_process_group
);
275 result
= ioctl (0, TIOCSPGRP
, &inferior_process_group
);
282 terminal_is_ours
= 0;
285 /* Put some of our terminal settings into effect,
286 enough to get proper results from our output,
287 but do not change into or out of RAW mode
288 so that no input is discarded.
290 After doing this, either terminal_ours or terminal_inferior
291 should be called to get back to a normal state of affairs. */
294 terminal_ours_for_output (void)
299 /* Put our terminal settings into effect.
300 First record the inferior's terminal settings
301 so they can be restored properly later. */
309 /* output_only is not used, and should not be used unless we introduce
310 separate terminal_is_ours and terminal_is_ours_for_output
314 terminal_ours_1 (int output_only
)
316 /* Checking inferior_thisrun_terminal is necessary so that
317 if GDB is running in the background, it won't block trying
318 to do the ioctl()'s below. Checking gdb_has_a_terminal
319 avoids attempting all the ioctl's when running in batch. */
320 if (inferior_thisrun_terminal
!= 0 || gdb_has_a_terminal () == 0)
323 if (!terminal_is_ours
)
326 /* Ignore this signal since it will happen when we try to set the
328 void (*osigttou
) () = NULL
;
332 terminal_is_ours
= 1;
336 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
339 if (inferior_ttystate
)
340 xfree (inferior_ttystate
);
341 inferior_ttystate
= serial_get_tty_state (stdin_serial
);
343 inferior_process_group
= tcgetpgrp (0);
346 inferior_process_group
= getpgrp ();
349 ioctl (0, TIOCGPGRP
, &inferior_process_group
);
352 /* Here we used to set ICANON in our ttystate, but I believe this
353 was an artifact from before when we used readline. Readline sets
354 the tty state when it needs to.
355 FIXME-maybe: However, query() expects non-raw mode and doesn't
356 use readline. Maybe query should use readline (on the other hand,
357 this only matters for HAVE_SGTTY, not termio or termios, I think). */
359 /* Set tty state to our_ttystate. We don't change in our out of raw
360 mode, to avoid flushing input. We need to do the same thing
361 regardless of output_only, because we don't have separate
362 terminal_is_ours and terminal_is_ours_for_output flags. It's OK,
363 though, since readline will deal with raw mode when/if it needs to.
366 serial_noflush_set_tty_state (stdin_serial
, our_ttystate
,
372 result
= tcsetpgrp (0, our_process_group
);
374 /* This fails on Ultrix with EINVAL if you run the testsuite
375 in the background with nohup, and then log out. GDB never
376 used to check for an error here, so perhaps there are other
377 such situations as well. */
379 fprintf_unfiltered (gdb_stderr
, "[tcsetpgrp failed in terminal_ours: %s]\n",
380 safe_strerror (errno
));
385 result
= ioctl (0, TIOCSPGRP
, &our_process_group
);
391 signal (SIGTTOU
, osigttou
);
396 signal (SIGINT
, sigint_ours
);
398 signal (SIGQUIT
, sigquit_ours
);
403 tflags_inferior
= fcntl (0, F_GETFL
, 0);
405 /* Is there a reason this is being done twice? It happens both
406 places we use F_SETFL, so I'm inclined to think perhaps there
407 is some reason, however perverse. Perhaps not though... */
408 result
= fcntl (0, F_SETFL
, tflags_ours
);
409 result
= fcntl (0, F_SETFL
, tflags_ours
);
415 term_info (char *arg
, int from_tty
)
417 target_terminal_info (arg
, from_tty
);
421 child_terminal_info (char *args
, int from_tty
)
423 if (!gdb_has_a_terminal ())
425 printf_filtered (_("This GDB does not control a terminal.\n"));
429 printf_filtered (_("Inferior's terminal status (currently saved by GDB):\n"));
431 /* First the fcntl flags. */
435 flags
= tflags_inferior
;
437 printf_filtered ("File descriptor flags = ");
440 #define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR)
442 /* (O_ACCMODE) parens are to avoid Ultrix header file bug */
443 switch (flags
& (O_ACCMODE
))
446 printf_filtered ("O_RDONLY");
449 printf_filtered ("O_WRONLY");
452 printf_filtered ("O_RDWR");
455 flags
&= ~(O_ACCMODE
);
458 if (flags
& O_NONBLOCK
)
459 printf_filtered (" | O_NONBLOCK");
460 flags
&= ~O_NONBLOCK
;
463 #if defined (O_NDELAY)
464 /* If O_NDELAY and O_NONBLOCK are defined to the same thing, we will
465 print it as O_NONBLOCK, which is good cause that is what POSIX
466 has, and the flag will already be cleared by the time we get here. */
467 if (flags
& O_NDELAY
)
468 printf_filtered (" | O_NDELAY");
472 if (flags
& O_APPEND
)
473 printf_filtered (" | O_APPEND");
476 #if defined (O_BINARY)
477 if (flags
& O_BINARY
)
478 printf_filtered (" | O_BINARY");
483 printf_filtered (" | 0x%x", flags
);
484 printf_filtered ("\n");
487 #ifdef PROCESS_GROUP_TYPE
488 printf_filtered ("Process group = %d\n",
489 (int) inferior_process_group
);
492 serial_print_tty_state (stdin_serial
, inferior_ttystate
, gdb_stdout
);
495 /* NEW_TTY_PREFORK is called before forking a new child process,
496 so we can record the state of ttys in the child to be formed.
497 TTYNAME is null if we are to share the terminal with gdb;
498 or points to a string containing the name of the desired tty.
500 NEW_TTY is called in new child processes under Unix, which will
501 become debugger target processes. This actually switches to
502 the terminal specified in the NEW_TTY_PREFORK call. */
505 new_tty_prefork (const char *ttyname
)
507 /* Save the name for later, for determining whether we and the child
508 are sharing a tty. */
509 inferior_thisrun_terminal
= ttyname
;
517 if (inferior_thisrun_terminal
== 0)
519 #if !defined(__GO32__) && !defined(_WIN32)
521 /* Disconnect the child process from our controlling terminal. On some
522 systems (SVR4 for example), this may cause a SIGTTOU, so temporarily
524 tty
= open ("/dev/tty", O_RDWR
);
529 osigttou
= (void (*)()) signal (SIGTTOU
, SIG_IGN
);
530 ioctl (tty
, TIOCNOTTY
, 0);
532 signal (SIGTTOU
, osigttou
);
536 /* Now open the specified new terminal. */
537 tty
= open (inferior_thisrun_terminal
, O_RDWR
| O_NOCTTY
);
540 print_sys_errmsg (inferior_thisrun_terminal
, errno
);
544 /* Avoid use of dup2; doesn't exist on all systems. */
562 /* Make tty our new controlling terminal. */
563 if (ioctl (tty
, TIOCSCTTY
, 0) == -1)
564 /* Mention GDB in warning because it will appear in the inferior's
565 terminal instead of GDB's. */
566 warning ("GDB: Failed to set controlling terminal: %s",
567 safe_strerror (errno
));
572 #endif /* !go32 && !win32 */
575 /* Kill the inferior process. Make us have no inferior. */
578 kill_command (char *arg
, int from_tty
)
580 /* FIXME: This should not really be inferior_ptid (or target_has_execution).
581 It should be a distinct flag that indicates that a target is active, cuz
582 some targets don't have processes! */
584 if (ptid_equal (inferior_ptid
, null_ptid
))
585 error (_("The program is not being run."));
586 if (!query ("Kill the program being debugged? "))
587 error (_("Not confirmed."));
590 init_thread_list (); /* Destroy thread info */
592 /* Killing off the inferior can leave us with a core file. If so,
593 print the state we are left in. */
594 if (target_has_stack
)
596 printf_filtered (_("In %s,\n"), target_longname
);
597 print_stack_frame (get_selected_frame (NULL
), 1, SRC_AND_LOC
);
599 bfd_cache_close_all ();
602 /* Call set_sigint_trap when you need to pass a signal on to an attached
603 process when handling SIGINT */
606 pass_signal (int signo
)
609 kill (PIDGET (inferior_ptid
), SIGINT
);
613 static void (*osig
) ();
616 set_sigint_trap (void)
618 if (attach_flag
|| inferior_thisrun_terminal
)
620 osig
= (void (*)()) signal (SIGINT
, pass_signal
);
625 clear_sigint_trap (void)
627 if (attach_flag
|| inferior_thisrun_terminal
)
629 signal (SIGINT
, osig
);
633 #if defined (SIGIO) && defined (FASYNC) && defined (FD_SET) && defined (F_SETOWN)
634 static void (*old_sigio
) ();
637 handle_sigio (int signo
)
642 signal (SIGIO
, handle_sigio
);
645 FD_SET (target_activity_fd
, &readfds
);
646 numfds
= gdb_select (target_activity_fd
+ 1, &readfds
, NULL
, NULL
, NULL
);
647 if (numfds
>= 0 && FD_ISSET (target_activity_fd
, &readfds
))
650 if ((*target_activity_function
) ())
651 kill (PIDGET (inferior_ptid
), SIGINT
);
656 static int old_fcntl_flags
;
659 set_sigio_trap (void)
661 if (target_activity_function
)
663 old_sigio
= (void (*)()) signal (SIGIO
, handle_sigio
);
664 fcntl (target_activity_fd
, F_SETOWN
, getpid ());
665 old_fcntl_flags
= fcntl (target_activity_fd
, F_GETFL
, 0);
666 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
| FASYNC
);
671 clear_sigio_trap (void)
673 if (target_activity_function
)
675 signal (SIGIO
, old_sigio
);
676 fcntl (target_activity_fd
, F_SETFL
, old_fcntl_flags
);
679 #else /* No SIGIO. */
681 set_sigio_trap (void)
683 if (target_activity_function
)
684 internal_error (__FILE__
, __LINE__
, _("failed internal consistency check"));
688 clear_sigio_trap (void)
690 if (target_activity_function
)
691 internal_error (__FILE__
, __LINE__
, _("failed internal consistency check"));
693 #endif /* No SIGIO. */
696 /* Create a new session if the inferior will run in a different tty.
697 A session is UNIX's way of grouping processes that share a controlling
698 terminal, so a new one is needed if the inferior terminal will be
699 different from GDB's.
701 Returns the session id of the new session, 0 if no session was created
702 or -1 if an error occurred. */
704 create_tty_session (void)
709 if (!job_control
|| inferior_thisrun_terminal
== 0)
714 warning ("Failed to create new terminal session: setsid: %s",
715 safe_strerror (errno
));
720 #endif /* HAVE_SETSID */
723 /* This is here because this is where we figure out whether we (probably)
724 have job control. Just using job_control only does part of it because
725 setpgid or setpgrp might not exist on a system without job control.
726 It might be considered misplaced (on the other hand, process groups and
727 job control are closely related to ttys).
729 For a more clean implementation, in libiberty, put a setpgid which merely
730 calls setpgrp and a setpgrp which does nothing (any system with job control
731 will have one or the other). */
739 #if defined (HAVE_TERMIOS) || defined (TIOCGPGRP)
741 /* The call setpgid (0, 0) is supposed to work and mean the same
742 thing as this, but on Ultrix 4.2A it fails with EPERM (and
743 setpgid (getpid (), getpid ()) succeeds). */
744 retval
= setpgid (getpid (), getpid ());
750 retval
= setpgrp (getpid (), getpid ());
752 #endif /* HAVE_SETPGRP */
753 #endif /* HAVE_SETPGID */
754 #endif /* defined (HAVE_TERMIOS) || defined (TIOCGPGRP) */
760 /* Get all the current tty settings (including whether we have a
761 tty at all!). We can't do this in _initialize_inflow because
762 serial_fdopen() won't work until the serial_ops_list is
763 initialized, but we don't want to do it lazily either, so
764 that we can guarantee stdin_serial is opened if there is
767 initialize_stdin_serial (void)
769 stdin_serial
= serial_fdopen (0);
773 _initialize_inflow (void)
775 add_info ("terminal", term_info
,
776 _("Print inferior's saved terminal status."));
778 add_com ("kill", class_run
, kill_command
,
779 _("Kill execution of program being debugged."));
781 inferior_ptid
= null_ptid
;
783 terminal_is_ours
= 1;
785 /* OK, figure out whether we have job control. If neither termios nor
786 sgtty (i.e. termio or go32), leave job_control 0. */
788 #if defined (HAVE_TERMIOS)
789 /* Do all systems with termios have the POSIX way of identifying job
790 control? I hope so. */
791 #ifdef _POSIX_JOB_CONTROL
794 #ifdef _SC_JOB_CONTROL
795 job_control
= sysconf (_SC_JOB_CONTROL
);
797 job_control
= 0; /* have to assume the worst */
798 #endif /* _SC_JOB_CONTROL */
799 #endif /* _POSIX_JOB_CONTROL */
800 #endif /* HAVE_TERMIOS */
807 #endif /* TIOCGPGRP */