| 1 | /* Fork a Unix child process, and set up to debug it, for GDBserver. |
| 2 | Copyright (C) 1989-2020 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 "server.h" |
| 20 | #include "gdbsupport/job-control.h" |
| 21 | #include "nat/fork-inferior.h" |
| 22 | #ifdef HAVE_SIGNAL_H |
| 23 | #include <signal.h> |
| 24 | #endif |
| 25 | |
| 26 | #ifdef SIGTTOU |
| 27 | /* A file descriptor for the controlling terminal. */ |
| 28 | static int terminal_fd; |
| 29 | |
| 30 | /* TERMINAL_FD's original foreground group. */ |
| 31 | static pid_t old_foreground_pgrp; |
| 32 | |
| 33 | /* Hand back terminal ownership to the original foreground group. */ |
| 34 | |
| 35 | static void |
| 36 | restore_old_foreground_pgrp (void) |
| 37 | { |
| 38 | tcsetpgrp (terminal_fd, old_foreground_pgrp); |
| 39 | } |
| 40 | #endif |
| 41 | |
| 42 | /* See nat/fork-inferior.h. */ |
| 43 | |
| 44 | void |
| 45 | prefork_hook (const char *args) |
| 46 | { |
| 47 | client_state &cs = get_client_state (); |
| 48 | if (debug_threads) |
| 49 | { |
| 50 | debug_printf ("args: %s\n", args); |
| 51 | debug_flush (); |
| 52 | } |
| 53 | |
| 54 | #ifdef SIGTTOU |
| 55 | signal (SIGTTOU, SIG_DFL); |
| 56 | signal (SIGTTIN, SIG_DFL); |
| 57 | #endif |
| 58 | |
| 59 | /* Clear this so the backend doesn't get confused, thinking |
| 60 | CONT_THREAD died, and it needs to resume all threads. */ |
| 61 | cs.cont_thread = null_ptid; |
| 62 | } |
| 63 | |
| 64 | /* See nat/fork-inferior.h. */ |
| 65 | |
| 66 | void |
| 67 | postfork_hook (pid_t pid) |
| 68 | { |
| 69 | } |
| 70 | |
| 71 | /* See nat/fork-inferior.h. */ |
| 72 | |
| 73 | void |
| 74 | postfork_child_hook () |
| 75 | { |
| 76 | /* This is set to the result of setpgrp, which if vforked, will be |
| 77 | visible to you in the parent process. It's only used by humans |
| 78 | for debugging. */ |
| 79 | static int debug_setpgrp = 657473; |
| 80 | |
| 81 | debug_setpgrp = gdb_setpgid (); |
| 82 | if (debug_setpgrp == -1) |
| 83 | perror (_("setpgrp failed in child")); |
| 84 | } |
| 85 | |
| 86 | /* See nat/fork-inferior.h. */ |
| 87 | |
| 88 | void |
| 89 | gdb_flush_out_err () |
| 90 | { |
| 91 | fflush (stdout); |
| 92 | fflush (stderr); |
| 93 | } |
| 94 | |
| 95 | /* See server.h. */ |
| 96 | |
| 97 | void |
| 98 | post_fork_inferior (int pid, const char *program) |
| 99 | { |
| 100 | client_state &cs = get_client_state (); |
| 101 | #ifdef SIGTTOU |
| 102 | signal (SIGTTOU, SIG_IGN); |
| 103 | signal (SIGTTIN, SIG_IGN); |
| 104 | terminal_fd = fileno (stderr); |
| 105 | old_foreground_pgrp = tcgetpgrp (terminal_fd); |
| 106 | tcsetpgrp (terminal_fd, pid); |
| 107 | atexit (restore_old_foreground_pgrp); |
| 108 | #endif |
| 109 | |
| 110 | startup_inferior (the_target, pid, |
| 111 | START_INFERIOR_TRAPS_EXPECTED, |
| 112 | &cs.last_status, &cs.last_ptid); |
| 113 | current_thread->last_resume_kind = resume_stop; |
| 114 | current_thread->last_status = cs.last_status; |
| 115 | signal_pid = pid; |
| 116 | target_post_create_inferior (); |
| 117 | fprintf (stderr, "Process %s created; pid = %d\n", program, pid); |
| 118 | fflush (stderr); |
| 119 | } |