| 1 | /* Copyright (C) 2016-2020 Free Software Foundation, Inc. |
| 2 | |
| 3 | This file is part of GDB. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #include "common-defs.h" |
| 19 | #include "signals-state-save-restore.h" |
| 20 | #include "gdbsupport/gdb-sigmask.h" |
| 21 | |
| 22 | #include <signal.h> |
| 23 | |
| 24 | /* The original signal actions and mask. */ |
| 25 | |
| 26 | #ifdef HAVE_SIGACTION |
| 27 | static struct sigaction original_signal_actions[NSIG]; |
| 28 | |
| 29 | static sigset_t original_signal_mask; |
| 30 | #endif |
| 31 | |
| 32 | /* See signals-state-save-restore.h. */ |
| 33 | |
| 34 | void |
| 35 | save_original_signals_state (bool quiet) |
| 36 | { |
| 37 | #ifdef HAVE_SIGACTION |
| 38 | int i; |
| 39 | int res; |
| 40 | |
| 41 | res = gdb_sigmask (0, NULL, &original_signal_mask); |
| 42 | if (res == -1) |
| 43 | perror_with_name (("sigprocmask")); |
| 44 | |
| 45 | bool found_preinstalled = false; |
| 46 | |
| 47 | for (i = 1; i < NSIG; i++) |
| 48 | { |
| 49 | struct sigaction *oldact = &original_signal_actions[i]; |
| 50 | |
| 51 | res = sigaction (i, NULL, oldact); |
| 52 | if (res == -1 && errno == EINVAL) |
| 53 | { |
| 54 | /* Some signal numbers in the range are invalid. */ |
| 55 | continue; |
| 56 | } |
| 57 | else if (res == -1) |
| 58 | perror_with_name (("sigaction")); |
| 59 | |
| 60 | /* If we find a custom signal handler already installed, then |
| 61 | this function was called too late. This is a warning instead |
| 62 | of an internal error because this can also happen if you |
| 63 | LD_PRELOAD a library that installs a signal handler early via |
| 64 | __attribute__((constructor)), like libSegFault.so. */ |
| 65 | if (!quiet |
| 66 | && oldact->sa_handler != SIG_DFL |
| 67 | && oldact->sa_handler != SIG_IGN) |
| 68 | { |
| 69 | found_preinstalled = true; |
| 70 | |
| 71 | /* Use raw fprintf here because we're being called in early |
| 72 | startup, before GDB's filtered streams are created. */ |
| 73 | fprintf (stderr, |
| 74 | _("warning: Found custom handler for signal " |
| 75 | "%d (%s) preinstalled.\n"), i, |
| 76 | strsignal (i)); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | if (found_preinstalled) |
| 81 | { |
| 82 | fprintf (stderr, _("\ |
| 83 | Some signal dispositions inherited from the environment (SIG_DFL/SIG_IGN)\n\ |
| 84 | won't be propagated to spawned programs.\n")); |
| 85 | } |
| 86 | #endif |
| 87 | } |
| 88 | |
| 89 | /* See signals-state-save-restore.h. */ |
| 90 | |
| 91 | void |
| 92 | restore_original_signals_state (void) |
| 93 | { |
| 94 | #ifdef HAVE_SIGACTION |
| 95 | int i; |
| 96 | int res; |
| 97 | |
| 98 | for (i = 1; i < NSIG; i++) |
| 99 | { |
| 100 | res = sigaction (i, &original_signal_actions[i], NULL); |
| 101 | if (res == -1 && errno == EINVAL) |
| 102 | { |
| 103 | /* Some signal numbers in the range are invalid. */ |
| 104 | continue; |
| 105 | } |
| 106 | else if (res == -1) |
| 107 | perror_with_name (("sigaction")); |
| 108 | } |
| 109 | |
| 110 | res = gdb_sigmask (SIG_SETMASK, &original_signal_mask, NULL); |
| 111 | if (res == -1) |
| 112 | perror_with_name (("sigprocmask")); |
| 113 | #endif |
| 114 | } |