1 /* Copyright (C) 2016-2023 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 } 115