1 /* 2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "runtime/arguments.hpp" 27 #include "runtime/os.hpp" 28 #include "runtime/thread.hpp" 29 #include "utilities/vmError.hpp" 30 31 #include <sys/types.h> 32 #include <sys/wait.h> 33 #include <sys/syscall.h> 34 #include <unistd.h> 35 #include <signal.h> 36 37 void VMError::show_message_box(char *buf, int buflen) { 38 bool yes; 39 do { 40 error_string(buf, buflen); 41 int len = (int)strlen(buf); 42 char *p = &buf[len]; 43 44 jio_snprintf(p, buflen - len, 45 "\n\n" 46 "Do you want to debug the problem?\n\n" 47 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n" 48 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n" 49 "Otherwise, press RETURN to abort...", 50 os::current_process_id(), os::current_process_id(), 51 os::current_thread_id(), os::current_thread_id()); 52 53 yes = os::message_box("Unexpected Error", buf); 54 55 if (yes) { 56 // yes, user asked VM to launch debugger 57 jio_snprintf(buf, buflen, "gdb /proc/%d/exe %d", 58 os::current_process_id(), os::current_process_id()); 59 60 os::fork_and_exec(buf); 61 yes = false; 62 } 63 } while (yes); 64 } 65 66 // handle all synchronous program error signals which may happen during error 67 // reporting. They must be unblocked, caught, handled. 68 // 69 // Note that in the hotspot signal handlers are installed with a fully filled 70 // signal mask, i.e. upon delivery all signals - also synchronous error signals 71 // - are blocked. For synchronous error signals this is deadly - program will 72 // hang or be ended immediately if secondary errors happend during error 73 // reporting. 74 75 static const int SIGNALS[] = { SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP }; // add more if needed 76 static const int NUM_SIGNALS = sizeof(SIGNALS) / sizeof(int); 77 78 // Space for our "saved" signal flags and handlers 79 static int resettedSigflags[NUM_SIGNALS]; 80 static address resettedSighandler[NUM_SIGNALS]; 81 82 static void save_signal(int idx, int sig) 83 { 84 struct sigaction sa; 85 sigaction(sig, NULL, &sa); 86 resettedSigflags[idx] = sa.sa_flags; 87 resettedSighandler[idx] = (sa.sa_flags & SA_SIGINFO) 88 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 89 : CAST_FROM_FN_PTR(address, sa.sa_handler); 90 } 91 92 int VMError::get_resetted_sigflags(int sig) { 93 for (int i = 0; i < NUM_SIGNALS; i++) { 94 if (SIGNALS[i] == sig) { 95 return resettedSigflags[i]; 96 } 97 } 98 return -1; 99 } 100 101 address VMError::get_resetted_sighandler(int sig) { 102 for (int i = 0; i < NUM_SIGNALS; i++) { 103 if (SIGNALS[i] == sig) { 104 return resettedSighandler[i]; 105 } 106 } 107 return NULL; 108 } 109 110 static void crash_handler(int sig, siginfo_t* info, void* ucVoid) { 111 // unmask current signal 112 sigset_t newset; 113 sigemptyset(&newset); 114 sigaddset(&newset, sig); 115 // also unmask other synchronous signals 116 for (int i = 0; i < NUM_SIGNALS; i++) { 117 sigaddset(&newset, SIGNALS[i]); 118 } 119 pthread_sigmask(SIG_UNBLOCK, &newset, NULL); 120 121 VMError err(NULL, sig, NULL, info, ucVoid); 122 err.report_and_die(); 123 } 124 125 void VMError::reset_signal_handlers() { 126 // install signal handlers for all synchronous program error signals 127 sigset_t newset; 128 sigemptyset(&newset); 129 130 for (int i = 0; i < NUM_SIGNALS; i++) { 131 save_signal(i, SIGNALS[i]); 132 os::signal(SIGNALS[i], CAST_FROM_FN_PTR(void *, crash_handler)); 133 sigaddset(&newset, SIGNALS[i]); 134 } 135 pthread_sigmask(SIG_UNBLOCK, &newset, NULL); 136 }