1 /* 2 * Copyright (c) 2003, 2017, 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 "memory/filemap.hpp" 27 #include "runtime/arguments.hpp" 28 #include "runtime/os.hpp" 29 #include "runtime/thread.hpp" 30 #include "utilities/vmError.hpp" 31 32 #include <sys/types.h> 33 #include <sys/wait.h> 34 #include <signal.h> 35 36 #ifdef LINUX 37 #include <sys/syscall.h> 38 #include <unistd.h> 39 #endif 40 #ifdef SOLARIS 41 #include <thread.h> 42 #endif 43 #ifdef AIX 44 #include <unistd.h> 45 #endif 46 #ifdef BSD 47 #include <sys/syscall.h> 48 #include <unistd.h> 49 #endif 50 51 52 // handle all synchronous program error signals which may happen during error 53 // reporting. They must be unblocked, caught, handled. 54 55 static const int SIGNALS[] = { SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP }; // add more if needed 56 static const int NUM_SIGNALS = sizeof(SIGNALS) / sizeof(int); 57 58 // Space for our "saved" signal flags and handlers 59 static int resettedSigflags[NUM_SIGNALS]; 60 static address resettedSighandler[NUM_SIGNALS]; 61 62 // Needed for cancelable steps. 63 static volatile pthread_t reporter_thread_id; 64 65 void VMError::reporting_started() { 66 // record pthread id of reporter thread. 67 reporter_thread_id = ::pthread_self(); 68 } 69 70 void VMError::interrupt_reporting_thread() { 71 // We misuse SIGILL here, but it does not really matter. We need 72 // a signal which is handled by crash_handler and not likely to 73 // occurr during error reporting itself. 74 ::pthread_kill(reporter_thread_id, SIGILL); 75 } 76 77 static void save_signal(int idx, int sig) 78 { 79 struct sigaction sa; 80 sigaction(sig, NULL, &sa); 81 resettedSigflags[idx] = sa.sa_flags; 82 resettedSighandler[idx] = (sa.sa_flags & SA_SIGINFO) 83 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 84 : CAST_FROM_FN_PTR(address, sa.sa_handler); 85 } 86 87 int VMError::get_resetted_sigflags(int sig) { 88 for (int i = 0; i < NUM_SIGNALS; i++) { 89 if (SIGNALS[i] == sig) { 90 return resettedSigflags[i]; 91 } 92 } 93 return -1; 94 } 95 96 address VMError::get_resetted_sighandler(int sig) { 97 for (int i = 0; i < NUM_SIGNALS; i++) { 98 if (SIGNALS[i] == sig) { 99 return resettedSighandler[i]; 100 } 101 } 102 return NULL; 103 } 104 105 static void crash_handler(int sig, siginfo_t* info, void* ucVoid) { 106 // unmask current signal 107 sigset_t newset; 108 sigemptyset(&newset); 109 sigaddset(&newset, sig); 110 // also unmask other synchronous signals 111 for (int i = 0; i < NUM_SIGNALS; i++) { 112 sigaddset(&newset, SIGNALS[i]); 113 } 114 os::Posix::unblock_thread_signal_mask(&newset); 115 116 // support safefetch faults in error handling 117 ucontext_t* const uc = (ucontext_t*) ucVoid; 118 address pc = (uc != NULL) ? os::Posix::ucontext_get_pc(uc) : NULL; 119 120 // Correct pc for SIGILL, SIGFPE (see JDK-8176872) 121 if (sig == SIGILL || sig == SIGFPE) { 122 pc = (address) info->si_addr; 123 } 124 125 if (uc && pc && StubRoutines::is_safefetch_fault(pc)) { 126 os::Posix::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 127 return; 128 } 129 130 VMError::report_and_die(NULL, sig, pc, info, ucVoid); 131 } 132 133 void VMError::reset_signal_handlers() { 134 // install signal handlers for all synchronous program error signals 135 sigset_t newset; 136 sigemptyset(&newset); 137 138 for (int i = 0; i < NUM_SIGNALS; i++) { 139 save_signal(i, SIGNALS[i]); 140 os::signal(SIGNALS[i], CAST_FROM_FN_PTR(void *, crash_handler)); 141 sigaddset(&newset, SIGNALS[i]); 142 } 143 os::Posix::unblock_thread_signal_mask(&newset); 144 145 } 146 147 // Write a hint to the stream in case siginfo relates to a segv/bus error 148 // and the offending address points into CDS archive. 149 void VMError::check_failing_cds_access(outputStream* st, const void* siginfo) { 150 #if INCLUDE_CDS 151 if (siginfo && UseSharedSpaces) { 152 const siginfo_t* const si = (siginfo_t*)siginfo; 153 if (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) { 154 const void* const fault_addr = si->si_addr; 155 if (fault_addr != NULL) { 156 FileMapInfo* const mapinfo = FileMapInfo::current_info(); 157 if (mapinfo->is_in_shared_space(fault_addr)) { 158 st->print("Error accessing class data sharing archive. " 159 "Mapped file inaccessible during execution, possible disk/network problem."); 160 } 161 } 162 } 163 } 164 #endif 165 } 166