1 /* 2 * Copyright (c) 2003, 2018, 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/metaspaceShared.hpp" 27 #include "runtime/arguments.hpp" 28 #include "runtime/os.hpp" 29 #include "runtime/thread.hpp" 30 #include "utilities/debug.hpp" 31 #include "utilities/vmError.hpp" 32 33 #include <sys/types.h> 34 #include <sys/wait.h> 35 #include <signal.h> 36 37 #ifdef LINUX 38 #include <sys/syscall.h> 39 #include <unistd.h> 40 #endif 41 #ifdef SOLARIS 42 #include <thread.h> 43 #endif 44 #ifdef AIX 45 #include <unistd.h> 46 #endif 47 #ifdef BSD 48 #include <sys/syscall.h> 49 #include <unistd.h> 50 #endif 51 52 53 // handle all synchronous program error signals which may happen during error 54 // reporting. They must be unblocked, caught, handled. 55 56 static const int SIGNALS[] = { SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP }; // add more if needed 57 static const int NUM_SIGNALS = sizeof(SIGNALS) / sizeof(int); 58 59 // Space for our "saved" signal flags and handlers 60 static int resettedSigflags[NUM_SIGNALS]; 61 static address resettedSighandler[NUM_SIGNALS]; 62 63 // Needed for cancelable steps. 64 static volatile pthread_t reporter_thread_id; 65 66 void VMError::reporting_started() { 67 // record pthread id of reporter thread. 68 reporter_thread_id = ::pthread_self(); 69 } 70 71 void VMError::interrupt_reporting_thread() { 72 // We misuse SIGILL here, but it does not really matter. We need 73 // a signal which is handled by crash_handler and not likely to 74 // occurr during error reporting itself. 75 ::pthread_kill(reporter_thread_id, SIGILL); 76 } 77 78 static void save_signal(int idx, int sig) 79 { 80 struct sigaction sa; 81 sigaction(sig, NULL, &sa); 82 resettedSigflags[idx] = sa.sa_flags; 83 resettedSighandler[idx] = (sa.sa_flags & SA_SIGINFO) 84 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 85 : CAST_FROM_FN_PTR(address, sa.sa_handler); 86 } 87 88 int VMError::get_resetted_sigflags(int sig) { 89 for (int i = 0; i < NUM_SIGNALS; i++) { 90 if (SIGNALS[i] == sig) { 91 return resettedSigflags[i]; 92 } 93 } 94 return -1; 95 } 96 97 address VMError::get_resetted_sighandler(int sig) { 98 for (int i = 0; i < NUM_SIGNALS; i++) { 99 if (SIGNALS[i] == sig) { 100 return resettedSighandler[i]; 101 } 102 } 103 return NULL; 104 } 105 106 static void crash_handler(int sig, siginfo_t* info, void* ucVoid) { 107 // unmask current signal 108 sigset_t newset; 109 sigemptyset(&newset); 110 sigaddset(&newset, sig); 111 // also unmask other synchronous signals 112 for (int i = 0; i < NUM_SIGNALS; i++) { 113 sigaddset(&newset, SIGNALS[i]); 114 } 115 os::Posix::unblock_thread_signal_mask(&newset); 116 117 // support safefetch faults in error handling 118 ucontext_t* const uc = (ucontext_t*) ucVoid; 119 address pc = (uc != NULL) ? os::Posix::ucontext_get_pc(uc) : NULL; 120 121 // Correct pc for SIGILL, SIGFPE (see JDK-8176872) 122 if (sig == SIGILL || sig == SIGFPE) { 123 pc = (address) info->si_addr; 124 } 125 126 // Needed to make it possible to call SafeFetch.. APIs in error handling. 127 if (uc && pc && StubRoutines::is_safefetch_fault(pc)) { 128 os::Posix::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 129 return; 130 } 131 132 // Needed because asserts may happen in error handling too. 133 #ifdef CAN_SHOW_REGISTERS_ON_ASSERT 134 if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) { 135 if (handle_assert_poison_fault(ucVoid, info->si_addr)) { 136 return; 137 } 138 } 139 #endif // CAN_SHOW_REGISTERS_ON_ASSERT 140 141 VMError::report_and_die(NULL, sig, pc, info, ucVoid); 142 } 143 144 void VMError::reset_signal_handlers() { 145 // install signal handlers for all synchronous program error signals 146 sigset_t newset; 147 sigemptyset(&newset); 148 149 for (int i = 0; i < NUM_SIGNALS; i++) { 150 save_signal(i, SIGNALS[i]); 151 os::signal(SIGNALS[i], CAST_FROM_FN_PTR(void *, crash_handler)); 152 sigaddset(&newset, SIGNALS[i]); 153 } 154 os::Posix::unblock_thread_signal_mask(&newset); 155 156 } 157 158 // Write a hint to the stream in case siginfo relates to a segv/bus error 159 // and the offending address points into CDS archive. 160 void VMError::check_failing_cds_access(outputStream* st, const void* siginfo) { 161 #if INCLUDE_CDS 162 if (siginfo && UseSharedSpaces) { 163 const siginfo_t* const si = (siginfo_t*)siginfo; 164 if (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) { 165 const void* const fault_addr = si->si_addr; 166 if (fault_addr != NULL) { 167 if (MetaspaceShared::is_in_shared_metaspace(fault_addr)) { 168 st->print("Error accessing class data sharing archive. " 169 "Mapped file inaccessible during execution, possible disk/network problem."); 170 } 171 } 172 } 173 } 174 #endif 175 } 176