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