1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <jni.h> 18 #include <signal.h> 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <sys/ucontext.h> 22 #include <unistd.h> 23 24 #include "base/macros.h" 25 26 static int signal_count; 27 static const int kMaxSignal = 2; 28 29 #if defined(__i386__) || defined(__x86_64__) 30 #if defined(__APPLE__) 31 #define ucontext __darwin_ucontext 32 33 #if defined(__x86_64__) 34 // 64 bit mac build. 35 #define CTX_EIP uc_mcontext->__ss.__rip 36 #else 37 // 32 bit mac build. 38 #define CTX_EIP uc_mcontext->__ss.__eip 39 #endif 40 41 #elif defined(__x86_64__) 42 // 64 bit linux build. 43 #define CTX_EIP uc_mcontext.gregs[REG_RIP] 44 #else 45 // 32 bit linux build. 46 #define CTX_EIP uc_mcontext.gregs[REG_EIP] 47 #endif 48 #endif 49 50 static void signalhandler(int sig ATTRIBUTE_UNUSED, siginfo_t* info ATTRIBUTE_UNUSED, 51 void* context) { 52 printf("signal caught\n"); 53 ++signal_count; 54 if (signal_count > kMaxSignal) { 55 abort(); 56 } 57 #if defined(__arm__) 58 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context); 59 struct sigcontext *sc = reinterpret_cast<struct sigcontext*>(&uc->uc_mcontext); 60 sc->arm_pc += 2; // Skip instruction causing segv. 61 #elif defined(__aarch64__) 62 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context); 63 struct sigcontext *sc = reinterpret_cast<struct sigcontext*>(&uc->uc_mcontext); 64 sc->pc += 4; // Skip instruction causing segv. 65 #elif defined(__i386__) 66 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context); 67 uc->CTX_EIP += 3; 68 #elif defined(__x86_64__) 69 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context); 70 uc->CTX_EIP += 2; 71 #else 72 UNUSED(context); 73 #endif 74 } 75 76 static struct sigaction oldaction; 77 78 extern "C" JNIEXPORT void JNICALL Java_Main_initSignalTest(JNIEnv*, jclass) { 79 struct sigaction action; 80 action.sa_sigaction = signalhandler; 81 sigemptyset(&action.sa_mask); 82 action.sa_flags = SA_SIGINFO | SA_ONSTACK; 83 #if !defined(__APPLE__) && !defined(__mips__) 84 action.sa_restorer = nullptr; 85 #endif 86 87 sigaction(SIGSEGV, &action, &oldaction); 88 } 89 90 extern "C" JNIEXPORT void JNICALL Java_Main_terminateSignalTest(JNIEnv*, jclass) { 91 sigaction(SIGSEGV, &oldaction, nullptr); 92 } 93 94 // Prevent the compiler being a smart-alec and optimizing out the assignment 95 // to null. 96 char *go_away_compiler = nullptr; 97 98 extern "C" JNIEXPORT jint JNICALL Java_Main_testSignal(JNIEnv*, jclass) { 99 #if defined(__arm__) || defined(__i386__) || defined(__aarch64__) 100 // On supported architectures we cause a real SEGV. 101 *go_away_compiler = 'a'; 102 #elif defined(__x86_64__) 103 // Cause a SEGV using an instruction known to be 2 bytes long to account for hardcoded jump 104 // in the signal handler 105 asm volatile("movl $0, %%eax;" "movb %%ah, (%%rax);" : : : "%eax"); 106 #else 107 // On other architectures we simulate SEGV. 108 kill(getpid(), SIGSEGV); 109 #endif 110 return 1234; 111 } 112
