signaltest.cc revision ab9a0dbf3b63d517da5278b8298e6cd316e09f68
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 <signal.h> 18#include <stdio.h> 19#include <unistd.h> 20 21#include "jni.h" 22 23#ifdef __arm__ 24#include <sys/ucontext.h> 25#endif 26 27static void signalhandler(int sig, siginfo_t* info, void* context) { 28 printf("signal caught\n"); 29#ifdef __arm__ 30 // On ARM we do a more exhaustive test to make sure the signal 31 // context is OK. 32 // We can do this because we know that the instruction causing 33 // the signal is 2 bytes long (thumb mov instruction). On 34 // other architectures this is more difficult. 35 // TODO: we could do this on other architectures too if necessary, it's just harder. 36 struct ucontext *uc = reinterpret_cast<struct ucontext*>(context); 37 struct sigcontext *sc = reinterpret_cast<struct sigcontext*>(&uc->uc_mcontext); 38 sc->arm_pc += 2; // Skip instruction causing segv. 39#endif 40} 41 42static struct sigaction oldaction; 43 44extern "C" JNIEXPORT void JNICALL Java_Main_initSignalTest(JNIEnv*, jclass) { 45 struct sigaction action; 46 action.sa_sigaction = signalhandler; 47 sigemptyset(&action.sa_mask); 48 action.sa_flags = SA_SIGINFO | SA_ONSTACK; 49#if !defined(__APPLE__) && !defined(__mips__) 50 action.sa_restorer = nullptr; 51#endif 52 53 sigaction(SIGSEGV, &action, &oldaction); 54} 55 56extern "C" JNIEXPORT void JNICALL Java_Main_terminateSignalTest(JNIEnv*, jclass) { 57 sigaction(SIGSEGV, &oldaction, nullptr); 58} 59 60// Prevent the compiler being a smart-alec and optimizing out the assignment 61// to nullptr. 62char *p = nullptr; 63 64extern "C" JNIEXPORT jint JNICALL Java_Main_testSignal(JNIEnv*, jclass) { 65#ifdef __arm__ 66 // On ARM we cause a real SEGV. 67 *p = 'a'; 68#else 69 // On other architectures we simulate SEGV. 70 kill(getpid(), SIGSEGV); 71#endif 72 return 1234; 73} 74 75