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
signalhandler(int sig ATTRIBUTE_UNUSED,siginfo_t * info ATTRIBUTE_UNUSED,void * context)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
Java_Main_initSignalTest(JNIEnv *,jclass)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
Java_Main_terminateSignalTest(JNIEnv *,jclass)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
Java_Main_testSignal(JNIEnv *,jclass)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