1 /* 2 * Copyright (C) 2013 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 /* 18 * Contributed by: Intel Corporation 19 */ 20 21 #include <gtest/gtest.h> 22 23 #include <dlfcn.h> 24 #include <signal.h> 25 #include <stdio.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <sys/types.h> 29 #include <unistd.h> 30 #include <unwind.h> 31 32 #include "ScopedSignalHandler.h" 33 34 #define noinline __attribute__((__noinline__)) 35 #define __unused __attribute__((__unused__)) 36 37 _Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx __unused, void* arg) { 38 int* count_ptr = reinterpret_cast<int*>(arg); 39 40 #if SHOW_FRAME_LOCATIONS 41 void* ip = reinterpret_cast<void*>(_Unwind_GetIP(ctx)); 42 43 const char* symbol = "<unknown>"; 44 int offset = 0; 45 46 Dl_info info; 47 memset(&info, 0, sizeof(info)); 48 if (dladdr(ip, &info) != 0) { 49 symbol = info.dli_sname; 50 if (info.dli_saddr != nullptr) { 51 offset = static_cast<int>(reinterpret_cast<char*>(ip) - reinterpret_cast<char*>(info.dli_saddr)); 52 } 53 } 54 55 fprintf(stderr, " #%02d %p %s%+d (%s)\n", *count_ptr, ip, symbol, offset, info.dli_fname ? info.dli_fname : "??"); 56 fflush(stderr); 57 #endif 58 59 ++*count_ptr; 60 return _URC_NO_REASON; 61 } 62 63 static int noinline unwind_one_frame_deeper() { 64 int count = 0; 65 _Unwind_Backtrace(FrameCounter, &count); 66 return count; 67 } 68 69 TEST(stack_unwinding, easy) { 70 int count = 0; 71 _Unwind_Backtrace(FrameCounter, &count); 72 int deeper_count = unwind_one_frame_deeper(); 73 ASSERT_EQ(count + 1, deeper_count); 74 } 75 76 struct UnwindData { 77 volatile bool signal_handler_complete = false; 78 int expected_frame_count = 0; 79 int handler_frame_count = 0; 80 int handler_one_deeper_frame_count = 0; 81 }; 82 83 static UnwindData g_unwind_data; 84 85 static void noinline UnwindSignalHandler(int) { 86 _Unwind_Backtrace(FrameCounter, &g_unwind_data.handler_frame_count); 87 88 g_unwind_data.handler_one_deeper_frame_count = unwind_one_frame_deeper(); 89 g_unwind_data.signal_handler_complete = true; 90 } 91 92 static void verify_unwind_data(const UnwindData& unwind_data) { 93 // In order to avoid a false positive, the caller must have at least 2 frames 94 // outside of the signal handler. This avoids a case where the only frame 95 // right after the signal handler winds up being garbage. 96 EXPECT_GT(unwind_data.handler_frame_count, unwind_data.expected_frame_count + 1); 97 98 EXPECT_EQ(unwind_data.handler_frame_count + 1, unwind_data.handler_one_deeper_frame_count); 99 } 100 101 static void noinline UnwindTest() { 102 g_unwind_data = {}; 103 104 _Unwind_Backtrace(FrameCounter, &g_unwind_data.expected_frame_count); 105 ASSERT_LE(2, g_unwind_data.expected_frame_count) 106 << "The current call must contain at least 2 frames for the test to be valid."; 107 108 ASSERT_EQ(0, kill(getpid(), SIGUSR1)); 109 while (!g_unwind_data.signal_handler_complete) {} 110 111 verify_unwind_data(g_unwind_data); 112 } 113 114 TEST(stack_unwinding, unwind_through_signal_frame) { 115 ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler); 116 117 UnwindTest(); 118 } 119 120 // On LP32, the SA_SIGINFO flag gets you __restore_rt instead of __restore. 121 TEST(stack_unwinding, unwind_through_signal_frame_SA_SIGINFO) { 122 ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler, SA_SIGINFO); 123 124 UnwindTest(); 125 } 126
