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
63static int noinline unwind_one_frame_deeper() {
64  int count = 0;
65  _Unwind_Backtrace(FrameCounter, &count);
66  return count;
67}
68
69TEST(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
76struct 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
83static UnwindData g_unwind_data;
84
85static 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
92static void verify_unwind_data(const UnwindData& unwind_data) {
93  EXPECT_GT(unwind_data.handler_frame_count, unwind_data.expected_frame_count);
94  EXPECT_EQ(unwind_data.handler_frame_count + 1, unwind_data.handler_one_deeper_frame_count);
95}
96
97TEST(stack_unwinding, unwind_through_signal_frame) {
98  g_unwind_data = {};
99  ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler);
100
101  _Unwind_Backtrace(FrameCounter, &g_unwind_data.expected_frame_count);
102
103  ASSERT_EQ(0, kill(getpid(), SIGUSR1));
104  while (!g_unwind_data.signal_handler_complete) {}
105
106  verify_unwind_data(g_unwind_data);
107}
108
109// On LP32, the SA_SIGINFO flag gets you __restore_rt instead of __restore.
110TEST(stack_unwinding, unwind_through_signal_frame_SA_SIGINFO) {
111  g_unwind_data = {};
112  ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler, SA_SIGINFO);
113
114  _Unwind_Backtrace(FrameCounter, &g_unwind_data.expected_frame_count);
115  ASSERT_EQ(0, kill(getpid(), SIGUSR1));
116  while (!g_unwind_data.signal_handler_complete) {}
117
118  verify_unwind_data(g_unwind_data);
119}
120