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
FrameCounter(_Unwind_Context * ctx __unused,void * arg)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
unwind_one_frame_deeper()63 static int noinline unwind_one_frame_deeper() {
64 int count = 0;
65 _Unwind_Backtrace(FrameCounter, &count);
66 return count;
67 }
68
TEST(stack_unwinding,easy)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
UnwindSignalHandler(int)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
verify_unwind_data(const UnwindData & unwind_data)92 static 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
TEST(stack_unwinding,unwind_through_signal_frame)97 TEST(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.
TEST(stack_unwinding,unwind_through_signal_frame_SA_SIGINFO)110 TEST(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