1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
/*
* Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Assertions.h>
#include <AK/HashMap.h>
#include <AK/LexicalPath.h>
#include <AK/LogStream.h>
#include <AK/ScopeGuard.h>
#include <LibCore/DirectoryWatcher.h>
#include <LibCore/File.h>
#include <LibCoreDump/Reader.h>
#include <LibDebug/DebugInfo.h>
#include <LibELF/Image.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>
static void wait_until_coredump_is_ready(const String& coredump_path)
{
while (true) {
struct stat statbuf;
if (stat(coredump_path.characters(), &statbuf) < 0) {
perror("stat");
ASSERT_NOT_REACHED();
}
if (statbuf.st_mode & 0400) // Check if readable
break;
usleep(10000); // sleep for 10ms
}
}
static String object_name(StringView memory_region_name)
{
if (memory_region_name.contains("Loader.so"))
return "Loader.so";
if (!memory_region_name.contains(":"))
return {};
return memory_region_name.substring_view(0, memory_region_name.find_first_of(":").value()).to_string();
}
struct ElfObjectInfo {
ElfObjectInfo(MappedFile&& file, Debug::DebugInfo&& debug_info)
: file(move(file))
, debug_info(move(debug_info))
{
}
MappedFile file;
Debug::DebugInfo debug_info;
};
// FIXME: This cache has to be invalidated when libraries/programs are re-compiled.
// We can store the last-modified timestamp of the elf files in ElfObjectInfo to invalidate cache entries.
static HashMap<String, NonnullOwnPtr<ElfObjectInfo>> s_debug_info_cache;
static const ElfObjectInfo* object_info_for_region(const ELF::Core::MemoryRegionInfo* region)
{
auto name = object_name(region->region_name);
String path;
if (name.contains(".so"))
path = String::formatted("/usr/lib/{}", name);
else {
path = name;
}
if (auto it = s_debug_info_cache.find(path); it != s_debug_info_cache.end())
return it->value.ptr();
if (!Core::File::exists(path.characters()))
return nullptr;
MappedFile object_file(path);
if (!object_file.is_valid())
return nullptr;
auto info = make<ElfObjectInfo>(move(object_file), Debug::DebugInfo { make<ELF::Image>((const u8*)object_file.data(), object_file.size()) });
auto* info_ptr = info.ptr();
s_debug_info_cache.set(path, move(info));
return info_ptr;
}
static String backtrace_line(const CoreDump::Reader& coredump, FlatPtr eip)
{
auto* region = coredump.region_containing((FlatPtr)eip);
if (!region)
return String::format("%p: ???", eip);
if (StringView { region->region_name }.contains("Loader.so"))
return {};
auto* object_info = object_info_for_region(region);
if (!object_info)
return {};
auto func_name = object_info->debug_info.elf().symbolicate(eip - region->region_start);
auto source_position = object_info->debug_info.get_source_position(eip - region->region_start);
auto source_position_string = String::empty();
if (source_position.has_value())
source_position_string = String::format(" (\033[34;1m%s\033[0m:%u)", LexicalPath(source_position.value().file_path).basename().characters(), source_position.value().line_number);
return String::format("%p: [%s] %s%s", eip, object_name(region->region_name).characters(), func_name.is_null() ? "???" : func_name.characters(), source_position_string.characters());
}
static void backtrace(const String& coredump_path)
{
size_t thread_index = 0;
auto coredump = CoreDump::Reader::create(coredump_path);
coredump->for_each_thread_info([&thread_index, &coredump](const ELF::Core::ThreadInfo& thread_info) {
dbgln("Backtrace for thread #{}, tid={}", thread_index++, thread_info.tid);
uint32_t* ebp = (uint32_t*)thread_info.regs.ebp;
uint32_t* eip = (uint32_t*)thread_info.regs.eip;
while (ebp && eip) {
auto line = backtrace_line(*coredump, (FlatPtr)eip);
if (!line.is_null())
dbgprintf("%s\n", line.characters());
auto next_eip = coredump->peek_memory((FlatPtr)(ebp + 1));
auto next_ebp = coredump->peek_memory((FlatPtr)(ebp));
if (!next_ebp.has_value() || !next_eip.has_value()) {
break;
}
eip = (uint32_t*)next_eip.value();
ebp = (uint32_t*)next_ebp.value();
}
return IterationDecision::Continue;
});
}
int main()
{
static constexpr const char* coredumps_dir = "/tmp/coredump";
mkdir(coredumps_dir, 0777);
Core::DirectoryWatcher watcher { coredumps_dir };
while (true) {
auto event = watcher.wait_for_event();
ASSERT(event.has_value());
if (event.value().type != Core::DirectoryWatcher::Event::Type::ChildAdded)
continue;
auto coredump_path = event.value().child_path;
dbgln("New coredump file: {}", coredump_path);
wait_until_coredump_is_ready(coredump_path);
backtrace(coredump_path);
}
}
|
