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/*
* 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 <LibCoreDump/CoreDumpReader.h>
#include <LibDebug/DebugInfo.h>
#include <LibELF/Loader.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 : public RefCounted<ElfObjectInfo> {
ElfObjectInfo(MappedFile&& file, NonnullRefPtr<ELF::Loader>&& loader, Debug::DebugInfo&& debug_info)
: file(move(file))
, loader(move(loader))
, debug_info(move(debug_info))
{
}
MappedFile file;
NonnullRefPtr<ELF::Loader> loader;
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, RefPtr<ElfObjectInfo>> s_debug_info_cache;
static RefPtr<ElfObjectInfo> object_info_for_region(const ELF::Core::MemoryRegionInfo* region)
{
StringView region_name { region->region_name };
auto name = object_name(region_name);
String path;
if (name.contains(".so"))
path = String::format("/usr/lib/%s", name.characters());
else {
path = name;
}
auto cached_value = s_debug_info_cache.get(path);
if (cached_value.has_value())
return cached_value.value();
struct stat st;
if (stat(path.characters(), &st)) {
return nullptr;
}
MappedFile object_file(path);
if (!object_file.is_valid())
return nullptr;
auto loader = ELF::Loader::create((const u8*)object_file.data(), object_file.size());
Debug::DebugInfo debug_info(loader);
RefPtr<ElfObjectInfo> info = adopt(*new ElfObjectInfo(
move(object_file),
move(loader),
move(debug_info)));
s_debug_info_cache.set(path, info);
return info;
}
static String backtrace_line(const CoreDumpReader& coredump, FlatPtr eip)
{
auto* region = coredump.region_containing((FlatPtr)eip);
if (!region) {
return String::format("%p: ???", eip);
}
StringView region_name { region->region_name };
if (region_name.contains("Loader.so"))
return {};
auto object_info = object_info_for_region(region);
if (object_info.is_null())
return {};
auto func_name = object_info->loader->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_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 = CoreDumpReader::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);
}
}
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