RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 09:58:11 +00:00
Code Issues Activity Actions

UserspaceEmulator: Make symbolication work when .text isn't the first

Browse source 
... segment

This happens with binaries build with Clang or with a custom linker
script. If this is the case, offsets should be calculated not from the
base address of `.text`, but from the first section loaded for the
library.

This commit moves all UserspaceEmulator symbolication into a common
helper function and fixes a FIXME.
This commit is contained in:
Daniel Bertalan 2021-07-28 17:18:43 +02:00 • committed by Andreas Kling
parent 980f314a03
commit c1d6637dc7
4 changed files with 77 additions and 55 deletions
Download patch file Download diff file Expand all files Collapse all files

103
Userland/DevTools/UserspaceEmulator/Emulator.cpp
View file

@ -276,19 +276,10 @@ void Emulator::handle_repl()
auto saved_eip = m_cpu.eip();
m_cpu.save_base_eip();
auto insn = X86::Instruction::from_stream(m_cpu, true, true);
// FIXME: This does not respect inlineing
// FIXME: This does not respect inlining
// another way of getting the current function is at need
if (auto const* region = load_library_from_address(m_cpu.base_eip())) {
auto separator_index = region->name().find(":").value();
String lib_name = region->name().substring(0, separator_index);
String lib_path = lib_name;
if (region->name().contains(".so"))
lib_path = String::formatted("/usr/lib/{}", lib_path);
auto it = m_dynamic_library_cache.find(lib_path);
auto& elf = it->value.debug_info->elf();
String symbol = elf.symbolicate(m_cpu.base_eip() - region->base());
outln("[{}]: {}", lib_name, symbol);
if (auto symbol = symbol_at(m_cpu.base_eip()); symbol.has_value()) {
outln("[{}]: {}", symbol->lib_name, symbol->symbol);
}
outln("==> {}", create_instruction_line(m_cpu.base_eip(), insn));
@ -405,11 +396,11 @@ MmapRegion const* Emulator::load_library_from_address(FlatPtr address)
auto const* region = find_text_region(address);
if (!region)
return {};
auto separator_index = region->name().find(':');
if (!separator_index.has_value())
String lib_name = region->lib_name();
if (lib_name.is_null())
return {};
String lib_name = region->name().substring(0, separator_index.value());
String lib_path = lib_name;
if (region->name().contains(".so"))
lib_path = String::formatted("/usr/lib/{}", lib_path);
@ -426,30 +417,49 @@ MmapRegion const* Emulator::load_library_from_address(FlatPtr address)
return region;
}
String Emulator::create_backtrace_line(FlatPtr address)
MmapRegion const* Emulator::first_region_for_object(StringView name)
{
auto minimal = String::formatted("=={{{}}}== {:p}", getpid(), (void*)address);
auto const* region = load_library_from_address(address);
if (!region)
return minimal;
// FIXME: This is redundant
auto separator_index = region->name().find(":").value();
String lib_name = region->name().substring(0, separator_index);
String lib_path = lib_name;
if (region->name().contains(".so"))
lib_path = String::formatted("/usr/lib/{}", lib_path);
MmapRegion* ret = nullptr;
mmu().for_each_region_of_type<MmapRegion>([&](auto& region) {
if (region.lib_name() == name) {
ret = &region;
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
return ret;
}
// FIXME: This disregards function inlining.
Optional<Emulator::SymbolInfo> Emulator::symbol_at(FlatPtr address)
{
auto const* address_region = load_library_from_address(address);
if (!address_region)
return {};
auto lib_name = address_region->lib_name();
auto const* first_region = (lib_name.is_null() || lib_name.is_empty()) ? address_region : first_region_for_object(lib_name);
VERIFY(first_region);
auto lib_path = lib_name.contains(".so"sv) ? String::formatted("/usr/lib/{}", lib_name) : lib_name;
auto it = m_dynamic_library_cache.find(lib_path);
auto& elf = it->value.debug_info->elf();
String symbol = elf.symbolicate(address - region->base());
auto const& elf = it->value.debug_info->elf();
auto symbol = elf.symbolicate(address - first_region->base());
auto line_without_source_info = String::formatted("=={{{}}}== {:p} [{}]: {}", getpid(), (void*)address, lib_name, symbol);
auto source_position = it->value.debug_info->get_source_position(address - first_region->base());
return { { lib_name, symbol, source_position } };
}
auto source_position = it->value.debug_info->get_source_position(address - region->base());
if (source_position.has_value())
return String::formatted("=={{{}}}== {:p} [{}]: {} (\e[34;1m{}\e[0m:{})", getpid(), (void*)address, lib_name, symbol, LexicalPath::basename(source_position.value().file_path), source_position.value().line_number);
return line_without_source_info;
String Emulator::create_backtrace_line(FlatPtr address)
{
auto maybe_symbol = symbol_at(address);
if (!maybe_symbol.has_value()) {
return String::formatted("=={{{}}}== {:p}", getpid(), address);
} else if (!maybe_symbol->source_position.has_value()) {
return String::formatted("=={{{}}}== {:p} [{}]: {}", getpid(), address, maybe_symbol->lib_name, maybe_symbol->symbol);
} else {
auto const& source_position = maybe_symbol->source_position.value();
return String::formatted("=={{{}}}== {:p} [{}]: {} (\e[34;1m{}\e[0m:{})", getpid(), address, maybe_symbol->lib_name, maybe_symbol->symbol, LexicalPath::basename(source_position.file_path), source_position.line_number);
}
}
void Emulator::dump_backtrace(Vector<FlatPtr> const& backtrace)
@ -486,26 +496,11 @@ void Emulator::emit_profile_event(AK::OutputStream& output, StringView event_nam
String Emulator::create_instruction_line(FlatPtr address, X86::Instruction insn)
{
auto minimal = String::formatted("{:p}: {}", (void*)address, insn.to_string(address));
auto const* region = load_library_from_address(address);
if (!region)
return minimal;
// FIXME: This is redundant
auto separator_index = region->name().find(":").value();
String lib_name = region->name().substring(0, separator_index);
String lib_path = lib_name;
if (region->name().contains(".so"))
lib_path = String::formatted("/usr/lib/{}", lib_path);
auto it = m_dynamic_library_cache.find(lib_path);
auto& elf = it->value.debug_info->elf();
String symbol = elf.symbolicate(address - region->base());
auto source_position = it->value.debug_info->get_source_position(address - region->base());
if (!source_position.has_value())
return minimal;
return String::formatted("{:p}: {} \e[34;1m{}\e[0m:{}", (void*)address, insn.to_string(address), LexicalPath::basename(source_position.value().file_path), source_position.value().line_number);
auto symbol = symbol_at(address);
if (!symbol.has_value() || !symbol->source_position.has_value())
return String::formatted("{:p}: {}", address, insn.to_string(address));
else
return String::formatted("{:p}: {} \e[34;1m{}\e[0m:{}", address, insn.to_string(address), LexicalPath::basename(symbol->source_position->file_path), symbol->source_position.value().line_number);
}
static void emulator_signal_handler(int signum)