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/*
* Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/JsonArray.h>
#include <AK/JsonObject.h>
#include <AK/JsonValue.h>
#include <AK/MappedFile.h>
#include <LibCore/File.h>
#include <LibDebug/DebugInfo.h>
#include <LibSymbolication/Symbolication.h>
namespace Symbolication {
struct CachedELF {
NonnullRefPtr<MappedFile> mapped_file;
NonnullOwnPtr<Debug::DebugInfo> debug_info;
};
static HashMap<String, OwnPtr<CachedELF>> s_cache;
Optional<Symbol> symbolicate(String const& path, FlatPtr address)
{
if (!s_cache.contains(path)) {
auto mapped_file = MappedFile::map(path);
if (mapped_file.is_error()) {
dbgln("Failed to map {}: {}", path, mapped_file.error().string());
s_cache.set(path, {});
return {};
}
auto elf = make<ELF::Image>(mapped_file.value()->bytes());
if (!elf->is_valid()) {
dbgln("ELF not valid: {}", path);
s_cache.set(path, {});
{};
}
auto cached_elf = make<CachedELF>(mapped_file.release_value(), make<Debug::DebugInfo>(move(elf)));
s_cache.set(path, move(cached_elf));
}
auto it = s_cache.find(path);
VERIFY(it != s_cache.end());
auto& cached_elf = it->value;
if (!cached_elf)
return {};
u32 offset = 0;
auto symbol = cached_elf->debug_info->elf().symbolicate(address, &offset);
auto source_position_with_inlines = cached_elf->debug_info->get_source_position_with_inlines(address);
Vector<Debug::DebugInfo::SourcePosition> positions;
for (auto& position : source_position_with_inlines.inline_chain) {
if (!positions.contains_slow(position))
positions.append(position);
}
if (source_position_with_inlines.source_position.has_value() && !positions.contains_slow(source_position_with_inlines.source_position.value())) {
positions.insert(0, source_position_with_inlines.source_position.value());
}
return Symbol {
.address = address,
.name = move(symbol),
.offset = offset,
.source_positions = move(positions),
};
}
Vector<Symbol> symbolicate_thread(pid_t pid, pid_t tid)
{
struct RegionWithSymbols {
FlatPtr base { 0 };
size_t size { 0 };
String path;
bool is_relative { true };
};
Vector<FlatPtr> stack;
Vector<RegionWithSymbols> regions;
regions.append(RegionWithSymbols {
.base = 0xc0000000,
.size = 0x3fffffff,
.path = "/boot/Kernel",
.is_relative = false });
{
auto stack_path = String::formatted("/proc/{}/stacks/{}", pid, tid);
auto file_or_error = Core::File::open(stack_path, Core::OpenMode::ReadOnly);
if (file_or_error.is_error()) {
warnln("Could not open {}: {}", stack_path, file_or_error.error());
return {};
}
auto json = JsonValue::from_string(file_or_error.value()->read_all());
if (!json.has_value() || !json.value().is_array()) {
warnln("Invalid contents in {}", stack_path);
return {};
}
stack.ensure_capacity(json.value().as_array().size());
for (auto& value : json.value().as_array().values()) {
stack.append(value.to_u32());
}
}
{
auto vm_path = String::formatted("/proc/{}/vm", pid);
auto file_or_error = Core::File::open(vm_path, Core::OpenMode::ReadOnly);
if (file_or_error.is_error()) {
warnln("Could not open {}: {}", vm_path, file_or_error.error());
return {};
}
auto json = JsonValue::from_string(file_or_error.value()->read_all());
if (!json.has_value() || !json.value().is_array()) {
warnln("Invalid contents in {}", vm_path);
return {};
}
for (auto& region_value : json.value().as_array().values()) {
auto& region = region_value.as_object();
auto name = region.get("name").to_string();
auto address = region.get("address").to_u32();
auto size = region.get("size").to_u32();
String path;
if (name == "/usr/lib/Loader.so") {
path = name;
} else if (name.ends_with(": .text")) {
auto parts = name.split_view(':');
path = parts[0];
if (!path.starts_with('/'))
path = String::formatted("/usr/lib/{}", path);
} else {
continue;
}
RegionWithSymbols r;
r.base = address;
r.size = size;
r.path = path;
regions.append(move(r));
}
}
Vector<Symbol> symbols;
bool first_frame = true;
for (auto address : stack) {
const RegionWithSymbols* found_region = nullptr;
for (auto& region : regions) {
if (address >= region.base && address < (region.base + region.size)) {
found_region = ®ion;
break;
}
}
if (!found_region) {
outln("{:p} ??", address);
continue;
}
FlatPtr adjusted_address;
if (found_region->is_relative)
adjusted_address = address - found_region->base;
else
adjusted_address = address;
// We're subtracting 1 from the address because this is the return address,
// i.e. it is one instruction past the call instruction.
// However, because the first frame represents the current
// instruction pointer rather than the return address we don't
// subtract 1 for that.
auto result = symbolicate(found_region->path, adjusted_address - (first_frame ? 0 : 1));
first_frame = false;
if (!result.has_value()) {
symbols.append(Symbol {
.address = address,
.source_positions = {},
});
continue;
}
symbols.append(result.value());
}
return symbols;
}
}
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