From 5574be21ccd8cf86eaba5c50d30ad898bafc8ea8 Mon Sep 17 00:00:00 2001 From: Zach Hilman Date: Fri, 17 May 2019 21:43:26 -0400 Subject: arm_interface: Expand backtrace generation Returns results as a vector of entries for further processing. Logs addresses, offsets, and mangled name. --- src/core/arm/arm_interface.cpp | 190 +++++++++++++++++++++++++++++++++++++++-- src/core/arm/arm_interface.h | 11 +++ 2 files changed, 194 insertions(+), 7 deletions(-) diff --git a/src/core/arm/arm_interface.cpp b/src/core/arm/arm_interface.cpp index 2223cbeed..2945fcff8 100644 --- a/src/core/arm/arm_interface.cpp +++ b/src/core/arm/arm_interface.cpp @@ -2,26 +2,202 @@ // Licensed under GPLv2 or any later version // Refer to the license.txt file included. +#include +#include +#include "common/bit_field.h" #include "common/common_types.h" #include "common/logging/log.h" #include "core/arm/arm_interface.h" +#include "core/core.h" #include "core/memory.h" namespace Core { -void ARM_Interface::LogBacktrace() const { - VAddr fp = GetReg(29); - VAddr lr = GetReg(30); - const VAddr sp = GetReg(13); - const VAddr pc = GetPC(); - LOG_ERROR(Core_ARM, "Backtrace, sp={:016X}, pc={:016X}", sp, pc); +namespace { + +constexpr u64 ELF_DYNAMIC_TAG_NULL = 0; +constexpr u64 ELF_DYNAMIC_TAG_STRTAB = 5; +constexpr u64 ELF_DYNAMIC_TAG_SYMTAB = 6; +constexpr u64 ELF_DYNAMIC_TAG_SYMENT = 11; + +enum class ELFSymbolType : u8 { + None = 0, + Object = 1, + Function = 2, + Section = 3, + File = 4, + Common = 5, + TLS = 6, +}; + +enum class ELFSymbolBinding : u8 { + Local = 0, + Global = 1, + Weak = 2, +}; + +enum class ELFSymbolVisibility : u8 { + Default = 0, + Internal = 1, + Hidden = 2, + Protected = 3, +}; + +struct ELFSymbol { + u32 name_index; + union { + u8 info; + + BitField<0, 4, ELFSymbolType> type; + BitField<4, 4, ELFSymbolBinding> binding; + }; + ELFSymbolVisibility visibility; + u16 sh_index; + u64 value; + u64 size; +}; +static_assert(sizeof(ELFSymbol) == 0x18, "ELFSymbol has incorrect size."); + +using Symbols = std::vector>; + +Symbols GetSymbols(VAddr text_offset) { + const auto mod_offset = text_offset + Memory::Read32(text_offset + 4); + + if (mod_offset < text_offset || (mod_offset & 0b11) != 0 || + Memory::Read32(mod_offset) != Common::MakeMagic('M', 'O', 'D', '0')) { + return {}; + } + + const auto dynamic_offset = Memory::Read32(mod_offset + 0x4) + mod_offset; + + VAddr string_table_offset{}; + VAddr symbol_table_offset{}; + u64 symbol_entry_size{}; + + VAddr dynamic_index = dynamic_offset; + while (true) { + const auto tag = Memory::Read64(dynamic_index); + const auto value = Memory::Read64(dynamic_index + 0x8); + dynamic_index += 0x10; + + if (tag == ELF_DYNAMIC_TAG_NULL) + break; + + if (tag == ELF_DYNAMIC_TAG_STRTAB) + string_table_offset = value; + else if (tag == ELF_DYNAMIC_TAG_SYMTAB) + symbol_table_offset = value; + else if (tag == ELF_DYNAMIC_TAG_SYMENT) + symbol_entry_size = value; + } + + if (string_table_offset == 0 || symbol_table_offset == 0 || symbol_entry_size == 0) { + return {}; + } + + const auto string_table_address = text_offset + string_table_offset; + const auto symbol_table_address = text_offset + symbol_table_offset; + + Symbols out; + + VAddr symbol_index = symbol_table_address; + while (symbol_index < string_table_address) { + ELFSymbol symbol{}; + Memory::ReadBlock(symbol_index, &symbol, sizeof(ELFSymbol)); + + VAddr string_offset = string_table_address + symbol.name_index; + std::string name; + for (u8 c = Memory::Read8(string_offset); c != 0; c = Memory::Read8(++string_offset)) { + name += static_cast(c); + } + + symbol_index += symbol_entry_size; + out.push_back({symbol, name}); + } + + return out; +} + +std::optional GetSymbolName(const Symbols& symbols, VAddr func_address) { + const auto iter = + std::find_if(symbols.begin(), symbols.end(), [func_address](const auto& pair) { + const auto& [symbol, name] = pair; + const auto end_address = symbol.value + symbol.size; + return func_address >= symbol.value && func_address < end_address; + }); + + if (iter == symbols.end()) + return std::nullopt; + return iter->second; +} + +} // Anonymous namespace + +constexpr u64 SEGMENT_BASE = 0x7100000000ull; + +std::vector ARM_Interface::GetBacktrace() const { + std::vector out; + + auto fp = GetReg(29); + auto lr = GetReg(30); + while (true) { - LOG_ERROR(Core_ARM, "{:016X}", lr); + out.push_back({"", 0, lr, 0}); if (!fp) { break; } lr = Memory::Read64(fp + 8) - 4; fp = Memory::Read64(fp); } + + const auto& modules{System::GetInstance().GetRegisteredNSOModules()}; + std::map symbols; + for (const auto& module : modules) { + symbols.insert_or_assign(module.second, GetSymbols(module.first)); + } + + for (auto& entry : out) { + VAddr base = 0; + for (const auto& module : modules) { + if (entry.original_address >= module.first) { + entry.module = module.second; + base = module.first; + break; + } + } + + entry.offset = entry.original_address - base; + entry.address = SEGMENT_BASE + entry.offset; + + if (entry.module.empty()) + entry.module = "unknown"; + + const auto symbol_set = symbols.find(entry.module); + if (symbol_set != symbols.end()) { + const auto symbol = GetSymbolName(symbol_set->second, entry.offset); + if (symbol.has_value()) { + // TODO(DarkLordZach): Add demangling of symbol names. + entry.name = *symbol; + } + } + } + + return out; } + +void ARM_Interface::LogBacktrace() const { + const VAddr sp = GetReg(13); + const VAddr pc = GetPC(); + LOG_ERROR(Core_ARM, "Backtrace, sp={:016X}, pc={:016X}", sp, pc); + LOG_ERROR(Core_ARM, "{:20}{:20}{:20}{:20}{}", "Module Name", "Address", "Original Address", + "Offset", "Symbol"); + LOG_ERROR(Core_ARM, "{}", std::string(100, '-')); + + const auto backtrace = GetBacktrace(); + for (const auto& entry : backtrace) { + LOG_ERROR(Core_ARM, "{:20}{:016X} {:016X} {:016X} {}", entry.module, entry.address, + entry.original_address, entry.offset, entry.name); + } +} + } // namespace Core diff --git a/src/core/arm/arm_interface.h b/src/core/arm/arm_interface.h index 978b1518f..c6691a8e1 100644 --- a/src/core/arm/arm_interface.h +++ b/src/core/arm/arm_interface.h @@ -5,6 +5,7 @@ #pragma once #include +#include #include "common/common_types.h" namespace Common { @@ -152,6 +153,16 @@ public: /// Prepare core for thread reschedule (if needed to correctly handle state) virtual void PrepareReschedule() = 0; + struct BacktraceEntry { + std::string module; + u64 address; + u64 original_address; + u64 offset; + std::string name; + }; + + std::vector GetBacktrace() const; + /// fp (= r29) points to the last frame record. /// Note that this is the frame record for the *previous* frame, not the current one. /// Note we need to subtract 4 from our last read to get the proper address -- cgit v1.2.3