From 5574be21ccd8cf86eaba5c50d30ad898bafc8ea8 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Fri, 17 May 2019 21:43:26 -0400
Subject: [PATCH] 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 2223cbeed2..2945fcff87 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 <map>
+#include <optional>
+#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<std::pair<ELFSymbol, std::string>>;
+
+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<char>(c);
+ }
+
+ symbol_index += symbol_entry_size;
+ out.push_back({symbol, name});
+ }
+
+ return out;
+}
+
+std::optional<std::string> 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::BacktraceEntry> ARM_Interface::GetBacktrace() const {
+ std::vector<BacktraceEntry> 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<std::string, Symbols> 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 978b1518fd..c6691a8e19 100644
--- a/src/core/arm/arm_interface.h
+++ b/src/core/arm/arm_interface.h
@@ -5,6 +5,7 @@
#pragma once
#include <array>
+#include <vector>
#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<BacktraceEntry> 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
--
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