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Scan for jumptables

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This commit is contained in:
Sajid
2024-09-18 13:07:07 +06:00
parent 7d7ab43bbc
commit 83e4da49e3
3 changed files with 332 additions and 27 deletions
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348
PowerAnalyse/main.cpp
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@@ -6,16 +6,335 @@
#include <print>
#include <xbox.h>
#define SWITCH_ABSOLUTE 0
#define SWITCH_COMPUTED 1
#define SWITCH_BYTEOFFSET 2
#define SWITCH_SHORTOFFSET 3
struct SwitchTable
{
std::vector<size_t> labels{};
size_t base{};
size_t defaultLabel{};
uint32_t r{};
uint32_t type{};
};
void ReadTable(Image& image, SwitchTable& table)
{
uint32_t pOffset;
ppc_insn insn;
auto* code = (uint32_t*)image.Find(table.base);
ppc::Disassemble(code, table.base, insn);
pOffset = insn.operands[1] << 16;
ppc::Disassemble(code + 1, table.base + 4, insn);
pOffset += insn.operands[2];
if (table.type == SWITCH_ABSOLUTE)
{
const auto* offsets = (be<uint32_t>*)image.Find(pOffset);
for (size_t i = 0; i < table.labels.size(); i++)
{
table.labels[i] = offsets[i];
}
}
else if (table.type == SWITCH_COMPUTED)
{
uint32_t base;
uint32_t shift;
const auto* offsets = (uint8_t*)image.Find(pOffset);
ppc::Disassemble(code + 4, table.base + 0x10, insn);
base = insn.operands[1] << 16;
ppc::Disassemble(code + 5, table.base + 0x14, insn);
base += insn.operands[2];
ppc::Disassemble(code + 3, table.base + 0x0C, insn);
shift = insn.operands[2];
for (size_t i = 0; i < table.labels.size(); i++)
{
table.labels[i] = base + (offsets[i] << shift);
}
}
else if (table.type == SWITCH_BYTEOFFSET || table.type == SWITCH_SHORTOFFSET)
{
if (table.type == SWITCH_BYTEOFFSET)
{
const auto* offsets = (uint8_t*)image.Find(pOffset);
uint32_t base;
ppc::Disassemble(code + 3, table.base + 0x0C, insn);
base = insn.operands[1] << 16;
ppc::Disassemble(code + 4, table.base + 0x10, insn);
base += insn.operands[2];
for (size_t i = 0; i < table.labels.size(); i++)
{
table.labels[i] = base + offsets[i];
}
}
else if (table.type == SWITCH_SHORTOFFSET)
{
const auto* offsets = (be<uint16_t>*)image.Find(pOffset);
uint32_t base;
ppc::Disassemble(code + 4, table.base + 0x10, insn);
base = insn.operands[1] << 16;
ppc::Disassemble(code + 5, table.base + 0x14, insn);
base += insn.operands[2];
for (size_t i = 0; i < table.labels.size(); i++)
{
table.labels[i] = base + offsets[i];
}
}
}
else
{
assert(false);
}
}
void ScanTable(const uint32_t* code, size_t base, SwitchTable& table)
{
ppc_insn insn;
uint32_t cr{ (uint32_t)-1 };
for (int i = 0; i < 32; i++)
{
ppc::Disassemble(&code[-i], base - (4 * i), insn);
if (insn.opcode == nullptr)
{
continue;
}
if (cr == -1 && (insn.opcode->id == PPC_INST_BGT || insn.opcode->id == PPC_INST_BGTLR || insn.opcode->id == PPC_INST_BLE || insn.opcode->id == PPC_INST_BLELR))
{
cr = insn.operands[0];
if (insn.opcode->operands[1] != 0)
{
table.defaultLabel = insn.operands[1] + 1;
}
}
else if (cr != -1)
{
if (insn.opcode->id == PPC_INST_CMPLWI && insn.operands[0] == cr)
{
table.r = insn.operands[1];
table.labels.resize(insn.operands[2]);
table.base = base;
break;
}
}
}
}
void MakeMask(const uint32_t* instructions, size_t count)
{
ppc_insn insn;
for (size_t i = 0; i < count; i++)
{
ppc::Disassemble(&instructions[i], 0, insn);
std::println("0x{:X}, // {}", std::byteswap(insn.opcode->opcode | (insn.instruction & insn.opcode->mask)), insn.opcode->name);
}
}
void* SearchMask(const void* source, const uint32_t* compare, size_t compareCount, size_t size)
{
assert(size % 4 == 0);
uint32_t* src = (uint32_t*)source;
size_t count = size / 4;
ppc_insn insn;
for (size_t i = 0; i < count; i++)
{
size_t c = 0;
for (c = 0; c < compareCount; c++)
{
ppc::Disassemble(&src[i + c], 0, insn);
if (insn.opcode == nullptr || insn.opcode->id != compare[c])
{
break;
}
}
if (c == compareCount)
{
return &src[i];
}
}
return nullptr;
}
int main()
{
const auto file = LoadFile("private/default.xex").value();
auto image = Image::ParseImage(file.data(), file.size()).value();
std::string out;
auto println = [&]<class... Args>(std::format_string<Args...> fmt, Args&&... args)
{
std::vformat_to(std::back_inserter(out), fmt.get(), std::make_format_args(args...));
out += '\n';
};
//for (const auto& section : image.sections)
//{
// image.symbols.emplace(section.name, section.base, section.size, Symbol_Section);
//}
// MakeMask((uint32_t*)image.Find(0x82C40D84), 6);
//auto data = "\x4D\x99\x00\x20";
//auto data2 = std::byteswap((2129));
//ppc_insn insn;
//ppc_insn insn2;
//ppc::Disassemble(data, 0, insn);
//ppc::Disassemble(&data2, 0, insn2);
//auto op = PPC_OP(insn.instruction);
//auto xop = PPC_XOP(insn.instruction);
auto printTable = [&](const SwitchTable& table)
{
println("[[switch]]");
println("base = 0x{:X}", table.base);
println("r = {}", table.r);
println("default = 0x{:X}", table.defaultLabel);
println("labels = [");
for (const auto& label : table.labels)
{
println(" 0x{:X},", label);
}
println("]");
println("");
};
std::vector<SwitchTable> switches{};
auto insertTable = [&](size_t base, size_t defaultLabel, size_t r, size_t nLabels, uint32_t type)
{
auto& sw = switches.emplace_back();
sw.base = base;
sw.defaultLabel = defaultLabel;
sw.r = r;
sw.labels.resize(nLabels);
sw.type = type;
};
println("#");
insertTable(0x830ADAD8, 0x830ADB28, 11, 0x1B, SWITCH_COMPUTED);
insertTable(0x830AE1B0, 0x830AE21C, 11, 0x1B, SWITCH_BYTEOFFSET);
insertTable(0x82CFE120, 0x82CFDE68, 11, 0x10, SWITCH_SHORTOFFSET);
println("# ---- MANUAL JUMPTABLE ----");
for (auto& table : switches)
{
ReadTable(image, table);
printTable(table);
}
auto scanPattern = [&](uint32_t* pattern, size_t count, size_t type)
{
for (const auto& section : image.sections)
{
if (!(section.flags & SectionFlags_Code))
{
continue;
}
size_t base = section.base;
uint8_t* data = section.data;
uint8_t* dataStart = section.data;
uint8_t* dataEnd = section.data + section.size;
while (data < dataEnd && data != nullptr)
{
data = (uint8_t*)SearchMask(data, pattern, count, dataEnd - data);
if (data != nullptr)
{
SwitchTable table{};
table.type = type;
ScanTable((uint32_t*)data, base + (data - dataStart), table);
// std::println("{:X} ; jmptable - {}", base + (data - dataStart), table.labels.size());
if (table.defaultLabel != 0)
{
ReadTable(image, table);
printTable(table);
switches.emplace_back(std::move(table));
}
data += 4;
}
continue;
}
}
};
uint32_t absoluteSwitch[] =
{
PPC_INST_LIS,
PPC_INST_ADDI,
PPC_INST_RLWINM,
PPC_INST_LWZX,
PPC_INST_MTCTR,
PPC_INST_BCTR,
};
uint32_t computedSwitch[] =
{
PPC_INST_LIS,
PPC_INST_ADDI,
PPC_INST_LBZX,
PPC_INST_RLWINM,
PPC_INST_LIS,
PPC_INST_ADDI,
PPC_INST_ADD,
PPC_INST_MTCTR,
};
uint32_t offsetSwitch[] =
{
PPC_INST_LIS,
PPC_INST_ADDI,
PPC_INST_LBZX,
PPC_INST_LIS,
PPC_INST_ADDI,
PPC_INST_ADD,
PPC_INST_MTCTR,
};
uint32_t wordOffsetSwitch[] =
{
PPC_INST_LIS,
PPC_INST_ADDI,
PPC_INST_RLWINM,
PPC_INST_LHZX,
PPC_INST_LIS,
PPC_INST_ADDI,
PPC_INST_ADD,
PPC_INST_MTCTR,
};
println("# ---- ABSOLUTE JUMPTABLE ----");
scanPattern(absoluteSwitch, std::size(absoluteSwitch), SWITCH_ABSOLUTE);
println("# ---- COMPUTED JUMPTABLE ----");
scanPattern(computedSwitch, std::size(computedSwitch), SWITCH_COMPUTED);
println("# ---- OFFSETED JUMPTABLE ----");
scanPattern(offsetSwitch, std::size(offsetSwitch), SWITCH_BYTEOFFSET);
scanPattern(wordOffsetSwitch, std::size(wordOffsetSwitch), SWITCH_SHORTOFFSET);
FILE* f = fopen("out/switches.toml", "w");
fwrite(out.data(), 1, out.size(), f);
fclose(f);
uint32_t cxxFrameHandler = std::byteswap(0x831B1C90);
uint32_t cSpecificFrameHandler = std::byteswap(0x8324B3BC);
image.symbols.emplace("__CxxFrameHandler", 0x831B1C90, 0x38, Symbol_Function);
@@ -26,7 +345,7 @@ int main()
image.symbols.emplace(std::format("sub_{:X}", 0x82EF5D78), 0x82EF5D78, 0x3F8, Symbol_Function);
auto fnd = Function::Analyze(image.Find(0x831B1358), image.size, 0x831B1358);
// auto fnd = Function::Analyze(image.Find(0x82C40D58), image.size, 0x82C40D58);
std::vector<Function> functions;
auto& pdata = *image.Find(".pdata");
@@ -45,7 +364,7 @@ int main()
image.symbols.emplace(std::format("sub_{:X}", f.base), f.base, f.size, Symbol_Function);
}
// auto sym = image.symbols.find(0x822C0000);
auto sym = image.symbols.find(0x82C40D58);
std::vector<Function> missingFunctions;
for (const auto& section : image.sections)
@@ -98,32 +417,7 @@ int main()
//uint8_t c[4] = { 0x10, 0x00, 0x59, 0xC3 };
//ppc::Disassemble(c, 0x831D6C64, insn);
//std::println("{:20}{}", insn.opcode->name, insn.op_str);
//for (const auto& section : image.sections)
//{
// if (!(section.flags & SectionFlags_Code))
// {
// continue;
// }
// size_t base = section.base;
// uint8_t* data = section.data;
// uint8_t* dataEnd = section.data + section.size;
// while (data < dataEnd)
// {
// if (*(uint32_t*)data == 0)
// {
// data += 4;
// base += 4;
// continue;
// }
// const auto& fn = functions.emplace_back(Function::Analyze(data, dataEnd - data, base));
// data += fn.size;
// base += fn.size;
// image.symbols.emplace(std::format("sub_{:X}", fn.base), fn.base, fn.size, Symbol_Function);
// }
//}
const auto entrySymbol = image.symbols.find(image.entry_point);
assert(entrySymbol != image.symbols.end());

9
PowerUtils/disasm.cpp
View File

@@ -22,3 +22,12 @@ int ppc::DisassemblerEngine::Disassemble(const void* code, size_t size, uint64_t
info.buffer_length = size;
return decode_insn_ppc(base, &info, &out);
}
int ppc::Disassemble(const void* code, uint64_t base, ppc_insn* out, size_t nOut)
{
for (size_t i = 0; i < nOut; i++)
{
Disassemble(static_cast<const uint32_t*>(code) + i, base, out[i]);
}
return static_cast<int>(nOut) * 4;
}

2
PowerUtils/disasm.h
View File

@@ -30,4 +30,6 @@ namespace ppc
{
return Disassemble(code, 4, base, out);
}
static int Disassemble(const void* code, uint64_t base, ppc_insn* out, size_t nOut);
}