skyline/app/src/main/cpp/skyline/loader/loader.cpp
2023-05-05 18:16:17 +02:00

216 lines
12 KiB
C++

// SPDX-License-Identifier: MPL-2.0
// Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)
#include <dlfcn.h>
#include <cxxabi.h>
#include <nce.h>
#include <os.h>
#include <kernel/types/KProcess.h>
#include <kernel/memory.h>
#include <hle/symbol_hook_table.h>
#include "loader.h"
namespace skyline::loader {
Loader::ExecutableLoadInfo Loader::LoadExecutable(const std::shared_ptr<kernel::type::KProcess> &process, const DeviceState &state, Executable &executable, size_t offset, const std::string &name, bool dynamicallyLinked) {
u8 *base{reinterpret_cast<u8 *>(process->memory.code.data() + offset)};
size_t textSize{executable.text.contents.size()};
size_t roSize{executable.ro.contents.size()};
size_t dataSize{executable.data.contents.size() + executable.bssSize};
if (!util::IsPageAligned(textSize) || !util::IsPageAligned(roSize) || !util::IsPageAligned(dataSize))
throw exception("Sections are not aligned with page size: 0x{:X}, 0x{:X}, 0x{:X}", textSize, roSize, dataSize);
if (executable.text.offset != 0)
throw exception("Executable's .text offset is not 0: 0x{:X}", executable.text.offset);
if (!util::IsPageAligned(executable.text.offset) || !util::IsPageAligned(executable.ro.offset) || !util::IsPageAligned(executable.data.offset))
throw exception("Section offsets are not aligned with page size: 0x{:X}, 0x{:X}, 0x{:X}", executable.text.offset, executable.ro.offset, executable.data.offset);
auto patch{state.nce->GetPatchData(executable.text.contents)};
span dynsym{reinterpret_cast<Elf64_Sym *>(executable.ro.contents.data() + executable.dynsym.offset), executable.dynsym.size / sizeof(Elf64_Sym)};
span dynstr{reinterpret_cast<char *>(executable.ro.contents.data() + executable.dynstr.offset), executable.dynstr.size};
std::vector<nce::NCE::HookedSymbolEntry> executableSymbols;
size_t hookSize{};
if (dynamicallyLinked) {
if constexpr (!hle::HookedSymbols.empty()) {
for (auto &symbol : dynsym) {
if (symbol.st_name == 0 || symbol.st_value == 0)
continue;
if (ELF64_ST_TYPE(symbol.st_info) != STT_FUNC || ELF64_ST_BIND(symbol.st_info) != STB_GLOBAL || symbol.st_shndx == SHN_UNDEF)
continue;
std::string_view symbolName{dynstr.data() + symbol.st_name};
auto item{std::find_if(hle::HookedSymbols.begin(), hle::HookedSymbols.end(), [&symbolName](const auto &item) {
return item.name == symbolName;
})};
if (item != hle::HookedSymbols.end()) {
executableSymbols.emplace_back(std::string{symbolName}, item->hook, &symbol.st_value);
continue;
}
#ifdef PRINT_HOOK_ALL
if (symbolName == "memcpy" || symbolName == "memcmp" || symbolName == "memset" || symbolName == "strcmp" || symbolName == "strlen")
// If symbol is from libc (such as memcpy, strcmp, strlen, etc), we don't need to hook it
continue;
executableSymbols.emplace_back(std::string{symbolName}, hle::EntryExitHook{
.entry = [](const DeviceState &, const hle::HookedSymbol &symbol) {
Logger::Error("Entering \"{}\" ({})", symbol.prettyName, symbol.name);
},
.exit = [](const DeviceState &, const hle::HookedSymbol &symbol) {
Logger::Error("Exiting \"{}\"", symbol.prettyName);
},
}, &symbol.st_value);
#endif
}
}
#ifdef PRINT_HOOK_ALL
for (auto &symbol : dynsym) {
if (symbolName == "memcpy" || symbolName == "memcmp" || symbolName == "memset" || symbolName == "strcmp" || symbolName == "strlen")
// If symbol is from libc (such as memcpy, strcmp, strlen, etc), we don't need to hook it
continue;
executableSymbols.emplace_back(std::string{symbolName}, hle::EntryExitHook{
.entry = [](const DeviceState &, const hle::HookedSymbol &symbol) {
Logger::Error("Entering \"{}\" ({})", symbol.prettyName, symbol.name);
},
.exit = [](const DeviceState &, const hle::HookedSymbol &symbol) {
Logger::Error("Exiting \"{}\"", symbol.prettyName);
},
}, &symbol.st_value);
}
#endif
hookSize = util::AlignUp(state.nce->GetHookSectionSize(executableSymbols), PAGE_SIZE);
}
if (process->memory.addressSpaceType == memory::AddressSpaceType::AddressSpace36Bit) {
process->memory.MapHeapMemory(span<u8>{base, patch.size + hookSize}); // ---
process->memory.SetRegionPermission(span<u8>{base, patch.size + hookSize}, memory::Permission{false, false, false});
} else {
process->memory.Reserve(span<u8>{base, patch.size + hookSize}); // ---
}
Logger::Debug("Successfully mapped section .patch @ 0x{:X}, Size = 0x{:X}", base, patch.size);
if (hookSize > 0)
Logger::Debug("Successfully mapped section .hook @ 0x{:X}, Size = 0x{:X}", base + patch.size, hookSize);
u8 *executableBase{base + patch.size + hookSize};
process->memory.MapCodeMemory(span<u8>{executableBase + executable.text.offset, textSize}, memory::Permission{true, false, true}); // R-X
Logger::Debug("Successfully mapped section .text @ 0x{:X}, Size = 0x{:X}", executableBase, textSize);
process->memory.MapCodeMemory(span<u8>{executableBase + executable.ro.offset, roSize}, memory::Permission{true, false, false}); // R--
Logger::Debug("Successfully mapped section .rodata @ 0x{:X}, Size = 0x{:X}", executableBase + executable.ro.offset, roSize);
process->memory.MapMutableCodeMemory(span<u8>{executableBase + executable.data.offset, dataSize}); // RW-
Logger::Debug("Successfully mapped section .data + .bss @ 0x{:X}, Size = 0x{:X}", executableBase + executable.data.offset, dataSize);
size_t size{patch.size + hookSize + textSize + roSize + dataSize};
{
// Note: We need to copy out the symbols here as it'll be overwritten by any hooks
ExecutableSymbolicInfo symbolicInfo{
.patchStart = base,
.hookStart = base + patch.size,
.programStart = executableBase,
.programEnd = base + size,
.name = name,
.patchName = name + ".patch",
.hookName = name + ".hook",
.symbols = {dynsym.begin(), dynsym.end()},
.symbolStrings = {dynstr.begin(), dynstr.end()},
};
executables.insert(std::upper_bound(executables.begin(), executables.end(), base, [](void *ptr, const ExecutableSymbolicInfo &it) { return ptr < it.patchStart; }), std::move(symbolicInfo));
}
state.nce->PatchCode(executable.text.contents, reinterpret_cast<u32 *>(base), patch.size, patch.offsets, hookSize);
if (hookSize)
state.nce->WriteHookSection(executableSymbols, span<u8>{base + patch.size, hookSize}.cast<u32>());
std::memcpy(executableBase, executable.text.contents.data(), executable.text.contents.size());
std::memcpy(executableBase + executable.ro.offset, executable.ro.contents.data(), roSize);
std::memcpy(executableBase + executable.data.offset, executable.data.contents.data(), dataSize - executable.bssSize);
Logger::EmulationContext.Flush();
return {base, size, executableBase + executable.text.offset};
}
Loader::SymbolInfo Loader::ResolveSymbol(void *ptr) {
auto executable{std::lower_bound(executables.begin(), executables.end(), ptr, [](const ExecutableSymbolicInfo &it, void *ptr) { return it.programEnd < ptr; })};
if (executable != executables.end() && ptr >= executable->patchStart && ptr <= executable->programEnd) {
if (ptr >= executable->programStart) {
auto offset{reinterpret_cast<u8 *>(ptr) - reinterpret_cast<u8 *>(executable->programStart)};
auto symbol{std::find_if(executable->symbols.begin(), executable->symbols.end(), [&offset](const Elf64_Sym &sym) { return sym.st_value <= offset && sym.st_value + sym.st_size > offset; })};
if (symbol != executable->symbols.end() && symbol->st_name && symbol->st_name < executable->symbolStrings.size()) {
return {executable->symbolStrings.data() + symbol->st_name, executable->name};
} else {
return {.executableName = executable->name};
}
} else if (ptr >= executable->hookStart) {
return {.executableName = executable->hookName};
} else {
return {.executableName = executable->patchName};
}
}
return {};
}
inline std::string GetFunctionStackTrace(Loader *loader, void *pointer) {
Dl_info info;
auto symbol{loader->ResolveSymbol(pointer)};
if (symbol.name) {
int status{};
size_t length{};
std::unique_ptr<char, decltype(&std::free)> demangled{abi::__cxa_demangle(symbol.name, nullptr, &length, &status), std::free};
return fmt::format("\n* 0x{:X} ({} from {})", reinterpret_cast<uintptr_t>(pointer), (status == 0) ? std::string_view(demangled.get()) : symbol.name, symbol.executableName);
} else if (!symbol.executableName.empty()) {
return fmt::format("\n* 0x{:X} (from {})", reinterpret_cast<uintptr_t>(pointer), symbol.executableName);
} else if (dladdr(pointer, &info)) {
int status{};
size_t length{};
std::unique_ptr<char, decltype(&std::free)> demangled{abi::__cxa_demangle(info.dli_sname, nullptr, &length, &status), std::free};
auto extractFilename{[](const char *path) {
const char *filename{path};
for (const char *p{path}; *p; p++)
if (*p == '/')
filename = p + 1;
return filename;
}}; //!< Extracts the filename from a path as we only want the filename of a shared object
if (info.dli_sname && info.dli_fname)
return fmt::format("\n* 0x{:X} ({} from {})", reinterpret_cast<uintptr_t>(pointer), (status == 0) ? std::string_view(demangled.get()) : info.dli_sname, extractFilename(info.dli_fname));
else if (info.dli_sname)
return fmt::format("\n* 0x{:X} ({})", reinterpret_cast<uintptr_t>(pointer), (status == 0) ? std::string_view(demangled.get()) : info.dli_sname);
else if (info.dli_fname)
return fmt::format("\n* 0x{:X} (from {})", reinterpret_cast<uintptr_t>(pointer), extractFilename(info.dli_fname));
else
return fmt::format("\n* 0x{:X}", reinterpret_cast<uintptr_t>(pointer));
} else {
return fmt::format("\n* 0x{:X}", reinterpret_cast<uintptr_t>(pointer));
}
}
std::string Loader::GetStackTrace(signal::StackFrame *frame) {
std::string trace;
if (!frame)
asm("MOV %0, FP" : "=r"(frame));
while (frame) {
trace += GetFunctionStackTrace(this, frame->lr);
frame = frame->next;
}
return trace;
}
std::string Loader::GetStackTrace(const std::vector<void *> &frames) {
std::string trace;
for (const auto &frame : frames)
trace += GetFunctionStackTrace(this, frame);
return trace;
}
}