Logic for PE, and a couple tweaks

This commit is contained in:
Jeremy 2024-03-09 21:25:57 -06:00
parent f135232933
commit e80a11d730
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GPG Key ID: BE03111EB7ED6E2E
4 changed files with 49 additions and 26 deletions

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@ -583,7 +583,7 @@ namespace detail {
return monostate{};
}
// If this is reached... something went wrong. The cpu we're on wasn't found.
throw internal_error("Couldn't find appropriate architecture in fat Mach-O");
return internal_error("Couldn't find appropriate architecture in fat Mach-O");
}
template<std::size_t Bits>

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@ -56,8 +56,8 @@ namespace detail {
if(it == cache.end()) {
// arguably it'd be better to release the lock while computing this, but also arguably it's good to not
// have two threads try to do the same computation
// TODO: Cache the error
auto obj = mach_o::open_mach_o(object_path);
// TODO: Cache the error
if(!obj) {
return obj.unwrap_error();
}
@ -81,7 +81,11 @@ namespace detail {
// arguably it'd be better to release the lock while computing this, but also arguably it's good to not
// have two threads try to do the same computation
auto base = pe_get_module_image_base(object_path);
cache.insert(it, {object_path, base});
// TODO: Cache the error
if(!base) {
return base.unwrap_error();
}
cache.insert(it, {object_path, base.unwrap_value()});
return base;
} else {
return it->second;

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@ -138,7 +138,7 @@ namespace detail {
inline object_frame resolve_safe_object_frame(const safe_object_frame& frame) {
auto base = get_module_image_base(frame.object_path);
if(base.is_error()) {
throw base.unwrap_error();
throw base.unwrap_error(); // This throw is intentional
}
return {
frame.raw_address,

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@ -26,7 +26,7 @@ namespace detail {
}
}
inline std::uintptr_t pe_get_module_image_base(const std::string& object_path) {
inline Result<std::uintptr_t, internal_error> pe_get_module_image_base(const std::string& object_path) {
// https://drive.google.com/file/d/0B3_wGJkuWLytbnIxY1J5WUs4MEk/view?pli=1&resourcekey=0-n5zZ2UW39xVTH8ZSu6C2aQ
// https://0xrick.github.io/win-internals/pe3/
// Endianness should always be little for dos and pe headers
@ -37,18 +37,37 @@ namespace detail {
throw file_error("Unable to read object file " + object_path);
}
auto magic = load_bytes<std::array<char, 2>>(file, 0);
VERIFY(std::memcmp(magic.data(), "MZ", 2) == 0, "File is not a PE file " + object_path);
DWORD e_lfanew = pe_byteswap_if_needed(load_bytes<DWORD>(file, 0x3c)); // dos header + 0x3c
DWORD nt_header_offset = e_lfanew;
if(!magic) {
return magic.unwrap_error();
}
if(std::memcmp(magic.unwrap_value().data(), "MZ", 2) != 0) {
return internal_error("File is not a PE file " + object_path);
}
auto e_lfanew = load_bytes<DWORD>(file, 0x3c); // dos header + 0x3c
if(!e_lfanew) {
return e_lfanew.unwrap_error();
}
DWORD nt_header_offset = pe_byteswap_if_needed(e_lfanew.unwrap_value());
auto signature = load_bytes<std::array<char, 4>>(file, nt_header_offset); // nt header + 0
VERIFY(std::memcmp(signature.data(), "PE\0\0", 4) == 0, "File is not a PE file " + object_path);
WORD size_of_optional_header = pe_byteswap_if_needed(
load_bytes<WORD>(file, nt_header_offset + 4 + 0x10) // file header + 0x10
);
VERIFY(size_of_optional_header != 0);
WORD optional_header_magic = pe_byteswap_if_needed(
load_bytes<WORD>(file, nt_header_offset + 0x18) // optional header + 0x0
);
if(!signature) {
return signature.unwrap_error();
}
if(std::memcmp(signature.unwrap_value().data(), "PE\0\0", 4) != 0) {
return internal_error("File is not a PE file " + object_path);
}
auto size_of_optional_header_raw = load_bytes<WORD>(file, nt_header_offset + 4 + 0x10); // file header + 0x10
if(!size_of_optional_header_raw) {
return size_of_optional_header_raw.unwrap_error();
}
WORD size_of_optional_header = pe_byteswap_if_needed(size_of_optional_header_raw.unwrap_value());
if(size_of_optional_header == 0) {
return internal_error("Unexpected optional header size for PE file");
}
auto optional_header_magic_raw = load_bytes<WORD>(file, nt_header_offset + 0x18); // optional header + 0x0
if(!optional_header_magic_raw) {
return optional_header_magic_raw.unwrap_error();
}
WORD optional_header_magic = pe_byteswap_if_needed(optional_header_magic_raw.unwrap_value());
VERIFY(
optional_header_magic == IMAGE_NT_OPTIONAL_HDR_MAGIC,
"PE file does not match expected bit-mode " + object_path
@ -56,19 +75,19 @@ namespace detail {
// finally get image base
if(optional_header_magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
// 32 bit
return to<std::uintptr_t>(
pe_byteswap_if_needed(
load_bytes<DWORD>(file, nt_header_offset + 0x18 + 0x1c) // optional header + 0x1c
)
);
auto bytes = load_bytes<DWORD>(file, nt_header_offset + 0x18 + 0x1c); // optional header + 0x1c
if(!bytes) {
return bytes.unwrap_error();
}
return to<std::uintptr_t>(pe_byteswap_if_needed(bytes.unwrap_value()));
} else {
// 64 bit
// I get an "error: 'QWORD' was not declared in this scope" for some reason when using QWORD
return to<std::uintptr_t>(
pe_byteswap_if_needed(
load_bytes<unsigned __int64>(file, nt_header_offset + 0x18 + 0x18) // optional header + 0x18
)
);
auto bytes = load_bytes<unsigned __int64>(file, nt_header_offset + 0x18 + 0x18); // optional header + 0x18
if(!bytes) {
return bytes.unwrap_error();
}
return to<std::uintptr_t>(pe_byteswap_if_needed(bytes.unwrap_value()));
}
}
}