ladybird/Userland/Libraries/LibELF/Image.h
2022-04-01 21:24:45 +01:00

366 lines
11 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Concepts.h>
#include <AK/Vector.h>
#include <Kernel/VirtualAddress.h>
#include <LibC/elf.h>
#ifndef KERNEL
# include <AK/String.h>
#endif
namespace ELF {
class Image {
public:
explicit Image(ReadonlyBytes, bool verbose_logging = true);
explicit Image(u8 const*, size_t, bool verbose_logging = true);
~Image() = default;
void dump() const;
bool is_valid() const { return m_valid; }
bool parse();
bool is_within_image(void const* address, size_t size) const
{
if (address < m_buffer)
return false;
if (((u8 const*)address + size) > m_buffer + m_size)
return false;
return true;
}
class Section;
class RelocationSection;
class Symbol;
class Relocation;
class Symbol {
public:
Symbol(Image const& image, unsigned index, const ElfW(Sym) & sym)
: m_image(image)
, m_sym(sym)
, m_index(index)
{
}
~Symbol() = default;
StringView name() const { return m_image.table_string(m_sym.st_name); }
unsigned section_index() const { return m_sym.st_shndx; }
FlatPtr value() const { return m_sym.st_value; }
size_t size() const { return m_sym.st_size; }
unsigned index() const { return m_index; }
#if ARCH(I386)
unsigned type() const
{
return ELF32_ST_TYPE(m_sym.st_info);
}
unsigned bind() const { return ELF32_ST_BIND(m_sym.st_info); }
#else
unsigned type() const
{
return ELF64_ST_TYPE(m_sym.st_info);
}
unsigned bind() const { return ELF64_ST_BIND(m_sym.st_info); }
#endif
Section section() const
{
return m_image.section(section_index());
}
bool is_undefined() const { return section_index() == 0; }
StringView raw_data() const;
private:
Image const& m_image;
const ElfW(Sym) & m_sym;
unsigned const m_index;
};
class ProgramHeader {
public:
ProgramHeader(Image const& image, unsigned program_header_index)
: m_image(image)
, m_program_header(image.program_header_internal(program_header_index))
, m_program_header_index(program_header_index)
{
}
~ProgramHeader() = default;
unsigned index() const { return m_program_header_index; }
u32 type() const { return m_program_header.p_type; }
u32 flags() const { return m_program_header.p_flags; }
size_t offset() const { return m_program_header.p_offset; }
VirtualAddress vaddr() const { return VirtualAddress(m_program_header.p_vaddr); }
size_t size_in_memory() const { return m_program_header.p_memsz; }
size_t size_in_image() const { return m_program_header.p_filesz; }
size_t alignment() const { return m_program_header.p_align; }
bool is_readable() const { return flags() & PF_R; }
bool is_writable() const { return flags() & PF_W; }
bool is_executable() const { return flags() & PF_X; }
char const* raw_data() const { return m_image.raw_data(m_program_header.p_offset); }
ElfW(Phdr) raw_header() const { return m_program_header; }
private:
Image const& m_image;
const ElfW(Phdr) & m_program_header;
unsigned m_program_header_index { 0 };
};
class Section {
public:
Section(Image const& image, unsigned sectionIndex)
: m_image(image)
, m_section_header(image.section_header(sectionIndex))
, m_section_index(sectionIndex)
{
}
~Section() = default;
StringView name() const { return m_image.section_header_table_string(m_section_header.sh_name); }
u32 type() const { return m_section_header.sh_type; }
size_t offset() const { return m_section_header.sh_offset; }
size_t size() const { return m_section_header.sh_size; }
size_t entry_size() const { return m_section_header.sh_entsize; }
size_t entry_count() const { return !entry_size() ? 0 : size() / entry_size(); }
FlatPtr address() const { return m_section_header.sh_addr; }
char const* raw_data() const { return m_image.raw_data(m_section_header.sh_offset); }
ReadonlyBytes bytes() const { return { raw_data(), size() }; }
Optional<RelocationSection> relocations() const;
auto flags() const { return m_section_header.sh_flags; }
bool is_writable() const { return flags() & SHF_WRITE; }
bool is_executable() const { return flags() & PF_X; }
protected:
friend class RelocationSection;
Image const& m_image;
const ElfW(Shdr) & m_section_header;
unsigned m_section_index;
};
class RelocationSection : public Section {
public:
explicit RelocationSection(Section const& section)
: Section(section.m_image, section.m_section_index)
{
}
size_t relocation_count() const { return entry_count(); }
Relocation relocation(unsigned index) const;
template<VoidFunction<Image::Relocation&> F>
void for_each_relocation(F) const;
};
class Relocation {
public:
Relocation(Image const& image, const ElfW(Rel) & rel)
: m_image(image)
, m_rel(rel)
{
}
~Relocation() = default;
size_t offset() const { return m_rel.r_offset; }
#if ARCH(I386)
unsigned type() const
{
return ELF32_R_TYPE(m_rel.r_info);
}
unsigned symbol_index() const { return ELF32_R_SYM(m_rel.r_info); }
#else
unsigned type() const
{
return ELF64_R_TYPE(m_rel.r_info);
}
unsigned symbol_index() const { return ELF64_R_SYM(m_rel.r_info); }
#endif
Symbol symbol() const
{
return m_image.symbol(symbol_index());
}
private:
Image const& m_image;
const ElfW(Rel) & m_rel;
};
unsigned symbol_count() const;
unsigned section_count() const;
unsigned program_header_count() const;
Symbol symbol(unsigned) const;
Section section(unsigned) const;
ProgramHeader program_header(unsigned) const;
FlatPtr program_header_table_offset() const;
template<IteratorFunction<Image::Section> F>
void for_each_section(F) const;
template<VoidFunction<Section> F>
void for_each_section(F) const;
template<IteratorFunction<Section&> F>
void for_each_section_of_type(unsigned, F) const;
template<VoidFunction<Section&> F>
void for_each_section_of_type(unsigned, F) const;
template<IteratorFunction<Symbol> F>
void for_each_symbol(F) const;
template<VoidFunction<Symbol> F>
void for_each_symbol(F) const;
template<IteratorFunction<ProgramHeader> F>
void for_each_program_header(F func) const;
template<VoidFunction<ProgramHeader> F>
void for_each_program_header(F) const;
Optional<Section> lookup_section(StringView name) const;
bool is_executable() const { return header().e_type == ET_EXEC; }
bool is_relocatable() const { return header().e_type == ET_REL; }
bool is_dynamic() const { return header().e_type == ET_DYN; }
VirtualAddress entry() const { return VirtualAddress(header().e_entry); }
FlatPtr base_address() const { return (FlatPtr)m_buffer; }
size_t size() const { return m_size; }
static Optional<StringView> object_file_type_to_string(ElfW(Half) type);
static Optional<StringView> object_machine_type_to_string(ElfW(Half) type);
static Optional<StringView> object_abi_type_to_string(Elf_Byte type);
bool has_symbols() const { return symbol_count(); }
#ifndef KERNEL
Optional<Symbol> find_demangled_function(StringView name) const;
String symbolicate(FlatPtr address, u32* offset = nullptr) const;
#endif
Optional<Image::Symbol> find_symbol(FlatPtr address, u32* offset = nullptr) const;
private:
char const* raw_data(unsigned offset) const;
const ElfW(Ehdr) & header() const;
const ElfW(Shdr) & section_header(unsigned) const;
const ElfW(Phdr) & program_header_internal(unsigned) const;
StringView table_string(unsigned offset) const;
StringView section_header_table_string(unsigned offset) const;
StringView section_index_to_string(unsigned index) const;
StringView table_string(unsigned table_index, unsigned offset) const;
u8 const* m_buffer { nullptr };
size_t m_size { 0 };
bool m_verbose_logging { true };
bool m_valid { false };
unsigned m_symbol_table_section_index { 0 };
unsigned m_string_table_section_index { 0 };
#ifndef KERNEL
struct SortedSymbol {
FlatPtr address;
StringView name;
String demangled_name;
Optional<Image::Symbol> symbol;
};
void sort_symbols() const;
SortedSymbol* find_sorted_symbol(FlatPtr) const;
mutable Vector<SortedSymbol> m_sorted_symbols;
#endif
};
template<IteratorFunction<Image::Section> F>
inline void Image::for_each_section(F func) const
{
auto section_count = this->section_count();
for (unsigned i = 0; i < section_count; ++i) {
if (func(section(i)) == IterationDecision::Break)
break;
}
}
template<VoidFunction<Image::Section> F>
inline void Image::for_each_section(F func) const
{
for_each_section([&](auto section) {
func(move(section));
return IterationDecision::Continue;
});
}
template<IteratorFunction<Image::Section&> F>
inline void Image::for_each_section_of_type(unsigned type, F func) const
{
auto section_count = this->section_count();
for (unsigned i = 0; i < section_count; ++i) {
auto section = this->section(i);
if (section.type() == type) {
if (func(section) == IterationDecision::Break)
break;
}
}
}
template<VoidFunction<Image::Section&> F>
inline void Image::for_each_section_of_type(unsigned type, F func) const
{
for_each_section_of_type(type, [&](auto& section) {
func(section);
return IterationDecision::Continue;
});
}
template<VoidFunction<Image::Relocation&> F>
inline void Image::RelocationSection::for_each_relocation(F func) const
{
auto relocation_count = this->relocation_count();
for (unsigned i = 0; i < relocation_count; ++i) {
func(relocation(i));
}
}
template<IteratorFunction<Image::Symbol> F>
inline void Image::for_each_symbol(F func) const
{
auto symbol_count = this->symbol_count();
for (unsigned i = 0; i < symbol_count; ++i) {
if (func(symbol(i)) == IterationDecision::Break)
break;
}
}
template<VoidFunction<Image::Symbol> F>
inline void Image::for_each_symbol(F func) const
{
for_each_symbol([&](auto symbol) {
func(move(symbol));
return IterationDecision::Continue;
});
}
template<IteratorFunction<Image::ProgramHeader> F>
inline void Image::for_each_program_header(F func) const
{
auto program_header_count = this->program_header_count();
for (unsigned i = 0; i < program_header_count; ++i) {
if (func(program_header(i)) == IterationDecision::Break)
break;
}
}
template<VoidFunction<Image::ProgramHeader> F>
inline void Image::for_each_program_header(F func) const
{
for_each_program_header([&](auto header) {
func(move(header));
return IterationDecision::Continue;
});
}
} // end namespace ELF