mirror of
https://github.com/rui314/mold.git
synced 2024-09-11 13:06:59 +03:00
2900 lines
84 KiB
C++
2900 lines
84 KiB
C++
#pragma once
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#include "elf.h"
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#include "../common/common.h"
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#include <atomic>
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#include <bitset>
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#include <cassert>
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#include <cstdint>
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#include <fstream>
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#include <functional>
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#include <iostream>
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#include <map>
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#include <memory>
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#include <mutex>
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#include <optional>
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#include <span>
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#include <sstream>
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#include <string>
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#include <string_view>
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#include <tbb/concurrent_hash_map.h>
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#include <tbb/concurrent_unordered_map.h>
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#include <tbb/concurrent_vector.h>
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#include <tbb/enumerable_thread_specific.h>
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#include <tbb/spin_mutex.h>
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#include <tbb/task_group.h>
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#include <type_traits>
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#include <unordered_map>
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#include <unordered_set>
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#include <variant>
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#include <vector>
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#ifndef _WIN32
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# include <unistd.h>
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#endif
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namespace mold::elf {
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template <typename E> class InputFile;
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template <typename E> class InputSection;
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template <typename E> class MergedSection;
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template <typename E> class ObjectFile;
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template <typename E> class Chunk;
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template <typename E> class OutputSection;
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template <typename E> class SharedFile;
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template <typename E> class Symbol;
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template <typename E> struct CieRecord;
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template <typename E> struct Context;
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template <typename E> struct FdeRecord;
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template <typename E> class RelocSection;
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template <typename E>
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std::ostream &operator<<(std::ostream &out, const Symbol<E> &sym);
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//
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// Mergeable section fragments
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//
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template <typename E>
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struct SectionFragment {
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SectionFragment(MergedSection<E> *sec, bool is_alive)
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: output_section(*sec), is_alive(is_alive) {}
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u64 get_addr(Context<E> &ctx) const;
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MergedSection<E> &output_section;
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u32 offset = -1;
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Atomic<u8> p2align = 0;
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Atomic<bool> is_alive = false;
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};
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// Additional class members for dynamic symbols. Because most symbols
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// don't need them and we allocate tens of millions of symbol objects
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// for large programs, we separate them from `Symbol` class to save
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// memory.
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template <typename E>
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struct SymbolAux {
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i32 got_idx = -1;
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i32 gottp_idx = -1;
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i32 tlsgd_idx = -1;
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i32 tlsdesc_idx = -1;
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i32 plt_idx = -1;
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i32 pltgot_idx = -1;
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i32 dynsym_idx = -1;
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u32 djb_hash = 0;
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};
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template <>
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struct SymbolAux<PPC64V1> : SymbolAux<X86_64> {
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i32 opd_idx = -1;
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};
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//
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// thunks.cc
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//
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template <typename E>
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class Thunk {};
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template <needs_thunk E>
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class Thunk<E> {
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public:
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Thunk(OutputSection<E> &osec, i64 offset)
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: output_section(osec), offset(offset) {}
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i64 size() const { return E::thunk_hdr_size + symbols.size() * E::thunk_size; }
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void copy_buf(Context<E> &ctx);
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u64 get_addr(i64 idx) const {
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return output_section.shdr.sh_addr + offset + E::thunk_hdr_size +
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idx * E::thunk_size;
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}
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static constexpr i64 alignment = 16;
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OutputSection<E> &output_section;
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i64 offset;
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std::mutex mu;
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std::vector<Symbol<E> *> symbols;
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};
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struct ThunkRef {
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i16 thunk_idx = -1;
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i16 sym_idx = -1;
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};
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//
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// input-sections.cc
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//
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// .eh_frame section contains CIE and FDE records to teach the runtime
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// how to handle exceptions. Usually, a .eh_frame contains one CIE
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// followed by as many FDEs as the number of functions defined by the
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// file. CIE contains common information for FDEs (it is actually
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// short for Common Information Entry). FDE contains the start address
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// of a function and its length as well as how to handle exceptions
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// for that function.
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//
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// Unlike other sections, the linker has to parse .eh_frame for optimal
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// output for the following reasons:
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//
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// - Compilers tend to emit the same CIE as long as the programming
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// language is the same, so CIEs in input object files are almost
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// always identical. We want to merge them to make a resulting
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// .eh_frame smaller.
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//
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// - If we eliminate a function (e.g. when we see two object files
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// containing the duplicate definition of an inlined function), we
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// want to also eliminate a corresponding FDE so that a resulting
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// .eh_frame doesn't contain a dead FDE entry.
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//
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// - If we need to compare two function definitions for equality for
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// ICF, we need to compare not only the function body but also its
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// exception handlers.
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//
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// Note that we assume that the first relocation entry for an FDE
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// always points to the function that the FDE is associated to.
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template <typename E>
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struct CieRecord {
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CieRecord(Context<E> &ctx, ObjectFile<E> &file, InputSection<E> &isec,
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u32 input_offset, std::span<ElfRel<E>> rels, u32 rel_idx)
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: file(file), input_section(isec), input_offset(input_offset),
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rel_idx(rel_idx), rels(rels), contents(file.get_string(ctx, isec.shdr())) {}
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i64 size() const {
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return *(U32<E> *)(contents.data() + input_offset) + 4;
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}
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std::string_view get_contents() const {
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return contents.substr(input_offset, size());
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}
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std::span<ElfRel<E>> get_rels() const {
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i64 end = rel_idx;
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while (end < rels.size() && rels[end].r_offset < input_offset + size())
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end++;
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return rels.subspan(rel_idx, end - rel_idx);
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}
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bool equals(const CieRecord &other) const;
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ObjectFile<E> &file;
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InputSection<E> &input_section;
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u32 input_offset = -1;
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u32 output_offset = -1;
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u32 rel_idx = -1;
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u32 icf_idx = -1;
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bool is_leader = false;
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std::span<ElfRel<E>> rels;
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std::string_view contents;
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};
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template <typename E>
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struct FdeRecord {
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FdeRecord(u32 input_offset, u32 rel_idx)
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: input_offset(input_offset), rel_idx(rel_idx) {}
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i64 size(ObjectFile<E> &file) const;
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std::string_view get_contents(ObjectFile<E> &file) const;
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std::span<ElfRel<E>> get_rels(ObjectFile<E> &file) const;
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u32 input_offset = -1;
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u32 output_offset = -1;
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u32 rel_idx = -1;
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u16 cie_idx = -1;
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Atomic<bool> is_alive = true;
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};
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// A struct to hold target-dependent input section members.
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template <typename E>
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struct InputSectionExtras {};
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template <needs_thunk E>
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struct InputSectionExtras<E> {
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std::vector<ThunkRef> thunk_refs;
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};
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template <is_riscv E>
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struct InputSectionExtras<E> {
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std::vector<i32> r_deltas;
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};
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// InputSection represents a section in an input object file.
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template <typename E>
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class InputSection {
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public:
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InputSection(Context<E> &ctx, ObjectFile<E> &file, i64 shndx);
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void uncompress(Context<E> &ctx);
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void uncompress_to(Context<E> &ctx, u8 *buf);
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void scan_relocations(Context<E> &ctx);
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void write_to(Context<E> &ctx, u8 *buf);
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void apply_reloc_alloc(Context<E> &ctx, u8 *base);
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void apply_reloc_nonalloc(Context<E> &ctx, u8 *base);
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void kill();
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std::string_view name() const;
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i64 get_priority() const;
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u64 get_addr() const;
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const ElfShdr<E> &shdr() const;
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std::span<ElfRel<E>> get_rels(Context<E> &ctx) const;
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std::span<FdeRecord<E>> get_fdes() const;
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std::string_view get_func_name(Context<E> &ctx, i64 offset) const;
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bool is_relr_reloc(Context<E> &ctx, const ElfRel<E> &rel) const;
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bool is_killed_by_icf() const;
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bool record_undef_error(Context<E> &ctx, const ElfRel<E> &rel);
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ObjectFile<E> &file;
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OutputSection<E> *output_section = nullptr;
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u64 sh_size = -1;
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std::string_view contents;
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[[no_unique_address]] InputSectionExtras<E> extra;
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i32 fde_begin = -1;
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i32 fde_end = -1;
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u64 offset = -1;
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u32 shndx = -1;
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u32 relsec_idx = -1;
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u32 reldyn_offset = 0;
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bool uncompressed = false;
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// For COMDAT de-duplication and garbage collection
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std::atomic_bool is_alive = true;
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u8 p2align = 0;
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// For ICF
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Atomic<bool> address_taken = false;
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// For garbage collection
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Atomic<bool> is_visited = false;
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// For ICF
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//
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// `leader` is the section that this section has been merged with.
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// Three kind of values are possible:
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// - `leader == nullptr`: This section was not eligible for ICF.
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// - `leader == this`: This section was retained.
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// - `leader != this`: This section was merged with another identical section.
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InputSection<E> *leader = nullptr;
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u32 icf_idx = -1;
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bool icf_eligible = false;
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bool icf_leaf = false;
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private:
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void scan_pcrel(Context<E> &ctx, Symbol<E> &sym, const ElfRel<E> &rel);
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void scan_absrel(Context<E> &ctx, Symbol<E> &sym, const ElfRel<E> &rel);
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void scan_dyn_absrel(Context<E> &ctx, Symbol<E> &sym, const ElfRel<E> &rel);
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void scan_toc_rel(Context<E> &ctx, Symbol<E> &sym, const ElfRel<E> &rel);
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void scan_tlsdesc(Context<E> &ctx, Symbol<E> &sym);
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void check_tlsle(Context<E> &ctx, Symbol<E> &sym, const ElfRel<E> &rel);
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void apply_dyn_absrel(Context<E> &ctx, Symbol<E> &sym, const ElfRel<E> &rel,
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u8 *loc, u64 S, i64 A, u64 P, ElfRel<E> **dynrel);
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void apply_toc_rel(Context<E> &ctx, Symbol<E> &sym, const ElfRel<E> &rel,
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u8 *loc, u64 S, i64 A, u64 P, ElfRel<E> **dynrel);
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void copy_contents_riscv(Context<E> &ctx, u8 *buf);
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std::pair<SectionFragment<E> *, i64>
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get_fragment(Context<E> &ctx, const ElfRel<E> &rel);
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u64 get_thunk_addr(i64 idx);
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std::optional<u64> get_tombstone(Symbol<E> &sym, SectionFragment<E> *frag);
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};
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//
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// tls.cc
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//
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template <typename E> u64 get_tls_begin(Context<E> &);
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template <typename E> u64 get_tp_addr(Context<E> &);
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template <typename E> u64 get_dtp_addr(Context<E> &);
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//
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// output-chunks.cc
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//
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template <typename E>
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u64 get_eflags(Context<E> &ctx);
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template <typename E>
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i64 to_phdr_flags(Context<E> &ctx, Chunk<E> *chunk);
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template <typename E>
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std::string_view get_output_name(Context<E> &ctx, std::string_view name, u64 flags);
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template <typename E>
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void write_plt_header(Context<E> &ctx, u8 *buf);
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template <typename E>
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void write_plt_entry(Context<E> &ctx, u8 *buf, Symbol<E> &sym);
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template <typename E>
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void write_pltgot_entry(Context<E> &ctx, u8 *buf, Symbol<E> &sym);
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// Chunk represents a contiguous region in an output file.
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template <typename E>
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class Chunk {
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public:
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virtual ~Chunk() = default;
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virtual bool is_header() { return false; }
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virtual OutputSection<E> *to_osec() { return nullptr; }
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virtual i64 get_reldyn_size(Context<E> &ctx) const { return 0; }
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virtual void construct_relr(Context<E> &ctx) {}
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virtual void copy_buf(Context<E> &ctx) {}
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virtual void write_to(Context<E> &ctx, u8 *buf) { unreachable(); }
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virtual void update_shdr(Context<E> &ctx) {}
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std::string_view name;
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ElfShdr<E> shdr = { .sh_addralign = 1 };
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i64 shndx = 0;
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bool is_relro = false;
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// For --gdb-index
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bool is_compressed = false;
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std::vector<u8> uncompressed_data;
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// Some synethetic sections add local symbols to the output.
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// For example, range extension thunks adds function_name@thunk
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// symbol for each thunk entry. The following members are used
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// for such synthesizing symbols.
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virtual void compute_symtab_size(Context<E> &ctx) {};
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virtual void populate_symtab(Context<E> &ctx) {};
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i64 local_symtab_idx = 0;
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i64 num_local_symtab = 0;
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i64 strtab_size = 0;
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i64 strtab_offset = 0;
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// Offset in .rel.dyn
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i64 reldyn_offset = 0;
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// For --section-order
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i64 sect_order = 0;
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// For --pack-dyn-relocs=relr
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std::vector<u64> relr;
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};
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// ELF header
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template <typename E>
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class OutputEhdr : public Chunk<E> {
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public:
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OutputEhdr(u32 sh_flags) {
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this->name = "EHDR";
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this->shdr.sh_flags = sh_flags;
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this->shdr.sh_size = sizeof(ElfEhdr<E>);
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this->shdr.sh_addralign = sizeof(Word<E>);
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}
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bool is_header() override { return true; }
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void copy_buf(Context<E> &ctx) override;
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};
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// Section header
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template <typename E>
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class OutputShdr : public Chunk<E> {
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public:
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OutputShdr() {
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this->name = "SHDR";
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this->shdr.sh_size = 1;
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this->shdr.sh_addralign = sizeof(Word<E>);
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}
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bool is_header() override { return true; }
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void copy_buf(Context<E> &ctx) override;
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};
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// Program header
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template <typename E>
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class OutputPhdr : public Chunk<E> {
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public:
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OutputPhdr(u32 sh_flags) {
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this->name = "PHDR";
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this->shdr.sh_flags = sh_flags;
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this->shdr.sh_addralign = sizeof(Word<E>);
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}
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bool is_header() override { return true; }
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void update_shdr(Context<E> &ctx) override;
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void copy_buf(Context<E> &ctx) override;
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std::vector<ElfPhdr<E>> phdrs;
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};
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template <typename E>
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class InterpSection : public Chunk<E> {
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public:
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InterpSection() {
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this->name = ".interp";
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this->shdr.sh_type = SHT_PROGBITS;
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this->shdr.sh_flags = SHF_ALLOC;
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}
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void update_shdr(Context<E> &ctx) override;
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void copy_buf(Context<E> &ctx) override;
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};
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// Sections
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template <typename E>
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class OutputSection : public Chunk<E> {
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public:
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OutputSection(std::string_view name, u32 type) {
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this->name = name;
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this->shdr.sh_type = type;
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}
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OutputSection<E> *to_osec() override { return this; }
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void construct_relr(Context<E> &ctx) override;
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void copy_buf(Context<E> &ctx) override;
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void write_to(Context<E> &ctx, u8 *buf) override;
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void compute_symtab_size(Context<E> &ctx) override;
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void populate_symtab(Context<E> &ctx) override;
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void create_range_extension_thunks(Context<E> &ctx);
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std::vector<InputSection<E> *> members;
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std::vector<std::unique_ptr<Thunk<E>>> thunks;
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std::unique_ptr<RelocSection<E>> reloc_sec;
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Atomic<u32> sh_flags;
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};
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template <typename E>
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class GotSection : public Chunk<E> {
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public:
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GotSection() {
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this->name = ".got";
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this->is_relro = true;
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this->shdr.sh_type = SHT_PROGBITS;
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this->shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
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this->shdr.sh_addralign = sizeof(Word<E>);
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// We always create a .got so that _GLOBAL_OFFSET_TABLE_ has
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// something to point to. s390x psABI define GOT[1] as a
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// reserved slot, so we allocate one more for them.
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this->shdr.sh_size = (is_s390x<E> ? 2 : 1) * sizeof(Word<E>);
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}
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void add_got_symbol(Context<E> &ctx, Symbol<E> *sym);
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void add_gottp_symbol(Context<E> &ctx, Symbol<E> *sym);
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void add_tlsgd_symbol(Context<E> &ctx, Symbol<E> *sym);
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void add_tlsdesc_symbol(Context<E> &ctx, Symbol<E> *sym);
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void add_tlsld(Context<E> &ctx);
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u64 get_tlsld_addr(Context<E> &ctx) const;
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bool has_tlsld(Context<E> &ctx) const { return tlsld_idx != -1; }
|
|
i64 get_reldyn_size(Context<E> &ctx) const override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
void construct_relr(Context<E> &ctx) override;
|
|
void compute_symtab_size(Context<E> &ctx) override;
|
|
void populate_symtab(Context<E> &ctx) override;
|
|
|
|
std::vector<Symbol<E> *> got_syms;
|
|
std::vector<Symbol<E> *> tlsgd_syms;
|
|
std::vector<Symbol<E> *> tlsdesc_syms;
|
|
std::vector<Symbol<E> *> gottp_syms;
|
|
u32 tlsld_idx = -1;
|
|
};
|
|
|
|
template <typename E>
|
|
class GotPltSection : public Chunk<E> {
|
|
public:
|
|
GotPltSection(Context<E> &ctx) {
|
|
this->name = ".got.plt";
|
|
this->is_relro = ctx.arg.z_now;
|
|
this->shdr.sh_type = is_ppc64<E> ? SHT_NOBITS : SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
this->shdr.sh_size = HDR_SIZE;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
static constexpr i64 HDR_SIZE = (is_ppc64v2<E> ? 2 : 3) * sizeof(Word<E>);
|
|
static constexpr i64 ENTRY_SIZE = (is_ppc64v1<E> ? 3 : 1) * sizeof(Word<E>);
|
|
};
|
|
|
|
template <typename E>
|
|
class PltSection : public Chunk<E> {
|
|
public:
|
|
PltSection() {
|
|
this->name = ".plt";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
|
|
if constexpr (is_sparc<E>) {
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_EXECINSTR | SHF_WRITE;
|
|
this->shdr.sh_addralign = 256;
|
|
} else {
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_EXECINSTR;
|
|
this->shdr.sh_addralign = 16;
|
|
}
|
|
}
|
|
|
|
void add_symbol(Context<E> &ctx, Symbol<E> *sym);
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
void compute_symtab_size(Context<E> &ctx) override;
|
|
void populate_symtab(Context<E> &ctx) override;
|
|
|
|
std::vector<Symbol<E> *> symbols;
|
|
};
|
|
|
|
template <typename E>
|
|
class PltGotSection : public Chunk<E> {
|
|
public:
|
|
PltGotSection() {
|
|
this->name = ".plt.got";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_EXECINSTR;
|
|
this->shdr.sh_addralign = 16;
|
|
}
|
|
|
|
void add_symbol(Context<E> &ctx, Symbol<E> *sym);
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
void compute_symtab_size(Context<E> &ctx) override;
|
|
void populate_symtab(Context<E> &ctx) override;
|
|
|
|
std::vector<Symbol<E> *> symbols;
|
|
};
|
|
|
|
template <typename E>
|
|
class RelPltSection : public Chunk<E> {
|
|
public:
|
|
RelPltSection() {
|
|
this->name = E::is_rela ? ".rela.plt" : ".rel.plt";
|
|
this->shdr.sh_type = E::is_rela ? SHT_RELA : SHT_REL;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_entsize = sizeof(ElfRel<E>);
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class RelDynSection : public Chunk<E> {
|
|
public:
|
|
RelDynSection() {
|
|
this->name = E::is_rela ? ".rela.dyn" : ".rel.dyn";
|
|
this->shdr.sh_type = E::is_rela ? SHT_RELA : SHT_REL;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_entsize = sizeof(ElfRel<E>);
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void sort(Context<E> &ctx);
|
|
};
|
|
|
|
template <typename E>
|
|
class RelrDynSection : public Chunk<E> {
|
|
public:
|
|
RelrDynSection() {
|
|
this->name = ".relr.dyn";
|
|
this->shdr.sh_type = SHT_RELR;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_entsize = sizeof(Word<E>);
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class StrtabSection : public Chunk<E> {
|
|
public:
|
|
StrtabSection() {
|
|
this->name = ".strtab";
|
|
this->shdr.sh_type = SHT_STRTAB;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
// Offsets in .strtab for ARM32 mapping symbols
|
|
static constexpr i64 ARM = 1;
|
|
static constexpr i64 THUMB = 4;
|
|
static constexpr i64 DATA = 7;
|
|
};
|
|
|
|
template <typename E>
|
|
class ShstrtabSection : public Chunk<E> {
|
|
public:
|
|
ShstrtabSection() {
|
|
this->name = ".shstrtab";
|
|
this->shdr.sh_type = SHT_STRTAB;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class DynstrSection : public Chunk<E> {
|
|
public:
|
|
DynstrSection() {
|
|
this->name = ".dynstr";
|
|
this->shdr.sh_type = SHT_STRTAB;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
}
|
|
|
|
i64 add_string(std::string_view str);
|
|
i64 find_string(std::string_view str);
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
i64 dynsym_offset = -1;
|
|
|
|
private:
|
|
std::unordered_map<std::string_view, i64> strings;
|
|
};
|
|
|
|
template <typename E>
|
|
class DynamicSection : public Chunk<E> {
|
|
public:
|
|
DynamicSection() {
|
|
this->name = ".dynamic";
|
|
this->is_relro = true;
|
|
this->shdr.sh_type = SHT_DYNAMIC;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
this->shdr.sh_entsize = sizeof(ElfDyn<E>);
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
ElfSym<E> to_output_esym(Context<E> &ctx, Symbol<E> &sym, u32 st_name,
|
|
U32<E> *shndx);
|
|
|
|
template <typename E>
|
|
class SymtabSection : public Chunk<E> {
|
|
public:
|
|
SymtabSection() {
|
|
this->name = ".symtab";
|
|
this->shdr.sh_type = SHT_SYMTAB;
|
|
this->shdr.sh_entsize = sizeof(ElfSym<E>);
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class SymtabShndxSection : public Chunk<E> {
|
|
public:
|
|
SymtabShndxSection() {
|
|
this->name = ".symtab_shndx";
|
|
this->shdr.sh_type = SHT_SYMTAB_SHNDX;
|
|
this->shdr.sh_entsize = 4;
|
|
this->shdr.sh_addralign = 4;
|
|
}
|
|
};
|
|
|
|
template <typename E>
|
|
class DynsymSection : public Chunk<E> {
|
|
public:
|
|
DynsymSection() {
|
|
this->name = ".dynsym";
|
|
this->shdr.sh_type = SHT_DYNSYM;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_entsize = sizeof(ElfSym<E>);
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void add_symbol(Context<E> &ctx, Symbol<E> *sym);
|
|
void finalize(Context<E> &ctx);
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
std::vector<Symbol<E> *> symbols;
|
|
bool finalized = false;
|
|
};
|
|
|
|
template <typename E>
|
|
class HashSection : public Chunk<E> {
|
|
public:
|
|
HashSection() {
|
|
this->name = ".hash";
|
|
this->shdr.sh_type = SHT_HASH;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_entsize = 4;
|
|
this->shdr.sh_addralign = 4;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class GnuHashSection : public Chunk<E> {
|
|
public:
|
|
GnuHashSection() {
|
|
this->name = ".gnu.hash";
|
|
this->shdr.sh_type = SHT_GNU_HASH;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
std::span<Symbol<E> *> get_exported_symbols(Context<E> &ctx);
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
static constexpr i64 LOAD_FACTOR = 8;
|
|
static constexpr i64 HEADER_SIZE = 16;
|
|
static constexpr i64 BLOOM_SHIFT = 26;
|
|
|
|
u32 num_buckets = -1;
|
|
u32 num_bloom = 1;
|
|
};
|
|
|
|
template <typename E>
|
|
class MergedSection : public Chunk<E> {
|
|
public:
|
|
static MergedSection<E> *
|
|
get_instance(Context<E> &ctx, std::string_view name, i64 type, i64 flags,
|
|
i64 entsize, i64 addralign);
|
|
|
|
SectionFragment<E> *insert(Context<E> &ctx, std::string_view data,
|
|
u64 hash, i64 p2align);
|
|
|
|
void assign_offsets(Context<E> &ctx);
|
|
void copy_buf(Context<E> &ctx) override;
|
|
void write_to(Context<E> &ctx, u8 *buf) override;
|
|
void print_stats(Context<E> &ctx);
|
|
|
|
HyperLogLog estimator;
|
|
|
|
private:
|
|
MergedSection(std::string_view name, i64 flags, i64 type, i64 entsize);
|
|
|
|
ConcurrentMap<SectionFragment<E>> map;
|
|
std::vector<i64> shard_offsets;
|
|
std::once_flag once_flag;
|
|
};
|
|
|
|
template <typename E>
|
|
class EhFrameSection : public Chunk<E> {
|
|
public:
|
|
EhFrameSection() {
|
|
this->name = ".eh_frame";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void construct(Context<E> &ctx);
|
|
void apply_eh_reloc(Context<E> &ctx, const ElfRel<E> &rel, u64 offset, u64 val);
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class EhFrameHdrSection : public Chunk<E> {
|
|
public:
|
|
EhFrameHdrSection() {
|
|
this->name = ".eh_frame_hdr";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = 4;
|
|
this->shdr.sh_size = HEADER_SIZE;
|
|
}
|
|
|
|
static constexpr i64 HEADER_SIZE = 12;
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
u32 num_fdes = 0;
|
|
};
|
|
|
|
template <typename E>
|
|
class EhFrameRelocSection : public Chunk<E> {
|
|
public:
|
|
EhFrameRelocSection() {
|
|
this->name = E::is_rela ? ".rela.eh_frame" : ".rel.eh_frame";
|
|
this->shdr.sh_type = E::is_rela ? SHT_RELA : SHT_REL;
|
|
this->shdr.sh_flags = SHF_INFO_LINK;
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
this->shdr.sh_entsize = sizeof(ElfRel<E>);
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class CopyrelSection : public Chunk<E> {
|
|
public:
|
|
CopyrelSection(bool is_relro) {
|
|
this->name = is_relro ? ".copyrel.rel.ro" : ".copyrel";
|
|
this->is_relro = is_relro;
|
|
this->shdr.sh_type = SHT_NOBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
|
|
}
|
|
|
|
void add_symbol(Context<E> &ctx, Symbol<E> *sym);
|
|
void update_shdr(Context<E> &ctx) override;
|
|
i64 get_reldyn_size(Context<E> &ctx) const override { return symbols.size(); }
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
std::vector<Symbol<E> *> symbols;
|
|
};
|
|
|
|
template <typename E>
|
|
class VersymSection : public Chunk<E> {
|
|
public:
|
|
VersymSection() {
|
|
this->name = ".gnu.version";
|
|
this->shdr.sh_type = SHT_GNU_VERSYM;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_entsize = 2;
|
|
this->shdr.sh_addralign = 2;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
std::vector<U16<E>> contents;
|
|
};
|
|
|
|
template <typename E>
|
|
class VerneedSection : public Chunk<E> {
|
|
public:
|
|
VerneedSection() {
|
|
this->name = ".gnu.version_r";
|
|
this->shdr.sh_type = SHT_GNU_VERNEED;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void construct(Context<E> &ctx);
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
std::vector<u8> contents;
|
|
};
|
|
|
|
template <typename E>
|
|
class VerdefSection : public Chunk<E> {
|
|
public:
|
|
VerdefSection() {
|
|
this->name = ".gnu.version_d";
|
|
this->shdr.sh_type = SHT_GNU_VERDEF;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = 8;
|
|
}
|
|
|
|
void construct(Context<E> &ctx);
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
std::vector<u8> contents;
|
|
};
|
|
|
|
template <typename E>
|
|
class BuildIdSection : public Chunk<E> {
|
|
public:
|
|
BuildIdSection() {
|
|
this->name = ".note.gnu.build-id";
|
|
this->shdr.sh_type = SHT_NOTE;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = 4;
|
|
this->shdr.sh_size = 1;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
void write_buildid(Context<E> &ctx);
|
|
|
|
static constexpr i64 HEADER_SIZE = 16;
|
|
};
|
|
|
|
template <typename E>
|
|
class NotePackageSection : public Chunk<E> {
|
|
public:
|
|
NotePackageSection() {
|
|
this->name = ".note.package";
|
|
this->shdr.sh_type = SHT_NOTE;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = 4;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
};
|
|
|
|
template <typename E>
|
|
class NotePropertySection : public Chunk<E> {
|
|
public:
|
|
NotePropertySection() {
|
|
this->name = ".note.gnu.property";
|
|
this->shdr.sh_type = SHT_NOTE;
|
|
this->shdr.sh_flags = SHF_ALLOC;
|
|
this->shdr.sh_addralign = sizeof(Word<E>);
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
private:
|
|
static constexpr i64 ENTRY_SIZE = E::is_64 ? 16 : 12;
|
|
|
|
std::map<u32, u32> properties;
|
|
};
|
|
|
|
template <typename E>
|
|
class GdbIndexSection : public Chunk<E> {
|
|
public:
|
|
GdbIndexSection() {
|
|
this->name = ".gdb_index";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_addralign = 4;
|
|
}
|
|
};
|
|
|
|
template <typename E>
|
|
class CompressedSection : public Chunk<E> {
|
|
public:
|
|
CompressedSection(Context<E> &ctx, Chunk<E> &chunk);
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
private:
|
|
ElfChdr<E> chdr = {};
|
|
std::unique_ptr<Compressor> compressor;
|
|
};
|
|
|
|
template <typename E>
|
|
class RelocSection : public Chunk<E> {
|
|
public:
|
|
RelocSection(Context<E> &ctx, OutputSection<E> &osec);
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
private:
|
|
OutputSection<E> &output_section;
|
|
std::vector<i64> offsets;
|
|
};
|
|
|
|
// PT_GNU_RELRO works on page granularity. We want to align its end to
|
|
// a page boundary. We append this section at end of a segment so that
|
|
// the segment always ends at a page boundary.
|
|
template <typename E>
|
|
class RelroPaddingSection : public Chunk<E> {
|
|
public:
|
|
RelroPaddingSection() {
|
|
this->name = ".relro_padding";
|
|
this->is_relro = true;
|
|
this->shdr.sh_type = SHT_NOBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
|
|
this->shdr.sh_addralign = 1;
|
|
this->shdr.sh_size = 1;
|
|
}
|
|
};
|
|
|
|
template <typename E>
|
|
class ComdatGroupSection : public Chunk<E> {
|
|
public:
|
|
ComdatGroupSection(Symbol<E> &sym, std::vector<Chunk<E> *> members)
|
|
: sym(sym), members(std::move(members)) {
|
|
this->name = ".group";
|
|
this->shdr.sh_type = SHT_GROUP;
|
|
this->shdr.sh_entsize = 4;
|
|
this->shdr.sh_addralign = 4;
|
|
this->shdr.sh_size = this->members.size() * 4 + 4;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
private:
|
|
Symbol<E> &sym;
|
|
std::vector<Chunk<E> *> members;
|
|
};
|
|
|
|
//
|
|
// gdb-index.cc
|
|
//
|
|
|
|
template <typename E> void write_gdb_index(Context<E> &ctx);
|
|
|
|
//
|
|
// input-files.cc
|
|
//
|
|
|
|
// A comdat section typically represents an inline function,
|
|
// which are de-duplicated by the linker.
|
|
//
|
|
// For each inline function, there's one comdat section, which
|
|
// contains section indices of the function code and its data such as
|
|
// string literals, if any.
|
|
//
|
|
// Comdat sections are identified by its signature. If two comdat
|
|
// sections have the same signature, the linker picks up one and
|
|
// discards the other by eliminating all sections that the other
|
|
// comdat section refers to.
|
|
struct ComdatGroup {
|
|
// The file priority of the owner file of this comdat section.
|
|
Atomic<u32> owner = -1;
|
|
};
|
|
|
|
template <typename E>
|
|
struct ComdatGroupRef {
|
|
ComdatGroup *group;
|
|
u32 sect_idx;
|
|
std::span<U32<E>> members;
|
|
};
|
|
|
|
template <typename E>
|
|
struct MergeableSection {
|
|
std::pair<SectionFragment<E> *, i64> get_fragment(i64 offset);
|
|
|
|
MergedSection<E> *parent;
|
|
u8 p2align = 0;
|
|
std::vector<std::string_view> strings;
|
|
std::vector<u64> hashes;
|
|
std::vector<u32> frag_offsets;
|
|
std::vector<SectionFragment<E> *> fragments;
|
|
};
|
|
|
|
// InputFile is the base class of ObjectFile and SharedFile.
|
|
template <typename E>
|
|
class InputFile {
|
|
public:
|
|
InputFile(Context<E> &ctx, MappedFile *mf);
|
|
InputFile() : filename("<internal>") {}
|
|
|
|
virtual ~InputFile() = default;
|
|
|
|
template <typename T>
|
|
std::span<T> get_data(Context<E> &ctx, const ElfShdr<E> &shdr);
|
|
|
|
template <typename T>
|
|
std::span<T> get_data(Context<E> &ctx, i64 idx);
|
|
|
|
std::string_view get_string(Context<E> &ctx, const ElfShdr<E> &shdr);
|
|
std::string_view get_string(Context<E> &ctx, i64 idx);
|
|
|
|
ElfEhdr<E> &get_ehdr() { return *(ElfEhdr<E> *)mf->data; }
|
|
std::span<ElfPhdr<E>> get_phdrs();
|
|
|
|
ElfShdr<E> *find_section(i64 type);
|
|
|
|
virtual void resolve_symbols(Context<E> &ctx) = 0;
|
|
void clear_symbols();
|
|
|
|
virtual void
|
|
mark_live_objects(Context<E> &ctx,
|
|
std::function<void(InputFile<E> *)> feeder) = 0;
|
|
|
|
std::span<Symbol<E> *> get_global_syms();
|
|
std::string_view get_source_name() const;
|
|
|
|
MappedFile *mf = nullptr;
|
|
std::span<ElfShdr<E>> elf_sections;
|
|
std::span<ElfSym<E>> elf_syms;
|
|
std::vector<Symbol<E> *> symbols;
|
|
i64 first_global = 0;
|
|
|
|
std::string filename;
|
|
bool is_dso = false;
|
|
u32 priority;
|
|
Atomic<bool> is_alive = false;
|
|
std::string_view shstrtab;
|
|
std::string_view symbol_strtab;
|
|
|
|
// To create an output .symtab
|
|
u64 local_symtab_idx = 0;
|
|
u64 global_symtab_idx = 0;
|
|
u64 num_local_symtab = 0;
|
|
u64 num_global_symtab = 0;
|
|
u64 strtab_offset = 0;
|
|
u64 strtab_size = 0;
|
|
|
|
// For --emit-relocs
|
|
std::vector<i32> output_sym_indices;
|
|
|
|
protected:
|
|
std::vector<Symbol<E>> local_syms;
|
|
std::vector<Symbol<E>> frag_syms;
|
|
};
|
|
|
|
template <typename E> struct ObjectFileExtras {};
|
|
|
|
template <is_riscv E>
|
|
struct ObjectFileExtras<E> {
|
|
std::optional<i64> stack_align;
|
|
std::optional<std::string_view> arch;
|
|
bool unaligned_access = false;
|
|
};
|
|
|
|
template <>
|
|
struct ObjectFileExtras<PPC32> {
|
|
InputSection<PPC32> *got2 = nullptr;
|
|
};
|
|
|
|
// ObjectFile represents an input .o file.
|
|
template <typename E>
|
|
class ObjectFile : public InputFile<E> {
|
|
public:
|
|
ObjectFile() = default;
|
|
|
|
static ObjectFile<E> *create(Context<E> &ctx, MappedFile *mf,
|
|
std::string archive_name, bool is_in_lib);
|
|
|
|
void parse(Context<E> &ctx);
|
|
void initialize_symbols(Context<E> &ctx);
|
|
void initialize_mergeable_sections(Context<E> &ctx);
|
|
void resolve_section_pieces(Context<E> &ctx);
|
|
void resolve_symbols(Context<E> &ctx) override;
|
|
void mark_live_objects(Context<E> &ctx,
|
|
std::function<void(InputFile<E> *)> feeder) override;
|
|
void convert_undefined_weak_symbols(Context<E> &ctx);
|
|
void scan_relocations(Context<E> &ctx);
|
|
void convert_common_symbols(Context<E> &ctx);
|
|
void compute_symtab_size(Context<E> &ctx);
|
|
void populate_symtab(Context<E> &ctx);
|
|
|
|
i64 get_shndx(const ElfSym<E> &esym);
|
|
InputSection<E> *get_section(const ElfSym<E> &esym);
|
|
|
|
std::string archive_name;
|
|
std::vector<std::unique_ptr<InputSection<E>>> sections;
|
|
std::vector<std::unique_ptr<MergeableSection<E>>> mergeable_sections;
|
|
bool is_in_lib = false;
|
|
std::vector<ElfShdr<E>> elf_sections2;
|
|
std::vector<CieRecord<E>> cies;
|
|
std::vector<FdeRecord<E>> fdes;
|
|
BitVector has_symver;
|
|
std::vector<ComdatGroupRef<E>> comdat_groups;
|
|
std::vector<InputSection<E> *> eh_frame_sections;
|
|
bool exclude_libs = false;
|
|
std::map<u32, u32> gnu_properties;
|
|
bool needs_executable_stack = false;
|
|
bool is_lto_obj = false;
|
|
bool is_gcc_offload_obj = false;
|
|
bool is_rust_obj = false;
|
|
|
|
i64 num_dynrel = 0;
|
|
i64 reldyn_offset = 0;
|
|
|
|
i64 fde_idx = 0;
|
|
i64 fde_offset = 0;
|
|
i64 fde_size = 0;
|
|
|
|
// For ICF
|
|
std::unique_ptr<InputSection<E>> llvm_addrsig;
|
|
|
|
// For .gdb_index
|
|
InputSection<E> *debug_info = nullptr;
|
|
InputSection<E> *debug_pubnames = nullptr;
|
|
InputSection<E> *debug_pubtypes = nullptr;
|
|
|
|
// For LTO
|
|
std::vector<ElfSym<E>> lto_elf_syms;
|
|
|
|
// Target-specific member
|
|
[[no_unique_address]] ObjectFileExtras<E> extra;
|
|
|
|
private:
|
|
ObjectFile(Context<E> &ctx, MappedFile *mf,
|
|
std::string archive_name, bool is_in_lib);
|
|
|
|
void initialize_sections(Context<E> &ctx);
|
|
void sort_relocations(Context<E> &ctx);
|
|
void initialize_ehframe_sections(Context<E> &ctx);
|
|
void parse_note_gnu_property(Context <E> &ctx, const ElfShdr <E> &shdr);
|
|
void parse_ehframe(Context<E> &ctx);
|
|
void override_symbol(Context<E> &ctx, Symbol<E> &sym,
|
|
const ElfSym<E> &esym, i64 symidx);
|
|
void merge_visibility(Context<E> &ctx, Symbol<E> &sym, u8 visibility);
|
|
|
|
bool has_common_symbol = false;
|
|
|
|
const ElfShdr<E> *symtab_sec;
|
|
std::span<U32<E>> symtab_shndx_sec;
|
|
};
|
|
|
|
// SharedFile represents an input .so file.
|
|
template <typename E>
|
|
class SharedFile : public InputFile<E> {
|
|
public:
|
|
static SharedFile<E> *create(Context<E> &ctx, MappedFile *mf);
|
|
|
|
void parse(Context<E> &ctx);
|
|
void resolve_symbols(Context<E> &ctx) override;
|
|
std::span<Symbol<E> *> find_aliases(Symbol<E> *sym);
|
|
i64 get_alignment(Symbol<E> *sym);
|
|
bool is_readonly(Symbol<E> *sym);
|
|
|
|
void mark_live_objects(Context<E> &ctx,
|
|
std::function<void(InputFile<E> *)> feeder) override;
|
|
|
|
void compute_symtab_size(Context<E> &ctx);
|
|
void populate_symtab(Context<E> &ctx);
|
|
|
|
std::string soname;
|
|
std::vector<std::string_view> version_strings;
|
|
std::vector<ElfSym<E>> elf_syms2;
|
|
|
|
private:
|
|
SharedFile(Context<E> &ctx, MappedFile *mf);
|
|
|
|
std::string get_soname(Context<E> &ctx);
|
|
void maybe_override_symbol(Symbol<E> &sym, const ElfSym<E> &esym);
|
|
std::vector<std::string_view> read_verdef(Context<E> &ctx);
|
|
|
|
std::vector<u16> versyms;
|
|
const ElfShdr<E> *symtab_sec;
|
|
|
|
// Used by find_aliases()
|
|
std::once_flag init_aliases;
|
|
std::vector<Symbol<E> *> aliases;
|
|
};
|
|
|
|
//
|
|
// linker-script.cc
|
|
//
|
|
|
|
template <typename E>
|
|
void parse_linker_script(Context<E> &ctx, MappedFile *mf);
|
|
|
|
template <typename E>
|
|
std::string_view
|
|
get_script_output_type(Context<E> &ctx, MappedFile *mf);
|
|
|
|
template <typename E>
|
|
void parse_version_script(Context<E> &ctx, MappedFile *mf);
|
|
|
|
struct DynamicPattern {
|
|
std::string_view pattern;
|
|
std::string_view source;
|
|
bool is_cpp = false;
|
|
};
|
|
|
|
template <typename E>
|
|
std::vector<DynamicPattern>
|
|
parse_dynamic_list(Context<E> &ctx, std::string_view path);
|
|
|
|
//
|
|
// lto.cc
|
|
//
|
|
|
|
template <typename E>
|
|
ObjectFile<E> *read_lto_object(Context<E> &ctx, MappedFile *mb);
|
|
|
|
template <typename E>
|
|
std::vector<ObjectFile<E> *> do_lto(Context<E> &ctx);
|
|
|
|
template <typename E>
|
|
void lto_cleanup(Context<E> &ctx);
|
|
|
|
//
|
|
// gc-sections.cc
|
|
//
|
|
|
|
template <typename E>
|
|
void gc_sections(Context<E> &ctx);
|
|
|
|
//
|
|
// icf.cc
|
|
//
|
|
|
|
template <typename E>
|
|
void icf_sections(Context<E> &ctx);
|
|
|
|
//
|
|
// relocatable.cc
|
|
//
|
|
|
|
template <typename E>
|
|
void combine_objects(Context<E> &ctx);
|
|
|
|
//
|
|
// mapfile.cc
|
|
//
|
|
|
|
template <typename E>
|
|
void print_map(Context<E> &ctx);
|
|
|
|
//
|
|
// subprocess.cc
|
|
//
|
|
|
|
std::function<void()> fork_child();
|
|
|
|
template <typename E>
|
|
[[noreturn]]
|
|
void process_run_subcommand(Context<E> &ctx, int argc, char **argv);
|
|
|
|
//
|
|
// cmdline.cc
|
|
//
|
|
|
|
template <typename E>
|
|
std::vector<std::string_view> expand_response_files(Context<E> &ctx, char **argv);
|
|
|
|
template <typename E>
|
|
std::vector<std::string> parse_nonpositional_args(Context<E> &ctx);
|
|
|
|
//
|
|
// passes.cc
|
|
//
|
|
|
|
template <typename E> int redo_main(Context<E> &, int argc, char **argv);
|
|
template <typename E> void create_internal_file(Context<E> &);
|
|
template <typename E> void apply_exclude_libs(Context<E> &);
|
|
template <typename E> void create_synthetic_sections(Context<E> &);
|
|
template <typename E> void set_file_priority(Context<E> &);
|
|
template <typename E> void resolve_symbols(Context<E> &);
|
|
template <typename E> void kill_eh_frame_sections(Context<E> &);
|
|
template <typename E> void resolve_section_pieces(Context<E> &);
|
|
template <typename E> void convert_common_symbols(Context<E> &);
|
|
template <typename E> void compute_merged_section_sizes(Context<E> &);
|
|
template <typename E> void create_output_sections(Context<E> &);
|
|
template <typename E> void add_synthetic_symbols(Context<E> &);
|
|
template <typename E> void check_cet_errors(Context<E> &);
|
|
template <typename E> void print_dependencies(Context<E> &);
|
|
template <typename E> void write_repro_file(Context<E> &);
|
|
template <typename E> void check_duplicate_symbols(Context<E> &);
|
|
template <typename E> void check_symbol_types(Context<E> &);
|
|
template <typename E> void sort_init_fini(Context<E> &);
|
|
template <typename E> void sort_ctor_dtor(Context<E> &);
|
|
template <typename E> void fixup_ctors_in_init_array(Context<E> &);
|
|
template <typename E> void shuffle_sections(Context<E> &);
|
|
template <typename E> void compute_section_sizes(Context<E> &);
|
|
template <typename E> void sort_output_sections(Context<E> &);
|
|
template <typename E> void claim_unresolved_symbols(Context<E> &);
|
|
template <typename E> void scan_relocations(Context<E> &);
|
|
template <typename E> void compute_imported_symbol_weakness(Context<E> &);
|
|
template <typename E> void construct_relr(Context<E> &);
|
|
template <typename E> void create_output_symtab(Context<E> &);
|
|
template <typename E> void report_undef_errors(Context<E> &);
|
|
template <typename E> void create_reloc_sections(Context<E> &);
|
|
template <typename E> void copy_chunks(Context<E> &);
|
|
template <typename E> void rewrite_endbr(Context<E> &);
|
|
template <typename E> void apply_version_script(Context<E> &);
|
|
template <typename E> void parse_symbol_version(Context<E> &);
|
|
template <typename E> void compute_import_export(Context<E> &);
|
|
template <typename E> void compute_address_significance(Context<E> &);
|
|
template <typename E> void clear_padding(Context<E> &);
|
|
template <typename E> void compute_section_headers(Context<E> &);
|
|
template <typename E> i64 set_osec_offsets(Context<E> &);
|
|
template <typename E> void fix_synthetic_symbols(Context<E> &);
|
|
template <typename E> i64 compress_debug_sections(Context<E> &);
|
|
template <typename E> void write_dependency_file(Context<E> &);
|
|
template <typename E> void show_stats(Context<E> &);
|
|
|
|
//
|
|
// arch-arm32.cc
|
|
//
|
|
|
|
template <> u64 get_eflags(Context<ARM32> &ctx);
|
|
void fixup_arm_exidx_section(Context<ARM32> &ctx);
|
|
|
|
//
|
|
// arch-riscv.cc
|
|
//
|
|
|
|
template <is_riscv E>
|
|
class RiscvAttributesSection : public Chunk<E> {
|
|
public:
|
|
RiscvAttributesSection() {
|
|
this->name = ".riscv.attributes";
|
|
this->shdr.sh_type = SHT_RISCV_ATTRIBUTES;
|
|
}
|
|
|
|
void update_shdr(Context<E> &ctx) override;
|
|
void copy_buf(Context<E> &ctx) override;
|
|
|
|
std::vector<u8> contents;
|
|
};
|
|
|
|
template <is_riscv E>
|
|
u64 get_eflags(Context<E> &ctx);
|
|
|
|
template <is_riscv E>
|
|
i64 riscv_resize_sections(Context<E> &ctx);
|
|
|
|
//
|
|
// arch-ppc64v1.cc
|
|
//
|
|
|
|
void ppc64v1_rewrite_opd(Context<PPC64V1> &ctx);
|
|
void ppc64v1_scan_symbols(Context<PPC64V1> &ctx);
|
|
|
|
class PPC64OpdSection : public Chunk<PPC64V1> {
|
|
public:
|
|
PPC64OpdSection() {
|
|
this->name = ".opd";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
|
|
this->shdr.sh_addralign = 8;
|
|
}
|
|
|
|
void add_symbol(Context<PPC64V1> &ctx, Symbol<PPC64V1> *sym);
|
|
i64 get_reldyn_size(Context<PPC64V1> &ctx) const override;
|
|
void copy_buf(Context<PPC64V1> &ctx) override;
|
|
|
|
static constexpr i64 ENTRY_SIZE = sizeof(Word<PPC64V1>) * 3;
|
|
|
|
std::vector<Symbol<PPC64V1> *> symbols;
|
|
};
|
|
|
|
//
|
|
// arch-ppc64v2.cc
|
|
//
|
|
|
|
extern const std::vector<std::pair<std::string_view, u32>>
|
|
ppc64_save_restore_insns;
|
|
|
|
class PPC64SaveRestoreSection : public Chunk<PPC64V2> {
|
|
public:
|
|
PPC64SaveRestoreSection() {
|
|
this->name = ".save_restore_gprs";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_EXECINSTR;
|
|
this->shdr.sh_addralign = 16;
|
|
this->shdr.sh_size = ppc64_save_restore_insns.size() * 4;
|
|
}
|
|
|
|
void copy_buf(Context<PPC64V2> &ctx) override;
|
|
};
|
|
|
|
template <> u64 get_eflags(Context<PPC64V2> &ctx);
|
|
|
|
//
|
|
// arch-sparc.cc
|
|
//
|
|
|
|
class SparcTlsGetAddrSection : public Chunk<SPARC64> {
|
|
public:
|
|
SparcTlsGetAddrSection() {
|
|
this->name = ".tls_get_addr";
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_EXECINSTR;
|
|
this->shdr.sh_addralign = 4;
|
|
this->shdr.sh_size = 24;
|
|
}
|
|
|
|
void copy_buf(Context<SPARC64> &ctx) override;
|
|
};
|
|
|
|
//
|
|
// arch-alpha.cc
|
|
//
|
|
|
|
class AlphaGotSection : public Chunk<ALPHA> {
|
|
public:
|
|
AlphaGotSection() {
|
|
this->name = ".alpha_got";
|
|
this->is_relro = true;
|
|
this->shdr.sh_type = SHT_PROGBITS;
|
|
this->shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
|
|
this->shdr.sh_addralign = 8;
|
|
}
|
|
|
|
void add_symbol(Symbol<ALPHA> &sym, i64 addend);
|
|
void finalize();
|
|
u64 get_addr(Symbol<ALPHA> &sym, i64 addend);
|
|
i64 get_reldyn_size(Context<ALPHA> &ctx) const override;
|
|
void copy_buf(Context<ALPHA> &ctx) override;
|
|
|
|
struct Entry {
|
|
bool operator==(const Entry &) const = default;
|
|
Symbol<ALPHA> *sym;
|
|
i64 addend;
|
|
};
|
|
|
|
private:
|
|
std::vector<Entry> entries;
|
|
std::mutex mu;
|
|
};
|
|
|
|
//
|
|
// main.cc
|
|
//
|
|
|
|
struct BuildId {
|
|
i64 size() const;
|
|
|
|
enum { NONE, HEX, HASH, UUID } kind = NONE;
|
|
std::vector<u8> value;
|
|
i64 hash_size = 0;
|
|
};
|
|
|
|
typedef enum { COMPRESS_NONE, COMPRESS_ZLIB, COMPRESS_ZSTD } CompressKind;
|
|
|
|
typedef enum {
|
|
UNRESOLVED_ERROR,
|
|
UNRESOLVED_WARN,
|
|
UNRESOLVED_IGNORE,
|
|
} UnresolvedKind;
|
|
|
|
typedef enum {
|
|
SEPARATE_LOADABLE_SEGMENTS,
|
|
SEPARATE_CODE,
|
|
NOSEPARATE_CODE,
|
|
} SeparateCodeKind;
|
|
|
|
typedef enum {
|
|
CET_REPORT_NONE,
|
|
CET_REPORT_WARNING,
|
|
CET_REPORT_ERROR,
|
|
} CetReportKind;
|
|
|
|
typedef enum {
|
|
SHUFFLE_SECTIONS_NONE,
|
|
SHUFFLE_SECTIONS_SHUFFLE,
|
|
SHUFFLE_SECTIONS_REVERSE,
|
|
} ShuffleSectionsKind;
|
|
|
|
struct VersionPattern {
|
|
std::string_view pattern;
|
|
std::string_view source;
|
|
std::string_view ver_str;
|
|
u16 ver_idx = -1;
|
|
bool is_cpp = false;
|
|
};
|
|
|
|
struct SectionOrder {
|
|
enum { NONE, SECTION, GROUP, ADDR, ALIGN, SYMBOL } type = NONE;
|
|
std::string name;
|
|
u64 value = 0;
|
|
};
|
|
|
|
// Target-specific context members
|
|
template <typename E>
|
|
struct ContextExtras {};
|
|
|
|
template <is_riscv E>
|
|
struct ContextExtras<E> {
|
|
RiscvAttributesSection<E> *riscv_attributes = nullptr;
|
|
};
|
|
|
|
template <>
|
|
struct ContextExtras<PPC32> {
|
|
Symbol<PPC32> *_SDA_BASE_ = nullptr;
|
|
};
|
|
|
|
template <>
|
|
struct ContextExtras<PPC64V1> {
|
|
PPC64OpdSection *opd = nullptr;
|
|
Symbol<PPC64V1> *TOC = nullptr;
|
|
};
|
|
|
|
template <>
|
|
struct ContextExtras<PPC64V2> {
|
|
PPC64SaveRestoreSection *save_restore = nullptr;
|
|
Symbol<PPC64V2> *TOC = nullptr;
|
|
Atomic<bool> is_power10 = false;
|
|
};
|
|
|
|
template <>
|
|
struct ContextExtras<SPARC64> {
|
|
SparcTlsGetAddrSection *tls_get_addr_sec = nullptr;
|
|
Symbol<SPARC64> *tls_get_addr_sym = nullptr;
|
|
};
|
|
|
|
template <>
|
|
struct ContextExtras<ALPHA> {
|
|
AlphaGotSection *got = nullptr;
|
|
};
|
|
|
|
// Context represents a context object for each invocation of the linker.
|
|
// It contains command line flags, pointers to singleton objects
|
|
// (such as linker-synthesized output sections), unique_ptrs for
|
|
// resource management, and other miscellaneous objects.
|
|
template <typename E>
|
|
struct Context {
|
|
Context() {
|
|
arg.entry = get_symbol(*this, "_start");
|
|
arg.fini = get_symbol(*this, "_fini");
|
|
arg.init = get_symbol(*this, "_init");
|
|
}
|
|
|
|
Context(const Context<E> &) = delete;
|
|
|
|
void checkpoint() {
|
|
if (has_error) {
|
|
cleanup();
|
|
_exit(1);
|
|
}
|
|
}
|
|
|
|
// Command-line arguments
|
|
struct {
|
|
BuildId build_id;
|
|
CetReportKind z_cet_report = CET_REPORT_NONE;
|
|
CompressKind compress_debug_sections = COMPRESS_NONE;
|
|
SeparateCodeKind z_separate_code = NOSEPARATE_CODE;
|
|
ShuffleSectionsKind shuffle_sections = SHUFFLE_SECTIONS_NONE;
|
|
Symbol<E> *entry = nullptr;
|
|
Symbol<E> *fini = nullptr;
|
|
Symbol<E> *init = nullptr;
|
|
UnresolvedKind unresolved_symbols = UNRESOLVED_ERROR;
|
|
bool Bsymbolic = false;
|
|
bool Bsymbolic_functions = false;
|
|
bool allow_multiple_definition = false;
|
|
bool apply_dynamic_relocs = true;
|
|
bool color_diagnostics = false;
|
|
bool default_symver = false;
|
|
bool demangle = true;
|
|
bool discard_all = false;
|
|
bool discard_locals = false;
|
|
bool eh_frame_hdr = true;
|
|
bool emit_relocs = false;
|
|
bool enable_new_dtags = true;
|
|
bool execute_only = false;
|
|
bool export_dynamic = false;
|
|
bool fatal_warnings = false;
|
|
bool fork = true;
|
|
bool gc_sections = false;
|
|
bool gdb_index = false;
|
|
bool hash_style_gnu = true;
|
|
bool hash_style_sysv = true;
|
|
bool icf = false;
|
|
bool icf_all = false;
|
|
bool ignore_data_address_equality = false;
|
|
bool is_static = false;
|
|
bool lto_pass2 = false;
|
|
bool nmagic = false;
|
|
bool noinhibit_exec = false;
|
|
bool oformat_binary = false;
|
|
bool omagic = false;
|
|
bool pack_dyn_relocs_relr = false;
|
|
bool perf = false;
|
|
bool pic = false;
|
|
bool pie = false;
|
|
bool print_dependencies = false;
|
|
bool print_gc_sections = false;
|
|
bool print_icf_sections = false;
|
|
bool print_map = false;
|
|
bool quick_exit = true;
|
|
bool relax = true;
|
|
bool relocatable = false;
|
|
bool relocatable_merge_sections = false;
|
|
bool repro = false;
|
|
bool rosegment = true;
|
|
bool shared = false;
|
|
bool start_stop = false;
|
|
bool stats = false;
|
|
bool strip_all = false;
|
|
bool strip_debug = false;
|
|
bool suppress_warnings = false;
|
|
bool trace = false;
|
|
bool undefined_version = false;
|
|
bool warn_common = false;
|
|
bool warn_once = false;
|
|
bool warn_textrel = false;
|
|
bool z_copyreloc = true;
|
|
bool z_defs = false;
|
|
bool z_delete = true;
|
|
bool z_dlopen = true;
|
|
bool z_dump = true;
|
|
bool z_dynamic_undefined_weak = true;
|
|
bool z_execstack = false;
|
|
bool z_execstack_if_needed = false;
|
|
bool z_ibt = false;
|
|
bool z_initfirst = false;
|
|
bool z_interpose = false;
|
|
bool z_keep_text_section_prefix = false;
|
|
bool z_nodefaultlib = false;
|
|
bool z_now = false;
|
|
bool z_origin = false;
|
|
bool z_relro = true;
|
|
bool z_rewrite_endbr = false;
|
|
bool z_sectionheader = true;
|
|
bool z_shstk = false;
|
|
bool z_text = false;
|
|
i64 filler = -1;
|
|
i64 spare_dynamic_tags = 5;
|
|
i64 spare_program_headers = 0;
|
|
i64 thread_count = 0;
|
|
i64 z_stack_size = 0;
|
|
u64 shuffle_sections_seed;
|
|
std::string_view emulation;
|
|
std::optional<Glob> unique;
|
|
std::optional<u64> physical_image_base;
|
|
std::string Map;
|
|
std::string chroot;
|
|
std::string dependency_file;
|
|
std::string directory;
|
|
std::string dynamic_linker;
|
|
std::string output = "a.out";
|
|
std::string package_metadata;
|
|
std::string plugin;
|
|
std::string rpaths;
|
|
std::string soname;
|
|
std::string sysroot;
|
|
std::unique_ptr<std::unordered_set<std::string_view>> retain_symbols_file;
|
|
std::unordered_map<std::string_view, u64> section_align;
|
|
std::unordered_map<std::string_view, u64> section_start;
|
|
std::unordered_set<std::string_view> ignore_ir_file;
|
|
std::unordered_set<std::string_view> wrap;
|
|
std::vector<SectionOrder> section_order;
|
|
std::vector<Symbol<E> *> require_defined;
|
|
std::vector<Symbol<E> *> undefined;
|
|
std::vector<std::pair<Symbol<E> *, std::variant<Symbol<E> *, u64>>> defsyms;
|
|
std::vector<std::string> library_paths;
|
|
std::vector<std::string> plugin_opt;
|
|
std::vector<std::string> version_definitions;
|
|
std::vector<std::string_view> auxiliary;
|
|
std::vector<std::string_view> exclude_libs;
|
|
std::vector<std::string_view> filter;
|
|
std::vector<std::string_view> trace_symbol;
|
|
u64 image_base = 0x200000;
|
|
} arg;
|
|
|
|
std::vector<VersionPattern> version_patterns;
|
|
std::vector<DynamicPattern> dynamic_list_patterns;
|
|
i64 default_version = VER_NDX_UNSPECIFIED;
|
|
i64 page_size = E::page_size;
|
|
|
|
// Reader context
|
|
bool as_needed = false;
|
|
bool whole_archive = false;
|
|
bool is_static;
|
|
bool in_lib = false;
|
|
i64 file_priority = 10000;
|
|
MappedFile *script_file = nullptr;
|
|
std::unordered_set<std::string_view> visited;
|
|
tbb::task_group tg;
|
|
|
|
bool has_error = false;
|
|
Atomic<bool> has_init_array = false;
|
|
Atomic<bool> has_ctors = false;
|
|
|
|
// Symbol table
|
|
tbb::concurrent_hash_map<std::string_view, Symbol<E>, HashCmp> symbol_map;
|
|
tbb::concurrent_hash_map<std::string_view, ComdatGroup, HashCmp> comdat_groups;
|
|
tbb::concurrent_vector<std::unique_ptr<MergedSection<E>>> merged_sections;
|
|
|
|
tbb::concurrent_vector<std::unique_ptr<TimerRecord>> timer_records;
|
|
tbb::concurrent_vector<std::function<void()>> on_exit;
|
|
|
|
tbb::concurrent_vector<std::unique_ptr<ObjectFile<E>>> obj_pool;
|
|
tbb::concurrent_vector<std::unique_ptr<SharedFile<E>>> dso_pool;
|
|
tbb::concurrent_vector<std::unique_ptr<u8[]>> string_pool;
|
|
tbb::concurrent_vector<std::unique_ptr<MappedFile>> mf_pool;
|
|
tbb::concurrent_vector<std::unique_ptr<Chunk<E>>> chunk_pool;
|
|
tbb::concurrent_vector<std::unique_ptr<OutputSection<E>>> osec_pool;
|
|
|
|
// Symbol auxiliary data
|
|
std::vector<SymbolAux<E>> symbol_aux;
|
|
|
|
// Fully-expanded command line args
|
|
std::vector<std::string_view> cmdline_args;
|
|
|
|
// Input files
|
|
std::vector<ObjectFile<E> *> objs;
|
|
std::vector<SharedFile<E> *> dsos;
|
|
|
|
ObjectFile<E> *internal_obj = nullptr;
|
|
std::vector<ElfSym<E>> internal_esyms;
|
|
|
|
// Output buffer
|
|
std::unique_ptr<OutputFile<Context<E>>> output_file;
|
|
u8 *buf = nullptr;
|
|
bool overwrite_output_file = true;
|
|
|
|
std::vector<Chunk<E> *> chunks;
|
|
Atomic<bool> needs_tlsld = false;
|
|
Atomic<bool> has_textrel = false;
|
|
Atomic<u32> num_ifunc_dynrels = 0;
|
|
|
|
tbb::concurrent_hash_map<Symbol<E> *, std::vector<std::string>> undef_errors;
|
|
|
|
// Output chunks
|
|
OutputEhdr<E> *ehdr = nullptr;
|
|
OutputShdr<E> *shdr = nullptr;
|
|
OutputPhdr<E> *phdr = nullptr;
|
|
InterpSection<E> *interp = nullptr;
|
|
GotSection<E> *got = nullptr;
|
|
GotPltSection<E> *gotplt = nullptr;
|
|
RelPltSection<E> *relplt = nullptr;
|
|
RelDynSection<E> *reldyn = nullptr;
|
|
RelrDynSection<E> *relrdyn = nullptr;
|
|
DynamicSection<E> *dynamic = nullptr;
|
|
StrtabSection<E> *strtab = nullptr;
|
|
DynstrSection<E> *dynstr = nullptr;
|
|
HashSection<E> *hash = nullptr;
|
|
GnuHashSection<E> *gnu_hash = nullptr;
|
|
ShstrtabSection<E> *shstrtab = nullptr;
|
|
PltSection<E> *plt = nullptr;
|
|
PltGotSection<E> *pltgot = nullptr;
|
|
SymtabSection<E> *symtab = nullptr;
|
|
SymtabShndxSection<E> *symtab_shndx = nullptr;
|
|
DynsymSection<E> *dynsym = nullptr;
|
|
EhFrameSection<E> *eh_frame = nullptr;
|
|
EhFrameHdrSection<E> *eh_frame_hdr = nullptr;
|
|
EhFrameRelocSection<E> *eh_frame_reloc = nullptr;
|
|
CopyrelSection<E> *copyrel = nullptr;
|
|
CopyrelSection<E> *copyrel_relro = nullptr;
|
|
VersymSection<E> *versym = nullptr;
|
|
VerneedSection<E> *verneed = nullptr;
|
|
VerdefSection<E> *verdef = nullptr;
|
|
BuildIdSection<E> *buildid = nullptr;
|
|
NotePackageSection<E> *note_package = nullptr;
|
|
NotePropertySection<E> *note_property = nullptr;
|
|
GdbIndexSection<E> *gdb_index = nullptr;
|
|
RelroPaddingSection<E> *relro_padding = nullptr;
|
|
|
|
[[no_unique_address]] ContextExtras<E> extra;
|
|
|
|
// For --gdb-index
|
|
std::span<u8> debug_info;
|
|
std::span<u8> debug_abbrev;
|
|
std::span<u8> debug_ranges;
|
|
std::span<u8> debug_addr;
|
|
std::span<u8> debug_rnglists;
|
|
|
|
// For thread-local variables
|
|
u64 tls_begin = 0;
|
|
u64 tp_addr = 0;
|
|
u64 dtp_addr = 0;
|
|
|
|
// Linker-synthesized symbols
|
|
Symbol<E> *_DYNAMIC = nullptr;
|
|
Symbol<E> *_GLOBAL_OFFSET_TABLE_ = nullptr;
|
|
Symbol<E> *_PROCEDURE_LINKAGE_TABLE_ = nullptr;
|
|
Symbol<E> *_TLS_MODULE_BASE_ = nullptr;
|
|
Symbol<E> *__GNU_EH_FRAME_HDR = nullptr;
|
|
Symbol<E> *__bss_start = nullptr;
|
|
Symbol<E> *__dso_handle = nullptr;
|
|
Symbol<E> *__ehdr_start = nullptr;
|
|
Symbol<E> *__executable_start = nullptr;
|
|
Symbol<E> *__exidx_end = nullptr;
|
|
Symbol<E> *__exidx_start = nullptr;
|
|
Symbol<E> *__fini_array_end = nullptr;
|
|
Symbol<E> *__fini_array_start = nullptr;
|
|
Symbol<E> *__global_pointer = nullptr;
|
|
Symbol<E> *__init_array_end = nullptr;
|
|
Symbol<E> *__init_array_start = nullptr;
|
|
Symbol<E> *__preinit_array_end = nullptr;
|
|
Symbol<E> *__preinit_array_start = nullptr;
|
|
Symbol<E> *__rel_iplt_end = nullptr;
|
|
Symbol<E> *__rel_iplt_start = nullptr;
|
|
Symbol<E> *_edata = nullptr;
|
|
Symbol<E> *_end = nullptr;
|
|
Symbol<E> *_etext = nullptr;
|
|
Symbol<E> *edata = nullptr;
|
|
Symbol<E> *end = nullptr;
|
|
Symbol<E> *etext = nullptr;
|
|
};
|
|
|
|
template <typename E>
|
|
std::string_view get_machine_type(Context<E> &ctx, MappedFile *mf);
|
|
|
|
template <typename E>
|
|
MappedFile *open_library(Context<E> &ctx, std::string path);
|
|
|
|
template <typename E>
|
|
MappedFile *find_library(Context<E> &ctx, std::string path);
|
|
|
|
template <typename E>
|
|
void read_file(Context<E> &ctx, MappedFile *mf);
|
|
|
|
template <typename E>
|
|
int elf_main(int argc, char **argv);
|
|
|
|
int main(int argc, char **argv);
|
|
|
|
template <typename E>
|
|
std::ostream &operator<<(std::ostream &out, const InputFile<E> &file);
|
|
|
|
//
|
|
// Symbol
|
|
//
|
|
|
|
enum {
|
|
NEEDS_GOT = 1 << 0,
|
|
NEEDS_PLT = 1 << 1,
|
|
NEEDS_CPLT = 1 << 2,
|
|
NEEDS_GOTTP = 1 << 3,
|
|
NEEDS_TLSGD = 1 << 4,
|
|
NEEDS_COPYREL = 1 << 5,
|
|
NEEDS_TLSDESC = 1 << 6,
|
|
NEEDS_PPC_OPD = 1 << 7, // for PPCv1
|
|
};
|
|
|
|
// A struct to hold target-dependent symbol members.
|
|
template <typename E>
|
|
struct SymbolExtras {};
|
|
|
|
template <needs_thunk E>
|
|
struct SymbolExtras<E> {
|
|
// For range extension thunks
|
|
i16 thunk_idx = -1;
|
|
i16 thunk_sym_idx = -1;
|
|
};
|
|
|
|
// Flags for Symbol<E>::get_addr()
|
|
enum {
|
|
NO_PLT = 1 << 0, // Request an address other than .plt
|
|
NO_OPD = 1 << 1, // Request an address other than .opd (PPC64V1 only)
|
|
};
|
|
|
|
// Symbol class represents a defined symbol.
|
|
//
|
|
// A symbol has not only one but several different addresses if it
|
|
// has PLT or GOT entries. This class provides various functions to
|
|
// compute different addresses.
|
|
template <typename E>
|
|
class Symbol {
|
|
public:
|
|
Symbol() = default;
|
|
Symbol(std::string_view name) : nameptr(name.data()), namelen(name.size()) {}
|
|
Symbol(const Symbol<E> &other) : Symbol(other.name()) {}
|
|
|
|
u64 get_addr(Context<E> &ctx, i64 flags = 0) const;
|
|
u64 get_got_addr(Context<E> &ctx) const;
|
|
u64 get_gotplt_addr(Context<E> &ctx) const;
|
|
u64 get_gottp_addr(Context<E> &ctx) const;
|
|
u64 get_tlsgd_addr(Context<E> &ctx) const;
|
|
u64 get_tlsdesc_addr(Context<E> &ctx) const;
|
|
u64 get_plt_addr(Context<E> &ctx) const;
|
|
u64 get_opd_addr(Context<E> &ctx) const;
|
|
u64 get_got_pltgot_addr(Context<E> &ctx) const;
|
|
|
|
void set_got_idx(Context<E> &ctx, i32 idx);
|
|
void set_gottp_idx(Context<E> &ctx, i32 idx);
|
|
void set_tlsgd_idx(Context<E> &ctx, i32 idx);
|
|
void set_tlsdesc_idx(Context<E> &ctx, i32 idx);
|
|
void set_plt_idx(Context<E> &ctx, i32 idx);
|
|
void set_pltgot_idx(Context<E> &ctx, i32 idx);
|
|
void set_opd_idx(Context<E> &ctx, i32 idx);
|
|
void set_dynsym_idx(Context<E> &ctx, i32 idx);
|
|
|
|
i32 get_got_idx(Context<E> &ctx) const;
|
|
i32 get_gottp_idx(Context<E> &ctx) const;
|
|
i32 get_tlsgd_idx(Context<E> &ctx) const;
|
|
i32 get_tlsdesc_idx(Context<E> &ctx) const;
|
|
i32 get_plt_idx(Context<E> &ctx) const;
|
|
i32 get_pltgot_idx(Context<E> &ctx) const;
|
|
i32 get_opd_idx(Context<E> &ctx) const;
|
|
i32 get_dynsym_idx(Context<E> &ctx) const;
|
|
|
|
bool has_plt(Context<E> &ctx) const;
|
|
bool has_got(Context<E> &ctx) const { return get_got_idx(ctx) != -1; }
|
|
bool has_gottp(Context<E> &ctx) const { return get_gottp_idx(ctx) != -1; }
|
|
bool has_tlsgd(Context<E> &ctx) const { return get_tlsgd_idx(ctx) != -1; }
|
|
bool has_tlsdesc(Context<E> &ctx) const { return get_tlsdesc_idx(ctx) != -1; }
|
|
bool has_opd(Context<E> &ctx) const { return get_opd_idx(ctx) != -1; }
|
|
|
|
u32 get_djb_hash(Context<E> &ctx) const;
|
|
void set_djb_hash(Context<E> &ctx, u32 hash);
|
|
|
|
bool is_absolute() const;
|
|
bool is_relative() const { return !is_absolute(); }
|
|
bool is_local(Context<E> &ctx) const;
|
|
bool is_ifunc() const { return get_type() == STT_GNU_IFUNC; }
|
|
bool is_pde_ifunc(Context<E> &ctx) const;
|
|
bool is_remaining_undef_weak() const;
|
|
|
|
bool is_pcrel_linktime_const(Context<E> &ctx) const;
|
|
bool is_tprel_linktime_const(Context<E> &ctx) const;
|
|
bool is_tprel_runtime_const(Context<E> &ctx) const;
|
|
|
|
InputSection<E> *get_input_section() const;
|
|
Chunk<E> *get_output_section() const;
|
|
SectionFragment<E> *get_frag() const;
|
|
|
|
void set_input_section(InputSection<E> *);
|
|
void set_output_section(Chunk<E> *);
|
|
void set_frag(SectionFragment<E> *);
|
|
|
|
void set_name(std::string_view);
|
|
std::string_view name() const;
|
|
|
|
u32 get_type() const;
|
|
std::string_view get_version() const;
|
|
i64 get_output_sym_idx(Context<E> &ctx) const;
|
|
const ElfSym<E> &esym() const;
|
|
void add_aux(Context<E> &ctx);
|
|
|
|
// A symbol is owned by a file. If two or more files define the
|
|
// same symbol, the one with the strongest definition owns the symbol.
|
|
// If `file` is null, the symbol is equivalent to nonexistent.
|
|
InputFile<E> *file = nullptr;
|
|
|
|
// A symbol usually belongs to an input section, but it can belong
|
|
// to a section fragment, an output section or nothing
|
|
// (i.e. absolute symbol). `origin` holds one of them. We use the
|
|
// least significant two bits to distinguish type.
|
|
enum : uintptr_t {
|
|
TAG_ABS = 0b00,
|
|
TAG_ISEC = 0b01,
|
|
TAG_OSEC = 0b10,
|
|
TAG_FRAG = 0b11,
|
|
TAG_MASK = 0b11,
|
|
};
|
|
|
|
static_assert(alignof(InputSection<E>) >= 4);
|
|
static_assert(alignof(Chunk<E>) >= 4);
|
|
static_assert(alignof(SectionFragment<E>) >= 4);
|
|
|
|
uintptr_t origin = 0;
|
|
|
|
// `value` contains symbol value. If it's an absolute symbol, it is
|
|
// equivalent to its address. If it belongs to an input section or a
|
|
// section fragment, value is added to the base of the input section
|
|
// to yield an address.
|
|
u64 value = 0;
|
|
|
|
const char *nameptr = nullptr;
|
|
i32 namelen = 0;
|
|
|
|
// Index into the symbol table of the owner file.
|
|
i32 sym_idx = -1;
|
|
|
|
i32 aux_idx = -1;
|
|
u16 ver_idx = VER_NDX_UNSPECIFIED;
|
|
|
|
// `flags` has NEEDS_ flags.
|
|
Atomic<u8> flags = 0;
|
|
|
|
tbb::spin_mutex mu;
|
|
Atomic<u8> visibility = STV_DEFAULT;
|
|
|
|
bool is_weak : 1 = false;
|
|
bool write_to_symtab : 1 = false; // for --strip-all and the like
|
|
bool is_traced : 1 = false; // for --trace-symbol
|
|
bool is_wrapped : 1 = false; // for --wrap
|
|
|
|
// If a symbol can be resolved to a symbol in a different ELF file at
|
|
// runtime, `is_imported` is true. If a symbol is a dynamic symbol and
|
|
// can be used by other ELF file at runtime, `is_exported` is true.
|
|
//
|
|
// Note that both can be true at the same time. Such symbol represents
|
|
// a function or data exported from this ELF file which can be
|
|
// imported by other definition at runtime. That is actually a usual
|
|
// exported symbol when creating a DSO. In other words, a dynamic
|
|
// symbol exported by a DSO is usually imported by itself.
|
|
//
|
|
// If is_imported is true and is_exported is false, it is a dynamic
|
|
// symbol just imported from other DSO.
|
|
//
|
|
// If is_imported is false and is_exported is true, there are two
|
|
// possible cases. If we are creating an executable, we know that
|
|
// exported symbols cannot be intercepted by any DSO (because the
|
|
// dynamic loader searches a dynamic symbol from an executable before
|
|
// examining any DSOs), so any exported symbol is export-only in an
|
|
// executable. If we are creating a DSO, export-only symbols
|
|
// represent a protected symbol (i.e. a symbol whose visibility is
|
|
// STV_PROTECTED).
|
|
bool is_imported : 1 = false;
|
|
bool is_exported : 1 = false;
|
|
|
|
// `is_canonical` is true if this symbol represents a "canonical" PLT.
|
|
// Here is the explanation as to what the canonical PLT is.
|
|
//
|
|
// In C/C++, the process-wide function pointer equality is guaranteed.
|
|
// That is, if you take an address of a function `foo`, it's always
|
|
// evaluated to the same address wherever you do that.
|
|
//
|
|
// For the sake of explanation, assume that `libx.so` exports a
|
|
// function symbol `foo`, and there's a program that uses `libx.so`.
|
|
// Both `libx.so` and the main executable take the address of `foo`,
|
|
// which must be evaluated to the same address because of the above
|
|
// guarantee.
|
|
//
|
|
// If the main executable is position-independent code (PIC), `foo` is
|
|
// evaluated to the beginning of the function code, as you would have
|
|
// expected. The address of `foo` is stored to GOTs, and the machine
|
|
// code that takes the address of `foo` reads the GOT entries at
|
|
// runtime.
|
|
//
|
|
// However, if it's not PIC, the main executable's code was compiled
|
|
// to not use GOT (note that shared objects are always PIC, only
|
|
// executables can be non-PIC). It instead assumes that `foo` (and any
|
|
// other global variables/functions) has an address that is fixed at
|
|
// link-time. This assumption is correct if `foo` is in the same
|
|
// position-dependent executable, but it's not if `foo` is imported
|
|
// from some other DSO at runtime.
|
|
//
|
|
// In this case, we use the address of the `foo`'s PLT entry in the
|
|
// main executable (whose address is fixed at link-time) as its
|
|
// address. In order to guarantee pointer equality, we also need to
|
|
// fill foo's GOT entries in DSOs with the addres of the foo's PLT
|
|
// entry instead of `foo`'s real address. We can do that by setting a
|
|
// symbol value to `foo`'s dynamic symbol. If a symbol value is set,
|
|
// the dynamic loader initialize `foo`'s GOT entries with that value
|
|
// instead of the symbol's real address.
|
|
//
|
|
// We call such PLT entry in the main executable as "canonical".
|
|
// If `foo` has a canonical PLT, its address is evaluated to its
|
|
// canonical PLT's address. Otherwise, it's evaluated to `foo`'s
|
|
// address.
|
|
//
|
|
// Only non-PIC main executables may have canonical PLTs. PIC
|
|
// executables and shared objects never have a canonical PLT.
|
|
//
|
|
// This bit manages if we need to make this symbol's PLT canonical.
|
|
// This bit is meaningful only when the symbol has a PLT entry.
|
|
bool is_canonical : 1 = false;
|
|
|
|
// If an input object file is not compiled with -fPIC (or with
|
|
// -fno-PIC), the file not position independent. That means the
|
|
// machine code included in the object file does not use GOT to access
|
|
// global variables. Instead, it assumes that addresses of global
|
|
// variables are known at link-time.
|
|
//
|
|
// Let's say `libx.so` exports a global variable `foo`, and a main
|
|
// executable uses the variable. If the executable is not compiled
|
|
// with -fPIC, we can't simply apply a relocation that refers `foo`
|
|
// because `foo`'s address is not known at link-time.
|
|
//
|
|
// In this case, we could print out the "recompile with -fPIC" error
|
|
// message, but there's a way to workaround.
|
|
//
|
|
// The loader supports a feature so-called "copy relocations".
|
|
// A copy relocation instructs the loader to copy data from a DSO to a
|
|
// specified location in the main executable. By using this feature,
|
|
// we can copy `foo`'s data to a BSS region at runtime. With that,
|
|
// we can apply relocations agianst `foo` as if `foo` existed in the
|
|
// main executable's BSS area, whose address is known at link-time.
|
|
//
|
|
// Copy relocations are used only by position-dependent executables.
|
|
// Position-independent executables and DSOs don't need them because
|
|
// they use GOT to access global variables.
|
|
//
|
|
// `has_copyrel` is true if we need to emit a copy relocation for this
|
|
// symbol. If the original symbol in a DSO is in a read-only memory
|
|
// region, `is_copyrel_readonly` is set to true so that the copied data
|
|
// will become read-only at run-time.
|
|
bool has_copyrel : 1 = false;
|
|
bool is_copyrel_readonly : 1 = false;
|
|
|
|
// For LTO. True if the symbol is referenced by a regular object (as
|
|
// opposed to IR object).
|
|
bool referenced_by_regular_obj : 1 = false;
|
|
|
|
// For `-z rewrite-endbr`
|
|
bool address_taken : 1 = false;
|
|
|
|
// Target-dependent extra members.
|
|
[[no_unique_address]] SymbolExtras<E> extra;
|
|
};
|
|
|
|
template <typename E>
|
|
Symbol<E> *get_symbol(Context<E> &ctx, std::string_view key,
|
|
std::string_view name);
|
|
|
|
template <typename E>
|
|
Symbol<E> *get_symbol(Context<E> &ctx, std::string_view name);
|
|
|
|
template <typename E>
|
|
std::string_view demangle(const Symbol<E> &sym);
|
|
|
|
template <typename E>
|
|
std::ostream &operator<<(std::ostream &out, const Symbol<E> &sym) {
|
|
if (opt_demangle)
|
|
out << demangle(sym);
|
|
else
|
|
out << sym.name();
|
|
return out;
|
|
}
|
|
|
|
//
|
|
// Inline objects and functions
|
|
//
|
|
|
|
template <typename E>
|
|
inline i64 FdeRecord<E>::size(ObjectFile<E> &file) const {
|
|
return *(U32<E> *)(file.cies[cie_idx].contents.data() + input_offset) + 4;
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::string_view FdeRecord<E>::get_contents(ObjectFile<E> &file) const {
|
|
return file.cies[cie_idx].contents.substr(input_offset, size(file));
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::span<ElfRel<E>>
|
|
FdeRecord<E>::get_rels(ObjectFile<E> &file) const {
|
|
std::span<ElfRel<E>> rels = file.cies[cie_idx].rels;
|
|
i64 end = rel_idx;
|
|
while (end < rels.size() && rels[end].r_offset < input_offset + size(file))
|
|
end++;
|
|
return rels.subspan(rel_idx, end - rel_idx);
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::ostream &
|
|
operator<<(std::ostream &out, const InputSection<E> &isec) {
|
|
out << isec.file << ":(" << isec.name() << ")";
|
|
return out;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 SectionFragment<E>::get_addr(Context<E> &ctx) const {
|
|
return output_section.shdr.sh_addr + offset;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void InputSection<E>::kill() {
|
|
if (is_alive.exchange(false))
|
|
for (FdeRecord<E> &fde : get_fdes())
|
|
fde.is_alive = false;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 InputSection<E>::get_addr() const {
|
|
return output_section->shdr.sh_addr + offset;
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::string_view InputSection<E>::name() const {
|
|
if (file.elf_sections.size() <= shndx)
|
|
return (shdr().sh_flags & SHF_TLS) ? ".tls_common" : ".common";
|
|
return file.shstrtab.data() + file.elf_sections[shndx].sh_name;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i64 InputSection<E>::get_priority() const {
|
|
return ((i64)file.priority << 32) | shndx;
|
|
}
|
|
|
|
template <typename E>
|
|
i64 get_addend(u8 *loc, const ElfRel<E> &rel);
|
|
|
|
template <typename E> requires E::is_rela && (!is_sh4<E>)
|
|
inline i64 get_addend(u8 *loc, const ElfRel<E> &rel) {
|
|
return rel.r_addend;
|
|
}
|
|
|
|
template <typename E>
|
|
i64 get_addend(InputSection<E> &isec, const ElfRel<E> &rel) {
|
|
return get_addend((u8 *)isec.contents.data() + rel.r_offset, rel);
|
|
}
|
|
|
|
template <typename E>
|
|
void write_addend(u8 *loc, i64 val, const ElfRel<E> &rel);
|
|
|
|
template <typename E> requires E::is_rela
|
|
void write_addend(u8 *loc, i64 val, const ElfRel<E> &rel) {}
|
|
|
|
template <typename E>
|
|
inline const ElfShdr<E> &InputSection<E>::shdr() const {
|
|
if (shndx < file.elf_sections.size())
|
|
return file.elf_sections[shndx];
|
|
return file.elf_sections2[shndx - file.elf_sections.size()];
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::span<ElfRel<E>> InputSection<E>::get_rels(Context<E> &ctx) const {
|
|
if (relsec_idx == -1)
|
|
return {};
|
|
return file.template get_data<ElfRel<E>>(ctx, file.elf_sections[relsec_idx]);
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::span<FdeRecord<E>> InputSection<E>::get_fdes() const {
|
|
if (fde_begin == -1)
|
|
return {};
|
|
std::span<FdeRecord<E>> span(file.fdes);
|
|
return span.subspan(fde_begin, fde_end - fde_begin);
|
|
}
|
|
|
|
template <typename E>
|
|
std::pair<SectionFragment<E> *, i64>
|
|
InputSection<E>::get_fragment(Context<E> &ctx, const ElfRel<E> &rel) {
|
|
assert(!(shdr().sh_flags & SHF_ALLOC));
|
|
|
|
const ElfSym<E> &esym = file.elf_syms[rel.r_sym];
|
|
if (esym.st_type == STT_SECTION)
|
|
if (std::unique_ptr<MergeableSection<E>> &m =
|
|
file.mergeable_sections[file.get_shndx(esym)])
|
|
return m->get_fragment(esym.st_value + get_addend(*this, rel));
|
|
|
|
return {nullptr, 0};
|
|
}
|
|
|
|
template <typename E>
|
|
u64 InputSection<E>::get_thunk_addr(i64 idx) {
|
|
if constexpr (needs_thunk<E>) {
|
|
ThunkRef ref = extra.thunk_refs[idx];
|
|
assert(ref.thunk_idx != -1);
|
|
return output_section->thunks[ref.thunk_idx]->get_addr(ref.sym_idx);
|
|
}
|
|
unreachable();
|
|
}
|
|
|
|
// Input object files may contain duplicate code for inline functions
|
|
// and such. Linkers de-duplicate them at link-time. However, linkers
|
|
// generaly don't remove debug info for de-duplicated functions because
|
|
// doing that requires parsing the entire debug section.
|
|
//
|
|
// Instead, linkers write "tombstone" values to dead debug info records
|
|
// instead of bogus values so that debuggers can skip them.
|
|
//
|
|
// This function returns a tombstone value for the symbol if the symbol
|
|
// refers a dead debug info section.
|
|
template <typename E>
|
|
inline std::optional<u64>
|
|
InputSection<E>::get_tombstone(Symbol<E> &sym, SectionFragment<E> *frag) {
|
|
if (frag)
|
|
return {};
|
|
|
|
InputSection<E> *isec = sym.get_input_section();
|
|
|
|
// Setting a tombstone is a special feature for a dead debug section.
|
|
if (!isec || isec->is_alive)
|
|
return {};
|
|
|
|
std::string_view s = name();
|
|
if (!s.starts_with(".debug"))
|
|
return {};
|
|
|
|
// If the section was dead due to ICF, we don't want to emit debug
|
|
// info for that section but want to set real values to .debug_line so
|
|
// that users can set a breakpoint inside a merged section.
|
|
if (isec->is_killed_by_icf() && s == ".debug_line")
|
|
return {};
|
|
|
|
// 0 is an invalid value in most debug info sections, so we use it
|
|
// as a tombstone value. .debug_loc and .debug_ranges reserve 0 as
|
|
// the terminator marker, so we use 1 if that's the case.
|
|
return (s == ".debug_loc" || s == ".debug_ranges") ? 1 : 0;
|
|
}
|
|
|
|
template <typename E>
|
|
inline bool
|
|
InputSection<E>::is_relr_reloc(Context<E> &ctx, const ElfRel<E> &rel) const {
|
|
return ctx.arg.pack_dyn_relocs_relr &&
|
|
!(shdr().sh_flags & SHF_EXECINSTR) &&
|
|
(shdr().sh_addralign % sizeof(Word<E>)) == 0 &&
|
|
(rel.r_offset % sizeof(Word<E>)) == 0;
|
|
}
|
|
|
|
template <typename E>
|
|
inline bool InputSection<E>::is_killed_by_icf() const {
|
|
return this->leader && this->leader != this;
|
|
}
|
|
|
|
template <typename E>
|
|
std::pair<SectionFragment<E> *, i64>
|
|
MergeableSection<E>::get_fragment(i64 offset) {
|
|
std::vector<u32> &vec = frag_offsets;
|
|
auto it = std::upper_bound(vec.begin(), vec.end(), offset);
|
|
i64 idx = it - 1 - vec.begin();
|
|
return {fragments[idx], offset - vec[idx]};
|
|
}
|
|
|
|
template <typename E>
|
|
template <typename T>
|
|
inline std::span<T>
|
|
InputFile<E>::get_data(Context<E> &ctx, const ElfShdr<E> &shdr) {
|
|
std::string_view view = this->get_string(ctx, shdr);
|
|
if (view.size() % sizeof(T))
|
|
Fatal(ctx) << *this << ": corrupted section";
|
|
return {(T *)view.data(), view.size() / sizeof(T)};
|
|
}
|
|
|
|
template <typename E>
|
|
template <typename T>
|
|
inline std::span<T> InputFile<E>::get_data(Context<E> &ctx, i64 idx) {
|
|
if (elf_sections.size() <= idx)
|
|
Fatal(ctx) << *this << ": invalid section index";
|
|
return this->template get_data<T>(elf_sections[idx]);
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::string_view
|
|
InputFile<E>::get_string(Context<E> &ctx, const ElfShdr<E> &shdr) {
|
|
u8 *begin = mf->data + shdr.sh_offset;
|
|
u8 *end = begin + shdr.sh_size;
|
|
if (mf->data + mf->size < end)
|
|
Fatal(ctx) << *this << ": section header is out of range: " << shdr.sh_offset;
|
|
return {(char *)begin, (size_t)(end - begin)};
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::string_view InputFile<E>::get_string(Context<E> &ctx, i64 idx) {
|
|
if (elf_sections.size() <= idx)
|
|
Fatal(ctx) << *this << ": invalid section index: " << idx;
|
|
return this->get_string(ctx, elf_sections[idx]);
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::span<Symbol<E> *> InputFile<E>::get_global_syms() {
|
|
return std::span<Symbol<E> *>(this->symbols).subspan(this->first_global);
|
|
}
|
|
|
|
template <typename E>
|
|
inline i64 ObjectFile<E>::get_shndx(const ElfSym<E> &esym) {
|
|
assert(&this->elf_syms[0] <= &esym);
|
|
assert(&esym <= &this->elf_syms[this->elf_syms.size() - 1]);
|
|
|
|
if (esym.st_shndx == SHN_XINDEX)
|
|
return symtab_shndx_sec[&esym - &this->elf_syms[0]];
|
|
return esym.st_shndx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline InputSection<E> *ObjectFile<E>::get_section(const ElfSym<E> &esym) {
|
|
return sections[get_shndx(esym)].get();
|
|
}
|
|
|
|
template <typename E>
|
|
OutputSection<E> *find_section(Context<E> &ctx, u32 sh_type) {
|
|
for (Chunk<E> *chunk : ctx.chunks)
|
|
if (OutputSection<E> *osec = chunk->to_osec())
|
|
if (osec->shdr.sh_type == sh_type)
|
|
return osec;
|
|
return nullptr;
|
|
}
|
|
|
|
template <typename E>
|
|
OutputSection<E> *find_section(Context<E> &ctx, std::string_view name) {
|
|
for (Chunk<E> *chunk : ctx.chunks)
|
|
if (OutputSection<E> *osec = chunk->to_osec())
|
|
if (osec->name == name)
|
|
return osec;
|
|
return nullptr;
|
|
}
|
|
|
|
template <typename E>
|
|
u64 Symbol<E>::get_addr(Context<E> &ctx, i64 flags) const {
|
|
if (SectionFragment<E> *frag = get_frag()) {
|
|
if (!frag->is_alive) {
|
|
// This condition is met if a non-alloc section refers an
|
|
// alloc section and if the referenced piece of data is
|
|
// garbage-collected. Typically, this condition occurs if a
|
|
// debug info section refers a string constant in .rodata.
|
|
return 0;
|
|
}
|
|
|
|
return frag->get_addr(ctx) + value;
|
|
}
|
|
|
|
if (has_copyrel) {
|
|
return is_copyrel_readonly
|
|
? ctx.copyrel_relro->shdr.sh_addr + value
|
|
: ctx.copyrel->shdr.sh_addr + value;
|
|
}
|
|
|
|
if constexpr (is_ppc64v1<E>)
|
|
if (!(flags & NO_OPD) && has_opd(ctx))
|
|
return get_opd_addr(ctx);
|
|
|
|
if (!(flags & NO_PLT) && has_plt(ctx)) {
|
|
assert(is_imported || is_ifunc());
|
|
return get_plt_addr(ctx);
|
|
}
|
|
|
|
InputSection<E> *isec = get_input_section();
|
|
if (!isec)
|
|
return value; // absolute symbol
|
|
|
|
if (!isec->is_alive) {
|
|
if (isec->is_killed_by_icf())
|
|
return isec->leader->get_addr() + value;
|
|
|
|
if (isec->name() == ".eh_frame") {
|
|
// .eh_frame contents are parsed and reconstructed by the linker,
|
|
// so pointing to a specific location in a source .eh_frame
|
|
// section doesn't make much sense. However, CRT files contain
|
|
// symbols pointing to the very beginning and ending of the section.
|
|
//
|
|
// If LTO is enabled, GCC may add `.lto_priv.<whatever>` as a symbol
|
|
// suffix. That's why we use starts_with() instead of `==` here.
|
|
if (name().starts_with("__EH_FRAME_BEGIN__") ||
|
|
name().starts_with("__EH_FRAME_LIST__") ||
|
|
name().starts_with(".eh_frame_seg") ||
|
|
esym().st_type == STT_SECTION)
|
|
return ctx.eh_frame->shdr.sh_addr;
|
|
|
|
if (name().starts_with("__FRAME_END__") ||
|
|
name().starts_with("__EH_FRAME_LIST_END__"))
|
|
return ctx.eh_frame->shdr.sh_addr + ctx.eh_frame->shdr.sh_size;
|
|
|
|
// ARM object files contain "$d" local symbol at the beginning
|
|
// of data sections. Their values are not significant for .eh_frame,
|
|
// so we just treat them as offset 0.
|
|
if (name() == "$d" || name().starts_with("$d."))
|
|
return ctx.eh_frame->shdr.sh_addr;
|
|
|
|
Fatal(ctx) << "symbol referring to .eh_frame is not supported: "
|
|
<< *this << " " << *file;
|
|
}
|
|
|
|
// The control can reach here if there's a relocation that refers
|
|
// a local symbol belonging to a comdat group section. This is a
|
|
// violation of the spec, as all relocations should use only global
|
|
// symbols of comdat members. However, .eh_frame tends to have such
|
|
// relocations.
|
|
return 0;
|
|
}
|
|
|
|
return isec->get_addr() + value;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_got_addr(Context<E> &ctx) const {
|
|
return ctx.got->shdr.sh_addr + get_got_idx(ctx) * sizeof(Word<E>);
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_gotplt_addr(Context<E> &ctx) const {
|
|
assert(get_plt_idx(ctx) != -1);
|
|
return ctx.gotplt->shdr.sh_addr + GotPltSection<E>::HDR_SIZE +
|
|
get_plt_idx(ctx) * GotPltSection<E>::ENTRY_SIZE;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_gottp_addr(Context<E> &ctx) const {
|
|
assert(get_gottp_idx(ctx) != -1);
|
|
return ctx.got->shdr.sh_addr + get_gottp_idx(ctx) * sizeof(Word<E>);
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_tlsgd_addr(Context<E> &ctx) const {
|
|
assert(get_tlsgd_idx(ctx) != -1);
|
|
return ctx.got->shdr.sh_addr + get_tlsgd_idx(ctx) * sizeof(Word<E>);
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_tlsdesc_addr(Context<E> &ctx) const {
|
|
assert(get_tlsdesc_idx(ctx) != -1);
|
|
return ctx.got->shdr.sh_addr + get_tlsdesc_idx(ctx) * sizeof(Word<E>);
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 to_plt_offset(i32 pltidx) {
|
|
if constexpr (is_ppc64v1<E>) {
|
|
// The PPC64 ELFv1 ABI requires PLT entries to vary in size
|
|
// depending on their indices. For entries whose PLT index is
|
|
// less than 32768, the entry size is 8 bytes. Other entries are
|
|
// 12 bytes long.
|
|
if (pltidx < 0x8000)
|
|
return E::plt_hdr_size + pltidx * 8;
|
|
return E::plt_hdr_size + 0x8000 * 8 + (pltidx - 0x8000) * 12;
|
|
} else {
|
|
return E::plt_hdr_size + pltidx * E::plt_size;
|
|
}
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_plt_addr(Context<E> &ctx) const {
|
|
if (i32 idx = get_plt_idx(ctx); idx != -1)
|
|
return ctx.plt->shdr.sh_addr + to_plt_offset<E>(idx);
|
|
return ctx.pltgot->shdr.sh_addr + get_pltgot_idx(ctx) * E::pltgot_size;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_opd_addr(Context<E> &ctx) const {
|
|
assert(get_opd_idx(ctx) != -1);
|
|
return ctx.extra.opd->shdr.sh_addr +
|
|
get_opd_idx(ctx) * PPC64OpdSection::ENTRY_SIZE;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u64 Symbol<E>::get_got_pltgot_addr(Context<E> &ctx) const {
|
|
// An ifunc symbol occupies two consecutive GOT slots in a
|
|
// position-dependent executable (PDE). The first slot contains the
|
|
// symbol's PLT address, and the second slot holds the resolved
|
|
// address. A PDE uses the ifunc symbol's PLT entry as the address
|
|
// for the symbol, akin to a canonical PLT.
|
|
//
|
|
// This function returns the address that the PLT entry should use
|
|
// to jump to the resolved address.
|
|
//
|
|
// Note that we don't use this function for PPC64. In PPC64, symbols
|
|
// are always accessed through the TOC table regardless of the
|
|
// -fno-PIE setting. We don't need canonical PLTs on the psABIs too.
|
|
if (is_pde_ifunc(ctx))
|
|
return get_got_addr(ctx) + sizeof(Word<E>);
|
|
return get_got_addr(ctx);
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_got_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
assert(ctx.symbol_aux[aux_idx].got_idx < 0);
|
|
ctx.symbol_aux[aux_idx].got_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_gottp_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
assert(ctx.symbol_aux[aux_idx].gottp_idx < 0);
|
|
ctx.symbol_aux[aux_idx].gottp_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_tlsgd_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
assert(ctx.symbol_aux[aux_idx].tlsgd_idx < 0);
|
|
ctx.symbol_aux[aux_idx].tlsgd_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_tlsdesc_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
assert(ctx.symbol_aux[aux_idx].tlsdesc_idx < 0);
|
|
ctx.symbol_aux[aux_idx].tlsdesc_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_plt_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
assert(ctx.symbol_aux[aux_idx].plt_idx < 0);
|
|
ctx.symbol_aux[aux_idx].plt_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_pltgot_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
assert(ctx.symbol_aux[aux_idx].pltgot_idx < 0);
|
|
ctx.symbol_aux[aux_idx].pltgot_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_opd_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
assert(ctx.symbol_aux[aux_idx].opd_idx < 0);
|
|
ctx.symbol_aux[aux_idx].opd_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_dynsym_idx(Context<E> &ctx, i32 idx) {
|
|
assert(aux_idx != -1);
|
|
ctx.symbol_aux[aux_idx].dynsym_idx = idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_got_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].got_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_gottp_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].gottp_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_tlsgd_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].tlsgd_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_tlsdesc_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].tlsdesc_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_plt_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].plt_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_pltgot_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].pltgot_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_opd_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].opd_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline i32 Symbol<E>::get_dynsym_idx(Context<E> &ctx) const {
|
|
return (aux_idx == -1) ? -1 : ctx.symbol_aux[aux_idx].dynsym_idx;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u32 Symbol<E>::get_djb_hash(Context<E> &ctx) const {
|
|
assert(aux_idx != -1);
|
|
return ctx.symbol_aux[aux_idx].djb_hash;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_djb_hash(Context<E> &ctx, u32 hash) {
|
|
assert(aux_idx != -1);
|
|
ctx.symbol_aux[aux_idx].djb_hash = hash;
|
|
}
|
|
|
|
template <typename E>
|
|
inline bool Symbol<E>::has_plt(Context<E> &ctx) const {
|
|
return get_plt_idx(ctx) != -1 || get_pltgot_idx(ctx) != -1;
|
|
}
|
|
|
|
template <typename E>
|
|
inline bool Symbol<E>::is_absolute() const {
|
|
return !is_imported && !get_frag() && !get_input_section() &&
|
|
!get_output_section();
|
|
}
|
|
|
|
template <typename E>
|
|
inline bool Symbol<E>::is_local(Context<E> &ctx) const {
|
|
if (ctx.arg.relocatable)
|
|
return esym().st_bind == STB_LOCAL;
|
|
return !is_imported && !is_exported;
|
|
}
|
|
|
|
template <typename E>
|
|
inline bool Symbol<E>::is_pde_ifunc(Context<E> &ctx) const {
|
|
// Returns true if this is an ifunc tha uses two GOT slots
|
|
return is_ifunc() && !ctx.arg.pic && !is_ppc64<E>;
|
|
}
|
|
|
|
// A remaining weak undefined symbol is promoted to a dynamic symbol
|
|
// in DSO and resolved to 0 in an executable. This function returns
|
|
// true if it's latter.
|
|
template <typename E>
|
|
inline bool Symbol<E>::is_remaining_undef_weak() const {
|
|
return !is_imported && esym().is_undef_weak();
|
|
}
|
|
|
|
// Returns true if the symbol's PC-relative address is known at link-time.
|
|
template <typename E>
|
|
inline bool Symbol<E>::is_pcrel_linktime_const(Context<E> &ctx) const {
|
|
return !is_imported && !is_ifunc() && (is_relative() || !ctx.arg.pic);
|
|
}
|
|
|
|
// Returns true if the symbol's Thread Pointer-relative address is
|
|
// known at link-time.
|
|
template <typename E>
|
|
inline bool Symbol<E>::is_tprel_linktime_const(Context<E> &ctx) const {
|
|
assert(get_type() == STT_TLS);
|
|
return !ctx.arg.shared && !is_imported;
|
|
}
|
|
|
|
// Returns true if the symbol's Thread Pointer-relative address is
|
|
// known at load-time.
|
|
template <typename E>
|
|
inline bool Symbol<E>::is_tprel_runtime_const(Context<E> &ctx) const {
|
|
// Returns true unless we are creating a dlopen'able DSO.
|
|
assert(get_type() == STT_TLS);
|
|
return !(ctx.arg.shared && ctx.arg.z_dlopen);
|
|
}
|
|
|
|
template <typename E>
|
|
inline InputSection<E> *Symbol<E>::get_input_section() const {
|
|
if ((origin & TAG_MASK) == TAG_ISEC)
|
|
return (InputSection<E> *)(origin & ~TAG_MASK);
|
|
return nullptr;
|
|
}
|
|
|
|
template <typename E>
|
|
inline Chunk<E> *Symbol<E>::get_output_section() const {
|
|
if ((origin & TAG_MASK) == TAG_OSEC)
|
|
return (Chunk<E> *)(origin & ~TAG_MASK);
|
|
return nullptr;
|
|
}
|
|
|
|
template <typename E>
|
|
inline SectionFragment<E> *Symbol<E>::get_frag() const {
|
|
if ((origin & TAG_MASK) == TAG_FRAG)
|
|
return (SectionFragment<E> *)(origin & ~TAG_MASK);
|
|
return nullptr;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_input_section(InputSection<E> *isec) {
|
|
uintptr_t addr = (uintptr_t)isec;
|
|
assert((addr & TAG_MASK) == 0);
|
|
origin = addr | TAG_ISEC;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_output_section(Chunk<E> *osec) {
|
|
uintptr_t addr = (uintptr_t)osec;
|
|
assert((addr & TAG_MASK) == 0);
|
|
origin = addr | TAG_OSEC;
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_frag(SectionFragment<E> *frag) {
|
|
uintptr_t addr = (uintptr_t)frag;
|
|
assert((addr & TAG_MASK) == 0);
|
|
origin = addr | TAG_FRAG;
|
|
}
|
|
|
|
template <typename E>
|
|
inline u32 Symbol<E>::get_type() const {
|
|
if (esym().st_type == STT_GNU_IFUNC && file->is_dso)
|
|
return STT_FUNC;
|
|
return esym().st_type;
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::string_view Symbol<E>::get_version() const {
|
|
if (file->is_dso)
|
|
return ((SharedFile<E> *)file)->version_strings[ver_idx];
|
|
return "";
|
|
}
|
|
|
|
template <typename E>
|
|
inline i64 Symbol<E>::get_output_sym_idx(Context<E> &ctx) const {
|
|
i64 i = file->output_sym_indices[sym_idx];
|
|
assert(i != -1);
|
|
if (is_local(ctx))
|
|
return file->local_symtab_idx + i;
|
|
return file->global_symtab_idx + i;
|
|
}
|
|
|
|
template <typename E>
|
|
inline const ElfSym<E> &Symbol<E>::esym() const {
|
|
return file->elf_syms[sym_idx];
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::set_name(std::string_view name) {
|
|
nameptr = name.data();
|
|
namelen = name.size();
|
|
}
|
|
|
|
template <typename E>
|
|
inline std::string_view Symbol<E>::name() const {
|
|
return {nameptr, (size_t)namelen};
|
|
}
|
|
|
|
template <typename E>
|
|
inline void Symbol<E>::add_aux(Context<E> &ctx) {
|
|
if (aux_idx == -1) {
|
|
aux_idx = ctx.symbol_aux.size();
|
|
ctx.symbol_aux.resize(aux_idx + 1);
|
|
}
|
|
}
|
|
|
|
inline bool is_c_identifier(std::string_view s) {
|
|
if (s.empty())
|
|
return false;
|
|
|
|
auto is_alpha = [](char c) {
|
|
return c == '_' || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z');
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};
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auto is_alnum = [&](char c) {
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return is_alpha(c) || ('0' <= c && c <= '9');
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};
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if (!is_alpha(s[0]))
|
|
return false;
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for (i64 i = 1; i < s.size(); i++)
|
|
if (!is_alnum(s[i]))
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return false;
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return true;
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}
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} // namespace mold::elf
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