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// Copyright 2019 The Cobalt Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef STARBOARD_ELF_LOADER_PROGRAM_TABLE_H_
#define STARBOARD_ELF_LOADER_PROGRAM_TABLE_H_
#include <vector>
#include "cobalt/extension/memory_mapped_file.h"
#include "starboard/elf_loader/elf.h"
#include "starboard/elf_loader/file.h"
namespace starboard {
namespace elf_loader {
// Loads the ELF's binary program table and memory maps
// the loadable segments.
//
// To properly initialize the program table and the segments
// the following calls are required:
// 1. LoadProgramHeader()
// 2. LoadSegments()
//
// After those calls the ProgramTable class is fully functional and
// the segments properly loaded.
class ProgramTable {
public:
explicit ProgramTable(
const CobaltExtensionMemoryMappedFileApi* memory_mapped_file_extension);
// Loads the program header.
bool LoadProgramHeader(const Ehdr* elf_header, File* elf_file);
// Loads the segments.
bool LoadSegments(File* elf_file);
// Retrieves the dynamic section table.
void GetDynamicSection(Dyn** dynamic,
size_t* dynamic_count,
Word* dynamic_flags);
// Adjusts the memory protection of read only segments.
// This call is used to make text segments writable in order
// to apply relocations. After the relocations are done the
// protection is restored to its original read only state.
int AdjustMemoryProtectionOfReadOnlySegments(int extra_prot_flags);
// Reserves a contiguous block of memory, page aligned for mapping all
// the segments of the binary.
bool ReserveLoadMemory();
// Retrieves the base load address for the binary.
Addr GetBaseMemoryAddress();
// Publish the memory mapping information of the library to
// the EvergreenInfo API.
void PublishEvergreenInfo(const char* file_path);
~ProgramTable();
private:
// Calculates the memory size of the binary.
size_t GetLoadMemorySize();
private:
size_t phdr_num_;
void* phdr_mmap_;
Phdr* phdr_table_;
Addr phdr_size_;
std::vector<uint8_t> build_id_;
// First page of reserved address space.
void* load_start_;
// Size in bytes of reserved address space.
Addr load_size_;
// The base memory address. All virtual addresses
// from the ELF file are offsets from this address.
Addr base_memory_address_;
const CobaltExtensionMemoryMappedFileApi* memory_mapped_file_extension_;
ProgramTable(const ProgramTable&) = delete;
void operator=(const ProgramTable&) = delete;
};
} // namespace elf_loader
} // namespace starboard
#endif // STARBOARD_ELF_LOADER_PROGRAM_TABLE_H_