David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 The Android Open Source Project |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * * Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * * Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in |
| 12 | * the documentation and/or other materials provided with the |
| 13 | * distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 16 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 17 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 18 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 19 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 21 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| 22 | * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 23 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 24 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 25 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | */ |
| 28 | #ifndef LINKER_PHDR_H |
| 29 | #define LINKER_PHDR_H |
| 30 | |
| 31 | /* Declarations related to the ELF program header table and segments. |
| 32 | * |
| 33 | * The design goal is to provide an API that is as close as possible |
| 34 | * to the ELF spec, and does not depend on linker-specific data |
| 35 | * structures (e.g. the exact layout of struct soinfo). |
| 36 | */ |
| 37 | |
| 38 | #include "linker.h" |
| 39 | |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 40 | class ElfReader { |
| 41 | public: |
| 42 | ElfReader(const char* name, int fd); |
| 43 | ~ElfReader(); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 44 | |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 45 | bool Load(); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 46 | |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 47 | size_t phdr_count() { return phdr_num_; } |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 48 | Elf_Addr load_start() { return reinterpret_cast<Elf_Addr>(load_start_); } |
Elliott Hughes | c00f2cb | 2013-10-04 17:01:33 -0700 | [diff] [blame] | 49 | size_t load_size() { return load_size_; } |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 50 | Elf_Addr load_bias() { return load_bias_; } |
| 51 | const Elf_Phdr* loaded_phdr() { return loaded_phdr_; } |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 52 | |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 53 | private: |
| 54 | bool ReadElfHeader(); |
| 55 | bool VerifyElfHeader(); |
| 56 | bool ReadProgramHeader(); |
| 57 | bool ReserveAddressSpace(); |
| 58 | bool LoadSegments(); |
| 59 | bool FindPhdr(); |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 60 | bool CheckPhdr(Elf_Addr); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 61 | |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 62 | const char* name_; |
| 63 | int fd_; |
| 64 | |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 65 | Elf_Ehdr header_; |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 66 | size_t phdr_num_; |
| 67 | |
| 68 | void* phdr_mmap_; |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 69 | Elf_Phdr* phdr_table_; |
| 70 | Elf_Addr phdr_size_; |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 71 | |
| 72 | // First page of reserved address space. |
| 73 | void* load_start_; |
| 74 | // Size in bytes of reserved address space. |
Elliott Hughes | c00f2cb | 2013-10-04 17:01:33 -0700 | [diff] [blame] | 75 | size_t load_size_; |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 76 | // Load bias. |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 77 | Elf_Addr load_bias_; |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 78 | |
| 79 | // Loaded phdr. |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 80 | const Elf_Phdr* loaded_phdr_; |
Elliott Hughes | 650be4e | 2013-03-05 18:47:58 -0800 | [diff] [blame] | 81 | }; |
| 82 | |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 83 | size_t phdr_table_get_load_size(const Elf_Phdr* phdr_table, size_t phdr_count, |
| 84 | Elf_Addr* min_vaddr = NULL, Elf_Addr* max_vaddr = NULL); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 85 | |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 86 | int phdr_table_protect_segments(const Elf_Phdr* phdr_table, size_t phdr_count, Elf_Addr load_bias); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 87 | |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 88 | int phdr_table_unprotect_segments(const Elf_Phdr* phdr_table, size_t phdr_count, Elf_Addr load_bias); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 89 | |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 90 | int phdr_table_protect_gnu_relro(const Elf_Phdr* phdr_table, size_t phdr_count, Elf_Addr load_bias); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 91 | |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 92 | |
Elliott Hughes | 4eeb1f1 | 2013-10-25 17:38:02 -0700 | [diff] [blame^] | 93 | #if defined(__arm__) |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 94 | int phdr_table_get_arm_exidx(const Elf_Phdr* phdr_table, size_t phdr_count, Elf_Addr load_bias, |
| 95 | Elf_Addr** arm_exidx, unsigned* arm_exidix_count); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 96 | #endif |
| 97 | |
Elliott Hughes | c620059 | 2013-09-30 18:43:46 -0700 | [diff] [blame] | 98 | void phdr_table_get_dynamic_section(const Elf_Phdr* phdr_table, size_t phdr_count, |
| 99 | Elf_Addr load_bias, |
| 100 | Elf_Dyn** dynamic, size_t* dynamic_count, Elf_Word* dynamic_flags); |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 101 | |
David 'Digit' Turner | c1bd559 | 2012-06-19 11:21:29 +0200 | [diff] [blame] | 102 | #endif /* LINKER_PHDR_H */ |