tools/reorder/elf_symbol_table.h@97036ab72558 (annotated)
tools/reorder/elf_symbol_table.h
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | /* -*- Mode: C++ -*- */ |
| michael@0 | 2 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 3 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 4 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 5 | |
| michael@0 | 6 | #ifndef elf_symbol_table_h__ |
| michael@0 | 7 | #define elf_symbol_table_h__ |
| michael@0 | 8 | |
| michael@0 | 9 | /* |
| michael@0 | 10 | |
| michael@0 | 11 | Utility class for reading ELF symbol tables. |
| michael@0 | 12 | |
| michael@0 | 13 | */ |
| michael@0 | 14 | |
| michael@0 | 15 | #include <elf.h> |
| michael@0 | 16 | #include <sys/mman.h> |
| michael@0 | 17 | |
| michael@0 | 18 | #include "interval_map.h" |
| michael@0 | 19 | |
| michael@0 | 20 | class elf_symbol_table { |
| michael@0 | 21 | protected: |
| michael@0 | 22 | int m_fd; |
| michael@0 | 23 | void *m_mapping; |
| michael@0 | 24 | size_t m_size; |
| michael@0 | 25 | const char *m_strtab; |
| michael@0 | 26 | const Elf32_Sym *m_symbols; |
| michael@0 | 27 | int m_nsymbols; |
| michael@0 | 28 | int m_text_shndx; |
| michael@0 | 29 | |
| michael@0 | 30 | typedef interval_map<unsigned int, const Elf32_Sym *> rsymtab_t; |
| michael@0 | 31 | rsymtab_t m_rsymtab; |
| michael@0 | 32 | |
| michael@0 | 33 | int verify_elf_header(const Elf32_Ehdr *hdr); |
| michael@0 | 34 | int finish(); |
| michael@0 | 35 | |
| michael@0 | 36 | public: |
| michael@0 | 37 | elf_symbol_table() |
| michael@0 | 38 | : m_fd(-1), |
| michael@0 | 39 | m_mapping(MAP_FAILED), |
| michael@0 | 40 | m_size(0), |
| michael@0 | 41 | m_strtab(0), |
| michael@0 | 42 | m_symbols(0), |
| michael@0 | 43 | m_nsymbols(0), |
| michael@0 | 44 | m_text_shndx(0) {} |
| michael@0 | 45 | |
| michael@0 | 46 | ~elf_symbol_table() { finish(); } |
| michael@0 | 47 | |
| michael@0 | 48 | /** |
| michael@0 | 49 | * Read the symbol table information from the specified file. (This will |
| michael@0 | 50 | * memory-map the file.) |
| michael@0 | 51 | * |
| michael@0 | 52 | * Currently, only symbols from the `.text' section are loaded. |
| michael@0 | 53 | */ |
| michael@0 | 54 | int init(const char *file); |
| michael@0 | 55 | |
| michael@0 | 56 | /** |
| michael@0 | 57 | * Determine what symbol the specified image address corresponds |
| michael@0 | 58 | * to. Addresses need not refer to a symbol's start address: |
| michael@0 | 59 | * symbol size information is used to reverse-map the address. |
| michael@0 | 60 | */ |
| michael@0 | 61 | const Elf32_Sym *lookup(unsigned int addr) const; |
| michael@0 | 62 | |
| michael@0 | 63 | /** |
| michael@0 | 64 | * Determine the symbol name for the specified symbol. |
| michael@0 | 65 | */ |
| michael@0 | 66 | const char *get_symbol_name(const Elf32_Sym *sym) const; |
| michael@0 | 67 | |
| michael@0 | 68 | /** |
| michael@0 | 69 | * Return `true' if the specified symbol is a function. |
| michael@0 | 70 | */ |
| michael@0 | 71 | bool is_function(const Elf32_Sym *sym) const { |
| michael@0 | 72 | return (sym->st_size > 0) && |
| michael@0 | 73 | (ELF32_ST_TYPE(sym->st_info) == STT_FUNC) && |
| michael@0 | 74 | (sym->st_shndx == m_text_shndx); } |
| michael@0 | 75 | |
| michael@0 | 76 | typedef const Elf32_Sym *const_iterator; |
| michael@0 | 77 | |
| michael@0 | 78 | const_iterator begin() const { return const_iterator(m_symbols); } |
| michael@0 | 79 | const_iterator end() const { return const_iterator(m_symbols + m_nsymbols); } |
| michael@0 | 80 | }; |
| michael@0 | 81 | |
| michael@0 | 82 | #endif // elf_symbol_table_h__ |
