tools/reorder/elf_symbol_table.h@97036ab72558
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.
1 /* -*- Mode: C++ -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 #ifndef elf_symbol_table_h__
7 #define elf_symbol_table_h__
9 /*
11 Utility class for reading ELF symbol tables.
13 */
15 #include <elf.h>
16 #include <sys/mman.h>
18 #include "interval_map.h"
20 class elf_symbol_table {
21 protected:
22 int m_fd;
23 void *m_mapping;
24 size_t m_size;
25 const char *m_strtab;
26 const Elf32_Sym *m_symbols;
27 int m_nsymbols;
28 int m_text_shndx;
30 typedef interval_map<unsigned int, const Elf32_Sym *> rsymtab_t;
31 rsymtab_t m_rsymtab;
33 int verify_elf_header(const Elf32_Ehdr *hdr);
34 int finish();
36 public:
37 elf_symbol_table()
38 : m_fd(-1),
39 m_mapping(MAP_FAILED),
40 m_size(0),
41 m_strtab(0),
42 m_symbols(0),
43 m_nsymbols(0),
44 m_text_shndx(0) {}
46 ~elf_symbol_table() { finish(); }
48 /**
49 * Read the symbol table information from the specified file. (This will
50 * memory-map the file.)
51 *
52 * Currently, only symbols from the `.text' section are loaded.
53 */
54 int init(const char *file);
56 /**
57 * Determine what symbol the specified image address corresponds
58 * to. Addresses need not refer to a symbol's start address:
59 * symbol size information is used to reverse-map the address.
60 */
61 const Elf32_Sym *lookup(unsigned int addr) const;
63 /**
64 * Determine the symbol name for the specified symbol.
65 */
66 const char *get_symbol_name(const Elf32_Sym *sym) const;
68 /**
69 * Return `true' if the specified symbol is a function.
70 */
71 bool is_function(const Elf32_Sym *sym) const {
72 return (sym->st_size > 0) &&
73 (ELF32_ST_TYPE(sym->st_info) == STT_FUNC) &&
74 (sym->st_shndx == m_text_shndx); }
76 typedef const Elf32_Sym *const_iterator;
78 const_iterator begin() const { return const_iterator(m_symbols); }
79 const_iterator end() const { return const_iterator(m_symbols + m_nsymbols); }
80 };
82 #endif // elf_symbol_table_h__
