1.1 --- a/core/MemoryUtils.cpp Wed Nov 04 13:52:12 2009 -0500
1.2 +++ b/core/MemoryUtils.cpp Fri Nov 06 16:24:40 2009 -0600
1.3 @@ -1,8 +1,8 @@
1.4 /**
1.5 - * vim: set ts=4 :
1.6 + * vim: set ts=4 sw=4 tw=99 noet :
1.7 * =============================================================================
1.8 * SourceMod
1.9 - * Copyright (C) 2004-2008 AlliedModders LLC. All rights reserved.
1.10 + * Copyright (C) 2004-2009 AlliedModders LLC. All rights reserved.
1.11 * =============================================================================
1.12 *
1.13 * This program is free software; you can redistribute it and/or modify it under
1.14 @@ -25,15 +25,14 @@
1.15 * this exception to all derivative works. AlliedModders LLC defines further
1.16 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
1.17 * or <http://www.sourcemod.net/license.php>.
1.18 - *
1.19 - * Version: $Id$
1.20 */
1.21
1.22 #include "MemoryUtils.h"
1.23 #include "ShareSys.h"
1.24 #ifdef PLATFORM_LINUX
1.25 -#include <string.h>
1.26 -#include <elf.h>
1.27 +#include <fcntl.h>
1.28 +#include <link.h>
1.29 +#include <sys/mman.h>
1.30 #endif
1.31
1.32 MemoryUtils g_MemUtils;
1.33 @@ -56,6 +55,17 @@
1.34 }
1.35 #endif
1.36
1.37 +MemoryUtils::~MemoryUtils()
1.38 +{
1.39 +#ifdef PLATFORM_LINUX
1.40 + for (size_t i = 0; i < m_SymTables.size(); i++)
1.41 + {
1.42 + delete m_SymTables[i];
1.43 + }
1.44 + m_SymTables.clear();
1.45 +#endif
1.46 +}
1.47 +
1.48 void MemoryUtils::OnSourceModAllInitialized()
1.49 {
1.50 g_ShareSys.AddInterface(NULL, this);
1.51 @@ -98,6 +108,149 @@
1.52 return NULL;
1.53 }
1.54
1.55 +void *MemoryUtils::ResolveSymbol(void *handle, const char *symbol)
1.56 +{
1.57 +#ifdef PLATFORM_WINDOWS
1.58 +
1.59 + return GetProcAddress((HMODULE)handle, symbol);
1.60 +
1.61 +#elif defined PLATFORM_LINUX
1.62 +
1.63 + struct link_map *dlmap;
1.64 + struct stat dlstat;
1.65 + int dlfile;
1.66 + uintptr_t map_base;
1.67 + Elf32_Ehdr *file_hdr;
1.68 + Elf32_Shdr *sections, *shstrtab_hdr, *symtab_hdr, *strtab_hdr;
1.69 + Elf32_Sym *symtab;
1.70 + const char *shstrtab, *strtab;
1.71 + uint16_t section_count;
1.72 + uint32_t symbol_count;
1.73 + LibSymbolTable *libtable;
1.74 + SymbolTable *table;
1.75 + Symbol *symbol_entry;
1.76 +
1.77 + dlmap = (struct link_map *)handle;
1.78 + symtab_hdr = NULL;
1.79 + strtab_hdr = NULL;
1.80 + table = NULL;
1.81 +
1.82 + /* See if we already have a symbol table for this library */
1.83 + for (size_t i = 0; i < m_SymTables.size(); i++)
1.84 + {
1.85 + libtable = m_SymTables[i];
1.86 + if (libtable->lib_base == dlmap->l_addr)
1.87 + {
1.88 + table = &libtable->table;
1.89 + break;
1.90 + }
1.91 + }
1.92 +
1.93 + /* If we don't have a symbol table for this library, then create one */
1.94 + if (table == NULL)
1.95 + {
1.96 + libtable = new LibSymbolTable();
1.97 + libtable->table.Initialize();
1.98 + libtable->lib_base = dlmap->l_addr;
1.99 + libtable->last_pos = 0;
1.100 + table = &libtable->table;
1.101 + m_SymTables.push_back(libtable);
1.102 + }
1.103 +
1.104 + /* See if the symbol is already cached in our table */
1.105 + symbol_entry = table->FindSymbol(symbol, strlen(symbol));
1.106 + if (symbol_entry != NULL)
1.107 + {
1.108 + return symbol_entry->address;
1.109 + }
1.110 +
1.111 + /* If symbol isn't in our table, then we have open the actual library */
1.112 + dlfile = open(dlmap->l_name, O_RDONLY);
1.113 + if (dlfile == -1 || fstat(dlfile, &dlstat) == -1)
1.114 + {
1.115 + close(dlfile);
1.116 + return NULL;
1.117 + }
1.118 +
1.119 + /* Map library file into memory */
1.120 + file_hdr = (Elf32_Ehdr *)mmap(NULL, dlstat.st_size, PROT_READ, MAP_PRIVATE, dlfile, 0);
1.121 + map_base = (uintptr_t)file_hdr;
1.122 + if (file_hdr == MAP_FAILED)
1.123 + {
1.124 + close(dlfile);
1.125 + return NULL;
1.126 + }
1.127 + close(dlfile);
1.128 +
1.129 + if (file_hdr->e_shoff == 0 || file_hdr->e_shstrndx == SHN_UNDEF)
1.130 + {
1.131 + munmap(file_hdr, dlstat.st_size);
1.132 + return NULL;
1.133 + }
1.134 +
1.135 + sections = (Elf32_Shdr *)(map_base + file_hdr->e_shoff);
1.136 + section_count = file_hdr->e_shnum;
1.137 + /* Get ELF section header string table */
1.138 + shstrtab_hdr = §ions[file_hdr->e_shstrndx];
1.139 + shstrtab = (const char *)(map_base + shstrtab_hdr->sh_offset);
1.140 +
1.141 + /* Iterate sections while looking for ELF symbol table and string table */
1.142 + for (uint16_t i = 0; i < section_count; i++)
1.143 + {
1.144 + Elf32_Shdr &hdr = sections[i];
1.145 + const char *section_name = shstrtab + hdr.sh_name;
1.146 +
1.147 + if (strcmp(section_name, ".symtab") == 0)
1.148 + {
1.149 + symtab_hdr = &hdr;
1.150 + }
1.151 + else if (strcmp(section_name, ".strtab") == 0)
1.152 + {
1.153 + strtab_hdr = &hdr;
1.154 + }
1.155 + }
1.156 +
1.157 + /* Uh oh, we don't have a symbol table or a string table */
1.158 + if (symtab_hdr == NULL || strtab_hdr == NULL)
1.159 + {
1.160 + munmap(file_hdr, dlstat.st_size);
1.161 + return NULL;
1.162 + }
1.163 +
1.164 + symtab = (Elf32_Sym *)(map_base + symtab_hdr->sh_offset);
1.165 + strtab = (const char *)(map_base + strtab_hdr->sh_offset);
1.166 + symbol_count = symtab_hdr->sh_size / symtab_hdr->sh_entsize;
1.167 +
1.168 + /* Iterate symbol table starting from the position we were at last time */
1.169 + for (uint32_t i = libtable->last_pos; i < symbol_count; i++)
1.170 + {
1.171 + Elf32_Sym &sym = symtab[i];
1.172 + unsigned char sym_type = ELF32_ST_TYPE(sym.st_info);
1.173 + const char *sym_name = strtab + sym.st_name;
1.174 + Symbol *cur_sym;
1.175 +
1.176 + /* Skip symbols that are undefined or do not refer to functions or objects */
1.177 + if (sym.st_shndx == SHN_UNDEF || (sym_type != STT_FUNC && sym_type != STT_OBJECT))
1.178 + {
1.179 + continue;
1.180 + }
1.181 +
1.182 + /* Caching symbols as we go along */
1.183 + cur_sym = table->InternSymbol(sym_name, strlen(sym_name), (void *)(dlmap->l_addr + sym.st_value));
1.184 + if (strcmp(symbol, sym_name) == 0)
1.185 + {
1.186 + symbol_entry = cur_sym;
1.187 + libtable->last_pos = ++i;
1.188 + break;
1.189 + }
1.190 + }
1.191 +
1.192 + munmap(file_hdr, dlstat.st_size);
1.193 + return symbol_entry ? symbol_entry->address : NULL;
1.194 +
1.195 +#endif
1.196 +}
1.197 +
1.198 bool MemoryUtils::GetLibraryInfo(const void *libPtr, DynLibInfo &lib)
1.199 {
1.200 unsigned long baseAddr;
