object_file.cc revision 13982
1/* 2 * Copyright (c) 2002-2004 The Regents of The University of Michigan 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 are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Nathan Binkert 29 * Steve Reinhardt 30 */ 31 32#include "base/loader/object_file.hh" 33 34#include <fcntl.h> 35#include <sys/mman.h> 36#include <sys/types.h> 37#include <unistd.h> 38#include <zlib.h> 39 40#include <cstdio> 41#include <list> 42#include <string> 43#include <vector> 44 45#include "base/cprintf.hh" 46#include "base/loader/aout_object.hh" 47#include "base/loader/dtb_object.hh" 48#include "base/loader/ecoff_object.hh" 49#include "base/loader/elf_object.hh" 50#include "base/loader/raw_object.hh" 51#include "base/loader/symtab.hh" 52#include "mem/port_proxy.hh" 53 54using namespace std; 55 56ObjectFile::ObjectFile(const string &_filename, 57 size_t _len, uint8_t *_data, 58 Arch _arch, OpSys _op_sys) 59 : filename(_filename), fileData(_data), len(_len), 60 arch(_arch), opSys(_op_sys), entry(0), globalPtr(0), 61 text{0, nullptr, 0}, data{0, nullptr, 0}, bss{0, nullptr, 0} 62{ 63} 64 65 66ObjectFile::~ObjectFile() 67{ 68 if (fileData) { 69 ::munmap((char*)fileData, len); 70 fileData = NULL; 71 } 72} 73 74 75bool 76ObjectFile::loadSection(Section *sec, PortProxy& mem_proxy, Addr addr_mask, 77 Addr offset) 78{ 79 if (sec->size != 0) { 80 Addr addr = (sec->baseAddr & addr_mask) + offset; 81 if (sec->fileImage) { 82 mem_proxy.writeBlob(addr, sec->fileImage, sec->size); 83 } 84 else { 85 // no image: must be bss 86 mem_proxy.memsetBlob(addr, 0, sec->size); 87 } 88 } 89 return true; 90} 91 92 93bool 94ObjectFile::loadSections(PortProxy& mem_proxy, Addr addr_mask, Addr offset) 95{ 96 return (loadSection(&text, mem_proxy, addr_mask, offset) 97 && loadSection(&data, mem_proxy, addr_mask, offset) 98 && loadSection(&bss, mem_proxy, addr_mask, offset)); 99} 100 101namespace 102{ 103 104typedef std::vector<ObjectFile::Loader *> LoaderList; 105 106LoaderList & 107object_file_loaders() 108{ 109 static LoaderList loaders; 110 return loaders; 111} 112 113} // anonymous namespace 114 115ObjectFile::Loader::Loader() 116{ 117 object_file_loaders().emplace_back(this); 118} 119 120Process * 121ObjectFile::tryLoaders(ProcessParams *params, ObjectFile *obj_file) 122{ 123 for (auto &loader: object_file_loaders()) { 124 Process *p = loader->load(params, obj_file); 125 if (p) 126 return p; 127 } 128 129 return nullptr; 130} 131 132static bool 133hasGzipMagic(int fd) 134{ 135 uint8_t buf[2] = {0}; 136 size_t sz = pread(fd, buf, 2, 0); 137 panic_if(sz != 2, "Couldn't read magic bytes from object file"); 138 return ((buf[0] == 0x1f) && (buf[1] == 0x8b)); 139} 140 141static int 142doGzipLoad(int fd) 143{ 144 const size_t blk_sz = 4096; 145 146 gzFile fdz = gzdopen(fd, "rb"); 147 if (!fdz) { 148 return -1; 149 } 150 151 size_t tmp_len = strlen(P_tmpdir); 152 char *tmpnam = (char*) malloc(tmp_len + 20); 153 strcpy(tmpnam, P_tmpdir); 154 strcpy(tmpnam+tmp_len, "/gem5-gz-obj-XXXXXX"); // 19 chars 155 fd = mkstemp(tmpnam); // repurposing fd variable for output 156 if (fd < 0) { 157 free(tmpnam); 158 gzclose(fdz); 159 return fd; 160 } 161 162 if (unlink(tmpnam) != 0) 163 warn("couldn't remove temporary file %s\n", tmpnam); 164 165 free(tmpnam); 166 167 auto buf = new uint8_t[blk_sz]; 168 int r; // size of (r)emaining uncopied data in (buf)fer 169 while ((r = gzread(fdz, buf, blk_sz)) > 0) { 170 auto p = buf; // pointer into buffer 171 while (r > 0) { 172 auto sz = write(fd, p, r); 173 assert(sz <= r); 174 r -= sz; 175 p += sz; 176 } 177 } 178 delete[] buf; 179 gzclose(fdz); 180 if (r < 0) { // error 181 close(fd); 182 return -1; 183 } 184 assert(r == 0); // finished successfully 185 return fd; // return fd to decompressed temporary file for mmap()'ing 186} 187 188ObjectFile * 189createObjectFile(const string &fname, bool raw) 190{ 191 // open the file 192 int fd = open(fname.c_str(), O_RDONLY); 193 if (fd < 0) { 194 return NULL; 195 } 196 197 // decompress GZ files 198 if (hasGzipMagic(fd)) { 199 fd = doGzipLoad(fd); 200 if (fd < 0) { 201 return NULL; 202 } 203 } 204 205 // find the length of the file by seeking to the end 206 off_t off = lseek(fd, 0, SEEK_END); 207 fatal_if(off < 0, 208 "Failed to determine size of object file %s\n", fname); 209 auto len = static_cast<size_t>(off); 210 211 // mmap the whole shebang 212 uint8_t *file_data = (uint8_t *)mmap(NULL, len, PROT_READ, MAP_SHARED, 213 fd, 0); 214 close(fd); 215 216 if (file_data == MAP_FAILED) { 217 return NULL; 218 } 219 220 ObjectFile *file_obj = NULL; 221 222 // figure out what we have here 223 if ((file_obj = ElfObject::tryFile(fname, len, file_data)) != NULL) { 224 return file_obj; 225 } 226 227 if ((file_obj = EcoffObject::tryFile(fname, len, file_data)) != NULL) { 228 return file_obj; 229 } 230 231 if ((file_obj = AoutObject::tryFile(fname, len, file_data)) != NULL) { 232 return file_obj; 233 } 234 235 if ((file_obj = DtbObject::tryFile(fname, len, file_data)) != NULL) { 236 return file_obj; 237 } 238 239 if (raw) 240 return RawObject::tryFile(fname, len, file_data); 241 242 // don't know what it is 243 munmap((char*)file_data, len); 244 return NULL; 245} 246