object_file.cc revision 11793
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 44#include "base/cprintf.hh" 45#include "base/loader/aout_object.hh" 46#include "base/loader/dtb_object.hh" 47#include "base/loader/ecoff_object.hh" 48#include "base/loader/elf_object.hh" 49#include "base/loader/raw_object.hh" 50#include "base/loader/symtab.hh" 51#include "mem/port_proxy.hh" 52 53using namespace std; 54 55ObjectFile::ObjectFile(const string &_filename, 56 size_t _len, uint8_t *_data, 57 Arch _arch, OpSys _op_sys) 58 : filename(_filename), fileData(_data), len(_len), 59 arch(_arch), opSys(_op_sys), entry(0), globalPtr(0), 60 text{0, nullptr, 0}, data{0, nullptr, 0}, bss{0, nullptr, 0} 61{ 62} 63 64 65ObjectFile::~ObjectFile() 66{ 67 if (fileData) { 68 ::munmap((char*)fileData, len); 69 fileData = NULL; 70 } 71} 72 73 74bool 75ObjectFile::loadSection(Section *sec, PortProxy& mem_proxy, Addr addr_mask, 76 Addr offset) 77{ 78 if (sec->size != 0) { 79 Addr addr = (sec->baseAddr & addr_mask) + offset; 80 if (sec->fileImage) { 81 mem_proxy.writeBlob(addr, sec->fileImage, sec->size); 82 } 83 else { 84 // no image: must be bss 85 mem_proxy.memsetBlob(addr, 0, sec->size); 86 } 87 } 88 return true; 89} 90 91 92bool 93ObjectFile::loadSections(PortProxy& mem_proxy, Addr addr_mask, Addr offset) 94{ 95 return (loadSection(&text, mem_proxy, addr_mask, offset) 96 && loadSection(&data, mem_proxy, addr_mask, offset) 97 && loadSection(&bss, mem_proxy, addr_mask, offset)); 98} 99 100static bool 101hasGzipMagic(int fd) 102{ 103 uint8_t buf[2] = {0}; 104 size_t sz = pread(fd, buf, 2, 0); 105 panic_if(sz != 2, "Couldn't read magic bytes from object file"); 106 return ((buf[0] == 0x1f) && (buf[1] == 0x8b)); 107} 108 109static int 110doGzipLoad(int fd) 111{ 112 const size_t blk_sz = 4096; 113 114 gzFile fdz = gzdopen(fd, "rb"); 115 if (!fdz) { 116 return -1; 117 } 118 119 size_t tmp_len = strlen(P_tmpdir); 120 char *tmpnam = (char*) malloc(tmp_len + 20); 121 strcpy(tmpnam, P_tmpdir); 122 strcpy(tmpnam+tmp_len, "/gem5-gz-obj-XXXXXX"); // 19 chars 123 fd = mkstemp(tmpnam); // repurposing fd variable for output 124 if (fd < 0) { 125 free(tmpnam); 126 gzclose(fdz); 127 return fd; 128 } 129 130 if (unlink(tmpnam) != 0) 131 warn("couldn't remove temporary file %s\n", tmpnam); 132 133 free(tmpnam); 134 135 auto buf = new uint8_t[blk_sz]; 136 int r; // size of (r)emaining uncopied data in (buf)fer 137 while ((r = gzread(fdz, buf, blk_sz)) > 0) { 138 auto p = buf; // pointer into buffer 139 while (r > 0) { 140 auto sz = write(fd, p, r); 141 assert(sz <= r); 142 r -= sz; 143 p += sz; 144 } 145 } 146 delete[] buf; 147 gzclose(fdz); 148 if (r < 0) { // error 149 close(fd); 150 return -1; 151 } 152 assert(r == 0); // finished successfully 153 return fd; // return fd to decompressed temporary file for mmap()'ing 154} 155 156ObjectFile * 157createObjectFile(const string &fname, bool raw) 158{ 159 // open the file 160 int fd = open(fname.c_str(), O_RDONLY); 161 if (fd < 0) { 162 return NULL; 163 } 164 165 // decompress GZ files 166 if (hasGzipMagic(fd)) { 167 fd = doGzipLoad(fd); 168 if (fd < 0) { 169 return NULL; 170 } 171 } 172 173 // find the length of the file by seeking to the end 174 off_t off = lseek(fd, 0, SEEK_END); 175 fatal_if(off < 0, 176 "Failed to determine size of object file %s\n", fname); 177 auto len = static_cast<size_t>(off); 178 179 // mmap the whole shebang 180 uint8_t *file_data = (uint8_t *)mmap(NULL, len, PROT_READ, MAP_SHARED, 181 fd, 0); 182 close(fd); 183 184 if (file_data == MAP_FAILED) { 185 return NULL; 186 } 187 188 ObjectFile *file_obj = NULL; 189 190 // figure out what we have here 191 if ((file_obj = ElfObject::tryFile(fname, len, file_data)) != NULL) { 192 return file_obj; 193 } 194 195 if ((file_obj = EcoffObject::tryFile(fname, len, file_data)) != NULL) { 196 return file_obj; 197 } 198 199 if ((file_obj = AoutObject::tryFile(fname, len, file_data)) != NULL) { 200 return file_obj; 201 } 202 203 if ((file_obj = DtbObject::tryFile(fname, len, file_data)) != NULL) { 204 return file_obj; 205 } 206 207 if (raw) 208 return RawObject::tryFile(fname, len, file_data); 209 210 // don't know what it is 211 munmap((char*)file_data, len); 212 return NULL; 213} 214