src/base/loader/object_file.cc

   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
  54 using namespace std;
  55
  56 ObjectFile::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)
  61 {}
  62
  63
  64 ObjectFile::~ObjectFile()
  65 {
  66     if (fileData) {
  67         ::munmap((char*)fileData, len);
  68         fileData = NULL;
  69     }
  70 }
  71
  72
  73 namespace
  74 {
  75
  76 typedef std::vector<ObjectFile::Loader *> LoaderList;
  77
  78 LoaderList &
  79 object_file_loaders()
  80 {
  81     static LoaderList loaders;
  82     return loaders;
  83 }
  84
  85 } // anonymous namespace
  86
  87 ObjectFile::Loader::Loader()
  88 {
  89     object_file_loaders().emplace_back(this);
  90 }
  91
  92 Process *
  93 ObjectFile::tryLoaders(ProcessParams *params, ObjectFile *obj_file)
  94 {
  95     for (auto &loader: object_file_loaders()) {
  96         Process *p = loader->load(params, obj_file);
  97         if (p)
  98             return p;
  99     }
 100
 101     return nullptr;
 102 }
 103
 104 static bool
 105 hasGzipMagic(int fd)
 106 {
 107     uint8_t buf[2] = {0};
 108     size_t sz = pread(fd, buf, 2, 0);
 109     panic_if(sz != 2, "Couldn't read magic bytes from object file");
 110     return ((buf[0] == 0x1f) && (buf[1] == 0x8b));
 111 }
 112
 113 static int
 114 doGzipLoad(int fd)
 115 {
 116     const size_t blk_sz = 4096;
 117
 118     gzFile fdz = gzdopen(fd, "rb");
 119     if (!fdz) {
 120         return -1;
 121     }
 122
 123     size_t tmp_len = strlen(P_tmpdir);
 124     char *tmpnam = (char*) malloc(tmp_len + 20);
 125     strcpy(tmpnam, P_tmpdir);
 126     strcpy(tmpnam+tmp_len, "/gem5-gz-obj-XXXXXX"); // 19 chars
 127     fd = mkstemp(tmpnam); // repurposing fd variable for output
 128     if (fd < 0) {
 129         free(tmpnam);
 130         gzclose(fdz);
 131         return fd;
 132     }
 133
 134     if (unlink(tmpnam) != 0)
 135         warn("couldn't remove temporary file %s\n", tmpnam);
 136
 137     free(tmpnam);
 138
 139     auto buf = new uint8_t[blk_sz];
 140     int r; // size of (r)emaining uncopied data in (buf)fer
 141     while ((r = gzread(fdz, buf, blk_sz)) > 0) {
 142         auto p = buf; // pointer into buffer
 143         while (r > 0) {
 144             auto sz = write(fd, p, r);
 145             assert(sz <= r);
 146             r -= sz;
 147             p += sz;
 148         }
 149     }
 150     delete[] buf;
 151     gzclose(fdz);
 152     if (r < 0) { // error
 153         close(fd);
 154         return -1;
 155     }
 156     assert(r == 0); // finished successfully
 157     return fd; // return fd to decompressed temporary file for mmap()'ing
 158 }
 159
 160 ObjectFile *
 161 createObjectFile(const string &fname, bool raw)
 162 {
 163     // open the file
 164     int fd = open(fname.c_str(), O_RDONLY);
 165     if (fd < 0) {
 166         return NULL;
 167     }
 168
 169     // decompress GZ files
 170     if (hasGzipMagic(fd)) {
 171         fd = doGzipLoad(fd);
 172         if (fd < 0) {
 173             return NULL;
 174         }
 175     }
 176
 177     // find the length of the file by seeking to the end
 178     off_t off = lseek(fd, 0, SEEK_END);
 179     fatal_if(off < 0,
 180              "Failed to determine size of object file %s\n", fname);
 181     auto len = static_cast<size_t>(off);
 182
 183     // mmap the whole shebang
 184     uint8_t *file_data = (uint8_t *)mmap(NULL, len, PROT_READ, MAP_SHARED,
 185                                          fd, 0);
 186     close(fd);
 187
 188     if (file_data == MAP_FAILED) {
 189         return NULL;
 190     }
 191
 192     ObjectFile *file_obj = NULL;
 193
 194     // figure out what we have here
 195     if ((file_obj = ElfObject::tryFile(fname, len, file_data)) != NULL) {
 196         return file_obj;
 197     }
 198
 199     if ((file_obj = EcoffObject::tryFile(fname, len, file_data)) != NULL) {
 200         return file_obj;
 201     }
 202
 203     if ((file_obj = AoutObject::tryFile(fname, len, file_data)) != NULL) {
 204         return file_obj;
 205     }
 206
 207     if ((file_obj = DtbObject::tryFile(fname, len, file_data)) != NULL) {
 208         return file_obj;
 209     }
 210
 211     if (raw)
 212         return RawObject::tryFile(fname, len, file_data);
 213
 214     // don't know what it is
 215     munmap((char*)file_data, len);
 216     return NULL;
 217 }