bool ElfReader::Load() {
return ReadElfHeader() &&
VerifyElfHeader() &&
ReadProgramHeader() &&
ReserveAddressSpace() &&
LoadSegments() &&
FindPhdr();
}
bool ElfLoader::LoadAt(const char* lib_path,
off_t file_offset,
uintptr_t wanted_address,
Error* error) {
LOG("%s: lib_path='%s', file_offset=%p, load_address=%p\n",
__FUNCTION__,
lib_path,
file_offset,
wanted_address);
// Check that the load address is properly page-aligned.
if (wanted_address != PAGE_START(wanted_address)) {
error->Format("Load address is not page aligned (%08x)", wanted_address);
return false;
}
wanted_load_address_ = reinterpret_cast<void*>(wanted_address);
// Check that the file offset is also properly page-aligned.
// PAGE_START() can't be used here due to the compiler complaining about
// comparing signed (off_t) and unsigned (size_t) values.
if ((file_offset & static_cast<off_t>(PAGE_SIZE - 1)) != 0) {
error->Format("File offset is not page aligned (%08x)", file_offset);
return false;
}
file_offset_ = file_offset;
// Open the file.
if (!fd_.OpenReadOnly(lib_path)) {
error->Format("Can't open file: %s", strerror(errno));
return false;
}
if (file_offset && fd_.SeekTo(file_offset) < 0) {
error->Format(
"Can't seek to file offset %08x: %s", file_offset, strerror(errno));
return false;
}
path_ = lib_path;
if (!ReadElfHeader(error) || !ReadProgramHeader(error) ||
!ReserveAddressSpace(error)) {
return false;
}
if (!LoadSegments(error) || !FindPhdr(error)) {
// An error occured, cleanup the address space by un-mapping the
// range that was reserved by ReserveAddressSpace().
if (load_start_ && load_size_)
munmap(load_start_, load_size_);
return false;
}
return true;
}
bool ElfReader::Read(const char* name, int fd, off64_t file_offset, off64_t file_size) {
CHECK(!did_read_);
CHECK(!did_load_);
name_ = name;
fd_ = fd;
file_offset_ = file_offset;
file_size_ = file_size;
if (ReadElfHeader() &&
VerifyElfHeader() &&
ReadProgramHeaders() &&
ReadSectionHeaders() &&
ReadDynamicSection()) {
did_read_ = true;
}
return did_read_;
}