/* * Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "classfile/classLoader.hpp" #include "classfile/sharedClassUtil.hpp" #include "classfile/symbolTable.hpp" #include "classfile/systemDictionaryShared.hpp" #include "classfile/altHashing.hpp" #include "memory/filemap.hpp" #include "memory/metadataFactory.hpp" #include "memory/oopFactory.hpp" #include "oops/objArrayOop.hpp" #include "runtime/arguments.hpp" #include "runtime/java.hpp" #include "runtime/os.hpp" #include "runtime/vm_version.hpp" #include "services/memTracker.hpp" #include "utilities/defaultStream.hpp" # include # include #ifndef O_BINARY // if defined (Win32) use binary files. #define O_BINARY 0 // otherwise do nothing. #endif PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC extern address JVM_FunctionAtStart(); extern address JVM_FunctionAtEnd(); // Complain and stop. All error conditions occurring during the writing of // an archive file should stop the process. Unrecoverable errors during // the reading of the archive file should stop the process. static void fail(const char *msg, va_list ap) { // This occurs very early during initialization: tty is not initialized. jio_fprintf(defaultStream::error_stream(), "An error has occurred while processing the" " shared archive file.\n"); jio_vfprintf(defaultStream::error_stream(), msg, ap); jio_fprintf(defaultStream::error_stream(), "\n"); // Do not change the text of the below message because some tests check for it. vm_exit_during_initialization("Unable to use shared archive.", NULL); } void FileMapInfo::fail_stop(const char *msg, ...) { va_list ap; va_start(ap, msg); fail(msg, ap); // Never returns. va_end(ap); // for completeness. } // Complain and continue. Recoverable errors during the reading of the // archive file may continue (with sharing disabled). // // If we continue, then disable shared spaces and close the file. void FileMapInfo::fail_continue(const char *msg, ...) { va_list ap; va_start(ap, msg); MetaspaceShared::set_archive_loading_failed(); if (PrintSharedArchiveAndExit && _validating_classpath_entry_table) { // If we are doing PrintSharedArchiveAndExit and some of the classpath entries // do not validate, we can still continue "limping" to validate the remaining // entries. No need to quit. tty->print("["); tty->vprint(msg, ap); tty->print_cr("]"); } else { if (RequireSharedSpaces) { fail(msg, ap); } else { if (PrintSharedSpaces) { tty->print_cr("UseSharedSpaces: %s", msg); } } UseSharedSpaces = false; assert(current_info() != NULL, "singleton must be registered"); current_info()->close(); } va_end(ap); } // Fill in the fileMapInfo structure with data about this VM instance. // This method copies the vm version info into header_version. If the version is too // long then a truncated version, which has a hash code appended to it, is copied. // // Using a template enables this method to verify that header_version is an array of // length JVM_IDENT_MAX. This ensures that the code that writes to the CDS file and // the code that reads the CDS file will both use the same size buffer. Hence, will // use identical truncation. This is necessary for matching of truncated versions. template static void get_header_version(char (&header_version) [N]) { assert(N == JVM_IDENT_MAX, "Bad header_version size"); const char *vm_version = VM_Version::internal_vm_info_string(); const int version_len = (int)strlen(vm_version); if (version_len < (JVM_IDENT_MAX-1)) { strcpy(header_version, vm_version); } else { // Get the hash value. Use a static seed because the hash needs to return the same // value over multiple jvm invocations. unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len); // Truncate the ident, saving room for the 8 hex character hash value. strncpy(header_version, vm_version, JVM_IDENT_MAX-9); // Append the hash code as eight hex digits. sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash); header_version[JVM_IDENT_MAX-1] = 0; // Null terminate. } } FileMapInfo::FileMapInfo() { assert(_current_info == NULL, "must be singleton"); // not thread safe _current_info = this; memset(this, 0, sizeof(FileMapInfo)); _file_offset = 0; _file_open = false; _header = SharedClassUtil::allocate_file_map_header(); _header->_version = _invalid_version; } FileMapInfo::~FileMapInfo() { assert(_current_info == this, "must be singleton"); // not thread safe _current_info = NULL; } void FileMapInfo::populate_header(size_t alignment) { _header->populate(this, alignment); } size_t FileMapInfo::FileMapHeader::data_size() { return SharedClassUtil::file_map_header_size() - sizeof(FileMapInfo::FileMapHeaderBase); } void FileMapInfo::FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) { _magic = 0xf00baba2; _version = _current_version; _alignment = alignment; _obj_alignment = ObjectAlignmentInBytes; _classpath_entry_table_size = mapinfo->_classpath_entry_table_size; _classpath_entry_table = mapinfo->_classpath_entry_table; _classpath_entry_size = mapinfo->_classpath_entry_size; // The following fields are for sanity checks for whether this archive // will function correctly with this JVM and the bootclasspath it's // invoked with. // JVM version string ... changes on each build. get_header_version(_jvm_ident); } void FileMapInfo::allocate_classpath_entry_table() { int bytes = 0; int count = 0; char* strptr = NULL; char* strptr_max = NULL; Thread* THREAD = Thread::current(); ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data(); size_t entry_size = SharedClassUtil::shared_class_path_entry_size(); for (int pass=0; pass<2; pass++) { ClassPathEntry *cpe = ClassLoader::classpath_entry(0); for (int cur_entry = 0 ; cpe != NULL; cpe = cpe->next(), cur_entry++) { const char *name = cpe->name(); int name_bytes = (int)(strlen(name) + 1); if (pass == 0) { count ++; bytes += (int)entry_size; bytes += name_bytes; if (TraceClassPaths || (TraceClassLoading && Verbose)) { tty->print_cr("[Add main shared path (%s) %s]", (cpe->is_jar_file() ? "jar" : "dir"), name); } } else { SharedClassPathEntry* ent = shared_classpath(cur_entry); if (cpe->is_jar_file()) { struct stat st; if (os::stat(name, &st) != 0) { // The file/dir must exist, or it would not have been added // into ClassLoader::classpath_entry(). // // If we can't access a jar file in the boot path, then we can't // make assumptions about where classes get loaded from. FileMapInfo::fail_stop("Unable to open jar file %s.", name); } EXCEPTION_MARK; // The following call should never throw, but would exit VM on error. SharedClassUtil::update_shared_classpath(cpe, ent, st.st_mtime, st.st_size, THREAD); } else { struct stat st; if ((os::stat(name, &st) == 0) && ((st.st_mode & S_IFDIR) == S_IFDIR)) { if (!os::dir_is_empty(name)) { ClassLoader::exit_with_path_failure("Cannot have non-empty directory in archived classpaths", name); } ent->_filesize = -1; } else { ent->_filesize = -2; } } ent->_name = strptr; if (strptr + name_bytes <= strptr_max) { strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0. strptr += name_bytes; } else { assert(0, "miscalculated buffer size"); } } } if (pass == 0) { EXCEPTION_MARK; // The following call should never throw, but would exit VM on error. Array* arr = MetadataFactory::new_array(loader_data, (bytes + 7)/8, THREAD); strptr = (char*)(arr->data()); strptr_max = strptr + bytes; SharedClassPathEntry* table = (SharedClassPathEntry*)strptr; strptr += entry_size * count; _classpath_entry_table_size = count; _classpath_entry_table = table; _classpath_entry_size = entry_size; } } } bool FileMapInfo::validate_classpath_entry_table() { _validating_classpath_entry_table = true; int count = _header->_classpath_entry_table_size; _classpath_entry_table = _header->_classpath_entry_table; _classpath_entry_size = _header->_classpath_entry_size; for (int i=0; i_name; bool ok = true; if (TraceClassPaths || (TraceClassLoading && Verbose)) { tty->print_cr("[Checking shared classpath entry: %s]", name); } if (os::stat(name, &st) != 0) { fail_continue("Required classpath entry does not exist: %s", name); ok = false; } else if (ent->is_dir()) { if (!os::dir_is_empty(name)) { fail_continue("directory is not empty: %s", name); ok = false; } } else if (ent->is_jar()) { if (ent->_timestamp != st.st_mtime || ent->_filesize != st.st_size) { ok = false; if (PrintSharedArchiveAndExit) { fail_continue(ent->_timestamp != st.st_mtime ? "Timestamp mismatch" : "File size mismatch"); } else { fail_continue("A jar file is not the one used while building" " the shared archive file: %s", name); } } } if (ok) { if (TraceClassPaths || (TraceClassLoading && Verbose)) { tty->print_cr("[ok]"); } } else if (!PrintSharedArchiveAndExit) { _validating_classpath_entry_table = false; return false; } } _classpath_entry_table_size = _header->_classpath_entry_table_size; _validating_classpath_entry_table = false; return true; } // Read the FileMapInfo information from the file. bool FileMapInfo::init_from_file(int fd) { size_t sz = _header->data_size(); char* addr = _header->data(); size_t n = os::read(fd, addr, (unsigned int)sz); if (n != sz) { fail_continue("Unable to read the file header."); return false; } if (_header->_version != current_version()) { fail_continue("The shared archive file has the wrong version."); return false; } _file_offset = (long)n; size_t info_size = _header->_paths_misc_info_size; _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass); if (_paths_misc_info == NULL) { fail_continue("Unable to read the file header."); return false; } n = os::read(fd, _paths_misc_info, (unsigned int)info_size); if (n != info_size) { fail_continue("Unable to read the shared path info header."); FREE_C_HEAP_ARRAY(char, _paths_misc_info); _paths_misc_info = NULL; return false; } size_t len = lseek(fd, 0, SEEK_END); struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[MetaspaceShared::mc]; if (si->_file_offset >= len || len - si->_file_offset < si->_used) { fail_continue("The shared archive file has been truncated."); return false; } _file_offset += (long)n; return true; } // Read the FileMapInfo information from the file. bool FileMapInfo::open_for_read() { _full_path = Arguments::GetSharedArchivePath(); int fd = open(_full_path, O_RDONLY | O_BINARY, 0); if (fd < 0) { if (errno == ENOENT) { // Not locating the shared archive is ok. fail_continue("Specified shared archive not found."); } else { fail_continue("Failed to open shared archive file (%s).", strerror(errno)); } return false; } _fd = fd; _file_open = true; return true; } // Write the FileMapInfo information to the file. void FileMapInfo::open_for_write() { _full_path = Arguments::GetSharedArchivePath(); if (PrintSharedSpaces) { tty->print_cr("Dumping shared data to file: "); tty->print_cr(" %s", _full_path); } #ifdef _WINDOWS // On Windows, need WRITE permission to remove the file. chmod(_full_path, _S_IREAD | _S_IWRITE); #endif // Use remove() to delete the existing file because, on Unix, this will // allow processes that have it open continued access to the file. remove(_full_path); int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444); if (fd < 0) { fail_stop("Unable to create shared archive file %s: %s.", _full_path, strerror(errno)); } _fd = fd; _file_offset = 0; _file_open = true; } // Write the header to the file, seek to the next allocation boundary. void FileMapInfo::write_header() { int info_size = ClassLoader::get_shared_paths_misc_info_size(); _header->_paths_misc_info_size = info_size; align_file_position(); size_t sz = _header->data_size(); char* addr = _header->data(); write_bytes(addr, (int)sz); // skip the C++ vtable write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size); align_file_position(); } // Dump shared spaces to file. void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) { align_file_position(); size_t used = space->used_bytes_slow(Metaspace::NonClassType); size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType); struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i]; write_region(i, (char*)space->bottom(), used, capacity, read_only, false); } // Dump region to file. void FileMapInfo::write_region(int region, char* base, size_t size, size_t capacity, bool read_only, bool allow_exec) { struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region]; if (_file_open) { guarantee(si->_file_offset == _file_offset, "file offset mismatch."); if (PrintSharedSpaces) { tty->print_cr("Shared file region %d: 0x%6x bytes, addr " INTPTR_FORMAT " file offset 0x%6x", region, size, base, _file_offset); } } else { si->_file_offset = _file_offset; } si->_base = base; si->_used = size; si->_capacity = capacity; si->_read_only = read_only; si->_allow_exec = allow_exec; si->_crc = ClassLoader::crc32(0, base, (jint)size); write_bytes_aligned(base, (int)size); } // Dump bytes to file -- at the current file position. void FileMapInfo::write_bytes(const void* buffer, int nbytes) { if (_file_open) { int n = ::write(_fd, buffer, nbytes); if (n != nbytes) { // It is dangerous to leave the corrupted shared archive file around, // close and remove the file. See bug 6372906. close(); remove(_full_path); fail_stop("Unable to write to shared archive file."); } } _file_offset += nbytes; } // Align file position to an allocation unit boundary. void FileMapInfo::align_file_position() { size_t new_file_offset = align_size_up(_file_offset, os::vm_allocation_granularity()); if (new_file_offset != _file_offset) { _file_offset = new_file_offset; if (_file_open) { // Seek one byte back from the target and write a byte to insure // that the written file is the correct length. _file_offset -= 1; if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) { fail_stop("Unable to seek."); } char zero = 0; write_bytes(&zero, 1); } } } // Dump bytes to file -- at the current file position. void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) { align_file_position(); write_bytes(buffer, nbytes); align_file_position(); } // Close the shared archive file. This does NOT unmap mapped regions. void FileMapInfo::close() { if (_file_open) { if (::close(_fd) < 0) { fail_stop("Unable to close the shared archive file."); } _file_open = false; _fd = -1; } } // JVM/TI RedefineClasses() support: // Remap the shared readonly space to shared readwrite, private. bool FileMapInfo::remap_shared_readonly_as_readwrite() { struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0]; if (!si->_read_only) { // the space is already readwrite so we are done return true; } size_t used = si->_used; size_t size = align_size_up(used, os::vm_allocation_granularity()); if (!open_for_read()) { return false; } char *base = os::remap_memory(_fd, _full_path, si->_file_offset, si->_base, size, false /* !read_only */, si->_allow_exec); close(); if (base == NULL) { fail_continue("Unable to remap shared readonly space (errno=%d).", errno); return false; } if (base != si->_base) { fail_continue("Unable to remap shared readonly space at required address."); return false; } si->_read_only = false; return true; } // Map the whole region at once, assumed to be allocated contiguously. ReservedSpace FileMapInfo::reserve_shared_memory() { struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[0]; char* requested_addr = si->_base; size_t size = FileMapInfo::shared_spaces_size(); // Reserve the space first, then map otherwise map will go right over some // other reserved memory (like the code cache). ReservedSpace rs(size, os::vm_allocation_granularity(), false, requested_addr); if (!rs.is_reserved()) { fail_continue("Unable to reserve shared space at required address " INTPTR_FORMAT, requested_addr); return rs; } // the reserved virtual memory is for mapping class data sharing archive MemTracker::record_virtual_memory_type((address)rs.base(), mtClassShared); return rs; } // Memory map a region in the address space. static const char* shared_region_name[] = { "ReadOnly", "ReadWrite", "MiscData", "MiscCode"}; char* FileMapInfo::map_region(int i) { struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i]; size_t used = si->_used; size_t alignment = os::vm_allocation_granularity(); size_t size = align_size_up(used, alignment); char *requested_addr = si->_base; // map the contents of the CDS archive in this memory char *base = os::map_memory(_fd, _full_path, si->_file_offset, requested_addr, size, si->_read_only, si->_allow_exec); if (base == NULL || base != si->_base) { fail_continue("Unable to map %s shared space at required address.", shared_region_name[i]); return NULL; } #ifdef _WINDOWS // This call is Windows-only because the memory_type gets recorded for the other platforms // in method FileMapInfo::reserve_shared_memory(), which is not called on Windows. MemTracker::record_virtual_memory_type((address)base, mtClassShared); #endif return base; } bool FileMapInfo::verify_region_checksum(int i) { if (!VerifySharedSpaces) { return true; } const char* buf = _header->_space[i]._base; size_t sz = _header->_space[i]._used; int crc = ClassLoader::crc32(0, buf, (jint)sz); if (crc != _header->_space[i]._crc) { fail_continue("Checksum verification failed."); return false; } return true; } // Unmap a memory region in the address space. void FileMapInfo::unmap_region(int i) { struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i]; size_t used = si->_used; size_t size = align_size_up(used, os::vm_allocation_granularity()); if (!os::unmap_memory(si->_base, size)) { fail_stop("Unable to unmap shared space."); } } void FileMapInfo::assert_mark(bool check) { if (!check) { fail_stop("Mark mismatch while restoring from shared file."); } } FileMapInfo* FileMapInfo::_current_info = NULL; SharedClassPathEntry* FileMapInfo::_classpath_entry_table = NULL; int FileMapInfo::_classpath_entry_table_size = 0; size_t FileMapInfo::_classpath_entry_size = 0x1234baad; bool FileMapInfo::_validating_classpath_entry_table = false; // Open the shared archive file, read and validate the header // information (version, boot classpath, etc.). If initialization // fails, shared spaces are disabled and the file is closed. [See // fail_continue.] // // Validation of the archive is done in two steps: // // [1] validate_header() - done here. This checks the header, including _paths_misc_info. // [2] validate_classpath_entry_table - this is done later, because the table is in the RW // region of the archive, which is not mapped yet. bool FileMapInfo::initialize() { assert(UseSharedSpaces, "UseSharedSpaces expected."); if (JvmtiExport::can_modify_any_class() || JvmtiExport::can_walk_any_space()) { fail_continue("Tool agent requires sharing to be disabled."); return false; } if (!open_for_read()) { return false; } init_from_file(_fd); if (!validate_header()) { return false; } SharedReadOnlySize = _header->_space[0]._capacity; SharedReadWriteSize = _header->_space[1]._capacity; SharedMiscDataSize = _header->_space[2]._capacity; SharedMiscCodeSize = _header->_space[3]._capacity; return true; } int FileMapInfo::FileMapHeader::compute_crc() { char* header = data(); // start computing from the field after _crc char* buf = (char*)&_crc + sizeof(int); size_t sz = data_size() - (buf - header); int crc = ClassLoader::crc32(0, buf, (jint)sz); return crc; } bool FileMapInfo::FileMapHeader::validate() { if (VerifySharedSpaces && compute_crc() != _crc) { fail_continue("Header checksum verification failed."); return false; } if (_version != current_version()) { FileMapInfo::fail_continue("The shared archive file is the wrong version."); return false; } if (_magic != (int)0xf00baba2) { FileMapInfo::fail_continue("The shared archive file has a bad magic number."); return false; } char header_version[JVM_IDENT_MAX]; get_header_version(header_version); if (strncmp(_jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) { if (TraceClassPaths) { tty->print_cr("Expected: %s", header_version); tty->print_cr("Actual: %s", _jvm_ident); } FileMapInfo::fail_continue("The shared archive file was created by a different" " version or build of HotSpot"); return false; } if (_obj_alignment != ObjectAlignmentInBytes) { FileMapInfo::fail_continue("The shared archive file's ObjectAlignmentInBytes of %d" " does not equal the current ObjectAlignmentInBytes of %d.", _obj_alignment, ObjectAlignmentInBytes); return false; } return true; } bool FileMapInfo::validate_header() { bool status = _header->validate(); if (status) { if (!ClassLoader::check_shared_paths_misc_info(_paths_misc_info, _header->_paths_misc_info_size)) { if (!PrintSharedArchiveAndExit) { fail_continue("shared class paths mismatch (hint: enable -XX:+TraceClassPaths to diagnose the failure)"); status = false; } } } if (_paths_misc_info != NULL) { FREE_C_HEAP_ARRAY(char, _paths_misc_info); _paths_misc_info = NULL; } return status; } // The following method is provided to see whether a given pointer // falls in the mapped shared space. // Param: // p, The given pointer // Return: // True if the p is within the mapped shared space, otherwise, false. bool FileMapInfo::is_in_shared_space(const void* p) { for (int i = 0; i < MetaspaceShared::n_regions; i++) { if (p >= _header->_space[i]._base && p < _header->_space[i]._base + _header->_space[i]._used) { return true; } } return false; } void FileMapInfo::print_shared_spaces() { gclog_or_tty->print_cr("Shared Spaces:"); for (int i = 0; i < MetaspaceShared::n_regions; i++) { struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i]; gclog_or_tty->print(" %s " INTPTR_FORMAT "-" INTPTR_FORMAT, shared_region_name[i], si->_base, si->_base + si->_used); } } // Unmap mapped regions of shared space. void FileMapInfo::stop_sharing_and_unmap(const char* msg) { FileMapInfo *map_info = FileMapInfo::current_info(); if (map_info) { map_info->fail_continue("%s", msg); for (int i = 0; i < MetaspaceShared::n_regions; i++) { if (map_info->_header->_space[i]._base != NULL) { map_info->unmap_region(i); map_info->_header->_space[i]._base = NULL; } } } else if (DumpSharedSpaces) { fail_stop("%s", msg); } }