| /* |
| * Copyright (c) 2003, 2012, 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/symbolTable.hpp" |
| #include "classfile/altHashing.hpp" |
| #include "memory/filemap.hpp" |
| #include "runtime/arguments.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/os.hpp" |
| #include "services/memTracker.hpp" |
| #include "utilities/defaultStream.hpp" |
| |
| # include <sys/stat.h> |
| # include <errno.h> |
| |
| #ifndef O_BINARY // if defined (Win32) use binary files. |
| #define O_BINARY 0 // otherwise do nothing. |
| #endif |
| |
| |
| 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"); |
| 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); |
| if (RequireSharedSpaces) { |
| fail(msg, ap); |
| } |
| va_end(ap); |
| UseSharedSpaces = false; |
| close(); |
| } |
| |
| // 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 <int N> 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. |
| } |
| } |
| |
| void FileMapInfo::populate_header(size_t alignment) { |
| _header._magic = 0xf00baba2; |
| _header._version = _current_version; |
| _header._alignment = alignment; |
| _header._obj_alignment = ObjectAlignmentInBytes; |
| |
| // 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(_header._jvm_ident); |
| |
| // Build checks on classpath and jar files |
| _header._num_jars = 0; |
| ClassPathEntry *cpe = ClassLoader::classpath_entry(0); |
| for ( ; cpe != NULL; cpe = cpe->next()) { |
| |
| if (cpe->is_jar_file()) { |
| if (_header._num_jars >= JVM_SHARED_JARS_MAX) { |
| fail_stop("Too many jar files to share.", NULL); |
| } |
| |
| // Jar file - record timestamp and file size. |
| struct stat st; |
| const char *path = cpe->name(); |
| if (os::stat(path, &st) != 0) { |
| // If we can't access a jar file in the boot path, then we can't |
| // make assumptions about where classes get loaded from. |
| fail_stop("Unable to open jar file %s.", path); |
| } |
| _header._jar[_header._num_jars]._timestamp = st.st_mtime; |
| _header._jar[_header._num_jars]._filesize = st.st_size; |
| _header._num_jars++; |
| } else { |
| |
| // If directories appear in boot classpath, they must be empty to |
| // avoid having to verify each individual class file. |
| const char* name = ((ClassPathDirEntry*)cpe)->name(); |
| if (!os::dir_is_empty(name)) { |
| fail_stop("Boot classpath directory %s is not empty.", name); |
| } |
| } |
| } |
| } |
| |
| |
| // Read the FileMapInfo information from the file. |
| |
| bool FileMapInfo::init_from_file(int fd) { |
| |
| size_t n = read(fd, &_header, sizeof(struct FileMapHeader)); |
| if (n != sizeof(struct FileMapHeader)) { |
| 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; |
| 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); |
| } |
| |
| // Remove the existing file in case another process has it open. |
| remove(_full_path); |
| #ifdef _WINDOWS // if 0444 is used on Windows, then remove() will fail. |
| int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0744); |
| #else |
| int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444); |
| #endif |
| if (fd < 0) { |
| fail_stop("Unable to create shared archive file %s.", _full_path); |
| } |
| _fd = fd; |
| _file_offset = 0; |
| _file_open = true; |
| } |
| |
| |
| // Write the header to the file, seek to the next allocation boundary. |
| |
| void FileMapInfo::write_header() { |
| write_bytes_aligned(&_header, sizeof(FileMapHeader)); |
| } |
| |
| |
| // Dump shared spaces to file. |
| |
| void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) { |
| align_file_position(); |
| size_t used = space->used_words(Metaspace::NonClassType) * BytesPerWord; |
| size_t capacity = space->capacity_words(Metaspace::NonClassType) * BytesPerWord; |
| 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; |
| 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.", NULL); |
| } |
| } |
| _file_offset += nbytes; |
| } |
| |
| |
| // Align file position to an allocation unit boundary. |
| |
| void FileMapInfo::align_file_position() { |
| long 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, _file_offset, SEEK_SET) < 0) { |
| fail_stop("Unable to seek.", NULL); |
| } |
| 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 alignment = os::vm_allocation_granularity(); |
| |
| size_t size = align_size_up(SharedReadOnlySize + SharedReadWriteSize + |
| SharedMiscDataSize + SharedMiscCodeSize, |
| alignment); |
| |
| // Reserve the space first, then map otherwise map will go right over some |
| // other reserved memory (like the code cache). |
| ReservedSpace rs(size, alignment, false, requested_addr); |
| if (!rs.is_reserved()) { |
| fail_continue(err_msg("Unable to reserved 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(err_msg("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; |
| } |
| |
| |
| // 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.", NULL); |
| } |
| } |
| |
| |
| FileMapInfo* FileMapInfo::_current_info = NULL; |
| |
| |
| // 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.] |
| 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()) { |
| return false; |
| } |
| |
| SharedReadOnlySize = _header._space[0]._capacity; |
| SharedReadWriteSize = _header._space[1]._capacity; |
| SharedMiscDataSize = _header._space[2]._capacity; |
| SharedMiscCodeSize = _header._space[3]._capacity; |
| return true; |
| } |
| |
| |
| bool FileMapInfo::validate() { |
| if (_header._version != current_version()) { |
| fail_continue("The shared archive file is the wrong version."); |
| return false; |
| } |
| if (_header._magic != (int)0xf00baba2) { |
| 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(_header._jvm_ident, header_version, JVM_IDENT_MAX-1) != 0) { |
| fail_continue("The shared archive file was created by a different" |
| " version or build of HotSpot."); |
| return false; |
| } |
| if (_header._obj_alignment != ObjectAlignmentInBytes) { |
| fail_continue("The shared archive file's ObjectAlignmentInBytes of %d" |
| " does not equal the current ObjectAlignmentInBytes of %d.", |
| _header._obj_alignment, ObjectAlignmentInBytes); |
| return false; |
| } |
| |
| // Cannot verify interpreter yet, as it can only be created after the GC |
| // heap has been initialized. |
| |
| if (_header._num_jars >= JVM_SHARED_JARS_MAX) { |
| fail_continue("Too many jar files to share."); |
| return false; |
| } |
| |
| // Build checks on classpath and jar files |
| int num_jars_now = 0; |
| ClassPathEntry *cpe = ClassLoader::classpath_entry(0); |
| for ( ; cpe != NULL; cpe = cpe->next()) { |
| |
| if (cpe->is_jar_file()) { |
| if (num_jars_now < _header._num_jars) { |
| |
| // Jar file - verify timestamp and file size. |
| struct stat st; |
| const char *path = cpe->name(); |
| if (os::stat(path, &st) != 0) { |
| fail_continue("Unable to open jar file %s.", path); |
| return false; |
| } |
| if (_header._jar[num_jars_now]._timestamp != st.st_mtime || |
| _header._jar[num_jars_now]._filesize != st.st_size) { |
| fail_continue("A jar file is not the one used while building" |
| " the shared archive file."); |
| return false; |
| } |
| } |
| ++num_jars_now; |
| } else { |
| |
| // If directories appear in boot classpath, they must be empty to |
| // avoid having to verify each individual class file. |
| const char* name = ((ClassPathDirEntry*)cpe)->name(); |
| if (!os::dir_is_empty(name)) { |
| fail_continue("Boot classpath directory %s is not empty.", name); |
| return false; |
| } |
| } |
| } |
| if (num_jars_now < _header._num_jars) { |
| fail_continue("The number of jar files in the boot classpath is" |
| " less than the number the shared archive was created with."); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // 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; |
| } |