Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * 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;

   // 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);

   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.", _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

   if (MemTracker::is_on()) {

     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;

   }

   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;

   }

   // 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;

 }