jdk8-mips64-public/hotspot: src/share/vm/memory/filemap.cpp@fe81517cfb77 (annotated)

src/share/vm/memory/filemap.cpp@fe81517cfb77 (annotated)

src/share/vm/memory/filemap.cpp

Wed, 28 Nov 2012 08:17:59 -0500

author: hseigel
date: Wed, 28 Nov 2012 08:17:59 -0500
changeset 4293: fe81517cfb77
parent 4193: 716c64bda5ba
child 4396: 6c3f47d964f3
permissions: -rw-r--r--

6924920: Class Data Sharing limit on the java version string can create failures
Summary: Truncate the java version string and add a hash value if it is too long.
Reviewed-by: dholmes, coleenp

 /*
  * 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;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/memory/filemap.cpp@fe81517cfb77 (annotated)

src/share/vm/memory/filemap.cpp