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

 /*

  * Copyright (c) 2003, 2014, 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 "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

 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);

       }

     }

   }

   va_end(ap);

   UseSharedSpaces = false;

   assert(current_info() != NULL, "singleton must be registered");

   current_info()->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.

   }

 }

 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 {

           ent->_filesize  = -1;

           if (!os::dir_is_empty(name)) {

             ClassLoader::exit_with_path_failure("Cannot have non-empty directory in archived classpaths", name);

           }

         }

         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<u8>* arr = MetadataFactory::new_array<u8>(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<count; i++) {

     SharedClassPathEntry* ent = shared_classpath(i);

     struct stat st;

     const char* name = ent->_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->_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, mtClass);

     _paths_misc_info = NULL;

     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.", _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() {

   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;

   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 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(err_msg("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(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;

 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;

 }

 bool FileMapInfo::FileMapHeader::validate() {

   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, mtClass);

     _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(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(msg, NULL);

   }

 }