/*

 * Copyright (c) 2003, 2018, 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 "jvm.h"

#include "classfile/classLoader.inline.hpp"

#include "classfile/compactHashtable.inline.hpp"

#include "classfile/sharedClassUtil.hpp"

#include "classfile/stringTable.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/systemDictionaryShared.hpp"

#include "classfile/altHashing.hpp"

#include "logging/log.hpp"

#include "logging/logStream.hpp"

#include "logging/logMessage.hpp"

#include "memory/filemap.hpp"

#include "memory/metadataFactory.hpp"

#include "memory/metaspaceClosure.hpp"

#include "memory/metaspaceShared.hpp"

#include "memory/oopFactory.hpp"

#include "oops/compressedOops.inline.hpp"

#include "oops/objArrayOop.hpp"

#include "prims/jvmtiExport.hpp"

#include "runtime/arguments.hpp"

#include "runtime/java.hpp"

#include "runtime/os.hpp"

#include "runtime/vm_version.hpp"

#include "services/memTracker.hpp"

#include "utilities/align.hpp"

#include "utilities/defaultStream.hpp"

#include "gc/g1/g1CollectedHeap.hpp"

#endif

# 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");

  // 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_shared_path_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 (log_is_enabled(Info, cds)) {

        ResourceMark rm;

        LogStream ls(Log(cds)::info());

        ls.print("UseSharedSpaces: ");

        ls.vprint_cr(msg, ap);

      }

    }

    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 <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((void*)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;

  _compact_strings = CompactStrings;

  _narrow_oop_mode = Universe::narrow_oop_mode();

  _narrow_oop_base = Universe::narrow_oop_base();

  _narrow_oop_shift = Universe::narrow_oop_shift();

  _max_heap_size = MaxHeapSize;

  _narrow_klass_base = Universe::narrow_klass_base();

  _narrow_klass_shift = Universe::narrow_klass_shift();

  _shared_path_table_size = mapinfo->_shared_path_table_size;

  _shared_path_table = mapinfo->_shared_path_table;

  _shared_path_entry_size = mapinfo->_shared_path_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 SharedClassPathEntry::init(const char* name, TRAPS) {

  _timestamp = 0;

  _filesize  = 0;

  struct stat st;

  if (os::stat(name, &st) == 0) {

    if ((st.st_mode & S_IFMT) == S_IFDIR) {

      _is_dir = true;

    } else {

      _is_dir = false;

      _timestamp = st.st_mtime;

      _filesize = st.st_size;

    }

  } else {

    // 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 file %s.", name);

  }

  size_t len = strlen(name) + 1;

  _name = MetadataFactory::new_array<char>(ClassLoaderData::the_null_class_loader_data(), (int)len, THREAD);

  strcpy(_name->data(), name);

}

bool SharedClassPathEntry::validate(bool is_class_path) {

  assert(UseSharedSpaces, "runtime only");

  struct stat st;

  const char* name = this->name();

  bool ok = true;

  log_info(class, path)("checking shared classpath entry: %s", name);

  if (os::stat(name, &st) != 0 && is_class_path) {

    // If the archived module path entry does not exist at runtime, it is not fatal

    // (no need to invalid the shared archive) because the shared runtime visibility check

    // filters out any archived module classes that do not have a matching runtime

    // module path location.

    FileMapInfo::fail_continue("Required classpath entry does not exist: %s", name);

    ok = false;

  } else if (is_dir()) {

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

      FileMapInfo::fail_continue("directory is not empty: %s", name);

      ok = false;

    }

  } else if (is_jar_or_bootimage()) {

    if (_timestamp != st.st_mtime ||

        _filesize != st.st_size) {

      ok = false;

      if (PrintSharedArchiveAndExit) {

        FileMapInfo::fail_continue(_timestamp != st.st_mtime ?

                                   "Timestamp mismatch" :

                                   "File size mismatch");

      } else {

        FileMapInfo::fail_continue("A jar/jimage file is not the one used while building"

                                   " the shared archive file: %s", name);

      }

    }

  }

  return ok;

}

void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {

  it->push(&_name);

  it->push(&_manifest);

}

void FileMapInfo::allocate_shared_path_table() {

  assert(DumpSharedSpaces, "Sanity");

  Thread* THREAD = Thread::current();

  ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();

  ClassPathEntry* jrt = ClassLoader::get_jrt_entry();

  assert(jrt != NULL,

         "No modular java runtime image present when allocating the CDS classpath entry table");

  size_t entry_size = SharedClassUtil::shared_class_path_entry_size(); // assert ( should be 8 byte aligned??)

  int num_boot_classpath_entries = ClassLoader::num_boot_classpath_entries();

  int num_app_classpath_entries = ClassLoader::num_app_classpath_entries();

  int num_module_path_entries = ClassLoader::num_module_path_entries();

  int num_entries = num_boot_classpath_entries + num_app_classpath_entries + num_module_path_entries;

  size_t bytes = entry_size * num_entries;

  _shared_path_table = MetadataFactory::new_array<u8>(loader_data, (int)(bytes + 7 / 8), THREAD);

  _shared_path_table_size = num_entries;

  _shared_path_entry_size = entry_size;

  // 1. boot class path

  int i = 0;

  ClassPathEntry* cpe = jrt;

  while (cpe != NULL) {

    const char* type = ((cpe == jrt) ? "jrt" : (cpe->is_jar_file() ? "jar" : "dir"));

    log_info(class, path)("add main shared path (%s) %s", type, cpe->name());

    SharedClassPathEntry* ent = shared_path(i);

    ent->init(cpe->name(), THREAD);

    if (cpe != jrt) { // No need to do jimage.

      EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.

      SharedClassUtil::update_shared_classpath(cpe, ent, THREAD);

    }

    cpe = ClassLoader::get_next_boot_classpath_entry(cpe);

    i++;

  }

  assert(i == num_boot_classpath_entries,

         "number of boot class path entry mismatch");

  // 2. app class path

  ClassPathEntry *acpe = ClassLoader::app_classpath_entries();

  while (acpe != NULL) {

    log_info(class, path)("add app shared path %s", acpe->name());

    SharedClassPathEntry* ent = shared_path(i);

    ent->init(acpe->name(), THREAD);

    EXCEPTION_MARK;

    SharedClassUtil::update_shared_classpath(acpe, ent, THREAD);

    acpe = acpe->next();

    i++;

  }

  // 3. module path

  ClassPathEntry *mpe = ClassLoader::module_path_entries();

  while (mpe != NULL) {

    log_info(class, path)("add module path %s",mpe->name());

    SharedClassPathEntry* ent = shared_path(i);

    ent->init(mpe->name(), THREAD);

    EXCEPTION_MARK;

    SharedClassUtil::update_shared_classpath(mpe, ent, THREAD);

    mpe = mpe->next();

    i++;

  }

  assert(i == num_entries, "number of shared path entry mismatch");

}

void FileMapInfo::check_nonempty_dir_in_shared_path_table() {

  assert(DumpSharedSpaces, "dump time only");

  bool has_nonempty_dir = false;

  int end = _shared_path_table_size;

  if (!ClassLoaderExt::has_platform_or_app_classes()) {

    // only check the boot path if no app class is loaded

    end = ClassLoaderExt::app_class_paths_start_index();

  }

  for (int i = 0; i < end; i++) {

    SharedClassPathEntry *e = shared_path(i);

    if (e->is_dir()) {

      const char* path = e->name();

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

        tty->print_cr("Error: non-empty directory '%s'", path);

        has_nonempty_dir = true;

      }

    }

  }

  if (has_nonempty_dir) {

    ClassLoader::exit_with_path_failure("Cannot have non-empty directory in paths", NULL);

  }

}

bool FileMapInfo::validate_shared_path_table() {

  assert(UseSharedSpaces, "runtime only");

  _validating_shared_path_table = true;

  _shared_path_table = _header->_shared_path_table;

  _shared_path_entry_size = _header->_shared_path_entry_size;

  _shared_path_table_size = _header->_shared_path_table_size;

  FileMapHeaderExt* header = (FileMapHeaderExt*)FileMapInfo::current_info()->header();

  int module_paths_start_index = header->_app_module_paths_start_index;

  // If the shared archive contain app or platform classes, validate all entries

  // in the shared path table. Otherwise, only validate the boot path entries (with

  // entry index < _app_class_paths_start_index).

  int count = header->has_platform_or_app_classes() ?

              _shared_path_table_size : header->_app_class_paths_start_index;

  for (int i=0; i<count; i++) {

    if (i < module_paths_start_index) {

      if (shared_path(i)->validate()) {

        log_info(class, path)("ok");

      }

    } else if (i >= module_paths_start_index) {

      if (shared_path(i)->validate(false /* not a class path entry */)) {

        log_info(class, path)("ok");

      }

    } else if (!PrintSharedArchiveAndExit) {

      _validating_shared_path_table = false;

      _shared_path_table = NULL;

      _shared_path_table_size = 0;

      return false;

    }

  }

  _validating_shared_path_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::last_valid_region];

  // The last space might be empty

  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).",

                    os::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();

  LogMessage(cds) msg;

  if (msg.is_info()) {

    msg.info("Dumping shared data to file: ");

    msg.info("   %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,

              os::strerror(errno));

  }

  _fd = fd;

  _file_offset = 0;

  _file_open = true;

}

// Write the header to the file, seek to the next allocation boundary.