/*

 * 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/classLoaderExt.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/heapShared.inline.hpp"

#include "memory/iterator.inline.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 "oops/oop.inline.hpp"

#include "prims/jvmtiExport.hpp"

#include "runtime/arguments.hpp"

#include "runtime/java.hpp"

#include "runtime/os.inline.hpp"

#include "runtime/vm_version.hpp"

#include "services/memTracker.hpp"

#include "utilities/align.hpp"

#include "utilities/defaultStream.hpp"

#if INCLUDE_G1GC

#include "gc/g1/g1CollectedHeap.hpp"

#include "gc/g1/heapRegion.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 = (FileMapHeader*)os::malloc(sizeof(FileMapHeader), mtInternal);

  _header->_version = INVALID_CDS_ARCHIVE_VERSION;

  _header->_has_platform_or_app_classes = true;

}

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);

}

void FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {

  _magic = CDS_ARCHIVE_MAGIC;

  _version = CURRENT_CDS_ARCHIVE_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;

  if (HeapShared::is_heap_object_archiving_allowed()) {

    _heap_reserved = Universe::heap()->reserved_region();

  }

  // 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);

  ClassLoaderExt::finalize_shared_paths_misc_info();

  _app_class_paths_start_index = ClassLoaderExt::app_class_paths_start_index();

  _app_module_paths_start_index = ClassLoaderExt::app_module_paths_start_index();

  _max_used_path_index = ClassLoaderExt::max_used_path_index();

  _verify_local = BytecodeVerificationLocal;

  _verify_remote = BytecodeVerificationRemote;

  _has_platform_or_app_classes = ClassLoaderExt::has_platform_or_app_classes();

  _shared_base_address = SharedBaseAddress;

  _allow_archiving_with_java_agent = AllowArchivingWithJavaAgent;

}

void SharedClassPathEntry::init(const char* name, bool is_modules_image, TRAPS) {

  assert(DumpSharedSpaces, "dump time only");

  _timestamp = 0;

  _filesize  = 0;

  struct stat st;

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

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

      _type = dir_entry;

    } else {

      // The timestamp of the modules_image is not checked at runtime.

      if (is_modules_image) {

        _type = modules_image_entry;

      } else {

        _type = jar_entry;

        _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;

  // In order to validate the runtime modules image file size against the archived

  // size information, we need to obtain the runtime modules image path. The recorded

  // dump time modules image path in the archive may be different from the runtime path

  // if the JDK image has beed moved after generating the archive.

  if (is_modules_image()) {

    name = ClassLoader::get_jrt_entry()->name();

  } else {

    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 ((has_timestamp() && _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 file is not the one used while building"

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

    }

  }

  if (PrintSharedArchiveAndExit && !ok) {

    // If PrintSharedArchiveAndExit is enabled, don't report failure to the

    // caller. Please see above comments for more details.

    ok = true;

  }

  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 = sizeof(SharedClassPathEntry); // 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) {

    bool is_jrt = (cpe == jrt);

    const char* type = (is_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(), is_jrt, THREAD);

    if (!is_jrt) {    // No need to do the modules image.

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

      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(), false, THREAD);

    EXCEPTION_MARK;

    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(), false, THREAD);

    EXCEPTION_MARK;

    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 last = _shared_path_table_size - 1;

  if (last > ClassLoaderExt::max_used_path_index()) {

     // no need to check any path beyond max_used_path_index

     last = ClassLoaderExt::max_used_path_index();

  }

  for (int i = 0; i <= last; 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);

  }

}

class ManifestStream: public ResourceObj {

  private:

  u1*   _buffer_start; // Buffer bottom

  u1*   _buffer_end;   // Buffer top (one past last element)

  u1*   _current;      // Current buffer position

 public:

  // Constructor

  ManifestStream(u1* buffer, int length) : _buffer_start(buffer),

                                           _current(buffer) {

    _buffer_end = buffer + length;

  }

  static bool is_attr(u1* attr, const char* name) {

    return strncmp((const char*)attr, name, strlen(name)) == 0;

  }

  static char* copy_attr(u1* value, size_t len) {

    char* buf = NEW_RESOURCE_ARRAY(char, len + 1);

    strncpy(buf, (char*)value, len);

    buf[len] = 0;

    return buf;

  }

  // The return value indicates if the JAR is signed or not

  bool check_is_signed() {

    u1* attr = _current;

    bool isSigned = false;

    while (_current < _buffer_end) {

      if (*_current == '\n') {

        *_current = '\0';

        u1* value = (u1*)strchr((char*)attr, ':');

        if (value != NULL) {

          assert(*(value+1) == ' ', "Unrecognized format" );

          if (strstr((char*)attr, "-Digest") != NULL) {

            isSigned = true;

            break;

          }

        }

        *_current = '\n'; // restore

        attr = _current + 1;

      }

      _current ++;

    }

    return isSigned;

  }

};

void FileMapInfo::update_shared_classpath(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS) {

  ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();

  ResourceMark rm(THREAD);

  jint manifest_size;

  if (cpe->is_jar_file()) {

    assert(ent->is_jar(), "the shared class path entry is not a JAR file");

    char* manifest = ClassLoaderExt::read_manifest(cpe, &manifest_size, CHECK);

    if (manifest != NULL) {

      ManifestStream* stream = new ManifestStream((u1*)manifest,

                                                  manifest_size);

      if (stream->check_is_signed()) {

        ent->set_is_signed();

      } else {

        // Copy the manifest into the shared archive

        manifest = ClassLoaderExt::read_raw_manifest(cpe, &manifest_size, CHECK);

        Array<u1>* buf = MetadataFactory::new_array<u1>(loader_data,

                                                        manifest_size,

                                                        THREAD);

        char* p = (char*)(buf->data());

        memcpy(p, manifest, manifest_size);

        ent->set_manifest(buf);

      }

    }

  }

}

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;

  int module_paths_start_index = _header->_app_module_paths_start_index;

  // validate the path entries up to the _max_used_path_index

  for (int i=0; i < _header->_max_used_path_index + 1; i++) {

    if (i < module_paths_start_index) {

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

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

      } else {

        assert(!UseSharedSpaces, "UseSharedSpaces should be disabled");