| /* |
| * Copyright (c) 2001, 2017, 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/vmSymbols.hpp" |
| #include "logging/log.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "os_windows.inline.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/os.hpp" |
| #include "runtime/perfMemory.hpp" |
| #include "services/memTracker.hpp" |
| #include "utilities/exceptions.hpp" |
| |
| #include <windows.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <errno.h> |
| #include <lmcons.h> |
| |
| typedef BOOL (WINAPI *SetSecurityDescriptorControlFnPtr)( |
| IN PSECURITY_DESCRIPTOR pSecurityDescriptor, |
| IN SECURITY_DESCRIPTOR_CONTROL ControlBitsOfInterest, |
| IN SECURITY_DESCRIPTOR_CONTROL ControlBitsToSet); |
| |
| // Standard Memory Implementation Details |
| |
| // create the PerfData memory region in standard memory. |
| // |
| static char* create_standard_memory(size_t size) { |
| |
| // allocate an aligned chuck of memory |
| char* mapAddress = os::reserve_memory(size); |
| |
| if (mapAddress == NULL) { |
| return NULL; |
| } |
| |
| // commit memory |
| if (!os::commit_memory(mapAddress, size, !ExecMem)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("Could not commit PerfData memory\n"); |
| } |
| os::release_memory(mapAddress, size); |
| return NULL; |
| } |
| |
| return mapAddress; |
| } |
| |
| // delete the PerfData memory region |
| // |
| static void delete_standard_memory(char* addr, size_t size) { |
| |
| // there are no persistent external resources to cleanup for standard |
| // memory. since DestroyJavaVM does not support unloading of the JVM, |
| // cleanup of the memory resource is not performed. The memory will be |
| // reclaimed by the OS upon termination of the process. |
| // |
| return; |
| |
| } |
| |
| // save the specified memory region to the given file |
| // |
| static void save_memory_to_file(char* addr, size_t size) { |
| |
| const char* destfile = PerfMemory::get_perfdata_file_path(); |
| assert(destfile[0] != '\0', "invalid Perfdata file path"); |
| |
| int fd = ::_open(destfile, _O_BINARY|_O_CREAT|_O_WRONLY|_O_TRUNC, |
| _S_IREAD|_S_IWRITE); |
| |
| if (fd == OS_ERR) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("Could not create Perfdata save file: %s: %s\n", |
| destfile, os::strerror(errno)); |
| } |
| } else { |
| for (size_t remaining = size; remaining > 0;) { |
| |
| int nbytes = ::_write(fd, addr, (unsigned int)remaining); |
| if (nbytes == OS_ERR) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("Could not write Perfdata save file: %s: %s\n", |
| destfile, os::strerror(errno)); |
| } |
| break; |
| } |
| |
| remaining -= (size_t)nbytes; |
| addr += nbytes; |
| } |
| |
| int result = ::_close(fd); |
| if (PrintMiscellaneous && Verbose) { |
| if (result == OS_ERR) { |
| warning("Could not close %s: %s\n", destfile, os::strerror(errno)); |
| } |
| } |
| } |
| |
| FREE_C_HEAP_ARRAY(char, destfile); |
| } |
| |
| // Shared Memory Implementation Details |
| |
| // Note: the win32 shared memory implementation uses two objects to represent |
| // the shared memory: a windows kernel based file mapping object and a backing |
| // store file. On windows, the name space for shared memory is a kernel |
| // based name space that is disjoint from other win32 name spaces. Since Java |
| // is unaware of this name space, a parallel file system based name space is |
| // maintained, which provides a common file system based shared memory name |
| // space across the supported platforms and one that Java apps can deal with |
| // through simple file apis. |
| // |
| // For performance and resource cleanup reasons, it is recommended that the |
| // user specific directory and the backing store file be stored in either a |
| // RAM based file system or a local disk based file system. Network based |
| // file systems are not recommended for performance reasons. In addition, |
| // use of SMB network based file systems may result in unsuccesful cleanup |
| // of the disk based resource on exit of the VM. The Windows TMP and TEMP |
| // environement variables, as used by the GetTempPath() Win32 API (see |
| // os::get_temp_directory() in os_win32.cpp), control the location of the |
| // user specific directory and the shared memory backing store file. |
| |
| static HANDLE sharedmem_fileMapHandle = NULL; |
| static HANDLE sharedmem_fileHandle = INVALID_HANDLE_VALUE; |
| static char* sharedmem_fileName = NULL; |
| |
| // return the user specific temporary directory name. |
| // |
| // the caller is expected to free the allocated memory. |
| // |
| static char* get_user_tmp_dir(const char* user) { |
| |
| const char* tmpdir = os::get_temp_directory(); |
| const char* perfdir = PERFDATA_NAME; |
| size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3; |
| char* dirname = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| |
| // construct the path name to user specific tmp directory |
| _snprintf(dirname, nbytes, "%s\\%s_%s", tmpdir, perfdir, user); |
| |
| return dirname; |
| } |
| |
| // convert the given file name into a process id. if the file |
| // does not meet the file naming constraints, return 0. |
| // |
| static int filename_to_pid(const char* filename) { |
| |
| // a filename that doesn't begin with a digit is not a |
| // candidate for conversion. |
| // |
| if (!isdigit(*filename)) { |
| return 0; |
| } |
| |
| // check if file name can be converted to an integer without |
| // any leftover characters. |
| // |
| char* remainder = NULL; |
| errno = 0; |
| int pid = (int)strtol(filename, &remainder, 10); |
| |
| if (errno != 0) { |
| return 0; |
| } |
| |
| // check for left over characters. If any, then the filename is |
| // not a candidate for conversion. |
| // |
| if (remainder != NULL && *remainder != '\0') { |
| return 0; |
| } |
| |
| // successful conversion, return the pid |
| return pid; |
| } |
| |
| // check if the given path is considered a secure directory for |
| // the backing store files. Returns true if the directory exists |
| // and is considered a secure location. Returns false if the path |
| // is a symbolic link or if an error occurred. |
| // |
| static bool is_directory_secure(const char* path) { |
| |
| DWORD fa; |
| |
| fa = GetFileAttributes(path); |
| if (fa == 0xFFFFFFFF) { |
| DWORD lasterror = GetLastError(); |
| if (lasterror == ERROR_FILE_NOT_FOUND) { |
| return false; |
| } |
| else { |
| // unexpected error, declare the path insecure |
| if (PrintMiscellaneous && Verbose) { |
| warning("could not get attributes for file %s: ", |
| " lasterror = %d\n", path, lasterror); |
| } |
| return false; |
| } |
| } |
| |
| if (fa & FILE_ATTRIBUTE_REPARSE_POINT) { |
| // we don't accept any redirection for the user specific directory |
| // so declare the path insecure. This may be too conservative, |
| // as some types of reparse points might be acceptable, but it |
| // is probably more secure to avoid these conditions. |
| // |
| if (PrintMiscellaneous && Verbose) { |
| warning("%s is a reparse point\n", path); |
| } |
| return false; |
| } |
| |
| if (fa & FILE_ATTRIBUTE_DIRECTORY) { |
| // this is the expected case. Since windows supports symbolic |
| // links to directories only, not to files, there is no need |
| // to check for open write permissions on the directory. If the |
| // directory has open write permissions, any files deposited that |
| // are not expected will be removed by the cleanup code. |
| // |
| return true; |
| } |
| else { |
| // this is either a regular file or some other type of file, |
| // any of which are unexpected and therefore insecure. |
| // |
| if (PrintMiscellaneous && Verbose) { |
| warning("%s is not a directory, file attributes = " |
| INTPTR_FORMAT "\n", path, fa); |
| } |
| return false; |
| } |
| } |
| |
| // return the user name for the owner of this process |
| // |
| // the caller is expected to free the allocated memory. |
| // |
| static char* get_user_name() { |
| |
| /* get the user name. This code is adapted from code found in |
| * the jdk in src/windows/native/java/lang/java_props_md.c |
| * java_props_md.c 1.29 02/02/06. According to the original |
| * source, the call to GetUserName is avoided because of a resulting |
| * increase in footprint of 100K. |
| */ |
| char* user = getenv("USERNAME"); |
| char buf[UNLEN+1]; |
| DWORD buflen = sizeof(buf); |
| if (user == NULL || strlen(user) == 0) { |
| if (GetUserName(buf, &buflen)) { |
| user = buf; |
| } |
| else { |
| return NULL; |
| } |
| } |
| |
| char* user_name = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal); |
| strcpy(user_name, user); |
| |
| return user_name; |
| } |
| |
| // return the name of the user that owns the process identified by vmid. |
| // |
| // This method uses a slow directory search algorithm to find the backing |
| // store file for the specified vmid and returns the user name, as determined |
| // by the user name suffix of the hsperfdata_<username> directory name. |
| // |
| // the caller is expected to free the allocated memory. |
| // |
| static char* get_user_name_slow(int vmid) { |
| |
| // directory search |
| char* latest_user = NULL; |
| time_t latest_ctime = 0; |
| |
| const char* tmpdirname = os::get_temp_directory(); |
| |
| DIR* tmpdirp = os::opendir(tmpdirname); |
| |
| if (tmpdirp == NULL) { |
| return NULL; |
| } |
| |
| // for each entry in the directory that matches the pattern hsperfdata_*, |
| // open the directory and check if the file for the given vmid exists. |
| // The file with the expected name and the latest creation date is used |
| // to determine the user name for the process id. |
| // |
| struct dirent* dentry; |
| char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname), mtInternal); |
| errno = 0; |
| while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) { |
| |
| // check if the directory entry is a hsperfdata file |
| if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) { |
| continue; |
| } |
| |
| char* usrdir_name = NEW_C_HEAP_ARRAY(char, |
| strlen(tmpdirname) + strlen(dentry->d_name) + 2, mtInternal); |
| strcpy(usrdir_name, tmpdirname); |
| strcat(usrdir_name, "\\"); |
| strcat(usrdir_name, dentry->d_name); |
| |
| DIR* subdirp = os::opendir(usrdir_name); |
| |
| if (subdirp == NULL) { |
| FREE_C_HEAP_ARRAY(char, usrdir_name); |
| continue; |
| } |
| |
| // Since we don't create the backing store files in directories |
| // pointed to by symbolic links, we also don't follow them when |
| // looking for the files. We check for a symbolic link after the |
| // call to opendir in order to eliminate a small window where the |
| // symlink can be exploited. |
| // |
| if (!is_directory_secure(usrdir_name)) { |
| FREE_C_HEAP_ARRAY(char, usrdir_name); |
| os::closedir(subdirp); |
| continue; |
| } |
| |
| struct dirent* udentry; |
| char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name), mtInternal); |
| errno = 0; |
| while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) { |
| |
| if (filename_to_pid(udentry->d_name) == vmid) { |
| struct stat statbuf; |
| |
| char* filename = NEW_C_HEAP_ARRAY(char, |
| strlen(usrdir_name) + strlen(udentry->d_name) + 2, mtInternal); |
| |
| strcpy(filename, usrdir_name); |
| strcat(filename, "\\"); |
| strcat(filename, udentry->d_name); |
| |
| if (::stat(filename, &statbuf) == OS_ERR) { |
| FREE_C_HEAP_ARRAY(char, filename); |
| continue; |
| } |
| |
| // skip over files that are not regular files. |
| if ((statbuf.st_mode & S_IFMT) != S_IFREG) { |
| FREE_C_HEAP_ARRAY(char, filename); |
| continue; |
| } |
| |
| // If we found a matching file with a newer creation time, then |
| // save the user name. The newer creation time indicates that |
| // we found a newer incarnation of the process associated with |
| // vmid. Due to the way that Windows recycles pids and the fact |
| // that we can't delete the file from the file system namespace |
| // until last close, it is possible for there to be more than |
| // one hsperfdata file with a name matching vmid (diff users). |
| // |
| // We no longer ignore hsperfdata files where (st_size == 0). |
| // In this function, all we're trying to do is determine the |
| // name of the user that owns the process associated with vmid |
| // so the size doesn't matter. Very rarely, we have observed |
| // hsperfdata files where (st_size == 0) and the st_size field |
| // later becomes the expected value. |
| // |
| if (statbuf.st_ctime > latest_ctime) { |
| char* user = strchr(dentry->d_name, '_') + 1; |
| |
| if (latest_user != NULL) FREE_C_HEAP_ARRAY(char, latest_user); |
| latest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal); |
| |
| strcpy(latest_user, user); |
| latest_ctime = statbuf.st_ctime; |
| } |
| |
| FREE_C_HEAP_ARRAY(char, filename); |
| } |
| } |
| os::closedir(subdirp); |
| FREE_C_HEAP_ARRAY(char, udbuf); |
| FREE_C_HEAP_ARRAY(char, usrdir_name); |
| } |
| os::closedir(tmpdirp); |
| FREE_C_HEAP_ARRAY(char, tdbuf); |
| |
| return(latest_user); |
| } |
| |
| // return the name of the user that owns the process identified by vmid. |
| // |
| // note: this method should only be used via the Perf native methods. |
| // There are various costs to this method and limiting its use to the |
| // Perf native methods limits the impact to monitoring applications only. |
| // |
| static char* get_user_name(int vmid) { |
| |
| // A fast implementation is not provided at this time. It's possible |
| // to provide a fast process id to user name mapping function using |
| // the win32 apis, but the default ACL for the process object only |
| // allows processes with the same owner SID to acquire the process |
| // handle (via OpenProcess(PROCESS_QUERY_INFORMATION)). It's possible |
| // to have the JVM change the ACL for the process object to allow arbitrary |
| // users to access the process handle and the process security token. |
| // The security ramifications need to be studied before providing this |
| // mechanism. |
| // |
| return get_user_name_slow(vmid); |
| } |
| |
| // return the name of the shared memory file mapping object for the |
| // named shared memory region for the given user name and vmid. |
| // |
| // The file mapping object's name is not the file name. It is a name |
| // in a separate name space. |
| // |
| // the caller is expected to free the allocated memory. |
| // |
| static char *get_sharedmem_objectname(const char* user, int vmid) { |
| |
| // construct file mapping object's name, add 3 for two '_' and a |
| // null terminator. |
| int nbytes = (int)strlen(PERFDATA_NAME) + (int)strlen(user) + 3; |
| |
| // the id is converted to an unsigned value here because win32 allows |
| // negative process ids. However, OpenFileMapping API complains |
| // about a name containing a '-' characters. |
| // |
| nbytes += UINT_CHARS; |
| char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| _snprintf(name, nbytes, "%s_%s_%u", PERFDATA_NAME, user, vmid); |
| |
| return name; |
| } |
| |
| // return the file name of the backing store file for the named |
| // shared memory region for the given user name and vmid. |
| // |
| // the caller is expected to free the allocated memory. |
| // |
| static char* get_sharedmem_filename(const char* dirname, int vmid) { |
| |
| // add 2 for the file separator and a null terminator. |
| size_t nbytes = strlen(dirname) + UINT_CHARS + 2; |
| |
| char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| _snprintf(name, nbytes, "%s\\%d", dirname, vmid); |
| |
| return name; |
| } |
| |
| // remove file |
| // |
| // this method removes the file with the given file name. |
| // |
| // Note: if the indicated file is on an SMB network file system, this |
| // method may be unsuccessful in removing the file. |
| // |
| static void remove_file(const char* dirname, const char* filename) { |
| |
| size_t nbytes = strlen(dirname) + strlen(filename) + 2; |
| char* path = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| |
| strcpy(path, dirname); |
| strcat(path, "\\"); |
| strcat(path, filename); |
| |
| if (::unlink(path) == OS_ERR) { |
| if (PrintMiscellaneous && Verbose) { |
| if (errno != ENOENT) { |
| warning("Could not unlink shared memory backing" |
| " store file %s : %s\n", path, os::strerror(errno)); |
| } |
| } |
| } |
| |
| FREE_C_HEAP_ARRAY(char, path); |
| } |
| |
| // returns true if the process represented by pid is alive, otherwise |
| // returns false. the validity of the result is only accurate if the |
| // target process is owned by the same principal that owns this process. |
| // this method should not be used if to test the status of an otherwise |
| // arbitrary process unless it is know that this process has the appropriate |
| // privileges to guarantee a result valid. |
| // |
| static bool is_alive(int pid) { |
| |
| HANDLE ph = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid); |
| if (ph == NULL) { |
| // the process does not exist. |
| if (PrintMiscellaneous && Verbose) { |
| DWORD lastError = GetLastError(); |
| if (lastError != ERROR_INVALID_PARAMETER) { |
| warning("OpenProcess failed: %d\n", GetLastError()); |
| } |
| } |
| return false; |
| } |
| |
| DWORD exit_status; |
| if (!GetExitCodeProcess(ph, &exit_status)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("GetExitCodeProcess failed: %d\n", GetLastError()); |
| } |
| CloseHandle(ph); |
| return false; |
| } |
| |
| CloseHandle(ph); |
| return (exit_status == STILL_ACTIVE) ? true : false; |
| } |
| |
| // check if the file system is considered secure for the backing store files |
| // |
| static bool is_filesystem_secure(const char* path) { |
| |
| char root_path[MAX_PATH]; |
| char fs_type[MAX_PATH]; |
| |
| if (PerfBypassFileSystemCheck) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("bypassing file system criteria checks for %s\n", path); |
| } |
| return true; |
| } |
| |
| char* first_colon = strchr((char *)path, ':'); |
| if (first_colon == NULL) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("expected device specifier in path: %s\n", path); |
| } |
| return false; |
| } |
| |
| size_t len = (size_t)(first_colon - path); |
| assert(len + 2 <= MAX_PATH, "unexpected device specifier length"); |
| strncpy(root_path, path, len + 1); |
| root_path[len + 1] = '\\'; |
| root_path[len + 2] = '\0'; |
| |
| // check that we have something like "C:\" or "AA:\" |
| assert(strlen(root_path) >= 3, "device specifier too short"); |
| assert(strchr(root_path, ':') != NULL, "bad device specifier format"); |
| assert(strchr(root_path, '\\') != NULL, "bad device specifier format"); |
| |
| DWORD maxpath; |
| DWORD flags; |
| |
| if (!GetVolumeInformation(root_path, NULL, 0, NULL, &maxpath, |
| &flags, fs_type, MAX_PATH)) { |
| // we can't get information about the volume, so assume unsafe. |
| if (PrintMiscellaneous && Verbose) { |
| warning("could not get device information for %s: " |
| " path = %s: lasterror = %d\n", |
| root_path, path, GetLastError()); |
| } |
| return false; |
| } |
| |
| if ((flags & FS_PERSISTENT_ACLS) == 0) { |
| // file system doesn't support ACLs, declare file system unsafe |
| if (PrintMiscellaneous && Verbose) { |
| warning("file system type %s on device %s does not support" |
| " ACLs\n", fs_type, root_path); |
| } |
| return false; |
| } |
| |
| if ((flags & FS_VOL_IS_COMPRESSED) != 0) { |
| // file system is compressed, declare file system unsafe |
| if (PrintMiscellaneous && Verbose) { |
| warning("file system type %s on device %s is compressed\n", |
| fs_type, root_path); |
| } |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // cleanup stale shared memory resources |
| // |
| // This method attempts to remove all stale shared memory files in |
| // the named user temporary directory. It scans the named directory |
| // for files matching the pattern ^$[0-9]*$. For each file found, the |
| // process id is extracted from the file name and a test is run to |
| // determine if the process is alive. If the process is not alive, |
| // any stale file resources are removed. |
| // |
| static void cleanup_sharedmem_resources(const char* dirname) { |
| |
| // open the user temp directory |
| DIR* dirp = os::opendir(dirname); |
| |
| if (dirp == NULL) { |
| // directory doesn't exist, so there is nothing to cleanup |
| return; |
| } |
| |
| if (!is_directory_secure(dirname)) { |
| // the directory is not secure, don't attempt any cleanup |
| os::closedir(dirp); |
| return; |
| } |
| |
| // for each entry in the directory that matches the expected file |
| // name pattern, determine if the file resources are stale and if |
| // so, remove the file resources. Note, instrumented HotSpot processes |
| // for this user may start and/or terminate during this search and |
| // remove or create new files in this directory. The behavior of this |
| // loop under these conditions is dependent upon the implementation of |
| // opendir/readdir. |
| // |
| struct dirent* entry; |
| char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname), mtInternal); |
| errno = 0; |
| while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) { |
| |
| int pid = filename_to_pid(entry->d_name); |
| |
| if (pid == 0) { |
| |
| if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) { |
| |
| // attempt to remove all unexpected files, except "." and ".." |
| remove_file(dirname, entry->d_name); |
| } |
| |
| errno = 0; |
| continue; |
| } |
| |
| // we now have a file name that converts to a valid integer |
| // that could represent a process id . if this process id |
| // matches the current process id or the process is not running, |
| // then remove the stale file resources. |
| // |
| // process liveness is detected by checking the exit status |
| // of the process. if the process id is valid and the exit status |
| // indicates that it is still running, the file file resources |
| // are not removed. If the process id is invalid, or if we don't |
| // have permissions to check the process status, or if the process |
| // id is valid and the process has terminated, the the file resources |
| // are assumed to be stale and are removed. |
| // |
| if (pid == os::current_process_id() || !is_alive(pid)) { |
| |
| // we can only remove the file resources. Any mapped views |
| // of the file can only be unmapped by the processes that |
| // opened those views and the file mapping object will not |
| // get removed until all views are unmapped. |
| // |
| remove_file(dirname, entry->d_name); |
| } |
| errno = 0; |
| } |
| os::closedir(dirp); |
| FREE_C_HEAP_ARRAY(char, dbuf); |
| } |
| |
| // create a file mapping object with the requested name, and size |
| // from the file represented by the given Handle object |
| // |
| static HANDLE create_file_mapping(const char* name, HANDLE fh, LPSECURITY_ATTRIBUTES fsa, size_t size) { |
| |
| DWORD lowSize = (DWORD)size; |
| DWORD highSize = 0; |
| HANDLE fmh = NULL; |
| |
| // Create a file mapping object with the given name. This function |
| // will grow the file to the specified size. |
| // |
| fmh = CreateFileMapping( |
| fh, /* HANDLE file handle for backing store */ |
| fsa, /* LPSECURITY_ATTRIBUTES Not inheritable */ |
| PAGE_READWRITE, /* DWORD protections */ |
| highSize, /* DWORD High word of max size */ |
| lowSize, /* DWORD Low word of max size */ |
| name); /* LPCTSTR name for object */ |
| |
| if (fmh == NULL) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("CreateFileMapping failed, lasterror = %d\n", GetLastError()); |
| } |
| return NULL; |
| } |
| |
| if (GetLastError() == ERROR_ALREADY_EXISTS) { |
| |
| // a stale file mapping object was encountered. This object may be |
| // owned by this or some other user and cannot be removed until |
| // the other processes either exit or close their mapping objects |
| // and/or mapped views of this mapping object. |
| // |
| if (PrintMiscellaneous && Verbose) { |
| warning("file mapping already exists, lasterror = %d\n", GetLastError()); |
| } |
| |
| CloseHandle(fmh); |
| return NULL; |
| } |
| |
| return fmh; |
| } |
| |
| |
| // method to free the given security descriptor and the contained |
| // access control list. |
| // |
| static void free_security_desc(PSECURITY_DESCRIPTOR pSD) { |
| |
| BOOL success, exists, isdefault; |
| PACL pACL; |
| |
| if (pSD != NULL) { |
| |
| // get the access control list from the security descriptor |
| success = GetSecurityDescriptorDacl(pSD, &exists, &pACL, &isdefault); |
| |
| // if an ACL existed and it was not a default acl, then it must |
| // be an ACL we enlisted. free the resources. |
| // |
| if (success && exists && pACL != NULL && !isdefault) { |
| FREE_C_HEAP_ARRAY(char, pACL); |
| } |
| |
| // free the security descriptor |
| FREE_C_HEAP_ARRAY(char, pSD); |
| } |
| } |
| |
| // method to free up a security attributes structure and any |
| // contained security descriptors and ACL |
| // |
| static void free_security_attr(LPSECURITY_ATTRIBUTES lpSA) { |
| |
| if (lpSA != NULL) { |
| // free the contained security descriptor and the ACL |
| free_security_desc(lpSA->lpSecurityDescriptor); |
| lpSA->lpSecurityDescriptor = NULL; |
| |
| // free the security attributes structure |
| FREE_C_HEAP_ARRAY(char, lpSA); |
| } |
| } |
| |
| // get the user SID for the process indicated by the process handle |
| // |
| static PSID get_user_sid(HANDLE hProcess) { |
| |
| HANDLE hAccessToken; |
| PTOKEN_USER token_buf = NULL; |
| DWORD rsize = 0; |
| |
| if (hProcess == NULL) { |
| return NULL; |
| } |
| |
| // get the process token |
| if (!OpenProcessToken(hProcess, TOKEN_READ, &hAccessToken)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("OpenProcessToken failure: lasterror = %d \n", GetLastError()); |
| } |
| return NULL; |
| } |
| |
| // determine the size of the token structured needed to retrieve |
| // the user token information from the access token. |
| // |
| if (!GetTokenInformation(hAccessToken, TokenUser, NULL, rsize, &rsize)) { |
| DWORD lasterror = GetLastError(); |
| if (lasterror != ERROR_INSUFFICIENT_BUFFER) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("GetTokenInformation failure: lasterror = %d," |
| " rsize = %d\n", lasterror, rsize); |
| } |
| CloseHandle(hAccessToken); |
| return NULL; |
| } |
| } |
| |
| token_buf = (PTOKEN_USER) NEW_C_HEAP_ARRAY(char, rsize, mtInternal); |
| |
| // get the user token information |
| if (!GetTokenInformation(hAccessToken, TokenUser, token_buf, rsize, &rsize)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("GetTokenInformation failure: lasterror = %d," |
| " rsize = %d\n", GetLastError(), rsize); |
| } |
| FREE_C_HEAP_ARRAY(char, token_buf); |
| CloseHandle(hAccessToken); |
| return NULL; |
| } |
| |
| DWORD nbytes = GetLengthSid(token_buf->User.Sid); |
| PSID pSID = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); |
| |
| if (!CopySid(nbytes, pSID, token_buf->User.Sid)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("GetTokenInformation failure: lasterror = %d," |
| " rsize = %d\n", GetLastError(), rsize); |
| } |
| FREE_C_HEAP_ARRAY(char, token_buf); |
| FREE_C_HEAP_ARRAY(char, pSID); |
| CloseHandle(hAccessToken); |
| return NULL; |
| } |
| |
| // close the access token. |
| CloseHandle(hAccessToken); |
| FREE_C_HEAP_ARRAY(char, token_buf); |
| |
| return pSID; |
| } |
| |
| // structure used to consolidate access control entry information |
| // |
| typedef struct ace_data { |
| PSID pSid; // SID of the ACE |
| DWORD mask; // mask for the ACE |
| } ace_data_t; |
| |
| |
| // method to add an allow access control entry with the access rights |
| // indicated in mask for the principal indicated in SID to the given |
| // security descriptor. Much of the DACL handling was adapted from |
| // the example provided here: |
| // http://support.microsoft.com/kb/102102/EN-US/ |
| // |
| |
| static bool add_allow_aces(PSECURITY_DESCRIPTOR pSD, |
| ace_data_t aces[], int ace_count) { |
| PACL newACL = NULL; |
| PACL oldACL = NULL; |
| |
| if (pSD == NULL) { |
| return false; |
| } |
| |
| BOOL exists, isdefault; |
| |
| // retrieve any existing access control list. |
| if (!GetSecurityDescriptorDacl(pSD, &exists, &oldACL, &isdefault)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("GetSecurityDescriptor failure: lasterror = %d \n", |
| GetLastError()); |
| } |
| return false; |
| } |
| |
| // get the size of the DACL |
| ACL_SIZE_INFORMATION aclinfo; |
| |
| // GetSecurityDescriptorDacl may return true value for exists (lpbDaclPresent) |
| // while oldACL is NULL for some case. |
| if (oldACL == NULL) { |
| exists = FALSE; |
| } |
| |
| if (exists) { |
| if (!GetAclInformation(oldACL, &aclinfo, |
| sizeof(ACL_SIZE_INFORMATION), |
| AclSizeInformation)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("GetAclInformation failure: lasterror = %d \n", GetLastError()); |
| return false; |
| } |
| } |
| } else { |
| aclinfo.AceCount = 0; // assume NULL DACL |
| aclinfo.AclBytesFree = 0; |
| aclinfo.AclBytesInUse = sizeof(ACL); |
| } |
| |
| // compute the size needed for the new ACL |
| // initial size of ACL is sum of the following: |
| // * size of ACL structure. |
| // * size of each ACE structure that ACL is to contain minus the sid |
| // sidStart member (DWORD) of the ACE. |
| // * length of the SID that each ACE is to contain. |
| DWORD newACLsize = aclinfo.AclBytesInUse + |
| (sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD)) * ace_count; |
| for (int i = 0; i < ace_count; i++) { |
| assert(aces[i].pSid != 0, "pSid should not be 0"); |
| newACLsize += GetLengthSid(aces[i].pSid); |
| } |
| |
| // create the new ACL |
| newACL = (PACL) NEW_C_HEAP_ARRAY(char, newACLsize, mtInternal); |
| |
| if (!InitializeAcl(newACL, newACLsize, ACL_REVISION)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| |
| unsigned int ace_index = 0; |
| // copy any existing ACEs from the old ACL (if any) to the new ACL. |
| if (aclinfo.AceCount != 0) { |
| while (ace_index < aclinfo.AceCount) { |
| LPVOID ace; |
| if (!GetAce(oldACL, ace_index, &ace)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| if (((ACCESS_ALLOWED_ACE *)ace)->Header.AceFlags && INHERITED_ACE) { |
| // this is an inherited, allowed ACE; break from loop so we can |
| // add the new access allowed, non-inherited ACE in the correct |
| // position, immediately following all non-inherited ACEs. |
| break; |
| } |
| |
| // determine if the SID of this ACE matches any of the SIDs |
| // for which we plan to set ACEs. |
| int matches = 0; |
| for (int i = 0; i < ace_count; i++) { |
| if (EqualSid(aces[i].pSid, &(((ACCESS_ALLOWED_ACE *)ace)->SidStart))) { |
| matches++; |
| break; |
| } |
| } |
| |
| // if there are no SID matches, then add this existing ACE to the new ACL |
| if (matches == 0) { |
| if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace, |
| ((PACE_HEADER)ace)->AceSize)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("AddAce failure: lasterror = %d \n", GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| } |
| ace_index++; |
| } |
| } |
| |
| // add the passed-in access control entries to the new ACL |
| for (int i = 0; i < ace_count; i++) { |
| if (!AddAccessAllowedAce(newACL, ACL_REVISION, |
| aces[i].mask, aces[i].pSid)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("AddAccessAllowedAce failure: lasterror = %d \n", |
| GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| } |
| |
| // now copy the rest of the inherited ACEs from the old ACL |
| if (aclinfo.AceCount != 0) { |
| // picking up at ace_index, where we left off in the |
| // previous ace_index loop |
| while (ace_index < aclinfo.AceCount) { |
| LPVOID ace; |
| if (!GetAce(oldACL, ace_index, &ace)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace, |
| ((PACE_HEADER)ace)->AceSize)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("AddAce failure: lasterror = %d \n", GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| ace_index++; |
| } |
| } |
| |
| // add the new ACL to the security descriptor. |
| if (!SetSecurityDescriptorDacl(pSD, TRUE, newACL, FALSE)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("SetSecurityDescriptorDacl failure:" |
| " lasterror = %d \n", GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| |
| // if running on windows 2000 or later, set the automatic inheritance |
| // control flags. |
| SetSecurityDescriptorControlFnPtr _SetSecurityDescriptorControl; |
| _SetSecurityDescriptorControl = (SetSecurityDescriptorControlFnPtr) |
| GetProcAddress(GetModuleHandle(TEXT("advapi32.dll")), |
| "SetSecurityDescriptorControl"); |
| |
| if (_SetSecurityDescriptorControl != NULL) { |
| // We do not want to further propagate inherited DACLs, so making them |
| // protected prevents that. |
| if (!_SetSecurityDescriptorControl(pSD, SE_DACL_PROTECTED, |
| SE_DACL_PROTECTED)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("SetSecurityDescriptorControl failure:" |
| " lasterror = %d \n", GetLastError()); |
| } |
| FREE_C_HEAP_ARRAY(char, newACL); |
| return false; |
| } |
| } |
| // Note, the security descriptor maintains a reference to the newACL, not |
| // a copy of it. Therefore, the newACL is not freed here. It is freed when |
| // the security descriptor containing its reference is freed. |
| // |
| return true; |
| } |
| |
| // method to create a security attributes structure, which contains a |
| // security descriptor and an access control list comprised of 0 or more |
| // access control entries. The method take an array of ace_data structures |
| // that indicate the ACE to be added to the security descriptor. |
| // |
| // the caller must free the resources associated with the security |
| // attributes structure created by this method by calling the |
| // free_security_attr() method. |
| // |
| static LPSECURITY_ATTRIBUTES make_security_attr(ace_data_t aces[], int count) { |
| |
| // allocate space for a security descriptor |
| PSECURITY_DESCRIPTOR pSD = (PSECURITY_DESCRIPTOR) |
| NEW_C_HEAP_ARRAY(char, SECURITY_DESCRIPTOR_MIN_LENGTH, mtInternal); |
| |
| // initialize the security descriptor |
| if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("InitializeSecurityDescriptor failure: " |
| "lasterror = %d \n", GetLastError()); |
| } |
| free_security_desc(pSD); |
| return NULL; |
| } |
| |
| // add the access control entries |
| if (!add_allow_aces(pSD, aces, count)) { |
| free_security_desc(pSD); |
| return NULL; |
| } |
| |
| // allocate and initialize the security attributes structure and |
| // return it to the caller. |
| // |
| LPSECURITY_ATTRIBUTES lpSA = (LPSECURITY_ATTRIBUTES) |
| NEW_C_HEAP_ARRAY(char, sizeof(SECURITY_ATTRIBUTES), mtInternal); |
| lpSA->nLength = sizeof(SECURITY_ATTRIBUTES); |
| lpSA->lpSecurityDescriptor = pSD; |
| lpSA->bInheritHandle = FALSE; |
| |
| return(lpSA); |
| } |
| |
| // method to create a security attributes structure with a restrictive |
| // access control list that creates a set access rights for the user/owner |
| // of the securable object and a separate set access rights for everyone else. |
| // also provides for full access rights for the administrator group. |
| // |
| // the caller must free the resources associated with the security |
| // attributes structure created by this method by calling the |
| // free_security_attr() method. |
| // |
| |
| static LPSECURITY_ATTRIBUTES make_user_everybody_admin_security_attr( |
| DWORD umask, DWORD emask, DWORD amask) { |
| |
| ace_data_t aces[3]; |
| |
| // initialize the user ace data |
| aces[0].pSid = get_user_sid(GetCurrentProcess()); |
| aces[0].mask = umask; |
| |
| if (aces[0].pSid == 0) |
| return NULL; |
| |
| // get the well known SID for BUILTIN\Administrators |
| PSID administratorsSid = NULL; |
| SID_IDENTIFIER_AUTHORITY SIDAuthAdministrators = SECURITY_NT_AUTHORITY; |
| |
| if (!AllocateAndInitializeSid( &SIDAuthAdministrators, 2, |
| SECURITY_BUILTIN_DOMAIN_RID, |
| DOMAIN_ALIAS_RID_ADMINS, |
| 0, 0, 0, 0, 0, 0, &administratorsSid)) { |
| |
| if (PrintMiscellaneous && Verbose) { |
| warning("AllocateAndInitializeSid failure: " |
| "lasterror = %d \n", GetLastError()); |
| } |
| return NULL; |
| } |
| |
| // initialize the ace data for administrator group |
| aces[1].pSid = administratorsSid; |
| aces[1].mask = amask; |
| |
| // get the well known SID for the universal Everybody |
| PSID everybodySid = NULL; |
| SID_IDENTIFIER_AUTHORITY SIDAuthEverybody = SECURITY_WORLD_SID_AUTHORITY; |
| |
| if (!AllocateAndInitializeSid( &SIDAuthEverybody, 1, SECURITY_WORLD_RID, |
| 0, 0, 0, 0, 0, 0, 0, &everybodySid)) { |
| |
| if (PrintMiscellaneous && Verbose) { |
| warning("AllocateAndInitializeSid failure: " |
| "lasterror = %d \n", GetLastError()); |
| } |
| return NULL; |
| } |
| |
| // initialize the ace data for everybody else. |
| aces[2].pSid = everybodySid; |
| aces[2].mask = emask; |
| |
| // create a security attributes structure with access control |
| // entries as initialized above. |
| LPSECURITY_ATTRIBUTES lpSA = make_security_attr(aces, 3); |
| FREE_C_HEAP_ARRAY(char, aces[0].pSid); |
| FreeSid(everybodySid); |
| FreeSid(administratorsSid); |
| return(lpSA); |
| } |
| |
| |
| // method to create the security attributes structure for restricting |
| // access to the user temporary directory. |
| // |
| // the caller must free the resources associated with the security |
| // attributes structure created by this method by calling the |
| // free_security_attr() method. |
| // |
| static LPSECURITY_ATTRIBUTES make_tmpdir_security_attr() { |
| |
| // create full access rights for the user/owner of the directory |
| // and read-only access rights for everybody else. This is |
| // effectively equivalent to UNIX 755 permissions on a directory. |
| // |
| DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_ALL_ACCESS; |
| DWORD emask = GENERIC_READ | FILE_LIST_DIRECTORY | FILE_TRAVERSE; |
| DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; |
| |
| return make_user_everybody_admin_security_attr(umask, emask, amask); |
| } |
| |
| // method to create the security attributes structure for restricting |
| // access to the shared memory backing store file. |
| // |
| // the caller must free the resources associated with the security |
| // attributes structure created by this method by calling the |
| // free_security_attr() method. |
| // |
| static LPSECURITY_ATTRIBUTES make_file_security_attr() { |
| |
| // create extensive access rights for the user/owner of the file |
| // and attribute read-only access rights for everybody else. This |
| // is effectively equivalent to UNIX 600 permissions on a file. |
| // |
| DWORD umask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; |
| DWORD emask = STANDARD_RIGHTS_READ | FILE_READ_ATTRIBUTES | |
| FILE_READ_EA | FILE_LIST_DIRECTORY | FILE_TRAVERSE; |
| DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; |
| |
| return make_user_everybody_admin_security_attr(umask, emask, amask); |
| } |
| |
| // method to create the security attributes structure for restricting |
| // access to the name shared memory file mapping object. |
| // |
| // the caller must free the resources associated with the security |
| // attributes structure created by this method by calling the |
| // free_security_attr() method. |
| // |
| static LPSECURITY_ATTRIBUTES make_smo_security_attr() { |
| |
| // create extensive access rights for the user/owner of the shared |
| // memory object and attribute read-only access rights for everybody |
| // else. This is effectively equivalent to UNIX 600 permissions on |
| // on the shared memory object. |
| // |
| DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_MAP_ALL_ACCESS; |
| DWORD emask = STANDARD_RIGHTS_READ; // attributes only |
| DWORD amask = STANDARD_RIGHTS_ALL | FILE_MAP_ALL_ACCESS; |
| |
| return make_user_everybody_admin_security_attr(umask, emask, amask); |
| } |
| |
| // make the user specific temporary directory |
| // |
| static bool make_user_tmp_dir(const char* dirname) { |
| |
| |
| LPSECURITY_ATTRIBUTES pDirSA = make_tmpdir_security_attr(); |
| if (pDirSA == NULL) { |
| return false; |
| } |
| |
| |
| // create the directory with the given security attributes |
| if (!CreateDirectory(dirname, pDirSA)) { |
| DWORD lasterror = GetLastError(); |
| if (lasterror == ERROR_ALREADY_EXISTS) { |
| // The directory already exists and was probably created by another |
| // JVM instance. However, this could also be the result of a |
| // deliberate symlink. Verify that the existing directory is safe. |
| // |
| if (!is_directory_secure(dirname)) { |
| // directory is not secure |
| if (PrintMiscellaneous && Verbose) { |
| warning("%s directory is insecure\n", dirname); |
| } |
| return false; |
| } |
| // The administrator should be able to delete this directory. |
| // But the directory created by previous version of JVM may not |
| // have permission for administrators to delete this directory. |
| // So add full permission to the administrator. Also setting new |
| // DACLs might fix the corrupted the DACLs. |
| SECURITY_INFORMATION secInfo = DACL_SECURITY_INFORMATION; |
| if (!SetFileSecurity(dirname, secInfo, pDirSA->lpSecurityDescriptor)) { |
| if (PrintMiscellaneous && Verbose) { |
| lasterror = GetLastError(); |
| warning("SetFileSecurity failed for %s directory. lasterror %d \n", |
| dirname, lasterror); |
| } |
| } |
| } |
| else { |
| if (PrintMiscellaneous && Verbose) { |
| warning("CreateDirectory failed: %d\n", GetLastError()); |
| } |
| return false; |
| } |
| } |
| |
| // free the security attributes structure |
| free_security_attr(pDirSA); |
| |
| return true; |
| } |
| |
| // create the shared memory resources |
| // |
| // This function creates the shared memory resources. This includes |
| // the backing store file and the file mapping shared memory object. |
| // |
| static HANDLE create_sharedmem_resources(const char* dirname, const char* filename, const char* objectname, size_t size) { |
| |
| HANDLE fh = INVALID_HANDLE_VALUE; |
| HANDLE fmh = NULL; |
| |
| |
| // create the security attributes for the backing store file |
| LPSECURITY_ATTRIBUTES lpFileSA = make_file_security_attr(); |
| if (lpFileSA == NULL) { |
| return NULL; |
| } |
| |
| // create the security attributes for the shared memory object |
| LPSECURITY_ATTRIBUTES lpSmoSA = make_smo_security_attr(); |
| if (lpSmoSA == NULL) { |
| free_security_attr(lpFileSA); |
| return NULL; |
| } |
| |
| // create the user temporary directory |
| if (!make_user_tmp_dir(dirname)) { |
| // could not make/find the directory or the found directory |
| // was not secure |
| return NULL; |
| } |
| |
| // Create the file - the FILE_FLAG_DELETE_ON_CLOSE flag allows the |
| // file to be deleted by the last process that closes its handle to |
| // the file. This is important as the apis do not allow a terminating |
| // JVM being monitored by another process to remove the file name. |
| // |
| fh = CreateFile( |
| filename, /* LPCTSTR file name */ |
| |
| GENERIC_READ|GENERIC_WRITE, /* DWORD desired access */ |
| FILE_SHARE_DELETE|FILE_SHARE_READ, /* DWORD share mode, future READONLY |
| * open operations allowed |
| */ |
| lpFileSA, /* LPSECURITY security attributes */ |
| CREATE_ALWAYS, /* DWORD creation disposition |
| * create file, if it already |
| * exists, overwrite it. |
| */ |
| FILE_FLAG_DELETE_ON_CLOSE, /* DWORD flags and attributes */ |
| |
| NULL); /* HANDLE template file access */ |
| |
| free_security_attr(lpFileSA); |
| |
| if (fh == INVALID_HANDLE_VALUE) { |
| DWORD lasterror = GetLastError(); |
| if (PrintMiscellaneous && Verbose) { |
| warning("could not create file %s: %d\n", filename, lasterror); |
| } |
| return NULL; |
| } |
| |
| // try to create the file mapping |
| fmh = create_file_mapping(objectname, fh, lpSmoSA, size); |
| |
| free_security_attr(lpSmoSA); |
| |
| if (fmh == NULL) { |
| // closing the file handle here will decrement the reference count |
| // on the file. When all processes accessing the file close their |
| // handle to it, the reference count will decrement to 0 and the |
| // OS will delete the file. These semantics are requested by the |
| // FILE_FLAG_DELETE_ON_CLOSE flag in CreateFile call above. |
| CloseHandle(fh); |
| fh = NULL; |
| return NULL; |
| } else { |
| // We created the file mapping, but rarely the size of the |
| // backing store file is reported as zero (0) which can cause |
| // failures when trying to use the hsperfdata file. |
| struct stat statbuf; |
| int ret_code = ::stat(filename, &statbuf); |
| if (ret_code == OS_ERR) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("Could not get status information from file %s: %s\n", |
| filename, os::strerror(errno)); |
| } |
| CloseHandle(fmh); |
| CloseHandle(fh); |
| fh = NULL; |
| fmh = NULL; |
| return NULL; |
| } |
| |
| // We could always call FlushFileBuffers() but the Microsoft |
| // docs indicate that it is considered expensive so we only |
| // call it when we observe the size as zero (0). |
| if (statbuf.st_size == 0 && FlushFileBuffers(fh) != TRUE) { |
| DWORD lasterror = GetLastError(); |
| if (PrintMiscellaneous && Verbose) { |
| warning("could not flush file %s: %d\n", filename, lasterror); |
| } |
| CloseHandle(fmh); |
| CloseHandle(fh); |
| fh = NULL; |
| fmh = NULL; |
| return NULL; |
| } |
| } |
| |
| // the file has been successfully created and the file mapping |
| // object has been created. |
| sharedmem_fileHandle = fh; |
| sharedmem_fileName = os::strdup(filename); |
| |
| return fmh; |
| } |
| |
| // open the shared memory object for the given vmid. |
| // |
| static HANDLE open_sharedmem_object(const char* objectname, DWORD ofm_access, TRAPS) { |
| |
| HANDLE fmh; |
| |
| // open the file mapping with the requested mode |
| fmh = OpenFileMapping( |
| ofm_access, /* DWORD access mode */ |
| FALSE, /* BOOL inherit flag - Do not allow inherit */ |
| objectname); /* name for object */ |
| |
| if (fmh == NULL) { |
| DWORD lasterror = GetLastError(); |
| if (PrintMiscellaneous && Verbose) { |
| warning("OpenFileMapping failed for shared memory object %s:" |
| " lasterror = %d\n", objectname, lasterror); |
| } |
| THROW_MSG_(vmSymbols::java_lang_IllegalArgumentException(), |
| err_msg("Could not open PerfMemory, error %d", lasterror), |
| INVALID_HANDLE_VALUE); |
| } |
| |
| return fmh;; |
| } |
| |
| // create a named shared memory region |
| // |
| // On Win32, a named shared memory object has a name space that |
| // is independent of the file system name space. Shared memory object, |
| // or more precisely, file mapping objects, provide no mechanism to |
| // inquire the size of the memory region. There is also no api to |
| // enumerate the memory regions for various processes. |
| // |
| // This implementation utilizes the shared memory name space in parallel |
| // with the file system name space. This allows us to determine the |
| // size of the shared memory region from the size of the file and it |
| // allows us to provide a common, file system based name space for |
| // shared memory across platforms. |
| // |
| static char* mapping_create_shared(size_t size) { |
| |
| void *mapAddress; |
| int vmid = os::current_process_id(); |
| |
| // get the name of the user associated with this process |
| char* user = get_user_name(); |
| |
| if (user == NULL) { |
| return NULL; |
| } |
| |
| // construct the name of the user specific temporary directory |
| char* dirname = get_user_tmp_dir(user); |
| |
| // check that the file system is secure - i.e. it supports ACLs. |
| if (!is_filesystem_secure(dirname)) { |
| FREE_C_HEAP_ARRAY(char, dirname); |
| FREE_C_HEAP_ARRAY(char, user); |
| return NULL; |
| } |
| |
| // create the names of the backing store files and for the |
| // share memory object. |
| // |
| char* filename = get_sharedmem_filename(dirname, vmid); |
| char* objectname = get_sharedmem_objectname(user, vmid); |
| |
| // cleanup any stale shared memory resources |
| cleanup_sharedmem_resources(dirname); |
| |
| assert(((size != 0) && (size % os::vm_page_size() == 0)), |
| "unexpected PerfMemry region size"); |
| |
| FREE_C_HEAP_ARRAY(char, user); |
| |
| // create the shared memory resources |
| sharedmem_fileMapHandle = |
| create_sharedmem_resources(dirname, filename, objectname, size); |
| |
| FREE_C_HEAP_ARRAY(char, filename); |
| FREE_C_HEAP_ARRAY(char, objectname); |
| FREE_C_HEAP_ARRAY(char, dirname); |
| |
| if (sharedmem_fileMapHandle == NULL) { |
| return NULL; |
| } |
| |
| // map the file into the address space |
| mapAddress = MapViewOfFile( |
| sharedmem_fileMapHandle, /* HANDLE = file mapping object */ |
| FILE_MAP_ALL_ACCESS, /* DWORD access flags */ |
| 0, /* DWORD High word of offset */ |
| 0, /* DWORD Low word of offset */ |
| (DWORD)size); /* DWORD Number of bytes to map */ |
| |
| if (mapAddress == NULL) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("MapViewOfFile failed, lasterror = %d\n", GetLastError()); |
| } |
| CloseHandle(sharedmem_fileMapHandle); |
| sharedmem_fileMapHandle = NULL; |
| return NULL; |
| } |
| |
| // clear the shared memory region |
| (void)memset(mapAddress, '\0', size); |
| |
| // it does not go through os api, the operation has to record from here |
| MemTracker::record_virtual_memory_reserve_and_commit((address)mapAddress, |
| size, CURRENT_PC, mtInternal); |
| |
| return (char*) mapAddress; |
| } |
| |
| // this method deletes the file mapping object. |
| // |
| static void delete_file_mapping(char* addr, size_t size) { |
| |
| // cleanup the persistent shared memory resources. since DestroyJavaVM does |
| // not support unloading of the JVM, unmapping of the memory resource is not |
| // performed. The memory will be reclaimed by the OS upon termination of all |
| // processes mapping the resource. The file mapping handle and the file |
| // handle are closed here to expedite the remove of the file by the OS. The |
| // file is not removed directly because it was created with |
| // FILE_FLAG_DELETE_ON_CLOSE semantics and any attempt to remove it would |
| // be unsuccessful. |
| |
| // close the fileMapHandle. the file mapping will still be retained |
| // by the OS as long as any other JVM processes has an open file mapping |
| // handle or a mapped view of the file. |
| // |
| if (sharedmem_fileMapHandle != NULL) { |
| CloseHandle(sharedmem_fileMapHandle); |
| sharedmem_fileMapHandle = NULL; |
| } |
| |
| // close the file handle. This will decrement the reference count on the |
| // backing store file. When the reference count decrements to 0, the OS |
| // will delete the file. These semantics apply because the file was |
| // created with the FILE_FLAG_DELETE_ON_CLOSE flag. |
| // |
| if (sharedmem_fileHandle != INVALID_HANDLE_VALUE) { |
| CloseHandle(sharedmem_fileHandle); |
| sharedmem_fileHandle = INVALID_HANDLE_VALUE; |
| } |
| } |
| |
| // this method determines the size of the shared memory file |
| // |
| static size_t sharedmem_filesize(const char* filename, TRAPS) { |
| |
| struct stat statbuf; |
| |
| // get the file size |
| // |
| // on win95/98/me, _stat returns a file size of 0 bytes, but on |
| // winnt/2k the appropriate file size is returned. support for |
| // the sharable aspects of performance counters was abandonded |
| // on the non-nt win32 platforms due to this and other api |
| // inconsistencies |
| // |
| if (::stat(filename, &statbuf) == OS_ERR) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("stat %s failed: %s\n", filename, os::strerror(errno)); |
| } |
| THROW_MSG_0(vmSymbols::java_io_IOException(), |
| "Could not determine PerfMemory size"); |
| } |
| |
| if ((statbuf.st_size == 0) || (statbuf.st_size % os::vm_page_size() != 0)) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("unexpected file size: size = " SIZE_FORMAT "\n", |
| statbuf.st_size); |
| } |
| THROW_MSG_0(vmSymbols::java_lang_Exception(), |
| "Invalid PerfMemory size"); |
| } |
| |
| return statbuf.st_size; |
| } |
| |
| // this method opens a file mapping object and maps the object |
| // into the address space of the process |
| // |
| static void open_file_mapping(const char* user, int vmid, |
| PerfMemory::PerfMemoryMode mode, |
| char** addrp, size_t* sizep, TRAPS) { |
| |
| ResourceMark rm; |
| |
| void *mapAddress = 0; |
| size_t size = 0; |
| HANDLE fmh; |
| DWORD ofm_access; |
| DWORD mv_access; |
| const char* luser = NULL; |
| |
| if (mode == PerfMemory::PERF_MODE_RO) { |
| ofm_access = FILE_MAP_READ; |
| mv_access = FILE_MAP_READ; |
| } |
| else if (mode == PerfMemory::PERF_MODE_RW) { |
| #ifdef LATER |
| ofm_access = FILE_MAP_READ | FILE_MAP_WRITE; |
| mv_access = FILE_MAP_READ | FILE_MAP_WRITE; |
| #else |
| THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), |
| "Unsupported access mode"); |
| #endif |
| } |
| else { |
| THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), |
| "Illegal access mode"); |
| } |
| |
| // if a user name wasn't specified, then find the user name for |
| // the owner of the target vm. |
| if (user == NULL || strlen(user) == 0) { |
| luser = get_user_name(vmid); |
| } |
| else { |
| luser = user; |
| } |
| |
| if (luser == NULL) { |
| THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), |
| "Could not map vmid to user name"); |
| } |
| |
| // get the names for the resources for the target vm |
| char* dirname = get_user_tmp_dir(luser); |
| |
| // since we don't follow symbolic links when creating the backing |
| // store file, we also don't following them when attaching |
| // |
| if (!is_directory_secure(dirname)) { |
| FREE_C_HEAP_ARRAY(char, dirname); |
| if (luser != user) FREE_C_HEAP_ARRAY(char, luser); |
| THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), |
| "Process not found"); |
| } |
| |
| char* filename = get_sharedmem_filename(dirname, vmid); |
| char* objectname = get_sharedmem_objectname(luser, vmid); |
| |
| // copy heap memory to resource memory. the objectname and |
| // filename are passed to methods that may throw exceptions. |
| // using resource arrays for these names prevents the leaks |
| // that would otherwise occur. |
| // |
| char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); |
| char* robjectname = NEW_RESOURCE_ARRAY(char, strlen(objectname) + 1); |
| strcpy(rfilename, filename); |
| strcpy(robjectname, objectname); |
| |
| // free the c heap resources that are no longer needed |
| if (luser != user) FREE_C_HEAP_ARRAY(char, luser); |
| FREE_C_HEAP_ARRAY(char, dirname); |
| FREE_C_HEAP_ARRAY(char, filename); |
| FREE_C_HEAP_ARRAY(char, objectname); |
| |
| if (*sizep == 0) { |
| size = sharedmem_filesize(rfilename, CHECK); |
| } else { |
| size = *sizep; |
| } |
| |
| assert(size > 0, "unexpected size <= 0"); |
| |
| // Open the file mapping object with the given name |
| fmh = open_sharedmem_object(robjectname, ofm_access, CHECK); |
| |
| assert(fmh != INVALID_HANDLE_VALUE, "unexpected handle value"); |
| |
| // map the entire file into the address space |
| mapAddress = MapViewOfFile( |
| fmh, /* HANDLE Handle of file mapping object */ |
| mv_access, /* DWORD access flags */ |
| 0, /* DWORD High word of offset */ |
| 0, /* DWORD Low word of offset */ |
| size); /* DWORD Number of bytes to map */ |
| |
| if (mapAddress == NULL) { |
| if (PrintMiscellaneous && Verbose) { |
| warning("MapViewOfFile failed, lasterror = %d\n", GetLastError()); |
| } |
| CloseHandle(fmh); |
| THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), |
| "Could not map PerfMemory"); |
| } |
| |
| // it does not go through os api, the operation has to record from here |
| MemTracker::record_virtual_memory_reserve_and_commit((address)mapAddress, size, |
| CURRENT_PC, mtInternal); |
| |
| |
| *addrp = (char*)mapAddress; |
| *sizep = size; |
| |
| // File mapping object can be closed at this time without |
| // invalidating the mapped view of the file |
| CloseHandle(fmh); |
| |
| log_debug(perf, memops)("mapped " SIZE_FORMAT " bytes for vmid %d at " |
| INTPTR_FORMAT "\n", size, vmid, mapAddress); |
| } |
| |
| // this method unmaps the the mapped view of the the |
| // file mapping object. |
| // |
| static void remove_file_mapping(char* addr) { |
| |
| // the file mapping object was closed in open_file_mapping() |
| // after the file map view was created. We only need to |
| // unmap the file view here. |
| UnmapViewOfFile(addr); |
| } |
| |
| // create the PerfData memory region in shared memory. |
| static char* create_shared_memory(size_t size) { |
| |
| return mapping_create_shared(size); |
| } |
| |
| // release a named, shared memory region |
| // |
| void delete_shared_memory(char* addr, size_t size) { |
| |
| delete_file_mapping(addr, size); |
| } |
| |
| |
| |
| |
| // create the PerfData memory region |
| // |
| // This method creates the memory region used to store performance |
| // data for the JVM. The memory may be created in standard or |
| // shared memory. |
| // |
| void PerfMemory::create_memory_region(size_t size) { |
| |
| if (PerfDisableSharedMem) { |
| // do not share the memory for the performance data. |
| PerfDisableSharedMem = true; |
| _start = create_standard_memory(size); |
| } |
| else { |
| _start = create_shared_memory(size); |
| if (_start == NULL) { |
| |
| // creation of the shared memory region failed, attempt |
| // to create a contiguous, non-shared memory region instead. |
| // |
| if (PrintMiscellaneous && Verbose) { |
| warning("Reverting to non-shared PerfMemory region.\n"); |
| } |
| PerfDisableSharedMem = true; |
| _start = create_standard_memory(size); |
| } |
| } |
| |
| if (_start != NULL) _capacity = size; |
| |
| } |
| |
| // delete the PerfData memory region |
| // |
| // This method deletes the memory region used to store performance |
| // data for the JVM. The memory region indicated by the <address, size> |
| // tuple will be inaccessible after a call to this method. |
| // |
| void PerfMemory::delete_memory_region() { |
| |
| assert((start() != NULL && capacity() > 0), "verify proper state"); |
| |
| // If user specifies PerfDataSaveFile, it will save the performance data |
| // to the specified file name no matter whether PerfDataSaveToFile is specified |
| // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag |
| // -XX:+PerfDataSaveToFile. |
| if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { |
| save_memory_to_file(start(), capacity()); |
| } |
| |
| if (PerfDisableSharedMem) { |
| delete_standard_memory(start(), capacity()); |
| } |
| else { |
| delete_shared_memory(start(), capacity()); |
| } |
| } |
| |
| // attach to the PerfData memory region for another JVM |
| // |
| // This method returns an <address, size> tuple that points to |
| // a memory buffer that is kept reasonably synchronized with |
| // the PerfData memory region for the indicated JVM. This |
| // buffer may be kept in synchronization via shared memory |
| // or some other mechanism that keeps the buffer updated. |
| // |
| // If the JVM chooses not to support the attachability feature, |
| // this method should throw an UnsupportedOperation exception. |
| // |
| // This implementation utilizes named shared memory to map |
| // the indicated process's PerfData memory region into this JVMs |
| // address space. |
| // |
| void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, |
| char** addrp, size_t* sizep, TRAPS) { |
| |
| if (vmid == 0 || vmid == os::current_process_id()) { |
| *addrp = start(); |
| *sizep = capacity(); |
| return; |
| } |
| |
| open_file_mapping(user, vmid, mode, addrp, sizep, CHECK); |
| } |
| |
| // detach from the PerfData memory region of another JVM |
| // |
| // This method detaches the PerfData memory region of another |
| // JVM, specified as an <address, size> tuple of a buffer |
| // in this process's address space. This method may perform |
| // arbitrary actions to accomplish the detachment. The memory |
| // region specified by <address, size> will be inaccessible after |
| // a call to this method. |
| // |
| // If the JVM chooses not to support the attachability feature, |
| // this method should throw an UnsupportedOperation exception. |
| // |
| // This implementation utilizes named shared memory to detach |
| // the indicated process's PerfData memory region from this |
| // process's address space. |
| // |
| void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { |
| |
| assert(addr != 0, "address sanity check"); |
| assert(bytes > 0, "capacity sanity check"); |
| |
| if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { |
| // prevent accidental detachment of this process's PerfMemory region |
| return; |
| } |
| |
| if (MemTracker::tracking_level() > NMT_minimal) { |
| // it does not go through os api, the operation has to record from here |
| Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); |
| remove_file_mapping(addr); |
| tkr.record((address)addr, bytes); |
| } else { |
| remove_file_mapping(addr); |
| } |
| } |