--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/os/windows/vm/perfMemory_windows.cpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1776 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_perfMemory_windows.cpp.incl"
+
+#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)) {
+ 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, 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, 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, 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) + 2;
+ char* dirname = NEW_C_HEAP_ARRAY(char, nbytes);
+
+ // 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 occured.
+//
+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);
+ 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* oldest_user = NULL;
+ time_t oldest_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));
+ 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) + 1);
+ strcpy(usrdir_name, tmpdirname);
+ 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));
+ 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);
+
+ 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;
+ }
+
+ // compare and save filename with latest creation time
+ if (statbuf.st_size > 0 && statbuf.st_ctime > oldest_ctime) {
+
+ if (statbuf.st_ctime > oldest_ctime) {
+ char* user = strchr(dentry->d_name, '_') + 1;
+
+ if (oldest_user != NULL) FREE_C_HEAP_ARRAY(char, oldest_user);
+ oldest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1);
+
+ strcpy(oldest_user, user);
+ oldest_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(oldest_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);
+ _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);
+ _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);
+
+ 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, 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
+ 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));
+ 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);
+
+ // 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);
+
+ 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++) {
+ newACLsize += GetLengthSid(aces[i].pSid);
+ }
+
+ // create the new ACL
+ newACL = (PACL) NEW_C_HEAP_ARRAY(char, newACLsize);
+
+ 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 inheritence
+ // control flags.
+ SetSecurityDescriptorControlFnPtr _SetSecurityDescriptorControl;
+ _SetSecurityDescriptorControl = (SetSecurityDescriptorControlFnPtr)
+ GetProcAddress(GetModuleHandle(TEXT("advapi32.dll")),
+ "SetSecurityDescriptorControl");
+
+ if (_SetSecurityDescriptorControl != NULL) {
+ // We do not want to further propogate 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);
+
+ // 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));
+ 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;
+
+ // 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.
+ //
+ // the FILE_SHARE_DELETE share mode is valid only in winnt
+ //
+ fh = CreateFile(
+ filename, /* LPCTSTR file name */
+
+ GENERIC_READ|GENERIC_WRITE, /* DWORD desired access */
+
+ (os::win32::is_nt() ? FILE_SHARE_DELETE : 0)|
+ 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;
+ }
+
+ // the file has been successfully created and the file mapping
+ // object has been created.
+ sharedmem_fileHandle = fh;
+ sharedmem_fileName = 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) {
+ if (PrintMiscellaneous && Verbose) {
+ warning("OpenFileMapping failed for shared memory object %s:"
+ " lasterror = %d\n", objectname, GetLastError());
+ }
+ THROW_MSG_(vmSymbols::java_lang_Exception(),
+ "Could not open PerfMemory", 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)) {
+ 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);
+
+ 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, 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;
+ 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);
+ 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);
+ assert(size != 0, "unexpected size");
+ }
+
+ // 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");
+ }
+
+ *addrp = (char*)mapAddress;
+ *sizep = size;
+
+ // File mapping object can be closed at this time without
+ // invalidating the mapped view of the file
+ CloseHandle(fmh);
+
+ if (PerfTraceMemOps) {
+ tty->print("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 || !os::win32::is_nt()) {
+ // 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;
+ }
+
+ remove_file_mapping(addr);
+}
+
+char* PerfMemory::backing_store_filename() {
+ return sharedmem_fileName;
+}