/* * Copyright (c) 2001, 2011, 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 "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/perfMemory.hpp" #include "utilities/exceptions.hpp" #include #include #include #include #include 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) + 3; 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 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); 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_ 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)); 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); 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)); 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; } // 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); 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); _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++) { 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); 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); // 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; 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. // // 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; } 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 stat file %s: %d\n", filename, ret_code); } 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 = 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 // 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 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 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 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; }