perfMemory_windows.cpp revision 10627:1537c752a7f5
1170754Sdelphij/* 2170754Sdelphij * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved. 3170754Sdelphij * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4170754Sdelphij * 5170754Sdelphij * This code is free software; you can redistribute it and/or modify it 6170754Sdelphij * under the terms of the GNU General Public License version 2 only, as 7170754Sdelphij * published by the Free Software Foundation. 8170754Sdelphij * 9170754Sdelphij * This code is distributed in the hope that it will be useful, but WITHOUT 10170754Sdelphij * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11170754Sdelphij * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12170754Sdelphij * version 2 for more details (a copy is included in the LICENSE file that 13170754Sdelphij * accompanied this code). 14170754Sdelphij * 15170754Sdelphij * You should have received a copy of the GNU General Public License version 16170754Sdelphij * 2 along with this work; if not, write to the Free Software Foundation, 17170754Sdelphij * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18170754Sdelphij * 19170754Sdelphij * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20170754Sdelphij * or visit www.oracle.com if you need additional information or have any 21170754Sdelphij * questions. 22170754Sdelphij * 23170754Sdelphij */ 24170754Sdelphij 25170754Sdelphij#include "precompiled.hpp" 26170754Sdelphij#include "classfile/vmSymbols.hpp" 27170754Sdelphij#include "memory/allocation.inline.hpp" 28170754Sdelphij#include "memory/resourceArea.hpp" 29170754Sdelphij#include "oops/oop.inline.hpp" 30170754Sdelphij#include "os_windows.inline.hpp" 31170754Sdelphij#include "runtime/handles.inline.hpp" 32170754Sdelphij#include "runtime/os.hpp" 33170754Sdelphij#include "runtime/perfMemory.hpp" 34170754Sdelphij#include "services/memTracker.hpp" 35170754Sdelphij#include "utilities/exceptions.hpp" 36170754Sdelphij 37170754Sdelphij#include <windows.h> 38170754Sdelphij#include <sys/types.h> 39170754Sdelphij#include <sys/stat.h> 40170754Sdelphij#include <errno.h> 41170754Sdelphij#include <lmcons.h> 42170754Sdelphij 43170754Sdelphijtypedef BOOL (WINAPI *SetSecurityDescriptorControlFnPtr)( 44170754Sdelphij IN PSECURITY_DESCRIPTOR pSecurityDescriptor, 45170754Sdelphij IN SECURITY_DESCRIPTOR_CONTROL ControlBitsOfInterest, 46170754Sdelphij IN SECURITY_DESCRIPTOR_CONTROL ControlBitsToSet); 47170754Sdelphij 48170754Sdelphij// Standard Memory Implementation Details 49170754Sdelphij 50170754Sdelphij// create the PerfData memory region in standard memory. 51170754Sdelphij// 52170754Sdelphijstatic char* create_standard_memory(size_t size) { 53170754Sdelphij 54170754Sdelphij // allocate an aligned chuck of memory 55170754Sdelphij char* mapAddress = os::reserve_memory(size); 56170754Sdelphij 57170754Sdelphij if (mapAddress == NULL) { 58170754Sdelphij return NULL; 59170754Sdelphij } 60170754Sdelphij 61170754Sdelphij // commit memory 62170754Sdelphij if (!os::commit_memory(mapAddress, size, !ExecMem)) { 63170754Sdelphij if (PrintMiscellaneous && Verbose) { 64170754Sdelphij warning("Could not commit PerfData memory\n"); 65170754Sdelphij } 66170754Sdelphij os::release_memory(mapAddress, size); 67170754Sdelphij return NULL; 68170754Sdelphij } 69170754Sdelphij 70170754Sdelphij return mapAddress; 71170754Sdelphij} 72170754Sdelphij 73170754Sdelphij// delete the PerfData memory region 74170754Sdelphij// 75170754Sdelphijstatic void delete_standard_memory(char* addr, size_t size) { 76170754Sdelphij 77170754Sdelphij // there are no persistent external resources to cleanup for standard 78170754Sdelphij // memory. since DestroyJavaVM does not support unloading of the JVM, 79170754Sdelphij // cleanup of the memory resource is not performed. The memory will be 80170754Sdelphij // reclaimed by the OS upon termination of the process. 81170754Sdelphij // 82170754Sdelphij return; 83170754Sdelphij 84170754Sdelphij} 85170754Sdelphij 86170754Sdelphij// save the specified memory region to the given file 87170754Sdelphij// 88170754Sdelphijstatic void save_memory_to_file(char* addr, size_t size) { 89170754Sdelphij 90170754Sdelphij const char* destfile = PerfMemory::get_perfdata_file_path(); 91170754Sdelphij assert(destfile[0] != '\0', "invalid Perfdata file path"); 92170754Sdelphij 93170754Sdelphij int fd = ::_open(destfile, _O_BINARY|_O_CREAT|_O_WRONLY|_O_TRUNC, 94170754Sdelphij _S_IREAD|_S_IWRITE); 95170754Sdelphij 96170754Sdelphij if (fd == OS_ERR) { 97170754Sdelphij if (PrintMiscellaneous && Verbose) { 98170754Sdelphij warning("Could not create Perfdata save file: %s: %s\n", 99170754Sdelphij destfile, os::strerror(errno)); 100170754Sdelphij } 101170754Sdelphij } else { 102170754Sdelphij for (size_t remaining = size; remaining > 0;) { 103170754Sdelphij 104170754Sdelphij int nbytes = ::_write(fd, addr, (unsigned int)remaining); 105170754Sdelphij if (nbytes == OS_ERR) { 106170754Sdelphij if (PrintMiscellaneous && Verbose) { 107170754Sdelphij warning("Could not write Perfdata save file: %s: %s\n", 108170754Sdelphij destfile, os::strerror(errno)); 109170754Sdelphij } 110170754Sdelphij break; 111170754Sdelphij } 112170754Sdelphij 113170754Sdelphij remaining -= (size_t)nbytes; 114170754Sdelphij addr += nbytes; 115170754Sdelphij } 116170754Sdelphij 117170754Sdelphij int result = ::_close(fd); 118170754Sdelphij if (PrintMiscellaneous && Verbose) { 119170754Sdelphij if (result == OS_ERR) { 120170754Sdelphij warning("Could not close %s: %s\n", destfile, os::strerror(errno)); 121170754Sdelphij } 122170754Sdelphij } 123170754Sdelphij } 124170754Sdelphij 125170754Sdelphij FREE_C_HEAP_ARRAY(char, destfile); 126170754Sdelphij} 127170754Sdelphij 128170754Sdelphij// Shared Memory Implementation Details 129170754Sdelphij 130170754Sdelphij// Note: the win32 shared memory implementation uses two objects to represent 131170754Sdelphij// the shared memory: a windows kernel based file mapping object and a backing 132170754Sdelphij// store file. On windows, the name space for shared memory is a kernel 133170754Sdelphij// based name space that is disjoint from other win32 name spaces. Since Java 134170754Sdelphij// is unaware of this name space, a parallel file system based name space is 135170754Sdelphij// maintained, which provides a common file system based shared memory name 136170754Sdelphij// space across the supported platforms and one that Java apps can deal with 137170754Sdelphij// through simple file apis. 138170754Sdelphij// 139170754Sdelphij// For performance and resource cleanup reasons, it is recommended that the 140170754Sdelphij// user specific directory and the backing store file be stored in either a 141170754Sdelphij// RAM based file system or a local disk based file system. Network based 142170754Sdelphij// file systems are not recommended for performance reasons. In addition, 143170754Sdelphij// use of SMB network based file systems may result in unsuccesful cleanup 144170754Sdelphij// of the disk based resource on exit of the VM. The Windows TMP and TEMP 145170754Sdelphij// environement variables, as used by the GetTempPath() Win32 API (see 146170754Sdelphij// os::get_temp_directory() in os_win32.cpp), control the location of the 147170754Sdelphij// user specific directory and the shared memory backing store file. 148170754Sdelphij 149170754Sdelphijstatic HANDLE sharedmem_fileMapHandle = NULL; 150170754Sdelphijstatic HANDLE sharedmem_fileHandle = INVALID_HANDLE_VALUE; 151170754Sdelphijstatic char* sharedmem_fileName = NULL; 152170754Sdelphij 153170754Sdelphij// return the user specific temporary directory name. 154170754Sdelphij// 155170754Sdelphij// the caller is expected to free the allocated memory. 156170754Sdelphij// 157170754Sdelphijstatic char* get_user_tmp_dir(const char* user) { 158170754Sdelphij 159170754Sdelphij const char* tmpdir = os::get_temp_directory(); 160170754Sdelphij const char* perfdir = PERFDATA_NAME; 161170754Sdelphij size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3; 162170754Sdelphij char* dirname = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); 163170754Sdelphij 164170754Sdelphij // construct the path name to user specific tmp directory 165170754Sdelphij _snprintf(dirname, nbytes, "%s\\%s_%s", tmpdir, perfdir, user); 166170754Sdelphij 167170754Sdelphij return dirname; 168170754Sdelphij} 169170754Sdelphij 170170754Sdelphij// convert the given file name into a process id. if the file 171170754Sdelphij// does not meet the file naming constraints, return 0. 172170754Sdelphij// 173170754Sdelphijstatic int filename_to_pid(const char* filename) { 174170754Sdelphij 175170754Sdelphij // a filename that doesn't begin with a digit is not a 176170754Sdelphij // candidate for conversion. 177170754Sdelphij // 178170754Sdelphij if (!isdigit(*filename)) { 179170754Sdelphij return 0; 180170754Sdelphij } 181170754Sdelphij 182170754Sdelphij // check if file name can be converted to an integer without 183170754Sdelphij // any leftover characters. 184170754Sdelphij // 185170754Sdelphij char* remainder = NULL; 186170754Sdelphij errno = 0; 187170754Sdelphij int pid = (int)strtol(filename, &remainder, 10); 188170754Sdelphij 189170754Sdelphij if (errno != 0) { 190170754Sdelphij return 0; 191170754Sdelphij } 192170754Sdelphij 193170754Sdelphij // check for left over characters. If any, then the filename is 194170754Sdelphij // not a candidate for conversion. 195170754Sdelphij // 196170754Sdelphij if (remainder != NULL && *remainder != '\0') { 197170754Sdelphij return 0; 198170754Sdelphij } 199170754Sdelphij 200170754Sdelphij // successful conversion, return the pid 201170754Sdelphij return pid; 202170754Sdelphij} 203170754Sdelphij 204170754Sdelphij// check if the given path is considered a secure directory for 205170754Sdelphij// the backing store files. Returns true if the directory exists 206170754Sdelphij// and is considered a secure location. Returns false if the path 207170754Sdelphij// is a symbolic link or if an error occurred. 208170754Sdelphij// 209170754Sdelphijstatic bool is_directory_secure(const char* path) { 210170754Sdelphij 211170754Sdelphij DWORD fa; 212170754Sdelphij 213170754Sdelphij fa = GetFileAttributes(path); 214170754Sdelphij if (fa == 0xFFFFFFFF) { 215170754Sdelphij DWORD lasterror = GetLastError(); 216170754Sdelphij if (lasterror == ERROR_FILE_NOT_FOUND) { 217170754Sdelphij return false; 218170754Sdelphij } 219170754Sdelphij else { 220170754Sdelphij // unexpected error, declare the path insecure 221170754Sdelphij if (PrintMiscellaneous && Verbose) { 222170754Sdelphij warning("could not get attributes for file %s: ", 223170754Sdelphij " lasterror = %d\n", path, lasterror); 224170754Sdelphij } 225170754Sdelphij return false; 226170754Sdelphij } 227170754Sdelphij } 228170754Sdelphij 229170754Sdelphij if (fa & FILE_ATTRIBUTE_REPARSE_POINT) { 230170754Sdelphij // we don't accept any redirection for the user specific directory 231170754Sdelphij // so declare the path insecure. This may be too conservative, 232170754Sdelphij // as some types of reparse points might be acceptable, but it 233170754Sdelphij // is probably more secure to avoid these conditions. 234170754Sdelphij // 235170754Sdelphij if (PrintMiscellaneous && Verbose) { 236170754Sdelphij warning("%s is a reparse point\n", path); 237170754Sdelphij } 238170754Sdelphij return false; 239170754Sdelphij } 240170754Sdelphij 241170754Sdelphij if (fa & FILE_ATTRIBUTE_DIRECTORY) { 242170754Sdelphij // this is the expected case. Since windows supports symbolic 243170754Sdelphij // links to directories only, not to files, there is no need 244170754Sdelphij // to check for open write permissions on the directory. If the 245170754Sdelphij // directory has open write permissions, any files deposited that 246170754Sdelphij // are not expected will be removed by the cleanup code. 247170754Sdelphij // 248170754Sdelphij return true; 249170754Sdelphij } 250170754Sdelphij else { 251170754Sdelphij // this is either a regular file or some other type of file, 252170754Sdelphij // any of which are unexpected and therefore insecure. 253170754Sdelphij // 254170754Sdelphij if (PrintMiscellaneous && Verbose) { 255170754Sdelphij warning("%s is not a directory, file attributes = " 256170754Sdelphij INTPTR_FORMAT "\n", path, fa); 257170754Sdelphij } 258170754Sdelphij return false; 259170754Sdelphij } 260170754Sdelphij} 261170754Sdelphij 262170754Sdelphij// return the user name for the owner of this process 263170754Sdelphij// 264170754Sdelphij// the caller is expected to free the allocated memory. 265170754Sdelphij// 266170754Sdelphijstatic char* get_user_name() { 267170754Sdelphij 268170754Sdelphij /* get the user name. This code is adapted from code found in 269170754Sdelphij * the jdk in src/windows/native/java/lang/java_props_md.c 270170754Sdelphij * java_props_md.c 1.29 02/02/06. According to the original 271170754Sdelphij * source, the call to GetUserName is avoided because of a resulting 272170754Sdelphij * increase in footprint of 100K. 273170754Sdelphij */ 274170754Sdelphij char* user = getenv("USERNAME"); 275170754Sdelphij char buf[UNLEN+1]; 276170754Sdelphij DWORD buflen = sizeof(buf); 277170754Sdelphij if (user == NULL || strlen(user) == 0) { 278170754Sdelphij if (GetUserName(buf, &buflen)) { 279170754Sdelphij user = buf; 280170754Sdelphij } 281170754Sdelphij else { 282170754Sdelphij return NULL; 283170754Sdelphij } 284170754Sdelphij } 285170754Sdelphij 286170754Sdelphij char* user_name = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal); 287170754Sdelphij strcpy(user_name, user); 288170754Sdelphij 289170754Sdelphij return user_name; 290170754Sdelphij} 291170754Sdelphij 292170754Sdelphij// return the name of the user that owns the process identified by vmid. 293170754Sdelphij// 294170754Sdelphij// This method uses a slow directory search algorithm to find the backing 295170754Sdelphij// store file for the specified vmid and returns the user name, as determined 296170754Sdelphij// by the user name suffix of the hsperfdata_<username> directory name. 297170754Sdelphij// 298170754Sdelphij// the caller is expected to free the allocated memory. 299170754Sdelphij// 300170754Sdelphijstatic char* get_user_name_slow(int vmid) { 301170754Sdelphij 302170754Sdelphij // directory search 303170754Sdelphij char* latest_user = NULL; 304170754Sdelphij time_t latest_ctime = 0; 305170754Sdelphij 306170754Sdelphij const char* tmpdirname = os::get_temp_directory(); 307170754Sdelphij 308170754Sdelphij DIR* tmpdirp = os::opendir(tmpdirname); 309170754Sdelphij 310170754Sdelphij if (tmpdirp == NULL) { 311170754Sdelphij return NULL; 312170754Sdelphij } 313170754Sdelphij 314170754Sdelphij // for each entry in the directory that matches the pattern hsperfdata_*, 315170754Sdelphij // open the directory and check if the file for the given vmid exists. 316170754Sdelphij // The file with the expected name and the latest creation date is used 317170754Sdelphij // to determine the user name for the process id. 318170754Sdelphij // 319170754Sdelphij struct dirent* dentry; 320170754Sdelphij char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname), mtInternal); 321170754Sdelphij errno = 0; 322170754Sdelphij while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) { 323170754Sdelphij 324170754Sdelphij // check if the directory entry is a hsperfdata file 325170754Sdelphij if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) { 326170754Sdelphij continue; 327170754Sdelphij } 328170754Sdelphij 329170754Sdelphij char* usrdir_name = NEW_C_HEAP_ARRAY(char, 330170754Sdelphij strlen(tmpdirname) + strlen(dentry->d_name) + 2, mtInternal); 331170754Sdelphij strcpy(usrdir_name, tmpdirname); 332170754Sdelphij strcat(usrdir_name, "\\"); 333170754Sdelphij strcat(usrdir_name, dentry->d_name); 334170754Sdelphij 335170754Sdelphij DIR* subdirp = os::opendir(usrdir_name); 336170754Sdelphij 337170754Sdelphij if (subdirp == NULL) { 338170754Sdelphij FREE_C_HEAP_ARRAY(char, usrdir_name); 339170754Sdelphij continue; 340170754Sdelphij } 341170754Sdelphij 342170754Sdelphij // Since we don't create the backing store files in directories 343170754Sdelphij // pointed to by symbolic links, we also don't follow them when 344170754Sdelphij // looking for the files. We check for a symbolic link after the 345170754Sdelphij // call to opendir in order to eliminate a small window where the 346170754Sdelphij // symlink can be exploited. 347170754Sdelphij // 348170754Sdelphij if (!is_directory_secure(usrdir_name)) { 349170754Sdelphij FREE_C_HEAP_ARRAY(char, usrdir_name); 350170754Sdelphij os::closedir(subdirp); 351170754Sdelphij continue; 352170754Sdelphij } 353170754Sdelphij 354170754Sdelphij struct dirent* udentry; 355170754Sdelphij char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name), mtInternal); 356170754Sdelphij errno = 0; 357170754Sdelphij while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) { 358170754Sdelphij 359170754Sdelphij if (filename_to_pid(udentry->d_name) == vmid) { 360170754Sdelphij struct stat statbuf; 361170754Sdelphij 362170754Sdelphij char* filename = NEW_C_HEAP_ARRAY(char, 363170754Sdelphij strlen(usrdir_name) + strlen(udentry->d_name) + 2, mtInternal); 364170754Sdelphij 365170754Sdelphij strcpy(filename, usrdir_name); 366170754Sdelphij strcat(filename, "\\"); 367170754Sdelphij strcat(filename, udentry->d_name); 368170754Sdelphij 369170754Sdelphij if (::stat(filename, &statbuf) == OS_ERR) { 370170754Sdelphij FREE_C_HEAP_ARRAY(char, filename); 371170754Sdelphij continue; 372170754Sdelphij } 373170754Sdelphij 374170754Sdelphij // skip over files that are not regular files. 375170754Sdelphij if ((statbuf.st_mode & S_IFMT) != S_IFREG) { 376170754Sdelphij FREE_C_HEAP_ARRAY(char, filename); 377170754Sdelphij continue; 378170754Sdelphij } 379170754Sdelphij 380170754Sdelphij // If we found a matching file with a newer creation time, then 381170754Sdelphij // save the user name. The newer creation time indicates that 382170754Sdelphij // we found a newer incarnation of the process associated with 383170754Sdelphij // vmid. Due to the way that Windows recycles pids and the fact 384170754Sdelphij // that we can't delete the file from the file system namespace 385170754Sdelphij // until last close, it is possible for there to be more than 386170754Sdelphij // one hsperfdata file with a name matching vmid (diff users). 387170754Sdelphij // 388170754Sdelphij // We no longer ignore hsperfdata files where (st_size == 0). 389170754Sdelphij // In this function, all we're trying to do is determine the 390170754Sdelphij // name of the user that owns the process associated with vmid 391170754Sdelphij // so the size doesn't matter. Very rarely, we have observed 392170754Sdelphij // hsperfdata files where (st_size == 0) and the st_size field 393170754Sdelphij // later becomes the expected value. 394170754Sdelphij // 395170754Sdelphij if (statbuf.st_ctime > latest_ctime) { 396170754Sdelphij char* user = strchr(dentry->d_name, '_') + 1; 397170754Sdelphij 398170754Sdelphij if (latest_user != NULL) FREE_C_HEAP_ARRAY(char, latest_user); 399170754Sdelphij latest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal); 400170754Sdelphij 401170754Sdelphij strcpy(latest_user, user); 402170754Sdelphij latest_ctime = statbuf.st_ctime; 403170754Sdelphij } 404170754Sdelphij 405170754Sdelphij FREE_C_HEAP_ARRAY(char, filename); 406170754Sdelphij } 407170754Sdelphij } 408170754Sdelphij os::closedir(subdirp); 409170754Sdelphij FREE_C_HEAP_ARRAY(char, udbuf); 410170754Sdelphij FREE_C_HEAP_ARRAY(char, usrdir_name); 411170754Sdelphij } 412170754Sdelphij os::closedir(tmpdirp); 413170754Sdelphij FREE_C_HEAP_ARRAY(char, tdbuf); 414170754Sdelphij 415170754Sdelphij return(latest_user); 416170754Sdelphij} 417170754Sdelphij 418170754Sdelphij// return the name of the user that owns the process identified by vmid. 419170754Sdelphij// 420170754Sdelphij// note: this method should only be used via the Perf native methods. 421170754Sdelphij// There are various costs to this method and limiting its use to the 422170754Sdelphij// Perf native methods limits the impact to monitoring applications only. 423170754Sdelphij// 424170754Sdelphijstatic char* get_user_name(int vmid) { 425170754Sdelphij 426170754Sdelphij // A fast implementation is not provided at this time. It's possible 427170754Sdelphij // to provide a fast process id to user name mapping function using 428170754Sdelphij // the win32 apis, but the default ACL for the process object only 429170754Sdelphij // allows processes with the same owner SID to acquire the process 430170754Sdelphij // handle (via OpenProcess(PROCESS_QUERY_INFORMATION)). It's possible 431170754Sdelphij // to have the JVM change the ACL for the process object to allow arbitrary 432170754Sdelphij // users to access the process handle and the process security token. 433170754Sdelphij // The security ramifications need to be studied before providing this 434170754Sdelphij // mechanism. 435170754Sdelphij // 436170754Sdelphij return get_user_name_slow(vmid); 437170754Sdelphij} 438170754Sdelphij 439170754Sdelphij// return the name of the shared memory file mapping object for the 440170754Sdelphij// named shared memory region for the given user name and vmid. 441170754Sdelphij// 442170754Sdelphij// The file mapping object's name is not the file name. It is a name 443170754Sdelphij// in a separate name space. 444170754Sdelphij// 445170754Sdelphij// the caller is expected to free the allocated memory. 446170754Sdelphij// 447170754Sdelphijstatic char *get_sharedmem_objectname(const char* user, int vmid) { 448170754Sdelphij 449170754Sdelphij // construct file mapping object's name, add 3 for two '_' and a 450170754Sdelphij // null terminator. 451170754Sdelphij int nbytes = (int)strlen(PERFDATA_NAME) + (int)strlen(user) + 3; 452170754Sdelphij 453170754Sdelphij // the id is converted to an unsigned value here because win32 allows 454170754Sdelphij // negative process ids. However, OpenFileMapping API complains 455170754Sdelphij // about a name containing a '-' characters. 456170754Sdelphij // 457170754Sdelphij nbytes += UINT_CHARS; 458170754Sdelphij char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); 459170754Sdelphij _snprintf(name, nbytes, "%s_%s_%u", PERFDATA_NAME, user, vmid); 460170754Sdelphij 461170754Sdelphij return name; 462170754Sdelphij} 463170754Sdelphij 464170754Sdelphij// return the file name of the backing store file for the named 465170754Sdelphij// shared memory region for the given user name and vmid. 466170754Sdelphij// 467170754Sdelphij// the caller is expected to free the allocated memory. 468170754Sdelphij// 469170754Sdelphijstatic char* get_sharedmem_filename(const char* dirname, int vmid) { 470170754Sdelphij 471170754Sdelphij // add 2 for the file separator and a null terminator. 472170754Sdelphij size_t nbytes = strlen(dirname) + UINT_CHARS + 2; 473170754Sdelphij 474170754Sdelphij char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); 475170754Sdelphij _snprintf(name, nbytes, "%s\\%d", dirname, vmid); 476170754Sdelphij 477170754Sdelphij return name; 478170754Sdelphij} 479170754Sdelphij 480170754Sdelphij// remove file 481170754Sdelphij// 482170754Sdelphij// this method removes the file with the given file name. 483170754Sdelphij// 484170754Sdelphij// Note: if the indicated file is on an SMB network file system, this 485170754Sdelphij// method may be unsuccessful in removing the file. 486170754Sdelphij// 487170754Sdelphijstatic void remove_file(const char* dirname, const char* filename) { 488170754Sdelphij 489170754Sdelphij size_t nbytes = strlen(dirname) + strlen(filename) + 2; 490170754Sdelphij char* path = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); 491170754Sdelphij 492170754Sdelphij strcpy(path, dirname); 493170754Sdelphij strcat(path, "\\"); 494170754Sdelphij strcat(path, filename); 495170754Sdelphij 496170754Sdelphij if (::unlink(path) == OS_ERR) { 497170754Sdelphij if (PrintMiscellaneous && Verbose) { 498170754Sdelphij if (errno != ENOENT) { 499170754Sdelphij warning("Could not unlink shared memory backing" 500170754Sdelphij " store file %s : %s\n", path, os::strerror(errno)); 501170754Sdelphij } 502170754Sdelphij } 503170754Sdelphij } 504170754Sdelphij 505170754Sdelphij FREE_C_HEAP_ARRAY(char, path); 506170754Sdelphij} 507170754Sdelphij 508170754Sdelphij// returns true if the process represented by pid is alive, otherwise 509170754Sdelphij// returns false. the validity of the result is only accurate if the 510170754Sdelphij// target process is owned by the same principal that owns this process. 511170754Sdelphij// this method should not be used if to test the status of an otherwise 512170754Sdelphij// arbitrary process unless it is know that this process has the appropriate 513170754Sdelphij// privileges to guarantee a result valid. 514170754Sdelphij// 515170754Sdelphijstatic bool is_alive(int pid) { 516170754Sdelphij 517170754Sdelphij HANDLE ph = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, pid); 518170754Sdelphij if (ph == NULL) { 519170754Sdelphij // the process does not exist. 520170754Sdelphij if (PrintMiscellaneous && Verbose) { 521170754Sdelphij DWORD lastError = GetLastError(); 522170754Sdelphij if (lastError != ERROR_INVALID_PARAMETER) { 523170754Sdelphij warning("OpenProcess failed: %d\n", GetLastError()); 524170754Sdelphij } 525170754Sdelphij } 526170754Sdelphij return false; 527170754Sdelphij } 528170754Sdelphij 529170754Sdelphij DWORD exit_status; 530170754Sdelphij if (!GetExitCodeProcess(ph, &exit_status)) { 531170754Sdelphij if (PrintMiscellaneous && Verbose) { 532170754Sdelphij warning("GetExitCodeProcess failed: %d\n", GetLastError()); 533170754Sdelphij } 534170754Sdelphij CloseHandle(ph); 535170754Sdelphij return false; 536170754Sdelphij } 537170754Sdelphij 538170754Sdelphij CloseHandle(ph); 539170754Sdelphij return (exit_status == STILL_ACTIVE) ? true : false; 540170754Sdelphij} 541170754Sdelphij 542170754Sdelphij// check if the file system is considered secure for the backing store files 543170754Sdelphij// 544170754Sdelphijstatic bool is_filesystem_secure(const char* path) { 545170754Sdelphij 546170754Sdelphij char root_path[MAX_PATH]; 547170754Sdelphij char fs_type[MAX_PATH]; 548170754Sdelphij 549170754Sdelphij if (PerfBypassFileSystemCheck) { 550170754Sdelphij if (PrintMiscellaneous && Verbose) { 551170754Sdelphij warning("bypassing file system criteria checks for %s\n", path); 552170754Sdelphij } 553170754Sdelphij return true; 554170754Sdelphij } 555170754Sdelphij 556170754Sdelphij char* first_colon = strchr((char *)path, ':'); 557170754Sdelphij if (first_colon == NULL) { 558170754Sdelphij if (PrintMiscellaneous && Verbose) { 559170754Sdelphij warning("expected device specifier in path: %s\n", path); 560170754Sdelphij } 561170754Sdelphij return false; 562170754Sdelphij } 563170754Sdelphij 564170754Sdelphij size_t len = (size_t)(first_colon - path); 565170754Sdelphij assert(len + 2 <= MAX_PATH, "unexpected device specifier length"); 566170754Sdelphij strncpy(root_path, path, len + 1); 567170754Sdelphij root_path[len + 1] = '\\'; 568170754Sdelphij root_path[len + 2] = '\0'; 569170754Sdelphij 570170754Sdelphij // check that we have something like "C:\" or "AA:\" 571170754Sdelphij assert(strlen(root_path) >= 3, "device specifier too short"); 572170754Sdelphij assert(strchr(root_path, ':') != NULL, "bad device specifier format"); 573170754Sdelphij assert(strchr(root_path, '\\') != NULL, "bad device specifier format"); 574170754Sdelphij 575170754Sdelphij DWORD maxpath; 576170754Sdelphij DWORD flags; 577170754Sdelphij 578170754Sdelphij if (!GetVolumeInformation(root_path, NULL, 0, NULL, &maxpath, 579170754Sdelphij &flags, fs_type, MAX_PATH)) { 580170754Sdelphij // we can't get information about the volume, so assume unsafe. 581170754Sdelphij if (PrintMiscellaneous && Verbose) { 582170754Sdelphij warning("could not get device information for %s: " 583170754Sdelphij " path = %s: lasterror = %d\n", 584170754Sdelphij root_path, path, GetLastError()); 585170754Sdelphij } 586170754Sdelphij return false; 587170754Sdelphij } 588170754Sdelphij 589170754Sdelphij if ((flags & FS_PERSISTENT_ACLS) == 0) { 590170754Sdelphij // file system doesn't support ACLs, declare file system unsafe 591170754Sdelphij if (PrintMiscellaneous && Verbose) { 592170754Sdelphij warning("file system type %s on device %s does not support" 593170754Sdelphij " ACLs\n", fs_type, root_path); 594170754Sdelphij } 595170754Sdelphij return false; 596170754Sdelphij } 597170754Sdelphij 598170754Sdelphij if ((flags & FS_VOL_IS_COMPRESSED) != 0) { 599170754Sdelphij // file system is compressed, declare file system unsafe 600170754Sdelphij if (PrintMiscellaneous && Verbose) { 601170754Sdelphij warning("file system type %s on device %s is compressed\n", 602170754Sdelphij fs_type, root_path); 603170754Sdelphij } 604170754Sdelphij return false; 605170754Sdelphij } 606170754Sdelphij 607170754Sdelphij return true; 608170754Sdelphij} 609170754Sdelphij 610170754Sdelphij// cleanup stale shared memory resources 611170754Sdelphij// 612170754Sdelphij// This method attempts to remove all stale shared memory files in 613170754Sdelphij// the named user temporary directory. It scans the named directory 614170754Sdelphij// for files matching the pattern ^$[0-9]*$. For each file found, the 615170754Sdelphij// process id is extracted from the file name and a test is run to 616170754Sdelphij// determine if the process is alive. If the process is not alive, 617170754Sdelphij// any stale file resources are removed. 618170754Sdelphij// 619170754Sdelphijstatic void cleanup_sharedmem_resources(const char* dirname) { 620170754Sdelphij 621170754Sdelphij // open the user temp directory 622170754Sdelphij DIR* dirp = os::opendir(dirname); 623170754Sdelphij 624170754Sdelphij if (dirp == NULL) { 625170754Sdelphij // directory doesn't exist, so there is nothing to cleanup 626170754Sdelphij return; 627170754Sdelphij } 628170754Sdelphij 629170754Sdelphij if (!is_directory_secure(dirname)) { 630170754Sdelphij // the directory is not secure, don't attempt any cleanup 631170754Sdelphij os::closedir(dirp); 632170754Sdelphij return; 633170754Sdelphij } 634170754Sdelphij 635170754Sdelphij // for each entry in the directory that matches the expected file 636170754Sdelphij // name pattern, determine if the file resources are stale and if 637170754Sdelphij // so, remove the file resources. Note, instrumented HotSpot processes 638170754Sdelphij // for this user may start and/or terminate during this search and 639170754Sdelphij // remove or create new files in this directory. The behavior of this 640170754Sdelphij // loop under these conditions is dependent upon the implementation of 641170754Sdelphij // opendir/readdir. 642170754Sdelphij // 643170754Sdelphij struct dirent* entry; 644170754Sdelphij char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname), mtInternal); 645170754Sdelphij errno = 0; 646170754Sdelphij while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) { 647170754Sdelphij 648170754Sdelphij int pid = filename_to_pid(entry->d_name); 649170754Sdelphij 650170754Sdelphij if (pid == 0) { 651170754Sdelphij 652170754Sdelphij if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) { 653170754Sdelphij 654170754Sdelphij // attempt to remove all unexpected files, except "." and ".." 655170754Sdelphij remove_file(dirname, entry->d_name); 656170754Sdelphij } 657170754Sdelphij 658170754Sdelphij errno = 0; 659170754Sdelphij continue; 660170754Sdelphij } 661170754Sdelphij 662170754Sdelphij // we now have a file name that converts to a valid integer 663170754Sdelphij // that could represent a process id . if this process id 664170754Sdelphij // matches the current process id or the process is not running, 665170754Sdelphij // then remove the stale file resources. 666170754Sdelphij // 667170754Sdelphij // process liveness is detected by checking the exit status 668170754Sdelphij // of the process. if the process id is valid and the exit status 669170754Sdelphij // indicates that it is still running, the file file resources 670170754Sdelphij // are not removed. If the process id is invalid, or if we don't 671170754Sdelphij // have permissions to check the process status, or if the process 672170754Sdelphij // id is valid and the process has terminated, the the file resources 673170754Sdelphij // are assumed to be stale and are removed. 674170754Sdelphij // 675170754Sdelphij if (pid == os::current_process_id() || !is_alive(pid)) { 676170754Sdelphij 677170754Sdelphij // we can only remove the file resources. Any mapped views 678170754Sdelphij // of the file can only be unmapped by the processes that 679170754Sdelphij // opened those views and the file mapping object will not 680170754Sdelphij // get removed until all views are unmapped. 681170754Sdelphij // 682170754Sdelphij remove_file(dirname, entry->d_name); 683170754Sdelphij } 684170754Sdelphij errno = 0; 685170754Sdelphij } 686170754Sdelphij os::closedir(dirp); 687170754Sdelphij FREE_C_HEAP_ARRAY(char, dbuf); 688170754Sdelphij} 689170754Sdelphij 690170754Sdelphij// create a file mapping object with the requested name, and size 691170754Sdelphij// from the file represented by the given Handle object 692170754Sdelphij// 693170754Sdelphijstatic HANDLE create_file_mapping(const char* name, HANDLE fh, LPSECURITY_ATTRIBUTES fsa, size_t size) { 694170754Sdelphij 695170754Sdelphij DWORD lowSize = (DWORD)size; 696170754Sdelphij DWORD highSize = 0; 697170754Sdelphij HANDLE fmh = NULL; 698170754Sdelphij 699170754Sdelphij // Create a file mapping object with the given name. This function 700170754Sdelphij // will grow the file to the specified size. 701170754Sdelphij // 702170754Sdelphij fmh = CreateFileMapping( 703170754Sdelphij fh, /* HANDLE file handle for backing store */ 704170754Sdelphij fsa, /* LPSECURITY_ATTRIBUTES Not inheritable */ 705170754Sdelphij PAGE_READWRITE, /* DWORD protections */ 706170754Sdelphij highSize, /* DWORD High word of max size */ 707170754Sdelphij lowSize, /* DWORD Low word of max size */ 708170754Sdelphij name); /* LPCTSTR name for object */ 709170754Sdelphij 710170754Sdelphij if (fmh == NULL) { 711170754Sdelphij if (PrintMiscellaneous && Verbose) { 712170754Sdelphij warning("CreateFileMapping failed, lasterror = %d\n", GetLastError()); 713170754Sdelphij } 714170754Sdelphij return NULL; 715170754Sdelphij } 716170754Sdelphij 717170754Sdelphij if (GetLastError() == ERROR_ALREADY_EXISTS) { 718170754Sdelphij 719170754Sdelphij // a stale file mapping object was encountered. This object may be 720170754Sdelphij // owned by this or some other user and cannot be removed until 721170754Sdelphij // the other processes either exit or close their mapping objects 722170754Sdelphij // and/or mapped views of this mapping object. 723170754Sdelphij // 724170754Sdelphij if (PrintMiscellaneous && Verbose) { 725170754Sdelphij warning("file mapping already exists, lasterror = %d\n", GetLastError()); 726170754Sdelphij } 727170754Sdelphij 728170754Sdelphij CloseHandle(fmh); 729170754Sdelphij return NULL; 730170754Sdelphij } 731170754Sdelphij 732170754Sdelphij return fmh; 733170754Sdelphij} 734170754Sdelphij 735170754Sdelphij 736170754Sdelphij// method to free the given security descriptor and the contained 737170754Sdelphij// access control list. 738170754Sdelphij// 739170754Sdelphijstatic void free_security_desc(PSECURITY_DESCRIPTOR pSD) { 740170754Sdelphij 741170754Sdelphij BOOL success, exists, isdefault; 742170754Sdelphij PACL pACL; 743170754Sdelphij 744170754Sdelphij if (pSD != NULL) { 745170754Sdelphij 746170754Sdelphij // get the access control list from the security descriptor 747170754Sdelphij success = GetSecurityDescriptorDacl(pSD, &exists, &pACL, &isdefault); 748170754Sdelphij 749170754Sdelphij // if an ACL existed and it was not a default acl, then it must 750170754Sdelphij // be an ACL we enlisted. free the resources. 751170754Sdelphij // 752170754Sdelphij if (success && exists && pACL != NULL && !isdefault) { 753170754Sdelphij FREE_C_HEAP_ARRAY(char, pACL); 754170754Sdelphij } 755170754Sdelphij 756170754Sdelphij // free the security descriptor 757170754Sdelphij FREE_C_HEAP_ARRAY(char, pSD); 758170754Sdelphij } 759170754Sdelphij} 760170754Sdelphij 761170754Sdelphij// method to free up a security attributes structure and any 762170754Sdelphij// contained security descriptors and ACL 763170754Sdelphij// 764170754Sdelphijstatic void free_security_attr(LPSECURITY_ATTRIBUTES lpSA) { 765170754Sdelphij 766170754Sdelphij if (lpSA != NULL) { 767170754Sdelphij // free the contained security descriptor and the ACL 768170754Sdelphij free_security_desc(lpSA->lpSecurityDescriptor); 769170754Sdelphij lpSA->lpSecurityDescriptor = NULL; 770170754Sdelphij 771170754Sdelphij // free the security attributes structure 772170754Sdelphij FREE_C_HEAP_ARRAY(char, lpSA); 773170754Sdelphij } 774170754Sdelphij} 775170754Sdelphij 776170754Sdelphij// get the user SID for the process indicated by the process handle 777170754Sdelphij// 778170754Sdelphijstatic PSID get_user_sid(HANDLE hProcess) { 779170754Sdelphij 780170754Sdelphij HANDLE hAccessToken; 781170754Sdelphij PTOKEN_USER token_buf = NULL; 782170754Sdelphij DWORD rsize = 0; 783170754Sdelphij 784170754Sdelphij if (hProcess == NULL) { 785170754Sdelphij return NULL; 786170754Sdelphij } 787170754Sdelphij 788170754Sdelphij // get the process token 789170754Sdelphij if (!OpenProcessToken(hProcess, TOKEN_READ, &hAccessToken)) { 790170754Sdelphij if (PrintMiscellaneous && Verbose) { 791170754Sdelphij warning("OpenProcessToken failure: lasterror = %d \n", GetLastError()); 792170754Sdelphij } 793170754Sdelphij return NULL; 794170754Sdelphij } 795170754Sdelphij 796170754Sdelphij // determine the size of the token structured needed to retrieve 797170754Sdelphij // the user token information from the access token. 798170754Sdelphij // 799170754Sdelphij if (!GetTokenInformation(hAccessToken, TokenUser, NULL, rsize, &rsize)) { 800170754Sdelphij DWORD lasterror = GetLastError(); 801170754Sdelphij if (lasterror != ERROR_INSUFFICIENT_BUFFER) { 802170754Sdelphij if (PrintMiscellaneous && Verbose) { 803170754Sdelphij warning("GetTokenInformation failure: lasterror = %d," 804170754Sdelphij " rsize = %d\n", lasterror, rsize); 805170754Sdelphij } 806170754Sdelphij CloseHandle(hAccessToken); 807170754Sdelphij return NULL; 808170754Sdelphij } 809170754Sdelphij } 810170754Sdelphij 811170754Sdelphij token_buf = (PTOKEN_USER) NEW_C_HEAP_ARRAY(char, rsize, mtInternal); 812170754Sdelphij 813170754Sdelphij // get the user token information 814170754Sdelphij if (!GetTokenInformation(hAccessToken, TokenUser, token_buf, rsize, &rsize)) { 815170754Sdelphij if (PrintMiscellaneous && Verbose) { 816170754Sdelphij warning("GetTokenInformation failure: lasterror = %d," 817170754Sdelphij " rsize = %d\n", GetLastError(), rsize); 818170754Sdelphij } 819170754Sdelphij FREE_C_HEAP_ARRAY(char, token_buf); 820170754Sdelphij CloseHandle(hAccessToken); 821170754Sdelphij return NULL; 822170754Sdelphij } 823170754Sdelphij 824170754Sdelphij DWORD nbytes = GetLengthSid(token_buf->User.Sid); 825170754Sdelphij PSID pSID = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal); 826170754Sdelphij 827170754Sdelphij if (!CopySid(nbytes, pSID, token_buf->User.Sid)) { 828170754Sdelphij if (PrintMiscellaneous && Verbose) { 829170754Sdelphij warning("GetTokenInformation failure: lasterror = %d," 830170754Sdelphij " rsize = %d\n", GetLastError(), rsize); 831170754Sdelphij } 832170754Sdelphij FREE_C_HEAP_ARRAY(char, token_buf); 833170754Sdelphij FREE_C_HEAP_ARRAY(char, pSID); 834170754Sdelphij CloseHandle(hAccessToken); 835170754Sdelphij return NULL; 836170754Sdelphij } 837170754Sdelphij 838170754Sdelphij // close the access token. 839170754Sdelphij CloseHandle(hAccessToken); 840170754Sdelphij FREE_C_HEAP_ARRAY(char, token_buf); 841170754Sdelphij 842170754Sdelphij return pSID; 843170754Sdelphij} 844170754Sdelphij 845170754Sdelphij// structure used to consolidate access control entry information 846170754Sdelphij// 847170754Sdelphijtypedef struct ace_data { 848170754Sdelphij PSID pSid; // SID of the ACE 849170754Sdelphij DWORD mask; // mask for the ACE 850170754Sdelphij} ace_data_t; 851170754Sdelphij 852170754Sdelphij 853170754Sdelphij// method to add an allow access control entry with the access rights 854170754Sdelphij// indicated in mask for the principal indicated in SID to the given 855170754Sdelphij// security descriptor. Much of the DACL handling was adapted from 856170754Sdelphij// the example provided here: 857170754Sdelphij// http://support.microsoft.com/kb/102102/EN-US/ 858170754Sdelphij// 859170754Sdelphij 860170764Sdelphijstatic bool add_allow_aces(PSECURITY_DESCRIPTOR pSD, 861170764Sdelphij ace_data_t aces[], int ace_count) { 862170764Sdelphij PACL newACL = NULL; 863170764Sdelphij PACL oldACL = NULL; 864170764Sdelphij 865170754Sdelphij if (pSD == NULL) { 866170754Sdelphij return false; 867170754Sdelphij } 868170754Sdelphij 869170754Sdelphij BOOL exists, isdefault; 870170754Sdelphij 871170754Sdelphij // retrieve any existing access control list. 872170754Sdelphij if (!GetSecurityDescriptorDacl(pSD, &exists, &oldACL, &isdefault)) { 873170754Sdelphij if (PrintMiscellaneous && Verbose) { 874170754Sdelphij warning("GetSecurityDescriptor failure: lasterror = %d \n", 875170754Sdelphij GetLastError()); 876170754Sdelphij } 877170754Sdelphij return false; 878170754Sdelphij } 879170754Sdelphij 880170754Sdelphij // get the size of the DACL 881170754Sdelphij ACL_SIZE_INFORMATION aclinfo; 882170754Sdelphij 883170754Sdelphij // GetSecurityDescriptorDacl may return true value for exists (lpbDaclPresent) 884170754Sdelphij // while oldACL is NULL for some case. 885170754Sdelphij if (oldACL == NULL) { 886170754Sdelphij exists = FALSE; 887170754Sdelphij } 888170754Sdelphij 889170754Sdelphij if (exists) { 890170754Sdelphij if (!GetAclInformation(oldACL, &aclinfo, 891170754Sdelphij sizeof(ACL_SIZE_INFORMATION), 892170754Sdelphij AclSizeInformation)) { 893170754Sdelphij if (PrintMiscellaneous && Verbose) { 894170754Sdelphij warning("GetAclInformation failure: lasterror = %d \n", GetLastError()); 895170754Sdelphij return false; 896170754Sdelphij } 897170754Sdelphij } 898170754Sdelphij } else { 899170754Sdelphij aclinfo.AceCount = 0; // assume NULL DACL 900170754Sdelphij aclinfo.AclBytesFree = 0; 901170754Sdelphij aclinfo.AclBytesInUse = sizeof(ACL); 902170754Sdelphij } 903170754Sdelphij 904170754Sdelphij // compute the size needed for the new ACL 905170754Sdelphij // initial size of ACL is sum of the following: 906170754Sdelphij // * size of ACL structure. 907170754Sdelphij // * size of each ACE structure that ACL is to contain minus the sid 908170754Sdelphij // sidStart member (DWORD) of the ACE. 909170754Sdelphij // * length of the SID that each ACE is to contain. 910170754Sdelphij DWORD newACLsize = aclinfo.AclBytesInUse + 911170754Sdelphij (sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD)) * ace_count; 912170754Sdelphij for (int i = 0; i < ace_count; i++) { 913170754Sdelphij assert(aces[i].pSid != 0, "pSid should not be 0"); 914170754Sdelphij newACLsize += GetLengthSid(aces[i].pSid); 915170754Sdelphij } 916170754Sdelphij 917170754Sdelphij // create the new ACL 918170754Sdelphij newACL = (PACL) NEW_C_HEAP_ARRAY(char, newACLsize, mtInternal); 919170754Sdelphij 920170764Sdelphij if (!InitializeAcl(newACL, newACLsize, ACL_REVISION)) { 921170764Sdelphij if (PrintMiscellaneous && Verbose) { 922170754Sdelphij warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); 923170754Sdelphij } 924170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 925170754Sdelphij return false; 926170754Sdelphij } 927170754Sdelphij 928170754Sdelphij unsigned int ace_index = 0; 929170754Sdelphij // copy any existing ACEs from the old ACL (if any) to the new ACL. 930170754Sdelphij if (aclinfo.AceCount != 0) { 931170754Sdelphij while (ace_index < aclinfo.AceCount) { 932170754Sdelphij LPVOID ace; 933170754Sdelphij if (!GetAce(oldACL, ace_index, &ace)) { 934170754Sdelphij if (PrintMiscellaneous && Verbose) { 935170764Sdelphij warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); 936170754Sdelphij } 937170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 938170754Sdelphij return false; 939170754Sdelphij } 940170754Sdelphij if (((ACCESS_ALLOWED_ACE *)ace)->Header.AceFlags && INHERITED_ACE) { 941170754Sdelphij // this is an inherited, allowed ACE; break from loop so we can 942170754Sdelphij // add the new access allowed, non-inherited ACE in the correct 943170754Sdelphij // position, immediately following all non-inherited ACEs. 944170754Sdelphij break; 945170754Sdelphij } 946170754Sdelphij 947170754Sdelphij // determine if the SID of this ACE matches any of the SIDs 948170754Sdelphij // for which we plan to set ACEs. 949170754Sdelphij int matches = 0; 950170754Sdelphij for (int i = 0; i < ace_count; i++) { 951170754Sdelphij if (EqualSid(aces[i].pSid, &(((ACCESS_ALLOWED_ACE *)ace)->SidStart))) { 952170754Sdelphij matches++; 953170754Sdelphij break; 954170754Sdelphij } 955170754Sdelphij } 956170754Sdelphij 957170754Sdelphij // if there are no SID matches, then add this existing ACE to the new ACL 958170754Sdelphij if (matches == 0) { 959170754Sdelphij if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace, 960170754Sdelphij ((PACE_HEADER)ace)->AceSize)) { 961170754Sdelphij if (PrintMiscellaneous && Verbose) { 962170754Sdelphij warning("AddAce failure: lasterror = %d \n", GetLastError()); 963170754Sdelphij } 964170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 965170754Sdelphij return false; 966170754Sdelphij } 967170754Sdelphij } 968170754Sdelphij ace_index++; 969170754Sdelphij } 970170754Sdelphij } 971170754Sdelphij 972170754Sdelphij // add the passed-in access control entries to the new ACL 973170764Sdelphij for (int i = 0; i < ace_count; i++) { 974170754Sdelphij if (!AddAccessAllowedAce(newACL, ACL_REVISION, 975170754Sdelphij aces[i].mask, aces[i].pSid)) { 976170754Sdelphij if (PrintMiscellaneous && Verbose) { 977170764Sdelphij warning("AddAccessAllowedAce failure: lasterror = %d \n", 978170754Sdelphij GetLastError()); 979170754Sdelphij } 980170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 981170754Sdelphij return false; 982170754Sdelphij } 983170754Sdelphij } 984170754Sdelphij 985170754Sdelphij // now copy the rest of the inherited ACEs from the old ACL 986170754Sdelphij if (aclinfo.AceCount != 0) { 987170754Sdelphij // picking up at ace_index, where we left off in the 988170754Sdelphij // previous ace_index loop 989170754Sdelphij while (ace_index < aclinfo.AceCount) { 990170754Sdelphij LPVOID ace; 991170754Sdelphij if (!GetAce(oldACL, ace_index, &ace)) { 992170754Sdelphij if (PrintMiscellaneous && Verbose) { 993170754Sdelphij warning("InitializeAcl failure: lasterror = %d \n", GetLastError()); 994170754Sdelphij } 995170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 996170754Sdelphij return false; 997170754Sdelphij } 998170754Sdelphij if (!AddAce(newACL, ACL_REVISION, MAXDWORD, ace, 999170754Sdelphij ((PACE_HEADER)ace)->AceSize)) { 1000170754Sdelphij if (PrintMiscellaneous && Verbose) { 1001170754Sdelphij warning("AddAce failure: lasterror = %d \n", GetLastError()); 1002170754Sdelphij } 1003170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 1004170754Sdelphij return false; 1005170754Sdelphij } 1006170754Sdelphij ace_index++; 1007170754Sdelphij } 1008170754Sdelphij } 1009170754Sdelphij 1010170754Sdelphij // add the new ACL to the security descriptor. 1011170754Sdelphij if (!SetSecurityDescriptorDacl(pSD, TRUE, newACL, FALSE)) { 1012170754Sdelphij if (PrintMiscellaneous && Verbose) { 1013170754Sdelphij warning("SetSecurityDescriptorDacl failure:" 1014170754Sdelphij " lasterror = %d \n", GetLastError()); 1015170754Sdelphij } 1016170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 1017170754Sdelphij return false; 1018170764Sdelphij } 1019170754Sdelphij 1020170754Sdelphij // if running on windows 2000 or later, set the automatic inheritance 1021170754Sdelphij // control flags. 1022170754Sdelphij SetSecurityDescriptorControlFnPtr _SetSecurityDescriptorControl; 1023170754Sdelphij _SetSecurityDescriptorControl = (SetSecurityDescriptorControlFnPtr) 1024170754Sdelphij GetProcAddress(GetModuleHandle(TEXT("advapi32.dll")), 1025170754Sdelphij "SetSecurityDescriptorControl"); 1026170754Sdelphij 1027170754Sdelphij if (_SetSecurityDescriptorControl != NULL) { 1028170754Sdelphij // We do not want to further propagate inherited DACLs, so making them 1029170754Sdelphij // protected prevents that. 1030170754Sdelphij if (!_SetSecurityDescriptorControl(pSD, SE_DACL_PROTECTED, 1031170754Sdelphij SE_DACL_PROTECTED)) { 1032170754Sdelphij if (PrintMiscellaneous && Verbose) { 1033170754Sdelphij warning("SetSecurityDescriptorControl failure:" 1034170754Sdelphij " lasterror = %d \n", GetLastError()); 1035170754Sdelphij } 1036170754Sdelphij FREE_C_HEAP_ARRAY(char, newACL); 1037170754Sdelphij return false; 1038170754Sdelphij } 1039170754Sdelphij } 1040170764Sdelphij // Note, the security descriptor maintains a reference to the newACL, not 1041170754Sdelphij // a copy of it. Therefore, the newACL is not freed here. It is freed when 1042170754Sdelphij // the security descriptor containing its reference is freed. 1043170754Sdelphij // 1044170754Sdelphij return true; 1045170754Sdelphij} 1046170754Sdelphij 1047170754Sdelphij// method to create a security attributes structure, which contains a 1048170754Sdelphij// security descriptor and an access control list comprised of 0 or more 1049170754Sdelphij// access control entries. The method take an array of ace_data structures 1050170754Sdelphij// that indicate the ACE to be added to the security descriptor. 1051170754Sdelphij// 1052170754Sdelphij// the caller must free the resources associated with the security 1053170754Sdelphij// attributes structure created by this method by calling the 1054170754Sdelphij// free_security_attr() method. 1055170754Sdelphij// 1056170754Sdelphijstatic LPSECURITY_ATTRIBUTES make_security_attr(ace_data_t aces[], int count) { 1057170754Sdelphij 1058170754Sdelphij // allocate space for a security descriptor 1059170754Sdelphij PSECURITY_DESCRIPTOR pSD = (PSECURITY_DESCRIPTOR) 1060170754Sdelphij NEW_C_HEAP_ARRAY(char, SECURITY_DESCRIPTOR_MIN_LENGTH, mtInternal); 1061170754Sdelphij 1062170754Sdelphij // initialize the security descriptor 1063170754Sdelphij if (!InitializeSecurityDescriptor(pSD, SECURITY_DESCRIPTOR_REVISION)) { 1064170754Sdelphij if (PrintMiscellaneous && Verbose) { 1065170754Sdelphij warning("InitializeSecurityDescriptor failure: " 1066170754Sdelphij "lasterror = %d \n", GetLastError()); 1067170754Sdelphij } 1068170754Sdelphij free_security_desc(pSD); 1069170754Sdelphij return NULL; 1070170754Sdelphij } 1071170754Sdelphij 1072170754Sdelphij // add the access control entries 1073170754Sdelphij if (!add_allow_aces(pSD, aces, count)) { 1074170754Sdelphij free_security_desc(pSD); 1075170754Sdelphij return NULL; 1076170754Sdelphij } 1077170754Sdelphij 1078170754Sdelphij // allocate and initialize the security attributes structure and 1079170754Sdelphij // return it to the caller. 1080170754Sdelphij // 1081170754Sdelphij LPSECURITY_ATTRIBUTES lpSA = (LPSECURITY_ATTRIBUTES) 1082170754Sdelphij NEW_C_HEAP_ARRAY(char, sizeof(SECURITY_ATTRIBUTES), mtInternal); 1083170754Sdelphij lpSA->nLength = sizeof(SECURITY_ATTRIBUTES); 1084170754Sdelphij lpSA->lpSecurityDescriptor = pSD; 1085170754Sdelphij lpSA->bInheritHandle = FALSE; 1086170754Sdelphij 1087170754Sdelphij return(lpSA); 1088170754Sdelphij} 1089170754Sdelphij 1090170754Sdelphij// method to create a security attributes structure with a restrictive 1091170754Sdelphij// access control list that creates a set access rights for the user/owner 1092170754Sdelphij// of the securable object and a separate set access rights for everyone else. 1093170754Sdelphij// also provides for full access rights for the administrator group. 1094170754Sdelphij// 1095170754Sdelphij// the caller must free the resources associated with the security 1096170754Sdelphij// attributes structure created by this method by calling the 1097170754Sdelphij// free_security_attr() method. 1098170754Sdelphij// 1099170754Sdelphij 1100170754Sdelphijstatic LPSECURITY_ATTRIBUTES make_user_everybody_admin_security_attr( 1101170754Sdelphij DWORD umask, DWORD emask, DWORD amask) { 1102170754Sdelphij 1103170754Sdelphij ace_data_t aces[3]; 1104170754Sdelphij 1105170754Sdelphij // initialize the user ace data 1106170754Sdelphij aces[0].pSid = get_user_sid(GetCurrentProcess()); 1107170754Sdelphij aces[0].mask = umask; 1108170754Sdelphij 1109170754Sdelphij if (aces[0].pSid == 0) 1110170754Sdelphij return NULL; 1111170754Sdelphij 1112170754Sdelphij // get the well known SID for BUILTIN\Administrators 1113170754Sdelphij PSID administratorsSid = NULL; 1114170754Sdelphij SID_IDENTIFIER_AUTHORITY SIDAuthAdministrators = SECURITY_NT_AUTHORITY; 1115170754Sdelphij 1116170754Sdelphij if (!AllocateAndInitializeSid( &SIDAuthAdministrators, 2, 1117170754Sdelphij SECURITY_BUILTIN_DOMAIN_RID, 1118170754Sdelphij DOMAIN_ALIAS_RID_ADMINS, 1119170754Sdelphij 0, 0, 0, 0, 0, 0, &administratorsSid)) { 1120170754Sdelphij 1121170754Sdelphij if (PrintMiscellaneous && Verbose) { 1122170754Sdelphij warning("AllocateAndInitializeSid failure: " 1123170754Sdelphij "lasterror = %d \n", GetLastError()); 1124170754Sdelphij } 1125170754Sdelphij return NULL; 1126170754Sdelphij } 1127170754Sdelphij 1128170754Sdelphij // initialize the ace data for administrator group 1129170754Sdelphij aces[1].pSid = administratorsSid; 1130170754Sdelphij aces[1].mask = amask; 1131170754Sdelphij 1132170754Sdelphij // get the well known SID for the universal Everybody 1133170754Sdelphij PSID everybodySid = NULL; 1134170754Sdelphij SID_IDENTIFIER_AUTHORITY SIDAuthEverybody = SECURITY_WORLD_SID_AUTHORITY; 1135170754Sdelphij 1136170754Sdelphij if (!AllocateAndInitializeSid( &SIDAuthEverybody, 1, SECURITY_WORLD_RID, 1137170754Sdelphij 0, 0, 0, 0, 0, 0, 0, &everybodySid)) { 1138170754Sdelphij 1139170754Sdelphij if (PrintMiscellaneous && Verbose) { 1140170754Sdelphij warning("AllocateAndInitializeSid failure: " 1141170754Sdelphij "lasterror = %d \n", GetLastError()); 1142170754Sdelphij } 1143170754Sdelphij return NULL; 1144170754Sdelphij } 1145170754Sdelphij 1146170754Sdelphij // initialize the ace data for everybody else. 1147170754Sdelphij aces[2].pSid = everybodySid; 1148170754Sdelphij aces[2].mask = emask; 1149170754Sdelphij 1150170754Sdelphij // create a security attributes structure with access control 1151170754Sdelphij // entries as initialized above. 1152170754Sdelphij LPSECURITY_ATTRIBUTES lpSA = make_security_attr(aces, 3); 1153170754Sdelphij FREE_C_HEAP_ARRAY(char, aces[0].pSid); 1154170754Sdelphij FreeSid(everybodySid); 1155170754Sdelphij FreeSid(administratorsSid); 1156170754Sdelphij return(lpSA); 1157170754Sdelphij} 1158170754Sdelphij 1159170754Sdelphij 1160170754Sdelphij// method to create the security attributes structure for restricting 1161170754Sdelphij// access to the user temporary directory. 1162170754Sdelphij// 1163170754Sdelphij// the caller must free the resources associated with the security 1164170754Sdelphij// attributes structure created by this method by calling the 1165170754Sdelphij// free_security_attr() method. 1166170754Sdelphij// 1167170754Sdelphijstatic LPSECURITY_ATTRIBUTES make_tmpdir_security_attr() { 1168170754Sdelphij 1169170754Sdelphij // create full access rights for the user/owner of the directory 1170170754Sdelphij // and read-only access rights for everybody else. This is 1171170754Sdelphij // effectively equivalent to UNIX 755 permissions on a directory. 1172170754Sdelphij // 1173170754Sdelphij DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_ALL_ACCESS; 1174170754Sdelphij DWORD emask = GENERIC_READ | FILE_LIST_DIRECTORY | FILE_TRAVERSE; 1175170754Sdelphij DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; 1176170754Sdelphij 1177170754Sdelphij return make_user_everybody_admin_security_attr(umask, emask, amask); 1178170754Sdelphij} 1179170754Sdelphij 1180170754Sdelphij// method to create the security attributes structure for restricting 1181170754Sdelphij// access to the shared memory backing store file. 1182170754Sdelphij// 1183170754Sdelphij// the caller must free the resources associated with the security 1184170754Sdelphij// attributes structure created by this method by calling the 1185170754Sdelphij// free_security_attr() method. 1186170754Sdelphij// 1187170754Sdelphijstatic LPSECURITY_ATTRIBUTES make_file_security_attr() { 1188170754Sdelphij 1189170754Sdelphij // create extensive access rights for the user/owner of the file 1190170754Sdelphij // and attribute read-only access rights for everybody else. This 1191170754Sdelphij // is effectively equivalent to UNIX 600 permissions on a file. 1192170754Sdelphij // 1193170754Sdelphij DWORD umask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; 1194170754Sdelphij DWORD emask = STANDARD_RIGHTS_READ | FILE_READ_ATTRIBUTES | 1195170754Sdelphij FILE_READ_EA | FILE_LIST_DIRECTORY | FILE_TRAVERSE; 1196170754Sdelphij DWORD amask = STANDARD_RIGHTS_ALL | FILE_ALL_ACCESS; 1197170754Sdelphij 1198170754Sdelphij return make_user_everybody_admin_security_attr(umask, emask, amask); 1199170754Sdelphij} 1200170754Sdelphij 1201170754Sdelphij// method to create the security attributes structure for restricting 1202170754Sdelphij// access to the name shared memory file mapping object. 1203170754Sdelphij// 1204170754Sdelphij// the caller must free the resources associated with the security 1205170754Sdelphij// attributes structure created by this method by calling the 1206170754Sdelphij// free_security_attr() method. 1207170754Sdelphij// 1208170754Sdelphijstatic LPSECURITY_ATTRIBUTES make_smo_security_attr() { 1209170754Sdelphij 1210170754Sdelphij // create extensive access rights for the user/owner of the shared 1211170754Sdelphij // memory object and attribute read-only access rights for everybody 1212170754Sdelphij // else. This is effectively equivalent to UNIX 600 permissions on 1213170754Sdelphij // on the shared memory object. 1214170754Sdelphij // 1215170754Sdelphij DWORD umask = STANDARD_RIGHTS_REQUIRED | FILE_MAP_ALL_ACCESS; 1216170754Sdelphij DWORD emask = STANDARD_RIGHTS_READ; // attributes only 1217170754Sdelphij DWORD amask = STANDARD_RIGHTS_ALL | FILE_MAP_ALL_ACCESS; 1218170754Sdelphij 1219170754Sdelphij return make_user_everybody_admin_security_attr(umask, emask, amask); 1220170754Sdelphij} 1221170754Sdelphij 1222170754Sdelphij// make the user specific temporary directory 1223170754Sdelphij// 1224170754Sdelphijstatic bool make_user_tmp_dir(const char* dirname) { 1225170754Sdelphij 1226170754Sdelphij 1227 LPSECURITY_ATTRIBUTES pDirSA = make_tmpdir_security_attr(); 1228 if (pDirSA == NULL) { 1229 return false; 1230 } 1231 1232 1233 // create the directory with the given security attributes 1234 if (!CreateDirectory(dirname, pDirSA)) { 1235 DWORD lasterror = GetLastError(); 1236 if (lasterror == ERROR_ALREADY_EXISTS) { 1237 // The directory already exists and was probably created by another 1238 // JVM instance. However, this could also be the result of a 1239 // deliberate symlink. Verify that the existing directory is safe. 1240 // 1241 if (!is_directory_secure(dirname)) { 1242 // directory is not secure 1243 if (PrintMiscellaneous && Verbose) { 1244 warning("%s directory is insecure\n", dirname); 1245 } 1246 return false; 1247 } 1248 // The administrator should be able to delete this directory. 1249 // But the directory created by previous version of JVM may not 1250 // have permission for administrators to delete this directory. 1251 // So add full permission to the administrator. Also setting new 1252 // DACLs might fix the corrupted the DACLs. 1253 SECURITY_INFORMATION secInfo = DACL_SECURITY_INFORMATION; 1254 if (!SetFileSecurity(dirname, secInfo, pDirSA->lpSecurityDescriptor)) { 1255 if (PrintMiscellaneous && Verbose) { 1256 lasterror = GetLastError(); 1257 warning("SetFileSecurity failed for %s directory. lasterror %d \n", 1258 dirname, lasterror); 1259 } 1260 } 1261 } 1262 else { 1263 if (PrintMiscellaneous && Verbose) { 1264 warning("CreateDirectory failed: %d\n", GetLastError()); 1265 } 1266 return false; 1267 } 1268 } 1269 1270 // free the security attributes structure 1271 free_security_attr(pDirSA); 1272 1273 return true; 1274} 1275 1276// create the shared memory resources 1277// 1278// This function creates the shared memory resources. This includes 1279// the backing store file and the file mapping shared memory object. 1280// 1281static HANDLE create_sharedmem_resources(const char* dirname, const char* filename, const char* objectname, size_t size) { 1282 1283 HANDLE fh = INVALID_HANDLE_VALUE; 1284 HANDLE fmh = NULL; 1285 1286 1287 // create the security attributes for the backing store file 1288 LPSECURITY_ATTRIBUTES lpFileSA = make_file_security_attr(); 1289 if (lpFileSA == NULL) { 1290 return NULL; 1291 } 1292 1293 // create the security attributes for the shared memory object 1294 LPSECURITY_ATTRIBUTES lpSmoSA = make_smo_security_attr(); 1295 if (lpSmoSA == NULL) { 1296 free_security_attr(lpFileSA); 1297 return NULL; 1298 } 1299 1300 // create the user temporary directory 1301 if (!make_user_tmp_dir(dirname)) { 1302 // could not make/find the directory or the found directory 1303 // was not secure 1304 return NULL; 1305 } 1306 1307 // Create the file - the FILE_FLAG_DELETE_ON_CLOSE flag allows the 1308 // file to be deleted by the last process that closes its handle to 1309 // the file. This is important as the apis do not allow a terminating 1310 // JVM being monitored by another process to remove the file name. 1311 // 1312 fh = CreateFile( 1313 filename, /* LPCTSTR file name */ 1314 1315 GENERIC_READ|GENERIC_WRITE, /* DWORD desired access */ 1316 FILE_SHARE_DELETE|FILE_SHARE_READ, /* DWORD share mode, future READONLY 1317 * open operations allowed 1318 */ 1319 lpFileSA, /* LPSECURITY security attributes */ 1320 CREATE_ALWAYS, /* DWORD creation disposition 1321 * create file, if it already 1322 * exists, overwrite it. 1323 */ 1324 FILE_FLAG_DELETE_ON_CLOSE, /* DWORD flags and attributes */ 1325 1326 NULL); /* HANDLE template file access */ 1327 1328 free_security_attr(lpFileSA); 1329 1330 if (fh == INVALID_HANDLE_VALUE) { 1331 DWORD lasterror = GetLastError(); 1332 if (PrintMiscellaneous && Verbose) { 1333 warning("could not create file %s: %d\n", filename, lasterror); 1334 } 1335 return NULL; 1336 } 1337 1338 // try to create the file mapping 1339 fmh = create_file_mapping(objectname, fh, lpSmoSA, size); 1340 1341 free_security_attr(lpSmoSA); 1342 1343 if (fmh == NULL) { 1344 // closing the file handle here will decrement the reference count 1345 // on the file. When all processes accessing the file close their 1346 // handle to it, the reference count will decrement to 0 and the 1347 // OS will delete the file. These semantics are requested by the 1348 // FILE_FLAG_DELETE_ON_CLOSE flag in CreateFile call above. 1349 CloseHandle(fh); 1350 fh = NULL; 1351 return NULL; 1352 } else { 1353 // We created the file mapping, but rarely the size of the 1354 // backing store file is reported as zero (0) which can cause 1355 // failures when trying to use the hsperfdata file. 1356 struct stat statbuf; 1357 int ret_code = ::stat(filename, &statbuf); 1358 if (ret_code == OS_ERR) { 1359 if (PrintMiscellaneous && Verbose) { 1360 warning("Could not get status information from file %s: %s\n", 1361 filename, os::strerror(errno)); 1362 } 1363 CloseHandle(fmh); 1364 CloseHandle(fh); 1365 fh = NULL; 1366 fmh = NULL; 1367 return NULL; 1368 } 1369 1370 // We could always call FlushFileBuffers() but the Microsoft 1371 // docs indicate that it is considered expensive so we only 1372 // call it when we observe the size as zero (0). 1373 if (statbuf.st_size == 0 && FlushFileBuffers(fh) != TRUE) { 1374 DWORD lasterror = GetLastError(); 1375 if (PrintMiscellaneous && Verbose) { 1376 warning("could not flush file %s: %d\n", filename, lasterror); 1377 } 1378 CloseHandle(fmh); 1379 CloseHandle(fh); 1380 fh = NULL; 1381 fmh = NULL; 1382 return NULL; 1383 } 1384 } 1385 1386 // the file has been successfully created and the file mapping 1387 // object has been created. 1388 sharedmem_fileHandle = fh; 1389 sharedmem_fileName = os::strdup(filename); 1390 1391 return fmh; 1392} 1393 1394// open the shared memory object for the given vmid. 1395// 1396static HANDLE open_sharedmem_object(const char* objectname, DWORD ofm_access, TRAPS) { 1397 1398 HANDLE fmh; 1399 1400 // open the file mapping with the requested mode 1401 fmh = OpenFileMapping( 1402 ofm_access, /* DWORD access mode */ 1403 FALSE, /* BOOL inherit flag - Do not allow inherit */ 1404 objectname); /* name for object */ 1405 1406 if (fmh == NULL) { 1407 if (PrintMiscellaneous && Verbose) { 1408 warning("OpenFileMapping failed for shared memory object %s:" 1409 " lasterror = %d\n", objectname, GetLastError()); 1410 } 1411 THROW_MSG_(vmSymbols::java_lang_Exception(), 1412 "Could not open PerfMemory", INVALID_HANDLE_VALUE); 1413 } 1414 1415 return fmh;; 1416} 1417 1418// create a named shared memory region 1419// 1420// On Win32, a named shared memory object has a name space that 1421// is independent of the file system name space. Shared memory object, 1422// or more precisely, file mapping objects, provide no mechanism to 1423// inquire the size of the memory region. There is also no api to 1424// enumerate the memory regions for various processes. 1425// 1426// This implementation utilizes the shared memory name space in parallel 1427// with the file system name space. This allows us to determine the 1428// size of the shared memory region from the size of the file and it 1429// allows us to provide a common, file system based name space for 1430// shared memory across platforms. 1431// 1432static char* mapping_create_shared(size_t size) { 1433 1434 void *mapAddress; 1435 int vmid = os::current_process_id(); 1436 1437 // get the name of the user associated with this process 1438 char* user = get_user_name(); 1439 1440 if (user == NULL) { 1441 return NULL; 1442 } 1443 1444 // construct the name of the user specific temporary directory 1445 char* dirname = get_user_tmp_dir(user); 1446 1447 // check that the file system is secure - i.e. it supports ACLs. 1448 if (!is_filesystem_secure(dirname)) { 1449 FREE_C_HEAP_ARRAY(char, dirname); 1450 FREE_C_HEAP_ARRAY(char, user); 1451 return NULL; 1452 } 1453 1454 // create the names of the backing store files and for the 1455 // share memory object. 1456 // 1457 char* filename = get_sharedmem_filename(dirname, vmid); 1458 char* objectname = get_sharedmem_objectname(user, vmid); 1459 1460 // cleanup any stale shared memory resources 1461 cleanup_sharedmem_resources(dirname); 1462 1463 assert(((size != 0) && (size % os::vm_page_size() == 0)), 1464 "unexpected PerfMemry region size"); 1465 1466 FREE_C_HEAP_ARRAY(char, user); 1467 1468 // create the shared memory resources 1469 sharedmem_fileMapHandle = 1470 create_sharedmem_resources(dirname, filename, objectname, size); 1471 1472 FREE_C_HEAP_ARRAY(char, filename); 1473 FREE_C_HEAP_ARRAY(char, objectname); 1474 FREE_C_HEAP_ARRAY(char, dirname); 1475 1476 if (sharedmem_fileMapHandle == NULL) { 1477 return NULL; 1478 } 1479 1480 // map the file into the address space 1481 mapAddress = MapViewOfFile( 1482 sharedmem_fileMapHandle, /* HANDLE = file mapping object */ 1483 FILE_MAP_ALL_ACCESS, /* DWORD access flags */ 1484 0, /* DWORD High word of offset */ 1485 0, /* DWORD Low word of offset */ 1486 (DWORD)size); /* DWORD Number of bytes to map */ 1487 1488 if (mapAddress == NULL) { 1489 if (PrintMiscellaneous && Verbose) { 1490 warning("MapViewOfFile failed, lasterror = %d\n", GetLastError()); 1491 } 1492 CloseHandle(sharedmem_fileMapHandle); 1493 sharedmem_fileMapHandle = NULL; 1494 return NULL; 1495 } 1496 1497 // clear the shared memory region 1498 (void)memset(mapAddress, '\0', size); 1499 1500 // it does not go through os api, the operation has to record from here 1501 MemTracker::record_virtual_memory_reserve_and_commit((address)mapAddress, 1502 size, CURRENT_PC, mtInternal); 1503 1504 return (char*) mapAddress; 1505} 1506 1507// this method deletes the file mapping object. 1508// 1509static void delete_file_mapping(char* addr, size_t size) { 1510 1511 // cleanup the persistent shared memory resources. since DestroyJavaVM does 1512 // not support unloading of the JVM, unmapping of the memory resource is not 1513 // performed. The memory will be reclaimed by the OS upon termination of all 1514 // processes mapping the resource. The file mapping handle and the file 1515 // handle are closed here to expedite the remove of the file by the OS. The 1516 // file is not removed directly because it was created with 1517 // FILE_FLAG_DELETE_ON_CLOSE semantics and any attempt to remove it would 1518 // be unsuccessful. 1519 1520 // close the fileMapHandle. the file mapping will still be retained 1521 // by the OS as long as any other JVM processes has an open file mapping 1522 // handle or a mapped view of the file. 1523 // 1524 if (sharedmem_fileMapHandle != NULL) { 1525 CloseHandle(sharedmem_fileMapHandle); 1526 sharedmem_fileMapHandle = NULL; 1527 } 1528 1529 // close the file handle. This will decrement the reference count on the 1530 // backing store file. When the reference count decrements to 0, the OS 1531 // will delete the file. These semantics apply because the file was 1532 // created with the FILE_FLAG_DELETE_ON_CLOSE flag. 1533 // 1534 if (sharedmem_fileHandle != INVALID_HANDLE_VALUE) { 1535 CloseHandle(sharedmem_fileHandle); 1536 sharedmem_fileHandle = INVALID_HANDLE_VALUE; 1537 } 1538} 1539 1540// this method determines the size of the shared memory file 1541// 1542static size_t sharedmem_filesize(const char* filename, TRAPS) { 1543 1544 struct stat statbuf; 1545 1546 // get the file size 1547 // 1548 // on win95/98/me, _stat returns a file size of 0 bytes, but on 1549 // winnt/2k the appropriate file size is returned. support for 1550 // the sharable aspects of performance counters was abandonded 1551 // on the non-nt win32 platforms due to this and other api 1552 // inconsistencies 1553 // 1554 if (::stat(filename, &statbuf) == OS_ERR) { 1555 if (PrintMiscellaneous && Verbose) { 1556 warning("stat %s failed: %s\n", filename, os::strerror(errno)); 1557 } 1558 THROW_MSG_0(vmSymbols::java_io_IOException(), 1559 "Could not determine PerfMemory size"); 1560 } 1561 1562 if ((statbuf.st_size == 0) || (statbuf.st_size % os::vm_page_size() != 0)) { 1563 if (PrintMiscellaneous && Verbose) { 1564 warning("unexpected file size: size = " SIZE_FORMAT "\n", 1565 statbuf.st_size); 1566 } 1567 THROW_MSG_0(vmSymbols::java_lang_Exception(), 1568 "Invalid PerfMemory size"); 1569 } 1570 1571 return statbuf.st_size; 1572} 1573 1574// this method opens a file mapping object and maps the object 1575// into the address space of the process 1576// 1577static void open_file_mapping(const char* user, int vmid, 1578 PerfMemory::PerfMemoryMode mode, 1579 char** addrp, size_t* sizep, TRAPS) { 1580 1581 ResourceMark rm; 1582 1583 void *mapAddress = 0; 1584 size_t size = 0; 1585 HANDLE fmh; 1586 DWORD ofm_access; 1587 DWORD mv_access; 1588 const char* luser = NULL; 1589 1590 if (mode == PerfMemory::PERF_MODE_RO) { 1591 ofm_access = FILE_MAP_READ; 1592 mv_access = FILE_MAP_READ; 1593 } 1594 else if (mode == PerfMemory::PERF_MODE_RW) { 1595#ifdef LATER 1596 ofm_access = FILE_MAP_READ | FILE_MAP_WRITE; 1597 mv_access = FILE_MAP_READ | FILE_MAP_WRITE; 1598#else 1599 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), 1600 "Unsupported access mode"); 1601#endif 1602 } 1603 else { 1604 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), 1605 "Illegal access mode"); 1606 } 1607 1608 // if a user name wasn't specified, then find the user name for 1609 // the owner of the target vm. 1610 if (user == NULL || strlen(user) == 0) { 1611 luser = get_user_name(vmid); 1612 } 1613 else { 1614 luser = user; 1615 } 1616 1617 if (luser == NULL) { 1618 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), 1619 "Could not map vmid to user name"); 1620 } 1621 1622 // get the names for the resources for the target vm 1623 char* dirname = get_user_tmp_dir(luser); 1624 1625 // since we don't follow symbolic links when creating the backing 1626 // store file, we also don't following them when attaching 1627 // 1628 if (!is_directory_secure(dirname)) { 1629 FREE_C_HEAP_ARRAY(char, dirname); 1630 if (luser != user) FREE_C_HEAP_ARRAY(char, luser); 1631 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), 1632 "Process not found"); 1633 } 1634 1635 char* filename = get_sharedmem_filename(dirname, vmid); 1636 char* objectname = get_sharedmem_objectname(luser, vmid); 1637 1638 // copy heap memory to resource memory. the objectname and 1639 // filename are passed to methods that may throw exceptions. 1640 // using resource arrays for these names prevents the leaks 1641 // that would otherwise occur. 1642 // 1643 char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1); 1644 char* robjectname = NEW_RESOURCE_ARRAY(char, strlen(objectname) + 1); 1645 strcpy(rfilename, filename); 1646 strcpy(robjectname, objectname); 1647 1648 // free the c heap resources that are no longer needed 1649 if (luser != user) FREE_C_HEAP_ARRAY(char, luser); 1650 FREE_C_HEAP_ARRAY(char, dirname); 1651 FREE_C_HEAP_ARRAY(char, filename); 1652 FREE_C_HEAP_ARRAY(char, objectname); 1653 1654 if (*sizep == 0) { 1655 size = sharedmem_filesize(rfilename, CHECK); 1656 } else { 1657 size = *sizep; 1658 } 1659 1660 assert(size > 0, "unexpected size <= 0"); 1661 1662 // Open the file mapping object with the given name 1663 fmh = open_sharedmem_object(robjectname, ofm_access, CHECK); 1664 1665 assert(fmh != INVALID_HANDLE_VALUE, "unexpected handle value"); 1666 1667 // map the entire file into the address space 1668 mapAddress = MapViewOfFile( 1669 fmh, /* HANDLE Handle of file mapping object */ 1670 mv_access, /* DWORD access flags */ 1671 0, /* DWORD High word of offset */ 1672 0, /* DWORD Low word of offset */ 1673 size); /* DWORD Number of bytes to map */ 1674 1675 if (mapAddress == NULL) { 1676 if (PrintMiscellaneous && Verbose) { 1677 warning("MapViewOfFile failed, lasterror = %d\n", GetLastError()); 1678 } 1679 CloseHandle(fmh); 1680 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), 1681 "Could not map PerfMemory"); 1682 } 1683 1684 // it does not go through os api, the operation has to record from here 1685 MemTracker::record_virtual_memory_reserve_and_commit((address)mapAddress, size, 1686 CURRENT_PC, mtInternal); 1687 1688 1689 *addrp = (char*)mapAddress; 1690 *sizep = size; 1691 1692 // File mapping object can be closed at this time without 1693 // invalidating the mapped view of the file 1694 CloseHandle(fmh); 1695 1696 if (PerfTraceMemOps) { 1697 tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at " 1698 INTPTR_FORMAT "\n", size, vmid, mapAddress); 1699 } 1700} 1701 1702// this method unmaps the the mapped view of the the 1703// file mapping object. 1704// 1705static void remove_file_mapping(char* addr) { 1706 1707 // the file mapping object was closed in open_file_mapping() 1708 // after the file map view was created. We only need to 1709 // unmap the file view here. 1710 UnmapViewOfFile(addr); 1711} 1712 1713// create the PerfData memory region in shared memory. 1714static char* create_shared_memory(size_t size) { 1715 1716 return mapping_create_shared(size); 1717} 1718 1719// release a named, shared memory region 1720// 1721void delete_shared_memory(char* addr, size_t size) { 1722 1723 delete_file_mapping(addr, size); 1724} 1725 1726 1727 1728 1729// create the PerfData memory region 1730// 1731// This method creates the memory region used to store performance 1732// data for the JVM. The memory may be created in standard or 1733// shared memory. 1734// 1735void PerfMemory::create_memory_region(size_t size) { 1736 1737 if (PerfDisableSharedMem) { 1738 // do not share the memory for the performance data. 1739 PerfDisableSharedMem = true; 1740 _start = create_standard_memory(size); 1741 } 1742 else { 1743 _start = create_shared_memory(size); 1744 if (_start == NULL) { 1745 1746 // creation of the shared memory region failed, attempt 1747 // to create a contiguous, non-shared memory region instead. 1748 // 1749 if (PrintMiscellaneous && Verbose) { 1750 warning("Reverting to non-shared PerfMemory region.\n"); 1751 } 1752 PerfDisableSharedMem = true; 1753 _start = create_standard_memory(size); 1754 } 1755 } 1756 1757 if (_start != NULL) _capacity = size; 1758 1759} 1760 1761// delete the PerfData memory region 1762// 1763// This method deletes the memory region used to store performance 1764// data for the JVM. The memory region indicated by the <address, size> 1765// tuple will be inaccessible after a call to this method. 1766// 1767void PerfMemory::delete_memory_region() { 1768 1769 assert((start() != NULL && capacity() > 0), "verify proper state"); 1770 1771 // If user specifies PerfDataSaveFile, it will save the performance data 1772 // to the specified file name no matter whether PerfDataSaveToFile is specified 1773 // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag 1774 // -XX:+PerfDataSaveToFile. 1775 if (PerfDataSaveToFile || PerfDataSaveFile != NULL) { 1776 save_memory_to_file(start(), capacity()); 1777 } 1778 1779 if (PerfDisableSharedMem) { 1780 delete_standard_memory(start(), capacity()); 1781 } 1782 else { 1783 delete_shared_memory(start(), capacity()); 1784 } 1785} 1786 1787// attach to the PerfData memory region for another JVM 1788// 1789// This method returns an <address, size> tuple that points to 1790// a memory buffer that is kept reasonably synchronized with 1791// the PerfData memory region for the indicated JVM. This 1792// buffer may be kept in synchronization via shared memory 1793// or some other mechanism that keeps the buffer updated. 1794// 1795// If the JVM chooses not to support the attachability feature, 1796// this method should throw an UnsupportedOperation exception. 1797// 1798// This implementation utilizes named shared memory to map 1799// the indicated process's PerfData memory region into this JVMs 1800// address space. 1801// 1802void PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, 1803 char** addrp, size_t* sizep, TRAPS) { 1804 1805 if (vmid == 0 || vmid == os::current_process_id()) { 1806 *addrp = start(); 1807 *sizep = capacity(); 1808 return; 1809 } 1810 1811 open_file_mapping(user, vmid, mode, addrp, sizep, CHECK); 1812} 1813 1814// detach from the PerfData memory region of another JVM 1815// 1816// This method detaches the PerfData memory region of another 1817// JVM, specified as an <address, size> tuple of a buffer 1818// in this process's address space. This method may perform 1819// arbitrary actions to accomplish the detachment. The memory 1820// region specified by <address, size> will be inaccessible after 1821// a call to this method. 1822// 1823// If the JVM chooses not to support the attachability feature, 1824// this method should throw an UnsupportedOperation exception. 1825// 1826// This implementation utilizes named shared memory to detach 1827// the indicated process's PerfData memory region from this 1828// process's address space. 1829// 1830void PerfMemory::detach(char* addr, size_t bytes, TRAPS) { 1831 1832 assert(addr != 0, "address sanity check"); 1833 assert(bytes > 0, "capacity sanity check"); 1834 1835 if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) { 1836 // prevent accidental detachment of this process's PerfMemory region 1837 return; 1838 } 1839 1840 if (MemTracker::tracking_level() > NMT_minimal) { 1841 // it does not go through os api, the operation has to record from here 1842 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 1843 remove_file_mapping(addr); 1844 tkr.record((address)addr, bytes); 1845 } else { 1846 remove_file_mapping(addr); 1847 } 1848} 1849