2796N/A

2796N/A#include "precompiled.hpp"

2796N/A#include "classfile/vmSymbols.hpp"

2796N/A#include "memory/allocation.inline.hpp"

2796N/A#include "memory/resourceArea.hpp"

2796N/A#include "oops/oop.inline.hpp"

2796N/A#include "os_bsd.inline.hpp"

2796N/A#include "runtime/handles.inline.hpp"

2796N/A#include "runtime/perfMemory.hpp"

4064N/A#include "services/memTracker.hpp"

2796N/A#include "utilities/exceptions.hpp"

2796N/A

2796N/A# include <sys/types.h>

2796N/A# include <sys/mman.h>

2796N/A# include <errno.h>

2796N/A# include <stdio.h>

2796N/A# include <unistd.h>

2796N/A# include <sys/stat.h>

2796N/A# include <signal.h>

2796N/A# include <pwd.h>

2796N/A

2796N/Astatic char* backing_store_file_name = NULL; // name of the backing store

2796N/A // file, if successfully created.

2796N/A

2796N/A

2796N/Astatic char* create_standard_memory(size_t size) {

2796N/A

2796N/A // allocate an aligned chuck of memory

2796N/A char* mapAddress = os::reserve_memory(size);

2796N/A

2796N/A if (mapAddress == NULL) {

2796N/A return NULL;

2796N/A }

2796N/A

2796N/A // commit memory

4552N/A if (!os::commit_memory(mapAddress, size, !ExecMem)) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("Could not commit PerfData memory\n");

2796N/A }

2796N/A os::release_memory(mapAddress, size);

2796N/A return NULL;

2796N/A }

2796N/A

2796N/A return mapAddress;

2796N/A}

2796N/A

2796N/Astatic void delete_standard_memory(char* addr, size_t size) {

2796N/A

2796N/A // there are no persistent external resources to cleanup for standard

2796N/A // memory. since DestroyJavaVM does not support unloading of the JVM,

2796N/A // cleanup of the memory resource is not performed. The memory will be

2796N/A // reclaimed by the OS upon termination of the process.

2796N/A //

2796N/A return;

2796N/A}

2796N/A

2796N/Astatic void save_memory_to_file(char* addr, size_t size) {

2796N/A

2796N/A const char* destfile = PerfMemory::get_perfdata_file_path();

2796N/A assert(destfile[0] != '\0', "invalid PerfData file path");

2796N/A

2796N/A int result;

2796N/A

2796N/A RESTARTABLE(::open(destfile, O_CREAT|O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE),

2796N/A result);;

2796N/A if (result == OS_ERR) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("Could not create Perfdata save file: %s: %s\n",

2796N/A destfile, strerror(errno));

2796N/A }

2796N/A } else {

2796N/A int fd = result;

2796N/A

2796N/A for (size_t remaining = size; remaining > 0;) {

2796N/A

2796N/A RESTARTABLE(::write(fd, addr, remaining), result);

2796N/A if (result == OS_ERR) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("Could not write Perfdata save file: %s: %s\n",

2796N/A destfile, strerror(errno));

2796N/A }

2796N/A break;

2796N/A }

2796N/A

2796N/A remaining -= (size_t)result;

2796N/A addr += result;

2796N/A }

2796N/A

2796N/A RESTARTABLE(::close(fd), result);

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A if (result == OS_ERR) {

2796N/A warning("Could not close %s: %s\n", destfile, strerror(errno));

2796N/A }

2796N/A }

2796N/A }

3863N/A FREE_C_HEAP_ARRAY(char, destfile, mtInternal);

2796N/A}

2796N/A

2796N/A

2796N/A

2796N/A

2796N/Astatic char* get_user_tmp_dir(const char* user) {

2796N/A

2796N/A const char* tmpdir = os::get_temp_directory();

2796N/A const char* perfdir = PERFDATA_NAME;

2796N/A size_t nbytes = strlen(tmpdir) + strlen(perfdir) + strlen(user) + 3;

3863N/A char* dirname = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);

2796N/A

2796N/A // construct the path name to user specific tmp directory

2796N/A snprintf(dirname, nbytes, "%s/%s_%s", tmpdir, perfdir, user);

2796N/A

2796N/A return dirname;

2796N/A}

2796N/A

2796N/Astatic pid_t filename_to_pid(const char* filename) {

2796N/A

2796N/A // a filename that doesn't begin with a digit is not a

2796N/A // candidate for conversion.

2796N/A //

2796N/A if (!isdigit(*filename)) {

2796N/A return 0;

2796N/A }

2796N/A

2796N/A // check if file name can be converted to an integer without

2796N/A // any leftover characters.

2796N/A //

2796N/A char* remainder = NULL;

2796N/A errno = 0;

2796N/A pid_t pid = (pid_t)strtol(filename, &remainder, 10);

2796N/A

2796N/A if (errno != 0) {

2796N/A return 0;

2796N/A }

2796N/A

2796N/A // check for left over characters. If any, then the filename is

2796N/A // not a candidate for conversion.

2796N/A //

2796N/A if (remainder != NULL && *remainder != '\0') {

2796N/A return 0;

2796N/A }

2796N/A

2796N/A // successful conversion, return the pid

2796N/A return pid;

2796N/A}

2796N/A

2796N/A

2796N/Astatic bool is_directory_secure(const char* path) {

2796N/A struct stat statbuf;

2796N/A int result = 0;

2796N/A

2796N/A RESTARTABLE(::lstat(path, &statbuf), result);

2796N/A if (result == OS_ERR) {

2796N/A return false;

2796N/A }

2796N/A

2796N/A // the path exists, now check it's mode

2796N/A if (S_ISLNK(statbuf.st_mode) || !S_ISDIR(statbuf.st_mode)) {

2796N/A // the path represents a link or some non-directory file type,

2796N/A // which is not what we expected. declare it insecure.

2796N/A //

2796N/A return false;

2796N/A }

2796N/A else {

2796N/A // we have an existing directory, check if the permissions are safe.

2796N/A //

2796N/A if ((statbuf.st_mode & (S_IWGRP|S_IWOTH)) != 0) {

2796N/A // the directory is open for writing and could be subjected

2796N/A // to a symlnk attack. declare it insecure.

2796N/A //

2796N/A return false;

2796N/A }

2796N/A }

2796N/A return true;

2796N/A}

2796N/A

2796N/A

2796N/Astatic char* get_user_name(uid_t uid) {

2796N/A

2796N/A struct passwd pwent;

2796N/A

2796N/A // determine the max pwbuf size from sysconf, and hardcode

2796N/A // a default if this not available through sysconf.

2796N/A //

2796N/A long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);

2796N/A if (bufsize == -1)

2796N/A bufsize = 1024;

2796N/A

3863N/A char* pwbuf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);

2796N/A

2796N/A // POSIX interface to getpwuid_r is used on LINUX

2796N/A struct passwd* p;

2796N/A int result = getpwuid_r(uid, &pwent, pwbuf, (size_t)bufsize, &p);

2796N/A

2796N/A if (result != 0 || p == NULL || p->pw_name == NULL || *(p->pw_name) == '\0') {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A if (result != 0) {

2796N/A warning("Could not retrieve passwd entry: %s\n",

2796N/A strerror(result));

2796N/A }

2796N/A else if (p == NULL) {

2796N/A // this check is added to protect against an observed problem

2796N/A // with getpwuid_r() on RedHat 9 where getpwuid_r returns 0,

2796N/A // indicating success, but has p == NULL. This was observed when

2796N/A // inserting a file descriptor exhaustion fault prior to the call

2796N/A // getpwuid_r() call. In this case, error is set to the appropriate

2796N/A // error condition, but this is undocumented behavior. This check

2796N/A // is safe under any condition, but the use of errno in the output

2796N/A // message may result in an erroneous message.

2796N/A // Bug Id 89052 was opened with RedHat.

2796N/A //

2796N/A warning("Could not retrieve passwd entry: %s\n",

2796N/A strerror(errno));

2796N/A }

2796N/A else {

2796N/A warning("Could not determine user name: %s\n",

2796N/A p->pw_name == NULL ? "pw_name = NULL" :

2796N/A "pw_name zero length");

2796N/A }

2796N/A }

3863N/A FREE_C_HEAP_ARRAY(char, pwbuf, mtInternal);

2796N/A return NULL;

2796N/A }

2796N/A

3863N/A char* user_name = NEW_C_HEAP_ARRAY(char, strlen(p->pw_name) + 1, mtInternal);

2796N/A strcpy(user_name, p->pw_name);

2796N/A

3863N/A FREE_C_HEAP_ARRAY(char, pwbuf, mtInternal);

2796N/A return user_name;

2796N/A}

2796N/A

2796N/Astatic char* get_user_name_slow(int vmid, TRAPS) {

2796N/A

2796N/A // short circuit the directory search if the process doesn't even exist.

2796N/A if (kill(vmid, 0) == OS_ERR) {

2796N/A if (errno == ESRCH) {

2796N/A THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),

2796N/A "Process not found");

2796N/A }

2796N/A else /* EPERM */ {

2796N/A THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno));

2796N/A }

2796N/A }

2796N/A

2796N/A // directory search

2796N/A char* oldest_user = NULL;

2796N/A time_t oldest_ctime = 0;

2796N/A

2796N/A const char* tmpdirname = os::get_temp_directory();

2796N/A

2796N/A DIR* tmpdirp = os::opendir(tmpdirname);

2796N/A

2796N/A if (tmpdirp == NULL) {

2796N/A return NULL;

2796N/A }

2796N/A

2796N/A // for each entry in the directory that matches the pattern hsperfdata_*,

2796N/A // open the directory and check if the file for the given vmid exists.

2796N/A // The file with the expected name and the latest creation date is used

2796N/A // to determine the user name for the process id.

2796N/A //

2796N/A struct dirent* dentry;

3863N/A char* tdbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(tmpdirname), mtInternal);

2796N/A errno = 0;

2796N/A while ((dentry = os::readdir(tmpdirp, (struct dirent *)tdbuf)) != NULL) {

2796N/A

2796N/A // check if the directory entry is a hsperfdata file

2796N/A if (strncmp(dentry->d_name, PERFDATA_NAME, strlen(PERFDATA_NAME)) != 0) {

2796N/A continue;

2796N/A }

2796N/A

2796N/A char* usrdir_name = NEW_C_HEAP_ARRAY(char,

3863N/A strlen(tmpdirname) + strlen(dentry->d_name) + 2, mtInternal);

2796N/A strcpy(usrdir_name, tmpdirname);

2796N/A strcat(usrdir_name, "/");

2796N/A strcat(usrdir_name, dentry->d_name);

2796N/A

2796N/A DIR* subdirp = os::opendir(usrdir_name);

2796N/A

2796N/A if (subdirp == NULL) {

3863N/A FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal);

2796N/A continue;

2796N/A }

2796N/A

2796N/A // Since we don't create the backing store files in directories

2796N/A // pointed to by symbolic links, we also don't follow them when

2796N/A // looking for the files. We check for a symbolic link after the

2796N/A // call to opendir in order to eliminate a small window where the

2796N/A // symlink can be exploited.

2796N/A //

2796N/A if (!is_directory_secure(usrdir_name)) {

3863N/A FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal);

2796N/A os::closedir(subdirp);

2796N/A continue;

2796N/A }

2796N/A

2796N/A struct dirent* udentry;

3863N/A char* udbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(usrdir_name), mtInternal);

2796N/A errno = 0;

2796N/A while ((udentry = os::readdir(subdirp, (struct dirent *)udbuf)) != NULL) {

2796N/A

2796N/A if (filename_to_pid(udentry->d_name) == vmid) {

2796N/A struct stat statbuf;

2796N/A int result;

2796N/A

2796N/A char* filename = NEW_C_HEAP_ARRAY(char,

3863N/A strlen(usrdir_name) + strlen(udentry->d_name) + 2, mtInternal);

2796N/A

2796N/A strcpy(filename, usrdir_name);

2796N/A strcat(filename, "/");

2796N/A strcat(filename, udentry->d_name);

2796N/A

2796N/A // don't follow symbolic links for the file

2796N/A RESTARTABLE(::lstat(filename, &statbuf), result);

2796N/A if (result == OS_ERR) {

3863N/A FREE_C_HEAP_ARRAY(char, filename, mtInternal);

2796N/A continue;

2796N/A }

2796N/A

2796N/A // skip over files that are not regular files.

2796N/A if (!S_ISREG(statbuf.st_mode)) {

3863N/A FREE_C_HEAP_ARRAY(char, filename, mtInternal);

2796N/A continue;

2796N/A }

2796N/A

2796N/A // compare and save filename with latest creation time

2796N/A if (statbuf.st_size > 0 && statbuf.st_ctime > oldest_ctime) {

2796N/A

2796N/A if (statbuf.st_ctime > oldest_ctime) {

2796N/A char* user = strchr(dentry->d_name, '_') + 1;

2796N/A

3863N/A if (oldest_user != NULL) FREE_C_HEAP_ARRAY(char, oldest_user, mtInternal);

3863N/A oldest_user = NEW_C_HEAP_ARRAY(char, strlen(user)+1, mtInternal);

2796N/A

2796N/A strcpy(oldest_user, user);

2796N/A oldest_ctime = statbuf.st_ctime;

2796N/A }

2796N/A }

2796N/A

3863N/A FREE_C_HEAP_ARRAY(char, filename, mtInternal);

2796N/A }

2796N/A }

2796N/A os::closedir(subdirp);

3863N/A FREE_C_HEAP_ARRAY(char, udbuf, mtInternal);

3863N/A FREE_C_HEAP_ARRAY(char, usrdir_name, mtInternal);

2796N/A }

2796N/A os::closedir(tmpdirp);

3863N/A FREE_C_HEAP_ARRAY(char, tdbuf, mtInternal);

2796N/A

2796N/A return(oldest_user);

2796N/A}

2796N/A

2796N/Astatic char* get_user_name(int vmid, TRAPS) {

2796N/A return get_user_name_slow(vmid, CHECK_NULL);

2796N/A}

2796N/A

2796N/Astatic char* get_sharedmem_filename(const char* dirname, int vmid) {

2796N/A

2796N/A // add 2 for the file separator and a null terminator.

2796N/A size_t nbytes = strlen(dirname) + UINT_CHARS + 2;

2796N/A

3863N/A char* name = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);

2796N/A snprintf(name, nbytes, "%s/%d", dirname, vmid);

2796N/A

2796N/A return name;

2796N/A}

2796N/A

2796N/A

2796N/Astatic void remove_file(const char* path) {

2796N/A

2796N/A int result;

2796N/A

2796N/A // if the file is a directory, the following unlink will fail. since

2796N/A // we don't expect to find directories in the user temp directory, we

2796N/A // won't try to handle this situation. even if accidentially or

2796N/A // maliciously planted, the directory's presence won't hurt anything.

2796N/A //

2796N/A RESTARTABLE(::unlink(path), result);

2796N/A if (PrintMiscellaneous && Verbose && result == OS_ERR) {

2796N/A if (errno != ENOENT) {

2796N/A warning("Could not unlink shared memory backing"

2796N/A " store file %s : %s\n", path, strerror(errno));

2796N/A }

2796N/A }

2796N/A}

2796N/A

2796N/A

2796N/Astatic void remove_file(const char* dirname, const char* filename) {

2796N/A

2796N/A size_t nbytes = strlen(dirname) + strlen(filename) + 2;

3863N/A char* path = NEW_C_HEAP_ARRAY(char, nbytes, mtInternal);

2796N/A

2796N/A strcpy(path, dirname);

2796N/A strcat(path, "/");

2796N/A strcat(path, filename);

2796N/A

2796N/A remove_file(path);

2796N/A

3863N/A FREE_C_HEAP_ARRAY(char, path, mtInternal);

2796N/A}

2796N/A

2796N/A

2796N/Astatic void cleanup_sharedmem_resources(const char* dirname) {

2796N/A

2796N/A // open the user temp directory

2796N/A DIR* dirp = os::opendir(dirname);

2796N/A

2796N/A if (dirp == NULL) {

2796N/A // directory doesn't exist, so there is nothing to cleanup

2796N/A return;

2796N/A }

2796N/A

2796N/A if (!is_directory_secure(dirname)) {

2796N/A // the directory is not a secure directory

2796N/A return;

2796N/A }

2796N/A

2796N/A // for each entry in the directory that matches the expected file

2796N/A // name pattern, determine if the file resources are stale and if

2796N/A // so, remove the file resources. Note, instrumented HotSpot processes

2796N/A // for this user may start and/or terminate during this search and

2796N/A // remove or create new files in this directory. The behavior of this

2796N/A // loop under these conditions is dependent upon the implementation of

2796N/A // opendir/readdir.

2796N/A //

2796N/A struct dirent* entry;

3863N/A char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(dirname), mtInternal);

2796N/A errno = 0;

2796N/A while ((entry = os::readdir(dirp, (struct dirent *)dbuf)) != NULL) {

2796N/A

2796N/A pid_t pid = filename_to_pid(entry->d_name);

2796N/A

2796N/A if (pid == 0) {

2796N/A

2796N/A if (strcmp(entry->d_name, ".") != 0 && strcmp(entry->d_name, "..") != 0) {

2796N/A

2796N/A // attempt to remove all unexpected files, except "." and ".."

2796N/A remove_file(dirname, entry->d_name);

2796N/A }

2796N/A

2796N/A errno = 0;

2796N/A continue;

2796N/A }

2796N/A

2796N/A // we now have a file name that converts to a valid integer

2796N/A // that could represent a process id . if this process id

2796N/A // matches the current process id or the process is not running,

2796N/A // then remove the stale file resources.

2796N/A //

2796N/A // process liveness is detected by sending signal number 0 to

2796N/A // the process id (see kill(2)). if kill determines that the

2796N/A // process does not exist, then the file resources are removed.

2796N/A // if kill determines that that we don't have permission to

2796N/A // signal the process, then the file resources are assumed to

2796N/A // be stale and are removed because the resources for such a

2796N/A // process should be in a different user specific directory.

2796N/A //

2796N/A if ((pid == os::current_process_id()) ||

2796N/A (kill(pid, 0) == OS_ERR && (errno == ESRCH || errno == EPERM))) {

2796N/A

2796N/A remove_file(dirname, entry->d_name);

2796N/A }

2796N/A errno = 0;

2796N/A }

2796N/A os::closedir(dirp);

3863N/A FREE_C_HEAP_ARRAY(char, dbuf, mtInternal);

2796N/A}

2796N/A

2796N/Astatic bool make_user_tmp_dir(const char* dirname) {

2796N/A

2796N/A // create the directory with 0755 permissions. note that the directory

2796N/A // will be owned by euid::egid, which may not be the same as uid::gid.

2796N/A //

2796N/A if (mkdir(dirname, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) == OS_ERR) {

2796N/A if (errno == EEXIST) {

2796N/A // The directory already exists and was probably created by another

2796N/A // JVM instance. However, this could also be the result of a

2796N/A // deliberate symlink. Verify that the existing directory is safe.

2796N/A //

2796N/A if (!is_directory_secure(dirname)) {

2796N/A // directory is not secure

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("%s directory is insecure\n", dirname);

2796N/A }

2796N/A return false;

2796N/A }

2796N/A }

2796N/A else {

2796N/A // we encountered some other failure while attempting

2796N/A // to create the directory

2796N/A //

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("could not create directory %s: %s\n",

2796N/A dirname, strerror(errno));

2796N/A }

2796N/A return false;

2796N/A }

2796N/A }

2796N/A return true;

2796N/A}

2796N/A

2796N/Astatic int create_sharedmem_resources(const char* dirname, const char* filename, size_t size) {

2796N/A

2796N/A // make the user temporary directory

2796N/A if (!make_user_tmp_dir(dirname)) {

2796N/A // could not make/find the directory or the found directory

2796N/A // was not secure

2796N/A return -1;

2796N/A }

2796N/A

2796N/A int result;

2796N/A

2796N/A RESTARTABLE(::open(filename, O_RDWR|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE), result);

2796N/A if (result == OS_ERR) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("could not create file %s: %s\n", filename, strerror(errno));

2796N/A }

2796N/A return -1;

2796N/A }

2796N/A

2796N/A // save the file descriptor

2796N/A int fd = result;

2796N/A

2796N/A // set the file size

2796N/A RESTARTABLE(::ftruncate(fd, (off_t)size), result);

2796N/A if (result == OS_ERR) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("could not set shared memory file size: %s\n", strerror(errno));

2796N/A }

2796N/A RESTARTABLE(::close(fd), result);

2796N/A return -1;

2796N/A }

2796N/A

2796N/A // Verify that we have enough disk space for this file.

2796N/A // We'll get random SIGBUS crashes on memory accesses if

2796N/A // we don't.

2796N/A

2796N/A for (size_t seekpos = 0; seekpos < size; seekpos += os::vm_page_size()) {

2796N/A int zero_int = 0;

2796N/A result = (int)os::seek_to_file_offset(fd, (jlong)(seekpos));

2796N/A if (result == -1 ) break;

2796N/A RESTARTABLE(::write(fd, &zero_int, 1), result);

2796N/A if (result != 1) {

2796N/A if (errno == ENOSPC) {

2796N/A warning("Insufficient space for shared memory file:\n %s\nTry using the -Djava.io.tmpdir= option to select an alternate temp location.\n", filename);

2796N/A }

2796N/A break;

2796N/A }

2796N/A }

2796N/A

2796N/A if (result != -1) {

2796N/A return fd;

2796N/A } else {

2796N/A RESTARTABLE(::close(fd), result);

2796N/A return -1;

2796N/A }

2796N/A}

2796N/A

2796N/Astatic int open_sharedmem_file(const char* filename, int oflags, TRAPS) {

2796N/A

2796N/A // open the file

2796N/A int result;

2796N/A RESTARTABLE(::open(filename, oflags), result);

2796N/A if (result == OS_ERR) {

2796N/A if (errno == ENOENT) {

2796N/A THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),

2796N/A "Process not found");

2796N/A }

2796N/A else if (errno == EACCES) {

2796N/A THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),

2796N/A "Permission denied");

2796N/A }

2796N/A else {

2796N/A THROW_MSG_0(vmSymbols::java_io_IOException(), strerror(errno));

2796N/A }

2796N/A }

2796N/A

2796N/A return result;

2796N/A}

2796N/A

2796N/Astatic char* mmap_create_shared(size_t size) {

2796N/A

2796N/A int result;

2796N/A int fd;

2796N/A char* mapAddress;

2796N/A

2796N/A int vmid = os::current_process_id();

2796N/A

2796N/A char* user_name = get_user_name(geteuid());

2796N/A

2796N/A if (user_name == NULL)

2796N/A return NULL;

2796N/A

2796N/A char* dirname = get_user_tmp_dir(user_name);

2796N/A char* filename = get_sharedmem_filename(dirname, vmid);

2796N/A

2796N/A // cleanup any stale shared memory files

2796N/A cleanup_sharedmem_resources(dirname);

2796N/A

2796N/A assert(((size > 0) && (size % os::vm_page_size() == 0)),

2796N/A "unexpected PerfMemory region size");

2796N/A

2796N/A fd = create_sharedmem_resources(dirname, filename, size);

2796N/A

3863N/A FREE_C_HEAP_ARRAY(char, user_name, mtInternal);

3863N/A FREE_C_HEAP_ARRAY(char, dirname, mtInternal);

2796N/A

2796N/A if (fd == -1) {

3863N/A FREE_C_HEAP_ARRAY(char, filename, mtInternal);

2796N/A return NULL;

2796N/A }

2796N/A

2796N/A mapAddress = (char*)::mmap((char*)0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);

2796N/A

2796N/A // attempt to close the file - restart it if it was interrupted,

2796N/A // but ignore other failures

2796N/A RESTARTABLE(::close(fd), result);

2796N/A assert(result != OS_ERR, "could not close file");

2796N/A

2796N/A if (mapAddress == MAP_FAILED) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("mmap failed - %s\n", strerror(errno));

2796N/A }

2796N/A remove_file(filename);

3863N/A FREE_C_HEAP_ARRAY(char, filename, mtInternal);

2796N/A return NULL;

2796N/A }

2796N/A

2796N/A // save the file name for use in delete_shared_memory()

2796N/A backing_store_file_name = filename;

2796N/A

2796N/A // clear the shared memory region

2796N/A (void)::memset((void*) mapAddress, 0, size);

2796N/A

4064N/A // it does not go through os api, the operation has to record from here

4559N/A MemTracker::record_virtual_memory_reserve((address)mapAddress, size, mtInternal, CURRENT_PC);

4064N/A

2796N/A return mapAddress;

2796N/A}

2796N/A

2796N/Astatic void unmap_shared(char* addr, size_t bytes) {

2796N/A os::release_memory(addr, bytes);

2796N/A}

2796N/A

2796N/Astatic char* create_shared_memory(size_t size) {

2796N/A

2796N/A // create the shared memory region.

2796N/A return mmap_create_shared(size);

2796N/A}

2796N/A

2796N/Astatic void delete_shared_memory(char* addr, size_t size) {

2796N/A

2796N/A // cleanup the persistent shared memory resources. since DestroyJavaVM does

2796N/A // not support unloading of the JVM, unmapping of the memory resource is

2796N/A // not performed. The memory will be reclaimed by the OS upon termination of

2796N/A // the process. The backing store file is deleted from the file system.

2796N/A

2796N/A assert(!PerfDisableSharedMem, "shouldn't be here");

2796N/A

2796N/A if (backing_store_file_name != NULL) {

2796N/A remove_file(backing_store_file_name);

2796N/A // Don't.. Free heap memory could deadlock os::abort() if it is called

2796N/A // from signal handler. OS will reclaim the heap memory.

2796N/A // FREE_C_HEAP_ARRAY(char, backing_store_file_name);

2796N/A backing_store_file_name = NULL;

2796N/A }

2796N/A}

2796N/A

2796N/Astatic size_t sharedmem_filesize(int fd, TRAPS) {

2796N/A

2796N/A struct stat statbuf;

2796N/A int result;

2796N/A

2796N/A RESTARTABLE(::fstat(fd, &statbuf), result);

2796N/A if (result == OS_ERR) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("fstat failed: %s\n", strerror(errno));

2796N/A }

2796N/A THROW_MSG_0(vmSymbols::java_io_IOException(),

2796N/A "Could not determine PerfMemory size");

2796N/A }

2796N/A

2796N/A if ((statbuf.st_size == 0) ||

2796N/A ((size_t)statbuf.st_size % os::vm_page_size() != 0)) {

2796N/A THROW_MSG_0(vmSymbols::java_lang_Exception(),

2796N/A "Invalid PerfMemory size");

2796N/A }

2796N/A

2796N/A return (size_t)statbuf.st_size;

2796N/A}

2796N/A

2796N/Astatic void mmap_attach_shared(const char* user, int vmid, PerfMemory::PerfMemoryMode mode, char** addr, size_t* sizep, TRAPS) {

2796N/A

2796N/A char* mapAddress;

2796N/A int result;

2796N/A int fd;

2796N/A size_t size;

2796N/A const char* luser = NULL;

2796N/A

2796N/A int mmap_prot;

2796N/A int file_flags;

2796N/A

2796N/A ResourceMark rm;

2796N/A

2796N/A // map the high level access mode to the appropriate permission

2796N/A // constructs for the file and the shared memory mapping.

2796N/A if (mode == PerfMemory::PERF_MODE_RO) {

2796N/A mmap_prot = PROT_READ;

2796N/A file_flags = O_RDONLY;

2796N/A }

2796N/A else if (mode == PerfMemory::PERF_MODE_RW) {

2796N/A#ifdef LATER

2796N/A mmap_prot = PROT_READ | PROT_WRITE;

2796N/A file_flags = O_RDWR;

2796N/A#else

2796N/A THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

2796N/A "Unsupported access mode");

2796N/A#endif

2796N/A }

2796N/A else {

2796N/A THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

2796N/A "Illegal access mode");

2796N/A }

2796N/A

2796N/A if (user == NULL || strlen(user) == 0) {

2796N/A luser = get_user_name(vmid, CHECK);

2796N/A }

2796N/A else {

2796N/A luser = user;

2796N/A }

2796N/A

2796N/A if (luser == NULL) {

2796N/A THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

2796N/A "Could not map vmid to user Name");

2796N/A }

2796N/A

2796N/A char* dirname = get_user_tmp_dir(luser);

2796N/A

2796N/A // since we don't follow symbolic links when creating the backing

2796N/A // store file, we don't follow them when attaching either.

2796N/A //

2796N/A if (!is_directory_secure(dirname)) {

3863N/A FREE_C_HEAP_ARRAY(char, dirname, mtInternal);

2796N/A THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),

2796N/A "Process not found");

2796N/A }

2796N/A

2796N/A char* filename = get_sharedmem_filename(dirname, vmid);

2796N/A

2796N/A // copy heap memory to resource memory. the open_sharedmem_file

2796N/A // method below need to use the filename, but could throw an

2796N/A // exception. using a resource array prevents the leak that

2796N/A // would otherwise occur.

2796N/A char* rfilename = NEW_RESOURCE_ARRAY(char, strlen(filename) + 1);

2796N/A strcpy(rfilename, filename);

2796N/A

2796N/A // free the c heap resources that are no longer needed

3863N/A if (luser != user) FREE_C_HEAP_ARRAY(char, luser, mtInternal);

3863N/A FREE_C_HEAP_ARRAY(char, dirname, mtInternal);

3863N/A FREE_C_HEAP_ARRAY(char, filename, mtInternal);

2796N/A

2796N/A // open the shared memory file for the give vmid

2796N/A fd = open_sharedmem_file(rfilename, file_flags, CHECK);

2796N/A assert(fd != OS_ERR, "unexpected value");

2796N/A

2796N/A if (*sizep == 0) {

2796N/A size = sharedmem_filesize(fd, CHECK);

2796N/A assert(size != 0, "unexpected size");

2796N/A }

2796N/A

2796N/A mapAddress = (char*)::mmap((char*)0, size, mmap_prot, MAP_SHARED, fd, 0);

2796N/A

2796N/A // attempt to close the file - restart if it gets interrupted,

2796N/A // but ignore other failures

2796N/A RESTARTABLE(::close(fd), result);

2796N/A assert(result != OS_ERR, "could not close file");

2796N/A

2796N/A if (mapAddress == MAP_FAILED) {

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("mmap failed: %s\n", strerror(errno));

2796N/A }

2796N/A THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(),

2796N/A "Could not map PerfMemory");

2796N/A }

2796N/A

4064N/A // it does not go through os api, the operation has to record from here

4559N/A MemTracker::record_virtual_memory_reserve((address)mapAddress, size, mtInternal, CURRENT_PC);

4064N/A

2796N/A *addr = mapAddress;

2796N/A *sizep = size;

2796N/A

2796N/A if (PerfTraceMemOps) {

2796N/A tty->print("mapped " SIZE_FORMAT " bytes for vmid %d at "

2796N/A INTPTR_FORMAT "\n", size, vmid, (void*)mapAddress);

2796N/A }

2796N/A}

2796N/A

2796N/A

2796N/A

2796N/A

2796N/Avoid PerfMemory::create_memory_region(size_t size) {

2796N/A

2796N/A if (PerfDisableSharedMem) {

2796N/A // do not share the memory for the performance data.

2796N/A _start = create_standard_memory(size);

2796N/A }

2796N/A else {

2796N/A _start = create_shared_memory(size);

2796N/A if (_start == NULL) {

2796N/A

2796N/A // creation of the shared memory region failed, attempt

2796N/A // to create a contiguous, non-shared memory region instead.

2796N/A //

2796N/A if (PrintMiscellaneous && Verbose) {

2796N/A warning("Reverting to non-shared PerfMemory region.\n");

2796N/A }

2796N/A PerfDisableSharedMem = true;

2796N/A _start = create_standard_memory(size);

2796N/A }

2796N/A }

2796N/A

2796N/A if (_start != NULL) _capacity = size;

2796N/A

2796N/A}

2796N/A

2796N/Avoid PerfMemory::delete_memory_region() {

2796N/A

2796N/A assert((start() != NULL && capacity() > 0), "verify proper state");

2796N/A

2796N/A // If user specifies PerfDataSaveFile, it will save the performance data

2796N/A // to the specified file name no matter whether PerfDataSaveToFile is specified

2796N/A // or not. In other word, -XX:PerfDataSaveFile=.. overrides flag

2796N/A // -XX:+PerfDataSaveToFile.

2796N/A if (PerfDataSaveToFile || PerfDataSaveFile != NULL) {

2796N/A save_memory_to_file(start(), capacity());

2796N/A }

2796N/A

2796N/A if (PerfDisableSharedMem) {

2796N/A delete_standard_memory(start(), capacity());

2796N/A }

2796N/A else {

2796N/A delete_shared_memory(start(), capacity());

2796N/A }

2796N/A}

2796N/A

2796N/Avoid PerfMemory::attach(const char* user, int vmid, PerfMemoryMode mode, char** addrp, size_t* sizep, TRAPS) {

2796N/A

2796N/A if (vmid == 0 || vmid == os::current_process_id()) {

2796N/A *addrp = start();

2796N/A *sizep = capacity();

2796N/A return;

2796N/A }

2796N/A

2796N/A mmap_attach_shared(user, vmid, mode, addrp, sizep, CHECK);

2796N/A}

2796N/A

2796N/Avoid PerfMemory::detach(char* addr, size_t bytes, TRAPS) {

2796N/A

2796N/A assert(addr != 0, "address sanity check");

2796N/A assert(bytes > 0, "capacity sanity check");

2796N/A

2796N/A if (PerfMemory::contains(addr) || PerfMemory::contains(addr + bytes - 1)) {

2796N/A // prevent accidental detachment of this process's PerfMemory region

2796N/A return;

2796N/A }

2796N/A

2796N/A unmap_shared(addr, bytes);

2796N/A}

2796N/A

2796N/Achar* PerfMemory::backing_store_filename() {

2796N/A return backing_store_file_name;

2796N/A}