1 /*
2 * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "logging/log.hpp"
27 #include "runtime/interfaceSupport.inline.hpp"
28 #include "runtime/os.inline.hpp"
29 #include "services/attachListener.hpp"
30 #include "services/dtraceAttacher.hpp"
31 #include "utilities/vmError.hpp"
32
33 #include <door.h>
34 #include <limits.h>
35 #include <string.h>
36 #include <signal.h>
37 #include <sys/types.h>
38 #include <sys/socket.h>
39 #include <sys/stat.h>
40
41 // stropts.h uses STR in stream ioctl defines
42 #undef STR
43 #include <stropts.h>
44 #undef STR
45 #define STR(a) #a
46
47 // The attach mechanism on Solaris is implemented using the Doors IPC
48 // mechanism. The first tool to attempt to attach causes the attach
49 // listener thread to startup. This thread creats a door that is
50 // associated with a function that enqueues an operation to the attach
51 // listener. The door is attached to a file in the file system so that
52 // client (tools) can locate it. To enqueue an operation to the VM the
53 // client calls through the door which invokes the enqueue function in
54 // this process. The credentials of the client are checked and if the
55 // effective uid matches this process then the operation is enqueued.
56 // When an operation completes the attach listener is required to send the
57 // operation result and any result data to the client. In this implementation
58 // the result is returned via a UNIX domain socket. A pair of connected
59 // sockets (socketpair) is created in the enqueue function and the file
60 // descriptor for one of the sockets is returned to the client as the
61 // return from the door call. The other end is retained in this process.
62 // When the operation completes the result is sent to the client and
63 // the socket is closed.
64
65 // forward reference
66 class SolarisAttachOperation;
67
68 class SolarisAttachListener: AllStatic {
69 private:
70
71 // the path to which we attach the door file descriptor
72 static char _door_path[PATH_MAX+1];
73 static volatile bool _has_door_path;
74
75 // door descriptor returned by door_create
76 static int _door_descriptor;
77
78 static bool _atexit_registered;
79
80 // mutex to protect operation list
81 static mutex_t _mutex;
82
83 // semaphore to wakeup listener thread
84 static sema_t _wakeup;
85
86 static mutex_t* mutex() { return &_mutex; }
87 static sema_t* wakeup() { return &_wakeup; }
88
89 // enqueued operation list
90 static SolarisAttachOperation* _head;
91 static SolarisAttachOperation* _tail;
92
93 static SolarisAttachOperation* head() { return _head; }
94 static void set_head(SolarisAttachOperation* head) { _head = head; }
95
96 static SolarisAttachOperation* tail() { return _tail; }
97 static void set_tail(SolarisAttachOperation* tail) { _tail = tail; }
98
99 // create the door
100 static int create_door();
101
102 public:
103 enum {
104 ATTACH_PROTOCOL_VER = 1 // protocol version
105 };
106 enum {
107 ATTACH_ERROR_BADREQUEST = 100, // error code returned by
108 ATTACH_ERROR_BADVERSION = 101, // the door call
109 ATTACH_ERROR_RESOURCE = 102,
110 ATTACH_ERROR_INTERNAL = 103,
111 ATTACH_ERROR_DENIED = 104
112 };
113
114 static void set_door_path(char* path) {
115 if (path == NULL) {
116 _door_path[0] = '\0';
117 _has_door_path = false;
118 } else {
119 strncpy(_door_path, path, PATH_MAX);
120 _door_path[PATH_MAX] = '\0'; // ensure it's nul terminated
121 _has_door_path = true;
122 }
123 }
124
125 static void set_door_descriptor(int dd) { _door_descriptor = dd; }
126
127 // initialize the listener
128 static int init();
129
130 static bool has_door_path() { return _has_door_path; }
131 static char* door_path() { return _door_path; }
132 static int door_descriptor() { return _door_descriptor; }
133
134 // enqueue an operation
135 static void enqueue(SolarisAttachOperation* op);
136
137 // dequeue an operation
138 static SolarisAttachOperation* dequeue();
139 };
140
141
142 // SolarisAttachOperation is an AttachOperation that additionally encapsulates
143 // a socket connection to the requesting client/tool. SolarisAttachOperation
144 // can additionally be held in a linked list.
145
146 class SolarisAttachOperation: public AttachOperation {
147 private:
148 friend class SolarisAttachListener;
149
150 // connection to client
151 int _socket;
152
153 // linked list support
154 SolarisAttachOperation* _next;
155
156 SolarisAttachOperation* next() { return _next; }
157 void set_next(SolarisAttachOperation* next) { _next = next; }
158
159 public:
160 void complete(jint res, bufferedStream* st);
161
162 int socket() const { return _socket; }
163 void set_socket(int s) { _socket = s; }
164
165 SolarisAttachOperation(char* name) : AttachOperation(name) {
166 set_socket(-1);
167 set_next(NULL);
168 }
169 };
170
171 // statics
172 char SolarisAttachListener::_door_path[PATH_MAX+1];
173 volatile bool SolarisAttachListener::_has_door_path;
174 int SolarisAttachListener::_door_descriptor = -1;
175 bool SolarisAttachListener::_atexit_registered = false;
176 mutex_t SolarisAttachListener::_mutex;
177 sema_t SolarisAttachListener::_wakeup;
178 SolarisAttachOperation* SolarisAttachListener::_head = NULL;
179 SolarisAttachOperation* SolarisAttachListener::_tail = NULL;
180
181 // Supporting class to help split a buffer into individual components
182 class ArgumentIterator : public StackObj {
183 private:
184 char* _pos;
185 char* _end;
186 public:
187 ArgumentIterator(char* arg_buffer, size_t arg_size) {
188 _pos = arg_buffer;
189 _end = _pos + arg_size - 1;
190 }
191 char* next() {
192 if (*_pos == '\0') {
193 // advance the iterator if possible (null arguments)
194 if (_pos < _end) {
195 _pos += 1;
196 }
197 return NULL;
198 }
199 char* res = _pos;
200 char* next_pos = strchr(_pos, '\0');
201 if (next_pos < _end) {
202 next_pos++;
203 }
204 _pos = next_pos;
205 return res;
206 }
207 };
208
209 // Calls from the door function to check that the client credentials
210 // match this process. Returns 0 if credentials okay, otherwise -1.
211 static int check_credentials() {
212 ucred_t *cred_info = NULL;
213 int ret = -1; // deny by default
214
215 // get client credentials
216 if (door_ucred(&cred_info) == -1) {
217 return -1; // unable to get them, deny
218 }
219
220 // get euid/egid from ucred_free
221 uid_t ucred_euid = ucred_geteuid(cred_info);
222 gid_t ucred_egid = ucred_getegid(cred_info);
223
224 // check that the effective uid/gid matches
225 if (os::Posix::matches_effective_uid_and_gid_or_root(ucred_euid, ucred_egid)) {
226 ret = 0; // allow
227 }
228
229 ucred_free(cred_info);
230 return ret;
231 }
232
233
234 // Parses the argument buffer to create an AttachOperation that we should
235 // enqueue to the attach listener.
236 // The buffer is expected to be formatted as follows:
237 // <ver>0<cmd>0<arg>0<arg>0<arg>0
238 // where <ver> is the version number (must be "1"), <cmd> is the command
239 // name ("load, "datadump", ...) and <arg> is an argument.
240 //
241 static SolarisAttachOperation* create_operation(char* argp, size_t arg_size, int* err) {
242 // assume bad request until parsed
243 *err = SolarisAttachListener::ATTACH_ERROR_BADREQUEST;
244
245 if (arg_size < 2 || argp[arg_size-1] != '\0') {
246 return NULL; // no ver or not null terminated
247 }
248
249 // Use supporting class to iterate over the buffer
250 ArgumentIterator args(argp, arg_size);
251
252 // First check the protocol version
253 char* ver = args.next();
254 if (ver == NULL) {
255 return NULL;
256 }
257 if (atoi(ver) != SolarisAttachListener::ATTACH_PROTOCOL_VER) {
258 *err = SolarisAttachListener::ATTACH_ERROR_BADVERSION;
259 return NULL;
260 }
261
262 // Get command name and create the operation
263 char* name = args.next();
264 if (name == NULL || strlen(name) > AttachOperation::name_length_max) {
265 return NULL;
266 }
267 SolarisAttachOperation* op = new SolarisAttachOperation(name);
268
269 // Iterate over the arguments
270 for (int i=0; i<AttachOperation::arg_count_max; i++) {
271 char* arg = args.next();
272 if (arg == NULL) {
273 op->set_arg(i, NULL);
274 } else {
275 if (strlen(arg) > AttachOperation::arg_length_max) {
276 delete op;
277 return NULL;
278 }
279 op->set_arg(i, arg);
280 }
281 }
282
283 // return operation
284 *err = 0;
285 return op;
286 }
287
288 // create special operation to indicate all clients have detached
289 static SolarisAttachOperation* create_detachall_operation() {
290 return new SolarisAttachOperation(AttachOperation::detachall_operation_name());
291 }
292
293 // This is door function which the client executes via a door_call.
294 extern "C" {
295 static void enqueue_proc(void* cookie, char* argp, size_t arg_size,
296 door_desc_t* dt, uint_t n_desc)
297 {
298 int return_fd = -1;
299 SolarisAttachOperation* op = NULL;
300
301 // wait up to 10 seconds for listener to be up and running
302 jint res = 0;
303 int sleep_count = 0;
304 while (!AttachListener::is_initialized()) {
305 sleep(1); // 1 second
306 sleep_count++;
307 if (sleep_count > 10) { // try for 10 seconds
308 debug_only(warning("door_call when not enabled"));
309 res = (jint)SolarisAttachListener::ATTACH_ERROR_INTERNAL;
310 break;
311 }
312 }
313
314 // check client credentials
315 if (res == 0) {
316 if (check_credentials() != 0) {
317 res = (jint)SolarisAttachListener::ATTACH_ERROR_DENIED;
318 }
319 }
320
321 // if we are stopped at ShowMessageBoxOnError then maybe we can
322 // load a diagnostic library
323 if (res == 0 && VMError::is_error_reported()) {
324 if (ShowMessageBoxOnError) {
325 // TBD - support loading of diagnostic library here
326 }
327
328 // can't enqueue operation after fatal error
329 res = (jint)SolarisAttachListener::ATTACH_ERROR_RESOURCE;
330 }
331
332 // create the operation
333 if (res == 0) {
334 int err;
335 op = create_operation(argp, arg_size, &err);
336 res = (op == NULL) ? (jint)err : 0;
337 }
338
339 // create a pair of connected sockets. Store the file descriptor
340 // for one end in the operation and enqueue the operation. The
341 // file descriptor for the other end wil be returned to the client.
342 if (res == 0) {
343 int s[2];
344 if (socketpair(PF_UNIX, SOCK_STREAM, 0, s) < 0) {
345 delete op;
346 res = (jint)SolarisAttachListener::ATTACH_ERROR_RESOURCE;
347 } else {
348 op->set_socket(s[0]);
349 return_fd = s[1];
350 SolarisAttachListener::enqueue(op);
351 }
352 }
353
354 // Return 0 (success) + file descriptor, or non-0 (error)
355 if (res == 0) {
356 door_desc_t desc;
357 // DOOR_RELEASE flag makes sure fd is closed after passing it to
358 // the client. See door_return(3DOOR) man page.
359 desc.d_attributes = DOOR_DESCRIPTOR | DOOR_RELEASE;
360 desc.d_data.d_desc.d_descriptor = return_fd;
361 door_return((char*)&res, sizeof(res), &desc, 1);
362 } else {
363 door_return((char*)&res, sizeof(res), NULL, 0);
364 }
365 }
366 }
367
368 // atexit hook to detach the door and remove the file
369 extern "C" {
370 static void listener_cleanup() {
371 int dd = SolarisAttachListener::door_descriptor();
372 if (dd >= 0) {
373 SolarisAttachListener::set_door_descriptor(-1);
374 ::close(dd);
375 }
376 if (SolarisAttachListener::has_door_path()) {
377 char* path = SolarisAttachListener::door_path();
378 ::fdetach(path);
379 ::unlink(path);
380 SolarisAttachListener::set_door_path(NULL);
381 }
382 }
383 }
384
385 // Create the door
386 int SolarisAttachListener::create_door() {
387 char door_path[PATH_MAX+1];
388 char initial_path[PATH_MAX+1];
389 int fd, res;
390
391 // register exit function
392 if (!_atexit_registered) {
393 _atexit_registered = true;
394 ::atexit(listener_cleanup);
395 }
396
397 // create the door descriptor
398 int dd = ::door_create(enqueue_proc, NULL, 0);
399 if (dd < 0) {
400 return -1;
401 }
402
403 // create initial file to attach door descriptor
404 snprintf(door_path, sizeof(door_path), "%s/.java_pid%d",
405 os::get_temp_directory(), os::current_process_id());
406 snprintf(initial_path, sizeof(initial_path), "%s.tmp", door_path);
407 RESTARTABLE(::creat(initial_path, S_IRUSR | S_IWUSR), fd);
408 if (fd == -1) {
409 log_debug(attach)("attempt to create door file %s failed (%d)", initial_path, errno);
410 ::door_revoke(dd);
411 return -1;
412 }
413 assert(fd >= 0, "bad file descriptor");
414 ::close(fd);
415
416 // attach the door descriptor to the file
417 if ((res = ::fattach(dd, initial_path)) == -1) {
418 // if busy then detach and try again
419 if (errno == EBUSY) {
420 ::fdetach(initial_path);
421 res = ::fattach(dd, initial_path);
422 }
423 if (res == -1) {
424 log_debug(attach)("unable to create door - fattach failed (%d)", errno);
425 ::door_revoke(dd);
426 dd = -1;
427 }
428 }
429
430 // rename file so that clients can attach
431 if (dd >= 0) {
432 if (::rename(initial_path, door_path) == -1) {
433 ::close(dd);
434 ::fdetach(initial_path);
435 log_debug(attach)("unable to create door - rename %s to %s failed (%d)", errno);
436 dd = -1;
437 }
438 }
439 if (dd >= 0) {
440 set_door_descriptor(dd);
441 set_door_path(door_path);
442 log_trace(attach)("door file %s created succesfully", door_path);
443 } else {
444 // unable to create door, attach it to file, or rename file into place
445 ::unlink(initial_path);
446 return -1;
447 }
448
449 return 0;
450 }
451
452 // Initialization - create the door, locks, and other initialization
453 int SolarisAttachListener::init() {
454 if (create_door()) {
455 return -1;
456 }
457
458 int status = os::Solaris::mutex_init(&_mutex);
459 assert_status(status==0, status, "mutex_init");
460
461 status = ::sema_init(&_wakeup, 0, NULL, NULL);
462 assert_status(status==0, status, "sema_init");
463
464 set_head(NULL);
465 set_tail(NULL);
466
467 return 0;
468 }
469
470 // Dequeue an operation
471 SolarisAttachOperation* SolarisAttachListener::dequeue() {
472 for (;;) {
473 int res;
474
475 // wait for somebody to enqueue something
476 while ((res = ::sema_wait(wakeup())) == EINTR)
477 ;
478 if (res) {
479 warning("sema_wait failed: %s", os::strerror(res));
480 return NULL;
481 }
482
483 // lock the list
484 res = os::Solaris::mutex_lock(mutex());
485 assert(res == 0, "mutex_lock failed");
486
487 // remove the head of the list
488 SolarisAttachOperation* op = head();
489 if (op != NULL) {
490 set_head(op->next());
491 if (head() == NULL) {
492 set_tail(NULL);
493 }
494 }
495
496 // unlock
497 os::Solaris::mutex_unlock(mutex());
498
499 // if we got an operation when return it.
500 if (op != NULL) {
501 return op;
502 }
503 }
504 }
505
506 // Enqueue an operation
507 void SolarisAttachListener::enqueue(SolarisAttachOperation* op) {
508 // lock list
509 int res = os::Solaris::mutex_lock(mutex());
510 assert(res == 0, "mutex_lock failed");
511
512 // enqueue at tail
513 op->set_next(NULL);
514 if (head() == NULL) {
515 set_head(op);
516 } else {
517 tail()->set_next(op);
518 }
519 set_tail(op);
520
521 // wakeup the attach listener
522 RESTARTABLE(::sema_post(wakeup()), res);
523 assert(res == 0, "sema_post failed");
524
525 // unlock
526 os::Solaris::mutex_unlock(mutex());
527 }
528
529
530 // support function - writes the (entire) buffer to a socket
531 static int write_fully(int s, char* buf, int len) {
532 do {
533 int n = ::write(s, buf, len);
534 if (n == -1) {
535 if (errno != EINTR) return -1;
536 } else {
537 buf += n;
538 len -= n;
539 }
540 }
541 while (len > 0);
542 return 0;
543 }
544
545 // Complete an operation by sending the operation result and any result
546 // output to the client. At this time the socket is in blocking mode so
547 // potentially we can block if there is a lot of data and the client is
548 // non-responsive. For most operations this is a non-issue because the
549 // default send buffer is sufficient to buffer everything. In the future
550 // if there are operations that involves a very big reply then it the
551 // socket could be made non-blocking and a timeout could be used.
552
553 void SolarisAttachOperation::complete(jint res, bufferedStream* st) {
554 if (this->socket() >= 0) {
555 JavaThread* thread = JavaThread::current();
556 ThreadBlockInVM tbivm(thread);
557
558 thread->set_suspend_equivalent();
559 // cleared by handle_special_suspend_equivalent_condition() or
560 // java_suspend_self() via check_and_wait_while_suspended()
561
562 // write operation result
563 char msg[32];
564 sprintf(msg, "%d\n", res);
565 int rc = write_fully(this->socket(), msg, strlen(msg));
566
567 // write any result data
568 if (rc == 0) {
569 write_fully(this->socket(), (char*) st->base(), st->size());
570 ::shutdown(this->socket(), 2);
571 }
572
573 // close socket and we're done
574 ::close(this->socket());
575
576 // were we externally suspended while we were waiting?
577 thread->check_and_wait_while_suspended();
578 }
579 delete this;
580 }
581
582
583 // AttachListener functions
584
585 AttachOperation* AttachListener::dequeue() {
586 JavaThread* thread = JavaThread::current();
587 ThreadBlockInVM tbivm(thread);
588
589 thread->set_suspend_equivalent();
590 // cleared by handle_special_suspend_equivalent_condition() or
591 // java_suspend_self() via check_and_wait_while_suspended()
592
593 AttachOperation* op = SolarisAttachListener::dequeue();
594
595 // were we externally suspended while we were waiting?
596 thread->check_and_wait_while_suspended();
597
598 return op;
599 }
600
601
602 // Performs initialization at vm startup
603 // For Solaris we remove any stale .java_pid file which could cause
604 // an attaching process to think we are ready to receive a door_call
605 // before we are properly initialized
606
607 void AttachListener::vm_start() {
608 char fn[PATH_MAX+1];
609 struct stat64 st;
610 int ret;
611
612 int n = snprintf(fn, sizeof(fn), "%s/.java_pid%d",
613 os::get_temp_directory(), os::current_process_id());
614 assert(n < sizeof(fn), "java_pid file name buffer overflow");
615
616 RESTARTABLE(::stat64(fn, &st), ret);
617 if (ret == 0) {
618 ret = ::unlink(fn);
619 if (ret == -1) {
620 log_debug(attach)("Failed to remove stale attach pid file at %s", fn);
621 }
622 }
623 }
624
625 int AttachListener::pd_init() {
626 JavaThread* thread = JavaThread::current();
627 ThreadBlockInVM tbivm(thread);
628
629 thread->set_suspend_equivalent();
630 // cleared by handle_special_suspend_equivalent_condition() or
631 // java_suspend_self()
632
633 int ret_code = SolarisAttachListener::init();
634
635 // were we externally suspended while we were waiting?
636 thread->check_and_wait_while_suspended();
637
638 return ret_code;
639 }
640
641 // Attach Listener is started lazily except in the case when
642 // +ReduseSignalUsage is used
643 bool AttachListener::init_at_startup() {
644 if (ReduceSignalUsage) {
645 return true;
646 } else {
647 return false;
648 }
649 }
650
651 bool AttachListener::check_socket_file() {
652 int ret;
653 struct stat64 st;
654 ret = stat64(SolarisAttachListener::door_path(), &st);
655 if (ret == -1) { // need to restart attach listener.
656 log_debug(attach)("Door file %s does not exist - Restart Attach Listener",
657 SolarisAttachListener::door_path());
658
659 listener_cleanup();
660
661 // wait to terminate current attach listener instance...
662 while (AttachListener::transit_state(AL_INITIALIZING,
663 AL_NOT_INITIALIZED) != AL_NOT_INITIALIZED) {
664 os::naked_yield();
665 }
666 is_init_trigger();
667 return true;
668 }
669 return false;
670 }
671
672 // If the file .attach_pid<pid> exists in the working directory
673 // or /tmp then this is the trigger to start the attach mechanism
674 bool AttachListener::is_init_trigger() {
675 if (init_at_startup() || is_initialized()) {
676 return false; // initialized at startup or already initialized
677 }
678 char fn[PATH_MAX + 1];
679 int ret;
680 struct stat64 st;
681 sprintf(fn, ".attach_pid%d", os::current_process_id());
682 RESTARTABLE(::stat64(fn, &st), ret);
683 if (ret == -1) {
684 log_trace(attach)("Failed to find attach file: %s, trying alternate", fn);
685 snprintf(fn, sizeof(fn), "%s/.attach_pid%d",
686 os::get_temp_directory(), os::current_process_id());
687 RESTARTABLE(::stat64(fn, &st), ret);
688 if (ret == -1) {
689 log_debug(attach)("Failed to find attach file: %s", fn);
690 }
691 }
692 if (ret == 0) {
693 // simple check to avoid starting the attach mechanism when
694 // a bogus non-root user creates the file
695 if (os::Posix::matches_effective_uid_or_root(st.st_uid)) {
696 init();
697 log_trace(attach)("Attach triggered by %s", fn);
698 return true;
699 } else {
700 log_debug(attach)("File %s has wrong user id %d (vs %d). Attach is not triggered", fn, st.st_uid, geteuid());
701 }
702 }
703 return false;
704 }
705
706 // if VM aborts then detach/cleanup
707 void AttachListener::abort() {
708 listener_cleanup();
709 }
710
711 void AttachListener::pd_data_dump() {
712 os::signal_notify(SIGQUIT);
713 }
714
715 static jint enable_dprobes(AttachOperation* op, outputStream* out) {
716 const char* probe = op->arg(0);
717 if (probe == NULL || probe[0] == '\0') {
718 out->print_cr("No probe specified");
719 return JNI_ERR;
720 } else {
721 char *end;
722 long val = strtol(probe, &end, 10);
723 if (end == probe || val < 0 || val > INT_MAX) {
724 out->print_cr("invalid probe type");
725 return JNI_ERR;
726 } else {
727 int probe_typess = (int) val;
728 DTrace::enable_dprobes(probe_typess);
729 return JNI_OK;
730 }
731 }
732 }
733
734 // platform specific operations table
735 static AttachOperationFunctionInfo funcs[] = {
736 { "enabledprobes", enable_dprobes },
737 { NULL, NULL }
738 };
739
740 AttachOperationFunctionInfo* AttachListener::pd_find_operation(const char* name) {
741 int i;
742 for (i = 0; funcs[i].name != NULL; i++) {
743 if (strcmp(funcs[i].name, name) == 0) {
744 return &funcs[i];
745 }
746 }
747 return NULL;
748 }
749
750 // Solaris specific global flag set. Currently, we support only
751 // changing ExtendedDTraceProbes flag.
752 jint AttachListener::pd_set_flag(AttachOperation* op, outputStream* out) {
753 const char* name = op->arg(0);
754 assert(name != NULL, "flag name should not be null");
755 bool flag = true;
756 const char* arg1;
757 if ((arg1 = op->arg(1)) != NULL) {
758 char *end;
759 flag = (strtol(arg1, &end, 10) != 0);
760 if (arg1 == end) {
761 out->print_cr("flag value has to be an integer");
762 return JNI_ERR;
763 }
764 }
765
766 if (strcmp(name, "ExtendedDTraceProbes") == 0) {
767 DTrace::set_extended_dprobes(flag);
768 return JNI_OK;
769 }
770
771 if (strcmp(name, "DTraceMonitorProbes") == 0) {
772 DTrace::set_monitor_dprobes(flag);
773 return JNI_OK;
774 }
775
776 out->print_cr("flag '%s' cannot be changed", name);
777 return JNI_ERR;
778 }
779
780 void AttachListener::pd_detachall() {
781 DTrace::detach_all_clients();
782 }