1 /*
2 * Copyright (c) 1999, 2014, 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 "utilities/globalDefinitions.hpp"
26 #include "prims/jvm.h"
27 #include "runtime/frame.inline.hpp"
28 #include "runtime/interfaceSupport.hpp"
29 #include "runtime/os.hpp"
30 #include "utilities/vmError.hpp"
31
32 #include <signal.h>
33 #include <unistd.h>
34 #include <sys/resource.h>
35 #include <sys/utsname.h>
36 #include <pthread.h>
37 #include <signal.h>
38
39 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
40
41 // Todo: provide a os::get_max_process_id() or similar. Number of processes
42 // may have been configured, can be read more accurately from proc fs etc.
43 #ifndef MAX_PID
44 #define MAX_PID INT_MAX
45 #endif
46 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
47
48 // Check core dump limit and report possible place where core can be found
49 void os::check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize) {
50 int n;
51 struct rlimit rlim;
52 bool success;
53
54 char core_path[PATH_MAX];
55 n = get_core_path(core_path, PATH_MAX);
56
57 if (n <= 0) {
58 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
59 success = true;
60 #ifdef LINUX
61 } else if (core_path[0] == '"') { // redirect to user process
62 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
63 success = true;
64 #endif
65 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
66 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
67 success = true;
68 } else {
69 switch(rlim.rlim_cur) {
70 case RLIM_INFINITY:
71 jio_snprintf(buffer, bufferSize, "%s", core_path);
72 success = true;
73 break;
74 case 0:
75 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
76 success = false;
77 break;
78 default:
79 jio_snprintf(buffer, bufferSize, "%s (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", core_path, (unsigned long)(rlim.rlim_cur >> 10));
80 success = true;
81 break;
82 }
83 }
84
85 VMError::report_coredump_status(buffer, success);
86 }
87
88 int os::get_native_stack(address* stack, int frames, int toSkip) {
89 #ifdef _NMT_NOINLINE_
90 toSkip++;
91 #endif
92
93 int frame_idx = 0;
94 int num_of_frames; // number of frames captured
95 frame fr = os::current_frame();
96 while (fr.pc() && frame_idx < frames) {
97 if (toSkip > 0) {
98 toSkip --;
99 } else {
100 stack[frame_idx ++] = fr.pc();
101 }
102 if (fr.fp() == NULL || os::is_first_C_frame(&fr)
103 ||fr.sender_pc() == NULL || fr.cb() != NULL) break;
104
105 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
106 fr = os::get_sender_for_C_frame(&fr);
107 } else {
108 break;
109 }
110 }
111 num_of_frames = frame_idx;
112 for (; frame_idx < frames; frame_idx ++) {
113 stack[frame_idx] = NULL;
114 }
115
116 return num_of_frames;
117 }
118
119
120 bool os::unsetenv(const char* name) {
121 assert(name != NULL, "Null pointer");
122 return (::unsetenv(name) == 0);
123 }
124
125 int os::get_last_error() {
126 return errno;
127 }
128
129 bool os::is_debugger_attached() {
130 // not implemented
131 return false;
132 }
133
134 void os::wait_for_keypress_at_exit(void) {
135 // don't do anything on posix platforms
136 return;
137 }
138
139 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
140 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
141 // rather than unmapping and remapping the whole chunk to get requested alignment.
142 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
143 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
144 "Alignment must be a multiple of allocation granularity (page size)");
145 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
146
147 size_t extra_size = size + alignment;
148 assert(extra_size >= size, "overflow, size is too large to allow alignment");
149
150 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
151
152 if (extra_base == NULL) {
153 return NULL;
154 }
155
156 // Do manual alignment
157 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
158
159 // [ | | ]
160 // ^ extra_base
161 // ^ extra_base + begin_offset == aligned_base
162 // extra_base + begin_offset + size ^
163 // extra_base + extra_size ^
164 // |<>| == begin_offset
165 // end_offset == |<>|
166 size_t begin_offset = aligned_base - extra_base;
167 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
168
169 if (begin_offset > 0) {
170 os::release_memory(extra_base, begin_offset);
171 }
172
173 if (end_offset > 0) {
174 os::release_memory(extra_base + begin_offset + size, end_offset);
175 }
176
177 return aligned_base;
178 }
179
180 void os::Posix::print_load_average(outputStream* st) {
181 st->print("load average:");
182 double loadavg[3];
183 os::loadavg(loadavg, 3);
184 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
185 st->cr();
186 }
187
188 void os::Posix::print_rlimit_info(outputStream* st) {
189 st->print("rlimit:");
190 struct rlimit rlim;
191
192 st->print(" STACK ");
193 getrlimit(RLIMIT_STACK, &rlim);
194 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
195 else st->print("%uk", rlim.rlim_cur >> 10);
196
197 st->print(", CORE ");
198 getrlimit(RLIMIT_CORE, &rlim);
199 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
200 else st->print("%uk", rlim.rlim_cur >> 10);
201
202 // Isn't there on solaris
203 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
204 st->print(", NPROC ");
205 getrlimit(RLIMIT_NPROC, &rlim);
206 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
207 else st->print("%d", rlim.rlim_cur);
208 #endif
209
210 st->print(", NOFILE ");
211 getrlimit(RLIMIT_NOFILE, &rlim);
212 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
213 else st->print("%d", rlim.rlim_cur);
214
215 st->print(", AS ");
216 getrlimit(RLIMIT_AS, &rlim);
217 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
218 else st->print("%uk", rlim.rlim_cur >> 10);
219 st->cr();
220 }
221
222 void os::Posix::print_uname_info(outputStream* st) {
223 // kernel
224 st->print("uname:");
225 struct utsname name;
226 uname(&name);
227 st->print("%s ", name.sysname);
228 #ifdef ASSERT
229 st->print("%s ", name.nodename);
230 #endif
231 st->print("%s ", name.release);
232 st->print("%s ", name.version);
233 st->print("%s", name.machine);
234 st->cr();
235 }
236
237 bool os::has_allocatable_memory_limit(julong* limit) {
238 struct rlimit rlim;
239 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
240 // if there was an error when calling getrlimit, assume that there is no limitation
241 // on virtual memory.
242 bool result;
243 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
244 result = false;
245 } else {
246 *limit = (julong)rlim.rlim_cur;
247 result = true;
248 }
249 #ifdef _LP64
250 return result;
251 #else
252 // arbitrary virtual space limit for 32 bit Unices found by testing. If
253 // getrlimit above returned a limit, bound it with this limit. Otherwise
254 // directly use it.
255 const julong max_virtual_limit = (julong)3800*M;
256 if (result) {
257 *limit = MIN2(*limit, max_virtual_limit);
258 } else {
259 *limit = max_virtual_limit;
260 }
261
262 // bound by actually allocatable memory. The algorithm uses two bounds, an
263 // upper and a lower limit. The upper limit is the current highest amount of
264 // memory that could not be allocated, the lower limit is the current highest
265 // amount of memory that could be allocated.
266 // The algorithm iteratively refines the result by halving the difference
267 // between these limits, updating either the upper limit (if that value could
268 // not be allocated) or the lower limit (if the that value could be allocated)
269 // until the difference between these limits is "small".
270
271 // the minimum amount of memory we care about allocating.
272 const julong min_allocation_size = M;
273
274 julong upper_limit = *limit;
275
276 // first check a few trivial cases
277 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
278 *limit = upper_limit;
279 } else if (!is_allocatable(min_allocation_size)) {
280 // we found that not even min_allocation_size is allocatable. Return it
281 // anyway. There is no point to search for a better value any more.
282 *limit = min_allocation_size;
283 } else {
284 // perform the binary search.
285 julong lower_limit = min_allocation_size;
286 while ((upper_limit - lower_limit) > min_allocation_size) {
287 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
288 temp_limit = align_size_down_(temp_limit, min_allocation_size);
289 if (is_allocatable(temp_limit)) {
290 lower_limit = temp_limit;
291 } else {
292 upper_limit = temp_limit;
293 }
294 }
295 *limit = lower_limit;
296 }
297 return true;
298 #endif
299 }
300
301 const char* os::get_current_directory(char *buf, size_t buflen) {
302 return getcwd(buf, buflen);
303 }
304
305 FILE* os::open(int fd, const char* mode) {
306 return ::fdopen(fd, mode);
307 }
308
309 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
310 // which is used to find statically linked in agents.
311 // Parameters:
312 // sym_name: Symbol in library we are looking for
313 // lib_name: Name of library to look in, NULL for shared libs.
314 // is_absolute_path == true if lib_name is absolute path to agent
315 // such as "/a/b/libL.so"
316 // == false if only the base name of the library is passed in
317 // such as "L"
318 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
319 bool is_absolute_path) {
320 char *agent_entry_name;
321 size_t len;
322 size_t name_len;
323 size_t prefix_len = strlen(JNI_LIB_PREFIX);
324 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
325 const char *start;
326
327 if (lib_name != NULL) {
328 len = name_len = strlen(lib_name);
329 if (is_absolute_path) {
330 // Need to strip path, prefix and suffix
331 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
332 lib_name = ++start;
333 }
334 if (len <= (prefix_len + suffix_len)) {
335 return NULL;
336 }
337 lib_name += prefix_len;
338 name_len = strlen(lib_name) - suffix_len;
339 }
340 }
341 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
342 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
343 if (agent_entry_name == NULL) {
344 return NULL;
345 }
346 strcpy(agent_entry_name, sym_name);
347 if (lib_name != NULL) {
348 strcat(agent_entry_name, "_");
349 strncat(agent_entry_name, lib_name, name_len);
350 }
351 return agent_entry_name;
352 }
353
354 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
355 assert(thread == Thread::current(), "thread consistency check");
356
357 ParkEvent * const slp = thread->_SleepEvent ;
358 slp->reset() ;
359 OrderAccess::fence() ;
360
361 if (interruptible) {
362 jlong prevtime = javaTimeNanos();
363
364 for (;;) {
365 if (os::is_interrupted(thread, true)) {
366 return OS_INTRPT;
367 }
368
369 jlong newtime = javaTimeNanos();
370
371 if (newtime - prevtime < 0) {
372 // time moving backwards, should only happen if no monotonic clock
373 // not a guarantee() because JVM should not abort on kernel/glibc bugs
374 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
375 } else {
376 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
377 }
378
379 if (millis <= 0) {
380 return OS_OK;
381 }
382
383 prevtime = newtime;
384
385 {
386 assert(thread->is_Java_thread(), "sanity check");
387 JavaThread *jt = (JavaThread *) thread;
388 ThreadBlockInVM tbivm(jt);
389 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
390
391 jt->set_suspend_equivalent();
392 // cleared by handle_special_suspend_equivalent_condition() or
393 // java_suspend_self() via check_and_wait_while_suspended()
394
395 slp->park(millis);
396
397 // were we externally suspended while we were waiting?
398 jt->check_and_wait_while_suspended();
399 }
400 }
401 } else {
402 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
403 jlong prevtime = javaTimeNanos();
404
405 for (;;) {
406 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
407 // the 1st iteration ...
408 jlong newtime = javaTimeNanos();
409
410 if (newtime - prevtime < 0) {
411 // time moving backwards, should only happen if no monotonic clock
412 // not a guarantee() because JVM should not abort on kernel/glibc bugs
413 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
414 } else {
415 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
416 }
417
418 if (millis <= 0) break ;
419
420 prevtime = newtime;
421 slp->park(millis);
422 }
423 return OS_OK ;
424 }
425 }
426
427 ////////////////////////////////////////////////////////////////////////////////
428 // interrupt support
429
430 void os::interrupt(Thread* thread) {
431 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
432 "possibility of dangling Thread pointer");
433
434 OSThread* osthread = thread->osthread();
435
436 if (!osthread->interrupted()) {
437 osthread->set_interrupted(true);
438 // More than one thread can get here with the same value of osthread,
439 // resulting in multiple notifications. We do, however, want the store
440 // to interrupted() to be visible to other threads before we execute unpark().
441 OrderAccess::fence();
442 ParkEvent * const slp = thread->_SleepEvent ;
443 if (slp != NULL) slp->unpark() ;
444 }
445
446 // For JSR166. Unpark even if interrupt status already was set
447 if (thread->is_Java_thread())
448 ((JavaThread*)thread)->parker()->unpark();
449
450 ParkEvent * ev = thread->_ParkEvent ;
451 if (ev != NULL) ev->unpark() ;
452
453 }
454
455 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
456 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
457 "possibility of dangling Thread pointer");
458
459 OSThread* osthread = thread->osthread();
460
461 bool interrupted = osthread->interrupted();
462
463 // NOTE that since there is no "lock" around the interrupt and
464 // is_interrupted operations, there is the possibility that the
465 // interrupted flag (in osThread) will be "false" but that the
466 // low-level events will be in the signaled state. This is
467 // intentional. The effect of this is that Object.wait() and
468 // LockSupport.park() will appear to have a spurious wakeup, which
469 // is allowed and not harmful, and the possibility is so rare that
470 // it is not worth the added complexity to add yet another lock.
471 // For the sleep event an explicit reset is performed on entry
472 // to os::sleep, so there is no early return. It has also been
473 // recommended not to put the interrupted flag into the "event"
474 // structure because it hides the issue.
475 if (interrupted && clear_interrupted) {
476 osthread->set_interrupted(false);
477 // consider thread->_SleepEvent->reset() ... optional optimization
478 }
479
480 return interrupted;
481 }
482
483 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
484 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
485
486 static const struct {
487 int sig; const char* name;
488 }
489 info[] =
490 {
491 { SIGABRT, "SIGABRT" },
492 #ifdef SIGAIO
493 { SIGAIO, "SIGAIO" },
494 #endif
495 { SIGALRM, "SIGALRM" },
496 #ifdef SIGALRM1
497 { SIGALRM1, "SIGALRM1" },
498 #endif
499 { SIGBUS, "SIGBUS" },
500 #ifdef SIGCANCEL
501 { SIGCANCEL, "SIGCANCEL" },
502 #endif
503 { SIGCHLD, "SIGCHLD" },
504 #ifdef SIGCLD
505 { SIGCLD, "SIGCLD" },
506 #endif
507 { SIGCONT, "SIGCONT" },
508 #ifdef SIGCPUFAIL
509 { SIGCPUFAIL, "SIGCPUFAIL" },
510 #endif
511 #ifdef SIGDANGER
512 { SIGDANGER, "SIGDANGER" },
513 #endif
514 #ifdef SIGDIL
515 { SIGDIL, "SIGDIL" },
516 #endif
517 #ifdef SIGEMT
518 { SIGEMT, "SIGEMT" },
519 #endif
520 { SIGFPE, "SIGFPE" },
521 #ifdef SIGFREEZE
522 { SIGFREEZE, "SIGFREEZE" },
523 #endif
524 #ifdef SIGGFAULT
525 { SIGGFAULT, "SIGGFAULT" },
526 #endif
527 #ifdef SIGGRANT
528 { SIGGRANT, "SIGGRANT" },
529 #endif
530 { SIGHUP, "SIGHUP" },
531 { SIGILL, "SIGILL" },
532 { SIGINT, "SIGINT" },
533 #ifdef SIGIO
534 { SIGIO, "SIGIO" },
535 #endif
536 #ifdef SIGIOINT
537 { SIGIOINT, "SIGIOINT" },
538 #endif
539 #ifdef SIGIOT
540 // SIGIOT is there for BSD compatibility, but on most Unices just a
541 // synonym for SIGABRT. The result should be "SIGABRT", not
542 // "SIGIOT".
543 #if (SIGIOT != SIGABRT )
544 { SIGIOT, "SIGIOT" },
545 #endif
546 #endif
547 #ifdef SIGKAP
548 { SIGKAP, "SIGKAP" },
549 #endif
550 { SIGKILL, "SIGKILL" },
551 #ifdef SIGLOST
552 { SIGLOST, "SIGLOST" },
553 #endif
554 #ifdef SIGLWP
555 { SIGLWP, "SIGLWP" },
556 #endif
557 #ifdef SIGLWPTIMER
558 { SIGLWPTIMER, "SIGLWPTIMER" },
559 #endif
560 #ifdef SIGMIGRATE
561 { SIGMIGRATE, "SIGMIGRATE" },
562 #endif
563 #ifdef SIGMSG
564 { SIGMSG, "SIGMSG" },
565 #endif
566 { SIGPIPE, "SIGPIPE" },
567 #ifdef SIGPOLL
568 { SIGPOLL, "SIGPOLL" },
569 #endif
570 #ifdef SIGPRE
571 { SIGPRE, "SIGPRE" },
572 #endif
573 { SIGPROF, "SIGPROF" },
574 #ifdef SIGPTY
575 { SIGPTY, "SIGPTY" },
576 #endif
577 #ifdef SIGPWR
578 { SIGPWR, "SIGPWR" },
579 #endif
580 { SIGQUIT, "SIGQUIT" },
581 #ifdef SIGRECONFIG
582 { SIGRECONFIG, "SIGRECONFIG" },
583 #endif
584 #ifdef SIGRECOVERY
585 { SIGRECOVERY, "SIGRECOVERY" },
586 #endif
587 #ifdef SIGRESERVE
588 { SIGRESERVE, "SIGRESERVE" },
589 #endif
590 #ifdef SIGRETRACT
591 { SIGRETRACT, "SIGRETRACT" },
592 #endif
593 #ifdef SIGSAK
594 { SIGSAK, "SIGSAK" },
595 #endif
596 { SIGSEGV, "SIGSEGV" },
597 #ifdef SIGSOUND
598 { SIGSOUND, "SIGSOUND" },
599 #endif
600 { SIGSTOP, "SIGSTOP" },
601 { SIGSYS, "SIGSYS" },
602 #ifdef SIGSYSERROR
603 { SIGSYSERROR, "SIGSYSERROR" },
604 #endif
605 #ifdef SIGTALRM
606 { SIGTALRM, "SIGTALRM" },
607 #endif
608 { SIGTERM, "SIGTERM" },
609 #ifdef SIGTHAW
610 { SIGTHAW, "SIGTHAW" },
611 #endif
612 { SIGTRAP, "SIGTRAP" },
613 #ifdef SIGTSTP
614 { SIGTSTP, "SIGTSTP" },
615 #endif
616 { SIGTTIN, "SIGTTIN" },
617 { SIGTTOU, "SIGTTOU" },
618 #ifdef SIGURG
619 { SIGURG, "SIGURG" },
620 #endif
621 { SIGUSR1, "SIGUSR1" },
622 { SIGUSR2, "SIGUSR2" },
623 #ifdef SIGVIRT
624 { SIGVIRT, "SIGVIRT" },
625 #endif
626 { SIGVTALRM, "SIGVTALRM" },
627 #ifdef SIGWAITING
628 { SIGWAITING, "SIGWAITING" },
629 #endif
630 #ifdef SIGWINCH
631 { SIGWINCH, "SIGWINCH" },
632 #endif
633 #ifdef SIGWINDOW
634 { SIGWINDOW, "SIGWINDOW" },
635 #endif
636 { SIGXCPU, "SIGXCPU" },
637 { SIGXFSZ, "SIGXFSZ" },
638 #ifdef SIGXRES
639 { SIGXRES, "SIGXRES" },
640 #endif
641 { -1, NULL }
642 };
643
644 const char* ret = NULL;
645
646 #ifdef SIGRTMIN
647 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
648 if (sig == SIGRTMIN) {
649 ret = "SIGRTMIN";
650 } else if (sig == SIGRTMAX) {
651 ret = "SIGRTMAX";
652 } else {
653 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
654 return out;
655 }
656 }
657 #endif
658
659 if (sig > 0) {
660 for (int idx = 0; info[idx].sig != -1; idx ++) {
661 if (info[idx].sig == sig) {
662 ret = info[idx].name;
663 break;
664 }
665 }
666 }
667
668 if (!ret) {
669 if (!is_valid_signal(sig)) {
670 ret = "INVALID";
671 } else {
672 ret = "UNKNOWN";
673 }
674 }
675
676 if (out && outlen > 0) {
677 strncpy(out, ret, outlen);
678 out[outlen - 1] = '\0';
679 }
680 return out;
681 }
682
683 // Returns true if signal number is valid.
684 bool os::Posix::is_valid_signal(int sig) {
685 // MacOS not really POSIX compliant: sigaddset does not return
686 // an error for invalid signal numbers. However, MacOS does not
687 // support real time signals and simply seems to have just 33
688 // signals with no holes in the signal range.
689 #ifdef __APPLE__
690 return sig >= 1 && sig < NSIG;
691 #else
692 // Use sigaddset to check for signal validity.
693 sigset_t set;
694 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
695 return false;
696 }
697 return true;
698 #endif
699 }
700
701 #define NUM_IMPORTANT_SIGS 32
702 // Returns one-line short description of a signal set in a user provided buffer.
703 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
704 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
705 // Note: for shortness, just print out the first 32. That should
706 // cover most of the useful ones, apart from realtime signals.
707 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
708 const int rc = sigismember(set, sig);
709 if (rc == -1 && errno == EINVAL) {
710 buffer[sig-1] = '?';
711 } else {
712 buffer[sig-1] = rc == 0 ? '0' : '1';
713 }
714 }
715 buffer[NUM_IMPORTANT_SIGS] = 0;
716 return buffer;
717 }
718
719 // Prints one-line description of a signal set.
720 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
721 char buf[NUM_IMPORTANT_SIGS + 1];
722 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
723 st->print("%s", buf);
724 }
725
726 // Writes one-line description of a combination of sigaction.sa_flags into a user
727 // provided buffer. Returns that buffer.
728 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
729 char* p = buffer;
730 size_t remaining = size;
731 bool first = true;
732 int idx = 0;
733
734 assert(buffer, "invalid argument");
735
736 if (size == 0) {
737 return buffer;
738 }
739
740 strncpy(buffer, "none", size);
741
742 const struct {
743 int i;
744 const char* s;
745 } flaginfo [] = {
746 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
747 { SA_ONSTACK, "SA_ONSTACK" },
748 { SA_RESETHAND, "SA_RESETHAND" },
749 { SA_RESTART, "SA_RESTART" },
750 { SA_SIGINFO, "SA_SIGINFO" },
751 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
752 { SA_NODEFER, "SA_NODEFER" },
753 #ifdef AIX
754 { SA_ONSTACK, "SA_ONSTACK" },
755 { SA_OLDSTYLE, "SA_OLDSTYLE" },
756 #endif
757 { 0, NULL }
758 };
759
760 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
761 if (flags & flaginfo[idx].i) {
762 if (first) {
763 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
764 first = false;
765 } else {
766 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
767 }
768 const size_t len = strlen(p);
769 p += len;
770 remaining -= len;
771 }
772 }
773
774 buffer[size - 1] = '\0';
775
776 return buffer;
777 }
778
779 // Prints one-line description of a combination of sigaction.sa_flags.
780 void os::Posix::print_sa_flags(outputStream* st, int flags) {
781 char buffer[0x100];
782 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
783 st->print("%s", buffer);
784 }
785
786 // Helper function for os::Posix::print_siginfo_...():
787 // return a textual description for signal code.
788 struct enum_sigcode_desc_t {
789 const char* s_name;
790 const char* s_desc;
791 };
792
793 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
794
795 const struct {
796 int sig; int code; const char* s_code; const char* s_desc;
797 } t1 [] = {
798 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
799 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
800 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
801 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
802 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
803 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
804 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
805 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
806 #if defined(IA64) && defined(LINUX)
807 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
808 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
809 #endif
810 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
811 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
812 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
813 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
814 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
815 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
816 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
817 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
818 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
819 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
820 #ifdef AIX
821 // no explanation found what keyerr would be
822 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
823 #endif
824 #if defined(IA64) && !defined(AIX)
825 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
826 #endif
827 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
828 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
829 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
830 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
831 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
832 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
833 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
834 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
835 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
836 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
837 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
838 #ifdef SIGPOLL
839 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
840 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
841 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
842 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
843 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
844 #endif
845 { -1, -1, NULL, NULL }
846 };
847
848 // Codes valid in any signal context.
849 const struct {
850 int code; const char* s_code; const char* s_desc;
851 } t2 [] = {
852 { SI_USER, "SI_USER", "Signal sent by kill()." },
853 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
854 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
855 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
856 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
857 // Linux specific
858 #ifdef SI_TKILL
859 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
860 #endif
861 #ifdef SI_DETHREAD
862 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
863 #endif
864 #ifdef SI_KERNEL
865 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
866 #endif
867 #ifdef SI_SIGIO
868 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
869 #endif
870
871 #ifdef AIX
872 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
873 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
874 #endif
875
876 #ifdef __sun
877 { SI_NOINFO, "SI_NOINFO", "No signal information" },
878 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
879 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
880 #endif
881
882 { -1, NULL, NULL }
883 };
884
885 const char* s_code = NULL;
886 const char* s_desc = NULL;
887
888 for (int i = 0; t1[i].sig != -1; i ++) {
889 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
890 s_code = t1[i].s_code;
891 s_desc = t1[i].s_desc;
892 break;
893 }
894 }
895
896 if (s_code == NULL) {
897 for (int i = 0; t2[i].s_code != NULL; i ++) {
898 if (t2[i].code == si->si_code) {
899 s_code = t2[i].s_code;
900 s_desc = t2[i].s_desc;
901 }
902 }
903 }
904
905 if (s_code == NULL) {
906 out->s_name = "unknown";
907 out->s_desc = "unknown";
908 return false;
909 }
910
911 out->s_name = s_code;
912 out->s_desc = s_desc;
913
914 return true;
915 }
916
917 // A POSIX conform, platform-independend siginfo print routine.
918 // Short print out on one line.
919 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) {
920 char buf[20];
921 os->print("siginfo: ");
922
923 if (!si) {
924 os->print("<null>");
925 return;
926 }
927
928 // See print_siginfo_full() for details.
929 const int sig = si->si_signo;
930
931 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
932
933 enum_sigcode_desc_t ed;
934 if (get_signal_code_description(si, &ed)) {
935 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
936 } else {
937 os->print(", si_code: %d (unknown)", si->si_code);
938 }
939
940 if (si->si_errno) {
941 os->print(", si_errno: %d", si->si_errno);
942 }
943
944 const int me = (int) ::getpid();
945 const int pid = (int) si->si_pid;
946
947 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
948 if (IS_VALID_PID(pid) && pid != me) {
949 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid);
950 }
951 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
952 sig == SIGTRAP || sig == SIGFPE) {
953 os->print(", si_addr: " PTR_FORMAT, si->si_addr);
954 #ifdef SIGPOLL
955 } else if (sig == SIGPOLL) {
956 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band);
957 #endif
958 } else if (sig == SIGCHLD) {
959 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status);
960 }
961 }
962
963 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
964 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
965 }
966
967 /*
968 * See the caveats for this class in os_posix.hpp
969 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
970 * method and returns false. If none of the signals are raised, returns true.
971 * The callback is supposed to provide the method that should be protected.
972 */
973 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
974 sigset_t saved_sig_mask;
975
976 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
977 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
978 "crash_protection already set?");
979
980 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
981 // since on at least some systems (OS X) siglongjmp will restore the mask
982 // for the process, not the thread
983 pthread_sigmask(0, NULL, &saved_sig_mask);
984 if (sigsetjmp(_jmpbuf, 0) == 0) {
985 // make sure we can see in the signal handler that we have crash protection
986 // installed
987 WatcherThread::watcher_thread()->set_crash_protection(this);
988 cb.call();
989 // and clear the crash protection
990 WatcherThread::watcher_thread()->set_crash_protection(NULL);
991 return true;
992 }
993 // this happens when we siglongjmp() back
994 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
995 WatcherThread::watcher_thread()->set_crash_protection(NULL);
996 return false;
997 }
998
999 void os::WatcherThreadCrashProtection::restore() {
1000 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1001 "must have crash protection");
1002
1003 siglongjmp(_jmpbuf, 1);
1004 }
1005
1006 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1007 Thread* thread) {
1008
1009 if (thread != NULL &&
1010 thread->is_Watcher_thread() &&
1011 WatcherThread::watcher_thread()->has_crash_protection()) {
1012
1013 if (sig == SIGSEGV || sig == SIGBUS) {
1014 WatcherThread::watcher_thread()->crash_protection()->restore();
1015 }
1016 }
1017 }