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 n = get_core_path(buffer, bufferSize);
55
56 if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
57 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d (may not exist)", current_process_id());
58 success = true;
59 } else {
60 switch(rlim.rlim_cur) {
61 case RLIM_INFINITY:
62 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d", current_process_id());
63 success = true;
64 break;
65
66 case 0:
67 {
68 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
69
70 #ifdef LINUX
71 /*
72 * Max length of /proc/sys/kernel/core_pattern is 128 characters.
73 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
74 */
75 const int core_pattern_len = 129;
76
77 char core_pattern[core_pattern_len] = {0};
78 bool is_redirect = false;
79 FILE *core_pattern_file = fopen("/proc/sys/kernel/core_pattern", "r");
80 if(core_pattern_file != NULL){
81 fgets(core_pattern, core_pattern_len, core_pattern_file);
82 fclose(core_pattern_file);
83 is_redirect = core_pattern[0] == '|';
84 }
85
86 if(is_redirect){
87 jio_snprintf(buffer, bufferSize,
88 "Core dumps may be treated with \"%s\"", &core_pattern[1]);
89 }
90 #endif
91
92 success = false;
93 break;
94 }
95
96 default:
97 jio_snprintf(buffer + n, bufferSize - n, "/core or core.%d (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", current_process_id(), (unsigned long)(rlim.rlim_cur >> 10));
98 success = true;
99 break;
100 }
101 }
102 VMError::report_coredump_status(buffer, success);
103 }
104
105 int os::get_native_stack(address* stack, int frames, int toSkip) {
106 #ifdef _NMT_NOINLINE_
107 toSkip++;
108 #endif
109
110 int frame_idx = 0;
111 int num_of_frames; // number of frames captured
112 frame fr = os::current_frame();
113 while (fr.pc() && frame_idx < frames) {
114 if (toSkip > 0) {
115 toSkip --;
116 } else {
117 stack[frame_idx ++] = fr.pc();
118 }
119 if (fr.fp() == NULL || os::is_first_C_frame(&fr)
120 ||fr.sender_pc() == NULL || fr.cb() != NULL) break;
121
122 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
123 fr = os::get_sender_for_C_frame(&fr);
124 } else {
125 break;
126 }
127 }
128 num_of_frames = frame_idx;
129 for (; frame_idx < frames; frame_idx ++) {
130 stack[frame_idx] = NULL;
131 }
132
133 return num_of_frames;
134 }
135
136
137 bool os::unsetenv(const char* name) {
138 assert(name != NULL, "Null pointer");
139 return (::unsetenv(name) == 0);
140 }
141
142 int os::get_last_error() {
143 return errno;
144 }
145
146 bool os::is_debugger_attached() {
147 // not implemented
148 return false;
149 }
150
151 void os::wait_for_keypress_at_exit(void) {
152 // don't do anything on posix platforms
153 return;
154 }
155
156 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
157 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
158 // rather than unmapping and remapping the whole chunk to get requested alignment.
159 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
160 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
161 "Alignment must be a multiple of allocation granularity (page size)");
162 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
163
164 size_t extra_size = size + alignment;
165 assert(extra_size >= size, "overflow, size is too large to allow alignment");
166
167 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
168
169 if (extra_base == NULL) {
170 return NULL;
171 }
172
173 // Do manual alignment
174 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
175
176 // [ | | ]
177 // ^ extra_base
178 // ^ extra_base + begin_offset == aligned_base
179 // extra_base + begin_offset + size ^
180 // extra_base + extra_size ^
181 // |<>| == begin_offset
182 // end_offset == |<>|
183 size_t begin_offset = aligned_base - extra_base;
184 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
185
186 if (begin_offset > 0) {
187 os::release_memory(extra_base, begin_offset);
188 }
189
190 if (end_offset > 0) {
191 os::release_memory(extra_base + begin_offset + size, end_offset);
192 }
193
194 return aligned_base;
195 }
196
197 void os::Posix::print_load_average(outputStream* st) {
198 st->print("load average:");
199 double loadavg[3];
200 os::loadavg(loadavg, 3);
201 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
202 st->cr();
203 }
204
205 void os::Posix::print_rlimit_info(outputStream* st) {
206 st->print("rlimit:");
207 struct rlimit rlim;
208
209 st->print(" STACK ");
210 getrlimit(RLIMIT_STACK, &rlim);
211 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
212 else st->print("%uk", rlim.rlim_cur >> 10);
213
214 st->print(", CORE ");
215 getrlimit(RLIMIT_CORE, &rlim);
216 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
217 else st->print("%uk", rlim.rlim_cur >> 10);
218
219 // Isn't there on solaris
220 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
221 st->print(", NPROC ");
222 getrlimit(RLIMIT_NPROC, &rlim);
223 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
224 else st->print("%d", rlim.rlim_cur);
225 #endif
226
227 st->print(", NOFILE ");
228 getrlimit(RLIMIT_NOFILE, &rlim);
229 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
230 else st->print("%d", rlim.rlim_cur);
231
232 st->print(", AS ");
233 getrlimit(RLIMIT_AS, &rlim);
234 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
235 else st->print("%uk", rlim.rlim_cur >> 10);
236 st->cr();
237 }
238
239 void os::Posix::print_uname_info(outputStream* st) {
240 // kernel
241 st->print("uname:");
242 struct utsname name;
243 uname(&name);
244 st->print("%s ", name.sysname);
245 #ifdef ASSERT
246 st->print("%s ", name.nodename);
247 #endif
248 st->print("%s ", name.release);
249 st->print("%s ", name.version);
250 st->print("%s", name.machine);
251 st->cr();
252 }
253
254 bool os::has_allocatable_memory_limit(julong* limit) {
255 struct rlimit rlim;
256 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
257 // if there was an error when calling getrlimit, assume that there is no limitation
258 // on virtual memory.
259 bool result;
260 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
261 result = false;
262 } else {
263 *limit = (julong)rlim.rlim_cur;
264 result = true;
265 }
266 #ifdef _LP64
267 return result;
268 #else
269 // arbitrary virtual space limit for 32 bit Unices found by testing. If
270 // getrlimit above returned a limit, bound it with this limit. Otherwise
271 // directly use it.
272 const julong max_virtual_limit = (julong)3800*M;
273 if (result) {
274 *limit = MIN2(*limit, max_virtual_limit);
275 } else {
276 *limit = max_virtual_limit;
277 }
278
279 // bound by actually allocatable memory. The algorithm uses two bounds, an
280 // upper and a lower limit. The upper limit is the current highest amount of
281 // memory that could not be allocated, the lower limit is the current highest
282 // amount of memory that could be allocated.
283 // The algorithm iteratively refines the result by halving the difference
284 // between these limits, updating either the upper limit (if that value could
285 // not be allocated) or the lower limit (if the that value could be allocated)
286 // until the difference between these limits is "small".
287
288 // the minimum amount of memory we care about allocating.
289 const julong min_allocation_size = M;
290
291 julong upper_limit = *limit;
292
293 // first check a few trivial cases
294 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
295 *limit = upper_limit;
296 } else if (!is_allocatable(min_allocation_size)) {
297 // we found that not even min_allocation_size is allocatable. Return it
298 // anyway. There is no point to search for a better value any more.
299 *limit = min_allocation_size;
300 } else {
301 // perform the binary search.
302 julong lower_limit = min_allocation_size;
303 while ((upper_limit - lower_limit) > min_allocation_size) {
304 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
305 temp_limit = align_size_down_(temp_limit, min_allocation_size);
306 if (is_allocatable(temp_limit)) {
307 lower_limit = temp_limit;
308 } else {
309 upper_limit = temp_limit;
310 }
311 }
312 *limit = lower_limit;
313 }
314 return true;
315 #endif
316 }
317
318 const char* os::get_current_directory(char *buf, size_t buflen) {
319 return getcwd(buf, buflen);
320 }
321
322 FILE* os::open(int fd, const char* mode) {
323 return ::fdopen(fd, mode);
324 }
325
326 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
327 // which is used to find statically linked in agents.
328 // Parameters:
329 // sym_name: Symbol in library we are looking for
330 // lib_name: Name of library to look in, NULL for shared libs.
331 // is_absolute_path == true if lib_name is absolute path to agent
332 // such as "/a/b/libL.so"
333 // == false if only the base name of the library is passed in
334 // such as "L"
335 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
336 bool is_absolute_path) {
337 char *agent_entry_name;
338 size_t len;
339 size_t name_len;
340 size_t prefix_len = strlen(JNI_LIB_PREFIX);
341 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
342 const char *start;
343
344 if (lib_name != NULL) {
345 len = name_len = strlen(lib_name);
346 if (is_absolute_path) {
347 // Need to strip path, prefix and suffix
348 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
349 lib_name = ++start;
350 }
351 if (len <= (prefix_len + suffix_len)) {
352 return NULL;
353 }
354 lib_name += prefix_len;
355 name_len = strlen(lib_name) - suffix_len;
356 }
357 }
358 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
359 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
360 if (agent_entry_name == NULL) {
361 return NULL;
362 }
363 strcpy(agent_entry_name, sym_name);
364 if (lib_name != NULL) {
365 strcat(agent_entry_name, "_");
366 strncat(agent_entry_name, lib_name, name_len);
367 }
368 return agent_entry_name;
369 }
370
371 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
372 assert(thread == Thread::current(), "thread consistency check");
373
374 ParkEvent * const slp = thread->_SleepEvent ;
375 slp->reset() ;
376 OrderAccess::fence() ;
377
378 if (interruptible) {
379 jlong prevtime = javaTimeNanos();
380
381 for (;;) {
382 if (os::is_interrupted(thread, true)) {
383 return OS_INTRPT;
384 }
385
386 jlong newtime = javaTimeNanos();
387
388 if (newtime - prevtime < 0) {
389 // time moving backwards, should only happen if no monotonic clock
390 // not a guarantee() because JVM should not abort on kernel/glibc bugs
391 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
392 } else {
393 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
394 }
395
396 if (millis <= 0) {
397 return OS_OK;
398 }
399
400 prevtime = newtime;
401
402 {
403 assert(thread->is_Java_thread(), "sanity check");
404 JavaThread *jt = (JavaThread *) thread;
405 ThreadBlockInVM tbivm(jt);
406 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
407
408 jt->set_suspend_equivalent();
409 // cleared by handle_special_suspend_equivalent_condition() or
410 // java_suspend_self() via check_and_wait_while_suspended()
411
412 slp->park(millis);
413
414 // were we externally suspended while we were waiting?
415 jt->check_and_wait_while_suspended();
416 }
417 }
418 } else {
419 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
420 jlong prevtime = javaTimeNanos();
421
422 for (;;) {
423 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
424 // the 1st iteration ...
425 jlong newtime = javaTimeNanos();
426
427 if (newtime - prevtime < 0) {
428 // time moving backwards, should only happen if no monotonic clock
429 // not a guarantee() because JVM should not abort on kernel/glibc bugs
430 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
431 } else {
432 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
433 }
434
435 if (millis <= 0) break ;
436
437 prevtime = newtime;
438 slp->park(millis);
439 }
440 return OS_OK ;
441 }
442 }
443
444 ////////////////////////////////////////////////////////////////////////////////
445 // interrupt support
446
447 void os::interrupt(Thread* thread) {
448 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
449 "possibility of dangling Thread pointer");
450
451 OSThread* osthread = thread->osthread();
452
453 if (!osthread->interrupted()) {
454 osthread->set_interrupted(true);
455 // More than one thread can get here with the same value of osthread,
456 // resulting in multiple notifications. We do, however, want the store
457 // to interrupted() to be visible to other threads before we execute unpark().
458 OrderAccess::fence();
459 ParkEvent * const slp = thread->_SleepEvent ;
460 if (slp != NULL) slp->unpark() ;
461 }
462
463 // For JSR166. Unpark even if interrupt status already was set
464 if (thread->is_Java_thread())
465 ((JavaThread*)thread)->parker()->unpark();
466
467 ParkEvent * ev = thread->_ParkEvent ;
468 if (ev != NULL) ev->unpark() ;
469
470 }
471
472 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
473 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
474 "possibility of dangling Thread pointer");
475
476 OSThread* osthread = thread->osthread();
477
478 bool interrupted = osthread->interrupted();
479
480 // NOTE that since there is no "lock" around the interrupt and
481 // is_interrupted operations, there is the possibility that the
482 // interrupted flag (in osThread) will be "false" but that the
483 // low-level events will be in the signaled state. This is
484 // intentional. The effect of this is that Object.wait() and
485 // LockSupport.park() will appear to have a spurious wakeup, which
486 // is allowed and not harmful, and the possibility is so rare that
487 // it is not worth the added complexity to add yet another lock.
488 // For the sleep event an explicit reset is performed on entry
489 // to os::sleep, so there is no early return. It has also been
490 // recommended not to put the interrupted flag into the "event"
491 // structure because it hides the issue.
492 if (interrupted && clear_interrupted) {
493 osthread->set_interrupted(false);
494 // consider thread->_SleepEvent->reset() ... optional optimization
495 }
496
497 return interrupted;
498 }
499
500 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
501 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
502
503 static const struct {
504 int sig; const char* name;
505 }
506 info[] =
507 {
508 { SIGABRT, "SIGABRT" },
509 #ifdef SIGAIO
510 { SIGAIO, "SIGAIO" },
511 #endif
512 { SIGALRM, "SIGALRM" },
513 #ifdef SIGALRM1
514 { SIGALRM1, "SIGALRM1" },
515 #endif
516 { SIGBUS, "SIGBUS" },
517 #ifdef SIGCANCEL
518 { SIGCANCEL, "SIGCANCEL" },
519 #endif
520 { SIGCHLD, "SIGCHLD" },
521 #ifdef SIGCLD
522 { SIGCLD, "SIGCLD" },
523 #endif
524 { SIGCONT, "SIGCONT" },
525 #ifdef SIGCPUFAIL
526 { SIGCPUFAIL, "SIGCPUFAIL" },
527 #endif
528 #ifdef SIGDANGER
529 { SIGDANGER, "SIGDANGER" },
530 #endif
531 #ifdef SIGDIL
532 { SIGDIL, "SIGDIL" },
533 #endif
534 #ifdef SIGEMT
535 { SIGEMT, "SIGEMT" },
536 #endif
537 { SIGFPE, "SIGFPE" },
538 #ifdef SIGFREEZE
539 { SIGFREEZE, "SIGFREEZE" },
540 #endif
541 #ifdef SIGGFAULT
542 { SIGGFAULT, "SIGGFAULT" },
543 #endif
544 #ifdef SIGGRANT
545 { SIGGRANT, "SIGGRANT" },
546 #endif
547 { SIGHUP, "SIGHUP" },
548 { SIGILL, "SIGILL" },
549 { SIGINT, "SIGINT" },
550 #ifdef SIGIO
551 { SIGIO, "SIGIO" },
552 #endif
553 #ifdef SIGIOINT
554 { SIGIOINT, "SIGIOINT" },
555 #endif
556 #ifdef SIGIOT
557 // SIGIOT is there for BSD compatibility, but on most Unices just a
558 // synonym for SIGABRT. The result should be "SIGABRT", not
559 // "SIGIOT".
560 #if (SIGIOT != SIGABRT )
561 { SIGIOT, "SIGIOT" },
562 #endif
563 #endif
564 #ifdef SIGKAP
565 { SIGKAP, "SIGKAP" },
566 #endif
567 { SIGKILL, "SIGKILL" },
568 #ifdef SIGLOST
569 { SIGLOST, "SIGLOST" },
570 #endif
571 #ifdef SIGLWP
572 { SIGLWP, "SIGLWP" },
573 #endif
574 #ifdef SIGLWPTIMER
575 { SIGLWPTIMER, "SIGLWPTIMER" },
576 #endif
577 #ifdef SIGMIGRATE
578 { SIGMIGRATE, "SIGMIGRATE" },
579 #endif
580 #ifdef SIGMSG
581 { SIGMSG, "SIGMSG" },
582 #endif
583 { SIGPIPE, "SIGPIPE" },
584 #ifdef SIGPOLL
585 { SIGPOLL, "SIGPOLL" },
586 #endif
587 #ifdef SIGPRE
588 { SIGPRE, "SIGPRE" },
589 #endif
590 { SIGPROF, "SIGPROF" },
591 #ifdef SIGPTY
592 { SIGPTY, "SIGPTY" },
593 #endif
594 #ifdef SIGPWR
595 { SIGPWR, "SIGPWR" },
596 #endif
597 { SIGQUIT, "SIGQUIT" },
598 #ifdef SIGRECONFIG
599 { SIGRECONFIG, "SIGRECONFIG" },
600 #endif
601 #ifdef SIGRECOVERY
602 { SIGRECOVERY, "SIGRECOVERY" },
603 #endif
604 #ifdef SIGRESERVE
605 { SIGRESERVE, "SIGRESERVE" },
606 #endif
607 #ifdef SIGRETRACT
608 { SIGRETRACT, "SIGRETRACT" },
609 #endif
610 #ifdef SIGSAK
611 { SIGSAK, "SIGSAK" },
612 #endif
613 { SIGSEGV, "SIGSEGV" },
614 #ifdef SIGSOUND
615 { SIGSOUND, "SIGSOUND" },
616 #endif
617 { SIGSTOP, "SIGSTOP" },
618 { SIGSYS, "SIGSYS" },
619 #ifdef SIGSYSERROR
620 { SIGSYSERROR, "SIGSYSERROR" },
621 #endif
622 #ifdef SIGTALRM
623 { SIGTALRM, "SIGTALRM" },
624 #endif
625 { SIGTERM, "SIGTERM" },
626 #ifdef SIGTHAW
627 { SIGTHAW, "SIGTHAW" },
628 #endif
629 { SIGTRAP, "SIGTRAP" },
630 #ifdef SIGTSTP
631 { SIGTSTP, "SIGTSTP" },
632 #endif
633 { SIGTTIN, "SIGTTIN" },
634 { SIGTTOU, "SIGTTOU" },
635 #ifdef SIGURG
636 { SIGURG, "SIGURG" },
637 #endif
638 { SIGUSR1, "SIGUSR1" },
639 { SIGUSR2, "SIGUSR2" },
640 #ifdef SIGVIRT
641 { SIGVIRT, "SIGVIRT" },
642 #endif
643 { SIGVTALRM, "SIGVTALRM" },
644 #ifdef SIGWAITING
645 { SIGWAITING, "SIGWAITING" },
646 #endif
647 #ifdef SIGWINCH
648 { SIGWINCH, "SIGWINCH" },
649 #endif
650 #ifdef SIGWINDOW
651 { SIGWINDOW, "SIGWINDOW" },
652 #endif
653 { SIGXCPU, "SIGXCPU" },
654 { SIGXFSZ, "SIGXFSZ" },
655 #ifdef SIGXRES
656 { SIGXRES, "SIGXRES" },
657 #endif
658 { -1, NULL }
659 };
660
661 const char* ret = NULL;
662
663 #ifdef SIGRTMIN
664 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
665 if (sig == SIGRTMIN) {
666 ret = "SIGRTMIN";
667 } else if (sig == SIGRTMAX) {
668 ret = "SIGRTMAX";
669 } else {
670 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
671 return out;
672 }
673 }
674 #endif
675
676 if (sig > 0) {
677 for (int idx = 0; info[idx].sig != -1; idx ++) {
678 if (info[idx].sig == sig) {
679 ret = info[idx].name;
680 break;
681 }
682 }
683 }
684
685 if (!ret) {
686 if (!is_valid_signal(sig)) {
687 ret = "INVALID";
688 } else {
689 ret = "UNKNOWN";
690 }
691 }
692
693 jio_snprintf(out, outlen, ret);
694 return out;
695 }
696
697 // Returns true if signal number is valid.
698 bool os::Posix::is_valid_signal(int sig) {
699 // MacOS not really POSIX compliant: sigaddset does not return
700 // an error for invalid signal numbers. However, MacOS does not
701 // support real time signals and simply seems to have just 33
702 // signals with no holes in the signal range.
703 #ifdef __APPLE__
704 return sig >= 1 && sig < NSIG;
705 #else
706 // Use sigaddset to check for signal validity.
707 sigset_t set;
708 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
709 return false;
710 }
711 return true;
712 #endif
713 }
714
715 #define NUM_IMPORTANT_SIGS 32
716 // Returns one-line short description of a signal set in a user provided buffer.
717 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
718 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
719 // Note: for shortness, just print out the first 32. That should
720 // cover most of the useful ones, apart from realtime signals.
721 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
722 const int rc = sigismember(set, sig);
723 if (rc == -1 && errno == EINVAL) {
724 buffer[sig-1] = '?';
725 } else {
726 buffer[sig-1] = rc == 0 ? '0' : '1';
727 }
728 }
729 buffer[NUM_IMPORTANT_SIGS] = 0;
730 return buffer;
731 }
732
733 // Prints one-line description of a signal set.
734 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
735 char buf[NUM_IMPORTANT_SIGS + 1];
736 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
737 st->print("%s", buf);
738 }
739
740 // Writes one-line description of a combination of sigaction.sa_flags into a user
741 // provided buffer. Returns that buffer.
742 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
743 char* p = buffer;
744 size_t remaining = size;
745 bool first = true;
746 int idx = 0;
747
748 assert(buffer, "invalid argument");
749
750 if (size == 0) {
751 return buffer;
752 }
753
754 strncpy(buffer, "none", size);
755
756 const struct {
757 int i;
758 const char* s;
759 } flaginfo [] = {
760 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
761 { SA_ONSTACK, "SA_ONSTACK" },
762 { SA_RESETHAND, "SA_RESETHAND" },
763 { SA_RESTART, "SA_RESTART" },
764 { SA_SIGINFO, "SA_SIGINFO" },
765 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
766 { SA_NODEFER, "SA_NODEFER" },
767 #ifdef AIX
768 { SA_ONSTACK, "SA_ONSTACK" },
769 { SA_OLDSTYLE, "SA_OLDSTYLE" },
770 #endif
771 { 0, NULL }
772 };
773
774 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
775 if (flags & flaginfo[idx].i) {
776 if (first) {
777 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
778 first = false;
779 } else {
780 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
781 }
782 const size_t len = strlen(p);
783 p += len;
784 remaining -= len;
785 }
786 }
787
788 buffer[size - 1] = '\0';
789
790 return buffer;
791 }
792
793 // Prints one-line description of a combination of sigaction.sa_flags.
794 void os::Posix::print_sa_flags(outputStream* st, int flags) {
795 char buffer[0x100];
796 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
797 st->print("%s", buffer);
798 }
799
800 // Helper function for os::Posix::print_siginfo_...():
801 // return a textual description for signal code.
802 struct enum_sigcode_desc_t {
803 const char* s_name;
804 const char* s_desc;
805 };
806
807 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
808
809 const struct {
810 int sig; int code; const char* s_code; const char* s_desc;
811 } t1 [] = {
812 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
813 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
814 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
815 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
816 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
817 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
818 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
819 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
820 #if defined(IA64) && defined(LINUX)
821 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
822 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
823 #endif
824 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
825 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
826 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
827 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
828 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
829 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
830 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
831 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
832 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
833 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
834 #ifdef AIX
835 // no explanation found what keyerr would be
836 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
837 #endif
838 #if defined(IA64) && !defined(AIX)
839 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
840 #endif
841 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
842 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
843 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
844 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
845 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
846 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
847 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
848 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
849 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
850 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
851 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
852 #ifdef SIGPOLL
853 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
854 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
855 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
856 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
857 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
858 #endif
859 { -1, -1, NULL, NULL }
860 };
861
862 // Codes valid in any signal context.
863 const struct {
864 int code; const char* s_code; const char* s_desc;
865 } t2 [] = {
866 { SI_USER, "SI_USER", "Signal sent by kill()." },
867 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
868 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
869 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
870 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
871 // Linux specific
872 #ifdef SI_TKILL
873 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
874 #endif
875 #ifdef SI_DETHREAD
876 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
877 #endif
878 #ifdef SI_KERNEL
879 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
880 #endif
881 #ifdef SI_SIGIO
882 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
883 #endif
884
885 #ifdef AIX
886 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
887 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
888 #endif
889
890 #ifdef __sun
891 { SI_NOINFO, "SI_NOINFO", "No signal information" },
892 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
893 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
894 #endif
895
896 { -1, NULL, NULL }
897 };
898
899 const char* s_code = NULL;
900 const char* s_desc = NULL;
901
902 for (int i = 0; t1[i].sig != -1; i ++) {
903 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
904 s_code = t1[i].s_code;
905 s_desc = t1[i].s_desc;
906 break;
907 }
908 }
909
910 if (s_code == NULL) {
911 for (int i = 0; t2[i].s_code != NULL; i ++) {
912 if (t2[i].code == si->si_code) {
913 s_code = t2[i].s_code;
914 s_desc = t2[i].s_desc;
915 }
916 }
917 }
918
919 if (s_code == NULL) {
920 out->s_name = "unknown";
921 out->s_desc = "unknown";
922 return false;
923 }
924
925 out->s_name = s_code;
926 out->s_desc = s_desc;
927
928 return true;
929 }
930
931 // A POSIX conform, platform-independend siginfo print routine.
932 // Short print out on one line.
933 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) {
934 char buf[20];
935 os->print("siginfo: ");
936
937 if (!si) {
938 os->print("<null>");
939 return;
940 }
941
942 // See print_siginfo_full() for details.
943 const int sig = si->si_signo;
944
945 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
946
947 enum_sigcode_desc_t ed;
948 if (get_signal_code_description(si, &ed)) {
949 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
950 } else {
951 os->print(", si_code: %d (unknown)", si->si_code);
952 }
953
954 if (si->si_errno) {
955 os->print(", si_errno: %d", si->si_errno);
956 }
957
958 const int me = (int) ::getpid();
959 const int pid = (int) si->si_pid;
960
961 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
962 if (IS_VALID_PID(pid) && pid != me) {
963 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid);
964 }
965 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
966 sig == SIGTRAP || sig == SIGFPE) {
967 os->print(", si_addr: " PTR_FORMAT, si->si_addr);
968 #ifdef SIGPOLL
969 } else if (sig == SIGPOLL) {
970 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band);
971 #endif
972 } else if (sig == SIGCHLD) {
973 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status);
974 }
975 }
976
977 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
978 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
979 }
980
981 /*
982 * See the caveats for this class in os_posix.hpp
983 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
984 * method and returns false. If none of the signals are raised, returns true.
985 * The callback is supposed to provide the method that should be protected.
986 */
987 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
988 sigset_t saved_sig_mask;
989
990 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
991 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
992 "crash_protection already set?");
993
994 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
995 // since on at least some systems (OS X) siglongjmp will restore the mask
996 // for the process, not the thread
997 pthread_sigmask(0, NULL, &saved_sig_mask);
998 if (sigsetjmp(_jmpbuf, 0) == 0) {
999 // make sure we can see in the signal handler that we have crash protection
1000 // installed
1001 WatcherThread::watcher_thread()->set_crash_protection(this);
1002 cb.call();
1003 // and clear the crash protection
1004 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1005 return true;
1006 }
1007 // this happens when we siglongjmp() back
1008 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1009 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1010 return false;
1011 }
1012
1013 void os::WatcherThreadCrashProtection::restore() {
1014 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1015 "must have crash protection");
1016
1017 siglongjmp(_jmpbuf, 1);
1018 }
1019
1020 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1021 Thread* thread) {
1022
1023 if (thread != NULL &&
1024 thread->is_Watcher_thread() &&
1025 WatcherThread::watcher_thread()->has_crash_protection()) {
1026
1027 if (sig == SIGSEGV || sig == SIGBUS) {
1028 WatcherThread::watcher_thread()->crash_protection()->restore();
1029 }
1030 }
1031 }