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