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