1 /*
2 * Copyright (c) 1999, 2016, 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 "semaphore_posix.hpp"
28 #include "runtime/frame.inline.hpp"
29 #include "runtime/interfaceSupport.hpp"
30 #include "runtime/os.hpp"
31 #include "utilities/vmError.hpp"
32
33 #include <signal.h>
34 #include <unistd.h>
35 #include <sys/resource.h>
36 #include <sys/utsname.h>
37 #include <pthread.h>
38 #include <semaphore.h>
39 #include <signal.h>
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_dump_limit(char* buffer, size_t bufferSize) {
50 int n;
51 struct rlimit rlim;
52 bool success;
53
54 char core_path[PATH_MAX];
55 n = get_core_path(core_path, PATH_MAX);
56
57 if (n <= 0) {
58 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
59 success = true;
60 #ifdef LINUX
61 } else if (core_path[0] == '"') { // redirect to user process
62 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
63 success = true;
64 #endif
65 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
66 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
67 success = true;
68 } else {
69 switch(rlim.rlim_cur) {
70 case RLIM_INFINITY:
71 jio_snprintf(buffer, bufferSize, "%s", core_path);
72 success = true;
73 break;
74 case 0:
75 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
76 success = false;
77 break;
78 default:
79 jio_snprintf(buffer, bufferSize, "%s (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", core_path, (unsigned long)(rlim.rlim_cur >> 10));
80 success = true;
81 break;
82 }
83 }
84
85 VMError::record_coredump_status(buffer, success);
86 }
87
88 int os::get_native_stack(address* stack, int frames, int toSkip) {
89 #ifdef _NMT_NOINLINE_
90 toSkip++;
91 #endif
92
93 int frame_idx = 0;
94 int num_of_frames; // number of frames captured
95 frame fr = os::current_frame();
96 while (fr.pc() && frame_idx < frames) {
97 if (toSkip > 0) {
98 toSkip --;
99 } else {
100 stack[frame_idx ++] = fr.pc();
101 }
102 if (fr.fp() == NULL || fr.cb() != NULL ||
103 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
104
105 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
106 fr = os::get_sender_for_C_frame(&fr);
107 } else {
108 break;
109 }
110 }
111 num_of_frames = frame_idx;
112 for (; frame_idx < frames; frame_idx ++) {
113 stack[frame_idx] = NULL;
114 }
115
116 return num_of_frames;
117 }
118
119
120 bool os::unsetenv(const char* name) {
121 assert(name != NULL, "Null pointer");
122 return (::unsetenv(name) == 0);
123 }
124
125 int os::get_last_error() {
126 return errno;
127 }
128
129 bool os::is_debugger_attached() {
130 // not implemented
131 return false;
132 }
133
134 void os::wait_for_keypress_at_exit(void) {
135 // don't do anything on posix platforms
136 return;
137 }
138
139 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
140 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
141 // rather than unmapping and remapping the whole chunk to get requested alignment.
142 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
143 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
144 "Alignment must be a multiple of allocation granularity (page size)");
145 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
146
147 size_t extra_size = size + alignment;
148 assert(extra_size >= size, "overflow, size is too large to allow alignment");
149
150 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
151
152 if (extra_base == NULL) {
153 return NULL;
154 }
155
156 // Do manual alignment
157 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
158
159 // [ | | ]
160 // ^ extra_base
161 // ^ extra_base + begin_offset == aligned_base
162 // extra_base + begin_offset + size ^
163 // extra_base + extra_size ^
164 // |<>| == begin_offset
165 // end_offset == |<>|
166 size_t begin_offset = aligned_base - extra_base;
167 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
168
169 if (begin_offset > 0) {
170 os::release_memory(extra_base, begin_offset);
171 }
172
173 if (end_offset > 0) {
174 os::release_memory(extra_base + begin_offset + size, end_offset);
175 }
176
177 return aligned_base;
178 }
179
180 int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
181 return vsnprintf(buf, len, fmt, args);
182 }
183
184 void os::Posix::print_load_average(outputStream* st) {
185 st->print("load average:");
186 double loadavg[3];
187 os::loadavg(loadavg, 3);
188 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
189 st->cr();
190 }
191
192 void os::Posix::print_rlimit_info(outputStream* st) {
193 st->print("rlimit:");
194 struct rlimit rlim;
195
196 st->print(" STACK ");
197 getrlimit(RLIMIT_STACK, &rlim);
198 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
199 else st->print("%luk", rlim.rlim_cur >> 10);
200
201 st->print(", CORE ");
202 getrlimit(RLIMIT_CORE, &rlim);
203 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
204 else st->print("%luk", rlim.rlim_cur >> 10);
205
206 // Isn't there on solaris
207 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
208 st->print(", NPROC ");
209 getrlimit(RLIMIT_NPROC, &rlim);
210 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
211 else st->print("%lu", rlim.rlim_cur);
212 #endif
213
214 st->print(", NOFILE ");
215 getrlimit(RLIMIT_NOFILE, &rlim);
216 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
217 else st->print("%lu", rlim.rlim_cur);
218
219 st->print(", AS ");
220 getrlimit(RLIMIT_AS, &rlim);
221 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
222 else st->print("%luk", rlim.rlim_cur >> 10);
223 st->cr();
224 }
225
226 void os::Posix::print_uname_info(outputStream* st) {
227 // kernel
228 st->print("uname:");
229 struct utsname name;
230 uname(&name);
231 st->print("%s ", name.sysname);
232 #ifdef ASSERT
233 st->print("%s ", name.nodename);
234 #endif
235 st->print("%s ", name.release);
236 st->print("%s ", name.version);
237 st->print("%s", name.machine);
238 st->cr();
239 }
240
241 bool os::get_host_name(char* buf, size_t buflen) {
242 struct utsname name;
243 uname(&name);
244 jio_snprintf(buf, buflen, "%s", name.nodename);
245 return true;
246 }
247
248 bool os::has_allocatable_memory_limit(julong* limit) {
249 struct rlimit rlim;
250 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
251 // if there was an error when calling getrlimit, assume that there is no limitation
252 // on virtual memory.
253 bool result;
254 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
255 result = false;
256 } else {
257 *limit = (julong)rlim.rlim_cur;
258 result = true;
259 }
260 #ifdef _LP64
261 return result;
262 #else
263 // arbitrary virtual space limit for 32 bit Unices found by testing. If
264 // getrlimit above returned a limit, bound it with this limit. Otherwise
265 // directly use it.
266 const julong max_virtual_limit = (julong)3800*M;
267 if (result) {
268 *limit = MIN2(*limit, max_virtual_limit);
269 } else {
270 *limit = max_virtual_limit;
271 }
272
273 // bound by actually allocatable memory. The algorithm uses two bounds, an
274 // upper and a lower limit. The upper limit is the current highest amount of
275 // memory that could not be allocated, the lower limit is the current highest
276 // amount of memory that could be allocated.
277 // The algorithm iteratively refines the result by halving the difference
278 // between these limits, updating either the upper limit (if that value could
279 // not be allocated) or the lower limit (if the that value could be allocated)
280 // until the difference between these limits is "small".
281
282 // the minimum amount of memory we care about allocating.
283 const julong min_allocation_size = M;
284
285 julong upper_limit = *limit;
286
287 // first check a few trivial cases
288 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
289 *limit = upper_limit;
290 } else if (!is_allocatable(min_allocation_size)) {
291 // we found that not even min_allocation_size is allocatable. Return it
292 // anyway. There is no point to search for a better value any more.
293 *limit = min_allocation_size;
294 } else {
295 // perform the binary search.
296 julong lower_limit = min_allocation_size;
297 while ((upper_limit - lower_limit) > min_allocation_size) {
298 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
299 temp_limit = align_size_down_(temp_limit, min_allocation_size);
300 if (is_allocatable(temp_limit)) {
301 lower_limit = temp_limit;
302 } else {
303 upper_limit = temp_limit;
304 }
305 }
306 *limit = lower_limit;
307 }
308 return true;
309 #endif
310 }
311
312 const char* os::get_current_directory(char *buf, size_t buflen) {
313 return getcwd(buf, buflen);
314 }
315
316 FILE* os::open(int fd, const char* mode) {
317 return ::fdopen(fd, mode);
318 }
319
320 void os::flockfile(FILE* fp) {
321 ::flockfile(fp);
322 }
323
324 void os::funlockfile(FILE* fp) {
325 ::funlockfile(fp);
326 }
327
328 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
329 // which is used to find statically linked in agents.
330 // Parameters:
331 // sym_name: Symbol in library we are looking for
332 // lib_name: Name of library to look in, NULL for shared libs.
333 // is_absolute_path == true if lib_name is absolute path to agent
334 // such as "/a/b/libL.so"
335 // == false if only the base name of the library is passed in
336 // such as "L"
337 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
338 bool is_absolute_path) {
339 char *agent_entry_name;
340 size_t len;
341 size_t name_len;
342 size_t prefix_len = strlen(JNI_LIB_PREFIX);
343 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
344 const char *start;
345
346 if (lib_name != NULL) {
347 name_len = strlen(lib_name);
348 if (is_absolute_path) {
349 // Need to strip path, prefix and suffix
350 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
351 lib_name = ++start;
352 }
353 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
354 return NULL;
355 }
356 lib_name += prefix_len;
357 name_len = strlen(lib_name) - suffix_len;
358 }
359 }
360 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
361 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
362 if (agent_entry_name == NULL) {
363 return NULL;
364 }
365 strcpy(agent_entry_name, sym_name);
366 if (lib_name != NULL) {
367 strcat(agent_entry_name, "_");
368 strncat(agent_entry_name, lib_name, name_len);
369 }
370 return agent_entry_name;
371 }
372
373 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
374 assert(thread == Thread::current(), "thread consistency check");
375
376 ParkEvent * const slp = thread->_SleepEvent ;
377 slp->reset() ;
378 OrderAccess::fence() ;
379
380 if (interruptible) {
381 jlong prevtime = javaTimeNanos();
382
383 for (;;) {
384 if (os::is_interrupted(thread, true)) {
385 return OS_INTRPT;
386 }
387
388 jlong newtime = javaTimeNanos();
389
390 if (newtime - prevtime < 0) {
391 // time moving backwards, should only happen if no monotonic clock
392 // not a guarantee() because JVM should not abort on kernel/glibc bugs
393 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
394 } else {
395 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
396 }
397
398 if (millis <= 0) {
399 return OS_OK;
400 }
401
402 prevtime = newtime;
403
404 {
405 assert(thread->is_Java_thread(), "sanity check");
406 JavaThread *jt = (JavaThread *) thread;
407 ThreadBlockInVM tbivm(jt);
408 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
409
410 jt->set_suspend_equivalent();
411 // cleared by handle_special_suspend_equivalent_condition() or
412 // java_suspend_self() via check_and_wait_while_suspended()
413
414 slp->park(millis);
415
416 // were we externally suspended while we were waiting?
417 jt->check_and_wait_while_suspended();
418 }
419 }
420 } else {
421 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
422 jlong prevtime = javaTimeNanos();
423
424 for (;;) {
425 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
426 // the 1st iteration ...
427 jlong newtime = javaTimeNanos();
428
429 if (newtime - prevtime < 0) {
430 // time moving backwards, should only happen if no monotonic clock
431 // not a guarantee() because JVM should not abort on kernel/glibc bugs
432 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
433 } else {
434 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
435 }
436
437 if (millis <= 0) break ;
438
439 prevtime = newtime;
440 slp->park(millis);
441 }
442 return OS_OK ;
443 }
444 }
445
446 ////////////////////////////////////////////////////////////////////////////////
447 // interrupt support
448
449 void os::interrupt(Thread* thread) {
450 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
451 "possibility of dangling Thread pointer");
452
453 OSThread* osthread = thread->osthread();
454
455 if (!osthread->interrupted()) {
456 osthread->set_interrupted(true);
457 // More than one thread can get here with the same value of osthread,
458 // resulting in multiple notifications. We do, however, want the store
459 // to interrupted() to be visible to other threads before we execute unpark().
460 OrderAccess::fence();
461 ParkEvent * const slp = thread->_SleepEvent ;
462 if (slp != NULL) slp->unpark() ;
463 }
464
465 // For JSR166. Unpark even if interrupt status already was set
466 if (thread->is_Java_thread())
467 ((JavaThread*)thread)->parker()->unpark();
468
469 ParkEvent * ev = thread->_ParkEvent ;
470 if (ev != NULL) ev->unpark() ;
471
472 }
473
474 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
475 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
476 "possibility of dangling Thread pointer");
477
478 OSThread* osthread = thread->osthread();
479
480 bool interrupted = osthread->interrupted();
481
482 // NOTE that since there is no "lock" around the interrupt and
483 // is_interrupted operations, there is the possibility that the
484 // interrupted flag (in osThread) will be "false" but that the
485 // low-level events will be in the signaled state. This is
486 // intentional. The effect of this is that Object.wait() and
487 // LockSupport.park() will appear to have a spurious wakeup, which
488 // is allowed and not harmful, and the possibility is so rare that
489 // it is not worth the added complexity to add yet another lock.
490 // For the sleep event an explicit reset is performed on entry
491 // to os::sleep, so there is no early return. It has also been
492 // recommended not to put the interrupted flag into the "event"
493 // structure because it hides the issue.
494 if (interrupted && clear_interrupted) {
495 osthread->set_interrupted(false);
496 // consider thread->_SleepEvent->reset() ... optional optimization
497 }
498
499 return interrupted;
500 }
501
502
503
504 static const struct {
505 int sig; const char* name;
506 }
507 g_signal_info[] =
508 {
509 { SIGABRT, "SIGABRT" },
510 #ifdef SIGAIO
511 { SIGAIO, "SIGAIO" },
512 #endif
513 { SIGALRM, "SIGALRM" },
514 #ifdef SIGALRM1
515 { SIGALRM1, "SIGALRM1" },
516 #endif
517 { SIGBUS, "SIGBUS" },
518 #ifdef SIGCANCEL
519 { SIGCANCEL, "SIGCANCEL" },
520 #endif
521 { SIGCHLD, "SIGCHLD" },
522 #ifdef SIGCLD
523 { SIGCLD, "SIGCLD" },
524 #endif
525 { SIGCONT, "SIGCONT" },
526 #ifdef SIGCPUFAIL
527 { SIGCPUFAIL, "SIGCPUFAIL" },
528 #endif
529 #ifdef SIGDANGER
530 { SIGDANGER, "SIGDANGER" },
531 #endif
532 #ifdef SIGDIL
533 { SIGDIL, "SIGDIL" },
534 #endif
535 #ifdef SIGEMT
536 { SIGEMT, "SIGEMT" },
537 #endif
538 { SIGFPE, "SIGFPE" },
539 #ifdef SIGFREEZE
540 { SIGFREEZE, "SIGFREEZE" },
541 #endif
542 #ifdef SIGGFAULT
543 { SIGGFAULT, "SIGGFAULT" },
544 #endif
545 #ifdef SIGGRANT
546 { SIGGRANT, "SIGGRANT" },
547 #endif
548 { SIGHUP, "SIGHUP" },
549 { SIGILL, "SIGILL" },
550 { SIGINT, "SIGINT" },
551 #ifdef SIGIO
552 { SIGIO, "SIGIO" },
553 #endif
554 #ifdef SIGIOINT
555 { SIGIOINT, "SIGIOINT" },
556 #endif
557 #ifdef SIGIOT
558 // SIGIOT is there for BSD compatibility, but on most Unices just a
559 // synonym for SIGABRT. The result should be "SIGABRT", not
560 // "SIGIOT".
561 #if (SIGIOT != SIGABRT )
562 { SIGIOT, "SIGIOT" },
563 #endif
564 #endif
565 #ifdef SIGKAP
566 { SIGKAP, "SIGKAP" },
567 #endif
568 { SIGKILL, "SIGKILL" },
569 #ifdef SIGLOST
570 { SIGLOST, "SIGLOST" },
571 #endif
572 #ifdef SIGLWP
573 { SIGLWP, "SIGLWP" },
574 #endif
575 #ifdef SIGLWPTIMER
576 { SIGLWPTIMER, "SIGLWPTIMER" },
577 #endif
578 #ifdef SIGMIGRATE
579 { SIGMIGRATE, "SIGMIGRATE" },
580 #endif
581 #ifdef SIGMSG
582 { SIGMSG, "SIGMSG" },
583 #endif
584 { SIGPIPE, "SIGPIPE" },
585 #ifdef SIGPOLL
586 { SIGPOLL, "SIGPOLL" },
587 #endif
588 #ifdef SIGPRE
589 { SIGPRE, "SIGPRE" },
590 #endif
591 { SIGPROF, "SIGPROF" },
592 #ifdef SIGPTY
593 { SIGPTY, "SIGPTY" },
594 #endif
595 #ifdef SIGPWR
596 { SIGPWR, "SIGPWR" },
597 #endif
598 { SIGQUIT, "SIGQUIT" },
599 #ifdef SIGRECONFIG
600 { SIGRECONFIG, "SIGRECONFIG" },
601 #endif
602 #ifdef SIGRECOVERY
603 { SIGRECOVERY, "SIGRECOVERY" },
604 #endif
605 #ifdef SIGRESERVE
606 { SIGRESERVE, "SIGRESERVE" },
607 #endif
608 #ifdef SIGRETRACT
609 { SIGRETRACT, "SIGRETRACT" },
610 #endif
611 #ifdef SIGSAK
612 { SIGSAK, "SIGSAK" },
613 #endif
614 { SIGSEGV, "SIGSEGV" },
615 #ifdef SIGSOUND
616 { SIGSOUND, "SIGSOUND" },
617 #endif
618 #ifdef SIGSTKFLT
619 { SIGSTKFLT, "SIGSTKFLT" },
620 #endif
621 { SIGSTOP, "SIGSTOP" },
622 { SIGSYS, "SIGSYS" },
623 #ifdef SIGSYSERROR
624 { SIGSYSERROR, "SIGSYSERROR" },
625 #endif
626 #ifdef SIGTALRM
627 { SIGTALRM, "SIGTALRM" },
628 #endif
629 { SIGTERM, "SIGTERM" },
630 #ifdef SIGTHAW
631 { SIGTHAW, "SIGTHAW" },
632 #endif
633 { SIGTRAP, "SIGTRAP" },
634 #ifdef SIGTSTP
635 { SIGTSTP, "SIGTSTP" },
636 #endif
637 { SIGTTIN, "SIGTTIN" },
638 { SIGTTOU, "SIGTTOU" },
639 #ifdef SIGURG
640 { SIGURG, "SIGURG" },
641 #endif
642 { SIGUSR1, "SIGUSR1" },
643 { SIGUSR2, "SIGUSR2" },
644 #ifdef SIGVIRT
645 { SIGVIRT, "SIGVIRT" },
646 #endif
647 { SIGVTALRM, "SIGVTALRM" },
648 #ifdef SIGWAITING
649 { SIGWAITING, "SIGWAITING" },
650 #endif
651 #ifdef SIGWINCH
652 { SIGWINCH, "SIGWINCH" },
653 #endif
654 #ifdef SIGWINDOW
655 { SIGWINDOW, "SIGWINDOW" },
656 #endif
657 { SIGXCPU, "SIGXCPU" },
658 { SIGXFSZ, "SIGXFSZ" },
659 #ifdef SIGXRES
660 { SIGXRES, "SIGXRES" },
661 #endif
662 { -1, NULL }
663 };
664
665 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
666 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
667
668 const char* ret = NULL;
669
670 #ifdef SIGRTMIN
671 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
672 if (sig == SIGRTMIN) {
673 ret = "SIGRTMIN";
674 } else if (sig == SIGRTMAX) {
675 ret = "SIGRTMAX";
676 } else {
677 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
678 return out;
679 }
680 }
681 #endif
682
683 if (sig > 0) {
684 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
685 if (g_signal_info[idx].sig == sig) {
686 ret = g_signal_info[idx].name;
687 break;
688 }
689 }
690 }
691
692 if (!ret) {
693 if (!is_valid_signal(sig)) {
694 ret = "INVALID";
695 } else {
696 ret = "UNKNOWN";
697 }
698 }
699
700 if (out && outlen > 0) {
701 strncpy(out, ret, outlen);
702 out[outlen - 1] = '\0';
703 }
704 return out;
705 }
706
707 int os::Posix::get_signal_number(const char* signal_name) {
708 char tmp[30];
709 const char* s = signal_name;
710 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
711 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
712 s = tmp;
713 }
714 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
715 if (strcmp(g_signal_info[idx].name, s) == 0) {
716 return g_signal_info[idx].sig;
717 }
718 }
719 return -1;
720 }
721
722 int os::get_signal_number(const char* signal_name) {
723 return os::Posix::get_signal_number(signal_name);
724 }
725
726 // Returns true if signal number is valid.
727 bool os::Posix::is_valid_signal(int sig) {
728 // MacOS not really POSIX compliant: sigaddset does not return
729 // an error for invalid signal numbers. However, MacOS does not
730 // support real time signals and simply seems to have just 33
731 // signals with no holes in the signal range.
732 #ifdef __APPLE__
733 return sig >= 1 && sig < NSIG;
734 #else
735 // Use sigaddset to check for signal validity.
736 sigset_t set;
737 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
738 return false;
739 }
740 return true;
741 #endif
742 }
743
744 // Returns:
745 // NULL for an invalid signal number
746 // "SIG<num>" for a valid but unknown signal number
747 // signal name otherwise.
748 const char* os::exception_name(int sig, char* buf, size_t size) {
749 if (!os::Posix::is_valid_signal(sig)) {
750 return NULL;
751 }
752 const char* const name = os::Posix::get_signal_name(sig, buf, size);
753 if (strcmp(name, "UNKNOWN") == 0) {
754 jio_snprintf(buf, size, "SIG%d", sig);
755 }
756 return buf;
757 }
758
759 #define NUM_IMPORTANT_SIGS 32
760 // Returns one-line short description of a signal set in a user provided buffer.
761 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
762 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
763 // Note: for shortness, just print out the first 32. That should
764 // cover most of the useful ones, apart from realtime signals.
765 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
766 const int rc = sigismember(set, sig);
767 if (rc == -1 && errno == EINVAL) {
768 buffer[sig-1] = '?';
769 } else {
770 buffer[sig-1] = rc == 0 ? '0' : '1';
771 }
772 }
773 buffer[NUM_IMPORTANT_SIGS] = 0;
774 return buffer;
775 }
776
777 // Prints one-line description of a signal set.
778 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
779 char buf[NUM_IMPORTANT_SIGS + 1];
780 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
781 st->print("%s", buf);
782 }
783
784 // Writes one-line description of a combination of sigaction.sa_flags into a user
785 // provided buffer. Returns that buffer.
786 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
787 char* p = buffer;
788 size_t remaining = size;
789 bool first = true;
790 int idx = 0;
791
792 assert(buffer, "invalid argument");
793
794 if (size == 0) {
795 return buffer;
796 }
797
798 strncpy(buffer, "none", size);
799
800 const struct {
801 // NB: i is an unsigned int here because SA_RESETHAND is on some
802 // systems 0x80000000, which is implicitly unsigned. Assignining
803 // it to an int field would be an overflow in unsigned-to-signed
804 // conversion.
805 unsigned int i;
806 const char* s;
807 } flaginfo [] = {
808 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
809 { SA_ONSTACK, "SA_ONSTACK" },
810 { SA_RESETHAND, "SA_RESETHAND" },
811 { SA_RESTART, "SA_RESTART" },
812 { SA_SIGINFO, "SA_SIGINFO" },
813 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
814 { SA_NODEFER, "SA_NODEFER" },
815 #ifdef AIX
816 { SA_ONSTACK, "SA_ONSTACK" },
817 { SA_OLDSTYLE, "SA_OLDSTYLE" },
818 #endif
819 { 0, NULL }
820 };
821
822 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
823 if (flags & flaginfo[idx].i) {
824 if (first) {
825 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
826 first = false;
827 } else {
828 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
829 }
830 const size_t len = strlen(p);
831 p += len;
832 remaining -= len;
833 }
834 }
835
836 buffer[size - 1] = '\0';
837
838 return buffer;
839 }
840
841 // Prints one-line description of a combination of sigaction.sa_flags.
842 void os::Posix::print_sa_flags(outputStream* st, int flags) {
843 char buffer[0x100];
844 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
845 st->print("%s", buffer);
846 }
847
848 // Helper function for os::Posix::print_siginfo_...():
849 // return a textual description for signal code.
850 struct enum_sigcode_desc_t {
851 const char* s_name;
852 const char* s_desc;
853 };
854
855 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
856
857 const struct {
858 int sig; int code; const char* s_code; const char* s_desc;
859 } t1 [] = {
860 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
861 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
862 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
863 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
864 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
865 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
866 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
867 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
868 #if defined(IA64) && defined(LINUX)
869 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
870 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
871 #endif
872 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
873 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
874 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
875 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
876 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
877 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
878 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
879 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
880 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
881 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
882 #ifdef AIX
883 // no explanation found what keyerr would be
884 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
885 #endif
886 #if defined(IA64) && !defined(AIX)
887 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
888 #endif
889 #if defined(__sparc) && defined(SOLARIS)
890 // define Solaris Sparc M7 ADI SEGV signals
891 #if !defined(SEGV_ACCADI)
892 #define SEGV_ACCADI 3
893 #endif
894 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
895 #if !defined(SEGV_ACCDERR)
896 #define SEGV_ACCDERR 4
897 #endif
898 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
899 #if !defined(SEGV_ACCPERR)
900 #define SEGV_ACCPERR 5
901 #endif
902 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
903 #endif // defined(__sparc) && defined(SOLARIS)
904 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
905 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
906 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
907 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
908 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
909 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
910 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
911 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
912 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
913 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
914 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
915 #ifdef SIGPOLL
916 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
917 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
918 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
919 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
920 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
921 #endif
922 { -1, -1, NULL, NULL }
923 };
924
925 // Codes valid in any signal context.
926 const struct {
927 int code; const char* s_code; const char* s_desc;
928 } t2 [] = {
929 { SI_USER, "SI_USER", "Signal sent by kill()." },
930 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
931 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
932 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
933 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
934 // Linux specific
935 #ifdef SI_TKILL
936 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
937 #endif
938 #ifdef SI_DETHREAD
939 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
940 #endif
941 #ifdef SI_KERNEL
942 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
943 #endif
944 #ifdef SI_SIGIO
945 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
946 #endif
947
948 #ifdef AIX
949 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
950 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
951 #endif
952
953 #ifdef __sun
954 { SI_NOINFO, "SI_NOINFO", "No signal information" },
955 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
956 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
957 #endif
958
959 { -1, NULL, NULL }
960 };
961
962 const char* s_code = NULL;
963 const char* s_desc = NULL;
964
965 for (int i = 0; t1[i].sig != -1; i ++) {
966 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
967 s_code = t1[i].s_code;
968 s_desc = t1[i].s_desc;
969 break;
970 }
971 }
972
973 if (s_code == NULL) {
974 for (int i = 0; t2[i].s_code != NULL; i ++) {
975 if (t2[i].code == si->si_code) {
976 s_code = t2[i].s_code;
977 s_desc = t2[i].s_desc;
978 }
979 }
980 }
981
982 if (s_code == NULL) {
983 out->s_name = "unknown";
984 out->s_desc = "unknown";
985 return false;
986 }
987
988 out->s_name = s_code;
989 out->s_desc = s_desc;
990
991 return true;
992 }
993
994 void os::print_siginfo(outputStream* os, const void* si0) {
995
996 const siginfo_t* const si = (const siginfo_t*) si0;
997
998 char buf[20];
999 os->print("siginfo:");
1000
1001 if (!si) {
1002 os->print(" <null>");
1003 return;
1004 }
1005
1006 const int sig = si->si_signo;
1007
1008 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1009
1010 enum_sigcode_desc_t ed;
1011 get_signal_code_description(si, &ed);
1012 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1013
1014 if (si->si_errno) {
1015 os->print(", si_errno: %d", si->si_errno);
1016 }
1017
1018 // Output additional information depending on the signal code.
1019
1020 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1021 // so it depends on the context which member to use. For synchronous error signals,
1022 // we print si_addr, unless the signal was sent by another process or thread, in
1023 // which case we print out pid or tid of the sender.
1024 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1025 const pid_t pid = si->si_pid;
1026 os->print(", si_pid: %ld", (long) pid);
1027 if (IS_VALID_PID(pid)) {
1028 const pid_t me = getpid();
1029 if (me == pid) {
1030 os->print(" (current process)");
1031 }
1032 } else {
1033 os->print(" (invalid)");
1034 }
1035 os->print(", si_uid: %ld", (long) si->si_uid);
1036 if (sig == SIGCHLD) {
1037 os->print(", si_status: %d", si->si_status);
1038 }
1039 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1040 sig == SIGTRAP || sig == SIGFPE) {
1041 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1042 #ifdef SIGPOLL
1043 } else if (sig == SIGPOLL) {
1044 os->print(", si_band: %ld", si->si_band);
1045 #endif
1046 }
1047
1048 }
1049
1050 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1051 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1052 }
1053
1054 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1055 #ifdef TARGET_OS_FAMILY_linux
1056 return Linux::ucontext_get_pc(ctx);
1057 #elif defined(TARGET_OS_FAMILY_solaris)
1058 return Solaris::ucontext_get_pc(ctx);
1059 #elif defined(TARGET_OS_FAMILY_aix)
1060 return Aix::ucontext_get_pc(ctx);
1061 #elif defined(TARGET_OS_FAMILY_bsd)
1062 return Bsd::ucontext_get_pc(ctx);
1063 #else
1064 VMError::report_and_die("unimplemented ucontext_get_pc");
1065 #endif
1066 }
1067
1068 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1069 #ifdef TARGET_OS_FAMILY_linux
1070 Linux::ucontext_set_pc(ctx, pc);
1071 #elif defined(TARGET_OS_FAMILY_solaris)
1072 Solaris::ucontext_set_pc(ctx, pc);
1073 #elif defined(TARGET_OS_FAMILY_aix)
1074 Aix::ucontext_set_pc(ctx, pc);
1075 #elif defined(TARGET_OS_FAMILY_bsd)
1076 Bsd::ucontext_set_pc(ctx, pc);
1077 #else
1078 VMError::report_and_die("unimplemented ucontext_get_pc");
1079 #endif
1080 }
1081
1082 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1083 size_t stack_size = 0;
1084 size_t guard_size = 0;
1085 int detachstate = 0;
1086 pthread_attr_getstacksize(attr, &stack_size);
1087 pthread_attr_getguardsize(attr, &guard_size);
1088 pthread_attr_getdetachstate(attr, &detachstate);
1089 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1090 stack_size / 1024, guard_size / 1024,
1091 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1092 return buf;
1093 }
1094
1095
1096 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
1097 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
1098 }
1099
1100 /*
1101 * See the caveats for this class in os_posix.hpp
1102 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1103 * method and returns false. If none of the signals are raised, returns true.
1104 * The callback is supposed to provide the method that should be protected.
1105 */
1106 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1107 sigset_t saved_sig_mask;
1108
1109 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
1110 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
1111 "crash_protection already set?");
1112
1113 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1114 // since on at least some systems (OS X) siglongjmp will restore the mask
1115 // for the process, not the thread
1116 pthread_sigmask(0, NULL, &saved_sig_mask);
1117 if (sigsetjmp(_jmpbuf, 0) == 0) {
1118 // make sure we can see in the signal handler that we have crash protection
1119 // installed
1120 WatcherThread::watcher_thread()->set_crash_protection(this);
1121 cb.call();
1122 // and clear the crash protection
1123 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1124 return true;
1125 }
1126 // this happens when we siglongjmp() back
1127 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1128 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1129 return false;
1130 }
1131
1132 void os::WatcherThreadCrashProtection::restore() {
1133 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1134 "must have crash protection");
1135
1136 siglongjmp(_jmpbuf, 1);
1137 }
1138
1139 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1140 Thread* thread) {
1141
1142 if (thread != NULL &&
1143 thread->is_Watcher_thread() &&
1144 WatcherThread::watcher_thread()->has_crash_protection()) {
1145
1146 if (sig == SIGSEGV || sig == SIGBUS) {
1147 WatcherThread::watcher_thread()->crash_protection()->restore();
1148 }
1149 }
1150 }
1151
1152 #define check_with_errno(check_type, cond, msg) \
1153 do { \
1154 int err = errno; \
1155 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
1156 os::errno_name(err)); \
1157 } while (false)
1158
1159 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
1160 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1161
1162 // POSIX unamed semaphores are not supported on OS X.
1163 #ifndef __APPLE__
1164
1165 PosixSemaphore::PosixSemaphore(uint value) {
1166 int ret = sem_init(&_semaphore, 0, value);
1167
1168 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1169 }
1170
1171 PosixSemaphore::~PosixSemaphore() {
1172 sem_destroy(&_semaphore);
1173 }
1174
1175 void PosixSemaphore::signal(uint count) {
1176 for (uint i = 0; i < count; i++) {
1177 int ret = sem_post(&_semaphore);
1178
1179 assert_with_errno(ret == 0, "sem_post failed");
1180 }
1181 }
1182
1183 void PosixSemaphore::wait() {
1184 int ret;
1185
1186 do {
1187 ret = sem_wait(&_semaphore);
1188 } while (ret != 0 && errno == EINTR);
1189
1190 assert_with_errno(ret == 0, "sem_wait failed");
1191 }
1192
1193 bool PosixSemaphore::trywait() {
1194 int ret;
1195
1196 do {
1197 ret = sem_trywait(&_semaphore);
1198 } while (ret != 0 && errno == EINTR);
1199
1200 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1201
1202 return ret == 0;
1203 }
1204
1205 bool PosixSemaphore::timedwait(struct timespec ts) {
1206 while (true) {
1207 int result = sem_timedwait(&_semaphore, &ts);
1208 if (result == 0) {
1209 return true;
1210 } else if (errno == EINTR) {
1211 continue;
1212 } else if (errno == ETIMEDOUT) {
1213 return false;
1214 } else {
1215 assert_with_errno(false, "timedwait failed");
1216 return false;
1217 }
1218 }
1219 }
1220
1221 #endif // __APPLE__