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/macros.hpp"
32 #include "utilities/vmError.hpp"
33
34 #include <signal.h>
35 #include <unistd.h>
36 #include <sys/resource.h>
37 #include <sys/utsname.h>
38 #include <pthread.h>
39 #include <semaphore.h>
40 #include <signal.h>
41
42 // Todo: provide a os::get_max_process_id() or similar. Number of processes
43 // may have been configured, can be read more accurately from proc fs etc.
44 #ifndef MAX_PID
45 #define MAX_PID INT_MAX
46 #endif
47 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
48
49 // Check core dump limit and report possible place where core can be found
50 void os::check_dump_limit(char* buffer, size_t bufferSize) {
51 if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
52 jio_snprintf(buffer, bufferSize, "CreateCoredumpOnCrash is disabled from command line");
53 VMError::record_coredump_status(buffer, false);
54 return;
55 }
56
57 int n;
58 struct rlimit rlim;
59 bool success;
60
61 char core_path[PATH_MAX];
62 n = get_core_path(core_path, PATH_MAX);
63
64 if (n <= 0) {
65 jio_snprintf(buffer, bufferSize, "core.%d (may not exist)", current_process_id());
66 success = true;
67 #ifdef LINUX
68 } else if (core_path[0] == '"') { // redirect to user process
69 jio_snprintf(buffer, bufferSize, "Core dumps may be processed with %s", core_path);
70 success = true;
71 #endif
72 } else if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
73 jio_snprintf(buffer, bufferSize, "%s (may not exist)", core_path);
74 success = true;
75 } else {
76 switch(rlim.rlim_cur) {
77 case RLIM_INFINITY:
78 jio_snprintf(buffer, bufferSize, "%s", core_path);
79 success = true;
80 break;
81 case 0:
82 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
83 success = false;
84 break;
85 default:
86 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));
87 success = true;
88 break;
89 }
90 }
91
92 VMError::record_coredump_status(buffer, success);
93 }
94
95 int os::get_native_stack(address* stack, int frames, int toSkip) {
96 int frame_idx = 0;
97 int num_of_frames; // number of frames captured
98 frame fr = os::current_frame();
99 while (fr.pc() && frame_idx < frames) {
100 if (toSkip > 0) {
101 toSkip --;
102 } else {
103 stack[frame_idx ++] = fr.pc();
104 }
105 if (fr.fp() == NULL || fr.cb() != NULL ||
106 fr.sender_pc() == NULL || os::is_first_C_frame(&fr)) break;
107
108 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
109 fr = os::get_sender_for_C_frame(&fr);
110 } else {
111 break;
112 }
113 }
114 num_of_frames = frame_idx;
115 for (; frame_idx < frames; frame_idx ++) {
116 stack[frame_idx] = NULL;
117 }
118
119 return num_of_frames;
120 }
121
122
123 bool os::unsetenv(const char* name) {
124 assert(name != NULL, "Null pointer");
125 return (::unsetenv(name) == 0);
126 }
127
128 int os::get_last_error() {
129 return errno;
130 }
131
132 bool os::is_debugger_attached() {
133 // not implemented
134 return false;
135 }
136
137 void os::wait_for_keypress_at_exit(void) {
138 // don't do anything on posix platforms
139 return;
140 }
141
142 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
143 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
144 // rather than unmapping and remapping the whole chunk to get requested alignment.
145 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
146 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
147 "Alignment must be a multiple of allocation granularity (page size)");
148 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
149
150 size_t extra_size = size + alignment;
151 assert(extra_size >= size, "overflow, size is too large to allow alignment");
152
153 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
154
155 if (extra_base == NULL) {
156 return NULL;
157 }
158
159 // Do manual alignment
160 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
161
162 // [ | | ]
163 // ^ extra_base
164 // ^ extra_base + begin_offset == aligned_base
165 // extra_base + begin_offset + size ^
166 // extra_base + extra_size ^
167 // |<>| == begin_offset
168 // end_offset == |<>|
169 size_t begin_offset = aligned_base - extra_base;
170 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
171
172 if (begin_offset > 0) {
173 os::release_memory(extra_base, begin_offset);
174 }
175
176 if (end_offset > 0) {
177 os::release_memory(extra_base + begin_offset + size, end_offset);
178 }
179
180 return aligned_base;
181 }
182
183 int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
184 return vsnprintf(buf, len, fmt, args);
185 }
186
187 int os::get_fileno(FILE* fp) {
188 return NOT_AIX(::)fileno(fp);
189 }
190
191 void os::Posix::print_load_average(outputStream* st) {
192 st->print("load average:");
193 double loadavg[3];
194 os::loadavg(loadavg, 3);
195 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
196 st->cr();
197 }
198
199 void os::Posix::print_rlimit_info(outputStream* st) {
200 st->print("rlimit:");
201 struct rlimit rlim;
202
203 st->print(" STACK ");
204 getrlimit(RLIMIT_STACK, &rlim);
205 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
206 else st->print("%luk", rlim.rlim_cur >> 10);
207
208 st->print(", CORE ");
209 getrlimit(RLIMIT_CORE, &rlim);
210 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
211 else st->print("%luk", rlim.rlim_cur >> 10);
212
213 // Isn't there on solaris
214 #if !defined(SOLARIS) && !defined(AIX)
215 st->print(", NPROC ");
216 getrlimit(RLIMIT_NPROC, &rlim);
217 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
218 else st->print("%lu", rlim.rlim_cur);
219 #endif
220
221 st->print(", NOFILE ");
222 getrlimit(RLIMIT_NOFILE, &rlim);
223 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
224 else st->print("%lu", rlim.rlim_cur);
225
226 st->print(", AS ");
227 getrlimit(RLIMIT_AS, &rlim);
228 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
229 else st->print("%luk", rlim.rlim_cur >> 10);
230 st->cr();
231 }
232
233 void os::Posix::print_uname_info(outputStream* st) {
234 // kernel
235 st->print("uname:");
236 struct utsname name;
237 uname(&name);
238 st->print("%s ", name.sysname);
239 #ifdef ASSERT
240 st->print("%s ", name.nodename);
241 #endif
242 st->print("%s ", name.release);
243 st->print("%s ", name.version);
244 st->print("%s", name.machine);
245 st->cr();
246 }
247
248 bool os::get_host_name(char* buf, size_t buflen) {
249 struct utsname name;
250 uname(&name);
251 jio_snprintf(buf, buflen, "%s", name.nodename);
252 return true;
253 }
254
255 bool os::has_allocatable_memory_limit(julong* limit) {
256 struct rlimit rlim;
257 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
258 // if there was an error when calling getrlimit, assume that there is no limitation
259 // on virtual memory.
260 bool result;
261 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
262 result = false;
263 } else {
264 *limit = (julong)rlim.rlim_cur;
265 result = true;
266 }
267 #ifdef _LP64
268 return result;
269 #else
270 // arbitrary virtual space limit for 32 bit Unices found by testing. If
271 // getrlimit above returned a limit, bound it with this limit. Otherwise
272 // directly use it.
273 const julong max_virtual_limit = (julong)3800*M;
274 if (result) {
275 *limit = MIN2(*limit, max_virtual_limit);
276 } else {
277 *limit = max_virtual_limit;
278 }
279
280 // bound by actually allocatable memory. The algorithm uses two bounds, an
281 // upper and a lower limit. The upper limit is the current highest amount of
282 // memory that could not be allocated, the lower limit is the current highest
283 // amount of memory that could be allocated.
284 // The algorithm iteratively refines the result by halving the difference
285 // between these limits, updating either the upper limit (if that value could
286 // not be allocated) or the lower limit (if the that value could be allocated)
287 // until the difference between these limits is "small".
288
289 // the minimum amount of memory we care about allocating.
290 const julong min_allocation_size = M;
291
292 julong upper_limit = *limit;
293
294 // first check a few trivial cases
295 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
296 *limit = upper_limit;
297 } else if (!is_allocatable(min_allocation_size)) {
298 // we found that not even min_allocation_size is allocatable. Return it
299 // anyway. There is no point to search for a better value any more.
300 *limit = min_allocation_size;
301 } else {
302 // perform the binary search.
303 julong lower_limit = min_allocation_size;
304 while ((upper_limit - lower_limit) > min_allocation_size) {
305 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
306 temp_limit = align_size_down_(temp_limit, min_allocation_size);
307 if (is_allocatable(temp_limit)) {
308 lower_limit = temp_limit;
309 } else {
310 upper_limit = temp_limit;
311 }
312 }
313 *limit = lower_limit;
314 }
315 return true;
316 #endif
317 }
318
319 const char* os::get_current_directory(char *buf, size_t buflen) {
320 return getcwd(buf, buflen);
321 }
322
323 FILE* os::open(int fd, const char* mode) {
324 return ::fdopen(fd, mode);
325 }
326
327 void os::flockfile(FILE* fp) {
328 ::flockfile(fp);
329 }
330
331 void os::funlockfile(FILE* fp) {
332 ::funlockfile(fp);
333 }
334
335 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
336 // which is used to find statically linked in agents.
337 // Parameters:
338 // sym_name: Symbol in library we are looking for
339 // lib_name: Name of library to look in, NULL for shared libs.
340 // is_absolute_path == true if lib_name is absolute path to agent
341 // such as "/a/b/libL.so"
342 // == false if only the base name of the library is passed in
343 // such as "L"
344 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
345 bool is_absolute_path) {
346 char *agent_entry_name;
347 size_t len;
348 size_t name_len;
349 size_t prefix_len = strlen(JNI_LIB_PREFIX);
350 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
351 const char *start;
352
353 if (lib_name != NULL) {
354 name_len = strlen(lib_name);
355 if (is_absolute_path) {
356 // Need to strip path, prefix and suffix
357 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
358 lib_name = ++start;
359 }
360 if (strlen(lib_name) <= (prefix_len + suffix_len)) {
361 return NULL;
362 }
363 lib_name += prefix_len;
364 name_len = strlen(lib_name) - suffix_len;
365 }
366 }
367 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
368 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
369 if (agent_entry_name == NULL) {
370 return NULL;
371 }
372 strcpy(agent_entry_name, sym_name);
373 if (lib_name != NULL) {
374 strcat(agent_entry_name, "_");
375 strncat(agent_entry_name, lib_name, name_len);
376 }
377 return agent_entry_name;
378 }
379
380 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
381 assert(thread == Thread::current(), "thread consistency check");
382
383 ParkEvent * const slp = thread->_SleepEvent ;
384 slp->reset() ;
385 OrderAccess::fence() ;
386
387 if (interruptible) {
388 jlong prevtime = javaTimeNanos();
389
390 for (;;) {
391 if (os::is_interrupted(thread, true)) {
392 return OS_INTRPT;
393 }
394
395 jlong newtime = javaTimeNanos();
396
397 if (newtime - prevtime < 0) {
398 // time moving backwards, should only happen if no monotonic clock
399 // not a guarantee() because JVM should not abort on kernel/glibc bugs
400 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
401 } else {
402 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
403 }
404
405 if (millis <= 0) {
406 return OS_OK;
407 }
408
409 prevtime = newtime;
410
411 {
412 assert(thread->is_Java_thread(), "sanity check");
413 JavaThread *jt = (JavaThread *) thread;
414 ThreadBlockInVM tbivm(jt);
415 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
416
417 jt->set_suspend_equivalent();
418 // cleared by handle_special_suspend_equivalent_condition() or
419 // java_suspend_self() via check_and_wait_while_suspended()
420
421 slp->park(millis);
422
423 // were we externally suspended while we were waiting?
424 jt->check_and_wait_while_suspended();
425 }
426 }
427 } else {
428 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
429 jlong prevtime = javaTimeNanos();
430
431 for (;;) {
432 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
433 // the 1st iteration ...
434 jlong newtime = javaTimeNanos();
435
436 if (newtime - prevtime < 0) {
437 // time moving backwards, should only happen if no monotonic clock
438 // not a guarantee() because JVM should not abort on kernel/glibc bugs
439 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
440 } else {
441 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
442 }
443
444 if (millis <= 0) break ;
445
446 prevtime = newtime;
447 slp->park(millis);
448 }
449 return OS_OK ;
450 }
451 }
452
453 ////////////////////////////////////////////////////////////////////////////////
454 // interrupt support
455
456 void os::interrupt(Thread* thread) {
457 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
458 "possibility of dangling Thread pointer");
459
460 OSThread* osthread = thread->osthread();
461
462 if (!osthread->interrupted()) {
463 osthread->set_interrupted(true);
464 // More than one thread can get here with the same value of osthread,
465 // resulting in multiple notifications. We do, however, want the store
466 // to interrupted() to be visible to other threads before we execute unpark().
467 OrderAccess::fence();
468 ParkEvent * const slp = thread->_SleepEvent ;
469 if (slp != NULL) slp->unpark() ;
470 }
471
472 // For JSR166. Unpark even if interrupt status already was set
473 if (thread->is_Java_thread())
474 ((JavaThread*)thread)->parker()->unpark();
475
476 ParkEvent * ev = thread->_ParkEvent ;
477 if (ev != NULL) ev->unpark() ;
478
479 }
480
481 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
482 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
483 "possibility of dangling Thread pointer");
484
485 OSThread* osthread = thread->osthread();
486
487 bool interrupted = osthread->interrupted();
488
489 // NOTE that since there is no "lock" around the interrupt and
490 // is_interrupted operations, there is the possibility that the
491 // interrupted flag (in osThread) will be "false" but that the
492 // low-level events will be in the signaled state. This is
493 // intentional. The effect of this is that Object.wait() and
494 // LockSupport.park() will appear to have a spurious wakeup, which
495 // is allowed and not harmful, and the possibility is so rare that
496 // it is not worth the added complexity to add yet another lock.
497 // For the sleep event an explicit reset is performed on entry
498 // to os::sleep, so there is no early return. It has also been
499 // recommended not to put the interrupted flag into the "event"
500 // structure because it hides the issue.
501 if (interrupted && clear_interrupted) {
502 osthread->set_interrupted(false);
503 // consider thread->_SleepEvent->reset() ... optional optimization
504 }
505
506 return interrupted;
507 }
508
509
510
511 static const struct {
512 int sig; const char* name;
513 }
514 g_signal_info[] =
515 {
516 { SIGABRT, "SIGABRT" },
517 #ifdef SIGAIO
518 { SIGAIO, "SIGAIO" },
519 #endif
520 { SIGALRM, "SIGALRM" },
521 #ifdef SIGALRM1
522 { SIGALRM1, "SIGALRM1" },
523 #endif
524 { SIGBUS, "SIGBUS" },
525 #ifdef SIGCANCEL
526 { SIGCANCEL, "SIGCANCEL" },
527 #endif
528 { SIGCHLD, "SIGCHLD" },
529 #ifdef SIGCLD
530 { SIGCLD, "SIGCLD" },
531 #endif
532 { SIGCONT, "SIGCONT" },
533 #ifdef SIGCPUFAIL
534 { SIGCPUFAIL, "SIGCPUFAIL" },
535 #endif
536 #ifdef SIGDANGER
537 { SIGDANGER, "SIGDANGER" },
538 #endif
539 #ifdef SIGDIL
540 { SIGDIL, "SIGDIL" },
541 #endif
542 #ifdef SIGEMT
543 { SIGEMT, "SIGEMT" },
544 #endif
545 { SIGFPE, "SIGFPE" },
546 #ifdef SIGFREEZE
547 { SIGFREEZE, "SIGFREEZE" },
548 #endif
549 #ifdef SIGGFAULT
550 { SIGGFAULT, "SIGGFAULT" },
551 #endif
552 #ifdef SIGGRANT
553 { SIGGRANT, "SIGGRANT" },
554 #endif
555 { SIGHUP, "SIGHUP" },
556 { SIGILL, "SIGILL" },
557 { SIGINT, "SIGINT" },
558 #ifdef SIGIO
559 { SIGIO, "SIGIO" },
560 #endif
561 #ifdef SIGIOINT
562 { SIGIOINT, "SIGIOINT" },
563 #endif
564 #ifdef SIGIOT
565 // SIGIOT is there for BSD compatibility, but on most Unices just a
566 // synonym for SIGABRT. The result should be "SIGABRT", not
567 // "SIGIOT".
568 #if (SIGIOT != SIGABRT )
569 { SIGIOT, "SIGIOT" },
570 #endif
571 #endif
572 #ifdef SIGKAP
573 { SIGKAP, "SIGKAP" },
574 #endif
575 { SIGKILL, "SIGKILL" },
576 #ifdef SIGLOST
577 { SIGLOST, "SIGLOST" },
578 #endif
579 #ifdef SIGLWP
580 { SIGLWP, "SIGLWP" },
581 #endif
582 #ifdef SIGLWPTIMER
583 { SIGLWPTIMER, "SIGLWPTIMER" },
584 #endif
585 #ifdef SIGMIGRATE
586 { SIGMIGRATE, "SIGMIGRATE" },
587 #endif
588 #ifdef SIGMSG
589 { SIGMSG, "SIGMSG" },
590 #endif
591 { SIGPIPE, "SIGPIPE" },
592 #ifdef SIGPOLL
593 { SIGPOLL, "SIGPOLL" },
594 #endif
595 #ifdef SIGPRE
596 { SIGPRE, "SIGPRE" },
597 #endif
598 { SIGPROF, "SIGPROF" },
599 #ifdef SIGPTY
600 { SIGPTY, "SIGPTY" },
601 #endif
602 #ifdef SIGPWR
603 { SIGPWR, "SIGPWR" },
604 #endif
605 { SIGQUIT, "SIGQUIT" },
606 #ifdef SIGRECONFIG
607 { SIGRECONFIG, "SIGRECONFIG" },
608 #endif
609 #ifdef SIGRECOVERY
610 { SIGRECOVERY, "SIGRECOVERY" },
611 #endif
612 #ifdef SIGRESERVE
613 { SIGRESERVE, "SIGRESERVE" },
614 #endif
615 #ifdef SIGRETRACT
616 { SIGRETRACT, "SIGRETRACT" },
617 #endif
618 #ifdef SIGSAK
619 { SIGSAK, "SIGSAK" },
620 #endif
621 { SIGSEGV, "SIGSEGV" },
622 #ifdef SIGSOUND
623 { SIGSOUND, "SIGSOUND" },
624 #endif
625 #ifdef SIGSTKFLT
626 { SIGSTKFLT, "SIGSTKFLT" },
627 #endif
628 { SIGSTOP, "SIGSTOP" },
629 { SIGSYS, "SIGSYS" },
630 #ifdef SIGSYSERROR
631 { SIGSYSERROR, "SIGSYSERROR" },
632 #endif
633 #ifdef SIGTALRM
634 { SIGTALRM, "SIGTALRM" },
635 #endif
636 { SIGTERM, "SIGTERM" },
637 #ifdef SIGTHAW
638 { SIGTHAW, "SIGTHAW" },
639 #endif
640 { SIGTRAP, "SIGTRAP" },
641 #ifdef SIGTSTP
642 { SIGTSTP, "SIGTSTP" },
643 #endif
644 { SIGTTIN, "SIGTTIN" },
645 { SIGTTOU, "SIGTTOU" },
646 #ifdef SIGURG
647 { SIGURG, "SIGURG" },
648 #endif
649 { SIGUSR1, "SIGUSR1" },
650 { SIGUSR2, "SIGUSR2" },
651 #ifdef SIGVIRT
652 { SIGVIRT, "SIGVIRT" },
653 #endif
654 { SIGVTALRM, "SIGVTALRM" },
655 #ifdef SIGWAITING
656 { SIGWAITING, "SIGWAITING" },
657 #endif
658 #ifdef SIGWINCH
659 { SIGWINCH, "SIGWINCH" },
660 #endif
661 #ifdef SIGWINDOW
662 { SIGWINDOW, "SIGWINDOW" },
663 #endif
664 { SIGXCPU, "SIGXCPU" },
665 { SIGXFSZ, "SIGXFSZ" },
666 #ifdef SIGXRES
667 { SIGXRES, "SIGXRES" },
668 #endif
669 { -1, NULL }
670 };
671
672 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
673 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
674
675 const char* ret = NULL;
676
677 #ifdef SIGRTMIN
678 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
679 if (sig == SIGRTMIN) {
680 ret = "SIGRTMIN";
681 } else if (sig == SIGRTMAX) {
682 ret = "SIGRTMAX";
683 } else {
684 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
685 return out;
686 }
687 }
688 #endif
689
690 if (sig > 0) {
691 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
692 if (g_signal_info[idx].sig == sig) {
693 ret = g_signal_info[idx].name;
694 break;
695 }
696 }
697 }
698
699 if (!ret) {
700 if (!is_valid_signal(sig)) {
701 ret = "INVALID";
702 } else {
703 ret = "UNKNOWN";
704 }
705 }
706
707 if (out && outlen > 0) {
708 strncpy(out, ret, outlen);
709 out[outlen - 1] = '\0';
710 }
711 return out;
712 }
713
714 int os::Posix::get_signal_number(const char* signal_name) {
715 char tmp[30];
716 const char* s = signal_name;
717 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
718 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
719 s = tmp;
720 }
721 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
722 if (strcmp(g_signal_info[idx].name, s) == 0) {
723 return g_signal_info[idx].sig;
724 }
725 }
726 return -1;
727 }
728
729 int os::get_signal_number(const char* signal_name) {
730 return os::Posix::get_signal_number(signal_name);
731 }
732
733 // Returns true if signal number is valid.
734 bool os::Posix::is_valid_signal(int sig) {
735 // MacOS not really POSIX compliant: sigaddset does not return
736 // an error for invalid signal numbers. However, MacOS does not
737 // support real time signals and simply seems to have just 33
738 // signals with no holes in the signal range.
739 #ifdef __APPLE__
740 return sig >= 1 && sig < NSIG;
741 #else
742 // Use sigaddset to check for signal validity.
743 sigset_t set;
744 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
745 return false;
746 }
747 return true;
748 #endif
749 }
750
751 // Returns:
752 // NULL for an invalid signal number
753 // "SIG<num>" for a valid but unknown signal number
754 // signal name otherwise.
755 const char* os::exception_name(int sig, char* buf, size_t size) {
756 if (!os::Posix::is_valid_signal(sig)) {
757 return NULL;
758 }
759 const char* const name = os::Posix::get_signal_name(sig, buf, size);
760 if (strcmp(name, "UNKNOWN") == 0) {
761 jio_snprintf(buf, size, "SIG%d", sig);
762 }
763 return buf;
764 }
765
766 #define NUM_IMPORTANT_SIGS 32
767 // Returns one-line short description of a signal set in a user provided buffer.
768 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
769 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
770 // Note: for shortness, just print out the first 32. That should
771 // cover most of the useful ones, apart from realtime signals.
772 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
773 const int rc = sigismember(set, sig);
774 if (rc == -1 && errno == EINVAL) {
775 buffer[sig-1] = '?';
776 } else {
777 buffer[sig-1] = rc == 0 ? '0' : '1';
778 }
779 }
780 buffer[NUM_IMPORTANT_SIGS] = 0;
781 return buffer;
782 }
783
784 // Prints one-line description of a signal set.
785 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
786 char buf[NUM_IMPORTANT_SIGS + 1];
787 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
788 st->print("%s", buf);
789 }
790
791 // Writes one-line description of a combination of sigaction.sa_flags into a user
792 // provided buffer. Returns that buffer.
793 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
794 char* p = buffer;
795 size_t remaining = size;
796 bool first = true;
797 int idx = 0;
798
799 assert(buffer, "invalid argument");
800
801 if (size == 0) {
802 return buffer;
803 }
804
805 strncpy(buffer, "none", size);
806
807 const struct {
808 // NB: i is an unsigned int here because SA_RESETHAND is on some
809 // systems 0x80000000, which is implicitly unsigned. Assignining
810 // it to an int field would be an overflow in unsigned-to-signed
811 // conversion.
812 unsigned int i;
813 const char* s;
814 } flaginfo [] = {
815 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
816 { SA_ONSTACK, "SA_ONSTACK" },
817 { SA_RESETHAND, "SA_RESETHAND" },
818 { SA_RESTART, "SA_RESTART" },
819 { SA_SIGINFO, "SA_SIGINFO" },
820 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
821 { SA_NODEFER, "SA_NODEFER" },
822 #ifdef AIX
823 { SA_ONSTACK, "SA_ONSTACK" },
824 { SA_OLDSTYLE, "SA_OLDSTYLE" },
825 #endif
826 { 0, NULL }
827 };
828
829 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
830 if (flags & flaginfo[idx].i) {
831 if (first) {
832 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
833 first = false;
834 } else {
835 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
836 }
837 const size_t len = strlen(p);
838 p += len;
839 remaining -= len;
840 }
841 }
842
843 buffer[size - 1] = '\0';
844
845 return buffer;
846 }
847
848 // Prints one-line description of a combination of sigaction.sa_flags.
849 void os::Posix::print_sa_flags(outputStream* st, int flags) {
850 char buffer[0x100];
851 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
852 st->print("%s", buffer);
853 }
854
855 // Helper function for os::Posix::print_siginfo_...():
856 // return a textual description for signal code.
857 struct enum_sigcode_desc_t {
858 const char* s_name;
859 const char* s_desc;
860 };
861
862 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
863
864 const struct {
865 int sig; int code; const char* s_code; const char* s_desc;
866 } t1 [] = {
867 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
868 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
869 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
870 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
871 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
872 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
873 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
874 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
875 #if defined(IA64) && defined(LINUX)
876 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
877 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
878 #endif
879 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
880 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
881 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
882 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
883 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
884 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
885 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
886 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
887 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
888 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
889 #ifdef AIX
890 // no explanation found what keyerr would be
891 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
892 #endif
893 #if defined(IA64) && !defined(AIX)
894 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
895 #endif
896 #if defined(__sparc) && defined(SOLARIS)
897 // define Solaris Sparc M7 ADI SEGV signals
898 #if !defined(SEGV_ACCADI)
899 #define SEGV_ACCADI 3
900 #endif
901 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
902 #if !defined(SEGV_ACCDERR)
903 #define SEGV_ACCDERR 4
904 #endif
905 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
906 #if !defined(SEGV_ACCPERR)
907 #define SEGV_ACCPERR 5
908 #endif
909 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
910 #endif // defined(__sparc) && defined(SOLARIS)
911 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
912 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
913 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
914 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
915 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
916 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
917 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
918 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
919 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
920 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
921 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
922 #ifdef SIGPOLL
923 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
924 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
925 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
926 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
927 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
928 #endif
929 { -1, -1, NULL, NULL }
930 };
931
932 // Codes valid in any signal context.
933 const struct {
934 int code; const char* s_code; const char* s_desc;
935 } t2 [] = {
936 { SI_USER, "SI_USER", "Signal sent by kill()." },
937 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
938 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
939 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
940 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
941 // Linux specific
942 #ifdef SI_TKILL
943 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
944 #endif
945 #ifdef SI_DETHREAD
946 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
947 #endif
948 #ifdef SI_KERNEL
949 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
950 #endif
951 #ifdef SI_SIGIO
952 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
953 #endif
954
955 #ifdef AIX
956 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
957 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
958 #endif
959
960 #ifdef __sun
961 { SI_NOINFO, "SI_NOINFO", "No signal information" },
962 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
963 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
964 #endif
965
966 { -1, NULL, NULL }
967 };
968
969 const char* s_code = NULL;
970 const char* s_desc = NULL;
971
972 for (int i = 0; t1[i].sig != -1; i ++) {
973 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
974 s_code = t1[i].s_code;
975 s_desc = t1[i].s_desc;
976 break;
977 }
978 }
979
980 if (s_code == NULL) {
981 for (int i = 0; t2[i].s_code != NULL; i ++) {
982 if (t2[i].code == si->si_code) {
983 s_code = t2[i].s_code;
984 s_desc = t2[i].s_desc;
985 }
986 }
987 }
988
989 if (s_code == NULL) {
990 out->s_name = "unknown";
991 out->s_desc = "unknown";
992 return false;
993 }
994
995 out->s_name = s_code;
996 out->s_desc = s_desc;
997
998 return true;
999 }
1000
1001 void os::print_siginfo(outputStream* os, const void* si0) {
1002
1003 const siginfo_t* const si = (const siginfo_t*) si0;
1004
1005 char buf[20];
1006 os->print("siginfo:");
1007
1008 if (!si) {
1009 os->print(" <null>");
1010 return;
1011 }
1012
1013 const int sig = si->si_signo;
1014
1015 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1016
1017 enum_sigcode_desc_t ed;
1018 get_signal_code_description(si, &ed);
1019 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1020
1021 if (si->si_errno) {
1022 os->print(", si_errno: %d", si->si_errno);
1023 }
1024
1025 // Output additional information depending on the signal code.
1026
1027 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1028 // so it depends on the context which member to use. For synchronous error signals,
1029 // we print si_addr, unless the signal was sent by another process or thread, in
1030 // which case we print out pid or tid of the sender.
1031 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1032 const pid_t pid = si->si_pid;
1033 os->print(", si_pid: %ld", (long) pid);
1034 if (IS_VALID_PID(pid)) {
1035 const pid_t me = getpid();
1036 if (me == pid) {
1037 os->print(" (current process)");
1038 }
1039 } else {
1040 os->print(" (invalid)");
1041 }
1042 os->print(", si_uid: %ld", (long) si->si_uid);
1043 if (sig == SIGCHLD) {
1044 os->print(", si_status: %d", si->si_status);
1045 }
1046 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1047 sig == SIGTRAP || sig == SIGFPE) {
1048 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1049 #ifdef SIGPOLL
1050 } else if (sig == SIGPOLL) {
1051 os->print(", si_band: %ld", si->si_band);
1052 #endif
1053 }
1054
1055 }
1056
1057 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1058 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1059 }
1060
1061 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1062 #if defined(AIX)
1063 return Aix::ucontext_get_pc(ctx);
1064 #elif defined(BSD)
1065 return Bsd::ucontext_get_pc(ctx);
1066 #elif defined(LINUX)
1067 return Linux::ucontext_get_pc(ctx);
1068 #elif defined(SOLARIS)
1069 return Solaris::ucontext_get_pc(ctx);
1070 #else
1071 VMError::report_and_die("unimplemented ucontext_get_pc");
1072 #endif
1073 }
1074
1075 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1076 #if defined(AIX)
1077 Aix::ucontext_set_pc(ctx, pc);
1078 #elif defined(BSD)
1079 Bsd::ucontext_set_pc(ctx, pc);
1080 #elif defined(LINUX)
1081 Linux::ucontext_set_pc(ctx, pc);
1082 #elif defined(SOLARIS)
1083 Solaris::ucontext_set_pc(ctx, pc);
1084 #else
1085 VMError::report_and_die("unimplemented ucontext_get_pc");
1086 #endif
1087 }
1088
1089 char* os::Posix::describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr) {
1090 size_t stack_size = 0;
1091 size_t guard_size = 0;
1092 int detachstate = 0;
1093 pthread_attr_getstacksize(attr, &stack_size);
1094 pthread_attr_getguardsize(attr, &guard_size);
1095 pthread_attr_getdetachstate(attr, &detachstate);
1096 jio_snprintf(buf, buflen, "stacksize: " SIZE_FORMAT "k, guardsize: " SIZE_FORMAT "k, %s",
1097 stack_size / 1024, guard_size / 1024,
1098 (detachstate == PTHREAD_CREATE_DETACHED ? "detached" : "joinable"));
1099 return buf;
1100 }
1101
1102
1103 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
1104 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
1105 }
1106
1107 /*
1108 * See the caveats for this class in os_posix.hpp
1109 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1110 * method and returns false. If none of the signals are raised, returns true.
1111 * The callback is supposed to provide the method that should be protected.
1112 */
1113 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1114 sigset_t saved_sig_mask;
1115
1116 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
1117 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
1118 "crash_protection already set?");
1119
1120 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1121 // since on at least some systems (OS X) siglongjmp will restore the mask
1122 // for the process, not the thread
1123 pthread_sigmask(0, NULL, &saved_sig_mask);
1124 if (sigsetjmp(_jmpbuf, 0) == 0) {
1125 // make sure we can see in the signal handler that we have crash protection
1126 // installed
1127 WatcherThread::watcher_thread()->set_crash_protection(this);
1128 cb.call();
1129 // and clear the crash protection
1130 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1131 return true;
1132 }
1133 // this happens when we siglongjmp() back
1134 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1135 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1136 return false;
1137 }
1138
1139 void os::WatcherThreadCrashProtection::restore() {
1140 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1141 "must have crash protection");
1142
1143 siglongjmp(_jmpbuf, 1);
1144 }
1145
1146 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1147 Thread* thread) {
1148
1149 if (thread != NULL &&
1150 thread->is_Watcher_thread() &&
1151 WatcherThread::watcher_thread()->has_crash_protection()) {
1152
1153 if (sig == SIGSEGV || sig == SIGBUS) {
1154 WatcherThread::watcher_thread()->crash_protection()->restore();
1155 }
1156 }
1157 }
1158
1159 #define check_with_errno(check_type, cond, msg) \
1160 do { \
1161 int err = errno; \
1162 check_type(cond, "%s; error='%s' (errno=%s)", msg, os::strerror(err), \
1163 os::errno_name(err)); \
1164 } while (false)
1165
1166 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
1167 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1168
1169 // POSIX unamed semaphores are not supported on OS X.
1170 #ifndef __APPLE__
1171
1172 PosixSemaphore::PosixSemaphore(uint value) {
1173 int ret = sem_init(&_semaphore, 0, value);
1174
1175 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1176 }
1177
1178 PosixSemaphore::~PosixSemaphore() {
1179 sem_destroy(&_semaphore);
1180 }
1181
1182 void PosixSemaphore::signal(uint count) {
1183 for (uint i = 0; i < count; i++) {
1184 int ret = sem_post(&_semaphore);
1185
1186 assert_with_errno(ret == 0, "sem_post failed");
1187 }
1188 }
1189
1190 void PosixSemaphore::wait() {
1191 int ret;
1192
1193 do {
1194 ret = sem_wait(&_semaphore);
1195 } while (ret != 0 && errno == EINTR);
1196
1197 assert_with_errno(ret == 0, "sem_wait failed");
1198 }
1199
1200 bool PosixSemaphore::trywait() {
1201 int ret;
1202
1203 do {
1204 ret = sem_trywait(&_semaphore);
1205 } while (ret != 0 && errno == EINTR);
1206
1207 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1208
1209 return ret == 0;
1210 }
1211
1212 bool PosixSemaphore::timedwait(struct timespec ts) {
1213 while (true) {
1214 int result = sem_timedwait(&_semaphore, &ts);
1215 if (result == 0) {
1216 return true;
1217 } else if (errno == EINTR) {
1218 continue;
1219 } else if (errno == ETIMEDOUT) {
1220 return false;
1221 } else {
1222 assert_with_errno(false, "timedwait failed");
1223 return false;
1224 }
1225 }
1226 }
1227
1228 #endif // __APPLE__