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