1 /*
2 * Copyright (c) 1999, 2015, 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 #ifndef PRODUCT
242 bool os::get_host_name(char* buf, size_t buflen) {
243 struct utsname name;
244 uname(&name);
245 jio_snprintf(buf, buflen, "%s", name.nodename);
246 return true;
247 }
248 #endif // PRODUCT
249
250 bool os::has_allocatable_memory_limit(julong* limit) {
251 struct rlimit rlim;
252 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
253 // if there was an error when calling getrlimit, assume that there is no limitation
254 // on virtual memory.
255 bool result;
256 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
257 result = false;
258 } else {
259 *limit = (julong)rlim.rlim_cur;
260 result = true;
261 }
262 #ifdef _LP64
263 return result;
264 #else
265 // arbitrary virtual space limit for 32 bit Unices found by testing. If
266 // getrlimit above returned a limit, bound it with this limit. Otherwise
267 // directly use it.
268 const julong max_virtual_limit = (julong)3800*M;
269 if (result) {
270 *limit = MIN2(*limit, max_virtual_limit);
271 } else {
272 *limit = max_virtual_limit;
273 }
274
275 // bound by actually allocatable memory. The algorithm uses two bounds, an
276 // upper and a lower limit. The upper limit is the current highest amount of
277 // memory that could not be allocated, the lower limit is the current highest
278 // amount of memory that could be allocated.
279 // The algorithm iteratively refines the result by halving the difference
280 // between these limits, updating either the upper limit (if that value could
281 // not be allocated) or the lower limit (if the that value could be allocated)
282 // until the difference between these limits is "small".
283
284 // the minimum amount of memory we care about allocating.
285 const julong min_allocation_size = M;
286
287 julong upper_limit = *limit;
288
289 // first check a few trivial cases
290 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
291 *limit = upper_limit;
292 } else if (!is_allocatable(min_allocation_size)) {
293 // we found that not even min_allocation_size is allocatable. Return it
294 // anyway. There is no point to search for a better value any more.
295 *limit = min_allocation_size;
296 } else {
297 // perform the binary search.
298 julong lower_limit = min_allocation_size;
299 while ((upper_limit - lower_limit) > min_allocation_size) {
300 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
301 temp_limit = align_size_down_(temp_limit, min_allocation_size);
302 if (is_allocatable(temp_limit)) {
303 lower_limit = temp_limit;
304 } else {
305 upper_limit = temp_limit;
306 }
307 }
308 *limit = lower_limit;
309 }
310 return true;
311 #endif
312 }
313
314 const char* os::get_current_directory(char *buf, size_t buflen) {
315 return getcwd(buf, buflen);
316 }
317
318 FILE* os::open(int fd, const char* mode) {
319 return ::fdopen(fd, mode);
320 }
321
322 void os::flockfile(FILE* fp) {
323 ::flockfile(fp);
324 }
325
326 void os::funlockfile(FILE* fp) {
327 ::funlockfile(fp);
328 }
329
330 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
331 // which is used to find statically linked in agents.
332 // Parameters:
333 // sym_name: Symbol in library we are looking for
334 // lib_name: Name of library to look in, NULL for shared libs.
335 // is_absolute_path == true if lib_name is absolute path to agent
336 // such as "/a/b/libL.so"
337 // == false if only the base name of the library is passed in
338 // such as "L"
339 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
340 bool is_absolute_path) {
341 char *agent_entry_name;
342 size_t len;
343 size_t name_len;
344 size_t prefix_len = strlen(JNI_LIB_PREFIX);
345 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
346 const char *start;
347
348 if (lib_name != NULL) {
349 len = name_len = strlen(lib_name);
350 if (is_absolute_path) {
351 // Need to strip path, prefix and suffix
352 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
353 lib_name = ++start;
354 }
355 if (len <= (prefix_len + suffix_len)) {
356 return NULL;
357 }
358 lib_name += prefix_len;
359 name_len = strlen(lib_name) - suffix_len;
360 }
361 }
362 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
363 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
364 if (agent_entry_name == NULL) {
365 return NULL;
366 }
367 strcpy(agent_entry_name, sym_name);
368 if (lib_name != NULL) {
369 strcat(agent_entry_name, "_");
370 strncat(agent_entry_name, lib_name, name_len);
371 }
372 return agent_entry_name;
373 }
374
375 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
376 assert(thread == Thread::current(), "thread consistency check");
377
378 ParkEvent * const slp = thread->_SleepEvent ;
379 slp->reset() ;
380 OrderAccess::fence() ;
381
382 if (interruptible) {
383 jlong prevtime = javaTimeNanos();
384
385 for (;;) {
386 if (os::is_interrupted(thread, true)) {
387 return OS_INTRPT;
388 }
389
390 jlong newtime = javaTimeNanos();
391
392 if (newtime - prevtime < 0) {
393 // time moving backwards, should only happen if no monotonic clock
394 // not a guarantee() because JVM should not abort on kernel/glibc bugs
395 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected in os::sleep(interruptible)");
396 } else {
397 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
398 }
399
400 if (millis <= 0) {
401 return OS_OK;
402 }
403
404 prevtime = newtime;
405
406 {
407 assert(thread->is_Java_thread(), "sanity check");
408 JavaThread *jt = (JavaThread *) thread;
409 ThreadBlockInVM tbivm(jt);
410 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
411
412 jt->set_suspend_equivalent();
413 // cleared by handle_special_suspend_equivalent_condition() or
414 // java_suspend_self() via check_and_wait_while_suspended()
415
416 slp->park(millis);
417
418 // were we externally suspended while we were waiting?
419 jt->check_and_wait_while_suspended();
420 }
421 }
422 } else {
423 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
424 jlong prevtime = javaTimeNanos();
425
426 for (;;) {
427 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
428 // the 1st iteration ...
429 jlong newtime = javaTimeNanos();
430
431 if (newtime - prevtime < 0) {
432 // time moving backwards, should only happen if no monotonic clock
433 // not a guarantee() because JVM should not abort on kernel/glibc bugs
434 assert(!os::supports_monotonic_clock(), "unexpected time moving backwards detected on os::sleep(!interruptible)");
435 } else {
436 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
437 }
438
439 if (millis <= 0) break ;
440
441 prevtime = newtime;
442 slp->park(millis);
443 }
444 return OS_OK ;
445 }
446 }
447
448 ////////////////////////////////////////////////////////////////////////////////
449 // interrupt support
450
451 void os::interrupt(Thread* thread) {
452 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
453 "possibility of dangling Thread pointer");
454
455 OSThread* osthread = thread->osthread();
456
457 if (!osthread->interrupted()) {
458 osthread->set_interrupted(true);
459 // More than one thread can get here with the same value of osthread,
460 // resulting in multiple notifications. We do, however, want the store
461 // to interrupted() to be visible to other threads before we execute unpark().
462 OrderAccess::fence();
463 ParkEvent * const slp = thread->_SleepEvent ;
464 if (slp != NULL) slp->unpark() ;
465 }
466
467 // For JSR166. Unpark even if interrupt status already was set
468 if (thread->is_Java_thread())
469 ((JavaThread*)thread)->parker()->unpark();
470
471 ParkEvent * ev = thread->_ParkEvent ;
472 if (ev != NULL) ev->unpark() ;
473
474 }
475
476 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
477 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
478 "possibility of dangling Thread pointer");
479
480 OSThread* osthread = thread->osthread();
481
482 bool interrupted = osthread->interrupted();
483
484 // NOTE that since there is no "lock" around the interrupt and
485 // is_interrupted operations, there is the possibility that the
486 // interrupted flag (in osThread) will be "false" but that the
487 // low-level events will be in the signaled state. This is
488 // intentional. The effect of this is that Object.wait() and
489 // LockSupport.park() will appear to have a spurious wakeup, which
490 // is allowed and not harmful, and the possibility is so rare that
491 // it is not worth the added complexity to add yet another lock.
492 // For the sleep event an explicit reset is performed on entry
493 // to os::sleep, so there is no early return. It has also been
494 // recommended not to put the interrupted flag into the "event"
495 // structure because it hides the issue.
496 if (interrupted && clear_interrupted) {
497 osthread->set_interrupted(false);
498 // consider thread->_SleepEvent->reset() ... optional optimization
499 }
500
501 return interrupted;
502 }
503
504
505
506 static const struct {
507 int sig; const char* name;
508 }
509 g_signal_info[] =
510 {
511 { SIGABRT, "SIGABRT" },
512 #ifdef SIGAIO
513 { SIGAIO, "SIGAIO" },
514 #endif
515 { SIGALRM, "SIGALRM" },
516 #ifdef SIGALRM1
517 { SIGALRM1, "SIGALRM1" },
518 #endif
519 { SIGBUS, "SIGBUS" },
520 #ifdef SIGCANCEL
521 { SIGCANCEL, "SIGCANCEL" },
522 #endif
523 { SIGCHLD, "SIGCHLD" },
524 #ifdef SIGCLD
525 { SIGCLD, "SIGCLD" },
526 #endif
527 { SIGCONT, "SIGCONT" },
528 #ifdef SIGCPUFAIL
529 { SIGCPUFAIL, "SIGCPUFAIL" },
530 #endif
531 #ifdef SIGDANGER
532 { SIGDANGER, "SIGDANGER" },
533 #endif
534 #ifdef SIGDIL
535 { SIGDIL, "SIGDIL" },
536 #endif
537 #ifdef SIGEMT
538 { SIGEMT, "SIGEMT" },
539 #endif
540 { SIGFPE, "SIGFPE" },
541 #ifdef SIGFREEZE
542 { SIGFREEZE, "SIGFREEZE" },
543 #endif
544 #ifdef SIGGFAULT
545 { SIGGFAULT, "SIGGFAULT" },
546 #endif
547 #ifdef SIGGRANT
548 { SIGGRANT, "SIGGRANT" },
549 #endif
550 { SIGHUP, "SIGHUP" },
551 { SIGILL, "SIGILL" },
552 { SIGINT, "SIGINT" },
553 #ifdef SIGIO
554 { SIGIO, "SIGIO" },
555 #endif
556 #ifdef SIGIOINT
557 { SIGIOINT, "SIGIOINT" },
558 #endif
559 #ifdef SIGIOT
560 // SIGIOT is there for BSD compatibility, but on most Unices just a
561 // synonym for SIGABRT. The result should be "SIGABRT", not
562 // "SIGIOT".
563 #if (SIGIOT != SIGABRT )
564 { SIGIOT, "SIGIOT" },
565 #endif
566 #endif
567 #ifdef SIGKAP
568 { SIGKAP, "SIGKAP" },
569 #endif
570 { SIGKILL, "SIGKILL" },
571 #ifdef SIGLOST
572 { SIGLOST, "SIGLOST" },
573 #endif
574 #ifdef SIGLWP
575 { SIGLWP, "SIGLWP" },
576 #endif
577 #ifdef SIGLWPTIMER
578 { SIGLWPTIMER, "SIGLWPTIMER" },
579 #endif
580 #ifdef SIGMIGRATE
581 { SIGMIGRATE, "SIGMIGRATE" },
582 #endif
583 #ifdef SIGMSG
584 { SIGMSG, "SIGMSG" },
585 #endif
586 { SIGPIPE, "SIGPIPE" },
587 #ifdef SIGPOLL
588 { SIGPOLL, "SIGPOLL" },
589 #endif
590 #ifdef SIGPRE
591 { SIGPRE, "SIGPRE" },
592 #endif
593 { SIGPROF, "SIGPROF" },
594 #ifdef SIGPTY
595 { SIGPTY, "SIGPTY" },
596 #endif
597 #ifdef SIGPWR
598 { SIGPWR, "SIGPWR" },
599 #endif
600 { SIGQUIT, "SIGQUIT" },
601 #ifdef SIGRECONFIG
602 { SIGRECONFIG, "SIGRECONFIG" },
603 #endif
604 #ifdef SIGRECOVERY
605 { SIGRECOVERY, "SIGRECOVERY" },
606 #endif
607 #ifdef SIGRESERVE
608 { SIGRESERVE, "SIGRESERVE" },
609 #endif
610 #ifdef SIGRETRACT
611 { SIGRETRACT, "SIGRETRACT" },
612 #endif
613 #ifdef SIGSAK
614 { SIGSAK, "SIGSAK" },
615 #endif
616 { SIGSEGV, "SIGSEGV" },
617 #ifdef SIGSOUND
618 { SIGSOUND, "SIGSOUND" },
619 #endif
620 #ifdef SIGSTKFLT
621 { SIGSTKFLT, "SIGSTKFLT" },
622 #endif
623 { SIGSTOP, "SIGSTOP" },
624 { SIGSYS, "SIGSYS" },
625 #ifdef SIGSYSERROR
626 { SIGSYSERROR, "SIGSYSERROR" },
627 #endif
628 #ifdef SIGTALRM
629 { SIGTALRM, "SIGTALRM" },
630 #endif
631 { SIGTERM, "SIGTERM" },
632 #ifdef SIGTHAW
633 { SIGTHAW, "SIGTHAW" },
634 #endif
635 { SIGTRAP, "SIGTRAP" },
636 #ifdef SIGTSTP
637 { SIGTSTP, "SIGTSTP" },
638 #endif
639 { SIGTTIN, "SIGTTIN" },
640 { SIGTTOU, "SIGTTOU" },
641 #ifdef SIGURG
642 { SIGURG, "SIGURG" },
643 #endif
644 { SIGUSR1, "SIGUSR1" },
645 { SIGUSR2, "SIGUSR2" },
646 #ifdef SIGVIRT
647 { SIGVIRT, "SIGVIRT" },
648 #endif
649 { SIGVTALRM, "SIGVTALRM" },
650 #ifdef SIGWAITING
651 { SIGWAITING, "SIGWAITING" },
652 #endif
653 #ifdef SIGWINCH
654 { SIGWINCH, "SIGWINCH" },
655 #endif
656 #ifdef SIGWINDOW
657 { SIGWINDOW, "SIGWINDOW" },
658 #endif
659 { SIGXCPU, "SIGXCPU" },
660 { SIGXFSZ, "SIGXFSZ" },
661 #ifdef SIGXRES
662 { SIGXRES, "SIGXRES" },
663 #endif
664 { -1, NULL }
665 };
666
667 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
668 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
669
670 const char* ret = NULL;
671
672 #ifdef SIGRTMIN
673 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
674 if (sig == SIGRTMIN) {
675 ret = "SIGRTMIN";
676 } else if (sig == SIGRTMAX) {
677 ret = "SIGRTMAX";
678 } else {
679 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
680 return out;
681 }
682 }
683 #endif
684
685 if (sig > 0) {
686 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
687 if (g_signal_info[idx].sig == sig) {
688 ret = g_signal_info[idx].name;
689 break;
690 }
691 }
692 }
693
694 if (!ret) {
695 if (!is_valid_signal(sig)) {
696 ret = "INVALID";
697 } else {
698 ret = "UNKNOWN";
699 }
700 }
701
702 if (out && outlen > 0) {
703 strncpy(out, ret, outlen);
704 out[outlen - 1] = '\0';
705 }
706 return out;
707 }
708
709 int os::Posix::get_signal_number(const char* signal_name) {
710 char tmp[30];
711 const char* s = signal_name;
712 if (s[0] != 'S' || s[1] != 'I' || s[2] != 'G') {
713 jio_snprintf(tmp, sizeof(tmp), "SIG%s", signal_name);
714 s = tmp;
715 }
716 for (int idx = 0; g_signal_info[idx].sig != -1; idx ++) {
717 if (strcmp(g_signal_info[idx].name, s) == 0) {
718 return g_signal_info[idx].sig;
719 }
720 }
721 return -1;
722 }
723
724 int os::get_signal_number(const char* signal_name) {
725 return os::Posix::get_signal_number(signal_name);
726 }
727
728 // Returns true if signal number is valid.
729 bool os::Posix::is_valid_signal(int sig) {
730 // MacOS not really POSIX compliant: sigaddset does not return
731 // an error for invalid signal numbers. However, MacOS does not
732 // support real time signals and simply seems to have just 33
733 // signals with no holes in the signal range.
734 #ifdef __APPLE__
735 return sig >= 1 && sig < NSIG;
736 #else
737 // Use sigaddset to check for signal validity.
738 sigset_t set;
739 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
740 return false;
741 }
742 return true;
743 #endif
744 }
745
746 // Returns:
747 // NULL for an invalid signal number
748 // "SIG<num>" for a valid but unknown signal number
749 // signal name otherwise.
750 const char* os::exception_name(int sig, char* buf, size_t size) {
751 if (!os::Posix::is_valid_signal(sig)) {
752 return NULL;
753 }
754 const char* const name = os::Posix::get_signal_name(sig, buf, size);
755 if (strcmp(name, "UNKNOWN") == 0) {
756 jio_snprintf(buf, size, "SIG%d", sig);
757 }
758 return buf;
759 }
760
761 #define NUM_IMPORTANT_SIGS 32
762 // Returns one-line short description of a signal set in a user provided buffer.
763 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
764 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
765 // Note: for shortness, just print out the first 32. That should
766 // cover most of the useful ones, apart from realtime signals.
767 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
768 const int rc = sigismember(set, sig);
769 if (rc == -1 && errno == EINVAL) {
770 buffer[sig-1] = '?';
771 } else {
772 buffer[sig-1] = rc == 0 ? '0' : '1';
773 }
774 }
775 buffer[NUM_IMPORTANT_SIGS] = 0;
776 return buffer;
777 }
778
779 // Prints one-line description of a signal set.
780 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
781 char buf[NUM_IMPORTANT_SIGS + 1];
782 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
783 st->print("%s", buf);
784 }
785
786 // Writes one-line description of a combination of sigaction.sa_flags into a user
787 // provided buffer. Returns that buffer.
788 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
789 char* p = buffer;
790 size_t remaining = size;
791 bool first = true;
792 int idx = 0;
793
794 assert(buffer, "invalid argument");
795
796 if (size == 0) {
797 return buffer;
798 }
799
800 strncpy(buffer, "none", size);
801
802 const struct {
803 // NB: i is an unsigned int here because SA_RESETHAND is on some
804 // systems 0x80000000, which is implicitly unsigned. Assignining
805 // it to an int field would be an overflow in unsigned-to-signed
806 // conversion.
807 unsigned int i;
808 const char* s;
809 } flaginfo [] = {
810 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
811 { SA_ONSTACK, "SA_ONSTACK" },
812 { SA_RESETHAND, "SA_RESETHAND" },
813 { SA_RESTART, "SA_RESTART" },
814 { SA_SIGINFO, "SA_SIGINFO" },
815 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
816 { SA_NODEFER, "SA_NODEFER" },
817 #ifdef AIX
818 { SA_ONSTACK, "SA_ONSTACK" },
819 { SA_OLDSTYLE, "SA_OLDSTYLE" },
820 #endif
821 { 0, NULL }
822 };
823
824 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
825 if (flags & flaginfo[idx].i) {
826 if (first) {
827 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
828 first = false;
829 } else {
830 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
831 }
832 const size_t len = strlen(p);
833 p += len;
834 remaining -= len;
835 }
836 }
837
838 buffer[size - 1] = '\0';
839
840 return buffer;
841 }
842
843 // Prints one-line description of a combination of sigaction.sa_flags.
844 void os::Posix::print_sa_flags(outputStream* st, int flags) {
845 char buffer[0x100];
846 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
847 st->print("%s", buffer);
848 }
849
850 // Helper function for os::Posix::print_siginfo_...():
851 // return a textual description for signal code.
852 struct enum_sigcode_desc_t {
853 const char* s_name;
854 const char* s_desc;
855 };
856
857 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
858
859 const struct {
860 int sig; int code; const char* s_code; const char* s_desc;
861 } t1 [] = {
862 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
863 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
864 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
865 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
866 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
867 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
868 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
869 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
870 #if defined(IA64) && defined(LINUX)
871 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
872 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
873 #endif
874 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
875 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
876 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
877 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
878 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
879 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
880 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
881 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
882 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
883 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
884 #ifdef AIX
885 // no explanation found what keyerr would be
886 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
887 #endif
888 #if defined(IA64) && !defined(AIX)
889 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
890 #endif
891 #if defined(__sparc) && defined(SOLARIS)
892 // define Solaris Sparc M7 ADI SEGV signals
893 #if !defined(SEGV_ACCADI)
894 #define SEGV_ACCADI 3
895 #endif
896 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
897 #if !defined(SEGV_ACCDERR)
898 #define SEGV_ACCDERR 4
899 #endif
900 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
901 #if !defined(SEGV_ACCPERR)
902 #define SEGV_ACCPERR 5
903 #endif
904 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
905 #endif // defined(__sparc) && defined(SOLARIS)
906 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
907 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
908 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
909 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
910 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
911 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
912 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
913 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
914 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
915 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
916 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
917 #ifdef SIGPOLL
918 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
919 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
920 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
921 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
922 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
923 #endif
924 { -1, -1, NULL, NULL }
925 };
926
927 // Codes valid in any signal context.
928 const struct {
929 int code; const char* s_code; const char* s_desc;
930 } t2 [] = {
931 { SI_USER, "SI_USER", "Signal sent by kill()." },
932 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
933 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
934 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
935 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
936 // Linux specific
937 #ifdef SI_TKILL
938 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
939 #endif
940 #ifdef SI_DETHREAD
941 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
942 #endif
943 #ifdef SI_KERNEL
944 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
945 #endif
946 #ifdef SI_SIGIO
947 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
948 #endif
949
950 #ifdef AIX
951 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
952 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
953 #endif
954
955 #ifdef __sun
956 { SI_NOINFO, "SI_NOINFO", "No signal information" },
957 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
958 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
959 #endif
960
961 { -1, NULL, NULL }
962 };
963
964 const char* s_code = NULL;
965 const char* s_desc = NULL;
966
967 for (int i = 0; t1[i].sig != -1; i ++) {
968 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
969 s_code = t1[i].s_code;
970 s_desc = t1[i].s_desc;
971 break;
972 }
973 }
974
975 if (s_code == NULL) {
976 for (int i = 0; t2[i].s_code != NULL; i ++) {
977 if (t2[i].code == si->si_code) {
978 s_code = t2[i].s_code;
979 s_desc = t2[i].s_desc;
980 }
981 }
982 }
983
984 if (s_code == NULL) {
985 out->s_name = "unknown";
986 out->s_desc = "unknown";
987 return false;
988 }
989
990 out->s_name = s_code;
991 out->s_desc = s_desc;
992
993 return true;
994 }
995
996 void os::print_siginfo(outputStream* os, const void* si0) {
997
998 const siginfo_t* const si = (const siginfo_t*) si0;
999
1000 char buf[20];
1001 os->print("siginfo:");
1002
1003 if (!si) {
1004 os->print(" <null>");
1005 return;
1006 }
1007
1008 const int sig = si->si_signo;
1009
1010 os->print(" si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
1011
1012 enum_sigcode_desc_t ed;
1013 get_signal_code_description(si, &ed);
1014 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
1015
1016 if (si->si_errno) {
1017 os->print(", si_errno: %d", si->si_errno);
1018 }
1019
1020 // Output additional information depending on the signal code.
1021
1022 // Note: Many implementations lump si_addr, si_pid, si_uid etc. together as unions,
1023 // so it depends on the context which member to use. For synchronous error signals,
1024 // we print si_addr, unless the signal was sent by another process or thread, in
1025 // which case we print out pid or tid of the sender.
1026 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
1027 const pid_t pid = si->si_pid;
1028 os->print(", si_pid: %ld", (long) pid);
1029 if (IS_VALID_PID(pid)) {
1030 const pid_t me = getpid();
1031 if (me == pid) {
1032 os->print(" (current process)");
1033 }
1034 } else {
1035 os->print(" (invalid)");
1036 }
1037 os->print(", si_uid: %ld", (long) si->si_uid);
1038 if (sig == SIGCHLD) {
1039 os->print(", si_status: %d", si->si_status);
1040 }
1041 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
1042 sig == SIGTRAP || sig == SIGFPE) {
1043 os->print(", si_addr: " PTR_FORMAT, p2i(si->si_addr));
1044 #ifdef SIGPOLL
1045 } else if (sig == SIGPOLL) {
1046 os->print(", si_band: %ld", si->si_band);
1047 #endif
1048 }
1049
1050 }
1051
1052 int os::Posix::unblock_thread_signal_mask(const sigset_t *set) {
1053 return pthread_sigmask(SIG_UNBLOCK, set, NULL);
1054 }
1055
1056 address os::Posix::ucontext_get_pc(const ucontext_t* ctx) {
1057 #ifdef TARGET_OS_FAMILY_linux
1058 return Linux::ucontext_get_pc(ctx);
1059 #elif defined(TARGET_OS_FAMILY_solaris)
1060 return Solaris::ucontext_get_pc(ctx);
1061 #elif defined(TARGET_OS_FAMILY_aix)
1062 return Aix::ucontext_get_pc(ctx);
1063 #elif defined(TARGET_OS_FAMILY_bsd)
1064 return Bsd::ucontext_get_pc(ctx);
1065 #else
1066 VMError::report_and_die("unimplemented ucontext_get_pc");
1067 #endif
1068 }
1069
1070 void os::Posix::ucontext_set_pc(ucontext_t* ctx, address pc) {
1071 #ifdef TARGET_OS_FAMILY_linux
1072 Linux::ucontext_set_pc(ctx, pc);
1073 #elif defined(TARGET_OS_FAMILY_solaris)
1074 Solaris::ucontext_set_pc(ctx, pc);
1075 #elif defined(TARGET_OS_FAMILY_aix)
1076 Aix::ucontext_set_pc(ctx, pc);
1077 #elif defined(TARGET_OS_FAMILY_bsd)
1078 Bsd::ucontext_set_pc(ctx, pc);
1079 #else
1080 VMError::report_and_die("unimplemented ucontext_get_pc");
1081 #endif
1082 }
1083
1084
1085 os::WatcherThreadCrashProtection::WatcherThreadCrashProtection() {
1086 assert(Thread::current()->is_Watcher_thread(), "Must be WatcherThread");
1087 }
1088
1089 /*
1090 * See the caveats for this class in os_posix.hpp
1091 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
1092 * method and returns false. If none of the signals are raised, returns true.
1093 * The callback is supposed to provide the method that should be protected.
1094 */
1095 bool os::WatcherThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
1096 sigset_t saved_sig_mask;
1097
1098 assert(Thread::current()->is_Watcher_thread(), "Only for WatcherThread");
1099 assert(!WatcherThread::watcher_thread()->has_crash_protection(),
1100 "crash_protection already set?");
1101
1102 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
1103 // since on at least some systems (OS X) siglongjmp will restore the mask
1104 // for the process, not the thread
1105 pthread_sigmask(0, NULL, &saved_sig_mask);
1106 if (sigsetjmp(_jmpbuf, 0) == 0) {
1107 // make sure we can see in the signal handler that we have crash protection
1108 // installed
1109 WatcherThread::watcher_thread()->set_crash_protection(this);
1110 cb.call();
1111 // and clear the crash protection
1112 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1113 return true;
1114 }
1115 // this happens when we siglongjmp() back
1116 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
1117 WatcherThread::watcher_thread()->set_crash_protection(NULL);
1118 return false;
1119 }
1120
1121 void os::WatcherThreadCrashProtection::restore() {
1122 assert(WatcherThread::watcher_thread()->has_crash_protection(),
1123 "must have crash protection");
1124
1125 siglongjmp(_jmpbuf, 1);
1126 }
1127
1128 void os::WatcherThreadCrashProtection::check_crash_protection(int sig,
1129 Thread* thread) {
1130
1131 if (thread != NULL &&
1132 thread->is_Watcher_thread() &&
1133 WatcherThread::watcher_thread()->has_crash_protection()) {
1134
1135 if (sig == SIGSEGV || sig == SIGBUS) {
1136 WatcherThread::watcher_thread()->crash_protection()->restore();
1137 }
1138 }
1139 }
1140
1141 #define check_with_errno(check_type, cond, msg) \
1142 do { \
1143 int err = errno; \
1144 check_type(cond, "%s; error='%s' (errno=%d)", msg, strerror(err), err); \
1145 } while (false)
1146
1147 #define assert_with_errno(cond, msg) check_with_errno(assert, cond, msg)
1148 #define guarantee_with_errno(cond, msg) check_with_errno(guarantee, cond, msg)
1149
1150 // POSIX unamed semaphores are not supported on OS X.
1151 #ifndef __APPLE__
1152
1153 PosixSemaphore::PosixSemaphore(uint value) {
1154 int ret = sem_init(&_semaphore, 0, value);
1155
1156 guarantee_with_errno(ret == 0, "Failed to initialize semaphore");
1157 }
1158
1159 PosixSemaphore::~PosixSemaphore() {
1160 sem_destroy(&_semaphore);
1161 }
1162
1163 void PosixSemaphore::signal(uint count) {
1164 for (uint i = 0; i < count; i++) {
1165 int ret = sem_post(&_semaphore);
1166
1167 assert_with_errno(ret == 0, "sem_post failed");
1168 }
1169 }
1170
1171 void PosixSemaphore::wait() {
1172 int ret;
1173
1174 do {
1175 ret = sem_wait(&_semaphore);
1176 } while (ret != 0 && errno == EINTR);
1177
1178 assert_with_errno(ret == 0, "sem_wait failed");
1179 }
1180
1181 bool PosixSemaphore::trywait() {
1182 int ret;
1183
1184 do {
1185 ret = sem_trywait(&_semaphore);
1186 } while (ret != 0 && errno == EINTR);
1187
1188 assert_with_errno(ret == 0 || errno == EAGAIN, "trywait failed");
1189
1190 return ret == 0;
1191 }
1192
1193 bool PosixSemaphore::timedwait(struct timespec ts) {
1194 while (true) {
1195 int result = sem_timedwait(&_semaphore, &ts);
1196 if (result == 0) {
1197 return true;
1198 } else if (errno == EINTR) {
1199 continue;
1200 } else if (errno == ETIMEDOUT) {
1201 return false;
1202 } else {
1203 assert_with_errno(false, "timedwait failed");
1204 return false;
1205 }
1206 }
1207 }
1208
1209 #endif // __APPLE__