1 /*
2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "utilities/globalDefinitions.hpp"
26 #include "prims/jvm.h"
27 #include "runtime/frame.inline.hpp"
28 #include "runtime/os.hpp"
29 #include "utilities/vmError.hpp"
30
31 #include <signal.h>
32 #include <unistd.h>
33 #include <sys/resource.h>
34 #include <sys/utsname.h>
35 #include <pthread.h>
36 #include <signal.h>
37
38 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
39
40 // Todo: provide a os::get_max_process_id() or similar. Number of processes
41 // may have been configured, can be read more accurately from proc fs etc.
42 #ifndef MAX_PID
43 #define MAX_PID INT_MAX
44 #endif
45 #define IS_VALID_PID(p) (p > 0 && p < MAX_PID)
46
47 // Check core dump limit and report possible place where core can be found
check_or_create_dump(void * exceptionRecord,void * contextRecord,char * buffer,size_t bufferSize)48 void os::check_or_create_dump(void* exceptionRecord, void* contextRecord, char* buffer, size_t bufferSize) {
49 int n;
50 struct rlimit rlim;
51 bool success;
52
53 n = get_core_path(buffer, bufferSize);
54
55 if (getrlimit(RLIMIT_CORE, &rlim) != 0) {
56 jio_snprintf(buffer + n, bufferSize - n, " (may not exist)");
57 success = true;
58 } else {
59 switch(rlim.rlim_cur) {
60 case RLIM_INFINITY:
61 success = true;
62 break;
63 case 0:
64 jio_snprintf(buffer, bufferSize, "Core dumps have been disabled. To enable core dumping, try \"ulimit -c unlimited\" before starting Java again");
65 success = false;
66 break;
67 default:
68 jio_snprintf(buffer + n, bufferSize - n, " (max size %lu kB). To ensure a full core dump, try \"ulimit -c unlimited\" before starting Java again", (unsigned long)(rlim.rlim_cur >> 10));
69 success = true;
70 break;
71 }
72 }
73 VMError::report_coredump_status(buffer, success);
74 }
75
get_native_stack(address * stack,int frames,int toSkip)76 int os::get_native_stack(address* stack, int frames, int toSkip) {
77 #ifdef _NMT_NOINLINE_
78 toSkip++;
79 #endif
80
81 int frame_idx = 0;
82 int num_of_frames; // number of frames captured
83 frame fr = os::current_frame();
84 while (fr.pc() && frame_idx < frames) {
85 if (toSkip > 0) {
86 toSkip --;
87 } else {
88 stack[frame_idx ++] = fr.pc();
89 }
90 if (fr.fp() == NULL || os::is_first_C_frame(&fr)
91 ||fr.sender_pc() == NULL || fr.cb() != NULL) break;
92
93 if (fr.sender_pc() && !os::is_first_C_frame(&fr)) {
94 fr = os::get_sender_for_C_frame(&fr);
95 } else {
96 break;
97 }
98 }
99 num_of_frames = frame_idx;
100 for (; frame_idx < frames; frame_idx ++) {
101 stack[frame_idx] = NULL;
102 }
103
104 return num_of_frames;
105 }
106
107
unsetenv(const char * name)108 bool os::unsetenv(const char* name) {
109 assert(name != NULL, "Null pointer");
110 return (::unsetenv(name) == 0);
111 }
112
get_last_error()113 int os::get_last_error() {
114 return errno;
115 }
116
is_debugger_attached()117 bool os::is_debugger_attached() {
118 // not implemented
119 return false;
120 }
121
wait_for_keypress_at_exit(void)122 void os::wait_for_keypress_at_exit(void) {
123 // don't do anything on posix platforms
124 return;
125 }
126
127 // Multiple threads can race in this code, and can remap over each other with MAP_FIXED,
128 // so on posix, unmap the section at the start and at the end of the chunk that we mapped
129 // rather than unmapping and remapping the whole chunk to get requested alignment.
reserve_memory_aligned(size_t size,size_t alignment)130 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
131 assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
132 "Alignment must be a multiple of allocation granularity (page size)");
133 assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
134
135 size_t extra_size = size + alignment;
136 assert(extra_size >= size, "overflow, size is too large to allow alignment");
137
138 char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
139
140 if (extra_base == NULL) {
141 return NULL;
142 }
143
144 // Do manual alignment
145 char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
146
147 // [ | | ]
148 // ^ extra_base
149 // ^ extra_base + begin_offset == aligned_base
150 // extra_base + begin_offset + size ^
151 // extra_base + extra_size ^
152 // |<>| == begin_offset
153 // end_offset == |<>|
154 size_t begin_offset = aligned_base - extra_base;
155 size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
156
157 if (begin_offset > 0) {
158 os::release_memory(extra_base, begin_offset);
159 }
160
161 if (end_offset > 0) {
162 os::release_memory(extra_base + begin_offset + size, end_offset);
163 }
164
165 return aligned_base;
166 }
167
vsnprintf(char * buf,size_t len,const char * fmt,va_list args)168 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
169 int result = ::vsnprintf(buf, len, fmt, args);
170 // If an encoding error occurred (result < 0) then it's not clear
171 // whether the buffer is NUL terminated, so ensure it is.
172 if ((result < 0) && (len > 0)) {
173 buf[len - 1] = '\0';
174 }
175 return result;
176 }
177
print_load_average(outputStream * st)178 void os::Posix::print_load_average(outputStream* st) {
179 st->print("load average:");
180 double loadavg[3];
181 os::loadavg(loadavg, 3);
182 st->print("%0.02f %0.02f %0.02f", loadavg[0], loadavg[1], loadavg[2]);
183 st->cr();
184 }
185
print_rlimit_info(outputStream * st)186 void os::Posix::print_rlimit_info(outputStream* st) {
187 st->print("rlimit:");
188 struct rlimit rlim;
189
190 st->print(" STACK ");
191 getrlimit(RLIMIT_STACK, &rlim);
192 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
193 else st->print("%uk", rlim.rlim_cur >> 10);
194
195 st->print(", CORE ");
196 getrlimit(RLIMIT_CORE, &rlim);
197 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
198 else st->print("%uk", rlim.rlim_cur >> 10);
199
200 // Isn't there on solaris
201 #if !defined(TARGET_OS_FAMILY_solaris) && !defined(TARGET_OS_FAMILY_aix)
202 st->print(", NPROC ");
203 getrlimit(RLIMIT_NPROC, &rlim);
204 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
205 else st->print("%d", rlim.rlim_cur);
206 #endif
207
208 st->print(", NOFILE ");
209 getrlimit(RLIMIT_NOFILE, &rlim);
210 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
211 else st->print("%d", rlim.rlim_cur);
212
213 #ifdef __OpenBSD__
214 st->print(", DATA ");
215 getrlimit(RLIMIT_DATA, &rlim);
216 #else
217 st->print(", AS ");
218 getrlimit(RLIMIT_AS, &rlim);
219 #endif
220 if (rlim.rlim_cur == RLIM_INFINITY) st->print("infinity");
221 else st->print("%uk", rlim.rlim_cur >> 10);
222 st->cr();
223 }
224
print_uname_info(outputStream * st)225 void os::Posix::print_uname_info(outputStream* st) {
226 // kernel
227 st->print("uname:");
228 struct utsname name;
229 uname(&name);
230 st->print("%s ", name.sysname);
231 st->print("%s ", name.release);
232 st->print("%s ", name.version);
233 st->print("%s", name.machine);
234 st->cr();
235 }
236
has_allocatable_memory_limit(julong * limit)237 bool os::has_allocatable_memory_limit(julong* limit) {
238 struct rlimit rlim;
239 #ifdef __OpenBSD__
240 int getrlimit_res = getrlimit(RLIMIT_DATA, &rlim);
241 #else
242 int getrlimit_res = getrlimit(RLIMIT_AS, &rlim);
243 #endif
244 // if there was an error when calling getrlimit, assume that there is no limitation
245 // on virtual memory.
246 bool result;
247 if ((getrlimit_res != 0) || (rlim.rlim_cur == RLIM_INFINITY)) {
248 result = false;
249 } else {
250 *limit = (julong)rlim.rlim_cur;
251 result = true;
252 }
253 #ifdef _LP64
254 return result;
255 #else
256 // arbitrary virtual space limit for 32 bit Unices found by testing. If
257 // getrlimit above returned a limit, bound it with this limit. Otherwise
258 // directly use it.
259 const julong max_virtual_limit = (julong)3800*M;
260 if (result) {
261 *limit = MIN2(*limit, max_virtual_limit);
262 } else {
263 *limit = max_virtual_limit;
264 }
265
266 // bound by actually allocatable memory. The algorithm uses two bounds, an
267 // upper and a lower limit. The upper limit is the current highest amount of
268 // memory that could not be allocated, the lower limit is the current highest
269 // amount of memory that could be allocated.
270 // The algorithm iteratively refines the result by halving the difference
271 // between these limits, updating either the upper limit (if that value could
272 // not be allocated) or the lower limit (if the that value could be allocated)
273 // until the difference between these limits is "small".
274
275 // the minimum amount of memory we care about allocating.
276 const julong min_allocation_size = M;
277
278 julong upper_limit = *limit;
279
280 // first check a few trivial cases
281 if (is_allocatable(upper_limit) || (upper_limit <= min_allocation_size)) {
282 *limit = upper_limit;
283 } else if (!is_allocatable(min_allocation_size)) {
284 // we found that not even min_allocation_size is allocatable. Return it
285 // anyway. There is no point to search for a better value any more.
286 *limit = min_allocation_size;
287 } else {
288 // perform the binary search.
289 julong lower_limit = min_allocation_size;
290 while ((upper_limit - lower_limit) > min_allocation_size) {
291 julong temp_limit = ((upper_limit - lower_limit) / 2) + lower_limit;
292 temp_limit = align_size_down_(temp_limit, min_allocation_size);
293 if (is_allocatable(temp_limit)) {
294 lower_limit = temp_limit;
295 } else {
296 upper_limit = temp_limit;
297 }
298 }
299 *limit = lower_limit;
300 }
301 return true;
302 #endif
303 }
304
get_current_directory(char * buf,size_t buflen)305 const char* os::get_current_directory(char *buf, size_t buflen) {
306 return getcwd(buf, buflen);
307 }
308
open(int fd,const char * mode)309 FILE* os::open(int fd, const char* mode) {
310 return ::fdopen(fd, mode);
311 }
312
opendir(const char * dirname)313 DIR* os::opendir(const char* dirname) {
314 assert(dirname != NULL, "just checking");
315 return ::opendir(dirname);
316 }
317
readdir(DIR * dirp)318 struct dirent* os::readdir(DIR* dirp) {
319 assert(dirp != NULL, "just checking");
320 return ::readdir(dirp);
321 }
322
closedir(DIR * dirp)323 int os::closedir(DIR *dirp) {
324 assert(dirp != NULL, "just checking");
325 return ::closedir(dirp);
326 }
327
328 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
329 // which is used to find statically linked in agents.
330 // Parameters:
331 // sym_name: Symbol in library we are looking for
332 // lib_name: Name of library to look in, NULL for shared libs.
333 // is_absolute_path == true if lib_name is absolute path to agent
334 // such as "/a/b/libL.so"
335 // == false if only the base name of the library is passed in
336 // such as "L"
build_agent_function_name(const char * sym_name,const char * lib_name,bool is_absolute_path)337 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
338 bool is_absolute_path) {
339 char *agent_entry_name;
340 size_t len;
341 size_t name_len;
342 size_t prefix_len = strlen(JNI_LIB_PREFIX);
343 size_t suffix_len = strlen(JNI_LIB_SUFFIX);
344 const char *start;
345
346 if (lib_name != NULL) {
347 len = name_len = strlen(lib_name);
348 if (is_absolute_path) {
349 // Need to strip path, prefix and suffix
350 if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
351 lib_name = ++start;
352 }
353 if (len <= (prefix_len + suffix_len)) {
354 return NULL;
355 }
356 lib_name += prefix_len;
357 name_len = strlen(lib_name) - suffix_len;
358 }
359 }
360 len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
361 agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
362 if (agent_entry_name == NULL) {
363 return NULL;
364 }
365 strcpy(agent_entry_name, sym_name);
366 if (lib_name != NULL) {
367 strcat(agent_entry_name, "_");
368 strncat(agent_entry_name, lib_name, name_len);
369 }
370 return agent_entry_name;
371 }
372
373 // Returned string is a constant. For unknown signals "UNKNOWN" is returned.
get_signal_name(int sig,char * out,size_t outlen)374 const char* os::Posix::get_signal_name(int sig, char* out, size_t outlen) {
375
376 static const struct {
377 int sig; const char* name;
378 }
379 info[] =
380 {
381 { SIGABRT, "SIGABRT" },
382 #ifdef SIGAIO
383 { SIGAIO, "SIGAIO" },
384 #endif
385 { SIGALRM, "SIGALRM" },
386 #ifdef SIGALRM1
387 { SIGALRM1, "SIGALRM1" },
388 #endif
389 { SIGBUS, "SIGBUS" },
390 #ifdef SIGCANCEL
391 { SIGCANCEL, "SIGCANCEL" },
392 #endif
393 { SIGCHLD, "SIGCHLD" },
394 #ifdef SIGCLD
395 { SIGCLD, "SIGCLD" },
396 #endif
397 { SIGCONT, "SIGCONT" },
398 #ifdef SIGCPUFAIL
399 { SIGCPUFAIL, "SIGCPUFAIL" },
400 #endif
401 #ifdef SIGDANGER
402 { SIGDANGER, "SIGDANGER" },
403 #endif
404 #ifdef SIGDIL
405 { SIGDIL, "SIGDIL" },
406 #endif
407 #ifdef SIGEMT
408 { SIGEMT, "SIGEMT" },
409 #endif
410 { SIGFPE, "SIGFPE" },
411 #ifdef SIGFREEZE
412 { SIGFREEZE, "SIGFREEZE" },
413 #endif
414 #ifdef SIGGFAULT
415 { SIGGFAULT, "SIGGFAULT" },
416 #endif
417 #ifdef SIGGRANT
418 { SIGGRANT, "SIGGRANT" },
419 #endif
420 { SIGHUP, "SIGHUP" },
421 { SIGILL, "SIGILL" },
422 { SIGINT, "SIGINT" },
423 #ifdef SIGIO
424 { SIGIO, "SIGIO" },
425 #endif
426 #ifdef SIGIOINT
427 { SIGIOINT, "SIGIOINT" },
428 #endif
429 #ifdef SIGIOT
430 // SIGIOT is there for BSD compatibility, but on most Unices just a
431 // synonym for SIGABRT. The result should be "SIGABRT", not
432 // "SIGIOT".
433 #if (SIGIOT != SIGABRT )
434 { SIGIOT, "SIGIOT" },
435 #endif
436 #endif
437 #ifdef SIGKAP
438 { SIGKAP, "SIGKAP" },
439 #endif
440 { SIGKILL, "SIGKILL" },
441 #ifdef SIGLOST
442 { SIGLOST, "SIGLOST" },
443 #endif
444 #ifdef SIGLWP
445 { SIGLWP, "SIGLWP" },
446 #endif
447 #ifdef SIGLWPTIMER
448 { SIGLWPTIMER, "SIGLWPTIMER" },
449 #endif
450 #ifdef SIGMIGRATE
451 { SIGMIGRATE, "SIGMIGRATE" },
452 #endif
453 #ifdef SIGMSG
454 { SIGMSG, "SIGMSG" },
455 #endif
456 { SIGPIPE, "SIGPIPE" },
457 #ifdef SIGPOLL
458 { SIGPOLL, "SIGPOLL" },
459 #endif
460 #ifdef SIGPRE
461 { SIGPRE, "SIGPRE" },
462 #endif
463 { SIGPROF, "SIGPROF" },
464 #ifdef SIGPTY
465 { SIGPTY, "SIGPTY" },
466 #endif
467 #ifdef SIGPWR
468 { SIGPWR, "SIGPWR" },
469 #endif
470 { SIGQUIT, "SIGQUIT" },
471 #ifdef SIGRECONFIG
472 { SIGRECONFIG, "SIGRECONFIG" },
473 #endif
474 #ifdef SIGRECOVERY
475 { SIGRECOVERY, "SIGRECOVERY" },
476 #endif
477 #ifdef SIGRESERVE
478 { SIGRESERVE, "SIGRESERVE" },
479 #endif
480 #ifdef SIGRETRACT
481 { SIGRETRACT, "SIGRETRACT" },
482 #endif
483 #ifdef SIGSAK
484 { SIGSAK, "SIGSAK" },
485 #endif
486 { SIGSEGV, "SIGSEGV" },
487 #ifdef SIGSOUND
488 { SIGSOUND, "SIGSOUND" },
489 #endif
490 { SIGSTOP, "SIGSTOP" },
491 { SIGSYS, "SIGSYS" },
492 #ifdef SIGSYSERROR
493 { SIGSYSERROR, "SIGSYSERROR" },
494 #endif
495 #ifdef SIGTALRM
496 { SIGTALRM, "SIGTALRM" },
497 #endif
498 { SIGTERM, "SIGTERM" },
499 #ifdef SIGTHAW
500 { SIGTHAW, "SIGTHAW" },
501 #endif
502 { SIGTRAP, "SIGTRAP" },
503 #ifdef SIGTSTP
504 { SIGTSTP, "SIGTSTP" },
505 #endif
506 { SIGTTIN, "SIGTTIN" },
507 { SIGTTOU, "SIGTTOU" },
508 #ifdef SIGURG
509 { SIGURG, "SIGURG" },
510 #endif
511 { SIGUSR1, "SIGUSR1" },
512 { SIGUSR2, "SIGUSR2" },
513 #ifdef SIGVIRT
514 { SIGVIRT, "SIGVIRT" },
515 #endif
516 { SIGVTALRM, "SIGVTALRM" },
517 #ifdef SIGWAITING
518 { SIGWAITING, "SIGWAITING" },
519 #endif
520 #ifdef SIGWINCH
521 { SIGWINCH, "SIGWINCH" },
522 #endif
523 #ifdef SIGWINDOW
524 { SIGWINDOW, "SIGWINDOW" },
525 #endif
526 { SIGXCPU, "SIGXCPU" },
527 { SIGXFSZ, "SIGXFSZ" },
528 #ifdef SIGXRES
529 { SIGXRES, "SIGXRES" },
530 #endif
531 { -1, NULL }
532 };
533
534 const char* ret = NULL;
535
536 #ifdef SIGRTMIN
537 if (sig >= SIGRTMIN && sig <= SIGRTMAX) {
538 if (sig == SIGRTMIN) {
539 ret = "SIGRTMIN";
540 } else if (sig == SIGRTMAX) {
541 ret = "SIGRTMAX";
542 } else {
543 jio_snprintf(out, outlen, "SIGRTMIN+%d", sig - SIGRTMIN);
544 return out;
545 }
546 }
547 #endif
548
549 if (sig > 0) {
550 for (int idx = 0; info[idx].sig != -1; idx ++) {
551 if (info[idx].sig == sig) {
552 ret = info[idx].name;
553 break;
554 }
555 }
556 }
557
558 if (!ret) {
559 if (!is_valid_signal(sig)) {
560 ret = "INVALID";
561 } else {
562 ret = "UNKNOWN";
563 }
564 }
565
566 jio_snprintf(out, outlen, ret);
567 return out;
568 }
569
570 // Returns true if signal number is valid.
is_valid_signal(int sig)571 bool os::Posix::is_valid_signal(int sig) {
572 // MacOS not really POSIX compliant: sigaddset does not return
573 // an error for invalid signal numbers. However, MacOS does not
574 // support real time signals and simply seems to have just 33
575 // signals with no holes in the signal range.
576 #ifdef __APPLE__
577 return sig >= 1 && sig < NSIG;
578 #else
579 // Use sigaddset to check for signal validity.
580 sigset_t set;
581 if (sigaddset(&set, sig) == -1 && errno == EINVAL) {
582 return false;
583 }
584 return true;
585 #endif
586 }
587
588 #define NUM_IMPORTANT_SIGS 32
589 // Returns one-line short description of a signal set in a user provided buffer.
describe_signal_set_short(const sigset_t * set,char * buffer,size_t buf_size)590 const char* os::Posix::describe_signal_set_short(const sigset_t* set, char* buffer, size_t buf_size) {
591 assert(buf_size == (NUM_IMPORTANT_SIGS + 1), "wrong buffer size");
592 // Note: for shortness, just print out the first 32. That should
593 // cover most of the useful ones, apart from realtime signals.
594 for (int sig = 1; sig <= NUM_IMPORTANT_SIGS; sig++) {
595 const int rc = sigismember(set, sig);
596 if (rc == -1 && errno == EINVAL) {
597 buffer[sig-1] = '?';
598 } else {
599 buffer[sig-1] = rc == 0 ? '0' : '1';
600 }
601 }
602 buffer[NUM_IMPORTANT_SIGS] = 0;
603 return buffer;
604 }
605
606 // Prints one-line description of a signal set.
print_signal_set_short(outputStream * st,const sigset_t * set)607 void os::Posix::print_signal_set_short(outputStream* st, const sigset_t* set) {
608 char buf[NUM_IMPORTANT_SIGS + 1];
609 os::Posix::describe_signal_set_short(set, buf, sizeof(buf));
610 st->print("%s", buf);
611 }
612
613 // Writes one-line description of a combination of sigaction.sa_flags into a user
614 // provided buffer. Returns that buffer.
describe_sa_flags(int flags,char * buffer,size_t size)615 const char* os::Posix::describe_sa_flags(int flags, char* buffer, size_t size) {
616 char* p = buffer;
617 size_t remaining = size;
618 bool first = true;
619 int idx = 0;
620
621 assert(buffer, "invalid argument");
622
623 if (size == 0) {
624 return buffer;
625 }
626
627 strncpy(buffer, "none", size);
628
629 const struct {
630 // NB: i is an unsigned int here because SA_RESETHAND is on some
631 // systems 0x80000000, which is implicitly unsigned. Assignining
632 // it to an int field would be an overflow in unsigned-to-signed
633 // conversion.
634 unsigned int i;
635 const char* s;
636 } flaginfo [] = {
637 { SA_NOCLDSTOP, "SA_NOCLDSTOP" },
638 { SA_ONSTACK, "SA_ONSTACK" },
639 { SA_RESETHAND, "SA_RESETHAND" },
640 { SA_RESTART, "SA_RESTART" },
641 { SA_SIGINFO, "SA_SIGINFO" },
642 { SA_NOCLDWAIT, "SA_NOCLDWAIT" },
643 { SA_NODEFER, "SA_NODEFER" },
644 #ifdef AIX
645 { SA_ONSTACK, "SA_ONSTACK" },
646 { SA_OLDSTYLE, "SA_OLDSTYLE" },
647 #endif
648 { 0, NULL }
649 };
650
651 for (idx = 0; flaginfo[idx].s && remaining > 1; idx++) {
652 if (flags & flaginfo[idx].i) {
653 if (first) {
654 jio_snprintf(p, remaining, "%s", flaginfo[idx].s);
655 first = false;
656 } else {
657 jio_snprintf(p, remaining, "|%s", flaginfo[idx].s);
658 }
659 const size_t len = strlen(p);
660 p += len;
661 remaining -= len;
662 }
663 }
664
665 buffer[size - 1] = '\0';
666
667 return buffer;
668 }
669
670 // Prints one-line description of a combination of sigaction.sa_flags.
print_sa_flags(outputStream * st,int flags)671 void os::Posix::print_sa_flags(outputStream* st, int flags) {
672 char buffer[0x100];
673 os::Posix::describe_sa_flags(flags, buffer, sizeof(buffer));
674 st->print("%s", buffer);
675 }
676
677 // Helper function for os::Posix::print_siginfo_...():
678 // return a textual description for signal code.
679 struct enum_sigcode_desc_t {
680 const char* s_name;
681 const char* s_desc;
682 };
683
get_signal_code_description(const siginfo_t * si,enum_sigcode_desc_t * out)684 static bool get_signal_code_description(const siginfo_t* si, enum_sigcode_desc_t* out) {
685
686 const struct {
687 int sig; int code; const char* s_code; const char* s_desc;
688 } t1 [] = {
689 { SIGILL, ILL_ILLOPC, "ILL_ILLOPC", "Illegal opcode." },
690 { SIGILL, ILL_ILLOPN, "ILL_ILLOPN", "Illegal operand." },
691 { SIGILL, ILL_ILLADR, "ILL_ILLADR", "Illegal addressing mode." },
692 { SIGILL, ILL_ILLTRP, "ILL_ILLTRP", "Illegal trap." },
693 { SIGILL, ILL_PRVOPC, "ILL_PRVOPC", "Privileged opcode." },
694 { SIGILL, ILL_PRVREG, "ILL_PRVREG", "Privileged register." },
695 { SIGILL, ILL_COPROC, "ILL_COPROC", "Coprocessor error." },
696 { SIGILL, ILL_BADSTK, "ILL_BADSTK", "Internal stack error." },
697 #if defined(IA64) && defined(LINUX)
698 { SIGILL, ILL_BADIADDR, "ILL_BADIADDR", "Unimplemented instruction address" },
699 { SIGILL, ILL_BREAK, "ILL_BREAK", "Application Break instruction" },
700 #endif
701 { SIGFPE, FPE_INTDIV, "FPE_INTDIV", "Integer divide by zero." },
702 { SIGFPE, FPE_INTOVF, "FPE_INTOVF", "Integer overflow." },
703 { SIGFPE, FPE_FLTDIV, "FPE_FLTDIV", "Floating-point divide by zero." },
704 { SIGFPE, FPE_FLTOVF, "FPE_FLTOVF", "Floating-point overflow." },
705 { SIGFPE, FPE_FLTUND, "FPE_FLTUND", "Floating-point underflow." },
706 { SIGFPE, FPE_FLTRES, "FPE_FLTRES", "Floating-point inexact result." },
707 { SIGFPE, FPE_FLTINV, "FPE_FLTINV", "Invalid floating-point operation." },
708 { SIGFPE, FPE_FLTSUB, "FPE_FLTSUB", "Subscript out of range." },
709 { SIGSEGV, SEGV_MAPERR, "SEGV_MAPERR", "Address not mapped to object." },
710 { SIGSEGV, SEGV_ACCERR, "SEGV_ACCERR", "Invalid permissions for mapped object." },
711 #ifdef AIX
712 // no explanation found what keyerr would be
713 { SIGSEGV, SEGV_KEYERR, "SEGV_KEYERR", "key error" },
714 #endif
715 #if defined(IA64) && !defined(AIX)
716 { SIGSEGV, SEGV_PSTKOVF, "SEGV_PSTKOVF", "Paragraph stack overflow" },
717 #endif
718 #if defined(__sparc) && defined(SOLARIS)
719 // define Solaris Sparc M7 ADI SEGV signals
720 #if !defined(SEGV_ACCADI)
721 #define SEGV_ACCADI 3
722 #endif
723 { SIGSEGV, SEGV_ACCADI, "SEGV_ACCADI", "ADI not enabled for mapped object." },
724 #if !defined(SEGV_ACCDERR)
725 #define SEGV_ACCDERR 4
726 #endif
727 { SIGSEGV, SEGV_ACCDERR, "SEGV_ACCDERR", "ADI disrupting exception." },
728 #if !defined(SEGV_ACCPERR)
729 #define SEGV_ACCPERR 5
730 #endif
731 { SIGSEGV, SEGV_ACCPERR, "SEGV_ACCPERR", "ADI precise exception." },
732 #endif // defined(__sparc) && defined(SOLARIS)
733 { SIGBUS, BUS_ADRALN, "BUS_ADRALN", "Invalid address alignment." },
734 { SIGBUS, BUS_ADRERR, "BUS_ADRERR", "Nonexistent physical address." },
735 { SIGBUS, BUS_OBJERR, "BUS_OBJERR", "Object-specific hardware error." },
736 { SIGTRAP, TRAP_BRKPT, "TRAP_BRKPT", "Process breakpoint." },
737 { SIGTRAP, TRAP_TRACE, "TRAP_TRACE", "Process trace trap." },
738 { SIGCHLD, CLD_EXITED, "CLD_EXITED", "Child has exited." },
739 { SIGCHLD, CLD_KILLED, "CLD_KILLED", "Child has terminated abnormally and did not create a core file." },
740 { SIGCHLD, CLD_DUMPED, "CLD_DUMPED", "Child has terminated abnormally and created a core file." },
741 { SIGCHLD, CLD_TRAPPED, "CLD_TRAPPED", "Traced child has trapped." },
742 { SIGCHLD, CLD_STOPPED, "CLD_STOPPED", "Child has stopped." },
743 { SIGCHLD, CLD_CONTINUED,"CLD_CONTINUED","Stopped child has continued." },
744 #ifdef SIGPOLL
745 { SIGPOLL, POLL_OUT, "POLL_OUT", "Output buffers available." },
746 { SIGPOLL, POLL_MSG, "POLL_MSG", "Input message available." },
747 { SIGPOLL, POLL_ERR, "POLL_ERR", "I/O error." },
748 { SIGPOLL, POLL_PRI, "POLL_PRI", "High priority input available." },
749 { SIGPOLL, POLL_HUP, "POLL_HUP", "Device disconnected. [Option End]" },
750 #endif
751 { -1, -1, NULL, NULL }
752 };
753
754 // Codes valid in any signal context.
755 const struct {
756 int code; const char* s_code; const char* s_desc;
757 } t2 [] = {
758 { SI_USER, "SI_USER", "Signal sent by kill()." },
759 { SI_QUEUE, "SI_QUEUE", "Signal sent by the sigqueue()." },
760 { SI_TIMER, "SI_TIMER", "Signal generated by expiration of a timer set by timer_settime()." },
761 #ifdef SI_ASYNCIO
762 { SI_ASYNCIO, "SI_ASYNCIO", "Signal generated by completion of an asynchronous I/O request." },
763 #endif
764 #ifdef SI_MESGQ
765 { SI_MESGQ, "SI_MESGQ", "Signal generated by arrival of a message on an empty message queue." },
766 #endif
767 // Linux specific
768 #ifdef SI_TKILL
769 { SI_TKILL, "SI_TKILL", "Signal sent by tkill (pthread_kill)" },
770 #endif
771 #ifdef SI_DETHREAD
772 { SI_DETHREAD, "SI_DETHREAD", "Signal sent by execve() killing subsidiary threads" },
773 #endif
774 #ifdef SI_KERNEL
775 { SI_KERNEL, "SI_KERNEL", "Signal sent by kernel." },
776 #endif
777 #ifdef SI_SIGIO
778 { SI_SIGIO, "SI_SIGIO", "Signal sent by queued SIGIO" },
779 #endif
780
781 #ifdef AIX
782 { SI_UNDEFINED, "SI_UNDEFINED","siginfo contains partial information" },
783 { SI_EMPTY, "SI_EMPTY", "siginfo contains no useful information" },
784 #endif
785
786 #ifdef __sun
787 { SI_NOINFO, "SI_NOINFO", "No signal information" },
788 { SI_RCTL, "SI_RCTL", "kernel generated signal via rctl action" },
789 { SI_LWP, "SI_LWP", "Signal sent via lwp_kill" },
790 #endif
791
792 { -1, NULL, NULL }
793 };
794
795 const char* s_code = NULL;
796 const char* s_desc = NULL;
797
798 for (int i = 0; t1[i].sig != -1; i ++) {
799 if (t1[i].sig == si->si_signo && t1[i].code == si->si_code) {
800 s_code = t1[i].s_code;
801 s_desc = t1[i].s_desc;
802 break;
803 }
804 }
805
806 if (s_code == NULL) {
807 for (int i = 0; t2[i].s_code != NULL; i ++) {
808 if (t2[i].code == si->si_code) {
809 s_code = t2[i].s_code;
810 s_desc = t2[i].s_desc;
811 }
812 }
813 }
814
815 if (s_code == NULL) {
816 out->s_name = "unknown";
817 out->s_desc = "unknown";
818 return false;
819 }
820
821 out->s_name = s_code;
822 out->s_desc = s_desc;
823
824 return true;
825 }
826
827 // A POSIX conform, platform-independend siginfo print routine.
828 // Short print out on one line.
print_siginfo_brief(outputStream * os,const siginfo_t * si)829 void os::Posix::print_siginfo_brief(outputStream* os, const siginfo_t* si) {
830 char buf[20];
831 os->print("siginfo: ");
832
833 if (!si) {
834 os->print("<null>");
835 return;
836 }
837
838 // See print_siginfo_full() for details.
839 const int sig = si->si_signo;
840
841 os->print("si_signo: %d (%s)", sig, os::Posix::get_signal_name(sig, buf, sizeof(buf)));
842
843 enum_sigcode_desc_t ed;
844 if (get_signal_code_description(si, &ed)) {
845 os->print(", si_code: %d (%s)", si->si_code, ed.s_name);
846 } else {
847 os->print(", si_code: %d (unknown)", si->si_code);
848 }
849
850 if (si->si_errno) {
851 os->print(", si_errno: %d", si->si_errno);
852 }
853
854 const int me = (int) ::getpid();
855 const int pid = (int) si->si_pid;
856
857 if (si->si_code == SI_USER || si->si_code == SI_QUEUE) {
858 if (IS_VALID_PID(pid) && pid != me) {
859 os->print(", sent from pid: %d (uid: %d)", pid, (int) si->si_uid);
860 }
861 } else if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
862 sig == SIGTRAP || sig == SIGFPE) {
863 os->print(", si_addr: " PTR_FORMAT, si->si_addr);
864 #ifdef SIGPOLL
865 } else if (sig == SIGPOLL) {
866 os->print(", si_band: " PTR64_FORMAT, (uint64_t)si->si_band);
867 #endif
868 } else if (sig == SIGCHLD) {
869 os->print_cr(", si_pid: %d, si_uid: %d, si_status: %d", (int) si->si_pid, si->si_uid, si->si_status);
870 }
871 }
872
873 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
874 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
875 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
876
ThreadCrashProtection()877 os::ThreadCrashProtection::ThreadCrashProtection() {
878 }
879
880 /*
881 * See the caveats for this class in os_posix.hpp
882 * Protects the callback call so that SIGSEGV / SIGBUS jumps back into this
883 * method and returns false. If none of the signals are raised, returns true.
884 * The callback is supposed to provide the method that should be protected.
885 */
call(os::CrashProtectionCallback & cb)886 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
887 sigset_t saved_sig_mask;
888
889 Thread::muxAcquire(&_crash_mux, "CrashProtection");
890
891 _protected_thread = ThreadLocalStorage::thread();
892 assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
893
894 // we cannot rely on sigsetjmp/siglongjmp to save/restore the signal mask
895 // since on at least some systems (OS X) siglongjmp will restore the mask
896 // for the process, not the thread
897 pthread_sigmask(0, NULL, &saved_sig_mask);
898 if (sigsetjmp(_jmpbuf, 0) == 0) {
899 // make sure we can see in the signal handler that we have crash protection
900 // installed
901 _crash_protection = this;
902 cb.call();
903 // and clear the crash protection
904 _crash_protection = NULL;
905 _protected_thread = NULL;
906 Thread::muxRelease(&_crash_mux);
907 return true;
908 }
909 // this happens when we siglongjmp() back
910 pthread_sigmask(SIG_SETMASK, &saved_sig_mask, NULL);
911 _crash_protection = NULL;
912 _protected_thread = NULL;
913 Thread::muxRelease(&_crash_mux);
914 return false;
915 }
916
restore()917 void os::ThreadCrashProtection::restore() {
918 assert(_crash_protection != NULL, "must have crash protection");
919 siglongjmp(_jmpbuf, 1);
920 }
921
check_crash_protection(int sig,Thread * thread)922 void os::ThreadCrashProtection::check_crash_protection(int sig,
923 Thread* thread) {
924
925 if (thread != NULL &&
926 thread == _protected_thread &&
927 _crash_protection != NULL) {
928
929 if (sig == SIGSEGV || sig == SIGBUS) {
930 _crash_protection->restore();
931 }
932 }
933 }
934