1 /*
2 * Copyright (c) 1999, 2014, 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 // no precompiled headers
26 #include "asm/macroAssembler.hpp"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "jvm_solaris.h"
34 #include "memory/allocation.inline.hpp"
35 #include "mutex_solaris.inline.hpp"
36 #include "os_share_solaris.hpp"
37 #include "prims/jniFastGetField.hpp"
38 #include "prims/jvm.h"
39 #include "prims/jvm_misc.hpp"
40 #include "runtime/arguments.hpp"
41 #include "runtime/extendedPC.hpp"
42 #include "runtime/frame.inline.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/java.hpp"
45 #include "runtime/javaCalls.hpp"
46 #include "runtime/mutexLocker.hpp"
47 #include "runtime/osThread.hpp"
48 #include "runtime/sharedRuntime.hpp"
49 #include "runtime/stubRoutines.hpp"
50 #include "runtime/thread.inline.hpp"
51 #include "runtime/timer.hpp"
52 #include "utilities/events.hpp"
53 #include "utilities/vmError.hpp"
54
55 // put OS-includes here
56 # include <sys/types.h>
57 # include <sys/mman.h>
58 # include <pthread.h>
59 # include <signal.h>
60 # include <setjmp.h>
61 # include <errno.h>
62 # include <dlfcn.h>
63 # include <stdio.h>
64 # include <unistd.h>
65 # include <sys/resource.h>
66 # include <thread.h>
67 # include <sys/stat.h>
68 # include <sys/time.h>
69 # include <sys/filio.h>
70 # include <sys/utsname.h>
71 # include <sys/systeminfo.h>
72 # include <sys/socket.h>
73 # include <sys/trap.h>
74 # include <sys/lwp.h>
75 # include <pwd.h>
76 # include <poll.h>
77 # include <sys/lwp.h>
78 # include <procfs.h> // see comment in <sys/procfs.h>
79
80 #ifndef AMD64
81 // QQQ seems useless at this point
82 # define _STRUCTURED_PROC 1 // this gets us the new structured proc interfaces of 5.6 & later
83 #endif // AMD64
84 # include <sys/procfs.h> // see comment in <sys/procfs.h>
85
86
87 #define MAX_PATH (2 * K)
88
89 // Minimum stack size for the VM. It's easier to document a constant value
90 // but it's different for x86 and sparc because the page sizes are different.
91 #ifdef AMD64
92 size_t os::Solaris::min_stack_allowed = 224*K;
93 #define REG_SP REG_RSP
94 #define REG_PC REG_RIP
95 #define REG_FP REG_RBP
96 #else
97 size_t os::Solaris::min_stack_allowed = 64*K;
98 #define REG_SP UESP
99 #define REG_PC EIP
100 #define REG_FP EBP
101 // 4900493 counter to prevent runaway LDTR refresh attempt
102
103 static volatile int ldtr_refresh = 0;
104 // the libthread instruction that faults because of the stale LDTR
105
106 static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs
107 };
108 #endif // AMD64
109
110 char* os::non_memory_address_word() {
111 // Must never look like an address returned by reserve_memory,
112 // even in its subfields (as defined by the CPU immediate fields,
113 // if the CPU splits constants across multiple instructions).
114 return (char*) -1;
115 }
116
117 //
118 // Validate a ucontext retrieved from walking a uc_link of a ucontext.
119 // There are issues with libthread giving out uc_links for different threads
120 // on the same uc_link chain and bad or circular links.
121 //
122 bool os::Solaris::valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect) {
123 if (valid >= suspect ||
124 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
125 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp ||
126 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) {
127 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)
128 return false;
129 }
130
131 if (thread->is_Java_thread()) {
132 if (!valid_stack_address(thread, (address)suspect)) {
133 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)
134 return false;
135 }
136 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) {
137 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)
138 return false;
139 }
140 }
141 return true;
142 }
143
144 // We will only follow one level of uc_link since there are libthread
145 // issues with ucontext linking and it is better to be safe and just
146 // let caller retry later.
147 ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
148 ucontext_t *uc) {
149
150 ucontext_t *retuc = NULL;
151
152 if (uc != NULL) {
153 if (uc->uc_link == NULL) {
154 // cannot validate without uc_link so accept current ucontext
155 retuc = uc;
156 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
157 // first ucontext is valid so try the next one
158 uc = uc->uc_link;
159 if (uc->uc_link == NULL) {
160 // cannot validate without uc_link so accept current ucontext
161 retuc = uc;
162 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
163 // the ucontext one level down is also valid so return it
164 retuc = uc;
165 }
166 }
167 }
168 return retuc;
169 }
170
171 // Assumes ucontext is valid
172 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(ucontext_t *uc) {
173 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]);
174 }
175
176 // Assumes ucontext is valid
177 intptr_t* os::Solaris::ucontext_get_sp(ucontext_t *uc) {
178 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
179 }
180
181 // Assumes ucontext is valid
182 intptr_t* os::Solaris::ucontext_get_fp(ucontext_t *uc) {
183 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
184 }
185
186 address os::Solaris::ucontext_get_pc(ucontext_t *uc) {
187 return (address) uc->uc_mcontext.gregs[REG_PC];
188 }
189
190 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
191 // is currently interrupted by SIGPROF.
192 //
193 // The difference between this and os::fetch_frame_from_context() is that
194 // here we try to skip nested signal frames.
195 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
196 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
197
198 assert(thread != NULL, "just checking");
199 assert(ret_sp != NULL, "just checking");
200 assert(ret_fp != NULL, "just checking");
201
202 ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
203 return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
204 }
205
206 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
207 intptr_t** ret_sp, intptr_t** ret_fp) {
208
209 ExtendedPC epc;
210 ucontext_t *uc = (ucontext_t*)ucVoid;
211
212 if (uc != NULL) {
213 epc = os::Solaris::ucontext_get_ExtendedPC(uc);
214 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
215 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc);
216 } else {
217 // construct empty ExtendedPC for return value checking
218 epc = ExtendedPC(NULL);
219 if (ret_sp) *ret_sp = (intptr_t *)NULL;
220 if (ret_fp) *ret_fp = (intptr_t *)NULL;
221 }
222
223 return epc;
224 }
225
226 frame os::fetch_frame_from_context(void* ucVoid) {
227 intptr_t* sp;
228 intptr_t* fp;
229 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
230 return frame(sp, fp, epc.pc());
231 }
232
233 frame os::get_sender_for_C_frame(frame* fr) {
234 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
235 }
236
237 extern "C" intptr_t *_get_current_sp(); // in .il file
238
239 address os::current_stack_pointer() {
240 return (address)_get_current_sp();
241 }
242
243 extern "C" intptr_t *_get_current_fp(); // in .il file
244
245 frame os::current_frame() {
246 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp
247 frame myframe((intptr_t*)os::current_stack_pointer(),
248 (intptr_t*)fp,
249 CAST_FROM_FN_PTR(address, os::current_frame));
250 if (os::is_first_C_frame(&myframe)) {
251 // stack is not walkable
252 frame ret; // This will be a null useless frame
253 return ret;
254 } else {
255 return os::get_sender_for_C_frame(&myframe);
256 }
257 }
258
259 static int threadgetstate(thread_t tid, int *flags, lwpid_t *lwp, stack_t *ss, gregset_t rs, lwpstatus_t *lwpstatus) {
260 char lwpstatusfile[PROCFILE_LENGTH];
261 int lwpfd, err;
262
263 if (err = os::Solaris::thr_getstate(tid, flags, lwp, ss, rs))
264 return (err);
265 if (*flags == TRS_LWPID) {
266 sprintf(lwpstatusfile, "/proc/%d/lwp/%d/lwpstatus", getpid(),
267 *lwp);
268 if ((lwpfd = open(lwpstatusfile, O_RDONLY)) < 0) {
269 perror("thr_mutator_status: open lwpstatus");
270 return (EINVAL);
271 }
272 if (pread(lwpfd, lwpstatus, sizeof (lwpstatus_t), (off_t)0) !=
273 sizeof (lwpstatus_t)) {
274 perror("thr_mutator_status: read lwpstatus");
275 (void) close(lwpfd);
276 return (EINVAL);
277 }
278 (void) close(lwpfd);
279 }
280 return (0);
281 }
282
283 #ifndef AMD64
284
285 // Detecting SSE support by OS
286 // From solaris_i486.s
287 extern "C" bool sse_check();
288 extern "C" bool sse_unavailable();
289
290 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};
291 static int sse_status = SSE_UNKNOWN;
292
293
294 static void check_for_sse_support() {
295 if (!VM_Version::supports_sse()) {
296 sse_status = SSE_NOT_SUPPORTED;
297 return;
298 }
299 // looking for _sse_hw in libc.so, if it does not exist or
300 // the value (int) is 0, OS has no support for SSE
301 int *sse_hwp;
302 void *h;
303
304 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {
305 //open failed, presume no support for SSE
306 sse_status = SSE_NOT_SUPPORTED;
307 return;
308 }
309 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {
310 sse_status = SSE_NOT_SUPPORTED;
311 } else if (*sse_hwp == 0) {
312 sse_status = SSE_NOT_SUPPORTED;
313 }
314 dlclose(h);
315
316 if (sse_status == SSE_UNKNOWN) {
317 bool (*try_sse)() = (bool (*)())sse_check;
318 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;
319 }
320
321 }
322
323 #endif // AMD64
324
325 bool os::supports_sse() {
326 #ifdef AMD64
327 return true;
328 #else
329 if (sse_status == SSE_UNKNOWN)
330 check_for_sse_support();
331 return sse_status == SSE_SUPPORTED;
332 #endif // AMD64
333 }
334
335 bool os::is_allocatable(size_t bytes) {
336 #ifdef AMD64
337 return true;
338 #else
339
340 if (bytes < 2 * G) {
341 return true;
342 }
343
344 char* addr = reserve_memory(bytes, NULL);
345
346 if (addr != NULL) {
347 release_memory(addr, bytes);
348 }
349
350 return addr != NULL;
351 #endif // AMD64
352
353 }
354
355 extern "C" JNIEXPORT int
356 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
357 int abort_if_unrecognized) {
358 ucontext_t* uc = (ucontext_t*) ucVoid;
359
360 #ifndef AMD64
361 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
362 // the SSE instruction faulted. supports_sse() need return false.
363 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
364 return true;
365 }
366 #endif // !AMD64
367
368 Thread* t = ThreadLocalStorage::get_thread_slow(); // slow & steady
369
370 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
371 // (no destructors can be run)
372 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
373
374 SignalHandlerMark shm(t);
375
376 if(sig == SIGPIPE || sig == SIGXFSZ) {
377 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
378 return true;
379 } else {
380 if (PrintMiscellaneous && (WizardMode || Verbose)) {
381 char buf[64];
382 warning("Ignoring %s - see 4229104 or 6499219",
383 os::exception_name(sig, buf, sizeof(buf)));
384
385 }
386 return true;
387 }
388 }
389
390 JavaThread* thread = NULL;
391 VMThread* vmthread = NULL;
392
393 if (os::Solaris::signal_handlers_are_installed) {
394 if (t != NULL ){
395 if(t->is_Java_thread()) {
396 thread = (JavaThread*)t;
397 }
398 else if(t->is_VM_thread()){
399 vmthread = (VMThread *)t;
400 }
401 }
402 }
403
404 guarantee(sig != os::Solaris::SIGinterrupt(), "Can not chain VM interrupt signal, try -XX:+UseAltSigs");
405
406 if (sig == os::Solaris::SIGasync()) {
407 if(thread || vmthread){
408 OSThread::SR_handler(t, uc);
409 return true;
410 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
411 return true;
412 } else {
413 // If os::Solaris::SIGasync not chained, and this is a non-vm and
414 // non-java thread
415 return true;
416 }
417 }
418
419 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
420 // can't decode this kind of signal
421 info = NULL;
422 } else {
423 assert(sig == info->si_signo, "bad siginfo");
424 }
425
426 // decide if this trap can be handled by a stub
427 address stub = NULL;
428
429 address pc = NULL;
430
431 //%note os_trap_1
432 if (info != NULL && uc != NULL && thread != NULL) {
433 // factor me: getPCfromContext
434 pc = (address) uc->uc_mcontext.gregs[REG_PC];
435
436 if (StubRoutines::is_safefetch_fault(pc)) {
437 uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
438 return true;
439 }
440
441 // Handle ALL stack overflow variations here
442 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
443 address addr = (address) info->si_addr;
444 if (thread->in_stack_yellow_zone(addr)) {
445 thread->disable_stack_yellow_zone();
446 if (thread->thread_state() == _thread_in_Java) {
447 // Throw a stack overflow exception. Guard pages will be reenabled
448 // while unwinding the stack.
449 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
450 } else {
451 // Thread was in the vm or native code. Return and try to finish.
452 return true;
453 }
454 } else if (thread->in_stack_red_zone(addr)) {
455 // Fatal red zone violation. Disable the guard pages and fall through
456 // to handle_unexpected_exception way down below.
457 thread->disable_stack_red_zone();
458 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
459 }
460 }
461
462 if (thread->thread_state() == _thread_in_vm) {
463 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
464 stub = StubRoutines::handler_for_unsafe_access();
465 }
466 }
467
468 if (thread->thread_state() == _thread_in_Java) {
469 // Support Safepoint Polling
470 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
471 stub = SharedRuntime::get_poll_stub(pc);
472 }
473 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
474 // BugId 4454115: A read from a MappedByteBuffer can fault
475 // here if the underlying file has been truncated.
476 // Do not crash the VM in such a case.
477 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
478 if (cb != NULL) {
479 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
480 if (nm != NULL && nm->has_unsafe_access()) {
481 stub = StubRoutines::handler_for_unsafe_access();
482 }
483 }
484 }
485 else
486 if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
487 // integer divide by zero
488 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
489 }
490 #ifndef AMD64
491 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
492 // floating-point divide by zero
493 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
494 }
495 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
496 // The encoding of D2I in i486.ad can cause an exception prior
497 // to the fist instruction if there was an invalid operation
498 // pending. We want to dismiss that exception. From the win_32
499 // side it also seems that if it really was the fist causing
500 // the exception that we do the d2i by hand with different
501 // rounding. Seems kind of weird. QQQ TODO
502 // Note that we take the exception at the NEXT floating point instruction.
503 if (pc[0] == 0xDB) {
504 assert(pc[0] == 0xDB, "not a FIST opcode");
505 assert(pc[1] == 0x14, "not a FIST opcode");
506 assert(pc[2] == 0x24, "not a FIST opcode");
507 return true;
508 } else {
509 assert(pc[-3] == 0xDB, "not an flt invalid opcode");
510 assert(pc[-2] == 0x14, "not an flt invalid opcode");
511 assert(pc[-1] == 0x24, "not an flt invalid opcode");
512 }
513 }
514 else if (sig == SIGFPE ) {
515 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
516 }
517 #endif // !AMD64
518
519 // QQQ It doesn't seem that we need to do this on x86 because we should be able
520 // to return properly from the handler without this extra stuff on the back side.
521
522 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
523 // Determination of interpreter/vtable stub/compiled code null exception
524 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
525 }
526 }
527
528 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
529 // and the heap gets shrunk before the field access.
530 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
531 address addr = JNI_FastGetField::find_slowcase_pc(pc);
532 if (addr != (address)-1) {
533 stub = addr;
534 }
535 }
536
537 // Check to see if we caught the safepoint code in the
538 // process of write protecting the memory serialization page.
539 // It write enables the page immediately after protecting it
540 // so we can just return to retry the write.
541 if ((sig == SIGSEGV) &&
542 os::is_memory_serialize_page(thread, (address)info->si_addr)) {
543 // Block current thread until the memory serialize page permission restored.
544 os::block_on_serialize_page_trap();
545 return true;
546 }
547 }
548
549 // Execution protection violation
550 //
551 // Preventative code for future versions of Solaris which may
552 // enable execution protection when running the 32-bit VM on AMD64.
553 //
554 // This should be kept as the last step in the triage. We don't
555 // have a dedicated trap number for a no-execute fault, so be
556 // conservative and allow other handlers the first shot.
557 //
558 // Note: We don't test that info->si_code == SEGV_ACCERR here.
559 // this si_code is so generic that it is almost meaningless; and
560 // the si_code for this condition may change in the future.
561 // Furthermore, a false-positive should be harmless.
562 if (UnguardOnExecutionViolation > 0 &&
563 (sig == SIGSEGV || sig == SIGBUS) &&
564 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault
565 int page_size = os::vm_page_size();
566 address addr = (address) info->si_addr;
567 address pc = (address) uc->uc_mcontext.gregs[REG_PC];
568 // Make sure the pc and the faulting address are sane.
569 //
570 // If an instruction spans a page boundary, and the page containing
571 // the beginning of the instruction is executable but the following
572 // page is not, the pc and the faulting address might be slightly
573 // different - we still want to unguard the 2nd page in this case.
574 //
575 // 15 bytes seems to be a (very) safe value for max instruction size.
576 bool pc_is_near_addr =
577 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
578 bool instr_spans_page_boundary =
579 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
580 (intptr_t) page_size) > 0);
581
582 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
583 static volatile address last_addr =
584 (address) os::non_memory_address_word();
585
586 // In conservative mode, don't unguard unless the address is in the VM
587 if (addr != last_addr &&
588 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
589
590 // Make memory rwx and retry
591 address page_start =
592 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
593 bool res = os::protect_memory((char*) page_start, page_size,
594 os::MEM_PROT_RWX);
595
596 if (PrintMiscellaneous && Verbose) {
597 char buf[256];
598 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
599 "at " INTPTR_FORMAT
600 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
601 page_start, (res ? "success" : "failed"), errno);
602 tty->print_raw_cr(buf);
603 }
604 stub = pc;
605
606 // Set last_addr so if we fault again at the same address, we don't end
607 // up in an endless loop.
608 //
609 // There are two potential complications here. Two threads trapping at
610 // the same address at the same time could cause one of the threads to
611 // think it already unguarded, and abort the VM. Likely very rare.
612 //
613 // The other race involves two threads alternately trapping at
614 // different addresses and failing to unguard the page, resulting in
615 // an endless loop. This condition is probably even more unlikely than
616 // the first.
617 //
618 // Although both cases could be avoided by using locks or thread local
619 // last_addr, these solutions are unnecessary complication: this
620 // handler is a best-effort safety net, not a complete solution. It is
621 // disabled by default and should only be used as a workaround in case
622 // we missed any no-execute-unsafe VM code.
623
624 last_addr = addr;
625 }
626 }
627 }
628
629 if (stub != NULL) {
630 // save all thread context in case we need to restore it
631
632 if (thread != NULL) thread->set_saved_exception_pc(pc);
633 // 12/02/99: On Sparc it appears that the full context is also saved
634 // but as yet, no one looks at or restores that saved context
635 // factor me: setPC
636 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
637 return true;
638 }
639
640 // signal-chaining
641 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
642 return true;
643 }
644
645 #ifndef AMD64
646 // Workaround (bug 4900493) for Solaris kernel bug 4966651.
647 // Handle an undefined selector caused by an attempt to assign
648 // fs in libthread getipriptr(). With the current libthread design every 512
649 // thread creations the LDT for a private thread data structure is extended
650 // and thre is a hazard that and another thread attempting a thread creation
651 // will use a stale LDTR that doesn't reflect the structure's growth,
652 // causing a GP fault.
653 // Enforce the probable limit of passes through here to guard against an
654 // infinite loop if some other move to fs caused the GP fault. Note that
655 // this loop counter is ultimately a heuristic as it is possible for
656 // more than one thread to generate this fault at a time in an MP system.
657 // In the case of the loop count being exceeded or if the poll fails
658 // just fall through to a fatal error.
659 // If there is some other source of T_GPFLT traps and the text at EIP is
660 // unreadable this code will loop infinitely until the stack is exausted.
661 // The key to diagnosis in this case is to look for the bottom signal handler
662 // frame.
663
664 if(! IgnoreLibthreadGPFault) {
665 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
666 const unsigned char *p =
667 (unsigned const char *) uc->uc_mcontext.gregs[EIP];
668
669 // Expected instruction?
670
671 if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
672
673 Atomic::inc(&ldtr_refresh);
674
675 // Infinite loop?
676
677 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
678
679 // No, force scheduling to get a fresh view of the LDTR
680
681 if(poll(NULL, 0, 10) == 0) {
682
683 // Retry the move
684
685 return false;
686 }
687 }
688 }
689 }
690 }
691 #endif // !AMD64
692
693 if (!abort_if_unrecognized) {
694 // caller wants another chance, so give it to him
695 return false;
696 }
697
698 if (!os::Solaris::libjsig_is_loaded) {
699 struct sigaction oldAct;
700 sigaction(sig, (struct sigaction *)0, &oldAct);
701 if (oldAct.sa_sigaction != signalHandler) {
702 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
703 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
704 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
705 }
706 }
707
708 if (pc == NULL && uc != NULL) {
709 pc = (address) uc->uc_mcontext.gregs[REG_PC];
710 }
711
712 // unmask current signal
713 sigset_t newset;
714 sigemptyset(&newset);
715 sigaddset(&newset, sig);
716 sigprocmask(SIG_UNBLOCK, &newset, NULL);
717
718 // Determine which sort of error to throw. Out of swap may signal
719 // on the thread stack, which could get a mapping error when touched.
720 address addr = (address) info->si_addr;
721 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
722 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
723 }
724
725 VMError err(t, sig, pc, info, ucVoid);
726 err.report_and_die();
727
728 ShouldNotReachHere();
729 return false;
730 }
731
732 void os::print_context(outputStream *st, void *context) {
733 if (context == NULL) return;
734
735 ucontext_t *uc = (ucontext_t*)context;
736 st->print_cr("Registers:");
737 #ifdef AMD64
738 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
739 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
740 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
741 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
742 st->cr();
743 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
744 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
745 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
746 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
747 st->cr();
748 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
749 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
750 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
751 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
752 st->cr();
753 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
754 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
755 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
756 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
757 st->cr();
758 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
759 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
760 #else
761 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
762 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
763 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
764 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
765 st->cr();
766 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
767 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
768 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
769 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
770 st->cr();
771 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
772 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
773 #endif // AMD64
774 st->cr();
775 st->cr();
776
777 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
778 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
779 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
780 st->cr();
781
782 // Note: it may be unsafe to inspect memory near pc. For example, pc may
783 // point to garbage if entry point in an nmethod is corrupted. Leave
784 // this at the end, and hope for the best.
785 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
786 address pc = epc.pc();
787 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
788 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
789 }
790
791 void os::print_register_info(outputStream *st, void *context) {
792 if (context == NULL) return;
793
794 ucontext_t *uc = (ucontext_t*)context;
795
796 st->print_cr("Register to memory mapping:");
797 st->cr();
798
799 // this is horrendously verbose but the layout of the registers in the
800 // context does not match how we defined our abstract Register set, so
801 // we can't just iterate through the gregs area
802
803 // this is only for the "general purpose" registers
804
805 #ifdef AMD64
806 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
807 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
808 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
809 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
810 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
811 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
812 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
813 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
814 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
815 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
816 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
817 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
818 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
819 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
820 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
821 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
822 #else
823 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
824 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
825 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
826 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
827 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
828 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
829 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
830 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
831 #endif
832
833 st->cr();
834 }
835
836
837 #ifdef AMD64
838 void os::Solaris::init_thread_fpu_state(void) {
839 // Nothing to do
840 }
841 #else
842 // From solaris_i486.s
843 extern "C" void fixcw();
844
845 void os::Solaris::init_thread_fpu_state(void) {
846 // Set fpu to 53 bit precision. This happens too early to use a stub.
847 fixcw();
848 }
849
850 // These routines are the initial value of atomic_xchg_entry(),
851 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
852 // until initialization is complete.
853 // TODO - replace with .il implementation when compiler supports it.
854
855 typedef jint xchg_func_t (jint, volatile jint*);
856 typedef jint cmpxchg_func_t (jint, volatile jint*, jint);
857 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
858 typedef jint add_func_t (jint, volatile jint*);
859
860 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
861 // try to use the stub:
862 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
863
864 if (func != NULL) {
865 os::atomic_xchg_func = func;
866 return (*func)(exchange_value, dest);
867 }
868 assert(Threads::number_of_threads() == 0, "for bootstrap only");
869
870 jint old_value = *dest;
871 *dest = exchange_value;
872 return old_value;
873 }
874
875 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
876 // try to use the stub:
877 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
878
879 if (func != NULL) {
880 os::atomic_cmpxchg_func = func;
881 return (*func)(exchange_value, dest, compare_value);
882 }
883 assert(Threads::number_of_threads() == 0, "for bootstrap only");
884
885 jint old_value = *dest;
886 if (old_value == compare_value)
887 *dest = exchange_value;
888 return old_value;
889 }
890
891 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
892 // try to use the stub:
893 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
894
895 if (func != NULL) {
896 os::atomic_cmpxchg_long_func = func;
897 return (*func)(exchange_value, dest, compare_value);
898 }
899 assert(Threads::number_of_threads() == 0, "for bootstrap only");
900
901 jlong old_value = *dest;
902 if (old_value == compare_value)
903 *dest = exchange_value;
904 return old_value;
905 }
906
907 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
908 // try to use the stub:
909 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
910
911 if (func != NULL) {
912 os::atomic_add_func = func;
913 return (*func)(add_value, dest);
914 }
915 assert(Threads::number_of_threads() == 0, "for bootstrap only");
916
917 return (*dest) += add_value;
918 }
919
920 xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap;
921 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap;
922 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
923 add_func_t* os::atomic_add_func = os::atomic_add_bootstrap;
924
925 extern "C" void _solaris_raw_setup_fpu(address ptr);
926 void os::setup_fpu() {
927 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
928 _solaris_raw_setup_fpu(fpu_cntrl);
929 }
930 #endif // AMD64
931
932 #ifndef PRODUCT
933 void os::verify_stack_alignment() {
934 #ifdef AMD64
935 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
936 #endif
937 }
938 #endif