1 /*
2 * Copyright (c) 1999, 2013, 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" void Fetch32PFI () ;
356 extern "C" void Fetch32Resume () ;
357 #ifdef AMD64
358 extern "C" void FetchNPFI () ;
359 extern "C" void FetchNResume () ;
360 #endif // AMD64
361
362 extern "C" JNIEXPORT int
363 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
364 int abort_if_unrecognized) {
365 ucontext_t* uc = (ucontext_t*) ucVoid;
366
367 #ifndef AMD64
368 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
369 // the SSE instruction faulted. supports_sse() need return false.
370 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
371 return true;
372 }
373 #endif // !AMD64
374
375 Thread* t = ThreadLocalStorage::get_thread_slow(); // slow & steady
376
377 SignalHandlerMark shm(t);
378
379 if(sig == SIGPIPE || sig == SIGXFSZ) {
380 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
381 return true;
382 } else {
383 if (PrintMiscellaneous && (WizardMode || Verbose)) {
384 char buf[64];
385 warning("Ignoring %s - see 4229104 or 6499219",
386 os::exception_name(sig, buf, sizeof(buf)));
387
388 }
389 return true;
390 }
391 }
392
393 JavaThread* thread = NULL;
394 VMThread* vmthread = NULL;
395
396 if (os::Solaris::signal_handlers_are_installed) {
397 if (t != NULL ){
398 if(t->is_Java_thread()) {
399 thread = (JavaThread*)t;
400 }
401 else if(t->is_VM_thread()){
402 vmthread = (VMThread *)t;
403 }
404 }
405 }
406
407 guarantee(sig != os::Solaris::SIGinterrupt(), "Can not chain VM interrupt signal, try -XX:+UseAltSigs");
408
409 if (sig == os::Solaris::SIGasync()) {
410 if(thread || vmthread){
411 OSThread::SR_handler(t, uc);
412 return true;
413 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
414 return true;
415 } else {
416 // If os::Solaris::SIGasync not chained, and this is a non-vm and
417 // non-java thread
418 return true;
419 }
420 }
421
422 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
423 // can't decode this kind of signal
424 info = NULL;
425 } else {
426 assert(sig == info->si_signo, "bad siginfo");
427 }
428
429 // decide if this trap can be handled by a stub
430 address stub = NULL;
431
432 address pc = NULL;
433
434 //%note os_trap_1
435 if (info != NULL && uc != NULL && thread != NULL) {
436 // factor me: getPCfromContext
437 pc = (address) uc->uc_mcontext.gregs[REG_PC];
438
439 // SafeFetch32() support
440 if (pc == (address) Fetch32PFI) {
441 uc->uc_mcontext.gregs[REG_PC] = intptr_t(Fetch32Resume) ;
442 return true ;
443 }
444 #ifdef AMD64
445 if (pc == (address) FetchNPFI) {
446 uc->uc_mcontext.gregs [REG_PC] = intptr_t(FetchNResume) ;
447 return true ;
448 }
449 #endif // AMD64
450
451 // Handle ALL stack overflow variations here
452 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
453 address addr = (address) info->si_addr;
454 if (thread->in_stack_yellow_zone(addr)) {
455 thread->disable_stack_yellow_zone();
456 if (thread->thread_state() == _thread_in_Java) {
457 // Throw a stack overflow exception. Guard pages will be reenabled
458 // while unwinding the stack.
459 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
460 } else {
461 // Thread was in the vm or native code. Return and try to finish.
462 return true;
463 }
464 } else if (thread->in_stack_red_zone(addr)) {
465 // Fatal red zone violation. Disable the guard pages and fall through
466 // to handle_unexpected_exception way down below.
467 thread->disable_stack_red_zone();
468 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
469 }
470 }
471
472 if (thread->thread_state() == _thread_in_vm) {
473 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
474 stub = StubRoutines::handler_for_unsafe_access();
475 }
476 }
477
478 if (thread->thread_state() == _thread_in_Java) {
479 // Support Safepoint Polling
480 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
481 stub = SharedRuntime::get_poll_stub(pc);
482 }
483 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
484 // BugId 4454115: A read from a MappedByteBuffer can fault
485 // here if the underlying file has been truncated.
486 // Do not crash the VM in such a case.
487 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
488 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
489 if (nm != NULL && nm->has_unsafe_access()) {
490 stub = StubRoutines::handler_for_unsafe_access();
491 }
492 }
493 else
494 if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
495 // integer divide by zero
496 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
497 }
498 #ifndef AMD64
499 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
500 // floating-point divide by zero
501 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
502 }
503 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
504 // The encoding of D2I in i486.ad can cause an exception prior
505 // to the fist instruction if there was an invalid operation
506 // pending. We want to dismiss that exception. From the win_32
507 // side it also seems that if it really was the fist causing
508 // the exception that we do the d2i by hand with different
509 // rounding. Seems kind of weird. QQQ TODO
510 // Note that we take the exception at the NEXT floating point instruction.
511 if (pc[0] == 0xDB) {
512 assert(pc[0] == 0xDB, "not a FIST opcode");
513 assert(pc[1] == 0x14, "not a FIST opcode");
514 assert(pc[2] == 0x24, "not a FIST opcode");
515 return true;
516 } else {
517 assert(pc[-3] == 0xDB, "not an flt invalid opcode");
518 assert(pc[-2] == 0x14, "not an flt invalid opcode");
519 assert(pc[-1] == 0x24, "not an flt invalid opcode");
520 }
521 }
522 else if (sig == SIGFPE ) {
523 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
524 }
525 #endif // !AMD64
526
527 // QQQ It doesn't seem that we need to do this on x86 because we should be able
528 // to return properly from the handler without this extra stuff on the back side.
529
530 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
531 // Determination of interpreter/vtable stub/compiled code null exception
532 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
533 }
534 }
535
536 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
537 // and the heap gets shrunk before the field access.
538 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
539 address addr = JNI_FastGetField::find_slowcase_pc(pc);
540 if (addr != (address)-1) {
541 stub = addr;
542 }
543 }
544
545 // Check to see if we caught the safepoint code in the
546 // process of write protecting the memory serialization page.
547 // It write enables the page immediately after protecting it
548 // so we can just return to retry the write.
549 if ((sig == SIGSEGV) &&
550 os::is_memory_serialize_page(thread, (address)info->si_addr)) {
551 // Block current thread until the memory serialize page permission restored.
552 os::block_on_serialize_page_trap();
553 return true;
554 }
555 }
556
557 // Execution protection violation
558 //
559 // Preventative code for future versions of Solaris which may
560 // enable execution protection when running the 32-bit VM on AMD64.
561 //
562 // This should be kept as the last step in the triage. We don't
563 // have a dedicated trap number for a no-execute fault, so be
564 // conservative and allow other handlers the first shot.
565 //
566 // Note: We don't test that info->si_code == SEGV_ACCERR here.
567 // this si_code is so generic that it is almost meaningless; and
568 // the si_code for this condition may change in the future.
569 // Furthermore, a false-positive should be harmless.
570 if (UnguardOnExecutionViolation > 0 &&
571 (sig == SIGSEGV || sig == SIGBUS) &&
572 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault
573 int page_size = os::vm_page_size();
574 address addr = (address) info->si_addr;
575 address pc = (address) uc->uc_mcontext.gregs[REG_PC];
576 // Make sure the pc and the faulting address are sane.
577 //
578 // If an instruction spans a page boundary, and the page containing
579 // the beginning of the instruction is executable but the following
580 // page is not, the pc and the faulting address might be slightly
581 // different - we still want to unguard the 2nd page in this case.
582 //
583 // 15 bytes seems to be a (very) safe value for max instruction size.
584 bool pc_is_near_addr =
585 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
586 bool instr_spans_page_boundary =
587 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
588 (intptr_t) page_size) > 0);
589
590 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
591 static volatile address last_addr =
592 (address) os::non_memory_address_word();
593
594 // In conservative mode, don't unguard unless the address is in the VM
595 if (addr != last_addr &&
596 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
597
598 // Make memory rwx and retry
599 address page_start =
600 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
601 bool res = os::protect_memory((char*) page_start, page_size,
602 os::MEM_PROT_RWX);
603
604 if (PrintMiscellaneous && Verbose) {
605 char buf[256];
606 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
607 "at " INTPTR_FORMAT
608 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
609 page_start, (res ? "success" : "failed"), errno);
610 tty->print_raw_cr(buf);
611 }
612 stub = pc;
613
614 // Set last_addr so if we fault again at the same address, we don't end
615 // up in an endless loop.
616 //
617 // There are two potential complications here. Two threads trapping at
618 // the same address at the same time could cause one of the threads to
619 // think it already unguarded, and abort the VM. Likely very rare.
620 //
621 // The other race involves two threads alternately trapping at
622 // different addresses and failing to unguard the page, resulting in
623 // an endless loop. This condition is probably even more unlikely than
624 // the first.
625 //
626 // Although both cases could be avoided by using locks or thread local
627 // last_addr, these solutions are unnecessary complication: this
628 // handler is a best-effort safety net, not a complete solution. It is
629 // disabled by default and should only be used as a workaround in case
630 // we missed any no-execute-unsafe VM code.
631
632 last_addr = addr;
633 }
634 }
635 }
636
637 if (stub != NULL) {
638 // save all thread context in case we need to restore it
639
640 if (thread != NULL) thread->set_saved_exception_pc(pc);
641 // 12/02/99: On Sparc it appears that the full context is also saved
642 // but as yet, no one looks at or restores that saved context
643 // factor me: setPC
644 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
645 return true;
646 }
647
648 // signal-chaining
649 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
650 return true;
651 }
652
653 #ifndef AMD64
654 // Workaround (bug 4900493) for Solaris kernel bug 4966651.
655 // Handle an undefined selector caused by an attempt to assign
656 // fs in libthread getipriptr(). With the current libthread design every 512
657 // thread creations the LDT for a private thread data structure is extended
658 // and thre is a hazard that and another thread attempting a thread creation
659 // will use a stale LDTR that doesn't reflect the structure's growth,
660 // causing a GP fault.
661 // Enforce the probable limit of passes through here to guard against an
662 // infinite loop if some other move to fs caused the GP fault. Note that
663 // this loop counter is ultimately a heuristic as it is possible for
664 // more than one thread to generate this fault at a time in an MP system.
665 // In the case of the loop count being exceeded or if the poll fails
666 // just fall through to a fatal error.
667 // If there is some other source of T_GPFLT traps and the text at EIP is
668 // unreadable this code will loop infinitely until the stack is exausted.
669 // The key to diagnosis in this case is to look for the bottom signal handler
670 // frame.
671
672 if(! IgnoreLibthreadGPFault) {
673 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
674 const unsigned char *p =
675 (unsigned const char *) uc->uc_mcontext.gregs[EIP];
676
677 // Expected instruction?
678
679 if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
680
681 Atomic::inc(&ldtr_refresh);
682
683 // Infinite loop?
684
685 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
686
687 // No, force scheduling to get a fresh view of the LDTR
688
689 if(poll(NULL, 0, 10) == 0) {
690
691 // Retry the move
692
693 return false;
694 }
695 }
696 }
697 }
698 }
699 #endif // !AMD64
700
701 if (!abort_if_unrecognized) {
702 // caller wants another chance, so give it to him
703 return false;
704 }
705
706 if (!os::Solaris::libjsig_is_loaded) {
707 struct sigaction oldAct;
708 sigaction(sig, (struct sigaction *)0, &oldAct);
709 if (oldAct.sa_sigaction != signalHandler) {
710 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
711 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
712 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
713 }
714 }
715
716 if (pc == NULL && uc != NULL) {
717 pc = (address) uc->uc_mcontext.gregs[REG_PC];
718 }
719
720 // unmask current signal
721 sigset_t newset;
722 sigemptyset(&newset);
723 sigaddset(&newset, sig);
724 sigprocmask(SIG_UNBLOCK, &newset, NULL);
725
726 // Determine which sort of error to throw. Out of swap may signal
727 // on the thread stack, which could get a mapping error when touched.
728 address addr = (address) info->si_addr;
729 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
730 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
731 }
732
733 VMError err(t, sig, pc, info, ucVoid);
734 err.report_and_die();
735
736 ShouldNotReachHere();
737 }
738
739 void os::print_context(outputStream *st, void *context) {
740 if (context == NULL) return;
741
742 ucontext_t *uc = (ucontext_t*)context;
743 st->print_cr("Registers:");
744 #ifdef AMD64
745 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
746 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
747 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
748 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
749 st->cr();
750 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
751 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
752 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
753 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
754 st->cr();
755 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
756 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
757 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
758 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
759 st->cr();
760 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
761 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
762 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
763 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
764 st->cr();
765 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
766 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
767 #else
768 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
769 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
770 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
771 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
772 st->cr();
773 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
774 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
775 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
776 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
777 st->cr();
778 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
779 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
780 #endif // AMD64
781 st->cr();
782 st->cr();
783
784 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
785 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
786 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
787 st->cr();
788
789 // Note: it may be unsafe to inspect memory near pc. For example, pc may
790 // point to garbage if entry point in an nmethod is corrupted. Leave
791 // this at the end, and hope for the best.
792 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
793 address pc = epc.pc();
794 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
795 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
796 }
797
798 void os::print_register_info(outputStream *st, void *context) {
799 if (context == NULL) return;
800
801 ucontext_t *uc = (ucontext_t*)context;
802
803 st->print_cr("Register to memory mapping:");
804 st->cr();
805
806 // this is horrendously verbose but the layout of the registers in the
807 // context does not match how we defined our abstract Register set, so
808 // we can't just iterate through the gregs area
809
810 // this is only for the "general purpose" registers
811
812 #ifdef AMD64
813 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
814 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
815 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
816 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
817 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
818 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
819 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
820 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
821 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
822 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
823 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
824 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
825 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
826 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
827 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
828 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
829 #else
830 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
831 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
832 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
833 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
834 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
835 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
836 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
837 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
838 #endif
839
840 st->cr();
841 }
842
843
844 #ifdef AMD64
845 void os::Solaris::init_thread_fpu_state(void) {
846 // Nothing to do
847 }
848 #else
849 // From solaris_i486.s
850 extern "C" void fixcw();
851
852 void os::Solaris::init_thread_fpu_state(void) {
853 // Set fpu to 53 bit precision. This happens too early to use a stub.
854 fixcw();
855 }
856
857 // These routines are the initial value of atomic_xchg_entry(),
858 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
859 // until initialization is complete.
860 // TODO - replace with .il implementation when compiler supports it.
861
862 typedef jint xchg_func_t (jint, volatile jint*);
863 typedef jint cmpxchg_func_t (jint, volatile jint*, jint);
864 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
865 typedef jint add_func_t (jint, volatile jint*);
866
867 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
868 // try to use the stub:
869 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
870
871 if (func != NULL) {
872 os::atomic_xchg_func = func;
873 return (*func)(exchange_value, dest);
874 }
875 assert(Threads::number_of_threads() == 0, "for bootstrap only");
876
877 jint old_value = *dest;
878 *dest = exchange_value;
879 return old_value;
880 }
881
882 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
883 // try to use the stub:
884 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
885
886 if (func != NULL) {
887 os::atomic_cmpxchg_func = func;
888 return (*func)(exchange_value, dest, compare_value);
889 }
890 assert(Threads::number_of_threads() == 0, "for bootstrap only");
891
892 jint old_value = *dest;
893 if (old_value == compare_value)
894 *dest = exchange_value;
895 return old_value;
896 }
897
898 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
899 // try to use the stub:
900 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
901
902 if (func != NULL) {
903 os::atomic_cmpxchg_long_func = func;
904 return (*func)(exchange_value, dest, compare_value);
905 }
906 assert(Threads::number_of_threads() == 0, "for bootstrap only");
907
908 jlong old_value = *dest;
909 if (old_value == compare_value)
910 *dest = exchange_value;
911 return old_value;
912 }
913
914 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
915 // try to use the stub:
916 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
917
918 if (func != NULL) {
919 os::atomic_add_func = func;
920 return (*func)(add_value, dest);
921 }
922 assert(Threads::number_of_threads() == 0, "for bootstrap only");
923
924 return (*dest) += add_value;
925 }
926
927 xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap;
928 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap;
929 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
930 add_func_t* os::atomic_add_func = os::atomic_add_bootstrap;
931
932 extern "C" void _solaris_raw_setup_fpu(address ptr);
933 void os::setup_fpu() {
934 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
935 _solaris_raw_setup_fpu(fpu_cntrl);
936 }
937 #endif // AMD64
938
939 #ifndef PRODUCT
940 void os::verify_stack_alignment() {
941 #ifdef AMD64
942 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
943 #endif
944 }
945 #endif