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