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/atomic.inline.hpp"
42 #include "runtime/extendedPC.hpp"
43 #include "runtime/frame.inline.hpp"
44 #include "runtime/interfaceSupport.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/osThread.hpp"
49 #include "runtime/sharedRuntime.hpp"
50 #include "runtime/stubRoutines.hpp"
51 #include "runtime/thread.inline.hpp"
52 #include "runtime/timer.hpp"
53 #include "utilities/events.hpp"
54 #include "utilities/vmError.hpp"
55
56 // put OS-includes here
57 # include <sys/types.h>
58 # include <sys/mman.h>
59 # include <pthread.h>
60 # include <signal.h>
61 # include <setjmp.h>
62 # include <errno.h>
63 # include <dlfcn.h>
64 # include <stdio.h>
65 # include <unistd.h>
66 # include <sys/resource.h>
67 # include <thread.h>
68 # include <sys/stat.h>
69 # include <sys/time.h>
70 # include <sys/filio.h>
71 # include <sys/utsname.h>
72 # include <sys/systeminfo.h>
73 # include <sys/socket.h>
74 # include <sys/trap.h>
75 # include <sys/lwp.h>
76 # include <pwd.h>
77 # include <poll.h>
78 # include <sys/lwp.h>
79 # include <procfs.h> // see comment in <sys/procfs.h>
80
81 #ifndef AMD64
82 // QQQ seems useless at this point
83 # define _STRUCTURED_PROC 1 // this gets us the new structured proc interfaces of 5.6 & later
84 #endif // AMD64
85 # include <sys/procfs.h> // see comment in <sys/procfs.h>
86
87
88 #define MAX_PATH (2 * K)
89
90 // Minimum stack size for the VM. It's easier to document a constant value
91 // but it's different for x86 and sparc because the page sizes are different.
92 #ifdef AMD64
93 size_t os::Solaris::min_stack_allowed = 224*K;
94 #define REG_SP REG_RSP
95 #define REG_PC REG_RIP
96 #define REG_FP REG_RBP
97 #else
98 size_t os::Solaris::min_stack_allowed = 64*K;
99 #define REG_SP UESP
100 #define REG_PC EIP
101 #define REG_FP EBP
102 // 4900493 counter to prevent runaway LDTR refresh attempt
103
104 static volatile int ldtr_refresh = 0;
105 // the libthread instruction that faults because of the stale LDTR
106
107 static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs
108 };
109 #endif // AMD64
110
111 char* os::non_memory_address_word() {
112 // Must never look like an address returned by reserve_memory,
113 // even in its subfields (as defined by the CPU immediate fields,
114 // if the CPU splits constants across multiple instructions).
115 return (char*) -1;
116 }
117
118 //
119 // Validate a ucontext retrieved from walking a uc_link of a ucontext.
120 // There are issues with libthread giving out uc_links for different threads
121 // on the same uc_link chain and bad or circular links.
122 //
123 bool os::Solaris::valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect) {
124 if (valid >= suspect ||
125 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
126 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp ||
127 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) {
128 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)
129 return false;
130 }
131
132 if (thread->is_Java_thread()) {
133 if (!valid_stack_address(thread, (address)suspect)) {
134 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)
135 return false;
136 }
137 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) {
138 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)
139 return false;
140 }
141 }
142 return true;
143 }
144
145 // We will only follow one level of uc_link since there are libthread
146 // issues with ucontext linking and it is better to be safe and just
147 // let caller retry later.
148 ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
149 ucontext_t *uc) {
150
151 ucontext_t *retuc = NULL;
152
153 if (uc != NULL) {
154 if (uc->uc_link == NULL) {
155 // cannot validate without uc_link so accept current ucontext
156 retuc = uc;
157 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
158 // first ucontext is valid so try the next one
159 uc = uc->uc_link;
160 if (uc->uc_link == NULL) {
161 // cannot validate without uc_link so accept current ucontext
162 retuc = uc;
163 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
164 // the ucontext one level down is also valid so return it
165 retuc = uc;
166 }
167 }
168 }
169 return retuc;
170 }
171
172 // Assumes ucontext is valid
173 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(ucontext_t *uc) {
174 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]);
175 }
176
177 // Assumes ucontext is valid
178 intptr_t* os::Solaris::ucontext_get_sp(ucontext_t *uc) {
179 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
180 }
181
182 // Assumes ucontext is valid
183 intptr_t* os::Solaris::ucontext_get_fp(ucontext_t *uc) {
184 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
185 }
186
187 address os::Solaris::ucontext_get_pc(ucontext_t *uc) {
188 return (address) uc->uc_mcontext.gregs[REG_PC];
189 }
190
191 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
192 // is currently interrupted by SIGPROF.
193 //
194 // The difference between this and os::fetch_frame_from_context() is that
195 // here we try to skip nested signal frames.
196 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
197 ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
198
199 assert(thread != NULL, "just checking");
200 assert(ret_sp != NULL, "just checking");
201 assert(ret_fp != NULL, "just checking");
202
203 ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
204 return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
205 }
206
207 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
208 intptr_t** ret_sp, intptr_t** ret_fp) {
209
210 ExtendedPC epc;
211 ucontext_t *uc = (ucontext_t*)ucVoid;
212
213 if (uc != NULL) {
214 epc = os::Solaris::ucontext_get_ExtendedPC(uc);
215 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
216 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc);
217 } else {
218 // construct empty ExtendedPC for return value checking
219 epc = ExtendedPC(NULL);
220 if (ret_sp) *ret_sp = (intptr_t *)NULL;
221 if (ret_fp) *ret_fp = (intptr_t *)NULL;
222 }
223
224 return epc;
225 }
226
227 frame os::fetch_frame_from_context(void* ucVoid) {
228 intptr_t* sp;
229 intptr_t* fp;
230 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
231 return frame(sp, fp, epc.pc());
232 }
233
234 frame os::get_sender_for_C_frame(frame* fr) {
235 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
236 }
237
238 extern "C" intptr_t *_get_current_sp(); // in .il file
239
240 address os::current_stack_pointer() {
241 return (address)_get_current_sp();
242 }
243
244 extern "C" intptr_t *_get_current_fp(); // in .il file
245
246 frame os::current_frame() {
247 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp
248 frame myframe((intptr_t*)os::current_stack_pointer(),
249 (intptr_t*)fp,
250 CAST_FROM_FN_PTR(address, os::current_frame));
251 if (os::is_first_C_frame(&myframe)) {
252 // stack is not walkable
253 frame ret; // This will be a null useless frame
254 return ret;
255 } else {
256 return os::get_sender_for_C_frame(&myframe);
257 }
258 }
259
260 static int threadgetstate(thread_t tid, int *flags, lwpid_t *lwp, stack_t *ss, gregset_t rs, lwpstatus_t *lwpstatus) {
261 char lwpstatusfile[PROCFILE_LENGTH];
262 int lwpfd, err;
263
264 if (err = os::Solaris::thr_getstate(tid, flags, lwp, ss, rs))
265 return (err);
266 if (*flags == TRS_LWPID) {
267 sprintf(lwpstatusfile, "/proc/%d/lwp/%d/lwpstatus", getpid(),
268 *lwp);
269 if ((lwpfd = open(lwpstatusfile, O_RDONLY)) < 0) {
270 perror("thr_mutator_status: open lwpstatus");
271 return (EINVAL);
272 }
273 if (pread(lwpfd, lwpstatus, sizeof (lwpstatus_t), (off_t)0) !=
274 sizeof (lwpstatus_t)) {
275 perror("thr_mutator_status: read lwpstatus");
276 (void) close(lwpfd);
277 return (EINVAL);
278 }
279 (void) close(lwpfd);
280 }
281 return (0);
282 }
283
284 #ifndef AMD64
285
286 // Detecting SSE support by OS
287 // From solaris_i486.s
288 extern "C" bool sse_check();
289 extern "C" bool sse_unavailable();
290
291 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};
292 static int sse_status = SSE_UNKNOWN;
293
294
295 static void check_for_sse_support() {
296 if (!VM_Version::supports_sse()) {
297 sse_status = SSE_NOT_SUPPORTED;
298 return;
299 }
300 // looking for _sse_hw in libc.so, if it does not exist or
301 // the value (int) is 0, OS has no support for SSE
302 int *sse_hwp;
303 void *h;
304
305 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {
306 //open failed, presume no support for SSE
307 sse_status = SSE_NOT_SUPPORTED;
308 return;
309 }
310 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {
311 sse_status = SSE_NOT_SUPPORTED;
312 } else if (*sse_hwp == 0) {
313 sse_status = SSE_NOT_SUPPORTED;
314 }
315 dlclose(h);
316
317 if (sse_status == SSE_UNKNOWN) {
318 bool (*try_sse)() = (bool (*)())sse_check;
319 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;
320 }
321
322 }
323
324 #endif // AMD64
325
326 bool os::supports_sse() {
327 #ifdef AMD64
328 return true;
329 #else
330 if (sse_status == SSE_UNKNOWN)
331 check_for_sse_support();
332 return sse_status == SSE_SUPPORTED;
333 #endif // AMD64
334 }
335
336 bool os::is_allocatable(size_t bytes) {
337 #ifdef AMD64
338 return true;
339 #else
340
341 if (bytes < 2 * G) {
342 return true;
343 }
344
345 char* addr = reserve_memory(bytes, NULL);
346
347 if (addr != NULL) {
348 release_memory(addr, bytes);
349 }
350
351 return addr != NULL;
352 #endif // AMD64
353
354 }
355
356 extern "C" JNIEXPORT int
357 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
358 int abort_if_unrecognized) {
359 ucontext_t* uc = (ucontext_t*) ucVoid;
360
361 #ifndef AMD64
362 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
363 // the SSE instruction faulted. supports_sse() need return false.
364 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
365 return true;
366 }
367 #endif // !AMD64
368
369 Thread* t = ThreadLocalStorage::get_thread_slow(); // slow & steady
370
371 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
372 // (no destructors can be run)
373 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
374
375 SignalHandlerMark shm(t);
376
377 if(sig == SIGPIPE || sig == SIGXFSZ) {
378 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
379 return true;
380 } else {
381 if (PrintMiscellaneous && (WizardMode || Verbose)) {
382 char buf[64];
383 warning("Ignoring %s - see 4229104 or 6499219",
384 os::exception_name(sig, buf, sizeof(buf)));
385
386 }
387 return true;
388 }
389 }
390
391 JavaThread* thread = NULL;
392 VMThread* vmthread = NULL;
393
394 if (os::Solaris::signal_handlers_are_installed) {
395 if (t != NULL ){
396 if(t->is_Java_thread()) {
397 thread = (JavaThread*)t;
398 }
399 else if(t->is_VM_thread()){
400 vmthread = (VMThread *)t;
401 }
402 }
403 }
404
405 guarantee(sig != os::Solaris::SIGinterrupt(), "Can not chain VM interrupt signal, try -XX:+UseAltSigs");
406
407 if (sig == os::Solaris::SIGasync()) {
408 if(thread || vmthread){
409 OSThread::SR_handler(t, uc);
410 return true;
411 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
412 return true;
413 } else {
414 // If os::Solaris::SIGasync not chained, and this is a non-vm and
415 // non-java thread
416 return true;
417 }
418 }
419
420 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
421 // can't decode this kind of signal
422 info = NULL;
423 } else {
424 assert(sig == info->si_signo, "bad siginfo");
425 }
426
427 // decide if this trap can be handled by a stub
428 address stub = NULL;
429
430 address pc = NULL;
431
432 //%note os_trap_1
433 if (info != NULL && uc != NULL && thread != NULL) {
434 // factor me: getPCfromContext
435 pc = (address) uc->uc_mcontext.gregs[REG_PC];
436
437 if (StubRoutines::is_safefetch_fault(pc)) {
438 uc->uc_mcontext.gregs[REG_PC] = intptr_t(StubRoutines::continuation_for_safefetch_fault(pc));
439 return true;
440 }
441
442 // Handle ALL stack overflow variations here
443 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
444 address addr = (address) info->si_addr;
445 if (thread->in_stack_yellow_zone(addr)) {
446 thread->disable_stack_yellow_zone();
447 if (thread->thread_state() == _thread_in_Java) {
448 // Throw a stack overflow exception. Guard pages will be reenabled
449 // while unwinding the stack.
450 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
451 } else {
452 // Thread was in the vm or native code. Return and try to finish.
453 return true;
454 }
455 } else if (thread->in_stack_red_zone(addr)) {
456 // Fatal red zone violation. Disable the guard pages and fall through
457 // to handle_unexpected_exception way down below.
458 thread->disable_stack_red_zone();
459 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
460 }
461 }
462
463 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) {
464 // Verify that OS save/restore AVX registers.
465 stub = VM_Version::cpuinfo_cont_addr();
466 }
467
468 if (thread->thread_state() == _thread_in_vm) {
469 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
470 stub = StubRoutines::handler_for_unsafe_access();
471 }
472 }
473
474 if (thread->thread_state() == _thread_in_Java) {
475 // Support Safepoint Polling
476 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
477 stub = SharedRuntime::get_poll_stub(pc);
478 }
479 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
480 // BugId 4454115: A read from a MappedByteBuffer can fault
481 // here if the underlying file has been truncated.
482 // Do not crash the VM in such a case.
483 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
484 if (cb != NULL) {
485 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
486 if (nm != NULL && nm->has_unsafe_access()) {
487 stub = StubRoutines::handler_for_unsafe_access();
488 }
489 }
490 }
491 else
492 if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
493 // integer divide by zero
494 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
495 }
496 #ifndef AMD64
497 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
498 // floating-point divide by zero
499 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
500 }
501 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
502 // The encoding of D2I in i486.ad can cause an exception prior
503 // to the fist instruction if there was an invalid operation
504 // pending. We want to dismiss that exception. From the win_32
505 // side it also seems that if it really was the fist causing
506 // the exception that we do the d2i by hand with different
507 // rounding. Seems kind of weird. QQQ TODO
508 // Note that we take the exception at the NEXT floating point instruction.
509 if (pc[0] == 0xDB) {
510 assert(pc[0] == 0xDB, "not a FIST opcode");
511 assert(pc[1] == 0x14, "not a FIST opcode");
512 assert(pc[2] == 0x24, "not a FIST opcode");
513 return true;
514 } else {
515 assert(pc[-3] == 0xDB, "not an flt invalid opcode");
516 assert(pc[-2] == 0x14, "not an flt invalid opcode");
517 assert(pc[-1] == 0x24, "not an flt invalid opcode");
518 }
519 }
520 else if (sig == SIGFPE ) {
521 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
522 }
523 #endif // !AMD64
524
525 // QQQ It doesn't seem that we need to do this on x86 because we should be able
526 // to return properly from the handler without this extra stuff on the back side.
527
528 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
529 // Determination of interpreter/vtable stub/compiled code null exception
530 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
531 }
532 }
533
534 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
535 // and the heap gets shrunk before the field access.
536 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
537 address addr = JNI_FastGetField::find_slowcase_pc(pc);
538 if (addr != (address)-1) {
539 stub = addr;
540 }
541 }
542
543 // Check to see if we caught the safepoint code in the
544 // process of write protecting the memory serialization page.
545 // It write enables the page immediately after protecting it
546 // so we can just return to retry the write.
547 if ((sig == SIGSEGV) &&
548 os::is_memory_serialize_page(thread, (address)info->si_addr)) {
549 // Block current thread until the memory serialize page permission restored.
550 os::block_on_serialize_page_trap();
551 return true;
552 }
553 }
554
555 // Execution protection violation
556 //
557 // Preventative code for future versions of Solaris which may
558 // enable execution protection when running the 32-bit VM on AMD64.
559 //
560 // This should be kept as the last step in the triage. We don't
561 // have a dedicated trap number for a no-execute fault, so be
562 // conservative and allow other handlers the first shot.
563 //
564 // Note: We don't test that info->si_code == SEGV_ACCERR here.
565 // this si_code is so generic that it is almost meaningless; and
566 // the si_code for this condition may change in the future.
567 // Furthermore, a false-positive should be harmless.
568 if (UnguardOnExecutionViolation > 0 &&
569 (sig == SIGSEGV || sig == SIGBUS) &&
570 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault
571 int page_size = os::vm_page_size();
572 address addr = (address) info->si_addr;
573 address pc = (address) uc->uc_mcontext.gregs[REG_PC];
574 // Make sure the pc and the faulting address are sane.
575 //
576 // If an instruction spans a page boundary, and the page containing
577 // the beginning of the instruction is executable but the following
578 // page is not, the pc and the faulting address might be slightly
579 // different - we still want to unguard the 2nd page in this case.
580 //
581 // 15 bytes seems to be a (very) safe value for max instruction size.
582 bool pc_is_near_addr =
583 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
584 bool instr_spans_page_boundary =
585 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
586 (intptr_t) page_size) > 0);
587
588 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
589 static volatile address last_addr =
590 (address) os::non_memory_address_word();
591
592 // In conservative mode, don't unguard unless the address is in the VM
593 if (addr != last_addr &&
594 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
595
596 // Make memory rwx and retry
597 address page_start =
598 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
599 bool res = os::protect_memory((char*) page_start, page_size,
600 os::MEM_PROT_RWX);
601
602 if (PrintMiscellaneous && Verbose) {
603 char buf[256];
604 jio_snprintf(buf, sizeof(buf), "Execution protection violation "
605 "at " INTPTR_FORMAT
606 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
607 page_start, (res ? "success" : "failed"), errno);
608 tty->print_raw_cr(buf);
609 }
610 stub = pc;
611
612 // Set last_addr so if we fault again at the same address, we don't end
613 // up in an endless loop.
614 //
615 // There are two potential complications here. Two threads trapping at
616 // the same address at the same time could cause one of the threads to
617 // think it already unguarded, and abort the VM. Likely very rare.
618 //
619 // The other race involves two threads alternately trapping at
620 // different addresses and failing to unguard the page, resulting in
621 // an endless loop. This condition is probably even more unlikely than
622 // the first.
623 //
624 // Although both cases could be avoided by using locks or thread local
625 // last_addr, these solutions are unnecessary complication: this
626 // handler is a best-effort safety net, not a complete solution. It is
627 // disabled by default and should only be used as a workaround in case
628 // we missed any no-execute-unsafe VM code.
629
630 last_addr = addr;
631 }
632 }
633 }
634
635 if (stub != NULL) {
636 // save all thread context in case we need to restore it
637
638 if (thread != NULL) thread->set_saved_exception_pc(pc);
639 // 12/02/99: On Sparc it appears that the full context is also saved
640 // but as yet, no one looks at or restores that saved context
641 // factor me: setPC
642 uc->uc_mcontext.gregs[REG_PC] = (greg_t)stub;
643 return true;
644 }
645
646 // signal-chaining
647 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
648 return true;
649 }
650
651 #ifndef AMD64
652 // Workaround (bug 4900493) for Solaris kernel bug 4966651.
653 // Handle an undefined selector caused by an attempt to assign
654 // fs in libthread getipriptr(). With the current libthread design every 512
655 // thread creations the LDT for a private thread data structure is extended
656 // and thre is a hazard that and another thread attempting a thread creation
657 // will use a stale LDTR that doesn't reflect the structure's growth,
658 // causing a GP fault.
659 // Enforce the probable limit of passes through here to guard against an
660 // infinite loop if some other move to fs caused the GP fault. Note that
661 // this loop counter is ultimately a heuristic as it is possible for
662 // more than one thread to generate this fault at a time in an MP system.
663 // In the case of the loop count being exceeded or if the poll fails
664 // just fall through to a fatal error.
665 // If there is some other source of T_GPFLT traps and the text at EIP is
666 // unreadable this code will loop infinitely until the stack is exausted.
667 // The key to diagnosis in this case is to look for the bottom signal handler
668 // frame.
669
670 if(! IgnoreLibthreadGPFault) {
671 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
672 const unsigned char *p =
673 (unsigned const char *) uc->uc_mcontext.gregs[EIP];
674
675 // Expected instruction?
676
677 if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
678
679 Atomic::inc(&ldtr_refresh);
680
681 // Infinite loop?
682
683 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
684
685 // No, force scheduling to get a fresh view of the LDTR
686
687 if(poll(NULL, 0, 10) == 0) {
688
689 // Retry the move
690
691 return false;
692 }
693 }
694 }
695 }
696 }
697 #endif // !AMD64
698
699 if (!abort_if_unrecognized) {
700 // caller wants another chance, so give it to him
701 return false;
702 }
703
704 if (!os::Solaris::libjsig_is_loaded) {
705 struct sigaction oldAct;
706 sigaction(sig, (struct sigaction *)0, &oldAct);
707 if (oldAct.sa_sigaction != signalHandler) {
708 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
709 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
710 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
711 }
712 }
713
714 if (pc == NULL && uc != NULL) {
715 pc = (address) uc->uc_mcontext.gregs[REG_PC];
716 }
717
718 // unmask current signal
719 sigset_t newset;
720 sigemptyset(&newset);
721 sigaddset(&newset, sig);
722 sigprocmask(SIG_UNBLOCK, &newset, NULL);
723
724 // Determine which sort of error to throw. Out of swap may signal
725 // on the thread stack, which could get a mapping error when touched.
726 address addr = (address) info->si_addr;
727 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
728 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
729 }
730
731 VMError err(t, sig, pc, info, ucVoid);
732 err.report_and_die();
733
734 ShouldNotReachHere();
735 return false;
736 }
737
738 void os::print_context(outputStream *st, void *context) {
739 if (context == NULL) return;
740
741 ucontext_t *uc = (ucontext_t*)context;
742 st->print_cr("Registers:");
743 #ifdef AMD64
744 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
745 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
746 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
747 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
748 st->cr();
749 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
750 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
751 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
752 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
753 st->cr();
754 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
755 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
756 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
757 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
758 st->cr();
759 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
760 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
761 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
762 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
763 st->cr();
764 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
765 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
766 #else
767 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
768 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
769 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
770 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
771 st->cr();
772 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
773 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
774 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
775 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
776 st->cr();
777 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
778 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
779 #endif // AMD64
780 st->cr();
781 st->cr();
782
783 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
784 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
785 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
786 st->cr();
787
788 // Note: it may be unsafe to inspect memory near pc. For example, pc may
789 // point to garbage if entry point in an nmethod is corrupted. Leave
790 // this at the end, and hope for the best.
791 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
792 address pc = epc.pc();
793 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
794 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
795 }
796
797 void os::print_register_info(outputStream *st, void *context) {
798 if (context == NULL) return;
799
800 ucontext_t *uc = (ucontext_t*)context;
801
802 st->print_cr("Register to memory mapping:");
803 st->cr();
804
805 // this is horrendously verbose but the layout of the registers in the
806 // context does not match how we defined our abstract Register set, so
807 // we can't just iterate through the gregs area
808
809 // this is only for the "general purpose" registers
810
811 #ifdef AMD64
812 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
813 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
814 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
815 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
816 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
817 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
818 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
819 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
820 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
821 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
822 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
823 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
824 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
825 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
826 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
827 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
828 #else
829 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
830 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
831 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
832 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
833 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
834 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
835 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
836 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
837 #endif
838
839 st->cr();
840 }
841
842
843 #ifdef AMD64
844 void os::Solaris::init_thread_fpu_state(void) {
845 // Nothing to do
846 }
847 #else
848 // From solaris_i486.s
849 extern "C" void fixcw();
850
851 void os::Solaris::init_thread_fpu_state(void) {
852 // Set fpu to 53 bit precision. This happens too early to use a stub.
853 fixcw();
854 }
855
856 // These routines are the initial value of atomic_xchg_entry(),
857 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
858 // until initialization is complete.
859 // TODO - replace with .il implementation when compiler supports it.
860
861 typedef jint xchg_func_t (jint, volatile jint*);
862 typedef jint cmpxchg_func_t (jint, volatile jint*, jint);
863 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
864 typedef jint add_func_t (jint, volatile jint*);
865
866 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
867 // try to use the stub:
868 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
869
870 if (func != NULL) {
871 os::atomic_xchg_func = func;
872 return (*func)(exchange_value, dest);
873 }
874 assert(Threads::number_of_threads() == 0, "for bootstrap only");
875
876 jint old_value = *dest;
877 *dest = exchange_value;
878 return old_value;
879 }
880
881 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
882 // try to use the stub:
883 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
884
885 if (func != NULL) {
886 os::atomic_cmpxchg_func = func;
887 return (*func)(exchange_value, dest, compare_value);
888 }
889 assert(Threads::number_of_threads() == 0, "for bootstrap only");
890
891 jint old_value = *dest;
892 if (old_value == compare_value)
893 *dest = exchange_value;
894 return old_value;
895 }
896
897 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
898 // try to use the stub:
899 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
900
901 if (func != NULL) {
902 os::atomic_cmpxchg_long_func = func;
903 return (*func)(exchange_value, dest, compare_value);
904 }
905 assert(Threads::number_of_threads() == 0, "for bootstrap only");
906
907 jlong old_value = *dest;
908 if (old_value == compare_value)
909 *dest = exchange_value;
910 return old_value;
911 }
912
913 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
914 // try to use the stub:
915 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
916
917 if (func != NULL) {
918 os::atomic_add_func = func;
919 return (*func)(add_value, dest);
920 }
921 assert(Threads::number_of_threads() == 0, "for bootstrap only");
922
923 return (*dest) += add_value;
924 }
925
926 xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap;
927 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap;
928 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
929 add_func_t* os::atomic_add_func = os::atomic_add_bootstrap;
930
931 extern "C" void _solaris_raw_setup_fpu(address ptr);
932 void os::setup_fpu() {
933 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
934 _solaris_raw_setup_fpu(fpu_cntrl);
935 }
936 #endif // AMD64
937
938 #ifndef PRODUCT
939 void os::verify_stack_alignment() {
940 #ifdef AMD64
941 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
942 #endif
943 }
944 #endif