1 /*
2 * Copyright (c) 1999, 2016, 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/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "code/vtableStubs.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_solaris.h"
35 #include "memory/allocation.inline.hpp"
36 #include "mutex_solaris.inline.hpp"
37 #include "os_share_solaris.hpp"
38 #include "prims/jniFastGetField.hpp"
39 #include "prims/jvm.h"
40 #include "prims/jvm_misc.hpp"
41 #include "runtime/arguments.hpp"
42 #include "runtime/atomic.inline.hpp"
43 #include "runtime/extendedPC.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/interfaceSupport.hpp"
46 #include "runtime/java.hpp"
47 #include "runtime/javaCalls.hpp"
48 #include "runtime/mutexLocker.hpp"
49 #include "runtime/osThread.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "runtime/stubRoutines.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/timer.hpp"
54 #include "utilities/events.hpp"
55 #include "utilities/vmError.hpp"
56
57 // put OS-includes here
58 # include <sys/types.h>
59 # include <sys/mman.h>
60 # include <pthread.h>
61 # include <signal.h>
62 # include <setjmp.h>
63 # include <errno.h>
64 # include <dlfcn.h>
65 # include <stdio.h>
66 # include <unistd.h>
67 # include <sys/resource.h>
68 # include <thread.h>
69 # include <sys/stat.h>
70 # include <sys/time.h>
71 # include <sys/filio.h>
72 # include <sys/utsname.h>
73 # include <sys/systeminfo.h>
74 # include <sys/socket.h>
75 # include <sys/trap.h>
76 # include <sys/lwp.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, const ucontext_t* valid, const 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 const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
149 const ucontext_t *uc) {
150
151 const 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(const ucontext_t *uc) {
174 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]);
175 }
176
177 void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) {
178 uc->uc_mcontext.gregs [REG_PC] = (greg_t) pc;
179 }
180
181 // Assumes ucontext is valid
182 intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {
183 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
184 }
185
186 // Assumes ucontext is valid
187 intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {
188 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
189 }
190
191 address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {
192 return (address) uc->uc_mcontext.gregs[REG_PC];
193 }
194
195 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
196 // is currently interrupted by SIGPROF.
197 //
198 // The difference between this and os::fetch_frame_from_context() is that
199 // here we try to skip nested signal frames.
200 // This method is also used for stack overflow signal handling.
201 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
202 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
203
204 assert(thread != NULL, "just checking");
205 assert(ret_sp != NULL, "just checking");
206 assert(ret_fp != NULL, "just checking");
207
208 const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
209 return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
210 }
211
212 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
213 intptr_t** ret_sp, intptr_t** ret_fp) {
214
215 ExtendedPC epc;
216 const ucontext_t *uc = (const ucontext_t*)ucVoid;
217
218 if (uc != NULL) {
219 epc = os::Solaris::ucontext_get_ExtendedPC(uc);
220 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
221 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc);
222 } else {
223 // construct empty ExtendedPC for return value checking
224 epc = ExtendedPC(NULL);
225 if (ret_sp) *ret_sp = (intptr_t *)NULL;
226 if (ret_fp) *ret_fp = (intptr_t *)NULL;
227 }
228
229 return epc;
230 }
231
232 frame os::fetch_frame_from_context(const void* ucVoid) {
233 intptr_t* sp;
234 intptr_t* fp;
235 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
236 return frame(sp, fp, epc.pc());
237 }
238
239 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
240 intptr_t* sp;
241 intptr_t* fp;
242 ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp);
243 return frame(sp, fp, epc.pc());
244 }
245
246 bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
247 address pc = (address) os::Solaris::ucontext_get_pc(uc);
248 if (Interpreter::contains(pc)) {
249 // interpreter performs stack banging after the fixed frame header has
250 // been generated while the compilers perform it before. To maintain
251 // semantic consistency between interpreted and compiled frames, the
252 // method returns the Java sender of the current frame.
253 *fr = os::fetch_frame_from_ucontext(thread, uc);
254 if (!fr->is_first_java_frame()) {
255 assert(fr->safe_for_sender(thread), "Safety check");
256 *fr = fr->java_sender();
257 }
258 } else {
259 // more complex code with compiled code
260 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
261 CodeBlob* cb = CodeCache::find_blob(pc);
262 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
263 // Not sure where the pc points to, fallback to default
264 // stack overflow handling
265 return false;
266 } else {
267 // in compiled code, the stack banging is performed just after the return pc
268 // has been pushed on the stack
269 intptr_t* fp = os::Solaris::ucontext_get_fp(uc);
270 intptr_t* sp = os::Solaris::ucontext_get_sp(uc);
271 *fr = frame(sp + 1, fp, (address)*sp);
272 if (!fr->is_java_frame()) {
273 assert(fr->safe_for_sender(thread), "Safety check");
274 *fr = fr->java_sender();
275 }
276 }
277 }
278 assert(fr->is_java_frame(), "Safety check");
279 return true;
280 }
281
282 frame os::get_sender_for_C_frame(frame* fr) {
283 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
284 }
285
286 extern "C" intptr_t *_get_current_sp(); // in .il file
287
288 address os::current_stack_pointer() {
289 return (address)_get_current_sp();
290 }
291
292 extern "C" intptr_t *_get_current_fp(); // in .il file
293
294 frame os::current_frame() {
295 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp
296 frame myframe((intptr_t*)os::current_stack_pointer(),
297 (intptr_t*)fp,
298 CAST_FROM_FN_PTR(address, os::current_frame));
299 if (os::is_first_C_frame(&myframe)) {
300 // stack is not walkable
301 frame ret; // This will be a null useless frame
302 return ret;
303 } else {
304 return os::get_sender_for_C_frame(&myframe);
305 }
306 }
307
308 #ifndef AMD64
309
310 // Detecting SSE support by OS
311 // From solaris_i486.s
312 extern "C" bool sse_check();
313 extern "C" bool sse_unavailable();
314
315 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};
316 static int sse_status = SSE_UNKNOWN;
317
318
319 static void check_for_sse_support() {
320 if (!VM_Version::supports_sse()) {
321 sse_status = SSE_NOT_SUPPORTED;
322 return;
323 }
324 // looking for _sse_hw in libc.so, if it does not exist or
325 // the value (int) is 0, OS has no support for SSE
326 int *sse_hwp;
327 void *h;
328
329 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {
330 //open failed, presume no support for SSE
331 sse_status = SSE_NOT_SUPPORTED;
332 return;
333 }
334 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {
335 sse_status = SSE_NOT_SUPPORTED;
336 } else if (*sse_hwp == 0) {
337 sse_status = SSE_NOT_SUPPORTED;
338 }
339 dlclose(h);
340
341 if (sse_status == SSE_UNKNOWN) {
342 bool (*try_sse)() = (bool (*)())sse_check;
343 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;
344 }
345
346 }
347
348 #endif // AMD64
349
350 bool os::supports_sse() {
351 #ifdef AMD64
352 return true;
353 #else
354 if (sse_status == SSE_UNKNOWN)
355 check_for_sse_support();
356 return sse_status == SSE_SUPPORTED;
357 #endif // AMD64
358 }
359
360 bool os::is_allocatable(size_t bytes) {
361 #ifdef AMD64
362 return true;
363 #else
364
365 if (bytes < 2 * G) {
366 return true;
367 }
368
369 char* addr = reserve_memory(bytes, NULL);
370
371 if (addr != NULL) {
372 release_memory(addr, bytes);
373 }
374
375 return addr != NULL;
376 #endif // AMD64
377
378 }
379
380 extern "C" JNIEXPORT int
381 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
382 int abort_if_unrecognized) {
383 ucontext_t* uc = (ucontext_t*) ucVoid;
384
385 #ifndef AMD64
386 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
387 // the SSE instruction faulted. supports_sse() need return false.
388 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
389 return true;
390 }
391 #endif // !AMD64
392
393 Thread* t = Thread::current_or_null_safe();
394
395 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
396 // (no destructors can be run)
397 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
398
399 SignalHandlerMark shm(t);
400
401 if(sig == SIGPIPE || sig == SIGXFSZ) {
402 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
403 return true;
404 } else {
405 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
406 return true;
407 }
408 }
409
410 JavaThread* thread = NULL;
411 VMThread* vmthread = NULL;
412
413 if (os::Solaris::signal_handlers_are_installed) {
414 if (t != NULL ){
415 if(t->is_Java_thread()) {
416 thread = (JavaThread*)t;
417 }
418 else if(t->is_VM_thread()){
419 vmthread = (VMThread *)t;
420 }
421 }
422 }
423
424 if (sig == os::Solaris::SIGasync()) {
425 if(thread || vmthread){
426 OSThread::SR_handler(t, uc);
427 return true;
428 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
429 return true;
430 } else {
431 // If os::Solaris::SIGasync not chained, and this is a non-vm and
432 // non-java thread
433 return true;
434 }
435 }
436
437 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
438 // can't decode this kind of signal
439 info = NULL;
440 } else {
441 assert(sig == info->si_signo, "bad siginfo");
442 }
443
444 // decide if this trap can be handled by a stub
445 address stub = NULL;
446
447 address pc = NULL;
448
449 //%note os_trap_1
450 if (info != NULL && uc != NULL && thread != NULL) {
451 // factor me: getPCfromContext
452 pc = (address) uc->uc_mcontext.gregs[REG_PC];
453
454 if (StubRoutines::is_safefetch_fault(pc)) {
455 os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
456 return true;
457 }
458
459 // Handle ALL stack overflow variations here
460 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
461 address addr = (address) info->si_addr;
462 if (thread->in_stack_yellow_reserved_zone(addr)) {
463 if (thread->thread_state() == _thread_in_Java) {
464 if (thread->in_stack_reserved_zone(addr)) {
465 frame fr;
466 if (os::Solaris::get_frame_at_stack_banging_point(thread, uc, &fr)) {
467 assert(fr.is_java_frame(), "Must be Java frame");
468 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
469 if (activation.sp() != NULL) {
470 thread->disable_stack_reserved_zone();
471 if (activation.is_interpreted_frame()) {
472 thread->set_reserved_stack_activation((address)(
473 activation.fp() + frame::interpreter_frame_initial_sp_offset));
474 } else {
475 thread->set_reserved_stack_activation((address)activation.unextended_sp());
476 }
477 return true;
478 }
479 }
480 }
481 // Throw a stack overflow exception. Guard pages will be reenabled
482 // while unwinding the stack.
483 thread->disable_stack_yellow_reserved_zone();
484 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
485 } else {
486 // Thread was in the vm or native code. Return and try to finish.
487 thread->disable_stack_yellow_reserved_zone();
488 return true;
489 }
490 } else if (thread->in_stack_red_zone(addr)) {
491 // Fatal red zone violation. Disable the guard pages and fall through
492 // to handle_unexpected_exception way down below.
493 thread->disable_stack_red_zone();
494 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
495 }
496 }
497
498 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) {
499 // Verify that OS save/restore AVX registers.
500 stub = VM_Version::cpuinfo_cont_addr();
501 }
502
503 if (thread->thread_state() == _thread_in_vm) {
504 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
505 address next_pc = Assembler::locate_next_instruction(pc);
506 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
507 }
508 }
509
510 if (thread->thread_state() == _thread_in_Java) {
511 // Support Safepoint Polling
512 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
513 stub = SharedRuntime::get_poll_stub(pc);
514 }
515 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
516 // BugId 4454115: A read from a MappedByteBuffer can fault
517 // here if the underlying file has been truncated.
518 // Do not crash the VM in such a case.
519 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
520 if (cb != NULL) {
521 CompiledMethod* nm = cb->as_compiled_method_or_null();
522 if (nm != NULL && nm->has_unsafe_access()) {
523 address next_pc = Assembler::locate_next_instruction(pc);
524 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
525 }
526 }
527 }
528 else
529 if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
530 // integer divide by zero
531 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
532 }
533 #ifndef AMD64
534 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
535 // floating-point divide by zero
536 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
537 }
538 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
539 // The encoding of D2I in i486.ad can cause an exception prior
540 // to the fist instruction if there was an invalid operation
541 // pending. We want to dismiss that exception. From the win_32
542 // side it also seems that if it really was the fist causing
543 // the exception that we do the d2i by hand with different
544 // rounding. Seems kind of weird. QQQ TODO
545 // Note that we take the exception at the NEXT floating point instruction.
546 if (pc[0] == 0xDB) {
547 assert(pc[0] == 0xDB, "not a FIST opcode");
548 assert(pc[1] == 0x14, "not a FIST opcode");
549 assert(pc[2] == 0x24, "not a FIST opcode");
550 return true;
551 } else {
552 assert(pc[-3] == 0xDB, "not an flt invalid opcode");
553 assert(pc[-2] == 0x14, "not an flt invalid opcode");
554 assert(pc[-1] == 0x24, "not an flt invalid opcode");
555 }
556 }
557 else if (sig == SIGFPE ) {
558 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
559 }
560 #endif // !AMD64
561
562 // QQQ It doesn't seem that we need to do this on x86 because we should be able
563 // to return properly from the handler without this extra stuff on the back side.
564
565 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
566 // Determination of interpreter/vtable stub/compiled code null exception
567 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
568 }
569 }
570
571 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
572 // and the heap gets shrunk before the field access.
573 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
574 address addr = JNI_FastGetField::find_slowcase_pc(pc);
575 if (addr != (address)-1) {
576 stub = addr;
577 }
578 }
579
580 // Check to see if we caught the safepoint code in the
581 // process of write protecting the memory serialization page.
582 // It write enables the page immediately after protecting it
583 // so we can just return to retry the write.
584 if ((sig == SIGSEGV) &&
585 os::is_memory_serialize_page(thread, (address)info->si_addr)) {
586 // Block current thread until the memory serialize page permission restored.
587 os::block_on_serialize_page_trap();
588 return true;
589 }
590 }
591
592 // Execution protection violation
593 //
594 // Preventative code for future versions of Solaris which may
595 // enable execution protection when running the 32-bit VM on AMD64.
596 //
597 // This should be kept as the last step in the triage. We don't
598 // have a dedicated trap number for a no-execute fault, so be
599 // conservative and allow other handlers the first shot.
600 //
601 // Note: We don't test that info->si_code == SEGV_ACCERR here.
602 // this si_code is so generic that it is almost meaningless; and
603 // the si_code for this condition may change in the future.
604 // Furthermore, a false-positive should be harmless.
605 if (UnguardOnExecutionViolation > 0 &&
606 (sig == SIGSEGV || sig == SIGBUS) &&
607 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault
608 int page_size = os::vm_page_size();
609 address addr = (address) info->si_addr;
610 address pc = (address) uc->uc_mcontext.gregs[REG_PC];
611 // Make sure the pc and the faulting address are sane.
612 //
613 // If an instruction spans a page boundary, and the page containing
614 // the beginning of the instruction is executable but the following
615 // page is not, the pc and the faulting address might be slightly
616 // different - we still want to unguard the 2nd page in this case.
617 //
618 // 15 bytes seems to be a (very) safe value for max instruction size.
619 bool pc_is_near_addr =
620 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
621 bool instr_spans_page_boundary =
622 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
623 (intptr_t) page_size) > 0);
624
625 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
626 static volatile address last_addr =
627 (address) os::non_memory_address_word();
628
629 // In conservative mode, don't unguard unless the address is in the VM
630 if (addr != last_addr &&
631 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
632
633 // Make memory rwx and retry
634 address page_start =
635 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
636 bool res = os::protect_memory((char*) page_start, page_size,
637 os::MEM_PROT_RWX);
638
639 log_debug(os)("Execution protection violation "
640 "at " INTPTR_FORMAT
641 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr),
642 p2i(page_start), (res ? "success" : "failed"), errno);
643 stub = pc;
644
645 // Set last_addr so if we fault again at the same address, we don't end
646 // up in an endless loop.
647 //
648 // There are two potential complications here. Two threads trapping at
649 // the same address at the same time could cause one of the threads to
650 // think it already unguarded, and abort the VM. Likely very rare.
651 //
652 // The other race involves two threads alternately trapping at
653 // different addresses and failing to unguard the page, resulting in
654 // an endless loop. This condition is probably even more unlikely than
655 // the first.
656 //
657 // Although both cases could be avoided by using locks or thread local
658 // last_addr, these solutions are unnecessary complication: this
659 // handler is a best-effort safety net, not a complete solution. It is
660 // disabled by default and should only be used as a workaround in case
661 // we missed any no-execute-unsafe VM code.
662
663 last_addr = addr;
664 }
665 }
666 }
667
668 if (stub != NULL) {
669 // save all thread context in case we need to restore it
670
671 if (thread != NULL) thread->set_saved_exception_pc(pc);
672 // 12/02/99: On Sparc it appears that the full context is also saved
673 // but as yet, no one looks at or restores that saved context
674 os::Solaris::ucontext_set_pc(uc, stub);
675 return true;
676 }
677
678 // signal-chaining
679 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
680 return true;
681 }
682
683 #ifndef AMD64
684 // Workaround (bug 4900493) for Solaris kernel bug 4966651.
685 // Handle an undefined selector caused by an attempt to assign
686 // fs in libthread getipriptr(). With the current libthread design every 512
687 // thread creations the LDT for a private thread data structure is extended
688 // and thre is a hazard that and another thread attempting a thread creation
689 // will use a stale LDTR that doesn't reflect the structure's growth,
690 // causing a GP fault.
691 // Enforce the probable limit of passes through here to guard against an
692 // infinite loop if some other move to fs caused the GP fault. Note that
693 // this loop counter is ultimately a heuristic as it is possible for
694 // more than one thread to generate this fault at a time in an MP system.
695 // In the case of the loop count being exceeded or if the poll fails
696 // just fall through to a fatal error.
697 // If there is some other source of T_GPFLT traps and the text at EIP is
698 // unreadable this code will loop infinitely until the stack is exausted.
699 // The key to diagnosis in this case is to look for the bottom signal handler
700 // frame.
701
702 if(! IgnoreLibthreadGPFault) {
703 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
704 const unsigned char *p =
705 (unsigned const char *) uc->uc_mcontext.gregs[EIP];
706
707 // Expected instruction?
708
709 if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
710
711 Atomic::inc(&ldtr_refresh);
712
713 // Infinite loop?
714
715 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
716
717 // No, force scheduling to get a fresh view of the LDTR
718
719 if(poll(NULL, 0, 10) == 0) {
720
721 // Retry the move
722
723 return false;
724 }
725 }
726 }
727 }
728 }
729 #endif // !AMD64
730
731 if (!abort_if_unrecognized) {
732 // caller wants another chance, so give it to him
733 return false;
734 }
735
736 if (!os::Solaris::libjsig_is_loaded) {
737 struct sigaction oldAct;
738 sigaction(sig, (struct sigaction *)0, &oldAct);
739 if (oldAct.sa_sigaction != signalHandler) {
740 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
741 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
742 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
743 }
744 }
745
746 if (pc == NULL && uc != NULL) {
747 pc = (address) uc->uc_mcontext.gregs[REG_PC];
748 }
749
750 // unmask current signal
751 sigset_t newset;
752 sigemptyset(&newset);
753 sigaddset(&newset, sig);
754 sigprocmask(SIG_UNBLOCK, &newset, NULL);
755
756 // Determine which sort of error to throw. Out of swap may signal
757 // on the thread stack, which could get a mapping error when touched.
758 address addr = (address) info->si_addr;
759 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
760 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
761 }
762
763 VMError::report_and_die(t, sig, pc, info, ucVoid);
764
765 ShouldNotReachHere();
766 return false;
767 }
768
769 void os::print_context(outputStream *st, const void *context) {
770 if (context == NULL) return;
771
772 const ucontext_t *uc = (const ucontext_t*)context;
773 st->print_cr("Registers:");
774 #ifdef AMD64
775 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
776 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
777 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
778 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
779 st->cr();
780 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
781 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
782 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
783 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
784 st->cr();
785 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
786 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
787 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
788 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
789 st->cr();
790 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
791 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
792 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
793 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
794 st->cr();
795 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
796 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
797 #else
798 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
799 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
800 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
801 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
802 st->cr();
803 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
804 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
805 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
806 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
807 st->cr();
808 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
809 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
810 #endif // AMD64
811 st->cr();
812 st->cr();
813
814 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
815 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
816 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
817 st->cr();
818
819 // Note: it may be unsafe to inspect memory near pc. For example, pc may
820 // point to garbage if entry point in an nmethod is corrupted. Leave
821 // this at the end, and hope for the best.
822 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
823 address pc = epc.pc();
824 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
825 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
826 }
827
828 void os::print_register_info(outputStream *st, const void *context) {
829 if (context == NULL) return;
830
831 const ucontext_t *uc = (const ucontext_t*)context;
832
833 st->print_cr("Register to memory mapping:");
834 st->cr();
835
836 // this is horrendously verbose but the layout of the registers in the
837 // context does not match how we defined our abstract Register set, so
838 // we can't just iterate through the gregs area
839
840 // this is only for the "general purpose" registers
841
842 #ifdef AMD64
843 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
844 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
845 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
846 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
847 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
848 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
849 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
850 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
851 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
852 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
853 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
854 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
855 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
856 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
857 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
858 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
859 #else
860 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
861 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
862 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
863 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
864 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
865 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
866 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
867 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
868 #endif
869
870 st->cr();
871 }
872
873
874 #ifdef AMD64
875 void os::Solaris::init_thread_fpu_state(void) {
876 // Nothing to do
877 }
878 #else
879 // From solaris_i486.s
880 extern "C" void fixcw();
881
882 void os::Solaris::init_thread_fpu_state(void) {
883 // Set fpu to 53 bit precision. This happens too early to use a stub.
884 fixcw();
885 }
886
887 // These routines are the initial value of atomic_xchg_entry(),
888 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
889 // until initialization is complete.
890 // TODO - replace with .il implementation when compiler supports it.
891
892 typedef jint xchg_func_t (jint, volatile jint*);
893 typedef jint cmpxchg_func_t (jint, volatile jint*, jint);
894 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
895 typedef jint add_func_t (jint, volatile jint*);
896
897 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
898 // try to use the stub:
899 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
900
901 if (func != NULL) {
902 os::atomic_xchg_func = func;
903 return (*func)(exchange_value, dest);
904 }
905 assert(Threads::number_of_threads() == 0, "for bootstrap only");
906
907 jint old_value = *dest;
908 *dest = exchange_value;
909 return old_value;
910 }
911
912 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
913 // try to use the stub:
914 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
915
916 if (func != NULL) {
917 os::atomic_cmpxchg_func = func;
918 return (*func)(exchange_value, dest, compare_value);
919 }
920 assert(Threads::number_of_threads() == 0, "for bootstrap only");
921
922 jint old_value = *dest;
923 if (old_value == compare_value)
924 *dest = exchange_value;
925 return old_value;
926 }
927
928 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
929 // try to use the stub:
930 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
931
932 if (func != NULL) {
933 os::atomic_cmpxchg_long_func = func;
934 return (*func)(exchange_value, dest, compare_value);
935 }
936 assert(Threads::number_of_threads() == 0, "for bootstrap only");
937
938 jlong old_value = *dest;
939 if (old_value == compare_value)
940 *dest = exchange_value;
941 return old_value;
942 }
943
944 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
945 // try to use the stub:
946 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
947
948 if (func != NULL) {
949 os::atomic_add_func = func;
950 return (*func)(add_value, dest);
951 }
952 assert(Threads::number_of_threads() == 0, "for bootstrap only");
953
954 return (*dest) += add_value;
955 }
956
957 xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap;
958 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap;
959 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
960 add_func_t* os::atomic_add_func = os::atomic_add_bootstrap;
961
962 extern "C" void _solaris_raw_setup_fpu(address ptr);
963 void os::setup_fpu() {
964 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
965 _solaris_raw_setup_fpu(fpu_cntrl);
966 }
967 #endif // AMD64
968
969 #ifndef PRODUCT
970 void os::verify_stack_alignment() {
971 #ifdef AMD64
972 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
973 #endif
974 }
975 #endif
976
977 int os::extra_bang_size_in_bytes() {
978 // JDK-8050147 requires the full cache line bang for x86.
979 return VM_Version::L1_line_size();
980 }