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 "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.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 <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 usable stack sizes required to get to user code. Space for
90 // HotSpot guard pages is added later.
91 #ifdef _LP64
92 size_t os::Posix::_compiler_thread_min_stack_allowed = 202 * K;
93 size_t os::Posix::_java_thread_min_stack_allowed = 48 * K;
94 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 224 * K;
95 #else
96 size_t os::Posix::_compiler_thread_min_stack_allowed = 32 * K;
97 size_t os::Posix::_java_thread_min_stack_allowed = 32 * K;
98 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
99 #endif // _LP64
100
101 #ifdef AMD64
102 #define REG_SP REG_RSP
103 #define REG_PC REG_RIP
104 #define REG_FP REG_RBP
105 #else
106 #define REG_SP UESP
107 #define REG_PC EIP
108 #define REG_FP EBP
109 // 4900493 counter to prevent runaway LDTR refresh attempt
110
111 static volatile int ldtr_refresh = 0;
112 // the libthread instruction that faults because of the stale LDTR
113
114 static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs
115 };
116 #endif // AMD64
117
118 char* os::non_memory_address_word() {
119 // Must never look like an address returned by reserve_memory,
120 // even in its subfields (as defined by the CPU immediate fields,
121 // if the CPU splits constants across multiple instructions).
122 return (char*) -1;
123 }
124
125 //
126 // Validate a ucontext retrieved from walking a uc_link of a ucontext.
127 // There are issues with libthread giving out uc_links for different threads
128 // on the same uc_link chain and bad or circular links.
129 //
130 bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) {
131 if (valid >= suspect ||
132 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
133 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp ||
134 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) {
135 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)
136 return false;
137 }
138
139 if (thread->is_Java_thread()) {
140 if (!valid_stack_address(thread, (address)suspect)) {
141 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)
142 return false;
143 }
144 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) {
145 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)
146 return false;
147 }
148 }
149 return true;
150 }
151
152 // We will only follow one level of uc_link since there are libthread
153 // issues with ucontext linking and it is better to be safe and just
154 // let caller retry later.
155 const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
156 const ucontext_t *uc) {
157
158 const ucontext_t *retuc = NULL;
159
160 if (uc != NULL) {
161 if (uc->uc_link == NULL) {
162 // cannot validate without uc_link so accept current ucontext
163 retuc = uc;
164 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
165 // first ucontext is valid so try the next one
166 uc = uc->uc_link;
167 if (uc->uc_link == NULL) {
168 // cannot validate without uc_link so accept current ucontext
169 retuc = uc;
170 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
171 // the ucontext one level down is also valid so return it
172 retuc = uc;
173 }
174 }
175 }
176 return retuc;
177 }
178
179 // Assumes ucontext is valid
180 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) {
181 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]);
182 }
183
184 void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) {
185 uc->uc_mcontext.gregs [REG_PC] = (greg_t) pc;
186 }
187
188 // Assumes ucontext is valid
189 intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {
190 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
191 }
192
193 // Assumes ucontext is valid
194 intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {
195 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
196 }
197
198 address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {
199 return (address) uc->uc_mcontext.gregs[REG_PC];
200 }
201
202 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
203 // is currently interrupted by SIGPROF.
204 //
205 // The difference between this and os::fetch_frame_from_context() is that
206 // here we try to skip nested signal frames.
207 // This method is also used for stack overflow signal handling.
208 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
209 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
210
211 assert(thread != NULL, "just checking");
212 assert(ret_sp != NULL, "just checking");
213 assert(ret_fp != NULL, "just checking");
214
215 const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
216 return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
217 }
218
219 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
220 intptr_t** ret_sp, intptr_t** ret_fp) {
221
222 ExtendedPC epc;
223 const ucontext_t *uc = (const ucontext_t*)ucVoid;
224
225 if (uc != NULL) {
226 epc = os::Solaris::ucontext_get_ExtendedPC(uc);
227 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
228 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc);
229 } else {
230 // construct empty ExtendedPC for return value checking
231 epc = ExtendedPC(NULL);
232 if (ret_sp) *ret_sp = (intptr_t *)NULL;
233 if (ret_fp) *ret_fp = (intptr_t *)NULL;
234 }
235
236 return epc;
237 }
238
239 frame os::fetch_frame_from_context(const void* ucVoid) {
240 intptr_t* sp;
241 intptr_t* fp;
242 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
243 return frame(sp, fp, epc.pc());
244 }
245
246 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
247 intptr_t* sp;
248 intptr_t* fp;
249 ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp);
250 return frame(sp, fp, epc.pc());
251 }
252
253 bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
254 address pc = (address) os::Solaris::ucontext_get_pc(uc);
255 if (Interpreter::contains(pc)) {
256 // interpreter performs stack banging after the fixed frame header has
257 // been generated while the compilers perform it before. To maintain
258 // semantic consistency between interpreted and compiled frames, the
259 // method returns the Java sender of the current frame.
260 *fr = os::fetch_frame_from_ucontext(thread, uc);
261 if (!fr->is_first_java_frame()) {
262 // get_frame_at_stack_banging_point() is only called when we
263 // have well defined stacks so java_sender() calls do not need
264 // to assert safe_for_sender() first.
265 *fr = fr->java_sender();
266 }
267 } else {
268 // more complex code with compiled code
269 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
270 CodeBlob* cb = CodeCache::find_blob(pc);
271 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
272 // Not sure where the pc points to, fallback to default
273 // stack overflow handling
274 return false;
275 } else {
276 // in compiled code, the stack banging is performed just after the return pc
277 // has been pushed on the stack
278 intptr_t* fp = os::Solaris::ucontext_get_fp(uc);
279 intptr_t* sp = os::Solaris::ucontext_get_sp(uc);
280 *fr = frame(sp + 1, fp, (address)*sp);
281 if (!fr->is_java_frame()) {
282 // See java_sender() comment above.
283 *fr = fr->java_sender();
284 }
285 }
286 }
287 assert(fr->is_java_frame(), "Safety check");
288 return true;
289 }
290
291 frame os::get_sender_for_C_frame(frame* fr) {
292 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
293 }
294
295 extern "C" intptr_t *_get_current_sp(); // in .il file
296
297 address os::current_stack_pointer() {
298 return (address)_get_current_sp();
299 }
300
301 extern "C" intptr_t *_get_current_fp(); // in .il file
302
303 frame os::current_frame() {
304 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp
305 // fp is for os::current_frame. We want the fp for our caller.
306 frame myframe((intptr_t*)os::current_stack_pointer(),
307 (intptr_t*)fp,
308 CAST_FROM_FN_PTR(address, os::current_frame));
309 frame caller_frame = os::get_sender_for_C_frame(&myframe);
310
311 if (os::is_first_C_frame(&caller_frame)) {
312 // stack is not walkable
313 frame ret; // This will be a null useless frame
314 return ret;
315 } else {
316 // return frame for our caller's caller
317 return os::get_sender_for_C_frame(&caller_frame);
318 }
319 }
320
321 #ifndef AMD64
322
323 // Detecting SSE support by OS
324 // From solaris_i486.s
325 extern "C" bool sse_check();
326 extern "C" bool sse_unavailable();
327
328 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};
329 static int sse_status = SSE_UNKNOWN;
330
331
332 static void check_for_sse_support() {
333 if (!VM_Version::supports_sse()) {
334 sse_status = SSE_NOT_SUPPORTED;
335 return;
336 }
337 // looking for _sse_hw in libc.so, if it does not exist or
338 // the value (int) is 0, OS has no support for SSE
339 int *sse_hwp;
340 void *h;
341
342 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {
343 //open failed, presume no support for SSE
344 sse_status = SSE_NOT_SUPPORTED;
345 return;
346 }
347 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {
348 sse_status = SSE_NOT_SUPPORTED;
349 } else if (*sse_hwp == 0) {
350 sse_status = SSE_NOT_SUPPORTED;
351 }
352 dlclose(h);
353
354 if (sse_status == SSE_UNKNOWN) {
355 bool (*try_sse)() = (bool (*)())sse_check;
356 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;
357 }
358
359 }
360
361 #endif // AMD64
362
363 bool os::supports_sse() {
364 #ifdef AMD64
365 return true;
366 #else
367 if (sse_status == SSE_UNKNOWN)
368 check_for_sse_support();
369 return sse_status == SSE_SUPPORTED;
370 #endif // AMD64
371 }
372
373 bool os::is_allocatable(size_t bytes) {
374 #ifdef AMD64
375 return true;
376 #else
377
378 if (bytes < 2 * G) {
379 return true;
380 }
381
382 char* addr = reserve_memory(bytes, NULL);
383
384 if (addr != NULL) {
385 release_memory(addr, bytes);
386 }
387
388 return addr != NULL;
389 #endif // AMD64
390
391 }
392
393 extern "C" JNIEXPORT int
394 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
395 int abort_if_unrecognized) {
396 ucontext_t* uc = (ucontext_t*) ucVoid;
397
398 #ifndef AMD64
399 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
400 // the SSE instruction faulted. supports_sse() need return false.
401 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
402 return true;
403 }
404 #endif // !AMD64
405
406 Thread* t = Thread::current_or_null_safe();
407
408 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
409 // (no destructors can be run)
410 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
411
412 SignalHandlerMark shm(t);
413
414 if(sig == SIGPIPE || sig == SIGXFSZ) {
415 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
416 return true;
417 } else {
418 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
419 return true;
420 }
421 }
422
423 JavaThread* thread = NULL;
424 VMThread* vmthread = NULL;
425
426 if (os::Solaris::signal_handlers_are_installed) {
427 if (t != NULL ){
428 if(t->is_Java_thread()) {
429 thread = (JavaThread*)t;
430 }
431 else if(t->is_VM_thread()){
432 vmthread = (VMThread *)t;
433 }
434 }
435 }
436
437 if (sig == os::Solaris::SIGasync()) {
438 if(thread || vmthread){
439 OSThread::SR_handler(t, uc);
440 return true;
441 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
442 return true;
443 } else {
444 // If os::Solaris::SIGasync not chained, and this is a non-vm and
445 // non-java thread
446 return true;
447 }
448 }
449
450 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
451 // can't decode this kind of signal
452 info = NULL;
453 } else {
454 assert(sig == info->si_signo, "bad siginfo");
455 }
456
457 // decide if this trap can be handled by a stub
458 address stub = NULL;
459
460 address pc = NULL;
461
462 //%note os_trap_1
463 if (info != NULL && uc != NULL && thread != NULL) {
464 // factor me: getPCfromContext
465 pc = (address) uc->uc_mcontext.gregs[REG_PC];
466
467 if (StubRoutines::is_safefetch_fault(pc)) {
468 os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
469 return true;
470 }
471
472 // Handle ALL stack overflow variations here
473 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
474 address addr = (address) info->si_addr;
475 if (thread->in_stack_yellow_reserved_zone(addr)) {
476 if (thread->thread_state() == _thread_in_Java) {
477 if (thread->in_stack_reserved_zone(addr)) {
478 frame fr;
479 if (os::Solaris::get_frame_at_stack_banging_point(thread, uc, &fr)) {
480 assert(fr.is_java_frame(), "Must be Java frame");
481 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
482 if (activation.sp() != NULL) {
483 thread->disable_stack_reserved_zone();
484 if (activation.is_interpreted_frame()) {
485 thread->set_reserved_stack_activation((address)(
486 activation.fp() + frame::interpreter_frame_initial_sp_offset));
487 } else {
488 thread->set_reserved_stack_activation((address)activation.unextended_sp());
489 }
490 return true;
491 }
492 }
493 }
494 // Throw a stack overflow exception. Guard pages will be reenabled
495 // while unwinding the stack.
496 thread->disable_stack_yellow_reserved_zone();
497 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
498 } else {
499 // Thread was in the vm or native code. Return and try to finish.
500 thread->disable_stack_yellow_reserved_zone();
501 return true;
502 }
503 } else if (thread->in_stack_red_zone(addr)) {
504 // Fatal red zone violation. Disable the guard pages and fall through
505 // to handle_unexpected_exception way down below.
506 thread->disable_stack_red_zone();
507 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
508 }
509 }
510
511 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) {
512 // Verify that OS save/restore AVX registers.
513 stub = VM_Version::cpuinfo_cont_addr();
514 }
515
516 if (thread->thread_state() == _thread_in_vm) {
517 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
518 address next_pc = Assembler::locate_next_instruction(pc);
519 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
520 }
521 }
522
523 if (thread->thread_state() == _thread_in_Java) {
524 // Support Safepoint Polling
525 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
526 stub = SharedRuntime::get_poll_stub(pc);
527 }
528 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
529 // BugId 4454115: A read from a MappedByteBuffer can fault
530 // here if the underlying file has been truncated.
531 // Do not crash the VM in such a case.
532 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
533 if (cb != NULL) {
534 CompiledMethod* nm = cb->as_compiled_method_or_null();
535 if (nm != NULL && nm->has_unsafe_access()) {
536 address next_pc = Assembler::locate_next_instruction(pc);
537 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
538 }
539 }
540 }
541 else
542 if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
543 // integer divide by zero
544 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
545 }
546 #ifndef AMD64
547 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
548 // floating-point divide by zero
549 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
550 }
551 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
552 // The encoding of D2I in i486.ad can cause an exception prior
553 // to the fist instruction if there was an invalid operation
554 // pending. We want to dismiss that exception. From the win_32
555 // side it also seems that if it really was the fist causing
556 // the exception that we do the d2i by hand with different
557 // rounding. Seems kind of weird. QQQ TODO
558 // Note that we take the exception at the NEXT floating point instruction.
559 if (pc[0] == 0xDB) {
560 assert(pc[0] == 0xDB, "not a FIST opcode");
561 assert(pc[1] == 0x14, "not a FIST opcode");
562 assert(pc[2] == 0x24, "not a FIST opcode");
563 return true;
564 } else {
565 assert(pc[-3] == 0xDB, "not an flt invalid opcode");
566 assert(pc[-2] == 0x14, "not an flt invalid opcode");
567 assert(pc[-1] == 0x24, "not an flt invalid opcode");
568 }
569 }
570 else if (sig == SIGFPE ) {
571 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
572 }
573 #endif // !AMD64
574
575 // QQQ It doesn't seem that we need to do this on x86 because we should be able
576 // to return properly from the handler without this extra stuff on the back side.
577
578 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
579 // Determination of interpreter/vtable stub/compiled code null exception
580 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
581 }
582 }
583
584 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
585 // and the heap gets shrunk before the field access.
586 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
587 address addr = JNI_FastGetField::find_slowcase_pc(pc);
588 if (addr != (address)-1) {
589 stub = addr;
590 }
591 }
592
593 // Check to see if we caught the safepoint code in the
594 // process of write protecting the memory serialization page.
595 // It write enables the page immediately after protecting it
596 // so we can just return to retry the write.
597 if ((sig == SIGSEGV) &&
598 os::is_memory_serialize_page(thread, (address)info->si_addr)) {
599 // Block current thread until the memory serialize page permission restored.
600 os::block_on_serialize_page_trap();
601 return true;
602 }
603 }
604
605 // Execution protection violation
606 //
607 // Preventative code for future versions of Solaris which may
608 // enable execution protection when running the 32-bit VM on AMD64.
609 //
610 // This should be kept as the last step in the triage. We don't
611 // have a dedicated trap number for a no-execute fault, so be
612 // conservative and allow other handlers the first shot.
613 //
614 // Note: We don't test that info->si_code == SEGV_ACCERR here.
615 // this si_code is so generic that it is almost meaningless; and
616 // the si_code for this condition may change in the future.
617 // Furthermore, a false-positive should be harmless.
618 if (UnguardOnExecutionViolation > 0 &&
619 (sig == SIGSEGV || sig == SIGBUS) &&
620 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault
621 int page_size = os::vm_page_size();
622 address addr = (address) info->si_addr;
623 address pc = (address) uc->uc_mcontext.gregs[REG_PC];
624 // Make sure the pc and the faulting address are sane.
625 //
626 // If an instruction spans a page boundary, and the page containing
627 // the beginning of the instruction is executable but the following
628 // page is not, the pc and the faulting address might be slightly
629 // different - we still want to unguard the 2nd page in this case.
630 //
631 // 15 bytes seems to be a (very) safe value for max instruction size.
632 bool pc_is_near_addr =
633 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
634 bool instr_spans_page_boundary =
635 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
636 (intptr_t) page_size) > 0);
637
638 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
639 static volatile address last_addr =
640 (address) os::non_memory_address_word();
641
642 // In conservative mode, don't unguard unless the address is in the VM
643 if (addr != last_addr &&
644 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
645
646 // Make memory rwx and retry
647 address page_start =
648 (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
649 bool res = os::protect_memory((char*) page_start, page_size,
650 os::MEM_PROT_RWX);
651
652 log_debug(os)("Execution protection violation "
653 "at " INTPTR_FORMAT
654 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr),
655 p2i(page_start), (res ? "success" : "failed"), errno);
656 stub = pc;
657
658 // Set last_addr so if we fault again at the same address, we don't end
659 // up in an endless loop.
660 //
661 // There are two potential complications here. Two threads trapping at
662 // the same address at the same time could cause one of the threads to
663 // think it already unguarded, and abort the VM. Likely very rare.
664 //
665 // The other race involves two threads alternately trapping at
666 // different addresses and failing to unguard the page, resulting in
667 // an endless loop. This condition is probably even more unlikely than
668 // the first.
669 //
670 // Although both cases could be avoided by using locks or thread local
671 // last_addr, these solutions are unnecessary complication: this
672 // handler is a best-effort safety net, not a complete solution. It is
673 // disabled by default and should only be used as a workaround in case
674 // we missed any no-execute-unsafe VM code.
675
676 last_addr = addr;
677 }
678 }
679 }
680
681 if (stub != NULL) {
682 // save all thread context in case we need to restore it
683
684 if (thread != NULL) thread->set_saved_exception_pc(pc);
685 // 12/02/99: On Sparc it appears that the full context is also saved
686 // but as yet, no one looks at or restores that saved context
687 os::Solaris::ucontext_set_pc(uc, stub);
688 return true;
689 }
690
691 // signal-chaining
692 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
693 return true;
694 }
695
696 #ifndef AMD64
697 // Workaround (bug 4900493) for Solaris kernel bug 4966651.
698 // Handle an undefined selector caused by an attempt to assign
699 // fs in libthread getipriptr(). With the current libthread design every 512
700 // thread creations the LDT for a private thread data structure is extended
701 // and thre is a hazard that and another thread attempting a thread creation
702 // will use a stale LDTR that doesn't reflect the structure's growth,
703 // causing a GP fault.
704 // Enforce the probable limit of passes through here to guard against an
705 // infinite loop if some other move to fs caused the GP fault. Note that
706 // this loop counter is ultimately a heuristic as it is possible for
707 // more than one thread to generate this fault at a time in an MP system.
708 // In the case of the loop count being exceeded or if the poll fails
709 // just fall through to a fatal error.
710 // If there is some other source of T_GPFLT traps and the text at EIP is
711 // unreadable this code will loop infinitely until the stack is exausted.
712 // The key to diagnosis in this case is to look for the bottom signal handler
713 // frame.
714
715 if(! IgnoreLibthreadGPFault) {
716 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
717 const unsigned char *p =
718 (unsigned const char *) uc->uc_mcontext.gregs[EIP];
719
720 // Expected instruction?
721
722 if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
723
724 Atomic::inc(&ldtr_refresh);
725
726 // Infinite loop?
727
728 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
729
730 // No, force scheduling to get a fresh view of the LDTR
731
732 if(poll(NULL, 0, 10) == 0) {
733
734 // Retry the move
735
736 return false;
737 }
738 }
739 }
740 }
741 }
742 #endif // !AMD64
743
744 if (!abort_if_unrecognized) {
745 // caller wants another chance, so give it to him
746 return false;
747 }
748
749 if (!os::Solaris::libjsig_is_loaded) {
750 struct sigaction oldAct;
751 sigaction(sig, (struct sigaction *)0, &oldAct);
752 if (oldAct.sa_sigaction != signalHandler) {
753 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
754 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
755 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
756 }
757 }
758
759 if (pc == NULL && uc != NULL) {
760 pc = (address) uc->uc_mcontext.gregs[REG_PC];
761 }
762
763 // unmask current signal
764 sigset_t newset;
765 sigemptyset(&newset);
766 sigaddset(&newset, sig);
767 sigprocmask(SIG_UNBLOCK, &newset, NULL);
768
769 // Determine which sort of error to throw. Out of swap may signal
770 // on the thread stack, which could get a mapping error when touched.
771 address addr = (address) info->si_addr;
772 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
773 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
774 }
775
776 VMError::report_and_die(t, sig, pc, info, ucVoid);
777
778 ShouldNotReachHere();
779 return false;
780 }
781
782 void os::print_context(outputStream *st, const void *context) {
783 if (context == NULL) return;
784
785 const ucontext_t *uc = (const ucontext_t*)context;
786 st->print_cr("Registers:");
787 #ifdef AMD64
788 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
789 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
790 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
791 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
792 st->cr();
793 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
794 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
795 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
796 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
797 st->cr();
798 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
799 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
800 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
801 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
802 st->cr();
803 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
804 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
805 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
806 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
807 st->cr();
808 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
809 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
810 #else
811 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
812 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
813 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
814 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
815 st->cr();
816 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
817 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
818 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
819 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
820 st->cr();
821 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
822 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
823 #endif // AMD64
824 st->cr();
825 st->cr();
826
827 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
828 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
829 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
830 st->cr();
831
832 // Note: it may be unsafe to inspect memory near pc. For example, pc may
833 // point to garbage if entry point in an nmethod is corrupted. Leave
834 // this at the end, and hope for the best.
835 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
836 address pc = epc.pc();
837 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
838 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
839 }
840
841 void os::print_register_info(outputStream *st, const void *context) {
842 if (context == NULL) return;
843
844 const ucontext_t *uc = (const ucontext_t*)context;
845
846 st->print_cr("Register to memory mapping:");
847 st->cr();
848
849 // this is horrendously verbose but the layout of the registers in the
850 // context does not match how we defined our abstract Register set, so
851 // we can't just iterate through the gregs area
852
853 // this is only for the "general purpose" registers
854
855 #ifdef AMD64
856 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
857 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
858 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
859 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
860 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
861 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
862 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
863 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
864 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
865 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
866 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
867 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
868 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
869 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
870 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
871 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
872 #else
873 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
874 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
875 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
876 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
877 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
878 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
879 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
880 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
881 #endif
882
883 st->cr();
884 }
885
886
887 #ifdef AMD64
888 void os::Solaris::init_thread_fpu_state(void) {
889 // Nothing to do
890 }
891 #else
892 // From solaris_i486.s
893 extern "C" void fixcw();
894
895 void os::Solaris::init_thread_fpu_state(void) {
896 // Set fpu to 53 bit precision. This happens too early to use a stub.
897 fixcw();
898 }
899
900 // These routines are the initial value of atomic_xchg_entry(),
901 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
902 // until initialization is complete.
903 // TODO - replace with .il implementation when compiler supports it.
904
905 typedef jint xchg_func_t (jint, volatile jint*);
906 typedef jint cmpxchg_func_t (jint, volatile jint*, jint);
907 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
908 typedef jint add_func_t (jint, volatile jint*);
909
910 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
911 // try to use the stub:
912 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
913
914 if (func != NULL) {
915 os::atomic_xchg_func = func;
916 return (*func)(exchange_value, dest);
917 }
918 assert(Threads::number_of_threads() == 0, "for bootstrap only");
919
920 jint old_value = *dest;
921 *dest = exchange_value;
922 return old_value;
923 }
924
925 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
926 // try to use the stub:
927 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
928
929 if (func != NULL) {
930 os::atomic_cmpxchg_func = func;
931 return (*func)(exchange_value, dest, compare_value);
932 }
933 assert(Threads::number_of_threads() == 0, "for bootstrap only");
934
935 jint old_value = *dest;
936 if (old_value == compare_value)
937 *dest = exchange_value;
938 return old_value;
939 }
940
941 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
942 // try to use the stub:
943 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
944
945 if (func != NULL) {
946 os::atomic_cmpxchg_long_func = func;
947 return (*func)(exchange_value, dest, compare_value);
948 }
949 assert(Threads::number_of_threads() == 0, "for bootstrap only");
950
951 jlong old_value = *dest;
952 if (old_value == compare_value)
953 *dest = exchange_value;
954 return old_value;
955 }
956
957 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
958 // try to use the stub:
959 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
960
961 if (func != NULL) {
962 os::atomic_add_func = func;
963 return (*func)(add_value, dest);
964 }
965 assert(Threads::number_of_threads() == 0, "for bootstrap only");
966
967 return (*dest) += add_value;
968 }
969
970 xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap;
971 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap;
972 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
973 add_func_t* os::atomic_add_func = os::atomic_add_bootstrap;
974
975 extern "C" void _solaris_raw_setup_fpu(address ptr);
976 void os::setup_fpu() {
977 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
978 _solaris_raw_setup_fpu(fpu_cntrl);
979 }
980 #endif // AMD64
981
982 #ifndef PRODUCT
983 void os::verify_stack_alignment() {
984 #ifdef AMD64
985 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
986 #endif
987 }
988 #endif
989
990 int os::extra_bang_size_in_bytes() {
991 // JDK-8050147 requires the full cache line bang for x86.
992 return VM_Version::L1_line_size();
993 }