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