1 /*
2 * Copyright (c) 1999, 2017, 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 "jvm.h"
27 #include "asm/macroAssembler.hpp"
28 #include "classfile/classLoader.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/codeCache.hpp"
32 #include "code/icBuffer.hpp"
33 #include "code/vtableStubs.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "logging/log.hpp"
36 #include "memory/allocation.inline.hpp"
37 #include "os_share_solaris.hpp"
38 #include "prims/jniFastGetField.hpp"
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.inline.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/align.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 usable stack sizes required to get to user code. Space for
91 // HotSpot guard pages is added later.
92 #ifdef _LP64
93 // The adlc generated method 'State::MachNodeGenerator(int)' used by the C2 compiler
94 // threads requires a large stack with the Solaris Studio C++ compiler version 5.13
95 // and product VM builds (debug builds require significantly less stack space).
96 size_t os::Posix::_compiler_thread_min_stack_allowed = 325 * K;
97 size_t os::Posix::_java_thread_min_stack_allowed = 48 * K;
98 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 224 * K;
99 #else
100 size_t os::Posix::_compiler_thread_min_stack_allowed = 32 * K;
101 size_t os::Posix::_java_thread_min_stack_allowed = 32 * K;
102 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
103 #endif // _LP64
104
105 #ifdef AMD64
106 #define REG_SP REG_RSP
107 #define REG_PC REG_RIP
108 #define REG_FP REG_RBP
109 #else
110 #define REG_SP UESP
111 #define REG_PC EIP
112 #define REG_FP EBP
113 // 4900493 counter to prevent runaway LDTR refresh attempt
114
115 static volatile int ldtr_refresh = 0;
116 // the libthread instruction that faults because of the stale LDTR
117
118 static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs
119 };
120 #endif // AMD64
121
122 char* os::non_memory_address_word() {
123 // Must never look like an address returned by reserve_memory,
124 // even in its subfields (as defined by the CPU immediate fields,
125 // if the CPU splits constants across multiple instructions).
126 return (char*) -1;
127 }
128
129 //
130 // Validate a ucontext retrieved from walking a uc_link of a ucontext.
131 // There are issues with libthread giving out uc_links for different threads
132 // on the same uc_link chain and bad or circular links.
133 //
134 bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) {
135 if (valid >= suspect ||
136 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
137 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp ||
138 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) {
139 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)
140 return false;
141 }
142
143 if (thread->is_Java_thread()) {
144 if (!valid_stack_address(thread, (address)suspect)) {
145 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)
146 return false;
147 }
148 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) {
149 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)
150 return false;
151 }
152 }
153 return true;
154 }
155
156 // We will only follow one level of uc_link since there are libthread
157 // issues with ucontext linking and it is better to be safe and just
158 // let caller retry later.
159 const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
160 const ucontext_t *uc) {
161
162 const ucontext_t *retuc = NULL;
163
164 if (uc != NULL) {
165 if (uc->uc_link == NULL) {
166 // cannot validate without uc_link so accept current ucontext
167 retuc = uc;
168 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
169 // first ucontext is valid so try the next one
170 uc = uc->uc_link;
171 if (uc->uc_link == NULL) {
172 // cannot validate without uc_link so accept current ucontext
173 retuc = uc;
174 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
175 // the ucontext one level down is also valid so return it
176 retuc = uc;
177 }
178 }
179 }
180 return retuc;
181 }
182
183 // Assumes ucontext is valid
184 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) {
185 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]);
186 }
187
188 void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) {
189 uc->uc_mcontext.gregs [REG_PC] = (greg_t) pc;
190 }
191
192 // Assumes ucontext is valid
193 intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {
194 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
195 }
196
197 // Assumes ucontext is valid
198 intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {
199 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
200 }
201
202 address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {
203 return (address) uc->uc_mcontext.gregs[REG_PC];
204 }
205
206 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
207 // is currently interrupted by SIGPROF.
208 //
209 // The difference between this and os::fetch_frame_from_context() is that
210 // here we try to skip nested signal frames.
211 // This method is also used for stack overflow signal handling.
212 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
213 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
214
215 assert(thread != NULL, "just checking");
216 assert(ret_sp != NULL, "just checking");
217 assert(ret_fp != NULL, "just checking");
218
219 const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
220 return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
221 }
222
223 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
224 intptr_t** ret_sp, intptr_t** ret_fp) {
225
226 ExtendedPC epc;
227 const ucontext_t *uc = (const ucontext_t*)ucVoid;
228
229 if (uc != NULL) {
230 epc = os::Solaris::ucontext_get_ExtendedPC(uc);
231 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
232 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc);
233 } else {
234 // construct empty ExtendedPC for return value checking
235 epc = ExtendedPC(NULL);
236 if (ret_sp) *ret_sp = (intptr_t *)NULL;
237 if (ret_fp) *ret_fp = (intptr_t *)NULL;
238 }
239
240 return epc;
241 }
242
243 frame os::fetch_frame_from_context(const void* ucVoid) {
244 intptr_t* sp;
245 intptr_t* fp;
246 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
247 return frame(sp, fp, epc.pc());
248 }
249
250 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
251 intptr_t* sp;
252 intptr_t* fp;
253 ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp);
254 return frame(sp, fp, epc.pc());
255 }
256
257 bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
258 address pc = (address) os::Solaris::ucontext_get_pc(uc);
259 if (Interpreter::contains(pc)) {
260 // interpreter performs stack banging after the fixed frame header has
261 // been generated while the compilers perform it before. To maintain
262 // semantic consistency between interpreted and compiled frames, the
263 // method returns the Java sender of the current frame.
264 *fr = os::fetch_frame_from_ucontext(thread, uc);
265 if (!fr->is_first_java_frame()) {
266 // get_frame_at_stack_banging_point() is only called when we
267 // have well defined stacks so java_sender() calls do not need
268 // to assert safe_for_sender() first.
269 *fr = fr->java_sender();
270 }
271 } else {
272 // more complex code with compiled code
273 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
274 CodeBlob* cb = CodeCache::find_blob(pc);
275 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
276 // Not sure where the pc points to, fallback to default
277 // stack overflow handling
278 return false;
279 } else {
280 // in compiled code, the stack banging is performed just after the return pc
281 // has been pushed on the stack
282 intptr_t* fp = os::Solaris::ucontext_get_fp(uc);
283 intptr_t* sp = os::Solaris::ucontext_get_sp(uc);
284 *fr = frame(sp + 1, fp, (address)*sp);
285 if (!fr->is_java_frame()) {
286 // See java_sender() comment above.
287 *fr = fr->java_sender();
288 }
289 }
290 }
291 assert(fr->is_java_frame(), "Safety check");
292 return true;
293 }
294
295 frame os::get_sender_for_C_frame(frame* fr) {
296 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
297 }
298
299 extern "C" intptr_t *_get_current_sp(); // in .il file
300
301 address os::current_stack_pointer() {
302 return (address)_get_current_sp();
303 }
304
305 extern "C" intptr_t *_get_current_fp(); // in .il file
306
307 frame os::current_frame() {
308 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp
309 // fp is for os::current_frame. We want the fp for our caller.
310 frame myframe((intptr_t*)os::current_stack_pointer(),
311 (intptr_t*)fp,
312 CAST_FROM_FN_PTR(address, os::current_frame));
313 frame caller_frame = os::get_sender_for_C_frame(&myframe);
314
315 if (os::is_first_C_frame(&caller_frame)) {
316 // stack is not walkable
317 frame ret; // This will be a null useless frame
318 return ret;
319 } else {
320 // return frame for our caller's caller
321 return os::get_sender_for_C_frame(&caller_frame);
322 }
323 }
324
325 #ifndef AMD64
326
327 // Detecting SSE support by OS
328 // From solaris_i486.s
329 extern "C" bool sse_check();
330 extern "C" bool sse_unavailable();
331
332 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};
333 static int sse_status = SSE_UNKNOWN;
334
335
336 static void check_for_sse_support() {
337 if (!VM_Version::supports_sse()) {
338 sse_status = SSE_NOT_SUPPORTED;
339 return;
340 }
341 // looking for _sse_hw in libc.so, if it does not exist or
342 // the value (int) is 0, OS has no support for SSE
343 int *sse_hwp;
344 void *h;
345
346 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {
347 //open failed, presume no support for SSE
348 sse_status = SSE_NOT_SUPPORTED;
349 return;
350 }
351 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {
352 sse_status = SSE_NOT_SUPPORTED;
353 } else if (*sse_hwp == 0) {
354 sse_status = SSE_NOT_SUPPORTED;
355 }
356 dlclose(h);
357
358 if (sse_status == SSE_UNKNOWN) {
359 bool (*try_sse)() = (bool (*)())sse_check;
360 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;
361 }
362
363 }
364
365 #endif // AMD64
366
367 bool os::supports_sse() {
368 #ifdef AMD64
369 return true;
370 #else
371 if (sse_status == SSE_UNKNOWN)
372 check_for_sse_support();
373 return sse_status == SSE_SUPPORTED;
374 #endif // AMD64
375 }
376
377 bool os::is_allocatable(size_t bytes) {
378 #ifdef AMD64
379 return true;
380 #else
381
382 if (bytes < 2 * G) {
383 return true;
384 }
385
386 char* addr = reserve_memory(bytes, NULL);
387
388 if (addr != NULL) {
389 release_memory(addr, bytes);
390 }
391
392 return addr != NULL;
393 #endif // AMD64
394
395 }
396
397 extern "C" JNIEXPORT int
398 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
399 int abort_if_unrecognized) {
400 ucontext_t* uc = (ucontext_t*) ucVoid;
401
402 #ifndef AMD64
403 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
404 // the SSE instruction faulted. supports_sse() need return false.
405 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
406 return true;
407 }
408 #endif // !AMD64
409
410 Thread* t = Thread::current_or_null_safe();
411
412 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
413 // (no destructors can be run)
414 os::ThreadCrashProtection::check_crash_protection(sig, t);
415
416 SignalHandlerMark shm(t);
417
418 if(sig == SIGPIPE || sig == SIGXFSZ) {
419 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
420 return true;
421 } else {
422 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
423 return true;
424 }
425 }
426
427 JavaThread* thread = NULL;
428 VMThread* vmthread = NULL;
429
430 if (os::Solaris::signal_handlers_are_installed) {
431 if (t != NULL ){
432 if(t->is_Java_thread()) {
433 thread = (JavaThread*)t;
434 }
435 else if(t->is_VM_thread()){
436 vmthread = (VMThread *)t;
437 }
438 }
439 }
440
441 if (sig == ASYNC_SIGNAL) {
442 if(thread || vmthread){
443 OSThread::SR_handler(t, uc);
444 return true;
445 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
446 return true;
447 } else {
448 // If ASYNC_SIGNAL not chained, and this is a non-vm and
449 // non-java thread
450 return true;
451 }
452 }
453
454 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
455 // can't decode this kind of signal
456 info = NULL;
457 } else {
458 assert(sig == info->si_signo, "bad siginfo");
459 }
460
461 // decide if this trap can be handled by a stub
462 address stub = NULL;
463
464 address pc = NULL;
465
466 //%note os_trap_1
467 if (info != NULL && uc != NULL && thread != NULL) {
468 // factor me: getPCfromContext
469 pc = (address) uc->uc_mcontext.gregs[REG_PC];
470
471 if (StubRoutines::is_safefetch_fault(pc)) {
472 os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
473 return true;
474 }
475
476 // Handle ALL stack overflow variations here
477 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
478 address addr = (address) info->si_addr;
479 if (thread->in_stack_yellow_reserved_zone(addr)) {
480 if (thread->thread_state() == _thread_in_Java) {
481 if (thread->in_stack_reserved_zone(addr)) {
482 frame fr;
483 if (os::Solaris::get_frame_at_stack_banging_point(thread, uc, &fr)) {
484 assert(fr.is_java_frame(), "Must be Java frame");
485 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
486 if (activation.sp() != NULL) {
487 thread->disable_stack_reserved_zone();
488 if (activation.is_interpreted_frame()) {
489 thread->set_reserved_stack_activation((address)(
490 activation.fp() + frame::interpreter_frame_initial_sp_offset));
491 } else {
492 thread->set_reserved_stack_activation((address)activation.unextended_sp());
493 }
494 return true;
495 }
496 }
497 }
498 // Throw a stack overflow exception. Guard pages will be reenabled
499 // while unwinding the stack.
500 thread->disable_stack_yellow_reserved_zone();
501 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
502 } else {
503 // Thread was in the vm or native code. Return and try to finish.
504 thread->disable_stack_yellow_reserved_zone();
505 return true;
506 }
507 } else if (thread->in_stack_red_zone(addr)) {
508 // Fatal red zone violation. Disable the guard pages and fall through
509 // to handle_unexpected_exception way down below.
510 thread->disable_stack_red_zone();
511 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
512 }
513 }
514
515 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) {
516 // Verify that OS save/restore AVX registers.
517 stub = VM_Version::cpuinfo_cont_addr();
518 }
519
520 if (thread->thread_state() == _thread_in_vm) {
521 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
522 address next_pc = Assembler::locate_next_instruction(pc);
523 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
524 }
525 }
526
527 if (thread->thread_state() == _thread_in_Java) {
528 // Support Safepoint Polling
529 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
530 stub = SharedRuntime::get_poll_stub(pc);
531 }
532 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
533 // BugId 4454115: A read from a MappedByteBuffer can fault
534 // here if the underlying file has been truncated.
535 // Do not crash the VM in such a case.
536 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
537 if (cb != NULL) {
538 CompiledMethod* nm = cb->as_compiled_method_or_null();
539 if (nm != NULL && nm->has_unsafe_access()) {
540 address next_pc = Assembler::locate_next_instruction(pc);
541 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
542 }
543 }
544 }
545 else
546 if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
547 // integer divide by zero
548 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
549 }
550 #ifndef AMD64
551 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
552 // floating-point divide by zero
553 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
554 }
555 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
556 // The encoding of D2I in i486.ad can cause an exception prior
557 // to the fist instruction if there was an invalid operation
558 // pending. We want to dismiss that exception. From the win_32
559 // side it also seems that if it really was the fist causing
560 // the exception that we do the d2i by hand with different
561 // rounding. Seems kind of weird. QQQ TODO
562 // Note that we take the exception at the NEXT floating point instruction.
563 if (pc[0] == 0xDB) {
564 assert(pc[0] == 0xDB, "not a FIST opcode");
565 assert(pc[1] == 0x14, "not a FIST opcode");
566 assert(pc[2] == 0x24, "not a FIST opcode");
567 return true;
568 } else {
569 assert(pc[-3] == 0xDB, "not an flt invalid opcode");
570 assert(pc[-2] == 0x14, "not an flt invalid opcode");
571 assert(pc[-1] == 0x24, "not an flt invalid opcode");
572 }
573 }
574 else if (sig == SIGFPE ) {
575 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
576 }
577 #endif // !AMD64
578
579 // QQQ It doesn't seem that we need to do this on x86 because we should be able
580 // to return properly from the handler without this extra stuff on the back side.
581
582 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
583 // Determination of interpreter/vtable stub/compiled code null exception
584 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
585 }
586 }
587
588 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
589 // and the heap gets shrunk before the field access.
590 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
591 address addr = JNI_FastGetField::find_slowcase_pc(pc);
592 if (addr != (address)-1) {
593 stub = addr;
594 }
595 }
596
597 // Check to see if we caught the safepoint code in the
598 // process of write protecting the memory serialization page.
599 // It write enables the page immediately after protecting it
600 // so we can just return to retry the write.
601 if ((sig == SIGSEGV) &&
602 os::is_memory_serialize_page(thread, (address)info->si_addr)) {
603 // Block current thread until the memory serialize page permission restored.
604 os::block_on_serialize_page_trap();
605 return true;
606 }
607 }
608
609 // Execution protection violation
610 //
611 // Preventative code for future versions of Solaris which may
612 // enable execution protection when running the 32-bit VM on AMD64.
613 //
614 // This should be kept as the last step in the triage. We don't
615 // have a dedicated trap number for a no-execute fault, so be
616 // conservative and allow other handlers the first shot.
617 //
618 // Note: We don't test that info->si_code == SEGV_ACCERR here.
619 // this si_code is so generic that it is almost meaningless; and
620 // the si_code for this condition may change in the future.
621 // Furthermore, a false-positive should be harmless.
622 if (UnguardOnExecutionViolation > 0 &&
623 (sig == SIGSEGV || sig == SIGBUS) &&
624 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault
625 int page_size = os::vm_page_size();
626 address addr = (address) info->si_addr;
627 address pc = (address) uc->uc_mcontext.gregs[REG_PC];
628 // Make sure the pc and the faulting address are sane.
629 //
630 // If an instruction spans a page boundary, and the page containing
631 // the beginning of the instruction is executable but the following
632 // page is not, the pc and the faulting address might be slightly
633 // different - we still want to unguard the 2nd page in this case.
634 //
635 // 15 bytes seems to be a (very) safe value for max instruction size.
636 bool pc_is_near_addr =
637 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
638 bool instr_spans_page_boundary =
639 (align_down((intptr_t) pc ^ (intptr_t) addr,
640 (intptr_t) page_size) > 0);
641
642 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
643 static volatile address last_addr =
644 (address) os::non_memory_address_word();
645
646 // In conservative mode, don't unguard unless the address is in the VM
647 if (addr != last_addr &&
648 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
649
650 // Make memory rwx and retry
651 address page_start = align_down(addr, page_size);
652 bool res = os::protect_memory((char*) page_start, page_size,
653 os::MEM_PROT_RWX);
654
655 log_debug(os)("Execution protection violation "
656 "at " INTPTR_FORMAT
657 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr),
658 p2i(page_start), (res ? "success" : "failed"), errno);
659 stub = pc;
660
661 // Set last_addr so if we fault again at the same address, we don't end
662 // up in an endless loop.
663 //
664 // There are two potential complications here. Two threads trapping at
665 // the same address at the same time could cause one of the threads to
666 // think it already unguarded, and abort the VM. Likely very rare.
667 //
668 // The other race involves two threads alternately trapping at
669 // different addresses and failing to unguard the page, resulting in
670 // an endless loop. This condition is probably even more unlikely than
671 // the first.
672 //
673 // Although both cases could be avoided by using locks or thread local
674 // last_addr, these solutions are unnecessary complication: this
675 // handler is a best-effort safety net, not a complete solution. It is
676 // disabled by default and should only be used as a workaround in case
677 // we missed any no-execute-unsafe VM code.
678
679 last_addr = addr;
680 }
681 }
682 }
683
684 if (stub != NULL) {
685 // save all thread context in case we need to restore it
686
687 if (thread != NULL) thread->set_saved_exception_pc(pc);
688 // 12/02/99: On Sparc it appears that the full context is also saved
689 // but as yet, no one looks at or restores that saved context
690 os::Solaris::ucontext_set_pc(uc, stub);
691 return true;
692 }
693
694 // signal-chaining
695 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
696 return true;
697 }
698
699 #ifndef AMD64
700 // Workaround (bug 4900493) for Solaris kernel bug 4966651.
701 // Handle an undefined selector caused by an attempt to assign
702 // fs in libthread getipriptr(). With the current libthread design every 512
703 // thread creations the LDT for a private thread data structure is extended
704 // and thre is a hazard that and another thread attempting a thread creation
705 // will use a stale LDTR that doesn't reflect the structure's growth,
706 // causing a GP fault.
707 // Enforce the probable limit of passes through here to guard against an
708 // infinite loop if some other move to fs caused the GP fault. Note that
709 // this loop counter is ultimately a heuristic as it is possible for
710 // more than one thread to generate this fault at a time in an MP system.
711 // In the case of the loop count being exceeded or if the poll fails
712 // just fall through to a fatal error.
713 // If there is some other source of T_GPFLT traps and the text at EIP is
714 // unreadable this code will loop infinitely until the stack is exausted.
715 // The key to diagnosis in this case is to look for the bottom signal handler
716 // frame.
717
718 if(! IgnoreLibthreadGPFault) {
719 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
720 const unsigned char *p =
721 (unsigned const char *) uc->uc_mcontext.gregs[EIP];
722
723 // Expected instruction?
724
725 if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
726
727 Atomic::inc(&ldtr_refresh);
728
729 // Infinite loop?
730
731 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
732
733 // No, force scheduling to get a fresh view of the LDTR
734
735 if(poll(NULL, 0, 10) == 0) {
736
737 // Retry the move
738
739 return false;
740 }
741 }
742 }
743 }
744 }
745 #endif // !AMD64
746
747 if (!abort_if_unrecognized) {
748 // caller wants another chance, so give it to him
749 return false;
750 }
751
752 if (!os::Solaris::libjsig_is_loaded) {
753 struct sigaction oldAct;
754 sigaction(sig, (struct sigaction *)0, &oldAct);
755 if (oldAct.sa_sigaction != signalHandler) {
756 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
757 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
758 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
759 }
760 }
761
762 if (pc == NULL && uc != NULL) {
763 pc = (address) uc->uc_mcontext.gregs[REG_PC];
764 }
765
766 // unmask current signal
767 sigset_t newset;
768 sigemptyset(&newset);
769 sigaddset(&newset, sig);
770 sigprocmask(SIG_UNBLOCK, &newset, NULL);
771
772 // Determine which sort of error to throw. Out of swap may signal
773 // on the thread stack, which could get a mapping error when touched.
774 address addr = (address) info->si_addr;
775 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
776 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
777 }
778
779 VMError::report_and_die(t, sig, pc, info, ucVoid);
780
781 ShouldNotReachHere();
782 return false;
783 }
784
785 void os::print_context(outputStream *st, const void *context) {
786 if (context == NULL) return;
787
788 const ucontext_t *uc = (const ucontext_t*)context;
789 st->print_cr("Registers:");
790 #ifdef AMD64
791 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
792 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
793 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
794 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
795 st->cr();
796 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
797 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
798 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
799 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
800 st->cr();
801 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
802 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
803 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
804 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
805 st->cr();
806 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
807 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
808 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
809 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
810 st->cr();
811 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
812 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
813 #else
814 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
815 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
816 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
817 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
818 st->cr();
819 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
820 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
821 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
822 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
823 st->cr();
824 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
825 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
826 #endif // AMD64
827 st->cr();
828 st->cr();
829
830 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
831 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
832 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
833 st->cr();
834
835 // Note: it may be unsafe to inspect memory near pc. For example, pc may
836 // point to garbage if entry point in an nmethod is corrupted. Leave
837 // this at the end, and hope for the best.
838 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
839 address pc = epc.pc();
840 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
841 print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
842 }
843
844 void os::print_register_info(outputStream *st, const void *context) {
845 if (context == NULL) return;
846
847 const ucontext_t *uc = (const ucontext_t*)context;
848
849 st->print_cr("Register to memory mapping:");
850 st->cr();
851
852 // this is horrendously verbose but the layout of the registers in the
853 // context does not match how we defined our abstract Register set, so
854 // we can't just iterate through the gregs area
855
856 // this is only for the "general purpose" registers
857
858 #ifdef AMD64
859 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
860 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
861 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
862 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
863 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
864 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
865 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
866 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
867 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
868 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
869 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
870 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
871 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
872 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
873 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
874 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
875 #else
876 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
877 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
878 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
879 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
880 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
881 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
882 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
883 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
884 #endif
885
886 st->cr();
887 }
888
889
890 #ifdef AMD64
891 void os::Solaris::init_thread_fpu_state(void) {
892 // Nothing to do
893 }
894 #else
895 // From solaris_i486.s
896 extern "C" void fixcw();
897
898 void os::Solaris::init_thread_fpu_state(void) {
899 // Set fpu to 53 bit precision. This happens too early to use a stub.
900 fixcw();
901 }
902
903 // These routines are the initial value of atomic_xchg_entry(),
904 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
905 // until initialization is complete.
906 // TODO - replace with .il implementation when compiler supports it.
907
908 typedef int32_t xchg_func_t (int32_t, volatile int32_t*);
909 typedef int32_t cmpxchg_func_t (int32_t, volatile int32_t*, int32_t);
910 typedef int64_t cmpxchg_long_func_t(int64_t, volatile int64_t*, int64_t);
911 typedef int32_t add_func_t (int32_t, volatile int32_t*);
912
913 int32_t os::atomic_xchg_bootstrap(int32_t exchange_value, volatile int32_t* dest) {
914 // try to use the stub:
915 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
916
917 if (func != NULL) {
918 os::atomic_xchg_func = func;
919 return (*func)(exchange_value, dest);
920 }
921 assert(Threads::number_of_threads() == 0, "for bootstrap only");
922
923 int32_t old_value = *dest;
924 *dest = exchange_value;
925 return old_value;
926 }
927
928 int32_t os::atomic_cmpxchg_bootstrap(int32_t exchange_value, volatile int32_t* dest, int32_t compare_value) {
929 // try to use the stub:
930 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
931
932 if (func != NULL) {
933 os::atomic_cmpxchg_func = func;
934 return (*func)(exchange_value, dest, compare_value);
935 }
936 assert(Threads::number_of_threads() == 0, "for bootstrap only");
937
938 int32_t old_value = *dest;
939 if (old_value == compare_value)
940 *dest = exchange_value;
941 return old_value;
942 }
943
944 int64_t os::atomic_cmpxchg_long_bootstrap(int64_t exchange_value, volatile int64_t* dest, int64_t compare_value) {
945 // try to use the stub:
946 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
947
948 if (func != NULL) {
949 os::atomic_cmpxchg_long_func = func;
950 return (*func)(exchange_value, dest, compare_value);
951 }
952 assert(Threads::number_of_threads() == 0, "for bootstrap only");
953
954 int64_t old_value = *dest;
955 if (old_value == compare_value)
956 *dest = exchange_value;
957 return old_value;
958 }
959
960 int32_t os::atomic_add_bootstrap(int32_t add_value, volatile int32_t* dest) {
961 // try to use the stub:
962 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
963
964 if (func != NULL) {
965 os::atomic_add_func = func;
966 return (*func)(add_value, dest);
967 }
968 assert(Threads::number_of_threads() == 0, "for bootstrap only");
969
970 return (*dest) += add_value;
971 }
972
973 xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap;
974 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap;
975 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
976 add_func_t* os::atomic_add_func = os::atomic_add_bootstrap;
977
978 extern "C" void _solaris_raw_setup_fpu(address ptr);
979 void os::setup_fpu() {
980 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
981 _solaris_raw_setup_fpu(fpu_cntrl);
982 }
983 #endif // AMD64
984
985 #ifndef PRODUCT
986 void os::verify_stack_alignment() {
987 #ifdef AMD64
988 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
989 #endif
990 }
991 #endif
992
993 int os::extra_bang_size_in_bytes() {
994 // JDK-8050147 requires the full cache line bang for x86.
995 return VM_Version::L1_line_size();
996 }