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