1 /*
2 * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 // no precompiled headers
26 #include "asm/macroAssembler.hpp"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "code/vtableStubs.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_solaris.h"
35 #include "memory/allocation.inline.hpp"
36 #include "os_share_solaris.hpp"
37 #include "prims/jniFastGetField.hpp"
38 #include "prims/jvm.h"
39 #include "prims/jvm_misc.hpp"
40 #include "runtime/arguments.hpp"
41 #include "runtime/atomic.hpp"
42 #include "runtime/extendedPC.hpp"
43 #include "runtime/frame.inline.hpp"
44 #include "runtime/interfaceSupport.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/osThread.hpp"
49 #include "runtime/sharedRuntime.hpp"
50 #include "runtime/stubRoutines.hpp"
51 #include "runtime/thread.inline.hpp"
52 #include "runtime/timer.hpp"
53 #include "utilities/events.hpp"
54 #include "utilities/vmError.hpp"
55
56 // put OS-includes here
57 # include <sys/types.h>
58 # include <sys/mman.h>
59 # include <pthread.h>
60 # include <signal.h>
61 # include <setjmp.h>
62 # include <errno.h>
63 # include <dlfcn.h>
64 # include <stdio.h>
65 # include <unistd.h>
66 # include <sys/resource.h>
67 # include <thread.h>
68 # include <sys/stat.h>
69 # include <sys/time.h>
70 # include <sys/filio.h>
71 # include <sys/utsname.h>
72 # include <sys/systeminfo.h>
73 # include <sys/socket.h>
74 # include <sys/trap.h>
75 # include <sys/lwp.h>
76 # include <poll.h>
77 # include <sys/lwp.h>
78 # include <procfs.h> // see comment in <sys/procfs.h>
79
80 #ifndef AMD64
81 // QQQ seems useless at this point
82 # define _STRUCTURED_PROC 1 // this gets us the new structured proc interfaces of 5.6 & later
83 #endif // AMD64
84 # include <sys/procfs.h> // see comment in <sys/procfs.h>
85
86
87 #define MAX_PATH (2 * K)
88
89 // Minimum usable stack sizes required to get to user code. Space for
90 // HotSpot guard pages is added later.
91 #ifdef _LP64
92 // The adlc generated method 'State::MachNodeGenerator(int)' used by the C2 compiler
93 // threads requires a large stack with the Solaris Studio C++ compiler version 5.13
94 // and product VM builds (debug builds require significantly less stack space).
95 size_t os::Posix::_compiler_thread_min_stack_allowed = 325 * K;
96 size_t os::Posix::_java_thread_min_stack_allowed = 48 * K;
97 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 224 * K;
98 #else
99 size_t os::Posix::_compiler_thread_min_stack_allowed = 32 * K;
100 size_t os::Posix::_java_thread_min_stack_allowed = 32 * K;
101 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K;
102 #endif // _LP64
103
104 #ifdef AMD64
105 #define REG_SP REG_RSP
106 #define REG_PC REG_RIP
107 #define REG_FP REG_RBP
108 #else
109 #define REG_SP UESP
110 #define REG_PC EIP
111 #define REG_FP EBP
112 // 4900493 counter to prevent runaway LDTR refresh attempt
113
114 static volatile int ldtr_refresh = 0;
115 // the libthread instruction that faults because of the stale LDTR
116
117 static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs
118 };
119 #endif // AMD64
120
121 char* os::non_memory_address_word() {
122 // Must never look like an address returned by reserve_memory,
123 // even in its subfields (as defined by the CPU immediate fields,
124 // if the CPU splits constants across multiple instructions).
125 return (char*) -1;
126 }
127
128 //
129 // Validate a ucontext retrieved from walking a uc_link of a ucontext.
130 // There are issues with libthread giving out uc_links for different threads
131 // on the same uc_link chain and bad or circular links.
132 //
133 bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) {
134 if (valid >= suspect ||
135 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
136 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp ||
137 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) {
138 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)
139 return false;
140 }
141
142 if (thread->is_Java_thread()) {
143 if (!valid_stack_address(thread, (address)suspect)) {
144 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)
145 return false;
146 }
147 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) {
148 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)
149 return false;
150 }
151 }
152 return true;
153 }
154
155 // We will only follow one level of uc_link since there are libthread
156 // issues with ucontext linking and it is better to be safe and just
157 // let caller retry later.
158 const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
159 const ucontext_t *uc) {
160
161 const ucontext_t *retuc = NULL;
162
163 if (uc != NULL) {
164 if (uc->uc_link == NULL) {
165 // cannot validate without uc_link so accept current ucontext
166 retuc = uc;
167 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
168 // first ucontext is valid so try the next one
169 uc = uc->uc_link;
170 if (uc->uc_link == NULL) {
171 // cannot validate without uc_link so accept current ucontext
172 retuc = uc;
173 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
174 // the ucontext one level down is also valid so return it
175 retuc = uc;
176 }
177 }
178 }
179 return retuc;
180 }
181
182 // Assumes ucontext is valid
183 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) {
184 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]);
185 }
186
187 void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) {
188 uc->uc_mcontext.gregs [REG_PC] = (greg_t) pc;
189 }
190
191 // Assumes ucontext is valid
192 intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {
193 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
194 }
195
196 // Assumes ucontext is valid
197 intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {
198 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
199 }
200
201 address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {
202 return (address) uc->uc_mcontext.gregs[REG_PC];
203 }
204
205 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
206 // is currently interrupted by SIGPROF.
207 //
208 // The difference between this and os::fetch_frame_from_context() is that
209 // here we try to skip nested signal frames.
210 // This method is also used for stack overflow signal handling.
211 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
212 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
213
214 assert(thread != NULL, "just checking");
215 assert(ret_sp != NULL, "just checking");
216 assert(ret_fp != NULL, "just checking");
217
218 const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
219 return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
220 }
221
222 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
223 intptr_t** ret_sp, intptr_t** ret_fp) {
224
225 ExtendedPC epc;
226 const ucontext_t *uc = (const ucontext_t*)ucVoid;
227
228 if (uc != NULL) {
229 epc = os::Solaris::ucontext_get_ExtendedPC(uc);
230 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
231 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc);
232 } else {
233 // construct empty ExtendedPC for return value checking
234 epc = ExtendedPC(NULL);
235 if (ret_sp) *ret_sp = (intptr_t *)NULL;
236 if (ret_fp) *ret_fp = (intptr_t *)NULL;
237 }
238
239 return epc;
240 }
241
242 frame os::fetch_frame_from_context(const void* ucVoid) {
243 intptr_t* sp;
244 intptr_t* fp;
245 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
246 return frame(sp, fp, epc.pc());
247 }
248
249 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
250 intptr_t* sp;
251 intptr_t* fp;
252 ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp);
253 return frame(sp, fp, epc.pc());
254 }
255
256 bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
257 address pc = (address) os::Solaris::ucontext_get_pc(uc);
258 if (Interpreter::contains(pc)) {
259 // interpreter performs stack banging after the fixed frame header has
260 // been generated while the compilers perform it before. To maintain
261 // semantic consistency between interpreted and compiled frames, the
262 // method returns the Java sender of the current frame.
263 *fr = os::fetch_frame_from_ucontext(thread, uc);
264 if (!fr->is_first_java_frame()) {
265 // get_frame_at_stack_banging_point() is only called when we
266 // have well defined stacks so java_sender() calls do not need
267 // to assert safe_for_sender() first.
268 *fr = fr->java_sender();
269 }
270 } else {
271 // more complex code with compiled code
272 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
273 CodeBlob* cb = CodeCache::find_blob(pc);
274 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
275 // Not sure where the pc points to, fallback to default
276 // stack overflow handling
277 return false;
278 } else {
279 // in compiled code, the stack banging is performed just after the return pc
280 // has been pushed on the stack
281 intptr_t* fp = os::Solaris::ucontext_get_fp(uc);
282 intptr_t* sp = os::Solaris::ucontext_get_sp(uc);
283 *fr = frame(sp + 1, fp, (address)*sp);
284 if (!fr->is_java_frame()) {
285 // See java_sender() comment above.
286 *fr = fr->java_sender();
287 }
288 }
289 }
290 assert(fr->is_java_frame(), "Safety check");
291 return true;
292 }
293
294 frame os::get_sender_for_C_frame(frame* fr) {
295 return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
296 }
297
298 extern "C" intptr_t *_get_current_sp(); // in .il file
299
300 address os::current_stack_pointer() {
301 return (address)_get_current_sp();
302 }
303
304 extern "C" intptr_t *_get_current_fp(); // in .il file
305
306 frame os::current_frame() {
307 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp
308 // fp is for os::current_frame. We want the fp for our caller.
309 frame myframe((intptr_t*)os::current_stack_pointer(),
310 (intptr_t*)fp,
311 CAST_FROM_FN_PTR(address, os::current_frame));
312 frame caller_frame = os::get_sender_for_C_frame(&myframe);
313
314 if (os::is_first_C_frame(&caller_frame)) {
315 // stack is not walkable
316 frame ret; // This will be a null useless frame
317 return ret;
318 } else {
319 // return frame for our caller's caller
320 return os::get_sender_for_C_frame(&caller_frame);
321 }
322 }
323
324 #ifndef AMD64
325
326 // Detecting SSE support by OS
327 // From solaris_i486.s
328 extern "C" bool sse_check();
329 extern "C" bool sse_unavailable();
330
331 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};
332 static int sse_status = SSE_UNKNOWN;
333
334
335 static void check_for_sse_support() {
336 if (!VM_Version::supports_sse()) {
337 sse_status = SSE_NOT_SUPPORTED;
338 return;
339 }
340 // looking for _sse_hw in libc.so, if it does not exist or
341 // the value (int) is 0, OS has no support for SSE
342 int *sse_hwp;
343 void *h;
344
345 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {
346 //open failed, presume no support for SSE
347 sse_status = SSE_NOT_SUPPORTED;
348 return;
349 }
350 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {
351 sse_status = SSE_NOT_SUPPORTED;
352 } else if (*sse_hwp == 0) {
353 sse_status = SSE_NOT_SUPPORTED;
354 }
355 dlclose(h);
356
357 if (sse_status == SSE_UNKNOWN) {
358 bool (*try_sse)() = (bool (*)())sse_check;
359 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;
360 }
361
362 }
363
364 #endif // AMD64
365
366 bool os::supports_sse() {
367 #ifdef AMD64
368 return true;
369 #else
370 if (sse_status == SSE_UNKNOWN)
371 check_for_sse_support();
372 return sse_status == SSE_SUPPORTED;
373 #endif // AMD64
374 }
375
376 bool os::is_allocatable(size_t bytes) {
377 #ifdef AMD64
378 return true;
379 #else
380
381 if (bytes < 2 * G) {
382 return true;
383 }
384
385 char* addr = reserve_memory(bytes, NULL);
386
387 if (addr != NULL) {
388 release_memory(addr, bytes);
389 }
390
391 return addr != NULL;
392 #endif // AMD64
393
394 }
395
396 extern "C" JNIEXPORT int
397 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
398 int abort_if_unrecognized) {
399 ucontext_t* uc = (ucontext_t*) ucVoid;
400
401 #ifndef AMD64
402 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
403 // the SSE instruction faulted. supports_sse() need return false.
404 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
405 return true;
406 }
407 #endif // !AMD64
408
409 Thread* t = Thread::current_or_null_safe();
410
411 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
412 // (no destructors can be run)
413 os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
414
415 SignalHandlerMark shm(t);
416
417 if(sig == SIGPIPE || sig == SIGXFSZ) {
418 if (os::Solaris::chained_handler(sig, info, ucVoid)) {
419 return true;
420 } else {
421 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
422 return true;
423 }
424 }
425
426 JavaThread* thread = NULL;
427 VMThread* vmthread = NULL;
428
429 if (os::Solaris::signal_handlers_are_installed) {
430 if (t != NULL ){
431 if(t->is_Java_thread()) {
432 thread = (JavaThread*)t;
433 }
434 else if(t->is_VM_thread()){
435 vmthread = (VMThread *)t;
436 }
437 }
438 }
439
440 if (sig == os::Solaris::SIGasync()) {
441 if(thread || vmthread){
442 OSThread::SR_handler(t, uc);
443 return true;
444 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
445 return true;
446 } else {
447 // If os::Solaris::SIGasync not chained, and this is a non-vm and
448 // non-java thread
449 return true;
450 }
451 }
452
453 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
454 // can't decode this kind of signal
455 info = NULL;
456 } else {
457 assert(sig == info->si_signo, "bad siginfo");
458 }
459
460 // decide if this trap can be handled by a stub
461 address stub = NULL;
462
463 address pc = NULL;
464
465 //%note os_trap_1
466 if (info != NULL && uc != NULL && thread != NULL) {
467 // factor me: getPCfromContext
468 pc = (address) uc->uc_mcontext.gregs[REG_PC];
469
470 if (StubRoutines::is_safefetch_fault(pc)) {
471 os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
472 return true;
473 }
474
475 // Handle ALL stack overflow variations here
476 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
477 address addr = (address) info->si_addr;
478 if (thread->in_stack_yellow_reserved_zone(addr)) {
479 if (thread->thread_state() == _thread_in_Java) {
480 if (thread->in_stack_reserved_zone(addr)) {
481 frame fr;
482 if (os::Solaris::get_frame_at_stack_banging_point(thread, uc, &fr)) {
483 assert(fr.is_java_frame(), "Must be Java frame");
484 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
485 if (activation.sp() != NULL) {
486 thread->disable_stack_reserved_zone();
487 if (activation.is_interpreted_frame()) {
488 thread->set_reserved_stack_activation((address)(
489 activation.fp() + frame::interpreter_frame_initial_sp_offset));
490 } else {
491 thread->set_reserved_stack_activation((address)activation.unextended_sp());
492 }
493 return true;
494 }
495 }
496 }
497 // Throw a stack overflow exception. Guard pages will be reenabled
498 // while unwinding the stack.
499 thread->disable_stack_yellow_reserved_zone();
500 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
501 } else {
502 // Thread was in the vm or native code. Return and try to finish.
503 thread->disable_stack_yellow_reserved_zone();
504 return true;
505 }
506 } else if (thread->in_stack_red_zone(addr)) {
507 // Fatal red zone violation. Disable the guard pages and fall through
508 // to handle_unexpected_exception way down below.
509 thread->disable_stack_red_zone();
510 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
511 }
512 }
513
514 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) {
515 // Verify that OS save/restore AVX registers.
516 stub = VM_Version::cpuinfo_cont_addr();
517 }
518
519 if (thread->thread_state() == _thread_in_vm) {
520 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
521 address next_pc = Assembler::locate_next_instruction(pc);
522 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
523 }
524 }
525
526 if (thread->thread_state() == _thread_in_Java) {
527 // Support Safepoint Polling
528 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
529 stub = SharedRuntime::get_poll_stub(pc);
530 }
531 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
532 // BugId 4454115: A read from a MappedByteBuffer can fault
533 // here if the underlying file has been truncated.
534 // Do not crash the VM in such a case.
535 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
536 if (cb != NULL) {
537 CompiledMethod* nm = cb->as_compiled_method_or_null();
538 if (nm != NULL && nm->has_unsafe_access()) {
539 address next_pc = Assembler::locate_next_instruction(pc);
540 stub = SharedRuntime::handle_unsafe_access(thread, next_pc);
541 }
542 }
543 }
544 else
545 if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
546 // integer divide by zero
547 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
548 }
549 #ifndef AMD64
550 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
551 // floating-point divide by zero
552 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
553 }
554 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
555 // The encoding of D2I in i486.ad can cause an exception prior
556 // to the fist instruction if there was an invalid operation
557 // pending. We want to dismiss that exception. From the win_32
558 // side it also seems that if it really was the fist causing
559 // the exception that we do the d2i by hand with different
560 // rounding. Seems kind of weird. QQQ TODO
561 // Note that we take the exception at the NEXT floating point instruction.
562 if (pc[0] == 0xDB) {
563 assert(pc[0] == 0xDB, "not a FIST opcode");
564 assert(pc[1] == 0x14, "not a FIST opcode");
565 assert(pc[2] == 0x24, "not a FIST opcode");
566 return true;
567 } else {
568 assert(pc[-3] == 0xDB, "not an flt invalid opcode");
569 assert(pc[-2] == 0x14, "not an flt invalid opcode");
570 assert(pc[-1] == 0x24, "not an flt invalid opcode");
571 }
572 }
573 else if (sig == SIGFPE ) {
574 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
575 }
576 #endif // !AMD64
577
578 // QQQ It doesn't seem that we need to do this on x86 because we should be able
579 // to return properly from the handler without this extra stuff on the back side.
580
581 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
582 // Determination of interpreter/vtable stub/compiled code null exception
583 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
584 }
585 }
586
587 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
588 // and the heap gets shrunk before the field access.
589 if ((sig == SIGSEGV) || (sig == SIGBUS)) {
590 address addr = JNI_FastGetField::find_slowcase_pc(pc);
591 if (addr != (address)-1) {
592 stub = addr;
593 }
594 }
595
596 // Check to see if we caught the safepoint code in the
597 // process of write protecting the memory serialization page.
598 // It write enables the page immediately after protecting it
599 // so we can just return to retry the write.
600 if ((sig == SIGSEGV) &&
601 os::is_memory_serialize_page(thread, (address)info->si_addr)) {
602 // Block current thread until the memory serialize page permission restored.
603 os::block_on_serialize_page_trap();
604 return true;
605 }
606 }
607
608 // Execution protection violation
609 //
610 // Preventative code for future versions of Solaris which may
611 // enable execution protection when running the 32-bit VM on AMD64.
612 //
613 // This should be kept as the last step in the triage. We don't
614 // have a dedicated trap number for a no-execute fault, so be
615 // conservative and allow other handlers the first shot.
616 //
617 // Note: We don't test that info->si_code == SEGV_ACCERR here.
618 // this si_code is so generic that it is almost meaningless; and
619 // the si_code for this condition may change in the future.
620 // Furthermore, a false-positive should be harmless.
621 if (UnguardOnExecutionViolation > 0 &&
622 (sig == SIGSEGV || sig == SIGBUS) &&
623 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault
624 int page_size = os::vm_page_size();
625 address addr = (address) info->si_addr;
626 address pc = (address) uc->uc_mcontext.gregs[REG_PC];
627 // Make sure the pc and the faulting address are sane.
628 //
629 // If an instruction spans a page boundary, and the page containing
630 // the beginning of the instruction is executable but the following
631 // page is not, the pc and the faulting address might be slightly
632 // different - we still want to unguard the 2nd page in this case.
633 //
634 // 15 bytes seems to be a (very) safe value for max instruction size.
635 bool pc_is_near_addr =
636 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
637 bool instr_spans_page_boundary =
638 (align_size_down((intptr_t) pc ^ (intptr_t) addr,
639 (intptr_t) page_size) > 0);
640
641 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
642 static volatile address last_addr =
643 (address) os::non_memory_address_word();
644
645 // In conservative mode, don't unguard unless the address is in the VM
646 if (addr != last_addr &&
647 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
648
649 // Make memory rwx and retry
650 address page_start =
651 (address) align_size_down((intptr_t) addr, (intptr_t) 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 jint xchg_func_t (jint, volatile jint*);
909 typedef jint cmpxchg_func_t (jint, volatile jint*, jint);
910 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
911 typedef jint add_func_t (jint, volatile jint*);
912
913 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* 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 jint old_value = *dest;
924 *dest = exchange_value;
925 return old_value;
926 }
927
928 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint 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 jint old_value = *dest;
939 if (old_value == compare_value)
940 *dest = exchange_value;
941 return old_value;
942 }
943
944 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong 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 jlong old_value = *dest;
955 if (old_value == compare_value)
956 *dest = exchange_value;
957 return old_value;
958 }
959
960 jint os::atomic_add_bootstrap(jint add_value, volatile jint* 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 }