1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * Copyright 2012, 2014 SAP AG. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 // no precompiled headers
27 #include "assembler_ppc.inline.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 "jvm_aix.h"
36 #include "memory/allocation.inline.hpp"
37 #include "mutex_aix.inline.hpp"
38 #include "nativeInst_ppc.hpp"
39 #include "os_share_aix.hpp"
40 #include "prims/jniFastGetField.hpp"
41 #include "prims/jvm.h"
42 #include "prims/jvm_misc.hpp"
43 #include "runtime/arguments.hpp"
44 #include "runtime/extendedPC.hpp"
45 #include "runtime/frame.inline.hpp"
46 #include "runtime/interfaceSupport.hpp"
47 #include "runtime/java.hpp"
48 #include "runtime/javaCalls.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "runtime/osThread.hpp"
51 #include "runtime/sharedRuntime.hpp"
52 #include "runtime/stubRoutines.hpp"
53 #include "runtime/thread.inline.hpp"
54 #include "runtime/timer.hpp"
55 #include "utilities/events.hpp"
56 #include "utilities/vmError.hpp"
57 #ifdef COMPILER1
58 #include "c1/c1_Runtime1.hpp"
59 #endif
60 #ifdef COMPILER2
61 #include "opto/runtime.hpp"
62 #endif
63
64 // put OS-includes here
65 # include <ucontext.h>
66
67 address os::current_stack_pointer() {
68 address csp;
69
70 #if !defined(USE_XLC_BUILTINS)
71 // inline assembly for `mr regno(csp), R1_SP':
72 __asm__ __volatile__ ("mr %0, 1":"=r"(csp):);
73 #else
74 csp = (address) __builtin_frame_address(0);
75 #endif
76
77 return csp;
78 }
79
80 char* os::non_memory_address_word() {
81 // Must never look like an address returned by reserve_memory,
82 // even in its subfields (as defined by the CPU immediate fields,
83 // if the CPU splits constants across multiple instructions).
84
85 return (char*) -1;
86 }
87
88 // OS specific thread initialization
89 //
90 // Calculate and store the limits of the memory stack.
91 void os::initialize_thread(Thread *thread) { }
92
93 // Frame information (pc, sp, fp) retrieved via ucontext
94 // always looks like a C-frame according to the frame
95 // conventions in frame_ppc.hpp.
96
97 address os::Aix::ucontext_get_pc(const ucontext_t * uc) {
98 return (address)uc->uc_mcontext.jmp_context.iar;
99 }
100
101 intptr_t* os::Aix::ucontext_get_sp(const ucontext_t * uc) {
102 // gpr1 holds the stack pointer on aix
103 return (intptr_t*)uc->uc_mcontext.jmp_context.gpr[1/*REG_SP*/];
104 }
105
106 intptr_t* os::Aix::ucontext_get_fp(const ucontext_t * uc) {
107 return NULL;
108 }
109
110 void os::Aix::ucontext_set_pc(ucontext_t* uc, address new_pc) {
111 uc->uc_mcontext.jmp_context.iar = (uint64_t) new_pc;
112 }
113
114 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
115 intptr_t** ret_sp, intptr_t** ret_fp) {
116
117 ExtendedPC epc;
118 const ucontext_t* uc = (const ucontext_t*)ucVoid;
119
120 if (uc != NULL) {
121 epc = ExtendedPC(os::Aix::ucontext_get_pc(uc));
122 if (ret_sp) *ret_sp = os::Aix::ucontext_get_sp(uc);
123 if (ret_fp) *ret_fp = os::Aix::ucontext_get_fp(uc);
124 } else {
125 // construct empty ExtendedPC for return value checking
126 epc = ExtendedPC(NULL);
127 if (ret_sp) *ret_sp = (intptr_t *)NULL;
128 if (ret_fp) *ret_fp = (intptr_t *)NULL;
129 }
130
131 return epc;
132 }
133
134 frame os::fetch_frame_from_context(const void* ucVoid) {
135 intptr_t* sp;
136 intptr_t* fp;
137 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
138 // Avoid crash during crash if pc broken.
139 if (epc.pc()) {
140 frame fr(sp, epc.pc());
141 return fr;
142 }
143 frame fr(sp);
144 return fr;
145 }
146
147 frame os::get_sender_for_C_frame(frame* fr) {
148 if (*fr->sp() == NULL) {
149 // fr is the last C frame
150 return frame(NULL, NULL);
151 }
152 return frame(fr->sender_sp(), fr->sender_pc());
153 }
154
155
156 frame os::current_frame() {
157 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
158 // hack.
159 frame topframe(csp, (address)0x8);
160 // return sender of current topframe which hopefully has pc != NULL.
161 return os::get_sender_for_C_frame(&topframe);
162 }
163
164 // Utility functions
165
166 extern "C" JNIEXPORT int
167 JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrecognized) {
168
169 ucontext_t* uc = (ucontext_t*) ucVoid;
170
171 Thread* t = Thread::current_or_null_safe();
172
173 SignalHandlerMark shm(t);
174
175 // Note: it's not uncommon that JNI code uses signal/sigset to install
176 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
177 // or have a SIGILL handler when detecting CPU type). When that happens,
178 // JVM_handle_aix_signal() might be invoked with junk info/ucVoid. To
179 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
180 // that do not require siginfo/ucontext first.
181
182 if (sig == SIGPIPE) {
183 if (os::Aix::chained_handler(sig, info, ucVoid)) {
184 return 1;
185 } else {
186 if (PrintMiscellaneous && (WizardMode || Verbose)) {
187 warning("Ignoring SIGPIPE - see bug 4229104");
188 }
189 return 1;
190 }
191 }
192
193 JavaThread* thread = NULL;
194 VMThread* vmthread = NULL;
195 if (os::Aix::signal_handlers_are_installed) {
196 if (t != NULL) {
197 if(t->is_Java_thread()) {
198 thread = (JavaThread*)t;
199 }
200 else if(t->is_VM_thread()) {
201 vmthread = (VMThread *)t;
202 }
203 }
204 }
205
206 // Decide if this trap can be handled by a stub.
207 address stub = NULL;
208
209 // retrieve program counter
210 address const pc = uc ? os::Aix::ucontext_get_pc(uc) : NULL;
211
212 // retrieve crash address
213 address const addr = info ? (const address) info->si_addr : NULL;
214
215 // SafeFetch 32 handling:
216 // - make it work if _thread is null
217 // - make it use the standard os::...::ucontext_get/set_pc APIs
218 if (uc) {
219 address const pc = os::Aix::ucontext_get_pc(uc);
220 if (pc && StubRoutines::is_safefetch_fault(pc)) {
221 os::Aix::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
222 return true;
223 }
224 }
225
226 // Handle SIGDANGER right away. AIX would raise SIGDANGER whenever available swap
227 // space falls below 30%. This is only a chance for the process to gracefully abort.
228 // We can't hope to proceed after SIGDANGER since SIGKILL tailgates.
229 if (sig == SIGDANGER) {
230 goto report_and_die;
231 }
232
233 if (info == NULL || uc == NULL || thread == NULL && vmthread == NULL) {
234 goto run_chained_handler;
235 }
236
237 // If we are a java thread...
238 if (thread != NULL) {
239
240 // Handle ALL stack overflow variations here
241 if (sig == SIGSEGV && thread->on_local_stack(addr)) {
242 // stack overflow
243 //
244 // If we are in a yellow zone and we are inside java, we disable the yellow zone and
245 // throw a stack overflow exception.
246 // If we are in native code or VM C code, we report-and-die. The original coding tried
247 // to continue with yellow zone disabled, but that doesn't buy us much and prevents
248 // hs_err_pid files.
249 if (thread->in_stack_yellow_reserved_zone(addr)) {
250 thread->disable_stack_yellow_reserved_zone();
251 if (thread->thread_state() == _thread_in_Java) {
252 // Throw a stack overflow exception.
253 // Guard pages will be reenabled while unwinding the stack.
254 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
255 goto run_stub;
256 } else {
257 // Thread was in the vm or native code. Return and try to finish.
258 return 1;
259 }
260 } else if (thread->in_stack_red_zone(addr)) {
261 // Fatal red zone violation. Disable the guard pages and fall through
262 // to handle_unexpected_exception way down below.
263 thread->disable_stack_red_zone();
264 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
265 goto report_and_die;
266 } else {
267 // This means a segv happened inside our stack, but not in
268 // the guarded zone. I'd like to know when this happens,
269 tty->print_raw_cr("SIGSEGV happened inside stack but outside yellow and red zone.");
270 goto report_and_die;
271 }
272
273 } // end handle SIGSEGV inside stack boundaries
274
275 if (thread->thread_state() == _thread_in_Java) {
276 // Java thread running in Java code
277
278 // The following signals are used for communicating VM events:
279 //
280 // SIGILL: the compiler generates illegal opcodes
281 // at places where it wishes to interrupt the VM:
282 // Safepoints, Unreachable Code, Entry points of Zombie methods,
283 // This results in a SIGILL with (*pc) == inserted illegal instruction.
284 //
285 // (so, SIGILLs with a pc inside the zero page are real errors)
286 //
287 // SIGTRAP:
288 // The ppc trap instruction raises a SIGTRAP and is very efficient if it
289 // does not trap. It is used for conditional branches that are expected
290 // to be never taken. These are:
291 // - zombie methods
292 // - IC (inline cache) misses.
293 // - null checks leading to UncommonTraps.
294 // - range checks leading to Uncommon Traps.
295 // On Aix, these are especially null checks, as the ImplicitNullCheck
296 // optimization works only in rare cases, as the page at address 0 is only
297 // write protected. //
298 // Note: !UseSIGTRAP is used to prevent SIGTRAPS altogether, to facilitate debugging.
299 //
300 // SIGSEGV:
301 // used for safe point polling:
302 // To notify all threads that they have to reach a safe point, safe point polling is used:
303 // All threads poll a certain mapped memory page. Normally, this page has read access.
304 // If the VM wants to inform the threads about impending safe points, it puts this
305 // page to read only ("poisens" the page), and the threads then reach a safe point.
306 // used for null checks:
307 // If the compiler finds a store it uses it for a null check. Unfortunately this
308 // happens rarely. In heap based and disjoint base compressd oop modes also loads
309 // are used for null checks.
310
311 // A VM-related SIGILL may only occur if we are not in the zero page.
312 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
313 // in the zero page, because it is filled with 0x0. We ignore
314 // explicit SIGILLs in the zero page.
315 if (sig == SIGILL && (pc < (address) 0x200)) {
316 if (TraceTraps) {
317 tty->print_raw_cr("SIGILL happened inside zero page.");
318 }
319 goto report_and_die;
320 }
321
322 // Handle signal from NativeJump::patch_verified_entry().
323 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) ||
324 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) {
325 if (TraceTraps) {
326 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
327 }
328 stub = SharedRuntime::get_handle_wrong_method_stub();
329 goto run_stub;
330 }
331
332 else if (sig == SIGSEGV && os::is_poll_address(addr)) {
333 if (TraceTraps) {
334 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", pc);
335 }
336 stub = SharedRuntime::get_poll_stub(pc);
337 goto run_stub;
338 }
339
340 // SIGTRAP-based ic miss check in compiled code.
341 else if (sig == SIGTRAP && TrapBasedICMissChecks &&
342 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) {
343 if (TraceTraps) {
344 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", pc);
345 }
346 stub = SharedRuntime::get_ic_miss_stub();
347 goto run_stub;
348 }
349
350 // SIGTRAP-based implicit null check in compiled code.
351 else if (sig == SIGTRAP && TrapBasedNullChecks &&
352 nativeInstruction_at(pc)->is_sigtrap_null_check()) {
353 if (TraceTraps) {
354 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", pc);
355 }
356 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
357 goto run_stub;
358 }
359
360 // SIGSEGV-based implicit null check in compiled code.
361 else if (sig == SIGSEGV && ImplicitNullChecks &&
362 CodeCache::contains((void*) pc) &&
363 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) {
364 if (TraceTraps) {
365 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", pc);
366 }
367 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
368 }
369
370 #ifdef COMPILER2
371 // SIGTRAP-based implicit range check in compiled code.
372 else if (sig == SIGTRAP && TrapBasedRangeChecks &&
373 nativeInstruction_at(pc)->is_sigtrap_range_check()) {
374 if (TraceTraps) {
375 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", pc);
376 }
377 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
378 goto run_stub;
379 }
380 #endif
381
382 else if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
383 if (TraceTraps) {
384 tty->print_raw_cr("Fix SIGFPE handler, trying divide by zero handler.");
385 }
386 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
387 goto run_stub;
388 }
389
390 else if (sig == SIGBUS) {
391 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
392 // underlying file has been truncated. Do not crash the VM in such a case.
393 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
394 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
395 if (nm != NULL && nm->has_unsafe_access()) {
396 // We don't really need a stub here! Just set the pending exeption and
397 // continue at the next instruction after the faulting read. Returning
398 // garbage from this read is ok.
399 thread->set_pending_unsafe_access_error();
400 os::Aix::ucontext_set_pc(uc, pc + 4);
401 return 1;
402 }
403 }
404 }
405
406 else { // thread->thread_state() != _thread_in_Java
407 // Detect CPU features. This is only done at the very start of the VM. Later, the
408 // VM_Version::is_determine_features_test_running() flag should be false.
409
410 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
411 // SIGILL must be caused by VM_Version::determine_features().
412 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL,
413 // flushing of icache is not necessary.
414 stub = pc + 4; // continue with next instruction.
415 goto run_stub;
416 }
417 else if (thread->thread_state() == _thread_in_vm &&
418 sig == SIGBUS && thread->doing_unsafe_access()) {
419 // We don't really need a stub here! Just set the pending exeption and
420 // continue at the next instruction after the faulting read. Returning
421 // garbage from this read is ok.
422 thread->set_pending_unsafe_access_error();
423 os::Aix::ucontext_set_pc(uc, pc + 4);
424 return 1;
425 }
426 }
427
428 // Check to see if we caught the safepoint code in the
429 // process of write protecting the memory serialization page.
430 // It write enables the page immediately after protecting it
431 // so we can just return to retry the write.
432 if ((sig == SIGSEGV) &&
433 os::is_memory_serialize_page(thread, addr)) {
434 // Synchronization problem in the pseudo memory barrier code (bug id 6546278)
435 // Block current thread until the memory serialize page permission restored.
436 os::block_on_serialize_page_trap();
437 return true;
438 }
439 }
440
441 run_stub:
442
443 // One of the above code blocks ininitalized the stub, so we want to
444 // delegate control to that stub.
445 if (stub != NULL) {
446 // Save all thread context in case we need to restore it.
447 if (thread != NULL) thread->set_saved_exception_pc(pc);
448 os::Aix::ucontext_set_pc(uc, stub);
449 return 1;
450 }
451
452 run_chained_handler:
453
454 // signal-chaining
455 if (os::Aix::chained_handler(sig, info, ucVoid)) {
456 return 1;
457 }
458 if (!abort_if_unrecognized) {
459 // caller wants another chance, so give it to him
460 return 0;
461 }
462
463 report_and_die:
464
465 // Use sigthreadmask instead of sigprocmask on AIX and unmask current signal.
466 sigset_t newset;
467 sigemptyset(&newset);
468 sigaddset(&newset, sig);
469 sigthreadmask(SIG_UNBLOCK, &newset, NULL);
470
471 VMError::report_and_die(t, sig, pc, info, ucVoid);
472
473 ShouldNotReachHere();
474 return 0;
475 }
476
477 void os::Aix::init_thread_fpu_state(void) {
478 #if !defined(USE_XLC_BUILTINS)
479 // Disable FP exceptions.
480 __asm__ __volatile__ ("mtfsfi 6,0");
481 #else
482 __mtfsfi(6, 0);
483 #endif
484 }
485
486 ////////////////////////////////////////////////////////////////////////////////
487 // thread stack
488
489 size_t os::Aix::min_stack_allowed = 128*K;
490
491 // return default stack size for thr_type
492 size_t os::Aix::default_stack_size(os::ThreadType thr_type) {
493 // default stack size (compiler thread needs larger stack)
494 // Notice that the setting for compiler threads here have no impact
495 // because of the strange 'fallback logic' in os::create_thread().
496 // Better set CompilerThreadStackSize in globals_<os_cpu>.hpp if you want to
497 // specify a different stack size for compiler threads!
498 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M);
499 return s;
500 }
501
502 size_t os::Aix::default_guard_size(os::ThreadType thr_type) {
503 return 2 * page_size();
504 }
505
506 /////////////////////////////////////////////////////////////////////////////
507 // helper functions for fatal error handler
508
509 void os::print_context(outputStream *st, const void *context) {
510 if (context == NULL) return;
511
512 const ucontext_t* uc = (const ucontext_t*)context;
513
514 st->print_cr("Registers:");
515 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.iar);
516 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.lr);
517 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.ctr);
518 st->cr();
519 for (int i = 0; i < 32; i++) {
520 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.jmp_context.gpr[i]);
521 if (i % 3 == 2) st->cr();
522 }
523 st->cr();
524 st->cr();
525
526 intptr_t *sp = (intptr_t *)os::Aix::ucontext_get_sp(uc);
527 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
528 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
529 st->cr();
530
531 // Note: it may be unsafe to inspect memory near pc. For example, pc may
532 // point to garbage if entry point in an nmethod is corrupted. Leave
533 // this at the end, and hope for the best.
534 address pc = os::Aix::ucontext_get_pc(uc);
535 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
536 print_hex_dump(st, pc - 64, pc + 64, /*instrsize=*/4);
537 st->cr();
538
539 // Try to decode the instructions.
540 st->print_cr("Decoded instructions: (pc=" PTR_FORMAT ")", pc);
541 st->print("<TODO: PPC port - print_context>");
542 // TODO: PPC port Disassembler::decode(pc, 16, 16, st);
543 st->cr();
544 }
545
546 void os::print_register_info(outputStream *st, const void *context) {
547 if (context == NULL) return;
548
549 ucontext_t *uc = (ucontext_t*)context;
550
551 st->print_cr("Register to memory mapping:");
552 st->cr();
553
554 st->print("pc ="); print_location(st, (intptr_t)uc->uc_mcontext.jmp_context.iar);
555 st->print("lr ="); print_location(st, (intptr_t)uc->uc_mcontext.jmp_context.lr);
556 st->print("sp ="); print_location(st, (intptr_t)os::Aix::ucontext_get_sp(uc));
557 for (int i = 0; i < 32; i++) {
558 st->print("r%-2d=", i);
559 print_location(st, (intptr_t)uc->uc_mcontext.jmp_context.gpr[i]);
560 }
561
562 st->cr();
563 }
564
565 extern "C" {
566 int SpinPause() {
567 return 0;
568 }
569 }
570
571 #ifndef PRODUCT
572 void os::verify_stack_alignment() {
573 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
574 }
575 #endif
576
577 int os::extra_bang_size_in_bytes() {
578 // PPC does not require the additional stack bang.
579 return 0;
580 }
581