1 /*
2 * Copyright (c) 1997, 2013, 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/icBuffer.hpp"
32 #include "code/vtableStubs.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_aix.h"
35 #include "memory/allocation.inline.hpp"
36 #include "mutex_aix.inline.hpp"
37 #include "nativeInst_ppc.hpp"
38 #include "os_share_aix.hpp"
39 #include "prims/jniFastGetField.hpp"
40 #include "prims/jvm.h"
41 #include "prims/jvm_misc.hpp"
42 #include "runtime/arguments.hpp"
43 #include "runtime/extendedPC.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/interfaceSupport.hpp"
46 #include "runtime/java.hpp"
47 #include "runtime/javaCalls.hpp"
48 #include "runtime/mutexLocker.hpp"
49 #include "runtime/osThread.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "runtime/stubRoutines.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/timer.hpp"
54 #include "utilities/events.hpp"
55 #include "utilities/vmError.hpp"
56 #ifdef COMPILER1
57 #include "c1/c1_Runtime1.hpp"
58 #endif
59 #ifdef COMPILER2
60 #include "opto/runtime.hpp"
61 #endif
62
63 // put OS-includes here
64 # include <ucontext.h>
65
66 address os::current_stack_pointer() {
67 address csp;
68
69 #if !defined(USE_XLC_BUILTINS)
70 // inline assembly for `mr regno(csp), R1_SP':
71 __asm__ __volatile__ ("mr %0, 1":"=r"(csp):);
72 #else
73 csp = (address) __builtin_frame_address(0);
74 #endif
75
76 return csp;
77 }
78
79 char* os::non_memory_address_word() {
80 // Must never look like an address returned by reserve_memory,
81 // even in its subfields (as defined by the CPU immediate fields,
82 // if the CPU splits constants across multiple instructions).
83
84 return (char*) -1;
85 }
86
87 // OS specific thread initialization
88 //
89 // Calculate and store the limits of the memory stack.
90 void os::initialize_thread(Thread *thread) { }
91
92 // Frame information (pc, sp, fp) retrieved via ucontext
93 // always looks like a C-frame according to the frame
94 // conventions in frame_ppc64.hpp.
95 address os::Aix::ucontext_get_pc(ucontext_t * uc) {
96 return (address)uc->uc_mcontext.jmp_context.iar;
97 }
98
99 intptr_t* os::Aix::ucontext_get_sp(ucontext_t * uc) {
100 // gpr1 holds the stack pointer on aix
101 return (intptr_t*)uc->uc_mcontext.jmp_context.gpr[1/*REG_SP*/];
102 }
103
104 intptr_t* os::Aix::ucontext_get_fp(ucontext_t * uc) {
105 return NULL;
106 }
107
108 void os::Aix::ucontext_set_pc(ucontext_t* uc, address new_pc) {
109 uc->uc_mcontext.jmp_context.iar = (uint64_t) new_pc;
110 }
111
112 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
113 intptr_t** ret_sp, intptr_t** ret_fp) {
114
115 ExtendedPC epc;
116 ucontext_t* uc = (ucontext_t*)ucVoid;
117
118 if (uc != NULL) {
119 epc = ExtendedPC(os::Aix::ucontext_get_pc(uc));
120 if (ret_sp) *ret_sp = os::Aix::ucontext_get_sp(uc);
121 if (ret_fp) *ret_fp = os::Aix::ucontext_get_fp(uc);
122 } else {
123 // construct empty ExtendedPC for return value checking
124 epc = ExtendedPC(NULL);
125 if (ret_sp) *ret_sp = (intptr_t *)NULL;
126 if (ret_fp) *ret_fp = (intptr_t *)NULL;
127 }
128
129 return epc;
130 }
131
132 frame os::fetch_frame_from_context(void* ucVoid) {
133 intptr_t* sp;
134 intptr_t* fp;
135 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
136 // Avoid crash during crash if pc broken.
137 if (epc.pc()) {
138 frame fr(sp, epc.pc());
139 return fr;
140 }
141 frame fr(sp);
142 return fr;
143 }
144
145 frame os::get_sender_for_C_frame(frame* fr) {
146 if (*fr->sp() == NULL) {
147 // fr is the last C frame
148 return frame(NULL, NULL);
149 }
150 return frame(fr->sender_sp(), fr->sender_pc());
151 }
152
153
154 frame os::current_frame() {
155 intptr_t* csp = (intptr_t*) *((intptr_t*) os::current_stack_pointer());
156 // hack.
157 frame topframe(csp, (address)0x8);
158 // return sender of current topframe which hopefully has pc != NULL.
159 return os::get_sender_for_C_frame(&topframe);
160 }
161
162 // Utility functions
163
164 extern "C" JNIEXPORT int
165 JVM_handle_aix_signal(int sig, siginfo_t* info, void* ucVoid, int abort_if_unrecognized) {
166
167 ucontext_t* uc = (ucontext_t*) ucVoid;
168
169 Thread* t = ThreadLocalStorage::get_thread_slow(); // slow & steady
170
171 SignalHandlerMark shm(t);
172
173 // Note: it's not uncommon that JNI code uses signal/sigset to install
174 // then restore certain signal handler (e.g. to temporarily block SIGPIPE,
175 // or have a SIGILL handler when detecting CPU type). When that happens,
176 // JVM_handle_aix_signal() might be invoked with junk info/ucVoid. To
177 // avoid unnecessary crash when libjsig is not preloaded, try handle signals
178 // that do not require siginfo/ucontext first.
179
180 if (sig == SIGPIPE) {
181 if (os::Aix::chained_handler(sig, info, ucVoid)) {
182 return 1;
183 } else {
184 if (PrintMiscellaneous && (WizardMode || Verbose)) {
185 warning("Ignoring SIGPIPE - see bug 4229104");
186 }
187 return 1;
188 }
189 }
190
191 JavaThread* thread = NULL;
192 VMThread* vmthread = NULL;
193 if (os::Aix::signal_handlers_are_installed) {
194 if (t != NULL) {
195 if(t->is_Java_thread()) {
196 thread = (JavaThread*)t;
197 }
198 else if(t->is_VM_thread()) {
199 vmthread = (VMThread *)t;
200 }
201 }
202 }
203
204 // Decide if this trap can be handled by a stub.
205 address stub = NULL;
206
207 // retrieve program counter
208 address const pc = uc ? os::Aix::ucontext_get_pc(uc) : NULL;
209
210 // retrieve crash address
211 address const addr = info ? (const address) info->si_addr : NULL;
212
213 // SafeFetch 32 handling:
214 // - make it work if _thread is null
215 // - make it use the standard os::...::ucontext_get/set_pc APIs
216 if (uc) {
217 address const pc = os::Aix::ucontext_get_pc(uc);
218 if (pc && StubRoutines::is_safefetch_fault(pc)) {
219 os::Aix::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
220 return true;
221 }
222 }
223
224 // Handle SIGDANGER right away. AIX would raise SIGDANGER whenever available swap
225 // space falls below 30%. This is only a chance for the process to gracefully abort.
226 // We can't hope to proceed after SIGDANGER since SIGKILL tailgates.
227 if (sig == SIGDANGER) {
228 goto report_and_die;
229 }
230
231 if (info == NULL || uc == NULL || thread == NULL && vmthread == NULL) {
232 goto run_chained_handler;
233 }
234
235 // If we are a java thread...
236 if (thread != NULL) {
237
238 // Handle ALL stack overflow variations here
239 if (sig == SIGSEGV && (addr < thread->stack_base() &&
240 addr >= thread->stack_base() - thread->stack_size())) {
241 // stack overflow
242 //
243 // If we are in a yellow zone and we are inside java, we disable the yellow zone and
244 // throw a stack overflow exception.
245 // If we are in native code or VM C code, we report-and-die. The original coding tried
246 // to continue with yellow zone disabled, but that doesn't buy us much and prevents
247 // hs_err_pid files.
248 if (thread->in_stack_yellow_zone(addr)) {
249 thread->disable_stack_yellow_zone();
250 if (thread->thread_state() == _thread_in_Java) {
251 // Throw a stack overflow exception.
252 // Guard pages will be reenabled while unwinding the stack.
253 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
254 goto run_stub;
255 } else {
256 // Thread was in the vm or native code. Return and try to finish.
257 return 1;
258 }
259 } else if (thread->in_stack_red_zone(addr)) {
260 // Fatal red zone violation. Disable the guard pages and fall through
261 // to handle_unexpected_exception way down below.
262 thread->disable_stack_red_zone();
263 tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
264 goto report_and_die;
265 } else {
266 // This means a segv happened inside our stack, but not in
267 // the guarded zone. I'd like to know when this happens,
268 tty->print_raw_cr("SIGSEGV happened inside stack but outside yellow and red zone.");
269 goto report_and_die;
270 }
271
272 } // end handle SIGSEGV inside stack boundaries
273
274 if (thread->thread_state() == _thread_in_Java) {
275 // Java thread running in Java code
276
277 // The following signals are used for communicating VM events:
278 //
279 // SIGILL: the compiler generates illegal opcodes
280 // at places where it wishes to interrupt the VM:
281 // Safepoints, Unreachable Code, Entry points of Zombie methods,
282 // This results in a SIGILL with (*pc) == inserted illegal instruction.
283 //
284 // (so, SIGILLs with a pc inside the zero page are real errors)
285 //
286 // SIGTRAP:
287 // The ppc trap instruction raises a SIGTRAP and is very efficient if it
288 // does not trap. It is used for conditional branches that are expected
289 // to be never taken. These are:
290 // - zombie methods
291 // - IC (inline cache) misses.
292 // - null checks leading to UncommonTraps.
293 // - range checks leading to Uncommon Traps.
294 // On Aix, these are especially null checks, as the ImplicitNullCheck
295 // optimization works only in rare cases, as the page at address 0 is only
296 // write protected. //
297 // Note: !UseSIGTRAP is used to prevent SIGTRAPS altogether, to facilitate debugging.
298 //
299 // SIGSEGV:
300 // used for safe point polling:
301 // To notify all threads that they have to reach a safe point, safe point polling is used:
302 // All threads poll a certain mapped memory page. Normally, this page has read access.
303 // If the VM wants to inform the threads about impending safe points, it puts this
304 // page to read only ("poisens" the page), and the threads then reach a safe point.
305 // used for null checks:
306 // If the compiler finds a store it uses it for a null check. Unfortunately this
307 // happens rarely. In heap based and disjoint base compressd oop modes also loads
308 // are used for null checks.
309
310 // A VM-related SIGILL may only occur if we are not in the zero page.
311 // On AIX, we get a SIGILL if we jump to 0x0 or to somewhere else
312 // in the zero page, because it is filled with 0x0. We ignore
313 // explicit SIGILLs in the zero page.
314 if (sig == SIGILL && (pc < (address) 0x200)) {
315 if (TraceTraps) {
316 tty->print_raw_cr("SIGILL happened inside zero page.");
317 }
318 goto report_and_die;
319 }
320
321 // Handle signal from NativeJump::patch_verified_entry().
322 if (( TrapBasedNotEntrantChecks && sig == SIGTRAP && nativeInstruction_at(pc)->is_sigtrap_zombie_not_entrant()) ||
323 (!TrapBasedNotEntrantChecks && sig == SIGILL && nativeInstruction_at(pc)->is_sigill_zombie_not_entrant())) {
324 if (TraceTraps) {
325 tty->print_cr("trap: zombie_not_entrant (%s)", (sig == SIGTRAP) ? "SIGTRAP" : "SIGILL");
326 }
327 stub = SharedRuntime::get_handle_wrong_method_stub();
328 goto run_stub;
329 }
330
331 else if (sig == SIGSEGV && os::is_poll_address(addr)) {
332 if (TraceTraps) {
333 tty->print_cr("trap: safepoint_poll at " INTPTR_FORMAT " (SIGSEGV)", pc);
334 }
335 stub = SharedRuntime::get_poll_stub(pc);
336 goto run_stub;
337 }
338
339 // SIGTRAP-based ic miss check in compiled code.
340 else if (sig == SIGTRAP && TrapBasedICMissChecks &&
341 nativeInstruction_at(pc)->is_sigtrap_ic_miss_check()) {
342 if (TraceTraps) {
343 tty->print_cr("trap: ic_miss_check at " INTPTR_FORMAT " (SIGTRAP)", pc);
344 }
345 stub = SharedRuntime::get_ic_miss_stub();
346 goto run_stub;
347 }
348
349 // SIGTRAP-based implicit null check in compiled code.
350 else if (sig == SIGTRAP && TrapBasedNullChecks &&
351 nativeInstruction_at(pc)->is_sigtrap_null_check()) {
352 if (TraceTraps) {
353 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGTRAP)", pc);
354 }
355 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
356 goto run_stub;
357 }
358
359 // SIGSEGV-based implicit null check in compiled code.
360 else if (sig == SIGSEGV && ImplicitNullChecks &&
361 CodeCache::contains((void*) pc) &&
362 !MacroAssembler::needs_explicit_null_check((intptr_t) info->si_addr)) {
363 if (TraceTraps) {
364 tty->print_cr("trap: null_check at " INTPTR_FORMAT " (SIGSEGV)", pc);
365 }
366 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
367 }
368
369 #ifdef COMPILER2
370 // SIGTRAP-based implicit range check in compiled code.
371 else if (sig == SIGTRAP && TrapBasedRangeChecks &&
372 nativeInstruction_at(pc)->is_sigtrap_range_check()) {
373 if (TraceTraps) {
374 tty->print_cr("trap: range_check at " INTPTR_FORMAT " (SIGTRAP)", pc);
375 }
376 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
377 goto run_stub;
378 }
379 #endif
380
381 else if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) {
382 if (TraceTraps) {
383 tty->print_raw_cr("Fix SIGFPE handler, trying divide by zero handler.");
384 }
385 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
386 goto run_stub;
387 }
388
389 else if (sig == SIGBUS) {
390 // BugId 4454115: A read from a MappedByteBuffer can fault here if the
391 // underlying file has been truncated. Do not crash the VM in such a case.
392 CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
393 nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
394 if (nm != NULL && nm->has_unsafe_access()) {
395 // We don't really need a stub here! Just set the pending exeption and
396 // continue at the next instruction after the faulting read. Returning
397 // garbage from this read is ok.
398 thread->set_pending_unsafe_access_error();
399 uc->uc_mcontext.jmp_context.iar = ((unsigned long)pc) + 4;
400 return 1;
401 }
402 }
403 }
404
405 else { // thread->thread_state() != _thread_in_Java
406 // Detect CPU features. This is only done at the very start of the VM. Later, the
407 // VM_Version::is_determine_features_test_running() flag should be false.
408
409 if (sig == SIGILL && VM_Version::is_determine_features_test_running()) {
410 // SIGILL must be caused by VM_Version::determine_features().
411 *(int *)pc = 0; // patch instruction to 0 to indicate that it causes a SIGILL,
412 // flushing of icache is not necessary.
413 stub = pc + 4; // continue with next instruction.
414 goto run_stub;
415 }
416 else if (thread->thread_state() == _thread_in_vm &&
417 sig == SIGBUS && thread->doing_unsafe_access()) {
418 // We don't really need a stub here! Just set the pending exeption and
419 // continue at the next instruction after the faulting read. Returning
420 // garbage from this read is ok.
421 thread->set_pending_unsafe_access_error();
422 uc->uc_mcontext.jmp_context.iar = ((unsigned long)pc) + 4;
423 return 1;
424 }
425 }
426
427 // Check to see if we caught the safepoint code in the
428 // process of write protecting the memory serialization page.
429 // It write enables the page immediately after protecting it
430 // so we can just return to retry the write.
431 if ((sig == SIGSEGV) &&
432 os::is_memory_serialize_page(thread, addr)) {
433 // Synchronization problem in the pseudo memory barrier code (bug id 6546278)
434 // Block current thread until the memory serialize page permission restored.
435 os::block_on_serialize_page_trap();
436 return true;
437 }
438 }
439
440 run_stub:
441
442 // One of the above code blocks ininitalized the stub, so we want to
443 // delegate control to that stub.
444 if (stub != NULL) {
445 // Save all thread context in case we need to restore it.
446 if (thread != NULL) thread->set_saved_exception_pc(pc);
447 uc->uc_mcontext.jmp_context.iar = (unsigned long)stub;
448 return 1;
449 }
450
451 run_chained_handler:
452
453 // signal-chaining
454 if (os::Aix::chained_handler(sig, info, ucVoid)) {
455 return 1;
456 }
457 if (!abort_if_unrecognized) {
458 // caller wants another chance, so give it to him
459 return 0;
460 }
461
462 report_and_die:
463
464 // Use sigthreadmask instead of sigprocmask on AIX and unmask current signal.
465 sigset_t newset;
466 sigemptyset(&newset);
467 sigaddset(&newset, sig);
468 sigthreadmask(SIG_UNBLOCK, &newset, NULL);
469
470 VMError err(t, sig, pc, info, ucVoid);
471 err.report_and_die();
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 = 768*K;
490
491 // Aix is always in floating stack mode. The stack size for a new
492 // thread can be set via pthread_attr_setstacksize().
493 bool os::Aix::supports_variable_stack_size() { return true; }
494
495 // return default stack size for thr_type
496 size_t os::Aix::default_stack_size(os::ThreadType thr_type) {
497 // default stack size (compiler thread needs larger stack)
498 // Notice that the setting for compiler threads here have no impact
499 // because of the strange 'fallback logic' in os::create_thread().
500 // Better set CompilerThreadStackSize in globals_<os_cpu>.hpp if you want to
501 // specify a different stack size for compiler threads!
502 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1024 * K);
503 return s;
504 }
505
506 size_t os::Aix::default_guard_size(os::ThreadType thr_type) {
507 return 2 * page_size();
508 }
509
510 /////////////////////////////////////////////////////////////////////////////
511 // helper functions for fatal error handler
512
513 void os::print_context(outputStream *st, void *context) {
514 if (context == NULL) return;
515
516 ucontext_t* uc = (ucontext_t*)context;
517
518 st->print_cr("Registers:");
519 st->print("pc =" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.iar);
520 st->print("lr =" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.lr);
521 st->print("ctr=" INTPTR_FORMAT " ", uc->uc_mcontext.jmp_context.ctr);
522 st->cr();
523 for (int i = 0; i < 32; i++) {
524 st->print("r%-2d=" INTPTR_FORMAT " ", i, uc->uc_mcontext.jmp_context.gpr[i]);
525 if (i % 3 == 2) st->cr();
526 }
527 st->cr();
528 st->cr();
529
530 intptr_t *sp = (intptr_t *)os::Aix::ucontext_get_sp(uc);
531 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
532 print_hex_dump(st, (address)sp, (address)(sp + 128), sizeof(intptr_t));
533 st->cr();
534
535 // Note: it may be unsafe to inspect memory near pc. For example, pc may
536 // point to garbage if entry point in an nmethod is corrupted. Leave
537 // this at the end, and hope for the best.
538 address pc = os::Aix::ucontext_get_pc(uc);
539 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
540 print_hex_dump(st, pc - 64, pc + 64, /*instrsize=*/4);
541 st->cr();
542
543 // Try to decode the instructions.
544 st->print_cr("Decoded instructions: (pc=" PTR_FORMAT ")", pc);
545 st->print("<TODO: PPC port - print_context>");
546 // TODO: PPC port Disassembler::decode(pc, 16, 16, st);
547 st->cr();
548 }
549
550 void os::print_register_info(outputStream *st, void *context) {
551 if (context == NULL) return;
552 st->print("Not ported - print_register_info\n");
553 }
554
555 extern "C" {
556 int SpinPause() {
557 return 0;
558 }
559 }
560
561 #ifndef PRODUCT
562 void os::verify_stack_alignment() {
563 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
564 }
565 #endif