1 /*
   2  * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "jvm.h"
  27 #include "asm/macroAssembler.hpp"
  28 #include "macroAssembler_sparc.hpp"
  29 #include "classfile/classLoader.hpp"
  30 #include "classfile/systemDictionary.hpp"
  31 #include "classfile/vmSymbols.hpp"
  32 #include "code/codeCache.hpp"
  33 #include "code/icBuffer.hpp"
  34 #include "code/vtableStubs.hpp"
  35 #include "interpreter/interpreter.hpp"
  36 #include "memory/allocation.inline.hpp"
  37 #include "nativeInst_sparc.hpp"
  38 #include "os_share_solaris.hpp"
  39 #include "prims/jniFastGetField.hpp"
  40 #include "prims/jvm_misc.hpp"
  41 #include "runtime/arguments.hpp"
  42 #include "runtime/extendedPC.hpp"
  43 #include "runtime/frame.inline.hpp"
  44 #include "runtime/interfaceSupport.inline.hpp"
  45 #include "runtime/java.hpp"
  46 #include "runtime/javaCalls.hpp"
  47 #include "runtime/mutexLocker.hpp"
  48 #include "runtime/osThread.hpp"
  49 #include "runtime/sharedRuntime.hpp"
  50 #include "runtime/stubRoutines.hpp"
  51 #include "runtime/thread.inline.hpp"
  52 #include "runtime/timer.hpp"
  53 #include "utilities/events.hpp"
  54 #include "utilities/vmError.hpp"
  55 
  56 # include <signal.h>        // needed first to avoid name collision for "std" with SC 5.0
  57 
  58 // put OS-includes here
  59 # include <sys/types.h>
  60 # include <sys/mman.h>
  61 # include <pthread.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/lwp.h>
  75 # include <poll.h>
  76 # include <sys/lwp.h>
  77 
  78 # define _STRUCTURED_PROC 1  //  this gets us the new structured proc interfaces of 5.6 & later
  79 # include <sys/procfs.h>     //  see comment in <sys/procfs.h>
  80 
  81 #define MAX_PATH (2 * K)
  82 
  83 // Minimum usable stack sizes required to get to user code. Space for
  84 // HotSpot guard pages is added later.
  85 size_t os::Posix::_compiler_thread_min_stack_allowed = 104 * K;
  86 size_t os::Posix::_java_thread_min_stack_allowed = 86 * K;
  87 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 128 * K;
  88 
  89 static void handle_unflushed_register_windows(gwindows_t *win) {
  90   int restore_count = win->wbcnt;
  91   int i;
  92 
  93   for(i=0; i<restore_count; i++) {
  94     address sp = ((address)win->spbuf[i]) + STACK_BIAS;
  95     address reg_win = (address)&win->wbuf[i];
  96     memcpy(sp,reg_win,sizeof(struct rwindow));
  97   }
  98 }
  99 
 100 char* os::non_memory_address_word() {
 101   // Must never look like an address returned by reserve_memory,
 102   // even in its subfields (as defined by the CPU immediate fields,
 103   // if the CPU splits constants across multiple instructions).
 104   // On SPARC, 0 != %hi(any real address), because there is no
 105   // allocation in the first 1Kb of the virtual address space.
 106   return (char*) 0;
 107 }
 108 
 109 // Validate a ucontext retrieved from walking a uc_link of a ucontext.
 110 // There are issues with libthread giving out uc_links for different threads
 111 // on the same uc_link chain and bad or circular links.
 112 //
 113 bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) {
 114   if (valid >= suspect ||
 115       valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
 116       valid->uc_stack.ss_sp    != suspect->uc_stack.ss_sp    ||
 117       valid->uc_stack.ss_size  != suspect->uc_stack.ss_size) {
 118     DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)
 119     return false;
 120   }
 121 
 122   if (thread->is_Java_thread()) {
 123     if (!valid_stack_address(thread, (address)suspect)) {
 124       DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)
 125       return false;
 126     }
 127     address _sp   = (address)((intptr_t)suspect->uc_mcontext.gregs[REG_SP] + STACK_BIAS);
 128     if (!valid_stack_address(thread, _sp) ||
 129         !frame::is_valid_stack_pointer(((JavaThread*)thread)->base_of_stack_pointer(), (intptr_t*)_sp)) {
 130       DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)
 131       return false;
 132     }
 133   }
 134   return true;
 135 }
 136 
 137 // We will only follow one level of uc_link since there are libthread
 138 // issues with ucontext linking and it is better to be safe and just
 139 // let caller retry later.
 140 const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
 141   const ucontext_t *uc) {
 142 
 143   const ucontext_t *retuc = NULL;
 144 
 145   // Sometimes the topmost register windows are not properly flushed.
 146   // i.e., if the kernel would have needed to take a page fault
 147   if (uc != NULL && uc->uc_mcontext.gwins != NULL) {
 148     ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);
 149   }
 150 
 151   if (uc != NULL) {
 152     if (uc->uc_link == NULL) {
 153       // cannot validate without uc_link so accept current ucontext
 154       retuc = uc;
 155     } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
 156       // first ucontext is valid so try the next one
 157       uc = uc->uc_link;
 158       if (uc->uc_link == NULL) {
 159         // cannot validate without uc_link so accept current ucontext
 160         retuc = uc;
 161       } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
 162         // the ucontext one level down is also valid so return it
 163         retuc = uc;
 164       }
 165     }
 166   }
 167   return retuc;
 168 }
 169 
 170 // Assumes ucontext is valid
 171 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) {
 172   address pc = (address)uc->uc_mcontext.gregs[REG_PC];
 173   // set npc to zero to avoid using it for safepoint, good for profiling only
 174   return ExtendedPC(pc);
 175 }
 176 
 177 void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) {
 178   uc->uc_mcontext.gregs [REG_PC]  = (greg_t) pc;
 179   uc->uc_mcontext.gregs [REG_nPC] = (greg_t) (pc + 4);
 180 }
 181 
 182 // Assumes ucontext is valid
 183 intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) {
 184   return (intptr_t*)((intptr_t)uc->uc_mcontext.gregs[REG_SP] + STACK_BIAS);
 185 }
 186 
 187 // Solaris X86 only
 188 intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) {
 189   ShouldNotReachHere();
 190   return NULL;
 191 }
 192 
 193 address os::Solaris::ucontext_get_pc(const ucontext_t *uc) {
 194   return (address) uc->uc_mcontext.gregs[REG_PC];
 195 }
 196 
 197 
 198 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
 199 // is currently interrupted by SIGPROF.
 200 //
 201 // ret_fp parameter is only used by Solaris X86.
 202 //
 203 // The difference between this and os::fetch_frame_from_context() is that
 204 // here we try to skip nested signal frames.
 205 // This method is also used for stack overflow signal handling.
 206 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
 207   const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 208 
 209   assert(thread != NULL, "just checking");
 210   assert(ret_sp != NULL, "just checking");
 211   assert(ret_fp == NULL, "just checking");
 212 
 213   const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
 214 
 215   return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
 216 }
 217 
 218 
 219 // ret_fp parameter is only used by Solaris X86.
 220 ExtendedPC os::fetch_frame_from_context(const void* ucVoid,
 221                     intptr_t** ret_sp, intptr_t** ret_fp) {
 222 
 223   ExtendedPC  epc;
 224   const ucontext_t *uc = (const ucontext_t*)ucVoid;
 225 
 226   if (uc != NULL) {
 227     epc = os::Solaris::ucontext_get_ExtendedPC(uc);
 228     if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
 229   } else {
 230     // construct empty ExtendedPC for return value checking
 231     epc = ExtendedPC(NULL);
 232     if (ret_sp) *ret_sp = (intptr_t *)NULL;
 233   }
 234 
 235   return epc;
 236 }
 237 
 238 frame os::fetch_frame_from_context(const void* ucVoid) {
 239   intptr_t* sp;
 240   intptr_t* fp;
 241   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
 242   return frame(sp, frame::unpatchable, epc.pc());
 243 }
 244 
 245 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) {
 246   intptr_t* sp;
 247   ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, NULL);
 248   return frame(sp, frame::unpatchable, epc.pc());
 249 }
 250 
 251 bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) {
 252   address pc = (address) os::Solaris::ucontext_get_pc(uc);
 253   if (Interpreter::contains(pc)) {
 254     *fr = os::fetch_frame_from_ucontext(thread, uc);
 255     if (!fr->is_first_java_frame()) {
 256       assert(fr->safe_for_sender(thread), "Safety check");
 257       *fr = fr->java_sender();
 258     }
 259   } else {
 260     // more complex code with compiled code
 261     assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
 262     CodeBlob* cb = CodeCache::find_blob(pc);
 263     if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
 264       // Not sure where the pc points to, fallback to default
 265       // stack overflow handling
 266       return false;
 267     } else {
 268       // Returned frame will be the caller of the method that faults on the stack bang.
 269       // Register window not yet rotated (happens at SAVE after stack bang), so there is no new
 270       // frame to go with the faulting PC. Using caller SP that is still in SP, and caller PC
 271       // that was written to O7 at call.
 272       intptr_t* sp = os::Solaris::ucontext_get_sp(uc);
 273       address pc = (address)uc->uc_mcontext.gregs[REG_O7];
 274       *fr = frame(sp, frame::unpatchable, pc);
 275 
 276       if (!fr->is_java_frame()) {
 277         assert(fr->safe_for_sender(thread), "Safety check");
 278         *fr = fr->java_sender();
 279       }
 280     }
 281   }
 282   assert(fr->is_java_frame(), "Safety check");
 283   return true;
 284 }
 285 
 286 frame os::get_sender_for_C_frame(frame* fr) {
 287   return frame(fr->sender_sp(), frame::unpatchable, fr->sender_pc());
 288 }
 289 
 290 // Returns an estimate of the current stack pointer. Result must be guaranteed to
 291 // point into the calling threads stack, and be no lower than the current stack
 292 // pointer.
 293 address os::current_stack_pointer() {
 294   volatile int dummy;
 295   address sp = (address)&dummy + 8;     // %%%% need to confirm if this is right
 296   return sp;
 297 }
 298 
 299 frame os::current_frame() {
 300   intptr_t* sp = StubRoutines::Sparc::flush_callers_register_windows_func()();
 301   frame myframe(sp, frame::unpatchable,
 302                 CAST_FROM_FN_PTR(address, os::current_frame));
 303   if (os::is_first_C_frame(&myframe)) {
 304     // stack is not walkable
 305     return frame(NULL, NULL, false);
 306   } else {
 307     return os::get_sender_for_C_frame(&myframe);
 308   }
 309 }
 310 
 311 bool os::is_allocatable(size_t bytes) {
 312    return true;
 313 }
 314 
 315 extern "C" JNIEXPORT int
 316 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
 317                           int abort_if_unrecognized) {
 318   ucontext_t* uc = (ucontext_t*) ucVoid;
 319 
 320   Thread* t = Thread::current_or_null_safe();
 321 
 322   // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
 323   // (no destructors can be run)
 324   os::ThreadCrashProtection::check_crash_protection(sig, t);
 325 
 326   SignalHandlerMark shm(t);
 327 
 328   if(sig == SIGPIPE || sig == SIGXFSZ) {
 329     if (os::Solaris::chained_handler(sig, info, ucVoid)) {
 330       return true;
 331     } else {
 332       // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219
 333       return true;
 334     }
 335   }
 336 
 337   JavaThread* thread = NULL;
 338   VMThread* vmthread = NULL;
 339   if (os::Solaris::signal_handlers_are_installed) {
 340     if (t != NULL ){
 341       if(t->is_Java_thread()) {
 342         thread = (JavaThread*)t;
 343       }
 344       else if(t->is_VM_thread()){
 345         vmthread = (VMThread *)t;
 346       }
 347     }
 348   }
 349 
 350   if (sig == ASYNC_SIGNAL) {
 351     if (thread || vmthread) {
 352       OSThread::SR_handler(t, uc);
 353       return true;
 354     } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
 355       return true;
 356     } else {
 357       // If ASYNC_SIGNAL not chained, and this is a non-vm and
 358       // non-java thread
 359       return true;
 360     }
 361   }
 362 
 363   if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
 364     // can't decode this kind of signal
 365     info = NULL;
 366   } else {
 367     assert(sig == info->si_signo, "bad siginfo");
 368   }
 369 
 370   // decide if this trap can be handled by a stub
 371   address stub = NULL;
 372 
 373   address pc          = NULL;
 374   address npc         = NULL;
 375 
 376   //%note os_trap_1
 377   if (info != NULL && uc != NULL && thread != NULL) {
 378     // factor me: getPCfromContext
 379     pc  = (address) uc->uc_mcontext.gregs[REG_PC];
 380     npc = (address) uc->uc_mcontext.gregs[REG_nPC];
 381 
 382     // SafeFetch() support
 383     if (StubRoutines::is_safefetch_fault(pc)) {
 384       os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
 385       return 1;
 386     }
 387 
 388     // Handle ALL stack overflow variations here
 389     if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
 390       address addr = (address) info->si_addr;
 391       if (thread->in_stack_yellow_reserved_zone(addr)) {
 392         // Sometimes the register windows are not properly flushed.
 393         if(uc->uc_mcontext.gwins != NULL) {
 394           ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);
 395         }
 396         if (thread->thread_state() == _thread_in_Java) {
 397           if (thread->in_stack_reserved_zone(addr)) {
 398             frame fr;
 399             if (os::Solaris::get_frame_at_stack_banging_point(thread, uc, &fr)) {
 400               assert(fr.is_java_frame(), "Must be a Java frame");
 401               frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
 402               if (activation.sp() != NULL) {
 403                 thread->disable_stack_reserved_zone();
 404                 RegisterMap map(thread);
 405                 int frame_size = activation.frame_size(&map);
 406                 thread->set_reserved_stack_activation((address)(((address)activation.sp()) - STACK_BIAS));
 407                 return true;
 408               }
 409             }
 410           }
 411           // Throw a stack overflow exception.  Guard pages will be reenabled
 412           // while unwinding the stack.
 413           thread->disable_stack_yellow_reserved_zone();
 414           stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
 415         } else {
 416           // Thread was in the vm or native code.  Return and try to finish.
 417           thread->disable_stack_yellow_reserved_zone();
 418           return true;
 419         }
 420       } else if (thread->in_stack_red_zone(addr)) {
 421         // Fatal red zone violation.  Disable the guard pages and fall through
 422         // to handle_unexpected_exception way down below.
 423         thread->disable_stack_red_zone();
 424         tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
 425         // Sometimes the register windows are not properly flushed.
 426         if(uc->uc_mcontext.gwins != NULL) {
 427           ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);
 428         }
 429       }
 430     }
 431 
 432 
 433     if (thread->thread_state() == _thread_in_vm ||
 434         thread->thread_state() == _thread_in_native) {
 435       if (sig == SIGBUS && thread->doing_unsafe_access()) {
 436         if (UnsafeCopyMemory::contains_pc(pc)) {
 437           npc = UnsafeCopyMemory::page_error_continue_pc(pc);
 438         }
 439         stub = SharedRuntime::handle_unsafe_access(thread, npc);
 440       }
 441     }
 442 
 443     else if (thread->thread_state() == _thread_in_Java) {
 444       // Java thread running in Java code => find exception handler if any
 445       // a fault inside compiled code, the interpreter, or a stub
 446 
 447       // Support Safepoint Polling
 448       if (sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
 449         stub = SharedRuntime::get_poll_stub(pc);
 450       }
 451 
 452       // Not needed on x86 solaris because verify_oops doesn't generate
 453       // SEGV/BUS like sparc does.
 454       if ( (sig == SIGSEGV || sig == SIGBUS)
 455            && pc >= MacroAssembler::_verify_oop_implicit_branch[0]
 456            && pc <  MacroAssembler::_verify_oop_implicit_branch[1] ) {
 457         stub     =  MacroAssembler::_verify_oop_implicit_branch[2];
 458         warning("fixed up memory fault in +VerifyOops at address " INTPTR_FORMAT, info->si_addr);
 459       }
 460 
 461       // This is not factored because on x86 solaris the patching for
 462       // zombies does not generate a SEGV.
 463       else if (sig == SIGSEGV && nativeInstruction_at(pc)->is_zombie()) {
 464         // zombie method (ld [%g0],%o7 instruction)
 465         stub = SharedRuntime::get_handle_wrong_method_stub();
 466 
 467         // At the stub it needs to look like a call from the caller of this
 468         // method (not a call from the segv site).
 469         pc = (address)uc->uc_mcontext.gregs[REG_O7];
 470       }
 471       else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
 472         // BugId 4454115: A read from a MappedByteBuffer can fault
 473         // here if the underlying file has been truncated.
 474         // Do not crash the VM in such a case.
 475         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
 476         CompiledMethod* nm = cb->as_compiled_method_or_null();
 477         bool is_unsafe_arraycopy = (thread->doing_unsafe_access() && UnsafeCopyMemory::contains_pc(pc));
 478         if ((nm != NULL && nm->has_unsafe_access()) || is_unsafe_arraycopy) {
 479           if (is_unsafe_arraycopy) {
 480             npc = UnsafeCopyMemory::page_error_continue_pc(pc);
 481           }
 482           stub = SharedRuntime::handle_unsafe_access(thread, npc);
 483         }
 484       }
 485 
 486       else if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
 487         // integer divide by zero
 488         stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
 489       }
 490       else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
 491         // floating-point divide by zero
 492         stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
 493       }
 494 #ifdef COMPILER2
 495       else if (sig == SIGILL && nativeInstruction_at(pc)->is_ic_miss_trap()) {
 496 #ifdef ASSERT
 497   #ifdef TIERED
 498         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
 499         assert(cb->is_compiled_by_c2(), "Wrong compiler");
 500   #endif // TIERED
 501 #endif // ASSERT
 502         // Inline cache missed and user trap "Tne G0+ST_RESERVED_FOR_USER_0+2" taken.
 503         stub = SharedRuntime::get_ic_miss_stub();
 504         // At the stub it needs to look like a call from the caller of this
 505         // method (not a call from the segv site).
 506         pc = (address)uc->uc_mcontext.gregs[REG_O7];
 507       }
 508 #endif  // COMPILER2
 509 
 510       else if (sig == SIGSEGV && info->si_code > 0 && MacroAssembler::uses_implicit_null_check(info->si_addr)) {
 511         // Determination of interpreter/vtable stub/compiled code null exception
 512         stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
 513       }
 514     }
 515 
 516     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
 517     // and the heap gets shrunk before the field access.
 518     if ((sig == SIGSEGV) || (sig == SIGBUS)) {
 519       address addr = JNI_FastGetField::find_slowcase_pc(pc);
 520       if (addr != (address)-1) {
 521         stub = addr;
 522       }
 523     }
 524   }
 525 
 526   if (stub != NULL) {
 527     // save all thread context in case we need to restore it
 528 
 529     thread->set_saved_exception_pc(pc);
 530     thread->set_saved_exception_npc(npc);
 531 
 532     // simulate a branch to the stub (a "call" in the safepoint stub case)
 533     // factor me: setPC
 534     os::Solaris::ucontext_set_pc(uc, stub);
 535 
 536     return true;
 537   }
 538 
 539   // signal-chaining
 540   if (os::Solaris::chained_handler(sig, info, ucVoid)) {
 541     return true;
 542   }
 543 
 544   if (!abort_if_unrecognized) {
 545     // caller wants another chance, so give it to him
 546     return false;
 547   }
 548 
 549   if (!os::Solaris::libjsig_is_loaded) {
 550     struct sigaction oldAct;
 551     sigaction(sig, (struct sigaction *)0, &oldAct);
 552     if (oldAct.sa_sigaction != signalHandler) {
 553       void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
 554                                           : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
 555       warning("Unexpected Signal %d occurred under user-defined signal handler " INTPTR_FORMAT, sig, (intptr_t)sighand);
 556     }
 557   }
 558 
 559   if (pc == NULL && uc != NULL) {
 560     pc = (address) uc->uc_mcontext.gregs[REG_PC];
 561   }
 562 
 563   // Sometimes the register windows are not properly flushed.
 564   if(uc->uc_mcontext.gwins != NULL) {
 565     ::handle_unflushed_register_windows(uc->uc_mcontext.gwins);
 566   }
 567 
 568   // unmask current signal
 569   sigset_t newset;
 570   sigemptyset(&newset);
 571   sigaddset(&newset, sig);
 572   sigprocmask(SIG_UNBLOCK, &newset, NULL);
 573 
 574   // Determine which sort of error to throw.  Out of swap may signal
 575   // on the thread stack, which could get a mapping error when touched.
 576   address addr = (address) info->si_addr;
 577   if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
 578     vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
 579   }
 580 
 581   VMError::report_and_die(t, sig, pc, info, ucVoid);
 582 
 583   ShouldNotReachHere();
 584   return false;
 585 }
 586 
 587 void os::print_context(outputStream *st, const void *context) {
 588   if (context == NULL) return;
 589 
 590   const ucontext_t *uc = (const ucontext_t*)context;
 591   st->print_cr("Registers:");
 592 
 593   st->print_cr(" G1=" INTPTR_FORMAT " G2=" INTPTR_FORMAT
 594                " G3=" INTPTR_FORMAT " G4=" INTPTR_FORMAT,
 595             uc->uc_mcontext.gregs[REG_G1],
 596             uc->uc_mcontext.gregs[REG_G2],
 597             uc->uc_mcontext.gregs[REG_G3],
 598             uc->uc_mcontext.gregs[REG_G4]);
 599   st->print_cr(" G5=" INTPTR_FORMAT " G6=" INTPTR_FORMAT
 600                " G7=" INTPTR_FORMAT " Y=" INTPTR_FORMAT,
 601             uc->uc_mcontext.gregs[REG_G5],
 602             uc->uc_mcontext.gregs[REG_G6],
 603             uc->uc_mcontext.gregs[REG_G7],
 604             uc->uc_mcontext.gregs[REG_Y]);
 605   st->print_cr(" O0=" INTPTR_FORMAT " O1=" INTPTR_FORMAT
 606                " O2=" INTPTR_FORMAT " O3=" INTPTR_FORMAT,
 607                  uc->uc_mcontext.gregs[REG_O0],
 608                  uc->uc_mcontext.gregs[REG_O1],
 609                  uc->uc_mcontext.gregs[REG_O2],
 610                  uc->uc_mcontext.gregs[REG_O3]);
 611   st->print_cr(" O4=" INTPTR_FORMAT " O5=" INTPTR_FORMAT
 612                " O6=" INTPTR_FORMAT " O7=" INTPTR_FORMAT,
 613             uc->uc_mcontext.gregs[REG_O4],
 614             uc->uc_mcontext.gregs[REG_O5],
 615             uc->uc_mcontext.gregs[REG_O6],
 616             uc->uc_mcontext.gregs[REG_O7]);
 617 
 618 
 619   intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
 620   st->print_cr(" L0=" INTPTR_FORMAT " L1=" INTPTR_FORMAT
 621                " L2=" INTPTR_FORMAT " L3=" INTPTR_FORMAT,
 622                sp[L0->sp_offset_in_saved_window()],
 623                sp[L1->sp_offset_in_saved_window()],
 624                sp[L2->sp_offset_in_saved_window()],
 625                sp[L3->sp_offset_in_saved_window()]);
 626   st->print_cr(" L4=" INTPTR_FORMAT " L5=" INTPTR_FORMAT
 627                " L6=" INTPTR_FORMAT " L7=" INTPTR_FORMAT,
 628                sp[L4->sp_offset_in_saved_window()],
 629                sp[L5->sp_offset_in_saved_window()],
 630                sp[L6->sp_offset_in_saved_window()],
 631                sp[L7->sp_offset_in_saved_window()]);
 632   st->print_cr(" I0=" INTPTR_FORMAT " I1=" INTPTR_FORMAT
 633                " I2=" INTPTR_FORMAT " I3=" INTPTR_FORMAT,
 634                sp[I0->sp_offset_in_saved_window()],
 635                sp[I1->sp_offset_in_saved_window()],
 636                sp[I2->sp_offset_in_saved_window()],
 637                sp[I3->sp_offset_in_saved_window()]);
 638   st->print_cr(" I4=" INTPTR_FORMAT " I5=" INTPTR_FORMAT
 639                " I6=" INTPTR_FORMAT " I7=" INTPTR_FORMAT,
 640                sp[I4->sp_offset_in_saved_window()],
 641                sp[I5->sp_offset_in_saved_window()],
 642                sp[I6->sp_offset_in_saved_window()],
 643                sp[I7->sp_offset_in_saved_window()]);
 644 
 645   st->print_cr(" PC=" INTPTR_FORMAT " nPC=" INTPTR_FORMAT,
 646             uc->uc_mcontext.gregs[REG_PC],
 647             uc->uc_mcontext.gregs[REG_nPC]);
 648   st->cr();
 649   st->cr();
 650 
 651   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
 652   print_hex_dump(st, (address)sp, (address)(sp + 32), sizeof(intptr_t));
 653   st->cr();
 654 
 655   // Note: it may be unsafe to inspect memory near pc. For example, pc may
 656   // point to garbage if entry point in an nmethod is corrupted. Leave
 657   // this at the end, and hope for the best.
 658   ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
 659   address pc = epc.pc();
 660   print_instructions(st, pc, sizeof(char));
 661   st->cr();
 662 }
 663 
 664 void os::print_register_info(outputStream *st, const void *context) {
 665   if (context == NULL) return;
 666 
 667   const ucontext_t *uc = (const ucontext_t*)context;
 668   intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
 669 
 670   st->print_cr("Register to memory mapping:");
 671   st->cr();
 672 
 673   // this is only for the "general purpose" registers
 674   st->print("G1="); print_location(st, uc->uc_mcontext.gregs[REG_G1]);
 675   st->print("G2="); print_location(st, uc->uc_mcontext.gregs[REG_G2]);
 676   st->print("G3="); print_location(st, uc->uc_mcontext.gregs[REG_G3]);
 677   st->print("G4="); print_location(st, uc->uc_mcontext.gregs[REG_G4]);
 678   st->print("G5="); print_location(st, uc->uc_mcontext.gregs[REG_G5]);
 679   st->print("G6="); print_location(st, uc->uc_mcontext.gregs[REG_G6]);
 680   st->print("G7="); print_location(st, uc->uc_mcontext.gregs[REG_G7]);
 681   st->cr();
 682 
 683   st->print("O0="); print_location(st, uc->uc_mcontext.gregs[REG_O0]);
 684   st->print("O1="); print_location(st, uc->uc_mcontext.gregs[REG_O1]);
 685   st->print("O2="); print_location(st, uc->uc_mcontext.gregs[REG_O2]);
 686   st->print("O3="); print_location(st, uc->uc_mcontext.gregs[REG_O3]);
 687   st->print("O4="); print_location(st, uc->uc_mcontext.gregs[REG_O4]);
 688   st->print("O5="); print_location(st, uc->uc_mcontext.gregs[REG_O5]);
 689   st->print("O6="); print_location(st, uc->uc_mcontext.gregs[REG_O6]);
 690   st->print("O7="); print_location(st, uc->uc_mcontext.gregs[REG_O7]);
 691   st->cr();
 692 
 693   st->print("L0="); print_location(st, sp[L0->sp_offset_in_saved_window()]);
 694   st->print("L1="); print_location(st, sp[L1->sp_offset_in_saved_window()]);
 695   st->print("L2="); print_location(st, sp[L2->sp_offset_in_saved_window()]);
 696   st->print("L3="); print_location(st, sp[L3->sp_offset_in_saved_window()]);
 697   st->print("L4="); print_location(st, sp[L4->sp_offset_in_saved_window()]);
 698   st->print("L5="); print_location(st, sp[L5->sp_offset_in_saved_window()]);
 699   st->print("L6="); print_location(st, sp[L6->sp_offset_in_saved_window()]);
 700   st->print("L7="); print_location(st, sp[L7->sp_offset_in_saved_window()]);
 701   st->cr();
 702 
 703   st->print("I0="); print_location(st, sp[I0->sp_offset_in_saved_window()]);
 704   st->print("I1="); print_location(st, sp[I1->sp_offset_in_saved_window()]);
 705   st->print("I2="); print_location(st, sp[I2->sp_offset_in_saved_window()]);
 706   st->print("I3="); print_location(st, sp[I3->sp_offset_in_saved_window()]);
 707   st->print("I4="); print_location(st, sp[I4->sp_offset_in_saved_window()]);
 708   st->print("I5="); print_location(st, sp[I5->sp_offset_in_saved_window()]);
 709   st->print("I6="); print_location(st, sp[I6->sp_offset_in_saved_window()]);
 710   st->print("I7="); print_location(st, sp[I7->sp_offset_in_saved_window()]);
 711   st->cr();
 712 }
 713 
 714 void os::Solaris::init_thread_fpu_state(void) {
 715     // Nothing needed on Sparc.
 716 }
 717 
 718 #ifndef PRODUCT
 719 void os::verify_stack_alignment() {
 720 }
 721 #endif
 722 
 723 int os::extra_bang_size_in_bytes() {
 724   // SPARC does not require an additional stack bang.
 725   return 0;
 726 }