1 /*
   2  * Copyright (c) 1999, 2017, 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 "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 "memory/allocation.inline.hpp"
  36 #include "os_share_solaris.hpp"
  37 #include "prims/jniFastGetField.hpp"
  38 #include "prims/jvm_misc.hpp"
  39 #include "runtime/arguments.hpp"
  40 #include "runtime/atomic.hpp"
  41 #include "runtime/extendedPC.hpp"
  42 #include "runtime/frame.inline.hpp"
  43 #include "runtime/interfaceSupport.hpp"
  44 #include "runtime/java.hpp"
  45 #include "runtime/javaCalls.hpp"
  46 #include "runtime/mutexLocker.hpp"
  47 #include "runtime/osThread.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 #include "runtime/stubRoutines.hpp"
  50 #include "runtime/thread.inline.hpp"
  51 #include "runtime/timer.hpp"
  52 #include "utilities/align.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::ThreadCrashProtection::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 == ASYNC_SIGNAL) {
 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 ASYNC_SIGNAL 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_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 = align_down(addr, page_size);
 651         bool res = os::protect_memory((char*) page_start, page_size,
 652                                       os::MEM_PROT_RWX);
 653 
 654         log_debug(os)("Execution protection violation "
 655                       "at " INTPTR_FORMAT
 656                       ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr),
 657                       p2i(page_start), (res ? "success" : "failed"), errno);
 658         stub = pc;
 659 
 660         // Set last_addr so if we fault again at the same address, we don't end
 661         // up in an endless loop.
 662         //
 663         // There are two potential complications here.  Two threads trapping at
 664         // the same address at the same time could cause one of the threads to
 665         // think it already unguarded, and abort the VM.  Likely very rare.
 666         //
 667         // The other race involves two threads alternately trapping at
 668         // different addresses and failing to unguard the page, resulting in
 669         // an endless loop.  This condition is probably even more unlikely than
 670         // the first.
 671         //
 672         // Although both cases could be avoided by using locks or thread local
 673         // last_addr, these solutions are unnecessary complication: this
 674         // handler is a best-effort safety net, not a complete solution.  It is
 675         // disabled by default and should only be used as a workaround in case
 676         // we missed any no-execute-unsafe VM code.
 677 
 678         last_addr = addr;
 679       }
 680     }
 681   }
 682 
 683   if (stub != NULL) {
 684     // save all thread context in case we need to restore it
 685 
 686     if (thread != NULL) thread->set_saved_exception_pc(pc);
 687     // 12/02/99: On Sparc it appears that the full context is also saved
 688     // but as yet, no one looks at or restores that saved context
 689     os::Solaris::ucontext_set_pc(uc, stub);
 690     return true;
 691   }
 692 
 693   // signal-chaining
 694   if (os::Solaris::chained_handler(sig, info, ucVoid)) {
 695     return true;
 696   }
 697 
 698 #ifndef AMD64
 699   // Workaround (bug 4900493) for Solaris kernel bug 4966651.
 700   // Handle an undefined selector caused by an attempt to assign
 701   // fs in libthread getipriptr(). With the current libthread design every 512
 702   // thread creations the LDT for a private thread data structure is extended
 703   // and thre is a hazard that and another thread attempting a thread creation
 704   // will use a stale LDTR that doesn't reflect the structure's growth,
 705   // causing a GP fault.
 706   // Enforce the probable limit of passes through here to guard against an
 707   // infinite loop if some other move to fs caused the GP fault. Note that
 708   // this loop counter is ultimately a heuristic as it is possible for
 709   // more than one thread to generate this fault at a time in an MP system.
 710   // In the case of the loop count being exceeded or if the poll fails
 711   // just fall through to a fatal error.
 712   // If there is some other source of T_GPFLT traps and the text at EIP is
 713   // unreadable this code will loop infinitely until the stack is exausted.
 714   // The key to diagnosis in this case is to look for the bottom signal handler
 715   // frame.
 716 
 717   if(! IgnoreLibthreadGPFault) {
 718     if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
 719       const unsigned char *p =
 720                         (unsigned const char *) uc->uc_mcontext.gregs[EIP];
 721 
 722       // Expected instruction?
 723 
 724       if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
 725 
 726         Atomic::inc(&ldtr_refresh);
 727 
 728         // Infinite loop?
 729 
 730         if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
 731 
 732           // No, force scheduling to get a fresh view of the LDTR
 733 
 734           if(poll(NULL, 0, 10) == 0) {
 735 
 736             // Retry the move
 737 
 738             return false;
 739           }
 740         }
 741       }
 742     }
 743   }
 744 #endif // !AMD64
 745 
 746   if (!abort_if_unrecognized) {
 747     // caller wants another chance, so give it to him
 748     return false;
 749   }
 750 
 751   if (!os::Solaris::libjsig_is_loaded) {
 752     struct sigaction oldAct;
 753     sigaction(sig, (struct sigaction *)0, &oldAct);
 754     if (oldAct.sa_sigaction != signalHandler) {
 755       void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
 756                                           : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
 757       warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
 758     }
 759   }
 760 
 761   if (pc == NULL && uc != NULL) {
 762     pc = (address) uc->uc_mcontext.gregs[REG_PC];
 763   }
 764 
 765   // unmask current signal
 766   sigset_t newset;
 767   sigemptyset(&newset);
 768   sigaddset(&newset, sig);
 769   sigprocmask(SIG_UNBLOCK, &newset, NULL);
 770 
 771   // Determine which sort of error to throw.  Out of swap may signal
 772   // on the thread stack, which could get a mapping error when touched.
 773   address addr = (address) info->si_addr;
 774   if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
 775     vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
 776   }
 777 
 778   VMError::report_and_die(t, sig, pc, info, ucVoid);
 779 
 780   ShouldNotReachHere();
 781   return false;
 782 }
 783 
 784 void os::print_context(outputStream *st, const void *context) {
 785   if (context == NULL) return;
 786 
 787   const ucontext_t *uc = (const ucontext_t*)context;
 788   st->print_cr("Registers:");
 789 #ifdef AMD64
 790   st->print(  "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
 791   st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
 792   st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
 793   st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
 794   st->cr();
 795   st->print(  "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
 796   st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
 797   st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
 798   st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
 799   st->cr();
 800   st->print(  "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
 801   st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
 802   st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
 803   st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
 804   st->cr();
 805   st->print(  "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
 806   st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
 807   st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
 808   st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
 809   st->cr();
 810   st->print(  "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
 811   st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
 812 #else
 813   st->print(  "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
 814   st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
 815   st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
 816   st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
 817   st->cr();
 818   st->print(  "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
 819   st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
 820   st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
 821   st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
 822   st->cr();
 823   st->print(  "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
 824   st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
 825 #endif // AMD64
 826   st->cr();
 827   st->cr();
 828 
 829   intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
 830   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
 831   print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
 832   st->cr();
 833 
 834   // Note: it may be unsafe to inspect memory near pc. For example, pc may
 835   // point to garbage if entry point in an nmethod is corrupted. Leave
 836   // this at the end, and hope for the best.
 837   ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
 838   address pc = epc.pc();
 839   st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
 840   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 841 }
 842 
 843 void os::print_register_info(outputStream *st, const void *context) {
 844   if (context == NULL) return;
 845 
 846   const ucontext_t *uc = (const ucontext_t*)context;
 847 
 848   st->print_cr("Register to memory mapping:");
 849   st->cr();
 850 
 851   // this is horrendously verbose but the layout of the registers in the
 852   // context does not match how we defined our abstract Register set, so
 853   // we can't just iterate through the gregs area
 854 
 855   // this is only for the "general purpose" registers
 856 
 857 #ifdef AMD64
 858   st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
 859   st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
 860   st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
 861   st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
 862   st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
 863   st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
 864   st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
 865   st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
 866   st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
 867   st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
 868   st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
 869   st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
 870   st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
 871   st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
 872   st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
 873   st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
 874 #else
 875   st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
 876   st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
 877   st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
 878   st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
 879   st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
 880   st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
 881   st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
 882   st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
 883 #endif
 884 
 885   st->cr();
 886 }
 887 
 888 
 889 #ifdef AMD64
 890 void os::Solaris::init_thread_fpu_state(void) {
 891   // Nothing to do
 892 }
 893 #else
 894 // From solaris_i486.s
 895 extern "C" void fixcw();
 896 
 897 void os::Solaris::init_thread_fpu_state(void) {
 898   // Set fpu to 53 bit precision. This happens too early to use a stub.
 899   fixcw();
 900 }
 901 
 902 // These routines are the initial value of atomic_xchg_entry(),
 903 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
 904 // until initialization is complete.
 905 // TODO - replace with .il implementation when compiler supports it.
 906 
 907 typedef int32_t  xchg_func_t        (int32_t,  volatile int32_t*);
 908 typedef int32_t  cmpxchg_func_t     (int32_t,  volatile int32_t*,  int32_t);
 909 typedef int64_t  cmpxchg_long_func_t(int64_t,  volatile int64_t*,  int64_t);
 910 typedef int32_t  add_func_t         (int32_t,  volatile int32_t*);
 911 
 912 int32_t os::atomic_xchg_bootstrap(int32_t exchange_value, volatile int32_t* dest) {
 913   // try to use the stub:
 914   xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
 915 
 916   if (func != NULL) {
 917     os::atomic_xchg_func = func;
 918     return (*func)(exchange_value, dest);
 919   }
 920   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 921 
 922   int32_t old_value = *dest;
 923   *dest = exchange_value;
 924   return old_value;
 925 }
 926 
 927 int32_t os::atomic_cmpxchg_bootstrap(int32_t exchange_value, volatile int32_t* dest, int32_t compare_value) {
 928   // try to use the stub:
 929   cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
 930 
 931   if (func != NULL) {
 932     os::atomic_cmpxchg_func = func;
 933     return (*func)(exchange_value, dest, compare_value);
 934   }
 935   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 936 
 937   int32_t old_value = *dest;
 938   if (old_value == compare_value)
 939     *dest = exchange_value;
 940   return old_value;
 941 }
 942 
 943 int64_t os::atomic_cmpxchg_long_bootstrap(int64_t exchange_value, volatile int64_t* dest, int64_t compare_value) {
 944   // try to use the stub:
 945   cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
 946 
 947   if (func != NULL) {
 948     os::atomic_cmpxchg_long_func = func;
 949     return (*func)(exchange_value, dest, compare_value);
 950   }
 951   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 952 
 953   int64_t old_value = *dest;
 954   if (old_value == compare_value)
 955     *dest = exchange_value;
 956   return old_value;
 957 }
 958 
 959 int32_t os::atomic_add_bootstrap(int32_t add_value, volatile int32_t* dest) {
 960   // try to use the stub:
 961   add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
 962 
 963   if (func != NULL) {
 964     os::atomic_add_func = func;
 965     return (*func)(add_value, dest);
 966   }
 967   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 968 
 969   return (*dest) += add_value;
 970 }
 971 
 972 xchg_func_t*         os::atomic_xchg_func         = os::atomic_xchg_bootstrap;
 973 cmpxchg_func_t*      os::atomic_cmpxchg_func      = os::atomic_cmpxchg_bootstrap;
 974 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
 975 add_func_t*          os::atomic_add_func          = os::atomic_add_bootstrap;
 976 
 977 extern "C" void _solaris_raw_setup_fpu(address ptr);
 978 void os::setup_fpu() {
 979   address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
 980   _solaris_raw_setup_fpu(fpu_cntrl);
 981 }
 982 #endif // AMD64
 983 
 984 #ifndef PRODUCT
 985 void os::verify_stack_alignment() {
 986 #ifdef AMD64
 987   assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
 988 #endif
 989 }
 990 #endif
 991 
 992 int os::extra_bang_size_in_bytes() {
 993   // JDK-8050147 requires the full cache line bang for x86.
 994   return VM_Version::L1_line_size();
 995 }
--- EOF ---