1 /*
   2  * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "asm/macroAssembler.hpp"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "code/icBuffer.hpp"
  31 #include "code/vtableStubs.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "jvm_solaris.h"
  34 #include "memory/allocation.inline.hpp"
  35 #include "mutex_solaris.inline.hpp"
  36 #include "os_share_solaris.hpp"
  37 #include "prims/jniFastGetField.hpp"
  38 #include "prims/jvm.h"
  39 #include "prims/jvm_misc.hpp"
  40 #include "runtime/arguments.hpp"
  41 #include "runtime/atomic.inline.hpp"
  42 #include "runtime/extendedPC.hpp"
  43 #include "runtime/frame.inline.hpp"
  44 #include "runtime/interfaceSupport.hpp"
  45 #include "runtime/java.hpp"
  46 #include "runtime/javaCalls.hpp"
  47 #include "runtime/mutexLocker.hpp"
  48 #include "runtime/osThread.hpp"
  49 #include "runtime/sharedRuntime.hpp"
  50 #include "runtime/stubRoutines.hpp"
  51 #include "runtime/thread.inline.hpp"
  52 #include "runtime/timer.hpp"
  53 #include "utilities/events.hpp"
  54 #include "utilities/vmError.hpp"
  55 
  56 // put OS-includes here
  57 # include <sys/types.h>
  58 # include <sys/mman.h>
  59 # include <pthread.h>
  60 # include <signal.h>
  61 # include <setjmp.h>
  62 # include <errno.h>
  63 # include <dlfcn.h>
  64 # include <stdio.h>
  65 # include <unistd.h>
  66 # include <sys/resource.h>
  67 # include <thread.h>
  68 # include <sys/stat.h>
  69 # include <sys/time.h>
  70 # include <sys/filio.h>
  71 # include <sys/utsname.h>
  72 # include <sys/systeminfo.h>
  73 # include <sys/socket.h>
  74 # include <sys/trap.h>
  75 # include <sys/lwp.h>
  76 # include <pwd.h>
  77 # include <poll.h>
  78 # include <sys/lwp.h>
  79 # include <procfs.h>     //  see comment in <sys/procfs.h>
  80 
  81 #ifndef AMD64
  82 // QQQ seems useless at this point
  83 # define _STRUCTURED_PROC 1  //  this gets us the new structured proc interfaces of 5.6 & later
  84 #endif // AMD64
  85 # include <sys/procfs.h>     //  see comment in <sys/procfs.h>
  86 
  87 
  88 #define MAX_PATH (2 * K)
  89 
  90 // Minimum stack size for the VM.  It's easier to document a constant value
  91 // but it's different for x86 and sparc because the page sizes are different.
  92 #ifdef AMD64
  93 size_t os::Solaris::min_stack_allowed = 224*K;
  94 #define REG_SP REG_RSP
  95 #define REG_PC REG_RIP
  96 #define REG_FP REG_RBP
  97 #else
  98 size_t os::Solaris::min_stack_allowed = 64*K;
  99 #define REG_SP UESP
 100 #define REG_PC EIP
 101 #define REG_FP EBP
 102 // 4900493 counter to prevent runaway LDTR refresh attempt
 103 
 104 static volatile int ldtr_refresh = 0;
 105 // the libthread instruction that faults because of the stale LDTR
 106 
 107 static const unsigned char movlfs[] = { 0x8e, 0xe0    // movl %eax,%fs
 108                        };
 109 #endif // AMD64
 110 
 111 char* os::non_memory_address_word() {
 112   // Must never look like an address returned by reserve_memory,
 113   // even in its subfields (as defined by the CPU immediate fields,
 114   // if the CPU splits constants across multiple instructions).
 115   return (char*) -1;
 116 }
 117 
 118 //
 119 // Validate a ucontext retrieved from walking a uc_link of a ucontext.
 120 // There are issues with libthread giving out uc_links for different threads
 121 // on the same uc_link chain and bad or circular links.
 122 //
 123 bool os::Solaris::valid_ucontext(Thread* thread, ucontext_t* valid, ucontext_t* suspect) {
 124   if (valid >= suspect ||
 125       valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags ||
 126       valid->uc_stack.ss_sp    != suspect->uc_stack.ss_sp    ||
 127       valid->uc_stack.ss_size  != suspect->uc_stack.ss_size) {
 128     DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");)
 129     return false;
 130   }
 131 
 132   if (thread->is_Java_thread()) {
 133     if (!valid_stack_address(thread, (address)suspect)) {
 134       DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");)
 135       return false;
 136     }
 137     if (!valid_stack_address(thread,  (address) suspect->uc_mcontext.gregs[REG_SP])) {
 138       DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");)
 139       return false;
 140     }
 141   }
 142   return true;
 143 }
 144 
 145 // We will only follow one level of uc_link since there are libthread
 146 // issues with ucontext linking and it is better to be safe and just
 147 // let caller retry later.
 148 ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread,
 149   ucontext_t *uc) {
 150 
 151   ucontext_t *retuc = NULL;
 152 
 153   if (uc != NULL) {
 154     if (uc->uc_link == NULL) {
 155       // cannot validate without uc_link so accept current ucontext
 156       retuc = uc;
 157     } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
 158       // first ucontext is valid so try the next one
 159       uc = uc->uc_link;
 160       if (uc->uc_link == NULL) {
 161         // cannot validate without uc_link so accept current ucontext
 162         retuc = uc;
 163       } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) {
 164         // the ucontext one level down is also valid so return it
 165         retuc = uc;
 166       }
 167     }
 168   }
 169   return retuc;
 170 }
 171 
 172 // Assumes ucontext is valid
 173 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(ucontext_t *uc) {
 174   return ExtendedPC((address)uc->uc_mcontext.gregs[REG_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 }
 180 
 181 // Assumes ucontext is valid
 182 intptr_t* os::Solaris::ucontext_get_sp(ucontext_t *uc) {
 183   return (intptr_t*)uc->uc_mcontext.gregs[REG_SP];
 184 }
 185 
 186 // Assumes ucontext is valid
 187 intptr_t* os::Solaris::ucontext_get_fp(ucontext_t *uc) {
 188   return (intptr_t*)uc->uc_mcontext.gregs[REG_FP];
 189 }
 190 
 191 address os::Solaris::ucontext_get_pc(ucontext_t *uc) {
 192   return (address) uc->uc_mcontext.gregs[REG_PC];
 193 }
 194 
 195 // For Forte Analyzer AsyncGetCallTrace profiling support - thread
 196 // is currently interrupted by SIGPROF.
 197 //
 198 // The difference between this and os::fetch_frame_from_context() is that
 199 // here we try to skip nested signal frames.
 200 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread,
 201   ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) {
 202 
 203   assert(thread != NULL, "just checking");
 204   assert(ret_sp != NULL, "just checking");
 205   assert(ret_fp != NULL, "just checking");
 206 
 207   ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc);
 208   return os::fetch_frame_from_context(luc, ret_sp, ret_fp);
 209 }
 210 
 211 ExtendedPC os::fetch_frame_from_context(void* ucVoid,
 212                     intptr_t** ret_sp, intptr_t** ret_fp) {
 213 
 214   ExtendedPC  epc;
 215   ucontext_t *uc = (ucontext_t*)ucVoid;
 216 
 217   if (uc != NULL) {
 218     epc = os::Solaris::ucontext_get_ExtendedPC(uc);
 219     if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc);
 220     if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(uc);
 221   } else {
 222     // construct empty ExtendedPC for return value checking
 223     epc = ExtendedPC(NULL);
 224     if (ret_sp) *ret_sp = (intptr_t *)NULL;
 225     if (ret_fp) *ret_fp = (intptr_t *)NULL;
 226   }
 227 
 228   return epc;
 229 }
 230 
 231 frame os::fetch_frame_from_context(void* ucVoid) {
 232   intptr_t* sp;
 233   intptr_t* fp;
 234   ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp);
 235   return frame(sp, fp, epc.pc());
 236 }
 237 
 238 frame os::get_sender_for_C_frame(frame* fr) {
 239   return frame(fr->sender_sp(), fr->link(), fr->sender_pc());
 240 }
 241 
 242 extern "C" intptr_t *_get_current_sp();  // in .il file
 243 
 244 address os::current_stack_pointer() {
 245   return (address)_get_current_sp();
 246 }
 247 
 248 extern "C" intptr_t *_get_current_fp();  // in .il file
 249 
 250 frame os::current_frame() {
 251   intptr_t* fp = _get_current_fp();  // it's inlined so want current fp
 252   frame myframe((intptr_t*)os::current_stack_pointer(),
 253                 (intptr_t*)fp,
 254                 CAST_FROM_FN_PTR(address, os::current_frame));
 255   if (os::is_first_C_frame(&myframe)) {
 256     // stack is not walkable
 257     frame ret; // This will be a null useless frame
 258     return ret;
 259   } else {
 260     return os::get_sender_for_C_frame(&myframe);
 261   }
 262 }
 263 
 264 #ifndef AMD64
 265 
 266 // Detecting SSE support by OS
 267 // From solaris_i486.s
 268 extern "C" bool sse_check();
 269 extern "C" bool sse_unavailable();
 270 
 271 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED};
 272 static int sse_status = SSE_UNKNOWN;
 273 
 274 
 275 static void  check_for_sse_support() {
 276   if (!VM_Version::supports_sse()) {
 277     sse_status = SSE_NOT_SUPPORTED;
 278     return;
 279   }
 280   // looking for _sse_hw in libc.so, if it does not exist or
 281   // the value (int) is 0, OS has no support for SSE
 282   int *sse_hwp;
 283   void *h;
 284 
 285   if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) {
 286     //open failed, presume no support for SSE
 287     sse_status = SSE_NOT_SUPPORTED;
 288     return;
 289   }
 290   if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) {
 291     sse_status = SSE_NOT_SUPPORTED;
 292   } else if (*sse_hwp == 0) {
 293     sse_status = SSE_NOT_SUPPORTED;
 294   }
 295   dlclose(h);
 296 
 297   if (sse_status == SSE_UNKNOWN) {
 298     bool (*try_sse)() = (bool (*)())sse_check;
 299     sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED;
 300   }
 301 
 302 }
 303 
 304 #endif // AMD64
 305 
 306 bool os::supports_sse() {
 307 #ifdef AMD64
 308   return true;
 309 #else
 310   if (sse_status == SSE_UNKNOWN)
 311     check_for_sse_support();
 312   return sse_status == SSE_SUPPORTED;
 313 #endif // AMD64
 314 }
 315 
 316 bool os::is_allocatable(size_t bytes) {
 317 #ifdef AMD64
 318   return true;
 319 #else
 320 
 321   if (bytes < 2 * G) {
 322     return true;
 323   }
 324 
 325   char* addr = reserve_memory(bytes, NULL);
 326 
 327   if (addr != NULL) {
 328     release_memory(addr, bytes);
 329   }
 330 
 331   return addr != NULL;
 332 #endif // AMD64
 333 
 334 }
 335 
 336 extern "C" JNIEXPORT int
 337 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid,
 338                           int abort_if_unrecognized) {
 339   ucontext_t* uc = (ucontext_t*) ucVoid;
 340 
 341 #ifndef AMD64
 342   if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) {
 343     // the SSE instruction faulted. supports_sse() need return false.
 344     uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable;
 345     return true;
 346   }
 347 #endif // !AMD64
 348 
 349   Thread* t = Thread::current_or_null_safe();
 350 
 351   // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away
 352   // (no destructors can be run)
 353   os::WatcherThreadCrashProtection::check_crash_protection(sig, t);
 354 
 355   SignalHandlerMark shm(t);
 356 
 357   if(sig == SIGPIPE || sig == SIGXFSZ) {
 358     if (os::Solaris::chained_handler(sig, info, ucVoid)) {
 359       return true;
 360     } else {
 361       if (PrintMiscellaneous && (WizardMode || Verbose)) {
 362         char buf[64];
 363         warning("Ignoring %s - see 4229104 or 6499219",
 364                 os::exception_name(sig, buf, sizeof(buf)));
 365 
 366       }
 367       return true;
 368     }
 369   }
 370 
 371   JavaThread* thread = NULL;
 372   VMThread* vmthread = NULL;
 373 
 374   if (os::Solaris::signal_handlers_are_installed) {
 375     if (t != NULL ){
 376       if(t->is_Java_thread()) {
 377         thread = (JavaThread*)t;
 378       }
 379       else if(t->is_VM_thread()){
 380         vmthread = (VMThread *)t;
 381       }
 382     }
 383   }
 384 
 385   if (sig == os::Solaris::SIGasync()) {
 386     if(thread || vmthread){
 387       OSThread::SR_handler(t, uc);
 388       return true;
 389     } else if (os::Solaris::chained_handler(sig, info, ucVoid)) {
 390       return true;
 391     } else {
 392       // If os::Solaris::SIGasync not chained, and this is a non-vm and
 393       // non-java thread
 394       return true;
 395     }
 396   }
 397 
 398   if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) {
 399     // can't decode this kind of signal
 400     info = NULL;
 401   } else {
 402     assert(sig == info->si_signo, "bad siginfo");
 403   }
 404 
 405   // decide if this trap can be handled by a stub
 406   address stub = NULL;
 407 
 408   address pc          = NULL;
 409 
 410   //%note os_trap_1
 411   if (info != NULL && uc != NULL && thread != NULL) {
 412     // factor me: getPCfromContext
 413     pc = (address) uc->uc_mcontext.gregs[REG_PC];
 414 
 415     if (StubRoutines::is_safefetch_fault(pc)) {
 416       os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
 417       return true;
 418     }
 419 
 420     // Handle ALL stack overflow variations here
 421     if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) {
 422       address addr = (address) info->si_addr;
 423       if (thread->in_stack_yellow_zone(addr)) {
 424         thread->disable_stack_yellow_zone();
 425         if (thread->thread_state() == _thread_in_Java) {
 426           // Throw a stack overflow exception.  Guard pages will be reenabled
 427           // while unwinding the stack.
 428           stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW);
 429         } else {
 430           // Thread was in the vm or native code.  Return and try to finish.
 431           return true;
 432         }
 433       } else if (thread->in_stack_red_zone(addr)) {
 434         // Fatal red zone violation.  Disable the guard pages and fall through
 435         // to handle_unexpected_exception way down below.
 436         thread->disable_stack_red_zone();
 437         tty->print_raw_cr("An irrecoverable stack overflow has occurred.");
 438       }
 439     }
 440 
 441     if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) {
 442       // Verify that OS save/restore AVX registers.
 443       stub = VM_Version::cpuinfo_cont_addr();
 444     }
 445 
 446     if (thread->thread_state() == _thread_in_vm) {
 447       if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) {
 448         stub = StubRoutines::handler_for_unsafe_access();
 449       }
 450     }
 451 
 452     if (thread->thread_state() == _thread_in_Java) {
 453       // Support Safepoint Polling
 454       if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) {
 455         stub = SharedRuntime::get_poll_stub(pc);
 456       }
 457       else if (sig == SIGBUS && info->si_code == BUS_OBJERR) {
 458         // BugId 4454115: A read from a MappedByteBuffer can fault
 459         // here if the underlying file has been truncated.
 460         // Do not crash the VM in such a case.
 461         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
 462         if (cb != NULL) {
 463           nmethod* nm = cb->is_nmethod() ? (nmethod*)cb : NULL;
 464           if (nm != NULL && nm->has_unsafe_access()) {
 465             stub = StubRoutines::handler_for_unsafe_access();
 466           }
 467         }
 468       }
 469       else
 470       if (sig == SIGFPE && info->si_code == FPE_INTDIV) {
 471         // integer divide by zero
 472         stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
 473       }
 474 #ifndef AMD64
 475       else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) {
 476         // floating-point divide by zero
 477         stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO);
 478       }
 479       else if (sig == SIGFPE && info->si_code == FPE_FLTINV) {
 480         // The encoding of D2I in i486.ad can cause an exception prior
 481         // to the fist instruction if there was an invalid operation
 482         // pending. We want to dismiss that exception. From the win_32
 483         // side it also seems that if it really was the fist causing
 484         // the exception that we do the d2i by hand with different
 485         // rounding. Seems kind of weird. QQQ TODO
 486         // Note that we take the exception at the NEXT floating point instruction.
 487         if (pc[0] == 0xDB) {
 488             assert(pc[0] == 0xDB, "not a FIST opcode");
 489             assert(pc[1] == 0x14, "not a FIST opcode");
 490             assert(pc[2] == 0x24, "not a FIST opcode");
 491             return true;
 492         } else {
 493             assert(pc[-3] == 0xDB, "not an flt invalid opcode");
 494             assert(pc[-2] == 0x14, "not an flt invalid opcode");
 495             assert(pc[-1] == 0x24, "not an flt invalid opcode");
 496         }
 497       }
 498       else if (sig == SIGFPE ) {
 499         tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code);
 500       }
 501 #endif // !AMD64
 502 
 503         // QQQ It doesn't seem that we need to do this on x86 because we should be able
 504         // to return properly from the handler without this extra stuff on the back side.
 505 
 506       else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) {
 507         // Determination of interpreter/vtable stub/compiled code null exception
 508         stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
 509       }
 510     }
 511 
 512     // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in
 513     // and the heap gets shrunk before the field access.
 514     if ((sig == SIGSEGV) || (sig == SIGBUS)) {
 515       address addr = JNI_FastGetField::find_slowcase_pc(pc);
 516       if (addr != (address)-1) {
 517         stub = addr;
 518       }
 519     }
 520 
 521     // Check to see if we caught the safepoint code in the
 522     // process of write protecting the memory serialization page.
 523     // It write enables the page immediately after protecting it
 524     // so we can just return to retry the write.
 525     if ((sig == SIGSEGV) &&
 526         os::is_memory_serialize_page(thread, (address)info->si_addr)) {
 527       // Block current thread until the memory serialize page permission restored.
 528       os::block_on_serialize_page_trap();
 529       return true;
 530     }
 531   }
 532 
 533   // Execution protection violation
 534   //
 535   // Preventative code for future versions of Solaris which may
 536   // enable execution protection when running the 32-bit VM on AMD64.
 537   //
 538   // This should be kept as the last step in the triage.  We don't
 539   // have a dedicated trap number for a no-execute fault, so be
 540   // conservative and allow other handlers the first shot.
 541   //
 542   // Note: We don't test that info->si_code == SEGV_ACCERR here.
 543   // this si_code is so generic that it is almost meaningless; and
 544   // the si_code for this condition may change in the future.
 545   // Furthermore, a false-positive should be harmless.
 546   if (UnguardOnExecutionViolation > 0 &&
 547       (sig == SIGSEGV || sig == SIGBUS) &&
 548       uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) {  // page fault
 549     int page_size = os::vm_page_size();
 550     address addr = (address) info->si_addr;
 551     address pc = (address) uc->uc_mcontext.gregs[REG_PC];
 552     // Make sure the pc and the faulting address are sane.
 553     //
 554     // If an instruction spans a page boundary, and the page containing
 555     // the beginning of the instruction is executable but the following
 556     // page is not, the pc and the faulting address might be slightly
 557     // different - we still want to unguard the 2nd page in this case.
 558     //
 559     // 15 bytes seems to be a (very) safe value for max instruction size.
 560     bool pc_is_near_addr =
 561       (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
 562     bool instr_spans_page_boundary =
 563       (align_size_down((intptr_t) pc ^ (intptr_t) addr,
 564                        (intptr_t) page_size) > 0);
 565 
 566     if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
 567       static volatile address last_addr =
 568         (address) os::non_memory_address_word();
 569 
 570       // In conservative mode, don't unguard unless the address is in the VM
 571       if (addr != last_addr &&
 572           (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
 573 
 574         // Make memory rwx and retry
 575         address page_start =
 576           (address) align_size_down((intptr_t) addr, (intptr_t) page_size);
 577         bool res = os::protect_memory((char*) page_start, page_size,
 578                                       os::MEM_PROT_RWX);
 579 
 580         if (PrintMiscellaneous && Verbose) {
 581           char buf[256];
 582           jio_snprintf(buf, sizeof(buf), "Execution protection violation "
 583                        "at " INTPTR_FORMAT
 584                        ", unguarding " INTPTR_FORMAT ": %s, errno=%d", addr,
 585                        page_start, (res ? "success" : "failed"), errno);
 586           tty->print_raw_cr(buf);
 587         }
 588         stub = pc;
 589 
 590         // Set last_addr so if we fault again at the same address, we don't end
 591         // up in an endless loop.
 592         //
 593         // There are two potential complications here.  Two threads trapping at
 594         // the same address at the same time could cause one of the threads to
 595         // think it already unguarded, and abort the VM.  Likely very rare.
 596         //
 597         // The other race involves two threads alternately trapping at
 598         // different addresses and failing to unguard the page, resulting in
 599         // an endless loop.  This condition is probably even more unlikely than
 600         // the first.
 601         //
 602         // Although both cases could be avoided by using locks or thread local
 603         // last_addr, these solutions are unnecessary complication: this
 604         // handler is a best-effort safety net, not a complete solution.  It is
 605         // disabled by default and should only be used as a workaround in case
 606         // we missed any no-execute-unsafe VM code.
 607 
 608         last_addr = addr;
 609       }
 610     }
 611   }
 612 
 613   if (stub != NULL) {
 614     // save all thread context in case we need to restore it
 615 
 616     if (thread != NULL) thread->set_saved_exception_pc(pc);
 617     // 12/02/99: On Sparc it appears that the full context is also saved
 618     // but as yet, no one looks at or restores that saved context
 619     os::Solaris::ucontext_set_pc(uc, stub);
 620     return true;
 621   }
 622 
 623   // signal-chaining
 624   if (os::Solaris::chained_handler(sig, info, ucVoid)) {
 625     return true;
 626   }
 627 
 628 #ifndef AMD64
 629   // Workaround (bug 4900493) for Solaris kernel bug 4966651.
 630   // Handle an undefined selector caused by an attempt to assign
 631   // fs in libthread getipriptr(). With the current libthread design every 512
 632   // thread creations the LDT for a private thread data structure is extended
 633   // and thre is a hazard that and another thread attempting a thread creation
 634   // will use a stale LDTR that doesn't reflect the structure's growth,
 635   // causing a GP fault.
 636   // Enforce the probable limit of passes through here to guard against an
 637   // infinite loop if some other move to fs caused the GP fault. Note that
 638   // this loop counter is ultimately a heuristic as it is possible for
 639   // more than one thread to generate this fault at a time in an MP system.
 640   // In the case of the loop count being exceeded or if the poll fails
 641   // just fall through to a fatal error.
 642   // If there is some other source of T_GPFLT traps and the text at EIP is
 643   // unreadable this code will loop infinitely until the stack is exausted.
 644   // The key to diagnosis in this case is to look for the bottom signal handler
 645   // frame.
 646 
 647   if(! IgnoreLibthreadGPFault) {
 648     if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) {
 649       const unsigned char *p =
 650                         (unsigned const char *) uc->uc_mcontext.gregs[EIP];
 651 
 652       // Expected instruction?
 653 
 654       if(p[0] == movlfs[0] && p[1] == movlfs[1]) {
 655 
 656         Atomic::inc(&ldtr_refresh);
 657 
 658         // Infinite loop?
 659 
 660         if(ldtr_refresh < ((2 << 16) / PAGESIZE)) {
 661 
 662           // No, force scheduling to get a fresh view of the LDTR
 663 
 664           if(poll(NULL, 0, 10) == 0) {
 665 
 666             // Retry the move
 667 
 668             return false;
 669           }
 670         }
 671       }
 672     }
 673   }
 674 #endif // !AMD64
 675 
 676   if (!abort_if_unrecognized) {
 677     // caller wants another chance, so give it to him
 678     return false;
 679   }
 680 
 681   if (!os::Solaris::libjsig_is_loaded) {
 682     struct sigaction oldAct;
 683     sigaction(sig, (struct sigaction *)0, &oldAct);
 684     if (oldAct.sa_sigaction != signalHandler) {
 685       void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
 686                                           : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
 687       warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand);
 688     }
 689   }
 690 
 691   if (pc == NULL && uc != NULL) {
 692     pc = (address) uc->uc_mcontext.gregs[REG_PC];
 693   }
 694 
 695   // unmask current signal
 696   sigset_t newset;
 697   sigemptyset(&newset);
 698   sigaddset(&newset, sig);
 699   sigprocmask(SIG_UNBLOCK, &newset, NULL);
 700 
 701   // Determine which sort of error to throw.  Out of swap may signal
 702   // on the thread stack, which could get a mapping error when touched.
 703   address addr = (address) info->si_addr;
 704   if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) {
 705     vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack.");
 706   }
 707 
 708   VMError::report_and_die(t, sig, pc, info, ucVoid);
 709 
 710   ShouldNotReachHere();
 711   return false;
 712 }
 713 
 714 void os::print_context(outputStream *st, void *context) {
 715   if (context == NULL) return;
 716 
 717   ucontext_t *uc = (ucontext_t*)context;
 718   st->print_cr("Registers:");
 719 #ifdef AMD64
 720   st->print(  "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]);
 721   st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]);
 722   st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]);
 723   st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]);
 724   st->cr();
 725   st->print(  "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]);
 726   st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]);
 727   st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]);
 728   st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]);
 729   st->cr();
 730   st->print(  "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]);
 731   st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]);
 732   st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]);
 733   st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]);
 734   st->cr();
 735   st->print(  "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]);
 736   st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]);
 737   st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]);
 738   st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]);
 739   st->cr();
 740   st->print(  "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]);
 741   st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]);
 742 #else
 743   st->print(  "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]);
 744   st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]);
 745   st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]);
 746   st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]);
 747   st->cr();
 748   st->print(  "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]);
 749   st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]);
 750   st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]);
 751   st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]);
 752   st->cr();
 753   st->print(  "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]);
 754   st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]);
 755 #endif // AMD64
 756   st->cr();
 757   st->cr();
 758 
 759   intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc);
 760   st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp);
 761   print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t));
 762   st->cr();
 763 
 764   // Note: it may be unsafe to inspect memory near pc. For example, pc may
 765   // point to garbage if entry point in an nmethod is corrupted. Leave
 766   // this at the end, and hope for the best.
 767   ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc);
 768   address pc = epc.pc();
 769   st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc);
 770   print_hex_dump(st, pc - 32, pc + 32, sizeof(char));
 771 }
 772 
 773 void os::print_register_info(outputStream *st, void *context) {
 774   if (context == NULL) return;
 775 
 776   ucontext_t *uc = (ucontext_t*)context;
 777 
 778   st->print_cr("Register to memory mapping:");
 779   st->cr();
 780 
 781   // this is horrendously verbose but the layout of the registers in the
 782   // context does not match how we defined our abstract Register set, so
 783   // we can't just iterate through the gregs area
 784 
 785   // this is only for the "general purpose" registers
 786 
 787 #ifdef AMD64
 788   st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]);
 789   st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]);
 790   st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]);
 791   st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]);
 792   st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]);
 793   st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]);
 794   st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]);
 795   st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]);
 796   st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]);
 797   st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]);
 798   st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]);
 799   st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]);
 800   st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]);
 801   st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]);
 802   st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]);
 803   st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]);
 804 #else
 805   st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]);
 806   st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]);
 807   st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]);
 808   st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]);
 809   st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]);
 810   st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]);
 811   st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]);
 812   st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]);
 813 #endif
 814 
 815   st->cr();
 816 }
 817 
 818 
 819 #ifdef AMD64
 820 void os::Solaris::init_thread_fpu_state(void) {
 821   // Nothing to do
 822 }
 823 #else
 824 // From solaris_i486.s
 825 extern "C" void fixcw();
 826 
 827 void os::Solaris::init_thread_fpu_state(void) {
 828   // Set fpu to 53 bit precision. This happens too early to use a stub.
 829   fixcw();
 830 }
 831 
 832 // These routines are the initial value of atomic_xchg_entry(),
 833 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry()
 834 // until initialization is complete.
 835 // TODO - replace with .il implementation when compiler supports it.
 836 
 837 typedef jint  xchg_func_t        (jint,  volatile jint*);
 838 typedef jint  cmpxchg_func_t     (jint,  volatile jint*,  jint);
 839 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong);
 840 typedef jint  add_func_t         (jint,  volatile jint*);
 841 
 842 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) {
 843   // try to use the stub:
 844   xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry());
 845 
 846   if (func != NULL) {
 847     os::atomic_xchg_func = func;
 848     return (*func)(exchange_value, dest);
 849   }
 850   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 851 
 852   jint old_value = *dest;
 853   *dest = exchange_value;
 854   return old_value;
 855 }
 856 
 857 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) {
 858   // try to use the stub:
 859   cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry());
 860 
 861   if (func != NULL) {
 862     os::atomic_cmpxchg_func = func;
 863     return (*func)(exchange_value, dest, compare_value);
 864   }
 865   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 866 
 867   jint old_value = *dest;
 868   if (old_value == compare_value)
 869     *dest = exchange_value;
 870   return old_value;
 871 }
 872 
 873 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) {
 874   // try to use the stub:
 875   cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry());
 876 
 877   if (func != NULL) {
 878     os::atomic_cmpxchg_long_func = func;
 879     return (*func)(exchange_value, dest, compare_value);
 880   }
 881   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 882 
 883   jlong old_value = *dest;
 884   if (old_value == compare_value)
 885     *dest = exchange_value;
 886   return old_value;
 887 }
 888 
 889 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) {
 890   // try to use the stub:
 891   add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry());
 892 
 893   if (func != NULL) {
 894     os::atomic_add_func = func;
 895     return (*func)(add_value, dest);
 896   }
 897   assert(Threads::number_of_threads() == 0, "for bootstrap only");
 898 
 899   return (*dest) += add_value;
 900 }
 901 
 902 xchg_func_t*         os::atomic_xchg_func         = os::atomic_xchg_bootstrap;
 903 cmpxchg_func_t*      os::atomic_cmpxchg_func      = os::atomic_cmpxchg_bootstrap;
 904 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap;
 905 add_func_t*          os::atomic_add_func          = os::atomic_add_bootstrap;
 906 
 907 extern "C" void _solaris_raw_setup_fpu(address ptr);
 908 void os::setup_fpu() {
 909   address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std();
 910   _solaris_raw_setup_fpu(fpu_cntrl);
 911 }
 912 #endif // AMD64
 913 
 914 #ifndef PRODUCT
 915 void os::verify_stack_alignment() {
 916 #ifdef AMD64
 917   assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
 918 #endif
 919 }
 920 #endif
 921 
 922 int os::extra_bang_size_in_bytes() {
 923   // JDK-8050147 requires the full cache line bang for x86.
 924   return VM_Version::L1_line_size();
 925 }