1 /* 2 * Copyright (c) 1999, 2016, 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/codeCache.hpp" 31 #include "code/icBuffer.hpp" 32 #include "code/vtableStubs.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_solaris.h" 35 #include "memory/allocation.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.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 <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 size_t os::Posix::_compiler_thread_min_stack_allowed = 202 * K; 93 size_t os::Posix::_java_thread_min_stack_allowed = 48 * K; 94 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 224 * K; 95 #else 96 size_t os::Posix::_compiler_thread_min_stack_allowed = 32 * K; 97 size_t os::Posix::_java_thread_min_stack_allowed = 32 * K; 98 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K; 99 #endif // _LP64 100 101 #ifdef AMD64 102 #define REG_SP REG_RSP 103 #define REG_PC REG_RIP 104 #define REG_FP REG_RBP 105 #else 106 #define REG_SP UESP 107 #define REG_PC EIP 108 #define REG_FP EBP 109 // 4900493 counter to prevent runaway LDTR refresh attempt 110 111 static volatile int ldtr_refresh = 0; 112 // the libthread instruction that faults because of the stale LDTR 113 114 static const unsigned char movlfs[] = { 0x8e, 0xe0 // movl %eax,%fs 115 }; 116 #endif // AMD64 117 118 char* os::non_memory_address_word() { 119 // Must never look like an address returned by reserve_memory, 120 // even in its subfields (as defined by the CPU immediate fields, 121 // if the CPU splits constants across multiple instructions). 122 return (char*) -1; 123 } 124 125 // 126 // Validate a ucontext retrieved from walking a uc_link of a ucontext. 127 // There are issues with libthread giving out uc_links for different threads 128 // on the same uc_link chain and bad or circular links. 129 // 130 bool os::Solaris::valid_ucontext(Thread* thread, const ucontext_t* valid, const ucontext_t* suspect) { 131 if (valid >= suspect || 132 valid->uc_stack.ss_flags != suspect->uc_stack.ss_flags || 133 valid->uc_stack.ss_sp != suspect->uc_stack.ss_sp || 134 valid->uc_stack.ss_size != suspect->uc_stack.ss_size) { 135 DEBUG_ONLY(tty->print_cr("valid_ucontext: failed test 1");) 136 return false; 137 } 138 139 if (thread->is_Java_thread()) { 140 if (!valid_stack_address(thread, (address)suspect)) { 141 DEBUG_ONLY(tty->print_cr("valid_ucontext: uc_link not in thread stack");) 142 return false; 143 } 144 if (!valid_stack_address(thread, (address) suspect->uc_mcontext.gregs[REG_SP])) { 145 DEBUG_ONLY(tty->print_cr("valid_ucontext: stackpointer not in thread stack");) 146 return false; 147 } 148 } 149 return true; 150 } 151 152 // We will only follow one level of uc_link since there are libthread 153 // issues with ucontext linking and it is better to be safe and just 154 // let caller retry later. 155 const ucontext_t* os::Solaris::get_valid_uc_in_signal_handler(Thread *thread, 156 const ucontext_t *uc) { 157 158 const ucontext_t *retuc = NULL; 159 160 if (uc != NULL) { 161 if (uc->uc_link == NULL) { 162 // cannot validate without uc_link so accept current ucontext 163 retuc = uc; 164 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) { 165 // first ucontext is valid so try the next one 166 uc = uc->uc_link; 167 if (uc->uc_link == NULL) { 168 // cannot validate without uc_link so accept current ucontext 169 retuc = uc; 170 } else if (os::Solaris::valid_ucontext(thread, uc, uc->uc_link)) { 171 // the ucontext one level down is also valid so return it 172 retuc = uc; 173 } 174 } 175 } 176 return retuc; 177 } 178 179 // Assumes ucontext is valid 180 ExtendedPC os::Solaris::ucontext_get_ExtendedPC(const ucontext_t *uc) { 181 return ExtendedPC((address)uc->uc_mcontext.gregs[REG_PC]); 182 } 183 184 void os::Solaris::ucontext_set_pc(ucontext_t* uc, address pc) { 185 uc->uc_mcontext.gregs [REG_PC] = (greg_t) pc; 186 } 187 188 // Assumes ucontext is valid 189 intptr_t* os::Solaris::ucontext_get_sp(const ucontext_t *uc) { 190 return (intptr_t*)uc->uc_mcontext.gregs[REG_SP]; 191 } 192 193 // Assumes ucontext is valid 194 intptr_t* os::Solaris::ucontext_get_fp(const ucontext_t *uc) { 195 return (intptr_t*)uc->uc_mcontext.gregs[REG_FP]; 196 } 197 198 address os::Solaris::ucontext_get_pc(const ucontext_t *uc) { 199 return (address) uc->uc_mcontext.gregs[REG_PC]; 200 } 201 202 // For Forte Analyzer AsyncGetCallTrace profiling support - thread 203 // is currently interrupted by SIGPROF. 204 // 205 // The difference between this and os::fetch_frame_from_context() is that 206 // here we try to skip nested signal frames. 207 // This method is also used for stack overflow signal handling. 208 ExtendedPC os::Solaris::fetch_frame_from_ucontext(Thread* thread, 209 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 210 211 assert(thread != NULL, "just checking"); 212 assert(ret_sp != NULL, "just checking"); 213 assert(ret_fp != NULL, "just checking"); 214 215 const ucontext_t *luc = os::Solaris::get_valid_uc_in_signal_handler(thread, uc); 216 return os::fetch_frame_from_context(luc, ret_sp, ret_fp); 217 } 218 219 ExtendedPC os::fetch_frame_from_context(const void* ucVoid, 220 intptr_t** ret_sp, intptr_t** ret_fp) { 221 222 ExtendedPC epc; 223 const ucontext_t *uc = (const ucontext_t*)ucVoid; 224 225 if (uc != NULL) { 226 epc = os::Solaris::ucontext_get_ExtendedPC(uc); 227 if (ret_sp) *ret_sp = os::Solaris::ucontext_get_sp(uc); 228 if (ret_fp) *ret_fp = os::Solaris::ucontext_get_fp(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 if (ret_fp) *ret_fp = (intptr_t *)NULL; 234 } 235 236 return epc; 237 } 238 239 frame os::fetch_frame_from_context(const void* ucVoid) { 240 intptr_t* sp; 241 intptr_t* fp; 242 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 243 return frame(sp, fp, epc.pc()); 244 } 245 246 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) { 247 intptr_t* sp; 248 intptr_t* fp; 249 ExtendedPC epc = os::Solaris::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp); 250 return frame(sp, fp, epc.pc()); 251 } 252 253 bool os::Solaris::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) { 254 address pc = (address) os::Solaris::ucontext_get_pc(uc); 255 if (Interpreter::contains(pc)) { 256 // interpreter performs stack banging after the fixed frame header has 257 // been generated while the compilers perform it before. To maintain 258 // semantic consistency between interpreted and compiled frames, the 259 // method returns the Java sender of the current frame. 260 *fr = os::fetch_frame_from_ucontext(thread, uc); 261 if (!fr->is_first_java_frame()) { 262 // get_frame_at_stack_banging_point() is only called when we 263 // have well defined stacks so java_sender() calls do not need 264 // to assert safe_for_sender() first. 265 *fr = fr->java_sender(); 266 } 267 } else { 268 // more complex code with compiled code 269 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above"); 270 CodeBlob* cb = CodeCache::find_blob(pc); 271 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) { 272 // Not sure where the pc points to, fallback to default 273 // stack overflow handling 274 return false; 275 } else { 276 // in compiled code, the stack banging is performed just after the return pc 277 // has been pushed on the stack 278 intptr_t* fp = os::Solaris::ucontext_get_fp(uc); 279 intptr_t* sp = os::Solaris::ucontext_get_sp(uc); 280 *fr = frame(sp + 1, fp, (address)*sp); 281 if (!fr->is_java_frame()) { 282 // See java_sender() comment above. 283 *fr = fr->java_sender(); 284 } 285 } 286 } 287 assert(fr->is_java_frame(), "Safety check"); 288 return true; 289 } 290 291 frame os::get_sender_for_C_frame(frame* fr) { 292 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 293 } 294 295 extern "C" intptr_t *_get_current_sp(); // in .il file 296 297 address os::current_stack_pointer() { 298 return (address)_get_current_sp(); 299 } 300 301 extern "C" intptr_t *_get_current_fp(); // in .il file 302 303 frame os::current_frame() { 304 intptr_t* fp = _get_current_fp(); // it's inlined so want current fp 305 // fp is for os::current_frame. We want the fp for our caller. 306 frame myframe((intptr_t*)os::current_stack_pointer(), 307 (intptr_t*)fp, 308 CAST_FROM_FN_PTR(address, os::current_frame)); 309 frame caller_frame = os::get_sender_for_C_frame(&myframe); 310 311 if (os::is_first_C_frame(&caller_frame)) { 312 // stack is not walkable 313 frame ret; // This will be a null useless frame 314 return ret; 315 } else { 316 // return frame for our caller's caller 317 return os::get_sender_for_C_frame(&caller_frame); 318 } 319 } 320 321 #ifndef AMD64 322 323 // Detecting SSE support by OS 324 // From solaris_i486.s 325 extern "C" bool sse_check(); 326 extern "C" bool sse_unavailable(); 327 328 enum { SSE_UNKNOWN, SSE_NOT_SUPPORTED, SSE_SUPPORTED}; 329 static int sse_status = SSE_UNKNOWN; 330 331 332 static void check_for_sse_support() { 333 if (!VM_Version::supports_sse()) { 334 sse_status = SSE_NOT_SUPPORTED; 335 return; 336 } 337 // looking for _sse_hw in libc.so, if it does not exist or 338 // the value (int) is 0, OS has no support for SSE 339 int *sse_hwp; 340 void *h; 341 342 if ((h=dlopen("/usr/lib/libc.so", RTLD_LAZY)) == NULL) { 343 //open failed, presume no support for SSE 344 sse_status = SSE_NOT_SUPPORTED; 345 return; 346 } 347 if ((sse_hwp = (int *)dlsym(h, "_sse_hw")) == NULL) { 348 sse_status = SSE_NOT_SUPPORTED; 349 } else if (*sse_hwp == 0) { 350 sse_status = SSE_NOT_SUPPORTED; 351 } 352 dlclose(h); 353 354 if (sse_status == SSE_UNKNOWN) { 355 bool (*try_sse)() = (bool (*)())sse_check; 356 sse_status = (*try_sse)() ? SSE_SUPPORTED : SSE_NOT_SUPPORTED; 357 } 358 359 } 360 361 #endif // AMD64 362 363 bool os::supports_sse() { 364 #ifdef AMD64 365 return true; 366 #else 367 if (sse_status == SSE_UNKNOWN) 368 check_for_sse_support(); 369 return sse_status == SSE_SUPPORTED; 370 #endif // AMD64 371 } 372 373 bool os::is_allocatable(size_t bytes) { 374 #ifdef AMD64 375 return true; 376 #else 377 378 if (bytes < 2 * G) { 379 return true; 380 } 381 382 char* addr = reserve_memory(bytes, NULL); 383 384 if (addr != NULL) { 385 release_memory(addr, bytes); 386 } 387 388 return addr != NULL; 389 #endif // AMD64 390 391 } 392 393 extern "C" JNIEXPORT int 394 JVM_handle_solaris_signal(int sig, siginfo_t* info, void* ucVoid, 395 int abort_if_unrecognized) { 396 ucontext_t* uc = (ucontext_t*) ucVoid; 397 398 #ifndef AMD64 399 if (sig == SIGILL && info->si_addr == (caddr_t)sse_check) { 400 // the SSE instruction faulted. supports_sse() need return false. 401 uc->uc_mcontext.gregs[EIP] = (greg_t)sse_unavailable; 402 return true; 403 } 404 #endif // !AMD64 405 406 Thread* t = Thread::current_or_null_safe(); 407 408 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 409 // (no destructors can be run) 410 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); 411 412 SignalHandlerMark shm(t); 413 414 if(sig == SIGPIPE || sig == SIGXFSZ) { 415 if (os::Solaris::chained_handler(sig, info, ucVoid)) { 416 return true; 417 } else { 418 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219 419 return true; 420 } 421 } 422 423 JavaThread* thread = NULL; 424 VMThread* vmthread = NULL; 425 426 if (os::Solaris::signal_handlers_are_installed) { 427 if (t != NULL ){ 428 if(t->is_Java_thread()) { 429 thread = (JavaThread*)t; 430 } 431 else if(t->is_VM_thread()){ 432 vmthread = (VMThread *)t; 433 } 434 } 435 } 436 437 if (sig == os::Solaris::SIGasync()) { 438 if(thread || vmthread){ 439 OSThread::SR_handler(t, uc); 440 return true; 441 } else if (os::Solaris::chained_handler(sig, info, ucVoid)) { 442 return true; 443 } else { 444 // If os::Solaris::SIGasync not chained, and this is a non-vm and 445 // non-java thread 446 return true; 447 } 448 } 449 450 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 451 // can't decode this kind of signal 452 info = NULL; 453 } else { 454 assert(sig == info->si_signo, "bad siginfo"); 455 } 456 457 // decide if this trap can be handled by a stub 458 address stub = NULL; 459 460 address pc = NULL; 461 462 //%note os_trap_1 463 if (info != NULL && uc != NULL && thread != NULL) { 464 // factor me: getPCfromContext 465 pc = (address) uc->uc_mcontext.gregs[REG_PC]; 466 467 if (StubRoutines::is_safefetch_fault(pc)) { 468 os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 469 return true; 470 } 471 472 // Handle ALL stack overflow variations here 473 if (sig == SIGSEGV && info->si_code == SEGV_ACCERR) { 474 address addr = (address) info->si_addr; 475 if (thread->in_stack_yellow_reserved_zone(addr)) { 476 if (thread->thread_state() == _thread_in_Java) { 477 if (thread->in_stack_reserved_zone(addr)) { 478 frame fr; 479 if (os::Solaris::get_frame_at_stack_banging_point(thread, uc, &fr)) { 480 assert(fr.is_java_frame(), "Must be Java frame"); 481 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr); 482 if (activation.sp() != NULL) { 483 thread->disable_stack_reserved_zone(); 484 if (activation.is_interpreted_frame()) { 485 thread->set_reserved_stack_activation((address)( 486 activation.fp() + frame::interpreter_frame_initial_sp_offset)); 487 } else { 488 thread->set_reserved_stack_activation((address)activation.unextended_sp()); 489 } 490 return true; 491 } 492 } 493 } 494 // Throw a stack overflow exception. Guard pages will be reenabled 495 // while unwinding the stack. 496 thread->disable_stack_yellow_reserved_zone(); 497 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 498 } else { 499 // Thread was in the vm or native code. Return and try to finish. 500 thread->disable_stack_yellow_reserved_zone(); 501 return true; 502 } 503 } else if (thread->in_stack_red_zone(addr)) { 504 // Fatal red zone violation. Disable the guard pages and fall through 505 // to handle_unexpected_exception way down below. 506 thread->disable_stack_red_zone(); 507 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 508 } 509 } 510 511 if ((sig == SIGSEGV) && VM_Version::is_cpuinfo_segv_addr(pc)) { 512 // Verify that OS save/restore AVX registers. 513 stub = VM_Version::cpuinfo_cont_addr(); 514 } 515 516 if (thread->thread_state() == _thread_in_vm) { 517 if (sig == SIGBUS && info->si_code == BUS_OBJERR && thread->doing_unsafe_access()) { 518 address next_pc = Assembler::locate_next_instruction(pc); 519 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 520 } 521 } 522 523 if (thread->thread_state() == _thread_in_Java) { 524 // Support Safepoint Polling 525 if ( sig == SIGSEGV && os::is_poll_address((address)info->si_addr)) { 526 stub = SharedRuntime::get_poll_stub(pc); 527 } 528 else if (sig == SIGBUS && info->si_code == BUS_OBJERR) { 529 // BugId 4454115: A read from a MappedByteBuffer can fault 530 // here if the underlying file has been truncated. 531 // Do not crash the VM in such a case. 532 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 533 if (cb != NULL) { 534 CompiledMethod* nm = cb->as_compiled_method_or_null(); 535 if (nm != NULL && nm->has_unsafe_access()) { 536 address next_pc = Assembler::locate_next_instruction(pc); 537 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 538 } 539 } 540 } 541 else 542 if (sig == SIGFPE && info->si_code == FPE_INTDIV) { 543 // integer divide by zero 544 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 545 } 546 #ifndef AMD64 547 else if (sig == SIGFPE && info->si_code == FPE_FLTDIV) { 548 // floating-point divide by zero 549 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 550 } 551 else if (sig == SIGFPE && info->si_code == FPE_FLTINV) { 552 // The encoding of D2I in i486.ad can cause an exception prior 553 // to the fist instruction if there was an invalid operation 554 // pending. We want to dismiss that exception. From the win_32 555 // side it also seems that if it really was the fist causing 556 // the exception that we do the d2i by hand with different 557 // rounding. Seems kind of weird. QQQ TODO 558 // Note that we take the exception at the NEXT floating point instruction. 559 if (pc[0] == 0xDB) { 560 assert(pc[0] == 0xDB, "not a FIST opcode"); 561 assert(pc[1] == 0x14, "not a FIST opcode"); 562 assert(pc[2] == 0x24, "not a FIST opcode"); 563 return true; 564 } else { 565 assert(pc[-3] == 0xDB, "not an flt invalid opcode"); 566 assert(pc[-2] == 0x14, "not an flt invalid opcode"); 567 assert(pc[-1] == 0x24, "not an flt invalid opcode"); 568 } 569 } 570 else if (sig == SIGFPE ) { 571 tty->print_cr("caught SIGFPE, info 0x%x.", info->si_code); 572 } 573 #endif // !AMD64 574 575 // QQQ It doesn't seem that we need to do this on x86 because we should be able 576 // to return properly from the handler without this extra stuff on the back side. 577 578 else if (sig == SIGSEGV && info->si_code > 0 && !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 579 // Determination of interpreter/vtable stub/compiled code null exception 580 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 581 } 582 } 583 584 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 585 // and the heap gets shrunk before the field access. 586 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 587 address addr = JNI_FastGetField::find_slowcase_pc(pc); 588 if (addr != (address)-1) { 589 stub = addr; 590 } 591 } 592 593 // Check to see if we caught the safepoint code in the 594 // process of write protecting the memory serialization page. 595 // It write enables the page immediately after protecting it 596 // so we can just return to retry the write. 597 if ((sig == SIGSEGV) && 598 os::is_memory_serialize_page(thread, (address)info->si_addr)) { 599 // Block current thread until the memory serialize page permission restored. 600 os::block_on_serialize_page_trap(); 601 return true; 602 } 603 } 604 605 // Execution protection violation 606 // 607 // Preventative code for future versions of Solaris which may 608 // enable execution protection when running the 32-bit VM on AMD64. 609 // 610 // This should be kept as the last step in the triage. We don't 611 // have a dedicated trap number for a no-execute fault, so be 612 // conservative and allow other handlers the first shot. 613 // 614 // Note: We don't test that info->si_code == SEGV_ACCERR here. 615 // this si_code is so generic that it is almost meaningless; and 616 // the si_code for this condition may change in the future. 617 // Furthermore, a false-positive should be harmless. 618 if (UnguardOnExecutionViolation > 0 && 619 (sig == SIGSEGV || sig == SIGBUS) && 620 uc->uc_mcontext.gregs[TRAPNO] == T_PGFLT) { // page fault 621 int page_size = os::vm_page_size(); 622 address addr = (address) info->si_addr; 623 address pc = (address) uc->uc_mcontext.gregs[REG_PC]; 624 // Make sure the pc and the faulting address are sane. 625 // 626 // If an instruction spans a page boundary, and the page containing 627 // the beginning of the instruction is executable but the following 628 // page is not, the pc and the faulting address might be slightly 629 // different - we still want to unguard the 2nd page in this case. 630 // 631 // 15 bytes seems to be a (very) safe value for max instruction size. 632 bool pc_is_near_addr = 633 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 634 bool instr_spans_page_boundary = 635 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 636 (intptr_t) page_size) > 0); 637 638 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 639 static volatile address last_addr = 640 (address) os::non_memory_address_word(); 641 642 // In conservative mode, don't unguard unless the address is in the VM 643 if (addr != last_addr && 644 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 645 646 // Make memory rwx and retry 647 address page_start = 648 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 649 bool res = os::protect_memory((char*) page_start, page_size, 650 os::MEM_PROT_RWX); 651 652 log_debug(os)("Execution protection violation " 653 "at " INTPTR_FORMAT 654 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr), 655 p2i(page_start), (res ? "success" : "failed"), errno); 656 stub = pc; 657 658 // Set last_addr so if we fault again at the same address, we don't end 659 // up in an endless loop. 660 // 661 // There are two potential complications here. Two threads trapping at 662 // the same address at the same time could cause one of the threads to 663 // think it already unguarded, and abort the VM. Likely very rare. 664 // 665 // The other race involves two threads alternately trapping at 666 // different addresses and failing to unguard the page, resulting in 667 // an endless loop. This condition is probably even more unlikely than 668 // the first. 669 // 670 // Although both cases could be avoided by using locks or thread local 671 // last_addr, these solutions are unnecessary complication: this 672 // handler is a best-effort safety net, not a complete solution. It is 673 // disabled by default and should only be used as a workaround in case 674 // we missed any no-execute-unsafe VM code. 675 676 last_addr = addr; 677 } 678 } 679 } 680 681 if (stub != NULL) { 682 // save all thread context in case we need to restore it 683 684 if (thread != NULL) thread->set_saved_exception_pc(pc); 685 // 12/02/99: On Sparc it appears that the full context is also saved 686 // but as yet, no one looks at or restores that saved context 687 os::Solaris::ucontext_set_pc(uc, stub); 688 return true; 689 } 690 691 // signal-chaining 692 if (os::Solaris::chained_handler(sig, info, ucVoid)) { 693 return true; 694 } 695 696 #ifndef AMD64 697 // Workaround (bug 4900493) for Solaris kernel bug 4966651. 698 // Handle an undefined selector caused by an attempt to assign 699 // fs in libthread getipriptr(). With the current libthread design every 512 700 // thread creations the LDT for a private thread data structure is extended 701 // and thre is a hazard that and another thread attempting a thread creation 702 // will use a stale LDTR that doesn't reflect the structure's growth, 703 // causing a GP fault. 704 // Enforce the probable limit of passes through here to guard against an 705 // infinite loop if some other move to fs caused the GP fault. Note that 706 // this loop counter is ultimately a heuristic as it is possible for 707 // more than one thread to generate this fault at a time in an MP system. 708 // In the case of the loop count being exceeded or if the poll fails 709 // just fall through to a fatal error. 710 // If there is some other source of T_GPFLT traps and the text at EIP is 711 // unreadable this code will loop infinitely until the stack is exausted. 712 // The key to diagnosis in this case is to look for the bottom signal handler 713 // frame. 714 715 if(! IgnoreLibthreadGPFault) { 716 if (sig == SIGSEGV && uc->uc_mcontext.gregs[TRAPNO] == T_GPFLT) { 717 const unsigned char *p = 718 (unsigned const char *) uc->uc_mcontext.gregs[EIP]; 719 720 // Expected instruction? 721 722 if(p[0] == movlfs[0] && p[1] == movlfs[1]) { 723 724 Atomic::inc(&ldtr_refresh); 725 726 // Infinite loop? 727 728 if(ldtr_refresh < ((2 << 16) / PAGESIZE)) { 729 730 // No, force scheduling to get a fresh view of the LDTR 731 732 if(poll(NULL, 0, 10) == 0) { 733 734 // Retry the move 735 736 return false; 737 } 738 } 739 } 740 } 741 } 742 #endif // !AMD64 743 744 if (!abort_if_unrecognized) { 745 // caller wants another chance, so give it to him 746 return false; 747 } 748 749 if (!os::Solaris::libjsig_is_loaded) { 750 struct sigaction oldAct; 751 sigaction(sig, (struct sigaction *)0, &oldAct); 752 if (oldAct.sa_sigaction != signalHandler) { 753 void* sighand = oldAct.sa_sigaction ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 754 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 755 warning("Unexpected Signal %d occurred under user-defined signal handler %#lx", sig, (long)sighand); 756 } 757 } 758 759 if (pc == NULL && uc != NULL) { 760 pc = (address) uc->uc_mcontext.gregs[REG_PC]; 761 } 762 763 // unmask current signal 764 sigset_t newset; 765 sigemptyset(&newset); 766 sigaddset(&newset, sig); 767 sigprocmask(SIG_UNBLOCK, &newset, NULL); 768 769 // Determine which sort of error to throw. Out of swap may signal 770 // on the thread stack, which could get a mapping error when touched. 771 address addr = (address) info->si_addr; 772 if (sig == SIGBUS && info->si_code == BUS_OBJERR && info->si_errno == ENOMEM) { 773 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "Out of swap space to map in thread stack."); 774 } 775 776 VMError::report_and_die(t, sig, pc, info, ucVoid); 777 778 ShouldNotReachHere(); 779 return false; 780 } 781 782 void os::print_context(outputStream *st, const void *context) { 783 if (context == NULL) return; 784 785 const ucontext_t *uc = (const ucontext_t*)context; 786 st->print_cr("Registers:"); 787 #ifdef AMD64 788 st->print( "RAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RAX]); 789 st->print(", RBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBX]); 790 st->print(", RCX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RCX]); 791 st->print(", RDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDX]); 792 st->cr(); 793 st->print( "RSP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSP]); 794 st->print(", RBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RBP]); 795 st->print(", RSI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RSI]); 796 st->print(", RDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RDI]); 797 st->cr(); 798 st->print( "R8 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R8]); 799 st->print(", R9 =" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R9]); 800 st->print(", R10=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R10]); 801 st->print(", R11=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R11]); 802 st->cr(); 803 st->print( "R12=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R12]); 804 st->print(", R13=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R13]); 805 st->print(", R14=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R14]); 806 st->print(", R15=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_R15]); 807 st->cr(); 808 st->print( "RIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RIP]); 809 st->print(", RFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[REG_RFL]); 810 #else 811 st->print( "EAX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EAX]); 812 st->print(", EBX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBX]); 813 st->print(", ECX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ECX]); 814 st->print(", EDX=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDX]); 815 st->cr(); 816 st->print( "ESP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[UESP]); 817 st->print(", EBP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EBP]); 818 st->print(", ESI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[ESI]); 819 st->print(", EDI=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EDI]); 820 st->cr(); 821 st->print( "EIP=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EIP]); 822 st->print(", EFLAGS=" INTPTR_FORMAT, uc->uc_mcontext.gregs[EFL]); 823 #endif // AMD64 824 st->cr(); 825 st->cr(); 826 827 intptr_t *sp = (intptr_t *)os::Solaris::ucontext_get_sp(uc); 828 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 829 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 830 st->cr(); 831 832 // Note: it may be unsafe to inspect memory near pc. For example, pc may 833 // point to garbage if entry point in an nmethod is corrupted. Leave 834 // this at the end, and hope for the best. 835 ExtendedPC epc = os::Solaris::ucontext_get_ExtendedPC(uc); 836 address pc = epc.pc(); 837 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 838 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 839 } 840 841 void os::print_register_info(outputStream *st, const void *context) { 842 if (context == NULL) return; 843 844 const ucontext_t *uc = (const ucontext_t*)context; 845 846 st->print_cr("Register to memory mapping:"); 847 st->cr(); 848 849 // this is horrendously verbose but the layout of the registers in the 850 // context does not match how we defined our abstract Register set, so 851 // we can't just iterate through the gregs area 852 853 // this is only for the "general purpose" registers 854 855 #ifdef AMD64 856 st->print("RAX="); print_location(st, uc->uc_mcontext.gregs[REG_RAX]); 857 st->print("RBX="); print_location(st, uc->uc_mcontext.gregs[REG_RBX]); 858 st->print("RCX="); print_location(st, uc->uc_mcontext.gregs[REG_RCX]); 859 st->print("RDX="); print_location(st, uc->uc_mcontext.gregs[REG_RDX]); 860 st->print("RSP="); print_location(st, uc->uc_mcontext.gregs[REG_RSP]); 861 st->print("RBP="); print_location(st, uc->uc_mcontext.gregs[REG_RBP]); 862 st->print("RSI="); print_location(st, uc->uc_mcontext.gregs[REG_RSI]); 863 st->print("RDI="); print_location(st, uc->uc_mcontext.gregs[REG_RDI]); 864 st->print("R8 ="); print_location(st, uc->uc_mcontext.gregs[REG_R8]); 865 st->print("R9 ="); print_location(st, uc->uc_mcontext.gregs[REG_R9]); 866 st->print("R10="); print_location(st, uc->uc_mcontext.gregs[REG_R10]); 867 st->print("R11="); print_location(st, uc->uc_mcontext.gregs[REG_R11]); 868 st->print("R12="); print_location(st, uc->uc_mcontext.gregs[REG_R12]); 869 st->print("R13="); print_location(st, uc->uc_mcontext.gregs[REG_R13]); 870 st->print("R14="); print_location(st, uc->uc_mcontext.gregs[REG_R14]); 871 st->print("R15="); print_location(st, uc->uc_mcontext.gregs[REG_R15]); 872 #else 873 st->print("EAX="); print_location(st, uc->uc_mcontext.gregs[EAX]); 874 st->print("EBX="); print_location(st, uc->uc_mcontext.gregs[EBX]); 875 st->print("ECX="); print_location(st, uc->uc_mcontext.gregs[ECX]); 876 st->print("EDX="); print_location(st, uc->uc_mcontext.gregs[EDX]); 877 st->print("ESP="); print_location(st, uc->uc_mcontext.gregs[UESP]); 878 st->print("EBP="); print_location(st, uc->uc_mcontext.gregs[EBP]); 879 st->print("ESI="); print_location(st, uc->uc_mcontext.gregs[ESI]); 880 st->print("EDI="); print_location(st, uc->uc_mcontext.gregs[EDI]); 881 #endif 882 883 st->cr(); 884 } 885 886 887 #ifdef AMD64 888 void os::Solaris::init_thread_fpu_state(void) { 889 // Nothing to do 890 } 891 #else 892 // From solaris_i486.s 893 extern "C" void fixcw(); 894 895 void os::Solaris::init_thread_fpu_state(void) { 896 // Set fpu to 53 bit precision. This happens too early to use a stub. 897 fixcw(); 898 } 899 900 // These routines are the initial value of atomic_xchg_entry(), 901 // atomic_cmpxchg_entry(), atomic_inc_entry() and fence_entry() 902 // until initialization is complete. 903 // TODO - replace with .il implementation when compiler supports it. 904 905 typedef jint xchg_func_t (jint, volatile jint*); 906 typedef jint cmpxchg_func_t (jint, volatile jint*, jint); 907 typedef jlong cmpxchg_long_func_t(jlong, volatile jlong*, jlong); 908 typedef jint add_func_t (jint, volatile jint*); 909 910 jint os::atomic_xchg_bootstrap(jint exchange_value, volatile jint* dest) { 911 // try to use the stub: 912 xchg_func_t* func = CAST_TO_FN_PTR(xchg_func_t*, StubRoutines::atomic_xchg_entry()); 913 914 if (func != NULL) { 915 os::atomic_xchg_func = func; 916 return (*func)(exchange_value, dest); 917 } 918 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 919 920 jint old_value = *dest; 921 *dest = exchange_value; 922 return old_value; 923 } 924 925 jint os::atomic_cmpxchg_bootstrap(jint exchange_value, volatile jint* dest, jint compare_value) { 926 // try to use the stub: 927 cmpxchg_func_t* func = CAST_TO_FN_PTR(cmpxchg_func_t*, StubRoutines::atomic_cmpxchg_entry()); 928 929 if (func != NULL) { 930 os::atomic_cmpxchg_func = func; 931 return (*func)(exchange_value, dest, compare_value); 932 } 933 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 934 935 jint old_value = *dest; 936 if (old_value == compare_value) 937 *dest = exchange_value; 938 return old_value; 939 } 940 941 jlong os::atomic_cmpxchg_long_bootstrap(jlong exchange_value, volatile jlong* dest, jlong compare_value) { 942 // try to use the stub: 943 cmpxchg_long_func_t* func = CAST_TO_FN_PTR(cmpxchg_long_func_t*, StubRoutines::atomic_cmpxchg_long_entry()); 944 945 if (func != NULL) { 946 os::atomic_cmpxchg_long_func = func; 947 return (*func)(exchange_value, dest, compare_value); 948 } 949 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 950 951 jlong old_value = *dest; 952 if (old_value == compare_value) 953 *dest = exchange_value; 954 return old_value; 955 } 956 957 jint os::atomic_add_bootstrap(jint add_value, volatile jint* dest) { 958 // try to use the stub: 959 add_func_t* func = CAST_TO_FN_PTR(add_func_t*, StubRoutines::atomic_add_entry()); 960 961 if (func != NULL) { 962 os::atomic_add_func = func; 963 return (*func)(add_value, dest); 964 } 965 assert(Threads::number_of_threads() == 0, "for bootstrap only"); 966 967 return (*dest) += add_value; 968 } 969 970 xchg_func_t* os::atomic_xchg_func = os::atomic_xchg_bootstrap; 971 cmpxchg_func_t* os::atomic_cmpxchg_func = os::atomic_cmpxchg_bootstrap; 972 cmpxchg_long_func_t* os::atomic_cmpxchg_long_func = os::atomic_cmpxchg_long_bootstrap; 973 add_func_t* os::atomic_add_func = os::atomic_add_bootstrap; 974 975 extern "C" void _solaris_raw_setup_fpu(address ptr); 976 void os::setup_fpu() { 977 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 978 _solaris_raw_setup_fpu(fpu_cntrl); 979 } 980 #endif // AMD64 981 982 #ifndef PRODUCT 983 void os::verify_stack_alignment() { 984 #ifdef AMD64 985 assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment"); 986 #endif 987 } 988 #endif 989 990 int os::extra_bang_size_in_bytes() { 991 // JDK-8050147 requires the full cache line bang for x86. 992 return VM_Version::L1_line_size(); 993 }