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_bsd.h" 35 #include "memory/allocation.inline.hpp" 36 #include "os_share_bsd.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/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/events.hpp" 53 #include "utilities/vmError.hpp" 54 55 // put OS-includes here 56 # include <sys/types.h> 57 # include <sys/mman.h> 58 # include <pthread.h> 59 # include <signal.h> 60 # include <errno.h> 61 # include <dlfcn.h> 62 # include <stdlib.h> 63 # include <stdio.h> 64 # include <unistd.h> 65 # include <sys/resource.h> 66 # include <pthread.h> 67 # include <sys/stat.h> 68 # include <sys/time.h> 69 # include <sys/utsname.h> 70 # include <sys/socket.h> 71 # include <sys/wait.h> 72 # include <pwd.h> 73 # include <poll.h> 74 #ifndef __OpenBSD__ 75 # include <ucontext.h> 76 #endif 77 78 #if !defined(__APPLE__) && !defined(__NetBSD__) 79 # include <pthread_np.h> 80 #endif 81 82 // needed by current_stack_region() workaround for Mavericks 83 #if defined(__APPLE__) 84 # include <errno.h> 85 # include <sys/types.h> 86 # include <sys/sysctl.h> 87 # define DEFAULT_MAIN_THREAD_STACK_PAGES 2048 88 # define OS_X_10_9_0_KERNEL_MAJOR_VERSION 13 89 #endif 90 91 #ifdef AMD64 92 #define SPELL_REG_SP "rsp" 93 #define SPELL_REG_FP "rbp" 94 #else 95 #define SPELL_REG_SP "esp" 96 #define SPELL_REG_FP "ebp" 97 #endif // AMD64 98 99 #ifdef __FreeBSD__ 100 # define context_trapno uc_mcontext.mc_trapno 101 # ifdef AMD64 102 # define context_pc uc_mcontext.mc_rip 103 # define context_sp uc_mcontext.mc_rsp 104 # define context_fp uc_mcontext.mc_rbp 105 # define context_rip uc_mcontext.mc_rip 106 # define context_rsp uc_mcontext.mc_rsp 107 # define context_rbp uc_mcontext.mc_rbp 108 # define context_rax uc_mcontext.mc_rax 109 # define context_rbx uc_mcontext.mc_rbx 110 # define context_rcx uc_mcontext.mc_rcx 111 # define context_rdx uc_mcontext.mc_rdx 112 # define context_rsi uc_mcontext.mc_rsi 113 # define context_rdi uc_mcontext.mc_rdi 114 # define context_r8 uc_mcontext.mc_r8 115 # define context_r9 uc_mcontext.mc_r9 116 # define context_r10 uc_mcontext.mc_r10 117 # define context_r11 uc_mcontext.mc_r11 118 # define context_r12 uc_mcontext.mc_r12 119 # define context_r13 uc_mcontext.mc_r13 120 # define context_r14 uc_mcontext.mc_r14 121 # define context_r15 uc_mcontext.mc_r15 122 # define context_flags uc_mcontext.mc_flags 123 # define context_err uc_mcontext.mc_err 124 # else 125 # define context_pc uc_mcontext.mc_eip 126 # define context_sp uc_mcontext.mc_esp 127 # define context_fp uc_mcontext.mc_ebp 128 # define context_eip uc_mcontext.mc_eip 129 # define context_esp uc_mcontext.mc_esp 130 # define context_eax uc_mcontext.mc_eax 131 # define context_ebx uc_mcontext.mc_ebx 132 # define context_ecx uc_mcontext.mc_ecx 133 # define context_edx uc_mcontext.mc_edx 134 # define context_ebp uc_mcontext.mc_ebp 135 # define context_esi uc_mcontext.mc_esi 136 # define context_edi uc_mcontext.mc_edi 137 # define context_eflags uc_mcontext.mc_eflags 138 # define context_trapno uc_mcontext.mc_trapno 139 # endif 140 #endif 141 142 #ifdef __APPLE__ 143 # if __DARWIN_UNIX03 && (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) 144 // 10.5 UNIX03 member name prefixes 145 #define DU3_PREFIX(s, m) __ ## s.__ ## m 146 # else 147 #define DU3_PREFIX(s, m) s ## . ## m 148 # endif 149 150 # ifdef AMD64 151 # define context_pc context_rip 152 # define context_sp context_rsp 153 # define context_fp context_rbp 154 # define context_rip uc_mcontext->DU3_PREFIX(ss,rip) 155 # define context_rsp uc_mcontext->DU3_PREFIX(ss,rsp) 156 # define context_rax uc_mcontext->DU3_PREFIX(ss,rax) 157 # define context_rbx uc_mcontext->DU3_PREFIX(ss,rbx) 158 # define context_rcx uc_mcontext->DU3_PREFIX(ss,rcx) 159 # define context_rdx uc_mcontext->DU3_PREFIX(ss,rdx) 160 # define context_rbp uc_mcontext->DU3_PREFIX(ss,rbp) 161 # define context_rsi uc_mcontext->DU3_PREFIX(ss,rsi) 162 # define context_rdi uc_mcontext->DU3_PREFIX(ss,rdi) 163 # define context_r8 uc_mcontext->DU3_PREFIX(ss,r8) 164 # define context_r9 uc_mcontext->DU3_PREFIX(ss,r9) 165 # define context_r10 uc_mcontext->DU3_PREFIX(ss,r10) 166 # define context_r11 uc_mcontext->DU3_PREFIX(ss,r11) 167 # define context_r12 uc_mcontext->DU3_PREFIX(ss,r12) 168 # define context_r13 uc_mcontext->DU3_PREFIX(ss,r13) 169 # define context_r14 uc_mcontext->DU3_PREFIX(ss,r14) 170 # define context_r15 uc_mcontext->DU3_PREFIX(ss,r15) 171 # define context_flags uc_mcontext->DU3_PREFIX(ss,rflags) 172 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 173 # define context_err uc_mcontext->DU3_PREFIX(es,err) 174 # else 175 # define context_pc context_eip 176 # define context_sp context_esp 177 # define context_fp context_ebp 178 # define context_eip uc_mcontext->DU3_PREFIX(ss,eip) 179 # define context_esp uc_mcontext->DU3_PREFIX(ss,esp) 180 # define context_eax uc_mcontext->DU3_PREFIX(ss,eax) 181 # define context_ebx uc_mcontext->DU3_PREFIX(ss,ebx) 182 # define context_ecx uc_mcontext->DU3_PREFIX(ss,ecx) 183 # define context_edx uc_mcontext->DU3_PREFIX(ss,edx) 184 # define context_ebp uc_mcontext->DU3_PREFIX(ss,ebp) 185 # define context_esi uc_mcontext->DU3_PREFIX(ss,esi) 186 # define context_edi uc_mcontext->DU3_PREFIX(ss,edi) 187 # define context_eflags uc_mcontext->DU3_PREFIX(ss,eflags) 188 # define context_trapno uc_mcontext->DU3_PREFIX(es,trapno) 189 # endif 190 #endif 191 192 #ifdef __OpenBSD__ 193 # define context_trapno sc_trapno 194 # ifdef AMD64 195 # define context_pc sc_rip 196 # define context_sp sc_rsp 197 # define context_fp sc_rbp 198 # define context_rip sc_rip 199 # define context_rsp sc_rsp 200 # define context_rbp sc_rbp 201 # define context_rax sc_rax 202 # define context_rbx sc_rbx 203 # define context_rcx sc_rcx 204 # define context_rdx sc_rdx 205 # define context_rsi sc_rsi 206 # define context_rdi sc_rdi 207 # define context_r8 sc_r8 208 # define context_r9 sc_r9 209 # define context_r10 sc_r10 210 # define context_r11 sc_r11 211 # define context_r12 sc_r12 212 # define context_r13 sc_r13 213 # define context_r14 sc_r14 214 # define context_r15 sc_r15 215 # define context_flags sc_rflags 216 # define context_err sc_err 217 # else 218 # define context_pc sc_eip 219 # define context_sp sc_esp 220 # define context_fp sc_ebp 221 # define context_eip sc_eip 222 # define context_esp sc_esp 223 # define context_eax sc_eax 224 # define context_ebx sc_ebx 225 # define context_ecx sc_ecx 226 # define context_edx sc_edx 227 # define context_ebp sc_ebp 228 # define context_esi sc_esi 229 # define context_edi sc_edi 230 # define context_eflags sc_eflags 231 # define context_trapno sc_trapno 232 # endif 233 #endif 234 235 #ifdef __NetBSD__ 236 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 237 # ifdef AMD64 238 # define __register_t __greg_t 239 # define context_pc uc_mcontext.__gregs[_REG_RIP] 240 # define context_sp uc_mcontext.__gregs[_REG_URSP] 241 # define context_fp uc_mcontext.__gregs[_REG_RBP] 242 # define context_rip uc_mcontext.__gregs[_REG_RIP] 243 # define context_rsp uc_mcontext.__gregs[_REG_URSP] 244 # define context_rax uc_mcontext.__gregs[_REG_RAX] 245 # define context_rbx uc_mcontext.__gregs[_REG_RBX] 246 # define context_rcx uc_mcontext.__gregs[_REG_RCX] 247 # define context_rdx uc_mcontext.__gregs[_REG_RDX] 248 # define context_rbp uc_mcontext.__gregs[_REG_RBP] 249 # define context_rsi uc_mcontext.__gregs[_REG_RSI] 250 # define context_rdi uc_mcontext.__gregs[_REG_RDI] 251 # define context_r8 uc_mcontext.__gregs[_REG_R8] 252 # define context_r9 uc_mcontext.__gregs[_REG_R9] 253 # define context_r10 uc_mcontext.__gregs[_REG_R10] 254 # define context_r11 uc_mcontext.__gregs[_REG_R11] 255 # define context_r12 uc_mcontext.__gregs[_REG_R12] 256 # define context_r13 uc_mcontext.__gregs[_REG_R13] 257 # define context_r14 uc_mcontext.__gregs[_REG_R14] 258 # define context_r15 uc_mcontext.__gregs[_REG_R15] 259 # define context_flags uc_mcontext.__gregs[_REG_RFL] 260 # define context_err uc_mcontext.__gregs[_REG_ERR] 261 # else 262 # define context_pc uc_mcontext.__gregs[_REG_EIP] 263 # define context_sp uc_mcontext.__gregs[_REG_UESP] 264 # define context_fp uc_mcontext.__gregs[_REG_EBP] 265 # define context_eip uc_mcontext.__gregs[_REG_EIP] 266 # define context_esp uc_mcontext.__gregs[_REG_UESP] 267 # define context_eax uc_mcontext.__gregs[_REG_EAX] 268 # define context_ebx uc_mcontext.__gregs[_REG_EBX] 269 # define context_ecx uc_mcontext.__gregs[_REG_ECX] 270 # define context_edx uc_mcontext.__gregs[_REG_EDX] 271 # define context_ebp uc_mcontext.__gregs[_REG_EBP] 272 # define context_esi uc_mcontext.__gregs[_REG_ESI] 273 # define context_edi uc_mcontext.__gregs[_REG_EDI] 274 # define context_eflags uc_mcontext.__gregs[_REG_EFL] 275 # define context_trapno uc_mcontext.__gregs[_REG_TRAPNO] 276 # endif 277 #endif 278 279 address os::current_stack_pointer() { 280 #if defined(__clang__) || defined(__llvm__) 281 register void *esp; 282 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 283 return (address) esp; 284 #elif defined(SPARC_WORKS) 285 register void *esp; 286 __asm__("mov %%"SPELL_REG_SP", %0":"=r"(esp)); 287 return (address) ((char*)esp + sizeof(long)*2); 288 #else 289 register void *esp __asm__ (SPELL_REG_SP); 290 return (address) esp; 291 #endif 292 } 293 294 char* os::non_memory_address_word() { 295 // Must never look like an address returned by reserve_memory, 296 // even in its subfields (as defined by the CPU immediate fields, 297 // if the CPU splits constants across multiple instructions). 298 299 return (char*) -1; 300 } 301 302 void os::initialize_thread(Thread* thr) { 303 // Nothing to do. 304 } 305 306 address os::Bsd::ucontext_get_pc(const ucontext_t * uc) { 307 return (address)uc->context_pc; 308 } 309 310 void os::Bsd::ucontext_set_pc(ucontext_t * uc, address pc) { 311 uc->context_pc = (intptr_t)pc ; 312 } 313 314 intptr_t* os::Bsd::ucontext_get_sp(const ucontext_t * uc) { 315 return (intptr_t*)uc->context_sp; 316 } 317 318 intptr_t* os::Bsd::ucontext_get_fp(const ucontext_t * uc) { 319 return (intptr_t*)uc->context_fp; 320 } 321 322 // For Forte Analyzer AsyncGetCallTrace profiling support - thread 323 // is currently interrupted by SIGPROF. 324 // os::Solaris::fetch_frame_from_ucontext() tries to skip nested signal 325 // frames. Currently we don't do that on Bsd, so it's the same as 326 // os::fetch_frame_from_context(). 327 // This method is also used for stack overflow signal handling. 328 ExtendedPC os::Bsd::fetch_frame_from_ucontext(Thread* thread, 329 const ucontext_t* uc, intptr_t** ret_sp, intptr_t** ret_fp) { 330 331 assert(thread != NULL, "just checking"); 332 assert(ret_sp != NULL, "just checking"); 333 assert(ret_fp != NULL, "just checking"); 334 335 return os::fetch_frame_from_context(uc, ret_sp, ret_fp); 336 } 337 338 ExtendedPC os::fetch_frame_from_context(const void* ucVoid, 339 intptr_t** ret_sp, intptr_t** ret_fp) { 340 341 ExtendedPC epc; 342 const ucontext_t* uc = (const ucontext_t*)ucVoid; 343 344 if (uc != NULL) { 345 epc = ExtendedPC(os::Bsd::ucontext_get_pc(uc)); 346 if (ret_sp) *ret_sp = os::Bsd::ucontext_get_sp(uc); 347 if (ret_fp) *ret_fp = os::Bsd::ucontext_get_fp(uc); 348 } else { 349 // construct empty ExtendedPC for return value checking 350 epc = ExtendedPC(NULL); 351 if (ret_sp) *ret_sp = (intptr_t *)NULL; 352 if (ret_fp) *ret_fp = (intptr_t *)NULL; 353 } 354 355 return epc; 356 } 357 358 frame os::fetch_frame_from_context(const void* ucVoid) { 359 intptr_t* sp; 360 intptr_t* fp; 361 ExtendedPC epc = fetch_frame_from_context(ucVoid, &sp, &fp); 362 return frame(sp, fp, epc.pc()); 363 } 364 365 frame os::fetch_frame_from_ucontext(Thread* thread, void* ucVoid) { 366 intptr_t* sp; 367 intptr_t* fp; 368 ExtendedPC epc = os::Bsd::fetch_frame_from_ucontext(thread, (ucontext_t*)ucVoid, &sp, &fp); 369 return frame(sp, fp, epc.pc()); 370 } 371 372 bool os::Bsd::get_frame_at_stack_banging_point(JavaThread* thread, ucontext_t* uc, frame* fr) { 373 address pc = (address) os::Bsd::ucontext_get_pc(uc); 374 if (Interpreter::contains(pc)) { 375 // interpreter performs stack banging after the fixed frame header has 376 // been generated while the compilers perform it before. To maintain 377 // semantic consistency between interpreted and compiled frames, the 378 // method returns the Java sender of the current frame. 379 *fr = os::fetch_frame_from_ucontext(thread, uc); 380 if (!fr->is_first_java_frame()) { 381 // get_frame_at_stack_banging_point() is only called when we 382 // have well defined stacks so java_sender() calls do not need 383 // to assert safe_for_sender() first. 384 *fr = fr->java_sender(); 385 } 386 } else { 387 // more complex code with compiled code 388 assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above"); 389 CodeBlob* cb = CodeCache::find_blob(pc); 390 if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) { 391 // Not sure where the pc points to, fallback to default 392 // stack overflow handling 393 return false; 394 } else { 395 *fr = os::fetch_frame_from_ucontext(thread, uc); 396 // in compiled code, the stack banging is performed just after the return pc 397 // has been pushed on the stack 398 *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp())); 399 if (!fr->is_java_frame()) { 400 // See java_sender() comment above. 401 *fr = fr->java_sender(); 402 } 403 } 404 } 405 assert(fr->is_java_frame(), "Safety check"); 406 return true; 407 } 408 409 // By default, gcc always save frame pointer (%ebp/%rbp) on stack. It may get 410 // turned off by -fomit-frame-pointer, 411 frame os::get_sender_for_C_frame(frame* fr) { 412 return frame(fr->sender_sp(), fr->link(), fr->sender_pc()); 413 } 414 415 intptr_t* _get_previous_fp() { 416 #if defined(SPARC_WORKS) || defined(__clang__) || defined(__llvm__) 417 register intptr_t **ebp; 418 __asm__("mov %%"SPELL_REG_FP", %0":"=r"(ebp)); 419 #else 420 register intptr_t **ebp __asm__ (SPELL_REG_FP); 421 #endif 422 // ebp is for this frame (_get_previous_fp). We want the ebp for the 423 // caller of os::current_frame*(), so go up two frames. However, for 424 // optimized builds, _get_previous_fp() will be inlined, so only go 425 // up 1 frame in that case. 426 #ifdef _NMT_NOINLINE_ 427 return **(intptr_t***)ebp; 428 #else 429 return *ebp; 430 #endif 431 } 432 433 434 frame os::current_frame() { 435 intptr_t* fp = _get_previous_fp(); 436 frame myframe((intptr_t*)os::current_stack_pointer(), 437 (intptr_t*)fp, 438 CAST_FROM_FN_PTR(address, os::current_frame)); 439 if (os::is_first_C_frame(&myframe)) { 440 // stack is not walkable 441 return frame(); 442 } else { 443 return os::get_sender_for_C_frame(&myframe); 444 } 445 } 446 447 // Utility functions 448 449 // From IA32 System Programming Guide 450 enum { 451 trap_page_fault = 0xE 452 }; 453 454 extern "C" JNIEXPORT int 455 JVM_handle_bsd_signal(int sig, 456 siginfo_t* info, 457 void* ucVoid, 458 int abort_if_unrecognized) { 459 ucontext_t* uc = (ucontext_t*) ucVoid; 460 461 Thread* t = Thread::current_or_null_safe(); 462 463 // Must do this before SignalHandlerMark, if crash protection installed we will longjmp away 464 // (no destructors can be run) 465 os::WatcherThreadCrashProtection::check_crash_protection(sig, t); 466 467 SignalHandlerMark shm(t); 468 469 // Note: it's not uncommon that JNI code uses signal/sigset to install 470 // then restore certain signal handler (e.g. to temporarily block SIGPIPE, 471 // or have a SIGILL handler when detecting CPU type). When that happens, 472 // JVM_handle_bsd_signal() might be invoked with junk info/ucVoid. To 473 // avoid unnecessary crash when libjsig is not preloaded, try handle signals 474 // that do not require siginfo/ucontext first. 475 476 if (sig == SIGPIPE || sig == SIGXFSZ) { 477 // allow chained handler to go first 478 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 479 return true; 480 } else { 481 // Ignoring SIGPIPE/SIGXFSZ - see bugs 4229104 or 6499219 482 return true; 483 } 484 } 485 486 JavaThread* thread = NULL; 487 VMThread* vmthread = NULL; 488 if (os::Bsd::signal_handlers_are_installed) { 489 if (t != NULL ){ 490 if(t->is_Java_thread()) { 491 thread = (JavaThread*)t; 492 } 493 else if(t->is_VM_thread()){ 494 vmthread = (VMThread *)t; 495 } 496 } 497 } 498 /* 499 NOTE: does not seem to work on bsd. 500 if (info == NULL || info->si_code <= 0 || info->si_code == SI_NOINFO) { 501 // can't decode this kind of signal 502 info = NULL; 503 } else { 504 assert(sig == info->si_signo, "bad siginfo"); 505 } 506 */ 507 // decide if this trap can be handled by a stub 508 address stub = NULL; 509 510 address pc = NULL; 511 512 //%note os_trap_1 513 if (info != NULL && uc != NULL && thread != NULL) { 514 pc = (address) os::Bsd::ucontext_get_pc(uc); 515 516 if (StubRoutines::is_safefetch_fault(pc)) { 517 os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc)); 518 return 1; 519 } 520 521 // Handle ALL stack overflow variations here 522 if (sig == SIGSEGV || sig == SIGBUS) { 523 address addr = (address) info->si_addr; 524 525 // check if fault address is within thread stack 526 if (thread->on_local_stack(addr)) { 527 // stack overflow 528 if (thread->in_stack_yellow_reserved_zone(addr)) { 529 if (thread->thread_state() == _thread_in_Java) { 530 if (thread->in_stack_reserved_zone(addr)) { 531 frame fr; 532 if (os::Bsd::get_frame_at_stack_banging_point(thread, uc, &fr)) { 533 assert(fr.is_java_frame(), "Must be a Java frame"); 534 frame activation = SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr); 535 if (activation.sp() != NULL) { 536 thread->disable_stack_reserved_zone(); 537 if (activation.is_interpreted_frame()) { 538 thread->set_reserved_stack_activation((address)( 539 activation.fp() + frame::interpreter_frame_initial_sp_offset)); 540 } else { 541 thread->set_reserved_stack_activation((address)activation.unextended_sp()); 542 } 543 return 1; 544 } 545 } 546 } 547 // Throw a stack overflow exception. Guard pages will be reenabled 548 // while unwinding the stack. 549 thread->disable_stack_yellow_reserved_zone(); 550 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW); 551 } else { 552 // Thread was in the vm or native code. Return and try to finish. 553 thread->disable_stack_yellow_reserved_zone(); 554 return 1; 555 } 556 } else if (thread->in_stack_red_zone(addr)) { 557 // Fatal red zone violation. Disable the guard pages and fall through 558 // to handle_unexpected_exception way down below. 559 thread->disable_stack_red_zone(); 560 tty->print_raw_cr("An irrecoverable stack overflow has occurred."); 561 } 562 } 563 } 564 565 if ((sig == SIGSEGV || sig == SIGBUS) && VM_Version::is_cpuinfo_segv_addr(pc)) { 566 // Verify that OS save/restore AVX registers. 567 stub = VM_Version::cpuinfo_cont_addr(); 568 } 569 570 // We test if stub is already set (by the stack overflow code 571 // above) so it is not overwritten by the code that follows. This 572 // check is not required on other platforms, because on other 573 // platforms we check for SIGSEGV only or SIGBUS only, where here 574 // we have to check for both SIGSEGV and SIGBUS. 575 if (thread->thread_state() == _thread_in_Java && stub == NULL) { 576 // Java thread running in Java code => find exception handler if any 577 // a fault inside compiled code, the interpreter, or a stub 578 579 if ((sig == SIGSEGV || sig == SIGBUS) && os::is_poll_address((address)info->si_addr)) { 580 stub = SharedRuntime::get_poll_stub(pc); 581 #if defined(__APPLE__) 582 // 32-bit Darwin reports a SIGBUS for nearly all memory access exceptions. 583 // 64-bit Darwin may also use a SIGBUS (seen with compressed oops). 584 // Catching SIGBUS here prevents the implicit SIGBUS NULL check below from 585 // being called, so only do so if the implicit NULL check is not necessary. 586 } else if (sig == SIGBUS && MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 587 #else 588 } else if (sig == SIGBUS /* && info->si_code == BUS_OBJERR */) { 589 #endif 590 // BugId 4454115: A read from a MappedByteBuffer can fault 591 // here if the underlying file has been truncated. 592 // Do not crash the VM in such a case. 593 CodeBlob* cb = CodeCache::find_blob_unsafe(pc); 594 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; 595 if (nm != NULL && nm->has_unsafe_access()) { 596 address next_pc = Assembler::locate_next_instruction(pc); 597 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 598 } 599 } 600 else 601 602 #ifdef AMD64 603 if (sig == SIGFPE && 604 (info->si_code == FPE_INTDIV || info->si_code == FPE_FLTDIV)) { 605 stub = 606 SharedRuntime:: 607 continuation_for_implicit_exception(thread, 608 pc, 609 SharedRuntime:: 610 IMPLICIT_DIVIDE_BY_ZERO); 611 #ifdef __APPLE__ 612 } else if (sig == SIGFPE && info->si_code == FPE_NOOP) { 613 int op = pc[0]; 614 615 // Skip REX 616 if ((pc[0] & 0xf0) == 0x40) { 617 op = pc[1]; 618 } else { 619 op = pc[0]; 620 } 621 622 // Check for IDIV 623 if (op == 0xF7) { 624 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime:: IMPLICIT_DIVIDE_BY_ZERO); 625 } else { 626 // TODO: handle more cases if we are using other x86 instructions 627 // that can generate SIGFPE signal. 628 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 629 fatal("please update this code."); 630 } 631 #endif /* __APPLE__ */ 632 633 #else 634 if (sig == SIGFPE /* && info->si_code == FPE_INTDIV */) { 635 // HACK: si_code does not work on bsd 2.2.12-20!!! 636 int op = pc[0]; 637 if (op == 0xDB) { 638 // FIST 639 // TODO: The encoding of D2I in i486.ad can cause an exception 640 // prior to the fist instruction if there was an invalid operation 641 // pending. We want to dismiss that exception. From the win_32 642 // side it also seems that if it really was the fist causing 643 // the exception that we do the d2i by hand with different 644 // rounding. Seems kind of weird. 645 // NOTE: that we take the exception at the NEXT floating point instruction. 646 assert(pc[0] == 0xDB, "not a FIST opcode"); 647 assert(pc[1] == 0x14, "not a FIST opcode"); 648 assert(pc[2] == 0x24, "not a FIST opcode"); 649 return true; 650 } else if (op == 0xF7) { 651 // IDIV 652 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO); 653 } else { 654 // TODO: handle more cases if we are using other x86 instructions 655 // that can generate SIGFPE signal on bsd. 656 tty->print_cr("unknown opcode 0x%X with SIGFPE.", op); 657 fatal("please update this code."); 658 } 659 #endif // AMD64 660 } else if ((sig == SIGSEGV || sig == SIGBUS) && 661 !MacroAssembler::needs_explicit_null_check((intptr_t)info->si_addr)) { 662 // Determination of interpreter/vtable stub/compiled code null exception 663 stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL); 664 } 665 } else if (thread->thread_state() == _thread_in_vm && 666 sig == SIGBUS && /* info->si_code == BUS_OBJERR && */ 667 thread->doing_unsafe_access()) { 668 address next_pc = Assembler::locate_next_instruction(pc); 669 stub = SharedRuntime::handle_unsafe_access(thread, next_pc); 670 } 671 672 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in 673 // and the heap gets shrunk before the field access. 674 if ((sig == SIGSEGV) || (sig == SIGBUS)) { 675 address addr = JNI_FastGetField::find_slowcase_pc(pc); 676 if (addr != (address)-1) { 677 stub = addr; 678 } 679 } 680 681 // Check to see if we caught the safepoint code in the 682 // process of write protecting the memory serialization page. 683 // It write enables the page immediately after protecting it 684 // so we can just return to retry the write. 685 if ((sig == SIGSEGV || sig == SIGBUS) && 686 os::is_memory_serialize_page(thread, (address) info->si_addr)) { 687 // Block current thread until the memory serialize page permission restored. 688 os::block_on_serialize_page_trap(); 689 return true; 690 } 691 } 692 693 #ifndef AMD64 694 // Execution protection violation 695 // 696 // This should be kept as the last step in the triage. We don't 697 // have a dedicated trap number for a no-execute fault, so be 698 // conservative and allow other handlers the first shot. 699 // 700 // Note: We don't test that info->si_code == SEGV_ACCERR here. 701 // this si_code is so generic that it is almost meaningless; and 702 // the si_code for this condition may change in the future. 703 // Furthermore, a false-positive should be harmless. 704 if (UnguardOnExecutionViolation > 0 && 705 (sig == SIGSEGV || sig == SIGBUS) && 706 uc->context_trapno == trap_page_fault) { 707 int page_size = os::vm_page_size(); 708 address addr = (address) info->si_addr; 709 address pc = os::Bsd::ucontext_get_pc(uc); 710 // Make sure the pc and the faulting address are sane. 711 // 712 // If an instruction spans a page boundary, and the page containing 713 // the beginning of the instruction is executable but the following 714 // page is not, the pc and the faulting address might be slightly 715 // different - we still want to unguard the 2nd page in this case. 716 // 717 // 15 bytes seems to be a (very) safe value for max instruction size. 718 bool pc_is_near_addr = 719 (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15); 720 bool instr_spans_page_boundary = 721 (align_size_down((intptr_t) pc ^ (intptr_t) addr, 722 (intptr_t) page_size) > 0); 723 724 if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) { 725 static volatile address last_addr = 726 (address) os::non_memory_address_word(); 727 728 // In conservative mode, don't unguard unless the address is in the VM 729 if (addr != last_addr && 730 (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) { 731 732 // Set memory to RWX and retry 733 address page_start = 734 (address) align_size_down((intptr_t) addr, (intptr_t) page_size); 735 bool res = os::protect_memory((char*) page_start, page_size, 736 os::MEM_PROT_RWX); 737 738 log_debug(os)("Execution protection violation " 739 "at " INTPTR_FORMAT 740 ", unguarding " INTPTR_FORMAT ": %s, errno=%d", p2i(addr), 741 p2i(page_start), (res ? "success" : "failed"), errno); 742 stub = pc; 743 744 // Set last_addr so if we fault again at the same address, we don't end 745 // up in an endless loop. 746 // 747 // There are two potential complications here. Two threads trapping at 748 // the same address at the same time could cause one of the threads to 749 // think it already unguarded, and abort the VM. Likely very rare. 750 // 751 // The other race involves two threads alternately trapping at 752 // different addresses and failing to unguard the page, resulting in 753 // an endless loop. This condition is probably even more unlikely than 754 // the first. 755 // 756 // Although both cases could be avoided by using locks or thread local 757 // last_addr, these solutions are unnecessary complication: this 758 // handler is a best-effort safety net, not a complete solution. It is 759 // disabled by default and should only be used as a workaround in case 760 // we missed any no-execute-unsafe VM code. 761 762 last_addr = addr; 763 } 764 } 765 } 766 #endif // !AMD64 767 768 if (stub != NULL) { 769 // save all thread context in case we need to restore it 770 if (thread != NULL) thread->set_saved_exception_pc(pc); 771 772 os::Bsd::ucontext_set_pc(uc, stub); 773 return true; 774 } 775 776 // signal-chaining 777 if (os::Bsd::chained_handler(sig, info, ucVoid)) { 778 return true; 779 } 780 781 if (!abort_if_unrecognized) { 782 // caller wants another chance, so give it to him 783 return false; 784 } 785 786 if (pc == NULL && uc != NULL) { 787 pc = os::Bsd::ucontext_get_pc(uc); 788 } 789 790 // unmask current signal 791 sigset_t newset; 792 sigemptyset(&newset); 793 sigaddset(&newset, sig); 794 sigprocmask(SIG_UNBLOCK, &newset, NULL); 795 796 VMError::report_and_die(t, sig, pc, info, ucVoid); 797 798 ShouldNotReachHere(); 799 return false; 800 } 801 802 // From solaris_i486.s ported to bsd_i486.s 803 extern "C" void fixcw(); 804 805 void os::Bsd::init_thread_fpu_state(void) { 806 #ifndef AMD64 807 // Set fpu to 53 bit precision. This happens too early to use a stub. 808 fixcw(); 809 #endif // !AMD64 810 } 811 812 813 // Check that the bsd kernel version is 2.4 or higher since earlier 814 // versions do not support SSE without patches. 815 bool os::supports_sse() { 816 return true; 817 } 818 819 bool os::is_allocatable(size_t bytes) { 820 #ifdef AMD64 821 // unused on amd64? 822 return true; 823 #else 824 825 if (bytes < 2 * G) { 826 return true; 827 } 828 829 char* addr = reserve_memory(bytes, NULL); 830 831 if (addr != NULL) { 832 release_memory(addr, bytes); 833 } 834 835 return addr != NULL; 836 #endif // AMD64 837 } 838 839 //////////////////////////////////////////////////////////////////////////////// 840 // thread stack 841 842 #ifdef AMD64 843 size_t os::Posix::_compiler_thread_min_stack_allowed = 64 * K; 844 size_t os::Posix::_java_thread_min_stack_allowed = 64 * K; 845 size_t os::Posix::_vm_internal_thread_min_stack_allowed = 64 * K; 846 #else 847 size_t os::Posix::_compiler_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K; 848 size_t os::Posix::_java_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K; 849 size_t os::Posix::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K; 850 851 #ifdef __GNUC__ 852 #define GET_GS() ({int gs; __asm__ volatile("movw %%gs, %w0":"=q"(gs)); gs&0xffff;}) 853 #endif 854 855 #endif // AMD64 856 857 // return default stack size for thr_type 858 size_t os::Posix::default_stack_size(os::ThreadType thr_type) { 859 // default stack size (compiler thread needs larger stack) 860 #ifdef AMD64 861 size_t s = (thr_type == os::compiler_thread ? 4 * M : 1 * M); 862 #else 863 size_t s = (thr_type == os::compiler_thread ? 2 * M : 512 * K); 864 #endif // AMD64 865 return s; 866 } 867 868 869 // Java thread: 870 // 871 // Low memory addresses 872 // +------------------------+ 873 // | |\ Java thread created by VM does not have glibc 874 // | glibc guard page | - guard, attached Java thread usually has 875 // | |/ 1 page glibc guard. 876 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 877 // | |\ 878 // | HotSpot Guard Pages | - red, yellow and reserved pages 879 // | |/ 880 // +------------------------+ JavaThread::stack_reserved_zone_base() 881 // | |\ 882 // | Normal Stack | - 883 // | |/ 884 // P2 +------------------------+ Thread::stack_base() 885 // 886 // Non-Java thread: 887 // 888 // Low memory addresses 889 // +------------------------+ 890 // | |\ 891 // | glibc guard page | - usually 1 page 892 // | |/ 893 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 894 // | |\ 895 // | Normal Stack | - 896 // | |/ 897 // P2 +------------------------+ Thread::stack_base() 898 // 899 // ** P1 (aka bottom) and size ( P2 = P1 - size) are the address and stack size returned from 900 // pthread_attr_getstack() 901 902 static void current_stack_region(address * bottom, size_t * size) { 903 #ifdef __APPLE__ 904 pthread_t self = pthread_self(); 905 void *stacktop = pthread_get_stackaddr_np(self); 906 *size = pthread_get_stacksize_np(self); 907 // workaround for OS X 10.9.0 (Mavericks) 908 // pthread_get_stacksize_np returns 128 pages even though the actual size is 2048 pages 909 if (pthread_main_np() == 1) { 910 if ((*size) < (DEFAULT_MAIN_THREAD_STACK_PAGES * (size_t)getpagesize())) { 911 char kern_osrelease[256]; 912 size_t kern_osrelease_size = sizeof(kern_osrelease); 913 int ret = sysctlbyname("kern.osrelease", kern_osrelease, &kern_osrelease_size, NULL, 0); 914 if (ret == 0) { 915 // get the major number, atoi will ignore the minor amd micro portions of the version string 916 if (atoi(kern_osrelease) >= OS_X_10_9_0_KERNEL_MAJOR_VERSION) { 917 *size = (DEFAULT_MAIN_THREAD_STACK_PAGES*getpagesize()); 918 } 919 } 920 } 921 } 922 *bottom = (address) stacktop - *size; 923 #elif defined(__OpenBSD__) 924 stack_t ss; 925 int rslt = pthread_stackseg_np(pthread_self(), &ss); 926 927 if (rslt != 0) 928 fatal("pthread_stackseg_np failed with err = %d", rslt); 929 930 *bottom = (address)((char *)ss.ss_sp - ss.ss_size); 931 *size = ss.ss_size; 932 #else 933 pthread_attr_t attr; 934 935 int rslt = pthread_attr_init(&attr); 936 937 // JVM needs to know exact stack location, abort if it fails 938 if (rslt != 0) 939 fatal("pthread_attr_init failed with err = %d", rslt); 940 941 rslt = pthread_attr_get_np(pthread_self(), &attr); 942 943 if (rslt != 0) 944 fatal("pthread_attr_get_np failed with err = %d", rslt); 945 946 if (pthread_attr_getstackaddr(&attr, (void **)bottom) != 0 || 947 pthread_attr_getstacksize(&attr, size) != 0) { 948 fatal("Can not locate current stack attributes!"); 949 } 950 951 pthread_attr_destroy(&attr); 952 #endif 953 assert(os::current_stack_pointer() >= *bottom && 954 os::current_stack_pointer() < *bottom + *size, "just checking"); 955 } 956 957 address os::current_stack_base() { 958 address bottom; 959 size_t size; 960 current_stack_region(&bottom, &size); 961 return (bottom + size); 962 } 963 964 size_t os::current_stack_size() { 965 // stack size includes normal stack and HotSpot guard pages 966 address bottom; 967 size_t size; 968 current_stack_region(&bottom, &size); 969 return size; 970 } 971 972 ///////////////////////////////////////////////////////////////////////////// 973 // helper functions for fatal error handler 974 975 void os::print_context(outputStream *st, const void *context) { 976 if (context == NULL) return; 977 978 const ucontext_t *uc = (const ucontext_t*)context; 979 st->print_cr("Registers:"); 980 #ifdef AMD64 981 st->print( "RAX=" INTPTR_FORMAT, uc->context_rax); 982 st->print(", RBX=" INTPTR_FORMAT, uc->context_rbx); 983 st->print(", RCX=" INTPTR_FORMAT, uc->context_rcx); 984 st->print(", RDX=" INTPTR_FORMAT, uc->context_rdx); 985 st->cr(); 986 st->print( "RSP=" INTPTR_FORMAT, uc->context_rsp); 987 st->print(", RBP=" INTPTR_FORMAT, uc->context_rbp); 988 st->print(", RSI=" INTPTR_FORMAT, uc->context_rsi); 989 st->print(", RDI=" INTPTR_FORMAT, uc->context_rdi); 990 st->cr(); 991 st->print( "R8 =" INTPTR_FORMAT, uc->context_r8); 992 st->print(", R9 =" INTPTR_FORMAT, uc->context_r9); 993 st->print(", R10=" INTPTR_FORMAT, uc->context_r10); 994 st->print(", R11=" INTPTR_FORMAT, uc->context_r11); 995 st->cr(); 996 st->print( "R12=" INTPTR_FORMAT, uc->context_r12); 997 st->print(", R13=" INTPTR_FORMAT, uc->context_r13); 998 st->print(", R14=" INTPTR_FORMAT, uc->context_r14); 999 st->print(", R15=" INTPTR_FORMAT, uc->context_r15); 1000 st->cr(); 1001 st->print( "RIP=" INTPTR_FORMAT, uc->context_rip); 1002 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_flags); 1003 st->print(", ERR=" INTPTR_FORMAT, uc->context_err); 1004 st->cr(); 1005 st->print(" TRAPNO=" INTPTR_FORMAT, uc->context_trapno); 1006 #else 1007 st->print( "EAX=" INTPTR_FORMAT, uc->context_eax); 1008 st->print(", EBX=" INTPTR_FORMAT, uc->context_ebx); 1009 st->print(", ECX=" INTPTR_FORMAT, uc->context_ecx); 1010 st->print(", EDX=" INTPTR_FORMAT, uc->context_edx); 1011 st->cr(); 1012 st->print( "ESP=" INTPTR_FORMAT, uc->context_esp); 1013 st->print(", EBP=" INTPTR_FORMAT, uc->context_ebp); 1014 st->print(", ESI=" INTPTR_FORMAT, uc->context_esi); 1015 st->print(", EDI=" INTPTR_FORMAT, uc->context_edi); 1016 st->cr(); 1017 st->print( "EIP=" INTPTR_FORMAT, uc->context_eip); 1018 st->print(", EFLAGS=" INTPTR_FORMAT, uc->context_eflags); 1019 #endif // AMD64 1020 st->cr(); 1021 st->cr(); 1022 1023 intptr_t *sp = (intptr_t *)os::Bsd::ucontext_get_sp(uc); 1024 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", sp); 1025 print_hex_dump(st, (address)sp, (address)(sp + 8*sizeof(intptr_t)), sizeof(intptr_t)); 1026 st->cr(); 1027 1028 // Note: it may be unsafe to inspect memory near pc. For example, pc may 1029 // point to garbage if entry point in an nmethod is corrupted. Leave 1030 // this at the end, and hope for the best. 1031 address pc = os::Bsd::ucontext_get_pc(uc); 1032 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", pc); 1033 print_hex_dump(st, pc - 32, pc + 32, sizeof(char)); 1034 } 1035 1036 void os::print_register_info(outputStream *st, const void *context) { 1037 if (context == NULL) return; 1038 1039 const ucontext_t *uc = (const ucontext_t*)context; 1040 1041 st->print_cr("Register to memory mapping:"); 1042 st->cr(); 1043 1044 // this is horrendously verbose but the layout of the registers in the 1045 // context does not match how we defined our abstract Register set, so 1046 // we can't just iterate through the gregs area 1047 1048 // this is only for the "general purpose" registers 1049 1050 #ifdef AMD64 1051 st->print("RAX="); print_location(st, uc->context_rax); 1052 st->print("RBX="); print_location(st, uc->context_rbx); 1053 st->print("RCX="); print_location(st, uc->context_rcx); 1054 st->print("RDX="); print_location(st, uc->context_rdx); 1055 st->print("RSP="); print_location(st, uc->context_rsp); 1056 st->print("RBP="); print_location(st, uc->context_rbp); 1057 st->print("RSI="); print_location(st, uc->context_rsi); 1058 st->print("RDI="); print_location(st, uc->context_rdi); 1059 st->print("R8 ="); print_location(st, uc->context_r8); 1060 st->print("R9 ="); print_location(st, uc->context_r9); 1061 st->print("R10="); print_location(st, uc->context_r10); 1062 st->print("R11="); print_location(st, uc->context_r11); 1063 st->print("R12="); print_location(st, uc->context_r12); 1064 st->print("R13="); print_location(st, uc->context_r13); 1065 st->print("R14="); print_location(st, uc->context_r14); 1066 st->print("R15="); print_location(st, uc->context_r15); 1067 #else 1068 st->print("EAX="); print_location(st, uc->context_eax); 1069 st->print("EBX="); print_location(st, uc->context_ebx); 1070 st->print("ECX="); print_location(st, uc->context_ecx); 1071 st->print("EDX="); print_location(st, uc->context_edx); 1072 st->print("ESP="); print_location(st, uc->context_esp); 1073 st->print("EBP="); print_location(st, uc->context_ebp); 1074 st->print("ESI="); print_location(st, uc->context_esi); 1075 st->print("EDI="); print_location(st, uc->context_edi); 1076 #endif // AMD64 1077 1078 st->cr(); 1079 } 1080 1081 void os::setup_fpu() { 1082 #ifndef AMD64 1083 address fpu_cntrl = StubRoutines::addr_fpu_cntrl_wrd_std(); 1084 __asm__ volatile ( "fldcw (%0)" : 1085 : "r" (fpu_cntrl) : "memory"); 1086 #endif // !AMD64 1087 } 1088 1089 #ifndef PRODUCT 1090 void os::verify_stack_alignment() { 1091 } 1092 #endif 1093 1094 int os::extra_bang_size_in_bytes() { 1095 // JDK-8050147 requires the full cache line bang for x86. 1096 return VM_Version::L1_line_size(); 1097 }